OtorhinolaryngologySfakianakis: Ιανουαρίου 2017

Τρίτη, 31 Ιανουαρίου 2017

Inside front cover continued (editorial board members)

Publication date: February 2017
Source:Biological Psychology, Volume 123

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Editorial board

Publication date: February 2017
Source:Biological Psychology, Volume 123

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The effects of microalloying on the precipitate microstructure at grain boundary regions in an Mg-Zn-based alloy

Publication date: 5 April 2017
Source:Materials & Design, Volume 119
Author(s): B. Langelier, G. Sha, A. Korinek, P. Donnadieu, S.P. Ringer, S. Esmaeili
Microalloying additions to Mg-Zn base alloys can refine precipitation and improve hardening, but their effect on the microstructure at the grain boundary regions are seldom analyzed. Here the grain boundary microstructure is examined in an Mg-4Zn (wt.%) alloy, which has been microalloyed with Ce-Ca. This combination of elements has previously been shown to successfully enhance ductility, texture, and precipitation hardening, compared to binary Mg-Zn. Coarse grain boundary precipitates are found with or without microalloying, but precipitate-free zones (PFZs) for β′1 that surround the boundaries are far narrower with Ce-Ca microalloying additions. Furthermore, fine basal precipitates containing Ca are found uniformly distributed up to the boundary, making those zones devoid of β′1 not truly precipitate-free. Electron microscopy and atom probe analysis of early-stage ageing conditions reveals that Ca readily forms clusters with Zn, and forms fine ordered GP zones, while Zn also segregates to the grain boundaries. The tendency of Ca to homogeneously form clusters and precipitates reduces Ca migration to the grain boundaries, which has a beneficial effect on producing the refined precipitate distributions at the grain boundary regions.

Graphical abstract

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Microstructure evolution and mechanical properties of ZnAl2O4-reinforced Al2O3/Al2O3 joints brazed with a bismuth borate zinc glass

Publication date: 5 April 2017
Source:Materials & Design, Volume 119
Author(s): Wei Guo, Tiesong Lin, Peng He, Tong Wang, Yini Wang
Amorphous bismuth borate zinc glass with a composition of 40Bi2O3–40B2O3–20ZnO (in mol.%) was used as a braze to join 95wt.% purity alumina ceramics (95Al2O3) in air. The interfacial phases in the brazed joints were characterized using scanning electron microscopy, transmission electron microscopy. Zinc aluminate (ZnAl2O4) was identified as the main reaction product in the joints due to the chemical reaction between the Al2O3 substrate and ZnO from the glass. Typical microstructure of the Al2O3/Al2O3 brazed joints was Al2O3 substrate/glassy matrix phase+ZnAl2O4 particles/Al2O3 substrate. The dependence of the microstructure and mechanical properties on brazing temperature was investigated. The size of ZnAl2O4 increased with an increase in brazing temperature. It was found the room lap shear strength of Al2O3/Al2O3 joints firstly increased and then declined with increasing brazing temperature. The maximum lap shear strength of 95MPa was obtained for the samples brazed at 675°C for 30min, which was mainly attributed to the formation of ZnAl2O4.

Graphical abstract

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Self-assembly of quaternized chitosan nanoparticles within nanoclay layers for enhancement of interfacial properties in toughened polymer nanocomposites

Publication date: 5 April 2017
Source:Materials & Design, Volume 119
Author(s): Omid Zabihi, Mojtaba Ahmadi, Minoo Naebe
Role of montmorillonite nanoclay in self-assembly of quaternized chitosan nanoparticles (QCn) within the clay layers was investigated. Inorganic-organic nanohybrid of clay-chitosan was used as a reactive reinforcing agent in preparation of toughened epoxy nanocomposites. Intercalation of QCn within the clay layers increases d-spacing of clay layers from 1.2nm to 3.6nm, leading to an enhanced exfoliation degree in epoxy nanocomposites. The nanohybrid of clay modified with QCn was then incorporated into an epoxy matrix. It was found that the strong interfacial interactions benefit not only the dispersion of the clay within epoxy but also the effective interfacial stress transfer, leading to significantly improved mechanical properties. Rheological investigations showed that the interfacial interactions between the QCn modified clay and epoxy are dominated by the covalent/hydrogen bondings between the amine/hydroxyl enriched QCn and the epoxy matrix.

Graphical abstract

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Structure-property relationships in ZnO:Al-hydroquinone films grown on flexible substrates by atomic and molecular layer deposition

Publication date: 5 April 2017
Source:Materials & Design, Volume 119
Author(s): Grzegorz Luka, Lukasz Wachnicki, Bartlomiej S. Witkowski, Rafal Jakiela, Ihor S. Virt
ZnO:Al-hydroquinone (AZO-HQ) films were grown on poly(ethylene terephthalate) (PET) substrates by atomic and molecular layer deposition (ALD/MLD). Organic contents in the films varied from 0 to ≈4vol%. Structural and electrical investigations of the films were carried out. Electrical measurements were performed under film bending. The piezoresistive effect in the films with different organic contents was observed and described. Critical bend radius, critical strain, and piezoresistive coefficient values were related to the film microstructure. The piezoresistivity was found to be enhanced for the deformations of ZnO crystallites along the a-axis whereas higher critical strain was influenced by long crystallites oriented in the deformation direction. AZO-HQ films having 2vol% of the organic content are characterized by the lowest critical bend radius and the highest critical strain among the films under study.

Graphical abstract

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Long-Term Follow-Up for Differentiated Thyroid Carcinoma Patients: A Reconsideration

Thyroid , Vol. 0, No. 0.

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Long-Term Follow-Up for Differentiated Thyroid Carcinoma Patients: A Reconsideration

Thyroid , Vol. 0, No. 0.

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Contribution of image-guided adaptive brachytherapy to pelvic nodes treatment in locally advanced cervical cancer

Publication date: Available online 31 January 2017
Source:Brachytherapy
Author(s): Warren Bacorro, Isabelle Dumas, Antonin Levy, Eleonor Rivin Del Campo, Charles-Henri Canova, Tony Felefly, Andres Huertas, Fanny Marsolat, Christine Haie-Meder, Cyrus Chargari, Renaud Mazeron
PurposeWith the increasing use of simultaneous integrated boost in the treatment of cervical cancer, there is a need to anticipate the brachytherapy (BT) contribution at the level of the pathologic pelvic lymph nodes. This study aimed to report the dose delivered at their level during BT.Methods and MaterialsPatients with pelvic nodal involvement and treated with a combination of chemoradiation followed by image-guided adaptive pulsed-dose-rate BT were selected. On per BT three-dimensional images, pelvic lymphadenopathies were delineated, without planning aim. For the purposes of the study, D100, D98, D90, and D50 were reviewed and converted in 2-Gy equivalent doses, using the linear quadratic model with an α/β of 10 Gy.ResultsNinety-one patients were identified, allowing evaluation at the level of 226 lymphadenopathies. The majority of them were external iliac (48%), followed by common iliac (25%), and internal iliac (16%) regions. The 2-Gy equivalent doses D98 were 4.4 ± 1.9 Gy, 5.4 ± 3.1 Gy, and 4.3 ± 2.1 Gy for the obturator, internal iliac, and external iliac, respectively, and 2.8 ± 2.5 Gy for the common iliac. The contribution to the common iliac nodes was significantly lower than the one of external and internal iliac (p < 0.001).ConclusionsBT significantly contributes to the treatment of pelvic nodes at the level of approximately 5 Gy in the internal, external, and obturator areas and 2.5 Gy in the common iliac, allowing the anticipation of nodal boost with the simultaneous integrated boost technique. However, important individual variations have been observed, and evaluation of the genuine BT contribution should be recommended.

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Monitoring of the posterior cricoarytenoid muscle represents another option for neural monitoring during thyroid surgery: Normative vagal and recurrent laryngeal nerve posterior cricoarytenoid muscle electromyographic data

Objective

Intraoperative neural monitoring (IONM) of laryngeal nerves using electromyography (EMG) is routinely performed using endotracheal tube surface electrodes adjacent to the vocalis muscles. Other laryngeal muscles such as the posterior cricoarytenoid muscle (PCA) are indirectly monitored. The PCA may be directly and reliably monitored through an electrode placed in the postcricoid region. Herein, we describe the method and normative data for IONM using PCA EMG.

Study Design

Retrospective review.

Methods

Data were reviewed retrospectively for thyroid and parathyroid surgery patients with IONM of laryngeal nerves from January to August 2016. Recordings of vocalis and PCA EMG amplitudes and latencies with stimulation of laryngeal nerves were obtained using endotracheal (ET) tube-based and postcricoid surface electrodes.

Results

Data comprised EMG responses in vocalis and PCA recording channels with stimulation of the vagus, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve from 20 subjects (11 left, 9 right), as well as PCA EMG threshold data with RLN stimulation from 17 subjects. Mean EMG amplitude was 725.69 ± 108.58 microvolts (µV) for the ipsilateral vocalis and 329.44 ± 34.12 µV for the PCA with vagal stimulation, and 1,059.75 ± 140.40 µV for the ipsilateral vocalis and 563.88 ± 116.08 µV for the PCA with RLN stimulation. There were no statistically significant differences in mean latency. For threshold cutoffs of the PCA with RLN stimulation, mean minimum and maximum threshold intensities were 0.37 milliamperes (mA) and 0.84 mA, respectively.

Conclusion

This study shows robust and reliable PCA EMG waveforms with direct nerve stimulation. Further studies will evaluate feasibility and application of the PCA electrode as a complementary quantitative tool in IONM.

Level of Evidence

4 Laryngoscope, 2016

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Rurality and determinants of hearing healthcare in adult hearing aid recipients

Objective

The objective of this study was to compare the timing of hearing aid (HA) acquisition between adults in rural and urban communities. We hypothesized that time of acquisition of HA after onset of hearing loss is greater in rural adults compared with urban adults. Secondary objectives included assessment of socioeconomic/educational status and impact of hearing loss and hearing rehabilitation of urban and rural HA recipients.

Study Design

Cross-sectional questionnaire survey.

Methods

We assessed demographics, timing of HA fitting from onset of hearing loss, and impact of hearing impairment in 336 adult HA recipients (273 urban, 63 rural) from a tertiary referral center. Amplification benefit was assessed using the International Outcome Inventory for Hearing Aids (IOI).

Results

The time to HA acquisition was greater for rural participants compared to urban participants (19.1 vs. 25.7 years, P = 0.024) for those with untreated hearing loss for at least 8 years. Age at hearing loss onset was correlated with time to HA acquisition (P = −0.54, P < 0.001). Rural HA participants experienced longer commutes to hearing specialists (68 vs. 32 minutes, P < 0.001), were less likely to achieve a degree beyond high school (P < 0.001), and were more likely to possess Medicaid coverage (P = 0.012) compared to urban participants. Hearing impairment caused job performance difficulty in 60% of all participants.

Conclusion

Rural adults are at risk for delayed HA acquisition, which may be related to distance to hearing specialists. Further research is indicated to investigate barriers to care and expand access for vulnerable populations.

Level of Evidence

4. Laryngoscope, 2017

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In Response to “Does the intraoperative nerve monitoring reliably aid in staging of total thyroidectomies?”

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Extracapsular dissection as sole therapy for small low-grade malignant tumors of the parotid gland

Objective

The aim of the study was to investigate whether extracapsular dissection of a primarily unsuspected lesion in the parotid gland could be oncologically sufficient for carefully selected cases of parotid gland malignomas.

Study Design

Retrospective clinical study.

Methods

The records of all patients treated for primary malignant tumors of the parotid gland solely by means of extracapsular dissection between 2006 and 2013 were studied retrospectively. Patients with manifestation of malignant tumors in the parotid gland that were not of primary salivary gland origin (squamous cell carcinomas, lymphomas, melanomas) or who had had revision surgery or other malignant tumors in their history, as well as patients with insufficient data, were excluded from our study sample.

Results

Nine patients, all with low-grade parotid malignancies, were detected. Our study showed acceptable oncologic and functional outcomes throughout.

Conclusion

Our study was able to show very encouraging preliminary results following primary extracapsular dissection as sole surgical therapy for carefully selected low-stage, low-grade, inferiorly located lesions in patients with high compliance.

Level of Evidence

4. Laryngoscope, 2017

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Monitoring of the posterior cricoarytenoid muscle represents another option for neural monitoring during thyroid surgery: Normative vagal and recurrent laryngeal nerve posterior cricoarytenoid muscle electromyographic data

Objective

Study Design

Retrospective review.

Methods

Results

Conclusion

Level of Evidence

4 Laryngoscope, 2016

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Rurality and determinants of hearing healthcare in adult hearing aid recipients

Objective

Study Design

Cross-sectional questionnaire survey.

Methods

Results

Conclusion

Level of Evidence

4. Laryngoscope, 2017

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In Response to “Does the intraoperative nerve monitoring reliably aid in staging of total thyroidectomies?”

from #ORL via a.lsfakia on Inoreader http://ift.tt/2kPIGR1
via IFTTT

Extracapsular dissection as sole therapy for small low-grade malignant tumors of the parotid gland

Objective

Study Design

Retrospective clinical study.

Methods

Results

Nine patients, all with low-grade parotid malignancies, were detected. Our study showed acceptable oncologic and functional outcomes throughout.

Conclusion

Level of Evidence

4. Laryngoscope, 2017

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Melanin-concentrating hormone in peripheral circulation in the human

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide with a well-characterised role in energy homeostasis and emergent roles in diverse physiologic functions such as arousal, mood and reproduction. Work to date has predominantly focused on its hypothalamic functions using animal models; however, little attention has been paid to its role in circulation in humans. The aims of this study were to (a) develop a radioimmunoassay for the detection of MCH in human plasma; (b) establish reference ranges for circulating MCH and (c) characterise the pattern of expression of circulating MCH in humans. A sensitive and specific RIA was developed and cross-validated by RP-HPLC and MS. The effective range was 19.5–1248 pg MCH/mL. Blood samples from 231 subjects were taken to establish a reference range of 19.5–55.4 pg/mL for fasting MCH concentrations. There were no significant differences between male and female fasting MCH concentrations; however, there were correlations between MCH concentrations and BMI in males and females with excess fat (P < 0.001 and P = 0.020) and between MCH concentrations and fat mass in females with excess fat (P = 0.038). Plasma MCH concentrations rose significantly after feeding in a group of older individuals (n = 50, males P = 0.006, females P = 0.023). There were no robust significant correlations between fasting or post-prandial MCH and resting metabolic rate, plasma glucose, insulin or leptin concentrations although there were correlations between circulating MCH and leptin concentrations in older individuals (P = 0.029). These results indicate that the role of circulating MCH may not be reflective of its regulatory hypothalamic role.

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Binding of the chemokine CXCL12α to its natural extracellular matrix ligand heparan sulfate enables myoblast adhesion and facilitates cell motility

Publication date: April 2017
Source:Biomaterials, Volume 123
Author(s): Dhruv Thakar, Fabien Dalonneau, Elisa Migliorini, Hugues Lortat-Jacob, Didier Boturyn, Corinne Albiges-Rizo, Liliane Coche-Guerente, Catherine Picart, Ralf P. Richter
The chemokine CXCL12α is a potent chemoattractant that guides the migration of muscle precursor cells (myoblasts) during myogenesis and muscle regeneration. To study how the molecular presentation of chemokines influences myoblast adhesion and motility, we designed multifunctional biomimetic surfaces as a tuneable signalling platform that enabled the response of myoblasts to selected extracellular cues to be studied in a well-defined environment. Using this platform, we demonstrate that CXCL12α, when presented by its natural extracellular matrix ligand heparan sulfate (HS), enables the adhesion and spreading of myoblasts and facilitates their active migration. In contrast, myoblasts also adhered and spread on CXCL12α that was quasi-irreversibly surface-bound in the absence of HS, but were essentially immotile. Moreover, co-presentation of the cyclic RGD peptide as integrin ligand along with HS-bound CXCL12α led to enhanced spreading and motility, in a way that indicates cooperation between CXCR4 (the CXCL12α receptor) and integrins (the RGD receptors). Our findings reveal the critical role of HS in CXCL12α induced myoblast adhesion and migration. The biomimetic surfaces developed here hold promise for mechanistic studies of cellular responses to different presentations of biomolecules. They may be broadly applicable for dissecting the signalling pathways underlying receptor cross-talks, and thus may guide the development of novel biomaterials that promote highly specific cellular responses.

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Limiting the protein corona: A successful strategy for in vivo active targeting of anti-HER2 nanobody-functionalized nanostars

Publication date: April 2017
Source:Biomaterials, Volume 123
Author(s): Antoine D'Hollander, Hilde Jans, Greetje Vande Velde, Charlotte Verstraete, Sam Massa, Nick Devoogdt, Tim Stakenborg, Serge Muyldermans, Liesbet Lagae, Uwe Himmelreich
Gold nanoparticles hold great promise as anti-cancer theranostic agents against cancer by actively targeting the tumor cells. As this potential has been supported numerously during in vitro experiments, the effective application is hampered by our limited understanding and control of the interactions within complex in vivo biological systems. When these nanoparticles are exposed to a biological environment, their surfaces become covered with proteins and biomolecules, referred to as the protein corona, reducing the active targeting capabilities. We demonstrate a chemical strategy to overcome this issue by reducing the protein corona's thickness by blocking the active groups of the self-assembled monolayer on gold nanostars. An optimal blocking agent, 2-mercapto ethanol, has been selected based on charge and length of the carbon chain. By using a nanobody as a biological ligand of the human epidermal growth factor 2 receptor (HER2), the active targeting is demonstrated in vitro and in vivo in an experimental tumor model by using darkfield microscopy and photoacoustic imaging. In this study, we have established gold nanostars as a conceivable theranostic agent with a specificity for HER2-positive tumors.

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Selective transduction of astrocytic and neuronal CNS subpopulations by lentiviral vectors pseudotyped with Chikungunya virus envelope

Publication date: April 2017
Source:Biomaterials, Volume 123
Author(s): Ioanna Eleftheriadou, Michael Dieringer, Xuan Ying Poh, Julia Sanchez-Garrido, Yunan Gao, Argyro Sgourou, Laura E. Simmons, Nicholas D. Mazarakis
Lentiviral vectors are gene delivery vehicles that integrate into the host genome of dividing and non-dividing mammalian cells facilitating long-term transgene expression. Lentiviral vector versatility is greatly increased by incorporating heterologous viral envelope proteins onto the vector particles instead of the native envelope, conferring on these pseudotyped vectors a modified tropism and host range specificity. We investigated the pseudotyping efficiency of HIV-1 based lentiviral vectors with alphaviral envelope proteins from the Chikungunya Virus (CHIKV-G) and Sindbis Virus (SINV-G). Following vector production optimisation, titres for the CHIKV-G pseudotype were comparable to the VSV-G pseudotype but those for the SINV-G pseudotype were significantly lower. High titre CHIKV-G pseudotyped vector efficiently transduced various human and mouse neural cell lines and normal human astrocytes (NHA) in vitro. Although transduction was broad, tropism for NHAs was observed. In vivo stereotaxic delivery in striatum, thalamus and hippocampus respectively in the adult rat brain revealed localised transduction restricted to striatal astrocytes and hippocampal dentate granule neurons. Transduction of different subtypes of granule neurons from precursor to post-mitotic stages of differentiation was evident in the sub-granular zone and dentate granule cell layer. No significant inflammatory response was observed, but comparable to that of VSV-G pseudotyped lentiviral vectors. Robust long-term expression followed for three months post-transduction along with absence of neuroinflammation, coupled to the selective and unique neuron/glial tropism indicates that these vectors could be useful for modelling and gene therapy studies in the CNS.

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IOP-details

Publication date: March 2017
Source:International Journal of Psychophysiology, Volume 113

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Editorial Board

Publication date: March 2017
Source:International Journal of Psychophysiology, Volume 113

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Instructions to Authors

Publication date: March 2017
Source:International Journal of Psychophysiology, Volume 113

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Correlation between auditory brainstem response and hearing prognosis in idiopathic sudden sensorineural hearing loss patients

Publication date: Available online 31 January 2017
Source:Auris Nasus Larynx
Author(s): Hung-Che Lin, Yu-Ching Chou, Chih-Hung Wang, Li-Wen Hung, Cheng-Ping Shih, Bor-Hwang Kang, Wen-Ying Yeh, Hsin-Chien Chen
ObjectiveTo investigate the latency and amplitude of auditory brainstem response (ABR) and hearing prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).MethodsPatients with ISSNHL were classified into four different recovery groups. All patients' clinical and demographic features were analyzed. Two-channel ABRs were collected in response to click stimuli at 90dB nHL. ABR amplitudes for wave I and ABR latency for waves I, III, and V were analyzed.ResultsOne hundred and two patients (54 men and 48 women) were included in the study. Hearing recovery was observed in 72 cases (70.6%). Waves I, III, and V latencies were significantly prolonged in the affected ears compared with the unaffected ears. A smaller wave I amplitude was found in the affected ear compared with the unaffected ear in the three recovery groups. There was a significant association between wave I latency and hearing outcome (p=0.009) with a prolonged trend from complete to slight hearing recovery group.ConclusionsThere was a significant correlation between wave I latency and hearing outcome in patients with ISSNHL. The finding may provide diagnostic information and serve as a potential prognostic indicator in patients with ISSNHL.

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Correlation between auditory brainstem response and hearing prognosis in idiopathic sudden sensorineural hearing loss patients

Biocompatibility of polymer-infiltrated-ceramic-network (PICN) materials with Human Gingival Keratinocytes (HGKs)

Publication date: Available online 31 January 2017
Source:Dental Materials
Author(s): Charlotte Grenade, Marie-Claire De Pauw-Gillet, Catherine Pirard, Virginie Bertrand, Corinne Charlier, Alain Vanheusden, Amélie Mainjot
ObjectiveBiocompatibility of polymer-infiltrated-ceramic-network (PICN) materials, a new class of CAD–CAM composites, is poorly explored in the literature, in particular, no data are available regarding Human Gingival Keratinocytes (HGK). The first objective of this study was to evaluate the in vitro biocompatibility of PICNs with HGKs in comparison with other materials typically used for implant prostheses. The second objective was to correlate results with PICN monomer release and indirect cytotoxicity.MethodsHGK attachment, proliferation and spreading on PICN, grade V titanium (Ti), yttrium zirconia (Zi), lithium disilicate glass-ceramic (eM) and polytetrafluoroethylene (negative control) discs were evaluated using a specific insert-based culture system. For PICN and eM samples, monomer release in the culture medium was quantified by high performance liquid chromatography and indirect cytotoxicity tests were performed.ResultsTi and Zi exhibited the best results regarding HGK viability, number and coverage. eM showed inferior results while PICN showed statistically similar results to eM but also to Ti regarding cell number and to Ti and Zi regarding cell viability. No monomer release from PICN discs was found, nor indirect cytotoxicity, as for eM.SignificanceThe results confirmed the excellent behavior of Ti and Zi with gingival cells. Even if polymer based, PICN materials exhibited intermediate results between Ti–Zi and eM. These promising results could notably be explained by PICN high temperature–high pressure (HT–HP) innovative polymerization mode, as confirmed by the absence of monomer release and indirect cytotoxicity.

Graphical abstract

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Crystal orientation of poly(ε-caprolactone) chains confined in lamellar nanodomains: Effects of chain-ends tethering to nanodomain interfaces

Publication date: Available online 31 January 2017
Source:Polymer
Author(s): Shintaro Nakagawa, Yuki Yoneguchi, Takashi Ishizone, Shuichi Nojima, Kazuo Yamaguchi, Seiichi Nakahama
We have examined the crystal orientation of poly (ε-caprolactone) (PCL) chains covalently tethered to nanodomain interfaces at both chain-ends (T2-PCL), one chain-end (T1-PCL), and no chain-end (PCL homopolymers, T0-PCL) all confined in an identical lamellar nanodomain (nanolamella). In order to prepare these PCL chains, we synthesized two kinds of lamella-forming polystyrene-block-PCL-block-polystyrene (PS-b-PCL-b-PS) triblock copolymers with photocleavable o-nitrobenzyl groups (ONB) at either or both of block junctions. The chain-ends tethering significantly affected the tilt angle φ between the c axis of PCL crystals and the normal of nanolamella interfaces (ND). That is, the c axis of T2-PCL crystals oriented almost perpendicular to ND (φ ≥ 70°), whereas that of T0-PCL crystals took completely parallel orientation against ND (φ ∼ 0°) at high crystallization temperatures (>32 °C). The T1-PCL crystal showed an intermediate orientation between T2-PCL and T0-PCL crystals (35° < φ < 55°), which depended moderately on the crystallization temperature. The difference in crystal orientation was discussed in terms of a delicate balance between the heterogeneous nucleation rate and subsequent crystal growth rate by considering the difference in chain mobility based on the state of chain-ends tethering.

Graphical abstract

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High-strength silk fibroin scaffolds with anisotropic mechanical properties

Publication date: Available online 31 January 2017
Source:Polymer
Author(s): Berkant Yetiskin, Oguz Okay
In contrast to isotropic morphologies of synthetic hydrogels, many biological tissues possess anisotropic hierarchical morphologies leading to extraordinary mechanical properties that cannot be mimicked by synthetic materials. Here, we report preparation of anisotropic silk fibroin cryogels and scaffolds exhibiting a Young's modulus in the range of MPa that sustain up to 20 MPa compressive stresses. The cryogels were prepared by a combined directional freezing – cryogelation process starting from an aqueous 4.2 wt% fibroin solution containing butanediol diglycidyl ether cross-linker and N,N,N′,N′-tetramethylethylenediamine. In the first step, the reactor containing the aqueous solution of fibroin, cross-linker, and TEMED was immersed into liquid nitrogen at a controlled rate to create a directionally frozen ice template. In the second step, cryogelation reactions were conducted in this frozen solution at −18 °C whereby the cryo-concentrated fibroin in the unfrozen microzones of the reaction system forms a 3D fibroin network. The scaffolds exhibit anisotropic microstructure and hence anisotropic mechanical properties, e.g., the Young's modulus is 3.4 ± 0.5 MPa and 0.8 ± 0.3 MPa when measured along the directions parallel and vertical to the freezing direction, respectively. All the cryogels could completely be compressed due to squeezing out of water from their pores. Upon removal of the load, the compressed cryogels immediately recover their original dimensions and mechanical properties by absorbing the released water into their pores.

Graphical abstract

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Sequence distribution and elastic properties of propylene-based elastomers

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): Andy H. Tsou, Alexander I. Norman, Yonglai Lu, Joseph A. Throckmorton, Benjamin S. Hsiao
Three iso-specific organometallic catalysts for ethylene and propylene copolymerization with varying r1r2 parameters, i.e., the products of ethylene and propylene reactivity ratios, were utilized to synthesize equal-molecular-weight propylene-based elastomers (PBEs) of alternating, random, and blocky backbone sequences. To compensate for the variations in catalyst iso-specificity and thus to maintain a constant amount of 50% isotactic propylene trimer concentration, the ethylene content of PBEs was varied between 11 wt % and 16 wt %. Although all three PBEs have an equal amount of crystallizable sequences, the high-C2 (high-ethylene) blocky PBE was found to have the highest crystallinity and crystallization rate, while the low-C2 alternating PBE possesses the lowest crystallinity and rate. This suggests that the backbone sequence distribution of a PBE affects its rate and degree of crystallization. The polypropylene (PP) crystallite width and perfection were enlarged and improved in the order of random, alternating, and blocky PBE, as measured by crystalline peak widths using the wide-angle X-ray scattering (WAXS) method. In addition, their crystals, cross-hatched lamellae web and embryonic axialites, which are the assembly of PP crystallites, are largest in the alternating PBE, followed by the random PBE as indicated by bimodal atomic force microscopy (AFM). A limited crystallite assembly was noted in the blocky PBE. Increasing crystallite assembly may have led to lowering the crosslink density (less crosslinks) and elasticity erosion. As a result of the wider and more perfect PP crystallites and the lack of assembly of these crystallites in the blocky PBE, it may have the highest crosslink density and strongest crosslinks and, hence, the best elasticity, as measured by set, hysteresis and retractive force, among the three, followed by the random PBE, and then the alternating PBE.

Graphical abstract

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Synthesis of polymeric ionic liquids with unidirectional chain topology by AB step growth polymerization

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): M. Suckow, M. Roy, K. Sahre, L. Häußler, N. Singha, B. Voit, F. Böhme
Poly(ionic liquid)s with alkyl imidazolium moieties in the main chain were synthesized by step growth addition polymerization of the AB monomers 1-(4-chlorobutyl)-1H-imidazole, 1-(6-chlorohexyl)-1H-imidazole, and 1-(6-bromohexyl)-1H-imidazole in the melt. The molar masses of the polymers were controlled by adding 1-butyl-1H-imidazole as monofunctional chain stopper. The bromine containing monomer polymerized spontaneously at room temperature whereas the chlorine containing monomers were sufficiently stable up to 40 °C. This could be evidenced by DSC measurements which showed a broad exothermal peak above 40 °C caused by the polymerization. MALDI-TOF investigations proved that dissociation of the alkyl imidazolium groups which might disturb the expected directional chain topology (AB-AB-AB…) did not occur. This is an important precondition for the intended cross-linking free grafting reactions of the AB monomers on halide containing polymers without any danger of gelation. Additionally, the results of the MALDI-TOF investigations indicated partial complexation of the polymer with the matrix and structural rearrangements during the measurements which converted the ionic imidazolium moieties into neutral moieties. The thermal behavior of the poly(ionic liquid)s has proved to be dependent on the length of the alkyl linking group between the imidazolium moieties and the type of counter ion.

Graphical abstract

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Radiochemical “degelation” of polymethyl methacrylate networks

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): Pierre Gilormini, Emmanuel Richaud, Jacques Verdu
Methyl methacrylate-ethylene glycol dimethacrylate networks were synthetized and submitted to radiochemical degradation, with ageing monitored by means of sol-gel analysis. The networks were shown to undergo chain scission predominantly, which leads to their degelation, i.e., the recovery of a thermoplastic-like behavior with loss of all elastically active chains. The degelation dose was shown to increase with crosslink density and the corresponding critical conversion ratio was discussed regarding a recent and general statistical theory that covers radiochemical as well as chemical chain scissions.

Graphical abstract

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Nanofiltration properties of asymmetric membranes prepared by phase inversion of sulfonated nitro-polyphenylsulfone

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): Matan V. Brami, Yoram Oren, Charles Linder, Roy Bernstein
This study is a systematic investigation of preparation and characteristics of membranes, made from sulfonated nitro-polyphenylsulfone (SPPS-NO2) with different degrees of sulfonation and prepared by non-solvent–induced phase separation in different immersion baths (deionized water, 0.1 M HCl, or 1 M NaCl).Following nitration, the PPS-NO2 was sulfonated with different amounts of chlorosulfonic acid to achieve polymers with different ion exchange capacities (IECs), from 0 to 2.2 meq/g.The cross-sectional membrane morphology changed from porous to dense following sulfonation as seen by scanning electron microscopy. The phase inversion of the polymer solution was studied using the cloud-point method, light microscopy, and Langmuir isotherm. It was found that the liquid-liquid demixing of the polymer solution changed due to the increase in the IEC. This was mainly attributed to an increase in polymer miscibility in the aqueous non-solvent bath with an increasing degree of sulfonation. In addition, the phase-inversion properties of the ionic polymers were influenced by changing the aqueous composition of the immersion baths, probably due to partial protonation of the ionic sulfonic groups (in the case of HCl as the non-solvent) or to solvation effect (when NaCl was the non-solvent).Changing the morphology and of the membrane influenced its performance. Increasing the IEC increased the salt rejection and decreased flux. However, the permeability was improved without a large loss of selectivity by changing the non-solvent to aqueous NaCl. In addition, the new membrane showed high chlorine resistance due to the addition of a nitro group to the polymer backbone, and high acid resistance property.

Graphical abstract

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Neutron diffraction study of conducting polyaniline doped with (±) camphorsulfonic acid

Publication date: 24 February 2017
Source:Polymer, Volume 111
Author(s): Tomasz Kozik, Maciej Śniechowski, Wojciech Łużny, Adam Proń, David Djurado
Fully hydrogenated and partially deuterated free standing films of polyaniline doped with (±) camphorsulfonic acid (PANIh5/CSA and PANId4/CSA) are subjected to neutron diffraction study. Obtained results are analyzed and compared with X-ray diffraction measurements. The very distinct differences observed between the two neutron diffraction profiles are described in detail. Making use of the recently published new model of the crystalline structure of the PANI/CSA system, the neutron diffraction curves for the analogous structures are calculated. The two calculated neutron diffraction patterns exhibit similar differences as those obtained in experiment. This fully confirms the validity of the refined molecular model elaborated for this still important material for applications as synthetic metals or organic thermoelectrics.

Graphical abstract

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Cross-linked, polyurethane-based, ammonium poly(ionic liquid)/ionic liquid composite films for organic vapor suppression and ion conduction

Publication date: Available online 31 January 2017
Source:Polymer
Author(s): Dylan I. Mori, Rhia M. Martin, Richard D. Noble, Douglas L. Gin
A series of ammonium-diol and -triol ionic liquid (IL) monomers were synthesized and used in step-growth polymerization with the commercial di-isocyanate monomer, toluene-di-isocyanate (TDI), in the presence of free ammonium IL to form new curable ammonium-based polymerized ionic liquid/ionic liquid (PIL/IL) composite film coatings. The use of polyurethane chemistry allows for the near-complete curing of the alcohol and isocyanate monomers to yield solid, homogeneous, cross-linked polyurethane-based PIL/IL composite materials with no volatile side product formation. The physical properties and curing rates of these PIL/IL films were altered by tailoring the structures of the ammonium-alcohol IL monomers, the ratio of the linear vs. cross-linking IL monomers employed, and the amount of free IL in the curing reactions. Although ammonium-based PILs have been reported to be less thermally and electrochemically stable than their imidazolium counterparts in the literature, TGA results indicated a Tonset of up to 300 °C under air for the ammonium PIL/IL composites prepared in this study. These new PIL/IL materials were also tested as curable coatings in a toxic industrial chemical (TIC) vapor suppression and liquid uptake assay using o-dichlorobenzene (o-DCB) as a simulant for polychlorinated biphenyls. The curable PIL/IL coatings were found to suppress 88% of the o-DCB vapor on o-DCB-contaminated painted steel substrates and 79% of the o-DCB vapor on o-DCB-contaminated rubber substrates, relative to uncoated control samples. However, although effective for TIC vapor suppression, these ammonium PIL/IL coatings only sorbed less than 50% of the applied liquid o-DCB from the same test substrates, making them slightly less effective for this latter application than previously reported imidazolium-based curable PIL/IL coatings. These materials exhibited comparable ionic conductivity values to other types of PIL/IL systems previously reported in the literature. However, it was found that the more heavily cross-linked ammonium-based PIL/IL films were more prone to free IL leach-out at higher temperatures, leading to their unexpectedly higher ionic conductivity at elevated temperatures.

Graphical abstract

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Investigation into dielectric behaviour and electromagnetic interference shielding effectiveness of conducting styrene butadiene rubber composites containing ionic liquid modified MWCNT

Publication date: Available online 31 January 2017
Source:Polymer
Author(s): Jiji Abraham, Mohammed Arif P, Priti Xavier, Suryasarathi Bose, Soney C. George, Nandakumar Kalarikkal, Sabu Thomas
Designing new conducting materials with a promise for electromagnetic shielding applications attracted a wide spread interest in recent years. Styrene-butadiene rubber (SBR) is a widely used low cost synthetic rubber for a large number of applications. However, their use in providing an effective barrier for electromagnetic radiations is limited by its poor electrical conductivity. Herein we report a facile synthesis of conducting polymer nanocomposite by incorporating non-covalently functionalized Multiwalled Carbon Nanotube (MWCNT) with ionic liquid into SBR matrix and achieve a shielding efficiency of ca.35.06 dB @ 18 GHz (i.e ∼99.99% shielding attenuation). Importantly, ionic liquid embedded MWCNT makes it dispersible facilitated through cation–π interaction. A synergy between ionic liquid and MWCNT was well understood by analysing the dielectric behaviour and ac conductivity of composites in the frequency range of 100–20 MHz. A 5 mm thick soft rubber shielding material is fabricated and the shielding performance is analysed by vector network analyser for a frequency range of 2 GHz–18 GHz. A significant enhancement in the shielding effectiveness of the polymer nanocomposite with different amounts of f-MWCNT loading is observed. Electron microscopy analysis (TEM and FESEM) clearly illustrate the excellent dispersion state and microstructural development of MWCNTs within the SBR matrix which in turn accounts for the increase in the shielding performance of the polymer nanocomposite. This work opens up new paradigm for EMI shielding applications based on soft elastomer with the aid of a sustainable and simplified methodology.

Graphical abstract

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Endothelin causes transactivation of the EGFR and HER2 in non-small cell lung cancer cells.

Publication date: Available online 31 January 2017
Source:Peptides
Author(s): Terry W. Moody, Irene Ramos-Alvarez, Paola Moreno Perez, Samuel A. Mantey, Lisa Ridnour, David Wink, Robert T. Jensen
Endothelin (ET)-1 is an important peptide in cancer progression stimulating cellular proliferation, tumor angiogenesis and metastasis. ET-1 binds with high affinity to the ETA receptor (R) and ETBR on cancer cells. High levels of tumor ET-1 and ETAR are associated with poor survival of lung cancer patients. Here the effects of ET-1 on epidermal growth factor (EGF)R and HER2 transactivation were investigated using non-small cell lung cancer (NSCLC) cells. ETAR mRNA was present in all 10 NSCLC cell lines examined. Addition of ET-1 to NCI-H838 or H1975 cells increased EGFR, HER2 and ERK tyrosine phosphorylation within 2min. The increase in EGFR and HER2 transactivation caused by ET-1 addition to NSCLC cells was inhibited by lapatinib (EGFR and HER2 tyrosine kinase inhibitor (TKI)), gefitinib (EGFR TKI), ZD4054 or BQ-123 (ETAR antagonist), GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor) or Tiron (superoxide scavenger). ET-1 addition to NSCLC cells increased cytosolic Ca²⁺ and reactive oxygen species. ET-1 increased NSCLC clonal growth, whereas BQ123, ZD4054, lapatinib or gefitinib inhibited proliferation. The results indicate that ET-1 may regulate NSCLC cellular proliferation in an EGFR- and HER2-dependent manner.

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A Near-peer Point-of-care Ultrasound Elective for Medical Students: Impact on Anatomy Knowledge, Perceptions About Ultrasound, and Self-reported Skill Level

Publication date: Available online 31 January 2017
Source:Academic Radiology
Author(s): Jacqueline T. DesJardin, Santo K. Ricceri, Stephen D. Brown, Emily M. Webb, David M. Naeger, Nathan A. Teismann
Rationale and ObjectivesWe aimed to assess the impact of our institution's recently created point-of-care ultrasound (POCUS) course for preclinical medical students by examining its effect on first–year-level medical knowledge, self-reported skill level, and beliefs regarding the importance of ultrasound in future clinical practice.Materials and MethodsA total of 18 first-year medical students completed a 5-month near–peer-led training program in POCUS consisting of 3-hour teaching sessions (7), 4-hour clinical sessions (10–12), and an independent study. Students completed pre- and postprogram assessments examining (1) student perceptions about ultrasound and its importance to future careers, (2) students' self-reported skill level with ultrasound, and (3) performance on an anatomy and physiology knowledge quiz. Scores and responses were compared to 20 controls.ResultsThe majority of students believed that ultrasound was useful for learning anatomy and would be important in their future clinical practice. Students who completed our training program tended to perform better than controls on a test of medical knowledge. Despite reporting far fewer hours of formal ultrasound training, control students rated their skill level comparably to POCUS-trained students.ConclusionsThis study provides evidence that ultrasound is well received by medical students and may be useful for teaching basic anatomy concepts.

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Genetic signature and profiling of head and neck cancer: where do we stand?.

Purpose of review: To focus on two novel aspects of head and neck squamous cell carcinoma (HNSCC) genetics of special interest: the epithelial-mesenchymal transition (EMT) process, an initial step in tumor progression that finally leads to metastasis formation, by explaining how genes as well as epigenetic factors control this process, and the new diagnostic options based on the analysis of circulating tumor cells (CTCs) and cell-free DNA (cfDNA) that could revolutionize diagnosis in the coming years. Recent findings: We present an intriguing recently described group of factors, namely miRNAs, deregulated during EMT. MiRNAs could serve as novel markers of EMT and metastasis formation and are also a potential therapeutic target. Second, we show recent findings on CTC and cfDNA analysis in HNSCC that demonstrate the usefulness of this new diagnostic approach. Summary: We stress the importance of EMT in the context of metastasis formation and the potential of liquid biopsies in clinical practice. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Is p16 an adequate surrogate for human papillomavirus status determination?.

Purpose of review: In head and neck cancer management, immunoexpression of protein p16 is widely used as a surrogate marker for human papillomavirus (HPV) positivity due to challenges of direct HPV testing. Previously p16 has been reported to have good sensitivity but only moderate specificity in HPV-status determination. The aim of this review is to evaluate the existing information on sensitivity and specificity of p16 immunohistochemistry (IHC) in HPV-status determination among the recent studies. Recent findings: We searched the time period from October 2014 to April 2016 and included 28 studies (a total of 31 analyses), which reported both p16 and HPV status in their series. The sensitivity of p16 in HPV determination ranged between 28.2 and 100.0%. The mean and median sensitivities were 90.5 and 95.4%, respectively. The specificity ranged between 31.1 and 100.0%. The mean and median specificities were 83.3 and 87.3%, respectively. Summary: Our review presents current information on the feasibility of p16 IHC in HPV status determination, which is in line with previous studies. Patients with HPV-positive tumors can be identified with p16 IHC, but a risk for misclassification of HPV-negative tumors as HPV positive exists. This fact has to be taken into consideration if HPV status will influence treatment planning. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Genetic signature and profiling of head and neck cancer: where do we stand?.

Is p16 an adequate surrogate for human papillomavirus status determination?.

Nasopharyngeal Adenocarcinoma: a Population-Based Analysis

To describe the incidence and determinants of survival of patients with nasopharyngeal adenocarcinoma between the years of 1973 to 2012 using the Surveillance, Epidemiology, and End Result (SEER) database.

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Hearing loss in Meniere's disease

Meniere"s disease is an inner ear disorder which episodic sensorineural hearing loss, vertigo, tinnitus and aural fullness sensation are its hallmark symptoms. Acute attacks are superimposed on a gradual deterioration in sensory neural hearing in the involved ear, typically in the low frequencies [1]. If audiometry is done during the attack phase of disease, it shows sensorineural hearing loss which will be reduced after the attack phase.

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Nasopharyngeal Adenocarcinoma: a Population-Based Analysis

Hearing loss in Meniere's disease

Meniere”s disease is an inner ear disorder which episodic sensorineural hearing loss, vertigo, tinnitus and aural fullness sensation are its hallmark symptoms. Acute attacks are superimposed on a gradual deterioration in sensory neural hearing in the involved ear, typically in the low frequencies [1]. If audiometry is done during the attack phase of disease, it shows sensorineural hearing loss which will be reduced after the attack phase.

http://ift.tt/2kP90uR

Antibiotic therapy in critically ill patients: expert opinion of the European Society of Anaesthesia Intensive Care Scientific Subcommittee: A narrative review.

Antimicrobial treatment is the cornerstone of infection treatment, and the selection of appropriate antibiotic treatment for critically ill patients is challenging. Clinicians working with critically ill patients usually feel a greater obligation towards their patient than towards maintenance of the delicate ecological balance of prevalent microbiological threats and their resistance patterns. Although antibiotic overtreatment is a frequent phenomenon, patient outcomes need not be compromised when antibiotic treatment is driven by informed decision-making. At the 2016 Euro Anaesthesia Conference (London, UK), the European Society of Anaesthesia Intensive Care Scientific Subcommittee convened an expert panel on antibiotic therapy. This article summarises the main conclusions of the panel, namely the principles of antibiotic therapy that all physicians working with critically ill patients must know. (C) 2017 European Society of Anaesthesiology

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Intraoperative monitoring of analgesia using nociceptive reflexes correlates with delayed extubation and immediate postoperative pain: A prospective observational study.

BACKGROUND: Immediate postoperative pain could be prevented by the administration of long-lasting analgesics before the end of the anaesthesia. However, to prevent over or underdosing of analgesics under anaesthesia, tools are required to estimate the analgesia-nociception balance. OBJECTIVE: We investigated whether the pupillary dilation reflex (PDR) and the nociceptive flexion reflex (NFR) at the end of general anaesthesia correlate with immediate postoperative pain, as a sign of analgesic underdosing, and with delayed tracheal extubation as a sign of analgesic overdosing. DESIGN: Prospective observational study. SETTING: Klinikum im Friedrichshain, Berlin, Germany, from May 2013 to April 2015. PATIENTS: A total of 110 patients scheduled for primary hip arthroplasty under general anaesthesia. OBSERVATIONS: Psychometric and clinical data were obtained preoperatively. The PDR and the NFR were assessed preoperatively and at the end of anaesthesia. Shortly after extubation of the trachea, patients rated their pain intensity. ENDPOINTS: The primary endpoint was the immediate postoperative numeric rating scale pain intensity (0 to 10) and the secondary endpoint was the length of the time interval between reflex measurements and tracheal extubation. RESULTS: PDR correlated significantly with the immediate postoperative pain intensity (Spearman's [rho] = -0.28, P

http://ift.tt/2kSEr34

Epidemiology and Risk Factors for Leisure Noise-Induced Hearing Damage in Flemish Young Adults

Sofie Degeest, Els Clays, Paul Corthals, Hannah Keppler

Noise and Health 2017 19(86):10-19

Context: Young people regularly expose themselves to leisure noise and are at risk for acquiring hearing damage. Aims: The objective of this study was to compare young adults' hearing status in relation to sociodemographic variables, leisure noise exposure and attitudes and beliefs towards noise. Settings and Design: A self-administered questionnaire regarding hearing, the amount of leisure noise exposure and attitudes towards noise and hearing protection as well as an audiological test battery were completed. Five hundred and seventeen subjects between 18 and 30 years were included. Subject and Methods: Hearing was evaluated using conventional audiometry, transient evoked and distortion product otoacoustic emissions. On the basis of their hearing status, participants were categorised into normal hearing, sub-clinical or clinical hearing loss. Statistical Analysis Used: Independent samples t-tests, chi-square tests and multiple regression models were used to evaluate the relation between groups based on hearing status, sociodemographics, leisure noise and attitudes towards noise. Results: Age was significantly related to hearing status. Although, the subjects in this study frequently participated in leisure activities, no significant associations between leisure noise exposure and hearing status could be detected. No relation with subjects' attitudes or the use of hearing protection devices was found. Conclusions: This study could not demonstrate clinically significant leisure noise-induced hearing damage, which may lead to more non-protective behaviour. However, the effects of leisure noise may become noticeable over a long-term use since age was found to be related with sub-clinical hearing loss. Longitudinal studies are needed to evaluate the long-term effects of noise exposure.

http://ift.tt/2jSZpPp

The Effects of Acoustic White Noise on the Rat Central Auditory System During the Fetal and Critical Neonatal Periods: A Stereological Study

Mohammad Saied Salehi, Mohammad Reza Namavar, Amin Tamadon, Raziyeh Bahmani, Mohammad Reza Jafarzadeh Shirazi, Homayoun Khazali, Leila Dargahi, Sareh Pandamooz, Farzad Mohammad-Rezazadeh, Fatemeh Sadat Rashidi

Noise and Health 2017 19(86):24-30

Aim: To evaluate the effects of long-term, moderate level noise exposure during crucial periods of rat infants on stereological parameters of medial geniculate body (MGB) and auditory cortex. Materials and Methods: Twenty-four male offspring of 12 pregnant rats were divided into four groups: fetal-to-critical period group, which were exposed to noise from the last 10 days of fetal life till postnatal day (PND) 29; fetal period group that exposed to noise during the last 10 days of fetal life; critical period group, exposed to noise from PND 15 till PND 29, and control group. White noise at 90 dB for 2 h per day was used. Statistical Analysis Used: Variance for variables was performed using Proc GLM followed by mean comparison by Duncan's multiple range test. Results: Numerical density of neurons in MGB of fetal-to-critical period group was lower than control group. Similar results were seen in numerical density of neurons in layers IV and VI of auditory cortex. Furthermore, no significant difference was observed in the volume of auditory cortex among groups, and only MGB volume in fetal-to-critical period group was higher than other groups. Estimated total number of neurons in MGB was not significantly different among groups. Conclusion: It seems necessary to prevent long-term moderate level noise exposure during fetal-to-critical neonatal period.

http://ift.tt/2jTmAvf

Using Auditory Steady-State Responses for Measuring Hearing Protector Attenuation

Olivier Valentin, Sasha M John, Frédéric Laville

Noise and Health 2017 19(86):1-9

Introduction: Present methods of measuring the attenuation of hearing protection devices (HPDs) have limitations. Objective measurements such as field microphone in real-ear do not assess bone-conducted sound. Psychophysical measurements such as real-ear attenuation at threshold (REAT) are biased due to the low frequency masking effects from test subjects' physiological noise and the variability of measurements based on subjective responses. An auditory steady-state responses (ASSRs) procedure is explored as a technique which might overcome these limitations. Subjects and Methods: Pure tone stimuli (500 and 1000 Hz), amplitude modulated at 40 Hz, are presented to 10 normal-hearing adults through headphones at three levels in 10 dB steps. Two conditions were assessed: unoccluded ear canal and occluded ear canal. ASSR amplitude data as a function of the stimulation level are linearized using least-square regressions. The "physiological attenuation" is then calculated as the average difference between the two measurements. The technical feasibility of measuring earplug attenuation is demonstrated for the group average attenuation across subjects. Results: No significant statistical difference is found between the average REAT attenuation and the average ASSR-based attenuation. Conclusion: Feasibility is not yet demonstrated for individual subjects since differences between the estimates occurred for some subjects.

http://ift.tt/2jTBWzV

Effect of Filters on the Noise Generated by Continuous Positive Airway Pressure Delivered via a Helmet

Ricardo Hernández-Molina, Francisco Fernández-Zacarías, Isabel Benavente-Fernández, Gema Jiménez-Gómez, Simón Lubián-López

Noise and Health 2017 19(86):20-23

Introduction: One of the problems that the delivery of continuous positive airway pressure (CPAP) via a helmet poses is the generation of noise. The objective of our study was to assess the effect that the use of filter has on sound pressure levels generated by the delivery of positive airway pressure at different gas flow rates. Materials and Methods: Sound pressure levels generated by neonatal helmet CPAP delivery were measured at different gas flows (20, 30, and 40 l/min) with and without a breathing filter. Noise intensity was measured by installing microphones in the inner ear of dummy heads wearing helmets. Results: The sound pressure level increased by 38% at a gas flow of 40 l/min, as compared to a gas flow of 20 l/min {74 dBA [interquartile range (IQR) 2,2] vs 52 dBA (IQR 5,9), respectively}. Using the breathing filter as a diffuser has a variety of effects on sound pressure levels according to the gas flow rate. Conclusion: The intensity of the noise generated by helmet delivery of positive airway pressure depends on the type of helmet used, gas flow, and use or not of a diffuser filter. Breathing filters with gas flows over 30 l/min might not be recommended since they would not attenuate but will rather amplify sound pressure.

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Classroom Listening Conditions in Indian Primary Schools: A Survey of Four Schools

Gayathri Sundaravadhanan, Heramba G Selvarajan, Bradley McPherson

Noise and Health 2017 19(86):31-40

Introduction: Background noise affects the listening environment inside classrooms, especially for younger children. High background noise level adversely affects not only student speech perception but also teacher vocal hygiene. The current study aimed to give an overview of the classroom listening conditions in selected government primary schools in India. Materials and Methods: Noise measurements were taken in 23 classrooms of four government primary schools in southern India, using a type 2 sound level meter. In each classroom measurements were taken in occupied and unoccupied conditions. Teacher voice level was measured in the same classrooms. In addition, the classroom acoustical conditions were observed and the reverberation time for each classroom was calculated. Results: The mean occupied noise level was 62.1 dBA and 65.6 dBC, and the mean unoccupied level was 62.2 dBA and 65 dBC. The mean unamplified teacher speech-to-noise ratio was 10.6 dBA. Both the occupied and unoccupied noise levels exceeded national and international recommended levels and the teacher speech-to-noise ratio was also found to be inadequate in most classrooms. The estimated reverberation time in all classrooms was greater than 2.6 seconds, which is almost double the duration of accepted standards. In addition, observation of classrooms revealed insufficient acoustical treatment to effectively reduce internal and external noise and minimize reverberation. Conclusion: The results of this study point out the need to improve the listening environment for children in government primary schools in India.

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Editorial Board

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

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APIC Masthead

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

http://ift.tt/2kSEvjz

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

http://ift.tt/2kpbfUq

Information for Authors

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

http://ift.tt/2kpj8JH

Knowledge of Ebola virus disease among a university population: A cross-sectional study

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2
Author(s): Muhammad Salman, Naureen Shehzadi, Khalid Hussain, Fahad Saleem, Muhammad Tanveer Khan, Nauman Asif, Maria Yousaf, Maham Rafique, Rushda Bedar, Sonia Tariq, Usman AbuBakar, Syed Azhar Syed Sulaiman
This cross-sectional study aimed to evaluate the knowledge of a Pakistani university population (students and employees) regarding Ebola virus disease. A total of 2,200 individuals were approached and 1,647 were enrolled in the study. We observed that the vast majority of study participants (91.8%) had inadequate knowledge of Ebola virus disease (knowledge score ≤ 12). Our findings highlight the need to increase the knowledge of Ebola virus disease by using multidimensional approach involving awareness campaigns, print, electronic, and social media.

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Information for Readers

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

http://ift.tt/2kSxBe0

The Effects of Acoustic White Noise on the Rat Central Auditory System During the Fetal and Critical Neonatal Periods: A Stereological Study

Mohammad Saied Salehi, Mohammad Reza Namavar, Amin Tamadon, Raziyeh Bahmani, Mohammad Reza Jafarzadeh Shirazi, Homayoun Khazali, Leila Dargahi, Sareh Pandamooz, Farzad Mohammad-Rezazadeh, Fatemeh Sadat Rashidi

Noise and Health 2017 19(86):24-30

Aim: To evaluate the effects of long-term, moderate level noise exposure during crucial periods of rat infants on stereological parameters of medial geniculate body (MGB) and auditory cortex. Materials and Methods: Twenty-four male offspring of 12 pregnant rats were divided into four groups: fetal-to-critical period group, which were exposed to noise from the last 10 days of fetal life till postnatal day (PND) 29; fetal period group that exposed to noise during the last 10 days of fetal life; critical period group, exposed to noise from PND 15 till PND 29, and control group. White noise at 90 dB for 2 h per day was used. Statistical Analysis Used: Variance for variables was performed using Proc GLM followed by mean comparison by Duncan’s multiple range test. Results: Numerical density of neurons in MGB of fetal-to-critical period group was lower than control group. Similar results were seen in numerical density of neurons in layers IV and VI of auditory cortex. Furthermore, no significant difference was observed in the volume of auditory cortex among groups, and only MGB volume in fetal-to-critical period group was higher than other groups. Estimated total number of neurons in MGB was not significantly different among groups. Conclusion: It seems necessary to prevent long-term moderate level noise exposure during fetal-to-critical neonatal period.

http://ift.tt/2jTmAvf

Epidemiology and Risk Factors for Leisure Noise-Induced Hearing Damage in Flemish Young Adults

Sofie Degeest, Els Clays, Paul Corthals, Hannah Keppler

Noise and Health 2017 19(86):10-19

Context: Young people regularly expose themselves to leisure noise and are at risk for acquiring hearing damage. Aims: The objective of this study was to compare young adults’ hearing status in relation to sociodemographic variables, leisure noise exposure and attitudes and beliefs towards noise. Settings and Design: A self-administered questionnaire regarding hearing, the amount of leisure noise exposure and attitudes towards noise and hearing protection as well as an audiological test battery were completed. Five hundred and seventeen subjects between 18 and 30 years were included. Subject and Methods: Hearing was evaluated using conventional audiometry, transient evoked and distortion product otoacoustic emissions. On the basis of their hearing status, participants were categorised into normal hearing, sub-clinical or clinical hearing loss. Statistical Analysis Used: Independent samples t-tests, chi-square tests and multiple regression models were used to evaluate the relation between groups based on hearing status, sociodemographics, leisure noise and attitudes towards noise. Results: Age was significantly related to hearing status. Although, the subjects in this study frequently participated in leisure activities, no significant associations between leisure noise exposure and hearing status could be detected. No relation with subjects’ attitudes or the use of hearing protection devices was found. Conclusions: This study could not demonstrate clinically significant leisure noise-induced hearing damage, which may lead to more non-protective behaviour. However, the effects of leisure noise may become noticeable over a long-term use since age was found to be related with sub-clinical hearing loss. Longitudinal studies are needed to evaluate the long-term effects of noise exposure.

http://ift.tt/2jSZpPp

Using Auditory Steady-State Responses for Measuring Hearing Protector Attenuation

Olivier Valentin, Sasha M John, Frédéric Laville

Noise and Health 2017 19(86):1-9

Introduction: Present methods of measuring the attenuation of hearing protection devices (HPDs) have limitations. Objective measurements such as field microphone in real-ear do not assess bone-conducted sound. Psychophysical measurements such as real-ear attenuation at threshold (REAT) are biased due to the low frequency masking effects from test subjects’ physiological noise and the variability of measurements based on subjective responses. An auditory steady-state responses (ASSRs) procedure is explored as a technique which might overcome these limitations. Subjects and Methods: Pure tone stimuli (500 and 1000 Hz), amplitude modulated at 40 Hz, are presented to 10 normal-hearing adults through headphones at three levels in 10 dB steps. Two conditions were assessed: unoccluded ear canal and occluded ear canal. ASSR amplitude data as a function of the stimulation level are linearized using least-square regressions. The “physiological attenuation” is then calculated as the average difference between the two measurements. The technical feasibility of measuring earplug attenuation is demonstrated for the group average attenuation across subjects. Results: No significant statistical difference is found between the average REAT attenuation and the average ASSR-based attenuation. Conclusion: Feasibility is not yet demonstrated for individual subjects since differences between the estimates occurred for some subjects.

http://ift.tt/2jTBWzV

Effect of Filters on the Noise Generated by Continuous Positive Airway Pressure Delivered via a Helmet

Classroom Listening Conditions in Indian Primary Schools: A Survey of Four Schools

Updated resource: The APIC/JCR Infection Prevention and Control Workbook, Third Edition

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2

http://ift.tt/2kSEv33

Inferior alveolar neurovascular bundle repositioning: a retrospective analysis

In this study, patients with an insufficient height of bone for implant placement in the posterior mandible were treated by repositioning of the inferior alveolar neurovascular bundle (IANVB). These patients were divided into two groups: those in group A (n=69) did not require a bone graft and implants were placed at the time of nerve repositioning; those in group B (n=9) received bone grafts in conjunction with nerve repositioning and implants were placed upon maturation of the grafts. One hundred and twenty-one nerves were repositioned in 78 patients and 308 implants were placed.

http://ift.tt/2jTsSLF

Longitudinal assessment of reprocessing effectiveness for colonoscopes and gastroscopes: Results of visual inspections, biochemical markers, and microbial cultures

1-s2.0-S0196655316X00156-cov150h.gif

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2
Author(s): Cori L. Ofstead, Harry P. Wetzler, Otis L. Heymann, Ellen A. Johnson, John E. Eiland, Michael J. Shaw
BackgroundFlexible endoscopes are currently reused following cleaning and high-level disinfection. Contamination has been found on endoscopes, and infections have been linked to gastrointestinal, respiratory, and urologic endoscopes.MethodsThis longitudinal study involved visual inspections with a borescope, microbial cultures, and biochemical tests for protein and adenosine triphosphate to identify endoscopes in need of further cleaning or maintenance. Three assessments were conducted over a 7-month period. Control group endoscopes reprocessed using customary practices were compared with intervention group endoscopes subjected to more rigorous reprocessing.ResultsAt final assessment, all endoscopes (N = 20) had visible irregularities. Researchers observed fluid (95%), discoloration, and debris in channels. Of 12 (60%) endoscopes with microbial growth, 4 had no growth until after 48 hours. There were no significant differences in culture results by study group, assessment period, or endoscope type. Similar proportions of control and intervention endoscopes (~20%) exceeded postcleaning biochemical test benchmarks. Adenosine triphosphate levels were higher for gastroscopes than colonoscopes (P = .014). Eighty-five percent of endoscopes required repair due to findings.ConclusionsMore rigorous reprocessing was not consistently effective. Seven-day incubation allowed identification of slow-growing microbes. These findings bolster the need for routine visual inspection and cleaning verification tests recommended in new reprocessing guidelines.

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The new frontier of diagnostics: Molecular assays and their role in infection prevention and control

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2
Author(s): Sanchita Das, Dena R. Shibib, Michael O. Vernon
Recent advances in technology over the last decade have propelled the microbiology laboratory into a pivotal role in infection prevention and control. The rapid adaptation of molecular technologies to the field of clinical microbiology now greatly influences infectious disease management and significantly impacts infection control practices. This review discusses recent developments in molecular techniques in the diagnosis of infectious diseases. It describes the basic concepts of molecular assays, discusses their advantages and limitations, and characterizes currently available commercial assays with respect to cost, interpretive requirements, and clinical utility.

http://ift.tt/2kSEtYZ

Infection control in the new age of genomic epidemiology

Publication date: 1 February 2017
Source:American Journal of Infection Control, Volume 45, Issue 2
Author(s): Patrick Tang, Matthew A. Croxen, Mohammad R. Hasan, William W.L. Hsiao, Linda M. Hoang
With the growing importance of infectious diseases in health care and communicable disease outbreaks garnering increasing attention, new technologies are playing a greater role in helping us prevent health care–associated infections and provide optimal public health. The microbiology laboratory has always played a large role in infection control by providing tools to identify, characterize, and track pathogens. Recently, advances in DNA sequencing technology have ushered in a new era of genomic epidemiology, where traditional molecular diagnostics and genotyping methods are being enhanced and even replaced by genomics-based methods to aid epidemiologic investigations of communicable diseases. The ability to analyze and compare entire pathogen genomes has allowed for unprecedented resolution into how and why infectious diseases spread. As these genomics-based methods continue to improve in speed, cost, and accuracy, they will be increasingly used to inform and guide infection control and public health practices.

http://ift.tt/2kpnuR5

Correlation between auditory brainstem response and hearing prognosis in idiopathic sudden sensorineural hearing loss patients

To investigate the latency and amplitude of auditory brainstem response (ABR) and hearing prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).

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Correlation between auditory brainstem response and hearing prognosis in idiopathic sudden sensorineural hearing loss patients

To investigate the latency and amplitude of auditory brainstem response (ABR) and hearing prognosis in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).

http://ift.tt/2koFT0C

Social media use for occupational lung disease.

Purpose of review: Social media have great impact on all aspects of life throughout the world. The utilization of social media for occupational lung disease, however, has been much more limited. This article summarizes recent literature concerning social media for occupational lung disease and identifies areas for additional use. Recent findings: Social media are used in six relevant areas: information dissemination, peer-to-peer communication, survey research data collection, participatory research and exposome data acquisition, assessing public concerns, and knowledge generation. There are very clear advantages for information dissemination from experts to workers and on a peer-to-peer basis, although variable credibility and accuracy concerns persist. For research, social media have been used for acquiring data posted for nonresearch purposes and for efficiently collecting information specifically for research. The benefits of efficiency, democracy, and very large data sources may counterbalance concerns about inadequate specification of recruitment strategies and limited control over data quality. Summary: The potential benefits of using social media for lung health-workplace interactions are much greater than the very limited current utilization. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Update on asthma and cleaning agents.

Purpose of review: Asthma due to cleaning products has been known for 20 years, and the interest in this topic is still large because of the number of cleaning workers with respiratory problems. In this review, we sought to highlight the most recent findings on the relationship between exposure to cleaning products and asthma and to summarize the specific literature published between 2013 and 2016. Recent findings: Women are confirmed as most of workers exposed to cleaning products and have a higher frequency than men of work-related respiratory symptoms and diseases. Many cases of asthma due to cleaning products occur in healthcare occupations. The increased risk of asthma has been shown to be related to the number of years in the job and to early life disadvantage. Recent evidence suggests that predisposition to adult-onset asthma may be related to interaction between genes and occupational exposure to low-molecular weight agents/irritants. There is some evidence that an irritant mechanism is more common, although several case reports showed animmunologic mechanism (e.g. disinfectants, amine compounds, aldehydes and fragrances). Summary: The review updated recent findings on epidemiology, cleaning agents and their mechanism, and prevention of asthma due to cleaning agents. This article provides new information on the level of exposure, which is still high in professional cleaners and even more in domestic cleaners, and on the frequency of asthma in professional and domestic cleaners. An irritant mechanism is more common, although an immunological mechanism is possible, especially in healthcare workers exposed to disinfectants. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

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Editorial: moving ahead faster than ever.

No abstract available

http://ift.tt/2kRLdWQ

Traffic-related air pollution and allergic disease: an update in the context of global urbanization.

Purpose of review: The review aims to give an update on the literature around traffic-related air pollution (TRAP) and allergic disease in the context of global urbanization, as the most populous countries in the world face severe TRAP exposure challenges. Recent findings: As research continues to show that gene-environment interactions and epigenetics contribute to the TRAP-allergy link, evidence around the links to climate change grows. Greenspace may provide a buffer to adverse effects of traffic on health, overall, but pose risks in terms of allergic disease. Summary: The link between traffic-related pollution and allergy continues to strengthen, in terms of supportive observational findings and mechanistic studies. Levels of TRAP across the world, particularly in Asia, continue to dramatically exceed acceptable levels, suggesting that the related adverse health consequences will accelerate. This could be counterbalanced by primary emission control and urban planning. Attention to combined effects of TRAP and allergen exposure is critical to avoiding misleading inferences drawn though examination only of isolated factors. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

http://ift.tt/2kRNP7c

A wide scope of new developments in occupational allergy and clinical immunology.

No abstract available

http://ift.tt/2jsp05t

Social media use for occupational lung disease.

Update on asthma and cleaning agents.

Editorial: moving ahead faster than ever.

No abstract available

http://ift.tt/2kRLdWQ

Traffic-related air pollution and allergic disease: an update in the context of global urbanization.

A wide scope of new developments in occupational allergy and clinical immunology.

No abstract available

http://ift.tt/2jsp05t

Ameloblastoma: Current Etiopathological Concepts and Management

Abstract

Ameloblastoma is a benign odontogenic tumor of epithelial origin. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 to 60 years.

Molecular and genetic factors that promote oncogenic transformation of odontogenic epithelium to ameloblastoma are strongly linked to dysregulation of multiple genes associated with mitogen activated protein kinase, sonic hedgehog and WNT/β-catenin signaling pathways. Treatment of ameloblastoma is focused on surgical resection with a wide margin of normal tissue because of its high propensity for loco-regional invasion; but this is often associated with significant patient morbidity.

The relatively high recurrence rate of ameloblastoma is influenced by the type of molecular etiologic factors, the management approach and how early the patient presents for treatment. It is expected that further elucidation of molecular factors that orchestrate pathogenesis and recurrence of ameloblastoma will lead to new diagnostic markers and targeted drug therapies for ameloblastoma.

http://ift.tt/2kSr5nL

Experimental comparison between tractional and compressive stress on temporomandibular joint

Abstract

Objective

We experimentally compared the effects of compressive and tractional mechanical stress on the temporomandibular joint (TMJ) of rabbits to assess the etiology of progressive condylar resorption.

Materials and Methods

We performed a cortical osteotomy using custom-made devices that were lengthened by 0.25 mm every 12 h for 1 week after surgery. During this time, the rabbit TMJ was under compressive or tractional mechanical stress. The samples in each group were examined using micro-computed tomography and histological staining.

Results

Scores for the area of bone resorption were higher in the compressive group than in the tractional group. Moreover, scores for the depth of bone resorption were higher in the compressive group than those in the tractional group. We observed a significantly higher prevalence of resorption in the subcondylar bone in the compressive group than in the tractional group. There were substantially more cells that were positive for tartrate-resistant acid phosphatase in the compressive group than in the control and tractional groups.

Conclusions

The outcomes here suggest that excessive mechanical stress, particularly compressive mechanical stress, may significantly affect morphological bone change findings in the TMJ.

http://ift.tt/2jTwcpZ

ΒΟΗΘΗΜΑΤΑ ΑΚΟΗΣ ΑΚΟΥΣΤΙΚΑ ΒΑΡΗΚΟΙΑΣ ΕΝΙΣΧΥΤΕΣ ΑΚΟΗΣ ΑΤΟΚΕΣ ΔΟΣΕΙΣ

ΒΟΗΘΗΜΑΤΑ ΑΚΟΗΣ ΑΚΟΥΣΤΙΚΑ ΒΑΡΗΚΟΙΑΣ ΕΝΙΣΧΥΤΕΣ ΑΚΟΗΣ ΑΤΟΚΕΣ ΔΟΣΕΙΣ

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Τρίτη, 31 Ιανουαρίου 2017

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ΒΟΗΘΗΜΑΤΑ ΑΚΟΗΣ ΑΚΟΥΣΤΙΚΑ ΒΑΡΗΚΟΙΑΣ ΕΝΙΣΧΥΤΕΣ ΑΚΟΗΣ ΑΤΟΚΕΣ ΔΟΣΕΙΣ

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