bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations between friendship characteristics and HIV and HSV‐2 status amongst young South African women in HPTN‐068
Authors: Fearon Elizabeth , Wiggins Richard D , Pettifor Audrey E , MacPhail Catherine , Kahn Kathleen , Selin Amanda , Gómez‐Olivé F Xavier , Delany‐Moretlwe Sinéad , Piwowar‐Manning Estelle , Laeyendecker Oliver , Hargreaves James R
Published: December 2017

Introduction

Prevalence of HIV among young women in South Africa remains extremely high. Adolescent peer groups have been found to be an important influence on a range of health behaviours. The characteristics of young women's friendships might influence their sexual health and HIV risk via connections to sexual partners, norms around sexual initiation and condom use, or provision of social support. We investigated associations between young women's friendships and their Herpes Simplex Virus Type 2 (HSV‐2) and HIV infection status in rural South Africa.

Methods

Our study is a cross‐sectional, egocentric network analysis. In 2011 to 2012, we tested 13‐ to 20‐year‐old young women for HIV and HSV‐2, and collected descriptions of five friendships for each. We generated summary measures describing friend socio‐demographic characteristics and the number of friends perceived to have had sex. We used logistic regression to analyse associations between friend characteristics and participant HIV and HSV‐2 infection, excluding likely perinatal HIV infections.

Results

There were 2326 participants included in the study sample, among whom HIV and HSV‐2 prevalence were 3.3% and 4.6% respectively. Adjusted for participant and friend socio‐demographic characteristics, each additional friend at least one year older than the participant was associated with raised odds of HIV (odds ratio (OR) = 1.37, 95% CI 1.03 to 1.82) and HSV‐2 (adjusted OR=1.41, 95% CI 1.18 to 1.69). Each additional friend perceived to have ever had sex also raised the odds of HIV (OR = 1.29, 95% CI 1.03 to 1.63) and HSV‐2 (OR=1.18, 95% CI 1.03 to 1.35).

Discussion

We found good evidence that a greater number of older friends and friends perceived to have had sex were associated with increased risk for HSV‐2 and HIV infection among young women.

Conclusions

The characteristics of young women's friendships could contribute to their risk of HIV infection. The extent to which policies or programmes influence age‐mixing and young women's normative environments should be considered.
Electrochemical oxidation of phosphatidylethanolamines studied by mass spectrometry
Authors: Colombo Simone , Coliva Giulia , Kraj Agnieszka , Chervet Jean‐Pierre , Fedorova Maria , Domingues Pedro , Domingues M. Rosário
Published: December 2017

Phosphatidylethanolamines (PEs) are widely present in cellular membranes and lipoproteins. Oxidation of PE fatty acyl chains generates several oxidized products, exerting a vast number of biological functions, not totally unveiled yet. In vitro biomimetic models have been used to identify oxidized PEs and to develop analytical strategies for their targeted detection in vivo. Most of the models are based on oxidation by reactive oxygen species (ROS), but the oxidative metabolism of PE also relies on controlled reactions catalyzed by enzymes as lipoxygenase, which can be mimicked by electrochemical (EC) oxidation. In this study, 3 PE standards (1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphoethanolamine (POPE), 1‐palmitoyl‐2‐linoleoyl‐sn‐glycero‐3‐phosphoethanolamine (PLPE), and 1‐palmitoyl‐2‐arachidonoyl‐sn‐glycero‐3‐phosphoethanolamine (PAPE)) were oxidized by EC oxidation, using an EC flow‐through cell system as a biomimetic model of oxidative injury. The new oxidation products were identified by online EC electrospray ionization mass spectrometry (EC‐ESI‐MS and MS/MS). Long‐chain and short‐chain oxidation products were identified, bearing modifications in the sn‐2 acyl chains, whereas the oxidation pattern was dependent on the unsaturation level. Long‐chain oxidation products of PEs (keto, hydroxy, hydroperoxy, poly‐hydroperoxy derivatives) were identified, bearing up to 5, 7, and 10 oxygens for POPE, PLPE, and PAPE, respectively. Fourteen short‐chain oxidation products, 7 from PLPE, and 7 from PAPE, including aldehydes, γ‐hydroxy‐α,β‐aldehydes, and dicarboxylic acids were characterized. Some of these oxidized species were previously reported during the oxidative metabolism of PEs driven by ROS. The EC‐ESI‐MS platform was, therefore, able to mimic the oxidative metabolism of PEs mediated by ROS.
Analysis of rainfall trends over Indo‐Pakistan summer monsoon and related dynamics based on CMIP5 climate model simulations
Authors: Latif M. , Hannachi A. , Syed F. S.
Published: December 2017

Understanding the effects of climate change and global warming on the South Asian summer monsoon rainfall trend is critically important for millions of inhabitants of this region. This study investigates seasonal (June–September) rainfall trend over the Indo‐Pakistan subcontinent by using 36 climate model outputs from the World Climate Research Programme's Coupled Model Inter‐comparison Project Phase 5. The historical (1951–2005) and future (2006–2100) simulations under two representative concentration pathways (RCPs), RCP4.5 and RCP8.5, are analysed for this purpose. Model reproducibility is evaluated based on spatial correlation of seasonal rainfall and vertically integrated meridional moisture transport between simulated and observed fields. It is found that the majority of models shows reasonable skill in capturing the observed pattern of rainfall climatology and trend over the subcontinent. Our results showed that the models are more skilful in simulating seasonal mean moisture transport than trend over the Arabian Sea and Bay of Bengal. Of the 36 models analysed, only two models HadGEM2‐AO and CNRM‐CM5 closely approximate both the climatology and trend based on statistical performance metrics. Our results suggest that the strengthening of northwards moisture transport over the Arabian Sea and Bay of Bengal is a likely reason for the increasing rainfall trend over Indo‐Pakistan subcontinent in a warmer climate. The RCP8.5 indicates marked increase in both rainfall and moisture transport trends compared to RCP4.5 forcing scenario.
Adjuvant therapy is associated with improved survival after curative resection for hilar cholangiocarcinoma: A multi‐institution analysis from the U.S. extrahepatic biliary malignancy consortium
Authors: Krasnick Bradley A. , Jin Linda X. , Davidson Jesse T. , Sanford Dominic E. , Ethun Cecilia G. , Pawlik Timothy M. , Poultsides George A. , Tran Thuy , Idrees Kamran , Hawkins William G. , Chapman William C. , Doyle Maria B.M. , Weber Sharon M. , Strasberg Steven M. , Salem Ahmed , Martin Robert C.G. , Isom Chelsea A. , Scoggins Charles , Schmidt Carl R. , Shen Perry , Beal Eliza , Hatzaras Ioannis , Shenoy Rivfka , Maithel Shishir K. , Fields Ryan C.
Published: December 2017

Background

Curative‐intent treatment for localized hilar cholangiocarcinoma (HC) requires surgical resection. However, the effect of adjuvant therapy (AT) on survival is unclear. We analyzed the impact of AT on overall (OS) and recurrence free survival (RFS) in patients undergoing curative resection.

Methods

We reviewed patients with resected HC between 2000 and 2015 from the ten institutions participating in the U.S. Extrahepatic Biliary Malignancy Consortium. We analyzed the impact of AT on RFS and OS. The probability of RFS and OS were calculated in the method of Kaplan and Meier and analyzed using multivariate Cox regression analysis.

Results

A total of 249 patients underwent curative resection for HC. Patients who received AT and those who did not had similar demographic and preoperative features. In a multivariate Cox regression analysis, AT conferred a significant protective effect on OS (HR 0.58, P = 0.013), and this was maintained in a propensity matched analysis (HR 0.66, P = 0.033). The protective effect of AT remained significant when node negative patients were excluded (HR 0.28, P = 0.001), while it disappeared (HR 0.76, P = 0.260) when node positive patients were excluded.

Conclusions

AT should be strongly considered after curative‐intent resection for HC, particularly in patients with node positive disease.
Percutaneous hepatic perfusion with melphalan in uveal melanoma: A safe and effective treatment modality in an orphan disease
Authors: Karydis Ioannis , Gangi Alexandra , Wheater Matthew J. , Choi Junsung , Wilson Iain , Thomas Kerry , Pearce Neil , Takhar Arjun , Gupta Sanjay , Hardman Danielle , Sileno Sean , Stedman Brian , Zager Jonathan S. , Ottensmeier Christian
Published: December 2017

Background

Metastatic uveal melanoma (UM) carries a poor prognosis; liver is the most frequent and often solitary site of recurrence. Available systemic treatments have not improved outcomes. Melphalan percutaneous hepatic perfusion (M‐PHP) allows selective intrahepatic delivery of high dose cytotoxic chemotherapy.

Methods

Retrospective analysis of outcomes data of UM patients receiving M‐PHP at two institutions was performed. Tumor response and toxicity were evaluated using RECIST 1.1 and Common Terminology Criteria for Adverse Events (CTCAE) v4.03, respectively.

Results

A total of 51 patients received 134 M‐PHP procedures (median of 2 M‐PHPs). 25 (49%) achieved a partial (N = 22, 43.1%) or complete hepatic response (N = 3, 5.9%). In 17 (33.3%) additional patients, the disease stabilized for at least 3 months, for a hepatic disease control rate of 82.4%. After median follow‐up of 367 days, median overall progression free (PFS) and hepatic progression free survival (hPFS) was 8.1 and 9.1 months, respectively and median overall survival was 15.3 months. There were no treatment related fatalities. Non‐hematologic grade 3‐4 events were seen in 19 (37.5%) patients and were mainly coagulopathic (N = 8) and cardiovascular (N = 9).

Conclusions

M‐PHP results in durable intrahepatic disease control and can form the basis for an integrated multimodality treatment approach in appropriately selected UM patients.
Determination of major aromatic constituents in vanilla using an on‐line supercritical fluid extraction coupled with supercritical fluid chromatography
Authors: Liang Yanshan , Liu Jiaqi , Zhong Qisheng , Shen Lingling , Yao Jinting , Huang Taohong , Zhou Ting
Published: December 2017

An on‐line supercritical fluid extraction coupled with supercritical fluid chromatography method was developed for the determination of four major aromatic constituents in vanilla. The parameters of supercritical fluid extraction were systematically investigated using single factor optimization experiments and response surface methodology by a Box–Behnken design. The modifier ratio, split ratio, and the extraction temperature and pressure were the major parameters which have significant effects on the extraction. While the static extraction time, dynamic extraction time, and recycle time had little influence on the compounds with low polarity. Under the optimized conditions, the relative extraction efficiencies of all the constituents reached 89.0–95.1%. The limits of quantification were in the range of 1.123–4.747 μg. The limits of detection were in the range of 0.3368–1.424 μg. The recoveries of the four analytes were in the range of 76.1–88.9%. The relative standard deviations of intra‐ and interday precision ranged from 4.2 to 7.6%. Compared with other off‐line methods, the present method obtained higher extraction yields for all four aromatic constituents. Finally, this method has been applied to the analysis of vanilla from different sources. On the basis of the results, the on‐line supercritical fluid extraction‐supercritical fluid chromatography method shows great promise in the analysis of aromatic constituents in natural products.
Environmentally assisted crack growth rate of an austenitic steel TP347HFG in high‐temperature medium
Authors: Khan Hasan Izhar , Zhang Naiqiang , Yue Guoqiang , Jiang Dongfang , Asif Tahir , Xu Hong
Published: December 2017

The crack growth rate (CGR) tests of austenitic steel TP347HFG were conducted under <10‐8000 ppb dissolved oxygen (DO) in steam, the alternating environment of air and steam and supercritical water (SCW) at 600–650 °C. A constant stress intensity factor (K) method and direct current potential drop technique were used in the tests to evaluate its environmentally assisted cracking (EAC) properties as superheater and reheater boiler tubes in ultra‐supercritical power plants. CGR increases monotonically with temperature and DO content. CGR in SCW is greater than that in the high‐temperature steam which indicates that exposure pressure has an obvious effect on crack propagation. The varying CGR in different experimental environments show that exposure medium participates in the cracking process. Fracture surface and cross‐sectional surface of compact tension specimen were analyzed by scanning electron microscope. The mechanism of crack propagation in different exposure environment is further discussed.
Manipulating the Surface Structure of Hybrid UV Curable Coatings through Photopolymerization‐Induced Phase Separation: Influence of Inorganic Portion and Photoinitiator Content
Authors: Mohammad Raei Nayini Mohsen , Bastani Saeed , Moradian Siamak , Croutxé‐Barghorn Céline , Allonas Xavier
Published: December 2017

Surface topography and phase‐manipulated distribution of hybrid UV curable coatings is performed. Accordingly, phase separation is controlled by changing the inorganic/organic ratio and the photoinitiator content as these are the main thermodynamic and kinetic affecting factors, respectively. Chemical and mechanical evolution of the samples during photopolymerization is investigated by time‐resolved Fourier transform infrared spectroscopy and photorheometry, respectively. It is found that the samples that contain larger portion of inorganic oligomers are polymerized faster, but undergo gelation later; this provides them more time to undergo phase separation prior to gelation. Therefore, their surfaces become rougher and more heterogeneous, which is confirmed by atomic force microscopey. Furthermore, adding larger amounts of photoinitiator into the samples leads to them being photopolymerized faster and undergo gelation at lower conversion. So, they have less time and thermodynamic tendency to undergo phase separation prior to gelation; their surfaces thus become smoother and more homogeneous.
Tau Imaging in Parkinsonism: What Have We Learned So Far?
Authors: Whitwell Jennifer L.
Published: December 2017

Background

Positron emission tomography ligands are now available that bind to tau proteins in the brain, providing the exciting opportunity to assess the presence and distribution of tau in vivo in living patients.

Methods

This manuscript performed a systematic review of studies that have performed tau PET imaging in patients with parkinsonian disorders. PubMed was searched through November 13, 2017 and the review included case reports and patient‐control studies.

Results

Most tau‐PET studies have utilized the [18F]AV‐1451 ligand, with a few using the [11C]PBB3 and [18F]THK‐5351 ligands. Elevated cortical tau‐PET uptake has been observed in Parkinson's disease dementia and dementia with Lewy bodies, presumed to be related to Alzheimer's disease‐related pathology. Mild patterns of tau‐PET uptake have been observed in subcortical structures in progressive supranuclear palsy and subcortical structures and motor cortex in corticobasal syndrome, although discrepancy with autoradiographic studies that show lack of binding to 4‐repeat tau and “off‐target” binding observed in subcortical structures limit the interpretation of these findings. Findings in frontotemporal dementia with tau mutations are variable, but elevated signal is most pronounced in mutations with deposition of both 3 and 4‐repeat tau. Elevated tau‐PET uptake has also been observed in multiple system atrophy, a synucleinopathy.

Conclusion

The value of the current generation of tau‐PET ligands varies across parkinsonian syndromes, depending upon underlying variability in tau pathology and “off‐target” binding. More work is needed to understand the biological basis of binding and more specific tau PET ligands are needed to study parkinsonian disorders.
Simultaneous editing of GABA and glutathione at 7T using semi‐LASER localization
Authors: Saleh Muhammad G. , Mikkelsen Mark , Oeltzschner Georg , Chan Kimberly L. , Berrington Adam , Barker Peter B. , Edden Richard A.E.
Published: December 2017

Purpose

To demonstrate simultaneous editing of the two most commonly edited and overlapping signals, γ‐aminobutyric acid (GABA), and glutathione (GSH), with Hadamard encoding and reconstruction of MEGA‐edited spectroscopy (HERMES) using sLASER localization at 7T.

Methods

Density matrix simulations of HERMES at 7T were carried out and compared with phantom experiments. Additional phantom experiments were performed to characterize the echo time (TE) ‐dependent modulation of GABA‐ and GSH‐edited HERMES spectra at TE of 80–160 ms. In vivo experiments were performed in 10 healthy volunteers, comparing HERMES (11 min) to sequentially acquired MEGA‐sLASER detection of GABA and GSH (2 × 11 min).

Results

Simulations of HERMES show GABA‐ and GSH‐edited spectra with negligible levels of crosstalk, and give modest agreement with phantom spectra. The TE series of GABA‐ and GSH‐edited HERMES spectra modulate as a result of T2 relaxation and coupling evolution, with GABA showing a stronger TE‐dependence. In vivo HERMES experiments show well‐edited GABA and GSH signals. Measured concentrations are not statistically different between HERMES and MEGA‐sLASER for GABA (1. 051 ± 0.254 i.u. and 1.053 ± 0.248 i.u; P > 0.985) or GSH (0.300 ± 0.091 i.u. and 0.302 ± 0.093 i.u; P > 0.940).

Conclusion

Simulated, phantom and in vivo measurements of HERMES show excellent segregation of GABA‐ and GSH‐edited signals, and excellent agreement with separately acquired MEGA‐sLASER data. HERMES allows two‐fold acceleration of editing while maintaining spectral quality compared with sequentially acquired MEGA‐sLASER measurements. Magn Reson Med 80:474–479, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Artifact‐reduced imaging of biopsy needles with 2D multispectral imaging
Authors: Weber Hans , Hargreaves Brian A. , Daniel Bruce L.
Published: December 2017

Purpose

Magnetic resonance (MR) guidance for biopsy procedures requires high intrinsic soft‐tissue contrast. However, artifacts induced by the metallic needle can reduce its localization and require low‐susceptibility needle materials with poorer cutting performance. In a proof of concept, we demonstrate the feasibility of 2D multispectral imaging (2DMSI) for both needle tracking and for needle artifact reduction for more precise needle localization and to enable the usage of needle materials with higher susceptibility.

Method

We applied 2DMSI for imaging of MR‐compatible biopsy needles, conventional stainless‐steel needles, and mixed‐material needles and compared it to conventional techniques. In addition, we exploited intrinsic off‐resonance information for passive needle tracking.

Results

2DMSI achieved a stronger reduction of the needle artifact compared to conventional techniques. For the mixed‐material needles, the artifact was reduced to a level below that for MR‐compatible needles with conventional imaging. The passive tracking also improved the ability to pinpoint the needle.

Conclusion

2DMSI is promising for both needle tracking and artifact‐reduced imaging of biopsy needles for a more precise needle localization. 2DMSI may be particularly promising for needles inducing large distortions or for targeting of small lesions. In addition, it may enable the use of needle materials with higher susceptibility and potentially better sampling performance. Magn Reson Med 80:655–661, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
From bad to worse: when lung cancer complicates idiopathic pulmonary fibrosis
Authors: Strock Stephen B , Alder Jonathan K , Kass Daniel J
Published: December 2017

Patients with idiopathic pulmonary fibrosis have a significantly increased risk for the development of lung cancer. The morbidity and mortality of this disease combination are substantial, and, unfortunately, there are currently few data to help guide clinicians in its diagnosis and treatment. In a recent issue of this journal, Hwang et al presented one of the first studies to evaluate lung cancer in patients with idiopathic pulmonary fibrosis at the molecular level. They demonstrate variants in regulators of the cell cycle, which are known to be important in malignant transformation and may also be important in the pathogenesis of idiopathic pulmonary fibrosis. Further understanding of the pathogenic overlap between lung cancer and idiopathic pulmonary fibrosis could help point the direction to specific diagnostic modalities and targeted treatment of both conditions in the future. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
MYH9‐macrothrombocytopenia caused by a novel variant (E1421K) initially presenting as apparent neonatal alloimmune thrombocytopenia
Authors: Samelson‐Jones Benjamin J. , Kramer Paula M. , Chicka Michael , Gunning William T. , Lambert Michele P.
Published: December 2017

MYH9‐related disease is a rare cause of thrombocytopenia. We report an infant girl who presented with severe thrombocytopenia at birth and was initially diagnosed with and treated for neonatal alloimmune thrombocytopenia. However, persistent thrombocytopenia led to the suspicion of congenital thrombocytopenia and subsequent identification of a novel variant in MYH9 (E1421K). In silico analysis strongly predicts that this is a disruptive substitution. Immunofluorescent analysis of neutrophils demonstrates abnormal aggregates of MYH9 protein. This case also suggests that a very high immature platelet fraction (≥40%) may be useful for rapidly differentiating MYH9‐related disease from other causes of neonatal thrombocytopenia.
The effectiveness of sound‐processing strategies on tonal language cochlear implant users: A systematic review
Authors: Liu Haihong , Peng Xiaoxia , Zhao Yawen , Ni Xin
Published: December 2017

Importance

Contemporary cochlear implants (CIs) are well established as a technology for people with severe‐to‐profound sensorineural hearing loss, with their effectiveness having been widely reported. However, for tonal language CI recipients, speech perception remains a challenge: Conventional signal processing strategies have been demonstrated to possibly provide insufficient information to encode tonal cues, and CI recipients have exhibited considerable deficits in tone perception. Thus, some tonal language–oriented sound‐processing strategies have been introduced. The effects of available tonal language–oriented strategies on tone perception are reviewed and evaluated in this study. The results may aid in designing and improving tonal language–appropriate sound‐processing strategies for CI recipients.

Objective

The objective of this systematic review was to investigate the effects of tonal‐language‐oriented signal processing strategies on tone perception, music perception, word and sentence recognition.

Methods

To evaluate the effects of tonal language–oriented strategies on tone perception, we conducted a systematic review. We searched for relevant reports dated from January 1979 to July 2017 using PubMed, Cochrane Library, EBSCO, Web of Science, EMBASE, and 4 Chinese periodical databases (CBMdisc, CNKI, VIP, and Wanfang Data).

Results

According to our search strategy, 672 potentially eligible studies were retrieved from the databases, with 12 of these studies included in the final review after a 4‐stage selection process. The majority of sound‐processing strategies designed for tonal language were HiResolution® with Fidelity 120 (HiRes 120), fine structure processing, temporal fine structure (TFS), and C‐tone. Generally, acute or short‐term comparisons between the tonal language–oriented strategies and the conventional strategy did not reveal statistically significant differences in speech perception (or show a small improvement). However, a tendency toward improved tone perception and subjectively reported overall preferred sound quality was observed with the tonal language–oriented strategies.

Interpretation

Conventional signal processing strategies typically provided very limited F0 information via temporal envelopes delivered to the stimulating electrodes. In contrast, tonal language–oriented coding strategies attempted to present more spectral information and TFS cues required for tone perception. Thus, a tendency of improved performance in tonal language perception in CI users was shown.
One‐Year Effectiveness Study of Intravitreous Ranibizumab in Wet (Neovascular) Age‐Related Macular Degeneration: A Meta‐Analysis
Authors: Guo Michael Y. , Etminan Mahyar , Cheng Jasmine Z. , Zafari Zafar , Maberley David A. L.
Published: December 2017

Purpose

The clinical efficacy of ranibizumab has been examined by a large number of prospective and retrospective studies to date. This meta‐analysis was conducted to summarize the current body of evidence on visual acuity (VA) changes with use of ranibizumab in the treatment of wet (neovascular) age‐related macular degeneration (wAMD).

Methods

A literature review of multiple electronic databases (EMBASE, MEDLINE, MedMEME) was conducted to find randomized controlled trials (RCTs) and observational studies that reported changes in VA while patients with wAMD were on ranibizumab. Study factors analyzed were baseline patient characteristics, study type, sample size, and 12‐month change in VA. Data were pooled in a meta‐analysis with VA change as the main outcome. Data were then stratified by study design and a meta‐regression was conducted to assess 12‐month VA change against baseline VA and age.

Results

A total of 42 studies were included for analysis. An overall increase of 5.58 letters (95% confidence interval [CI]: 4.42–6.75; p heterogeneity, < 0.001) was shown with use of ranibizumab compared to baseline. Improvements in VA were larger for RCTs, at 7.71 letters (95% CI: 6.66–8.76; p heterogeneity, 0.013), compared to observational studies, at 4.85 letters (95% CI: 3.32–6.38; p heterogeneity, < 0.001). The meta‐regression showed a significant decrease in effect size between baseline VA and 12‐month VA change.

Conclusion

This meta‐analysis suggests visual improvements at 12 months of 0.5‐mg ranibizumab use in patients with wAMD. A higher gain in VA was observed when pooling results from RCTs compared to those in observational studies.
Impact of blend ratio on the properties of graphene oxide‐filled carboxylated acrylonitrile–butadiene rubber/styrene–butadiene rubber blends
Authors: Zhang Xumin , Yin Qing , Xue Xiaodong , Jia Hongbing , Xu Zhaodong
Published: December 2017

Carboxylated acrylonitrile–butadiene rubber (XNBR) and styrene–butadiene rubber (SBR) composites with 3 phr (parts per hundred rubber) graphene oxide (GO) were prepared using a latex mixing method. Effects of XNBR/SBR blend ratios on the mechanical properties, thermal conductivity, solvent resistance and thermal stability of the XNBR/SBR/GO nanocomposites were studied. The tensile strength, tear strength, thermal conductivity and solvent resistance of the XNBR/SBR/GO (75/25/3) nanocomposite were significantly increased by 86, 96, 12 and 21%, respectively, compared to those of the XNBR/SBR (75/25) blend. The thermal stability of the nanocomposite was significantly enhanced; in other words, the temperature for 5% weight loss and the temperature of the maximal rate of degradation process were increased by 26.01 and 14.97 °C, respectively. Theoretical analysis and dynamic mechanical analysis showed that the GO tended to locate in the XNBR phase, which led to better properties of the XNBR/SBR/GO (75/25/3) nanocomposite. © 2017 Society of Chemical Industry
Properties of polyamide 6,10/poly(vinyl alcohol) blends and impact on oxygen barrier performance
Authors: Wu Jia‐wei , Huang Ya‐qiong , Li Hong‐bo , Runt James , Yeh Jen‐taut
Published: December 2017

The oxygen transmission rate, average volume of free‐volume cavities (Vf) and fractional free volume (Fv) of polyamide 6,10 (PA610)/poly(vinyl alcohol) (PVA) (i.e. PA610xPVA05y, PA610xPVA08y and PA610xPVA14y) blend films reduced to minimum values when their PVA contents reached corresponding optimal values. Oxygen transmission rate, Vf and Fv values obtained for optimal PA610xPVAzy blown films were reduced considerably with decreasing PVA degrees of polymerization. The oxygen transmission rate of the optimal bio‐based PA61080PVA0520 blown film was only 2.4 cm3 (m2·day·atm)−1, which is about the same as that of the most often used high‐barrier polymer, ethylene–vinyl alcohol copolymer. Experimental findings from dynamic mechanical analysis, differential scanning calorimetry, wide‐angle X‐ray diffraction and Fourier transform infrared spectroscopy of the PA610xPVAzy blends indicate that PA610 and PVA in the blends are miscible to some extent at the molecular level when the PVA contents are less than or equal to the corresponding optimal values. The considerably enhanced oxygen barrier properties of the PA610xPVAzy blend films with optimized compositions are attributed to the significantly reduced local free‐volume characteristics. © 2017 Society of Chemical Industry
Conserved redox‐dependent DNA binding of ROXY glutaredoxins with TGA transcription factors
Authors: Gutsche Nora , Holtmannspötter Michael , Maß Lucia , O'Donoghue Martin , Busch Andrea , Lauri Andrea , Schubert Veit , Zachgo Sabine
Published: December 2017

The Arabidopsis thaliana CC‐type glutaredoxin (GRX) ROXY1 and the bZIP TGA transcription factor (TF) PERIANTHIA (PAN) interact in the nucleus and together regulate petal development. The CC‐type GRXs exist exclusively in land plants, and in contrast to the ubiquitously occurring CPYC and CGFS GRX classes, only the CC‐type GRXs expanded strongly during land plant evolution. Phylogenetic analyses show that TGA TFs evolved before the CC‐type GRXs in charophycean algae. MpROXY1/2 and MpTGA were isolated from the liverwort Marchantia polymorpha to analyze regulatory ROXY/TGA interactions in a basal land plant. Homologous and heterologous protein interaction studies demonstrate that nuclear ROXY/TGA interactions are conserved since the occurrence of CC‐type GRXs in bryophytes and mediated by a conserved ROXY C‐terminus. Redox EMSA analyses show a redox‐sensitive binding of MpTGA to the cis‐regulatory as‐1‐like element. Furthermore, we demonstrate that MpTGA binds together with MpROXY1/2 to this motif under reducing conditions, whereas this interaction is not observed under oxidizing conditions. Remarkably, heterologous complementation studies reveal a strongly conserved land plant ROXY activity, suggesting an ancestral role for CC‐type GRXs in modulating the activities of TGA TFs. Super‐resolution microscopy experiments detected a strong colocalization of ROXY1 with the active form of the RNA polymerase II in the nucleus. Together, these data shed new light on the function of ROXYs and TGA TFs and the evolution of redox‐sensitive transcription regulation processes, which likely contributed to adapt land plants to novel terrestrial habitats.
Mesoporous GaN Made by Selective Area Sublimation for Efficient Light Emission on Si Substrate
Authors: Damilano Benjamin , Vézian Stéphane , Massies Jean
Published: December 2017

Selective area sublimation of thin (≤0.3 μm) GaN‐on‐Si epitaxial layers through nanoholes of an incomplete monolayer of SixNy results in the formation of mesoporous GaN. This morphologic change from a two‐dimensional flat layer to a nanostructured material presents the unexpected property of a huge increase (more than three orders of magnitude) of the GaN band edge photoluminescence intensity. Furthermore, the integrated photoluminescence intensity of such mesoporous GaN layers is comparable to a high quality 3.5 μm‐thick GaN‐on‐sapphire epitaxial layer or a 350 μm‐thick GaN substrate. Different possible mechanisms are discussed to explain the origin of the strong improvement of the optical properties.
Autonomous recovery of a fixed‐wing UAV using a net suspended by two multirotor UAVs
Authors: Klausen Kristian , Fossen Thor I. , Johansen Tor Arne
Published: December 2017

This article presents a novel recovery method for fixed‐wing unmanned aerial vehicles (UAVs), aimed at enabling operations from marine vessels. Instead of using the conventional method of using a fixed net on the ship deck, we propose to suspend a net under two cooperative multirotor UAVs. While keeping their relative formation, the multirotor UAVs are able to intercept the incoming fixed‐wing UAV along a virtual runway over the sea and transport it back to the ship. In addition to discussing the concept and design a control system, this paper also presents experimental validation of the proposed concept for a small‐scale UAV platform.
Design Nitrogen (N) and Sulfur (S) Co‐Doped 3D Graphene Network Architectures for High‐Performance Sodium Storage
Authors: Jiang Yu , Wu Ying , Chen Yuexi , Qi Zhenyu , Shi Jinan , Gu Lin , Yu Yan
Published: December 2017

To develop high‐performance sodium‐ion batteries (NIBs), electrodes should possess well‐defined pathways for efficient electronic/ionic transport. In this work, high‐performance NIBs are demonstrated by designing a 3D interconnected porous structure that consists of N, S co‐doped 3D porous graphene frameworks (3DPGFs‐NS). The most typical electrode materials (i.e., Na3V2(PO4)3 (NVP), MoS2, and TiO2) are anchored onto the 3DPGFs‐NS matrix (denoted as NVP@C@3DPGFs‐NS; MoS2@C@3DPGFs‐NS and TiO2@C@3DPGFs‐NS) to demonstrate its general process to boost the energy density of NIBs. The N, S co‐doped porous graphene structure with a large surface area offers fast ionic transport within the electrode and facilitates efficient electron transport, and thus endows the 3DPGFs‐NS‐based composite electrodes with excellent sodium storage performance. The resulting NVP@C@3DPGFs‐NS displays excellent electrochemical performance as both cathode and anode for NIBs. The MoS2@C@3DPGFs‐NS and TiO2@C@3DPGFs‐NS deliver capacities of 317 mAhg−1 at 5 Ag−1 after 1000 cycles and 185 mAhg−1 at 1 Ag−1 after 2000 cycles, respectively. The excellent long cycle life is attributed to the 3D porous structure that could greatly release mechanical stress from repeated Na+ extraction/insertion. The novel structure 3D PGFs‐NS provides a general approach to modify electrodes of NIBs and holds great potential applications in other energy storage fields.
A hybrid assessment approach for medical device software development companies
Authors: Özcan‐Top Özden , McCaffery Fergal
Published: December 2017

Medical device software development organizations are bound by regulatory requirements and constraints to ensure that developed medical devices will not harm patients. Medical devices have to be treated as complete systems and be evaluated in this manner. Instead of manufacturers having to ensure compliance to various regulatory standards individually, the authors previously developed a medical device software process assessment framework called MDevSPICE® that integrates the regulatory requirements from all the relevant medical device software standards. The MDevSPICE® was developed in a manner that suits plan‐driven software development. To improve the usability of MDevSPICE® in agile settings, we extended the assessment approach. The hybrid assessment approach described here combines the MDevSPICE®‐based process assessment method with steps for prioritization of improvement needs through value stream mapping and enabling process improvement through the use of KATA technique. This approach integrates agile methods into the medical device software development process while adhering to the requirements of the regulatory standards. This paper describes the implementation of the approach within 4 organizations that develop software in line with medical device regulations.
Investigating the impacts of targeted professional development around models and modeling on teachers' instructional practice and student learning
Authors: Miller Alison R. , Kastens Kim A.
Published: December 2017

Developing understanding of models and proficiency with modeling practice is challenging for both teachers and students. This 2‐year study first investigated existing instructional strategies employed by teachers while teaching Earth and Space Science with dynamic physical models. Summer professional development introduced a conceptual framework, based on analogical reasoning, to help students strengthen and deepen the connections they make between a model and its real‐world referent. The framework draws explicit attention to correspondences and non‐correspondences between model and referent, an often overlooked component of modeling practice which underpins the ability to evaluate and thus improve a model. Teachers were guided to reflect on their own instructional use of models and to plan for integrating specific instructional strategies around models into their Year 2 practice. Classroom observation data reveal that from Years 1 to 2, teachers shifted from a more didactic approach in which they used physical models primarily as tools for demonstration toward more student engagement with models as problem‐solving tools. On an assessment measuring their students' ability to reason with and about models, pre‐post learning gains were higher in Year 2 than Year 1 across students at all ability levels. Together, these findings present evidence that teachers can learn to guide their students toward using physical models in ways that approximate key aspects of how scientists use runnable models, as envisioned by the Developing and Using Models practice of the Next Generation Science Standards.
Adsorption kinetics, equilibrium and radiation effect studies of radioactive cesium by polymer‐based adsorbent
Authors: Olatunji Michael Adekunle , Khandaker Mayeen Uddin , Mahmud H.N.M. Ekramul
Published: December 2017

Electroactive polypyrrole has been synthesized by oxidative polymerization of pyrrole using ferric chloride hexahydrate as oxidant in the presence of sodium dodecylbenzene sulfonate (SDBS), and used to remove radioactive cesium from aqueous solution. The SDBS‐doped polypyrrole (PPy/SDBS) adsorbent was characterized by Field emission scanning electron microscopy, X‐ray diffraction and Fourier transform infrared techniques. A rapid and efficient adsorption of 137Cs radionuclide with a maximum sorption capacity of 26.2 mg/g has been achieved at 313 K. The kinetic data show the best fitting by the pseudo first‐order model while the Langmuir model properly reproduced the isotherm data. The thermodynamics parameters revealed an endothermic and spontaneous nature of the adsorption process. The adsorption efficiency shows only an insignificant variation with the gamma‐ray doses of 100 and 200 kGy. Considering the toxicity and nonbiodegradable nature of radioactive cesium, SDBS‐doped polypyrrole could be a good adsorbent for the recovery of 137Cs from radioactive effluents. J. VINYL ADDIT. TECHNOL., 24:347–357, 2018. © 2017 Society of Plastics Engineers
Positivity, Grassmannian geometry and simplex-like structures of scattering amplitudes
Authors: Rao Junjie
Published: December 2017

Abstract

This article revisits and elaborates the significant role of positive geometry of momentum twistor Grassmannian for planar

$$ \mathcal{N}=4 $$

N
=
4

SYM scattering amplitudes. First we establish the fundamentals of positive Grassmannian geometry for tree amplitudes, including the ubiquitous Plücker coordinates and the representation of reduced Grassmannian geometry. Then we formulate this subject, without making reference to on-shell diagrams and decorated permutations, around these four major facets: 1. Deriving the tree and 1-loop BCFW recursion relations solely from positivity, after introducing the simple building blocks called positive components for a positive matrix. 2. Applying Grassmannian geometry and Plücker coordinates to determine the signs of N2MHV homological identities, which interconnect various Yangian invariants. It reveals that most of the signs are in fact the secret incarnation of the simple 6-term NMHV identity. 3. Deriving the stacking positivity relation, which is powerful for parameterizing matrix representatives in terms of positive variables in the d log form. It will be used with the reduced Grassmannian geometry representation to produce the positive matrix of a given geometric configuration, which is an independent approach besides the combinatoric way involving a sequence of BCFW bridges. 4. Introducing an elegant and highly refined formalism of BCFW recursion relation for tree amplitudes, which reveals its two-fold simplex-like structures. First, the BCFW contour in terms of (reduced) Grassmannian geometry representatives is delicately dissected into a triangle-shape sum, as only a small fraction of the sum needs to be explicitly identified. Second, this fraction can be further dissected, according to different growing modes with corresponding growing parameters. The growing modes possess the shapes of solid simplices of various dimensions, with which infinite number of BCFW cells can be entirely captured by the characteristic objects called fully-spanning cells. We find that for a given k, beyond n =4 k+1 there is no more new fully-spanning cell, which signifies the essential termination of the recursive growth of BCFW cells. As n increases beyond the termination point, the BCFW contour simply replicates itself according to the simplex-like patterns, which enables us to master all BCFW cells once for all without actually identifying most of them.
The Effect of Intraoperative Nefopam Administration on Acute Postoperative Pain and Chronic Discomfort After Robotic or Endoscopic Assisted Thyroidectomy: A Randomized Clinical Trial
Authors: Kim B. G. , Moon J. Y. , Choi J. Y. , Park I. S. , Oh A. Y. , Jeon Y. T. , Hwang J. W. , Ryu J. H.
Published: December 2017

Background

Acute postoperative pain and chronic discomfort are reported after robotic or endoscopic thyroidectomy. The purpose of this prospective, randomized, and double‐blinded clinical trial was to investigate whether intraoperative infusion of nefopam decreases acute postoperative pain and chronic discomfort following either a robotic or endoscopic thyroidectomy via the bilateral axillo‐breast approach (BABA).

Methods

Patients were randomized into two groups: The control group (n = 29) or the nefopam group (n = 29). Patients in each group were infused with the same volume of saline or nefopam (0.2 mg/kg bolus, 120 μg/kg/h continuous infusion) during surgery. Acute postoperative pain, the need for rescue analgesics, and other postoperative adverse effects were assessed at 1, 6, 24, and 48 h postoperatively. Chronic pain and discomfort was recorded at 3 months after surgery.

Results

Patients in the nefopam group reported lower pain scores in the neck, as well as the axilla and anterior chest areas at 1, 6, 24, and 48 h postoperatively, when compared with the control group (P < 0.05 at each time points). Rescue analgesics were required less in the nefopam group than in the control group (1.4 [1] vs. 2.3 [1.5]; P = 0.001). The degree of chronic pain and discomfort were relatively lower in the nefopam group (P < 0.05).

Conclusion

We report that intravenous nefopam infusion during surgery decreased acute postoperative pain and the need for rescue analgesics, as well as chronic discomfort, following BABA robotic or endoscopic thyroidectomy without adverse events.
Factors Predicting the Recovery of Unilateral Vocal Fold Paralysis After Thyroidectomy
Authors: Choi Yong‐Sug , Joo Young‐Hoon , Park Young‐Hak , Kim Sang‐Yeon , Sun Dong‐Il
Published: December 2017

Background

We used voice analysis and clinicopathological factors to explore the prognosis of unilateral vocal fold paralysis after thyroid surgery.

Methods

The medical records of 63 females who developed unilateral vocal fold paralysis after thyroidectomy were reviewed. All patients were divided into two groups: those who recovered from vocal fold paralysis and those who did not. We analyzed clinical parameters and voice analysis results in a search for correlations with recovery from paralysis.

Results

Of the 63 patients, 37 (58%) recovered from paralysis. A small tumor size, incomplete paralysis, the absence of arytenoid tilting, no compensatory movement of the normal side, lower postoperative shimmer, a higher postoperative maximum phonation time (MPT), and lower postoperative subglottic pressure correlated significantly with recovery from vocal fold paralysis. Multivariate analysis confirmed that the absence of compensatory movement of the normal side on videostroboscopy was independently prognostic. A postoperative MPT of 6.86 appeared to be optimal for prediction of recovery. Most patients recovered within 6 months, but those with incomplete paralysis recovered about 3 months earlier. At the 12‐month follow‐up, the thyroidectomy‐related voice questionnaire scores had returned to preoperative values in only 12 patients (19.0%); 51 patients (81.0%) did not fully recover.

Conclusion

Compensatory movement of the normal side evident on videostroboscopy was a poor prognostic factor. Voice analysis can be helpful in counseling vocal fold paralysis patients after thyroidectomy, and early intervention may be considered in patients who are expected to have a poor prognosis.
Koyna, India, an Ideal Site for Near Field Earthquake Observations
Authors: Gupta Harsh K.
Published: December 2017

The Koyna earthquake of M 6.3 on December 10, 1967 is the largest artificial water reservoir triggered earthquake globally. It claimed ∼ 200 human lives and devastated the Koyna township. Before the impoundment of the Shivaji Sagar Lake created by the Koyna Dam, there were no earthquakes reported from the region. Initially a few stations were operated in the region by the Central Water and Power Research Station (CWPRS). The seismic station network grew with time and currently the National Geophysical Research Institute (NGRI), Hyderabad is operating 23 broadband seismographs and 6 bore hole seismic stations. Another reservoir, Warna, was created in 1985, which provided a further impetus to Reservoir Triggered Seismicity (RTS). Every year following the monsoon, water levels rise in the two reservoirs and there is an immediate increase in triggered earthquakes in the vicinity of Koyna-Warna reservoirs in the months of August – September. Peak RTS is observed in September and later during December. Another spurt in triggered earthquakes is observed during the draining of the reservoirs in the months of April-May. A comparative study of RTS earthquake sequences and the ones occurring in nearby regions made it possible to identify four common characteristics of RTS sequences that discriminate them from normal earthquake sequences. As the RTS events continue to occur at Koyna in a large number in a limited area of 20 km x 30 km, at shallow depths (mostly 2 to 9 km), the region being accessible for all possible observations and there being no other source of earthquakes within 100 km of Koyna Dam, it was suggested to be an ideal site for near field observations of earthquakes. This suggestion was discussed by the global community at an ICDP sponsored workshop held at Hyderabad and Koyna in 2011. There was an unanimous agreement about the suitability of the site for deep scientific drilling; however, a few additional observations/experiments were suggested. These were carried out in the following three years and another ICDP workshop was held in 2014, which totally supported setting up a borehole laboratory for near field investigations at Koyna. Location of a Pilot Bore-hole was decided on the basis of seismic activity and other logistics. The 3 km deep Pilot Borehole was spudded on December 20, 2016 and completed on June 11, 2017.