bluuebunny/crossref_metadata_2025 huggingface dataset:
CE method for analyzing Salmonella typhimurium in water samples
Authors: Arce Cristina , Cahya‐Mawarda Panji , Arroyo‐Manzanares Natalia , Garrido Juan J. , Arce Lourdes
Published: October 2017

Salmonella typhimurium is commonly described as a food‐borne pathogen. However, natural and drinking water are known to be important sources for the transmission of this pathogen in developing and developed countries. The standard method to determine Salmonella is laborious and many false positives are detected. To solve this, the present work was focused on the development of a capillary zone electrophoresis method coupled to ultraviolet detection for determination of Salmonella typhimurium in water (mineral and tap water). Separations were performed in less than 11 minutes using 4.5 mM Tris (hydroxymethyl)‐aminomethane, 4.5 mM boric acid and 0.1 mM ethylene diamine tetraacetate (pH 8.4) with 0.1% v/v poly ethylene oxide as separation buffer. The precision of the method was evaluated in terms of repeatability obtaining a relative standard deviation of 10.5%. Using the proposed method Salmonella typhimurium could be separated from other bacteria that could be present in water such as Escherichia coli. Finally, the proposed methodology was applied to determine Salmonella typhimurium in tap and mineral water.
Upper airway stimulation therapy and prior airway surgery for obstructive sleep apnea
Authors: Mahmoud Ahmad F. , Thaler Erica R.
Published: October 2017

Objective

To determine if patients with prior airway surgery for obstructive sleep apnea (OSA) had increased benefit following implantation with hypoglossal nerve stimulator.

Study Design

Retrospective chart review at a single institution tertiary academic care center.

Methods

Following implantation with hypoglossal nerve stimulator device, the outcomes of patients who underwent prior airway surgery for OSA were compared with those who did not. Primary outcome measures included apnea‐hypopnea index (AHI) and nadir oxyhemoglobin saturation (NOS) as measured by polysomnography. Secondary outcome measures included Epworth Sleepiness Scale.

Results

Forty‐seven patients underwent implantation with hypoglossal nerve stimulator. Of these, 30 patients had undergone prior airway surgery for OSA, whereas 16 did not. Mean preoperative AHI and NOS were 39.3 ± 2.8 and 78% ± 1.8% for all patients, 39.4 ± 3.7 and 79% ± 14% for patients with prior airway surgery, and 39.1 ± 4.0 and 77% ± 2.6% for patients without prior surgery. Mean postoperative AHI and NOS were 3.9 ± 1.2 and 91% ± 0.4% for all patients, 4.2 ± 1.7 and 91% ± 0.5% for patients with prior surgery, and 3.4 ± 1.5 and 93% ± 0.6% for patients without prior surgery (P = 0.756 and 0.053, respectively).

Conclusion

Overall, patients had significant improvement following implantation with hypoglossal nerve stimulator. Prior airway surgery had no statistically significant effect on postoperative AHI or NOS.

Level of Evidence

4. Laryngoscope, 128:1486–1489, 2018
Process of tight junction recovery in the injured vocal fold epithelium: Morphological and paracellular permeability analysis
Authors: Suzuki Ryo , Katsuno Tatsuya , Kishimoto Yo , Nakamura Ryosuke , Mizuta Masanobu , Suehiro Atsushi , Yamashita Masaru , Nakamura Tatsuo , Tateya Ichiro , Omori Koichi
Published: October 2017

Objectives/Hypothesis

The vocal fold epithelium that includes tight junction (TJ)‐based barrier function protects underlying connective tissues from external insults. TJs play an important role to control paracellular permeability of not only solutes but also ions, and preserve the vocal fold homeostasis. However, the distribution of TJs and paracellular diffusion barrier across the entire vocal fold epithelium are still unknown. The aim of this study was to identify the distribution of TJs in the vocal fold epithelium and to characterize the recovery process of TJ‐based paracellular diffusion barrier in a rat model of vocal fold injury.

Study Design

Animal experiments with controls.

Methods

Normal and vocal fold–injured rats were used. Larynges were harvested for immunohistochemical examination of TJ proteins. For functional analysis, a tracer permeability assay was performed using EZ‐Link Sulfo‐NHS‐LC‐Biotin.

Results

TJ proteins occludin and zonula occludens 1 signals were localized to the junctional regions of the most luminal cell layers of the vocal fold epithelium. The injured region had been recovered with epithelium at 5 days postinjury, but the paracellular diffusion barrier assays revealed that biotinylation reagents diffused into the lamina propria at 5 days postinjury, and were blocked at the epithelium at 14 and 28 days postinjury.

Conclusions

It was strongly suggested that TJs in the vocal fold epithelium exist at the junctional regions of the first layer of stratified squamous epithelium. TJ‐based paracellular diffusion barrier following vocal fold injury is recovered by 14 days postinjury, and this period corresponds with the time course of structural changes in the regenerating epithelium layer.

Level of Evidence

NA. Laryngoscope, 128:E150–E156, 2018
A matched comparison of human papillomavirus–induced squamous cancer of unknown primary with early oropharynx cancer
Authors: Ross Richard Blake , Koyfman Shlomo A. , Reddy Chandana A. , Houston Narcissa , Geiger Jessica L. , Woody Neil M. , Joshi Nikhil P. , Greskovich John F. , Burkey Brian B. , Scharpf Joseph , Lamarre Eric D. , Prendes Brandon , Lorenz Robert R. , Adelstein David J. , Ward Matthew C.
Published: October 2017

Objectives/Hypothesis

Patients with human papillomavirus (HPV)–induced cancer of unknown primary (CUP) are generally excluded from clinical trials, despite surgical series reporting detection rates of occult oropharynx primaries of >80%. We performed a matched‐pair analysis to compare outcomes between T0N1‐3M0 HPV+ CUP and T1‐2N1‐3M0 HPV+ oropharynx known primary (OPX).

Study Design

Retrospective cohort study at a single institution.

Methods

Patients with early T stage, node positive HPV+ OPX or CUP treated with curative intent between 1998 and 2016 were identified. For a subgroup of CUP patients with an unknown HPV status, we imputed HPV status and included patients with a >80% probability of being HPV+. Cohorts were matched based on patient demographics using a nearest neighbor propensity technique. After matching, patients were grouped according to either a favorable or unfavorable risk stratification designations per current NRG Oncology clinical trial enrollment criteria. Disease‐free survival (DFS) and overall survival (OS) were calculated using Kaplan‐Meier analysis.

Results

Of 298 patients with T1‐2N1‐3 OPX, 48 were matched to 48 HPV+ CUP patients (32 with confirmed and 16 imputed HPV status). Median follow‐up for CUP (34.1 months) and OPX (27.8 months) patients were similar (P = .23).There were no significant differences between the CUP and OPX groups for 3‐year DFS (89% vs. 85%, P = .44), and 3‐year OS (91% vs. 91%, P = .11), respectively.

Conclusions

Patients with T0N+M0 HPV‐induced CUP have similar survival outcomes to matched patients with T1‐2N+M0 HPV+ OPX. These patients can reasonably be included in clinical trials investigating the role of treatment deintensification and risk stratified similar to patients with early‐stage known primary OPX cancer.

Level of Evidence

4. Laryngoscope, 128:1379–1385, 2018
Selective recurrent laryngeal nerve stimulation using a penetrating electrode array in the feline model
Authors: Haidar Yarah M. , Sahyouni Ronald , Moshtaghi Omid , Wang Beverly Y. , Djalilian Hamid R. , Middlebrooks John C. , Verma Sunil P. , Lin Harrison W.
Published: October 2017

Objectives/Hypothesis

Laryngeal muscles (LMs) are controlled by the recurrent laryngeal nerve (RLN), injury of which can result in vocal fold (VF) paralysis (VFP). We aimed to introduce a bioelectric approach to selective stimulation of LMs and graded muscle contraction responses.

Study Design

Acute experiments in cats.

Methods

The study included six anesthetized cats. In four cats, a multichannel penetrating microelectrode array (MEA) was placed into an uninjured RLN. For RLN injury experiments, one cat received a standardized hemostat‐crush injury, and one cat received a transection‐reapproximation injury 4 months prior to testing. In each experiment, three LMs (thyroarytenoid, posterior cricoarytenoid, and cricothyroid muscles) were monitored with an electromyographic (EMG) nerve integrity monitoring system. Electrical current pulses were delivered to each stimulating channel individually. Elicited EMG voltage outputs were recorded for each muscle. Direct videolaryngoscopy was performed for visualization of VF movement.

Results

Stimulation through individual channels led to selective activation of restricted nerve populations, resulting in selective contraction of individual LMs. Increasing current levels resulted in rising EMG voltage responses. Typically, activation of individual muscles was successfully achieved via single placement of the MEA by selection of appropriate stimulation channels. VF abduction was predominantly observed on videolaryngoscopy. Nerve histology confirmed injury in cases of RLN crush and transection experiments.

Conclusions

We demonstrated the ability of a penetrating MEA to selectively stimulate restricted fiber populations within the feline RLN and selectively elicit contractions of discrete LMs in both acute and injury‐model experiments, suggesting a potential role for intraneural MEA implantation in VFP management.

Level of Evidence

NA. Laryngoscope, 128:1606–1614, 2018
Feasibility of preservation of chorda tympani nerve during noninflammatory ear surgery: A systematic review
Authors: Ziylan Fuat , Smeeing Diederik P.J. , Bezdjian A. , Stegeman Inge , Thomeer Hans G.X.M.
Published: October 2017

Objective

The objective of our systematic review is to investigate the postoperative gustatory function of the chorda tympani nerve following noninflammatory ear surgery for which the chorda tympani is at risk for iatrogenic injury (stretching, handling, or sacrificing).

Data Sources

PubMed and EMBASE.

Review Methods

A PubMed and EMBASE databases search was conducted on November 15, 2016. Study inclusion criteria included: 1) ear surgery performed for noninflammatory ear diseases, and 2) gustatory function of the chorda tympani reported as an outcome. The quality of eligible studies was assessed using the risk of bias assessment tool for nonrandomized studies. Study characteristics and outcome data of the included studies were extracted.

Results

In total 1,094 articles were retrieved. Fourteen studies encompassing 1,062 operated ears were included after quality assessment. Stapedectomy was the most frequent surgical procedure performed in 398 ears. The follow‐up time varied between 6 weeks and 99 months. Patients with a preserved chorda tympani were less symptomatic (24% was symptomatic) compared to patients with a stretched (53% was symptomatic) or sacrificed chorda tympani (47% was symptomatic). The recovery rate varied from 61% to 79%. The results of the electrogustometry and strip test showed a discrepancy with the subjective complaints of the patients.

Conclusion

Patients with a stretched chorda tympani were slightly more symptomatic compared to patients with a sacrificed chorda tympani. Therefore, in cases for which the chorda tympani greatly hinders a proper view of the surgical field, sacrificing the nerve could be considered to maximize surgical performance and have a satisfactory postoperative result. Laryngoscope, 1904–1913, 2018
Outpatient management of cholesteatoma with canal wall reconstruction tympanomastoidectomy
Authors: Kao Richard , Wannemuehler Todd , Yates Charles W. , Nelson Rick F.
Published: October 2017

Objectives

The postoperative wound infection rate for canal wall reconstruction (CWR) tympanomastoidectomy with mastoid obliteration in the treatment of chronic otitis media with cholesteatoma has been reported to be 3.6%. Postoperative administration of 24–48 hours of intravenous antibiotics has been recommended. We aim to determine the infection rate of CWR with postoperative outpatient oral antibiotics.

Study Design

Institutional review board—approved retrospective case review.

Setting

Tertiary referral center.

Patients: Retrospective review of consecutive patients who underwent CWR tympanomastoidectomy with mastoid obliteration at a single institution from 2014 to 2016.

Main Outcome Measure: Patient characteristics (age, sex) were calculated. Rate of postoperative complications and infections within 1 month of surgery were calculated. Comparison to previous published infection rates with postoperative intravenous antibiotics.

Results

51 patients underwent CWR followed by outpatient oral antibiotics with a mean age of 25.9 years (16 patients were less than 10 years old). There were no postoperative wound infections. Outpatient antibiotics showed non‐inferiority to IV antibiotic historic controls (0% vs. 3.6%; 95% confidence interval [CI], 0–6.09%; p = 0.03). One patient had small postoperative wound dehiscence with CSF leak that was managed conservatively. One patient developed Clostridium difficile colitis on postoperative day 2.

Conclusions

The infection rate after CWR tympanomastoidectomy with use of outpatient antibiotics is low and is non‐inferior to a historic cohort treated with inpatient intravenous antibiotics. A larger randomized controlled trial is warranted.

Level of Evidence

4.
The Impact of Diet‐Induced Weight Loss on Biomarkers for Colorectal Cancer: An Exploratory Study (INTERCEPT)
Authors: Beeken Rebecca J. , Croker Helen , Heinrich Malgorzata , Obichere Austin , Finer Nicholas , Murphy Neil , Goldin Robert , Guppy Naomi J. , Wilson Rose , Fisher Abigail , Steptoe Andrew , Gunter Marc J. , Wardle Jane
Published: October 2017

Objective

The aim of this study was to explore the potential effects of diet‐induced weight loss on molecular biomarkers of colorectal cancer risk in serum and colorectal tissue.

Methods

This single‐arm exploratory study included 20 adults with BMI ≥ 30 kg/m2 completing an 8‐week, complete, low‐energy liquid diet. Pre‐ and postintervention anthropometric measurements, fasting blood draws, and endoscopic examinations to procure colorectal biopsies were performed. Fasting insulin, glucose, insulinlike growth factor 1 (IGF‐1), C‐reactive protein (CRP), and blood lipids were measured in serum, and tissue markers of apoptosis (M30), colonocyte proliferation (Ki‐67), and insulin signaling (phospho‐mTOR) were assessed using immunohistochemical staining.

Results

Participants achieved substantial weight loss (mean = 13.56%). Mean concentrations of insulin, glucose, and cholesterol were significantly reduced (P < 0.05), but IGF‐1 and CRP were not. Colorectal tissue expression of Ki‐67 was significantly reduced (preintervention mean score = 7, postintervention mean score = 3.9, mean % change −43.8; P = 0.027). There were no significant changes in M30 or phospho‐mTOR.

Conclusions

Weight loss in individuals with obesity was associated with improvements in insulin sensitivity and blood lipid profiles and a significant reduction in tissue Ki‐67 expression. This is one of the first studies to demonstrate potential cancer‐relevant changes in colorectal tissue following weight loss achieved through diet.
Increased Physical Activity Associated with Less Weight Regain Six Years After “The Biggest Loser” Competition
Authors: Kerns Jennifer C. , Guo Juen , Fothergill Erin , Howard Lilian , Knuth Nicolas D. , Brychta Robert , Chen Kong Y. , Skarulis Monica C. , Walter Peter J. , Hall Kevin D.
Published: October 2017

Objective

The aim of this study was to explore how physical activity (PA) and energy intake (EI) changes were related to weight loss and regain following “The Biggest Loser” competition.

Methods

At baseline, week 6 and week 30 of the competition, and 6 years after the competition, body composition was measured via dual‐energy x‐ray absorptiometry, resting energy expenditure was measured by using indirect calorimetry, and EI and PA were measured by using doubly labeled water.

Results

Six years after the competition, median weight loss in 14 of “The Biggest Loser” participants was 13%, with those maintaining a greater weight loss (mean ± SE) of 24.9% ± 3.8% having increased PA by 160% ± 23%, compared with a PA increase of 34% ± 25% (P = 0.0033) in the weight regainers who were 1.1% ± 4.0% heavier than the precompetition baseline. EI changes were similar between weight loss maintainers and regainers (−8.7% ± 5.6% vs. −7.4% ± 2.7%, respectively; P = 0.83). Weight regain was inversely associated with absolute changes in PA (r = −0.82; P = 0.0003) but not with changes in EI (r = −0.15; P = 0.61). EI and PA changes explained 93% of the individual weight loss variability at 6 years.

Conclusions

Consistent with previous reports, large and persistent increases in PA may be required for long‐term maintenance of lost weight.
Perceptions of Barriers to Effective Obesity Care: Results from the National ACTION Study
Authors: Kaplan Lee M. , Golden Angela , Jinnett Kimberly , Kolotkin Ronette L. , Kyle Theodore K. , Look Michelle , Nadglowski Joseph , O'Neil Patrick M. , Parry Thomas , Tomaszewski Kenneth J. , Stevenin Boris , Lilleøre Søren Kruse , Dhurandhar Nikhil V.
Published: October 2017

Objective

ACTION (Awareness, Care, and Treatment in Obesity maNagement) examined obesity‐related perceptions, attitudes, and behaviors among people with obesity (PwO), health care providers (HCPs), and employer representatives (ERs).

Methods

A total of 3,008 adult PwO (BMI ≥ 30 by self‐reported height and weight), 606 HCPs, and 153 ERs completed surveys in a cross‐sectional design.

Results

Despite several weight loss (WL) attempts, only 23% of PwO reported 10% WL during the previous 3 years. Many PwO (65%) recognized obesity as a disease, but only 54% worried their weight may affect future health. Most PwO (82%) felt “completely” responsible for WL; 72% of HCPs felt responsible for contributing to WL efforts; few ERs (18%) felt even partially responsible. Only 50% of PwO saw themselves as “obese,” and 55% reported receiving a formal diagnosis of obesity. Despite HCPs' reported comfort with weight‐related conversations, time constraints deprioritized these efforts. Only 24% of PwO had a scheduled follow‐up to initial weight‐related conversations. Few PwO (17%) perceived employer‐sponsored wellness offerings as helpful in supporting WL.

Conclusions

Although generally perceived as a disease, obesity is not commonly treated as such. Divergence in perceptions and attitudes potentially hinders better management. This study highlights inconsistent understanding of the impact of obesity and need for both self‐directed and medical management.
Association of interleukin‐6 polymorphisms with obesity or metabolic traits in young Mexican‐Americans
Authors: Boeta‐Lopez K. , Duran J. , Elizondo D. , Gonzales E. , Rentfro A. , Schwarzbach A. E. , Nair S.
Published: October 2017

Objective

The objective of the study is to investigate the association of interleukin‐6 (IL6) promoter single‐nucleotide polymorphisms rs1800797 (‐597 G/A) and rs1800796 (‐572 G/C) with obesity or metabolic syndrome in Mexican‐Americans.

Methods

The rs1800797 and rs1800796 single‐nucleotide polymorphisms were genotyped in Mexican‐Americans (n = 437) from South Texas, and results were correlated with measures of obesity and metabolic syndrome including body mass index, waist circumference, blood pressure, cholesterol, triglycerides, glucose, liver enzymes, plasma IL6 and high‐sensitive C‐reactive protein (hs‐CRP).

Results

Significant associations were found for the rs1800796 variant with increased waist circumference, insulin resistance, lower IL6 levels and higher hs‐CRP levels. The rs1800797 variant showed no associations with metabolic traits but was associated with higher IL6 levels and lower hs‐CRP levels.

Conclusions

Findings in this study support the anti‐inflammatory, anti‐obesity and glucose homeostatic roles of IL6 in Mexican‐American youth.
Genome‐wide binding analysis of AtGNC and AtCGA1 demonstrates their cross‐regulation and common and specific functions
Authors: Xu Zhenhua , Casaretto José A. , Bi Yong‐Mei , Rothstein Steven J.
Published: October 2017

GATA transcription factors are involved in multiple processes in plant growth and development. Two GATA factors, NITRATE‐INDUCIBLE, CARBON METABOLISM‐INVOLVED (GNC) and CYTOKININ‐RESPONSIVE GATA FACTOR 1 (CGA1, also named GNL), are important regulators in greening, flowering, senescence, and hormone signaling. However, their direct target genes related to these biological processes are poorly characterized. Here, GNC and CGA1 are shown to be transcription activators and by using chromatin immunoprecipitation sequencing (ChIP‐seq), 1475 and 638 genes are identified to be associated with GNC and CGA1 binding, respectively. Enrichment of diverse motifs in the peak binding regions for GNC and CGA1 suggests the possibility that these two transcription factors also interact with other transcription factors and in addition genes coding for DNA‐binding proteins are highly enriched among GNC‐ and CGA1‐associated genes. Despite the fact that these two GATA factors are known to share a large portion of co‐expressed genes, our analysis revealed a low percentage of overlapping binding‐associated genes for these two homologues. This suggests a possible cross‐regulation between these, which is verified using ChIP‐qPCR. The common and specific biological processes regulated by GNC and CGA1 also support this notion. Functional analysis of the binding‐associated genes revealed that those encoding transcription factors, E3 ligase, as well as genes with roles in plant development are highly enriched, indicating that GNC and CGA1 mediate complex genetic networks in regulating different aspects of plant growth and development.
TET3‐mediated demethylation in tomato activates expression of a CETS gene that stimulates vegetative growth
Authors: Hollwey Elizabeth , Out Suzan , Watson Michael R. , Heidmann Iris , Meyer Peter
Published: October 2017

Expression of the mammalian DNA demethylase enzyme TET3 in plants can be used to induce hypomethylation of DNA. In tomato lines that express a TET3 transgene, we observed distinct phenotypes including an increase in the length and number of leaves of primary shoots. As these changes resemble phenotypes observed in plants with strong expression of SELF PRUNING (SP), a member of the PEBP/CETS family, we investigated in TET3 lines the expression levels of members of the PEBP/CETS gene family, which affect shoot architecture and growth of sympodial units in tomato. We did not detect any changes in SP expression in TET3 lines, but for CEN1.1, a putative family member that has not been functionally characterized, we identified changes in gene expression that corresponded to hypomethylation in the upstream region. In tomato wild type, CEN1.1 is expressed in roots, petals, and shoot apices but not in mature leaves. In contrast, in TET3 transformants, the CEN1.1 gene became hypomethylated and activated in leaves. Ectopic expression of CEN1.1 in tomato caused similar phenotypes to those seen in TET3 transformants. Vegetative growth was increased, resulting both in a delay in inflorescence development and in an instability of the inflorescences, which frequently reverted to a vegetative state. Ectopic expression of CEN1.1 in Arabidopsis thaliana also caused floral repression. Our data suggest that the phenotypes observed in TET3 lines are a consequence of ectopic activation of CEN1.1, which promotes vegetative growth, and that CEN1.1 expression is sensitive to DNA methylation changes.
Proteomic Screen of Brain Glycoproteome Reveals Prion Specific Marker of Pathogenesis
Authors: Lamoureux Lise , Simon Sharon L.R. , Waitt Brooks , Knox J. David
Published: October 2017

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative disorders caused by the presence of an infectious prion protein. The primary site of pathology is the brain characterized by neuroinflammation, astrogliosis, prion fibrils, and vacuolation. The events preceding the observed pathology remain in question. We sought to identify biomarkers in the brain of TSE‐infected and aged‐matched control mice using two‐dimensional fluorescence difference gel electrophoresis (2D‐DIGE). Since the brain proteome is too complex to resolve all proteins using 2D‐DIGE, protein samples are initially filtered through either concanavalin A (ConA) or wheat‐germ agglutinin (WGA) columns. Four differentially abundant proteins are identified through screening of the two different glycoproteomes: Neuronal growth regulator 1 (NEGR1), calponin‐3 (CNN3), peroxiredoxin‐6 (Prdx6), and glial fibrillary acidic protein (GFAP). Confirmatory Western blots are performed with samples from TSE‐infected and comparative Alzheimer's disease (AD) affected brains and their respective controls from time points throughout the disease courses. The abundance of three of the four proteins increases significantly during later stages of prion disease whereas NEGR1 decreases in abundance. Comparatively, no significant changes are observed in later stages of AD. Our lab is the first to associate the glycosylated NEGR1 protein with prion disease pathology.
Mechanical and viscoelastic properties of confined amorphous polymers
Authors: Vogt Bryan D.
Published: October 2017

Confinement of polymers to nanoscale dimensions can dramatically impact their physical properties. Substantial efforts have focused on the glass transition temperature (Tg) of polymers confined to thin films, but their mechanical properties are less studied despite their technological importance. In this review, challenges with mechanical measurements of polymer thin films are discussed along with novel metrologies that provide insight into their mechanical properties. A comparison of experimental measurements, simulations and theory provide several general conclusions about the mechanical properties under confinement. Confinement impacts the elastic modulus, rubbery compliance and viscosity of polystyrene, the archetypal polymer for confinement, but the confinement effect appears to depend on the measurement technique. This effect may be due to the details of averaging of gradients in properties that are dependent on the measurement details. Routes to minimize confinement effects are addressed. Despite progress in the measurements of mechanical properties of polymer thin films, there remain unresolved questions about the impact of confinement, which we highlight at the end of this review. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 9–30
Ionic liquid‐based organic–inorganic hybrid electrolytes: Impact of in situ obtained and dispersed silica
Authors: Khurana Shilpa , Chandra Amita
Published: October 2017

Organic–inorganic hybrid electrolytes based on PEO‐NaTFSI‐ionic liquid (HMIMTFSI)‐silica (in situ production via sol gel process) are being reported in this article. The variation in conductivity with ionic liquid (IL) addition has been explained on the basis of number of free TFSI anions evaluated using ATR‐IR data. The deconvolution of the IR spectra of these hybrid electrolytes has given evidence of ion‐pair formation which has been compared vis‐á‐vis the conductivity variation. The hybrid electrolyte with maximum conductivity comprises the highest number of free imide ions and has lowest glass transition temperature. FESEM has displayed a porous and layered surface morphology with dispersed silica nanoparticles. In addition, the optimized hybrid electrolyte has been compared with 5 wt% (limit of mechanical stability) ex situ silica added composite where the temperature cycling of conductivity has shown that the ex situ dispersed hybrid electrolytes do not retrace their conductivity path contrary to the in situ prepared hybrid electrolytes. This behavior has been explained to be due to the hindrance offered by the ex situ added silica in the recrystallization kinetics of PEO. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 207–218
Improving waterproof/breathable performance of electrospun poly(vinylidene fluoride) fibrous membranes by thermo‐pressing
Authors: Li Xiang , Lin Jinyou , Bian Fenggang , Zeng Yongchun
Published: October 2017

Facing the ever‐increasing demand for waterproof/breathable materials, a rapid and efficient fabrication method of these functional materials with excellent performance as well as robust mechanical properties remains challenging. Herein, a simple and scalable strategy referred to as thermo‐pressing is introduced to improve the waterproof/breathable performance and mechanical properties of electrospun PVDF fibrous membranes. The synergistic effect of temperature and pressure acted on the electrospun PVDF membranes on the fiber morphology and crystal structure was investigated, which can be able to effectively enhance waterproof performance and mechanical properties, endowing the as‐prepared membranes with a modest breathability. The membranes thermo‐pressed at 150 °C with a pressure of 8.27 MPa exhibit robust tensile strength of 40.65 MPa, which is superior to those of the previous reports (below 32.8 MPa). Notably, the optimized membranes enable to show a high hydrostatic pressure of 102 kPa, good WVTR of 10.87 kg m−2 d−1 and excellent abrasion resistance, which implies that the thermo‐pressing is an efficient and facile way to steer the fiber morphology and crystal structure of electrospun membranes to improve their application performance. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 36–45
Initial lamellar thickness dependency of recrystallization behavior of poly(4‐methyl‐1‐pentene)
Authors: Chen Ran , Lu Ying , Jiang Zhiyong , Men Yongfeng
Published: October 2017

The isothermal crystallization and subsequent melting process in semicrystalline poly(4‐methyl‐1‐pentene) were investigated via temperature‐dependent small‐ and wide‐angle X‐ray scattering and Flash DSC techniques. In a phase diagram of inversed crystalline lamellar thickness and temperature, the crystallization and melting lines can be described by two linear dependencies of different slopes and different limiting temperatures at infinite lamellar thickness. Upon subsequent heating, recrystallization lines with different slopes were observed for samples with different lamellar thickness, indicating changes in surface free energy difference between stabilized crystallites and mesomorphic phase. The surface free energy of native crystallites with extended‐chain conformation decreased with increasing lamellar thickness due to a more ordered surface region and less chain ends which changes cooperatively with mesomorphic phase. The surface free energy of stabilized crystallites remained unchanged for all lamellar thickness. Therefore, the recrystallization lines with different slopes are consequences of changes in surface free energy of mesomorphic phase. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 219–224
Computational study of the phosphoryl donor activity of dihydroxyacetone kinase from ATP to inorganic polyphosphate
Authors: Bordes Isabel , García‐Junceda Eduardo , Sánchez‐Moreno Israel , Castillo Raquel , Moliner Vicent
Published: October 2017

Adenosine triphosphate (ATP) is the main biological phosphoryl donor required in many enzymes including dihydroxyacetone kinases (DHAKs) that convert dihydroxyacetone (Dha) into dihydroxyacetone phosphate (Dha‐P), a key species with potential applications in synthesis. Herein, we present a theoretical study of the molecular mechanism for the phosphoryl transfer reaction from an inorganic polyphosphate to Dha catalyzed by DHAK from C. freundii. This is part of a project devoted to modify the phosphoryl donor specificity of this enzyme avoiding the use of the problematic direct addition of ATP. Based on the use of hybrid QM/MM potentials, with the QM region described by semiempirical and DFT methods, the reaction mechanism of the wild‐type enzyme and the most active experimentally measured mutant (Glu526Lys) with poly‐P as phosphoryl donor has been explored to elucidate the origin of the activity of this mutant. The similar energy barriers obtained in both systems confirm our previous studies on the binding step (Sánchez‐Moreno et al., Int. J. Mol. Sci. 2015, 16, 27835) suggesting that this mutation favors a more adequate position of the poly‐P in the active site for the following step, the chemical reaction, to take place.
What does three‐dimensional teaching and learning look like?: Examining the potential for crosscutting concepts to support the development of science knowledge
Authors: Fick Sarah J.
Published: October 2017

Science education reforms focus on the integration of three dimensions: disciplinary core ideas (DCIs), scientific and engineering practices (SEPs), and crosscutting concepts (CCCs). While research has examined the role of DCIs and SEPs in teaching and learning, little research has explored how the CCCs might be integrated. This research proposes an approach for integrating the CCCs into instruction to support students to understand the utility of the CCCs before applying them to make connections across science ideas. Using lessons co‐developed with the teacher who enacted them, this design experiment describes a teacher's use of the three dimensions to support student learning. The findings use students’ conceptual models and classroom dialogue as evidence to illustrate the roles that the CCC played in opportunities to learn. The CCCs appear to play three roles: (1) they implicitly served as a frame for the classroom activities and dialogue, (2) they explicitly framed a discussion to develop students’ understanding about their use as a lens to examine the phenomenon, and (3) the components of the CCC appeared in students’ conceptual models highlighting aspects of their understanding. This research has implications for how learning environments can be developed to support students’ learning of three‐dimensional science knowledge.
Using Q methodology to investigate undergraduate students’ attitudes toward the geosciences
Authors: Young Julia M. , Shepardson Daniel P.
Published: October 2017

Undergraduate students have different attitudes toward the geosciences, but few studies have investigated these attitudes using Q methodology. Q methodology allows the researcher to identify more detailed reasons for students’ attitudes toward geology than Likert methodology. Thus this study used Q methodology to investigate the attitudes that 15 undergraduate students had toward the geosciences. Three different groups of undergraduates were sampled: geoscience majors, science majors, and nonscience majors. Three distinct perspectives emerged from the analysis: (1) knowledge‐based outlook, (2) class isolated knowledge, and (3) specific geoscientific interests. Even though all students see value and importance in learning geoscience concepts, several students suggested that a better connection of the geosciences to their everyday lives would improve their attitude toward geology.
A study on mechanical and thermal properties of polypropylene/recycled acrylonitrile butadiene rubber/palm kernel shell composites with maleic anhydride grafted polypropylene as compatibilizer
Authors: Affandi Ranggita D. , Ragunathan Santiagoo , Ismail Hanafi , Sam SungTing
Published: October 2017

Thermal properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (rNBR)/palm kernel shell (PKS) composites with maleic anhydride grafted polypropylene (MAH‐g‐PP) as compatibilizer were carried out. The properties of PP/rNBR/PKS with and without MAH‐g‐PP compatibilization were studied at six different loadings (i.e., 100/0/15, 80/20/15, 70/30/15, 60/40/15, 50/50/15, and 40/60/15 phr). MAH‐g‐PP loading for each composites was fixed at 4 phr. The effects of MAH‐g‐PP on thermal, mechanical, morphological properties were investigated. The results showed that the addition of MAH‐g‐PP exhibited better thermal stability compared to uncompatibilized composites. The temperature degradation (Tdeg) were slightly increased around 5%. Total weight losses of MAH‐g‐PP compatibilized composites lower were then compared to uncompatibilized composites. The melting temperature (Tm) was slightly increased about 1–2°C with addition of MAH‐g‐PP. The crystallinity (Xc) of the composites increased from 18 to 42% with addition of MAH‐g‐PP. Higher tensile strength, Young's modulus and impact strength but lower elongation at break were also obtained in MAH‐g‐PP compatibilized composites. This was shown by the scanning electron microscope which indicated improved adhesion of the PKS filler with PP/rNBR matrices in the presence of MAH‐g‐PP. J. VINYL ADDIT. TECHNOL., 24:E125–E132, 2018. © 2017 Society of Plastics Engineers
Nonlinear wave equation with damping: Periodic forcing and non‐resonant solutions to the Kuznetsov equation
Authors: Celik Aday , Kyed Mads
Published: October 2017

Existence of non‐resonant solutions of time‐periodic type is established for the Kuznetsov equation with a periodic forcing term. The equation is considered in a three‐dimensional whole‐space, half‐space and bounded domain, and with both non‐homogeneous Dirichlet and Neumann boundary values. A method based on estimates for the corresponding linearization, namely the wave equation with Kelvin‐Voigt damping, is employed.
An Observational View of Relationships Between Moisture Aggregation, Cloud, and Radiative Heating Profiles
Authors: Lebsock Matthew D. , L’Ecuyer Tristan S. , Pincus Robert
Published: October 2017

Data from several coincident satellite sensors are analyzed to determine the dependence of cloud and precipitation characteristics of tropical regions on the variance in the water vapor field. Increased vapor variance is associated with decreased high cloud fraction and an enhancement of low-level radiative cooling in dry regions of the domain. The result is found across a range of sea surface temperatures and rain rates. This suggests the possibility of an enhanced low-level circulation feeding the moist convecting areas when vapor variance is large. These findings are consistent with idealized models of self-aggregation, in which the aggregation of convection is maintained by a combination of low-level radiative cooling in dry regions and mid-to-upper-level radiative warming in cloudy regions.
A Multivariate Model of Strategic Asset Allocation with Longevity Risk
Authors: Bisetti Emilio , Favero Carlo A. , Nocera Giacomo , Tebaldi Claudio
Published: October 2017

Population-wide increase in life expectancy is a source of aggregate risk. Longevity-linked securities are a natural instrument to reallocate that risk. This paper extends the standard Campbell–Viceira (2005) strategic asset allocation model by including a longevity-linked investment possibility. Model estimation, based on prices for standardized annuities publicly offered by U.S. insurance companies, shows that aggregate shocks to survival probabilities are predictors for long-term returns of the longevity-linked securities, and reveals an unexpected predictability pattern. Valuation of longevity risk premium confirms that longevity-linked securities offer inexpensive funding opportunities to asset managers.
Returns to work after retirement: a prospective study of unretirement in the United Kingdom
Authors: PLATTS LORETTA G. , CORNA LAURIE M. , WORTS DIANA , MCDONOUGH PEGGY , PRICE DEBORA , GLASER KAREN
Published: October 2017

Despite the complexity of the retirement process, most research treats it as an abrupt and one-way transition. Our study takes a different approach by examining retirement reversals (unretirement) and their predictors. Using the British Household Panel Survey (1991–2008), and following participants into Understanding Society (2010–2015), we undertake a survival analysis to investigate retirement reversals among Britons aged 50–69 years who were born in 1920–1959 (N = 2,046). Unretirement was defined as: (a) reporting being retired and subsequently recommencing paid employment, or (b) beginning full-time work following partial retirement (the latter defined here as reporting being retired and working fewer than 30 hours per week). A cumulative proportion of around 25 per cent of participants experienced a retirement reversal after reporting being retired; about half of these reversals occurred within the first five years of retirement. Unretirement was more common for participants who were male, more educated, in better health, owned a house with a mortgage (compared to owning it outright) and whose partner was in paid work. However, unretirement rates were not higher for participants in greater financial need, whether measured as subjective assessment of finances or household income quintiles. These results suggest that unretirement is a strategy more often used by those who are already advantaged and that it has the potential to exacerbate income inequalities in later life.
Degradation of hydrogen peroxide at the ocean’s surface: the influence of the microbial community on the realized thermal niche of Prochlorococcus
Authors: Ma Lanying , Calfee Benjamin C , Morris J Jeffrey , Johnson Zackary I , Zinser Erik R
Published: October 2017

Prochlorococcus, the smallest and most abundant phytoplankter in the ocean, is highly sensitive to hydrogen peroxide (HOOH), and co-occurring heterotrophs such as Alteromonas facilitate the growth of Prochlorococcus by scavenging HOOH. Temperature is also a major influence on Prochlorococcus abundance and distribution in the ocean, and studies in other photosynthetic organisms have shown that HOOH and temperature extremes can act together as synergistic stressors. To address potential synergistic effects of temperature and HOOH on Prochlorococcus growth, high- and low-temperature-adapted representative strains were cultured at ecologically relevant concentrations under a range of HOOH concentrations and temperatures. Higher concentrations of HOOH severely diminished the permissive temperature range for growth of both Prochlorococcus strains. At the permissive temperatures, the growth rates of both Prochlorococcus strains decreased as a function of HOOH, and cold temperature increased susceptibility of photosystem II to HOOH-mediated damage. Serving as a proxy for the natural community, co-cultured heterotrophic bacteria increased the Prochlorococcus growth rate under these temperatures, and expanded the permissive range of temperature for growth. These studies indicate that in the ocean, the cross-protective function of the microbial community may confer a fitness increase for Prochlorococcus at its temperature extremes, especially near the ocean surface where oxidative stress is highest. This interaction may play a substantial role in defining the realized thermal niche and habitat range of Prochlorococcus with respect to latitude.
Buildup of a highly twisted magnetic flux rope during a solar eruption
Authors: Wang Wensi , Liu Rui , Wang Yuming , Hu Qiang , Shen Chenglong , Jiang Chaowei , Zhu Chunming
Published: October 2017

The magnetic flux rope is among the most fundamental magnetic configurations in plasma. Although its presence after solar eruptions has been verified by spacecraft measurements near Earth, its formation on the Sun remains elusive, yet is critical to understanding a broad spectrum of phenomena. Here we study the dynamic formation of a magnetic flux rope during a classic two-ribbon flare. Its feet are identified unambiguously with conjugate coronal dimmings completely enclosed by irregular bright rings, which originate and expand outward from the far ends of flare ribbons. The expansion is associated with the rapid ribbon separation during the flare main phase. Counting magnetic flux through the feet and the ribbon-swept area reveals that the rope’s core is more twisted than its average of four turns. It propagates to the Earth as a typical magnetic cloud possessing a similar twist profile obtained by the Grad-Shafranov reconstruction of its three dimensional structure.
Shifts in pore connectivity from precipitation versus groundwater rewetting increases soil carbon loss after drought
Authors: Smith A. Peyton , Bond-Lamberty Ben , Benscoter Brian W. , Tfaily Malak M. , Hinkle C. Ross , Liu Chongxuan , Bailey Vanessa L.
Published: October 2017

Droughts and other extreme precipitation events are predicted to increase in intensity, duration, and extent, with uncertain implications for terrestrial carbon (C) sequestration. Soil wetting from above (precipitation) results in a characteristically different pattern of pore-filling than wetting from below (groundwater), with larger, well-connected pores filling before finer pore spaces, unlike groundwater rise in which capillary forces saturate the finest pores first. Here we demonstrate that pore-scale wetting patterns interact with antecedent soil moisture conditions to alter pore-scale, core-scale, and field-scale C dynamics. Drought legacy and wetting direction are perhaps more important determinants of short-term C mineralization than current soil moisture content in these soils. Our results highlight that microbial access to C is not solely limited by physical protection, but also by drought or wetting-induced shifts in hydrologic connectivity. We argue that models should treat soil moisture within a three-dimensional framework emphasizing hydrologic conduits for C and resource diffusion.
VSIG4 inhibits proinflammatory macrophage activation by reprogramming mitochondrial pyruvate metabolism
Authors: Li Jialin , Diao Bo , Guo Sheng , Huang Xiaoyong , Yang Chengying , Feng Zeqing , Yan Weiming , Ning Qin , Zheng Lixin , Chen Yongwen , Wu Yuzhang
Published: October 2017

Exacerbation of macrophage-mediated inflammation contributes to pathogenesis of various inflammatory diseases, but the immunometabolic programs underlying regulation of macrophage activation are unclear. Here we show that V-set immunoglobulin-domain-containing 4 (VSIG4), a B7 family-related protein that is expressed by resting macrophages, inhibits macrophage activation in response to lipopolysaccharide. Vsig4
−/−
mice are susceptible to high-fat diet-caused obesity and murine hepatitis virus strain-3 (MHV-3)-induced fulminant hepatitis due to excessive macrophage-dependent inflammation. VSIG4 activates the PI3K/Akt–STAT3 pathway, leading to pyruvate dehydrogenase kinase-2 (PDK2) upregulation and subsequent phosphorylation of pyruvate dehydrogenase, which results in reduction in pyruvate/acetyl-CoA conversion, mitochondrial reactive oxygen species secretion, and macrophage inhibition. Conversely, interruption of Vsig4 or Pdk2 promotes inflammation. Forced expression of Vsig4 in mice ameliorates MHV-3-induced viral fulminant hepatitis. These data show that VSIG4 negatively regulates macrophage activation by reprogramming mitochondrial pyruvate metabolism.
Field enhancement of electronic conductance at ferroelectric domain walls
Authors: Vasudevan Rama K. , Cao Ye , Laanait Nouamane , Ievlev Anton , Li Linglong , Yang Jan-Chi , Chu Ying-Hao , Chen Long-Qing , Kalinin Sergei V. , Maksymovych Petro
Published: October 2017

Ferroelectric domain walls have continued to attract widespread attention due to both the novelty of the phenomena observed and the ability to reliably pattern them in nanoscale dimensions. However, the conductivity mechanisms remain in debate, particularly around nominally uncharged walls. Here, we posit a conduction mechanism relying on field-modification effect from polarization re-orientation and the structure of the reverse-domain nucleus. Through conductive atomic force microscopy measurements on an ultra-thin (001) BiFeO3 thin film, in combination with phase-field simulations, we show that the field-induced twisted domain nucleus formed at domain walls results in local-field enhancement around the region of the atomic force microscope tip. In conjunction with slight barrier lowering, these two effects are sufficient to explain the observed emission current distribution. These results suggest that different electronic properties at domain walls are not necessary to observe localized enhancement in domain wall currents.