bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and in vitro anticancer activity of some novel tetrahydroquinoline derivatives bearing pyrazol and hydrazide moiety
Authors: Fathy Usama , Azzam Mariam A. , Mahdy Fathia , El‐Maghraby Somia , Allam Rasha M.
Published: February 2020

A new series of tetrahydroquinoline derivatives having pyrazol and hydrazide moieties were synthesized for the purpose of anticancer cell line evaluation. Syntheses of these compounds were firstly achieved by one pot four reactions. The reaction of 3‐amino‐tetrahydro‐1H‐pyrazolo [3,4‐b]quinolin with aldehydes, indoline‐2,3‐dione derivatives to give 9a‐c, 11a‐c, and 13a,b, respectively. In similar manner for biological comparison, the reactions of compound 5 with the same aldehydes and indoline‐2,3‐dione derivatives to give 19a‐c and 20a‐c. The newly synthesized compounds were examined in vitro for their cytotoxic activity against HepG‐2 and A549 cancer cells. The compounds 11a‐c and 20a‐c showed promising activity as anticancer agents against HepG‐2 and A549 cancer cells.
Changes in kidney function among men having sex with men starting on demand tenofovir disoproxil fumarate – emtricitabine for HIV pre‐exposure prophylaxis
Authors: Liegeon Geoffroy , Antoni Guillemette , Pialoux Gilles , Capitant Catherine , Cotte Laurent , Charreau Isabelle , Tremblay Cécile , Cua Eric , Senneville Eric , Raffi François , Meyer Laurence , Molina Jean‐Michel ,   for the ANRS‐IPERGAY study group
Published: February 2020

Introduction

Daily pre‐exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) is associated with a small but statistically significant decrease in estimated glomerular filtration rate (eGFR). We assessed the renal safety of on‐demand PrEP with TDF/FTC in HIV‐1 uninfected men.

Methods

We used data from the randomized double‐blind placebo‐controlled ANRS‐IPERGAY trial and its open‐label extension conducted between February 2012 and June 2016 among HIV‐uninfected MSM starting on‐demand PrEP. Using linear mixed model, we evaluated the mean eGFR decline from baseline over time and determined risks factors associated with eGFR decline during the study.

Results

During the blind phase, with a median follow‐up of 9.4 months, the mean decline slope of eGFR from baseline was −0.88 and −1.53 mL/min/1.73 m2 per year in the placebo (n = 201) and the TDF/FTC group (n = 198) respectively, with a slope difference of 0.65 mL/min/1.73 m2 per year (p = 0.27). Including both phases, 389 participants started on‐demand TDF/FTC with a median follow‐up of 19.2 months and a mean decline of eGFR from baseline of −1.14 mL/min/1.73 m2 per year (p < 0.001). The slope of eGFR reduction was not significantly different in participants with baseline eGFR ≤ 90 mL/min/1.73 m2 (p = 0.44), age >40 years (p = 0.24) or hypertension (p = 0.21). There was a dose‐response relationship between recent tenofovir exposure and lower eGFR when considering the number of pills taken in the two months prior the visit (eGFR difference of −0.88 mL/min/1.73 m2 between >15 pills/month vs. ≤15 pills/month, p < 0.01) or plasma tenofovir concentrations at the visit (eGFR difference compared to ≤2 ng/mL: >2 to ≤10ng/mL: −0.98 mL/min/1.73 m2, >10 to ≤40ng/mL: −1.28 mL/min/1.73 m2, >40 ng/mL: −1.82 mL/min/1.73 m2, p < 0.001). Three participants discontinued TDF/FTC for eGFR < 60 mL/min/1.73 m2 during the OLE phase. No case of Fanconi syndrome was reported.

Conclusions

The renal safety of on‐demand PrEP with TDF/FTC was good. The overall reduction and intermittent exposure to TDF/FTC may explain this good renal safety.
Quality, but not quantity of physical activity is associated with metal ion concentrations in unilateral hip resurfacing
Authors: Jelsma Jetse , Schotanus Martijn G. M. , van Kuijk Sander M. J. , Buil Ivo T. A. F. , Heyligers Ide C. , Grimm Bernd
Published: February 2020

Little is known about the influence of physical activity (PA) on metal ion concentrations in subjects with metal‐on‐metal hip arthroplasty. Implant wear is thought to be a function of use and thus of patient activity levels. It is hypothesized that daily habitual PA of patients with hip resurfacing arthroplasty (HRA) is associated with metal ion concentrations. Therefore a study was conducted in patients with a unilateral HRA at 10‐years follow‐up. Blood metal ion concentrations were determined. An acceleration‐based activity monitor was used to measure PA in daily life. The cohort consisted of 12 males (75%) and 4 females (25%) with a median age at surgery of 55.5 ± 9.7 years [43.0–67.9] and a median follow‐up of 9.9 ± 1.0 years [9.1–10.9]. The median cobalt and chromium ion concentrations were 25 ± 13 and 38 ± 28 nmol/L. A significant association between sit‐stand transfers and high‐intensity peaks with cobalt ion concentrations were found. Regarding PA and metal ion concentrations as a proxy of wear in HRA, specific activities like transfers or qualitative aspects of activity behavior like intensity, seem to matter more than the quantity of low‐intensity activities like walking or cycling. This suggests that patients may safely engage in such activities to achieve important general health benefits and quality of life.
Thiol precursors in Vitis mould‐tolerant hybrid varieties
Authors: Nicolini Giorgio , Roman Tomas , Flamini Riccardo , Tonidandel Loris , Gardiman Massimo , Larcher Roberto
Published: February 2020

BACKGROUND

Over recent years, a new wave of disease‐tolerant to mildew varieties has flooded the viticulture sector, for reasons of human safety and economic expediency. These hybrid grape cultivars are selected mainly on the basis of their intrinsic capability to counter the attack of the main fungal diseases that affect grape production, such as downy mildew and powdery mildew. However, their organoleptic and oenological characteristics have not yet been studied in depth for purposes of both juice and wine production, due to the high number of newly proposed germplasms and the lack of information about their adaptability to different environments. This work examines the thiol aroma precursors concentration in 64 red and white disease‐tolerant hybrid varieties in the vine germplasm collections of Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria–Viticulture and Enology Research Center and Fondazione Edmund Mach, both from the north‐east of Italy.

RESULTS

All cultivars showed the presence of 3‐mercaptohexan‐1‐ol (3MH) precursors, ranging from 4.4 to 1141 μg kg−1 for 3‐S‐glutathionyl hexan‐1‐ol (GSH‐3MH), and from 0.3 to 136 μg kg−1 for 3‐S‐cysteinyl 3‐hexan‐1‐ol. The concentration of GSH‐3MH exceeded 600 μg kg−1 in eight varieties, with values comparable to those of the richest Vitis vinifera reported so far. On average, red grapes showed higher concentrations of 3MH precursors than white ones did. Only two hybrids had 4‐mercapto‐4‐methylpentan‐2‐one (4MMP) precursors over the limit of quantification, albeit with a much higher concentration than those normally reported in Sauvignon Blanc.

CONCLUSION

This is the first detailed survey of 3MH and 4MMP precursors carried out taking into account a considerable number of hybrid grape varieties. The results show that some of these varieties could be interesting for the production of tropical juices or tropical‐aromatic wines and soft drinks, through the enzymatic liberation of thiol aromas, as well as for the production of aromatizing tannins to be used in the food industry. © 2020 Society of Chemical Industry
Black tea polyphenol theaflavin as promising antioxidant and potential copper chelator
Authors: Sharma Neha , Phan Huong T , Chikae Miyuki , Takamura Yuzuru , Azo‐Oussou Auriane F , Vestergaard Mun'delanji C
Published: February 2020

BACKGROUND

In this work, we investigated the antioxidant and copper chelating abilities of theaflavin, a polyphenol responsible for astringency, color, and sensation in black tea. Using voltammetric techniques, the analyses were conducted with disposable electrochemical printed carbon chips in conjunction with a portable hand‐held potentiostat.

RESULTS

Voltammograms of theaflavin showed five separate oxidation peaks, corresponding to the oxidation of five individual functional groups. Electroanalytical data indicated that, after interaction with copper, theaflavin had higher antioxidant potential and was a better copper chelator than epigallocatechin gallate, a major polyphenol present in green tea and a well‐known antioxidant. This could be attributed to the extra fused ring and larger number of OH groups in theaflavin.

CONCLUSIONS

Our findings introduce another natural compound as a potential nutraceutical in oxidation‐ and copper‐modulated illnesses. This simple and fast approach would also be highly pertinent to the inspection of the health benefits of natural food products. To the best of our knowledge, this is the first report of the electrochemical analysis of Cu (II) chelation with theaflavin. © 2020 Society of Chemical Industry
Posttraumatic Stress Disorder Symptoms and Reckless Behaviors: A Network Analysis Approach
Authors: Armour Cherie , Greene Talya , Contractor Ateka A. , Weiss Nicole , Dixon‐Gordon Katherine , Ross Jana
Published: February 2020

Existing literature indicates a theoretical and empirical relation between engagement in reckless behaviors and posttraumatic stress disorder (PTSD). Thus, theDSM‐5revision of the PTSD nosology added a new “reckless or self‐destructive behavior” (RSDB) symptom (Criterion E2). The current study applied a network analytic approach to examine the item‐level relations among a range of reckless behaviors and PTSD symptom clusters. Participants were recruited from Amazon's Mechanical Turk (N= 417), and network analysis was conducted with 20 variables: six PTSD symptom clusters, corresponding to the hybrid model of PTSD (Armour et al., 2015) and excluding the externalizing behavior cluster (Community 1), and 14 items related to reckless behavior (Community 2). The results showed that the network associations were strongest within each construct (i.e., within PTSD and within reckless behaviors), although several bridge connections (i.e., between PTSD clusters and reckless behaviors) were identified. Most reckless behavior items had direct associations with one or more PTSD symptom clusters. The present findings support the existence of close relations between a variety of reckless behaviors and PTSD symptom clusters beyond their relations withDSMCriterion E2. The results provide testable hypotheses about the associations between specific reckless behaviors and PTSD symptom clusters, which may inform future research.
Dietary Fat Does Not Overcome trans‐10, cis‐12 Conjugated Linoleic Acid Inhibition of Milk Fat Synthesis in Lactating mice
Authors: Robblee Megan M. , Boisclair Yves R. , Bauman Dale E. , Harvatine Kevin J.
Published: February 2020

Trans‐10, cis‐12 conjugated linoleic acid (CLA) is a potent inhibitor of milk fat synthesis in the cow and similarly reduces milk fat in rodents. The objective of this study was to determine whether dietary fat can overcome CLA inhibition of milk fat concentration in lactating mice. Wild type C57Bl/6J mice (n = 31) were fed semipurified diets containing either low fat (LF; 4% fat) or high fat (HF; 23.6% fat) starting 4–6 days postpartum. Dietary fat was increased by inclusion of high oleic sunflower oil. After 2 days on the experimental diets, lactating dams were orally dosed with either water (control) or trans‐10, cis‐12 CLA (20 mg/day) for 5 days. CLA treatment decreased pup growth similarly in both HF and LF diets. Milk fat percent was increased over 16% by the HF diet and decreased over 12% by CLA, but there was no interaction of dietary fat and CLA. Both CLA and the HF diet reduced the proportion of short‐ and medium‐chain fatty acids that originate from de novo synthesis, and there was no interaction of diet and CLA. CLA had no effect on the percent of preformed fatty acids, but the HF diet increased their abundance. Dietary fat and CLA both modified mammary expression of lipogenic enzymes and regulators, but no interactions were observed. In conclusion, CLA reduced milk fat concentration and litter growth, but these effects were not overcome by increased dietary fat from high oleic sunflower oil. CLA inhibition of milk fat in the mammary gland is not substrate dependent, and the mechanism is independent from dietary supply of oleic acid.
Robust PEDOT:PSS Wet‐Spun Fibers for Thermoelectric Textiles
Authors: Kim Youngseok , Lund Anja , Noh Hyebin , Hofmann Anna I. , Craighero Mariavittoria , Darabi Sozan , Zokaei Sepideh , Park Jae Il , Yoon Myung‐Han , Müller Christian
Published: February 2020

To realize thermoelectric textiles that can convert body heat to electricity, fibers with excellent mechanical and thermoelectric properties are needed. Although poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is among the most promising organic thermoelectric materials, reports that explore its use for thermoelectric fibers are all but absent. Herein, the mechanical and thermoelectric properties of wet‐spun PEDOT:PSS fibers are reported, and their use in energy‐harvesting textiles is discussed. Wet‐spinning into sulfuric acid results in water‐stable semicrystalline fibers with a Young's modulus of up to 1.9 GPa, an electrical conductivity of 830 S cm−1, and a thermoelectric power factor of 30 μV m−1 K−2. Stretching beyond the yield point as well as repeated tensile deformation and bending leave the electrical properties of these fibers almost unaffected. The mechanical robustness/durability and excellent underwater stability of semicrystalline PEDOT:PSS fibers, combined with a promising thermoelectric performance, opens up their use in practical energy‐harvesting textiles, as illustrated by an embroidered thermoelectric fabric module.
Estimates of Red Drum Mortality via Acoustic Telemetry
Authors: Nelson T. Reid , Powers Sean P.
Published: February 2020

Subadult (age < 3) Red Drum Sciaenops ocellatus support a valuable recreational fishery, and mortality estimates for young Red Drum are needed for proper management. To obtain these estimates, age-1 and age-2 Red Drum were implanted with acoustic transmitters and external Floy tags in two coastal Alabama rivers (Fowl and Dog rivers). Fates of tagged fish were inferred from stationary receiver detections and active relocations over 1 year. These fates were used in a Bayesian multistate model to estimate instantaneous monthly and annual mortality and emigration rates for each river and overall from both rivers. Instantaneous monthly fishing mortality (F) ranged from 0.001 to 0.112 (annual F =0.414) in Dog River, from 0.001 to 0.126 in Fowl River (annual F =0.309), and was 0.001–0.054 (annual F =0.337) overall. Instantaneous monthly natural mortality (M) ranged from 0.001 to 0.002 (annual M =0.069) in Dog River, from 0.001 to 0.036 (annual M =0.178) in Fowl River, and from 0.001 to 0.017 (annual M =0.090) overall. The overall annual estimate of instantaneous total mortality (Z) was 0.435. The median escapement percentage was estimated at 36.3% (95% posterior credible interval = 19.5–56.0%) using M and Z from the overall model. Unfortunately, the error on this estimate was large and inconclusive as to whether the 30% escapement goal for juvenile Red Drum to the adult population from Dog and Fowl rivers is being met. Monthly residency estimates were typically greater than 0.90, and overall annual residency was estimated at 0.716. Fishing mortality estimates from the current study are higher than recent catch curve estimates that did not include young Red Drum. These results demonstrate that young Red Drum need to be accounted for when generating mortality estimates and provide needed data for the Red Drum recreational fishery.
Placebo Response in Fragile X‐associated Tremor/Ataxia Syndrome
Authors: Hill Emily J. , Goetz Christopher G. , Stebbins Glenn T. , Hagerman Randi , Ouyang Bichun , Hall Deborah A.
Published: February 2020

Background

Fragile X‐associated tremor/ataxia syndrome (FXTAS) is a neurodegenerative disorder characterized by intention tremor, cerebellar ataxia, and executive dysfunction in carriers of a CGG repeat expansion premutation (55–200 repeats) in the fragile X mental retardation 1 (FMR1) gene. Given reports of poor insight in FXTAS, we postulated that patients with FXTAS would be less likely to exhibit placebo response.

Objective

To analyze placebo response from the first randomized controlled trial in FXTAS that evaluated cognitive and motor outcomes after 1 year of treatment with memantine.

Methods

Data from the placebo arm of the first randomized controlled trial in FXTAS were analyzed. There were 2 coprimary outcomes. Based on studies in Parkinson's disease, placebo responders were defined as individuals with an improvement of at least 50% in the coprimary outcomes. Improvements of 20% and 30% served as secondary cutoff values based on the suggested magnitude of placebo response in other movement disorders.

Results

A total of 36 participants in the placebo group completed baseline and follow‐up evaluations. The average age was 66 ± 7 years, and 60% were men. Average CGG repeat size was 86 ± 18. A total of 19 participants had stage 3 disease. Only 1 patient showed 50% improvement in both coprimary outcomes. At 30% and 20% improvement, there were 2 and 3 patients showing placebo response in the coprimary outcomes, respectively.

Conclusions

Patients with FXTAS exhibited low rates of placebo response in a randomized controlled trial. Further studies on the relationship between baseline insight and placebo responsivity are applicable to FXTAS and other disorders exhibiting cognitive impairment.
Frequency diverse array with random logarithmically increasing frequency offset
Authors: Huang Gaojian , Ding Yuan , Ouyang Shan , Fusco Vincent
Published: February 2020

The frequency diverse arrays (FDAs) have been extensively investigated since it can provide a unique angle‐range‐dependent beampattern. This range‐dependent characteristic can suppress the range ambiguous clutters, leading to many novel potential Radar applications. Two issues, however, exist in conventional FDA (CFDA) beampatterns, that is, range‐angle coupling and range periodicity. Therefore, for a CFDA Radar, target range information cannot be obtained directly from the beampattern peaks and target ambiguity occurs in the range domain. In this work, a new frequency diverse array (FDA) transmitter architecture with random logarithmically increasing frequency offset (log‐RFDA) is presented. It is shown that the proposed strategy provides a nonperiodic thumbtack‐like beampattern, eliminating the ambiguity in range domain, suffered in the CFDA Radar. Furthermore, reduced side lobe and higher detection resolution can be achieved, compared with the previously reported log‐FDA.
Influence of limb position on assessment of nerve mechanical properties by using shear wave ultrasound elastography
Authors: Rugel Chelsea L. , Franz Colin K. , Lee Sabrina S. M.
Published: February 2020

Introduction

Evaluation of nerve mechanical properties has the potential to improve assessment of nerve impairment. Shear wave velocity, as measured by using shear wave (SW) ultrasound elastography, is a promising indicator of nerve mechanical properties such as stiffness. However, elucidation of external factors that influence SW velocity, particularly nerve tension, is required for accurate interpretations.

Methods

Median and ulnar nerve SW velocities were measured at proximal and distal locations with limb positions that indirectly altered nerve tension.

Results

Shear wave velocity was greater at proximal and distal locations for limb positions that induced greater tension in the median (mean increase proximal 89.3%, distal 64%) and ulnar (mean increase proximal 91.1%, distal 37.4%) nerves.

Discussion

Due to the influence of nerve tension when SW ultrasound elastography is used, careful consideration must be given to limb positioning.
Multiscale design of three‐dimensional nonlinear composites using an interface‐enriched generalized finite element method
Authors: Brandyberry David R. , Najafi Ahmad R. , Geubelle Philippe H.
Published: February 2020

A computational framework is developed to model and optimize the nonlinear multiscale response of three‐dimensional particulate composites using an interface‐enriched generalized finite element method. The material nonlinearities are associated with interfacial debonding of inclusions from a surrounding matrix which is modeled using C−1 continuous enrichment functions and a cohesive failure model. Analytic material and shape sensitivities of the homogenized constitutive response are derived and used to drive a nonlinear inverse homogenization problem using gradient‐based optimization methods. Spherical and ellipsoidal particulate microstructures are designed to match a component of the homogenized stress‐strain response to a desired constructed macroscopic stress‐strain behavior.
Organizational capacity and entrepreneurial behavior
Authors: Svensson Per G. , Andersson Fredrik O. , Faulk Lewis
Published: February 2020

In this research note, we examine the relationship between organizational capacity and entrepreneurial behavior in a global sample of 165 nonprofit organizations operating in a single, rapidly growing field of nonprofit activity. Our findings show a strong relationship between organizations' entrepreneurial behavior and levels of organizational capacity. We discuss our results relative to the importance of both organizational capacity and entrepreneurial behavior in a rapidly growing nonprofit subsector. The results contribute to the continued development and refinement of theoretical and empirical work on the causal links between organizational capacity and entrepreneurial behavior more generally.
Continued Decline in Obesity and Severe Obesity Prevalence Among New York City Public School Youth in Grades K‐8: 2011‐2017
Authors: Day Sophia E. , D’Agostino Emily M. , Huang Terry T.‐K. , Larkin Michael , Harr Lindsey , Konty Kevin J.
Published: February 2020

Objective

This study aimed to estimate population‐level prevalence of obesity and severe obesity for New York City youth and examine the most recent trends over time.

Methods

All public school youth in grades kindergarten through eighth (K‐8) (2011‐2012 through 2016‐2017) with valid weight and height measures were included (N = 1,137,782 unique students; 3,720,297 observations). Age‐ and sex‐specific BMI percentiles for obesity and severe obesity were estimated using Centers for Disease Control and Prevention growth charts. Repeated cross‐sectional analyses were conducted using logistic regression, weighting for missing or invalid responses and accounting for clustering by students and schools to examine trends over time and by sociodemographics.

Results

Among youth in K‐8 (aged 5‐15 years, 48.8% girls), the prevalence of obesity and severe obesity in 2011‐2012 was 21.5% and 6.4%, respectively, compared with 20.2% and 6.0%, respectively, in 2016‐2017. Since 2011‐2012, decreasing trends in obesity and severe obesity (relative declines: 6.0% and 6.3%, respectively,P < 0.001) have been observed. Significant decreases were observed for all subgroups (P < 0.001), although there remained disparities in relative declines over time by race/ethnicity and poverty.

Conclusions

Decreasing trends in obesity and severe obesity among all New York City K‐8 public school youth are promising; however, persistent disparities highlight the need to improve intervention design and implementation strategies for groups disproportionately burdened by obesity.
Striatal Dopamine Responses to Feeding are Altered in People with Obesity
Authors: Eisenstein Sarah A. , Black Kevin J. , Samara Amjad , Koller Jonathan M. , Dunn Julia P. , Hershey Tamara , Klein Samuel , Smith Gordon I.
Published: February 2020

Objective

This study determined whether striatal dopamine (DA) release is affected by food ingestion and whether the DA response to high‐calorie food images is greater in the fasted than in the fed state in people with obesity.

Methods

Striatal DA release was evaluated in 10 people with obesity and prediabetes after consuming a meal to satiation and after fasting overnight as well as in response to viewing images of high‐calorie compared with low‐calorie foods after consuming a meal to satiation or fasting overnight by using positron emission tomography with [11C]raclopride injection.

Results

Striatal DA D2/D3 receptor availability was not different during fasted and fed conditions. Viewing images of high‐calorie foods induced striatal DA release relative to viewing images of low‐calorie foods (P < 0.05), but there was no difference in the magnitude of the response between fasting and fed conditions.

Conclusions

People with obesity and prediabetes do not increase striatal DA release after eating a meal to satiation compared with fasting overnight and fail to inhibit DA release in response to high‐calorie food stimuli after eating a meal to satiation. These data suggest that impaired DA signaling contributes to greater energy intake during meals in this population.
Current controversies in prenatal diagnosis 2: The 59 genes ACMG recommends reporting as secondary findings when sequencing postnatally should be reported when detected on fetal (and parental) sequencing
Authors: Amor David J. , Chitty Lyn S. , Van den Veyver Ignatia B.
Published: February 2020

Genome sequencing is increasingly being used to aid genetic diagnosis in fetuses with structural abnormalities detected on ultrasound examination. However, with clinical exome and genome sequencing, there is potential for the recognition and reporting of incidental or secondary findings unrelated to the indication for ordering the sequencing, but of potential medical value for patient care. In the postnatal setting, the American College of Medical Genetics and Genomics (ACMG) has clear guidelines that state that when offering sequencing, secondary findings should be reported in 59 genes for which ACMG consider there is a clinical evidence that pathogenic variants may result in disease that might be prevented or treated, with the option to opt out of receiving this information. However, these guidelines specifically exclude prenatal sequencing. Here, we report the debate on whether or not pathogenic findings in these 59 genes should or should not be reported in the prenatal setting. Although more were in favour of reporting before the debate, there was no significant consensus from the audience. After the debate there was a swing toward not reporting, but a slim majority (55%) remained in favour, indicating that this is an area requiring further research and the development of evidence‐based guidelines applicable to prenatal proband and trio sequencing.
Ultraviolet‐induced chain extension of poly(ethylene terephthalate) based on radical reaction with the aid of trimethylolpropane triacrylate and glycidyl methacrylate during extrusion
Authors: Huang Wei‐Tao , He Guang‐Jian , Tang Wen‐Dong , Cao Xian‐Wu
Published: February 2020

In order to improve the processing properties of poly(ethylene terephthalate) (PET), carbon–carbon double bonds were end‐capped onto the chain end of PET by reacting with glycidyl methacrylate (GMA) and then the product was reacted with trimethylolpropane triacrylate (TMPTA) based on a free radical reaction initiated by ultraviolet light to form long‐chain branching structures. The reaction was demonstrated by intrinsic viscosity measurements, carboxyl content analysis, Fourier transform infrared spectroscopy and size exclusion chromatography. Then the rheological and thermal properties of PET were investigated with various TMPTA and GMA contents. Chain extended PET displayed higher complex viscosity than pristine PET and pronounced shear‐thinning behavior. Moreover, the relaxation time spectrum revealed that the modified PET displayed a longer relaxation time during the relaxation process, which was attributed to the higher degree of entanglements resulting from long‐chain branching. Besides, its crystallization temperature and melt temperature shifted to lower temperatures, and the glass transition temperature shifted to higher temperature, indicating that the thermal properties of the modified PET had also been improved. Thus this method can be used to improve the overall properties of PET. © 2020 Society of Chemical Industry
Controlled and highly effective ring‐opening polymerization of α‐chloro‐ε‐caprolactone using Zn‐ and Al‐based catalysts
Authors: Bolley Anaëlle , Mameri Samir , Dagorne Samuel
Published: February 2020

The present study details the highly effective and controlled ring‐opening polymerization (ROP) of α‐chloro‐ε‐caprolactone (1, αClεCL), a cyclic ester that has been little explored thus far in ROP catalysis, using Zn‐ and Al‐based catalysts [Zn(C6F5)2(toluene)] (4), [N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)1,3‐diaminopropanato]aluminium(III)benzyloxide (5) and [N,N′‐bis(3,5‐di‐tert‐butylsalicylidene)1,3‐diamino‐2,2′‐dimethylpropanato]aluminium(III)benzyloxide] (6). Chain‐length‐controlled PαClεCL material is produced under solution ROP conditions, as deduced from GPC, NMR, MALDI‐TOF, and kinetic data. In contrast, the ROP of 1 is ill‐defined under bulk ROP conditions due to partial thermal degradation of the polymer chain (presumably through C–Cl cleavage), reflecting the limited stability of PαClεCL. The Al Catalysts 5 and 6 are highly active ROP catalysts of αClεCL at room temperature (TOF up to 2,400 hr−1) to afford well‐defined P(αClεCL). In the case of Catalyst 6, carrying out the ROP of αClεCL under immortal conditions (with BnOH as chain transfer agent) is clearly beneficial to ROP activity and control, with no apparent side‐reaction of chloro‐functionalized PCL chains as the ROP proceeds. The controlled character of these ROPs was further exploited for the production of chain‐length‐controlled PLLA‐b‐PαClεCL diblocks through sequential ROP of l‐lactide and αClεCL, affording copolymers with improved thermal and biodegradable properties.
Observations and modelling of ground temperature evolution in the discontinuous permafrost zone in Nadym, north‐west Siberia
Authors: Kukkonen Ilmo T. , Suhonen Elli , Ezhova Ekaterina , Lappalainen Hanna , Gennadinik Victor , Ponomareva Olga , Gravis Andrey , Miles Victoria , Kulmala Markku , Melnikov Vladimir , Drozdov Dmitry
Published: February 2020

We analyze ground temperatures measured daily at depths of 0–10 m in the Nadym region, north‐west Siberia (65°18′N, 72°6′E). Nadym is located within the discontinuous permafrost zone and the forest–tundra transition subzone, thus representing an area threatened by permafrost thawing. Soil comprises a 0.4–1.0‐m‐thick topmost layer of peat with high porosity (~0.9), underlain by layers of mineral soil (sand, clay, loam) with lower porosities of 0.3–0.4. With a numerical heat transfer model, we provide predictions of general permafrost development for the next 300 years. Furthermore, we apply the model with the same time frame, to predict permafrost evolution in two monitoring boreholes (BH) in the Nadym area, BH 1‐09 and 3‐09 with present (2012–2016) temperatures at the top of the permafrost (TTOP) of −2.0 and 0.0 °C, respectively. Applying a mild warming trend (0.02 °C/yr in mean annual air temperature [MAAT], corresponding to the IPCC representative concentration pathway trend RCP 2.6) does not lead to thawing of permafrost during the applied 300 years of simulation time in BH 1‐09, whereas in BH 3‐09 thawing has already begun. Applying a strong warming trend of 0.05 °C/yr in MAAT (corresponding to RCP 8.5) leads to gradual thawing of permafrost in both boreholes.
Re‐examining how Munc13‐1 facilitates opening of syntaxin‐1
Authors: Magdziarek Magdalena , Bolembach Agnieszka A. , Stepien Karolina P. , Quade Bradley , Liu Xiaoxia , Rizo Josep
Published: February 2020

Munc13‐1 is crucial for neurotransmitter release and, together with Munc18‐1, orchestrates assembly of the neuronal SNARE complex formed by syntaxin‐1, SNAP‐25, and synaptobrevin. Assembly starts with syntaxin‐1 folded into a self‐inhibited closed conformation that binds to Munc18‐1. Munc13‐1 is believed to catalyze the opening of syntaxin‐1 to facilitate SNARE complex formation. However, different types of Munc13‐1‐syntaxin‐1 interactions have been reported to underlie this activity, and the critical nature of Munc13‐1 for release may arise because of its key role in bridging the vesicle and plasma membranes. To shed light into the mechanism of action of Munc13‐1, we have used NMR spectroscopy, SNARE complex assembly experiments, and liposome fusion assays. We show that point mutations in a linker region of syntaxin‐1 that forms intrinsic part of the closed conformation strongly impair stimulation of SNARE complex assembly and liposome fusion mediated by Munc13‐1 fragments, even though binding of this linker region to Munc13‐1 is barely detectable. Conversely, the syntaxin‐1 SNARE motif clearly binds to Munc13‐1, but a mutation that disrupts this interaction does not affect SNARE complex assembly or liposome fusion. We also show that Munc13‐1 cannot be replaced by an artificial tethering factor to mediate liposome fusion. Overall, these results emphasize how very weak interactions can play fundamental roles in promoting conformational transitions and strongly support a model whereby the critical nature of Munc13‐1 for neurotransmitter release arises not only from its ability to bridge two membranes but also from an active role in opening syntaxin‐1 via interactions with the linker.
The comforts of home: The association between coresidence with parents and young adults' residential mobility and migration in the United States
Authors: Lei Lei , South Scott J.
Published: February 2020

This study uses data from the 2005 through 2015 waves of the Panel Study of Income Dynamics' Transition to Adulthood supplement to examine the association between young adults' living arrangements and their likelihood of moving. Compared with young adults who live with their parents, young adults who live independently are about twice as likely to move within a state, and four times as likely to move between states, over a biennial period. The negative association between parental coresidence and residential movement is stronger for young men than for young women and for Hispanics than for non‐Hispanic Whites. Increases in parental coresidence explain 70% of the decline in young adults' odds of making an intrastate move, and almost one third of the decline in the odds of making an interstate move, between 2005 and 2015.
Impact of Femtosecond Laser Treatment Accompanied with Anodization of Titanium Alloy on Fibroblast Cell Growth
Authors: Lone Shaukat Ali , Muck Martina , Fosodeder Peter , Mardare Cezarina Cela , Florian Camilo , Weth Agnes , Krüger Jörg , Steinwender Clemens , Baumgartner Werner , Bonse Jörn , Heitz Johannes , Hassel Achim Walter
Published: February 2020

Herein, Ti6Al4V alloy is surface modified by femtosecond laser ablation. The microstructure image obtained by secondary electron microscopy reveals a combination of micrometer spikes or cones superimposed by nanoripples (laser‐induced periodic surface structures). To make the surface hydrophilic, anodization is performed resulting in further smoothness of microstructure and a final thickness of 35 ± 4 nm is estimated for oxide produced after anodization at 10 V (scan rate = 0.1 V s−1) versus standard hydrogen electrode. The obtained electrochemically active surface area (ECSA) is approximately 8 times larger compared with flat mirror polished Ti6Al4V surface. Combined chemical analysis by Pourbaix diagram and X‐ray photoelectron spectroscopy (XPS) analyses reveal that titanium and aluminum are passivating into TiO2 and Al2O3, but the dissolution of aluminum in the form of solvated ion is inevitable. Finally, cell seeding experiments on anodized and laser‐treated titanium alloy samples show that the growth of murine fibroblast cells is significantly suppressed due to unique surface texture of the laser‐treated and anodized titanium alloy sample.
Adaptive neural network tracking control for uncertain nonlinear systems with input delay and saturation
Authors: Ma Jiali , Xu Shengyuan , Zhuang Guangming , Wei Yunliang , Zhang Zhengqiang
Published: February 2020

In this article, the adaptive tracking control problem is considered for a class of uncertain nonlinear systems with input delay and saturation. To compensate for the effect of the input delay and saturation, a compensation system is designed. Radial basis function neural networks are directly utilized to approximate the unknown nonlinear functions. With the aid of the backstepping method, novel adaptive neural network tracking controllers are developed, which can guarantee all the signals in the closed‐loop system are semiglobally uniformly ultimately bounded, and the system output can track the desired signal with a small tracking error. In the end, a simulation example is given to illustrate the effectiveness of the proposed methods.
Secure data dissemination techniques for IoT applications: Research challenges and opportunities
Authors: Bodkhe Umesh , Tanwar Sudeep
Published: February 2020

Internet of Things (IoT) connects different objects in the physical world to the Internet, and various Internet protocols are used to provide communication services to a large number of these embedded devices termed as smart devices. But, these devices are resource‐constrained, low configured, and have very low power storage capacity, which depends on the services offered by the protocols. For the exchange of information to the end‐users, smart devices communicate through an open channel, such as the Internet, which is not secure enough. Moreover, efficient delivery ratio, secure data forwarding are not achieved because of the enormous amount of data produced by these smart devices and the possibility of security threats. So there is a need to devise a secure and reliable data dissemination scheme for the IoT environment. Motivated from the these facts, this paper presents a systematic review and propose a solution taxonomy for secure data dissemination techniques for various smart IoT‐based applications. This paper also includes a comparison of the state‐of‐the‐art data dissemination techniques used for the Internet of Vehicles (IoVs), Internet of Drones (IoDs), and Internet of Battlefield Things (IoBTs) applications along with their merits and demerits. Finally, the research challenges and possible countermeasures are also discussed in detail, which gives insights to the beginners who want to start work in this emerging
area.
A methodology for modeling sociotechnical systems to facilitate exploratory policy analysis
Authors: Pennock Michael J. , Bodner Douglas A.
Published: February 2020

Addressing modern societal challenges often requires the consideration of sociotechnical systems. Sociotechnical systems consist of technological, organizational, and social systems interacting to achieve a goal. Developing effective approaches to modeling sociotechnical systems could enable policy makers to better understand the implications of policy options prior to implementation. Through past work, the authors evaluated a modeling methodology intended to accomplish that goal. While the methodology was found to be useful, there were also significant limitations. In this paper, the authors analyze these limitations through the lens of consolidative versus exploratory modeling. The result is a substantial revision of the modeling methodology that moves from a sequential 10‐step process to a multiphase process intended to facilitate exploratory modeling and detect unintended policy consequences.
Conceptualizing Language Teacher Education Centered on Language Teacher Identity Development: A Competencies‐Based Approach and Practical Applications
Authors: Fairley Mariah J.
Published: February 2020

Language teacher identity (LTI) has become an increasingly central focus in language teaching recently, perhaps because identity is now defined as multiple, complex, shifting, socially constructed, and a site of struggle (Norton, 2013; Song, 2016)—and thus a construct that can and should be intentionally influenced (Varghese, Motha, Park, Reeves, & Trent, 2016). With greater understanding that social justice and a critical orientation to education are not only important but also the duty of educators to enact (Kubota & Miller, 2017), some advocate the placement of LTI development at the center of language teacher education (LTE; De Costa & Norton, 2017a; Varghese et al., 2016). However, the conceptualization of such intentional models of LTE needs development (Varghese et al., 2016). This article begins to conceptualize such an LTE program. The author theorizes LTI and the need for adopting an LTI that is transformative, agentive, and advocacy (TAA)‐oriented, and proposes a competencies‐based approach as a foundation for developing an LTE program centered on the development of a TAA‐oriented LTI, suggesting key competencies to include in such an approach. She presents practical affordances and activities that could be helpful in developing these competencies. The article ends with questions aimed at furthering this emerging scholarly conversation in the field.
Risk factors and spatial relative risk assessment for influenza A virus in poultry and swine in backyard production systems of central Chile
Authors: Bravo‐Vasquez Nicolas , Baumberger Cecilia , Jimenez‐Bluhm Pedro , Di Pillo Francisca , Lazo Andres , Sanhueza Juan , Schultz‐Cherry Stacey , Hamilton‐West Christopher
Published: February 2020

Backyard production systems (BPS) are a common form of poultry and swine production worldwide. The limited implementation of biosecurity standards in these operations makes BPS a potential source for the emergence of pathogens that have an impact on both animal and public health. Information regarding circulation of influenza A virus (IAV) in poultry and swine raised in BPS is scarce; particularly in South American countries. The objective of this study was to estimate prevalence and seroprevalence of IAV in BPS in central Chile, identify subtype diversity, evaluate risk factors and spatial relative risk for IAV. Samples were collected from 329 BPS from central Chile. Seroprevalence at BPS level was 34.7% (95% CI: 23.1%–46.2%), 19.7% (95% CI: 9.9%–30.6%) and 11.7% (95% CI: 7.2%–16.4%), whereas prevalence at BPS level was 4.2% (95% CI: 0.0%–8.8%), 8.2% (95% CI: 0.8%–14.0%) and 9.2% (95% CI: 4.8%–13.1%), for the Metropolitan, Valparaiso and LGB O’Higgins regions, respectively. Spatial analysis revealed that central‐western area of Metropolitan region and the southern province of Valparaiso region could be considered as high‐risk areas for IAV (spatial relative risk = 2.2, p < .05). Logistic regression models identified the practice of breeding both poultry and pigs at the BPS as a risk factor (95% CI 1.06–3.75). From 75 IAV ELISA‐positive sera, 20 chicken sera had haemagglutination inhibition titres ranging from 20 to 160, and of these, 11 had microneutralization titres ranging from 40 to 960 for one or more IAV subtypes. Identified subtypes were H1, H3, H4, H9, H10 and H12. Results from this study highlight the need for further IAV surveillance programmes in BPS in Chile. Early detection of IAV strains circulating in backyard animals, especially in regions with large human populations, could have an enormous impact on animal and public health.
Enhanced removal of antimony in dyeing wastewater by mixing Fe3O4 with manganese sand filter material
Authors: Liu Hongbo , Ying Qiyan , Li Congyu , Norra Stefan , Lichtfouse Eric
Published: February 2020

Wastewaters from the printing and dyeing industries contain many contaminants in particular antimony (Sb) that end up in the environment. Both manganese sand filter and Fe3O4 have good removal effect on Sb, and are cheap and easy to obtain. We made a filter material by mechanically mixing the manganese sand filter material and ferro‐ferric oxide (Fe3O4). The Fe–Mn oxide filter material was analyzed by X‐ray diffraction. We studied the filtration of real wastewater from a dyeing wastewater resource recovery facility in Suzhou, China, containing Sb at high concentration of 410 μg/L, using dynamic tests in adsorption columns during 7 days. We tested the effects of filter material volume filling ratio, the empty bed contact time (EBCT), pH, and back washing on the removal of Sb. Results show that the addition of Fe3O4 enhanced the removal of Sb, reaching 85% of initial Sb. When the initial influent pH of the raw water is 3.0, the volume filling ratio of filter material is 60%, the EBCT is 20 min, and the developed dynamic Fe–Mn oxide filter has the best removal effect on Sb. Daily back washing of the filter keeps a Sb removal rate of about 80%.

Practitioner points

A novel and cheap Fe–Mn oxide was developed for Sb removal from dyeing wastewater.

A self‐designed filter device was designed to verify performance of the low‐cost material.

Optimal design and operational parameters of the filtration process were determined.
Novel adipokine associated with OA: retinol binding protein 4 (RBP4) is produced by cartilage and is correlated with MMPs in osteoarthritis patients
Authors: Scotece Morena , Koskinen-Kolasa Anna , Pemmari Antti , Leppänen Tiina , Hämäläinen Mari , Moilanen Teemu , Moilanen Eeva , Vuolteenaho Katriina
Published: February 2020

Objective

Retinol binding protein 4 (RBP4) is a member of the lipocalin family and a vitamin A carrier in the blood. More recently, RBP4 has been described as an adipokine that is involved in insulin resistance and metabolic syndrome (MetS). As obesity, MetS and some adipokines contribute to the pathogenesis of osteoarthritis (OA), we investigated RBP4 in patients with OA.

Materials and methods

Cartilage, synovial fluid and blood samples were collected from 100 OA patients undergoing total knee replacement surgery. Primary chondrocytes and cartilage tissue were cultured to measure the RBP4 expression. The concentrations of RBP4, other adipokines (adipsin, adiponectin, leptin and resistin) and biomarkers of OA (COMP, MMP-1, MMP-3 and YKL-40) were measured by immunoassay, and gene expression was measured by next-generation RNA sequencing.

Results

The OA cartilage samples released RBP4 into the culture medium, and the levels correlated positively with the expression of the adipokines adipsin, adiponectin, leptin and resistin. RBP4 was the most prominently expressed of these adipokines in the OA chondrocytes, and the expression of the RBP4 receptors STRA6 (stimulated by retinoic acid gene homologue 6) and TLR4 (Toll-like receptor 4) was also detected. Within the cartilage culture medium, RBP4 showed a positive correlation with MMP-1, MMP-3 and YKL-40. RBP4 was also present in the synovial fluid from the OA patients and correlated positively with the concentrations of RBP4 found in the plasma and the cartilage culture medium. Plasma RBP4 concentrations also showed a positive correlation with MMP-3 and adipsin.

Conclusions

We show here, for the first time, that RBP4 is produced within OA joints and that it is associated with increased levels of adipokines and MMPs. The results suggest a role for RBP4 in the pathogenesis of OA and as a possible target for the disease-modifying drugs for the treatment of OA.