bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Electrochemical Synthesis of Sulfur‐Containing Triazolium Inner Salts
Authors: Li Yueheng , Huang Zhixing , Mo Guangquan , Jiang Wei , Zheng Chengwei , Feng Pengju , Ruan Zhixiong
Published: December 2020

Main observation and conclusion

The electrochemical thiocyanation/cyclization of aldehyde hydrazones was developed under external oxidant‐free and catalyst‐free conditions. In contrast to previous thiocyanation, this electrosynthetic approach enabled a cascade C—H thiocyanation/cyclization through a mild, direct electrolysis manner in an undivided cell without the additive of halogens and stoichiometric oxidants. In this protocol, commercially available and inexpensive sodium thiocyanate was used, which played a dual role as a thiocyanation reagent and electrolyte. This strategy provides expedient access to functionalized sulfur‐containing triazolium inner salts with ample scope and diverse functional group tolerance. Based on the findings of mechanistic studies, a reaction mechanism was proposed.
Enantioselective Hydrogenation of Endocyclic Enones: the Solution to a Historical Problem†
Authors: Lang Qiwei , Yang Huaxin , Gu Guoxian , Feng Qiang , Wen Jialin , Zhang Xumu
Published: December 2020

Main observation and conclusion

The enantioselective hydrogenation of endocyclic enones has been a historical problem for homogeneous catalysis. We herein report an efficient method to reduce endocyclic enones with molecular hydrogen. Catalyzed by a rhodium/Zhaophos complex, a variety of enones with five‐, six‐ or seven‐member ring were hydrogenated with high enantioselectivity (92%—99% ee). Excellent chemo‐ and enantioselectivity demonstrated this method was successfully applied in the enantioselective hydrogenation of citral to produce enantio‐enriched citronellal.
Whole‐exome sequencing analysis of juvenile papillomatosis and coexisting breast carcinoma
Authors: D'Alfonso Timothy M , Pareja Fresia , Da Cruz Paula Arnaud , Vahdatinia Mahsa , Gazzo Andrea , Ferrando Lorenzo , da Silva Edaise M , Cheng Esther , Sclafani Lisa , Chandarlapaty Sarat , Zhang Hong , Hoda Syed A , Wen Hannah Y , Brogi Edi , Weigelt Britta , Reis‐Filho Jorge S
Published: December 2020

Juvenile papillomatosis (JP) of the breast is a rare benign mass‐forming lesion occurring in young women, which is histologically characterized by a constellation of proliferative changes and large cysts, giving it the gross appearance of Swiss cheese. A subset of patients with JP report a family history of breast carcinoma and/or coexisting or subsequent breast carcinoma. We performed whole‐exome sequencing of the hyperplastic epithelial component of three JPs, including one with coexisting ductal carcinoma in situ (DCIS) and invasive ductal carcinoma of no special type (IDC‐NST). JPs harbored clonal somatic PIK3CA hotspot mutations in two cases. In the JP with coexisting DCIS and IDC‐NST, these lesions were clonally related to the associated JP, sharing a clonal PIK3CA E542K somatic hotspot mutation. JP showed a paucity of copy number alterations, whereas the associated DCIS and IDC‐NST showed concurrent 1q gains/16q losses, hallmarks of estrogen receptor (ER)‐positive breast cancers. We observed JP to harbor a dominant aging‐related mutational signature, whereas coexisting DCIS and IDC‐NST showed greater exposure to an APOBEC signature. Taken together, our findings suggest that, at least in a subset of cases, JP might constitute the substrate from which DCIS and invasive breast carcinomas develop.
Application of Discrete First‐Row Transition‐Metal Complexes as Photosensitisers
Authors: Behm Kira , McIntosh Ruaraidh D.
Published: December 2020

This Minireview summarises and critically evaluates recent advances in the utilisation of discrete first‐row transition‐metal (TM) complexes as photosensitisers. Whilst many compounds absorb light, TM complexes are generally more desirable for photochemical applications, as they usually exhibit strong absorption of visible light, making them ideally suited to exploiting the sun as a freely available light source. Due to their outstanding activities, precious metals, such as iridium and ruthenium, are currently still at the forefront of photochemistry research. However, they also bear disadvantages with respect to abundance, cost and toxicity. Therefore, it is desirable to move to more abundant and less expensive systems that retain good photosensitising abilities. This Minireview will focus on first‐row transition‐metals, specifically titanium, copper, iron, and zinc, which have become the focus of increased attention over recent years as potential replacements for noble metals as photosensitisers. Their structure – activity relationships are explored and challenges in designing the ligands and complexes are discussed.
How CEO social capital drives corporate social performance: The roles of stakeholders, and CEO tenure
Authors: Tran Mai Dong , Adomako Samuel
Published: December 2020

This paper investigates the role of a chief executive officer's (CEO's) social capital on corporate social performance (CSP) through the mediating mechanism of stakeholder integration. Data were collected from 256 small and medium‐sized enterprises (SMEs). Results from the hierarchical regression analysis suggest that stakeholder integration mediates the relationship between CEO social capital and CSP. The results further reveal that the effect of CEO social capital on stakeholder integration is moderated by CEO tenure, such that the relationship is more significant for long‐tenured CEOs than short‐tenured CEOs. These findings extend the social capital and corporate social responsibility research and practice.
Social and environmental reporting, sustainable development and institutional voids: Evidence from a developing country
Authors: Alshbili Ibrahem , Elamer Ahmed A. , Moustafa Maha W.
Published: December 2020

This study adopts the concept of institutional voids to examine the perceptions of managers and policymakers in developing markets with respect to the actual barriers that hinder social and environmental reporting (SER) towards sustainable development. The study uses in‐depth semi‐structured interviews with managers and decision‐makers and policymakers of the main oil and gas companies in weak institutional settings (Libya). The findings suggest that the absence of environment general authority's role, the absence of a clear legal requirement that refers to SER, the shortage of knowledge and awareness, the lack of motivation from the government, fear of change, and the absence of civil society organisations are perceived as the major barriers that hinder the development of SER. These findings contribute to the literature on institutional voids and sustainable development by providing evidence on SER barriers in the context of a developing country. Therefore, it could be useful to corporate regulators and policymakers to mitigate institutional voids to develop a more focussed SER agenda, when considering regulations for the disclosure and sustainable development.
Concordant geographic and genetic structure revealed by genotyping‐by‐sequencing in a New Zealand marine isopod
Authors: Pearman William S. , Wells Sarah J. , Silander Olin K. , Freed Nikki E. , Dale James
Published: December 2020

Population genetic structure in the marine environment can be influenced by life‐history traits such as developmental mode (biphasic, with distinct adult and larval morphology, and direct development, in which larvae resemble adults) or habitat specificity, as well as geography and selection. Developmental mode is thought to significantly influence dispersal, with direct developers expected to have much lower dispersal potential. However, this prediction can be complicated by the presence of geophysical barriers to dispersal. In this study, we use a panel of 8,020 SNPs to investigate population structure and biogeography over multiple spatial scales for a direct‐developing species, the New Zealand endemic marine isopod Isocladus armatus. Because our sampling range is intersected by two well‐known biogeographic barriers (the East Cape and the Cook Strait), our study provides an opportunity to understand how such barriers influence dispersal in direct developers. On a small spatial scale (20 km), gene flow between locations is extremely high, suggestive of an island model of migration. However, over larger spatial scales (600 km), populations exhibit a clear pattern of isolation‐by‐distance. Our results indicate that I. armatus exhibits significant migration across the hypothesized barriers and suggest that large‐scale ocean currents associated with these locations do not present a barrier to dispersal. Interestingly, we find evidence of a north‐south population genetic break occurring between Māhia and Wellington. While no known geophysical barrier is apparent in this area, it coincides with the location of a proposed border between bioregions. Analysis of loci under selection revealed that both isolation‐by‐distance and adaption may be contributing to the degree of population structure we have observed here. We conclude that developmental life history largely predicts dispersal in the intertidal isopod I. armatus. However, localized biogeographic processes can disrupt this expectation, and this may explain the potential meta‐population detected in the Auckland region.
Yolk–Shell P3‐Type K0.5[Mn0.85Ni0.1Co0.05]O2: A Low‐Cost Cathode for Potassium‐Ion Batteries
Authors: Hao Jiaxin , Xiong Ke , Zhou Jiang , Rao Apparao M. , Wang Xianyou , Liu Huan , Lu Bingan
Published: December 2020

Low‐cost preparation methods for cathodes with high capacity and long cycle life are crucial for commercializing potassium‐ion batteries (PIBs). Presently, the charging/discharging strain that develops in the active cathode material of PIBs causes cracks in the particles, leading to a sharp capacity fade. Here, to abate the strain release and the need for an industrially relevant process, a simple low‐cost co‐precipitation method for synthesizing yolk–shell P3‐type K0.5[Mn0.85Ni0.1Co0.05]O2 (YS‐KMNC) was reported. As cathode material for PIBs, the YS‐KMNC delivers a high reversible capacity (96 mAh g–1 at 20 mA g–1) and excellent cycle stability (80.5% retention over 400 cycles at a high current density of 200 mA g–1). More importantly, a full battery assembled with the YS‐KMNC cathode and a commercial graphite anode exhibits a high operating voltage (0.5‐3.4 V) and an excellent cycling performance (84.2% retention for 100 cycles at 100 mA g–1). Considering the low‐cost, simple production process and high performance of YS‐KMNC cathode, this work could pave the way for the commercial development of PIBs.
Eradication of hepatitis C virus infection in kidney transplant recipients using direct‐acting antiviral therapy: Qatar experience
Authors: Alkadi Mohamad M. , Abuhelaiqa Essa A. , Elshirbeny Mostafa F. , Hamdi Ahmed F. , Fituri Omar M. , Asim Muhammad , Alkaabi Saad R. , Derbala Moutaz F. , Jarman Mona E. , Ashour Adel M. , Nauman Awais , Al Maslamani Yousuf K. , Butt Adeel A. , Al‐Malki Hassan A.
Published: December 2020

Introduction

Hepatitis C virus (HCV) infection has detrimental effects on patient and graft survival after kidney transplantation. In the pre‐direct‐acting antiviral (DAA) era, treatment of HCV infection was associated with low response rates, poor tolerance, and increased risk of allograft rejection. However, DAAs have revolutionized HCV treatment. The aims of this study were to determine the impact of DAA on the sustained virologic response (SVR), renal function, and calcineurin inhibitor (CNI) levels and assess the tolerability to treatment in kidney transplant recipients with HCV infection in Qatar.

Methods

This retrospective study included the medical records of all kidney transplant recipients with confirmed HCV infection before January 1, 2020. All data were obtained from the patients’ electronic medical records; these included patient demographics; virologic responses to treatment; serum creatinine levels during treatment; urine protein to creatinine ratios and CNI levels before, during, and after treatment; and side effects related to DAA therapy.

Results

A total of 27 kidney transplant recipients with HCV were identified, 23 of whom received DAA therapy. The length of treatment ranged from 12 to 24 weeks, and 52% of patients had HCV genotype 1 infection. The median log10 HCV RNA was 6.6 copies per milliliter. None of the patients had liver cirrhosis, and all of them achieved SVR. There was no statistically significant difference in the glomerular filtration rate before, during, and after treatment. Most patients had stable CNI trough levels during treatment and did not require dose adjustment.

Conclusions

HCV infection was successfully eradicated by DAA therapy in kidney transplant recipients, with a 100% SVR rate. Moreover, DAA therapy was well‐tolerated, and kidney function remained stable without an increased risk of rejection. These results are expected to drive the eradication of hepatitis C from the entire country.
Lung segmentation on chest X‐ray images in patients with severe abnormal findings using deep learning
Authors: Nishio Mizuho , Fujimoto Koji , Togashi Kaori
Published: December 2020

Several studies have evaluated the usefulness of deep learning for lung segmentation using chest X‐ray (CXR) images with small‐ or medium‐sized abnormal findings. Here, we built a database including both CXR images with severe abnormalities and experts' lung segmentation results, and aimed to evaluate our network's efficacy in lung segmentation from these images. For lung segmentation, CXR images from the Japanese Society of Radiological Technology (JSRT, N = 247) and Montgomery databases (N = 138) were included, and 65 additional images depicting severe abnormalities from a public database were evaluated and annotated by a radiologist, thereby adding lung segmentation results to these images. U‐net was used to segment the lungs in images from the three databases. Subsequently, the U‐net network architecture was automatically optimized for lung segmentation from CXR images using Bayesian optimization. Dice similarity coefficient (DSC) was calculated to confirm segmentation. Our results demonstrated that using baseline U‐net yielded poorer lung segmentation results in our database than those in the JSRT and Montgomery databases, implying that robust segmentation of lungs may be difficult because of severe abnormalities. The DSC values with baseline U‐net for the JSRT, Montgomery and our databases were 0.979, 0.941, and 0.889, respectively, and with optimized U‐net, 0.976, 0.973, and 0.932, respectively. For robust lung segmentation, the U‐net architecture was optimized via Bayesian optimization, and our results demonstrate that the optimized U‐net was more robust than baseline U‐net in lung segmentation from CXR images with large‐sized abnormalities.
The impact of internal and external factors of credit risk on businesses: An empirical study of Chinese commercial banks
Authors: Twum Angelina K. , ZhongMing Tan , Agyemang Andrew O. , Ayamba Emmanuel C. , Chibsah Rahmatu
Published: December 2020

Credit risk has great impact on the banks' profitability as large chunk of banks' revenue and interest income comes from loans. Factors that affects credit risk can be classified into microeconomic and macroeconomic factors. These factors have an impact on credit risk levels. Using secondary data from 2005 to 2018 for listed commercial banks on the two stock exchanges in China mainland, the study explored the effect of both internal and external factors that influences credit risk in the banking industry. A positive relationship was found between bank solvency and credit risk. Similarly, the study revealed a positive correlation between credit risk and interest rate. On the contrary, operation efficiency and gross domestic product growth rate revealed an inverse relationship with credit risk. The findings will add up to existing literature and guide policy‐makers in implementing measures to control the influencing factors of credit risk in the banking industry.
A metal‐free visible light promoted three‐component facile synthesis of 4‐oxo‐tetrahydroindoles in ethanol–water
Authors: Ansari Khursheed , Nazeef Mohd , Ali Shabir , Waseem Malik A. , Shah Wajaht A. , Ansari Saif , Siddiqui Ibadur R. , Singh Jagdamba
Published: December 2020

A mild and efficient visible light–mediated one‐pot multicomponent tandem approach to construct 4‐oxo‐tetrahydroindoles in ethanol–water medium at room temperature has been described. The characteristics of reported methodology are the utilization of visible light, an ideal source of energy to generate CC and CN bonds from commercially available substrates namely dimedone, phenacyl bromides, and amines. The presented protocol is highly compatible for developing 4‐oxo‐tetrahydroindole derivatives with improved selectivity and high yields. Moreover, metal‐free synthesis, environmental friendly solvent, easy workup process, high atom economy, cost‐effectiveness, short reaction time, and broad substratescope are the major advantages of reported protocol.
Meta‐analysis as a system of springs
Authors: Papakonstantinou Theodoros , Nikolakopoulou Adriani , Egger Matthias , Salanti Georgia
Published: December 2020

Meta‐analysis results are usually presented in forest plots, which show the individual study results and the summary effect along with their confidence intervals. In this paper, we propose a system of linear springs as a mechanical analogue of meta‐analysis that enables visualization and enhances intuition. The length of a spring corresponds to a study treatment effect and the stiffness of the spring corresponds to its inverse variance. To synthesize study springs we use two main operations: connection in parallel and connection in series. We show the equivalence between meta‐analysis and linear springs for fixed effect and random effects pairwise meta‐analysis and we also derive indirect treatment effects. We use examples to illustrate the different meta‐analytical schemes using the corresponding system of springs. The proposed visualization can serve as an educational tool, especially useful for researchers with no statistical background. The analogy between meta‐analysis and springs facilitates intuition for notions such as heterogeneity and the differences between fixed and random effects meta‐analysis.
Optimization and characterization of eco‐friendly antimicrobial nanocellulose sheet prepared using carbon dots of white mulberry (Morus alba L.)
Authors: Salimi Fatemeh , Moradi Mehran , Tajik Hossein , Molaei Rahim
Published: December 2020

BACKGROUND

Carbon dots (C‐dots) with antimicrobial activity were synthesized from the white mulberry extract with the aim of fabricating anti‐listeria nanopaper using bacterial nanocellulose (BNC). Highly dispersed synthesized C‐dots with a size smaller than 10 nm (approximately 4.9 nm) were impregnated into BNC by an ex situ coating method and then mechanical, morphological, UV‐protectant and antibacterial activity were assessed. Randomized response surface methodology using a central composite design was applied to investigate the optimized concentration of C‐dots in the BNC membrane.

RESULTS

An optimized nanopaper including C‐dots at a concentration of 530 g L−1 and an impregnation time of 14 h at 30 °C with significant antimicrobial activity on Listeria monocytogenes was designed. The addition of C‐dots into BNC significantly increased ultimate tensile strength and decreased strain with respect to breaking BNC. A BNC sheet with high‐efficient UV‐blocking property was prepared using C‐dots.

CONCLUSION

Based on the results, the designed nanopaper shows a substantial capacity with respect to the fabrication of antimicrobial/UV‐blocking sheets for food active packaging. © 2020 Society of Chemical Industry
A challenging choice of aptamer for the selective enrichment of ochratoxin A
Authors: Torabi Raheleh , Rezvanipour Abbas Ali , Heiat Mohammad
Published: December 2020

In a recent study, the adenosine monophosphate‐specific aptamer has been applied for the rapid extraction of ochratoxin A. Although several publications have already reported the selection of adenosine monophosphate, adenosine triphosphate, and adenosine, there is no report on the detection of ochratoxin A using this aptamer. The data of the previous study are surprising since its aptamer‐based magnetic metal‐organic framework has shown a high selectivity with a very low detection limit for the selection of ochratoxin A. However, numerous studies have demonstrated that each aptamer can specifically bind to a target by folding into a unique structure and can differentiate molecules that differ by only one functional group. This study aimed to deal with the possibility of recognizing ochratoxin A and adenosine monophosphate by adenosine monophosphate‐specific aptamer. The procedure was performed by determining structural similarity and alignment, docking adenosine monophosphate and ochratoxin A on aptamer, and monitoring the interactions between ochratoxin A and adenosine monophosphate specific aptamer complex. The results indicated not only the lack of structural similarity between adenosine monophosphate and ochratoxin A but also the little possibility for strong bonds between the ochratoxin A and aptamer.
Effect of Machine Settings on Ultrasound Assessment of B‐lines
Authors: Matthias Isaac , Panebianco Nova L. , Maltenfort Mitchell G. , Dean Anthony J. , Baston Cameron
Published: December 2020

Objectives

B‐lines are a lung ultrasound (LUS) artifact that often indicate pathology. Little is known about the optimal ultrasound machine settings to assess B‐lines. We compared settings typically used to evaluate B‐lines at our institution with adjusted settings based on recent studies.

Methods

In order to determine typical settings for B‐line assessment, we retrospectively reviewed LUS images obtained at our institution. We then prospectively performed LUS with both typical and adjusted settings, using curvilinear and phased array probes, in 20 patients presenting to the emergency department with shortness of breath. The prospectively obtained clips were rated for quality and quantity of B‐lines by 14 clinicians with experience in LUS, with 1 assigned for typical settings “much greater,” 2 for typical settings “slightly greater,” 3 for both settings “similar,” 4 for adjusted settings “slightly greater,” and 5 for adjusted settings “much greater.”

Results

Mean ratings and 95% confidence intervals significantly exceeded the null value of 3 for both B line quality (curvilinear probe: 4.68, 4.50–4.85; phased array probe: 4.02, 3.70–4.35) and B line quantity (curvilinear probe: 4.16, 3.84–4.49; phased array probe: 3.68, 3.41–3.96).

Conclusions

B‐line quality and quantity were rated higher using adjusted settings based on recently published evidence than when using settings that are typically employed in our institution. Our findings suggest that B‐line assessment should be performed with focal zone at the level of the pleura, harmonics off, and gain increased in the far field.
Obesity as a Possible Risk Factor for Pediatric Sensorineural Hearing Loss
Authors: Bluher Andrew , Kawai Kosuke , Wang Alicia , Stiles Derek , Licameli Greg
Published: December 2020

Objectives/Hypothesis

Childhood hearing loss impacts linguistic, academic, social, and psychologic development, and may have lasting implications for future workforce performance. Current evidence for obesity as a pediatric sensorineural hearing loss (SNHL) risk factor is intriguing but equivocal. We hypothesized that obesity is associated with a higher risk of SNHL. We additionally examined whether underweight is associated with a higher risk of SNHL.

Study Design

Retrospective database review.

Methods

A single‐institution audiologic database from 2015 to 2020 was queried for audiograms with type‐A tympanograms from children aged 5 to 18 years old. Comorbidities known to be associated with hearing loss were excluded. We then examined both for sub‐clinical (≥15 dB) high‐ or low‐frequency hearing loss, and for clinical (≥21 dB) hearing loss, with the aim of examining the association between obesity and SNHL. Multivariable logistic regression was performed to adjust for age, gender, diabetes mellitus, attention deficit hyperactivity disorder, and autism.

Results

A total of 3,142 children were included. Obesity was not associated with risk of SNHL (adjusted OR 0.82; 95% CI: 0.60, 1.12). Underweight children had a higher risk of SNHL than normal weight children (adjusted OR 1.78; 95% CI: 1.08, 2.95). Autism was significantly associated with increased risk of sub‐clinical SNHL only (adjusted OR 2.00; 95% CI 1.34, 2.98).

Conclusions

No association was found between obesity and pediatric SNHL. Underweight children may represent a higher‐risk population for SNHL. There appears to be an increasing risk of SNHL as children approach adolescence. Further study of systemic risk factors for SNHL is indicated.

Level of Evidence

3 Laryngoscope, 131:1416–1419, 2021
Weed management in azuki bean with preplant incorporated herbicides
Authors: Soltani Nader , Brown Lynette , Sikkema Peter H.
Published: December 2020

There are only two soil‐applied herbicides, pendimethalin and imazethapyr, registered for weed management in azuki bean production in Ontario, Canada. Three experiments were completed in Ontario over three consecutive years (2017, 2018, and 2019) to develop weed management programs in azuki bean with various preplant incorporated (PPI) herbicides. There was up to 6% azuki bean injury with the herbicide treatments evaluated. Pendimethalin + S‐metolachlor controlled redroot pigweed, common lambsquarters, barnyard grass, and green foxtail at ≥99% but provided poor control of common ragweed and wild mustard. The two‐way mixtures of pendimethalin + imazethapyr and pendimethalin + halosulfuron, and the three‐way mixtures of pendimethalin + S‐metolachlor + imazethapyr and pendimethalin + S‐metolachlor + halosulfuron controlled redroot pigweed, common lambsquarters, wild mustard, barnyard grass, and green foxtail at ≥99% and common ragweed at >73%. Common ragweed control was consistently higher with tankmixes that contained halosulfuron. Metribuzin controlled redroot pigweed, common ragweed, common lambsquarters, wild mustard, barnyard grass, and green foxtail at >93%, 88%, 99%, 97%, 68%, and 50%, respectively. Weed density and aboveground biomass reductions were similar to those of weed control. Weed presence reduced azuki bean yield by 83%. Reduced weed presence with the herbicide treatments assessed resulted in azuki bean yield that was similar to that of the weed‐free control with the exception of pendimethalin, halosulfuron, and metribuzin (low rate); weed interference with the aforementioned herbicides decreased azuki bean yield by 50%, 56%, and 44%, respectively. Based on these results, pendimethalin, S‐metolachlor, halosulfuron, and imazethapyr applied PPI, applied alone, or in a two‐way or three‐way tankmixture can be used safely for the control of common annual grass and broadleaf weeds in Ontario, Canada.
Bulk Modification of Thermoplastic Polyurethanes for Self‐Sterilization of Trachea Intubation
Authors: Guo Yifan , Zhang Hongfa , Duan Shun , Ding Xiaokang , Hu Yang , Ding Xuejia , Xu Fu‐Jian
Published: December 2020

Implantable medical devices are widely used, but biomaterial‐associated infections (BAIs) impose a huge economic burden and increase the mortality of patients. Therefore, BAIs are a serious concern that must be urgently resolved. Materials with antibacterial properties have become hotspots of current research and development. In the present work, quaternized chitosan (QCS) is used as an antibacterial agent and blended with thermoplastic polyurethane (TPU) to create an antibacterial material for tracheal intubation tubes. The modified TPU material (QCS‐TPU) exhibited good mechanical properties and excellent long‐term antibacterial performance. Under in vitro hydrodynamic conditions, QCS‐TPU retained its strong antibacterial properties. QCS‐TPU also possessed a low hemolysis rate and cytotoxicity. The current work is expected to provide a facile and feasible strategy for the preparation of antibacterial catheters and aid in the discovery of promising clinical applications to prevent BAIs.
Catalytic Halogen Exchange in Supplementary Activator and Reducing Agent Atom Transfer Radical Polymerization for the Synthesis of Block Copolymers
Authors: De Bon Francesco , Abreu Carlos M. R. , Serra Arménio C. , Gennaro Armando , Coelho Jorge F. J. , Isse Abdirisak A.
Published: December 2020

Synthesis of block copolymers (BCPs) by catalytic halogen exchange (cHE) is reported, using supplemental activator and reducing agent Atom Transfer Radical Polymerization (SARA ATRP). The cHE mechanism is based on the use of a small amount of a copper catalyst in the presence of a suitable excess of halide ions, for the synthesis of block copolymers from macroinitiators with monomers of mismatching reactivity. cHE overcomes the problem of inefficient initiation in block copolymerizations in which the second monomer provides dormant species that are more reactive than the initiator. Model macroinitiators with low dispersity are prepared and extended to afford well‐defined block copolymers of various compositions. Combined cHE/SARA ATRP is therefore a simple and potent polymerization tool for the copolymerization of a wide range of monomers allowing the production of tailored block copolymers.
Computational 1H and 13C NMR of strychnobaillonine: On the way to larger molecules calculated at lower computational costs
Authors: Semenov Valentin A. , Krivdin Leonid B.
Published: December 2020

The 1H and 13C NMR chemical shifts of strychnobaillonine, a very large dimeric indole alkaloid, consisting of as many as 46 nonhydrogen atoms, were calculated with using the established earlier the most effective computational protocol, PBE0/pcSseg‐2//pcseg‐2. A very good result was achieved at this level, characterized by the root mean square deviation of only 0.14 ppm for protons and 2.4 ppm for carbons, which enabled the verification of the configurations of its all 13 asymmetrical centers. Essential deviations of the calculated and experimental 1H NMR spectrum of strychnobaillonine were established in several cases, which enabled the performance of some additional NMR assignments and reassignments of the originally proposed structure.
Visceral Adiposity Elevates the Risk of Critical Condition in COVID‐19: A Systematic Review and Meta‐Analysis
Authors: Földi Mária , Farkas Nelli , Kiss Szabolcs , Dembrovszky Fanni , Szakács Zsolt , Balaskó Márta , Erőss Bálint , Hegyi Péter , Szentesi Andrea
Published: December 2020

Objective

A higher BMI has become acknowledged as one of the important risk factors for developing critical condition in coronavirus disease 2019 (COVID‐19). In addition to BMI, body composition, and particularly visceral adiposity, might be an even more accurate measure to stratify patients. Therefore, the aim of this study was to evaluate the association between the distributions of computed‐tomography‐quantified fat mass and critical condition of patients with COVID‐19.

Methods

A systematic search was conducted in five databases for studies published until November 17, 2020. In the meta‐analysis, pooled mean difference (standardized mean difference [SMD]) of visceral fat area (VFA; in square centimeters) was calculated between patients in the intensive care unit and those in general ward and between patients with the requirement for invasive mechanical ventilation (IMV) and those without the IMV requirement.

Results

The quantitative synthesis revealed that patients requiring intensive care had higher VFA values (SMD = 0.46, 95% CI: 0.20‐0.71, P < 0.001) compared with patients on the general ward. Similarly, patients requiring IMV had higher VFA values (SMD = 0.38, 95% CI: 0.05‐0.71, P = 0.026) compared with patients without the IMV requirement.

Conclusions

VFA values were found to be significantly higher in patients with critical condition. Therefore, abdominal adiposity seems to be a risk factor in COVID‐19, and patients with central obesity might need special attention.
Comparison of the OI and PaO2/FiO2 score in evaluating PARDS requiring mechanical ventilation
Authors: Shen Huili , Qu Dong , Na Weilan , Liu Shuang , Huang Siyuan , Hui Yi
Published: December 2020

Aim

To examine the differences between oxygenation index (OI) and arterial partial pressure of oxygen to the fraction of inspired oxygen (PaO2/FiO2, [P/F]) in evaluating the severity of pediatric acute respiratory distress syndrome (PARDS).

Methods

The severity of PARDS was graded by using the OI score and P/F ratio, respectively. The data including clinical indexes and prognosis indicators were recorded and analyzed.

Results

During the 3‐year study period, there were significant differences between OI and P/F scores in the severity grading of PARDS patients (p < .05). However, in severe diseases, both the scorings of OI and P/F were consistent (24.6% vs. 25.6%). The OI scores appeared more accurate when compared with P/F in the correlation between them and the pediatric critical illness score, multiple organ dysfunction syndromes (MODS), pressure indexes of ventilators and patients' prognosis. In the receiver operating characteristic curve, the critical values of OI and P/F were 8.42 and 144.71. Area under the curve of them were 0.839 and 0.853. The sensitivity values were both 0.854. The specificity values were 0.584 and 0.602.

Conclusions

The OI and P/F were consistent in designating patients with severe PARDS. Among patients with mild to moderate diseases, the P/F could still be used for rapid determination given its simple calculation. Combined with the prognostic factors, the OI score was more accurate.
Purification, characterization, and crystal structure of YhdA‐type azoreductase from Bacillus velezensis
Authors: Bafana Amit , Khan Farha , Suguna Kaza
Published: December 2020

Azoreductases are being extensively investigated for their ability to initiate degradation of recalcitrant azo dyes through reduction of azo bonds. There is great interest in studying their diversity, structure, and function to facilitate better understanding and effective application. Current study reports azoreductase enzyme from Bacillus velezensis, which showed 69.5% identity to the Bacillus subtilis azoreductase YhdA. The enzyme was homotetrameric and molecular weight of each subunit was 20 kDa. It decolorized azo dyes with different structures. The Vmax for decolorization of congo red, methyl orange and methyl red was 14.7, 28.6, and 77.9 nmol/min/mg, respectively. The enzyme contained FMN as cofactor and used NADPH as the favored co‐substrate. It was oxygen‐insensitive, but the presence of reducing agents enhanced its activity, which is a new finding. The azoreductase expression in B. velezensis was found to be unaffected by addition of azo dyes, although azo dyes are known to induce azoreductase expression in few organisms. The enzyme was thermostable with melting temperature of 89.5°C and functioned in wide temperature range. Further, the enzyme was crystallized and its structure was solved. The structural basis of its functional attributes is discussed. In our knowledge, this is the first report on characterization of azoreductase enzyme from B. velezensis.
Hierarchical, rotation‐equivariant neural networks to select structural models of protein complexes
Authors: Eismann Stephan , Townshend Raphael J.L. , Thomas Nathaniel , Jagota Milind , Jing Bowen , Dror Ron O.
Published: December 2020

Predicting the structure of multi‐protein complexes is a grand challenge in biochemistry, with major implications for basic science and drug discovery. Computational structure prediction methods generally leverage predefined structural features to distinguish accurate structural models from less accurate ones. This raises the question of whether it is possible to learn characteristics of accurate models directly from atomic coordinates of protein complexes, with no prior assumptions. Here we introduce a machine learning method that learns directly from the 3D positions of all atoms to identify accurate models of protein complexes, without using any precomputed physics‐inspired or statistical terms. Our neural network architecture combines multiple ingredients that together enable end‐to‐end learning from molecular structures containing tens of thousands of atoms: a point‐based representation of atoms, equivariance with respect to rotation and translation, local convolutions, and hierarchical subsampling operations. When used in combination with previously developed scoring functions, our network substantially improves the identification of accurate structural models among a large set of possible models. Our network can also be used to predict the accuracy of a given structural model in absolute terms. The architecture we present is readily applicable to other tasks involving learning on 3D structures of large atomic systems.
Fucoidan mitigated diabetic nephropathy through the downregulation of PKC and modulation of NF‐κB signaling pathway: in vitro and in vivo investigations
Authors: Xu Jingge , Wang Yan , Wang Zhen , Guo Lanping , Li Xinpeng
Published: December 2020

The persistence of hyperglycemia and oxidative stress in diabetic patients ultimately leads to diabetic nephropathy (DN). In this study, we investigated the effect of sulfated polysaccharides (SPS) extracted from Laminaria japonica in relieving DN symptoms. To induce the diabetic model, normal rats were kept on a high‐sugar, high‐fat diet, then they were injected with streptozocin. Groups of these rats were later treated with SPS and/or protein kinase C (PKC) inhibitor. The analyses performed herein demonstrate that although diabetes significantly decreases the body weights of rats, SPS and inhibitor treatments increase these weights, as well as the ratios of renal to total body weight. Serum biochemical analyses indicate that blood urea nitrogen and serum creatinine levels gradually decrease in the SPS group. In addition, DN symptoms are substantially relieved by SPS and/or inhibitor treatments, as evidenced by histopathological analyses. Changes in the expressions of PKC‐α, PKC‐β, P‐selectin, nuclear factor kappa B (NF‐κB), and p65, detected by immunohistochemistry and western blot assessments, show that SPS regulates diabetic nephropathy via the PKC/NF‐κB pathway.
Activity and stability descriptors of Ni based alloy catalysts for dry reforming of methane: A density functional theory study
Authors: Ray Koustuv , Sandupatla Aditya Shankar , Deo Goutam
Published: December 2020

Experimentally determined catalytic activity and stability of alumina supported Ni and Ni3M (M = Fe, Co, Cu) alloy catalysts for the dry reforming of methane (DRM) were rationalized by density functional theory (DFT) studies. Ni3M slab models were prepared based on the experimental characterization data and DFT calculated segregation energies. First dehydrogenation step of CH4 which is the rate determining step in DRM was modeled on the Ni(111) and Ni3M(111) surfaces. Calculated reaction energetics show that Brønsted–Evans–Polanyi relationship holds true for this catalytic reaction system. A linear correlation was found between turnover frequency values of CH4 and the calculated dissociation energy of CH4. Interestingly, a linear correlation was found between percentage deactivation of catalysts and the calculated carbon adsorption energy. Based on these correlations, we propose that the dissociation energy of CH4 is a suitable activity descriptor and the adsorption energy of carbon is a suitable stability descriptor for these Ni and Ni3M alloy catalysts.
Zn2+‐Doped PVA Composite Electrospun Nanofiber for Upgrading of Enzymatic Properties of Acetylcholinesterase**
Authors: Işık Ceyhun , Doğaç Yasemin İspirli , Deveci İlyas , Teke Mustafa
Published: December 2020

Enzyme immobilization provides improve mechanical characteristic of enzymes and stability to environmental alters. It also helps to enzymes maintain their activities for a long time and offers the possibility to use them again. With these unique features, they can reduce production costs in industrial applications. In this study, acetylcholinesterase (AChE) immobilized on Zn2+‐doped PVA nanofibers via adsorption and cross‐linking methods. Morphological structures of Zn2+‐doped PVA nanofibers were characterized by Scanning Electron Microscopy (SEM) before and after immobilization. It was observed that the enzyme gained resistance against temperature and pH changes occurring in the reaction medium after immobilization process. In addition, immobilized Zn2+‐doped PVA nanofibers retained of its activity approximately 75 % after 8 reuse and its activity decreased below 50 % after 12 reuse. As a result, AChE immobilized Zn2+‐doped PVA nanofibers offers numerous advantages for various biotechnological applications, such as hydrolysis and determination of pesticides, use in the structure of reactors and electrodes, thanks to the unique stability and reusability features that AChE gains after immobilization.
Aerobic and Additive‐free Oxidative Dehydrogenation of N‐heterocycles over Commercial MnCO3‐derived Manganese Oxides
Authors: Chen Bo , Zhao Zengbing , Liu Fei , Yang Shucheng , Zhao Yili , Cheng Lanxing
Published: December 2020

Herein, manganese oxides by simply pyrolyzing commercial MnCO3 are found to be active and stable for aerobic oxidative dehydrogenation of N‐heterocycles in the absence of any additives. The oxides are fully characterized by XRD, BET, XPS, and SEM. The analysis results suggest that high surface area, the involvement of Mn3+ and Mn4+ species, and labile lattice oxygen are key factors for the reactions. Moreover, kinetic analysis demonstrates that the apparent activation for oxidative dehydrogenation of 1,2,3,4‐tetrahydroquinoline is 37.7 kJ mol−1, and radical anions may involve in the reaction.
Performance of Agency in Real‐Life Encounters: Turning Unequal Power and Structural Constraint into Collaboration
Authors: Mik‐Meyer Nanna , Haugaard Mark
Published: December 2020

This article explores the performance of agency within the context of unequal power resources and structural constraint. Based on 23 video‐recorded placement meetings in three homeless shelters, we find that participants' agency is the outcome of both collaboration and resistance. To avoid interaction that fails to empower, social actors engage in “repair work” and face‐saving practices. When clients display “wrong face”—that is, bring problems to the table that are not considered “reasonable”—then the service providers engage in “repair work.” Participants turn conflict into collaborative agency because interactions that fail to deliver mutually empowering forms of agency have costs for both: clients' problems are not solved, and service providers fail to reach organizational goals.
Organic Molecule Modified Phosphotungstate with Helical Structure for Electrochemical Detection of Dopamine
Authors: Liu Hui , Zhang Jianguo , Yang Guang , Zhao Qian , Wang Deqiang
Published: December 2020

To overcome the water solubility and aggregation of heteropoly acids (HPAs), and to promote its application in the electrochemical biosensors, organic molecular modification strategy was employed by simple hydrothermal synthesis. Herein, an unprecedented phosphotungstate (PTA)‐based three‐dimensional supramolecular framework with helical structure, [(bix)2(H3PW12O40)·H2O] [PTA‐bix, bix = 1,3‐bis(imidazol‐1‐ylmethyl) benzene], was synthesized and characterized. And the PTA‐bix modified glassy carbon electrode shows the high sensitivity and catalytic activity for detecting the neurotransmitter dopamine (DA) with the linear detection range from 1 μM to 100 μM, and the detection limit of differential pulse voltammetry (DPV) is 0.85 μM. The concept behinds the new architecture to modify electrodes should promote the further development of HPA hybrid crystal material‐based biosensors.
Comparison of force loss during sliding of low friction and conventional TMA orthodontic archwires
Authors: Alsabti Nouf , Bourauel Christoph , Talic Nabeel
Published: December 2020

Objective

The goal was to measure and compare the amount of force loss during tooth movement guided by archwires, including a newly introduced low-friction titanium molybdenum alloy (TMA), conventional TMA, and stainless steel archwires.

Methods

The force loss was measured using a specialized biomechanical set-up, the orthodontic measurement and simulation system (OMSS). A total of 30 specimen were used (10 low-friction TMA (TMA-Low), 10 conventional TMA (TMA-C), and 10 stainless steel (SS) archwires, each having a dimension of 0.016 × 0.022 inches). The conventional and low friction TMA archwires served as test groups, while the SS archwires served as the control group.

Results

The mean values of force loss between the three types of wires (TMA‑C, TMA-Low, and SS) were significantly different (p < 0.0001). The highest mean force loss during sliding movement was found in the conventional TMA group (72.1%), followed by low friction TMA (48.8%) and stainless steel wires (33.7%) in a descending order.

Conclusion

The friction property of the low friction TMA archwire was superior to the conventional TMA archwire but was still inferior to the stainless steel archwire.
Pediatric aseptic lower leg fracture nonunion
Authors: von Rüden Christian , Dietz Sven-Oliver , Schmittenbecher Peter , Fernandez Francisco F. , Lieber Justus , Wilkens Björn , Rüger Matthias , Schneidmueller Dorien
Published: December 2020

Purpose

Lower leg nonunion in pediatric patients is a rarity. Therefore, eight European pediatric trauma units retrospectively analyzed all patients younger than 18 years suffering lower leg fractures resulting in aseptic nonunion.

Methods

Thirteen children and adolescents less than 18 years old (2 girls and 11 boys) diagnosed with aseptic nonunion of the tibia and/or fibula were evaluated. In all patients, epidemiological data, mechanism of injury, fracture configuration, and the initial treatment concept were assessed, and the entire medical case documentation was observed. Furthermore, potential causes of nonunion development were evaluated.

Results

The mean age of patients was 12.3 years with the youngest patient being seven and the oldest being 17 years old. Open fractures were found in six out of thirteen patients (46%). Nonunion was hypertrophic in ten and oligotrophic in three patients. Mean range of time to nonunion occurrence was 7.3 ± 4.6 months. Nonunion healing resulting in complete metal removal was found in 12 out of 13 patients (92%), only in one case of a misinterpreted CPT type II osseous consolidation could not be found during the observation period. Mean range of time between surgical nonunion revision and osseous healing was 7.3 months as well.

Conclusion

If treatment principles of the growing skeleton are followed consistently, aseptic nonunion of the lower leg remains a rare complication in children and adolescents. Factors influencing the risk of fracture nonunion development include patient’s age, extended soft tissue damage, relevant bone loss, and inadequate initial treatment.