bluuebunny/crossref_metadata_2025 huggingface dataset:
An efficient primary screening of COVID‐19 by serum Raman spectroscopy
Authors: Yin Gang , Li Lintao , Lu Shun , Yin Yu , Su Yuanzhang , Zeng Yilan , Luo Mei , Ma Maohua , Zhou Hongyan , Orlandini Lucia , Yao Dezhong , Liu Gang , Lang Jinyi
Published: February 2021

The outbreak of COVID‐19 coronavirus disease around the end of 2019 has become a pandemic. The preferred method for COVID‐19 detection is the real‐time polymerase chain reaction (RT‐PCR)‐based technique; however, it also has certain limitations, such as sample‐dependent procedures with a relatively high false negative ratio. We propose a safe and efficient method for screening COVID‐19 based on Raman spectroscopy. A total of 177 serum samples are collected from 63 confirmed COVID‐19 patients, 59 suspected cases, and 55 healthy individuals as a control group. Raman spectroscopy is adopted to analyze these samples, and a machine learning support‐vector machine (SVM) method is applied to the spectrum dataset to build a diagnostic algorithm. Furthermore, 20 independent individuals, including 5 asymptomatic COVID‐19 patients and 5 symptomatic COVID‐19 patients, 5 suspected patients, and 5 healthy patients, were sampled for external validation. In these three groups—confirmed COVID‐19, suspected, and healthy individuals—the distribution of statistically significant points of difference showed highly consistency for intergroups after repeated sampling processes. The classification accuracy between the COVID‐19 cases and the suspected cases is 0.87 (95% confidence interval [CI]: 0.85–0.88), and the accuracy between the COVID‐19 and the healthy controls is 0.90 (95% CI: 0.89–0.91), while the accuracy between the suspected cases and the healthy control group is 0.68 (95% CI: 0.67–0.73). For the independent test dataset, we apply the obtained SVM model to the classification of the independent test dataset to have all the results correctly classified. Our model showed that the serum‐level classification results were all correct for independent test dataset. Our results suggest that Raman spectroscopy could be a safe and efficient technique for COVID‐19 screening.
Synthesis, characterization and surface enhanced Raman spectroscopy study of a new family of different substituted cruciform molecular systems deposited on gold nanoparticles
Authors: Sánchez‐González Rodrigo , Imbarack Elizabeth , Suazo Constanza , Soto Juan Pablo , Leyton Patricio , Sánchez‐Cortés Santiago , Campos‐Vallette Marcelo
Published: February 2021

In this work, the adsorption and orientation on gold nanoparticles (AuNps) of a new family of cruciform systems consisting of thiophene rings and imino groups were studied. The structural modification and its influence on the adsorbate‐substrate interaction were evaluated by UV–Vis spectroscopy and Surface Enhanced Raman Spectroscopy (SERS). The absence of SERS spectrum for (N,N′‐bis(4‐(trifluoromethyl)benzylidene)‐2,5‐di (thiophene‐2‐yl)‐1,4‐diaminobenzene) CFF shows that the inclusion of a trifluoromethyl group (‐CF3) on the benzylidene fragment limits the interaction of the CFF system with the gold substrate, in contrast, to that obtained for (N, N′‐dibenzylidene‐2,5‐di (thiophene‐2‐yl) ‐1,4‐diaminobenzene) 2‐CF and (N, N′‐bis (4‐methoxybenzylidene) ‐2,5‐di (thiophene‐2yl) ‐1,4‐diaminobenzene) CMF, where the adsorption took place preferentially through the thiophene rings, resulting in partial quinoidization. On the other hand, the interaction for compound (N, N′‐bis (4‐methylenepyridinyl) ‐2,5‐di (thiophene‐2‐yl) ‐1,4‐diaminobenzene) CPy with the surface was conducted by means of the pyridinic fragments. The systematic modification of the bifunctional cruciform systems, with groups of different nature, makes it possible to rationalize the structural aspects that directly influence the adsorbate‐substrate interaction and molecular orientation on gold substrates. These structural parameters are the basis to the development of stable molecular assemblies, which can act as basic building blocks in the manufacture of molecular switches.
Cigarette smoke extract promotes DNA methyltransferase 3a expression in dendritic cells, inducing Th‐17/Treg imbalance via the c‐Jun/allograft inflammatory factor 1 axis
Authors: Huang Dan , Zhou Bin , Luo Zhen‐Zhong , Yu Shu‐Chun , Tang Bin
Published: February 2021

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disorder. Although numerous studies on COPD have been conducted, therapeutic strategies for COPD are limited, and its pathological mechanism is still unclear. The present study aimed to explore the role of DNA methyltransferase 3a (DNMT3a) in dendritic cells (DCs) and the possible role of the Th‐17/Treg cell balance in COPD. Immature DCs (iDCs) were induced and cocultured with CD4+ T cells. An in vitro COPD model was established by treatment with cigarette smoke extract (CSE). DNMT3a or allograft inflammatory factor 1 (AIF1) and c‐Jun N‐terminal kinase (JNK) were inhibited and overexpressed, respectively, by transfection with sh‐DNMT3a or sh‐AIF1 and JNK overexpression plasmids. The 3‐ (4,5‐cimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay was used to measure cell viability. The Th17/Treg cell ratio was determined by flow cytometry. The expression levels of DNMT3a, c‐Jun and AIF1 were measured using RT‐qPCR or western blotting. Chromatin immunoprecipitation (CHIP) was used to confirm the interaction between c‐Jun and the AIF1 promoter region. CSE stimulation promoted the expression of DNMT3a, and AIF1, and the ratio of p‐c‐Jun/c‐Jun in iDCs. Besides, the iDC‐mediated differentiation of Th17 cells was in a dose‐dependent manner. However, knockdown of DNMT3a or AIF1 reversed the above effects caused by CSE. Inhibition of c‐Jun signaling by treatment with the JNK inhibitor SP600125 also suppressed the iDC‐mediated differentiation of Th17 cells, which was promoted by CSE. CHIP analysis showed that c‐Jun could bind to the promoter region of AIF1. DNMT3a could regulate the iDC‐mediated Th17/Treg balance by regulating the c‐Jun/AIF1 axis.
Intrinsic Disruption of the M1 Cortical Network in a Mouse Model of Parkinson's Disease
Authors: Aeed Fadi , Cermak Nathan , Schiller Jackie , Schiller Yitzhak
Published: February 2021

Background

Parkinson's disease (PD) disrupts motor performance by affecting the basal ganglia system. Yet, despite the critical position of the primary motor cortex in linking basal ganglia computations with motor performance, its contribution to motor disability in PD is largely unknown. The objective of this study was to characterize the role of the primary motor cortex in PD‐related motor disability.

Methods

Two‐photon calcium imaging and optogenetic stimulation of primary motor cortex neurons was done during performance of a dexterous reach‐to‐grasp motor task in control and 6‐hydroxydopamine‐induced PD mice.

Results

Experimental PD disrupted performance of the reach‐to‐grasp motor task and especially initiation of the task, which was partially restored by optogenetic activation of the primary motor cortex. Two‐photon calcium imaging during task performance revealed experimental‐PD affected the primary motor cortex in a cell‐type‐specific manner. It suppressed activation of output layer 5 pyramidal tract neurons, with greater effects on freeze versus nonfreeze trials. In contrast, it did not attenuate the initial movement‐related activation response of layer 2/3 pyramidal neurons while diminishing the late inhibitory phase of their response. At the network level, experimental PD disrupted movement‐related population dynamics of the layer 5 pyramidal tract network while almost not affecting the dynamics of the layer 2/3 neuronal population. It also disrupted short‐ and long‐term robustness and stability of the pyramidal tract subnetwork, with reduced intertrial temporal accuracy and diminished reproducibility of motor parameter encoding and temporal recruitment of the output pyramidal tract neurons over repeated daily sessions.

Conclusions

Experimental PD disrupts both external driving and intrinsic properties of the primary motor cortex. Motor disability in experimental PD results primarily from the inability to generate robust and stable output motor sequences in the parkinsonian primary motor cortex output layer 5 pyramidal tract subnetwork. © 2021 International Parkinson and Movement Disorder Society
Public‐private partnership manifests in opening of integrated‐care campus
Authors: Enos Gary
Published: February 2021

Orange County, California, leaders are beaming over an important manifestation of what they consider a transformative public‐private partnership in behavioral health care: the opening of the first of three planned wellness campuses housing services for which all county residents will be eligible.
Leaders unite on first scientific advisory board to promote EBPs
Authors: Canady Valerie A.
Published: February 2021

An online platform for mental health education, considered by the field to be the most comprehensive in the world, has marked another significant breakthrough with the launch of its Scientific Advisory Board, a united front of the industry's most influential mental health and substance use insurers and researchers to promote scientifically validated practices.
Virtual eating disorder treatment company raises millions
Authors: Canady Valerie A.
Published: February 2021

In the months before the pandemic hit, one health tech company was well on its way to pioneering a program to provide virtual evidence‐based eating disorder treatment to families at home. Its mission: to make gold‐standard eating disorder treatment accessible to all people through family‐based treatment (FBT).
Note on norms of two integral‐type operators on some spaces of functions on ℝn
Authors: Stević Stevo
Published: February 2021

We consider two integral‐type operators, generalizing several classical ones, and calculate their norms on the weighted Lebesgue space , whenp ≥ 1,α > −n, weighted‐type space , whenα > 0, and space,p ≥ 1, extending and complementing some results in the literature.
Convexity, monotonicity, and positivity results for sequential fractional nabla difference operators with discrete exponential kernels
Authors: Goodrich Christopher S. , Jonnalagadda Jagan M. , Lyons Benjamin
Published: February 2021

We consider positivity, monotonicity, and convexity results for discrete fractional operators with exponential kernels. Our results cover both the sequential and nonsequential cases, and we demonstrate both similarities and dissimilarities between the exponential kernel case and fractional differences with other types of kernels. This shows that the qualitative information gleaned in the exponential kernel case is not precisely the same as in other cases.
Analysis of characteristics of images acquired with a prototype clinical proton radiography system
Authors: Sarosiek Christina , DeJongh Ethan A. , Coutrakon George , DeJongh Don F. , Duffin Kirk L. , Karonis Nicholas T. , Ordoñez Caesar E. , Pankuch Mark , Rykalin Victor , Winans John R. , Welsh James S.
Published: February 2021

Purpose

Verification of patient‐specific proton stopping powers obtained in the patient’s treatment position can be used to reduce the distal and proximal margins needed in particle beam planning. Proton radiography can be used as a pretreatment instrument to verify integrated stopping power consistency with the treatment planning CT. Although a proton radiograph is a pixel by pixel representation of integrated stopping powers, the image may also be of high enough quality and contrast to be used for patient alignment. This investigation quantifies the accuracy and image quality of a prototype proton radiography system on a clinical proton delivery system.

Methods

We have developed a clinical prototype proton radiography system designed for integration into efficient clinical workflows. We tested the images obtained by this system for water‐equivalent thickness (WET) accuracy, image noise, and spatial resolution. We evaluated the WET accuracy by comparing the average WET and rms error in several regions of interest (ROI) on a proton radiograph of a custom peg phantom. We measured the spatial resolution on a CATPHAN Line Pair phantom and a custom edge phantom by measuring the 10% value of the modulation transfer function (MTF). In addition, we tested the ability to detect proton range errors due to anatomical changes in a patient with a customized CIRS pediatric head phantom and inserts of varying WET placed in the posterior fossae of the brain. We took proton radiographs of the phantom with each insert in place and created difference maps between the resulting images. Integrated proton range was measured from an ROI in the difference maps.

Results

We measured the WET accuracy of the proton radiographic images to be ±0.2 mm (0.33%) from known values. The spatial resolution of the images was 0.6 lp/mm on the line pair phantom and 1.13 lp/mm on the edge phantom. We were able to detect anatomical changes producing changes in WET as low as 0.6 mm.

Conclusion

The proton radiography system produces images with image quality sufficient for pretreatment range consistency verification.
Stochastic modeling of multiline orders in integrated storage‐order picking system
Authors: Bansal Vishal , Roy Debjit
Published: February 2021

Due to demanding service levels in e‐commerce order fulfillment, modeling and analysis of integrated storage and order picking processes in warehouses deserve special attention. The upstream storage system can have a significant impact on the performance of the downstream order picking process. With a particular focus on multiline e‐commerce orders, we develop an analytical modeling framework for integrated analysis of upstream (shuttle‐based storage and retrieval system) and downstream (pick system) networks. To capture the consolidation delays in fulfilling multiline orders, the downstream pick system is modeled with a closed queuing network that includes synchronization nodes. The configuration of the synchronization station is adapted to model the variety of order profiles handled at the pick station. For the downstream closed queuing network, we propose a decomposition‐based solution methodology that results in good solution accuracy. The resulting semi‐open queuing network (SOQN) of the integrated system is analyzed using the matrix‐geometric method (MGM). To improve the accuracy of analytical estimates of the measures, we propose a hybrid simulation/analytical framework, where the performance measures of complex subnetworks are obtained from simulation. We also develop a detailed simulation model of the physical system for validating the analytical and hybrid estimates of the performance measures. The results from experiments indicate that the hybrid simulation/analytical approach reduces the error in the throughput time estimates to 3% from 18% obtained from the analytical model. Then, we investigate the effect of the upstream network configuration (such as the number of storage aisles) and the downstream network configuration (such as the mixed vs. dedicated picking, CONWIP control for orders, order batching) on the order throughput times. Our analysis provides a threshold on the maximum numbers of allowable orders (CONWIP control) and number of aisles beyond which the improvement in average throughput time of the integrated system is marginal. Numerical experiments with high‐order arrivals also highlight that mixed picking in the downstream network can result in significant throughput time reduction in comparison to dedicated picking.
The roots of the gender pay gap for nonprofit CEOs
Authors: Lee Young‐Joo , Lee Chang Kil
Published: February 2021

A simple comparison of male and female nonprofit executives' salaries cannot give an accurate picture of the gender pay gap because it ignores the gender disparity in executive hiring among large nonprofit organizations, where the CEO receives a higher salary. This study examines CEO salaries at 668 regional chapters of a public benefit nonprofit organization in the U.S., while taking the connection between hiring and compensation disparities into consideration. The findings reveal that the underrepresentation of women CEOs in more resourceful organizations is at the root of gender pay gap for nonprofit executives. This study concludes that improving the gender equity in hiring will help narrow the pay disparity between male and female CEOs.
Suicide prevention strategies for older persons—An integrative review of empirical and theoretical papers
Authors: Holm Anne Lise , Salemonsen Elin , Severinsson Elisabeth
Published: February 2021

Aim

To synthesize suicide prevention strategies for older adults. The review question was Which suicide prevention strategies are useful for older adults?

Design

Integrative review.

Data sources

Academic Search Premier, CINAHL, Ovid PsycINFO and PubMed were searched for articles published between January 2009 and December 2019.

Review methods

An integrative review of quantitative, qualitative and theoretical papers with a qualitative thematic analysis.

Results

Key aspects of the included studies contributed to the formulation of four themes: (1) Recognizing older adults’ physical and/or mental health problems and referring them for help and treatment, (2) Designing an educational programme, (3) Communication and dialogue about warning signs and (4) Social support and awareness of causing significant others emotional pain. The findings indicate an urgent need to identify effective suicide prevention strategies for older adults.
Effects of traditional Chinese exercise on patients with cognitive impairment: A systematic review and Bayesian network meta‐analysis
Authors: Li Chen , Zheng Dongxiang , Luo Jinglan
Published: February 2021

Objective

To systematically review the effectiveness of four types of traditional Chinese exercise (TCE) on patients with cognitive impairment (CI) and to rank these four TCE types.

Design

A Bayesian network meta‐analysis.

Methods

Four English databases, including PubMed, EMBASE, Cochrane Library and Web of Science, and three Chinese databases, including CNKI, VIP and Wanfang, were searched from their inception to December 2019. Randomized control trials conducted to verify the effects of TCE on patients with CI were included. We used network meta‐analysis to evaluate the relative effects and rank probabilities of the four types of TCE.

Results

The results of the network meta‐analysis indicated that baduanjin (N = 9), tai chi (N = 11), liuzijue (N = 2) and qigong (N = 1) all had significant benefits compared with control conditions. According to the ranking probabilities, baduanjin was most likely to be associated with substantial improvement in cognition, followed by tai chi, liuzijue and qigong.

Conclusion

Our study revealed the effectiveness of TCE for improving global cognition in adults with cognitive impairment. Baduanjin may be the most effective exercise type. The evidence summarized in our study still contains bias, and more research should be carried out to verify the validity of TCE.
Psychometric properties of Postpartum Partner Support Scale—Persian version
Authors: Eslahi Zahra , Alimoradi Zainab , Bahrami Nasim , Lin Chung‐Ying , Griffiths Mark D. , Pakpour Amir H
Published: February 2021

Aim

The aim of the present study was to translate the Postpartum Partner Support Scale (PPSS) into Persian and evaluate its psychometric properties among postpartum women.

Design

A total of 248 women aged 18–39 years participated in this psychometric study. The PPSS was translated into Persian using a forward‐backward method. Confirmatory factor analysis (CFA) and Rasch model analysis were used to assess the psychometric properties of the PPSS. In addition, the Edinburgh Postpartum Depression Scale (EPDS) was completed simultaneously to assess the construct validity. Internal consistency of the questionnaire was assessed by calculating the Cronbach's alpha coefficient and corrected item‐total correlation.

Results

The unidimensionality of the PPSS was supported in both CFA and Rasch analysis. The PPSS had a significant negative association with EPDS (r = −0.39p < .001). The scale had excellent internal consistency (Cronbach's alpha = 0.94) and the correlation between items and total score was satisfactory.

Conclusion

The Persian version of PPSS with 20 items is a valid and reliable scale to assess postpartum support.
Sense of coherence and coping strategies: How they influence quality of life in Iranian women with breast cancer
Authors: Zamanian Hadi , Amini‐Tehrani Mohammadali , Mahdavi Adeli Aliyeh , Daryaafzoon Mona , Arsalani Mahnaz , Enzevaei Anahita , Farjami Maryam
Published: February 2021

Aim

To investigate the mediation/moderation effect between Coping Behaviors (CBs) and Sense of Coherence (SOC) in the prediction of health‐related quality of life (HRQoL) in breast cancer patients.

Design

Cross‐sectional.

Methods

A total of 221 patients were included in this study. The 13‐item Orientation to Life Questionnaire, Brief COPE and Functional Assessment of Cancer Therapy—Breast were investigated. Pearson's correlation coefficient and mediation/moderation analysis were performed.

Results

Significant correlations were observed for SOC, active coping, acceptance, positive reframing (PR), planning, use of emotional support (UES), use of instrumental support, behaviour disengagement and self‐blame with HRQoL. Except for planning and acceptance, SOC partially mediated the CBs' effect on HRQoL. The UES and PR's effects on HRQoL were significant at lower SOC levels and diminished at higher SOC levels.

Conclusion

Practitioners can incorporate SOC and adaptive CBs, including PR and UES, into the rehabilitation programmes to improve HRQoL in patients.
Development and psychometric evaluation of a quality nursing care scale from nurses’ perspective
Authors: Liu Ying , Aungsuroch Yupin , Gunawan Joko , Sha Liyan , Shi Tieying
Published: February 2021

Aim

To develop and evaluate psychometric property of quality nursing care scale (QNCS) from nurses’ perspective in the Chinese context.

Design

A cross‐sectional survey design.

Methods

This study was conducted in two phases. In Phase I, literature review and interviews were conducted to develop the items. In Phase II, content validity was evaluated by five experts. Construct validity was tested through exploratory factor analysis (EFA) among 302 nurses and confirmatory factor analysis (CFA) among 510 nurses from October 2014 to January 2015. Additionally, internal consistency reliability was tested.

Results

The EFA extracted six factors including staff characteristics, task‐oriented activities, human‐oriented activities, physical environment, patient outcomes and precondition. All six factors accounted for 74.78% of the total variance to explain quality nursing care. The modified measurement model of the final version of QNCS was supported by the CFA with 48 items in six dimensions. The internal consistency reliability of final QNCS was acceptable.
No adverse events were observed in clozapine‐treated patients on extended hematologic monitoring intervals during the coronavirus pandemic in four psychiatric centers in Japan
Authors: Hata Masahiro , Fujimoto Michiko , Kanai Koji , Yoshiyama Kenji , Nakatani Yoshitaka , Nakabayashi Daiji , Maemura Saki , Kawata Shinya , Hakozaki Takaaki , Nishikura Shuya , Umemoto Aiko , Sasada Toru , Iwata Kazuhiko , Tanaka Hideki , Mamoto Akiko , Toi Yuuki , Taniguchi Norio , Saito Makiko , Kimura Yoshio , Kishimoto Kazuko , Hayami Megumi , Ikeda Manabu
Published: February 2021

Aim

As an emergency measure during the coronavirus disease pandemic, the monitoring interval for clozapine use was temporarily extended beyond the regulatory requirement in Japan, which is the safest monitoring interval worldwide. In this study, we aimed to explore the effect of this measure on patients undergoing clozapine treatment.

Methods

This retrospective chart review study included patients with treatment‐resistant schizophrenia (TRS) who were undergoing clozapine treatment at four psychiatric institutions in Japan. Demographic characteristics and clinical information of these patients were collected on April 27, 2020, when Japanese psychiatrists were virtually allowed to prescribe clozapine beyond the regulatory requirement. Furthermore, information of adverse events related to the emergency measure was collected and analyzed.

Results

Of the 41 patients with TRS included in this study, 19 patients underwent extended hematological monitoring during clozapine treatment. No psychiatric or hematological adverse events were observed in the patients during the extended monitoring interval.

Conclusion

This study suggested that there were few adverse events of clozapine‐treated patients related to emergency measures in Japan. However, hematological monitoring intervals during clozapine treatment have been emergently extended worldwide; hence, it is necessary to verify the results of these measures.
Revenue, welfare and trade effects of African Continental Free Trade Agreement (AFCFTA) on Nigerian economy
Authors: Oyelami Lukman O.
Published: February 2021

African Continental Free Trade Agreement (AFCFTA) is gradually becoming a reality and there are needs now more than ever to investigate how African countries will thrive under this new trade regime. Based on this consideration, this study seeks to investigate the revenue, welfare and trade effect of ACFTA on Nigerian economy with the Partial Equilibrium Analysis approach using the World Trade Integrated Solution‐Single Market Partial Equilibrium Simulation Tool (SMART) model. SMART is a trade simulation model developed by the World Bank and the UNCTAD using trade flow data and tariff data from Trade Analysis and Information Systems, the World Trade Organization Integrated Database and Consolidated Tariff Schedule. The findings from the study show that AFCFTA is a trade creating Free Trade Agreement in Africa and sectors like petrochemical industries, textile and maritime products are the leading trade creating sector in Nigeria. On the other hand, manufacturing activities in the production of sanitary, papers, electronics and automobiles are trade diverting in Nigeria. Overall, the total trade effect in Nigeria is US$ 145 million with an accompanying welfare effect of US$ 13 million. However, the Nigerian government might experience a loss of revenue of US$104 million as a result of tariff removal. Thus, this study concludes that AFCFTA is a trade creating and expanding policy but it comes at a huge loss of revenue on the part of the Nigerian government and this can be ameliorated with the introduction of the more comprehensive consumption tax system.
COVID‐19 pandemic and transmission factors: An empirical investigation of different countries
Authors: Singh Pawan Kumar , Kiran Ravi , Bhatt Rajiv Kumar , Tabash Mosab I. , Pandey Alok Kumar , Chouhan Anushka
Published: February 2021

The present work evaluates the impact of age, population density, total population, rural population, annual average temperature, basic sanitation facilities, and diabetes prevalence on the transmission of COVID‐19. This research is an effort to identify the major predictors that have a significant impact on the number of COVID‐19 cases per million population for 83 countries. The findings highlight that a population with a greater share of old people (aged above 65) shows a higher number of COVID‐19 positive cases and a population with a lower median age has fewer cases. This can be explained in terms of higher co‐morbidities and the lower general immunity in the older age group. The analysis restates the widely seen results that a higher median age and greater prevalence of co‐morbidities leads to higher cases per million and lesser population density and interpersonal contact helps in containing the spread of the virus. The study finds foundation in the assertion that a higher temperature might lower the number of cases, or that temperature in general can affect the infectivity. The study suggests that better access to sanitation is a certain measure to contain the spread of the virus. The outcome of this study will be helpful in ascertaining the impact of these indicators in this pandemic, and help in policy formation and decision‐making strategies to fight against it.
Thermally induced fire early warning aerogel with efficient thermal isolation and flame‐retardant properties
Authors: Cao Chengran , Yuan Bihe
Published: February 2021

Due to the energy‐saving demands in chemical industries and building fields, thermal isolation materials (TIMs) are widely used. The general exploitation of combustible TIMs calls for timely fire alerts as well as flame‐retardant modifications. This work provides a novel paradigm to address the issues simultaneously by preparing a multifunctional aerogel via a facile and environmentally friendly freeze‐drying method. With the doping of ammonium polyphosphate and graphene oxide (GO), cellulose nanofiber‐based aerogel exhibits excellent thermal‐isolating as well as flame‐retardant properties. The composite aerogel displays flameless pyrolysis as well as increased residue char. A fire‐warning detector is designed to reliably monitor the early fire. Based on the flame‐induced electrical resistance transformation characteristic of GO, it endows the composite aerogel with an ultra‐fast fire‐response time of ~2.6 s and a durable alarm signal. The flame‐retardant and fire‐alarm mechanisms are concluded. Overall, these results suggest that this composite aerogel has an enticing prospect in chemical industries and high‐rise buildings, which may lay the foundation for designing multifunctional TIMs. The modified aerogel broadens its application territory by intrinsic fire‐alarm characteristics, which covers the deficiency of delaying reaction as well as restricted application scenarios in traditional fire detectors.
Material properties and phase behavior of crosslinkable acrylonitrile‐butadiene copolymer/ethylene vinyl acetate/carbon black composites
Authors: Brigandi Paul J. , Sengupta Saurav , Weinhold Jeffrey , Reffner John R.
Published: February 2021

Crosslinkable composites of ethylene vinyl acetate copolymer (EVA)/acrylonitrile‐butadiene copolymer (NBR)/carbon black (CB) finds widespread use in industrial applications. Crosslinking and phase behavior and resulting mechanical properties have been reported, but a systematic investigation as a function of varying molecular architecture is still elusive. The present work combines an experimental and theoretical approach to understand the phase morphology and physical properties of crosslinked EVA/NBR/CB polymer composites. Crosslinking behavior is studied by varying the functionality content in the two polymers. A theoretical model was developed to calculate and predict the overall phase behavior of the composites as well as the preferential solubility of the peroxide in the phases. The phase morphology of the immiscible EVA/NBR polymer blend investigated clearly showed two distinct phases with the NBR phase dispersed in the continuous EVA phase and the CB particles tend to reside at the interface. The influence of varying molecular architecture and functionality of the NBR and EVA on material properties was investigated and did not significantly contribute to the crosslinking and tensile behavior of the composites. The mechanical properties were found to correlate with the degree of crosslinking and CB loading.
Identifying new compounds with potential pharmaceutical and physiological activity in Areca catechu and Areca triandra via a non‐targeted metabolomic approach
Authors: Wu Jiao , Cui Chuang , Zhang He , Liu Dongjun , Schreiber Lukas , Qin Weiquan , Wan Yinglang
Published: February 2021

Introduction

The fruits of Areca catechu, also called areca nuts, are widely used as popular masticatory and traditional herbal medicine in Asia. Besides arecoline and related alkaloids, limited information is available about further primary and secondary metabolites and their potential biological activities.

Objective

Here we aimed to further enhance our knowledge on phytochemical profiles of A. catechu and Areca triandra fruits. We intended to comprehensively identify metabolites in A. catechu and A. triandra fruits.

Methodology

Metabolites were identified by ultra‐performance liquid chromatography triple‐quadrupole tandem mass spectrometry (UPLC–MS/MS). The occurrence of 12 selected bioactive compounds in 4 different developmental stages of A. catechu and A. triandra was quantified by LC–MS/MS.

Results

A total of 791 metabolites was identified. Of these, 115 metabolites could successfully be mapped to 44 Kyoto Encyclopedia of Genes and Genomes metabolic pathways, and 154 metabolites occurred at significantly different levels in A. catechu compared to A. triandra. Several components with known biological activities were identified for the first time in A. catechu and A. triandra. The abundance of many of these new components was similar in A. catechu and A. triandra, but significantly different between the pericarp and the seeds of A. catechu fruits.

Conclusions

Metabolic profiles indicate that fruits of the Areca species compared here have similar primary and secondary metabolites. Our findings provide new insights into A. catechu and A. triandra as valuable sources for traditional medicine and they pave the way for further studies to potentially improve the underlying pharmaceutical and physiological effects.
Chronic opioid use and complication risks in women with endometriosis: A cohort study in US administrative claims
Authors: Chiuve Stephanie E. , Kilpatrick Ryan D. , Hornstein Mark D. , Petruski‐Ivleva Natalia , Wegrzyn Lani R. , Dabrowski Elizabeth C. , Velentgas Priscilla , Snabes Michael C. , Bateman Brian T.
Published: February 2021

Background

Women with endometriosis are prescribed opioids for pain relief but may be vulnerable to chronic opioid use given their comorbidity profile.

Methods

A cohort study was conducted in the Clinformatics™ DataMart database between 2006 and 2017 comparing women aged 18–50 years with endometriosis (N = 36 373) to those without (N = 2 172 936) in terms of risk of chronic opioid use, opioid dependence diagnosis, and opioid overdose. Chronic opioid use was defined as ≥120 days' supply dispensed or ≥10 fills of an opioid during any 365‐day interval. Among women with endometriosis, we evaluated factors associated with higher risk of chronic opioid use and quantified the risk of complications associated with the use of opioids.

Results

Women with endometriosis were at greater risk for chronic opioid use (OR: 3.76; 95%CI: 3.57–3.96), dependence (OR: 2.73, 95%CI: 2.38–3.13) and overdose (OR: 4.34, 95%CI: 3.06–6.15) compared to women without. Chronic users displayed dose escalation and increase in days supplied over time, as well as co‐prescribing with benzodiazepines and sedatives. Approximately 34% of chronic users developed constipation, 20% experienced falls, and 8% reported dizziness. Among endometriosis patients, women in younger age groups, those with other comorbidities associated with pain symptoms, as well as those with depression or anxiety were at a higher risk of developing chronic opioid use.

Conclusions

Women with endometriosis had a four times greater risk of chronic opioid use compared to women without. Multimorbidity among these patients was associated with the elevated risk of chronic opioid use and should be taken into account during treatment selection.
A novel kinetic approach to crystallization mechanisms in polymers
Authors: Arshad Muhammad Azeem
Published: February 2021

Kinetics of polymer crystallization is capable of modeling the polymer crystallization processes by revealing their mechanisms. Although complexities of polymer crystallization processes are familiar, a generalized approach for their kinetic modeling has not yet been suggested. This paper presents a concise review of the pre‐existing kinetic approaches to polymer crystallization, including their pros and cons, putting a special emphasis on the necessity of approaches to polymer crystallization. A systematic and advanced approach comprising an innovative kinetic framework to model polymer crystallization processes is put forward using Hoffman‐Lauritzen theory. Kinetic functions are developed for predicting the crystallization mechanisms of simple as well as complicated polymer crystallization processes. The suggested kinetic approach is experimentally justified by its effective applications to non‐isothermal glass and melt crystallization of poly(ethylene 2,5‐furandicarboxylate). An account of the soundness of the proposed kinetic approach and its prospective applications are also discussed.
Environmental impacts of examination gloves made of natural rubber and nitrile rubber, identified by life‐cycle assessment
Authors: Patrawoot Supatra , Tran Thierry , Arunchaiya Marisa , Somsongkul Voranuch , Chisti Yusuf , Hansupalak Nanthiya
Published: February 2021

Medical examination gloves made of natural rubber (NR; powdered and non‐powdered) and synthetic nitrile rubber (NBR) were compared in terms of their environmental impact using life cycle assessments spanning material extraction, transportation to the glove production factory, the production process, and disposal by total incineration. ReCiPe Midpoint (H) V1.13/World Recipe H life cycle assessment method implemented using the SimaPro 9.0.0.48, was used. Single scores of each glove type and stage were determined by using weighting factors specifically obtained from a 2014 survey in Thailand. With current technologies, the overall environmental impact, or the total single score, of NR gloves was higher than of NBR gloves, because the glove production stage of NR gloves required more energy and sulfur use. In addition, the overall environmental impact of both types of gloves was found to be lower if powder coating was used rather than chlorination to reduce stickiness, and if glove production relied on natural gas for energy rather than coal. The single score approach revealed the hotspots for potential improvements for each glove type.
A comparison of insecticide susceptibility levels in 12 species of urban pest ants with special focus on the odorous house ant, Tapinoma sessile
Authors: Buczkowski Grzegorz
Published: February 2021

BACKGROUND

Many ant species are pests in urban, agricultural, and natural habitats around the world. The primary means of reducing or eliminating ant infestations utilizes chemical control, mainly applications of residual insecticides. Control failures with residual insecticides are common, driven in part by a lack of understanding of basic biological and life history characteristics, including interspecific variation in susceptibility to insecticides. The current study evaluated the susceptibility of 12 species of urban pest ants to three classes of insecticides.

RESULTS

Results show significant variation in susceptibility across species. Contrary to the hypothesis of proportionality, no significant relationship was detected between body mass and median lethal time (LT50) or time to 100% mortality. The odorous house ant (Tapinoma sessile) was consistently the least susceptible to all insecticides, as indicated by the highest LT50 values and the greatest amount of time required to reach 100% mortality. Comparatively low susceptibility to commonly used spray insecticides may explain why T. sessile is such a persistent pest. Broadcast applications of spray insecticides may kill off the most susceptible species, leaving behind T. sessile. Lack of competition from other ant species, combined with increased access to nesting and feeding resources may allow T. sessile to fill a vacant ecological niche and expand its range.

CONCLUSION

Considering T. sessile's relatively low susceptibility to insecticides, its ability to become established in areas colonized by other invasive ants, and its highly invasive behaviors, it should be watched for by biosecurity programs as it has high potential to become a globally invasive pest.

© 2021 Society of Chemical Industry.
A high‐accuracy global prognostic model for the simulation of Rossby and gravity wave dynamics
Authors: Vasylkevych Sergiy , Žagar Nedjeljka
Published: February 2021

A model for studying Transient Inertia–Gravity And Rossby wave dynamics (TIGAR) is introduced. The presented horizontal component of the model solves the nonlinear rotating shallow‐water equations on the sphere using Hough harmonics. Spectral modelling using Hough harmonics as basis functions describes atmospheric dynamics in terms of physically identifiable structures: Rossby and inertia–gravity eigensolutions of linearized primitive equations. This offers an attractive framework for detangling gravity wave dynamics in high‐resolution simulations. Accurate computations are achieved through the use of higher order integrating factor and exponential time‐differencing methods, leading to a major increase in computational efficiency and stability. A comparison with classical time‐stepping schemes shows accuracy improvements of several orders of magnitude at no additional computational cost. In particular, stability gains are achieved through enhanced accuracy and efficiency in the computation of gravity waves, rather than through their damping. In the new framework, reduced models using Rossby and gravity waves aimed at studying dynamical aspects of data assimilation or wave interactions are easily implemented.
Empirical determination of the covariance of forecast errors: An empirical justification and reformulation of hybrid covariance models
Authors: Carrió Diego S. , Bishop Craig H. , Kotsuki Shunji
Published: February 2021

During the last decade, the replacement of static climatological forecast error covariance models with hybrid error covariance models that linearly combine localised ensemble covariances with static climatological error covariances has led to significant forecast improvements at several major forecasting centres. Here, a deeper understanding of why the hybrid's superficially ad hoc mix of ensemble‐based and climatological covariances yields such significant improvements is pursued. In practice, ensemble covariances are not equal to the true flow‐dependent forecast error covariance matrix. Here, the relationship between actual forecast error covariance and the corresponding ensemble covariance is empirically demonstrated. Using a simplified global circulation model and the local ensemble transform Kalman filter (LETKF), the covariance of the set of actual forecast errors corresponding to ensemble covariances close to a fixed target value is computed. By doing this for differing target values, an estimate of the actual forecast error covariance as a function of ensemble covariance is obtained. A demonstration that the hybrid is a much better approximation to this estimate than either the static climatological covariance or the localised ensemble covariance is given. The empirical estimate has two features that current hybrid error covariance models fail to represent: (i) The weight given to the static covariance matrix is an increasing function of the horizontal separation distance of the covarying model variables, and (ii) for small ensemble sizes and ensemble covariances near zero but negative, the actual forecast error covariance is a decreasing function of increasing ensemble covariance. While the first finding has been anticipated by other authors, the second finding has not been anticipated, as far as the authors are aware. Here, (ii) is hypothesised to be a consequence of spurious sample correlations and variances associated with reduced ensembles. Consistent with this hypothesis, the non‐monotonicity of this relationship is almost eliminated by quadrupling the ensemble size.
Distance based and bond additive topological indices of certain repurposed antiviral drug compounds tested for treating COVID‐19
Authors: Liu Jia‐Bao , Arockiaraj Micheal , Arulperumjothi M. , Prabhu Savari
Published: February 2021

The entire world is struggling to control the spread of coronavirus (COVID‐19) as there are no proper drugs for treating the disease. Under clinical trials, some of the repurposed antiviral drugs have been applied to COVID‐19 patients and reported the efficacy of the drugs with the diverse inferences. Molecular topology has been developed in recent years as an influential approach for drug design and discovery in which molecules that are structurally related show similar pharmacological properties. It permits a purely mathematical description of the molecular structure so that in the development of identification of new drugs can be found through adequate topological indices. In this paper, we study the structural properties of the several antiviral drugs such as chloroquine, hydroxychloroquine, lopinavir, ritonavir, remdesivir, theaflavin, nafamostat, camostat, umifenovir and bevacizumab by considering the distance and bond measures of chemical compounds. Our quantitative values of the topological indices are extremely useful in the recent development of designing new drugs for COVID‐19.
Examining conductance values in the biphenyl molecular switch with reduced density matrices
Authors: Bones Don X. , Malme Justin T. , Hoy Erik P.
Published: February 2021

Electronic switches built from single molecules such as biphenyl dithiol are promising replacements for traditional electronic devices. To support experimental investigations of molecular switches, charge transport values are typically predicted using non‐equilibrium Green's functions constructed using density functional theory (NEGF‐DFT). Previous studies of biphenyl dithiol, however, have usually overestimated experimental conductance values and have not reproduced a drop in conductance at low torsional angles. In this paper, we employ a methodology that constructs the non‐equilibrium Green's functions from 2‐electron reduced density matrix theory (NEGF‐RDM). This approach has previously predicted lower conductance values than NEGF‐DFT for systems where NEGF‐DFT is known to overestimate transport. In the first direct comparison of the NEGF‐RDM method and experimental results, we examine the biphenyl dithiol at a range of torsional angles. We evaluate both the quantitative accuracy of multiple NEGF methods and provide insights into the experimentally observed drop in conductance at small torsional angles.
Dam‐influenced seasonally varying water temperature in the Three Gorges Reservoir
Authors: Sun Jian , Lin Jie , Zhang Xiaofeng , Xiao Zijun , Lin Binliang , Xu Haoyang
Published: February 2021

Water temperature is a fundamental parameter for both hydrological and ecological processes in aquatic systems. Usually, a sinusoidal function is used to represent the seasonal variation of water temperature in natural surface water. However, a large number of dams have been built on rivers worldwide, and water mass transport is retarded due to the reservoir impoundment. As a result, the water temperature lags seasonally behind the natural cycle due to seasonal dam‐operation, and the ordinary sinusoidal function is no more valid in describing the thermal process. In this study, a composite cosine function (CCF) is introduced to address the dam‐influenced seasonally varying water temperature pattern, which includes a time varying phase‐lag for temperature variations. The proposed method is applied to the Three Gorges Reservoir (TGR), a major impoundment on the Yangtze River, China. It is found that the annual thermal process of warming and cooling becomes asymmetry during the post‐TGR stage, that is, the seasonally varying temperature follows an asymmetric sinusoidal wave pattern. In frequency spectrum, both annual and semi‐annual components are main contributors to the time varying water temperature. The minimum temperature of TGR's discharge has increased by 1.86°C after the normal operation of the reservoir, and the coldest water arrival timing is postponed by up to 40 days in the dry season. The benefit of using CCF in temperature reconstruction is that it can prevent the mistake of ascribing the semi‐annual component to short‐term fluctuations. The present study can help in improving the understanding of the asymmetric seasonal temperature processes due to dam operation.