bluuebunny/crossref_metadata_2025 huggingface dataset:
Mouse aging cell atlas analysis reveals global and cell type-specific aging signatures
Authors: Zhang Martin Jinye , Pisco Angela Oliveira , Darmanis Spyros , Zou James
Published: April 2021

Aging is associated with complex molecular and cellular processes that are poorly understood. Here we leveraged the Tabula Muris Senis single-cell RNA-seq data set to systematically characterize gene expression changes during aging across diverse cell types in the mouse. We identified aging-dependent genes in 76 tissue-cell types from 23 tissues and characterized both shared and tissue-cell-specific aging behaviors. We found that the aging-related genes shared by multiple tissue-cell types also change their expression congruently in the same direction during aging in most tissue-cell types, suggesting a coordinated global aging behavior at the organismal level. Scoring cells based on these shared aging genes allowed us to contrast the aging status of different tissues and cell types from a transcriptomic perspective. In addition, we identified genes that exhibit age-related expression changes specific to each functional category of tissue-cell types. Altogether, our analyses provide one of the most comprehensive and systematic characterizations of the molecular signatures of aging across diverse tissue-cell types in a mammalian system.
Membrane binding controls ordered self-assembly of animal septins
Authors: Szuba Agata , Bano Fouzia , Castro-Linares Gerard , Iv Francois , Mavrakis Manos , Richter Ralf P , Bertin Aurélie , Koenderink Gijsje H
Published: April 2021

Septins are conserved cytoskeletal proteins that regulate cell cortex mechanics. The mechanisms of their interactions with the plasma membrane remain poorly understood. Here, we show by cell-free reconstitution that binding to flat lipid membranes requires electrostatic interactions of septins with anionic lipids and promotes the ordered self-assembly of fly septins into filamentous meshworks. Transmission electron microscopy reveals that both fly and mammalian septin hexamers form arrays of single and paired filaments. Atomic force microscopy and quartz crystal microbalance demonstrate that the fly filaments form mechanically rigid, 12- to 18-nm thick, double layers of septins. By contrast, C-terminally truncated septin mutants form 4-nm thin monolayers, indicating that stacking requires the C-terminal coiled coils on DSep2 and Pnut subunits. Our work shows that membrane binding is required for fly septins to form ordered arrays of single and paired filaments and provides new insights into the mechanisms by which septins may regulate cell surface mechanics.
Vi har en plan
Authors: Grepperud Gunnar
Published: April 2021

I denne rapporten oppsummeres sentrale trekk ved samtlige søknader om pedagogiske utviklingsmidler ved UiT Norges arktiske universitet for perioden 2011-2019. Til sammen kom det inn 299 søknader. 55 prosent av dem fikk støtte. De tema som tas opp i rapporten er fordeling av søknader på fakultet og institutt, begrunnelser, de undervisnings- og læringsformer som søkes utprøvd, kunnskapsgrunnlaget og planlagt samarbeid. Avslutningsvis drøftes noen av de sentrale trekkene ved søknadene.
The prevalence of fatigue among Chinese nursing students in post-COVID-19 era
Authors: Liu Shou , Xi Hai-Tao , Zhu Qian-Qian , Ji Mengmeng , Zhang Hongyan , Yang Bing-Xiang , Bai Wei , Cai Hong , Zhao Yan-Jie , Chen Li , Ge Zong-Mei , Wang Zhiwen , Han Lin , Chen Pan , Liu Shuo , Cheung Teris , Hall Brian J. , An Feng-Rong , Xiang Yu-Tao
Published: April 2021

Background

Due to the COVID-19 outbreak, all teaching activities in nursing schools were suspended in China, and many nursing students were summoned to work in hospitals to compensate for the shortage of manpower. This study examined the prevalence of fatigue and its association with quality of life (QOL) among nursing students during the post-COVID-19 era in China.

Methods

This was a multicenter, cross-sectional study. Nursing students in five Chinese universities were invited to participate. Fatigue, depressive and anxiety symptoms, pain and QOL were measured using standardized instruments.

Results

A total of 1,070 nursing students participated. The prevalence of fatigue was 67.3% (95% CI [64.4–70.0]). Multiple logistic regression analysis revealed that male gender (P = 0.003, OR = 1.73, 95% CI [1.20–2.49]), and being a senior nursing student (second year: OR = 2.20, 95% CI [1.46–3.33], P < 0.001; third year: OR = 3.53, 95% CI [2.31–5.41], P < 0.001; and fourth year OR = 3.59, 95% CI [2.39–5.40], P < 0.001) were significantly associated with more severe fatigue. In addition, moderate economic loss during the COVID-19 pandemic (OR = 1.48, 95% CI [1.08–3.33], P < 0.015; compared to low loss), participants with more severe depressive (OR = 1.48, 95% CI [1.22–1.78], P < 0.001) and anxiety symptoms (OR = 1.12, 95% CI [1.05–1.20], P = 0.001), and more severe pain (OR = 1.67, 95%CI [1.46–1.91], P < 0.001) were significantly associated with reported more severe fatigue. After controlling for covariates, nursing students with fatigue had a lower overall QOL score compared to those without (F(1, 1070) = 31.4, P < 0.001).

Conclusion

Fatigue was common among nursing students in the post-COVID-19 era. Considering the negative impact of fatigue on QOL and daily functioning, routine physical and mental health screening should be conducted for nursing students. Effective stress-reduction measures should be enforced to assist this subpopulation to combat fatigue and restore optimal health.
Motor expertise and performance in sport-specific priming tasks: a systematic review and meta-analysis
Authors: Jiang Ruichen , Xie Fei , Li Anmin
Published: April 2021

Objective

The present study aimed to summarize findings relevant to the influence of motor expertise on performance in sport-specific priming tasks and to examine potential moderators of this effect.

Methodology

Data were collected from the China National Knowledge Infrastructure (CNKI), PsychInfo, Medline, Google Scholar, Web of Science, Baidu Scholar and Sport Discus and Dissertation Abstracts Online databases from January 1999 to April 2020, supplemented by manual bibliographies and meeting minutes. Stata software was used to perform the meta-analysis. Study quality was evaluated systematically using the Newcastle-Ottawa scale (NOS). Standard mean differences (SMDs) with 95% CIs were calculated with a random-effects model. The Cochrane Q test and I2 statistic were used to evaluate heterogeneity. Begg funnel plots and Egger tests were conducted to assess publication bias.

Results

Nine articles (including 12 studies) were ultimately included in the meta-analysis. Significant heterogeneity was observed among these studies (Q = 44.42, P < 0.001, I2 = 75.2%) according to random-effects modeling. The results showed an overall advantage in favor of motor experts in sport-specific priming tasks (SMD = −1.01, 95% CI [−1.41 to −0.61]). However, the magnitude of that effect was moderated by sport type (interceptive sports/independent sports) and prime stimulus type (subliminal stimulus/supraliminal stimulus). No publication bias was detected by the Begg and Egger tests.

Conclusions

In general, compared with those of nonexperts, the responses of motor experts’ responses to a target stimulus are easier and faster when the prime and target stimuli are consistent. However, the magnitude of this effect is moderated by sport type and prime stimulus type.
The Impact of Ransomware on Individuals and Organizations in this Modern Era, Ways Forward
Authors: Mgbeafulike Ike , Justin N. Ifeose
Published: April 2021

Ransomware is a severe security bottleneck and threat faced by individuals and organizations today in computer and information technology, and ransomware attacks are on the increase by the day. There is no infallible solution for protecting against Ransomware as the malware code uses metamorphic and polymorphic algorithms to generate different versions, thus evading signature detection. Ransomware also uses domain generator algorithms (DGA) to generate new domains for the command and control server (C&C), they constantly exploit new vulnerabilities, and they use various infection vectors. Thus, for an individual or organization to protect itself, an adaptive security architecture must constantly monitor the system to detect new ransomware infections at an early stage such that they block them before encryption of the files done. This approach is a defense in depth approach that supplements the network defenses such as patch management, anti-virus software, intrusion detection, firewalls, and content filtering. A framework for implementing the preempt and preventive security architecture model using open -source software was presented and the proposed framework is tested against the WannaCry and Petya Ransomware. The proposed framework was successfully able to alert of the ransomware attack and, it was even possible to prevent the Petya ransomware from executing on the victim host.
Effect of Anaesthesiologists’ Experience on Preferred Technique and Volume of Local Anaesthetic Administered for Brachial Plexus Nerve Block: A Retrospective Observational Analysis
Authors: Kaur Depinder , Mahajan Reena , Singh Shiv Kumar , Malhotra Suchitra
Published: April 2021

Introduction: Faculty and Residents are trained in peripheral nerve blocks guided by blind technique, Peripheral Neuro Stimulator (PNS) or Ultrasound (USG) guided technique. But due to unavailability of USG machine in all institutes and requiring special training, techniques used for peripheral nerve blocks vary from institute to institute. Aim: To analyse the effect of anaesthesiologists’ experience on preferred technique and Local Anaesthetic (LA) volume used for brachial plexus nerve block retrospectively. Materials and Methods: In this retrospective observational study, 129 adults American Society of Anesthesiologists (ASA) grade I and II patients requiring brachial plexus nerve block for upper limb orthopaedic surgical anaesthesia for both elective and emergency surgery were divided into three groups for each year depending on technique for nerve block used. Group A: Received USG guided (Micromaxx Sonosite Inc, USA) brachial plexus nerve block. Group B: Received peripheral nerve stimulator (Inmed) guided brachial plexus nerve block. Group C: Received brachial plexus nerve block by traditional anatomical landmark based paraesthesia elicitation blind technique. Patients with inadequate surgical analgesia were given general anaesthesia and were categorised as failure rate. Year wise demographic data, type of technique used for giving brachial plexus nerve block, volume of drug used, failure rate, complications observed were collected and analysed by Student’s t-test and Chi-square test. Results: USG guided technique was the most prefered technique in both years (57.6%, n=38 in year 2018 and 49.2%, n=31 in year 2019). In remaining nearly half of the patients PNS and blind technique was used (PNS 24.2%, n=16 in year 2018 and 20.6%, n=13 in year 2019; blind technique 18.2%, n=12 in year 2018 and 30.2%, n=19 in year 2019). Significantly, less volume of LA drug (mL) was used in group A in year 2019 (16.43±6.07) than in year 2018 (22.34±4.75) (p<0.001). Failure rate in group A in year 2019 (3.2%) was significantly less than in year 2018 (5.2%), but the difference was insignificant in all three groups. In group A, no complications were observed in year 2019 while one incidence of hemidiaphragm paralysis was observed in year 2018, while in group B and C, complications were observed in both years. Conclusion: USG guided nerve block was the most preferred technique for nerve block in the study institute. In 24 months observation period, with increasing experience with USG there was significant increase in success rate and decrease in the volume of LA administered and complications.
Efficacy of Priming Principle in Propofol Induction-A Randomised Controlled Trial
Authors: Dhanapalan Sri Sowmiya , Vyas Manisha B
Published: April 2021

Introduction: Priming refers to administration of a small calculated dose of a drug before giving the total induction dose. Priming principle is well-documented with the use of non-depolarising muscle relaxants. Over the years, propofol has emerged as an effective alternative to thiopentone for intravenous induction. Aim: To evaluate whether priming with propofol reduces the total induction dose of propofol. Materials and Methods: Fifty patients with American Society of Anaesthesiologists (ASA) I and II grades, aged 18-55 years, and undergoing elective surgical procedures under general anaesthesia were randomly allocated into two groups; with 25 patients each. Patients in Control Group (CG) received calculated induction dose of injection propofol 2 mg/kg whereas patients in Study Group (SG) received 20% of total calculated induction dose of propofol 2 mg/kg as a priming dose and remaining dose after 30 seconds titrated till the loss of the eyelash reflex. The total induction dose and the associated haemodynamic parameters were noted. The data thus obtained was then analysed using Chi-square test and Student’s t-test. Results: The CG required a higher dose of inj. propofol (2.15 mg/kg) as compared with the SG (1.77 mg/kg), i.e., there was 17.43% reduction of the total dose in the SG. The preoperative baseline vitals {Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP)} in both the groups were comparable. The changes in HR, at 1 minute and 3 minutes after induction were higher in CG than SG, which was statistically significant. The MAP at 1 minute and 3 minutes after induction was higher in SG than CG and was statistically significant. Conclusion: The priming principle when applied to induction with propofol reduces the total dose requirements of propofol and reduces the hypotension that it causes, thereby proving a stable haemodynamic state.
Что творится с климатом и что он творит с нами? Эхо одного интервью, "Природа"
Authors: Киселев А.А.
Published: April 2021

На примере экстремального 2020 г. рассмотрены среднемесячные, среднесезонные отклонения температуры приземного воздуха от их средних за двадцатилетний период значений в трех городах Европейской части России. В оценках использованы простейшие методы математической статистики. Обсуждаются особенности среднесрочного прогнозирования температурного режима.
Птеранодоны России, "Природа"
Authors: Аверьянов А.О. , Архангельский М.С.
Published: April 2021

Первая находка птерозавра в России была сделана в 1911 г. в верхнем мелу Пензенской области. Найденный фрагмент шейного позвонка (голотип Bogolubovia orientalis) относили последовательно к представителям птеранодонтид и аждархид. Новые находки в верхнем мелу Саратовской обл. позволили установить одновременное существование двух таксонов птерозавров — аждархид и птеранодонтид. К птеранодонтидам отнесен второй таксон волжских птерозавров –— Volgadraco bogolubovi. К этой группе также должна относиться боголюбовия. Новые находки свидетельствуют, что птеранодонтиды были успешной и широко распространенной группой позднемеловых птерозавров.
Engineering Graphene‐Ceramic 3D Composite Foams by Freeze Drying
Authors: Thomas Tony , Zhang Cheng , Feliciano Ruiz Kristal M. , Ramos-Pagan Carolina I. , Negron Dariana M. Ramos , Boesl Benjamin , Agarwal Arvind
Published: April 2021

A 3D graphene foam produced by the chemical vapor deposition (CVD) technique is recognized as an effective nanofiller material, as it does not agglomerate in the matrix. Though CVD facilitates pristine graphene foam production, the method poses limitations in developing large‐scale 3D graphene composite foams as advanced engineering materials. Herein, a freeze‐drying (FD) process is used to produce a composite 3D foam, which is a mixture of graphene nanoplatelet (GNP) and a low‐temperature co‐fired ceramic (LTCC). The freeze‐dried GNP‐LTCC reticulated 3D composite foam has an average pore size ranging from 70 to 100 μm. Pore size is varied by regulating the heat transfer rate during the freezing process using a thermally conductive aluminum (Al) mold and a thermally insulating acrylonitrile butadiene styrene (ABS) mold. Computational thermal modeling is used to visualize the heat transfer and its effect on foam pore size. Subsequently, a freeze‐dried GNP‐LTCC composite foam is embedded into the LTCC matrix to form a hierarchical assembly by a spark plasma technique without compromising the 3D structure of the FD foam. This study established that a simple, eco‐friendly, and scalable processing methodology can produce advanced graphene‐based 3D composite foams as the future tailorable nanofillers for designing multimatrix materials.
RuV‐Acylimido Intermediate in [RuIV(Por)Cl2]‐Catalyzed C–N Bond Formation: Spectroscopic Characterization, Reactivity, and Catalytic Reactions
Authors: Hong Dan‐Yan , Liu Yungen , Wu Liangliang , Lo Vanessa Kar‐Yan , Toy Patrick H. , Law Siu‐Man , Huang Jie‐Sheng , Che Chi‐Ming
Published: April 2021

Metal‐catalyzed C−N bond formation reactions via acylnitrene transfer have recently attracted much attention, but direct detection of the proposed acylnitrenoid/acylimido M(NCOR) (R=aryl or alkyl) species in these reactions poses a formidable challenge. Herein, we report on Ru(NCOR) intermediates in C−N bond formation catalyzed by [RuIV(Por)Cl2]/N3COR, a catalytic method applicable to aziridine/oxazoline formation from alkenes, amination of substituted indoles, α‐amino ketone formation from silyl enol ethers, amination of C(sp3)−H bonds, and functionalization of natural products and carbohydrate derivatives (up to 99 % yield). Experimental studies, including HR‐ESI‐MS and EPR measurements, coupled with DFT calculations, lend evidence for the formulation of the Ru(NCOR) acylnitrenoids as a RuV‐imido species.
Multidimensional Characterization of Single‐Molecule Dynamics in a Plasmonic Nanocavity
Authors: Domulevicz Lucas , Jeong Hyunhak , Paul Nayan K. , Gomez‐Diaz Juan Sebastian , Hihath Joshua
Published: April 2021

Nanoscale manipulation and characterization of individual molecules is necessary to understand the intricacies of molecular structure, which governs phenomena such as reaction mechanisms, catalysis, local effective temperatures, surface interactions, and charge transport. Here we utilize Raman enhancement between two nanostructured electrodes in combination with direct charge transport measurements to allow for simultaneous characterization of the electrical, optical, and mechanical properties of a single molecule. This multi‐dimensional information yields repeatable, self‐consistent, verification of single‐molecule resolution, and allows for detailed analysis of structural and configurational changes of the molecule in situ. These experimental results are supported by a machine‐learning based statistical analysis of the spectral information and calculations to provide insight into the correlation between structural changes in a single‐molecule and its charge‐transport properties.
Synthesis and Characterization of 16π Antiaromatic 2,7‐Dihydrodiazapyrenes: Antiaromatic Polycyclic Hydrocarbons with Embedded Nitrogen
Authors: Nakazato Takumi , Takekoshi Haruka , Sakurai Takahiro , Shinokubo Hiroshi , Miyake Yoshihiro
Published: April 2021

We describe the two‐electron reduction of N,N′‐dimethyl‐2,7‐diazapyrenium dications (MDAP2+), which afforded the corresponding reduced form (MDAP0) as a highly electron‐rich 16π antiaromatic system. A single‐crystal X‐ray diffraction analysis of MDAP0 revealed a distorted quinoidal structure with high bond‐length alternation. The 1H NMR spectrum of MDAP0 exhibited a diagnostic proton signal (4.6 ppm) that is distinctly upfield shifted compared to that of aromatic diazapyrene (8.3 ppm). Theoretical calculations supported the existence of a paratropic ring current. These results indicate that MDAP0 exhibits antiaromatic character derived from its peripheral 16π‐electron conjugation.
Diversity‐Oriented Synthesis of Aliphatic Fluorides via Reductive C(sp3)−C(sp3) Cross‐Coupling Fluoroalkylation
Authors: Sheng Jie , Ni Hui‐Qi , Ni Shan‐Xiu , He Yan , Cui Ru , Liao Guang‐Xu , Bian Kang‐Jie , Wu Bing‐Bing , Wang Xi‐Sheng
Published: April 2021

Monofluorinated alkyl compounds are of great importance in pharmaceuticals, agrochemicals and materials. Herein, we describe a direct nickel‐catalyzed monofluoromethylation of unactivated alkyl halides using a low‐cost industrial raw material, bromofluoromethane, by demonstrating a general and efficient reductive cross‐coupling of two alkyl halides. Results with 1‐bromo‐1‐fluoroalkane also demonstrate the viability of monofluoroalkylation, which further established the first example of reductive C(sp3)‐C(sp3) cross‐coupling fluoroalkylation. These transformations demonstrate high efficiency, mild conditions, and excellent functional‐group compatibility, especially for a range of pharmaceuticals and biologically active compounds. Mechanistic studies support a radical pathway. Kinetic studies reveal that the reaction is first‐order dependent on catalyst and alkyl bromide whereas the generation of monofluoroalkyl radical is not involved in the rate‐determining step. This strategy provides a general and efficient method for the synthesis of aliphatic fluorides.
Molecularly Compensated Pre‐Metallation Strategy for Metal‐Ion Batteries and Capacitors
Authors: Zou Kangyu , Song Zirui , Gao Xu , Liu Huanqing , Luo Zheng , Chen Jun , Deng Xinglan , Chen Libao , Zou Guoqiang , Hou Hongshuai , Ji Xiaobo
Published: April 2021

The use of a sacrificial cathode additive as a pre‐metallation method could ensure adequate metal sources for advanced energy storage devices. However, this pre‐metallation technique suffers from the precise regulation of decomposition potential of additive. Herein, a molecularly compensated pre‐metallation (Li/Na/K) strategy has been achieved through Kolbe electrolysis, in which the electrochemical oxidation potential of a metal carboxylate is manipulated by the bonding energy of the oxygen–metal (O–M) moiety. The electron‐donating effect of the substituent and the low charge density of the cation can dramatically weaken the O–M bond strength, further bringing out the reduced potential. Thus, sodium acetate exhibits a superior pre‐sodiation feature for sodium‐ion battery accompanied with a large irreversible specific capacity of 301.8 mAh g−1, remarkably delivering 70.6 % enhanced capacity retention in comparison to the additive‐free system after 100 cycles. This methodology has been extended to construct a high‐performance lithium‐ion battery and a lithium/sodium/potassium‐ion capacitor.
Separation‐Controlled Redox Reactions
Authors: Grzelak Adam , Lorenzana José , Grochala Wojciech
Published: April 2021

In the era of molecular devices and nanotechnology, precise control over electron‐transfer processes is strongly desired. However, redox reactions are usually characterized by reaction equilibrium constants strongly departing from unity. This leads to strong favoring of either reactants or products and does not permit subtle control of transferred charge (doping). Here we propose, based on theoretical studies for periodic systems, how charge transfer between reactants could be finely manipulated in the epitaxially grown system composed of extremely strong oxidizer, reducing agent, and an inert separator—the key factor of control.
Urea biosensors: A comprehensive review
Authors: Botewad Sunil N. , Gaikwad Dhammajyot K. , Girhe Nitin B. , Thorat Hanuman N. , Pawar Pravina P.
Published: April 2021

Present study is specially designed for the recent advances in biosensors to detect and quantify urea concentration. Urea (carbamide) is an organic compound made up of the carbonyl (C=O) functional group with two −NH2 groups having chemical formula CO (NH2)2. In nature, urea is found everywhere as the result of various processes, and in the human body, urea is an end product of nitrogen metabolism. An excessive concentration of urea in the human body is responsible for different critical diseases such as indigestion, acidity, ulcers, cancer, malfunctioning of kidneys, renal failure, urinary tract obstruction, dehydration, shock, burns, gastrointestinal bleeding, and so on. Moreover, below the normal level may cause hepatic failure, nephritic syndrome, cachexia, and so on. As well as in various fields such as fishery, dairy, food preservation, agriculture, and so on, urea is normally found and its detection is necessary. In urea biosensors, enzyme urease (Urs) is used as a bioreceptor element and retains its long last activity is the critical issue in front of the researcher. During recent decades, different nanoparticles (zinc oxide, nickel oxide, iron oxide, titanium dioxide, tin(IV) oxide, etc.), conducting polymer (polyaniline, polypyrrole, etc.), conducting polymer–nanoparticles composites, carbon materials (carbon nanotubes, graphene oxide, reduced graphene oxide graphene), and so on are used in urea biosensors. The main emphasis of the present study is to provide cumulative and comprehensive information about the sensing parameters of urea biosensors based on the materials used for enzyme immobilization. Besides this special task, this review provides a fruitful discussion on the basics of biosensors briefly for new and upcoming researchers. Thus, the present study may act as a gift for a large audience that come from different fields and are working in biosensors research.
Generation of a tissue‐specific transgenic model for K8 phosphomutants: A tool to investigate the role of K8 phosphorylation during skin carcinogenesis in vivo
Authors: Tiwari Richa , Ganguli Nirmalya , Alam Hunain , Sahu Indrajit , Vadivel Chella Krishna , Sinha Shruti , Patel Shweta , Jamghare Sayli Nitin , Bane Sanjay , Thorat Rahul , Majumdar Subeer S. , Vaidya Milind M.
Published: April 2021

Keratin 8/18, the predominant keratin pair of simple epithelia, is known to be aberrantly expressed in several squamous cell carcinomas (SCCs), where its expression is often correlated with increased invasion, neoplastic progression, and poor prognosis. The majority of keratin 8/18 structural and regulatory functions are governed by posttranslational modifications, particularly phosphorylation. Apart from filament reorganization, cellular processes including cell cycle, cell growth, cellular stress, and apoptosis are known to be orchestrated by K8 phosphorylation at specific residues in the head and tail domains. Even though deregulation of K8 phosphorylation at two significant sites (Serine73/Serine431) has been implicated in neoplastic progression of SCCs by various in vitro studies, including ours, it is reported to be highly context‐dependent. Therefore, to delineate the precise role of Kereatin 8 phosphorylation in cancer initiation and progression, we have developed the tissue‐specific transgenic mouse model expressing Keratin 8 wild type and phosphodead mutants under Keratin 14 promoter. Subjecting these mice to 7,12‐dimethylbenz(a)anthracene/12‐O‐tetradecanoylphorbol‐13‐acetate‐mediated skin carcinogenesis revealed that Keratin 8 phosphorylation may lead to an early onset of tumors compared to Keratin 8 wild‐type expressing mice. Conclusively, the transgenic mouse model developed in the present study ascertained a positive impact of Keratin 8 phosphorylation on the neoplastic transformation of skin‐squamous cells.
Partial least squares and silver nanoparticles in spectrophotometric prediction of total hardness of water
Authors: Shariati‐Rad Masoud , Heidari Saeideh
Published: April 2021

Among parameters relating to quality of water, total hardness has been investigated owed to its environmental, domestic, and industrial impact. In the present work, silver nanoparticles were greenly synthesized and used to determine total hardness of water. The results showed that in the presence of different water samples, UV–Vis absorption spectrum of AgNPs varies in intensity and location. It was observed that these changes can be related to total hardness of water samples. For this purpose, multivariate calibration method of partial least squares (PLS) was employed. A linear multivariate PLS model for total hardness in the range of 56–400 mg L−1 was constructed with root‐mean‐square error of cross validation (RMSECV) of 96.7 with three latent variables. The model was successfully used to predict total hardness of 16 bottled or natural water samples.
Nickel/Cobalt Molybdate Hollow Rods Induced by Structure and Defect Engineering as Exceptional Electrode Materials for Hybrid Supercapacitor
Authors: Chu Dawei , Zhao Xun , Xiao Boxin , Libanori Alberto , Zhou Yihao , Tan Lichao , Ma Huiyuan , Pang Haijun , Wang Xinming , Jiang Yanxia , Chen Jun
Published: April 2021

Oxygen defects and hollow structures positively impact pseudocapacitive properties of diffusion/surface‐controlled processes, a component of critical importance when building high‐performance supercapacitors. Hence, we fabricated hollow nickel/cobalt molybdate rods with O‐defects (D−H−NiMoO4@CoMoO4) through a soft‐template and partial reduction method, enhancing D−H−NiMoO4@CoMoO4’s electrochemical performance, yielding a specific capacitance of 1329 F g−1, and demonstrating excellent durability with 95.8 % capacity retention after 3000 cycles. D−H−NiMoO4@CoMoO4 was used as the positive electrode to construct an asymmetric supercapacitor, displaying an energy density of up to 34.13 Wh kg−1 and demonstrating good predisposition towards practical applications. This work presents an effective approach to fabricate and use hollow nickel/cobalt molybdate rods with O‐defects as pseudocapacitor material for high‐performance capacitive energy storage devices.
Molecular Disorder Induces an Unusual Phase Transition in a Potential 2D Chiral Ferroelectric Perovskite
Authors: Sui Li Lin , Juan Wei Wen , Qiang Gao Hong , Hui Tan Yu , Bo Han Xiao
Published: April 2021

Two‐dimensional hybrid halide perovskites with single chiral and ferroelectricity together with various structural phase transitions provide the possibility for more diverse functional properties. Here, we present a 2D chiral hybrid halide perovskite ferroelectric, [C6H5(CH2)4NH3]2CdCl4 (4PBA−CdCl4, 4PBA=4‐phenylbutylamine) that experiences two continuous phase transitions from centrosymmetric triclinic P
to polar chiral monoclinic P2 and then to another centrosymmetric tetragonal P4/mmm with increasing temperature, accompanied by symmetry breaking, due to the prominent octahedral distortion and disorder transformation of organic 4PBA cations. In the polar chiral phase, 4PBA−CdCl4 gives a significant CD signal and has a moderate ferroelectric polarization of 0.35 μC/cm2. In addition, 4PBA−CdCl4 occupies a wide band gap of 4.376 eV that is chiefly contributed by the inorganic CdCl6 octahedron. This finding offers an alternative pathway for designing new phase transitions and related physical properties in hybrid halide perovskites and other hybrid crystals.
Structure‐Activity‐Relationship‐Aided Design and Synthesis of xCT Antiporter Inhibitors
Authors: Cirillo Davide , Sarowar Shahin , Enger Per Øyvind , Bjørsvik Hans‐René
Published: April 2021

The xCT antiporter is a cell membrane protein involved in active counter‐transportation of glutamate (outflux) with cystine (influx) over the human cell membrane. This feature makes the xCT antiporter a crucial element of the biosynthesis of the vital free radical scavenger glutathione. The prodrug sulfasalazine, a medication for the treatment of ulcerative colitis, was previously proven to inhibit the xCT antiporter. Starting from sulfasalazine, a molecular scaffold jumping followed by SAR‐assisted design and synthesis provided a series of styryl hydroxy‐benzoic acid analogues that were biologically tested in vitro for their ability to decrease intracellular glutathione levels using four different cancer cell lines: A172 (glioma), A375 (melanoma), U87 (glioma) and MCF7 (breast carcinoma). Depletion of glutathione levels varied among the compounds as well as among the cell lines. Flow cytometry using propidium iodide and the annexin V marker demonstrated minimal toxicity in normal human astrocytes for a promising candidate molecule (E)‐5‐(2‐([1,1′‐biphenyl]‐4‐yl)vinyl)‐2‐hydroxybenzoic acid.
Substituent Effects in Organic Luminogens with Room Temperature Phosphorescence
Authors: Liao Qiuyan , Li Qianqian , Li Zhen
Published: April 2021

Organic room temperature phosphorescence (RTP) materials have attracted much attention for their potential applications in various areas. Many diverse molecular design strategies have been proposed to achieve efficient intersystem crossing (ISC) and stable triplet excited states of organic materials. Among them, the introduction of substituents with different types, linkage positions and amounts, can play a key role in moderating the RTP effect resulting from their tunable electronic properties and steric hindrance. Minor differences between substituents can change the molecular packing in aggregated states significantly, facilitating improved RTP performance with rational design. This Concept reviews the relationship between substituent effects, aggregated structure and RTP properties by the systematic investigation of organic luminogens bearing different substituents. The aim of this Concept is to aid researchers so as to accelerate the development of RTP materials by providing insight into the internal mechanism and reviewing efficient strategies through the introduction of suitable substituents.
Potential antiviral activity of isorhamnetin against SARS‐CoV‐2 spike pseudotyped virus in vitro
Authors: Zhan Yingzhuan , Ta Wenjing , Tang Wenjuan , Hua Ruochen , Wang Jue , Wang Cheng , Lu Wen
Published: April 2021

Coronavirus Disease 2019 (COVID‐19) cases and deaths are still rising worldwide, there is currently no effective treatment for severe inflammation and acute lung injury caused by new coronavirus (SARS‐COV‐2) infection. Therapies to prevent or treat COVID‐19, including antiviral drug and several vaccines, are still being development. Human angiotensin‐converting enzyme 2 (ACE2), expressing in lung, has been confirmed to be a receptor for SARS‐COV‐2 infection, interventions for attachment of spike protein of SARS‐CoV‐2 to ACE2 may be a potential approach to prevent viral infections and it is considered as a potential target for drug development. In this study, we observed that seabuckthorn and its flavonoid compounds quercetin and isorhamnetin were shown strong retention to ACE2 overexpression HEK293 (ACE2h) cells by CMC analysis. Based on drug receptor interaction analysis and viral entry studies in vitro, we evaluated the interaction of two flavonoid compounds and ACE2 as well as the inhibitory effect of the two compounds on viral entry. Surface plasmon resonance assay proved the effect that isorhamnetin bound to the ACE2, and its affinity (KD value) was at the micromolar level, that was, 2.51 ± 0.68 μM. Viral entry studies in vitro indicated that isorhamnetin inhibited SARS‐CoV‐2 spike pseudotyped virus entering ACE2h cells. Based on promising in vitro results, we proposed isorhamnetin to be a potential therapeutic candidate compound against COVID‐19.
Electrochemical Enhanced Detection of Uric Acid Based on Peroxidase‐like Activity of Fe3O4@Au
Authors: Guan Huanan , Peng Bo , Gong Dezhuang , Han Bolin , Zhang Na
Published: April 2021

Fe3O4@Au nanomaterials were prepared by the self‐assembly method. An enzyme‐free, ultrasensitive electrochemical detection of uric acid was achieved based on the peroxidase‐like activity of Fe3O4@Au. The proposed procedure has exhibited excellent catalytic activities and achieved significant enhancements of the current responses to uric acid. The detection range was from 0.1 to 10 mmol/L, and the limit of detection was 0.087 μmol/L. Under the action of external magnetic field, the magnetic particles can be easily separated from the bottom liquid, which has the advantages of simple operation and high separation efficiency. Moreover, this detection method combining a simulated enzyme and electrochemical can enhance the effective output of the overall electrochemical signal without modifying the electrode, and excellent reproducibility can be achieved. Compared to colorimetric assay, the electrochemical one has higher sensitivity and selectivity, and was further applied in ultrasensitive detection of uric acid in food samples. In short, the proposed electrochemical assay has great potential in the fields of food quality control and biomedical analysis.
Multiplexed Determination of Fertility‐related Hormones in Saliva Using Amperometric Immunosensing
Authors: Arévalo Beatriz , Serafín Verónica , Campuzano Susana , Yáñez‐Sedeño Paloma , Pingarrón José M.
Published: April 2021

This paper reports a dual immunosensor for the simultaneous determination of two important fertility‐related hormones: 17β‐estradiol, E2, and follicle‐stimulating hormone, FSH. The implemented method involves direct competitive (E2) or sandwich‐type (FSH) immunoassays carried out on magnetic microparticles (MBs) and amperometric detection at screen‐printed dual carbon electrodes (SPdCEs) involving the hydroquinone (HQ)/H2O2 system. The developed immune platform demonstrates LOD values of 6.88 pg mL−1 and 0.11 mIU mL−1 for E2 and FSH standards, respectively and usefulness for the determination in saliva samples collected from different volunteers, giving results in agreement with the conventional ELISA methodologies.
Provable secure dynamic lightweight group communication in VANETs
Authors: Naresh Vankamamidi Srinivasa , Reddi Sivaranjani , Allavarpu VVL Divakar
Published: April 2021

The advent of group‐oriented communication applications in Vehicular Ad Hoc Networks (VANETs) has trigger research on lightweight privacy‐preserving Secure Group Communication (SGC) in VANETs. In view of this, many researchers proposed privacy‐preserving, authentication, and key agreements schemes. However, these schemes need to address the dynamic nature, heavier processing loads, massive storage, and higher communication. In this direction, we proposed a framework for lightweight dynamic SGC with privacy‐preserving and authentication in VANETs, encompassing (i) A lightweight Elliptic Curve Cryptography (ECC)‐based two‐party key agreement and its extension to a Dynamic Group Key Agreement, in which fixed Road Side Unit (RSU) acts as Group Controller (GC) with superior computational ability than the On‐Board Unit equipped on the vehicles. (ii) An identify‐based authentication and privacy‐preserving schemes using only two lightweight operations XOR and hashing. (iii) A lightweight encryption and decryption with Exclusive Or (XOR) and hashing only. And (iv) a formal security model for SGC in VANETs. The security analysis shows that the proposed system provides confidentiality of session key, anonymity, secure session key enhancement, and immune to password guessing attack, replay attack, insider attack based on an assumption of the computational G‐ECDDH problem. The experimentation is done for authentication, group key agreement, encryption, and decryption times by a varying number of vehicles in the group to 10, 20, 40, 60, 80, and 100 and shown that the proposed technique is taking considerably less computation than other techniques. So the proposed technique is highly desirable in VANETs.
Magnitude of radial forearm free flaps and factors associated with loss of volume in oral cancer reconstructive surgery: Prospective study
Authors: Wang Si‐Min , Yin Shou‐Cheng , Su Xing‐Zhou , Xu Qiang , Liu Yi‐Hao , Xu Zhong‐Fei
Published: April 2021

Background

Adequate flap volume is key to maintaining oral function after oral cancer surgery. This study aimed to evaluate changes in radial forearm free flap (RFFF) volumes after 1 year of follow‐up following ablative tumor surgery in the head and neck.

Methods

A prospective study that recorded the clinical data of 20 patients with head and neck cancer who underwent RFFF reconstruction. Magnetic resonance (MR) and Mimics Research 19.0 software were used to measure the RFFF volumes at 1, 3, 6, and 12 postoperative months.

Results

Compared with one postoperative month, the RFFF volume decreased by 15.5%, 29.4%, and 42.0% at 3, 6, and 12 months, respectively, after surgery. A significant positive correlation between postoperative radiotherapy and RFFF volume changes was detected.

Conclusion

The volume of RFFF decreases with time. It is recommended to use overcorrection, with a 40% increase in RFFF volume, to reconstruct head and neck tumor‐related defects.
Culture and performance appraisal in multinational enterprises: Implementing French headquarters' practices inMiddle East and North Africasubsidiaries
Authors: Yahiaoui Dorra , Nakhle Samer F. , Farndale Elaine
Published: April 2021

Performance appraisal requires interactions between managers and employees and as such can be highly sensitive to differences in cultural values. This can be challenging when multinational enterprises (MNEs) are active across different institutional contexts, particularly when operating in the culturally complex Middle East and North Africa (MENA) region. In this qualitative study, we apply institutional theory to explore how performance appraisal practices are implemented and internalized in MNE subsidiaries in the MENA region through manager–employee interactions. A total of 117 interviews were conducted with different headquarter and subsidiary stakeholders (managers and employees) of four French MNEs operating in Lebanon and Tunisia. The findings indicate that, during implementation, performance appraisal criteria, evaluation, and feedback were adapted based on socio‐cultural values to achieve internalization. Such values include the emotional relationship between managers and employees, the fear of losing face, high power distance, the desire to avoid confrontation, and high‐context communication. Insights for future research are presented regarding the viability of MNEs operating in the MENA region implementing corporate performance appraisal practices.
An overview of the state of the regulatory and preclinical requirements for nanomaterials including medical devices
Authors: Rehman Naheed , Moore Simon
Published: April 2021

Nanomaterials when exposed to biological systems may produce oxidative stress, genotoxicity, and carcinogenicity, as nanoparticle toxicity is speculated to be different from larger particles of the same chemical composition due to the change of their physical properties from their smaller size and resultant higher surface area. Regulatory frameworks have become established to address the influx of nanomaterials to assess the potential benefit to human health but also where there is a risk to both human health and the environment. This article focuses on these regulatory frameworks, including the risk from inhalation, where these changes have already been implemented and reflected in the revised Organisation for Economic Co-operation and Development OECD 412 and OECD 413 guidelines as additional investigations and endpoints have been added to determine the risk posed by this novel group of materials. Integr Environ Assess Manag 2021;17:1098–1104. © 2021 SETAC

KEY POINTS

Nanomaterials are used in a broad range of applications, including their use in medicine as nanomedicines. Nanoparticle toxicity is speculated to be different from larger particles of the same chemical composition due to the change of their physical properties from their smaller size and resultant higher surface area. This article describes the evolution of global regulatory frameworks to assess the risk of nanomaterials to human health, focusing on the risk from inhalation, which has led to changes to OECD guideline studies to determine the risk of nanomaterials.
A blocking peptide stabilizes lysophosphatidic acid receptor 1 and promotes lysophosphatidic acid‐induced cellular responses
Authors: Taleb Sarah J , Wei Jianxin , Mialki Rachel K , Dong Su , Li Yanhui , Zhao Jing , Zhao Yutong
Published: April 2021

G protein‐coupled receptors regulate a variety of cellular responses and have been considered as therapeutic targets for human diseases. Lysophosphatidic acid receptor 1 (LPA1) is a receptor for bioactive lysophospholipid, LPA. LPA/LPA1‐mediated signaling contributes to inflammatory and fibrotic responses in lung diseases; thus understanding regulation of LPA1 stability is important for modulating LPA/LPA1 signaling. Our previous study has shown that LPA1 is degraded in the Nedd4 like (Nedd4L) E3 ubiquitin ligase‐mediated ubiquitin‐proteasome system. In the current study, we attempt to identify a peptide that stabilizes LPA1 through disrupting LPA1 association with Nedd4L. LPA treatment induces both endogenous and overexpressed LPA1 degradation, which is attenuated by a proteasome inhibitor, suggesting that LPA1 is degraded in the proteasome. LPA increases phosphorylation of extracellular signal‐regulated kinase 1/2 (Erk1/2) and I‐κB kinase in lung epithelial cells, and this effect is promoted by overexpression of a peptide (P1) that mimics C‐terminal of LPA1. P1, not a control peptide, attenuates LPA‐induced LPA1 ubiquitination and degradation, suggesting that P1 stabilizes LPA1. Further, P1 diminishes Nedd4L‐mediated degradation of LPA1 and Nedd4L/LPA1 association. In addition to increasing LPA1 signaling, P1 enhances LPA‐induced cell migration and gene expression of Elafin, matrix metallopeptidase 1, and serpin family B member 2 in lung epithelial cells. These data suggest that disruption of LPA1 interaction with Nedd4L by P1 increases LPA1 stability and LPA/LPA1 signaling.
Explicit Baranyai partitions for quadruples, Part I: Quadrupling constructions
Authors: Chee Yeow Meng , Etzion Tuvi , Kiah Han Mao , Vardy Alexander , Wang Chengmin
Published: April 2021

It is well known that, whenever divides , the complete ‐uniform hypergraph on vertices can be partitioned into disjoint perfect matchings. Equivalently, the set of ‐subsets of n‐set can be partitioned into parallel classes so that each parallel class is a partition of the ‐set. This result is known as Baranyai's theorem, which guarantees the existence of Baranyai partitions. Unfortunately, the proof of Baranyai's theorem uses network flow arguments, making this result nonexplicit. In particular, there is no known method to produce Baranyai partitions in time and space that scale linearly with the number of hyperedges in the hypergraph. It is desirable for certain applications to have an explicit construction that generates Baranyai partitions in linear time. Such an efficient construction is known for and 3. In this paper, we present an explicit recursive quadrupling construction for and , where . In a follow‐up paper (Part II), the other values of , namely, , will be considered.