bluuebunny/crossref_metadata_2025 huggingface dataset:
Intermolecular Carbosilylation of α‐Olefins with C(sp3)−C(sp) Bond Formation Involving Silylium‐Ion Regeneration
Authors: He Tao , Qu Zheng‐Wang , Klare Hendrik F. T. , Grimme Stefan , Oestreich Martin
Published: March 2022

A regioselective addition of alkynylsilanes across unactivated, terminal alkenes is reported. The reaction is initiated by the capture of a sterically unhindered silylium ion by a silylated phenylacetylene derivative to form a bis(silylated) ketene‐like carbocation. This in situ‐generated key intermediate is the actual catalyst that maintains the catalytic cycle by a series of electrophilic addition reactions of silylium ions and β‐silicon‐stabilized carbocations. The computed reaction mechanism is fully consistent with the experimental findings. This unprecedented two‐component carbosilylation establishes a C(sp3)−C(sp) bond and a C(sp3)−Si bond in atom‐economic fashion.
Nanofibrous electroconductive nerve guide conduits based on polyaniline‐co‐polydopamine random copolymer for peripheral nerve regeneration
Authors: Moosaipour Majid , Pakinia Simin , Izadi Zhila , Khalilzadeh Balal , Jaymand Mehdi , Samadian Hadi
Published: March 2022

The main aim of the current study was to fabricate bio‐ and electro‐active electrospun nanofibrous neural conduits for peripheral nerve regeneration. At first, polyaniline‐co‐polydopamine (PANI‐co‐PDA) random copolymer was synthesized using a chemical oxidation polymerization method. The synthesized copolymer was blended with poly(vinyl alcohol) (PVA) and used for the electrospinning to afford nanofibrous neural conduits. The characterization showed that the fabricated nanofibers have a diameter in the range of 500–600 nm, and the incorporation of PANI‐co‐PDA slightly reduced the hydrophilicity, water absorption capacity, while the electrical conductivity and mechanical properties were increased. The in vitro studies revealed the biodegradability (evaluated using weight loss and morphology study), hemocompatibility (assessed using hemolysis measurement), and biocompatibility (investigated using MTT assay kit) of the fabricated nanofibers. Moreover, the assembled homemade conduit fabricating electrospinning setup resulted in a conduit with proper dimensions, 2 mm in diameter and 2 cm in length. It was found that the fabricated nanofibrous conduits confer proper biological, mechanical, and electrical properties and can be applied as the peripheral nerve regenerating construct.
Harmonic control of a dual‐valve hydraulic servo system with dynamically allocated flows
Authors: Su Shijie , Xue Ting , Chen Yun , Yang Hui
Published: March 2022

Modern industries face increasing demands to improve the precision and workability of equipment, leading to stringent requirements for hydraulic servo systems in terms of flow, accuracy, and output power. High‐flow servo valves and multi‐valve synchronous control methods have seen more applications in the industry to meet these demands. However, high‐flow servo valves are expensive and have unsatisfactory performance, and synchronous control methods require servo valves to have the same hydraulic characteristics, resulting in higher cost and lower accuracy of high‐flow hydraulic servo systems. Also, very little has been conducted on controlling single actuators using multiple valves. In this study, we design a novel dual‐valve hydraulic servo system structure with a high‐flow proportional directional valve that is connected in parallel with a low‐flow servo valve and further develop the mathematical model of this dual‐valve system. Next, a harmonic control scheme was proposed, which included a flow allocation layer and trajectory tracking layer. Thereby, we achieved optimal control of two valves, and robust performance was guaranteed. Finally, we investigate the relationships between the flows of two valves, the deadband of the proportional directional valve, and trajectory tracking errors. Experimental results show that the proposed control scheme can effectively adjust the output flow of each valve dynamically according to the tracking trajectory and the hydraulic characteristics of the two valves, and the tracking performance of the servo system is significantly improved. This method is promised to enable the realization of an economical, high‐flow, high‐precision hydraulic servo system that can be generally used in various fields, such as marine engineering and construction.
Hybridization of nickel oxide nanoparticles with carbon dots and its application for antibacterial activities
Authors: Nemera Dugasa Jabesa , Etefa Habtamu Fekadu , Kumar Vinod , Dejene Francis Birhanu
Published: March 2022

A nickel oxide nanoparticle (NiO NP) composite with carbon dots (C‐dots), (NiO NPs@C‐dots) was synthesized, characterized, and then its antibacterial activity was evaluated. NiO NPs were prepared using Buddleja polystachya Fresen leaf extract and Ni(NO3)2.6H2O as precursors. The C‐dots were synthesized from benzene‐1,4‐diamine and citric acid. The cubic structure of the NiO NPs and NiO NPs@C‐dots was in phase with their average particle size distributions of 21.47 ± 0.56 and 21.61 ± 0.34 nm, respectively. The surface morphology of the NiO NPs@C‐dots was characterized using field emission scanning electron microscopy and also revealed a large surface area, which is advantageous for the specified application. The X‐ray diffraction result indicated a cubic face wurtzite structure and the crystalline nature of the NiO NPs. Carbon‐doped compounds had no influence on the crystal structure of the NiO compound and no new peaks were observed. The antibacterial activity of a composite made up of NiO NPs@C‐dots was tested, as well as the antibacterial activities of compounds produced against human photogenic bacterial strains. Both NiO NPs and NiO NPs@C‐dots were found to be powerful against all bacterial strains, based on the bioassay results. NiO NPs and NiO@C‐dots appeared to display strong to inhibitory effects of 14–20 mm and 17–23 mm, respectively.
Difficulty in predicting intra‐abdominal adhesion before cesarean section: A case report
Authors: Suzuki Nanao , Wakaki Yu , Watanabe Kaori , Kumasaka Yukiko , Suzuki Rika
Published: March 2022

Severe adhesions between the bladder and uterus necessitated an atypical incision in the cesarean section of a woman with endometriosis. This could not be predicted with pre‐surgery MRI. No methods in the literature are able to predict adhesions with true certainty; it is therefore still difficult to diagnose intra‐abdominal adhesions.
PRISMA2020: An R package and Shiny app for producing PRISMA 2020‐compliant flow diagrams, with interactivity for optimised digital transparency and Open Synthesis
Authors: Haddaway Neal R. , Page Matthew J. , Pritchard Chris C. , McGuinness Luke A.
Published: March 2022

Background

Reporting standards, such as PRISMA aim to ensure that the methods and results of systematic reviews are described in sufficient detail to allow full transparency. Flow diagrams in evidence syntheses allow the reader to rapidly understand the core procedures used in a review and examine the attrition of irrelevant records throughout the review process. Recent research suggests that use of flow diagrams in systematic reviews is poor and of low quality and called for standardised templates to facilitate better reporting in flow diagrams. The increasing options for interactivity provided by the Internet gives us an opportunity to support easy‐to‐use evidence synthesis tools, and here we report on the development of a tool for the production of PRISMA 2020‐compliant systematic review flow diagrams.

Methods and Findings

We developed a free‐to‐use, Open Source R package and web‐based Shiny app to allow users to design PRISMA flow diagrams for their own systematic reviews. Our tool allows users to produce standardised visualisations that transparently document the methods and results of a systematic review process in a variety of formats. In addition, we provide the opportunity to produce interactive, web‐based flow diagrams (exported as HTML files), that allow readers to click on boxes of the diagram and navigate to further details on methods, results or data files. We provide an interactive example here; https://prisma-flowdiagram.github.io/.

Conclusions

We have developed a user‐friendly tool for producing PRISMA 2020‐compliant flow diagrams for users with coding experience and, importantly, for users without prior experience in coding by making use of Shiny (https://estech.shinyapps.io/prisma_flowdiagram/). This free‐to‐use tool will make it easier to produce clear and PRISMA 2020‐compliant systematic review flow diagrams. Significantly, users can also produce interactive flow diagrams for the first time, allowing readers of their reviews to smoothly and swiftly explore and navigate to further details of the methods and results of a review. We believe this tool will increase use of PRISMA flow diagrams, improve the compliance and quality of flow diagrams, and facilitate strong science communication of the methods and results of systematic reviews by making use of interactivity. We encourage the systematic review community to make use of the tool, and provide feedback to streamline and improve their usability and efficiency.
High‐Efficiency and Stable Zn−Na3V2(PO4)3 Aqueous Battery Enabled by Electrolyte‐Induced Interphasial Engineering
Authors: Guo Gaoli , Tan Xiaoping , Wang Kaidi , Zhang Huang
Published: March 2022

Aqueous zinc batteries have been regarded as a promising energy storage technology due to their high energy, high material abundance, low toxicity, and intrinsic safety. NASICON‐type materials have been proposed as efficient cathodes for rechargeable batteries, yet they suffer from fast degradation and low Coulombic efficiency in aqueous batteries. Here we demonstrate that a rationally designed aqueous electrolyte containing a supporting Na salt and polymer additive can efficiently suppress the water activity through hydrogen bonding and facilitate the anion involvement in interfacial reactions, thus enabling the stable operation of sodium superionic conductor (NASICON) cathodes in aqueous zinc batteries. As exemplified by a Na3V2(PO4)3 cathode, the cell with zinc metal anode exhibits high cycling Coulombic efficiencies (around 99.9 % in average) with a steady output voltage and capacity retention for 300 cycles. This work addresses the potential issues with NASICON‐type cathodes in aqueous zinc batteries and proposes an effective solution via fundamental interphasial chemistry to design efficient and sustainable aqueous electrolytes.
Ubiquitylation of cyclin C by HACE1 regulates cisplatin‐associated sensitivity in gastric cancer
Authors: Jiang Hong‐yue , Chen Ying‐ling , Xu Xing‐xing , Li Chuan‐yin , Chen Yun , Li Dong‐ping , Zeng Xiao‐qing , Gao Hong
Published: March 2022

Background

Cyclin C (CCNC) was reported to take part in regulating mitochondria‐derived oxidative stress under cisplatin stimulation. However, its effect in gastric cancer is unknown. This study aimed to investigate the role of cyclin C and its ubiquitylation in regulating cisplatin resistance in gastric cancer.

Methods

The interaction between HECT domain and ankyrin repeat‐containing E3 ubiquitin‐protein ligase 1 (HACE1) and cyclin C was investigated by GST pull‐down assay, co‐immunoprecipitation and ubiquitylation assay. Mitochondria‐derived oxidative stress was studied by MitoSOX Red assay, seahorse assay and mitochondrial membrane potential measurement. Cyclin C‐associated cisplatin resistance was studied in vivo via xenograft.

Results

HACE1 catalysed the ubiquitylation of cyclin C by adding Lys11‐linked ubiquitin chains when cyclin C translocates to cytoplasm induced by cisplatin treatment. The ubiquitin‐modified cyclin C then anchor at mitochondira, which induced mitochondrial fission and ROS synthesis. Depleting CCNC or mutation on the ubiquitylation sites decreased mitochondrial ROS production and reduced cell apoptosis under cisplatin treatment. Xenograft study showed that disrupting cyclin C ubiquitylation by HACE1 conferred impairing cell apoptosis response upon cisplatin administration.

Conclusions

Cyclin C is a newly identified substrate of HACE1 E3 ligase. HACE1‐mediated ubiquitylation of cyclin C sheds light on a better understanding of cisplatin‐associated resistance in gastric cancer patients. Ubiquitylation of cyclin C by HACE1 regulates cisplatin‐associated sensitivity in gastric cancer. With cisplatin‐induced nuclear–mitochondrial translocation of cyclin C, its ubiquitylation by HACE1 increased mitochondrial fission and mitochondrial‐derived oxidative stress, leading to cell apoptosis.
Men and women show partly distinct effects of physical activity on brain integrity
Authors: Gonneaud Julie , Moreau Ilana , Felisatti Francesca , Arenaza‐Urquijo Eider , Ourry Valentin , Touron Edelweiss , de la Sayette Vincent , Vivien Denis , Chételat Gaël
Published: March 2022

Introduction

Physical inactivity and female sex are independently associated with increased Alzheimer's disease (AD) lifetime risk. This study investigates the possible interactions between sex and physical activity on neuroimaging biomarkers.

Methods

In 134 cognitively unimpaired older adults (≥65 years, 82 women) from the Age‐Well randomized controlled trial (baseline data), we investigated the association between physical activity and multimodal neuroimaging (gray matter volume, glucose metabolism, perfusion, and amyloid burden), and how sex modulates these associations.

Results

The anterior cingulate cortex volume was independently associated with sex and physical activity. Sex and physical activity interacted on perfusion and amyloid deposition in medial parietal regions, such that physical activity was related to perfusion only in women, and to amyloid burden only in men.

Discussion

Physical activity has both sex‐dependent and sex‐independent associations with brain integrity. Our findings highlight partly distinct reserve mechanisms in men and women, which might in turn influence their risk of AD.

Highlights

Sex and physical activity have been linked to Alzheimer's disease (AD) progression.

The association of sex and physical activity with brain health is partly independent.

Different reserve mechanisms exist in men and women.
Effects of the physical and social environment on youth cognitive performance
Authors: Meredith Wesley J. , Cardenas‐Iniguez Carlos , Berman Marc G. , Rosenberg Monica D.
Published: March 2022

Individual differences in children's cognitive abilities impact life and health outcomes. What factors influence these individual differences during development? Here, we test whether children's environments predict cognitive performance, independent of well‐characterized socioeconomic effects. We analyzed data from 9002 9‐ to 10‐year olds from the Adolescent Brain Cognitive Development Study, an ongoing longitudinal study with community samples across the United States. Using youth‐ and caregiver‐report questionnaires and national database registries (e.g., neighborhood crime, walkability), we defined principal components summarizing children's home, school, neighborhood, and cultural environments. In two independent samples (ns = 3475, 5527), environmental components explained unique variance in children's general cognitive ability, executive functioning, and learning/memory abilities. Furthermore, increased neighborhood enrichment was associated with an attenuated relationship between sociodemographics and general cognitive abilities. Thus, the environment accounts for unique variance in cognitive performance in children and should be considered alongside sociodemographic factors to better understand brain functioning and behavior across development.
Evaluation of RapidSTAT®, DrugWipe® 6S, DrugScreen® 5TK and DrugScreen® 7TR for on‐site drug testing in German police roadside traffic patrol
Authors: Liut Jennifer , Bott Ulrich , Madea Burkhard , Krämer Michael , Maas Alexandra
Published: March 2022

Driving under the influence of drugs (DUID) remains a subject of concern worldwide, and its increasing trend is likely to continue. Therefore, there is a constant need for reliable on‐site drug tests to identify drugged drivers during roadside patrols. Performance and reliability of four on‐site drug tests were evaluated among a high number of DUID cases in Germany. Results of oral fluid (OF) (RapidSTAT® and DrugWipe® 6S) and urine (DrugScreen® 5TK and 7TR) test devices were compared with corresponding serum/plasma results obtained by confirmation analyses in consideration of recommended analytical limits for substances pertaining the annex of the German Road Traffic Code (‘Straßenverkehrsgesetz’, StVG) s. 24a (2). Overall, the screening devices performed well for individual drugs; however, none of the test devices assessed in this study fulfilled the ROSITA‐1 criteria (sensitivity, specificity ≥ 90% and accuracy ≥ 95%) for all substances. Our data demonstrated that both urine tests showed high sensitivities for most compounds. DrugWipe® 6S (94%) and RapidSTAT® (93%) revealed high sensitivities, especially for amphetamine screening. Poor specificities (<90%) and accuracies (<95%) were observed for all tests except for low‐prevalent substances (e.g., opiates). For drug testing in OF, Δ9‐tetrahydrocannabinol (THC) still seems to be a compound of concern due to poor sensitivity (RapidSTAT®, 77%; DrugWipe® 6S, 85%), although the results indicate improvements compared with previously reported data. Although the obtained data indicate reliable detection for some substances, deployment of trained police officers is inevitable to identify DUID suspects by signs of recent use and recognising impairment.
Assessing the quality of offshoreBinomialsampling biosecurity inspections using onshore inspections
Authors: Trouvé Raphaël , Arthur Anthony D. , Robinson Andrew P.
Published: March 2022

Introduction of pests and diseases through trade is one of the main socio‐ecological challenges worldwide. Although Binomial sampling inspection at the border can reduce pest entry risk, it is common for consignments to fail inspection, wasting resources for both exporter and importer. Outsourcing the inspection to the exporting country could reduce the cost of inspection for both parties. However, there is then a need to assess the quality of the offshore inspection. In this paper, we develop an inverse method combining past inspection data on the pathway, an onshore inspection sample, and the Beta‐Binomial model to infer the sample size of the offshore inspection. We illustrate the method on two case studies: the importation of live plants through germplasm into Australia and the importation of pelleted seeds in New Zealand. In these case studies, we found that detecting four to five infested units in a single onshore inspection was typically sufficient to significantly doubt the presence of a compliant offshore inspection. We also ran a simulation experiment to quantify the statistical power to reject or accept the presence of compliant offshore inspection in practice: In highly infested pathways, we could detect the absence of offshore inspections after inspecting five consignments onshore. Less infested pathways required inspecting 20 to 60 consignments onshore. Our study demonstrates that Binomial sampling onshore can be used to assess the quality of offshore inspections.
Body mass and sex, but not breeding condition and season, influence open‐field exploration in the yellow‐necked mouse
Authors: Bednarz Paula A. , Zwolak Rafał
Published: March 2022

Theory predicts that risk taking should be influenced by external (e.g., season) and internal (e.g., breeding condition, sex, and body mass) conditions. We investigated whether these factors are associated with a potentially risky behavior: exploration of a novel environment. We conducted repeated open‐field tests of exploration in a common forest rodent, the yellow‐necked mouse Apodemus flavicollis. Contrary to expectations, the exploration did not vary with the season (spring vs. fall) or the reproductive status of the tested animals. Also unexpectedly, there was an inverted U‐shaped relationship between body mass and exploration: animals with intermediate body mass tended to have the highest exploration tendencies. Males were more exploratory than females. Finally, even after adjusting for the effects of body mass and sex, individuals exhibited consistent, repeatable differences in exploration tendencies (“behavioral types” or “personalities”). The discrepancies between certain broad generalizations and our results suggest that risk taking depends on details of species‐specific biology.
High ward occupancy, bedspacing, and 60 day mortality for patients with myocardial infarction, stroke, and heart failure
Authors: Asheim Andreas , Nilsen Sara Marie , Aam Stina , Anthun Kjartan Sarheim , Carlsen Fredrik , Janszky Imre , Vatten Lars Johan , Bjørngaard Johan Håkon
Published: March 2022

Aims

To study the consequences of crowded wards among patients with cardiovascular disease.

Methods and results

This is a cohort study among 201 801 patients with 258 807 admissions who were acutely admitted for myocardial infarction (N = 107 895), stroke (N = 87 336), or heart failure (N = 63 576) to any Norwegian hospital between 2008 and 2016. The ward admitting most patients with the given clinical condition was considered a patient's home ward. We compared patients with the same condition admitted when home ward occupancy was different, at the same hospital and during comparable time periods. Occupancy was standardized such that a one‐unit difference corresponded to the interquartile range in occupancy in the given month. One interquartile increase in home ward occupancy was associated with 7% higher odds of admission to an alternate ward [odds ratio (OR) 1.07, 95% confidence interval (CI) 1.09 to 1.11], and length of stay was shorter (−0.10 days, 95% CI −0.18 to −0.09). Patients with heart failure had 15% higher odds of admission to alternate wards (OR 1.15, 95% CI 1.08 to 1.23) and increased mortality [hazard ratio (HR) 1.08, 95% CI 1.03 to 1.15]. We found no apparent effect on mortality for patients with myocardial infarction (HR 0.99, 95% CI 0.94 to 1.05) or stroke (HR 1.00, 95% CI 0.96 to 1.05).

Conclusions

Patients with heart failure had higher risk of admission to alternate wards when home ward occupancy was high. These patients may be negatively affected by full wards.
Voltammetric Determination of Copper by Biosorption‐based Mesorhizobium Opportonistum Modified Microbial Biosensor
Authors: Alasağ Özlem , Alpat Şenol , Alpat Sibel Kılınç
Published: March 2022

In this study, Cu (II) was determined with a carbon paste electrode modified with Mesorhizobium opportonistum bacteria species used for the first time in the production of a microbial biosensor (MOMB). Cu (II) ions were first accumulated on an electrode surface via open circuit, then electrochemical determination was conducted with cyclic and differential pulse cathodic stripping voltammetry techniques. Experimental conditions such as pH, scan rate etc. were optimized. The MOMB exhibited linearity in the range of 5.0×10−8 M to 2.0×10−6 M for Cu (II) (correlation coefficients: 0.9914) with detection limit (LOD) of 2.0×10−8 M, a limit of quantification (LOQ) 6.64×10−8 M and a detection sensitivity (10.34 μA/μM), for Cu (II). The electrode‐to electrode reproducibility of the MOMB was found to be 2.41 % (n=6) coefficient of variation. The MOMB has advantages for Cu (II) determination, including good sensitivity and reproducibility, easy preparation, low cost, applicability to sample and not having a need for additional chemical processes.
Efficient performance of copper oxide nanoparticles synthesized with pomegranate leaf extract for neutral red dye adsorption
Authors: Vidovix Taynara Basso , Januário Eduarda Freitas Diogo , Araújo Micael Furioso , Bergamasco Rosângela , Vieira Angélica Marquetotti Salcedo
Published: March 2022

The adsorption of dyes in water and wastewater using metallic nanoparticles stands out due to its high removal capacity and low environmental impact. The present study proposed the use of copper oxide nanoparticles (CuO_NP), synthesized with pomegranate leaves extract (Punica granatum) to remove the neutral red (NR) dye from the aqueous medium. The characterization confirmed the efficiency of the redox process and the formation of nanoparticles. The adsorption results were promising, wherein the maximum adsorption capacity was 283 mg/g (298 K), with 0.4 g/L of adsorbent concentration, equilibrium time at 120 min, and removal rate of 96%. The pseudo‐second‐order and Langmuir models had a better fit concerning the kinetic and isothermal data, respectively. Thermodynamic parameters revealed an exothermic, spontaneous, and reversible process. The mechanisms that described the adsorptive process were hydrogen bonds, π‐interactions, and electrostatic attraction. CuO_NP showed good regeneration performance up to four reuse cycles (98–52 mg/g). In addition, not pronounced changes were verified in its adsorption capacity with dissociated ions (90–102 mg/g, in relation to the adsorption with no salts 104 mg/g). This secures the material versatility and cost‐effectiveness, justifying its high potential for industrial application to remove NR from water and wastewater.
Application of barley flour processed by different methods as an alternative to fat in emulsion‐type sausage
Authors: Zhu Ying , Huang Shiting , Jia Donghao , Zhao Yansheng , Zhang Jiayan , Bai Juan , Xiao Xiang
Published: March 2022

Physicochemical properties of three types of barley flour, whole barley flour (BF), electromagnetic stir‐frying whole barley flour, and extruded whole barley powder (EBF), and their potential application in emulsion type sausage were evaluated in this study. The water solubility index, water absorption index, and pasting properties of barley flour treated by different processing technologies were significantly different. The EBF has the highest water solubility index (12.67%) and water absorption index (503.20%), and with the minimum peak viscosity (2593.67 cp) and pasting temperature (50.20°C). The water‐holding capacity and cooking loss of emulsified sausage improved significantly after adding the barley flour processed by different methods, especially the 9%BF substitution, the pressure water loss rate and cooking loss rate were reduced to 5.32% and 14.52%, respectively. The emulsified sausage added with BF indicated better color quality and texture properties comparable with the control. Scanning electron microscopy also showed that the addition of three kinds of barley flour in sausage formation led to a difference in the microstructure of the sausages. This study suggested that barley flour improved the physicochemical and textural properties of the emulsified sausage.
An implicit p‐adaptive discontinuous Galerkin solver for CAA/CFD simulations
Authors: Colombo Alessandro , Crivellini Andrea , Ghidoni Antonio , Nigro Alessandra , Noventa Gianmaria
Published: March 2022

In the last decades flow simulations have become a routine practice in many industrial fields for the aerodynamic and noise prediction. Moreover, the ever increasing interest in simulating off‐design operating conditions promoted the development of high‐fidelity simulation tools to overcome the modeling and accuracy limits of standard industrial codes in predicting turbulent separated flows. The discontinuous Galerkin (DG) method is well suited for this class of simulations, but today DG‐based CFD and CAA (Computational AeroAcoustics) solvers cannot yet reach the computational efficiency of well‐established commercial codes. As a consequence, the present paper aims at exploiting some attractive strategies, such as the adaptation of the elemental polynomial degree (‐adaptation) and of the degree of exactness of quadrature rules, to enhance the computational efficiency of an implicit DG platform for CFD and CAA simulations. Moreover, a sponge layer non‐reflecting boundary treatment has been also implemented for CAA. The predicting capabilities of the method have been assessed on classical CAA and CFD test cases. The proposed adaptive strategy guarantees a significant reduction () of the computational effort for both CFD and CAA simulations, compared to uniform‐order discretizations, while not spoiling the high accuracy requested to an high‐fidelity simulation tool.
Heat and mass transfer in MHD stagnation‐point flow toward an inclined stretching sheet embedded in a porous medium
Authors: Biswal Manasa M. , Swain Bharat K. , Das Manjula , Dash Gouranga Charan
Published: March 2022

The present study elucidates the magnetohydrodynamics boundary layer free convective stagnation‐point flow toward an inclined nonlinearly stretching sheet embedded in a porous medium. The recent search explores the consequence of permeability of the medium, thermal as well as mass buoyancy, most importantly obliqueness, and thermal slip at the bounding surface. The solutions of the essential equations are achieved with MATLAB'S inbuilt solver bvp4c. The novelty of the present study is to account for the effect of dissipative heat, nonuniform space‐dependent volumetric heat power, and a linear first‐order chemical reaction of diffusive species and convective flow phenomena on an inclined plate subjected to thermal slip and space‐dependent transverse magnetic field acting at a distance. The important findings are laid down as follows: The oblique‐surface reduces the effect of body forces, low permeability of the medium causes instability in the flow due to sudden fall in velocity, Biot number contributes to the Newtonian cooling of the surface, these may be of use in a design requirement of the heat exchanger.
Time‐varying neural network for stock return prediction
Authors: Wong Steven Y. K. , Chan Jennifer S. K. , Azizi Lamiae , Xu Richard Y. D.
Published: March 2022

We consider the problem of neural network training in a time‐varying context. Machine learning algorithms have excelled in problems that do not change over time. However, problems encountered in financial markets are often time varying. We propose the online early stopping algorithm and show that a neural network trained using this algorithm can track a function changing with unknown dynamics. We compare the proposed algorithm to current approaches on predicting monthly US stock returns and show its superiority. We also show that prominent factors (such as the size and momentum effects) and industry indicators exhibit time‐varying predictive power on stock returns. We find that during market distress, industry indicators experience an increase in importance at the expense of firm level features. This indicates that industries play a role in explaining stock returns during periods of heightened risk.
The GRN concept as a guide for evolutionary developmental biology
Authors: Feigin Charles , Li Sha , Moreno Jorge , Mallarino Ricardo
Published: March 2022

Organismal phenotypes result largely from inherited developmental programs, usually executed during embryonic and juvenile life stages. These programs are not blank slates onto which natural selection can draw arbitrary forms. Rather, the mechanisms of development play an integral role in shaping phenotypic diversity and help determine the evolutionary trajectories of species. Modern evolutionary biology must, therefore, account for these mechanisms in both theory and in practice. The gene regulatory network (GRN) concept represents a potent tool for achieving this goal whose utility has grown in tandem with advances in “omic” technologies and experimental techniques. However, while the GRN concept is widely utilized, it is often less clear what practical implications it has for conducting research in evolutionary developmental biology. In this Perspective, we attempt to provide clarity by discussing how experiments and projects can be designed in light of the GRN concept. We first map familiar biological notions onto the more abstract components of GRN models. We then review how diverse functional genomic approaches can be directed toward the goal of constructing such models and discuss current methods for functionally testing evolutionary hypotheses that arise from them. Finally, we show how the major steps of GRN model construction and experimental validation suggest generalizable workflows that can serve as a scaffold for project design. Taken together, the practical implications that we draw from the GRN concept provide a set of guideposts for studies aiming at unraveling the molecular basis of phenotypic diversity.
An induced subgraph of the Hamming graph with maximum degree 1
Authors: Tandya Vincent
Published: March 2022

For every graph , let denote its independence number. What is the minimum of the maximum degree of an induced subgraph of with vertices? We study this question for the ‐dimensional Hamming graph over an alphabet of size . In this paper, we give a construction to prove that the answer is 1 for all and with . This is an improvement over an earlier work showing that the answer is at most .
Hospital's observed specific standard practice: A novel measure of variation in care for common inpatient pediatric conditions
Authors: Bakel Leigh Anne , Richardson Troy , De Souza Heidi Gruhler , Kaiser Sunitha V. , Mahant Sanjay , Treasure Jennifer D. , Waynik Ilana Y. , Winer Jeffrey C. , Bajaj Lalit
Published: March 2022

Background

Previously few means existed to broadly examine variability across conditions/practices within or between hospitals for common pediatric conditions.

Objective

Our objective was to develop a novel empiric measure of variation in care and test its association with patient‐centered outcomes.

Designs

We conducted a retrospective cohort study of children hospitalized from January 2016 to December 2018 using the Pediatric Hospital Information Systems database.

Settings and Participants

We included children ages 0–18 years hospitalized with asthma, bronchiolitis, or gastroenteritis.

Intervention

We developed a hospital‐specific measure of variation in care, the hospital's observed specific standard practice (HOSSP), the most common combination of laboratory studies, imaging, and medications used at each hospital.

Main Outcome and Measures

The outcomes were standardized costs, length of stay (LOS), and 7‐day all‐cause readmissions.

Results

Among 133,392 hospitalizations from 41 hospitals (asthma = 50,382, bronchiolitis = 54,745, and gastroenteritis = 28,265), there was significant variation in overall HOSSP adherence across hospitals for these conditions (asthma: 3.5%–47.4% [p < .001], bronchiolitis: 2.5%–19.8% [p < .001], gastroenteritis: 1.6%–11.6% [p < .001]). The majority of HOSSP variation was driven by differences in medication prescribing for asthma and bronchiolitis and laboratory ordering for gastroenteritis. For all three conditions, greater HOSSP adherence was associated with significantly lower hospital costs (asthma: p = .04, bronchiolitis: p < .001, acute gastroenteritis: p = .01), without increases in LOS or 7‐day all cause readmissions.

Conclusion

We found substantial variation in the components and adherence to HOSSP. Hospitals with greater HOSSP adherence had lower costs for these conditions. This suggests hospitals can use data around laboratory, imaging, and medication prescribing practices to drive standardization of care, reduce unnecessary testing and treatment, determine best practices, and reduce costs.
Is returning a product worth my time? The impact of time cues on consumer product returns
Authors: Lee Shinhyoung , Yi Youjae
Published: March 2022

Considering that returning a purchased product involves time costs to consumers, we posit that making a time cue salient will influence their likelihood of returning a product. Four studies reveal that consumers primed with time cues are less willing to return a product. Specifically, presenting time cues can reduce product returns by amplifying consumers' perception of time pressure and alleviating their psychological discomfort. Furthermore, private self‐awareness is found to moderate the time‐cue effect through perceived discomfort. The results are replicated even when time pressure and psychological discomfort are directly manipulated, supporting the causal account. This study contributes to the literature on consumer product returns by proposing the time‐cue effect and its psychological mechanisms and helps retailers manage product returns using various time cues.
Advances in the Stimuli‐Responsive Injectable Hydrogel for Controlled Release of Drugs
Authors: Mo Chunxiang , Luo Rui , Chen Yuping
Published: March 2022

The stimuli‐responsiveness of injectable hydrogel has been drastically developed for the controlled release of drugs and has achieved encouraging curative effects in a variety of diseases including wounds, cardiovascular diseases, and tumors. The gelation, swelling, and degradation of such hydrogels respond to endogenous biochemical factors (such as pH, reactive oxygen species, glutathione, enzymes, glucose) and/or to exogenous physical stimulations (like light, magnetism, electricity, and ultrasound), thereby accurately releasing loaded drugs in response to specifically pathological status and as desired for treatment plan, and thus improving therapeutic efficacy effectively. This paper gives a detailed introduction of recent progresses in responsive injectable hydrogels and focuses on the design strategy of various stimuli‐sensitivities and their resultant alteration of gel dissociation and drug liberation behavior. Their application in disease treatment is also discussed.
Bulk Enthalpy of Melting of Poly (l‐lactic acid) (PLLA) Determined by Fast Scanning Chip Calorimetry
Authors: Jariyavidyanont Katalee , Du Mengxue , Yu Qiang , Thurn‐Albrecht Thomas , Schick Christoph , Androsch René
Published: March 2022

The bulk enthalpy of melting of α‐crystals of poly (L‐lactic acid) (PLLA) is evaluated by fast scanning calorimetry (FSC), by correlating the melting enthalpy of samples of different crystallinity with the corresponding heat capacity at 90 °C, that is at a temperature higher than the glass transition temperature of the bulk amorphous phase and lower than the melting temperature. Extrapolation of this relationship for crystals formed at 140 °C towards the heat capacity of fully solid PLLA yields a value of 104.5±6 J g−1 when melting occurs at 180–200 °C. The analysis relies on a two‐phase structure, that is, absence of a vitrified rigid amorphous fraction (RAF) at the temperature of analysis the solid fraction (90 °C). Formation and vitrification of an RAF are suppressed by avoiding continuation of primary crystallization and secondary crystallization during cooling the system from the crystallization temperature of 140 °C to 90 °C, making use of the high cooling capacity of FSC. Small‐angle X‐ray scattering (SAXS) confirmed thickening of initially grown lamellae which only is possible if these lamellae are not surrounded by a glassy RAF. Linear crystallinity values obtained by SAXS and calorimetrically determined enthalpy‐based crystallinities agree close to each other.
Longitudinal analysis of electroencephalography pattern changes in an infant with Schaaf‐Yang syndrome and a novel mutation in melanoma antigen L2 (MAGEL2)
Authors: Mizuno Shinsuke , Yokoyama Koji , Yokoyama Atsushi , Nukata Takayuki , Ikeda Yuka , Hara Shigeto
Published: March 2022

Background

Schaaf‐Yang syndrome (SYS) is a rare hereditary disease caused by truncating point mutations of the paternal allele of melanoma antigen L2 (MAGEL2), one of five protein‐coding genes within the Prader‐Willi syndrome (PWS) critical domain. SYS shares many clinical and molecular characteristics with PWS but has some distinct features, such as joint contractures and autism. Patients with PWS show abnormal electroencephalography (EEG) patterns. However, there are very few reports on EEG findings in patients with SYS.

Methods

A SYS patient was included in this study. Detailed neurological examinations and EEG were performed from neonate to infant ages. Sanger sequencing was performed.

Results

Our patient presented abnormal EEG findings and had diffuse brain dysfunction symptoms including a reduced level of consciousness, diminished spontaneous movements, hypotonia, feeding difficulties, and hypoventilation from early after birth. As she grew older and her background activity of EEG normalized, her neurodevelopmental symptoms remained but improved. Sanger sequencing of this patient revealed a novel, heterozygous c.2005C > T, truncating mutation in the MEGAL2 gene.

Conclusions

We described an SYS‐associated, time‐dependent, EEG pattern in a patient with SYS. Our findings of longitudinal EEG changes in a patient with SYS revealed a specific pattern of how affected individuals develop brain function.
Validity of equivalent square field concept in small field dosimetry
Authors: Das Indra J. , Dogan Serpil K. , Gopalakrishnan Mahesh , Ding George X. , Longo Mariaconcetta , Franscescon Paolo
Published: March 2022

Purpose

The equivalent square (ES) concept has been used for traditional radiation fields defined by the machine collimating system. For small fields, the concept Sclin was introduced based on measuring dosimetric field width (full‐width half maximum, FWHM) of the cardinal axis of the beam profiles. The pros and cons of this concept are evaluated in small fields and compared with the traditional ES using area and perimeter (4A/P) method based on geometric field size settings, for example, light field settings.

Methods

One hundred thirty‐seven square and rectangular fields from 5–50 mm with every possible permutation (keeping one jaw fixed and varying other jaw from 5 to 50 mm) were utilized to measure FWHM for the validation of Sclin. Using a microSilicon detector and a scanning water tank, measurements were performed on an Elekta (Versa) machine with Agility head and a Varian TrueBeam with different MLC/Jaw design to evaluate the Sclin concept and to understand the effect of exchange factor in small fields. Field output factors were also measured for all 137 fields.

Results

The data fitting for fields ranging from 5–50 mm between the traditional 4A/P method and Sclin shows differences and indicates a linear relationship with distinct separation of slope for Elekta and Varian machines. For Elekta Agility machine ES based on 4A/P < Sclin and for the VarianTrueBeam  4A/P > Sclin for square fields. Our measured data show that both methods are equally valid but does vary by the machine design. The field output factor is dependent on the elongation factor as well as machine design. For fields with sides ≥10 mm, the exchange factor is nearly identical in both machines with magnitude up to 4%, which is close to measurement uncertainty (±3%), but for small fields (< 10 mm), the Elekta machine has higher exchange factors compared to the Varian machine.

Conclusion

The results demonstrate that the two concepts for defining equivalent field (Sclin and 4A/P) are equivalent and can be directly related through an empirical equation. This study confirms that 4A/P is still valid for small fields except for very small fields (≤10 mm) where source occlusion is a dominating factor. The Sclin method is potentially sensitive to measurement uncertainty due to measurement of FWHM which is machine‐, detector‐ and user‐dependent, while the 4A/P method relies mainly on geometry of the machine and has less dependency on type of machine, detector, and user. The exchange factors are comparable for both types of machines. The conclusion is based on data from an Elekta with Agility head and a Varian TrueBeam machine that may have potential for bias due to light field/collimator set up and alignment. Care should be taken in extrapolating these data to any other machine.
Nonlinear droop compensation for current waveforms in MRIgradient systems
Authors: Babaloo Reza , Atalar Ergin
Published: March 2022

Purpose

Providing accurate gradient currents is challenging due to the gradient chain nonlinearities, arising from gradient power amplifiers and power supply stages. This work introduces a new characterization approach that takes the amplifier and power supply into account, resulting in a nonlinear model that compensates for the current droop.

Methods

The gradient power amplifier and power supply stage were characterized by a modified state‐space averaging technique. The resulting nonlinear model was inverted and used in feedforward to control the gradient coil current. A custom‐built two‐channelz‐gradient coil was driven by high‐switching (1 MHz), low‐cost amplifiers (<$200) using linear and nonlinear controllers. High‐resolution (<80 ps) pulse‐width‐modulation signals were used to drive the amplifiers. MRI experiments were performed to validate the nonlinear controller's effectiveness.

Results

The simulation results validated the functionality of the state‐space averaging method in characterizing the gradient system. The performance of linear and nonlinear controllers in generating a trapezoidal current waveform was compared in simulations and experiments. The integral errors between the desired waveform and waveforms generated by linear and nonlinear controllers were 1.9% and 0.13%, respectively, confirming the capability of the nonlinear controller to compensate for the current droop. Phantom images validated the nonlinear controller's ability to correct droop‐induced distortions.

Conclusion

Benchtop measurements and MRI experiments demonstrated that the proposed nonlinear characterization and digitally implemented feedforward controller could drive gradient coils with droop‐free current waveforms (without a feedback loop). In experiments, the nonlinear controller outperformed the linear controller by a 14‐fold reduction in the integral error of a test waveform.