bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling and Simulation of Hydrodynamics and Filtration in a Membrane‐Assisted Stirred Slurry Reactor
Authors: Qiu Meizhong , Liu Yefei , Xu Lei , Wang Cong , Jiang Hong , Chen Rizhi
Published: June 2021

A membrane‐assisted stirred slurry reactor is developed by equipping a membrane tube into a stirred tank. Liquid‐solid flow is simulated by the Euler‐Lagrange method with filtration and particle deposition models. Acceptable predictions on the cake mass and particle deposition patterns are achieved by comparing with experimental data. The introduction of the membrane tube generates an asymmetric flow field. Shear stress on the membrane surface has a direct influence on the particle deposition. Increasing the impeller rotating speed leads to larger shear stress and mitigates the particle deposition. The cake mass is reduced by placing the membrane tube close to the impeller. The upward liquid flow pumped by the pitched‐blade impeller results in low shear stress and the vertical‐blade impeller is preferable.
Preparation of Three‐Dimensional Copper‐Zinc Alloy Current Collector by Powder Metallurgy for Lithium Metal Battery Anode
Authors: Qiang Zhe , Liu Bao , Yang Bingjun , Ma Pengjun , Yan Xingbin , Wang Bixia
Published: June 2021

Lithium metal batteries (LMB) have been considered as the most promising energy storage devices for electric vehicles and portable electronic devices, however their applications are usually limited due to the poor cycle stability and serious safety problems of the battery, which were caused by uncontrolled growth of lithium dendrite and unlimited volume change of anode during Li plating/stripping. Herein, we design a three‐dimensional porous copper‐zinc alloy (3D Cu−Zn) by powder metallurgy method, which has suitable and controllable porous structure for lithium deposition in lithium metal battery. By systematically tailoring particle size of metal powder and other parameters, the 3D Cu−Zn was prepared, which can be used as current collector of lithium anode and shows good cyclic stability. The Li metal anode with 3D Cu−Zn porous current collector can stably cycle for as long as 800 h under a high Li plating/stripping capacity of 1 mA h cm−2 and high current density of 1 mA cm−2. Li@3D Cu−Zn||LiFePO4 cell has excellent rate performance and cycle performance. This work may open a new avenue for building better lithium metal battery with long cycle performance.
Telechelic Triblock Poly(α‐Amino Acid)‐Poly(Tetrahydrofuran)‐Poly(α‐Amino Acid) Copolymers: Chain‐End Transformation, Polymerization and pH‐Responsive Hydrolysis†
Authors: Zhou Peng , Li Zixian , Lu Yanzhi , Kong Jie , Ling Jun
Published: June 2021

Main observation and conclusion

Block copolymers not only combine properties of different segments but also generate new application prospects. Poly(α‐amino acid)‐b‐poly(tetrahydrofuran)‐b‐poly(α‐amino acid) (PAA‐PTHF‐PAA) is one of the copolymers. In this contribution, di‐hydroxyl‐ended HO‐PTHF‐OH is transferred into di‐oxyamino‐ended H2NO‐PTHF‐ONH2 quantitatively, which is used as a macroinitiator to polymerize sarcosine N‐thiocarboxyanhydride (Sar‐NTA) and N‐phenyoxycarbonyl N‐ε‐carbobenzyloxy‐D‐lysine (ZDL‐NPC). Well‐defined triblock PAA‐NHO‐PTHF‐ONH‐PAA is produced with high molecular weight (up to 25.3 kg/mol) and narrow dispersity. The amphiphilic PSar‐NHO‐PTHF‐ONH‐PSar (STS) self‐assembles into micelles with uniform diameters of 30—40 nm according to DLS. Owing to oxygen amide groups inside the backbone of these copolymers, the polyether‐poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.
Unravelling the Reaction Mechanisms of N2 Fixation on Molybdenum Nitride: A Full DFT Study from the Pristine Surface to Heteroatom Anchoring
Authors: Kong Youchao , He Tianwei , Puente Santiago Alain R. , Liu Dong , Du Aijun , Wang Shuangpeng , Pan Hui
Published: June 2021

Transition metal nitrides (TMNs)‐based materials have attracted increasing attention in electrochemical nitrogen reduction reaction (eNRR) because of their unique structures and inherent electronic properties. However, the eNRR mechanism on such nitrogen contained catalysts is still unclear, for example, which part of the catalyst act as the active sites, and how to achieve the optimal efficiency is also challenging. In this work, a comprehensive study was conducted to unravel the reaction mechanisms of N2 fixation on molybdenum nitride by using density functional theory (DFT) calculations. The activity and selectivity of eNRR on pristine (001) and (110) Mo5N6 surfaces as well as few specific numbers of heteroatom‐anchored N‐terminated surfaces were all evaluated and compared. It was found that the Mo and N atoms on the pristine Mo5N6 surface were both active for eNRR while following different pathways in mechanism. Moreover, the eNRR catalytic performance of Mo5N6 could be further boosted by specific metal atoms anchoring, such as single atom, metal dimer, and heterodiatom pair. Finally, a full map of eNRR mechanism on pristine and metal atom‐decorated Mo5N6 surfaces was illustrated. This work not only provides a fundamental understanding of eNRR mechanism on TMNs based materials but also offers powerful strategies towards the rational design of efficient NRR electrocatalysts.
Psychosocial factors, mental health, and coordination capacity in patients with heart failure with preserved ejection fraction compared with heart failure with reduced ejection fraction
Authors: Bekfani Tarek , Nisser Jenny , Derlien Steffen , Hamadanchi Ali , Fröb Elisabeth , Dannberg Gudrun , Lichtenauer Michael , Smolenski Ulrich C. , Lehmann Gabriele , Möbius‐Winkler Sven , Schulze Paul Christian
Published: June 2021

Aims

Patients with heart failure (HF) suffer from reduced quality‐of‐life (QoL). We aimed to compare QoL, depression, and anxiety scores among outpatients with preserved (HFpEF) and reduced (HFrEF) ejection fraction and non‐HF controls and its relationship to coordination capacity.

Methods and results

Fifty‐five participants were recruited prospectively at the University Hospital Jena, Germany (17 HFpEF, 18 HFrEF, and 20 non‐HF controls). All participants underwent echocardiography, cardiopulmonary exercise testing (CPET), 10 m walking test (10‐MWT), isokinetic muscle function and coordination tests, and QoL assessments using the short form of health survey (SF‐36), and hospital anxiety and depression scale (HADS). Furthermore, inflammatory biomarkers such as growth differentiation factor‐15 (GDF‐15) were assessed. Patients with HFpEF showed compared with HFrEF and non‐HF controls reduced QoL [mental component score (MCS): 43.6 ± 7.1 vs. 50.2 ± 10.0 vs. 50.5 ± 5.0, P = 0.03), vitality (VT): 47.5 ± 8.4 vs. 53.6 ± 8.6 vs. 57.1 ± 5.2, P = 0.004), and elevated anxiety (6.5 ± 3.2 vs. 3.3 ± 2.8 vs. 3.8 ± 2. 8, P = 0.02) and depression scores (6.5 [3.5–10.0] vs. 3.0 [1.0–6.5] vs. 2.0 [0.75–3.0], P = 0.01)]. After adjusting to multiple comparisons, anxiety remained higher in HFpEF patients compared with HFrEF (ppost‐hoc = 0.009). HFpEF and HFrEF patients showed reduced coordination capacity compared with non‐HF controls (P < 0.05). In a logistic regression, the presence of depression score ≥8 remained an independent factor for predicting reduced coordination capacity after adjusting for peak VO2, GDF‐15, 10‐MWT, physical component score (PCS), and peak torque of the leg [odds ratio (OR): 0.1, 95% confidence interval (CI): 0.004–0.626, P = 0.02].

Conclusion

Outpatients with HFpEF had worse QoL and higher anxiety and depression scores compared with HFrEF and non‐HF controls. Depression is associated with reduced QoL and is an independent predictor for reduced coordination capacity.
Subblock design aided orthogonal frequency division multiplexing with all index modulation using search algorithm
Authors: Shi Yuxin , Lu Xinjin , Luo Junshan , Wang Shilian
Published: June 2021

Orthogonal frequency division multiplexing with index modulation (OFDM‐IM) harvests significantly better error performance compared with OFDM due to its design of the index bits. However, the structure of conventional OFDM‐IM scheme does not fully focus on the enhancement of the bit error rate (BER) performance. In the proposed subblock design aided OFDM with all index modulation (SD‐OFDM‐AIM), unconditional pairwise error probability (UPEP) is taken as the objective function to select the subblock realizations with low error rates, leading to the BER performance enhancement. Noticing that UPEP uses the channel state information (CSI), we fully discuss the calculation of CSI and analyze the effect on subblock design under imperfect channel evaluation. Moreover, inspired by sphere decoding method, we propose the low complexity decoder to remove the high burden of computational complexity in former OFDM with all index modulation (OFDM‐AIM) after the reconstruction of the look‐up table. The simulation results demonstrate its superiority at BER performance compared with the index modulated OFDM schemes and OFDM‐AIM.
A century-long record of plant evolution reconstructed from a coastal marsh seed bank
Authors: Blum Michael J. , Saunders Colin J. , McLachlan Jason S. , Summers Jennifer , Craft Christopher , Herrick Jeffrey D.
Published: June 2021

Evidence is mounting that climate-driven shifts in environmental conditions can elicit organismal evolution, yet there are sparingly few long-term records that document the tempo and progression of responses, particularly for plants capable of transforming ecosystems. In this study, we “resurrected” cohorts of a foundational coastal marsh sedge (Schoenoplectus americanus) from a time-stratified seed bank to reconstruct a century-long record of heritable variation in response to salinity exposure. Common-garden experiments revealed that S. americanus exhibits heritable variation in phenotypic traits and biomass-based measures of salinity tolerance. We found that responses to salinity exposure differed among the revived cohorts, with plants from the early 20th century exhibiting greater salinity tolerance than those from the mid to late 20th century. Fluctuations in salinity tolerance could reflect stochastic variation but a congruent record of genotypic variation points to the alternative possibility that the loss and gain in functionality are driven by selection, with comparisons to historical rainfall and paleosalinity records suggesting that selective pressures vary according to shifting estuarine conditions. Because salinity tolerance in S. americanus is tightly coupled to primary productivity and other vital ecosystem attributes, these findings indicate that organismal evolution merits further consideration as a factor shaping coastal marsh responses to climate change.
Safety, probiotic properties, antimicrobial activity, and technological performance of Lactobacillus strains isolated from Iranian raw milk cheeses
Authors: Barzegar Hassan , Alizadeh Behbahani Behrooz , Falah Fereshteh
Published: June 2021

The objective of this study was to investigate probiotic, antimicrobial, technological and safety properties of lactobacillus strains isolated from local Iranian cheese made from raw milk. Six different samples were prepared, after serial dilution, culture was performed on MRS culture medium. The gram‐positive and catalase‐negative lactobacillus strains were subjected to grouping and identifying using biochemical tests, carbohydrates fermentation profiles, and 16S rDNA analysis. The results of sequence analysis showed the Lactobacillus spp. belonged to Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus casei. After 3 hr incubation at pH=2, 3–6 log units of strains decreased which Lactobacillus acidophilus (B14) and Lactobacillus brevis (B2) showed highest resistance to low pH as well as simulated GIT juices. The highest and lowest hydrophobicity degree was belonged to L. acidophilus (B14) (65.9%) and L. casei (B22) (25.6%), respectively. Also, the highest auto‐aggregation and coaggregation were observed in L. acidophilus (B14) (51.3%) and L. plantarum (B20) (43.6%). The adhered percentage of strains varied from 2.5% to 14.6%. L. plantarum (B20) showed highest proteolytic activity followed by L. acidophilus (B14). Also, the highest autolytic activity belonged to L. acidophilus (B14). All of the strains showed low acidifying potential, except for L. acidophilus (B17) which decreased 2.05 unit of pH after 24 hr. The isolates did not show lipolytic activity as well as biogenic amines production (except L. brevis B3). All of the strains were sensitive to chloramphenicol and erythromycin except L. acidophilus (B15) and L. casei (B22). All strains showed no hemolysis activity which make them safe for consumption. Based on the obtained results, L. acidophilus (B14) presented the best probiotic and technological characteristics and is proposed for using as coculture in the dairy industrial.
Lipid composition and molecular species of phospholipid in oyster Crassostrea lugubris (Sowerby, 1871) from Lang Co Beach, Hue Province, Vietnam
Authors: Thi Le Thanh Tra , Tran Quoc Toan , Velansky PeteVladimirovich , Dam Tien Duc , Bach Long Giang , Pham Long Quoc
Published: June 2021

Oysters are widely distributed worldwide, but are mainly concentrated in tropics and subtropics. Total lipid (TL), fatty acid (FA) composition of TL and polar lipid (PoL) fractions, phospholipid (PL) class, and molecular species composition in soft tissues of Crassostrea lugubris were investigated for the first time from Vietnam. Phosphatidylglycolic acid (PGA) is the new phospholipid class first identified in marine species in general and Crassostrea lugubris in particular. Main eight classes of PL were determined in PoL fraction: diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylserine (PS), ceramide aminoethylphosphonate (CAEP), CAEP with hydroxylated FAs (CAEP‐OH), and lysophosphatidylcholine. PE and PC accounted for approximately 63% of total known PL. Polyunsaturated FAs accounted for more than 30% of TL. Ninety molecular species of glycerophospholipids, including PGA, PE, PC, PS, PI, DPG, and PG, and sphingophosphonolipids (CAEP) were identified in PoL. Alkenyl‐acyl forms of glycerophospholipids were predominated in the molecular species of PGA, PE, and PS. PGA 38:1 (p18:0/20:1), PE 40:6 (p18:0/22:6 and p18:1/22:5), PC 30:0 (14:0/16:0), PS 38:1 (p18:0/20:1), PI 40:5 (20:1/20:4), PG 32:0 (16:0/16:0), DPG 88:24 (22:6/22:6/22:6/22:6), and CAEP 34:2 (d18:2/16:0) were major molecular species.
Performance‐Based Regulation and Climate Change
Authors: Lowry Mark Newton , Makos Matt
Published: June 2021

Performance‐based regulation (PBR) has been used for several decades to incentivize and regulate US energy utilities. Its popularity has been bolstered in recent years by mounting concerns over the impact that greenhouse gas (GHG) emissions from the production and consumption of natural gas and the generation of electricity have on the world's climate. In combination with other policy measures, PBR has helped to mitigate adverse climate impacts in part by reducing energy use and moving toward cleaner energy choices. Mounting climate concerns have caused PBR to change. In this article these authors provide a useful taxonomy of PBR tools and then discuss how PBR has grown and evolved.
Clean Energy and The Need for Effective Transformation and Continuous Improvement
Authors: Vance John , Chung Hara , Hoeppner Emily
Published: June 2021

The world's economy and society are embarking on one of the most challenging and important transformations in the history of humankind. The need to reduce carbon emissions and transition to cleaner energy sources is existential, and as such we as a society are facing both temporal deadlines and massive upheaval in human behaviors. If we are to be successful in preventing significant and irreversible damage, we will have to change the way we work, live, and play. The introduction of clean energy is a major component of society's response, requiring multi‐tiered levels of change, with coordination across governments at local, national, and global levels driving action across energy producers and consumers.
Location capabilities, institutional distance, and start‐up survival
Authors: Bustamante Carla V. , Matusik Sharon F. , Benavente Jose Miguel
Published: June 2021

Research summary

Location considerations play a key role in shaping venture performance. Using data from the largest accelerator in the world, we examine the effects of institutional distance and location capabilities on international start‐ups' survival rates. We find that international start‐ups' survival is shaped by whether it internationalizes to a country with stronger or weaker institutions than those in its home country. Further, the interaction between the directionality of institutional distance and location capabilities is important such that ventures that develop location capabilities in contexts of positive institutional distance experience greater survival rates. Through this study, we make an important theoretical contribution at the intersection of institutional and resource based theory by developing more granular knowledge about institutional dynamics across home and host countries.

Managerial summary

Internationalizing into emerging countries poses immense challenges to start‐ups. This study explores the factors that shape the survival rates of 268 start‐ups that have internationalized in the context of a business‐accelerator program. We find that their ability to survive is shaped by the difference between home and host‐country institutions, in addition to start‐up's location capabilities to engage with local resources in the host country. Developing location capabilities in the host country does not directly lead to increased survival rates. The value of developing location capabilities is affected by whether the venture is operating in a country with stronger or weaker institutions than those in start‐ups' home country; ventures that develop location capabilities in contexts of positive institutional distance experience greater survival rates.
Modeling and prediction of NOx emission in an LPG–diesel dual‐fuel CI engine
Authors: Murthy Krishna , Srinivas Vijay Gaddle , Kumar Shiva
Published: June 2021

Different alternative fuels have been proposed by various researchers in diesel engines in view of increased NOx and particulate emissions. Out of the various methods proposed, dual fueling is one of the most important techniques that helps solve the different operational problems related to diesel engine combustion and emission. In the current study, modeling and predicting the formation of NOx emission in a duel fuel liquefied petroleum gas (LPG)–diesel engine has been undertaken. Simulations have been conducted for various LPG flow rates at different engine loads and the predicted NOx values are compared with the experimental values. The results found that there is a decent agreement between the forecasted and the investigational results, where the average difference is within 13.7%. Furthermore, it is found that minimum NOx emission was observed for an LPG flow rate in the range of 0.4–0.6 kg/h and when the engine is running with 75% loading.
Effects of HIV infection on metastatic cervical cancer and age at diagnosis among patients in Lusaka, Zambia
Authors: Trejo Mario Jesus , Soliman Amr S. , Chen Yuli , Kalima Mulele , Chuba Alick , Chama Eslone , Mwaba Catherine K. , Banda Lewis , Lishimpi Kennedy
Published: June 2021

Objective

To examine the association between the duration of HIV infection and the stage of cervical cancer in Lusaka, Zambia.

Methods

This retrospective case‐case study included 1583 cervical cancer patients from the Cancer Diseases Hospital in Lusaka, Zambia. A sub‐population of HIV‐positive patients with additional clinical HIV information was identified following linkage of cancer and HIV databases. Logistic regression models examined the relationship between HIV status and early‐onset cervical cancer diagnosis, and between HIV infection duration and initial diagnosis of metastatic cervical cancer.

Results

The study population had an average age of 49 years and 40.9% had an initial diagnosis of metastatic cancer. HIV‐positive women were more than twice as likely to be diagnosed at early‐onset cervical cancer compared with HIV‐negative women. Among the sub‐population of HIV‐positive patients, a longer duration of HIV infection was associated with 20% lowered odds of initial metastatic cancer diagnosis.

Conclusion

The availability, accessibility, and impact of the cervical screening program in this population should be further examined to elucidate the relationship between cervical screening, age, and duration of HIV infection and the the stage of diagnosis of cervical cancer.
Structure‐based investigation of MARK4 inhibitory potential of Naringenin for therapeutic management of cancer and neurodegenerative diseases
Authors: Anwar Saleha , Khan Shama , Shamsi Anas , Anjum Farah , Shafie Alaa , Islam Asimul , Ahmad Faizan , Hassan Md. Imtaiyaz
Published: June 2021

MAP/microtubule affinity‐regulating kinase 4 (MARK4) is a member of serine/threonine kinase family and considered an attractive drug target for many diseases. Screening of Indian Medicinal Plants, Phytochemistry, and Therapeutics (IMPPAT) using virtual high‐throughput screening coupled with enzyme assay suggested that Naringenin (NAG) could be a potent inhibitor of MARK4. Structure‐based molecular docking analysis showed that NAG binds to the critical residues found in the active site pocket of MARK4. Furthermore, molecular dynamics (MD) simulation studies for 100 ns have delineated the binding mechanism of NAG to MARK4. Results of MD simulation suggested that binding of NAG further stabilizes the structure of MARK4 by forming a stable complex. In addition, no significant conformational change in the MARK4 structure was observed. Fluorescence binding and isothermal titration calorimetric measurements revealed an excellent binding affinity of NAG to MARK4 with a binding constant (K) = 0.13 × 106 M−1 obtained from fluorescence binding studies. Further, enzyme inhibition studies showed that NAG has an admirable IC50 value of 4.11 µM for MARK4. Together, these findings suggest that NAG could be an effective MARK4 inhibitor that can potentially be used to treat cancer and neurodegenerative diseases.
A dynamic nomogram for predicting the risk of asthma: Development and validation in a database study
Authors: Yang Lifen , Li Meihua , Zheng Qinling , Ren Chaofeng , Ma Wei , Yang Yanxia
Published: June 2021

Background

Asthma remains a serious health problem with increasing prevalence and incidence. This study was to develop and validate a dynamic nomogram for predicting asthma risk.

Methods

Totally 597 subjects whose age ≥18 years old with asthma, an accurate age at first cigarette, and clear smoking status were selected from the National Health and Nutrition Examination Survey (NHANES) database (2013–2018). The dataset was randomly split into the training set and the testing set at a ratio of 4:6. Simple and multiple logistic regressions were used for identifying independent predictors. Then the nomogram was developed and internally validated using data from the testing set. The receiver operator characteristic (ROC) curve was used for assessing the performance of the nomogram.

Results

According to the simple and multiple logistic regressions, smoking ≥40 years, female gender, the age for the first smoking, having close relative with asthma were independently associated with the risk of an asthma attack. The nomogram was thereby developed with the link of https://yanglifen.shinyapps.io/Dynamic_Nomogram_for_Asthma/. The ROC analyses showed an AUC of 0.726 (0.724–0.728) with a sensitivity of 0.887 (0.847–0.928) in the training set, and an AUC of 0.702 (0.700–0.703) with a sensitivity of 0.860 (0.804–0.916) in the testing set, fitting well in calibration curves. Decision curve analysis further confirmed the clinical usefulness of the nomogram.

Conclusion

Our dynamic nomogram could help clinicians to assess the individual probability of asthma attack, which was helpful for improving the treatment and prognosis of asthma.
Hidden morphological and structural characteristics in scales of mullid species (Teleostei: Mullidae) using light and scanning electron digital imaging
Authors: Echreshavi Sorour , Esmaeili Hamid Reza , Teimori Azad , Safaie Mohsen , Owfi Freedon
Published: June 2021

The scale morphology of nine Mullidae taxa consisting of three genera and nine species from the Persian Gulf and the Gulf of Oman was described and compared using light and scanning electron microscopy from four different body regions. The general scale type in the studied mullid species was ctenoid except in the head region of Mulloidichthys vanicolensis and Parupeneus margaritatus, which had cycloid scales. The scales demonstrated a large focus with the central or centro‐posterior position. The large variations of scale morphology were observed for the scales from different body regions of a single species. The shape of focus was in five types with the round type being the most common. In the scales of most examined species, there were 5–6 radii present in the anterior field. No radii exist in the lateral and posterior fields, and the radii orientation was parallel in all the studied species. The rostral margin of scales represented five types among the studied species; waved (M. vanicolensis), smooth in (P. rubescens), dentate (Upeneus doriae), scalloped (U. vittatus), and fluted (U. tragula). The lepidont shape varied among the species from blunt to flat, pointed, tiny, sharp, pointed, triangle, short, and long. The results also showed that the relative scale size has a desirable contribution to separate the examined genera. The scale morphological‐based tree was largely consistent with the known systematics of the studied fishes. It was concluded that variation of scale characters has probably taxonomic and even phylogenetic information in both species and genus levels in the studied mullid fishes. However, variation of scale morphology between body regions, as shown in this study, suggests that scale characters should be used cautiously for taxonomic studies of these fishes.
Electrocardiography on admission is associated with poor outcomes in coronavirus disease 2019 (COVID‐19) patients: A systematic review and meta‐analysis
Authors: Alsagaff Mochamad Yusuf , Oktaviono Yudi Her , Dharmadjati Budi Baktijasa , Lefi Achmad , Al‐Farabi Makhyan Jibril , Gandi Parama , Marsudi Bagas Adhimurda , Azmi Yusuf
Published: June 2021

Background

Electrocardiogram (ECG) is a widely accessible diagnostic tool that can easily be obtained on admission and can reduce excessive contact with coronavirus disease 2019 (COVID‐19) patients. A systematic review and meta‐analysis were performed to evaluate the latest evidence on the association of ECG on admission and the poor outcomes in COVID‐19.

Methods

A literature search was conducted on online databases for observational studies evaluating ECG parameters and composite poor outcomes comprising ICU admission, severe illness, and mortality in COVID‐19 patients.

Results

A total of 2,539 patients from seven studies were included in this analysis. Pooled analysis showed that a longer corrected QT (QTc) interval and more frequent prolonged QTc interval were associated with composite poor outcome ([WMD 6.04 [2.62‐9.45], P = .001; I2:0%] and [RR 1.89 [1.52‐2.36], P < .001; I2:17%], respectively). Patients with poor outcome had a longer QRS duration and a faster heart rate compared with patients with good outcome ([WMD 2.03 [0.20‐3.87], P = .030; I2:46.1%] and [WMD 5.96 [0.96‐10.95], P = .019; I2:55.9%], respectively). The incidence of left bundle branch block (LBBB), premature atrial contraction (PAC), and premature ventricular contraction (PVC) were higher in patients with poor outcome ([RR 2.55 [1.19‐5.47], P = .016; I2:65.9%]; [RR 1.94 [1.32‐2.86], P = .001; I2:62.8%]; and [RR 1.84 [1.075‐3.17], P = .026; I2:70.6%], respectively). T‐wave inversion and ST‐depression were more frequent in patients with poor outcome ([RR 1.68 [1.31‐2.15], P < .001; I2:14.3%] and [RR 1.61 [1.31‐2.00], P < .001; I2:49.5%], respectively).

Conclusion

Most ECG abnormalities on admission are significantly associated with an increased composite poor outcome in patients with COVID‐19.
Hydrogels Based on Oxidized Cellulose Sulfates and Carboxymethyl Chitosan: Studies on Intrinsic Gel Properties, Stability, and Biocompatibility
Authors: Willems Christian , Trutschel Marie‐Luise , Mazaikina Vera , Strätz Juliane , Mäder Karsten , Fischer Steffen , Groth Thomas
Published: June 2021

Cellulose and chitosan are excellent components for the fabrication of bioactive scaffolds, as they are biocompatible and abundantly available. Their derivatives Ocarboxymethyl chitosan (CMChi) and oxidized cellulose sulfate (oxCS) can form in situ gelling, bioactive hydrogels, due to the formation of imine bonds for crosslinking. Here the influence of the degrees of sulfation (DS), oxidation (DO), and the molecular weight of oxCS on intrinsic and rheological properties of such hydrogels and their ability to support the survival and growth of human‐adipose‐derived stem cells (hADSC) is investigated. It is found that the pH of the hydrogels is generally slightly acidic, while their network density and E‐modulus are found to be dependent on the DS and DO, which makes the properties of hydrogels tunable. Extensive studies show that hydrogels can be stable for up to 14 days and that their stability is largely dependent on the DO, molecular weight, and the components mixing ratio. Cytotoxicity studies of the hydrogel with hADSCs show biocompatible gels in dependence on the molecular weight and degree of oxidation with viable cells up to 14 days. These findings can help to develop specifically tailored hydrogels for tissue engineering applications to replace different types of connective tissue.
Inversion formula and range conditions for a linear system related with the multi‐interval finite Hilbert transform in L2
Authors: Katsevich Alexander , Bertola Marco , Tovbis Alexander
Published: June 2021

Given n disjoint intervals on together with n functions , , and an matrix , the problem is to find an L2 solution , , to the linear system , where , is a matrix of finite Hilbert transforms with defined on , and is a matrix of the corresponding characteristic functions on . Since we can interpret , as a generalized multi‐interval finite Hilbert transform, we call the formula for the solution as “the inversion formula” and the necessary and sufficient conditions for the existence of a solution as the “range conditions”. In this paper we derive the explicit inversion formula and the range conditions in two specific cases: a) the matrix Θ is symmetric and positive definite, and; b) all the entries of Θ are equal to one. We also prove the uniqueness of solution, that is, that our transform is injective. In the case a), that is, when the matrix Θ is positive definite, the inversion formula is given in terms of the solution of the associated matrix Riemann–Hilbert Problem. In the case b) we reduce the multi interval problem to a problem on n copies of and then express our answers in terms of the Fourier transform. We also discuss other cases of the matrix Θ.
Firms' innovation strategy under the shadow of corporate social responsibility disclosure: Evidence from China
Authors: Mbanyele William
Published: June 2021

This paper examines how corporate social responsibility (CSR) disclosure impacts innovation using a sample of Chinese firms. We find that an increase in CSR disclosure leads firms to invest more in R&D investments and generate more patents. Additionally, our findings reveal that firms with high CSR disclosure nurture innovation by engaging less in short‐termism activities that crowd resources for innovation. Furthermore, we uncover that CSR disclosure promotes the optimum allocation of R&D expenditure by allocating risky capital towards good investment opportunities and away from poor investment opportunity sets. In addition, we show that CSR disclosure promotes innovation through information and human capital channels.
q‐regular variation and the existence of solutions of half‐linear q‐difference equation
Authors: Djordjević Katarina S. , Manojlović Jelena V.
Published: June 2021

The half‐linear q‐difference equation

where
,
, is analyzed in the framework of q‐regular variation. Necessary and sufficient conditions for the existence of q‐regularly varying solutions are given, under the assumption that p is a q‐regularly varying function and with no sign restriction on r. It is examined in the case when r is eventually negative, whether all positive solutions are q‐regularly varying. Using generalized regularly varying sequences, these results are applied to the half‐linear difference equation case.
HILUCSI: Simple, robust, and fast multilevel ILU for large‐scale saddle‐point problems from PDEs
Authors: Chen Qiao , Ghai Aditi , Jiao Xiangmin
Published: June 2021

Incomplete factorization is a widely used preconditioning technique for Krylov subspace methods for solving large‐scale sparse linear systems. Its multilevel variants, such as ILUPACK, are more robust for many symmetric or unsymmetric linear systems than the traditional, single‐level incomplete LU (or ILU) techniques. However, the previous multilevel ILU techniques still lacked robustness and efficiency for some large‐scale saddle‐point problems, which often arise from systems of PDEs. We introduce HILUCSI, or Hierarchical Incomplete LU‐Crout with Scalability‐oriented and Inverse‐based dropping. As a multilevel preconditioner, HILUCSI statically and dynamically permutes individual rows and columns to the next level for deferred factorization. Unlike ILUPACK, HILUCSI applies symmetric preprocessing techniques at the top levels but always uses unsymmetric preprocessing and unsymmetric factorization at the coarser levels. The deferring combined with mixed preprocessing enabled a unified treatment for nearly or partially symmetric systems and simplified the implementation by avoiding mixed and pivots for symmetric indefinite systems. We show that this combination improves robustness for indefinite systems without compromising efficiency. Furthermore, to enable superior efficiency for large‐scale systems with millions or more unknowns, HILUCSI introduces a scalability‐oriented dropping in conjunction with a variant of inverse‐based dropping. We demonstrate the effectiveness of HILUCSI for dozens of benchmark problems, including those from the mixed formulation of the Poisson equation, Stokes equations, and Navier–Stokes equations. We also compare its performance with ILUPACK and the supernodal ILUTP in SuperLU.
Electronic Benefit Transfer and Food Expenditure Cycles
Authors: Kuhn Michael A.
Published: June 2021

Previous research shows that the way transfer income is disbursed can affect what households purchase with that income. In this paper, I provide evidence that disbursement technique can affect the timing of purchases as well. I examine the U.S. Supplemental Nutrition Assistance Program (SNAP), which switched on a state‐by‐state basis from cash‐similar food coupons to Electronic Benefit Transfer (EBT)—a secure debit card—from 1993 to 2004. I find that EBT mitigated boom and bust cycles in food spending associated with SNAP disbursement. This effect is entirely driven by households with children (about two thirds of the SNAP population), who experienced more severe cycles prior to EBT. The effect operates only through the intensive margin—the amount spent on food during a shopping trip—and not at all on the extensive margin—the likelihood of going food shopping.
Race as a factor in donor selection and survival of children with hematologic malignancies undergoing hematopoietic stem cell transplant in Florida
Authors: Horn Biljana , Lamba Nikhil , Chellapandian Deepak , Sunkersett Gauri , Silva Jorge Galvez , Ziga Edward , Alperstein Warren , Joyce Michael , Castillo Paul , Fort John , Zhao Jing , Oshrine Benjamin
Published: June 2021

Background

Previous studies have explored posthematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce.

Procedure

This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 at one of the five Florida pediatric HCT centers.

Results

We found no differences between W and B children in transplant characteristics, other than donor type. There was a significant difference in use of human leukocyte antigen (HLA)‐mismatched donors (HLA‐MMD) (53% W, 71% B, p = .01). When comparing HLA‐MMD use to fully HLA‐matched donors, B had relative risk (RR) of 1.47 (95% CI 0.7–3) of receiving a mismatched unrelated donor (MMUD), RR of 2.34 (95% CI 1.2–4.4) of receiving a mismatched related donor (MMRD), and RR of 1.9 (95% CI 0.99–3.6) of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p = .1, or cGVHD (19% W, 28% B, p = .1), or primary cause of death. Overall 24‐month survival was 61% (95% CI 55%–68%) for W, and 60% (95% CI 48–75) for B children, log‐rank p = .7. While HLA matching improved survival in W children, the number of B children receiving HLA‐matched HCT was too small to identify the impact of HLA matching on survival.

Conclusions

In this contemporary cohort of children with HM, we found that B children were more likely to receive HLA‐MMD transplants, but this did not adversely affect survival or GVHD rates.
Unmasking latent thioesters under hydrophobic‐compatible conditions
Authors: Perkins Wade S. , Davison Ryan T. , Shelkey Gregory B. , Lawson Vernon E. , Hutton Grace E. , Miller Justin S.
Published: June 2021

Hydrophobic latent C‐terminal thioesters were converted into thioesters, and were also coupled with cysteine in one‐pot reactions, using conditions generally compatible with hydrophobic materials. The reaction conditions (ethanethiol and triethylamine in a mixture of DMF and THF) are compatible with acid‐labile protecting groups (Boc/t‐Bu) that are standard in Fmoc peptide synthesis.
Topological aspects of cavity‐induced degeneracies in polyatomic molecules
Authors: Badankó Péter , Umarov Otabek , Fábri Csaba , Halász Gábor J. , Vibók Ágnes
Published: June 2021

Conical intersections are degeneracies between multidimensional potential energy surfaces of molecular systems. It is well known that, besides these phenomena significantly modify the spectroscopic and dynamical properties of molecules, their presence in a molecular system has noticeable topological implications, as well. Such a consequence is the appearance of the topological or geometric phase. Conical intersections not only occur in nature but they can also be created by light. This can either be classical laser light or quantum light in an optical cavity. As a showcase example, by placing the formaldehyde (H2CO) molecule into a cavity, the topological properties (e.g., geometric or Berry phase) of the emerging light‐induced conical intersection have been investigated for different cavity parameters and geometrical arrangements.
Tracking the Relations Between Children’s Reading and Emotional Health Across Time: Evidence From Four Large Longitudinal Studies
Authors: McArthur Genevieve , Badcock Nicholas , Castles Anne , Robidoux Serje
Published: June 2021

There is good evidence for an association between poor reading and anxiety, but the mechanisms responsible for this association are currently unknown. In this study, we used structural equation modeling of four large longitudinal databases from the United Kingdom (n = 7,870), the United States (ns = 8,001 and 7,160), and Australia (n = 768) to explore relations between reading and emotional health across childhood. We found that emotional health at age 5 was not related to reading at age 7 but that reading at 7 was related to emotional health at age 9 or 11. We also found that reading, behavior, and attention may be related across development. These findings suggest a working hypothesis that poor reading may have an influence on emotional health rather than vice versa.
A hypothesis test of feasibility for external pilot trials assessing recruitment, follow‐up, and adherence rates
Authors: Wilson Duncan T. , Brown Julia , Farrin Amanda J. , Walwyn Rebecca E. A.
Published: June 2021

The power of a large clinical trial can be adversely affected by low recruitment, follow‐up, and adherence rates. External pilot trials estimate these rates and use them, via prespecified decision rules, to determine if the definitive trial is feasible and should go ahead. There is little methodological research underpinning how these decision rules, or the sample size of the pilot, should be chosen. In this article we propose a hypothesis test of the feasibility of a definitive trial, to be applied to the external pilot data and used to make progression decisions. We quantify feasibility by the power of the planned trial, as a function of recruitment, follow‐up, and adherence rates. We use this measure to define hypotheses to test in the pilot, propose a test statistic, and show how the error rates of this test can be calculated for the common scenario of a two‐arm parallel group definitive trial with a single normally distributed primary endpoint. We use our method to redesign TIGA‐CUB, an external pilot trial comparing a psychotherapy with treatment as usual for children with conduct disorders. We then extend our formulation to include using the pilot data to estimate the standard deviation of the primary endpoint and incorporate this into the progression decision.
Learning and confirming a class of treatment responders in clinical trials
Authors: Talisa Victor B. , Chang Chung‐Chou H.
Published: June 2021

Clinical trials require substantial effort and time to complete, and regulatory agencies may require two successful efficacy trials before approving a new drug. One way to improve the chance of follow‐up success is to identify a subpopulation among whom treatment effects are estimated to be beneficial, and enrolling future studies from this subpopulation. In this article we studyconfirmable responder class (CRC)learning, where the objective is to learn in a random half of the dataset (training set) a subpopulation among whom the predicted conditional ATE (CATE) suggests clinically meaningful benefit, with maximum power of being confirmed via hypothesis test in the other half (test set). We studied a set of CRC learners across simulated datasets in which either all patients benefited, or only some did. Performance metrics included the rate of confirmation in the test set, and the classification accuracy of the CRC compared with the group with true CATE>0. In trials where all patients benefitted, only two learners were able to consistently identify most of the population as the CRC. One of these also performed especially well when only some patients benefitted, having relatively high confirmation rates, and showing robustness to the dimension of the covariate vector and population characteristics. This learner is based on cross‐validation, and is a possible avenue for further development of model selection criteria for CRC learning. We also show that the performance of all methods can be improved by using both halves of the original dataset as training and test sets in turn.
Synthesis of 2‐Aryl‐N‐(EWG‐methyl)‐N‐methylpyrrolidinium Salts as Precursors of Ylides Entering the [1,2] Stevens Rearrangement
Authors: Jończyk Andrzej , Maurin Jan K. , Moreń Monika , Kowalkowska Anna
Published: June 2021

N‐(EWG‐CH2)‐N‐methyl‐2‐phenylpyrrolidinium (EWG ‐ electron‐withdrawing group) salts were obtained in two different ways. N‐(EWG‐CH2)‐2‐phenylpyrrolidines were quaternized with iodomethane, dimethylsulfate or methyl trifluoromethanesulfonate forming pyrrolidinium iodides, methylsulfates and triflates. The counterion exchange in the methylsulfates was carried out yielding respective tetrafluoroborates. The second method was based on the quaternization of N‐methyl‐2‐phenylpyrrolidine with methyl α‐halogenoacetate or phenacyl bromide. All listed salts were oily and formed in high yields as mixtures of diastereoisomers, with cis or trans isomer predominating, depending on the method applied. The effect of the counterion present in the obtained salts was analyzed. Ylides generated from these salts in different base/solvent systems afforded products of the [1,2] Stevens rearrangement, 2‐EWG‐1‐methyl‐3‐phenylpiperidines, with the trans isomers predominating, in moderate to good yields. In case of the [1,2] shift, the yields of respective products depended on EWG present in the substrate (methoxycarbonyl, acetyl, dimethylcarbamoyl and benzoyl).
A Solvent‐Free Strategy to Synthesize MoS2/Mo2C‐Embedded, N, S Co‐Doped Mesoporous Carbon as Electrocatalysts for Hydrogen Evolution
Authors: Miao Sijia , Xu Jing , Zhang Wenting , Tang Duihai , Huang Yuan , Wang Jianjun , Zhao Zhen
Published: June 2021

A solvent‐free strategy was developed to synthesize MoS2/Mo2C embedded, N, S co‐doped carbon via a green and environmentally friendly process. The precursors were blended and carbonized under the inert atmosphere. Water and other solvents were not involved in the whole synthesis process. According to the characterization results, the as‐received samples consisted of Mo2C, MoS2, and carbon with mesoporous structures. Moreover, the obtained sample possessed a high BET surface area (373.3 m2 g−1), as well as high electrochemical active surface area (145.4 mF cm−2). When utilized as the electrocatalyst towards hydrogen evolution reaction (HER), the optimal sample of T2.0G4.0Mo1.0 revealed superior electrochemical activity in alkaline media, which could show a low overpotential and an excellent stability.
Advances of Nonlinear Photonics in Low‐Dimensional Halide Perovskites
Authors: Wang Gang , Mei Shiliang , Liao Jinfeng , Wang Wei , Tang Yuxin , Zhang Qing , Tang Zikang , Wu Bo , Xing Guichuan
Published: June 2021

Hybrid halide perovskites emerging as a highly promising class of functional materials for semiconductor optoelectronic applications have drawn great attention from worldwide researchers. In the past few years, prominent nonlinear optical properties have been demonstrated in perovskite bulk structures indicating their bright prospect in the field of nonlinear optics (NLO). Following the surge of 3D perovskites, more recently, the low‐dimensional perovskites (LDPs) materials ranging from two‐, one‐, to zero‐dimension such as quantum‐wells or colloidal nanostructures have displayed unexpectedly attractive NLO response due to the strong quantum confinement, remarkable exciton effect, and structural diversity. In this perspective, the current state of the art is reviewed in the field of NLO for LDP materials. The relationship between confinement effect and NLO is analyzed systematically to give a comprehensive understanding of the function of dimension reduction. Furthermore, future directions and challenges toward the improvement of the NLO in LDP materials are discussed to provide an outlook in this rapidly developing field.