bluuebunny/crossref_metadata_2025 huggingface dataset:
NASICON‐Type Na3Zr2Si2PO12 Solid‐State Electrolytes for Sodium Batteries**
Authors: Yang Zhendong , Tang Bin , Xie Zhaojun , Zhou Zhen
Published: January 2021

Owing to their low cost, high energy density, and reliable safety, all‐solid‐state sodium batteries have been regarded as one of the most promising candidates beyond lithium‐ion batteries. Sodium super ionic conductor (NASICON)‐structured solid‐state electrolytes (SSEs), with good electrochemical stability and environmental friendliness, are potential candidates for SSEs. In this Minireview, we summarize the basic properties of Na3Zr2Si2PO12 SSEs, including structural characteristics, preparation methods, ionic conductivity, and the strategies, substituting proper elements, optimizing preparation approaches, increasing packing density, and so forth, to improve the bulk and grain boundary conductivity. Additionally, we also analyze the challenges and approaches for interfacial modification between electrodes and SSEs in all‐solid‐state sodium batteries. Finally, future research directions for facilitating the development of all‐solid‐state sodium batteries are proposed.
Different nanofluids effect on bubble characteristics at the isothermal bubble column
Authors: Dousti Ahmad , Gharedaghi Hamed , Hanafizadeh Pedram , Ashjaee Mehdi
Published: January 2021

In this study, the effect of different nanofluids such as SiO2, Fe3O4, and Al2O3 on bubble characteristics is studied experimentally. The nanoparticles concentration for the SiO2 nanofluid is 0.05 wt% and for other nanofluids is 0.005 wt%. Bubbles are formed by injection of air at a constant gas flow rate (between 600‐1200 mL/h) into a stagnant isothermal liquid column. Experimental data of formation, growth, and detachment of the air bubbles were recorded by a high‐speed digital camera (1200 fps), and the image processing method was used to analyze the bubble characteristics. In the present study, bubble characteristics such as diameter, size, aspect ratio, and detachment frequency were studied in four different liquids. The results show that a bubble has the biggest size in the pure water and adding nanoparticles to the pure water decreases bubble size. Also, the variation of detachment frequency has an inverse relation with the bubble size behaviour. Between different nanoparticles, Fe3O4 has maximum and SiO2 has minimum effect on bubble features. By adding Fe3O4 to pure water, bubble diameter decreases nearly 7%‐8% and bubble detachment frequency increases nearly 15%‐20%. In order to analyze the variation of the bubble characteristics, a force modelling on bubbles during the growth was proposed. Moreover, a correlation has been proposed for the prediction of bubble diameter at detachment time in three different nanofluids and in the pure water. The mean absolute error of this correlation is 2.65% and has a good agreement with experimental results.
Semiparametric inference of the Youden index and the optimal cut‐off point under density ratio models
Authors: Yuan Meng , Li Pengfei , Wu Changbao
Published: January 2021

The Youden index is a popular summary statistic for receiver operating characteristic curves. It gives the optimal cut‐off point of a biomarker to distinguish the diseased and healthy individuals. In this article, we model the distributions of a biomarker for individuals in the healthy and diseased groups via a semiparametric density ratio model. Based on this model, we propose using the maximum empirical likelihood method to estimate the Youden index and the optimal cut‐off point. We further establish the asymptotic normality of the proposed estimators and construct valid confidence intervals for the Youden index and the corresponding optimal cut‐off point. The proposed method automatically covers both cases when there is no lower limit of detection (LLOD) and when there is a fixed and finite LLOD for the biomarker. Extensive simulation studies and a real data example are used to illustrate the effectiveness of the proposed method and its advantages over the existing methods.
Tuning Crystallinity and Surface Hydrophobicity of a Cobalt Phosphide Cocatalyst to Boost CO2 Photoreduction Performance
Authors: Niu Pingping , Pan Zhiming , Wang Sibo , Wang Xinchen
Published: January 2021

Photocatalytic CO2 conversion is a promising method to yield carbon fuels, but it remains challenging to regulate catalytic materials for enhanced reaction efficiency and tunable product selectivity. This study concerns the development of a facile and efficient thermal post‐treatment method to improve the crystallinity and surface hydrophobicity of a cobalt phosphide (CoP) cocatalyst, which promotes the separation and transfer of photoexcited charge carriers, reinforces CO2 chemisorption, and weakens the H2O affinity. Compared with pristine CoP, the optimal CoP‐600 cocatalyst displays a 3.5‐fold enhancement in activity and a 2.3‐fold increase in selectivity for the reduction of CO2 to CO with a high rate of 68.1 μmol h−1.
Quantification of cannabinoids in human hair using a modified derivatization procedure and liquid chromatography–tandem mass spectrometry
Authors: Al‐Zahrani Mansour A. , Al‐Asmari Ahmed I. , Al‐Zahrani Farouq F. , Torrance Hazel J. , Watson David G.
Published: January 2021

The aim of this work was to develop and validate a liquid chromatography–tandem mass spectrometry method for detecting of the main cannabinoids, cannabinol (CBN) and tetrahydrocannabinol (THC) and the primary metabolite 11‐nor‐9‐carboxy‐Δ9‐tetrahydrocannabinol (THC‐COOH) in hair samples. Extraction of the cannabinoids was carried out by a polymeric strong anion mixed‐mode solid‐phase extraction cartridge and then employing methanolic HCl followed by 2‐fluoro‐1‐methylpyridinium‐p‐toluenesulfonate (FMP‐TS) as a derivatization procedure of carboxyl and phenolic groups, respectively, offering enhanced sensitivity for the detection of THC‐COOH in hair matrices. Formation of a methyl ester increased its lipophilicity and removed the negative charge on the carboxyl group. Calibration curves were prepared over the range of 0.02–4 pg/mg of hair for THC and CBN and 0.2–12 pg/mg of hair for THC‐COOH. The extraction recovery was between 81% and 105% for all compounds. The limit of detection (LOD) and limit of quantification (LOQ) were 2 and 20 pg/mg, respectively, for both CBN and THC and 0.1 and 0.2 pg/mg, respectively, for THC‐COOH, which met the society of hair testing recommendation. Intra‐assay and interassay precision were always lower than 4% and 11%, respectively for these cannabinoids, whereas intra‐assay and interassay bias were between +14% and −18% and +15% and −12%, respectively. Twenty‐seven hair specimens from cannabis users were investigated. The concentrations of CBN, THC and THC‐COOH gave ranges of (0.022–2.562 ng/mg), (0.049–0.431 ng/mg) and (0.222–4.867 pg/mg), respectively. This new method of derivatization improves the LOD to ensure detection of the metabolite.
Alkali Metal Reduction of 1,2‐Bis[(2,6‐dibenzhydryl‐4‐methylphenyl)imino]acenaphthene (ArBIG‐bian) to Radical‐Anion
Authors: Moskalev Mikhail V. , Razborov Danila A. , Skatova Alexandra A. , Bazanov Andrey A. , Fedushkin Igor L.
Published: January 2021

Reduction of ArBIG‐bian (1, 1,2‐bis[(2,6‐dibenzhydryl‐4‐methylphenyl)imino]acenaphthene) with one molar equivalent of Li, Na or K in tetrahydrofuran (THF) affords corresponding radical‐anionic salts (ArBIG‐bian)M(THF) (M=Li, 2; Na, 3; K, 4). Compounds 2–4 were isolated in good yields and characterized by the elemental analysis, IR and ESR spectroscopy as well as the single‐crystal X‐Ray analysis. Bulky Ph2(H)C groups in ArBIG‐bian ligand prevent dimerization of complexes 2–4 and limit a number of coordinated THF molecules to one. In all three products a saturation of the alkali metal coordination sphere is achieved through an interaction with Ph rings of Ph2(H)C substituents.
Flame Retardant Modified Bio‐Based Waterborne Polyurethane Dispersions Derived from Castor Oil and Soy Polyol
Authors: Wang Chengshuang , Zhang Jie , Huang Jieru , Wang Han , He Meng , Ding Liang
Published: January 2021

Although tremendous efforts have been dedicated to developing environmentally friendly bio‐based waterborne polyurethane (WPU) dispersions from vegetable oil, the fabrication of WPU dispersions solely derived from vegetable oil‐based polyol with excellent comprehensive properties is still challenging. In the present work, novel bio‐based WPU dispersions derived from castor oil and soy polyol is successfully modified by phosphorus‐nitrogen chain extender [bis(2‐hydroxyethyl)amino]‐methyl‐phosphonic acid dimethyl ester (BH). The structure and properties of the dispersions and films are characterized systematically by Fourier transform infrared spectroscopy, thermogravimetric analysis , mechanical test, and limiting oxygen index (LOI), etc. The results indicate that bio‐based WPU films display moderate mechanical performance by adjusting BH content, and the WPU film containing
100% BH with 47.8% biobased content has a tensile strength of 8 MPa and the highest Young's modulus of 62.3 MPa. The incorporation of BH can increase the production of char residue. The flame retardancy of WPU films increase gradually with the BH molar content, and the LOI value of the WPU100 with 1.53 wt% phosphorus content can reach as high as 28.1%. This work may provide a new approach to develop high biobased content, eco‐friendly, flame retardant WPU for application in the surface coating industry.
Effects of Moisture and Amphiphilic Compounds on the Oxidative Stability of Microwave‐Treated Corn Oil
Authors: Na HeeSun , Choi Hyuk , Lee YoonHee , Lee JaeHwan
Published: January 2021

Effects of moisture and amphiphilic compounds, including oleic acid, lecithin, and monoacylglycerols (MAGs), on the oxidative stability are evaluated in microwave‐treated corn oil. Moreover, the physical properties including critical micelle concentration (CMC) and moisture content are determined in oils treated by microwave irradiation. The CMC of lecithin and moisture content of oils decreases remarkably, whereas the temperature of the oil increases rapidly with microwave irradiation. The addition of lecithin results in increased moisture content significantly in the edible oils, whereas oleic acid and MAGs do not exhibit these effects. Primary oxidation products in all the oil samples increase, despite the type of amphiphilic compounds used. Corn oil containing oleic acid and samples with lecithin exhibits lower and higher p‐anisidine values (p‐AV), respectively. Remarkably high moisture content in corn oils containing lecithin may contribute to the formation of volatile compounds and high p‐AV. Collectively, moisture and amphiphilic compounds affect the degree of lipid oxidation in microwave‐irradiated bulk oils.

Practical application: A microwave oven is an irreplaceable home appliance and is widely used in households nowadays. Effects of amphiphilic compounds and moisture on the oxidative stability are evaluated and it is found that the amphiphilic compounds in lipids affect heat transfer and oxidative stability of oils. The results of this study can provide fundamental insights into lipid oxidation in edible oils, and can provide a direction to the food industry with respect to the development of more efficient and safe methods for the preparation of microwavable foods.
Competencies, Self‐awareness, and Practice: Notes on My Reading of Chapters 5–7
Authors: Hall Melvin E.
Published: January 2021

As part of this NDE issue with its focus on the 2018 American Evaluation Association (AEA) Evaluator Competencies, this chapter discusses the content and delivery of material in Chapters 5 through 7. The reviewed chapters, and therefore this article, address potential uses of the 2018 AEA Evaluator Competencies to promote professional self‐knowledge, enhance education and training programs for new and in‐service professionals, and facilitate evaluator and evaluation pursuit of social justice. This chapter will assist readers of these chapters by providing a review from the perspective of an experienced evaluation professional. Its critiques and related admonitions to the profession are the sole and independent opinions of the author.
Next Steps for AEA and the Newly Created AEA Professionalization and Competencies Working Group
Authors: Tucker Susan A. , King Jean A.
Published: January 2021

The final chapter summarizes the content of Parts I and II, addresses issues raised by our critical friends in Chapters 4 and 8, and offers multiple steps that the newly formed American Evaluation Association (AEA) Professionalization and Competencies Working Group may consider exploring when it addresses its three charges. Overall suggestions include four areas of activity: continuing development of the competencies, encouragement of voluntary use in a variety of spheres, extensive engagement of the AEA membership, and exploration of additional ways to professionalize the field. A summary table identifies specific recommendations from this issue's chapters.
Protein expression alteration in hippocampus upon genetic repression of AMPKα isoforms
Authors: Yang Wenzhong , Zhou Xueyan , Wang Xin , Lee Jingyun , Wu Dan , Sun Peiqing , Furdui Cristina M. , Ma Tao
Published: January 2021

The AMP‐activated protein kinase (AMPK) is a molecular sensor to help maintain cellular energy homeostasis. AMPK is a heterotrimeric complex and its enzymatic catalytic subunit includes two isoforms: α1 and α2. Dysregulation of AMPK signaling is linked to neuronal diseases characterized with cognitive impairments. Emerging evidence also suggest isoform‐specific roles of AMPK in the brain. AMPK regulates protein synthesis, which is critical for memory formation and neuronal plasticity. However, the consequence of altering AMPK activity on the translation of specific proteins in the brain is unknown. Here, we use unbiased mass spectrometry‐based proteomics approach to analyze protein profile alterations in hippocampus and prefrontal cortex of transgenic mice in which the genes for the two AMPKα isoforms are conditionally deleted. The study revealed identities of proteins whose expression is sensitive to suppression of AMPKα1 and/or α2 isoform. These data may serve as a basis for future in‐depth study. Elucidation of the functional relevance of the alteration of specific proteins could provide insights into identification of novel therapeutic targets for neuronal disorders characterized with AMPK signaling dysregulation and impaired cellular energy metabolism.
Acute caffeine intake in humans reduces post exercise performance in learning and memory
Authors: Berg Jade , Cooper Jesse , Salonikas Chris , Seyedsadjadi Neda , Grant Ross
Published: January 2021

Abstarct

Objective

To clarify the acute effect of caffeine on postexercise memory and learning performance.

Methods

Eight male slow‐to‐normal caffeine metabolizers, unhabituated to caffeine, were recruited into this randomized, double blind, placebo controlled, cross over study. Caffeine (150 mg) or the placebo was consumed one hour prior to two 30 min submaximal cycling sessions. Blood was collected at the beginning, after 20 and 35 min of exercise and 30 min postexercise. Mature brain‐derived neurotrophic factor (BDNF) and proBDNF concentrations were determined. Auditory memory was assessed immediately, 30 min and 24 h postexercise.

Results

Participants averaged lower scores in every measure of learning and memory after ingesting caffeine compared to the placebo. Although the mean did not differ significantly for all measures, significant differences were found between the caffeine and placebo groups for the three indices; learning over time, short‐term index and retroactive interference. The ratio of serum mBDNF:proBDNF increased with exercise across all time points. No significant difference in the mBDNF:proBDNF ratio was observed between treatment groups.

Conclusion

The consumption of caffeine prior to exercise may impair an unhabituated individual's capacity to learn and recall auditory information postexercise. However it is yet to be elucidated whether this is through caffeine's modulating effects on brain BDNF.
A prospective study on the course of sleep disturbances in first‐time fathers during the transition to parenthood
Authors: Da Costa Deborah , Lai Jonathan K. , Zelkowitz Phyllis
Published: January 2021

Introduction

This study examined sleep disturbances in first‐time fathers from the third trimester of their partner's pregnancy to 2 months postpartum to determine prevalence, incidence, and persistence of sleep disturbances and identify associated determinants.

Methods

Men expecting their first child were recruited from local prenatal classes and university‐affiliated obstetric clinics. During their partner's third trimester of pregnancy and 2 months postpartum, 459 men completed standardized online self‐report questionnaires measuring sociodemographics, lifestyle, and psychosocial variables and sleep quality.

Results

Disturbed sleep (Pittsburgh Sleep Quality Index [PSQI] global score >5) increased from 29.6% during the third trimester to 44.7% at 2 months postpartum. The incidence of poor sleep at 2 months postpartum was 33.7%. Among men with disturbed sleep at the antenatal assessment, 70.6% continued to have sleep disturbances at 2 months postpartum. An increase in depressive symptoms and higher parenting stress was independently associated with onset and persistence of disturbed sleep at 2 months postpartum.

Conclusions

Sleep is compromised in expectant and new fathers. Strategies aimed at improving sleep, depressed mood, and managing the challenges of parenting may be important components to include in prenatal interventions aimed at enhancing the transition to parenthood and infant development.
Does CEO pay slice reflect poor corporate governance?
Authors: Lel Ugur , Tepe Mete
Published: January 2021

We examine whether high CEO pay inequality, measured by the share of total managerial pay captured by the CEO (CEO pay slice or CPS), is an outcome of poor corporate governance, and its implications for shareholder wealth. We exploit the 2002 NYSE and NASDAQ governance reforms that mandated firms to have majority independent boards as a quasi‐exogenous source of variation in the internal governance environment of firms. Results show that CPS decreases following the passage of these exchange listing regulations, for firms with entrenched CEOs affected by the exchange listing regulations. Firm value also increases for firms that likely suffer from agency conflicts in the pre‐regulation period. The novelty of our paper stems from combining the difference‐in‐difference estimation with CPS as a measure of CEO compensation, reducing the endogeneity concerns. Our paper links board independence, CPS, CEO entrenchment, and firm value by documenting that the impact of governance reforms on CPS is conditional on CEO entrenchment. Overall, our results suggest that poor corporate governance environments are associated with high CPS and consequently lower firm valuations, supporting the view that high CEO pay inequality reflects managerial entrenchment.
Comparative hematopoiesis and signal transduction in model organisms
Authors: Gautam Dushyant Kumar , Chimata Anuradha Venkatakrishnan , Gutti Ravi Kumar , Paddibhatla Indira
Published: January 2021

Hematopoiesis is a continuous phenomenon involving the formation of hematopoietic stem cells (HSCs) giving rise to diverse functional blood cells. This developmental process of hematopoiesis is evolutionarily conserved, yet comparably different in various model organisms. Vertebrate HSCs give rise to all types of mature cells of both the myeloid and the lymphoid lineages sequentially colonizing in different anatomical tissues. Signal transduction in HSCs facilitates their potency and specifies branching of lineages. Understanding the hematopoietic signaling pathways is crucial to gain insights into their deregulation in several blood‐related disorders. The focus of the review is on hematopoiesis corresponding to different model organisms and pivotal role of indispensable hematopoietic pathways. We summarize and discuss the fundamentals of blood formation in both invertebrate and vertebrates, examining the requirement of key signaling nexus in hematopoiesis. Knowledge obtained from such comparative studies associated with developmental dynamics of hematopoiesis is beneficial to explore the therapeutic options for hematopoietic diseases.
The effect of deposition times in DC‐magnetron sputtering on micromorphology of TiO2 thin films
Authors: Rezaee Sahar
Published: January 2021

TiO2 thin films have been prepared by DC‐magnetron sputtering process with various deposition times (8, 14, 16, and 20 min) and the micromorphology of their surface has been investigated by means of multifractal analysis. As the main purpose of the manuscript, the topography of all samples are examined by atomic force microscopy (AFM) through the Mountains Map® Premium software which characterizes motifs of significant peaks and pits through stereometric data by the watershed segmentation algorithm. In addition, multifractal features of samples provide deeper insight into texture characteristics and used as the supplementary of the results.
Cadmium and antibiotic‐resistant Acinetobacter calcoaceticus strain STP14 reported from sewage treatment plant
Authors: Din Ghufranud , Farooqi Asifa , Sajjad Wasim , Irfan Muhammad , Gul Sarah , Ali Shah Aamer
Published: January 2021

A bacterium designated as strain STP14 was isolated from a sewage treatment plant and identified as Acinetobacter calcoaceticus based on 16S ribosomal RNA gene sequencing. Strain STP14 exhibited resistance to several metals such as mercury, cobalt, copper, nickel, lead, and cadmium. Among these metals, the bacterium showed maximum resistance to cadmium in concentration up to 1200 mg/L. The antimicrobial susceptibility test of A. calcoaceticus strain STP14 showed coresistance to all tested antibiotics except tigecycline and chloramphenicol for which 16 ± 1‐ and 15 ± 1‐mm zone of inhibition was observed, respectively. The protein pattern of the crude cellular extract revealed substantial differences in protein bands of untreated control and cadmium treated A. calcoaceticus strain STP14 suggesting variable protein expression under cadmium stress. Metals and antibiotic resistance are increasing phenomenon and universal concern of public health. This study improves our understanding regarding the bacterial coresistance against metals and antibiotics and the possible emergence of multidrug resistance due to selective pressure and coselection in the metal polluted sewage sludge.
The influence of acute water stresses on the biochemical composition of bell pepper (Capsicum annuumL.) berries
Authors: Borràs Dionis , Plazas Mariola , Moglia Andrea , Lanteri Sergio
Published: January 2021

BACKGROUND

Crops are exposed to recurrent and acute drought stress episodes during their vegetative and reproductive cycles, and these episodes are increasingly frequent due to ongoing climate change. Sweet pepper (Capsicum annuum), alias bell pepper, is one of the most widely cultivated vegetables and is grown in open fields worldwide. Here we assessed the effect of acute water stress, applied to a breeding line of sweet pepper at three stages of plant development: five true‐leaves (Stage 1), production of the third flower (Stage 2) and setting of the first fruit (Stage 3), on the production and biochemical composition of its ripe fruits.

RESULTS

The water stress at Stages 1 and 2 induced a delay in fruit ripening, while at Stage 3 caused a drop in production. The biochemical composition of ripe fruits was assessed by quantifying their content in vitamin C, sugars, organic acids, flavonoids as well as 190 volatile organic compounds, mainly belonging to the chemical classes of hydrocarbons, alcohols, ketones, esters, terpenes, aldehydes and ethers. Our results highlight that, at different stages of plant development, acute water stresses modulate differently the accumulation of bioactive compounds in fruits, which play a key role in setting the redox‐status and osmotic adjustment of the plant. This was also the case for volatile compounds since, within each chemical class, different compounds varied their content in ripe fruits.

CONCLUSIONS

On the whole, our results demonstrate that water stresses potentially affect the organoleptic and sensory qualities of bell pepper fruits depending on when they occur. © 2021 Society of Chemical Industry
Particle packed mixed‐mode chromatographic stationary phase for the separation of peptide in liquid chromatography
Authors: Ali Faiz , Cheong Won Jo , Rafique Aamra , AlOthman Zeid A. , sadia Maria , Muhammad Mian
Published: January 2021

A particle‐based stationary phase has been prepared for the separation of five synthetic peptides and a mixture containing tryptic digest of cytochrome C in liquid chromatography. Particles originating from silica monolith were differentially sedimented to obtain 1–2 μm particles. A stationary phase was achieved by the coating of poly(styrene‐methacrylic acid‐N‐phenylacrylamide) copolymer onto the particles via reversible addition‐fragmentation chain transfer polymerization reaction. Stainless steel column (30 cm long and 1 mm internal diameter) was packed with stationary phase. Very high separation efficiency (ca. 351 000 plates/m) was achieved for five commercial peptides with a percent relative standard deviation of less than 1%. Protocol for the synthesis and modification of silica monolith particles has been well optimized with a good reproducibility both in particle and pore size. The column resolved about 21 peptide components from a mixture containing tryptic digest of cytochrome C, under the elution conditions of acetonitrile/15 mM ammonium format (65/35 v/v%) with a flow rate of 28 μL/min.
A Narrative Review of Pharmacologic Treatments for COVID‐19: Safety Considerations and Ototoxicity
Authors: Little Christine , Cosetti Maura K.
Published: January 2021

Objective/Hypothesis

The purpose of this review is to summarize evidence‐based data regarding the ototoxic effects of potential COVID‐19 therapeutics to treat patients suffering from SARS‐CoV‐2.

Methods

Medications under investigation as novel therapeutics to treat COVID‐19 were identified using the search term coronavirus therapeutics, COVID therapeutics, and SARS‐CoV‐2 therapeutics on ClinicalTrials.gov and the PubMed Database. A literature review was performed using the PubMed Database for each proposed COVID‐19 therapeutic to identify relevant articles. Search criteria included Medical Subject Headings (MeSH) and key word search terms for ototoxicity, vestibulotoxicity, hearing disorders, and vertigo.

Results

Six proposed COVID‐19 therapeutics were identified as possessing ototoxic side effects including chloroquine and hydroxychloroquine, azithromycin, lopinavir‐ritonavir, interferon, ribavirin, and ivermectin.

Conclusions

Available evidence suggests that ototoxic effects may be improved or mitigated by stopping the offending agent. Recognition of hearing loss, tinnitus, or imbalance/vertigo is therefore crucial to facilitate early intervention and prevent long‐term damage. Hospitals should consider the inclusion of audiologic monitoring protocols for patients receiving COVID‐19 therapeutics with known ototoxicity, especially in high‐risk patient groups such as the elderly and hearing impaired. Laryngoscope, 131:1626–1632, 2021
Outcomes in Living Donor Compared With Deceased Donor Primary Liver Transplantation in Lower Acuity Patients With Model for End‐Stage Liver Disease Scores <30
Authors: Kitajima Toshihiro , Moonka Dilip , Yeddula Sirisha , Collins Kelly , Rizzari Michael , Yoshida Atsushi , Abouljoud Marwan S. , Nagai Shunji
Published: January 2021

Although recent studies have reported favorable outcomes in living donor liver transplantation (LDLT), it remains unclear which populations benefit most from LDLT. This study aims to evaluate LDLT outcomes compared with deceased donor LT (DDLT) according to Model for End‐Stage Liver Disease (MELD) score categories. Using data from the United Network for Organ Sharing registry, outcomes were compared between 1486 LDLTs; 13,568 donation after brain death (DBD)‐DDLTs; and 1171 donation after circulatory death (DCD)‐DDLTs between 2009 and 2018. Because LDLT for patients with MELD scores >30 was rare, all patients with scores >30 were excluded to equalize LDLT and DDLT cohorts. Risk factors for 1‐year graft loss (GL) were determined separately for LDLT and DDLT. Compared with LDLT, DBD‐DDLT had a lower risk of 30‐day (adjusted hazard ratio [aHR], 0.60; P < 0.001) and 1‐year GL (aHR, 0.57; P < 0.001). The lower risk of GL was more prominent in the mid‐MELD score category (score 15‐29). Compared with LDLT, DCD‐DDLT had a lower risk of 30‐day GL but a comparable risk of 1‐year GL, regardless of MELD score category. In LDLT, significant ascites was an independent risk for GL in patients with mid‐MELD scores (aHR, 1.68; P = 0.02), but not in the lower‐MELD score group. The risk of 1‐year GL in LDLT patients with ascites who received a left liver was higher than either those who received a right liver or those without ascites who received a left liver. In LDLT, combinations of MELD scores of 15 to 29, moderate/severe ascites, and the use of a left liver are associated with worse outcomes. These findings help calibrate appropriate patient and graft selection in LDLT.
Gut Microbial Signature of Hepatocellular Cancer in Men With Cirrhosis
Authors: Albhaisi Somaya , Shamsaddini Amirhossein , Fagan Andrew , McGeorge Sara , Sikaroodi Masoumeh , Gavis Edith , Patel Samarth , Davis Brian C. , Acharya Chathur , Sterling Richard K. , Matherly Scott , Fuchs Michael , Gillevet Patrick M. , Bajaj Jasmohan S.
Published: January 2021

The gut microbiome is altered in cirrhosis. Recent evidence has suggested a key role for the gut microbiota in the progression of cirrhosis and the development of hepatocellular carcinoma (HCC). We studied the differences in the microbial composition in patients with cirrhosis with prior and future HCC in the context of other complications (eg, infections, hepatic encephalopathy). The following 2 cohorts were recruited prospectively: the prior HCC cohort, in which outpatients with HCC within 2 years were age‐matched, sex‐matched, and Model for End‐Stage Liver Disease (MELD) score–matched with those without HCC; and the future HCC cohort, in which patients were followed for 2 years and divided into future HCC versus no HCC after age, sex, and MELD‐score matching and other complications were also recorded. Microbiota composition and predicted function were analyzed with ribosomal RNA sequencing and Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PiCRUST)and compared between (1) prior HCC versus none and (2) future HCC versus none, and in the future cohort, comparisons were also made between those patients who developed (1) HCC only versus without complications, (2) HCC only versus non‐HCC complications only, and (3) HCC + other complications versus non‐HCC complications only. A total of 142 men (76 total in the prior cohort [38 with/38 without HCC] and 66 total in the future cohort [33 with/33 without future HCC]) were included. The groups had similar etiology, lactulose/rifaximin/proton pump inhibitor use, diabetes mellitus, and non‐HCC complications. Microbial diversity was similar between prior HCC/not or future HCC/not. On DESeq2 higher Clostridium sensu stricto and Anaerotruncus were significantly associated with protection from HCC, whereas the reverse was seen with Raoultella and Haemophilus regardless of prior/future HCC comparisons. Functions focused on urea cycle, bioenergetics, tryptophan, and toluene metabolism were different between the groups. Rothia was specific for other complications. Despite age, sex, and MELD‐score matching and accounting for other complications, gut microbiota composition and the predicted function are different in men with cirrhosis with and without prior HCC and can be extended toward future HCC development.
Biobased Polyester‐Amide/Cellulose Nanocrystal Nanocomposites for Food Packaging
Authors: Rader Chris , Weder Christoph , Marti Roger
Published: January 2021

The worldwide plastic waste production is steadily increasing, since the use of polymeric materials continues to rise. One area of particular high plastic consumption is food packaging. Flexible and rigid packaging films are typically made from petrochemical‐sourced polymers, which are utilized because of their low cost, ductility, melt‐processability, and gas barrier properties, but a major downside is their inability to biodegrade in a reasonable time. Packaging‐relevant properties of nanocomposites based on polyester‐amides (PEAs) are reported, which are chosen on account of their tunable crystallinity, biobased starting materials, and biodegradability. These polymers are synthesized via melt polycondensation of a building block made from caprolactone and 1,4‐diaminobutane, with the addition of 1,4‐butanediol and dimethyl adipate. The fraction of the amide segment is varied between 25 and 75 mol%. The oxygen transmission rate (O2TR) drops upon increasing the amide content from 1.6 × 105 to 2.9 × 10−4 cm3 m−2 d−1 on account of increasing crystallinity. In order to improve the gas barrier properties further, nanocomposites of the PEAs and 1–10 wt% cellulose nanocrystals (CNCs) are prepared. These nanocomposites have indeed lower O2TR values than the neat PEAs, with reductions of as much as 50% for a CNC content of 10 wt%.
Different ion mobility‐mass spectrometry coupling techniques to promote metabolomics
Authors: Delvaux Aurélie , Rathahao‐Paris Estelle , Alves Sandra
Published: January 2021

Metabolomics has become increasingly popular in recent years for many applications ranging from clinical diagnosis, human health to biotechnological questioning. Despite technological advances, metabolomic studies are still currently limited by the difficulty of identifying all metabolites, a class of compounds with great chemical diversity. Although lengthy chromatographic analyses are often used to obtain comprehensive data, many isobar and isomer metabolites still remain unresolved, which is a critical point for the compound identification. Currently, ion mobility spectrometry is being explored in metabolomics as a way to improve metabolome coverage, analysis throughput and isomer separation. In this review, all the steps of a typical workflow for untargeted metabolomics are discussed considering the use of an ion mobility instrument. An overview of metabolomics is first presented followed by a brief description of ion mobility instrumentation. The ion mobility potential for complex mixture analysis is discussed regarding its coupling with a mass spectrometer alone, providing gas‐phase separation before mass analysis as well as its combination with different separation platforms (conventional hyphenation but also multidimensional ion mobility couplings), offering multidimensional separation. Various instrumental and analytical conditions for improving the ion mobility separation are also described. Finally, data mining, including software packages and visualization approaches, as well as the construction of ion mobility databases for the metabolite identification are examined.
Modeling Study of Propane/Propylene Membrane Separation Using CFD Method
Authors: Safaei Siamak , Zeynali Rahman , Safaei Babak
Published: January 2021

Based on the wide applications of olefins in industries, especially in petrochemical industries which are among the major income sources, the separation of olefins from paraffin with membrane processes has been considered. Therefore, for the investigation of the performance of membrane processes, modeling can be used as a suitable and low‐cost method to estimate and predict the performance of these processes. In this research, membrane separation of propane/propylene is investigated, and then the performance of one‐step membrane unit and operational parameters such as temperature, pressure, membrane surface, and stage cut for current and cocurrent flow patterns are analyzed using computational fluid dynamic method which according to the obtained results the membrane process has high potential for this kind of separation. In all parameters investigation, the flow direction shows sensible effect, and in all of the parameters, countercurrent flow has more positive effect in comparison with cocurrent condition.
The Chebyshev collocation method for a class of time fractional convection‐diffusion equation with variable coefficients
Authors: Saw Vijay , Kumar Sushil
Published: January 2021

In this paper, an efficient and accurate computational scheme based on the Chebyshev collocation method and finite difference approximation is proposed to solve the time‐fractional convection‐diffusion equation (TFCDE) on a finite domain. The time fractional‐order derivativeμ ∈ (0, 1]is considered in the Caputo sense. The finite‐difference approximation is used in time direction while the Chebyshev collocation method is used in space direction to reduce the TFCDE into a system of algebraic equations. We also illustrate the error and convergence analysis of the proposed scheme. The proposed method is very convenient for solving such problems since the initial and boundary conditions are automatically taken into account. The efficiency and accuracy of the proposed algorithm are examined through some examples and comparisons with existing methods.
Solving the team orienteering problem with nonidentical agents: A Lagrangian approach
Authors: Chakraborty Shuvabrata , Agarwal Yogesh K.
Published: January 2021

The team orienteering problem (TOP) requires a team of time‐constrained agents to maximize the total collected profit by serving a subset of given customers. The exact solution approaches for TOP in the literature have considered only the case of identical agents, even though the heterogeneity of the agents is of essence in many applications. The heuristic approaches, on the other hand, although providing good feasible solutions, do not offer any measure of solution quality, such as an optimality gap. In this study, we consider an extension of the conventional TOP in which the agents are allowed to be identical as well as completely nonidentical. We explore a Lagrangian relaxation based approach that simultaneously obtains tight upper and lower bounds on the optimal solution of the problem and, therefore, provides a measure of solution quality by way of duality gap. Our algorithm achieves an average gap of less than 2% within an average time of around 120 s across 135 randomly generated instances with up to 100 customers and five nonidentical agents. We also introduce a new set of valid symmetry breaking constraints that significantly improves the effectiveness of our formulation and Lagrangian implementation for the case of identical agents. For the three most difficult sets of benchmark instances for TOP with identical agents, our approach achieves upper bounds that are, on average, 1.08% above the best‐known solutions, and feasible solutions that are 0.35% below the best‐known solutions. The average time taken to solve these problems was about 115 s.
A new and efficient numerical method based on shifted fractional‐order Jacobi operational matrices for solving some classes of two‐dimensional nonlinear fractional integral equations
Authors: Maleknejad Khosrow , Rashidinia Jalil , Eftekhari Tahereh
Published: January 2021

The aim of this paper is to present a new and efficient numerical method to approximate the solutions of two‐dimensional nonlinear fractional Fredholm and Volterra integral equations. For this aim, the two‐variable shifted fractional‐order Jacobi polynomials are introduced and their operational matrices of fractional integration and product are derived. These operational matrices and shifted fractional‐order Jacobi collocation method are utilized to reduce the understudy equations to systems of nonlinear algebraic equations. Then, the arising systems can be solved by the Newton method. Discussion on the convergence analysis and error bound of the proposed method is presented. The efficiency, accuracy, and validity of the presented method are demonstrated by its application to three test examples and by comparing our results with the results obtained by existing numerical methods in the literature recently.
Adiposity Measures and Morning Serum Cortisol in African Americans: Jackson Heart Study
Authors: Kluwe Bjorn , Zhao Songzhu , Kline David , Ortiz Robin , Brock Guy , Echouffo‐Tcheugui Justin B. , Sims Mario , Kalyani Rita R. , Golden Sherita H. , Joseph Joshua J.
Published: January 2021

Objective

Altered hormonal regulation, including cortisol, is a proposed mechanism linking adiposity to obesity‐related disorders. We examined the association of anthropometric, adipokine, and body fat distribution measures of adiposity with morning serum cortisol in an African American (AA) cohort.

Methods

We investigated the cross‐sectional associations of adiposity measures (BMI, waist circumference, leptin, adiponectin, leptin:adiponectin ratio, subcutaneous and visceral adipose tissue) and liver attenuation with cortisol in the Jackson Heart Study. Linear regression models were used to analyze the association between exposures and cortisol. Models were adjusted for multiple covariates.

Results

Among 4,211 participants, a 1‐SD higher BMI and waist circumference were associated with a 3.92% and 3.05% lower cortisol, respectively. A 1‐SD higher leptin and leptin:adiponectin ratio were associated with a 6.48% and 4.97% lower morning serum cortisol, respectively. A 1‐SD higher subcutaneous adipose tissue was associated with a 4.97% lower cortisol (all P < 0.001). There were no associations of liver attenuation or visceral adipose tissue with cortisol.

Conclusions

Several measures of adiposity are associated with lower morning serum cortisol among AAs, with leptin having the greatest magnitude. Future studies examining the role of morning serum cortisol in the pathway from adiposity to cardiometabolic disease in AAs are warranted.
Interpregnancy Weight Change and Gestational Diabetes Mellitus: A Systematic Review and Meta‐Analysis
Authors: Martínez‐Hortelano Jose Alberto , Cavero‐Redondo Iván , Álvarez‐Bueno Celia , Díez‐Fernández Ana , Hernández‐Luengo Montserrat , Martínez‐Vizcaíno Vicente
Published: January 2021

Objective

This study aimed to synthesize evidence regarding the association between interpregnancy weight change (IPWC) and gestational diabetes mellitus (GDM) in the subsequent pregnancy.

Methods

MEDLINE, EMBASE, Cochrane Library, and Web of Science were searched from inception to May 10, 2020. This review included studies that reported the association between IPWC and GDM in the subsequent pregnancy without restriction on study design, IPWC classification, or parity. The “no weight change” interpregnancy category was defined by each study, and data were synthesized to analyze the risk of GDM according to weight change.

Results

Thirteen observational studies were included. A higher risk of GDM in the subsequent pregnancy when there was interpregnancy weight gain (odds ratio [OR] = 1.56; 95% CI: 1.30‐1.83; I2 = 82.30%) was found. However, interpregnancy weight loss was associated with lower risk of GDM in the subsequent pregnancy (OR = 0.83; 95% CI: 0.68‐0.98; I2 = 58.10%), but the decrease in the risk of GDM in the subsequent pregnancy was greater among women with pregestational BMI higher than 25 kg/m2 (OR = 0.58; 95% CI: 0.39‐0.77; I2 = 0.00%).

Conclusions

The risk of GDM in the subsequent pregnancy increases with interpregnancy weight gain, whereas it decreases with interpregnancy weight loss.
Alpha‐Melanocyte–Stimulating Hormone is Elevated in Hypothalamic Obesity Associated with Childhood Craniopharyngioma
Authors: Emet Dicle Canoruc , Ozon Alev , Alikasifoglu Ayfer , Kandemir Nurgun , Gonc Nazlı
Published: January 2021

Objective

The purpose of this study was to investigate the peripheral concentrations of leptin and neuropeptides taking part in the melanocortin pathway in hypothalamic obesity (HO) associated with craniopharyngioma (CP) and to find a peripheral marker for diagnosis.

Methods

Thirty‐one patients (52% girls; median age 16 years) with CP were enrolled in the study group. They were grouped as CP with obesity (CPobesity, n = 17) and CP without obesity (CPnonobesity, n = 14). Two control groups without CP consisted of 27 children with obesity (OC) (55% girls; median age 13.8 years) and 25 children without obesity (normal control [NC]) (72% girls; median age 14.5 years). Obesity was defined as BMI percentile ≥ 95%. Fasting serum concentrations of leptin, brain‐derived neurotrophic factor (BDNF), and alpha‐melanocyte–stimulating hormone (α‐MSH) were measured in the groups.

Results

Leptin and BDNF concentrations were correlated with BMI SD score (SDS) in controls (OC + NC) and CP. However, there was no correlation between α‐MSH and BMI‐SDS in CP or control groups. After adjusting for age, sex, and BMI‐SDS, α‐MSH was found to be significantly higher in CPobesity than in other groups, whereas leptin and BDNF were comparable among the four groups.

Conclusions

Serum BDNF, just like leptin, increased with BMI, regardless of hypothalamic damage. On the contrary, α‐MSH concentration was significantly high in HO, designating a potential biomarker for HO in CP.
Maximum principle of optimal control of a Cahn–Hilliard–Navier–Stokes model with state constraints
Authors: Tachim Medjo Theodore , Tone Cristina , Tone Florentina
Published: January 2021

We investigate in this article Pontryagin's maximum principle for a class of control problems associated with a Cahn–Hilliard–Navier–Stokes model in a two dimensional bounded domain. The model consists of the Navier–Stokes equations for the velocity v, coupled with a Cahn–Hilliard model for the order (phase) parameter . We derive Pontryagin's maximum principle for the control problems assuming that a solution exists. Let us note that the coupling between the Navier–Stokes and the Cahn–Hilliard systems makes the analysis of the control problem more involved.
Impact of economic policy uncertainty on CO2 emissions in the US: Evidence from bootstrap ARDL approach
Authors: Syed Qasim Raza , Bouri Elie
Published: January 2021

Environmental degradation, global warming, and climate change have become eminent risk factors posing a serious threat to global security. One of the reasons behind those risk factors is greenhouse gases (GHGs) that are mainly consisted of carbon dioxide (CO2) emissions. Previous studies try to discern the economic and noneconomic determinants of CO2 emissions to impede environmental degradation. However, the impact of economic policy uncertainty (EPU) on CO2 emissions remains largely understudied. To address this gap, this study examines the impact of EPU on CO2 emissions in the US using a novel methodology of bootstrap ARDL approach that allows for discerning heterogeneity in the impacts between the short run and the long run. The results indicate that EPU intensifies CO2 emissions in short run, suggesting that high EPU is responsible for environmental degradation in the short run. Conversely, in long run, EPU plunges CO2 emissions, implying that high EPU ameliorates environmental quality in the long run. Such evidence on trade‐off between EPU and CO2 emissions implies that policymakers should adopt measures to reduce EPU in the short run to improve environmental quality. In long run, if policymakers seek to simultaneously control EPU and CO2 emissions, they should search for alternate ways (e.g., renewable energy consumption) to mitigate CO2.
Vorticity‐stream function approaches are inappropriate to solve the surface Navier‐Stokes equation on a torus
Authors: Nitschke Ingo , Reuther Sebastian , Voigt Axel
Published: January 2021

The growing interest in interfacial flows in engineering and biological applications demands to numerically solve the incompressible surface (Navier)‐Stokes equation. A common approach, based on a vorticity‐stream function formulation reformulates the equation into a system of scalar‐valued surface partial differential equations, for which various numerical methods have been developed. However, on surfaces, which are not simply connected, this approach is not appropriate. We here explain the underlying situation and provide details and examples.