bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linear segmented polyurethanes. III. Mathematical model for a two‐steps polymerization
Authors: Polo Mara L. , Spontón Marisa E. , Huespe Alfredo , Estenoz Diana A. , Meira Gregorio R. 
Published: August 2020

AbstractIn the first article of this sequel (J. Appl. Polym. Sci., 2018, 135, 45747), an experimental and theoretical investigation was developed on the two‐steps synthesis of linear segmented thermoplastic polyurethanes. The reactions were carried out at 60°C, with methylene diphenyl diisocyanate (MDI), two poly(tetramethylene oxide) macrodiols, and 1,4‐butanediol (BD) as chain extender. In our second article (J. Appl. Polym. Sci., 2019, 136, 46946), a mathematical model for the prepolymerization was developed, that involved integrating a differential equation for each generated polymer species. The present article extends such model, and predicts the molecular structure along the finishing stage. In each stage, the new model first solves the molar balances at polymer topologies level (i.e.,: Disregarding the molar mass distribution [MMD] of the reacted macrodiol chains), and then calculates the MMD of the evolving polymer and its main subsets through an algebraic convolution procedure. The model reproduces the prepolymerization predictions of our previous article, but is three orders of magnitude faster. In the finishing stage, up to 156,000 polymer topologies and 4.53 × 108 polymer species were calculated; and the rate constant was readjusted to (k2 = 0.00129 L mol−1 s−1), in order to fit the measured MMDs.
Thermo‐responsive block copolymer micelle‐supported (S)‐α,α‐diphenylprolinol trimethylsilyl ether for asymmetric Michael addition of nitroalkenes and aldehydes in water
Authors: Li Tao , Wang Weilin , Wang Songmeng , Liu Lingyan , Chang Weixing , Li Jing 
Published: August 2020

AbstractAn amphiphilic block copolymer PNIPAM53‐b‐(PS30‐co‐P4AMS10) was facilely prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization. The immobilization of (S)‐α,α‐diphenylprolinol trimethylsilyl ether onto the block copolymers was then performed through using copper‐catalyzed alkyne‐azide cycloaddition (CuAAC), and the generating amphiphilic diblock copolymer supported chiral catalyst PNIPAM53‐b‐(PS30‐co‐P4AMS10)/proTMS was self‐assembled into micelles with regular diameters about 50 nm in aqueous solution. The micellar catalyst was further used for the asymmetric Michael reaction between propanal and trans‐β‐nitrostyrene in water. Using only 1 mol% micellar catalyst, the corresponding Michael addition products could be obtained in good yields and high enantioselectivities as well as good diastereoselectivities. In addition, this micellar catalyst could be reused at least for four times. Moreover, the micellar catalyst could be applied for the asymmetric addition reaction of 4‐chlorocinnamyl aldehyde and nitromethane, and thus constructing the baclofen pharmaceutical intermediate.
Fabrication of co‐PVDF/modacrylic/SiO2 nanofibrous membrane: Composite separator for safe and high performance lithium‐ion batteries
Authors: Al Rai Adel , Stojanovska Elena , Akgul Yasin , Khan Mohammad Mansoob , Kilic Ali , Yilmaz Safak 
Published: August 2020

AbstractHighly porous free‐standing co‐poly(vinylidene fluoride)/modacrylic/SiO2 nanofibrous membrane was developed using electrically‐assisted solution blow spinning method. The performance and the potential of the membrane as a lithium‐ion battery separator were investigated. The addition of modacrylic enhanced the solution spinnability that resulted in defect‐free membranes. Moreover, the presence of modacrylic enhanced the dimensional and thermal stabilities, while the addition of hydrophilic SiO2 nanoparticle enhanced both mechanical property and ionic conductivity. Combustion test results illustrated that the presence of modacrylic provide flame retarding property over a set of different polymeric‐based membranes. Electrochemical performance results showed that the developed membrane can increase the battery capacity compared with the commercial separator.
Evaluation of the removal of n‐butanol vapor by the poly(lactic acid)‐zeolite‐TiO2 composite and formation of by‐products
Authors: Miranda Luciana Gampert , Peglow Carolina Pereira , Deorristt Victória Cardoso , Sales Neto Geórgia Campos , Cardoso Ariela Milbrath , Ferrarini Suzana Frighetto , Pires Marçal José Rodrigues 
Published: August 2020

AbstractThe use of polymeric films incorporated with zeolite‐TiO2 composites associated with UV radiation can be an alternative in the removal of volatile organic compounds (VOCs) through the adsorption and photodegradation processes. This study produced poly(lactic acid) (PLA) films incorporated with 13× zeolite, TiO2, and 13×‐TiO2 zeolite composite to remove n‐butanol and evaluate the by‐products generated in the process. The results showed that 13× zeolite and TiO2 added individually or as a composite to PLA, gave the polymer matrix a significant increase in the removal capacity of n‐butanol. The best performance was presented by the zeolite‐TiO2, composite, confirming a synergistic effect. However, the formation of CO and CO2 exceeded the expected values, with the verification that the polymeric matrix underwent photodegradation action by TiO2. The polymeric film only containing zeolite is the most suitable for the removal of VOCs, as it did not present degradation of the PLA, generating a lower concentration of by‐products.
Image analysis of flame behavior for polyolefins and polystyrene in vertical flame test
Authors: Hosokawa Yoshifumi , Nakashima Erika , Ueno Tomonaga 
Published: August 2020

AbstractAlthough the UL‐94 vertical flame test is often used to evaluate the flammability of polymers based on ignition time and combustion duration parameters, a significant amount of information regarding the time course of combustion is difficult to analyze in detail. Herein, image analysis of the time course of the upper and lower end heights, total area, and color division of flame was performed for polyolefins and polystyrene with different molecular weights in the vertical flame test. The combustion process was classified into two stages: before and after the first drip. In the first stage, the upward spread velocity, oscillation, and color of flame were analyzed. It was assumed that the difference in the fuel production rates or thermal decomposition products depends on the molecular structure. In the second stage, the melt flowability, flame position, and combustion continuity differed vastly depending on the molecular structure or molecular weight.
Increased energy expenditure and activated β3‐AR‐cAMP‐PKA signaling pathway in the interscapular brown adipose tissue of 6‐OHDA‐induced Parkinson's disease model rats
Authors: Lian Hui , Zhou Li , Zhang Yang , Song Yan‐Hai , Zhang Yi‐Min , Cao Zheng‐Hao , Wang Zhi‐Yong 
Published: August 2020

AbstractTo explore the possible mechanism of weight loss in Parkinson's disease (PD). Bilateral injections of 6‐hydroxydopamine (6‐OHDA) into substantia nigra (SN) were performed to induce the PD model rats. The rotarod test, food intake, body weight, and interscapular brown adipose tissue (IBAT) weight were recorded 6 weeks postoperation. HE staining was performed to observe the morphology of multilocular adipose cells in IBAT. Immunohistochemistry and western blot were used to determine the protein levels of tyrosine hydroxylase (TH) in the SN, and the levels of uncoupling protein 1 (UCP1), peroxisome proliferator‐activated receptor gamma coactivator‐1α (PGC‐1α), phosphorylated‐hormone sensitive lipase (p‐HSL), HSL, TH, β3‐adrenergic receptor (β3‐AR), cyclic adenosine monophosphate (cAMP), and protein kinase A (PKA) in IBAT. After treatment with 6‐OHDA for 6 weeks, 6‐OHDA rats exhibited decreased TH expression in SN accompanied with shortened staying time on the rotating rod. This motor impairment paralleled with no significant alteration in body mass, IBAT weight, and food intake until the end of the experimental protocol. However, the decreasing diameter of the single fat vesicle in IBAT was observed in the 6‐OHDA group. Meanwhile, compared with the control group, the protein expression of UCP1, PGC‐1α, p‐HSL, TH, β3‐AR, cAMP, and PKA in IBAT were increased significantly in the 6‐OHDA group, whereas no obvious change in the expression of HSL. The present study suggested an increased energy expenditure and activation of the β3‐AR‐cAMP‐PKA signaling pathway in the IBAT after the destruction of the dopamine system in the SN of the rat.
The Role of Executive Functioning in Predicting Social Competence in Children with and without Autism Spectrum Disorder
Authors: Fong Vanessa Clarisse , Iarocci Grace 
Published: August 2020

AbstractAll children with autism spectrum disorder (ASD) experience social difficulties but they differ with regard to the type and severity of their challenges. Potentially powerful interventions targeting social skills in children with ASD may have limited effectiveness if they are not tailored to the child's specific needs. One factor that may influence social competence is executive functioning (EF). EF may impact social competence by facilitating higher‐order strategies such as emotional and cognitive regulation which are necessary for social interactions. Participants included 132 children and adolescents, aged 7–13, including 77 with ASD (M = 10.11, SD = 1.94), and 55 without ASD (M = 9.54, SD = 1.67). Caregivers completed the Behavior Rating Inventory of Executive Functioning, Version 2 (BRIEF‐2) Parent Form, assessing everyday EF skills, and the Multidimensional Social Competence Scale (MSCS). Hierarchical multiple regression analyses were conducted separately for the group without ASD and the group with ASD, with MSCS entered as the dependent variables and EF indices and scales of the BRIEF‐2 as the main predictor variables. EF deficits in emotional control predicted poor emotion regulation for both children with and without ASD. For the group without ASD, better emotional control and initiation skills predicted empathic concern and social knowledge, respectively. Challenges in self‐monitoring significantly predicted difficulties with social inferencing and social knowledge for children with ASD. The findings highlight the importance of targeting specific EF skills that contribute to various aspects of social competence to increase the effectiveness of interventions for children with ASD. Autism Res 2020, 13: 1856‐1866. © 2020 International Society for Autism Research and Wiley Periodicals LLCLay SummaryWe examined whether parents' ratings of their children's higher‐order thinking skills (e.g., paying attention, organizing and planning, initiating tasks, regulating emotions, self‐monitoring) predicted social competence among children with and without autism spectrum disorder (ASD). For children without ASD, emotional control and initiation skills were strongly linked to their displays of empathy and social knowledge, respectively. For children with ASD, their abilities to be aware of their own behaviors and its impact on others were strongly related to their ability to interpret social cues and their social knowledge. For both groups, the ability to regulate their emotions were important predictors of their ability to modulate their emotions in social contexts.
Nickel Metaphosphate as a Conversion Positive Electrode for Lithium‐Ion Batteries
Authors: Xia Qingbo , Avdeev Maxim , Schmid Siegbert , Liu Hongwei , Johannessen Bernt , Ling Chris D. 
Published: August 2020

AbstractLithium storage schemes based on conversion chemistry have been used in a large variety of negative electrodes achieving capacities 2–3 times higher than graphite. However, to date, relatively few positive electrode examples have been reported. Here, we report a new conversion positive electrode, Ni(PO3)2, and systematic studies on its working and degradation mechanisms. Crystalline Ni(PO3)2 undergoes an electrochemistry‐driven amorphization process in the first discharge to form a fine microstructure, consisting of Ni domains ∼2 nm wide that form a percolating electron‐conducting network, embedded in a glassy LiPO3 matrix. P does not participate electrochemically, remaining as P5+ in [PO3]− throughout. The electrode does not recrystallise in the following first charge process, remaining amorphous over all subsequent cycles. The low ionicity of the Ni−[PO3] bond and the high Li+ conductivity of the LiPO3 glass lead to high intrinsic electrochemical activity, allowing the micro‐sized Ni(PO3)2 to achieve its theoretical capacity of 247 mAh/g. The performance of the Ni(PO3)2 electrode ultimately degrades due to the growth of larger and more isolated Ni grains. While the theoretical capacity of Ni(PO3)2 is itself limited, this study sheds new light on the underlying chemical mechanisms of conversion positive electrodes, an important new class of electrode for solid‐state batteries.
Inhibition of microRNA‐27b‐3p relieves osteoarthritis pain via regulation of KDM4B‐dependent DLX5
Authors: Zhang Guixiang , Zhou Yang , Su Manman , Yang Xucheng , Zeng Biyun 
Published: August 2020

AbstractOsteoarthritis (OA) represents a progressive degenerative disorder that predominantly affects the synovial membranes of joints. Recent studies have highlighted the significant role played by microRNAs (miRNAs) in OA development. The current study aimed to elucidate the underlying modulatory role of miR‐27b‐3p in the development of OA. The expression of miR‐27b‐3p in the OA patients and rat models post anterior cruciate ligament transection operation was measured using reverse transcription quantitative polymerase chain reaction, through which overexpressed miR‐27b‐3p was found in both of the samples. To further explore the miR‐27b‐3p functions in OA, western blot analysis, enzyme‐linked immunosorbent assay, and β‐galactosidase activity assay were conducted with the results showing that knockdown of miR‐27b‐3p promoted expression of the osteogenic differentiation markers while inhibiting expression of the adipogenic differentiation markers, inflammatory factors, and cellular senescence of bone marrow mesenchymal stem cells (BMSCs). After that, the interactions between miR‐27b‐3p, lysine Demethylase 4B (KDM4B), and Distal‐Less Homeobox 5 (DLX5) identified using dual‐luciferase reporter gene assay and ChIP assay revealed that miR‐27b‐3p inhibited KDM4B and further reduced expression of DLX5. Finally, the paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were assessed in rat models, and increased PWT and PWL were detected after miR‐27b‐3p silencing. In conclusion, suppression of miR‐27b‐3p could enhance KDM4B and DLX5 to alleviate OA pain, shedding light on a new potential therapeutic target for OA.
Determination of dopamine, noradrenaline, and adrenaline in Krebs–Henseleit solution by liquid chromatography coupled with tandem mass spectrometry and measurement of their basal release from Chelonoidis carbonaria aortae in vitro
Authors: Britto‐Júnior José , Antunes Natalícia J. , Campos Rafael , Sucupira Mauro , Mendes Gustavo Duarte , Fernandes Fernanda , Moraes Manoel Odorico , Moraes Maria Elisabete A. , De Nucci Gilberto 
Published: August 2020

AbstractThis study presented for the first time the development and validation of a sensitive method for quantification of dopamine, noradrenaline, and adrenaline in Krebs–Henseleit solution by LC–tandem mass spectrometry. Aliquots of 2.0 mL calibrators, quality controls, and samples of Krebs–Henseleit solution incubated with tortoise's aortic ring for 30 min were extracted by solid‐phase extraction. Catecholamine separation was achieved on a 100 × 4.6 mm LiChrospher RP‐8 column and the quantification was performed by a mass spectrometer equipped with an electrospray interface operating in positive ion mode. The run time was 4 min and the calibration curve was linear over the range of 0.1–20.0 ng/mL. The method was applied to the measurement of basal release of dopamine, noradrenaline, and adrenaline from the tortoise Chelonoidis carbonaria aortae in vitro. One aortic ring (30 mm) per tortoise (n = 5) was incubated for 30 min in a 5 mL organ bath filled with Krebs–Henseleit solution. The method demonstrated sensitivity, precision, and accuracy enough for its application in the measurement of basal release of these catecholamines from C. carbonaria aortic rings in vitro. The mean (standard deviation) concentrations of dopamine, noradrenaline, and adrenaline were 3.48 (2.55) ng/mL, 1.40 (0.57) ng/mL, and 1.87 (1.09) ng/mL, respectively.
Bridging “Big Data” and Mechanistic Insight To Enable Precision Medicine
Authors: Douglass Eugene F. 
Published: August 2020

AbstractRealizing the promise of precision medicine will require breaking down communication barriers between genomic, screening and literature “big data.” We discuss the opportunities and challenges of reconciling data science approaches with the scientific method and the critical role of chemical biologists as a bridge between data and mechanism. Finally we propose next steps on the road to precision medicine and give examples of new tools designed to catalyze these steps.
Comparison of clinical results between percutaneous closure and surgical repair of ruptured sinus of Valsalva aneurysm
Authors: Yang Kai , Luo Xiaokang , Tang Yue , Hu Haibo , Sun Hansong 
Published: August 2020

AbstractObjectivesThis study was conducted to investigate whether percutaneous closure of ruptured sinus of Valsalva aneurysm (SVA) is as safe and effective as surgery repair.BackgroundPercutaneous closure of ruptured SVA has been becoming an alternative to the traditional surgical repair recently. The reports regarding direct comparison of these two treatment options are scarce.MethodsThe medical records from the institutional database were retrospectively analyzed. A total of 134 patients were reviewed, including 26 patients undergoing percutaneous closure and 108 patients being treated surgically. To reduce the potential bias, 32 patients from Surgical Repair group were selected by propensity score matching.ResultsAll the ruptured SVAs were successfully closed in each group. No severe procedure‐related complications were found in the perioperative period. After matching, there were no significant differences in the baseline clinical characteristics. The median postoperative hospital stays of Matched group were significantly longer than that of Percutaneous Closure group (7 days vs. 1 day, p < .001). Aortic regurgitation, residual shunt and recurrence of SVAs were common complications in both Percutaneous Closure group and Surgical Repair group.ConclusionsThe appropriately selected patients with ruptured SVA could be treated by percutaneous closure with an acceptable risk of short‐term complications. Though surgical repair remains the main treatment option for ruptured SVAs, percutaneous closure could be considered in patients with a small‐size rupture and no associated cardiac abnormalities.
Ileocecal knotting in a young man: A very rare and unique cause of intestinal obstruction
Authors: Gebresellassie Hailu Wondimu 
Published: August 2020

AbstractIleocecal knitting should be considered as a differential diagnosis of small intestinal obstruction. Aggressive resuscitation and early surgery will be life‐saving. One should anticipate finding extensive bowel gangrene which requires aggressive resection.
Stereoselective Copper‐Catalyzed Direct Aldol Reaction of β, γ‐Unsaturated α‐Ketoesters with Coumaran‐3‐Ones
Authors: Li Kuiliang , Sun Xiang , Li Linge , Zha Zhenggen , Zhang Feng‐Lian , Wang Zhiyong 
Published: August 2020

AbstractAn efficient direct aldol reaction between coumaran‐3‐ones and β, γ‐unsaturated α‐ketoesters by virtue of a chiral copper complex is developed. A series of coumaran‐3‐one derivatives containing chiral tertiary alcohol structures are obtained in excellent yields and stereoselectivities.
AAV Production Everywhere: A Simple, Fast, and Reliable Protocol for In‐house AAV Vector Production Based on Chloroform Extraction
Authors: Negrini Matilde , Wang Gang , Heuer Andreas , Björklund Tomas , Davidsson Marcus 
Published: August 2020

AbstractRecombinant adeno‐associated virus (rAAV) is a mammalian virus that has been altered to be used as a gene delivery vehicle. Several changes to the viral genome have made them replication deficient so that this aspect of the viral infection cycle is under full control of the experimenter, while maintaining gene expression machinery. Over the last decades, rAAVs have become the gold standard for studying in vivo gene function and are especially favorable for gene transfer in the central nervous system. AAVs have been proven safe and provide stable gene expression over a long period of time. They are extensively used in preclinical experiments and show great potential for clinical applications. However, the use of AAVs in preclinical settings are often held back due to availability. Waiting lines are long at commercial production facilities, and in‐lab production is hindered due to lack of specific laboratory equipment needed. Here we present a novel production method that can be carried out in any molecular biology laboratory using standard laboratory equipment. We provide a simple, fast, and streamlined protocol for production that can result in titers comparable with the more time‐consuming iodixanol gradient ultracentrifugation method. The yield using this protocol is high enough for any type of study where AAV is the vector of choice. © 2020 The Authors.
Model Informed Development of VRC01 in Newborn Infants Using a Population Pharmacokinetics Approach
Authors: Li Jerry , Nikanjam Mina , Cunningham Coleen K. , McFarland Elizabeth J. , Coates Emily E. , Houser Katherine V. , Lin Bob C. , McDermott Adrian B. , Flach Britta , Gama Lucio , Koup Richard A. , Graham Barney S. , Mascola John R. , Ledgerwood Julie E. , Capparelli Edmund V. 
Published: August 2020

VRC01 is a first‐in‐class, potent, broadly neutralizing antibody that targets the CD4 binding site of gp120 on HIV‐1 viruses, and is under development as a novel HIV therapeutic. This study utilized population pharmacokinetic (PK) modeling to characterize VRC01 PK to guide dosing selection for ongoing phase II clinical trials in pediatric patients. Combining VRC01 PK data from 3 adult and 1 infant clinical trials, a total of 1,475 VRC01 serum concentrations from 100 participants were used in the analysis (40 infants and 60 adults). VRC01 was administered either i.v. or s.c. (1–40 mg/kg). All infants received s.c. doses as compared with 13% s.c. and 87% i.v. in adults. The data were well‐described by a two‐compartment model. Clearance was 37% higher in adults with HIV infection and 83% lower in infants than adults. Subcutaneous bioavailability was 55% in adults. Rapid absorption was seen in infants indicating therapeutic levels could be achieved quickly. Monte Carlo simulations were used to determine optimal dosing and demonstrated 40 mg/kg s.c. at weeks 0, 2, 6, and 10 would maintain VRC01 levels at the suppressive target concentration of 50 μg/mL for the first 14 weeks of life in infants. The current analysis provides new insight into differences in monoclonal antibody PK between infants and adults and demonstrates the utility of a population PK approach in informing drug development for infant populations.