bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating Allyl Electrophiles into Nickel‐Catalyzed Conjunctive Cross‐Coupling
Authors: Tran Van T. , Li Zi‐Qi , Gallagher Timothy J. , Derosa Joseph , Liu Peng , Engle Keary M. 
Published: January 2020

AbstractAllylation and conjunctive cross‐coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel‐catalyzed conjunctive cross‐coupling with a non‐conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate aza‐heterocycle directing groups that are useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated by the facile reactivity of the β‐γ alkene of the starting material, whereas the ϵ‐ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of an analogous method with alkyne substrates. Mechanistic studies reveal the importance of the dissociation of the weakly coordinating directing group to allow the allyl moiety to bind and facilitate C(sp3)−C(sp3) reductive elimination.
Effects of dual‐crosslinking networks on shape memory performance of polynorbornene
Authors: Gong Xiaowen , Yin Hao , Zhang Maolin , Shi Xinyan 
Published: January 2020

ABSTRACTIn this article, Polynorbornene (PNB)/Zinc dimethacrylate (ZDMA)/Dicumyl peroxide (DCP) composites can form dual‐crosslinking networks, which contain an ionic crosslinking network, and a part of the C─C covalent crosslinking network. DCP was used to initiate the polymerization of ZDMA to form ionic crosslinking bonds. With the increase of ZDMA, the total crosslink density (Vr) and ionic crosslink density (Vr2) increased. DCP was consumed in ZDMA polymerization, which made the PNB reduce the covalent crosslinking networks. Leading to the covalent crosslink density (Vr1) decreased. Compared with covalent crosslinking network, the dual‐crosslinking networks stored more energy when deformed, provided better restoring force and a higher shape recovery ratio for materials. When ZDMA exceeded 3.9 wt%, the ZDMA aggregates hindered the movement of molecular chains leading to the shape recovery ratio slightly decreased. When ZDMA was 2.4 wt%, the composite had an optimum shape fixing and shape recovery ratio. This article provided the experimental basis for the research of PNB dual‐crosslinking networks, also widened the research of PNB shape memory materials. © 2020 Wiley Periodicals Inc. J. Appl. Polym. Sci. 2020, 137, 48955.
Compatibilities and properties of poly lactide/poly (methyl acrylate) grafted chicken feather composite: Effects of graft chain length
Authors: Chen Sikai , Hori Naruhito , Kajiyama Mikio , Takemura Akio 
Published: January 2020

AbstractSurface modified poly(methyl acrylate) (PMA) grafted chicken feather fiber was applied as a reinforcement for polylactide (PLA)‐based composite film. The PMA grafted feather fiber with different PMA lengths were obtained for surface initiated Cu(0)‐mediated reversible‐deactivation radical polymerization. PLA‐based composite films with different unmodified or PMA‐grafted chicken feather fiber loading were prepared by solvent casting. Grafting PMA onto feather fiber enhanced interfacial bonding. Cracks and voids between matrix and fiber were eliminated. Thermal stability of these films also improved after introducing PMA. Feather fiber with high graft ratio showed worse dispersity in PLA due to its self‐aggregation. The heterogeneous nucleation agent behavior of feather grafted with longer PMA was also suppressed. Tensile tests showed that after modification, tensile strength and modulus was able to increase twice at 20% fiber loading. However, increasing PMA length improved break elongation but strength and modulus would drop slightly. These results indicated that grafting short PMA chain onto feather fiber surface was an effective and optimized method to improve dispersity and mechanical properties especially for higher filler loading.
Enhanced dielectric properties of sandwich‐structured biaxially oriented polypropylene by grafting hyper‐branched aromatic polyamide as surface layers
Authors: Han Chengcheng , Zhang Xianhong , Chen Dong , Ma Yuhong , Zhao Changwen , Yang Wantai 
Published: January 2020

AbstractThis work represents multilayer films with sandwich structure by grafting hyper‐branched aromatic polyamide (HBP) on both sides of biaxially oriented polypropylene (BOPP) (HBPBOPPHBP). BOPP serves as the middle layer to offer high breakdown strength and HBP acts as surface layers to boost the dielectric constant. As a result, the dielectric constant increases significantly from 2.2 of control BOPP to 5.5 (almost increased 1.5 times) after grafting 2.06 μm HBP surface layers, while the dielectric loss still remains at a very low level (<0.03). In addition, all HBPBOPPHBP sandwich‐structured films show higher charge energy density than that of unmodified BOPP. For instance, the discharge energy density of HBPBOPPHBP (1‐20‐1) film is up to 2.38 J/cm3 at an applied electric field of 400 kV/mm, which increases about 36% over that of pure BOPP (i.e., 1.75 J/cm3). Meanwhile, charge–discharge efficiency retains about 90%. This work offers a simple strategy to fabricate polymer‐based high performance dielectric composites.
Predictions of electrical percolation of graphene‐based nanocomposites by the three‐dimensional Monte Carlo simulation
Authors: Liu Yue , Wu Chen , Zhou Huanfeng , Liu Ping , Liu Caixia , Wu Hao , Zhao Junnan , Zhang Yugang , Ma Yuanming , Huang Ying , Song Aiguo , Ge Yunjian 
Published: January 2020

AbstractDisk model is usually used to represent graphene nanoplatelets (GNPs) which are considered as frame‐like structure with edges and corners, and it has lack of quantitative accuracy. In order to minimize error caused by morphology, distribution, and interaction between GNPs and matrix, square and folded plate models were constructed to predict the percolation volume fraction (ϕc) of GNPs‐based nanocomposites by calculating connection possibility. Meanwhile, disk model is used for comparison. The results revealed that the ϕc of square and folded plate models is smaller than that of disk model with consistent parameters, and it is concluded that the ϕc of GNPs‐based nanocomposites predicted by disk model should be higher than that of experimental. The correctness of mixed model of square and folded plate is also verified by experimental. Due to the agglomeration of GNPs under the actual situation, the result of simulation is slightly smaller than that of experiment.
KOtBu‐Catalyzed Michael Addition Reactions Under Mild and Solvent‐Free Conditions
Authors: Thiyagarajan Subramanian , Krishnakumar Varadhan , Gunanathan Chidambaram 
Published: January 2020

AbstractDesigned transition metal complexes predominantly catalyze Michael addition reactions. Inorganic and organic base‐catalyzed Michael addition reactions have been reported. However, known base‐catalyzed reactions suffer from the requirement of solvents, additives, high pressure and also side‐reactions. Herein, we demonstrate a mild and environmentally friendly strategy of readily available KOtBu‐catalyzed Michael addition reactions. This simple inorganic base efficiently catalyzes the Michael addition of underexplored acrylonitriles, esters and amides with (oxa‐, aza‐, and thia‐) heteroatom nucleophiles. This catalytic process proceeds under solvent‐free conditions and at room temperature. Notably, this protocol offers an easy operational procedure, broad substrate scope with excellent selectivity, reaction scalability and excellent TON (>9900). Preliminary mechanistic studies revealed that the reaction follows an ionic mechanism. Formal synthesis of promazine is demonstrated using this catalytic protocol.
Stabilization of a new commensurate/incommensurate fractional order chaotic system
Authors: Gholamin P. , Sheikhani A.H. Refahi , Ansari A. 
Published: January 2020

AbstractIn the current article, agreeing on the stability theory of fractional order systems, the conditions for the asymptotic stability of nonlinear fractional order systems are presented. We discuss the stabilization of new fractional order chaotic system where the state equations contain the same or different fractional orders. Then we design a control strategy for stabilization of new fractional order chaotic system. Our aim is to stabilize the unstable equilibrium points of fractional order chaotic systems by planning a fit linear state feedback controller. In the following, a comparison between linear state feedback controller and sliding mode control for commensurate and incommensurate new fractional order chaotic systems is conducted. Numerical simulations approve the validity of the presented results.
Control charts for monitoring ship operating conditions and CO2 emissions based on scalar‐on‐function regression
Authors: Capezza Christian , Lepore Antonio , Menafoglio Alessandra , Palumbo Biagio , Vantini Simone 
Published: January 2020

AbstractTo respond to the compelling air pollution programs, shipping companies are nowadays setting‐up on their fleets modern multisensor systems that stream massive amounts of observational data, which can be considered as varying over a continuous domain. Motivated by this context, a novel procedure is proposed, which extends classical multivariate techniques to the monitoring of multivariate functional data and a scalar quality characteristic related to them. The proposed procedure is shown to be also applicable in real time and is illustrated by means of a real‐case study in the maritime field on the continuous monitoring of operating conditions (ie, the multivariate functional data) and total CO2 emissions (ie, the scalar quality characteristic) at each voyage of a cruise ship. The real‐time monitoring is particularly helpful for promptly supporting managerial decision making by indicating if and when an anomaly occurs during the navigation.
Optimization of maintenance policy under warranty length‐based demand with consideration of both manufacturer and buyer satisfaction
Authors: Salmasnia Ali , Baratian Maryam 
Published: January 2020

AbstractThis study proposes a model to optimize postsale services consisting of four factors: (a) the basic warranty length, (b) the extended warranty length, (c) the preventive maintenance level, and (d) the preventive maintenance interval. Furthermore, consumer demand for the product and extended warranty are considered as functions of the length of the basic warranty and extended warranty periods, respectively. Because buyer dissatisfaction with a product can lead to the loss of potential buyers and the switch of current customers to the competitors, both manufacturer and buyer satisfaction are considered in the model. Three comparative studies are done for showing the effectiveness of the model. The first one compares the results of simultaneous optimization from the two perspectives of manufacture and customer with the single‐objective optimization results from each of the mentioned viewpoints. The second comparison studies the provision of extended warranty contract in the proposed model, and the third comparison investigates the effect of preventive maintenance actions on the results of the model.
Enzymatic depolymerization of industrial lignins by laccase‐mediator systems in 1,4‐dioxane/water
Authors: Dillies Justine , Vivien Céline , Chevalier Mickael , Rulence Alexandre , Châtaigné Gabrielle , Flahaut Christophe , Senez Vincent , Froidevaux Renato 
Published: January 2020

AbstractLignin is the second most abundant polymer after cellulose in lignocellulosic biomass. Its aromatic composition and recalcitrant nature make its valorization a major challenge for obtaining low molecular weight aromatics compounds with high value‐added from the enzymatic depolymerization of industrial lignins. The oxidation reaction of lignin polymer using laccases alone remains inefficient. Therefore, researches are focused on the use of a laccase‐mediator system (LMS) to facilitate enzymatic depolymerization. Until today, the LMS system was studied using water‐soluble lignin only (commercial lignins, modified lignins, or lignin model compounds). This work reports a study of three LMS systems to depolymerize the three major industrial lignins (organosolv lignin, Kraft lignin, and sodium lignosulfonate). We show that an enzymatic depolymerization of these lignins can be achieved by LMS using laccase from Trametes versicolor, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt as mediator and a cosolvent (25% of 1,4‐dioxane) to enhance the solubilization of lignins.
A design criterion for symmetric model discrimination based on flexible nominal sets
Authors: Harman Radoslav , Müller Werner G. 
Published: January 2020

AbstractExperimental design applications for discriminating between models have been hampered by the assumption to know beforehand which model is the true one, which is counter to the very aim of the experiment. Previous approaches to alleviate this requirement were either symmetrizations of asymmetric techniques, or Bayesian, minimax, and sequential approaches. Here we present a genuinely symmetric criterion based on a linearized distance between mean‐value surfaces and the newly introduced tool of flexible nominal sets. We demonstrate the computational efficiency of the approach using the proposed criterion and provide a Monte‐Carlo evaluation of its discrimination performance on the basis of the likelihood ratio. An application for a pair of competing models in enzyme kinetics is given.
Modeling tails for collinear data with outliers in the English Longitudinal Study of Ageing: Quantile profile regression
Authors: Liu Xi , Liverani Silvia , Smith Kimberley J. , Yu Keming 
Published: January 2020

AbstractResearch has shown that high blood glucose levels are important predictors of incident diabetes. However, they are also strongly associated with other cardiometabolic risk factors such as high blood pressure, adiposity, and cholesterol, which are also highly correlated with one another. The aim of this analysis was to ascertain how these highly correlated cardiometabolic risk factors might be associated with high levels of blood glucose in older adults aged 50 or older from wave 2 of the English Longitudinal Study of Ageing (ELSA). Due to the high collinearity of predictor variables and our interest in extreme values of blood glucose we proposed a new method, called quantile profile regression, to answer this question. Profile regression, a Bayesian nonparametric model for clustering responses and covariates simultaneously, is a powerful tool to model the relationship between a response variable and covariates, but the standard approach of using a mixture of Gaussian distributions for the response model will not identify the underlying clusters correctly, particularly with outliers in the data or heavy tail distribution of the response. Therefore, we propose quantile profile regression to model the response variable with an asymmetric Laplace distribution, allowing us to model more accurately clusters that are asymmetric and predict more accurately for extreme values of the response variable and/or outliers. Our new method performs more accurately in simulations when compared to Normal profile regression approach as well as robustly when outliers are present in the data. We conclude with an analysis of the ELSA.
False discovery rate control for multiple testing based on discretep‐values
Authors: Chen Xiongzhi 
Published: January 2020

AbstractFor multiple testing based on discretep‐values, we propose a false discovery rate (FDR) procedure “BH+” with proven conservativeness. BH+ is at least as powerful as the BH (i.e., Benjamini‐Hochberg) procedure when they are applied to superuniformp‐values. Further, when applied to mid‐p‐values, BH+ can be more powerful than it is applied to conventionalp‐values. An easily verifiable necessary and sufficient condition for this is provided. BH+ is perhaps the first conservative FDR procedure applicable to mid‐p‐values and top‐values with general distributions. It is applied to multiple testing based on discretep‐values in a methylation study, an HIV study and a clinical safety study, where it makes considerably more discoveries than the BH procedure. In addition, we propose an adaptive version of the BH+ procedure, prove its conservativeness under certain conditions, and provide evidence on its excellent performance via simulation studies.
Overexpression of transcription factor Foxa1 and target genes remediate therapeutic protein production bottlenecks in Chinese hamster ovary cells
Authors: Berger Audrey , Le Fourn Valérie , Masternak Jacqueline , Regamey Alexandre , Bodenmann Iris , Girod Pierre‐Alain , Mermod Nicolas 
Published: January 2020

AbstractDespite extensive research conducted to increase protein production from Chinese hamster ovary (CHO) cells, cellular bottlenecks often remain, hindering high yields. In this study, a transcriptomic analysis led to the identification of 32 genes that are consistently upregulated in high producer clones and thus might mediate high productivity. Candidate genes were associated with functions such as signaling, protein folding, cytoskeleton organization, and cell survival. We focused on two engineering targets, Erp27, which binds unfolded proteins and the Erp57 disulfide isomerase in the endoplasmic reticulum, and Foxa1, a pioneering transcription factor involved in organ development. Erp27 moderate overexpression increased production of an easy‐to‐express antibody, whereas Erp27 and Erp57 co‐overexpression increased cell density, viability, and the yield of difficult‐to‐express proteins. Foxa1 overexpression increased cell density, cell viability, and easy‐ and difficult‐to‐express protein yields, whereas it decreased reactive oxygen species late in fed‐batch cultures. Foxa1 overexpression upregulated two other candidate genes that increased the production of difficult‐ and/or easy‐to‐express proteins, namely Ca3, involved in protecting cells from oxidative stress, and Tagap, involved in signaling and cytoskeleton remodeling. Overall, several genes allowing to overcome CHO cell bottlenecks were identified, including Foxa1, which mediated multiple favorable metabolic changes that improve therapeutic protein yields.
A versatile oscillating‐flow microfluidic PCR system utilizing a thermal gradient for nucleic acid analysis
Authors: Kopparthy Varun L. , Crews Niel D. 
Published: January 2020

AbstractWe report the development of a versatile system based on the oscillating‐flow methodology in a thermal gradient system for nucleic acid analysis. Analysis of DNA and RNA samples were performed in the device, without additional temperature control and complexity. The technique reported in this study eliminates the need for predetermined fluidic channels for thermocycles, and complexity involved with additional incubation steps required for RNA amplification. A microfluidic device was fabricated using rapid prototyping by simply sandwiching dual side adhesive Kapton tape and a polydimethylsiloxane spacer between glass microscope slides. Amplification of the 181‐bp segment of a viral phage DNA (ΦX174) and B2M gene in human RNA samples was demonstrated using the system. The developed system enables simultaneous acquisition of amplification and melt curves, eliminating the need for postprocessing. A direct comparison between the oscillating‐flow system and a commercial real‐time polymerase chain reaction (PCR) instrument showed complete agreement in PCR data and improved sample‐to‐result time by eliminating an additional 30 min melt curve step required in commercial PCR systems.
Differential roles of exogenous protein disulfide isomerase A3 on proliferating cell and neuroblast numbers in the normal and ischemic gerbils
Authors: Yoo Dae Young , Cho Su Bin , Jung Hyo Young , Kim Woosuk , Nam Sung Min , Kim Jong Whi , Moon Seung Myung , Yoon Yeo Sung , Kim Dae Won , Choi Soo Young , Hwang In Koo 
Published: January 2020

AbstractIntroductionWe examined the effects of exogenous protein disulfide isomerase A3 (PDIA3) on hippocampal neurogenesis in gerbils under control and ischemic damage.MethodsTo facilitate the delivery of PDIA3 to the brain, we constructed Tat‐PDIA3 protein and administered vehicle (10% glycerol) or Tat‐PDIA3 protein once a day for 28 days. On day 24 of vehicle or Tat‐PDIA3 treatment, ischemia was transiently induced by occlusion of both common carotid arteries for 5 min.ResultsAdministration of Tat‐PDIA3 significantly reduced ischemia‐induced spontaneous motor activity, and the number of NeuN‐positive nuclei in the Tat‐PDIA3‐treated ischemic group was significantly increased in the CA1 region compared to that in the vehicle‐treated ischemic group. Ki67‐ and DCX‐immunoreactive cells were significantly higher in the Tat‐PDIA3‐treated group compared to the vehicle‐treated control group. In vehicle‐ and Tat‐PDIA3‐treated ischemic groups, the number of Ki67‐ and DCX‐immunoreactive cells was significantly higher as compared to those in the vehicle‐ and Tat‐PDIA3‐treated control groups, respectively. In the dentate gyrus, the numbers of Ki67‐immunoreactive cells were comparable between vehicle‐ and Tat‐PDIA3‐treated ischemic groups, while more DCX‐immunoreactive cells were observed in the Tat‐PDIA3‐treated group. Transient forebrain ischemia increased the expression of phosphorylated cAMP‐response element‐binding protein (pCREB) in the dentate gyrus, but the administration of Tat‐PDIA3 robustly increased pCREB‐positive nuclei in the normal gerbils, but not in the ischemic gerbils. Brain‐derived neurotrophic factor (BDNF) mRNA expression was significantly increased in the Tat‐PDIA3‐treated group compared to that in the vehicle‐treated group. Transient forebrain ischemic increased BDNF mRNA levels in both vehicle‐ and Tat‐PDIA3‐treated groups, and there were no significant differences between groups.ConclusionsThese results suggest that Tat‐PDIA3 enhances cell proliferation and neuroblast numbers in the dentate gyrus in normal, but not in ischemic gerbils, by increasing BDNF mRNA and phosphorylation of pCREB.
The economic consequences of environmental regulation in China: From a perspective of the environmental protection admonishing talk policy
Authors: Tian Zhihua , Tian Yanfang , Chen Yang , Shao Shuai 
Published: January 2020

AbstractEnvironmental regulation may lead to undesired economic consequences. China has tightened its environmental policies to deal with severe environmental pollution in recent years, but existing studies pay little attention to the economic consequences of China's environmental policies. Using the panel data of 211 prefecture‐level and above cities in China from 2003 to 2016, we for the first time estimate the economic impact of the environmental protection admonishing talk (EPAT) policy, a newly implemented environmental regulation policy in China. We use the difference‐in‐differences strategy to identify the economic effects of the EPAT policy combined with the propensity score matching method to control a potential selection problem. The results show that a relative decline occurs in gross domestic product per capita in target cities after the implementation of the EPAT, and the negative impact is exerted on the secondary industry rather than the tertiary industry. Furthermore, we find that target cities respond to the environmental protection requirements of higher authorities through a one‐size‐fits‐all approach of limiting the production activities of industrial enterprises. Meanwhile, the EPAT policy does not improve environmental efficiency. Such findings are instructive for policymakers who need to trade off economic welfare and environmental quality when formulating and implementing new environmental policies.