bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymer Crystallization Kinetics
Authors: Hobbs Jamie , Androsch René , Hu Wenbing , Di Lorenzo Maria Laura , Schick Christoph 
Published: May 2019

AbstractPolymer crystallization, like many other phase transitions, occurs through a process of nucleation and growth. Although of fundamental importance, the nucleation step is still poorly understood, nevertheless, though major progress has been achieved in the past decade by using novel analytical tools. Herein, we outline the key experimental data and theories that have been developed to explain these data. A brief look at some more recent approaches is also given. The majority of this article considers the growth process itself, concentrating on linear, flexible polymers as this is the area where the most complete data set is available. An outline of the theories that have been developed to explain and predict crystallization kinetics is also given, focusing on their fundamental assumptions and predictions rather than their mathematical intricacies. This article is not intended to be an all‐inclusive review on the topic but rather a tutorial style introduction. For the sake of brevity, this article will, therefore, concentrate on areas that are of particular interest to the authors and to principles and observations that have, in the authors’ opinion, the widest applicability.
Polymer Composites: Reinforcing Fillers
Authors: Pegoretti Alessandro , Dorigato Andrea 
Published: May 2019

AbstractAddition of reinforcing fillers is a well‐established method to enhance mechanical, electrical, and thermal properties of plastics. Formulation and compounding of polymer matrices with inorganic and organic fillers having peculiar morphology enables the development of new multifunctional materials. Among the physical properties affected by the introduction of fillers in plastics, particular attention has been devoted to the mechanical behavior of the resulting composites. Moreover, introduction of inorganic fillers can reduce the cost of plastics, as they are sometime less expensive than polymers. It is well known that with a correct formulation and compounding, the tensile and impact strength and elastic modulus of polymers can be considerably enhanced, allowing to extend the application of plastics in technical fields previously undreamt of. Many other physical properties, such as friction coefficient, molding shrinkage, and weatherability, can be considerably affected by filler addition.This article aims at providing an overview of the various types of fillers available in the market to reinforce plastic products. After a general introduction, the article discusses both particulate microfillers as well as nanostructured fillers. For all the fillers considered, information on their morphological behavior, important physical properties, and production processes are provided. In addition, select examples of fillers’ effectiveness in improving the properties of polymer matrices (thermoplastic, thermosetting, and elastomers) are also presented.
Ring‐Opening Polymerization of α‐Amino Acid
N
‐Carboxyanhydrides and Side‐Chain Functionalized Polypeptides
Authors: Fu Xiaohui , Sun Jing , Li Zhibo 
Published: May 2019

Abstract

Synthetic polypeptides from ring‐opening polymerization of α‐amino acid
N
‐carboxyanhydrides (NCA) are versatile materials for various biomedical applications due to their biocompatibility, biodegradability, and bioactivity. This article overviews recent progress in NCA polymerizations and side‐chain functionalization of polypeptides. Initiating systems, mechanism studies, and optimized polymerization conditions for the NCA polymerization are comprehensively reviewed and evaluated here. The substituents of NCA monomers are also described. Finally, the design and synthesis of functional polypeptides is summarized and discussed.
MiR‐21‐5p regulates mycobacterial survival and inflammatory responses by targeting Bcl‐2 and TLR4 in Mycobacterium tuberculosis‐infected macrophages
Authors: Zhao Zhonghua , Hao Jinzhu , Li Xia , Chen Yanfang , Qi Xiaoyan 
Published: May 2019

To date, very little is known about the role of microRNA‐21‐5p (miR‐21‐5p) in Mycobacterium tuberculosis (M.tb)‐infected macrophages. Here, we show that M.tb infection of RAW264.7 and THP‐1 cells increases the expression of miR‐21‐5p. MiR‐21‐5p enhances M.tb survival and apoptosis, and attenuates the secretion of inflammatory cytokines, including interleukin (IL)‐1β, IL‐6, and tumor necrosis factor‐α in M.tb‐infected macrophages. Dual‐luciferase reporter assay revealed that the 3′‐UTR of B‐cell lymphoma 2 (Bcl‐2) or toll‐like receptor 4 (TLR4) is a direct target of miR‐21‐5p. Enforced expressions of Bcl‐2 or TLR4 partially attenuate the suppressive effects of miR‐21‐5p on cell viability and inflammatory cytokines, and effectively decrease bacterial burden. Therefore, the present study highlights a novel role for miR‐21‐5p in regulation of mycobacterial survival and inflammatory responses by targeting Bcl‐2 and TLR4 in M.tb‐infected macrophages.
Fibroblast Growth Factors in Development
Authors: Kinnunen Tarja K 
Published: May 2019

Abstract

The fibroblast growth factors (FGF) are a family of structurally related proteins that contribute to virtually all aspects of embryonic and postembryonic development, and after birth for regulation of tissue repair and maintenance and control of metabolic physiology in adults. Most FGFs are secreted and act as paracrine or endocrine factors, but a subfamily exists as intracellular proteins. The secreted FGFs bind to their cell surface tyrosine kinase receptors (FGFRs), which when activated trigger intracellular signalling pathways. FGF signalling is evolutionarily conserved in all metazoans and plays a critical role in the development and homeostasis of all multicellular organisms studied so far. A recurring theme of FGFs in development is the reciprocal signalling between different tissues and cell types such as signalling between epithelial and mesenchymal tissues. Abnormal FGF signalling leads to developmental defects, skeletal disorders, metabolic and neuroendocrine disorders and many types of cancer.

Key Concepts

FGF signalling is highly conserved in the metazoan evolution.

FGF signalling is critical for the normal development of all multicellular organisms.

FGFs play a key role in reciprocal signalling between epithelial and mesenchymal tissues.

FGF signalling is tightly regulated by the means of differential expression of specific splice isoforms of the receptors, by the requirement of protein co‐factors for the active signalling complex and by post‐translational modification of the receptors.

Altered levels of FGF signalling leads to developmental and metabolic defects, impaired regeneration, and different types of cancers.
2D Laminar Membranes for Selective Water and Ion Transport
Authors: Kang Yuan , Xia Yun , Wang Huanting , Zhang Xiwang 
Published: May 2019

AbstractSelective water and ion transport are essential in fields related to the environment, resources, energy, and more. Membranes, especially those constituted by 2D materials, are promising to control mass transport within nano‐ and sub‐nanoscales. When stacked together, the ultrathin nanosheets of these materials can build up laminar membranes with an ordered layer‐like structure. Numerous channels are thereby created among layers for fast and selective mass transport, which arouses huge research and application interests. This Review aims to present the latest theoretical and experimental advances of 2D laminar membranes for selective water and ion transport, covering three fundamental aspects. Starting with a concise introduction to the materials and assembly for laminar membranes, it then mainly focuses on systematically discussing the transport‐controlling effects caused by intrinsic membrane structure and extrinsic influences. The relation between these effects and current membrane selective performance as well as future membrane designs is then elucidated. The most urgent challenges and corresponding opportunities that emerge around 2D laminar membranes are highlighted thereafter.
Hyperthermia Nanofiber Platform Synergized by Sustained Release of Paclitaxel to Improve Antitumor Efficiency
Authors: Niiyama Eri , Uto Koichiro , Lee Chun Man , Sakura Kazuma , Ebara Mitsuhiro 
Published: May 2019

AbstractEffective cancer therapy can be achieved by designing a smart nanofiber system with the combination of chemotherapy and hyperthermia. This study demonstrates the in vivo antitumor effect of a nanofiber mesh that can deliver heat and antitumor drug in a controlled manner. The mesh is composed of biodegradable poly(ε‐caprolactone) (PCL) with paclitaxel (PTX) and magnetic nanoparticles (MNPs). The PCL mesh releases PTX slowly for at least 6 weeks when tested in vitro. The prolonged therapeutic effect is observed in vivo as a continuous release of medication from the mesh over an extended period of time compared with direct injection of PTX into the tumor site. In addition, the synergistic anticancer effect is achieved upon excitation of the mesh with an alternating magnetic field because the MNPs within the nanofiber generate localized heat which causes heat‐induced cell killing as well as enhanced chemotherapeutic effect of PTX. Based on these results, the smart nanofiber system may be very promising for cancer therapeutics in the future and may provide knowledge for new development of localized drug delivery.
Toxicity‐Attenuated Glycol Chitosan Adhesive Inspired by Mussel Adhesion Mechanisms
Authors: Park Eunsook , Lee Jeehee , Huh Kang Moo , Lee Soo Hyeon , Lee Haeshin 
Published: May 2019

AbstractChitosan‐catechol, inspired from mussel‐adhesive‐proteins, is characterized by the formation of an adhesive membrane complex through instant bonding with serum proteins not found in chitosan. Using this intrinsic property, chitosan‐catechol is widely applied for hemostatic needles, general hemostatic materials, nanoparticle composites, and 3D printing. Despite its versatility, the practical use of chitosan‐catechol in the clinic is limited due to its undesired immune responses. Herein, a catechol‐conjugated glycol chitosan is proposed as an alternative hemostatic hydrogel with negligible immune responses enabling the replacement of chitosan‐catechol. Comparative cellular toxicity and in vivo skin irritation between chitosan‐catechol and glycol chitosan‐catechol are evaluated. Their immune responses are also assessed using histological analysis after subcutaneous implantation into mice. The results show that glycol chitosan‐catechol significantly attenuates the immune response compared with chitosan‐catechol; this finding is likely due to the antibiofouling effect of ethylene glycol groups and the reduced adhesion of immune cells. Finally, the tissue adhesion and hemostatic ability of glycol chitosan‐catechol hydrogels reveal that these ethylene glycol groups do not dramatically modify the adhesiveness and hemostatic ability compared with nonglycol chitosan‐catechol. This study suggests that glycol chitosan‐catechol can be a promising alternative to chitosan‐catechol in various biomedical fields such as hemostatic agents.
Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition
Authors: Pradhan Tapas R. , Mohapatra Debendra K. 
Published: May 2019

AbstractA metal‐free oxyacetoxylation method of primary, secondary and tertiary propargylic carboxylates with retention of chirality was presented. The reaction proceeds through the intramolecular nucleophilic attack of the neighboring carbonyl group on an alkynyliodonium intermediate. The process is general with broad substrate scope and is amenable for application to a variety of propargyl carboxylates including those obtained from natural products. Insight into the mechanistic pathway by isotopic labelling (using H2O18 and D2O) and controlled experiments confirmed.magnified image
The Reaction of o‐Aminoacetophenone N‐Tosylhydrazone and CO2 toward 1,4‐Dihydro‐2H‐3,1‐benzoxazin‐2‐ones
Authors: Xiong Hao , Wu Xiaopeng , Wang Hepan , Sun Song , Yu Jin‐Tao , Cheng Jiang 
Published: May 2019

AbstractA transition‐metal‐free reaction of o‐aminoacetophenone N‐tosylhydrazone and CO2 has been developed, leading to a series of 1,4‐dihydro‐2H‐3,1‐benzoxazin‐2‐ones in moderate to good yields. This procedure proceeds with the sequential fixation of CO2 by amino leading to carbamic acid and the intra‐ molecular insertion of hydroxyl to carbene.magnified image
[3+2]‐Cycloaddition of Azaoxyallyl Cations with Cyclopropenones and Cyclopropenethiones: Synthesis of Spirocyclic Oxazole and Thiazole Derivatives
Authors: Zhou Shuang‐Jing , Cheng Xiao , Xuan Jun 
Published: May 2019

AbstractA [3+2]‐cycloaddition reaction of in‐situ‐formed azaoxyallyl cations with cyclopropenones and cyclopropenethiones for the synthesis of biologically important spirocyclic oxazole and thiazole derivatives is reported. This concise procedure exhibited good functional group tolerance under very mild conditions and provided the corresponding spirocyclic products in good to excellent yields.
N‐(4‐Thiazolylmethyl)Morpholine N‐Oxide as N,O‐Bidentate Ligand for Copper‐Catalyzed Ullmann‐Type N‐Arylation of Azoles/Amines with Aryl Halides
Authors: Jia Xuefeng , Peng Pai 
Published: May 2019

AbstractAn effective and practical protocol for the CuI‐catalyzed Ullmann‐type N‐arylation of azoles/amines with aryl halides is reported. The key strategy is the employment of CH2 linker N,O‐bidentate ligands, especially N‐(4‐thiazolylmethyl)morpholine N‐oxide, as superior supporting ligands. The highly efficient C−N coupling reactions between various azoles/amines and aryl halides bearing different functional groups can be achieved under CuI/N‐(4‐thiazolylmethyl)morpholine N‐oxide catalytic system, affording a variety of N‐arylated products. The use of cheap copper(I) salt and readily available N,O‐bidentate ligands make this procedure more attractive for synthesis of valuable functionalized nitrogen‐containing heterocyclic compounds.
Possible mineral contributions to the diet and health of wild chimpanzees in three East African forests
Authors: Reynolds Vernon , Pascual‐Garrido Alejandra , Lloyd Andrew W. , Lyons Peter , Hobaiter Catherine 
Published: May 2019

AbstractWe present new data on the ingestion of minerals from termite mound soil by East African chimpanzees (Pan troglodytes schweinfurthii) living in the Budongo Forest Reserve, Uganda, the Gombe National Park and the Mahale Mountains National Park, Tanzania. Termite mound soil is here shown to be a rich source of minerals, containing high concentrations of iron and aluminum. Termite mound soil is not, however, a source of sodium. The concentrations of iron and aluminum are the highest yet found in any of the mineral sources consumed. Levels of manganese and copper, though not so high as for iron and aluminum, are also higher than in other dietary sources. We focus on the contribution of termite mound soil to other known sources of mineral elements consumed by these apes, and compare the mineral content of termite soil with that of control forest soil, decaying wood, clay, and the normal plant‐based chimpanzee diet at Budongo. Samples obtained from Mahale Mountains National Park and Gombe National Park, both in Tanzania, show similar mineral distribution across sources. We suggest three distinct but related mechanisms by which minerals may come to be concentrated in the above‐mentioned sources, serving as potentially important sources of essential minerals in the chimpanzee diet.
Relationship Between Physiological Umbilical Herniation and Liver Morphogenesis During the Human Embryonic Period: A Morphological and Morphometric Study
Authors: Kanahashi Toru , Yamada Shigehito , Yoneyama Akio , Takakuwa Tetsuya 
Published: May 2019

ABSTRACTIt is widely hypothesized that physiological umbilical herniation (PUH) in humans occurs, because the liver occupies a large space in the abdominal cavity, which pushes the intestine into the extraembryonic coelom during the embryonic period. We have recently shown the presence of the intestinal loop in the extraembryonic coelom in embryos with liver malformation. Here, we analyzed the relationship between the liver and the PUH at Carnegie stage 21 of four embryos with liver malformation, including two with hypogenesis (HY1, HY2) and two with agenesis (AG1, AG2), using phase‐contrast X‐ray computed tomography and compared them with two control embryos. The intestinal loop morphology in the malformed embryos differed from that in the control embryos, except in HY1. The length of the digestive tract in the extraembryonic coelom of the embryos with liver malformation was similar to or longer than that of the controls. The rate of intestinal loop lengthening in the extraembryonic coelom compared with that of the total digestive tract in all embryos with liver malformation was similar to or higher than that of the controls. The estimated total abdominal cavity volume in the embryos with liver malformation was considerably smaller than that of the controls, while the intestinal volume was similar. The cardia and proximal portion of the pancreas connecting to the duodenum were located at almost identical positions in all the embryos, whereas other parts of the upper digestive tract deviated in the embryos with abnormal livers. Thus, our results provided evidence that PUH occurred independently of liver volume. Anat Rec, 302:1968–1976, 2019. © 2019 American Association for Anatomy
A comparison of machine learning algorithms and covariate balance measures for propensity score matching and weighting
Authors: Cannas Massimo , Arpino Bruno 
Published: May 2019

AbstractPropensity score matching (PSM) and propensity score weighting (PSW) are popular tools to estimate causal effects in observational studies. We address two open issues: how to estimate propensity scores and assess covariate balance. Using simulations, we compare the performance of PSM and PSW based on logistic regression and machine learning algorithms (CART; Bagging; Boosting; Random Forest; Neural Networks; naive Bayes). Additionally, we consider several measures of covariate balance (Absolute Standardized Average Mean (ASAM) with and without interactions; measures based on the quantile‐quantile plots; ratio between variances of propensity scores; area under the curve (AUC)) and assess their ability in predicting the bias of PSM and PSW estimators. We also investigate the importance of tuning of machine learning parameters in the context of propensity score methods. Two simulation designs are employed. In the first, the generating processes are inspired to birth register data used to assess the effect of labor induction on the occurrence of caesarean section. The second exploits more general generating mechanisms. Overall, among the different techniques, random forests performed the best, especially in PSW. Logistic regression and neural networks also showed an excellent performance similar to that of random forests. As for covariate balance, the simplest and commonly used metric, the ASAM, showed a strong correlation with the bias of causal effects estimators. Our findings suggest that researchers should aim at obtaining an ASAM lower than 10% for as many variables as possible. In the empirical study we found that labor induction had a small and not statistically significant impact on caesarean section.
Education for all: The Good Inclusion Game
Authors: Dillenburger Karola , Coyle Caleb 
Published: May 2019

The term “education for all” in the context of inclusive schooling describes the aim that children with identified special/additional needs are fully included in education together with their typically developing peers. However, this is easier said than done as there are few easy‐to‐use methods that teachers can use while at the same time teaching the approbate curriculum to children with a full range of different abilities. The Good Inclusion Game (GIG) is a group contingency‐based tool to create inclusive classrooms that utilizes principles of the applied branch of the science of behavior analysis (applied behavior analysis) and can be used across settings and academic subjects. The GIG was evaluated across nine classrooms including 93 boys and girls aged between 9 and 15 years of age, including 20 children with identified special educational needs. Findings show that the GIG reliably led to a significant increase of inclusive curriculum‐focused activities with the collateral effect of decreasing disruptive behaviors for all children. Findings are discussed in the context of inclusive schooling and evidence‐based education.
Polypeptoids synthesis based on Ugi reaction: Advances and perspectives
Authors: Tao Yue , Wang Zhen , Tao Youhua 
Published: May 2019

AbstractPolypeptoids are peptidomimetic polymers invented in the early 1990s. Although polypeptoid chemistry is developing rapidly, the simple synthesis of polypeptoids and sequence‐controlled polypeptoids still remains a challenge. Fortunately, we have seen a drastic rising trend in the area of Ugi reaction for polypeptoid chemistry. In the following article, recent examples of the Ugi reaction for polypeptoids synthesis will be presented, as will their suitability for sequence‐defined peptide‐peptoid hybrids. The advantages and limitations of the Ugi reaction will be discussed, which is important for the simple and general synthesis of polypeptoids.
Characterization of Cas proteins for CRISPR‐Cas editing in streptomycetes
Authors: Yeo Wan Lin , Heng Elena , Tan Lee Ling , Lim Yi Wee , Lim Yee Hwee , Hoon Shawn , Zhao Huimin , Zhang Mingzi M. , Wong Fong Tian 
Published: May 2019

AbstractApplication of the well‐characterized Streptococcus pyogenes CRISPR‐Cas9 system in actinomycetes streptomycetes has enabled high‐efficiency multiplex genome editing and CRISPRi‐mediated transcriptional regulation in these prolific bioactive metabolite producers. Nonetheless, SpCas9 has its limitations and can be ineffective depending on the strains and target sites. Here, we built and tested alternative CRISPR‐Cas constructs based on the standalone pCRISPomyces‐2 editing plasmid. We showed that Streptococcus thermophilus CRISPR1 Cas9 (sth1Cas9), Staphylococcus aureus Cas9 (saCas9), and Francisella tularensis subsp. novicida U112 Cpf1 (fnCpf1) are functional in multiple streptomycetes, enabling efficient homology‐directed repair‐mediated knock‐in and deletion. In strains where spCas9 was nonfunctional, these alternative Cas systems enabled precise genomic modifications within biosynthetic gene clusters for the discovery, production, and diversification of natural products. These additional Cas proteins provide us with the versatility to overcome the limitations of individual CRISPR‐Cas systems for genome editing and transcriptional regulation of these industrially important bacteria.