bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and preparation of ZnS‐ZnFe2O4: a green and efficient hybrid nanocatalyst for the multicomponent synthesis of 2,4,5‐triaryl‐1H‐imidazoles
Authors: Varzi Zahra , Maleki Ali 
Published: May 2019

In the present work, a new protocol was introduced for the preparation of an efficient hybrid nanocatalyst ZnS‐ZnFe2O4 via the co‐precipitation method as well as its application in the synthesis of 2,4,5‐triaryl‐1H‐imidazoles derivatives starting from various aromatic aldehydes, benzil and ammonium acetate under ultrasonic irradiation in ethanol. ZnS‐ZnFe2O4 was characterized by Fourier transform infrared (FT‐IR) spectroscopy, energy‐dispersive X‐ray spectroscopy (EDS) analysis, scanning electron microscopy (SEM) image, X‐ray diffraction (XRD) pattern and vibrating sample magnetometer (VSM) curve. This method has advantages such as high efficiency of the heterogeneous catalyst, the use of environmentally‐friendly solvent, high yields, short reaction times and easy isolation of the products and chromatography‐free purification. Our outcomes illustrated that the present nanocatalyst with nearly spherical and Cauliflower‐like morphology and average particle size of 36 nm could be applied as an effective and magnetically recyclable catalyst without any significant decreasing of activity. Furthermore, the synergic effect of bimetallic Lewis acids was studied for the synthesis of imidazole derivatives.
Medium dielectric constant and low‐loss PTFE composites filled with MgO‐LiF co‐doped Li2TiO3 particles
Authors: Wang Hao , Yang Hui , Tong Jianxi , Zhang Qilong 
Published: May 2019

ABSTRACTIn this work, we presented a simple strategy to fabricate medium dielectric constant and low‐loss composites for microwave substrate applications. MgO‐LiF co‐doped Li2TiO3 (LT) powders were fabricated by the solid‐state reaction route and modified by perfluorooctyltriethoxysilane (F8261). The LT/polytetrafluoroethylene (PTFE) composites were fabricated by cold pressing and hot treatment. The XPS and contact angle analysis indicated that the fluorinated group was introduced to LT particle successfully. The effects of modified LT powders content on the dielectric, thermal, and mechanical properties of composites were investigated. As the modified LT content increases, the dielectric constant, dielectric loss, and temperature coefficient of dielectric constant (τε) increase while the bending strength and coefficient of thermal expansion (CTE) decrease, which is attributed to the higher dielectric constant of LT ceramic, more pores, stable τε of LT ceramic, interface defects and low CTE of LT ceramic, respectively. The composites with 60 wt % LT exhibit the best microwave dielectric properties: εr = 6.8, tanδ = 0.001, τε = −29.6 ppm °C−1 at 8 GHz and acceptable coefficient of thermal expansion (28.3 ppm °C−1). Therefore, modified LT powders filled PTFE composites are potential materials for high‐frequency microwave substrate applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47980.
Infusible acrylic thermoplastic resins: Tailoring of chemorheological properties
Authors: Cousins Dylan S. , Howell Jackson , Suzuki Yasuhito , Samaniuk Joseph R. , Stebner Aaron P. , Dorgan John R. 
Published: May 2019

ABSTRACTInfusible liquid resins that polymerize into a thermoplastic are desirable for many applications. Similar to unsaturated and vinylester thermosetting systems, they consist of polymers dissolved in reactive monomer. This work presents a method to decrease cycle time by tuning the molecular weight and concentration of the predissolved polymer in the resin. Variation of these properties allows precise control of the viscosity which in turn controls the time at which peak exotherm is reached, the maximum temperature for a given part thickness, and cure time. Predictive models for the viscosity dependence on molecular weight, polymer concentration, shear rate, and temperature are developed. Two fiberglass panels are fabricated and tested; one with a lower molecular weight (Mw~30 kg mol−1) poly(methyl methacrylate) dissolved in methyl methacrylate and the second with higher molecular weight (Mw~500 kg mol−1) predissolved polymer in the resin. Mechanical properties are indistinguishable but the lower molecular weight panel cures up to three times faster. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48006.
A shell disc bead maker's workshop from Kavewa Island, northern Fiji
Authors: BURLEY DAVID V. , FREELAND TRAVIS 
Published: May 2019

ABSTRACTTest excavations of an early Lapita colonising site on Kavewa Island off the north‐east coast of Vanua Levu in 2012 encountered an abundant assemblage of Anadara shell disc beads and preforms, as well as lithic micro‐drills for bead perforation. Concentrated in the upper strata of a 1 × 1 m unit, radiocarbon dates place this assemblage in the interval 2490–2280 calBP. Production stages (chaîne opératoire) in bead manufacture are described as is the fabrication of micro‐drills through bipolar flaking of small quartz, chalcedony and chert clasts, locally acquired from Malau breccia. A survey of the Oceanic literature relating to stone drills and shell bead production finds a comparable assemblage only at Bootless Bay, Motupore Island, Papua New Guinea. This assemblage, however, is 3500 km distant and 1750 years more recent in time. The production of beads and micro‐drills represents specialised expertise. Whether this supported an external exchange system, or was exclusively related to household use, cannot be determined.
Synthesis of 2‐(2‐oxo‐2H‐chromen‐4‐yl)acetamides as potent acetylcholinesterase inhibitors and molecular insights into binding interactions
Authors: Kara Jiraporn , Suwanhom Paptawan , Wattanapiromsakul Chatchai , Nualnoi Teerapat , Puripattanavong Jindaporn , Khongkow Pasarat , Lee Vannajan Sanghiran , Gaurav Anand , Lomlim Luelak 
Published: May 2019

AbstractSixteen novel coumarin‐based compounds are reported as potent acetylcholinesterase (AChE) inhibitors. The most active compound in this series, 5a (IC50 0.04 ± 0.01 µM), noncompetitively inhibited AChE with a higher potency than tacrine and galantamine. Compounds 5d, 5j, and 5 m showed a moderate antilipid peroxidation activity. The compounds showed cytotoxicity in the same range as the standard drugs in HEK‐293 cells. Molecular docking demonstrated that 5a acted as a dual binding site inhibitor. The coumarin moiety occupied the peripheral anionic site and showed π‐π interaction with Trp278. The tertiary amino group displayed significant cation‐π interaction with Phe329. The aromatic group showed π‐π interaction with Trp83 at the catalytic anionic site. The long chain of methylene lay along the gorge interacting with Phe330 via hydrophobic interaction. Molecular docking was applied to postulate the selectivity toward AChE of 5a in comparison with donepezil and tacrine. Structural insights into the selectivity of the coumarin derivatives toward huAChE were explored by molecular docking and 3D QSAR and molecular dynamics simulation for 20 ns. ADMET analysis suggested that the 2‐(2‐oxo‐2H‐chromen‐4‐yl)acetamides showed a good pharmacokinetic profile and no hepatotoxicity. These coumarin derivatives showed high potential for further development as anti‐Alzheimer agents.
Müssen Imperfektionen bei der Bemessung von brandbeanspruchten Stahlbetonstützen berücksichtigt werden?
Authors: Richter Ekkehard , Zehfuß Jochen 
Published: May 2019

AbstractIm vorliegenden Beitrag wird der Einfluss von Imperfektionen auf die Zuverlässigkeit von brandbeanspruchten Stahlbeton‐Kragstützen – schwerpunktmäßig der Feuerwiderstandsklasse R 90 – untersucht. Dabei wird „Zuverlässigkeit“ im Sinne von DIN EN 1990 als die Fähigkeit eines Bauteils verstanden, die festgelegten Anforderungen innerhalb der geplanten Nutzungsdauer zu erfüllen. Die Zuverlässigkeit wird in der Regel mit probabilistischen Größen ausgedrückt.Auslöser der Untersuchungen war ein Beitrag von Pauli in [1], in dem darauf hingewiesen wurde, dass der Nachweis mit dem allgemeinen Rechenverfahren nach DIN EN 1992‐1‐2 oftmals eine geringere Feuerwiderstandsdauer ergibt als die Nachweise mit tabellierten Werten bzw. mit dem vereinfachten Berechnungsverfahren. Als Ursache der Diskrepanzen wurde die fehlende Regelung über Imperfektionen im Zusammenhang mit einer Heißbemessung genannt.
Comprehensive genomic profiling of high‐grade serous ovarian carcinoma from Chinese patients identifies co‐occurring mutations in the Ras/Raf pathway with TP53
Authors: Zhong Fangfang , Zhu Tao , Pan Xuedong , Zhang Yanling , Yang Haikun , Wang Xiangping , Hu Jinwei , Han Hongxia , Mei Lei , Chen Donglin , Wang Kai , Zhou Xianrong , Li Xiuqin , Dong Xiaowei 
Published: May 2019

AbstractHigh‐grade serous ovarian carcinoma (HGSOC) is a major form of ovarian epithelial tumor that is often diagnosed only at an advanced stage when it is already highly aggressive. We performed comprehensive genomic profiling using an analytically validated clinical next‐generation sequencing assay to identify genomic alterations in 450 cancer‐related genes in a cohort of 88 Chinese HGSOC patients. Overall, we detected 547 genomic alterations with an average of 6.2 alterations per tumor. Most of these HGSOC tumors had low tumor mutation burden and were microsatellite stable. Consistent with earlier studies, TP53 mutations were present in the majority (96.6%) of the tumors studied, and mutations in BRCA1/2 that affect DNA repair were also detected frequently in 20.5% of the tumors. However, we observed a 10.2% of mutated genes in the Ras/Raf pathway, all co‐occurring with TP53 mutations in the same tumor, which was unrecognized previously. Our results show that in HGSOC patients, there may be an unrecognized co‐occurrence of TP53 mutations with mutations in Ras/Raf pathway.
Poly(Ionic Liquid)‐Based Composite Gel Electrolyte for Lithium Batteries
Authors: Safa Meer , Adelowo Ebenezer , Chamaani Amir , Chawla Neha , Baboukani Amin Rabiei , Herndon Marcus , Wang Chunlei , El‐Zahab Bilal 
Published: May 2019

AbstractComposite gel polymer electrolyte (cGPE) containing a poly(ionic liquid) (PIL) polymer, imidazolium cation‐based ionic liquid as a solvent, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as salt, and glass fillers with various concentrations have been developed and tested in lithium batteries. cGPEs with 1 wt% glass filler shows the highest ionic conductivity and lithium‐ion transference number with 25 % and 18.18 % improvement compared to gel polymer electrolyte (GPE), respectively. Raman results show that the improvement is due to the improved ion‐pair dissociation of LiTFSI, which causes improvement of Li+ mobility. Cyclic charge‐discharge studies using binder‐free LiFePO4/C cathode and lithium anode for 100 cycles at various C‐rates and at a fixed rate of C/2 for 300 cycles show superior performances compared to other cGPEs and GPE. Electrochemical impedance spectroscopy and scanning electron microscopy confirm uniform deposition of reaction products on the cathode surface, which improves the charge‐transfer reactions and hence improves cyclic performances for cGPE‐1 cells with increasing cycles.
BitFlow: Enabling real‐time cash‐flow evaluations through blockchain
Authors: Herskind Lasse , Giaretta Alberto , De Donno Michele , Dragoni Nicola 
Published: May 2019

SummaryDisbursement registration has always been a cumbersome, opaque, and inefficient process, up to the point that most businesses perform cash‐flow evaluations only on a quarterly basis. We believe that automatic cash‐flow evaluations can actively mitigate these issues. In this paper, we present BitFlow, a blockchain‐based architecture that provides complete cash‐flow transparency and diminishes the probability of undetected frauds through the BitKrone, a non‐volatile cryptocurrency that maps to the Danish Krone (DKK). We show that confidentiality can be effectively achieved on a permissionless blockchain using Zero‐Knowledge proofs, ensuring verifiable transfers and automatic evaluations. Furthermore, we discuss several experiments to evaluate our proposal, in particular, the impact that confidential transactions have on the whole system, in terms of responsiveness and from an economical expenditure perspective.
A Fast and Reliable Method to Isolate Human Placental Macrophages
Authors: Mezouar Soraya , Ben Amara Amira , Chartier Céline , Gorvel Laurent , Mege Jean‐Louis 
Published: May 2019

AbstractMacrophages are specialized cells involved in recognition, uptake, and destruction of microorganisms. Human placental macrophages are poorly investigated because of the lack of a convenient protocol for their isolation. Here, we present a straightforward and reliable method to isolate macrophages from full‐term human placentas. After enzymatic digestion of placental tissue and centrifugation of the cell suspension on a Ficoll cushion, placental macrophages are selected using magnetic beads coated with anti‐CD14 antibodies. Isolated cells are characterized by flow cytometry. Ninety eight percent of isolated CD14+ placental macrophages also express the macrophage marker CD68. Thus, this efficient and reliable method yields placental macrophages at high purity and sufficient quantity for functional studies. © 2019 by John Wiley & Sons, Inc.
Statin users have an elevated risk of dysglycemia and new‐onset‐diabetes
Authors: Zigmont Victoria A. , Shoben Abigail B. , Lu Bo , Kaye Gail L. , Clinton Steven K. , Harris Randall E. , Olivo‐Marston Susan E. 
Published: May 2019

AbstractObjectiveStatins are one of the most widely prescribed medications in the United States; however, there is a concern that they are associated with new‐onset‐diabetes (NOD) development. We sought to understand the risk of dysglycemia and NOD for a cohort of individuals that reflect real‐world physician prescribing patterns.MethodsA retrospective cohort study was conducted among individuals with indications for statin use (n = 7064). To examine elevated glycosylated hemoglobin (>6.0%), logistic regression with inverse probability weighting was used to create balance between incident statin users and nonusers. To evaluate the risk of NOD development, Cox PH models with time varying statin use compared NOD diagnoses among statin users and nonusers.ResultsA higher prevalence of elevated HbA1c (PD = 0.065; 95% CI: 0.002, 0.129, P = 0.045) occurred among nondiabetic incident users of statins. Additionally, statin users had a higher risk of developing NOD (AHR = 2.20; 95% CI: 1.35, 3.58, P = 0.002). Those taking statins for 2 years or longer (AHR = 3.33; 95% CI: 1.84, 6.01, P < 0.001) were at the greatest risk of developing NOD; no differences were observed by statin class or intensity of dose.ConclusionAs lifestyle programs like the Diabetes Prevention Program are promoted in primary care settings, we hope physicians will integrate and insurers support healthy lifestyle strategies as part of the optimal management of individuals at risk for both NOD and cardiovascular disease. The relationships between statin use and glycemic control should be evaluated in large cohort studies, medical record databases, and mechanistic investigations to inform clinical judgment and treatment.
Chemical profiling of the synthetic cannabinoid MDMB‐CHMICA: Identification, assessment, and stability study of synthesis‐related impurities in seized and synthesized samples
Authors: Münster‐Müller Sascha , Hansen Steven , Opatz Till , Zimmermann Ralf , Pütz Michael 
Published: May 2019

AbstractIn this work, the most discriminating synthesis‐related impurities found in samples from seizures and controlled synthesis of the synthetic cannabinoid MDMB‐CHMICA (methyl (S)‐2‐(1‐(cyclohexylmethyl)‐1H‐indole‐3‐carboxamido)‐3,3‐dimethylbutanoate) were characterized. Based on 61 available powder samples of MDMB‐CHMICA, 15 key‐impurities were assessed, isolated in larger quantities via flash chromatography and structurally elucidated and characterized via high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Apart from verifying the relation of the impurities to the major component, the interpretation of their chemical structures with distinct structural elements provided first insights into the manufacturing process and the precursor compounds used. Following liquid chromatography mass spectrometry analysis of the 15 key‐impurities, the 61 seized samples of MDMB‐CHMICA were evaluated and classified via multivariate data analysis based on the corresponding relative peak areas. In a second part of this work, stability tests and multiple controlled syntheses of MDMB‐CHMICA were carried out to better understand variations in impurity signatures and to assess the significance of variations in the impurity patterns of seized samples. The last coupling step of the amino acid with 1‐(cyclohexylmethyl)‐1H‐indole‐3‐carboxylic acid was performed using the coupling agents oxalyl chloride, thionyl chloride, and HATU. Furthermore, the impact of reaction time and temperature on the impurity profile were investigated. Overall, eight new impurities were found in the controlled syntheses and two degradation products of MDMB‐CHIMCA were found in the course of the stability tests. Replicates of a synthesis conducted on the same day showed similar impurity signatures; on different days they showed discriminable signatures. The use of different coupling reagents or conditions gave clearly distinguishable impurity signatures.
Contingency rules for pathogen competition and antagonism in a genetically based, plant defense hierarchy
Authors: Busby Posy E. , Crutsinger Gregory , Barbour Matthew , Newcombe George 
Published: May 2019

Abstract

Plant defense against pathogens includes a range of mechanisms, including, but not limited to, genetic resistance, pathogen‐antagonizing endophytes, and pathogen competitors. The relative importance of each mechanism can be expressed in a hierarchical view of defense. Several recent studies have shown that pathogen antagonism is inconsistently expressed within the plant defense hierarchy. Our hypothesis is that the hierarchy is governed by contingency rules that determine when and where antagonists reduce plant disease severity.

Here, we investigated whether pathogen competition influences pathogen antagonism using Populus as a model system. In three independent field experiments, we asked whether competition for leaf mesophyll cells between a Melampsora rust pathogen and a microscopic, eriophyid mite affects rust pathogen antagonism by fungal leaf endophytes. The rust pathogen has an annual, phenological disadvantage in competition with the mite because the rust pathogen must infect its secondary host in spring before infecting Populus. We varied mite–rust competition by utilizing Populus genotypes characterized by differential genetic resistance to the two organisms. We inoculated plants with endophytes and allowed mites and rust to infect plants naturally.

Two contingency rules emerged from the three field experiments: (a) Pathogen antagonism by endophytes can be preempted by host genes for resistance that suppress pathogen development, and (b) pathogen antagonism by endophytes can secondarily be preempted by competitive exclusion of the rust by the mite.

Synthesis: Our results point to a Populus defense hierarchy with resistance genes on top, followed by pathogen competition, and finally pathogen antagonism by endophytes. We expect these rules will help to explain the variation in pathogen antagonism that is currently attributed to context dependency.
Institutional differences and arbitration mechanisms in international joint ventures
Authors: Devarakonda Shivaram , Klijn Elko , Reuer Jeffrey , Duplat Valérie 
Published: May 2019

AbstractResearch summaryWe theoretically and empirically study the effects of legal institutions on the inclusion of arbitration provisions in international joint venture (IJV) contracts. Legal institutions offer a public trilateral forum to handle interpartner disputes. However, these institutions function differently across countries, which can impede IJV partners from resolving disputes effectively through court systems. Alternatively, partners can take advantage of private trilateral resolution mechanisms in the form of arbitration. We argue and demonstrate that differences among partners' home country legal institutions regarding the legal traditions, as well as the importance of procedures and costs imposed in these countries for enforcing contracts, increase the likelihood of choosing arbitration over litigation. We also compare results for partners' recourse to IJV boards as a private, bilateral means of addressing conflicts.Managerial summaryIJVs are powerful levers for market expansion and access to resources and capabilities. The risks of corrosive disputes caused by conflicting interests or misunderstandings among partners are nonetheless far from being negligible. Our study helps decision makers and managers increase their understanding of the options and remedies available for resolving disputes. We consider three mechanisms in particular: public courts, arbitration, and the board of directors. Findings show that considering the partners' home country legal environments but also the discrepancies between these environments is essential when it comes to giving preference to arbitration over public courts. Findings also suggest that decisions related to internal private ordering (i.e., relying on the JV board of directors) are driven by the exchange characteristics more than by institutional considerations.
Determination of Planting Time of Watermelon Under a Shallow Groundwater Table in Tidal Lowland Agriculture Areas of South Sumatra, Indonesia
Authors: Imanudin Momon Sodik , Armanto M.E. , Bakri  
Published: May 2019

AbstractWatermelon cultivation is one of the appropriate alternatives in order to increase farmers' income from tidal lowland agriculture. Research into crop adaptation to wet soil conditions is required to enable farmers to decide the best planting time under various conditions within the existing land classification. The research to determine crop physiological response during the initial growth period was conducted in a greenhouse. This was combined with field treatments based on groundwater table depths at 15, 10 and 5 cm‐surface, respectively. Analysis of crop potential based on the water status conditions in the root zone was conducted by using secondary and primary data (daily records). Results of crop adaptation at shallow groundwater table depth showed that the treatments with groundwater table depth of 10 and 5 cm‐surface were not significantly different in terms of plant height, with a size of 12.6 and 12.3 cm, having three leaves. However, it had a significant effect on root length, with a length of 11.9 and 3.1 cm, respectively. Maximum plant height of 15.2 cm and four leaves were found for the treatment with a groundwater table depth of 15 cm‐surface. It may be concluded that it is best for farmers to plant at a groundwater table depth of 10 cm‐surface. © 2019 John Wiley & Sons, Ltd.