bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silicon‐containing fluorenylacetylene resins with low curing temperature and high thermal stability
Authors: Lu Liewei , Guo Kangkang , Zhu Junli , Wang Fan , Zhu Yaping , Qi Huimin 
Published: July 2019

ABSTRACTSilicon‐containing arylacetylene resins (PSAs) are promising thermal stability polymers for many applications. However, the controllability of curing reaction limited their application because of the high curing temperature and enthalpy. In this study, Materials Genome Initiative was utilized to screen out a target monomer, 2,7‐diethynyl‐9H‐fluorene (DEF), for design of new PSAs with low curing temperature and enthalpy. After incorporation of DEF, the obtained silicon‐containing fluorenylacetylene resins (PSA‐VBF) could be cured at a lower temperature of 149.2 °C with lower enthalpy (239.8 J g−1) than the reported PSA‐V (190.0 °C, 368.3 J g−1). Moreover, the thermal curing behavior and mechanism were investigated by differential scanning calorimetry, Fourier transform infrared, and pyrolysis‐gas chromatography–mass spectrometry. The results revealed that with the increased of DEF, the curing reaction of PSA‐VBF became dominated by Diels–Alder reaction. And the formed aromatic fused rings endowed the cured PSA‐VBF with excellent thermal stability, which were proved by thermogravimetric analysis results that the temperature at 5% weight loss (Td5) of the cured copolymers ranged from 630 to 639 °C, and the char yield at 1000 °C was above 90%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48262.
Preparation of PEI nanofiber membrane based on in situ and solution crosslinking technology and their adsorption properties
Authors: Song Yan , Wang Fang‐Fei , Lu Guan‐Xiu , Zhou Lin‐Yuan , Yang Qing‐Biao 
Published: July 2019

ABSTRACTTwo kinds of PEI (Polyethyleneimine) nanofibers membrane were successfully prepared by electrospinning and crosslinking technology, which were insoluble in water. One Polyethyleneimine/ Epichlorohydrin/ Polyacrylonitrile nanofibrous films (abbreviated as PEI/ EPI/ PAN NFs) was prepared by in situ crosslinking of PEI/PAN nanofiber containing of EPI, and the other PEI/ PAN/ EPI NFs was prepared by crosslinking PEI/ PAN nanofibers using EPI solution. The composition and morphology of nanofibers before and after crosslinking were investigated by infrared spectroscopy and scanning electron microscopy. PEI/EPI/PAN nanofibers exhibited excellent adsorption properties toward heavy metal ions and methyl orange dyes, which can also be reused multiple times. The adsorption rate of methyl orange remained around 75% after 4 cycles, meanwhile, the adsorption rate of copper and lead still remained around 90% after 5 cycles. In addition, we found that PEI/ PAN/ EPI nanofibers prepared by solution crosslinking technology solved the problem of easy gel formation in in situ crosslinking technology and facilitated the continuous production of PEI/ EPI/ PAN nanofibers, which is better than in situ crosslinking technology. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48279.
Characterization of multicopper oxidase genes in the green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), with focus on salivary gland‐specific genes
Authors: Matsumoto Yukiko , Hattori Makoto 
Published: July 2019

AbstractMulticopper oxidase (MCO) enzymes are present ubiquitously and act on diverse substrates. Recently, the presence of multiple MCO genes has been described in many insects. Based on sialotranscriptome data, we identified and comprehensively characterized six MCO genes: NcLac1S, 1G, and 2–5 in the green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae). NcLac1S and NcLac1G belong to the MCO1 ortholog of other insects. NcLac2 forms a clade with MCO2s involved in the sclerotization and pigmentation of the cuticle. NcLac3 and NcLac4 form a clade with NlMCO3
–5 of the hemipteran Nilaparvata luges. NcLac5 forms a clade with MCORPs (MCO‐related proteins) that lack amino acid residues normally highly conserved in copper‐coordinated MCOs. NcLac1S and NcLac3 were specifically expressed in the salivary glands; whereas NcLac5 was primarily expressed in the salivary glands. Only NcLac3 protein is considered to have laccase activity in the salivary glands and salivary sheaths ejected by the insect. NcLac1G expression was relatively high in the testis. NcLac2 and NcLac4 were specifically expressed in the integument and in Malpighian tubules, respectively. Knockdown by RNA interference (RNAi) of either NcLac2 and NcLac5 in nymphs caused high mortality. All NcLac2‐knockdown nymphs showed depigmentation and soft cuticle, and eventually died, as did other MCO2‐knockdown insects. DsNcLac5‐injected nymphs (third, fourth, and fifth‐instar) showed high mortality, but injection into adults had no effect on survival or number of eggs deposited, suggesting that NcLac5 is not essential for survival after molting (eclosion). NcLac5 could be a promising target gene for control of N. cincticeps.
Design, synthesis, and evaluation of anticonvulsant activities of benzoxazole derivatives containing the 1,2,4‐triazolone moiety
Authors: Song Ming‐Xia , Huang Yuping , Wang Shiben , Wang Zeng‐Tao , Deng Xian‐Qing 
Published: July 2019

AbstractA novel series of benzoxazole derivatives containing 1,2,4‐triazolone (5a‐m) was designed. These compounds were synthesized in order to screen their anticonvulsant activities by the maximal electroshock seizure (MES) model and the subcutaneous pentylenetetrazole (sc‐PTZ) seizure model in mice. The rotarod test was used to evaluate their neurotoxicities. Most of the compounds showed anti‐MES activities at 100 and 300 mg/kg. Compound5f, which showed potential anticonvulsant activity in the MES model with ED50values of 22.0 mg/kg, was considered as the most promising one in this study. It exhibited greater safety than that of carbamazepine and valproate regarding neurotoxicity. The efficacy of compound5fin inhibiting the tonic seizures and death induced by the convulsants 3‐mercaptopropionic acid and BIC was also verified. In an enzyme‐linked immunosorbent assay, compound5fand the positive drug phenytoin significantly increased the γ‐aminobutyric acid (GABA) level in the mouse brain. Further, pretreatment with an inhibitor of the GABA synthesizing enzyme dramatically raised the ED50value of5fin the MES model. These results confirmed that the compound5fplays its anticonvulsive action via regulating the GABA function in the brain. Also, a docking study of the compound5fin the benzodiazepine (BZD) binding site of the GABAAreceptor confirmed possible binding of the compound5fwith BZD receptors.
Understanding the role of Fischer–Tropsch reaction kinetics in techno‐economic analysis for co‐conversion of natural gas and biomass to liquid transportation fuels
Authors: Sahir Asad H. , Zhang Yanan , Tan Eric C. D. , Tao Ling 
Published: July 2019

AbstractWith the increased availability of low‐cost natural gas, the co‐conversion of natural gas and biomass‐to‐liquid fuels has attracted attention from industry due to its potential for improving liquid fuel yields while lowering greenhouse gas emissions. This study provides an understanding of Fischer–Tropsch kinetics, improvements in processing strategies for hydrocarbon production, and of its impact on cost for the co‐conversion of natural gas and biomass‐to‐transportation fuels. Studies that investigate the effect of Fischer–Tropsch reaction kinetics on techno‐economic analysis can be used to develop process models that consider reaction stoichiometry and account for the effect of the paraffin‐to‐olefin ratio. We consider two processing scenarios: (1) one that does not employ a hydrocracker, and (2) the other where a hydrocracker serves as an integral part of the process scheme. Our analysis shows that co‐processing natural gas not only facilitates the economic benefits of converting biomass‐to‐liquid fuels but also facilitates flexibility in process integration. The resulting minimum fuel selling price ranged from $2.47–$3.47/GGE (gallon gasoline equivalent) without the hydrocracker and ranged from $2.17–$3.60/GGE with the inclusion of the hydrocracker, for a 50 million GGE hydrocarbon fuel production facility and for varying blending ratios for biomass from 0–100% with natural gas. The hydrocracker helps to increase the production of diesel and jet fuels substantially, with carbon efficiencies of 50% attained for a chain growth probability of 0.87. The cost penalty comes from the capital expenses of the hydrocracker, and the expense may not be offset with hydrocarbon yield improvement. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
Spectroscopic and computational exploration of hypoxanthine riboside interacting with plasma albumin
Authors: Zhang Hua‐xin , Zhou Dan , Xia Qing‐hua 
Published: July 2019

AbstractHypoxanthine riboside (HXR) is a nucleoside essential for wobble base pairs to translate the genetic code. In this work, an absorption and luminescence study showed that HXR and human serum albumin (HSA) formed a new complex through hydrogen bonds and van der Waals forces at ground state. Fluorescence probe experiments indicated that HXR entered the first subdomain of domain II in HSA and was fixed by amino acid residues in site I defined by Sudlow, and after competing with a known site marker. The recognition interaction featured negative ΔHϴ, ΔSϴ and ΔGϴ thermodynamic parameters. Fluorescence and circular dichroism spectra described the polarity of residues and α‐helix and β‐strand content changed because of HXR binding. The most rational structure for the HXR–HSA complex was recommended by the molecular docking method, in which the binding location, molecular orientation, adjacent amino acid residues, and hydrogen bonds were included. In addition, the influence of β‐cyclodextrin and some essential metal ions on the balance of the HSA–HXR system interaction was measured. The study gained comprehensive information on the transportation mechanism for HXR in blood, and was of great significance in understanding the theory of HXR biotransformation and in discussing its clinical in vivo half‐life.
The structure and luminescence properties of Mn2+/Eu2+/Er3+‐doped MgO‐Ga2O3‐SiO2 glasses and glass‐ceramics
Authors: Gao Zhenyu , Yu Lixin , Man Xiaoqin , Zhong Jianlin , Guo Qihuang , Zou Yingxuan 
Published: July 2019

AbstractThe MgO–Ga2O3–SiO2 glasses and glass‐ceramics samples doped with Eu2+/Mn2+/Er3+ and heated in reductive atmosphere were prepared by the sol–gel method. The structure, morphology and the luminescence properties were studied using X‐ray diffraction, high‐resolution transmission electron microscope, fluorescence spectra, and up‐conversion emission. The luminescence characteristics of doped ions could be influenced by temperature and matrix component. The characteristic emission of Mn2+, Eu2+ and Er3+ were seen and the energy transfer efficiency from Eu2+ to Mn2+ was enhanced as Mn2+ concentration was increased. In addition, the two‐photon process was determined for the Er3+‐doped samples.
The intellectual structure of the journal Business Strategy and the Environment: A 25‐year author cocitation analysis
Authors: Kabongo Jean D. 
Published: July 2019

AbstractThis article presents the intellectual structure and 25‐year author cocitation analysis of the journal Business Strategy and the Environment. The findings show that Business Strategy and the Environment is an emerging, well‐established journal in its field. The journal needs a core set of authors who are actively engaged in the production and certification of knowledge; further, it consists of a number of loosely linked research team contributors, each with its own areas of interest. The existence of these research teams is a sign of strength that characterizes the journal as it strives to foster a community of unified scholars whose published works advance our understanding of business strategic decisions and behavior with regard to the natural environment. This study is useful for contributors, readers, and editorial board members who form the journal's community of knowledge creation and certification.
Resection of the primary tumor improves survival in patients with gastro‐entero‐pancreatic neuroendocrine neoplasms with liver metastases: A SEER‐based analysis
Authors: Zheng Mengzhen , Li Yan , Li Tong , Zhang Lianfeng , Zhou Lin 
Published: July 2019

AbstractPatients who suffer from gastro‐entero‐pancreatic neuroendocrine neoplasms (GEP‐NENs) often present with liver metastatic disease. The efficacy of primary tumor resection (PTR) for these patients remains controversial due to the relatively heterogeneous behavior of the primary tumor and the lack of clinical evidence. In this series, GEP‐NEN patients with liver metastases (LM) were selected from the Surveillance, Epidemiology, and End Results database between 2010 and 2015. A logistic regression model was used to analyze variables that were associated with PTR. A Cox proportional hazards model was used to identify independent prognostic risk factors. In total, 1547 patients were enrolled in our study, including 897 patients who underwent PTR. Resection of the primary tumor was associated with prolonged survival in all patients (5‐year overall survival (OS) rates: 57.0% vs 15.4%, P < .001), and improved 5‐year OS rates were observed in patients with gastric, small intestinal, colorectal, and pancreatic subtypes (39.7%, 73.3%, 24.6%, and 59.7%, respectively). On the multivariate analysis, PTR was an independent prognostic factor of prolonged OS (HR = 0.48, 95% CI: 0.39‐0.59, P < .001). Patients with a young age (≤60 years), small intestinal or colorectal NENs, a large primary tumor, lymph node (LN) metastases, and high tumor differentiation were more likely to undergo PTR. However, patients with colorectal NENs or a large primary tumor (≥4 cm) were at an increased risk of death independently in the PTR subgroup. The risk factors for OS also included old age, gastric tumor location, and poor differentiation. In conclusion, although PTR prolonged OS in all GEP‐NEN patients presenting with LM, surgical recipients should be considered carefully. Age, primary tumor site, size, and differentiation might help surgeons identify patients who could benefit from PTR.
Phialomyces macrosporus: Chemical Constituents, Antimicrobial Activity and Complete NMR Assignments for the 7,7′‐Biphyscion
Authors: da Silva Brandão Mauricio , Silva Abreu Lucas , Geris Regina 
Published: July 2019

AbstractFive known secondary metabolites, chrysophanol (1), 7,7′‐biphyscion (2), secalonic acid D (3), mannitol (4) and trehalose (5) were isolated for the first time from the extracts of the fungus Phialomyces macrosporus. Their structures were elucidated by NMR methods (1D and 2D NMR analysis), optical activity and ESI‐MS. Complete 1H and 13C assignments were performed for compound 2. The antimicrobial activity was evaluated by serial microdilution assay for compounds 2 and 3 and results showed that compound 3 exhibited a significant growth inhibition at concentrations of 15.6 mg/ml (S. aureus and S. choleraesius) and 0.97 mg/mL (B. subtilis), comparable to the positive control.
MicroRNA‐214 suppresses cell proliferation and migration and cell metabolism by targeting PDK2 and PHF6 in hepatocellular carcinoma
Authors: Yu Qiangfeng , Zhou Jianyin , Jian Yizeng , Xiu Zhe , Xiang Leyang , Yang Dinghua , Zeng Wenlong 
Published: July 2019

AbstractMiR‐214 has been reported to act as a tumor suppressor or oncogene involved in various malignancies. However, the biological functions and molecular mechanisms of miR‐214 in hepatocellular carcinoma (HCC) still remain unclear. Previous studies suggest that pyruvate dehydrogenase kinase 2 (PDK2) and plant homeodomain finger protein 6 (PHF6) may be involved in some tumor cell proliferation and migration. Therefore, we studied the relationship between PDK2/PHF6 and miR‐214. The expression of miR‐214, PDK2, and PHF6 was determined by quantitative real‐time polymerase chain reaction in HCC tissues and cell lines. The Luciferase reporter assay was used to confirm the interaction between miR‐214 and PDK2/PHF6. Cell proliferation, apoptosis, and migration were evaluated by cell counting kit‐8 assay, flow cytometry, and transwell assay, respectively. The expressions levels of α‐smooth muscle actin (α‐SMA) and E‐cadherin were detected via immunofluorescence assay. Here, we found that the expression of miR‐214 decreased in HCC and was negatively correlated with PDK2 and PHF6. Moreover, PDK2 and PHF6 were the direct targets of miR‐214 in HCC cells. Functional analysis showed that knockdown of PDK2 or PHF6 as well as miR‐214 overexpression significantly suppressed cell proliferation and migration in HCC cells. Furthermore, we found that the suppression of cell proliferation and migration through PDK2 or PHF6 knockdown could be partially reversed by miR‐214 down‐regulation. Moreover, we demonstrated a decrease of mesenchymal cell marker α‐SMA and increase of the epithelial marker E‐cadherin after miR‐214 overexpression, PDK2 knockdown or PHF6 knockdown, respectively, which also suggested that cell proliferation and migration were suppressed. Additionally, lactate and pyruvic acid production experiments confirmed miR‐214 could suppress the HCC cell lactate and pyruvic acid levels by down‐regulating PDK2/PHF6. In conclusion, MiR‐214 may act as a tumor suppressor gene, presenting its suppressive role in cell proliferation and migration of HCC cells by targeting PDK2 and PHF6, and might provide a potential therapy target for patients with HCC.
Chemical Doped Ternary and Quaternary Transition‐Metal‐Based Electrocatalysts for Hydrogen Evolution Reaction
Authors: Li Jiayuan , Zhang Mingkai , Zang Hang , Yu Baozhi , Ma Yuanyuan , Qu Yongquan 
Published: July 2019

AbstractElectrocatalytic hydrogen evolution reaction (HER) through transition‐metal‐based (TMB) catalysts represents a totally sustainable and cost‐effective technology for practical hydrogen (H2) production with high purity. Unfortunately, most of the catalysts have the unsuitable hydrogen adsorption behavior and thereby insufficient H2 generation efficiency. The general strategy to address the problem is to introduce various cation or/and anion dopants for designing multivariate TMB catalysts, which comes down to the optimized electronic structures and thus hydrogen adsorption of surface active sites. In this minireview, we summarize the recent significant advances in multivariate TMB catalysts for HER, especially highlighting the contributions of various dopants as the modulator for the host materials. Finally, the remaining challenges and future perspectives on multivariate TMB catalysts for HER are also discussed.
Chemical Synthesis of Oligoribonucleotide (ASL of tRNALysT. brucei) Containing a Recently Discovered Cyclic Form of 2‐Methylthio‐N6‐threonylcarbamoyladenosine (ms2ct6A)
Authors: Debiec Katarzyna , Matuszewski Michal , Podskoczyj Karolina , Leszczynska Grazyna , Sochacka Elzbieta 
Published: July 2019

AbstractThe synthesis of the protected form of 2‐methylthio‐N6‐threonylcarbamoyl adenosine (ms2t6A) was developed starting from adenosine or guanosine by using the optimized carbamate method and, for the first time, an isocyanate route. The hypermodified nucleoside was subsequently transformed into the protected ms2t6A‐phosphoramidite monomer and used in a large‐scale synthesis of the precursor 17nt ms2t6A‐oligonucleotide (the anticodon stem and loop fragment of tRNALys from T. brucei). Finally, stereochemically secure ms2t6A→ms2ct6A cyclization at the oligonucleotide level efficiently afforded a tRNA fragment bearing the ms2ct6A unit. The applied post‐synthetic approach provides two sequentially homologous ms2t6A‐ and ms2ct6A‐oligonucleotides that are suitable for further comparative structure–activity relationship studies.
Hierarchy in the Halogen Activation During Surface‐Promoted Ullmann Coupling
Authors: Merino‐Díez Néstor , Pérez Paz Alejandro , Li Jingcheng , Vilas‐Varela Manuel , Lawrence James , Mohammed Mohammed S. G. , Berdonces‐Layunta Alejandro , Barragán Ana , Pascual Jose Ignacio , Lobo‐Checa Jorge , Peña Diego , de Oteyza Dimas G. 
Published: July 2019

AbstractWithin the collection of surface‐supported reactions currently accessible for the production of extended molecular nanostructures under ultra‐high vacuum, Ullmann coupling has been the most successful in the controlled formation of covalent single C−C bonds. Particularly advanced control of this synthetic tool has been obtained by means of hierarchical reactivity, commonly achieved by the use of different halogen atoms that consequently display distinct activation temperatures. Here we report on the site‐selective reactivity of certain carbon‐halogen bonds. We use precursor molecules halogenated with bromine atoms at two non‐equivalent carbon atoms and found that the Ullmann coupling occurs on Au(111) with a remarkable predilection for one of the positions. Experimental evidence is provided by means of scanning tunneling microscopy and core level photoemission spectroscopy, and a rationalized understanding of the observed preference is obtained from density functional theory calculations.
A Cobalt‐Modified Covalent Triazine‐Based Framework as an Efficient Cocatalyst for Visible‐Light‐Driven Photocatalytic CO2 Reduction
Authors: Bi Jinhong , Xu Bin , Sun Long , Huang Huimin , Fang Shengqiong , Li Liuyi , Wu Ling 
Published: July 2019

AbstractPhotocatalytic CO2 reduction into carbonaceous feedstock chemicals is a promising renewable energy technology to convert solar energy and greenhouse gases into chemical fuels. Here, a covalent triazine‐based framework (CTF) is demonstrated as an efficient cocatalyst to reduce CO2 under visible‐light irradiation. The nitrogen‐rich triazine moieties in CTF contribute to CO2 adsorption, while the periodical pore structure of CTF favors the accommodation of CO2 and electron mediator. Immobilization of cobalt species onto CTF promotes the photocatalytic activity with a 44‐fold enhancement over pristine CTF and the optimal CO production rate of the obtained Co/CTFs was up to 50 μmol g−1 h−1. The results of solid‐state UV‐vis diffuse reflectance spectra (UV‐vis DRS), CO2 adsorption and electrochemical impedance spectroscopy (EIS) illustrated that the increased activity was ascribed to the enhanced CO2 capture capacity, improved absorption of visible‐light and facilitated the transfer of charge from CTF to CO2 molecules. The CTF not only serves as a substrate for active Co species, but also bridges the photosensitizer with cobalt catalytic sites for the efficient transfer of photoexcited electrons. This work highlights the capability and ease of fabricating covalent organic framework‐based photocatalytic systems that are potentially useful for energy‐conversion applications.
Helical Self‐Assembly of Optically Active Glycoconjugated Phthalocyanine J‐Aggregates
Authors: Bächle Felix , Maichle‐Mössmer Cäcilia , Ziegler Thomas 
Published: July 2019

AbstractFour galactoconjugated zinc(II) phthalocyanines (Pcs) have been prepared and fully characterized. The carbohydrate‐containing phthalonitrile precursors of the Pcs were synthesized through a copper‐catalysed azide‐alkyne cycloaddition (CuAAC). The Pcs show a remarkable aggregation behaviour in solution, depending on the nature of the solvent, the temperature and the substitution position on the phthalocyanine. Solvent‐dependent CD‐spectroscopy experiments show that these Pcs aggregate as chiral helices in solution. Crystal structure data of a phthalocyanine bearing two carbohydrate units substantiate the properties shown by CD spectroscopy. Furthermore, the 1,2,3‐triazole moieties of the Pcs play a decisive role in the formation of supramolecular aggregates. The glycoconjugated zinc(II) phthalocyanines described here show molar extinction coefficients ϵmax>105 M−1 cm−1 and absorption maxima λmax>680 nm, which make them attractive photosensitizers for Photodynamic Therapy (PDT).