bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Facile Regioselectively Synthesis of 2‐Alkenylbenzo[1,2‐b:4,5‐b’]dithiophene by Pd/Cu/Ag‐Catalyzed C‐H Functionalization
Authors: Dung Tran Ngoc , Van Trang Nguyen , Thanh Dinh Thi Mai , Van Khanh Nguyen Thi , Nguyen Hien , Nguyen Hue Minh Thi 
Published: May 2020

AbstractIn this work, several alkenylated benzo[1,2‐b:4,5‐b′]dithiophene were synthesized by Pd‐catalyzed C−H functionalization of benzo[1,2‐b:4,5‐b′]dithiophene with various alkenes. This direct alkenylation took place regioselectively at the C‐2 position of the fused heterocycle. The obtained compounds were structurally characterized by NMR and MS spectroscopic methods. Moreover, DFT calculations have been employed to shed light on the regioselectivity of the reaction as well as on the geometry and electronic properties of the newly formed C=C double bonds.
Current Advances of Hollow Capsules as Controlled Drug Delivery Systems
Authors: Quang Tran Huy , Bhave Mrinal , Yu Aimin 
Published: May 2020

AbstractPolymeric hollow capsules have attracted increasing interest for the development of controlled drug delivery systems due to their capacities to load high amount of drugs and be able to finely tune the drug release profile. Various methods and strategies for capsule preparation and drug loading have been developed over time. Besides that, the controlled drug release from hollow capsules upon external and internal triggers is of great interest and has been a research focus in this area. This article aims to give the most recent progress review on hollow capsule based controlled drug delivery systems with a highlight on strategies being used for drug loading and stimuli‐release. In detail, the fabrication of hollow capsules using template‐assisted or template‐free methods will be introduced first. This will be followed by current strategies for pre‐loading and post‐loading of therapeutic agents into capsules. The article will then be particularly focused on discussing diverse drug‐release systems corresponding to various stimuli conditions including temperature, pH, ultrasound, light irradiation and enzyme degradation.
Synthesis of γ‐Spirolactams from Blaise Reaction Intermediates and 1,2‐Dicarbonyl Compounds
Authors: Liu Jin , Shi Guang , Chen Zhiwei 
Published: May 2020

AbstractA intermolecular nucleophilic addition/pinacol rearrangement cascade reaction of 1,2‐dicarbonyl compounds and Blaise reaction intermediates has been developed. This highly efficient transformation enables the quick construction of γ‐spiro lactams in a single operation with moderate to good yields as well as mild reaction condition.
Recent Advances in Homogeneous and Heterogeneous Catalyst in Biginelli Reaction from 2015‐19: A Concise Review
Authors: Chopda Lakha V. , Dave Pragnesh N. 
Published: May 2020

AbstractIn the chemistry world, the year 1891 was considered as milestone year for the discovery of new type of heterocyclic compounds by Pietro Biginelli. The Biginelli protocol provides 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones in the presence of Bronsted acids and Lewis acids. Multifunctional Dihydropyrimidones (DHPMs) are displayed wide medicinal properties. Several of homogeneous and heterogeneous catalysts have been reported to improve the yield of product. This review includes the progress of ionic liquids, combination of ionic liquids with homogeneous & heterogeneous catalyst, homogeneous, heterogeneous and asymmetric catalyst took place in last five year (2015–2019) for Biginelli reaction. Most of catalysts showed good catalytic activity (more than 80 %) towards the synthesis of Biginelli adducts.
Effect of Cobalt Phthalocyanine on the Chemical Polymerization of Aniline
Authors: Andriianova Anastasia N. , Abyalilova Aigul R. , Biglova Yulia N. , Mustafin Akhat G. 
Published: May 2020

AbstractThe synthesis of polyaniline (PANI) using organic metal complexes, for example, cobalt phthalocyanine (CoPc), is currently one of the promising approaches for PANI modification. Compounds of this kind favor the improvement of the properties of the target material and participate in the oxidative polymerization of aniline as catalysts. To fully understand the effect of CoPc on the synthesis and properties of PANI, the oxidative polymerization of aniline was monitored by measuring the open‐circuit potential (OCP) and pH, as well as by UV spectroscopy. Combining these techniques allows one to estimate the effect of the catalyst and assume the likely scheme of aniline oxidative polymerization with participation of the catalyst, as well as determine the extent of process acceleration.
Anthraimidazoledione Derivatives in Fluoride Sensing Ensuing Si‐O Bond Cleavage in Organic and Aqueous Medium
Authors: Mondal Subhendu , Roy Saswati Ghosh , Ghosh Kumaresh 
Published: May 2020

AbstractAnthraimidazoledione derivatives 1 and 2 containing silyl groups have been synthesized and characterized. Anion binding properties with reference to Si−O bond cleavage are documented in organic and aqueous medium. Both compounds 1 and 2 selectively sense F− ion over a series of other anions by exhibiting ratiometric change in UV‐vis spectra in CH3CN. In fluorescence, significant quenching of emission of both 1 and 2 occurs in presence of F−. Other anions in this event are silent. Compounds are also found working in aqueous CH3CN. Both show quenching of emission while aqueous solution of KF is added to their acetonitrile solutions. Importantly, Si−O bond cleavage in 1 and 2 follows first order kinetics and the cleavage is more facile in 1 than 2. The detection limits for fluoride with compounds 1 and 2 were found to be 49.6 μM and 20.1 μM, respectively.
Improving the Interfacial Adhesion of Carbon Fiber/Polyether Ether Ketone Composites by Polyimide Coating
Authors: Wang Tao , Jiao Yongsheng , Mi Zhiming , Wang Chunbo , Wang Daming , Zhao Xiaogang , Zhou Hongwei , Chen Chunhai 
Published: May 2020

AbstractPolyimide (PI) as a sizing agent for short carbon fiber (SCF) was explored, and a series of SCF‐reinforced polyether ether ketone (PEEK) composites with PI sizing concentrations varying from 0 to 2.0 wt % were fabricated using the extrusion and injection molding techniques. It was found that the PI sizing layer forms homogeneously and compact on the SCF surfaces, and when the PI sizing concentrations was 1.0 wt %, the tensile strength and flexural strength of the corresponding SCF/PEEK composite was significantly increased by 16.8 % and 8.2 % respectively in comparison with the untrelated case. Additionally, dynamic mechanical analysis (DMA) curves demonstrated that storage modulus of SCF/PEEK composites were enhanced with the increasing concentration of PI sizing, resulting the higher stiffness and the lower damping behavior of the composites. Further, the single fiber pull‐out testing was also measured, with the increased interfacial shear strength (IFSS) of CF/PEEK composites by 24.8 % from 70.6 to 88.1 MPa for the CF modified with 1.0 wt % PI sizing, which illustrated that PI sizing can improve fiber surface wettability and interfacial adhesion between CF and PEEK.
Synthesis of 4,4‐Disubstituted 1,2‐Thiazinane‐5‐one 1,1‐Dioxides via the CSIC[≠]Reaction Strategy
Authors: Dyachenko Maksim S. , Kochetkov Artem O. , Dobrydnev Alexey V. , Milokhov Demyd S. , Shishkina Svitlana V. , Konovalova Irina S. , Omelchenko Irina V. , Volovenko Yulian M. 
Published: May 2020

AbstractA series ofsp3‐enriched 2,2‐disubstituted 1,2‐thiazinane‐5‐one 1,1‐dioxides (including spirocyclic derivatives) has been synthesized through the CSIC [Carbanion mediated Sulfonate (Sulfonamido) Intramolecular Cyclization] reaction strategy. In particular, 2,2‐disubstituted alkyl 3‐aminopropanoates were subsequently sulfonylated with mesyl chloride followed by alkylation with methyl iodide to give the key precursor 2,2‐disubstituted methyl 3‐(methylsulfonamido)propanoates. The latter were treated with sodium hydride and underwent the intramolecular sulfa‐Dieckmann cyclization yielding the target 4,4‐disubstituted 1,2‐thiazinane‐5‐one 1,1‐dioxides (so‐called β‐keto‐δ‐sultams). The structure of the target compounds was confirmed by an X‐ray diffraction study.
NiCo2O4/C Core‐Shell Nanoneedles on Ni Foam for All‐Solid‐State Asymmetric Supercapacitors
Authors: Li Yaoyin , Wang Qiyuan , Shao Jian , Li Kang , Zhao Weiwei 
Published: May 2020

AbstractHerein, NiCo2O4/C core‐shell nanoneedles grown on Ni foam are prepared by a simple route and applied in supercapacitors. Electrochemical results show that the area specific capacitance of NiCo2O4/C reaches 2057 mF/cm2 at 1 mA/cm2, which is about 4 times than that of the pristine NiCo2O4. The electrode exhibits excellent rate capability (92 % of capacitance retention at 10 mA/cm2) and remarkable cycling stability (81 % of capacitance retention after 10000 cycles). The as‐fabricated all‐solid‐state asymmetric supercapacitor (NiCo2O4/C//AC(active carbon)) achieves an energy density of 2 mW h cm−3 at a power density of 37 mW cm−3 and remains 1.6 mW h cm−3 at a power density of 120 mW cm−3. Moreover, the ASC device can retain 87 % capacitance after 4000 cycles. The result reveals that it is a feasible method to achieve excellent performance in energy storage devices by the dipping method.
A numerical algorithm for multiple cracks propagation in concrete structure
Authors: Wen Ming , Fang Qian , Zhang Dingli , Fang Huangcheng 
Published: May 2020

AbstractMultiple cracks are extremely common in aged or partially damaged concrete structures. These cracks have a decisive influence on the safety of structures. In this study, a novel multiple‐crack‐length‐controlled method is presented for analyzing the cracking behavior of multiple cracks in concrete structures. This method introduces topological variables into the finite element calculation to identify the correct crack propagation pattern of multiple‐crack problems. The values of topological variables that are used to active and inactive cracks are continually updated by the maximum stress criterion during calculation. The mathematical formulation of the proposed method is constructed in the incremental form. Thus, it is easy to be implemented in the nonlinear problems and capable of considering the influences of stress history on the plastic behaviors. Furthermore, several numerical examples with different cracking modes are studied. The results show that the proposed method provides a robust, effective, and fast way to solve the multiple‐crack problems in concrete.
Performance assessment of reinforced concrete columns under vehicle impact load using P‐I diagram
Authors: Ma Haiying , Cao Zhen , Shi Xuefei , Hu Ke , Zhou Junyong 
Published: May 2020

AbstractP‐I diagrams are widely used for structures subjected to blast loads. In the same manner, structures subjected to vehicle impact load, such as bridge columns, could potentially take advantages of the P‐I diagram if the dynamic characteristics of vehicle impact load and bridge columns are well considered. In the paper, the performance of bridge columns and hence the use of P‐I diagram is evaluated under vehicle impact load. The main tasks of the paper are (1) to determine the dynamic characteristics of vehicle impact load through finite element method, and three simplified load shapes are obtained including isosceles triangle, right triangle, and rectangular shapes; (2) to investigate structural failure modes under various shear‐bending ratios and impact loads; (3) to establish the damage index based on the residual axial capacity of bridge columns and to obtain P‐I diagrams at different damage levels of bridge columns under vehicle impact load; (4) to parametrically analyze the effects on the impulse asymptotic and the peak load asymptotic of P‐I diagrams, including column diameter, stirrup reinforcement ratio, longitudinal reinforcement ratio, and strength of the concrete. Finally, a simplified calculation method of P‐I diagrams is proposed to evaluate the performance of bridge columns under vehicle impact load.
Multiscale Investigation of Water Chemistry Effects on Fish Guild Species Richness in Regulated and Nonregulated Rivers of India's Western Ghats: Implications for Restoration
Authors: Atkore Vidyadhar , Kelkar Nachiket , Badiger Shrinivas , Shanker Kartik , Krishnaswamy Jagdish 
Published: May 2020

AbstractTropical rivers across the world are experiencing rapid degradation and loss of fish species due to flow regulation, pollution, and other anthropogenic pressures. Knowledge of how flow alterations at different scales affect tropical fish diversity remains limited, especially in terms of how resulting changes in water chemistry affect fish communities. We investigated fish guild composition and responses of guild richness to water chemistry in 120 river segments with and without local‐scale water removals and pollution. This included two regulated subbasins (with flow regulation by barrages and large‐scale water diversions) and two nonregulated subbasins (flows not regulated by these barriers) in India's Western Ghats. Using multivariate ordination and regression models, we identified covariates related to water chemistry and environmental characteristics that explained differences in fish species composition and species richness of three water column position‐based fish guilds in the study area. At the subbasin scale, effects of water chemistry were stronger for individual river segments. At the segment scale, no differences in water chemistry were found between segments with and without water removals or pollution in both regulated and nonregulated subbasins. Guild‐wise species richness, especially of surface‐dwelling fishes, was positively correlated with water temperature and total dissolved solids across regulated and nonregulated subbasins. In regulated subbasins, total alkalinity was positively correlated with species richness of bottom‐dwelling and mid‐column‐dwelling fishes. Landscape‐scale flow alterations and degree of flow regulation by river barriers significantly influenced fish composition and species richness over and above local water withdrawal or pollution. River restoration at both the local (segment) and landscape (basin) scales is crucial for fish conservation. To sustain fish guild diversity, maintenance of ecological flow regimes downstream of barriers needs to receive priority over mitigating local disturbances in regulated river catchments of the Western Ghats.
Danshen (Salvia miltiorhiza) inhibits Leu27 IGF‐II‐induced hypertrophy in H9c2 cells
Authors: Ho Tsung‐Jung , Wu Hsi Chin , Bharath Kumar V. , Kuo Wei‐Wen , Weng Yueh‐Shan , Yeh Yu‐Lan , Mahalakshmi B. , Day Cecilia Hsuan , Li Chi‐Cheng , Huang Chih‐Yang 
Published: May 2020

AbstractIn this study, we used ICI 182 780 (ICI), an estrogen receptor (ER) antagonist, to investigate the estrogenic activity of Danshen, and to further explored whether Danshen extract can block Leu27IGF‐II‐induced hypertrophy in H9c2 cardiomyoblast cells. We first used an IGF‐II analog Leu27IGF‐II, which specifically activates IGF2R signaling cascades and induces H9c2 cardiomyoblast cell hypertrophy. However, Danshen extract completely inhibited Leu27IGF‐II‐induced cell size increase, ANP and BNP hypertrophic marker expression, and IGF2R induction. We also observed that Danshen extract inhibited calcineurin protein expression and NFAT3 nuclear translocation, leading to suppression of Leu27IGF‐II‐induced cardiac hypertrophy. Moreover, the anti‐Leu27IGF‐II‐IGF2R signaling effect of Danshen was totally reversed by ICI, which suggest the cardio protective effect of Danshen is mediated through estrogen receptors. Our study suggests that, Danshen exerts estrogenic activity, and thus, it could be used as a selective ER modulator in IGFIIR induced hypertrophy model.
A laryngeal inflammatory polyp in a miniature dachshund
Authors: Sugimoto Keisuke , Kanda Teppei , Mitsui Ikki , Miyabe Masahiro , Maeta Noritaka 
Published: May 2020

AbstractA 15‐year old, female miniature dachshund was presented for a 5‐year history of progressive dyspnoea. A laryngeal mass was detected on cervical radiographs. Surgery was performed 5 days later to reduce the volume of the mass and to obtain biopsy samples; the dyspnoea improved. Based on the histopathological findings, the mass was diagnosed as inflammatory polyp. This case of inflammatory polyp in the larynx suggests that it should be listed in the differential diagnoses for laryngeal masses in dogs and that surgical treatment may be curative.
Comparison of evapotranspiration estimates using the water balance and the eddy covariance methods
Authors: Denager Tanja , Looms Majken C. , Sonnenborg Torben O. , Jensen Karsten H. 
Published: May 2020

AbstractThe eddy covariance method estimates the energy flux of latent heat for evapotranspiration. However, imbalance between the land surface energy output and input is a well‐known fact. Energy balance closure is most commonly not achieved, and therefore the eddy covariance method potentially underestimates actual evapotranspiration. Notwithstanding, the method is one of the most established measurement techniques for estimating evapotranspiration. Here, evapotranspiration from eddy covariance (ETEC) is cross‐checked with evapotranspiration calculated as the residual of the water balance (ETwb). The water balance closure using ETEC is simultaneously validated. Over a 6‐yr period, all major terms of the water balance are measured including precipitation, recharge from percolation lysimeters, and soil moisture content from a cosmic‐ray neutron sensor, a capacitance sensor network, and time domain reflectometry (TDR), respectively. In addition, we estimate their respective uncertainties. The study demonstrates that both monthly and yearly ETEC and ETwb compare well and that the water balance is closed when ETEC is used. Concurrently, incoming available energy (net radiation minus ground heat flux) on average exceeds the turbulent energy fluxes (latent heat flux and sensible heat flux) by 31%, exposing the energy–surface imbalance. Consequently, the imbalance in the energy balance using the eddy covariance method must, to a lesser degree, be caused by errors in the latent heat estimates but can mainly be attributed to errors in the other energy flux components.
Hydrogen bond design principles
Authors: Karas Lucas J. , Wu Chia‐Hua , Das Ranjita , Wu Judy I‐Chia 
Published: May 2020

AbstractHydrogen bonding principles are at the core of supramolecular design. This overview features a discussion relating molecular structure to hydrogen bond strengths, highlighting the following electronic effects on hydrogen bonding: electronegativity, steric effects, electrostatic effects, π‐conjugation, and network cooperativity. Historical developments, along with experimental and computational efforts, leading up to the birth of the hydrogen bond concept, the discovery of nonclassical hydrogen bonds (CH…O, OH…π, dihydrogen bonding), and the proposal of hydrogen bond design principles (e.g., secondary electrostatic interactions, resonance‐assisted hydrogen bonding, and aromaticity effects) are outlined. Applications of hydrogen bond design principles are presented.This article is categorized under:Structure and Mechanism > Molecular StructuresStructure and Mechanism > Reaction Mechanisms and Catalysis
Presentation of a novel real-time production supply concept with cyber-physical systems and efficiency validation by process status indicators
Authors: Bayhan Haci , Meißner Matthias , Kaiser Pascal , Meyer Maria , Hompel Michael ten 
Published: May 2020

AbstractIndustry 4.0, digitization, and Internet of Things enable companies to react quickly and flexibly to market changes. The objective is the production of customized products at the cost of a mass-produced product. The widespread entry of cyber-physical systems enables a networking of all entities. The introduction of cyber-physical systems in production and logistic systems dissolves existing rigid structures and as a result versatile cyber-physical production systems occur. To support the flexibility of the cyber-physical production systems, the production supply needs to be adapted. For this reason, this paper proposes a novel universal production supply concept. This concept introduces a decentralized controlled supply. It is executed by several cyber-physical system entities, which are represented by software agents. These agents negotiate autonomously with each other. The novel concept was implemented in a research lab and evaluated quantitatively and qualitatively. For the quantitative evaluation, the efficiency of the novel concept is evaluated and compared with a kanban supply. An innovative key performance indicator system called process status indicators evaluates the efficiency. The result of this indicator system states that the novel concept is more efficient than the kanban supply.
Effect of print orientation and bronze existence on tribological and mechanical properties of 3D-printed bronze/PLA composite
Authors: Hanon Muammel M. , Alshammas Yazan , Zsidai László 
Published: May 2020

AbstractIn this work, fused deposition modeling (FDM) technology is employed for manufacturing tribological and tensile testing specimens. The test pieces are fabricated in diverse directions to examine the influence of print orientation. The tribological tests are carried out in reciprocating sliding and under dry condition. Due to their relevance, the surface roughness and the hardness of the products are studied as well. Many images are captured under a microscope to better understand the surface morphology of 3D-printed parts before and after testing. The findings reveal that the existence of various print orientations determines differences in mechanical properties and tribological behavior. Among the investigated parameters, the one with the highest tensile strength at break point is the On-Edge print orientation. The vertically oriented test pieces offer the highest friction tendency but the lowest wear depth. Meanwhile, less wear is observed when sliding under low loads but the tendency for stick-slip phenomenon occurrence increases. Although PLA is presently one of the most popular filaments for 3D printing, it can be employed in some industrial applications (e.g., bushings and bearings), if the tribological properties are amended. Bronze is characterized by excellent sliding capability because of its very low metal-on-metal friction. To date, very limited attention has been given to research on the tribology of 3D-printed objects. Therefore, the purpose of the current work is to fill the gap in knowledge by being the first study to evaluate the impact of bronze presence and 3D printing orientation on the tribological properties of bronze/PLA composite.