bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Zeolite Framework Composition and Flexibility on Methanol‐To‐Olefins Selectivity: Confinement or Diffusion?
Authors: Ferri Pau , Li Chengeng , Millán Reisel , Martínez‐Triguero Joaquín , Moliner Manuel , Boronat Mercedes , Corma Avelino 
Published: June 2020

AbstractThe methanol‐to‐olefins reaction catalyzed by small‐pore cage‐based acid zeolites and zeotypes produces a mixture of short chain olefins, whose selectivity to ethene, propene and butene varies with the cavity architecture and with the framework composition. The product distribution of aluminosilicates and silicoaluminophosphates with the CHA and AEI structures (H‐SSZ‐13, H‐SAPO‐34, H‐SSZ‐39 and H‐SAPO‐18) has been experimentally determined, and the impact of acidity and framework flexibility on the stability of the key cationic intermediates involved in the mechanism and on the diffusion of the olefin products through the 8r windows of the catalysts has been evaluated by means of periodic DFT calculations and ab initio molecular dynamics simulations. The preferential stabilization by confinement of fully methylated hydrocarbon pool intermediates favoring the paring pathway is the main factor controlling the final olefin product distribution.
Water Oxidation with Cobalt‐Loaded Linear Conjugated Polymer Photocatalysts
Authors: Sprick Reiner Sebastian , Chen Zheng , Cowan Alexander J. , Bai Yang , Aitchison Catherine M. , Fang Yuanxing , Zwijnenburg Martijn A. , Cooper Andrew I. , Wang Xinchen 
Published: June 2020

AbstractThe first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger are reported. The oxygen evolution rates, which are higher than for related organic materials, can be rationalized by a combination of the thermodynamic driving force for water oxidation, the light absorption of the polymer, and the aqueous dispersibility of the relatively hydrophilic polymer particles. We also used transient absorption spectroscopy to study the best performing system and we found that fast oxidative quenching of the exciton occurs (picoseconds) in the presence of an electron scavenger, minimizing recombination.
Enantioselective Synthesis of β‐Amino Acid Derivatives Enabled by Ligand‐Controlled Reversal of Hydrocupration Regiochemistry
Authors: Guo Sheng , Zhu Jiaqi , Buchwald Stephen L. 
Published: June 2020

AbstractA Cu‐catalyzed enantioselective hydroamination of α,β‐unsaturated carbonyl compounds for the synthesis of β‐amino acid derivatives was achieved through ligand‐controlled reversal of the hydrocupration regioselectivity. While the hydrocupration of α,β‐unsaturated carbonyl compounds to form α‐cuprated species has been extensively investigated, we report herein that, in the presence of an appropriate ancillary chiral ligand, the opposite regiochemistry can be observed for cinnamic acid derivatives, leading to the delivery of the copper to the β‐position. This copper can react with an electrophilic aminating reagent, 1,2‐benzisoxazole, to provide enantioenriched β‐amino acid derivatives, which are important building blocks for the synthesis of natural products and bioactive small molecules.
Ordered Solid‐State Microstructures of Conjugated Polymers Arising from Solution‐State Aggregation
Authors: Yao Ze‐Fan , Wang Zi‐Yuan , Wu Hao‐Tian , Lu Yang , Li Qi‐Yi , Zou Lin , Wang Jie‐Yu , Pei Jian 
Published: June 2020

AbstractControlling the solution‐state aggregation of conjugated polymers for producing specific microstructures remains challenging. Herein, a practical approach is developed to finely tune the solid‐state microstructures through temperature‐controlled solution‐state aggregation and polymer crystallization. High temperature generates significant conformation fluctuation of conjugated backbones in solution, which facilitates the polymer crystallization from solvated aggregates to orderly packed structures. The polymer films deposited at high temperatures exhibit less structural disorders and higher electron mobilities (up to two orders of magnitude) in field‐effect transistors, compared to those deposited at low temperatures. This work provides an effective strategy to tune the solution‐state aggregation to reveal the relationship between solution‐state aggregation and solid‐state microstructures of conjugated polymers.
New 1,2,3‐triazole–(thio)barbituric acid hybrids as urease inhibitors: Design, synthesis, in vitro urease inhibition, docking study, and molecular dynamic simulation
Authors: Asgari Mohammad S. , Azizian Homa , Nazari Montazer Mohammad , Mohammadi‐Khanaposhtani Maryam , Asadi Mehdi , Sepehri Saghi , Ranjbar Parviz R. , Rahimi Rahmatollah , Biglar Mahmood , Larijani Bagher , Amanlou Massoud , Mahdavi Mohammad 
Published: June 2020

AbstractA new series of 1,2,3‐triazole–(thio)barbituric acid hybrids 8a–n was designed and synthesized on the basis of potent pharmacophores with urease inhibitory activity. Therefore, these compounds were evaluated against Helicobacter pylori urease. The obtained result demonstrated that all the synthesized compounds, 8a–n, were more potent than the standard urease inhibitor, hydroxyurea. Moreover, among them, compounds 8a, 8c–e, 8g,h, and 8k,l exhibited higher urease inhibitory activities than the other standard inhibitor used: thiourea. Docking studies were performed with the synthesized compounds. Furthermore, molecular dynamic simulation of the most potent compounds, 8e and 8l, showed that these compounds interacted with the conserved residues Cys592 and His593, which belong to the active site flap and are essential for enzymatic activity. These interactions have two consequences: (a) blocking the movement of a flap at the entrance of the active site channel and (b) stabilizing the closed active site flap conformation, which significantly reduces the catalytic activity of urease. Calculation of the physicochemical and topological properties of the synthesized compounds 8a–n predicted that all these compounds can be orally active. The ADME prediction of compounds 8a–n was also performed.
MoS2 quantum dots as a specific fluorescence sensor for selection of rutin and for temperature sensing
Authors: Sun Yunyun , He Wei , Sun Xiangying , Liu Bin 
Published: June 2020

AbstractA selective and sensitive method for detecting rutin using MoS2 quantum dots (QDs) as a fluorescent probe is reported in the paper, a one‐step hydrothermal synthesis method was used to prepare MoS2 QDs. The synthesized MoS2 QDs had good stability and water solubility, and the fluorescence of MoS2 QDs was quenched by rutin due to the inner filter effect. There was a good linear relationship between the intensity of MoS2 QDs and rutin concentration ranging from 5.0 × 10−7 to 3.2 × 10−5 mol/L with a detection limit of 3.5 × 10−7 mol/L. MoS2 QDs showed temperature‐dependent fluorescence that had an excellent linear relationship between 20 and 80°C. Therefore MoS2 QDs can be used as specific fluorescence sensors for selection of rutin and for temperature sensing.
Enrichment of flavonoid‐rich extract from Bidens bipinnata L. by macroporous resin using response surface methodology, UHPLC–Q‐TOF MS/MS‐assisted characterization and comprehensive evaluation of its bioactivities by analytical hierarchy process
Authors: Yang Xiudong , Bai Zi‐Fan , Zhang Da‐Wei , Zhang Yan , Cui Hao , Zhou Hong‐Li 
Published: June 2020

AbstractThe extract of Bidens bipinnata L. exhibited wide spectrum of bioactivities owing to the presence of flavonoids. In this study, a purification process was developed to enrich the flavonoid‐rich extract from B. bipinnata L. (BBTF). AB‐8 resin was selected for the purification of total flavonoids. Response surface methodology coupled with Box–Behnken design was employed to optimize the purification condition; it was optimized as pH 5.1, volume of ethanol 80 ml, flow rate of ethanol 1.8 bed volume per hour (BV/h) and concentration of ethanol 76.0%. The total flavonoid content of BBTF was 56.48% under the optimal conditions. The identification of flavonoids in BBTF was conducted using UHPLC–ESI‐Q‐TOF MS. A total of 14 compounds, including 12 flavonoids, were identified in BBTF. Finally, the in vitro antioxidant activities, α‐glucosidase and α‐amylase inhibitory activities of BBTF were comprehensively analyzed by an analytical hierarchy process. The results indicated that it exhibited higher bioactivities than the crude extract. These findings suggested that the optimized process could significantly enhance the purity of flavonoids and their bioactivities. This study showed a comprehensive analysis of a total flavonoid extract of B. bipinnata L. for the first time, which could provide a useful approach for its purification process and quality control as well as bioactivities.
Implementation of Activated Sludge Model No. 3 as an educational tool: bioXL3
Authors: Demir Selami , Manav Demir Neslihan 
Published: June 2020

AbstractImplementation of an Microsoft (MS) Excel add‐in, called bioXL3, is presented in this paper. bioXL3 is an educational tool for undergraduate‐ and graduate‐level education in the environmental engineering field. The add‐in is an open‐source tool and is used for the simulation of conventional biological wastewater treatment plants based on Activated Sludge Model No. 3. The software is developed using visual basic for applications (VBA) in MS Excel and is tested with a number of sample model setups. All formulations used in VBA programming are provided here. Also, simulation results of a sample predenitrification system are summarized. The performance of the software in engineering education was tested by a teaching session. Results indicated that the add‐in can prove useful in undergraduate and graduate‐level education in environmental engineering.
Synthesis and Evaluation of Anticonvulsant Activity of Some Schiff Bases of 7‐Amino‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one
Authors: Nilkanth Pankaj R. , Ghorai Sujit K. , Sathiyanarayanan Arulmozhi , Dhawale Kiran , Ahamad Tansir , Gawande Manoj B. , Shelke Sharad N. 
Published: June 2020

AbstractA variety of 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethines and 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one benzamide were prepared, characterized and evaluated for the anticonvulsant activity in the rat using picrotoxin‐induced seizure model. The prepared 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethine derivatives emerged potentially anticonvulsant molecular scaffolds exemplified by compounds, 7‐{(E)‐[(4‐nitrophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐{(E)‐[(4‐bromo‐2,6‐difluorophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one and 7‐[(E)‐{[3‐(4‐fluorophenyl)‐1‐phenyl‐1H‐pyrazol‐4‐yl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one. All these four compounds have shown substantial decrease in the wet dog shake numbers and grade of convulsions with respect to the standard drug diazepam. The most active compound, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, exhibited 74 % protection against convulsion which was higher than the standard drug diazepam. Furthermore, to identify the binding mode of the interaction amongst the target analogs and binding site of the benzodiazepine receptor, molecular docking study and molecular dynamic simulation were carried out. Additionally, in silico pharmacokinetic and toxicity predictions of target compounds were carried out using AdmetSAR tool. Results of ADMET studies suggest that the pharmacokinetic parameters of all the target compounds were within the acceptable range to become a potential drug candidate as antiepileptic agents.
Efficient Chemoenzymatic Synthesis of N‐Glycans with a β1,4‐Galactosylated Bisecting GlcNAc Motif
Authors: Weiss Michael , Ott Dimitri , Karagiannis Theodoros , Weishaupt Markus , Niemietz Mathäus , Eller Steffen , Lott Marie , Martínez‐Orts Mónica , Canales Ángeles , Razi Nahid , Paulson James C. , Unverzagt Carlo 
Published: June 2020

AbstractIn human serum immunoglobulin G (IgG), a rare modification of biantennary complex N‐glycans lead to a β1,4‐galactosylated bisecting GlcNAc branch. We found that the bisecting GlcNAc on a biantennary core‐fucosylated N‐glycan was enzymatically galactosylated under stringent reaction conditions. Further optimizations led to an efficient enzymatic approach to this particular modification for biantennary substrates. Notably, tri‐ and tetra‐antennary complex N‐glycans were not converted by bovine galactosyltransferase. An N‐glycan with a galactosylated bisecting GlcNAc was linked to a lanthanide binding tag. The pseudo‐contact shifts (PCS) obtained from the corresponding Dy‐complex were used to calculate the conformational preferences of the rare N‐glycan. Besides two extended conformations only a single folded conformation was found.
Phrenic nerve injury secondary to extracorporeal membrane oxygenation in pregnancy: A case report
Authors: Godcharles Cheryl , Safarzadeh Melody , Oliver Emily A. , Roman Amanda , Al‐Kouatly Huda B. 
Published: June 2020

AbstractExtracorporeal membrane oxygenation (ECMO) is used to provide acute respiratory and/or hemodynamic support to patients with severe, refractory respiratory failure. Phrenic nerve injury with subsequent hemidiaphragm paralysis should be included in the differential diagnosis of pregnant women with persistent hypoxia after ECMO cannulation.
Simultaneous Detection of Quercetin and Carbendazim in Wine Samples Using Disposable Electrochemical Sensors
Authors: Raymundo‐Pereira Paulo A. , Gomes Nathalia O. , Carvalho Jefferson H. S. , Machado Sergio A. S. , Oliveira Osvaldo N. , Janegitz Bruno C. 
Published: June 2020

AbstractDeveloping low‐cost and fast methods for on‐site analysis is a long‐sought goal of the wine industry, especially to detect excessive concentrations of naturally occurring compounds such as polyphenols and pesticide residues. In this paper, we report on the treatment of screen‐printed electrodes, which were capable of detecting the flavonoid quercetin and the pesticide carbendazim simultaneously in wine samples with limits of detection of 51.8×10−9 mol L−1 and 60×10−9 mol L−1, respectively. Furthermore, no significant interference was observed with electroactive substances that can co‐exist in wine. We found that the electrochemical pretreatment in Na2CO3 solution eliminated residues and impurities from homemade carbon ink comprising graphite and alkyd resin eventually deposited on the electrodes, which were characterized by combining scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. These findings pave the way for monitoring multiple analytes with screen‐printed electrodes, which could be extended to clinical biomarkers.
Rapid Discrimination of Crystal Handedness by X‐ray Natural Circular Dichroism (XNCD) Mapping
Authors: Cortijo Miguel , Valentín‐Pérez Ángela , Rogalev Andrei , Wilhelm Fabrice , Sainctavit Philippe , Rosa Patrick , Hillard Elizabeth A. 
Published: June 2020

AbstractAn original method for determining the handedness of individual non‐centrosymmetric crystals in a mixture using a tightly‐focused, circularly polarized X‐ray beam is presented. The X‐ray natural circular dichroism (XNCD) spectra recorded at the metal K‐edge on selected crystals of [Δ‐M(en)3](NO3)2 and [Λ‐M(en)3](NO3)2 (M=CoII, NiII) show extrema at the metal pre‐edge (7712 eV for Co, 8335 eV for Ni). A mapping of a collection of some 220 crystals was performed at the respective energies by using left and right circular polarizations. The difference in absorption for the two polarizations, being either negative or positive, directly yielded the handedness of the crystal volume probed by the beam. By using this technique, it was found that the addition of l‐ascorbic acid during the synthesis of [Co(en)3](NO3)2 resulted in an enantiomeric enrichment of the Λ‐isomer of 67±13 %, whereas the Ni analogue was similarly, but conversely, enriched in the Δ‐isomer (65±22 %).
Pseudocapacitive Lithium Storage of Cauliflower‐Like CoFe2O4 for Low‐Temperature Battery Operation
Authors: Fan Honghong , Bahmani Farzaneh , Kaneti Yusuf Valentino , Guo Yanna , Alothman Asma A. , Wu Xinglong , Yamauchi Yusuke , Li Wenliang , Zhang Jingping 
Published: June 2020

AbstractBinary transition‐metal oxides (BTMOs) with hierarchical micro–nano‐structures have attracted great interest as potential anode materials for lithium‐ion batteries (LIBs). Herein, we report the fabrication of hierarchical cauliflower‐like CoFe2O4 (cl‐CoFe2O4) via a facile room‐temperature co‐precipitation method followed by post‐synthetic annealing. The obtained cauliflower structure is constructed by the assembly of microrods, which themselves are composed of small nanoparticles. Such hierarchical micro–nano‐structure can promote fast ion transport and stable electrode–electrolyte interfaces. As a result, the cl‐CoFe2O4 can deliver a high specific capacity (1019.9 mAh g−1 at 0.1 A g−1), excellent rate capability (626.0 mAh g−1 at 5 A g−1), and good cyclability (675.4 mAh g−1 at 4 A g−1 for over 400 cycles) as an anode material for LIBs. Even at low temperatures of 0 °C and −25 °C, the cl‐CoFe2O4 anode can deliver high capacities of 907.5 and 664.5 mAh g−1 at 100 mA g−1, respectively, indicating its wide operating temperature. More importantly, the full‐cell assembled with a commercial LiFePO4 cathode exhibits a high rate performance (214.2 mAh g−1 at 5000 mA g−1) and an impressive cycling performance (612.7 mAh g−1 over 140 cycles at 300 mA g−1) in the voltage range of 0.5–3.6 V. Kinetic analysis reveals that the electrochemical performance of cl‐CoFe2O4 is dominated by pseudocapacitive behavior, leading to fast Li+ insertion/extraction and good cycling life.
Temperature Induced Aggregation of Organic Semiconductors
Authors: Du Baocai , Yi Jicheng , Yan He , Wang Tao 
Published: June 2020

AbstractOne important feature of organic semiconductors is their solution processability, which allows researchers to tune their aggregation states in solution and solid states and to control the processing conditions to reach desirable electronic and optoelectronic properties. Temperature is one of the most important processing parameters of organic semiconductors and has been studied extensively particularly for those conjugated small‐ and macro‐ molecules with strong temperature‐dependent aggregation properties. This minireview summarizes the temperature‐induced aggregation behaviors of organic semiconductors in solution, during solution casting and upon thermal annealing post‐treatment of solid‐state thin films. The influences of different aggregation states on the optoelectronic properties, in particular the photovoltaic properties, are discussed. The conclusions in this work will provide a rational guide to precisely control the aggregation states of organic semiconductors to fabricate high‐performance optoelectronic devices.
Nickel‐Catalyzed Amination of (Hetero)aryl Halides Facilitated by a Catalytic Pyridinium Additive
Authors: Han Dongyang , Li Sasa , Xia Siqi , Su Mincong , Jin Jian 
Published: June 2020

AbstractAn efficient and operationally simple Ni‐catalyzed amination protocol has been developed. This methodology features a simple NiII salt, an organic base and catalytic amounts of both a pyridinium additive and Zn metal. A diverse number of (hetero)aryl halides were coupled successfully with primary and secondary alkyl amines, and anilines in good to excellent yields. Similarly, benzophenone imine gave the corresponding N‐arylation product in an excellent yield.
Improved region convolutional neural network for ship detection in multiresolution synthetic aperture radar images
Authors: Xiao Qilin , Cheng Yun , Xiao Minlei , Zhang Jun , Shi Hongji , Niu Lihui , Ge Chenguang , Lang Haitao 
Published: June 2020

SummaryEffectively obtaining the location and direction of the ship target is an important prerequisite for maritime traffic management and marine accident rescue. Thanks to the rapid development of the target detection methods based on deep learning, this article proposed a ship target detection method for multiresolution synthetic aperture radar (SAR) images based on improved region convolution neural network (R‐CNN). According to the characteristics of ship target in the SAR images, we make several improvements such as enlarging the input, proposal optimization, database target categorization, and weight balance on the basis of the standard Faster R‐CNN. The experimental results proved that the proposed method can detect target effectively and precisely in complicated scenes of multiresolution SAR images, such as in‐shore and dense targets. It has a good potential in practical application.
Searchable encryption scheme for multiple cloud storage using double‐layer blockchain
Authors: Fu Shaojing , Zhang Chao , Ao Weijun 
Published: June 2020

SummaryWith the emergence of cloud storage security, how to ensure the security of cloud storage has become a research focus. The typical searchable encryption model consists of a single cloud service provider and has some unsolvable drawbacks. In this article, a new searchable encryption scheme in multi‐cloud was proposed based on blockchain. We first define a system model in multiple clouds and combine multiple cloud service providers to store data through a consortium chain. Then we store the encrypted documents and indexes in The Interplanetary File System (IPFS) and store the hash value and IPFS address of the documents in the blockchain. Our scheme can provide outsourced encrypted data retrieval based on multiple keywords, as well as verification schemes for the integrity of retrieved files. The theoretical analysis and experiments on real‐world data show the security and high performance of our scheme.
Sentiment analysis on product reviews based on weighted word embeddings and deep neural networks
Authors: Onan Aytuğ 
Published: June 2020

SummarySentiment analysis is one of the major tasks of natural language processing, in which attitudes, thoughts, opinions, or judgments toward a particular subject has been extracted. Web is an unstructured and rich source of information containing many text documents with opinions and reviews. The recognition of sentiment can be helpful for individual decision makers, business organizations, and governments. In this article, we present a deep learning‐based approach to sentiment analysis on product reviews obtained from Twitter. The presented architecture combines TF‐IDF weighted Glove word embedding with CNN‐LSTM architecture. The CNN‐LSTM architecture consists of five layers, that is, weighted embedding layer, convolution layer (where, 1‐g, 2‐g, and 3‐g convolutions have been employed), max‐pooling layer, followed by LSTM, and dense layer. In the empirical analysis, the predictive performance of different word embedding schemes (ie, word2vec, fastText, GloVe, LDA2vec, and DOC2vec) with several weighting functions (ie, inverse document frequency, TF‐IDF, and smoothed inverse document frequency function) have been evaluated in conjunction with conventional deep neural network architectures. The empirical results indicate that the proposed deep learning architecture outperforms the conventional deep learning methods.