bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Phenolic Alkaloid from Halocnemum strobilaceum Endophytes: Antimicrobial, Antioxidant and Biofilm Inhibitory Activities
Authors: Abdel Razek Mohamed M. M. , Moussa Ashaimaa Y. , El‐Shanawany Mohamed A. , Singab Abdel Nasser B. 
Published: August 2020

AbstractHuman infections caused by microbial biofilm formation represent a growing major health threat. A new alkaloid, 3‐amino‐5‐(3‐hydroxybutan‐2‐yl)‐4‐methylphenol, was isolated from the corn grit culture of the endophytic isolate Penicillium citrinum‐314 associated with Halocnemum strobilaceum, a halophyte growing in the Egyptian marshes. The new alkaloid was identified by 1D, 2D‐NMR and HR‐ESI‐MS‐MS and given the trivial name halociline. The antioxidant, antimicrobial and antibiofilm activities were recorded. Furthermore, another known compound, 1,3,6‐trihydroxy‐7‐methoxy‐9H‐xanthen‐9‐one, was obtained in smaller amounts and revealed a non‐microbicidal 100 % reduction in biofilm formation, with an MBIC value of 62.5 μg/mL (228 μM) against Pseudomonas aeruginosa (Ferm‐BAM), a FRAP value of 447.941±37.876 mM/L as well as a marked safety profile against three cancer cell lines. Through in silico molecular docking study, in the binding sites of Pseudomonas enzymes, key ligand enzyme interactions were determined to support the in vitro results.
N‐Heterocyclization in Gliotoxin Biosynthesis is Catalyzed by a Distinct Cytochrome P450 Monooxygenase
Authors: Scharf Daniel H. , Chankhamjon Pranatchareeya , Scherlach Kirstin , Dworschak Jan , Heinekamp Thorsten , Roth Martin , Brakhage Axel A. , Hertweck Christian 
Published: August 2020

AbstractGliotoxin and related epidithiodiketopiperazines (ETP) from diverse fungi feature highly functionalized hydroindole scaffolds with an array of medicinally and ecologically relevant activities. Mutation analysis, heterologous reconstitution, and biotransformation experiments revealed that a cytochrome P450 monooxygenase (GliF) from the human‐pathogenic fungus Aspergillus fumigatus plays a key role in the formation of the complex heterocycle. In vitro assays using a biosynthetic precursor from a blocked mutant showed that GliF is specific to ETPs and catalyzes an unprecedented heterocyclization reaction that cannot be emulated with current synthetic methods. In silico analyses indicate that this rare biotransformation takes place in related ETP biosynthetic pathways.
Response Surface Methodology and Artificial Neural Networks for Optimization of Catalytic Esterification of Lactic Acid
Authors: Chandane Vishal S. , Rathod Ajit P. , Wasewar Kailas L. , Jadhav Prakash. G. 
Published: August 2020

AbstractResponse surface methodology (RSM) and artificial neural network (ANN) models were employed to study the esterification of lactic acid and isoamyl alcohol. A carbon‐based solid acid catalyst prepared by wet impregnation was used in the esterification reaction. Experimental characterization revealed its potential to serve as catalyst for the esterification reaction. The experiments were performed based on the design of experiments provided by RSM and ANN models. Both models were compared on the basis of prediction efficacies and deviation from actual data. The prediction data results demonstrated that the ANN model gave better prediction efficiency and lower prediction deviation than the RSM model. The ANN model provided a higher coefficient of determination and lower error values than the RSM model. Moreover, the catalyst exhibited a good stability and recyclability up to four reaction cycles.
Intensification of Mass Transfer in the Extraction Process with a Nanofluid Prepared in a Natural Deep Eutectic Solvent
Authors: Mitar Anamarija , Prlić Kardum Jasna 
Published: August 2020

AbstractThe phytotoxic residues after olive oil production and residue leaves after pruning contain valuable bioactive compounds. A natural deep eutectic solvent (NADES) and an ethanol‐water mixture were used for polyphenol extraction from olive pomace and leaves. Type of solvent, extraction temperature, and particle size of the leaves were optimized. NADES demonstrated better efficiency in the extraction process than conventional solvents; with higher temperature and smaller fraction of olive leaves, a higher yield of polyphenols was obtained from leaves. Extraction with a nanofluid as solvent was carried out. A stable nanofluid was prepared from NADES by adding Al2O3 nanoparticles. A higher yield was obtained with nanofluid from leaves, while an improvement of polyphenol extraction was achieved after the removal of oil from olive pomace.
Mixture analysis using non‐negative elastic net for Raman spectroscopy
Authors: Zeng Hui‐Tao , Hou Ming‐Hui , Ni Yi‐Ping , Fang Zhi , Fan Xia‐Qiong , Lu Hong‐Mei , Zhang Zhi‐Min 
Published: August 2020

AbstractRaman spectrum is wealth of structural information, which can be used as molecular fingerprint to identify compounds. There are relations between the intensities of Raman peaks and the concentrations of compound, and they can be used to estimate relative concentrations of the compounds in mixture. However, it is still challenging to interpret the Raman spectrum of mixture. The non‐negative lasso (NN‐LASSO) has been used to solve this problem, but it failed to identify highly correlated compounds. The quadratic term of non‐negative elastic net (NN‐EN) can ensure the stability of the fitted model. Therefore, a novel mixture analysis method was developed based on NN‐EN in this study. It has been applied to analyze the simulated, liquid, powder, tablet, and quantitative mixture datasets. Results showed that NN‐EN can identify the compounds in mixture with high accuracy and estimate their relative concentrations with small deviation. Furthermore, NN‐EN was more stable than NN‐LASSO when the spectra of some compounds are highly correlated. It is a promising approach for analyzing Raman spectra of mixtures.
A Giant [8+12] Boronic Ester Cage with 48 Terminal Alkene Units in the Periphery for Postsynthetic Alkene Metathesis
Authors: Hähsler Martin , Mastalerz Michael 
Published: August 2020

AbstractDynamic covalent chemistry (DCC) is a powerful synthetic tool to construct large defined molecules in one step from rather simple precursors. The advantage of the intrinsic dynamics of the applied reversible reaction steps is a self‐correction under the chosen conditions, to achieve high yields of the target compound. To date, only a few examples are known, in which DCC was used to build up a molecular defined but larger product that was chemically transferred to a more stable congener in a second (irreversible) step. Here, we present a nanometer‐sized [8+12] boronic ester cage containing 48 peripheral terminal alkene units which allows to put a hydrocarbon exoskeleton around the cage via alkene metathesis.
Anorganische Namensreaktionen
Authors: Hasenpusch Wolfgang 
Published: August 2020

ZusammenfassungNaturwissenschaftler und Techniker dürfen neben ganzen Büchern mit organischen Namensreaktionen nicht verkennen, dass auch in der anorganischen und physikalischen Chemie eine Reihe von Namensreaktionen bekannt geworden ist. Wenig verwunderlich scheint, dass die mit Persönlichkeiten bedachten Verfahren, Methoden, Regeln, Verbindungen und anderes mehr schon älteren Datums sind. Denn neben den mnemotechnischen Vorteilen der Verknüpfung mit Entdecker‐ und Entwickler‐Namen haben sie auch einen gewissen Zeitraum der Bewährung zu durchlaufen.Auch wird es immer seltener, dass einzelne Forscher ihre Entdeckungen und Erfindungen in Unternehmen und Instituten alleine publizieren und patentrechtlich anmelden dürfen, denn zum einen sind doch entscheidende Untersuchungen mit der Hilfe anderer Abteilungen notwendig, zum anderen laufen viele Forschungs‐ und Entwicklungsprojekte von Anfang an in Teams ab.
Design, Synthesis, and in vitro Evaluation of P2X7 Antagonists
Authors: T. Pournara Dimitra , Durner Anna , Kritsi Eftichia , Papakostas Alexios , Zoumpoulakis Panagiotis , Nicke Annette , Koufaki Maria 
Published: August 2020

AbstractThe P2X7 receptor is a promising target for the treatment of various diseases due to its significant role in inflammation and immune cell signaling. This work describes the design, synthesis, and in vitro evaluation of a series of novel derivatives bearing diverse scaffolds as potent P2X7 antagonists. Our approach was based on structural modifications of reported (adamantan‐1‐yl)methylbenzamides able to inhibit the receptor activation. The adamantane moieties and the amide bond were replaced, and the replacements were evaluated by a ligand‐based pharmacophore model. The antagonistic potency of the synthesized analogues was assessed by two‐electrode voltage clamp experiments, using Xenopus laevis oocytes that express the human P2X7 receptor. SAR studies suggested that the replacement of the adamantane ring by an aryl‐cyclohexyl moiety afforded the most potent antagonists against the activation of the P2X7 cation channel, with analogue 2‐chloro‐N‐[1‐(3‐(nitrooxymethyl)phenyl)cyclohexyl)methyl]benzamide (56) exhibiting the best potency with an IC50 value of 0.39 μM.
A natural endocast of an early Miocene odontocete and its implications in cetacean brain evolution
Authors: Bisconti Michelangelo , Damarco Piero , Tartarelli Giandonato , Pavia Marco , Carnevale Giorgio 
Published: August 2020

AbstractThe natural endocast Museo di Geologia e Paleontologia of the Università degli Studi di Torino (MGPT)‐PU 13873 is described and analyzed in order to interpret its taxonomic affinities and its potential significance on our understanding of cetacean brain evolution. The endocast is from the early Miocene of Piedmont (between ca. 19 and 16 million years ago), Northwestern Italy, and shows a number of plesiomorphic characters. These include: scarcely rounded cerebral hemispheres, cerebellum exposed in dorsal view with little superimposition by the cerebral hemispheres, short temporal lobe, and long sylvian fissure. The distance between the hypophysis and the rostral pons is particularly high, as it was determined by the calculus of the hypothalamus quotient, suggesting that the development of a deep interpeduncular fossa was not as advanced as in living odontocetes. The encephalization quotient (EQ) of MGPT‐PU 13873 is ~1.81; therefore, this specimen shows an EQ in line with other fossil whales of the same geological age (early Miocene). Comparative analysis shows that there is a critical lack of data from the late Miocene and Pliocene that prevents us to fully understand the recent evolution of the EQ diversity in whales. Moreover, the past diversity of brain size and shape in mysticetes is virtually unknown. All these observations point to the need of additional efforts to uncover evolutionary patterns and processes on cetacean brain evolution.
Polymorphic Metastability in Colloidal Semiconductor Nanocrystals
Authors: Tappan Bryce A. , Brutchey Richard L. 
Published: August 2020

AbstractMetastable polymorphs of inorganic solids often possess material properties not present in the corresponding thermodynamic polymorphs, making them targets for the development of new functional materials. In contrast with isolating metastable bulk materials, syntheses of metastable polymorphs on the nanoscale are aided by fast non‐equilibrium reaction kinetics and the favorable thermodynamic influence of surface energies, giving rise to greater ease of access to metastable high‐temperature polymorphs and, in some cases, new polymorphs that do not exist in the bulk. The syntheses of metastable semiconductor nanocrystals are of interest for their potentially unique optoelectronic and physicochemical properties. However, in many material systems, synthesizing nanocrystalline products away from thermodynamic equilibrium in a predictable manner remains an outstanding challenge. This review outlines direct synthetic methodologies that have been developed to enable control over the nucleation and growth of metastable polymorphs of semiconductor nanocrystals by tailoring reaction conditions, precursor kinetics, ligand and surface effects, and other synthetic levers. The case studies reviewed herein expound on the direct syntheses of metastable ZnSe, Cu2SnSe3, CuInSe2, Ag2Se, and AgInSe2 nanocrystals, and although there remain numerous examples of metastable nanocrystal syntheses outside of these metal chalcogenide systems, the concepts discussed are of general utility to the field of metastable nanocrystal syntheses as a whole. Explicit examples in which new functional properties are afforded by metastable polymorphs of the aforementioned material systems are presented within the context of applications for solar cells, photonics, and optical sensing. Finally, the factors that affect the kinetic persistence of metastable nanocrystalline polymorphs are discussed at length for these material systems.
Phenylglyoxylic Acid: An Efficient Initiator for the Photochemical Hydrogen Atom Transfer C−H Functionalization of Heterocycles
Authors: Papadopoulos Giorgos N. , Kokotou Maroula G. , Spiliopoulou Nikoleta , Nikitas Nikolaos F. , Voutyritsa Errika , Tzaras Dimitrios I. , Kaplaneris Nikolaos , Kokotos Christoforos G. 
Published: August 2020

AbstractC−H functionalization at the α‐position of heterocycles has become a rapidly growing area of research. Herein, a cheap and efficient photochemical method was developed for the C−H functionalization of heterocycles. Phenylglyoxylic acid (PhCOCOOH) could behave as an alternative to metal‐based catalysts and organic dyes and provided a very general and wide array of photochemical C−H alkylation, alkenylation, and alkynylation, as well as C−N bond forming reaction methodologies. This novel, mild, and metal‐free protocol was successfully employed in the functionalization of a wide range of C−H bonds, utilizing not only O‐ or N‐heterocycles, but also the less studied S‐heterocycles.
Bit rate improvement of spatially seamless local communication system using signal multiplexing technique
Authors: Akagawa Tetsuro , Arai Yoshikazu , Imai Shintaro , Inomata Toshimitsu 
Published: August 2020

AbstractIn recent years, application of multiple robot system for a large scale system, such as a smart factory, is expected. A system consisting of heterogeneous robots can select the function by switching a combination of the robots according to a purpose. Therefore, the system is more versatile than a single robot on which multiple functions are installed. When the system is controlled by distributed management, it is an essential technique that the robots communicate with each other for mutual understanding to achieve complex task. We have developed spatially seamless local communication system in order to exchange information between the robots without convergences. This system ensures spatially seamless communicable area towards robot's surroundings by rotating a transmitter and a receiver. However, a bit rate of communication using the system is insufficient. Although the system has redundant frame structure to detect interference between signals from different transmitters, it causes decrease of the bit rate. In this paper, we aim to improve the bit rate by reducing frame length of transmission pulse while retaining the interference detection function.
Collapse prognosis of a long‐span cable‐stayed bridge based on shake table test and nonlinear model updating
Authors: Lin Kaiqi , Xu You‐Lin , Lu Xinzheng , Guan Zhongguo , Li Jianzhong 
Published: August 2020

SummaryThe collapse of long‐span cable‐stayed bridges under strong earthquakes will not only result in severe casualties and loss of property but also significantly delay the rehabilitation of the affected area. It is therefore essential to study the failure progress and potential collapse mechanisms of these bridges under strong earthquakes for assisting their inspection and maintenance and helping them survive an earthquake. Collapse simulations in existing studies are commonly conducted with design‐document‐based finite element (FE) models, which usually neglect the actual damage state of the bridges. The influences of modelling uncertainties on the simulated responses cannot be addressed. This study proposes a nonlinear FE model updating‐based collapse prognosis method for long‐span cable‐stayed bridges, which includes (1) a correlated‐updating‐parameter‐based nonlinear FE model updating algorithm, (2) a restarted time history analysis‐based seismic response prediction method and (3) an elemental deactivation‐based collapse simulation algorithm. The shake table test of a scaled Sutong cable‐stayed bridge in China is adopted to illustrate the proposed earthquake‐induced collapse prognosis method. A refined FE model of the bridge is first established and nonlinearly updated using the measurement data. The collapse prognosis of the bridge under a subsequent strong ground motion is then performed based on the updated model. The predicted structural responses and final failure mechanisms are compared with the measured responses and experimental observations with good agreement, indicating that the proposed method is feasible and accurate for evaluating the seismic performance and failure mechanisms of long‐span cable‐stayed bridges.
An automated procedure to calculate the morphological parameters of superimposed rhythmic bedforms
Authors: Wang Li , Yu Qian , Zhang Yongzhan , Flemming Burghard W. , Wang Yunwei , Gao Shu 
Published: August 2020

AbstractSubaqueous dunes are often observed to be superimposed on larger dunes, sand bars and tidal ridges, while smaller dunes may also be found superimposed on larger dunes. In this study an automated method has been developed by which the geometry of superimposed rhythmic bedforms can be analysed. The method combines two‐dimensional (2D) Fourier analysis, wavelet transform, zero‐crossing analysis and a variety of filters. Instead of applying conventional manual procedures, the wavelength of interest can be automatically determined by a series of 2D Fourier analyses, which is a critical first step for automated analysis of dune geometries. Based on such efficient data preprocessing, the method can accurately determine dune orientation, separate target bedform profiles, and identify crests and troughs. With the input of bathymetry, the dominant regional dune orientation can be determined together with the geometric parameters of individual dunes (wavelength, height, leeside angles) and their spatial distribution. The method was applied to both synthetic and observed bathymetries of a tidal ridge off the Jiangsu coast, China, and a sand bank in the Dover Strait, UK. The results show that almost all dunes in the domain were detected and their geometric parameters accurately calculated, especially in areas of bedform superimposition. © 2020 John Wiley & Sons, Ltd.
Inhibitory effect of four types of tea on the in vitro digestion of starch
Authors: Gutierrez Alyssa , Feng Jiannan , Tan Libo , Kong Lingyan 
Published: August 2020

AbstractPhenolic compounds have been shown to decrease the rate of starch hydrolysis by inhibiting digestive enzymes for starch. Tea, rich in phenolic compounds, has been widely reported for its beneficial health effects. This study explored the inhibitory abilities of four types of tea, that is, green tea (GT), oolong tea (OT), black tea (BT), and white tea (WT), on the in vitro enzymatic digestion of potato starch (PS) and high‐amylose maize starch (HAMS), using two in vitro digestion methods. All teas significantly inhibited the digestion of both starches, with a few exceptions at some time points. The resistant starch content was increased by all four teas in HAMS, but only by BT and WT in PS. The total phenolic contents in the teas could not predict the inhibitory ability of the teas, possibly due to the structural diversity of phenolic compounds and the presence of other compounds that could also alter enzymatic activity. Our results suggested that tea, regardless of its type, can slow down the enzymatic digestion of starch and therefore imply a potential benefit for controlling postprandial hyperglycemia.
Vascular endothelial growth factor receptor‐3 regulates astroglial glutamate transporter‐1 expression via mTOR activation in reactive astrocytes following pilocarpine‐induced status epilepticus
Authors: Jeong Kyoung Hoon , Cho Kyung‐Ok , Lee Mun‐Yong , Kim Seong Yun , Kim Won‐Joo 
Published: August 2020

AbstractRecent evidence has shown that the vascular endothelial growth factor (VEGF) system plays a crucial role in several neuropathological processes. We previously reported an upregulation of VEGF‐C and its receptor, VEGFR‐3, in reactive astrocytes after the onset of status epilepticus (SE). However, it remains unknown, which molecules act as downstream signals following VEGFR‐3 upregulation, and are involved in reactive astrogliosis after SE. Therefore, we investigated whether VEGFR‐3 upregulation within reactive astrocytes is associated with the activation of mammalian target of rapamycin (mTOR) signaling, which we confirmed by assaying for the phosphorylated form of S6 protein (pS6), and whether VEGFR‐3‐mediated mTOR activation induces astroglial glutamate transporter‐1 (GLT‐1) expression in the hippocampus after pilocarpine‐induced SE. We found that spatiotemporal expression of pS6 was consistent with VEGFR‐3 expression in the hippocampus after SE, and that both pS6 and VEGFR‐3 were highly expressed in SE‐induced reactive astrocytes. Treatment with the mTOR inhibitor rapamycin decreased astroglial VEGFR‐3 expression and GLT‐1 expression after SE. Treatment with a selective inhibitor for VEGFR‐3 attenuated astroglial pS6 expression as well as suppressed GLT‐1 expression and astroglial reactivity in the hippocampus after SE. These findings demonstrate that VEGFR‐3‐mediated mTOR activation could contribute to the regulation of GLT‐1 expression in reactive astrocytes during the subacute phase of epilepsy. In conclusion, the present study suggests that VEGFR‐3 upregulation in reactive astrocytes may play a role in preventing hyperexcitability induced by continued seizure activity.
Endoscopic transoral approach for resection of retrostyloid parapharyngeal space tumors: Retrospective analysis of 16 patients
Authors: Li Lifeng , London Nyall R. , Gao Yanyong , Carrau Ricardo L. , Chen Xiaohong 
Published: August 2020

AbstractBackgroundThe purpose of this study was to assess the feasibility of the endoscopic transoral approach for resection of retrostyloid benign tumors.MethodsWe retrospectively reviewed 16 patients with retrostyloid parapharyngeal space (PPS) tumors resected via an endoscopic transoral approach. After separation and control of the internal carotid artery (ICA), tumors in the retrostyloid PPS were then removed under the guidance of angled endoscope (45°).ResultsAll 16 patients with retrostyloid PPS tumors were successfully removed via an endoscopic transoral approach. There were 15 schwannomas and 1 paraganglioma. Two tumors were removed en bloc, and the other 14 tumors were removed by piecemeal. In five patients, the tumor extended into the jugular foramen, and was completely removed via the transoral corridor, without cerebrospinal fluid leak. No ICA injury was encountered in any of the 16 patients.ConclusionThe endoscopic transoral approach is suitable for the resection of retrostyloid PPS tumors and is associated with low morbidity.