bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Catechin‐Rare Earth Complex with Efficient and Broad‐Spectrum Anti‐Biofilm Activity
Authors: Liu Lu , Xiao Xiao , Li Ke , Li Xia , Shi Bi , Liao Xuepin
Published: January 2020

Biofilm is the crucial reason of clinical infections. Herein, green tea based polyphenol (catechin) and rare earth (RE) metal ions were employed for the preparation of catechin–RE complexes with significant anti‐biofilm properties. The complexes were characterized by FT‐IR, Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS), which suggested that catechin coordinated with RE3+ through its ortho phenolic hydroxy groups. The prepared catechin‐RE showed significant effects in anti‐biofilm growth against P. aeruginosa (Gram‐negative bacteria), S. sciuri (Gram‐positive bacteria), and A. niger (fungi), which significantly exceeded the utilization of catechin or RE3+. Morphological observations indicated that catechin supplied cell affinity to transfer RE3+ and helped to damage cell membrane, which act as a carrier to exert cytotoxicity of RE3+ to realize anti‐biofilm. Differential gene expression analysis described gene expression changes induced by catechin‐RE, including 56, 272 and 2160 downregulated genes for P. aeruginosa, S. sciuri and A. niger, respectively, which suggested critical changes in cellular metabolism, growth and other processes. These results illustrate the outstanding superiority of catechin‐RE complexes in anti‐infection aspect, i. e., the green tea based rare earth complexes are promising candidates for anti‐biofilm applications to address serious challenges in the prevention of multiple infections.
Role of IL‐9 and IL‐10 in the pathogenesis of chronic spontaneous urticaria through the JAK/STAT signalling pathway
Authors: Feng Hua , Feng Jiangao , Zhang Zhongwei , Xu Qunying , Hu Min , Wu Yongning , Lu Yuanan
Published: January 2020

This study investigated the role of interleukin (IL)‐9 and IL‐10 in the pathogenesis of chronic spontaneous urticaria (CSU). Autologous serum skin test and histamine release test were performed in CSU patients and normal subjects. Kunming mice were used to develop a mouse model for CSU. We induced IL‐9 overexpression, IL‐10 overexpression, and JAK/STAT pathway inhibition as well as a combination of all three conditions in CSU and control mice. Eosinophils in the skin tissues, inflammatory cytokine expression, and distribution of T lymphocyte subsets in peripheral blood of mice were detected. Expression patterns of IL‐9, IL‐10, STAT3, JAK2, and INF‐γ in clinical samples and mice were detected by reverse transcription quantitative polymerase chain reaction (RT‐qPCR) and western blot analysis. The positive rate of autologous serum skin test and the histamine release rate of CSU patients, compared with normal subjects, were apparently elevated. Compared with controls, mice with CSU experienced longer duration and higher frequency of pruritus and demonstrated enhanced levels of CD8+, the ratio of CD4+/CD8+, number of eosinophils, and inflammatory cytokine expression in serum as well as activated JAK/STAT signalling pathway; at the same time, levels of CD4+ and INF‐γ were reduced. This trend was found in CSU mice overexpressing IL‐9 and IL‐10 when compared with the CSU mice without treatment. In contrast, JAK/STAT inhibition reversed the above trend. Overall, our study suggests that IL‐9 and IL‐10 contribute to CSU development via activation of the JAK/STAT signalling pathway.
Severe muscle pain and stiffness due to dexmethylphenidate
Authors: Kon Jacob J. , Kon Alexander A.
Published: January 2020

Dexmethylphenidate, and potentially other methylphenidates used in the treatment of attention deficit hyperactivity disorder (ADHD), may cause severe muscle pain and stiffness. Medication side effects should be considered as the possible cause if a patient with ADHD develops severe symptoms.
Multilayered Two‐Dimensional V2CTx MXene for Methane Dehydroaromatization
Authors: Thakur Raj , Hoffman Megan , VahidMohammadi Armin , Smith Justin , Chi Mingyang , Tatarchuk Bruce , Beidaghi Majid , Carrero Carlos A.
Published: January 2020

We report a thermally stable multilayered two‐dimensional vanadium carbide (V2CTx) MXenes catalyst for the direct conversion of methane (CH4) into benzene (C6H6). The multilayered carbide structure shows state‐of‐the‐art CH4 conversion 11.8 % with a C6H6 formation rate of 1.9 mmol gcat−1h−1 (4.84 % C6H6 yield) at 700 °C, which is comparable to the benchmark Mo/ZSM‐5 catalyst. The structure‐activity relationship was explored by numerous characterization techniques including in‐situ/operando Raman‐MS, ex‐situ X‐ray diffraction (XRD), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and ammonia temperature programmed desorption (NH3‐TPD). This work provides a new platform to design and explore multilayered two‐dimensional catalysts demonstrating confinement effect to convert CH4 into *C2H3 intermediates which further oligomerize inside multilayered structures producing C6H6 as the final product.
Manipulating the Geometric and Electronic Structures of Manganese Nitrides for Ammonia Synthesis
Authors: Shan Nannan , Huang Chaoran , Lee Robert T. , Manavi Narges , Xu Lianbin , Chikan Viktor , Pfromm Peter Heinz , Liu Bin
Published: January 2020

Manganese (Mn) nitrides are important nitrogen (N) carriers for small‐scale intermittent ammonia (NH3) synthesis. However, only 3∼8 % of lattice N are converted into NH3. In this study, the geometric and electronic structures of well‐defined Mn4N and Mn2N lattices were altered using transition metal heteroatoms (Cr, Fe, Co, Ni, Mo) to understand the driving force behind lattice N diffusion and extraction. Density Functional Theory (DFT) revealed that the binding of early hydrogenation product (NH) follows a linear relationship with lattice N over a wide range of close‐packed surfaces. But, the binding of NH2 and NH3 are more sensitive to the geometric and electronic structures. Further, the chemical bonding can be quantitatively characterized with the covalency derived from Crystal Orbital Hamiltonian Population (COHP). In the Eley Rideal‐Mars van Krevelan pathway, the overall NH3 formation free energy (
) and lattice N diffusion barrier (
) are the respective thermodynamic and kinetic determining factors. Aided by a rate‐determining step (RDS) model, Mn4N modified with Fe, Co, Ni single‐atom dopants all show enhanced rates for NH3 formation.
Quantifying Capacitive‐Like and Battery‐Like Charge Storage Contributions Using Single‐Nanoparticle Electro‐optical Imaging
Authors: Evans R. Colby , Nilsson Zach , Balch Brenden , Wang Li , Neilson James R. , Weinberger Christopher R. , Sambur Justin B.
Published: January 2020

Pseudocapacitors promise to combine the high‐rate capability of electrochemical capacitors with the high energy‐density of batteries. A major challenge in the field is to demonstrate that pseudocapacitors behave electrochemically like a capacitor and the charge storage process is faradaic in nature. It is challenging to do so because pseudocapacitive charging has the same electrical signatures as non‐faradaic electrical double‐layer charging. Here we use electro‐optical imaging to measure Li‐ion insertion reactions in single WO3 nanoparticles. On average, these WO3 particles exhibit a hybrid charge storage mechanism: both diffusion‐limited (battery‐like) and pseudocapacitive (capacitor‐like) mechanisms contribute to the total charge stored. Individual particles exhibit different charge storage mechanisms at the same applied potential. Longer nanorods store more pseudocapacitive charge than shorter nanorods, presumably due to 1) a surface step edge gradient that exposes large hexagonal window Li‐ion binding sites along the nanorod length and/or 2) higher structural water content that influences the Li‐ion binding energetics and diffusion behavior. Importantly, we quantified the penetration depth of Li‐ion insertion and concluded that Li ions insert as deep as two‐unit cells below the surface. The methodology presented herein can be applied to a wide range of solid‐state ion‐insertion materials.
A Two‐Step Modified Sequential Deposition Method‐based Pb‐Free (CH3NH3)3Sb2I9 Perovskite with Improved Open Circuit Voltage and Performance
Authors: Ahmad Khursheed , Kumar Praveen , Mobin Shaikh M.
Published: January 2020

In the last decade, photovoltaic devices employing lead halide perovskites as light absorber have pulled the attention of researchers due to their outstanding performance. However, the lead halide perovskite based photovoltaic devices suffering from the toxicity of lead (Pb) and lower stability in air. Herein, we have replaced Pb with less toxic antimony (Sb) to prepare air stable and Pb‐free perovskite light absorber. Moreover, we have developed a two‐step procedure to prepare the high quality films of perovskite light absorber with device architecture of FTO/CL‐TiO2/m‐TiO2/MASbI/HTM/Au. This fabricated Pb‐free perovskite solar cell device prepared with two‐step procedure shows good performance with remarkably good open circuit voltage of 740 mV.
FeIII–Salen‐Based Probes for the Selective and Sensitive Detection of E450 in Foodstuff
Authors: Yadav Prerna , Jakubaszek Marta , Spingler Bernhard , Goud Bruno , Gasser Gilles , Zelder Felix
Published: January 2020

Inorganic pyrophosphate (PPi) is considered as a diagnostic marker for various diseases such as cancer and vascular calcification. PPi also plays an important preservative role as an additive E450 in foodstuff. In this work, a selective FeIII–salen‐based probe for PPi is described; this probe disassembles in the presence of the target analyte into its molecular blocks, 1,2‐propanediamine and 3‐chloro‐5‐formyl‐4‐hydroxybenzenesulfonic acid. The latter signaling unit leads to a fluorometric response. Compared with a related prototype, the new complex shows a 2.3‐times stronger emission at 500 nm and a 155‐times better selectivity of PPi over adenosine triphosphate (ATP). Importantly, the new probe was successfully applied for detecting E450 in foodstuff.
How to Bend a Cumulene
Authors: Barquera‐Lozada José Enrique
Published: January 2020

Allenes (carbodicarbenes) and [3]cumulenes are linear carbon chains that can be bent when the terminal group has a strong carbene nature. This bending can be quite pronounced in allenes but not in [3]cumulenes. In this study, how N‐heterocyclic or cyclic (alkyl)(amino) carbene (NHC and CAAC, respectively) terminal groups can modify the linear structure of [n]cumulenes has been analyzed. A low π acidity of the terminal carbene affects the linearity of [2n]cumulenes. Indeed, it has been found that the NHC [4]cumulene is extremely bent, contrary to classical [4]cumulenes. The predicted NHC [4]cumulene or tricarbodicarbene has two lone pairs and the π electrons are delocalized over the whole molecule. More significantly, DFT calculations have shown that this bent [4]cumulene is very stable, considerably more so than the corresponding [3]cumulene, which has been elusive to synthesize. Remarkably, calculations have shown that all the NHC [2n]cumulenes are more than 25 kcal mol−1 more stable than the [2n−1]cumulenes.
The impact of signboard‐building color combinations on color harmony and legibility
Authors: Won Seahwa , Lee YounJin , Park YungKyung
Published: January 2020

The aim of this study was to investigate the impact of signboard‐building color combinations on color harmony and legibility. Two hundred and three participants rated 54 signboard‐building color combinations against two scales of color harmony and legibility. In this article, the terms “brick,” “stone,” and “glass” refer to three types of building exteriors used in the experiment (ie, brick masonry, greystone, and curtain walls, respectively). Major findings are as follows: (a) there was a positive linear correlation between color harmony and legibility in all three types of building exteriors, (b) the type of building exterior affected the color harmony and legibility of signboard colors, (c) no hue‐related patterns were observed, (d) the effects of chroma differences on color harmony were weak and the effects of chroma differences on legibility were moderate, (e) the effects of lightness differences on color harmony and legibility were strong in brick, but the effects of lightness differences were weak in stone and glass, (f) white color combinations (ie, color pairs including white signboards) turned out to be the most harmonious and legible, and (g) color combinations of light signboards and dark buildings (negative polarity) were rated most harmonious and legible, with the exception of vivid red (positive polarity). The findings of this study provide insight into the characteristics of harmonious and legible colors in the context of signboard design.
In SituShell‐Isolated Nanoparticle‐Enhanced Raman Spectroscopy of Nickel‐Catalyzed Hydrogenation Reactions
Authors: Wondergem Caterina S. , Kromwijk Josepha J. G. , Slagter Mark , Vrijburg Wilbert L. , Hensen Emiel J. M. , Monai Matteo , Vogt Charlotte , Weckhuysen Bert M.
Published: January 2020

Synthesis methods to prepare lower transition metal catalysts and specifically Ni for Shell‐Isolated Nanoparticle‐Enhanced Raman Spectroscopy (SHINERS) are explored. Impregnation, colloidal deposition, and spark ablation have been investigated as suitable synthesis routes to prepare SHINERS‐active Ni/Au@SiO2catalyst/Shell‐Isolated Nanoparticles (SHINs). Ni precursors are confirmed to be notoriously difficult to reduce and the temperatures required are generally harsh enough to destroy SHINs, rendering SHINERS experiments on Ni infeasible using this approach. For colloidally synthesized Ni nanoparticles deposited on Au@SiO2SHINs, stabilizing ligands first need to be removed before application is possible in catalysis. The required procedure results in transformation of the metallic Ni core to a fully oxidized metal nanoparticle, again too challenging to reduce at temperatures still compatible with SHINs. Finally, by use of spark ablation we were able to prepare metallic Ni catalysts directly on Au@SiO2SHINs deposited on a Si wafer. These Ni/Au@SiO2catalyst/SHINs were subsequently successfully probed with several molecules (i. e. CO and acetylene) of interest for heterogeneous catalysis, and we show that they could be used to study thein situhydrogenation of acetylene. We observe the interaction of acetylene with the Ni surface. This study further illustrates the true potential of SHINERS by opening the door to studying industrially relevant reactions underin situoroperandoreaction conditions.
Origin of Hydrocarbons Stability from a Computational Perspective: A Case Study of Ortho‐Xylene Isomers
Authors: Mitoraj Mariusz P. , Sagan Filip , Szczepanik Dariusz W. , de Lange Jurgens H. , Ptaszek Aleksandra L. , van Niekerk Daniel M. E. , Cukrowski Ignacy
Published: January 2020

It is shown herein that intuitive and text‐book steric‐clash based interpretation of the higher energy “in‐in” xylene isomer (as arising solely from the repulsive CH⋅⋅⋅HC contact) with respect to the corresponding global‐minimum “out‐out” configuration (where the clashing C−H bonds are tilted out) is misleading. It is demonstrated that the two hydrogen atoms engaged in the CH⋅⋅⋅HC contact in “in‐in” are involved in attractive interaction so they cannot explain the lower stability of this isomer. We have proven, based on the arsenal of modern bonding descriptors (EDDB, HOMA, NICS, FALDI, ETS‐NOCV, DAFH, FAMSEC, IQA), that in order to understand the relative stability of “in‐in” versus “out‐out” xylenes isomers one must consider the changes in the electronic structure encompassing the entire molecules as arising from the cooperative action of hyperconjugation, aromaticity and unintuitive London dispersion plus charge delocalization based intra‐molecular CH⋅⋅⋅HC interactions.
Photoelectrochemistry for Measuring the Photocatalytic Activity of Soluble Photosensitizers
Authors: Khan Shahid Ullah , Trashin Stanislav A. , Korostei Yuliya S. , Dubinina Tatiana V. , Tomilova Larisa G. , Verbruggen Sammy W. , De Wael Karolien
Published: January 2020

We introduce a rapid method to test the photocatalytic activity of singlet‐oxygen‐producing photosensitizers using a batch cell, a LED laser and a conventional potentiostat. The strategy is based on coupling of photo‐oxidation of hydroquinone and simultaneous electrochemical reduction of its oxidized form at a carbon electrode in an organic solvent (methanol). This scheme gives an immediate response and avoids complications related to long‐term experiments such as oxidative photo‐degradation of photosensitizers and singlet oxygen traps by reactive oxygen species (ROS). Among the tested compounds, a fluoro‐substituted subphthalocyanine showed the highest photocurrent and singlet oxygen quantum yield (ΦΔ) in comparison to phenoxy‐ and tert‐butyl‐substituted analogues, whereas the lowest photocurrents and yields were observed for aggregated and dimeric phthalocyanine complexes. The method is useful for fast screening of the photosensitizing activity and represents the first example of one‐pot coupling of electrochemical and photocatalytic reactions in organic media.
Eutectic Synthesis of High‐Entropy Metal Phosphides for Electrocatalytic Water Splitting
Authors: Zhao Xinhui , Xue Zhimin , Chen Wenjun , Wang Yaqing , Mu Tiancheng
Published: January 2020

High‐entropy materials, a new class of alloys that incorporate five or more principal elements into single‐phase crystal structures, have received considerable interest in materials science and engineering. Considering the tailored composition and disordered configuration, these high‐entropy materials may arouse functional synergism towards electrocatalysis. Here, a new strategy for preparing high‐entropy metal phosphides (HEMPs) was developed by a eutectic solvent method. The as‐prepared HEMP possessed a single metal phosphide phase with up to five homogenously distributed metal components. The versatile application of high‐entropy materials was highlighted by integrating the HEMP catalyst into a two‐electrode configuration for electrocatalytic water splitting.
Improve uniformity for an indoor visible light communication system
Authors: Gismalla Mohammed S.M. , Abdullah Mohammad F.L. , Niass Mussaab I. , Das Bhagwan , Mabrouk Wafi A.
Published: January 2020

Visible light communication (VLC) is an alternative technology to the radio frequency (RF) for different applications in the indoor and outdoor environments, it could be utilized for illumination and communication simultaneously, and it offers several advantages over contemporary RF technologies such as low power consumption, free license, large bandwidth, and being friendly to the environment. In this paper, an indoor VLC system uniformity improvement in terms of high received power, signal‐to‐noise ratio (SNR), and bit rate, with RMS delay spread reduction, is proposed. It features a novel model that utilizes a 13‐optical attocells configuration on the ceiling. Moreover, proposed model was evaluated at different semi‐angle at half power. The average received power and SNR were improved to 2.85 dBm and 75.5 dB, while achieved received power and SNR levels at the center of the room were 4.92 dBm and 79.5 dB, respectively. A minimum average RMS delay spread of 0.4749 nanoseconds is obtained, while the highest average bit rate calculated is 211 Mb/s. The proposed model provides a better communication quality and meets illumination standards requirements.
Manganese(II) Thiocyanate Complexes with Bis(phosphine Oxide) Ligands: Synthesis and Excitation Wavelength‐Dependent Multicolor Luminescence
Authors: Davydova Maria P. , Bauer Irina A. , Brel Valery K. , Rakhmanova Mariana I. , Bagryanskaya Irina Yu. , Artem'ev Alexander V.
Published: January 2020

First examples of luminescent MnII thiocyanate complexes are presented. A series of such compounds has been synthesized via the reaction of Mn(NCS)2 with bis(phosphine oxides), Ph2P(O)–X–(O)PPh2, where X = CH2 (L1), CH2CH2 (L2), CH2CH2CH2 (L3), CH2C(=CH2)CH2 (L4), C(=CH2)C(=CH2) (L5) and C≡C (L6). The L1, L3 and L4 ligands, when reacted with Mn(NCS)2 on air (EtOH/acetone, r.t.), produce chelate complexes [MnII(O^O)2(NCS)2]. Under similar conditions, L5 gives ionic complex [MnII(L5)3][MnII(NCS)4], whereas L6 affords chain coordination polymer (CP) [MnII(L6)2(NCS)2]n. By contrast, ligand L2 results in formation of mixed‐valent chain CP [MnIIMnIII(L2)3(NCS)5]n. Complex [Mn(L4)2(NCS)2] and CP [Mn(L6)2(NCS)2]n display unique dual luminescence, i.e. the intraligand fluorescence (blue band) and MnII‐centered phosphorescence (red band), the ratio of which is largely modulated by excitation wavelength. Through this feature, the luminescence color of these complexes can be smoothly tuned from deep‐blue to red. Complex [Mn(L5)3][Mn(NCS)4] shows MnII‐based phosphorescence only.
Aryl‐Diadamantyl Phosphine Ligands in Palladium‐Catalyzed Cross‐Coupling Reactions: Synthesis, Structural Analysis, and Application
Authors: Sinai Ádám , Simkó Dániel Cs. , Szabó Fruzsina , Paczal Attila , Gáti Tamás , Bényei Attila , Novák Zoltán , Kotschy András
Published: January 2020

Synthesis, temperature‐dependent NMR structure investigation and utilization of a new, stable and easily accessible aryl‐diadamantylphosphine ligand family is reported. The bulky and electron‐rich phosphorus center of the ligand enhances the catalytic activity of palladium in cross‐coupling reactions of sterically demanding ortho‐substituted aryl halides. In our study, we demonstrated the synthetic applicability of the new phosphine ligands in Buchwald‐Hartwig and tosyl hydrazone coupling reactions.
Supramolecular Catalysts Featuring Crown Ethers as Recognition Units
Authors: Di Stefano Stefano , Capocasa Giorgio , Mandolini Luigi
Published: January 2020

In its minimal expression, a supramolecular catalyst that acts on a single bound substrate consists of (i) a binding unit that is complementary to a non‐reacting part of the substrate, (ii) a reactive unit capable of catalyzing the reaction of the bound substrate, and (iii) a spacer connecting the two units in a geometry suitable for productive binding. When binding of two or more species is wanted, the number of binding units increases accordingly. This minireview deals with supramolecular catalysts that use crown ether units for the recognition of one or two reactants involved in a variety of reactions, including cleavage of esters and amides, hydride transfer from dihydropyridine to pyridinium, pyruvate decarboxylation, enolate allylation, radical addition to sodium metacrylate, reduction of NO2– anion to NO, C–H oxidation of aliphatic chains, and Diels‐Alder reactions.
Synthesis of [18F]Fluoroform with High Molar Activity
Authors: Pees Anna , Windhorst Albert D. , Vosjan Maria J. W. D. , Tadino Vincent , Vugts Danielle J.
Published: January 2020

Fluoroform is an interesting motif for the isotopologue labelling of biologically active compounds with fluorine‐18 for PET imaging. However, so far the building block [18F]fluoroform and consequently the [18F]trifluoromethylated products suffered from low molar activities ranging from 0.1 to 30 GBq/µmol due to isotopic dilution under the strongly basic standard radiofluorination conditions. In this article the synthesis of high molar activity [18F]fluoroform is described. By implementing a recently reported novel radiofluorination reagent, [18F]triflyl fluoride, the concentration of base‐cryptand complex in the reaction could be reduced 100‐fold compared to standard radiofluorination conditions and molar activities close to 100 GBq/µmol (at end of [18F]fluoroform synthesis) could be obtained, enabling the imaging of low density receptors. Furthermore, an automated procedure was developed on the commercially available NEPTIS® perform synthesizer to provide access of high molar activity [18F]fluoroform to other PET centres.
Biocascade Synthesis of L‐Tyrosine Derivatives by Coupling a Thermophilic Tyrosine Phenol‐Lyase and L‐Lactate Oxidase
Authors: Li Guosi , Lian Jiazhang , Xue Hailong , Jiang Yiqi , Ju Shuyun , Wu Mianbin , Lin Jianping , Yang Lirong
Published: January 2020

A one‐pot biocascade of two enzymatic steps catalyzed by an l‐lactate oxidase and a tyrosine phenol‐lyase has been successfully developed in the present study. The reaction provides an efficient method for the synthesis of l‐tyrosine derivatives, which exhibits readily available starting materials and excellent yields. In the first step, an in situ generation of pyruvate from readily available bio‐based l‐lactate catalyzed by a highly active l‐lactate oxidase from Aerococcus viridans (AvLOX) was developed (using oxygen as oxidant and catalase as hydrogen peroxide removing reagent). Pyruvate thus produced underwent C–C coupling with phenol derivatives as acceptor substrate using specially designed thermophilic tyrosine phenol‐lyase mutants from Symbiobacterium toebii (TTPL). Overall, this cascade avoids the high cost and easy decomposition of pyruvate and offered an efficient and environmentally friendly procedure for l‐tyrosine derivatives synthesis.
Cauliflower‐like NiCo2O4−Zn/Al Layered Double Hydroxide Nanocomposite as an Efficient Electrochemical Sensing Platform for Selective Pyridoxine Detection
Authors: Amini Roghayeh , Asadpour‐Zeynali Karim
Published: January 2020

In the present study, a cauliflower‐like NiCo2O4−Zn/Al
layered double hydroxide (NiCo2O4−Zn/Al LDH) nanocomposite was used as a novel electrode material for the sensitive and selective determination of pyridoxine (vitamin B6). The structure and morphology of the as‐prepared nanocomposite were characterized by X‐ray diffraction (XRD), FT‐IR, field emission scanning electron microscopy (FESEM) and energy dispersive X‐ray spectroscopy (EDX). The NiCo2O4−Zn/Al LDH nanocomposite exhibited excellent electrocatalytic ability in the oxidation of pyridoxine, which could result from the synergistic effect of the two components. The developed sensor also provided a selective determination of pyridoxine in the presence of other species such as vitamins (B1, B2, B12 and ascorbic acid), inorganic ions and biomolecules. The fabricated sensor showed a good linear response for pyridoxine over the concentration ranges 2×10−7–2.0×10−4 mol L−1 with a low detection limit of 8.6×10−8 mol L−1. Finally, the proposed method was successfully applied for the determination of pyridoxine in commercial tablets and plasma samples with satisfactory results. Furthermore, this novel sensor displayed superior benefits in terms of stability, sensitivity, repeatability and cost. The present work aims to expand NiCo2O4 based nanocomposites to sensor fields and promote the development of pyridoxine sensors.
Protocol for sand control screen design of production wells for clayey silt hydrate reservoirs: A case study
Authors: Li Yanlong , Ning Fulong , Wu Nengyou , Chen Qiang , Nouri Alireza , Hu Gaowei , Sun Jiaxin , Kuang Zenggui , Meng Qingguo
Published: January 2020

The process of extracting natural gas from gas hydrate‐bearing sediments (GHBS) may yield significant sand influx due to the metastable nature of GHBS. Selecting appropriate sand control media is vital to addressing the challenges caused by excessive sand production. This study proposes a protocol called holding coarse expelling fine particles (HCEFP) for sand control design. The protocol aims to provide a new optimization method for screen mesh size selection for clayey silt hydrate reservoirs. Detailed optimizing procedures of proper candidate screen mesh sizes in hydrate exploitation well in clayey silt hydrate reservoirs are depicted based on the HCEFP. Then, the site W18, which is located in the Shenhu area of the northern South China Sea, is taken as an example to illustrate the optimization procedure for screen mesh size selection. The results reveal that complete solid retention via a standalone screen is rarely beneficial as high clay contents can adversely affect wellbore productivity due to excessive plugging. Screen aperture size selection for clayey silt hydrate wells should strike a balance between retaining coarser particles and avoiding screen blockage by the relatively fine particles. Furthermore, longitudinal heterogeneity of the PSDs also increases the difficulties associated with sand control design. Multistage sand control optimization is necessary in hydrate production wells. For Site W18, we recommend that the entire production interval can be divided into two subintervals for multistage sand control operations.
Numerical modeling of motion of displacement interface in eccentric annulus during primary cementing
Authors: Sun Jinfei , Li Zaoyuan , Luo Pingya , Huang Sheng
Published: January 2020

Cementing operations are of major importance to the long‐term zonal isolation and safety of oil and gas wells. As one of the well barriers, the cement sheath is key to the long‐term integrity of the wellbore. If the cement slurry does not completely fill the annulus between the casing and formation during the primary cementing displacement process, a potential leakage channel for subsurface fluids is created. In this study, the motion of the interface between the cement and other displaced fluids was examined during cementing displacement. By dividing an eccentric annulus into two 2D planes along the radial and azimuthal directions, a set of motion models of the interface were developed and solved numerically using a first‐order upwind finite‐difference method. The influences of modified density differenceF*, Bingham numbersB1andB2, plastic viscosity ratiom, eccentricitye*, and diffusion coefficientD*on the motion behavior of the displacement interface were determined. The results indicated that the interface of the eccentric annulus showed serious channeling and a physical mixing phenomenon. Some residual displaced fluid could remain at the casing‐cement and cement‐formation interfaces as a result of the improper design of the fluid parameters. KeepingF* > 0 andB2 < 5 beneficially removed residue from the displaced fluid on the wall, and increasingF*andB1(or decreasingB2,m,e*andD*) was conducive to the smooth motion of the displacement interface. This work showed that the interface motion model could predict the displacement quality and has great potential for improving the design of the primary cementing parameters.
Characteristics of fracture field in different stress zones during multi‐seam mining: Quantification based on theoretical analysis and BBM‐DEM accurate simulation method
Authors: Cheng Zhiheng , Ouyang Zhenhua , Zou Quanle , Lu Yun , Zhao Xidong , Li Meichen
Published: January 2020

The revelation of the distribution characteristics of stress and fractures in the floor strata is of great significance to improve the regional gas drainage efficiency and to eliminate or reduce the risk of coal and gas outburst in adjacent coal seams during multi‐seam mining. In this paper, the stress distribution in the floor under mining condition was derived, and the characteristics of stress zones in the floor were elaborated while mining the 22201 working face in Shaqu coal mine in Shanxi province, China. Besides, the propagation laws of fractures in different stress zones were theoretically analyzed, and the distribution law of fracture angles in the floor strata under different mining‐induced stresses was obtained. The research results demonstrate that the compression and transition zones show high vertical stress and less developed fractures and are dominated by fractures with a large angle (>60°), which is unfavorable for gas drainage. The expansion zone in the floor within 2‐40 m in the rear of the working face is characterized by high unloading degree of vertical stress and developed fractures. Moreover, fractures with a small angle (<60°) dominate the spatial distribution of the fractures, which is favorable for gas drainage. The research results can not only be a beneficial supplement to the theory of coal and gas co‐exploitation in multi‐seam mining but also provide theoretical support for optimizing the design parameters of cross‐measure boreholes under similar conditions.
Sampling and resolution characteristics in reduced order models of shallow water equations: Intrusive vs nonintrusive
Authors: Ahmed Shady E. , San Omer , Bistrian Diana A. , Navon Ionel M.
Published: January 2020

We investigate the sensitivity of reduced order models (ROMs) to training data spatial resolution as well as sampling rate. In particular, we consider proper orthogonal decomposition (POD), coupled with Galerkin projection (POD‐GP), as an intrusive ROM technique. For nonintrusive ROMs, we consider two frameworks. The first is using dynamic mode decomposition (DMD), and the second is based on artificial neural networks (ANNs). For ANN, we utilized a residual deep neural network, and for DMD we have studied two versions of DMD approaches; one with hard thresholding and the other with sorted bases selection. Also, we highlight the differences between mean subtracting the data (centering) and using the data without mean subtraction. We tested these ROMs using a system of 2D shallow water equations for four different numerical experiments, adopting combinations of sampling rates and spatial resolutions. For these cases, we found that the DMD basis obtained with hard thresholding is sensitive to sampling rate. The sorted DMD algorithm helps to mitigate this problem and yields more stabilized and converging solution. Furthermore, we demonstrate that both DMD approaches without mean subtraction provide significantly more accurate results than DMD with mean subtracting the data. On the other hand, POD is relatively insensitive to sampling rate and yields better representation of the flow field. Meanwhile, spatial resolution has little effect on both POD and DMD performances. Numerical results reveal that an ANN on POD subspace (POD‐ANN) performs remarkably better than POD‐GP and DMD in capturing system dynamics, even with a small number of modes.
Geometry, differential displacement, and evolution of the Cenozoic fault system in the western offshore Bohai Bay Basin: A case study in the Shaleitian Uplift with surrounding areas
Authors: Ma Xiao , Liu Jingyan , Lin Changsong , Niu Chengmin , Schulte Lothar
Published: January 2020

The western offshore Bohai Bay Basin (BBB) is located at the intersection of the Zhangjiakou–Penglai Fault Zone (ZPFZ) and the Huanghua–Dongming Fault Zone (HDFZ). Exploration experience proves that faults' activity played an import role in hydrocarbon accumulation, whereas characters and evolution of the fault system remain poorly understood. In this study, characters and evolution of the fault system were investigated through abundant seismic data from oil fields. Six NE and two NW strike‐slip faults were identified by composite flower structures on seismic profiles and show broom‐like or en echelon patterns with different scales in plan view. Massive flower‐like structures were observed, which serve as an indicator of early extension and consequent shear activity. Based on published physical modelling, the different plan forms and scales of strike‐slip faults were deciphered as an outcome of diverse strike‐slip displacements. The character and evolution of the fault system were investigated using fault activity rate, balanced restoration, and typical‐structure analysis. The result suggests that the NW‐trending faults have a more intense fault activity and strike‐slip faults in the north, and the east have larger displacements than those in the south and the west. Considered together with the basin evolution, we suggested a three‐stage fault evolution model for the fault system in the study area, mainly comprising (a) early extension; (b) mid transtension, and (c) late transpression, which resulted from multiple geodynamic events during the Cenozoic. Our study reveals that the ZPFZ and the HDFZ have a significant impact over faults in the western offshore BBB, which is demonstrated by unusual intense fault activity in the extension period and different strike‐slip displacement in the strike‐slip period.
MicroRNA‐based risk scoring system to identify early‐stage oral squamous cell carcinoma patients at high‐risk for cancer‐specific mortality
Authors: Yoon Angela J. , Wang Shuang , Kutler David I. , Carvajal Richard D. , Philipone Elizabeth , Wang Tian , Peters Scott M. , LaRoche Dominic , Hernandez Brenda Y. , McDowell Bradley D. , Stewart Claire R. , Momen‐Heravi Fatemeh , Santella Regina M.
Published: January 2020

Background

For early‐stage oral squamous cell carcinoma (OSCC), there is no existing risk‐stratification modality beyond conventional TNM staging system to identify patients at high risk for cancer‐specific mortality.

Methods

A total of 568 early‐stage OSCC patients who had surgery only and also with available 5‐year clinical outcomes data were identified. Signature microRNAs (miRNAs) were discovered using deep sequencing analysis and validated by qRT‐PCR. The final 5‐plex prognostic marker panel was utilized to generate a cancer‐specific mortality risk score using the multivariate Cox regression analyses. The prognostic markers were validated in the internal and external validation cohorts.

Results

The risk score from the 5‐plex marker panel consisting of miRNAs‐127‐3p, 4736, 655‐3p, TNM stage and histologic grading stratified patients into four risk categories. Compared to the low‐risk group, the high‐risk group had 23‐fold increased mortality risk (hazard ratio 23, 95% confidence interval 13‐42), with a median time‐to‐recurrence of 6 months and time‐to‐death of 11 months (vs >60 months for each among low‐risk patient; p < .001).

Conclusion

The miRNA‐based 5‐plex marker panel driven mortality risk score formula provides clinically practical and reliable measures to assess the prognosis of patients assigned to an early‐stage OSCC.
In silico identification and characterization of antineoplastic asparaginase enzyme from endophytic bacteria
Authors: Zadeh Hosseingholi Elaheh , Neghabi Neda , Molavi Ghader , Gheibi Hayat Seyed Mohammad , Shahriarpour Hamed
Published: January 2020

It is generally accepted that L‐asparagine is an important amino acid required for the fast growth of cells. Cancerous cells receive this amino acid from extracellular sources. The depletion of L‐asparagine from its surrounding environments by asparaginase enzyme can be used as a therapeutic strategy in cancer patients. This therapeutic enzyme is produced commercially mainly from bacteria such as Escherichia coli and Erwinia chrysanthemi. The side effects of such drugs have persuaded scientists to find new enzyme sources. In this study, in silico approach was applied to investigate L‐asparaginase producing endophytic bacteria that produce more compatible enzymes within the body. Protein–protein basic local alignment search tool with E. coli and E. chrysanthemi asparaginase enzyme sequences against 262 endophytic bacteria were performed. The results with identity more than 35%, coverage more than 80%, and E‐value less than 10−4 were selected. Then, some of bioinformatics tools were used to characterize them. A total of nine sequences consisting of seven known and two hypothetical proteins were identified in six bacterial species. The results showed that some of the asparaginase enzymes produced by endophytic bacteria possess more suitable immunological indices compared with asparaginase enzymes of E. coli and E. chrysanthemi. Herbaspirillum rubrisubalbicans was predicted to produce a nonallergen and nonantigen asparaginase enzyme. The number of antigenic determinants was predicted to be lower in asparaginase enzymes produced by Bacillus amyloliquefaciens, H. rubrisubalbicans, and H. seropedicae. Moreover, the number of high‐scored B‐cell epitopes was lower in enzyme sequences related to the mentioned bacteria and Paenibacillus polymyxa. The number of discontinuous epitopes and the number of T‐cell epitopes were lower in B. amyloliquefaciens produced enzymes. Therefore, the therapeutic use of these enzymes is possible.
Nail matrix regenerative engineering: in vitro evaluation of poly(lactide‐co‐glycolide)/gelatin fibrous substrates
Authors: Montgomery Aundrya B. , McClinton Aneesah , Nair Lakshmi , Laurencin Cato T.
Published: January 2020

Acute traumatic nail injury treatment repair procedures are commonly conducted in emergency departments and primary care offices. Current repair methods use nail splints that are inserted within the nail root to prevent the fusion of the proximal nail fold and the matrix tissue. Splints provide a protective barrier overlying the nail bed soft tissue during recovery periods, but uncertain prognoses (i.e., aesthetic and functional disadvantages) reveal a need for improved nail repair techniques. Nail splints are not specifically designed for nail organ restoration via biological mechanisms, thus, a clinical application that utilizes regenerative engineering techniques can prove useful in improving the nail injury prognoses. Using the coaxial electrospinning method, hybrid poly(lactide‐co‐glycolide) (PLGA) (85:15) and gelatin fibrous scaffolds (Hybrid1: PLGA shell, gelatin core and Hybrid2: gelatin shell, PLGA core) with average fiber diameters of 540 ± 118 and 2,215 ± 1,135 nm, respectively, were produced and successful encapsulation of core fibers was observed. Furthermore, nail stem cells expressing stem cell characteristic markers CD90, CD29, and Lgr6 showed preferred attachment to Hybrid2 scaffolds after 24 hr. Overall, an in vitro regenerative engineered nail matrix may aid to improve the cosmetic appearance and function of injured nail organs post‐traumatic injury.
Enhanced osteogenic differentiation of human mesenchymal stromal cells as response to periodical microstructured Ti6Al4V surfaces
Authors: Janßen Simon , Gach Stefan , Kant Sebastian , Aveic Sanja , Rütten Stephan , Olschok Simon , Reisgen Uwe , Fischer Horst
Published: January 2020

Titanium‐based alloys, for example, Ti6Al4V, are frequently employed for load‐bearing orthopedic and dental implants. Growth of new bone tissue and therefore osseointegration can be promoted by the implant's microtopography, which can lead to improved long‐term stability of the implant. This study investigates the effect that an organized, periodical microstructure produced by an electron beam (EB) technique has on the viability, morphology, and osteogenic differentiation capacity of human mesenchymal stromal cells (hMSC) in vitro. The technique generates topographical features of 20 μm in height with varying distances of 80–240 μm. Applied alterations of the surface roughness and local alloy composition do not impair hMSC viability (>94%) or proliferation. A favorable growth of hMSC onto the structure peaks and well‐defined focal adhesions of the analyzed cells to the electron beam microstructured surfaces is verified. The morphological adaptation of hMSC to the underlying topography is detected using a three‐dimensional (3D) visualization. In addition to the morphological changes, an increase in the expression of osteogenic markers such as osteocalcin (up to 17‐fold) and osteoprotegerin (up to sixfold) is observed. Taken together, these results imply that the proposed periodical microstucturing method could potentially accelerate and enhance osseointegration of titanium‐based bone implants.
Therapeutic plasma exchange for exogenous insulin antibody syndrome in combined variable immunodeficiency: a case report
Authors: Robbins Daniel J. , Taylor Natalie E. , Narayanan Damodaran , Hess Aaron S. , Rose William N.
Published: January 2020

A 32‐year‐old male with type I diabetes presented with profound hypoglycemia due to exogenous insulin antibody syndrome in the setting of newly‐diagnosed common variable immunodeficiency. Immunomodulatory therapy was not initially effective, but after the initiation of plasma exchange hypoglycemia resolved, and glucose lability improved.
Endothelin‐1 rs9296344 associates with the susceptibility of childhood primary nephrotic syndrome
Authors: Zhang Ruifeng , Yang Huandan , Zhu Bingbing , Yuan Tingting , Peng Qianqian , Lv Juan , Qiu Shan , Zhou Suqin , Li Yan , Zhong Zhaowen
Published: January 2020

Background

Recently, the rs5370 single nucleotide polymorphisms (SNPs) of Endothelin‐1 (EDN1) showed association with the susceptibility of childhood primary nephrotic syndrome (CPNS). This study aims to investigate potential relationships between other EDN1 SNPs and CPNS.

Methods

Seven SNPs (rs5370, rs10478723, rs1476046, rs1800541, rs2070698, rs2071942, and rs9296344) of the EDN1 gene were genotyped in 579 CPNS patients and 586 age‐matched healthy children. Then, we analyzed potential associations of the six SNPs with susceptibility of CPNS by using rs5370 as a conditional variant in a logistic regression model. SNP‐SNP interaction analysis was performed to investigate the joint effects of the seven SNPs in the pathogenesis of CPNS.

Results

Independent with rs5370, only rs9296344 significantly associated (T vs C, odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.57‐0.88, P = .001) with the susceptibility of CPNS. Meanwhile, no joint effect among the analyzed seven SNPs was discovered in this study.

Conclusions

This study discovered that C allele of rs9296344 on EDN1 is a novel independent risk factor for CPNS.
Self‐compassion, meaning in life, and experiential avoidance explain the relationship between meditation and positive mental health outcomes
Authors: Yela José Ramón , Crego Antonio , Gómez‐Martínez María Ángeles , Jiménez Laura
Published: January 2020

Objective

Despite consistent evidence for the beneficial effects of meditation on mental health, little is known about the mechanisms that make mindfulness meditation effective.

Method

The levels of mental health, self‐compassion, presence of meaning in life, and experiential avoidance of meditators (n = 414) and nonmeditators (n = 414) were measured and compared. Bootstrap‐based structural equation modeling (SEM) modeling analyses were used to test multiple‐step multiple‐mediator models.

Results

Meditation was positively associated with mental health, although the regularity of practice was an influential element to be considered. Significant indirect effects of meditation on mental health through self‐compassion, meaning in life, and experiential avoidance were found. SEM models were able to account for 58% of the variance in mental health scores.

Conclusions

Self‐compassion, presence of meaning in life, and reduced experiential avoidance may be active components of healthy meditation practices. Identifying the mechanisms involved in effective meditation practices has relevant implications for well‐being and mental health‐promoting interventions.