bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing chemical space of tick‐borne encephalitis virus reproduction inhibitors with organoselenium compounds
Authors: Orlov Alexey A. , Eletskaya Anastasia A. , Frolov Konstantin A. , Golinets Anastasia D. , Palyulin Vladimir A. , Krivokolysko Sergey G. , Kozlovskaya Liubov I. , Dotsenko Victor V. , Osolodkin Dmitry I.
Published: April 2018

Tick‐borne encephalitis virus (TBEV), a member of the genus Flavivirus, is the leading cause of arboviral neuroinfections in Europe. Only a few classes of the nucleoside and non‐nucleoside inhibitors were investigated against TBEV reproduction. Paving the way to previously unexplored areas of anti‐TBEV chemical space, we assessed the inhibition of TBEV reproduction in the plaque reduction assay by various compounds derived from cyanothioacetamide and cyanoselenoacetamide. Compounds from seven classes, including 4‐(alkylthio)‐2‐aryl‐3‐azaspiro[5.5]undec‐4‐ene‐1,1,5‐tricarbonitriles, 3‐arylamino‐2‐(selenazol‐2‐yl)acrylonitriles, ethyl 6‐(alkylseleno)‐5‐cyano‐2‐oxo‐1,2‐dihydropyridine‐3‐carboxylates, 6‐(alkylseleno)‐2‐oxo‐1,4,5,6‐tetrahydropyridine‐3‐carbonitriles, 2‐(alkylseleno)‐5‐oxo‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carbonitriles, 8‐selenoxo‐3,5,7,11‐tetraazatricyclo[7.3.1.02,7]tridec‐2‐ene‐1,9‐dicarbonitriles, and selenolo[2,3‐b]quinolines, inhibited TBEV reproduction with EC50 values in the micromolar range while showing moderate cytotoxicity and no inhibition of enterovirus reproduction. Thus, new scaffolds with promising anti‐TBEV activity were found.
Enantioselective Mukaiyama–Michael Reaction Catalyzed by a Chiral Rhodium Complex Based on Pinene‐Modified Pyridine Ligands
Authors: Gong Jun , Wan Qian , Kang Qiang
Published: April 2018

The rhodium complex Λ‐Rh1 containing chiral pinene‐modified pyridine ligands is prepared through a two‐step synthetic procedure; it exhibits excellent reactivity and enantiocontrol towards the enantioselective Mukaiyama–Michael reaction of α,β‐unsaturated 2‐acyl imidazoles with silyl enol ethers, affording enantioenriched 1,5‐dicarbonyl compounds in good yields (up to 99 %) with excellent enantioselectivities (up to 99 % ee).
C−H Alkenylation of Pyrroles by Electronically Matching Ligand Control
Authors: Kim Hyun Tae , Lee Woohyeong , Kim Eunmin , Joo Jung Min
Published: April 2018

Directing group and substrate control strategies have frequently been employed for the regioselective C−H alkenylation of acid‐ and oxidant‐sensitive pyrrole heterocycles. We developed an undirected, aerobic strategy for the C−H alkenylation of N‐alkylpyrroles by ligand control. For C2‐alkenylation of electron‐rich N‐alkylpyrroles, an electrophilic palladium catalyst derived from Pd(OAc)2 and 4,5‐diazafluoren‐9‐one (DAF) was used. Alternatively, a combination of Pd(OAc)2 and a mono‐protected amino acid ligand, Ac‐Val‐OH, was useful for C5‐alkenylation of N‐alkylpyrroles possessing electron‐withdrawing groups at the C2 position. This approach based on the electronic effects of heterocycles and catalysts can rapidly provide a wide range of alkenyl pyrroles from readily available N‐alkylpyrroles and alkenes.
Selectivity Control on Hydrogenation of Substituted Nitroarenes through End‐On Adsorption of Reactants in Zeolite‐Encapsulated Platinum Nanoparticles
Authors: Chen Qiang , Wang Mengyue , Zhang Chengxi , Ren Kui , Xin Yue , Zhao Ming , Xing Enhui
Published: April 2018

Platinum nanoparticles encapsulated into zeolite Y (Pt@Y catalyst) exhibit excellent catalytic selectivity in the hydrogenation of substituted nitroarenes to form the corresponding aromatic amines, even after complete conversion. With the hydrogenation of p‐chloronitrobenzene as a model, the role of zeolite encapsulation toward perfect selectivity can be attributed to constraint of the substrate adsorbed on the platinum surface in an end‐on conformation. This conformation results in the activation of only one adsorbed group, with little influence on the other one in the molecule. Owing to a much lower apparent activation energy of Pt@Y for the hydrogenation of a separately adsorbed nitro group than that of the adsorbed chloro group, the Pt@Y catalyst can prevent hydrodechlorination of p‐chloronitrobenzene under mild conditions. Moreover, such a conformation results in a reduced adsorption energy of target p‐chloroaniline on the platinum surface; thus suppressing the reactivity of hydrodechlorination of p‐chloroaniline to circumvent further C−Cl bond breakage.
Some Controllability Aspects for Iterative Learning Control
Authors: Leissner Patrik , Gunnarsson Svante , Norrlöf Mikael
Published: April 2018

Some controllability aspects for iterative learning control (ILC) are discussed. Via a batch (lifted) description of the problem a state space model of the system to be controlled is formulated in the iteration domain. This model provides insight and enables analysis of the conditions for and relationships between controllability, output controllability and target path controllability. In addition, the property miminum lead target path controllability is introduced. This property, which is connected to the number of time delays, plays an important role in the design of ILC algorithms. The properties are illustrated by a numerical example.
A Filter‐based Clock Synchronization Protocol for Wireless Sensor Networks
Authors: Yang Wenlun , Fu Minyue
Published: April 2018

Clock parameters in wireless sensors experience slow changes due to low‐cost construction and environmental conditions. In this paper, a filter‐based distributed protocol, called FBP, is proposed to dynamically achieve clock synchronization for wireless sensor networks. The idea of FBP is derived from a first‐order filter which is robust to environmental noises. The proposed protocol is fully distributed, meaning that each node relies only on its local clock readings and reading announcements from its neighbouring sensor nodes. This will allow the proposed protocol applicable to large sensor networks. By applying FBP, the compensated clock skews can be bounded into a small steady‐state error. Numerical simulations show that the proposed protocol yields better performances in both convergence property and synchronization accuracy.
Quadrotor Control Via Robust Generalized Dynamic Inversion and Adaptive Non‐Singular Terminal Sliding Mode
Authors: Ansari Uzair , Bajodah Abdulrahman H. , Hamayun Mirza Tariq
Published: April 2018

A robust two‐loops structured control system design for quadrotor's position/attitude trajectory tracking is proposed. The aim of the outer loop is to provide the roll/pitch tilting commands to the inner loop, which in turns generates the tilting angles that control the quadrotor's center of gravity in the horizontal plane. The outer loop utilizes Robust Generalized Dynamic Inversion (RGDI) of a prescribed asymptotically stable differential equation in the deviation function of the horizontal position coordinates from their reference trajectories. The inner loop employs an Adaptive Non‐singular Terminal Sliding Mode (ANTSM) to control the tilting angles, in addition to controlling the yaw attitude angle and the vertical position coordinate. The proposed scheme solves the singularity avoidance problems of generalized inversion and terminal sliding mode control. The stability of outer and inner loop is ensured by utilizing positive definite Lyapunov energy function for stable tracking performance against parametric variations and bounded unknown external disturbances. Numerous simulations are conducted on a six Degrees of Freedom (DoF) quadrotor model in the presence of parametric variations, un modeled dynamics, and external disturbances.
Cellular ATP levels are affected by moderate and strong static magnetic fields
Authors: Wang Dongmei , Wang Ze , Zhang Lei , Li Zhiyuan , Tian XiaoFei , Fang Jun , Lu Qingyou , Zhang Xin
Published: April 2018

Mitochondrion is the major cellular energy producing organelle that is at the boundary between chemical reactions and physical processes. Although mitochondria have been shown to be affected by physical methods such as nonthermal plasma, whether static magnetic field (SMF) could also affect them is still unclear. Here we used rat adrenal PC12 cells to compare SMFs of different intensities for their effects on ATP (adenosine‐5′‐triphosphate), the major energy source produced by mitochondria, which is essential for various cellular processes. Our results show that although 0.26 or 0.50 T SMFs did not affect ATP, 1 T and 9 T SMFs affected ATP level differently and time‐dependently. Moreover, SMF‐induced ATP level fluctuations are correlated with mitochondrial membrane potential changes. Our study provides insights not only into understanding various cellular effects of SMFs, but also the potential clinical applications of SMFs. Bioelectromagnetics. 39:352–360, 2018. © 2018 Wiley Periodicals, Inc.
Reduction of the geomagnetic field delays Arabidopsis thaliana flowering time through downregulation of flowering‐related genes
Authors: Agliassa Chiara , Narayana Ravishankar , Bertea Cinzia M. , Rodgers Christopher T. , Maffei Massimo E.
Published: April 2018

Variations in magnetic field (MF) intensity are known to induce plant morphological and gene expression changes. In Arabidopsis thaliana Col‐0, near‐null magnetic field (NNMF, i.e., <100 nT MF) causes a delay in the transition to flowering, but the expression of genes involved in this response has been poorly studied. Here, we showed a time‐course quantitative analysis of the expression of both leaf (including clock genes, photoperiod pathway, GA20ox, SVP, and vernalization pathway) and floral meristem (including GA2ox, SOC1, AGL24, LFY, AP1, FD, and FLC) genes involved in the transition to flowering in A. thaliana under NNMF. NNMF induced a delayed flowering time and a significant reduction of leaf area index and flowering stem length, with respect to controls under geomagnetic field. Generation experiments (F1‐ and F2‐NNMF) showed retention of flowering delay. The quantitative expression (qPCR) of some A. thaliana genes expressed in leaves and floral meristem was studied during transition to flowering. In leaves and flowering meristem, NNMF caused an early downregulation of clock, photoperiod, gibberellin, and vernalization pathways and a later downregulation of TSF, AP1, and FLC. In the floral meristem, the downregulation of AP1, AGL24, FT, and FLC in early phases of floral development was accompanied by a downregulation of the gibberellin pathway. The progressive upregulation of AGL24 and AP1 was also correlated to the delayed flowering by NNMF. The flowering delay is associated with the strong downregulation of FT, FLC, and GA20ox in the floral meristem and FT, TSF, FLC, and GA20ox in leaves. Bioelectromagnetics. 39:361–374, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.
Effects of 1.8 GHz radiofrequency field on microstructure and bone metabolism of femur in mice
Authors: Guo Ling , Zhang Jun‐Ping , Zhang Ke‐Ying , Wang Huan‐Bo , Wang Huan , An Guang‐Zhou , Zhou Yan , Meng Guo‐Lin , Ding Gui‐Rong
Published: April 2018

To investigate the effects of 1.8 GHz radiofrequency (RF) field on bone microstructure and metabolism of femur in mice, C57BL/6 mice (male, age 4 weeks) were whole‐body exposed or sham exposed to 1.8 GHz RF field. Specific absorption rates of whole body and bone were approximately 2.70 and 1.14 W/kg (6 h/day for 28 days). After exposure, microstructure and morphology of femur were observed by microcomputed tomography (micro‐CT), Hematoxylin and Eosin (HE) and Masson staining. Subsequently, bone parameters were calculated directly from the reconstructed images, including structure model index, bone mineral density, trabecular bone volume/total volume, connectivity density, trabecular number, trabecular thickness, and trabecular separation. Biomarkers that reflect bone metabolism, such as serum total alkaline phosphatase (ALP), bone‐specific alkaline phosphatase (BALP), and tartrate‐resistant acid phosphatase 5b (TRACP‐5b), were determined by biochemical assay methods. Micro‐CT and histology results showed that there was no significant change in bone microstructure and the above parameters in RF group, compared with sham group. The activity of serum ALP and BALP increased 29.47% and 16.82%, respectively, in RF group, compared with sham group (P < 0.05). In addition, there were no significant differences in the activity of serum TRACP‐5b between RF group and sham group. In brief, under present experimental conditions, we did not find support for an effect of 1.8 GHz RF field on bone microstructure; however, it might promote metabolic function of osteoblasts in mice. Bioelectromagnetics. 39:386–393, 2018. © 2018 Wiley Periodicals, Inc.
miRNA‐regulated transcription associated with mouse strains predisposed to hypnotic effects of ethanol
Authors: Vestal B. , Russell P. , Radcliffe R.A. , Bemis L. , Saba L.M. , Kechris K.
Published: April 2018

Introduction

Studying innate sensitivity to ethanol can be an important first step toward understanding alcohol use disorders. In brain, we investigated transcripts, with evidence of miRNA modulation related to a predisposition to the hypnotic effect of ethanol, as measured by loss of righting reflex (LORR).

Methods

Expression of miRNAs (12 samples) and expression of mRNAs (353 samples) in brain were independently analyzed for an association with LORR in mice from the LXS recombinant inbred panel gathered across several small studies. These results were then integrated via a meta‐analysis of miRNA–mRNA target pairs identified in miRNA‐target interaction databases.

Results

We found 112 significant miRNA–mRNA pairs where a large majority of miRNAs and mRNAs were highly interconnected. Most pairs indicated a pattern of increased levels of miRNAs and reduced levels of mRNAs being associated with more alcohol‐sensitive strains. For example, CaMKIIn1 was targeted by multiple miRNAs associated with LORR. CAMK2N1 is an inhibitor of CAMK2, which among other functions, phosphorylates, or binds to GABAA and NMDA receptors.

Conclusions

Our results suggest a novel role of miRNA‐mediated regulation of an inhibitor of CAMK2 and its downstream targets including the GABAA and NMDA receptors, which have been previously implicated to have a role in ethanol‐induced sedation and sensitivity.
The role of sustainable human resource practices in influencing employee behavior for corporate sustainability
Authors: Pellegrini Chiara , Rizzi Francesco , Frey Marco
Published: April 2018

This article theorizes and empirically tests the relationship between employee perceptions of human resource practices and their propensity to adopt sustainable behavior (SB) to support organizational change for sustainability. Informed by the literature on corporate greening and organizational behaviour, we developed a structural equation model that links frontline employee perceptions of internal sustainability orientation, supervisory support, training and reward systems to their propensity to adopt in‐role and extra‐role SB. Furthermore, we investigated the mediating role of “affective commitment to change” with regard to the relationships between human resource practices and SB. Our results show that when sustainability is valued and promoted by the organization and line managers, employees are more likely to internalize and make sense of sustainability, which is subsequently reflected in a higher commitment to adopt SB. Although we also expected that training and rewards would strengthen commitment and willingness to adopt in‐role and extra‐role SB, rewards appeared to have no effect, and training affected willingness to adopt in‐role sustainable behaviour only when mediated by affective commitment. These results provide scholars of corporate sustainability and managers with evidence‐based insights on how to design HR practices and strategies to enhance employees' commitment and behaviour supporting organizational change for sustainability.
The role of institutional pressures in the introduction of energy‐efficiency innovations
Authors: Garrone Paola , Grilli Luca , Mrkajic Boris
Published: April 2018

Relying on the institutional and innovation theories, we argue that the institutional features of countries are significantly influencing energy‐efficiency innovation (EEI), a relevant and particular type of environmental innovation activities. Analysis of a cross‐sectional sample of 22,936 firms from nine European countries, drawn from the 2006–8 Community Innovation Survey, confirms the hypothesis that formal and informal institutions influence the propensity of firms to introduce EEIs in general. Furthermore, formal institutions that generate regulatory pressures are found to spur both product and process EEI activities, while informal institutions exerting social pressures are able to significantly drive only product EEI activities. Large firms appear to be relatively more reactive to high regulatory pressures. We draw implications for policy‐makers and managers based on the findings.
A Reversible Redox Reaction in a Keggin Polyoxometalate Crystal Driven by Visible Light: A Programmable Solid‐State Photochromic Switch
Authors: Tandekar Kesar , Garai Somenath , Supriya Sabbani
Published: April 2018

The colourless crystals of (PPh4)3[PW12O40]⋅3 C3H7NO (1) are converted to the dark blue crystals of {(PPh4)3[PW12O40]⋅3C3H7NO}0.85{(PPh4)3 (C3H7NO)+.[PWVWVI11O40]−⋅2C3H7NO)}0.15 (2) upon irradiation with visible light in an interesting single crystal to single crystal transformation. This photochromic conversion is accompanied by the reduction of concerned Keggin anion from {PWVI12} to {PWVWVI11}. This redox conversion is characterized by various spectroscopic techniques including single crystal X‐ray diffraction studies. The photochromic properties of compound 1 can be controlled reversibly through the dimethylformamide (DMF) molecule as a function of temperature and proton exposure in a gas‐solid reaction. The present work can be described as a new concept of programmable photochromism with the formation of photochromic pockets in crystalline 1 host (solid state), wherein a solvent can be plugged at a time to show light induced coloration.
Influence of Physicochemical Properties of Lipopeptide Adjuvants on the Immune Response: A Rationale for Engineering a Potent Vaccine
Authors: Eskandari Sharareh , Pattinson David J. , Stephenson Rachel J. , Groves Penny L. , Apte Simon H. , Sedaghat Bita , Chandurudu Saranya , Doolan Denise L. , Toth Istvan
Published: April 2018

Adjuvant development and understanding the physicochemical properties of particles and interpreting the subsequent immunological responses is a challenge faced by many researchers in the vaccine field. We synthesized and investigated the physicochemical properties and immunogenicity of a library of multiple epitope self‐adjuvant lipopeptides in a novel asymmetric arrangement. Vaccine candidates were synthesized using a combination of solid‐phase peptide synthesis and copper‐mediated click chemistry. In vivo studies showed that vaccine constructs containing a single OVA CD8+ T‐cell epitope and two N‐terminally located C16 lipid moieties were more effective at generating robust cellular immune responses compared to the same molecule containing multiple copies of the OVA CD8+ T‐cell epitope with or without the C16 moieties. Furthermore, attachment of the two C16 lipids to the N‐terminus provoked formation of long β‐sheet fibrils and was shown to induce a higher CD8+ donor T‐cell frequency and IFN‐γ secretion, compared to vaccine constructs with an internal lipid placement. A regression analysis indicated that particle secondary structure had a significant impact on CD8+ donor T‐cell frequency and cytolytic activity. In addition, IFN‐γ production was influenced significantly by particle shape. The findings of this research will impact the future design of a vaccine intended to elicit cellular immune responses.
Tetraacylstannanes as Long‐Wavelength Visible‐Light Photoinitiators with Intriguing Low Toxicity
Authors: Radebner Judith , Eibel Anna , Leypold Mario , Jungwirth Nina , Pickl Thomas , Torvisco Ana , Fischer Roland , Fischer Urs Karl , Moszner Norbert , Gescheidt Georg , Stueger Harald , Haas Michael
Published: April 2018

The first tetraacylstannanes Sn[(CO)R]4 (R=2,4,6‐trimethylphenyl (1 a) and 2,6‐dimethylphenyl (1 b)), a class of highly efficient Sn‐based photoinitiators, were synthesized. The formation of these derivatives was confirmed by NMR spectroscopy, mass spectrometry, and X‐ray crystallography. The UV/Vis absorption spectra of 1 a, b reveal a significant redshift of the longest wavelength absorption compared to the corresponding germanium compounds. In contrast to the known toxicity of organotin derivatives, the AMES test and cytotoxicity studies reveal intriguing low toxicity. The excellent performance of 1 as photoinitiators is demonstrated by photobleaching (UV/Vis) and NMR/CIDNP investigations, as well as photo‐DSC studies.
DNA‐Analyse in der forensischen Spurenuntersuchung
Authors: Schleenbecker Uwe , Schmitter Hermann
Published: April 2018

Ziel der DNA‐Analyse ist es, Spurenmaterial menschlicher Herkunftz. B. Blut, Sekret, Sperma – einer bestimmten Person zuzuordnen oder diese Person als Spurenverursacher auszuschlieβen.
Die Chemie der Fullerene
Authors: Hirsch Andreas
Published: April 2018

Fullerene, z. B. C60 und C70, sind Käfigverbindungen aus durchkonjugierten Fünf‐ und Sechsringen; sie können an der Oberfläche z. B. mit Nucleophilen reagieren oder aber im Hohlraum Metall‐Ionen oder Edelgasatome aufnehmen.
Increasing prevalence of human papillomavirus–positive oropharyngeal cancers among older adults
Authors: Windon Melina J. , D'Souza Gypsyamber , Rettig Eleni M. , Westra William H. , van Zante Annemieke , Wang Steven J. , Ryan William R. , Mydlarz Wojciech K. , Ha Patrick K. , Miles Brett A. , Koch Wayne , Gourin Christine , Eisele David W. , Fakhry Carole
Published: April 2018

BACKGROUND

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing among older adults. It is unknown whether these trends can be explained by human papillomavirus (HPV) and whether HPV‐related tumors remain associated with an improved prognosis among older patients.

METHODS

In a retrospective study of OPSCCs diagnosed from 1995 to 2013 at 2 National Comprehensive Cancer Network–designated cancer centers, p16 immunohistochemistry and in situ hybridization (ISH) for HPV‐16, high‐risk DNA, and/or E6/E7 RNA were performed. The median age at diagnosis was compared by p16 and ISH tumor status. Trends in age were analyzed with nonparametric trends. Survival was analyzed with the Kaplan‐Meier method and Cox proportional hazards models.

RESULTS

Among 239 patients, 144 (60%) were p16‐positive. During 1998‐2013, the median age increased among p16‐positive patients (Ptrend = .01) but not among p16‐negative patients (Ptrend = .71). The median age of p16‐positive patients increased from 53 years (interquartile range [IQR] in 1995‐2000, 45‐65 years) to 58 years (IQR for 2001‐2013, 53‐64 years). Among patients ≥ 65 years old, the proportion of OPSCCs that were p16‐positive increased from 41% during 1995‐2000 to 75% during 2007‐2013 (Ptrend = .04). Among all age groups, including older patients, a p16‐positive tumor status conferred improved overall survival in comparison with a p16‐negative status.

CONCLUSIONS

The median age at diagnosis for HPV‐related OPSCC is increasing as the proportion of OPSCCs caused by HPV rises among older adults. The favorable survival conferred by an HPV‐positive tumor status persists in older adults. Cancer 2018;124:2993‐9. © 2018 American Cancer Society.
Accidental and Programmed Cell Death in Investigative and Toxicologic Pathology
Authors: Radi Zaher A. , Stewart Zachary S. , O'Neil Shawn P.
Published: April 2018

Cellular development and homeostasis are regulated via programmed cell death (PCD; apoptosis), which is a genetically regulated cellular process. Accidental cell death (ACD; necrosis) can be triggered by chemical, physical, or mechanical stress. Necrosis is the presence of dead tissues or cells in a living organism regardless of the initiating process and can be observed in infectious and non‐infectious diseases and toxicities. This article describes tissue‐based immunohistotechnical protocols used for assessing PCD and necrosis in formalin‐fixed tissues obtained from preclinical species used in investigative and toxicologic pathology. Two commonly employed protocols for the identification of PCD and necrosis are described in this article: immunohistochemistry (IHC) for cleaved caspase 3, and terminal deoxynucleotidyl transferase (TdT)‐mediated dUTP nick‐end labeling (TUNEL). TUNEL has been used to detect DNA fragmentation by labeling the terminal ends of nucleic acids in necrotic and apoptotic cells. © 2018 by John Wiley & Sons, Inc.
Semantic segmentation of mFISH images using convolutional networks
Authors: Pardo Esteban , Morgado José Mário T. , Malpica Norberto
Published: April 2018

Multicolor in situ hybridization (mFISH) is a karyotyping technique used to detect major chromosomal alterations using fluorescent probes and imaging techniques. Manual interpretation of mFISH images is a time consuming step that can be automated using machine learning; in previous works, pixel or patch wise classification was employed, overlooking spatial information which can help identify chromosomes. In this work, we propose a fully convolutional semantic segmentation network for the interpretation of mFISH images, which uses both spatial and spectral information to classify each pixel in an end‐to‐end fashion. The semantic segmentation network developed was tested on samples extracted from a public dataset using cross validation. Despite having no labeling information of the image it was tested on, our algorithm yielded an average correct classification ratio (CCR) of 87.41%. Previously, this level of accuracy was only achieved with state of the art algorithms when classifying pixels from the same image in which the classifier has been trained. These results provide evidence that fully convolutional semantic segmentation networks may be employed in the computer aided diagnosis of genetic diseases with improved performance over the current image analysis methods. © 2018 International Society for Advancement of Cytometry
A Perspective on Energy Densities of Rechargeable Li‐S Batteries and Alternative Sulfur‐Based Cathode Materials
Authors: Guo Wei , Fu Yongzhu
Published: April 2018

Lithium‐ion battery has reached its capacity and energy density limits. In the past decade, significant efforts have been taken to explore new electrode materials that have the potential to enable high‐energy‐density battery systems. Among them, elemental sulfur is one of the high‐capacity cathode candidates and has been studied intensively over the past decade. The formation of lithium polysulfides in ethereal liquid electrolyte upon cycling results in several challenges such as active material dissolution, shuttle effect, and limited cycle life. Although some approaches have been developed to overcome these issues, the attainable energy densities of lithium–sulfur (Li‐S) batteries seem to be low. The main reason is largely due to the high electrolyte/sulfur (E/S) ratios used in the sulfur cathode. This perspective provides new insights on the energy density analysis of sulfur cathode. The “average mass density” of sulfur cathode is found to be a useful parameter for this purpose. Some emerging alternative sulfur‐based cathode materials such as organopolysulfides and metal polysulfides which possess unique properties and performances are presented. They are promising to overcome the intrinsic issues associated with elemental sulfur cathode and enable truly high‐energy‐density Li‐S battery systems.
Inhibitors of elastase stimulate murine B lymphocyte differentiation into IgG‐ and IgA‐producing cells
Authors: Attia Zayed , Rowe John C. , Kim Eunsoo , Varikuti Sanjay , Steiner Haley E. , Zaghawa Ahmad , Hassan Hany , Cormet‐Boyaka Estelle , Satoskar Abhay R. , Boyaka Prosper N.
Published: April 2018

It is well established that dendritic cells and macrophages play a role in antigen presentation to B and T cells and in shaping B and T cell responses via cytokines they produce. We have previously reported that depletion of neutrophils improves the production of mucosal IgA after sublingual immunization with Bacillus anthracis edema toxin as adjuvant. These past studies also demonstrated that an inverse correlation exists between the number of neutrophils and production of IgA by B cells. Using specific inhibitors of elastase, we addressed whether the elastase activity of neutrophil could be the factor that interferes with production of IgA and possibly other immunoglobulin isotypes. We found that murine splenocytes and mesenteric lymph node cells cultured for 5 days in the presence of neutrophil elastase inhibitors secreted higher levels of IgG and IgA than cells cultured in the absence of inhibitors. The effect of the inhibitors was dose‐dependent and was consistent with increased frequency of CD138+ cells expressing IgG or IgA. Finally, neutrophil elastase inhibitors increased transcription of mRNA for AID, IL‐10, BAFF and APRIL, factors involved in B cell differentiation. These findings identify inhibitors of elastase as potential adjuvants for increasing production of antibodies.
Production of Cycloalkanes in Hydrodeoxygenation of Isoeugenol Over Pt‐ and Ir‐Modified Bifunctional Catalysts
Authors: Bomont Louis , Alda‐Onggar Moldir , Fedorov Vyacheslav , Aho Atte , Peltonen Janne , Eränen Kari , Peurla Markus , Kumar Narendra , Wärnå Johan , Russo Vincenzo , Mäki‐Arvela Päivi , Grénman Henrik , Lindblad Marina , Murzin Dmitry Yu.
Published: April 2018

Hydrodeoxygenation of isoeugenol was investigated at 200 °C under 3 MPa total pressure in dodecane as a solvent, in hydrogen, over bifunctional Pt‐ and Ir‐modified Beta zeolites and mesoporous materials. As a comparison, Pt and Ir supported on Al2O3, SiO2 and mesoporous MCM‐41 were also tested. The catalysts were characterized by XRD, CO pulse chemisorption, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption and FTIR pyridine adsorption desorption. The results revealed that the most active and selective catalyst was Pt‐H‐Beta‐300, which exhibits the lowest acidity and largest crystal size of Beta zeolite among the studied Pt‐ and Ir‐modified Beta zeolites. Complete conversion of isoeugenol and 89 % selectivity to propylcyclohexane was obtained with this catalyst in 240 min. The overall deoxygenation selectivity was 100 %, giving dialkylated cyclohexanes as the second major product. The catalyst was regenerated, reduced and reused in the hydrodeoxygenation of isoeugenol with almost the same performance as the fresh catalyst. Thermodynamic analyses and kinetic modelling of the data were also performed.
Gold‐Catalyzed Synthesis of Spirofused Indoloquinuclidines
Authors: Glinsky‐Olivier Nicolas , Retailleau Pascal , Guinchard Xavier
Published: April 2018

A novel series of spirofused indoloquinuclidines was obtained by a tandem Pictet–Spengler/AuI‐catalyzed cyclization sequence. By combining N‐propargyl tryptamine with aldehydes in the presence of acetic acid and a gold complex, the target indoloquinuclidines were obtained. The combination of a chiral phosphoric acid catalyst for the asymmetric Pictet–Spengler reaction with a gold complex furnished the target compounds with ee values up to 90 % in high diastereoselectivity.
Perineural invasion: Independent prognostic factor in oral cancer that warrants adjuvant treatment
Authors: Nair Deepa , Mair Manish , Singhvi Hitesh , Mishra Aseem , Nair Sudhir , Agrawal Jaiprakash , Chaturvedi Pankaj
Published: April 2018

Background

Controversy exists regarding the administration of adjuvant radiotherapy (RT) when perineural invasion (PNI) is the only adverse histological feature. The purpose of this study was to evaluate the impact of PNI on the survival of patients with oral cavity squamous cell carcinoma (SCC).

Methods

A retrospective study of 1524 treatment naive patients with oral cavity SCC who underwent surgery from January 2012 to March 2015 was conducted. Survival analysis was performed using Cox regression model.

Results

The incidence of PNI was 20.3% and higher in tongue cancers (odds ratio 2.43). The PNI significantly affected both disease‐free survival (DFS; hazard ratio [HR] 1.84) as well as overall survival (OS; HR 1.7). Patients with early node‐negative oral cavity SCC with PNI are more likely to develop recurrences and have mortality (HR 2.79 for DFS; HR 2.54 for OS). However, the addition of adjuvant radiation in these patients showed improvement in survival (p = .022). Forest plot analysis showed a trend toward poor survival across all subgroups in patients with PNI.

Conclusion

Aggressive treatment of the primary cancer with the coincident management of the neck is important in the presence of PNI. The PNI worsens survival and warrants intensification of adjuvant treatment.
Association of low‐activity ALDH2 and alcohol consumption with risk of esophageal cancer in Chinese adults: A population‐based cohort study
Authors: Yu Canqing , Guo Yu , Bian Zheng , Yang Ling , Millwood Iona Y. , Walters Robin G. , Chen Yiping , Chen Yan , Zhang Xi , Lei Yulong , Chen Junshi , Chen Zhengming , Lv Jun , Li Liming ,   on behalf of the China Kadoorie Biobank Collaborative Group
Published: April 2018

Existing evidence remains inconclusive as to how the association between inactive ALDH2 and esophageal cancer (EC) depends on alcohol consumption. The study is based on the China Kadoorie Biobank cohort, with 10 years follow‐up of 0.5 million adults aged 30–79 years. ALDH2 activity was assessed by both self‐reported flushing response and Glu504Lys (rs671 G > A) polymorphism. Among both male and female participants who consumed alcohol less than weekly (n = 69,519; 211 EC cases), low active or inactive ALDH2 was not associated with increased EC risk [HRs (95% CIs): GA vs. GG 0.75 (0.54, 1.04); AA vs. GG 1.01 (0.46, 2.20)]. Among male weekly alcohol consumers, both flushing response [n = 59,380; 501 EC cases; HRs (95% CIs): “soon after drinking” vs. “no” flushing response 1.45 (1.05, 2.01)] and rs671 [n = 10,692; 94 EC cases; GA vs. GG 3.31 (1.94, 5.67)] were associated with EC risk. The increased EC risk associated with “soon” response or rs671 GA was apparent in men consuming alcohol ≥30g/d. Among male daily consumers, the HRs (95% CIs) for EC associated with 15g/d of alcohol were 1.28 (1.15, 1.44) for “soon” response [vs. other responses: 1.12 (1.09, 1.15); pinteraction = 0.047; n = 36,401, 425 EC cases] and 1.41 (1.08, 1.82) for rs671 GA [vs. GG: 1.16 (1.06, 1.27); pinteraction = 0.493; n = 6,607, 80 EC cases]. Self‐reported flushing response had low sensitivity (56.8%) and high specificity (88.4%) in identifying rs671 A allele among male weekly alcohol consumers. In conclusion, low‐activity ALDH2 was associated with increased EC risk among male heavy alcohol consumers. More accurate measurement of alcohol‐related EC risk allows better achievement of precision prevention.
Risk of gastric cancer among patients with gastric intestinal metaplasia
Authors: Shao Liming , Li Peiwei , Ye Jun , Chen Jiamin , Han Yuehua , Cai Jianting , Lu Xinliang
Published: April 2018

Plenty of studies have assessed the association between intestinal metaplasia (IM) and gastric cancer risk, while the results were inconsistent. We aimed to assess the risk of gastric cancer among patients with IM. Systematic literature searches were conducted in PubMed, Embase and Cochrane databases. Baseline characteristics and outcomes from the included studies were extracted independently by two investigators. Either a fixed‐effects or a random‐effects model was used to composite the pooled OR for gastric cancer risk. Finally, a total of 21 studies, which comprised 402,636 participants and 4,535 gastric cancer patients, were finally included in the current meta‐analysis. Compared with those participants without IM, IM patients were at a higher risk of gastric cancer (pooled OR = 3.58, 95% CI 2.71–4.73). We observed that incomplete IM (pooled OR = 9.48, 95% CI 4.33–20.78) but not complete IM (pooled OR = 1.55, 95% CI 0.91–2.65) was significantly associated with a higher gastric cancer risk. Besides, it appeared that gastric cancer risk was higher among patients with IM in the corpus (pooled OR = 7.39, 95% CI 4.94–11.06) than those with IM in the antrum only (pooled OR = 4.06, 95% CI 2.79–5.91). And the pooled ORs for gastric noncardia cancer and gastric cardia cancer were 4.98 (95% CI 3.12–7.95) and 1.93 (95% CI 1.15–3.24), respectively. In conclusion, patients with IM were at a higher risk of gastric cancer, especially for incomplete IM and IM in the corpus. The current evidence supports the use of IM subtypes in the surveillance of gastric cancer.
Alcohol, smoking, and risk of Her2‐overexpressing and triple‐negative breast cancer relative to estrogen receptor‐positive breast cancer
Authors: Baglia Michelle L. , Cook Linda S. , Mei‐Tzu C. , Wiggins Charles , Hill Deirdre , Porter Peggy , Li Christopher I.
Published: April 2018

Epidemiological evidence is limited on how alcohol consumption and smoking are associated with risk of different subtypes of breast cancer, such as triple‐negative (TN) and human epidermal growth factor receptor 2‐overexpressing (H2E) breast cancers, which may have different etiologies from more common luminal (estrogen receptor [ER+]) breast cancers. In this population‐based case‐case study, we evaluated the association between alcohol, smoking, and risk of H2E and TN breast cancer, compared with ER+ breast cancers, among women aged 20–69 years. Using polytomous regression, associations between alcohol consumption, smoking, and breast cancer risk were evaluated in 909 ER+, 1,290 TN, and 489 H2E breast cancer patients, with ER+ breast cancer patients as the reference group. Current alcohol consumption at diagnosis was associated with a lower risk of H2E breast cancer (odds ratio = 0.74, 95% confidence interval: 0.58–0.92) relative to ER+ cancers. No difference in association was observed by menopausal status. No association between alcohol consumption and TN breast cancer relative to ER+ breast cancer was observed. Women who smoked did not have an altered risk of TN or H2E breast cancer, relative to ER+ cancer. Our results suggest that alcohol is associated with lower risk of H2E breast cancer relative to ER+ breast cancer. This study adds to the body of epidemiologic evidence that breast cancer etiology differs by breast cancer subtype.
Three‐dimensional porous poly(propylene fumarate)‐co‐poly(lactic‐co‐glycolic acid) scaffolds for tissue engineering
Authors: Wu Wei , Liu Xifeng , Zhou Zifei , Miller A. Lee , Lu Lichun
Published: April 2018

Three‐dimensional structural scaffolds have played an important role in tissue engineering, especially broad applications in areas such as regenerative medicine. We have developed novel biodegradable porous poly(propylene fumarate)‐co‐poly(lactic‐co‐glycolic acid) (PPF‐co‐PLGA) scaffolds using thermally induced phase separation, and determined the effects of critical parameters such as copolymer concentration (6, 8, and 10 wt %) and the binary solvent ratio of dioxane:water (78/22, 80/20, 82/18 wt/wt %) on the fabrication process. The cloud‐point temperatures of PPF‐co‐PLGA changed in parallel with increasing copolymer concentration, but inversely with increasing dioxane content. The compressive moduli of the scaffolds increased with greater weight composition and dioxane:water ratio. Scaffolds formed using high copolymer concentrations and solvent ratios exhibited preferable biomineralization. All samples showed biodegradation capability in both accelerated solution and phosphate‐buffered saline (PBS). Cell toxicity testing indicated that the scaffolds had good biocompatibility with bone and nerve cells, which adhered well to the scaffolds. Variations in the copolymer concentration and solvent ratio exercised a remarkable influence on morphology, mechanical properties, biomineralization, and biodegradation, but not on the cell viability and adhesion of the cross‐linked scaffolds. An 8 to 10 wt % solute concentration and 80/20 to 82/18 wt/wt dioxane:water ratio were the optimum parameters for scaffold fabrication. PPF‐co‐PLGA scaffolds thus possess several promising prospects for tissue engineering applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A:2507–2517, 2018.
An open library of relativistic core electron density function for the QTAIM analysis with pseudopotentials
Authors: Zou Wenli , Cai Ziyu , Wang Jiankang , Xin Kunyu
Published: April 2018

Based on two‐component relativistic atomic calculations, a free electron density function (EDF) library has been developed for nearly all the known ECPs of the elements Li (Z = 3) up to Ubn (Z = 120), which can be interfaced into modern quantum chemistry programs to save the .wfx wavefunction file. The applicability of this EDF library is demonstrated by the analyses of the quantum theory of atoms in molecules (QTAIM) and other real space functions on HeCuF,, OgF4, and TlCl3(DMSO)2. When a large‐core ECP is used, it shows that the corrections by EDF may significantly improve the properties of some density‐derived real space functions, but they are invalid for the wavefunction‐depending real space functions. To classify different chemical bonds and especially some nonclassical interactions, a list of universal criteria has also been proposed. © 2018 Wiley Periodicals, Inc.
Force constant decomposition for penta‐coordinated XH3Cl2‐(X = C, Si, Ge) structures
Authors: Sakata Ken
Published: April 2018

Based on the energy decomposition analysis of an interacting system, we propose a method for force constant decomposition analysis with respect to the specific normal coordinate. Using the presented method, we examined the penta‐coordinatedsystem (X = C, Si, Ge), which possesses a three‐center four‐electron bond. The origin of the difference in the stability of the penta‐coordinatedD3hstructures was clearly shown to be the effect of electron delocalization–polarization term. © 2018 Wiley Periodicals, Inc.
Fragment‐based quantum mechanical calculation of protein–protein binding affinities
Authors: Wang Yaqian , Liu Jinfeng , Li Jinjin , He Xiao
Published: April 2018

The electrostatically embedded generalized molecular fractionation with conjugate caps (EE‐GMFCC) method has been successfully utilized for efficient linear‐scaling quantum mechanical (QM) calculation of protein energies. In this work, we applied the EE‐GMFCC method for calculation of binding affinity of Endonuclease colicin–immunity protein complex. The binding free energy changes between the wild‐type and mutants of the complex calculated by EE‐GMFCC are in good agreement with experimental results. The correlation coefficient (R) between the predicted binding energy changes and experimental values is 0.906 at the B3LYP/6‐31G*‐D level, based on the snapshot whose binding affinity is closest to the average result from the molecular mechanics/Poisson–Boltzmann surface area (MM/PBSA) calculation. The inclusion of the QM effects is important for accurate prediction of protein–protein binding affinities. Moreover, the self‐consistent calculation of PB solvation energy is required for accurate calculations of protein–protein binding free energies. This study demonstrates that the EE‐GMFCC method is capable of providing reliable prediction of relative binding affinities for protein–protein complexes. © 2018 Wiley Periodicals, Inc.
Theoretical insights on the inhibition mechanism of a class A Serine Hydrolase by avibactam
Authors: Lizana Ignacio , Delgado Eduardo J.
Published: April 2018

The inhibition mechanism of CTX‐M‐15 class A serine hydrolase by the inhibitor avibactam is addressed by a combined molecular dynamics (MD) and quantum mechanics/molecular mechanics (QM/MM) approach postulating that the residue Ser70 is the sole reacting residue, that is, itself may play the role of the acid–base species required for the enzyme inhibition. Other residues located in the active site have key participation in the positioning of the inhibitor in the right conformation to favor the attack of Ser70, in addition to the stabilization of the transition state by electrostatic interactions with avibactam. The results validate the hypothesis and show that the reaction follows an asynchronous concerted mechanism, in which the nucleophilic attack of the hydroxyl oxygen of Ser70 precedes the protonation of the amidic nitrogen and ring opening. The calculated activation barrier is 16 kcal/mol in agreement with the experimental evidence. © 2018 Wiley Periodicals, Inc.
Nanofibers as novel platform for high‐functional ion exchangers
Authors: Zhang Shaoling , Tanioka Akihiko , Matsumoto Hidetoshi
Published: April 2018

Nanofibers have unique functionalities based on their nanoscaled cross‐section, high specific surface area, and high molecular orientation inside the fibers. These functionalities can be improved by controlling their diameter, surface and internal structures. The introduction of ion‐exchange sites on the surface and/or inside the nanofibers provides novel high‐functional ion‐exchangers with high surface areas, high ion‐exchange and adsorption capacities, and high ionic conductivities. The present review highlights the fundamental aspects of ion‐exchange nanofibers (i.e. their size‐dependent unique properties and production methods) and their recent advances in the environment and energy applications (i.e. separation/purification processes and fuel cells). © 2018 Society of Chemical Industry
Subdivisions of oriented cycles in digraphs with large chromatic number
Authors: Cohen Nathann , Havet Frédéric , Lochet William , Nisse Nicolas
Published: April 2018

An oriented cycle is an orientation of a undirected cycle. We first show that for any oriented cycle C, there are digraphs containing no subdivision of C (as a subdigraph) and arbitrarily large chromatic number. In contrast, we show that for any C a cycle with two blocks, every strongly connected digraph with sufficiently large chromatic number contains a subdivision of C. We prove a similar result for the antidirected cycle on four vertices (in which two vertices have out‐degree 2 and two vertices have in‐degree 2).
Size of the largest induced forest in subcubic graphs of girth at least four and five
Authors: Kelly Tom , Liu Chun‐Hung
Published: April 2018

In this article, we address the maximum number of vertices of induced forests in subcubic graphs with girth at least four or five. We provide a unified approach to prove that every 2‐connected subcubic graph on n vertices and m edges with girth at least four or five, respectively, has an induced forest on at least or vertices, respectively, except for finitely many exceptional graphs. Our results improve a result of Liu and Zhao and are tight in the sense that the bounds are attained by infinitely many 2‐connected graphs. Equivalently, we prove that such graphs admit feedback vertex sets with size at most or , respectively. Those exceptional graphs will be explicitly constructed, and our result can be easily modified to drop the 2‐connectivity requirement.