bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of redox‐switchable zinc complexes of 10,15,20‐triaryl‐15‐aza‐5‐oxaporphyrin
Authors: Sudoh Keisuke , Furukawa Ko , Nakano Haruyuki , Shimizu Soji , Matano Yoshihiro 
Published: November 2018

AbstractThe synthesis, aromaticity, and optical and electrochemical properties of zinc(II) complexes of 10,15,20‐triaryl‐15‐aza‐5‐oxaporphyrin (TriAAOP) were investigated. Metal‐templated cyclization of a zinc(II) 1,19‐dichloro‐5,10,15‐triaryl‐10‐azatetrapyrrin complex with an oxygen source afforded 20π TriAAOP in the neutral form. Oxidation of 20π TriAAOP with silver (I) hexafluorophosphate generated the 19π radical cation or 18π dication depending on the content of oxidant used. The interconversion between the three oxidation states (18π, 19π, and 20π) resulted in distinct changes in the aromaticity and optical properties of the 15‐aza‐5‐oxaporphyrin π‐system. Nuclear magnetic resonance spectroscopy of 20π TriAAOP revealed its antiaromatic character, whereas that of the 18π TriAAOP dication showed its aromatic character. The combined effect of the two meso‐heteroatoms was directly reflected in the redox properties of the porphyrin ring; TriAAOP was reduced more easily and more difficult to oxidize than the zinc(II) complex of 5,10,15,20‐tetraaryl‐5,15‐diaz‐aporphyrin (TADAP). In the ultraviolet‐visible‐near–infrared spectra of the materials, the lowest‐energy electronic excitations of the 19π and 18π TriAAOP derivatives were considerably red‐shifted compared with those of the isoelectronic TADAP derivatives. Based on the results of density functional theory calculations, it was concluded that the observed differences between TriAAOP and TADAP would arise from the high electronegativity of oxygen; specific frontier orbitals of the TriAAOP π‐systems were energetically stabilized relative to those of the TADAP π‐system. The present findings corroborate that the meso‐modification of a porphyrin rings with different kinds of heteroatoms is a promising strategy to fine tune their light‐response properties that are switchable by reversible single electron transfer processes.
Encapsulation of Organic Dyes within an Electron‐Deficient Redox Metal‐Organic Tetrahedron for Photocatalytic Proton Reduction
Authors: Wang Hailing , Li Lili , Li Xuezhao , He Cheng 
Published: November 2018

AbstractThe design of artificial systems that mimic highly evolved and finely tuned natural photosynthetic systems is a subject of intensive research. By incorporating electron‐deficient anthraquinone within the ligand backbone, a redox‐active Ni‐based tetrahedron was developed as a redox vehicle for the construction of an artificial photosynthesis system. The tetrahedron can encapsulate fluorescein within its cavity for light‐driven H2 evolution, with the turnover number reaching 1200 moles H2 per mole redox catalyst. This well‐designed supramolecular system displayed a significantly superior activities compared with the reference mononuclear compound or introducing an inactive inhibitor (ATP), which confirmed this enzymatic photocatalytic behaviour.
Role of HA and BG in engineering poly(ε‐caprolactone) porous scaffolds for accelerating cranial bone regeneration
Authors: Yin Hua‐Mo , Li Xiang , Wang Peng , Ren Yue , Liu Wei , Xu Jia‐Zhuang , Li Ji‐Hua , Li Zhong‐Ming 
Published: November 2018

AbstractEffects of varied bioactive fillers on the biological behavior of porous polymer/inorganic composite scaffolds are lack of comprehensive comparison and remain elusive. Moreover, composite scaffolds with high porosity suffer from inferior mechanical performance. Herein, high‐pressure molding and salt leaching were employed to prepare poly(ε‐caprolactone) (PCL) composite porous scaffolds loaded with hydroxyapatite (HA) and bioactive glass (BG), respectively. Structural analysis indicated all the porous scaffolds presented interconnected open‐pore structure with the porosity of ~87% and pore size of ~180 μm, hinging on the amounts and size of porogen. Compared to PCL/HA scaffolds, PCL/BG scaffolds showed ~2.3‐fold augment in the water absorption. Attributing to the compact framework, the PCL/HA and PCL/BG porous scaffolds exhibited outstanding compressive modulus, which was notably higher than other PCL composite porous scaffolds reported in literatures. Cells culture results demonstrated that PCL/BG scaffolds displayed higher expression of osteogenic differentiation than PCL and PCL/HA scaffolds. Furthermore, in vivo results showed that more mature bone was formed within PCL/BG scaffolds than PCL/HA scaffolds, manifesting that the introduction of BG accelerated cranial bone regeneration to obtain complete bone healing within a short time. Therefore, these data indicate that PCL/BG scaffolds are more competitive for bone tissue engineering application. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 654–662, 2019.
An in vivo comparative study of the gelatin microtissue‐based bottom‐up strategy and top‐down strategy in bone tissue engineering application
Authors: Luo Chao , Fang Huimin , Li Jialun , Hou Jinfei , Yang Jie , Yuan Quan , Guo Liang , Zhong Aimei , Wang Jiecong , Sun Jiaming , Wang Zhenxing 
Published: November 2018

AbstractTissue‐engineered bone grafts (TEBGs) represent a promising treatment for bone defects. Nevertheless, drawbacks of the current construction strategy (top‐down [TD] strategy) such as limited transmission of nutrients and nonuniform distribution of seeded cells, result in an unsatisfied therapeutic effect on large segmental bone defects. Theoretically, tissue‐engineered microtissue (TEMT)‐based bottom‐up (BU) strategy is effective in preserving seed cells and vascularization, thus being regarded as a better alternative for TEBGs. Yet, there are few studies focusing on the comparison of the in vivo performance of TEBGs fabricated by TD or BU strategy. Here, we developed an ectopic bone formation rat model to compare the performance of these two construction strategies in vivo. TEBGs made from gelatin TEMT (BU strategy) and bulk tissue (BT; TD strategy) were seeded with equal number of rat bone marrow‐derived mesenchymal stem cells and fabricated in 5 mm polydimethylsiloxane chambers. The grafts were implanted into subcutaneous pockets in the same rat. Four weeks after implantation, microcomputed tomography and hematoxylin and eosin staining results demonstrated that more bony tissue was formed in the microtissue (MT) group than in the BT group. CD31 staining further confirmed that there were more blood vessels in the MT group, indicating that the BU strategy was superior in inducing angiogenesis. This comparative study provides evidence that the BU construction strategy is more effective for in vivo application and bone defect treatment by bone tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 678–688, 2019.
Long noncoding RNAs C2dat1 enhances vascular smooth muscle cell proliferation and migration by targeting MiR‐34a‐5p
Authors: Wang Hairong , Jin Zhili , Pei Tu , Song Wenhao , Gong Yao , Chen Deliang , Zhang Lin , Zhang Meichun , Zhang Gangchen 
Published: November 2018

AbstractDeregulated proliferation of vascular smooth muscle cells (VSMCs) is one common phenomenon of atherosclerosis progression. Long noncoding RNAs (lncRNAs) are one group of noncoding RNAs that play essential roles in many cell biological processes, including cell development, growth, and migration. However, the role of a novel calcium/calmodulin‐dependent protein kinase type II subunit delta (CAMK2D)‐associated lncRNA, CAMK2D‐associated transcript 1 (C2dat1), in VSMCs is still uncovered. In this study, we showed that the expression level of C2dat1 was higher in coronary artery disease (CAD) tissues than in normal arterial tissues and the C2dat1 expression level was upregulated in the proliferating VSMC after being treated with PDGF‐bb or TNF‐α. In addition, we indicated that overexpression of C2dat1 promoted VSMC growth and enhanced proliferating cell nuclear antigen (PCNA) expression in VSMC. Moreover, ectopic expression of C2dat1 increased VSMC migration. Furthermore, we showed that elevated expression of C2dat1 suppressed microRNA‐34a (miR‐34a) expression and promoted sirtuin 1 (SIRT1) expression, which was a direct target gene of miR‐34a. We demonstrated that the expression level of miR‐34a was lower in CAD tissues than in normal arterial tissues and the expression of miR‐34a was negatively correlated with C2dat1 expression. Restored expression of C2dat1 increased VSMC proliferation and migration through promoting SIRT1 expression. These data suggested that lncRNA C2dat1 might be a potential therapeutic target to promote VSMC growth and migration in CAD.
Clinical exigencies, psychosocial realities: negotiating HIV pre‐exposure prophylaxis beyond the cascade among gay, bisexual and other men who have sex with men in Canada
Authors: Newman Peter A , Guta Adrian , Lacombe‐Duncan Ashley , Tepjan Suchon 
Published: November 2018

AbstractIntroductionNotwithstanding the efficacy of oral pre‐exposure prophylaxis (PrEP) in clinical trials, a number of obstacles exist to achieving population‐level impact among gay, bisexual and other men who have sex with men (GBM). However, few studies have explored the subjective experiences of GBM PrEP users and non‐users in the community, outside of clinical trials. The objectives of this study were to explore GBM's experiences of considering, accessing and using (or not using) PrEP, and to understand emerging sexual health, social and community issues among GBM in the PrEP era.MethodsFrom October 2015 to March 2016, we purposively sampled PrEP‐naïve and PrEP‐experienced GBM from community organizations and health centres in Toronto, Canada. In‐depth, 45‐ to 90‐minute semi‐structured interviews explored PrEP perspectives and decision‐making, access, initiation, use over time, sexual practices and psychosocial considerations. Interviews were recorded, transcribed verbatim, uploaded into NVIVO, reviewed using thematic analysis and then contrasted with the PrEP cascade.ResultsParticipants included PrEP users (n = 15) and non‐users (n = 14) (mean age = 36.7 years; SD = 8.2), largely gay‐identified (86.2%), cisgender male (89.7%) and white (79.3%). Themes indicate not only correspondences, but also limitations of the PrEP cascade by complicating a user/non‐user binary and challenging the unilateral presupposition that HIV risk perception leads to PrEP acceptance. Findings further call into question assumptions of a linear stage progression and retention in care as a universal endpoint, instead revealing alternate trajectories of seasonal or intermittent PrEP use and, for some, an end goal of terminating PrEP. GBM's narratives also revealed potent psychological/affective experiences of untethering sex from HIV anxiety; multifaceted PrEP stigma; and challenges to sexual norms and practices that complicate existing behavioural prevention strategies and sexual and social relationships.ConclusionsAn expanded PrEP cascade should consider alternate trajectories of use based on dynamic relationships and behavioural risks that may call for seasonal or intermittent use; systemic barriers in access to and sustaining PrEP; and multiple end goals including PrEP maintenance and discontinuation. Incorporating GBM's lived experiences, evolving preferences, and psychosocial and community‐level challenges into PrEP implementation models, rather than a circumscribed biomedical approach, may more effectively support HIV prevention and GBM's broader sexual and psychological health.
Biotic elicitation as a tool to improve strawberry and raspberry extract potential on metabolic syndrome‐related enzymes in vitro
Authors: Gutierrez‐Albanchez Enrique , Kirakosyan Ara , Bolling Steven F , García‐Villaraco Ana , Gutierrez‐Mañero Javier , Ramos‐Solano Beatriz 
Published: November 2018

AbstractBackgroundRaspberry and strawberry are high value‐added food products that can contribute to human health due to the abundance of polyphenols that they contain. Polyphenols are secondary metabolites and therefore devoted to improve plant adaptation, these polyphenol profile can be induced applying different stimuli, such as certain bacteria. The aim of this study was twofold: (i) to evaluate the ability of two bacterial strains to modulate secondary metabolisms in strawberry and raspberry, and (ii) to explore the ability of plant extracts to modify enzyme activities related to metabolic syndrome.ResultsTotal phenolic and anthocyanin content was higher in strawberries than in raspberries, despite similar antioxidant capacities. Strawberry extracts performed better on the tested enzymes, except on α‐glucosidase inhibition capacity. Bacillus amyloliquefaciens stabilized the effects of extracts at different points in time, and Pseudomonas fluorescens modified plant metabolism after more inoculations (spring) in both species, improving the effects of raspberry extracts on α‐glucosidase, COX1, and COX2, and of strawberry on α‐amylase and COX1.ConclusionIt is good to include these two fruits in the diet because they improve the activity of metabolic syndrome‐related enzymes. Applying either strain during plant growth modifies the bioactive profile of the plants, improving the effects of the fruit extracts on human health. © 2018 Society of Chemical Industry
Ergonomic hazards in otolaryngology
Authors: Vaisbuch Yona , Aaron Ksenia A. , Moore Justin M. , Vaughan John , Ma Yifei , Gupta Raghav , Jackler Robert K. 
Published: November 2018

Objectives/HypothesisTo evaluate the presence of postural‐related strain and musculoskeletal discomfort, along with the level of ergonomics training and the availability of ergonomic equipment among otolaryngology surgeons.Study DesignIntraoperative observations and survey study.MethodsUsing the Rapid Entire Body Assessment score system to identify ergonomic hazards, we conducted intraoperative observations assessing operating room personnel during different otolaryngological subspecialty procedures. Based on these findings, otolaryngology surgeons at a single academic institution in the United States were sent a survey that evaluated ergonomic practice, environmental infrastructure, and prior ergonomic training or education.ResultsA response rate of 69% was obtained from 70 surgeons, with 72.9% of responding surgeons suffering from some level of back pain, with cervical spine pain being the most common. Interestingly, residents were equally affected when compared to more senior surgeons both in subjective survey reports and from observational risk analysis. Furthermore, 43.8% of surgeons reported suffering from the highest level of pain when standing, whereas only 12.5% experienced pain when sitting. Importantly, 10% stated that pain impacted their work. Only 24% of surgeons had any prior ergonomic training or education.ConclusionsOur data suggest that pain and disability induced by poor ergonomics are widespread among the otolaryngology community and confirm that surgeons rarely receive ergonomic training in the surgical context. Additionally, intraoperative observational findings identified that the majority of observed surgeons display poor posture, particularly a poor cervical angle and use of ergonomic setups, both of which increase ergonomic risk hazard. These data provide guidance for future interventional studies.Level of EvidenceNA Laryngoscope, 129:370–376, 2019
Modeling the effective spawning and nursery habitats of northern pike within a large spatiotemporally variable river landscape (St. Lawrence River, Canada)
Authors: Foubert Aline , Le Pichon Céline , Mingelbier Marc , Farrell John M. , Morin Jean , Lecomte Frédéric 
Published: November 2018

AbstractSpawning and nursery habitats are often spatially disjunct as a consequence of specific life history stage habitat requirements and spatiotemporal habitat changes. Nevertheless, free‐swimming larvae originating from spawning habitats must reach productive nurseries to maximize survival. We examined spawning and nursery habitats of northern pike (Esox lucius) over the past 50 yr to investigate how habitat connectivity and hydrological variability interact to alter the distribution of effective spawning habitat. Habitat models coupled to a least‐cost approach were developed to quantify connectivity between habitats in two contrasting regions of the St. Lawrence River (Canada): a riverine corridor lake (~ 46 km) and a large fluvial lake (~ 48 km). Our simulations demonstrate that depending on hydrological conditions, between 3% to 51% of spawning habitat used by adults in the riverine corridor, and 22% to 90% in the lake, allowed larval survival up to the fifth week of development. Although rapid dewatering of spawning habitat is responsible for most spawning losses in the fluvial lake, increasing water currents were responsible for dispersing larvae away from suitable habitats in the riverine corridor. However, stable hydrological conditions led to spatial overlapping of spawning and nursery habitats favoring larval survival and growth. In addition, downstream larval dispersal by low water currents allowed larvae to reach spatially disjunct nursery habitat, especially in the lake. Our results indicate that despite the vast areas of potentially suitable habitats provided by large vegetated floodplains of fluvial lakes, the effective spawning habitats favoring early‐life recruitment are much more heterogeneous and variable both spatially and temporally.
Strong Coupling in Microcavity Structures: Principle, Design, and Practical Application
Authors: Yu Xiantong , Yuan Yufeng , Xu Jianhua , Yong Ken‐Tye , Qu Junle , Song Jun 
Published: November 2018

AbstractWhen interaction between light and matter is in the strong coupling region, matter has a significant influence on the whole system, with potential to develop low‐power active optical devices. Strong coupling can verify some basic problems of quantum physics, and it is an ideal system to study light–matter interaction, providing an intuitive and accurate demonstration of some pure quantum effects with small mass and easy optical control. Here, the most important advances in strong coupling in recent years are described. Of late, an extensive series of experimental and theoretical findings, and remarkable achievements have been made in this field. Strong coupling between cavities and some new materials such as semiconductors, two‐dimensional (2D) material, and quantum dots (QDs) are the focus of research in this field. Another field that has made outstanding progress is the application of this optical phenomenon, including resonance‐enhanced Raman and infrared spectra, nanolasers, and cavity‐enhanced sensing. Furthermore, the potential in this field arises for future quantum information and quantum optical devices. It is now developing at a very fast rate and can be predicted to have broad prospects for development in the future. Some prospects in terms of design and application are included.
Ecotoxicological Modeling, Ranking and Prioritization of Pharmaceuticals Using QSTR and i‐QSTTR Approaches: Application of 2D and Fragment Based Descriptors
Authors: Khan Kabiruddin , Kar Supratik , Sanderson Hans , Roy Kunal , Leszczynski Jerzy 
Published: November 2018

AbstractThere is a huge lack of experimental data on ecotoxicity of pharmaceuticals, while existing resources are insufficient to gather these data against all possible environmental endpoints. Computational tools such as quantitative structure‐toxicity relationship (QSTR) can help us to a great extent to overcome this problem through filling of data gaps. In the current study, QSTR models have been developed for toxicity of 260 diverse pharmaceuticals on three different trophic level species namely algae, daphnia and fish, using partial least squares (PLS) regression approach with 2D descriptors selected through a genetic algorithm approach in order to study underlying chemical features responsible for the observed acute toxicity. The final obtained statistically reliable QSTR models were extensively validated following the OECD guidelines. Interspecies quantitative structure‐toxicity‐toxicity (QSTTR) models were also developed using genetic algorithm followed by multiple linear regression (GA‐MLR) approach to check for the pattern of responses observed as we move across the hierarchy of genetics in different taxonomical class. The obtained interspecies models were finally utilized to fill the data gaps for 260 pharmaceuticals, where experimental data were missing for at least one of the endpoints. Finally, a prioritized list for 7106 existing drug like substances was prepared by predicting their acute toxicity using developed QSTR models.
After Salisbury Nerve Agents Revisited
Authors: Carlsen Lars 
Published: November 2018

AbstractIn March 2018 the term Novichok (Hoвичoκ) became publically known following an attempted murder of a former Russian spy in Salisbury, UK. Novichok is the name of a group of nerve agents secretly produced by Russia in the later stages of the Cold War. These compounds were never declared under the Chemical Weapons Convention and very little is known about the actual identity and characteristics of these compounds. Structures of some of the Novichoks have been reported by a former Russian chemist, Vil Mirzayanov, previously working at the Russian State Scientific Research Institute of Organic Chemistry and Technology (GOSNIIOKhT). It was in this context claimed that at least two compounds of the Novichok family, known as Novichok‐5 and Novichok‐7 were 5–8 times more potent than the hitherto most toxic nerve agent, VX. The present study elucidates, applying a series of QSAR models toxicity, skin permeation, pharmacokinetic aspects as well as the environmental fate of a series of Novichoks. Virtually the results from the different studies related to human health point in the same direction, i. e., the Novichoks are significantly less toxic than VX and the skin permeation much lower and less efficient than observed for VX. Hence, the claim by Mirzayanov could not be substantiated.
Gaussian Process Regression Models for the Prediction of Hydrogen Bond Acceptor Strengths
Authors: Bauer Christoph A. , Schneider Gisbert , Göller Andreas H. 
Published: November 2018

AbstractWe present two approaches for the computation of hydrogen bond acceptor strengths, one by machine‐learning and one by a composite quantum‐mechanical protocol, both based on the well‐established pKBHX scale and dataset. The QM calculations after a necessary linear fit reproduce the complexation free energies in solution with an RMSE of 2.6 kJ mol−1, not far off the expected error of 2 kJ mol−1 obtained from the comparison of experimental data from two different sources. The second approach is by Gaussian Process Regression (GPR) machine‐learning. We describe the hydrogen bond acceptor atoms by a radial atomic reactivity descriptor that encodes their electronic and steric environment. The performance of the GPR model on an external test set corresponds to 3.3 kJ mol−1, which is also close to the experimental error. We apply the GPR model built on experimental data to model the hydrogen bond acceptor strengths of a series of hydrogen bond acceptor sites of 10 phosphodiesterase 10 A inhibitors. The predicted values correlate well with the experimentally measured IC50 values.