bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fullerene Stability by Geometrical Thermodynamics
Authors: Parker Michael C. , Jeynes Chris 
Published: January 2020

AbstractThis work proves that stability of C60 is a geometrical property of the thermodynamics of the system: a significant methodological advance since a detailed treatment of the energetics may be avoidable. This approach may be fruitful, not only for fullerenes but also for general problems of molecular stability and in other applications of conformational chemistry. For the non‐chiral C60, C384, and the weakly‐chiral C28, C76 and C380 (of these, C380 and C384 are classed as “unspirallable”), Schlegel projections are used to show that these fullerenes can all be represented by pairs of spirals counter‐propagating in anti‐parallel (C2) symmetry. For C60, the high symmetry is used to construct an analytical approximation for the spherical double‐spirals, shown mathematically to be Maximum Entropy (MaxEnt) using the formalism of Quantitative Geometrical Thermodynamics (QGT). Therefore C60 is necessarily stable. This MaxEnt stability criterion is general, depending only on the geometry and not the kinematics of the system. The sense and degree of chirality for C76 and C380 is also quantified using a Shannon entropy‐based fragmentation metric.
Preparation, Characterization and Application of Copper Schiff base Complex Supported on MCM‐41 as a Recyclable Catalyst for the Ullmann‐type N‐arylation Reaction
Authors: Niakan Mahsa , Asadi Zahra , Zare Sayeh 
Published: January 2020

AbstractIn this study, a Cu‐Schiff base complex supported on highly ordered mesoporous silica MCM‐41 was successfully prepared to form a heterogeneous catalyst. The structural and textural properties of the newly prepared catalyst were determined by various microscopic and spectroscopic techniques such as FT‐IR, BET, TGA, DRS UV‐vis, EDX, XPS, ICP‐OES, XRD, and TEM. The catalyst was used in the N‐arylation of various amines through formation of intramolecular C(aryl)‐N bond from the relevant aryl halides (Ar−I and Ar−Br) with amines by coupling reactions of Ullmann type. The significant advantages of this protocol were generality, low metal content, high yield of products, and simple work‐up procedure. Moreover, the catalyst could be recycled efficiently for seven runs without any appreciable decrease in reactivity and no leaching of copper was found during this course.
Chalcogenborines and Derivatives: Probing the Origin of Relative Thermodynamic Stabilities
Authors: Muhammad Rouf Alvi , Iqbal Sajid , Ejaz Anam 
Published: January 2020

AbstractChalcogenborines (or BX‐doped benzenes, where X=O/S) are interesting for intriguing photophysical and electronic properties. In spite of several advances, origin of their relative thermodynamic stability remains elusive. Now, based on density functional theory (DFT) calculations, we reveal that the relative stability of their mono BX‐doped isomers (here called BX isomers) is in a good relation with the geometry, natural bond orbital partial atomic charges (qs) and bonding energy. Substitution by an electronegative F group in a BX stabilizes boron position significantly than the carbon. On the other hand, substitution by an electropositive SiH3 group imparts small stability to carbon position than the boron. The qs in the parent BX can predict relative stability of the F‐substituted isomers excellently. However, such speculation fails for the SiH3‐substituted isomers due to the close electronegativity of SiH3, C and B. These findings could be helpful for the synthesis of BX derivatives.
One‐step Green Synthetic Approach for the Preparation of Orange Light Emitting Copper Nanoclusters for Sensitive Detection of Mercury(II) Ions
Authors: Cai Zhifeng , Zhu Ruitao , Pang Shulin , Tian Fang , Zhang Caifeng 
Published: January 2020

AbstractIn this paper, we synthesized water‐soluble fluorescent Cu nanoclusters (Cu NCs) through simple reduction reaction with 2‐mercaptobenzimidazole as a protective agent, polyvinyl pyrrolidone (PVP) as a stabilizer and ascorbic acid as a reducing agent for the first time. The optical properties and structures of as‐prepared Cu NCs were characterized by fluorescence spectroscopy, UV‐vis, FT‐IR, TEM and XPS. The characterization results showed that the Cu NCs had better fluorescence intensity, high dispersion and large Stokes shift. The Cu NCs had excellent stability against photo‐illumination and ionic strength and displayed an excitation‐independent fluorescence characteristic. The as‐prepared Cu NCs was selectively and sensitively quenched by Hg2+. Furthermore, the fluorescence of Cu NCs was linearly quenched in the range of 2–40 μM (concentration of Hg2+) with a detection limit of 23.0 nM. More importantly, this prepared Cu NCs could be successfully utilized as a probe for detection of Hg2+ in real water samples.
Synthesis and Antiproliferative Evaluation of 5′‐Arylchalcogenyl‐3‐(phenylselanyl‐triazoyl)‐thymidine
Authors: Quoos Natália , Dornelles Luciano , Buss Julieti , Begnini Karine Rech , Collares Tiago , Seixas Fabiana K. , Garcia Fabio Dutra , Rodrigues Oscar E. D. 
Published: January 2020

AbstractThis article discloses the synthesis and biological in vitro activity of a novel class of compounds derived from 5′‐arylchalcogenyl‐3‐(phenylselanyl‐triazoyl)‐thymidine as antitumor agents in the 5637 bladder carcinoma. The synthesis of the new molecules obtained good yields and proved to be efficient. The antitumor biological property, which was presented by a series of these unpublished compounds, demonstrates the importance of the presence of the nucleoside portion and the chalcogenium atom in the molecule.
Recent Progress in the Removal of Heavy Metal Ions from Water Using Metal‐Organic Frameworks
Authors: Shayegan Hossein , Ali Gomaa A. M. , Safarifard Vahid 
Published: January 2020

AbstractThe efficient adsorption of heavy metal ions from wastewater has become a serious challenge from both environmental and biological viewpoints. Recently, porous metal‐organic frameworks (MOFs), with metallic clusters and organic linkers, have been developed as promising structures in the capture of different toxic and hazardous substances, including heavy metal ions, because of their unique features. Here there is a collection for recent progress in the field of water remediation from the variable‐valent metals in polluted water and the corresponding MOFs which are able to remove these pollutant agents from water. Meanwhile, effective factors in the absorption of metal ions are discussed. MOFs are considered to be a promising candidate for metal ions removal from wastewater.
Osmium(IV) Halide Complexes with Dimethyl Sulfoxide[H(dmso)2][OsX5(dmso‐κO)], X=Cl, Br: Synthesis, Structure, and Properties
Authors: Rudnitskaya Olga V. , Dobrokhotova Ekaterina V. , Kultyshkina Ekaterina K. , Tereshina Tatiana A. , Trigub Alexander L. , Zubavichus Yan V. , Khrustalev Victor N. 
Published: January 2020

AbstractTwo osmium complexes of common formula [H(dmso)2][OsIVХ5(dmso‐κO)] 1 (Х=Cl) and 2 (Х=Br) are synthesized via the reaction of H2OsX6 (Х=Cl, Br) with DMSO. The complex 1 crystallized in the orthorhombic space group Pca21. For 2, two orthorhombic polymorphs are found, namely, 2 a in space group Cmcm and 2 b in space group Pbca. Within the [H(dmso)2]+ cations of 1 and 2 a, the cis‐configuration of the DMSO moieties has been observed for the first time. The complexes are characterized by a set of spectroscopic (NMR, IR, UV‐Vis, EXAFS/XANES) and diffraction (single crystal and powder) techniques. Both complexes 1 and 2 retain their molecular structures in DMSO and acetone solutions, as evidenced by Os L3‐edge EXAFS/XANES. 1H NMR spectra of 1 and 2 in DMSO solutions reveal signals of coordinated DMSO. In acetone solutions, signals of the [H(dmso)2]+ cations are observed in addition to those of coordinated neutral DMSO.
Language Use in the Classroom: Balancing Target Language Exposure With the Need for Other Languages
Authors: Brevik Lisbeth M. , Rindal Ulrikke 
Published: January 2020

Recent trends in language education have promoted the use of students’ linguistic repertoires in the classroom. However, research is lacking into how languages are actually used in target language instruction. This study contributes new knowledge from lower secondary classrooms in Norway, combining a large data set of video observed English lessons (N= 60) of naturally occurring instruction over time, with a survey of students’ (N= 179) experiences of their teachers’ language practices. The study reports how languages were used and perceived in seven classrooms across Grades 9–10. Findings indicate three main patterns. First, there was considerable variation in language use in these classrooms, which seemed dependent on the teacher rather than students and school. Second, there was hardly any use of languages other than the language of schooling (Norwegian) and the target language (English), but a few references to linguistic repertoires signalled a focus on multilingualism in some classrooms. Third, survey data indicate that students perceived teachers’ use of Norwegian, regardless of amount, helpful. The study demonstrates teachers’ and students’ balancing of target language exposure with the need for other languages, even with extensive variation in the use of English and Norwegian and infrequent references to students’ other linguistic repertoires in most classrooms.
Cost comparison and optimization of gas electric hybrid heat pumps
Authors: Amirkhizi Tara S. , Jensen Ida G. 
Published: January 2020

AbstractThe residential heating sector can offer significant load‐shifting possibilities to the energy system. Currently 400,000 households in Denmark are heated by natural gas boilers. The power consumption corresponding to these boilers can offer high value to the stabilization of the wind intensive Danish energy system. Gas electric hybrid heat pumps (GEHHPs) are individual heat pumps consisting of an electric heat pump and a gas boiler. They enable a fully flexible operation of electric heat pumps by supplementing electricity with gas when necessary. In this paper, we construct a cost optimization model of a GEHHP and compare the levelized cost of heat of this system with other individual heating systems. We investigate the changes in the operation schedule of the GEHHP, both from a socio‐ and a private‐economic perspective, and analyze how certain economic and technological framework conditions influence their operation schedule. Our article shows that the end‐consumer's optimal operation schedule uses the gas boiler component of the GEHHP 24% of the time. Additionally, comparing the levelized cost of heat of the GEHHP with other heating alternatives proves that the GEHHP setup is the most cost efficient individual heating alternative.This article is categorized under:
Energy Systems Analysis > Economics and Policy
Energy Systems Economics > Economics and Policy
Energy Systems Economics > Systems and Infrastructure
The second-order effect of Earth’s rotation on Cryosat-2 fully focused SAR processing
Authors: Kleinherenbrink Marcel , Smith Walter H. F. , Naeije Marc C. , Slobbe D. Cornelis , Hoogeboom Peter 
Published: January 2020

AbstractWe investigated the sensitivity of fully focused SAR (FF-SAR) processing of Cryosat-2 altimeter data to Earth rotation. Earth’s rotation causes scatterers at varying cross-track locations to have a different relative velocity with respect to the satellite. This second-order effect of Earth rotation on the phase is currently not corrected for in FF-SAR processing of altimetry data. The difference is largest near the poles, where the satellite flies parallel to the equator. Not correcting for the second-order effect yields a parabolic shape in the counter-rotated phase, which increases with the cross-track distance. Its effect is, however, limited by the time-in-view of the scatterer, which is shorter at the edge of the altimeter footprint, and therefore destructive interference will not occur when using Cryosat-2 data. For Cryosat-2, the only expected effect is a reduction in power and along-track resolution in the waveform tail and in the grating lobes. If the FF-SAR processor focuses on one point, and there is a bright scatterer at another, then there is a residual parabolic phase, whose sign and shape depend on the cross-track distance and whether the signal is left or right of the chosen focal point. In theory, if the viewed scene only has few bright coherent scatterers, then it might be possible to determine the cross-track position of each. In practice, however, natural targets are rarely coherent over the integration time.
Gynaecomastia in the Durban Breast Unit: A Comparison of HIV‐ and Non‐HIV‐Infected Individuals
Authors: Osman Safeeya , Mansoor E. , Buccimazza I. 
Published: January 2020

AbstractBackgroundThe clinical profile of gynaecomastia patients, both in human immunodeficiency virus (HIV)‐positive and HIV‐negative patients, in resource‐limited settings remains largely undocumented. The aim of this study was to compare and contrast these groups with a view to developing an appropriate treatment algorithm for the South African population.MethodsA retrospective chart review at the Durban Breast Unit for the period 2000–2015 was undertaken with ethics approval [BE012/16 (sub‐study of BCA173/15)]. Statistical analysis was done with IBM SPSS version 25. A p value <0.05 indicated statistical significance.ResultsOne hundred and four patients were documented. The mean age was 37 years. Gynaecomastia was most commonly attributed to puberty, HAART, other medications or an idiopathic aetiology. HIV status was known in 49 patients. There was a 97% prevalence of HAART use in the HIV‐positive subgroup (n = 31). Efavirenz was the most common inciting drug. Incidence of gynaecomastia correlated with duration of HAART use. Age, late presentation, advanced Simon grade and bilateral disease appear to necessitate surgical intervention more frequently.ConclusionPatients on HAART are advised to seek early advice upon noticing gynaecomastia. Drug cessation/change is likely to assist only upon early presentation resulting in static progression, and ultimate cure would still entail surgical excision. Extensive blood and imaging studies should be done only where clinically indicated and can be considered in cases of recurrence post‐surgery. Management option must be discussed with patients, and surgeons are required to be familiar with the various surgical techniques necessary to treat gynaecomastia.
A Low‐Cost Synthetic Abdominal Wall Model (“Raj Model”) for the Training of Laparoscopic Port Insertion
Authors: Kailavasan Mithun , Berridge Christopher , Kandaswamy Gokul , Rai Bhavan , Wilkinson Beverley , Jain Sunjay , Biyani Chandra Shekhar , Gowda Basavaraj 
Published: January 2020

AbstractObjectiveTo assess the content validity of a low‐cost bench‐top model (“Raj Model”) for the training of laparoscopic port insertion at the Urology Simulation Bootcamp course (USBC).Materials and methodsA low‐cost abdominal wall model of 40 × 40 cm was created to simulate laparoscopic port placement. The model was made using different synthetic materials to represent layers (skin—vinyl sheet, subcutaneous fat—10 mm soft foam, anterior rectus sheath and muscle—floor mat, posterior rectus sheath—masking wall tape, peritoneum—sellotape). Each model was used by up to 3 trainees to practise laparoscopic port placement. The model was assessed for content validity by trainees and experts using a 5‐point Likert scale.ResultIn total, 88 trainees and 6 experts participated in the study. For all aspects of the synthetic abdominal wall, good (4) or very good (5) scores ranged from 52.7–69.2%, whereas very poor (1) rating ranged from 0 to 4.3%. There was no significant difference in responses for the content validity of the model between trainees and experts. There was a high intraclass correlation amongst responses from trainees (0.89) and experts (0.79). Approximately 76.3% of trainees and experts felt that the model is suitable for training.ConclusionThis is the first validation study of a low‐cost abdominal wall model for teaching laparoscopic port placement for trainees. Our study demonstrates that this synthetic model has high content validity and is useful for surgical training.
Early onset sepsis calculator implementation is associated with reduced healthcare utilization and financial costs in late preterm and term newborns
Authors: Achten Niek B. , Visser Douwe H. , Tromp Ellen , Groot Wim , van Goudoever Johannes B. , Plötz Frans B. 
Published: January 2020

AbstractThe neonatal early onset sepsis (EOS) calculator is a novel tool for antibiotic stewardship in newborns, associated with a reduction of empiric antibiotic treatment for suspected EOS. We studied if implementation of the EOS calculator results in less healthcare utilization and lower financial costs of suspected EOS. For this, we compared two single-year cohorts of hospitalizations within 3 days after birth in a Dutch nonacademic teaching hospital, before and after implementation of the EOS calculator. All admitted newborns born at or after 35 weeks of gestation were eligible for inclusion. We analyzed data from 881 newborns pre-implementation and 827 newborns post-implementation. We found significant reductions in EOS-related laboratory tests performed and antibiotic days, associated with implementation of the EOS calculator. Mean length of hospital stay was shorter, and EOS-related financial costs were lower after implementation among term, but not among preterm newborns.Conclusion: In addition to the well-known positive impact on antibiotic stewardship, implementation of the EOS calculator is also clearly associated with reductions in healthcare utilization related to suspected EOS in late preterm and term newborns and with a reduction in associated financial costs among those born term.What is Known:• The early-onset sepsis (EOS) calculator is a novel tool for antibiotic stewardship in newborns, associated with a reduction in empiric antibiotic treatment for suspected EOS.What is New:• In newborns at risk for EOS, EOS calculator implementation is associated with a significant reduction in laboratory investigations related to suspected EOS and significantly shorter stay in those born term.• EOS calculator implementation in term newborns is associated with a mean reduction of €207 in costs for EOS-related care per admitted newborn.
Hypoxia preconditioning protects neuronal cells against traumatic brain injury through stimulation of glucose transport mediated by HIF-1α/GLUTs signaling pathway in rat
Authors: Wu Xiaogang , Wang Chunlin , Wang Jinbiao , Zhu Meijie , Yao Yinsheng , Liu Jiachuan 
Published: January 2020

AbstractHypoxia preconditioning (HPC), a well-established preconditioning model, has been shown to protect the brain against severe hypoxia or ischemia caused by traumatic brain injury (TBI), but the mechanism has not been well elucidated. Anaerobic glycolysis is the major way for neurons to produce energy under cerebral ischemia and hypoxia after TBI, and it requires large amounts of glucose. We hypothesized that glucose transport, as a rate-limiting step of glucose metabolism, may play key roles in the neuroprotective effects of HPC on cerebral cortex tissue against TBI. The aim of this study was to investigate the effect of HPC on glucose transport activity of rat cerebral cortex tissue after TBI through examining the gene expression of two major glucose transporters (GLUT1 and GLUT3) and their upstream target gene hypoxia-inducible factor-1α (HIF-1α). Sprague-Dawley rats were treated with HPC (50.47 kPa, 3 h/d, 3d). Twenty-four hours after the last treatment, the rats were injured using the Feeney free falling model. Cortex tissues of injured rats were removed at 1 h, 4 h, 8 h, 12 h, 1 day, 3 days, 7 d, and 14 days post-injury for histological analysis. Compared with TBI alone, HPC before TBI resulted in the expression of HIF-1α, GLUT1, and GLUT3 to increase at 1 h; they were markedly increased at 4 h, 8 h, 12 h, 1 day, and 3 days and decreased thereafter (p < 0.05). HPC before TBI could improve neuronal survival in rats by examining NeuN staining and observing reduced apoptosis by examining TUNEL staining. The result showed that HPC before TBI could increase the expression of GLUT1 and GLUT3. And through double immunofluorescence staining for GLUT3 and NeuN, the results strongly suggest that HPC improved glucose transport activity of neurons in rats with TBI. In summary, our results further support that HPC can improve hypoxia tolerance and attenuate neuronal loss of cerebral cortex in rats after TBI. The mechanism is mainly related to the increase of glucose transport activity through inducing GLUT1 and GLUT3 expression through upregulating HIF-1α expression.
Data association and uncertainty pruning for tracks determined on short arcs
Authors: Pirovano Laura , Principe Gennaro , Armellin Roberto 
Published: January 2020

AbstractWhen building a space catalogue, it is necessary to acquire multiple observations of the same object for the estimated state to be considered meaningful. A first concern is then to establish whether different sets of observations belong to the same object, which is the association problem. Due to illumination constraints and adopted observation strategies, small objects may be detected on short arcs, which contain little information about the curvature of the orbit. Thus, a single detection is usually of little value in determining the orbital state due to the very large associated uncertainty. In this work, we propose a method that both recognizes associated observations and sequentially reduces the solution uncertainty when two or more sets of observations are associated. The six-dimensional (6D) association problem is addressed as a cascade of 2D and 4D optimization problems. The performance of the algorithm is assessed using objects in geostationary Earth orbit, with observations spread over short arcs.
Perspectives of future pharmacists on the potential for development and implementation of pharmacist prescribing in Qatar
Authors: Diab Mohammad Issam , Ibrahim Angham , Abdallah Oraib , El-Awaisi Alla , Zolezzi Monica , Ageeb Rwedah Anwar , Elkhalifa Wishah Hamza Imam , Awaisu Ahmed 
Published: January 2020

AbstractBackground Pharmacists in many developed countries have been granted prescribing authorities under what is known as “non-medical prescribing” or “pharmacist prescribing”. However, such prescribing privileges are not available in many developing countries. Objective The objective of this study was to determine the perspectives of future pharmacists (recent pharmacy graduates and pharmacy students) on pharmacist prescribing and its potential implementation in Qatar. Methods A convergent parallel mixed-methods design was used: (1) a cross-sectional survey using a pre-tested questionnaire and; (2) focus group discussions to allow for an in-depth understanding of the issue, with a focus on pharmacists prescribing competencies as well as barriers for its implementation. Main outcome measures Future pharmacists’ perspectives and attitudes towards pharmacist prescribing in Qatar. Results The majority of the respondents (94.4%) indicated awareness of the prescribing competency related to selecting treatment options. Furthermore, the majority (92.4%) believed that pharmacists should undergo prescribing training and accreditation before been legally allowed to prescribe, a point that was reiterated in the focus group discussions. Participants generally expressed support for collaborative and supplementary prescribing models when developing prescribing frameworks for Qatar. Four categories emerged under the theme barriers to implementation of pharmacist prescribing: lack of prescribing competency, pharmacist mindset, lack of accessibility to patient records and counseling rooms, and diversity of education and training background. Conclusion The majority of recent pharmacy graduates and students were in favor of pharmacist prescribing been implemented in Qatar. However, a special training program was deemed necessary to qualify pharmacists to prescribe safely and effectively.