bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen‐doped Porous Carbon with Brain‐like Structure Derived from Quaternary Bipyridinium‐type Framework for Efficient Oxygen Reduction Electrocatalysis and Supercapacitors
Authors: Lei Zhidan , Long Xuan , Yang Mei , Yang Duanguang , Chen Hongbiao , Li Huaming 
Published: January 2019

AbstractNitrogen‐doped porous carbon materials have now become one of the most important candidates for efficient oxygen reduction electrocatalysis and supercapacitors because of their low cost and high stability. In the present study, a novel triazine‐based, quaternary bipyridinium‐type framework (TBPF) is synthesized by polycondensation of 4,4′‐bipyridine with cyanuric chloride. The as‐synthesized TBPF is then subject to pyrolysis at 900 °C, yielding N‐doped porous carbon (N/C‐900). The N/C‐900 material possesses brain‐like architecture, high N‐containing functionalities (5.40 at.% N), and relatively high specific surface area (684 m2 g−1), which can act as a truly metal‐free catalyst toward ORR and an electrode material for supercapacitors. Due to the synergistic effects, the N/C‐900 material shows outstanding ORR electrocatalytic activity and stability in alkaline media with an onset potential of 0.969 V (vs RHE), a half‐wave potential of 0.843 V (vs RHE), a limited current density of 5.05 mA cm−2, and a 3 mV negative shift of half‐wave potential after 3000 cycles. Furthermore, the N/C‐900‐based supercapacitor electrode also displays relatively high specific capacitance (217 F g−1 at 0.5 A g−1) and excellent stability (96 % capacitance retention after 10000 cycles) in 6 M KOH electrolyte.
Increasing the Electric Double‐Layer Capacitance in Boron‐Doped Diamond Electrodes
Authors: Takagi Kazuaki , Natsui Keisuke , Watanabe Takeshi , Einaga Yasuaki 
Published: January 2019

AbstractHighly boron‐doped diamond (BDD) electrodes containing sp2 carbon impurities exhibit an increase in the electric double‐layer capacitance (Cdl) after anodic oxidation. Although it is known that the electrochemical properties of BDD electrodes are affected by several factors, including the boron concentration, the amount of sp2 carbon impurity, and the surface termination and orientation, clarification of the mechanism for the increase in Cdl needs to be done. To this end, we prepared several BDD samples under various conditions and the properties of these samples, including Cdl, were systematically investigated. The mechanism for the increase in Cdl in particular, including the effect of the surface termination, is discussed.
Directing Foldamer Self‐Assembly with a Cyclopropanoyl Cap
Authors: Lim Danim , Kim Hyunjoong , Gong Jintaek , Eom Jae‐Hoon , Yoon Eunyoung , Driver Russell W. , Baik Mu‐Hyun , Lee Hee‐Seung 
Published: January 2019

AbstractThe rational design of self‐assembling organic materials is extremely challenging due to the difficulty in precisely predicting solid‐state architectures from first principles, especially if synthons are conformationally flexible. A tractable model system to study self‐assembly was constructed by appending cyclopropanoyl caps to the N termini of helical α/β‐peptide foldamers, designed to form both N−H⋅⋅⋅O and Cα−H⋅⋅⋅O hydrogen bonds, which then rapidly self‐assembled to form foldectures (foldamer architectures). Through a combined analytical and computational investigation, cyclopropanoyl capping was observed to markedly enhance self‐assembly in recalcitrant substrates and direct the formation of a single intermolecular N−H⋅⋅⋅O/Cα−H⋅⋅⋅O bonding motif in single crystals, regardless of peptide sequence or foldamer conformation. In contrast to previous studies, foldamer constituents of single crystals and foldectures assumed different secondary structures and different molecular packing modes, despite a conserved N−H⋅⋅⋅O/Cα−H⋅⋅⋅O bonding motif. DFT calculations validated the experimental results by showing that the N−H⋅⋅⋅O/Cα−H⋅⋅⋅O interaction created by the cap was sufficiently attractive to influence self‐assembly. This versatile strategy to harness secondary noncovalent interactions in the rational design of self‐assembling organic materials will allow for the exploration of new substrates and speed up the development of novel applications within this increasingly important class of materials.
Wie kommt das Kilogramm in meine Laborwaage?
Authors: Haller Julian , Banholzer Karlheinz , Baumfalk Reinhard 
Published: January 2019

ZusammenfassungWenn am 20. Mai 2019 neue Definitionen für die Einheiten „Kilogramm“, „Kelvin“, „Ampere“ und „Mol“ auf Basis von Naturkonstanten in Kraft treten, ändert sich für Endanwender in Laboren zunächst einmal nichts. Mittel‐ und langfristig wird damit aber der Grundstein gelegt, dass die metrologischen Anforderungen zukünftiger Entwicklungen in Industrie und Forschung nicht aufgrund starrer oder veralteter Definitionen nicht erfüllt werden können.
Controllable Synthesis of One‐Dimensional MoO3/MoS2 Hybrid Composites with their Enhanced Efficient Electromagnetic Wave Absorption Properties
Authors: Li Chao‐Qin , Shen Xun , Ding Ruo‐Cheng , Wang Guang‐Sheng 
Published: January 2019

AbstractOne‐dimensional MoO3/MoS2 hybrid composites were synthesized by hydrothermal synthesis, and flexible MoO3/MoS2/PVDF nanocomposites could be prepared in a controlled fashion by combining the MoO3/MoS2 composites with polyvinylidene fluoride (PVDF) matrix. The MoO3/MoS2/PVDF hybrids with a low filler content (20 wt %) exhibited distinct microwave absorption properties in the range of 2–18 GHz. The minimum reflection loss can reach −38.5 dB at 8.7 GHz, and the reflection loss was less than −10 dB in the frequency range from 3.03–11.02 GHz with an absorber thickness of 2.0–5.0 mm. The MoO3/MoS2/PVDF nanocomposites exhibited better absorption properties than pure MoO3 and MoS2. The possible microwave absorption mechanism was also discussed in detail.
Graph theoretical analysis, in silico modeling, prediction of toxicity, metabolism and synthesis of novel 2‐(methyl/phenyl)‐3‐(4‐(5‐substituted‐1,3,4‐oxadiazol‐2‐yl) phenyl) quinazolin‐4(3H)‐ones as NMDA receptor inhibitor
Authors: Saravanan Govindaraj , Panneerselvam Theivendren , Kunjiappan Selvaraj , Parasuraman Pavadai , Alagarsamy Veerachamy , Udayakumar Padmaja , Soundararajan Muthukrishnan , Joshi Shrinivas D. , Ramalingam Suresh , Ammunje Damodar Nayak 
Published: January 2019

Abstract

Hit, Lead & Candidate Discovery

A variety of novel 2‐(methyl/phenyl)‐3‐(4‐(5‐substituted‐1,3,4‐oxadiazol‐2‐yl)phenyl) quinazolin‐4(3H)‐ones have been synthesized by treating 3‐(4‐(5‐mercapto‐1,3,4‐oxadiazol‐2‐yl)phenyl)‐2‐(methyl/phenyl)‐quinazolin‐4(3H)‐one with a variety of secondary amines. Graph theoretical analysis was used in identification of drug target that is, NMDAR (N‐methyl‐d‐aspartate receptors). The observed reports of in silico modeling and ligand based toxicity, metabolism prediction studies were encouraging us to synthesize of title compounds and evaluate their antiepileptic effects. The title compounds were tested for its antiepileptic potency by MES and scPTZ model. Rotorod test is used to assess its neurotoxicity. In the preliminary test it was found that in MES test, analogs 6d, 6e, 6f, and 6l were potent; whereas in scPTZ test analogs 6d, 6e, 6f, and 6k displayed potent antiepileptic activity. Additionally these five derivatives were tested in rats orally at a dose of 30 mg/kg and found that compounds 2‐methyl‐3‐(4‐(5‐morpholino‐1,3,4‐oxadiazol‐2‐yl)phenyl)quinazolin‐4(3H)‐one 6e and 2‐methyl‐3‐(4‐(5‐(piperidin‐1‐yl)‐1,3,4‐oxadiazol‐2‐yl)phenyl)quinazolin‐4(3H)‐one 6f exhibited superior activity than reference Phenytoin. In MES test, these derivatives 6e and 6f showed activity at 30 mg/kg i.p. dose after 0.5 hr and 4.0 hr. In scPTZ test these derivatives 6e and 6f showed activity at 100 and 300 mg/kg i.p. dose after 0.5 hr and 4.0 hr, respectively.
Running scared: when predators become prey
Authors: Engelbrecht Tamlyn M. , Kock Alison A. , O'Riain M. Justin 
Published: January 2019

AbstractApex predators play an important role in structuring food webs and are thus key components of healthy, stable ecosystems. While the loss of apex predators has been shown to disrupt ecosystems and trigger trophic cascades, the introduction of novel apex predators to functionally intact systems is less well understood. False Bay, South Africa, is an aggregation site for both white (Carcharodon carcharias) and broadnose sevengill sharks (Notorynchus cepedianus) which together fulfill the role of coastal apex predators. However, since 2009, their position at the top of the food chain has been subverted by the increased presence of killer whales (Orcinus orca) in False Bay. These super predators are known to specialize on certain prey species, and up until 2015 were only documented preying on marine mammals within False Bay. However, in 2015 and 2016 we documented two events in which killer whales preyed upon broadnose sevengill sharks, using a specialized feeding method in which only the liver of each shark was consumed. Although selective feeding on shark liver by killer whales is established, this is the first record of killer whale predations on sevengill sharks in False Bay, and the first documentation of a novel feeding technique, in which killer whales used force applied to the pectoral fins of each shark to rupture the pectoral girdle and thereby access the liver. These predation events resulted in the prolonged absence of sevengill sharks from what is the largest known aggregation site for this species globally, which remained abandoned for up to a month. We briefly review the literature on killer whale behavior, dietary specialization, and population delineation globally and locally, and hypothesize that the novel predations on broadnose sevengill sharks in False Bay are possibly indicative of the arrival of a different sub‐group or ecotype of killer whale in the bay, which habitually feeds on sharks. Due to the unique predatory niche occupied by sevengill sharks in False Bay, the increased presence of these particular killer whales in False Bay could have profound impacts throughout the ecosystem.
Pyrogenic flowering of Aristida beyrichiana following 50 years of fire exclusion
Authors: Shearman Timothy M. , Varner J. Morgan , Kreye Jesse K. 
Published: January 2019

AbstractFire‐stimulated or pyrogenic flowering is one of many traits that enable plants in fire‐prone ecosystems to persist or dominate following frequent fires. Obligate pyrogenic flowering has long been observed in wiregrass (Aristida beyrichiana), a foundation bunchgrass in frequently burned longleaf pine ecosystems in the southeastern United States. Widespread fire exclusion in this ecosystem has contributed to well‐documented declines in plant and animal biodiversity prompting the need for restoration efforts. We studied the effect of fire reintroduction on the flowering of wiregrass in northern Florida, USA. Prescribed fires were ignited in a 50‐yr unburned site and an adjacent frequently burned site in the summer of 2017. Wiregrass was measured eight months after the burns in both stands. As expected, the frequently burned stand had higher density, basal area, and percent flowering of wiregrass tussocks. Logistic regression revealed that wiregrass initiated flowering at significantly larger sizes in the long‐unburned stand. Despite these differences, wiregrass size distributions were similar in both stands, with the long‐unburned stand lacking tussocks in the largest (100+ cm2) size class. We did not find differences in the number of flower culms per unit of mass between the two stands. Even though diminished in nearly every measure, the ability of wiregrass to flower after five decades of fire exclusion, and presumably no sexual reproduction, provides evidence of resilience of the dominant herb of these ecosystems.
Clinical correlates and outcome associated with changes in 6‐minute walking distance in patients with heart failure: findings from the BIOSTAT‐CHF study
Authors: Ferreira João Pedro , Metra Marco , Anker Stefan D. , Dickstein Kenneth , Lang Chim C. , Ng Leong , Samani Nilesh J. , Cleland John G. , van Veldhuisen Dirk J. , Voors Adriaan A. , Zannad Faiez 
Published: January 2019

AbstractBackgroundThe 6‐minute walk test (6MWT) is a simple and inexpensive way of measuring exercise capacity in patients with heart failure (HF) that predicts morbidity and mortality. However, there are few reports from large multicentre cohorts assessing the predictive value of baseline and changing walk distance.Methods and resultsIn BIOSTAT‐CHF, a 6MWT was performed at baseline (n = 1714) and 9 months (n = 1520). Cox proportional hazards models were used to assess the associations between 6MWT distance and the composite of HF hospitalization and/or death. Median follow‐up was 21 months. The median (pct25‐75) of the 6MWT distance at baseline was 300 m (200–388 m). Independent predictors of a shorter 6MWT distance included older age, female sex, higher heart rate, New York Heart Association class III/IV, orthopnoea, ischaemic heart disease, a previous stroke, current malignancy, and higher N‐terminal pro‐B‐type natriuretic peptide (all P < 0.05). Patients in the lowest baseline 6MWT tertile (≤ 240 m) were less likely to receive guideline‐recommended doses of disease‐modifying therapies (P < 0.05). Compared to patients in the highest baseline 6MWT tertile (> 360 m), those in the lowest and middle tertiles had a worse prognosis [adjusted hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.38–2.18]. Patients with a decrease in the distance walked had a worse prognosis (adjusted HR for each 50 m decrease 1.09, 95% CI 1.06–1.12). 6MWT distance was not modified by treatment up‐titration nor the 6MWT improved the BIOSTAT‐CHF prognostic models.ConclusionsThe 6‐minute walk test distance at baseline and a decline in walking distance were both associated with worse prognosis but did not improve the prognostic models. 6MWT distance was not modified by treatment up‐titration and its use for assessing the benefits of pharmacologic treatment up‐titration may be limited.
Capillary electrophoresis‐based approaches for the study of affinity interactions combined with various sensitive and nontraditional detection techniques
Authors: Nevídalová Hana , Michalcová Lenka , Glatz Zdeněk 
Published: January 2019

AbstractNearly all processes in living organisms are controlled and regulated by the synergy of many biomolecule interactions involving proteins, peptides, nucleic acids, nucleotides, saccharides, and small molecular weight ligands. There is growing interest in understanding them, not only for the purposes of interactomics as an essential part of system biology, but also in their further elucidation in disease pathology, diagnostics, and treatment. The necessity of detailed investigation of these interactions leads to the requirement of laboratory methods characterized by high efficiency and sensitivity. As a result, many instrumental approaches differing in their fundamental principles have been developed, including those based on capillary electrophoresis. Although capillary electrophoresis offers numerous advantages for such studies, it still has one serious limitation, its poor concentration sensitivity with the most commonly used detection method–ultraviolet‐visible spectrometry. However, coupling capillary electrophoresis with a more sensitive detector fulfils the above‐mentioned requirement. In this review, capillary electrophoresis combined with fluorescence, mass spectrometry, and several nontraditional detection techniques in affinity interaction studies are summarized and discussed, together with the possibility of conducting these measurements in microchip format.
Petrogeochemical characteristics, zirconSHRIMP U—Pbages andLu—Hfisotopic compositions ofLate Carboniferous A‐typegranitoids,Yiliarea,Inner Mongolia (China)
Authors: Shi Yi , Yao Yuan , Liu Zheng‐Hong , Liu Jin , Wei Ming‐Hui , Gu Yu‐Chao , Yang Fan , Zhang Li , Shi Shao‐Shan 
Published: January 2019

A large Late Palaeozoic A‐type granite belt lies along the Hegenshan‐Nenjiang‐Heihe belt in the Central Asian Orogenic Belt (CAOB). The Kuleqi, Naimanhe, and Gejiadian plutons at Yili are developed within this A‐type granite belt. The genesis and formation environment of these A‐type granites are controversial. The results of zircon SHRIMP UPb dating analyses indicate that the A‐type granites at Yili formed during the Late Carboniferous (302–307 Ma), and their geochemical data indicate that they principally represent a weakly peraluminous (A/CNK 1.01–1.21), high‐K calc‐alkaline series. These granites are enriched in HFSEs, Th, Rb, and K and depleted in LILEs, Ba, Nb, Sr, P, and Ti, which suggests that they record signatures of evolution of continental magma arc. The Nb/Ta ratios of these granites range from 6.84 to17.51, with an average value of 11.65, indicating that they represent crustal‐sourced magma. Their Zr/Hf ratios range from 37.05 to 88.70, with an average value of 59.72 (all values >39), suggesting that these rocks are dominated by mantle‐sourced components. The zircon Hf isotopic compositions of these rocks show εHf(t) values ranging from 6.8 to 12.5 (all positive), with an average value of 9.9, and depleted mantle two‐stage model ages ranging from 518 to 887 Ma, implying that these zircons may contain Early Palaeozoic–Neoproterozoic depleted mantle material. Based on these data, combined with their trace element characteristics, we conclude that the A‐type granitoids at Yili were mainly produced by the mixing of crust and mantle materials; together with their regional tectonic characteristics, these data indicate that these granitoids are related to the collision of the Xing'an and Songliao blocks, which was triggered by the subduction of the Palaeo‐Asian Ocean.
Transient effect of mossy fiber stimulation on spatial firing of CA3 neurons
Authors: Lee Joonyeup , Yun Miru , Cho Eunjae , Lee Jong Won , Lee Doyun , Jung Min Whan 
Published: January 2019

AbstractStrong hippocampal mossy fiber synapses are thought to function as detonators, imposing “teaching” signals onto CA3 neurons during new memory formation. For an empirical test of this long‐standing view, we examined effects of optogenetically stimulating mossy fibers on spatial firing of CA3 neurons in freely‐moving mice. We found that spatially restricted mossy fiber stimulation drives novel place‐specific firing in some CA3 pyramidal neurons. Such neurons comprise only a minority, however, and many more CA3 neurons showed inhibited spatial firing during mossy fiber stimulation. Also, changes in spatial firing induced by mossy fiber stimulation, both activated and inhibited, reverted immediately upon stimulation termination, leaving CA3 place fields unaltered. Our results do not support the traditional view that mossy fibers impose teaching signals onto CA3 network, and show robustness of established CA3 spatial representations.
Scientific integrity issues in Environmental Toxicology and Chemistry: Improving research reproducibility, credibility, and transparency
Authors: Mebane Christopher A , Sumpter John P , Fairbrother Anne , Augspurger Thomas P , Canfield Timothy J , Goodfellow William L , Guiney Patrick D , LeHuray Anne , Maltby Lorraine , Mayfield David B , McLaughlin Michael J , Ortego Lisa S , Schlekat Tamar , Scroggins Richard P , Verslycke Tim A 
Published: January 2019

Abstract

High-profile reports of detrimental scientific practices leading to retractions in the scientific literature contribute to lack of trust in scientific experts. Although the bulk of these have been in the literature of other disciplines, environmental toxicology and chemistry are not free from problems. While we believe that egregious misconduct such as fraud, fabrication of data, or plagiarism is rare, scientific integrity is much broader than the absence of misconduct. We are more concerned with more commonly encountered and nuanced issues such as poor reliability and bias. We review a range of topics including conflicts of interests, competing interests, some particularly challenging situations, reproducibility, bias, and other attributes of ecotoxicological studies that enhance or detract from scientific credibility. Our vision of scientific integrity encourages a self-correcting culture that promotes scientific rigor, relevant reproducible research, transparency in competing interests, methods and results, and education. Integr Environ Assess Manag 2019;00:000–000. © 2019 SETAC
The early biopsychosocial development of boys and the origins of violence in males
Authors: Golding Paul , Fitzgerald Hiram E. 
Published: January 2019

ABSTRACTWe apply a biopsychosocial approach to introduce early‐in‐life experiences that explain a significant part of the male preponderance in the perpetration of violence. Early caregiver abuse and neglect, father absence, and exposure to family and neighborhood violence exacerbate boys’ greater risk for aggressive behavior and increase the probability of carrying out violent acts later in life. We examine the development of the psychological self and explore conditions that encourage physical aggression, focusing on the impact on the infant and toddler's emergent mental representation of self, others, and self–other relationships. Boys’ slower developmental timetable in the first years of life may enhance their vulnerability for disorganization in emergent neurobiological networks mediating organization of socioemotional relationships. Emergent attachment and activation relationship systems may differentially affect risk and resilience in boys and girls, particularly in single‐parent families. Evidence has suggested that the dramatic increase in single‐parent families is especially linked to corresponding increases in behavioral undercontrol, antisocial behavior, and the emergence of violence in boys.
Periosteal Mesenchymal Progenitor Dysfunction and Extraskeletally-Derived Fibrosis Contribute to Atrophic Fracture Nonunion
Authors: Wang Luqiang , Tower Robert J , Chandra Abhishek , Yao Lutian , Tong Wei , Xiong Zekang , Tang Kai , Zhang Yejia , Liu X Sherry , Boerckel Joel D , Guo Xiaodong , Ahn Jaimo , Qin Ling 
Published: January 2019

ABSTRACT

Atrophic nonunion represents an extremely challenging clinical dilemma for both physicians and fracture patients alike, but its underlying mechanisms are still largely unknown. Here, we established a mouse model that recapitulates clinical atrophic nonunion through the administration of focal radiation to the long bone midshaft 2 weeks before a closed, semistabilized, transverse fracture. Strikingly, fractures in previously irradiated bone showed no bony bridging with a 100% nonunion rate. Radiation triggered distinct repair responses, separated by the fracture line: a less robust callus formation at the proximal side (close to the knee) and bony atrophy at the distal side (close to the ankle) characterized by sustained fibrotic cells and type I collagen-rich matrix. These fibrotic cells, similar to human nonunion samples, lacked osteogenic and chondrogenic differentiation and exhibited impaired blood vessel infiltration. Mechanistically, focal radiation reduced the numbers of periosteal mesenchymal progenitors and blood vessels and blunted injury-induced proliferation of mesenchymal progenitors shortly after fracture, with greater damage particularly at the distal side. In culture, radiation drastically suppressed proliferation of periosteal mesenchymal progenitors. Radiation did not affect hypoxia-induced periosteal cell chondrogenesis but greatly reduced osteogenic differentiation. Lineage tracing using multiple reporter mouse models revealed that mesenchymal progenitors within the bone marrow or along the periosteal bone surface did not contribute to nonunion fibrosis. Therefore, we conclude that atrophic nonunion fractures are caused by severe damage to the periosteal mesenchymal progenitors and are accompanied by an extraskeletal, fibro-cellular response. In addition, we present this radiation-induced periosteal damage model as a new, clinically relevant tool to study the biologic basis of therapies for atrophic nonunion. © 2018 American Society for Bone and Mineral Research.