bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Hyperfine Transition for the Definition of the Second
Authors: Arias Elisa Felicitas , Petit Gérard 
Published: April 2019

AbstractThe unit of time of the International System of Units (SI), the “atomic second” was defined through a constant of physics in 1967. It is derived from the frequency of the hyperfine transition of the atom of cesium 133. From the astronomical definition of the second until today, the accuracy of the realization of the second has improved by eight orders of magnitude, with a rate that has increased since the development of the cesium frequency standards, to reach parts in 1016 for the best clocks today. In 2018, when the new SI was adopted, the time metrology community proved that a new generation of frequency standards operating in optical wavelengths has uncertainties at the level of 10–18, and challenge the implementation of high accurate frequency and time comparison techniques to decide on a revision of the definition of the second. Herein, the progress in the definition and realization of the second from astronomy until today is reviewed, an inventory of the present resources is assembled and a brief view for the future given.
Synthesis, Structures, and Near‐IR Absorption of Heterole‐Fused Earring Porphyrins
Authors: Wu Licheng , Li Feilong , Rao Yutao , Wen Bin , Xu Ling , Zhou Mingbo , Tanaka Takayuki , Osuka Atsuhiro , Song Jianxin 
Published: April 2019

AbstractA reaction sequence of regioselective peripheral bromination, Suzuki–Miyaura coupling with 2‐borylated thiophene or pyrrole, and oxidative ring‐closure with FeCl3 allowed the synthesis of heterole‐fused earring porphyrins 4Pd and 9Pd from the parent earring porphyrin 1. Differently pyrrole‐fused porphyrins 5H and 6H and their PdII complexes 5Pd and 6Pd were also synthesized. The structures of 4Pd, 5H, 6Pd, and 8Pd have been revealed by X‐ray analysis to be slightly twisted owing to constraints imposed by heterole‐fused structures. 5Pd exhibits an intensified band at 1505 nm, while 4Pd and 9Pd display small but remarkably red‐shifted absorption bands reaching around 2200 nm.
Continuous local anaesthetic wound catheter infiltration after clamshell thoracotomy
Authors: Lan‐Pak‐Kee V. , Egan T. , Tarrell T. , Konig T. 
Published: April 2019

SummaryWe report on the novel and successful use of local anaesthetic wound infusions via elastomeric pumps in a 17‐year‐old male who underwent emergent clamshell thoracotomy after sustaining a stab wound to the flank. This formed one component of a multi‐modal analgesic regimen aimed at reducing opioid requirements and their associated side‐effects. The patient was mobilising and was discharged from the intensive care unit 24 h postoperatively. There was an unplanned break in the local anaesthetic infusion during which the patient's reported pain scores increased significantly. The catheters were removed on the fifth postoperative day and he was discharged from hospital on day 7.
Ultra‐small sugar‐substituted N‐heterocyclic carbene‐protected palladium nanoparticles and catalytic activity
Authors: Zhou Zhonggao , Li Mei , Liu Guangsheng , Xu Guohai , Xue Jun 
Published: April 2019

Ultra‐small Pd nanoparticles (UNPs) represent a distinctive type of nanomaterial making them very attractive for a range of applications. Herein, chiral sugar‐substituted N‐heterocyclic carbenes (NHCs) with various lengths of alkyl chain (sugar‐NHCs‐nCnH2n+1) were first used to prepare water‐soluble Pd@NHCs‐sugar UNPs via an efficient ligand‐exchange strategy, which can be handled under air and are stable over 10 months. The Pd@NHCs‐sugar UNPs were highly monodisperse, with tunable core diameters from 1.7 to 2.1 nm, and an effect of the particle size on the N‐substituted aliphatic chains was observed. To investigate the accessibility of the surface, the Pd@NHCs‐sugar UNPs were studied as catalysts for C–C coupling reaction in eco‐friendly ethanol aqueous solution without any precipitation of metallic Pd. The presence of the longest aliphatic group in the Pd@NHCs‐sugar UNPs imparts to them the highest catalyst activity (turnover number and turnover frequency up to 196 000 and 3 920 000 h−1).
Investigation of covalently grafted polyacrylate chains onto graphene oxide for epoxy composites with reinforced mechanical performance
Authors: Xie Yankun , Liu Weiqu , Liu Chunhua , He Sha , Zhang Fengyuan , Shi Hongyi , Yang Maiping , Wang Zhengfang 
Published: April 2019

ABSTRACTTo enhance the dispersion and interfacial interaction of graphene–epoxy matrix, polyacrylate chains grafted graphene oxide (PA‐GO) was manufactured with A‐174 functionalized GO (A‐GO), methyl acrylate, and glycidyl methacrylate via free‐radical random copolymerization technique. Fourier transform infrared, thermogravimetric analysis, X‐ray photoelectron spectrum, Raman spectroscopy, X‐ray diffraction, transmission electron microscopy, and nuclear magnetic resonance were performed to investigate the structure of A‐GO and PA‐GO. Then, the PA‐GO was incorporated into epoxy resin via in situ solution intercalation dispersion method in order to form an interpenetrating network structure with epoxy resin. Field emission scanning electron microscope results indicate that the PA‐GO exhibits excellent dispersion and interfacial compatibility in the epoxy matrix. In compared with pure epoxy, the tensile strength and impact strength of the epoxy composite with 1 wt % PA‐GO were shifted from 62.78 ± 2.54 to 70.68 ± 2.02 MPa (about 12.6%) and 3.55 ± 0.41 to 4.98 ± 0.33 kJ m−2 (about 40.3%), respectively. Moreover, increased storage modulus is also observed in the dynamic mechanical analysis measurements compared with that of neat epoxy resin. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47842.
Turn‐Number‐Dependent Motion Behavior of Catalytic Helical Carbon Micro/Nanomotors
Authors: Xu Dandan , Zhan Chen , Sun Yanming , Dong Zhijun , Wang Guo Ping , Ma Xing 
Published: April 2019

AbstractHelical micro/nanomotors (MNMs) can be propelled by external fields to swim through highly viscous fluids like complex biological environments, which promises miniaturized robotic tools to perform assigned tasks at small scales. However, the catalytic propulsion method, most widely adopted to drive MNMs, is seldom studied to actuate helical MNMs. Herein, we report catalytic helical carbon MNMs (CHCM) by sputtering Pt onto helical carbon nano‐coils (HCNC) that are in bulk prepared by a thermal chemical vapor deposition method. The Pt‐triggered H2O2 decomposition can drive the MNMs by an electrokinetic mechanism. The MNMs demonstrate versatile motion behaviors including both directional propulsion and rotation depending on the turn number of the carbon helix. Besides, due to the ease of surface functionalization on carbon and other properties such as biocompatibility and photothermal effect, the helical carbon MNMs promise multifunctional applications for biomedical or environmental applications.
Maternal vitamin D deficiency increases the thromboxane/prostacyclin ratio through alterations in the one‐carbon cycle in Wistar rats
Authors: Nandi Anindita A. , Wadhwani Nisha S. , Joshi Sadhana R. 
Published: April 2019

AbstractThis study aims to test the hypothesis that vitamin D deficiency can influence long‐chain polyunsaturated fatty acid metabolism through alterations in the one‐carbon cycle. Wistar rats (n = 8 per group) were given either a control (1,000 IU D3/kg diet) or a vitamin D deficient (VDD) (0 IU D3/kg diet) diet from pre‐pregnancy to delivery. On day 20 of gestation, pregnant female rats were delivered by C‐section to collect placenta and blood. VDD group demonstrated high serum parathyroid hormone, low serum phosphate, low plasma folate, higher plasma homocysteine, and higher plasma malondialdehyde levels (P < 0.05 for all) as compared to control. Lower protein levels of placental cystathionine‐β‐synthase enzyme (P < 0.05) were observed in the VDD group as compared to control. VDD group demonstrated higher placental mRNA levels of the enzymes phospholipase A2 and cyclooxygenase‐2 (P < 0.05 for both) as compared to control. Protein levels of the enzymes phospholipase A2 and cyclooxygenase‐2 were lower (P < 0.05 for both) in the VDD group as compared to the control group. The ratio of thromboxane B2 and 6‐keto prostaglandin F1α in serum was higher (P < 0.05) in the VDD group as compared to control; although the serum levels of 6‐keto prostaglandin F1α and thromboxane B2 were similar in both the groups. Our findings suggest that increased oxidative stress due to maternal vitamin D deficiency results in the imbalance between the vasoconstrictor (thromboxane B2) and vasodilator (6‐keto prostaglandin F1α) eicosanoids, which may lead to endothelial dysfunction and poor pregnancy outcome. © 2019 BioFactors, 45 (4):548–555, 2019
Analysis of phenolic acids and flavonoids in leaves of Lycium barbarum from different habitats by ultra‐high‐performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry
Authors: Zhao Xue‐qin , Guo Sheng , Yan Hui , Lu You‐yuan , Zhang Fang , Qian Da‐wei , Wang Han‐qing , Duan Jin‐ao 
Published: April 2019

AbstractThe leaves of Lycium barbarum (LLB) have been utilized as crude drugs and functional tea for human health in China and Southeast Asia for thousands of years. To control its quality, a rapid and sensitive ultra‐high‐performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry method was established and validated for the first time for simultaneous determination of 10 phenolic acids and flavonoids (including neochlorogenic acid, protocatechuic aldehyde, p‐hydroxybenzoic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, p‐coumaric acid, ferulic acid, rutin and kaempferol‐3‐O‐rutinoside) in LLB. The separation was performed on an Acquity UPLC C18 chromatographic column (100 × 2.1 mm internal diameter, 1.7 μm particle size) with 0.1% formic acid in water (A)–acetonitrile (B) as the mobile phase under gradient elution. Multiple reaction monitoring mode was adopted to simultaneously monitor the target components. The developed method was fully validated in terms of linearity (r2 ≥ 0.9860), precision (RSD ≤ 6.58%), repeatability (RSD ≤ 6.60%), stability (RSD ≤ 6.17%), recovery (95.56–108.06%, RSD ≤ 4.64%) and limit of detection (0.021–0.664 ng/mL) and limit of quantitation (0.069–2.210 ng/mL), and then successfully applied to evaluate the quality of 64 batches of LLB collected from 41 producing areas in four different provinces of China. The results showed that the LLB, especially collected from Inner Mongolia regions, were rich in the phenolic acids and flavonoids. Rutin, kaempferol‐3‐O‐rutinoside and chlorogenic acid are the predominant compounds contained in LLB. The above findings will provide helpful information for the effective utilization of LLB.
Highly sensitive UHPLC–DAD method for simultaneous determination of two synergistically acting antiepileptic drugs; levetiracetam and lacosamide: Application to pharmaceutical tablets and human urine
Authors: Mohamed Fardous A. , Ali Marwa F.B. , Rageh Azza H. , Mostafa Aya M. 
Published: April 2019

AbstractA simple and highly sensitive ultra‐high‐performance liquid chromatographic–diode array (UHPLC‐DAD) detection method was developed and validated for the simultaneous estimation of levetiracetam (LEV) and lacosamide (LAC). It was clinically proven that the combination of LEV and LAC exhibits a synergistic effect against refractory seizures in mice, which was the motivation for the analysis of this binary mixture both in bulk and in human urine samples. The binary mixture was resolved on a Hypersil BDS C18 analytical column, utilizing a mobile phase of 0.050 mol L−1 phosphate buffer (pH 5.60), methanol and acetonitrile in the ratio (80:10:10 v/v/v) using catechol as an internal standard. The mobile phase was pumped at a flow rate of 1.2 mL min−1 with diode array detection at 205 nm for both drugs and 270 nm for IS. Calibration curves were linear with correlation coefficient >0.9990 over the studied concentration range of 0.1–70.0 μg mL−1 for both drugs. The developed method was reproducible with low relative standard deviation values for intra‐ and inter‐day precision (<2.0%). Both drugs were determined in bulk, pharmaceutical formulations and human urine samples without any interference from complex matrices.
Women's experiences of group intervention with schema therapy techniques: A qualitative process analysis
Authors: Sarı Sevda , Gençöz Faruk 
Published: April 2019

AbstractAimsOur study focused on a self‐soothing system and analysed how women feeling shame experienced compassion‐focused group intervention with schema therapy techniques. Group schema therapy, which is process‐oriented and person‐oriented (Farrell & Shaw, 2012), inspired us to combine schema therapy techniques with Compassionate Mind Training in the interventions for this study.MethodsData were collected through the programme that comprised 2‐hr sessions over a period of 10 weeks and self‐compassion and self‐criticism diaries of women.AnalysisData analysis was conducted according to the phases of thematic analysis (Braun & Clarke, 2006). Twenty hours of group sessions (2 hr per session) and follow‐up sessions were audio recorded and transcribed. Thematic analysis was conducted to analyse 26 hr of group intervention and follow‐up sessions and also women's self‐compassion and self‐criticism diaries, to understand how shame‐prone women experienced change process.FindingsThematic analysis of the group sessions yielded two superordinate themes: overcoming the threat of compassion and the process of change. Overcoming the threat of compassion was divided into three subthemes; fear of self‐compassion, the difficulty of accessing the vulnerable child side, and feeling anger at others and self. The process of change involved two subthemes; the feeling of acceptance, and recognising self‐compassion and its sources in the self. When the women could access their self‐soothing system, they could better understand the needs of their vulnerable child side and address these needs by transferring the emotions of compassion to their vulnerable child side.
Bryophyllum pinnatum in the treatment of restless legs syndrome: A case series documented with polysomnography
Authors: von Manitius Sigrid , Flügel Dominique , Gievers Steinlein Bettina , Schnelle Martin , von Mandach Ursula , Simões‐Wüst Ana Paula 
Published: April 2019

Key Clinical MessageRestless legs syndrome may seriously affect patients' sleep and quality of life, but established pharmacological therapy can often have severe side effects. Therefore, new therapeutic approaches such as well‐tolerated preparations from the medicinal plant Bryophyllum pinnatum should be considered as alternatives. Their sedative and spasmolytic properties might contribute to improve patients' condition.
Transcatheter embolization for idiopathic peripheral pulmonary arterial aneurysm: A case report
Authors: Tamura Tomoki , Yabuki Takayuki , Kawajiri Tomoka , Nishi Tatsuya , Kudo Kenichiro , Kuyama Shoichi 
Published: April 2019

Key Clinical MessageThe natural history of idiopathic peripheral pulmonary arterial aneurysms (PAAs) is unclear; however, they can cause sudden death by rupture. Our case illustrates the utility and low invasiveness of transcatheter embolization using an AMPLATZER™ Vascular Plug 4 and hydrogel‐coated metallic coils in patients with idiopathic peripheral PAAs.
Enhanced Photocatalytic Hydrogen Evolution of the Hydrogenated Deficient g‐C3N4 via Surface Hydrotreating
Authors: Liu Junying , Wei Zhidong , Fang Wenjian , Jiang Zhi , Shangguan Wenfeng 
Published: April 2019

AbstractUnreacted amino groups (−NHx) existed in the bulk g‐C3N4 always act as charge trap sites which resulting in low photocatalytic activity. In this paper, the hydrogenated deficient g‐C3N4 (HDCN) was prepared by calcining bulk g‐C3N4 with NaBH4 under an inert atmosphere. It was found that −NHx groups were absolutely reduced into both nitrogen vacancies and the cyano groups (−C≡N groups) in the frameworks of g‐C3N4 after this surface hydrotreating. Therefore, the photo‐induced carrier recombination is suppressed dues to the disappeared −NHx groups. As a result, the HDCN sample displayed a higher photocatalytic H2 evolution activity than the bulk g‐C3N4.
Precipitation of Cobalt Salts for Recovery in Leachates
Authors: Djoudi Neila , Le Page Mostefa Marie , Muhr Hervé 
Published: April 2019

AbstractMetals such as cobalt are particularly strategic since they are present in many high‐added‐value products. Besides, at the rate of current consumption, specifically of cobalt, the manufacturers are facing risks of shortage for their supply. So, research on these metals' recovery from industrial or urban waste is highly important for the future. Current work focuses on cobalt recovery from Li‐ion batteries by precipitation. Literature was evaluated on the various anions allowing to precipitate Co(II), in particular hydroxide, carbonate, and sulfide ions, and the focus was set on the hydroxide way. Simulations were performed using speciation software to highlight the various parameters influencing the precipitation process and the formed species. From simulation results, experiments were carried out in a synthetic solution containing only Co(II).
Mixing Time in Intermediate‐Sized Orbitally Shaken Reactors with Small Orbital Diameters
Authors: Li Yi , Ducci Andrea , Micheletti Martina 
Published: April 2019

AbstractOrbitally shaken reactors (OSR) are widely used in bioprocess development; however, a scaling law between large reactors, usually shaken in incubators at an orbital diameter of do = 1.5–5 cm, and microwell plates, shaken in benchtop thermomixers at do = 3 mm, is still missing. Here, the mixing time was measured in two reactors with the same volume but either cylindrical or square geometry for do = 3 mm. For such a small do, the acceleration mode to reach the final speed in the cylinder was found to greatly affect the free surface oscillations and thus the mixing time. The stepwise mode resulted in mixing times approximately six times smaller than in the direct mode. The natural frequency of the reactor, which is independent of do, was found to be an effective scaling parameter for systems with small do.
Benchmarking of Halogen Bond Strength in Solution with Nickel Fluorides: Bromine versus Iodine and Perfluoroaryl versus Perfluoroalkyl Donors
Authors: Pike Sarah J. , Hunter Christopher A. , Brammer Lee , Perutz Robin N. 
Published: April 2019

AbstractThe energetics of halogen bond formation in solution have been investigated for a series of nickel fluoride halogen bond acceptors; trans‐[NiF(2‐C5NF4)(PEt3)2] (A1), trans‐[NiF{2‐C5NF3(4‐H)}(PEt3)2] (A2), trans‐[NiF{2‐C5NF3(4‐NMe2)}(PEt3)2] (A3) and trans‐[NiF{2‐C5NF2H(4‐CF3)}(PCy3)2] (A4) with neutral organic halogen bond donors, iodopentafluorobenzene (D1), 1‐iodononafluorobutane (D2) and bromopentafluorobenzene (D3), in order to establish the significance of changes from perfluoroaryl to perfluoroalkyl donors and from iodine to bromine donors. 19F NMR titration experiments have been employed to obtain the association constants, enthalpy, and entropy for the halogen bond formed between these donor‐acceptor partners in protiotoluene. For A2–A4, association constants of the halogen bonds formed with iodoperfluoroalkane (D2) are consistently larger than those obtained for analogous complexes with the iodoperfluoroarene (D1). For complexes formed with A2–A4, the strength of the halogen bond is significantly lowered upon modification of the halogen donor atom from I (in D1) to Br (in D3) (for D1: 5≤K285≤12 m−1, for D3: 1.0≤K193≤1.6 m−1). The presence of the electron donating NMe2 substituent on the pyridyl ring of acceptor A3 led to an increase in −ΔH, and the association constants of the halogen bond complexes formed with D1–D3, compared to those formed by A1, A2 and A4 with the same donors.
Organocatalytic Transformation of Aldehydes to Thioesters with Visible Light
Authors: Zhang Yueteng , Ji Peng , Hu Wenbo , Wei Yongyi , Huang He , Wang Wei 
Published: April 2019

AbstractA metal‐ and oxidant‐free catalytic method for accessing structurally diverse thioesters from readily accessible, widespread aldehydes, is described. A strategy of a simple organic 9,10‐phenanthrenequinone‐promoted hydrogen atom transfer (HAT) with visible light was successfully implemented to selectively generate acyl radicals without inducing crossover reactivity of thioester products. The preparative power of the method was demonstrated by broad substrate scope and wide functional group tolerance, and enabled the late‐stage modification of complex structures, which are difficult to achieve with the existing protocols.
Nickel Foam Supported Co3O4@Ni3Se4 Core‐Shell Nanorod Arrays with Long‐Term and Efficient Catalytic Performance for Water Splitting
Authors: Que Ronghui , Ji Gang , Liu Daoshuang , Li Maolin , Liu Sheng 
Published: April 2019

AbstractExploitation of the efficient and highly stable catalytic performance provided by bi‐functional catalysts is important for practical water splitting. Herein, Co3O4@Ni3Se4 core‐shell nanorod arrays on nickel foam (Co3O4@Ni3Se4/NF) are successfully synthesized as long‐term and efficient bi‐functional catalysts for water splitting in 1.0 M KOH. The satisfactory Co3O4@Ni3Se4/NF catalyst exhibits excellent activity with low overpotentials of 260 mV and 180 mV at 10 mA cm−2 for OER and HER, respectively. In addition, its overpotential is only higher than the initial overpotential within 10 mV when the Co3O4@Ni3Se4/NF has been used after 30 hours at OER and HER. Significantly, the cell based on bi‐functional Co3O4@Ni3Se4/NF||Co3O4@Ni3Se4/NF couple shows a low potential of 1.735 V at 10 mA cm−2 in alkaline electrolyte and remains a current density of 10 mA cm−2 for 30 hours without serious attenuation, indicating that the as‐prepared catalyst has huge potential in practical water splitting.
Marine reserves stabilize fish populations and fisheries yields in disturbed coral reef systems
Authors: Hopf Jess K. , Jones Geoffrey P. , Williamson David H. , Connolly Sean R. 
Published: April 2019

AbstractMarine reserve networks are increasingly implemented to conserve biodiversity and enhance the persistence and resilience of exploited species and ecosystems. However, the efficacy of marine reserve networks in frequently disturbed systems, such as coral reefs, has rarely been evaluated. Here we analyze a well‐mixed larval pool model and a spatially explicit model based on a well‐documented coral trout (Plectropomus spp.) metapopulation in the Great Barrier Reef Marine Park, Australia, to determine the effects of marine reserve coverage and placement (in relation to larval connectivity and disturbance heterogeneity) on the temporal stability of fisheries yields and population biomass in environmentally disturbed systems. We show that marine reserves can contribute to stabilizing fishery yield while increasing metapopulation persistence, irrespective of whether reserves enhance or diminish average fishery yields. However, reserve placement and the level of larval connectivity among subpopulations were important factors affecting the stability and sustainability of fisheries and fish metapopulations. Protecting a mix of disturbed and non‐disturbed reefs, rather than focusing on the least‐disturbed habitats, was the most consistently beneficial approach across a range of dispersal and reserve coverage scenarios. Placing reserves only in non‐disturbed areas was the most beneficial for biomass enhancement, but had variable results for fisheries and could potentially destabilize yields in systems with well‐mixed larval or those that are moderately fished. We also found that focusing protection on highly disturbed areas could actually increase variability in yields and biomass, especially when degraded reef reserves were distant and poorly connected to the meta‐population. Our findings have implications for the design and implementation of reserve networks in the presence of stochastic, patchy environmental disturbances.