bluuebunny/crossref_metadata_2025_split huggingface dataset:
CuBr‐Catalyzed Synthesis of Indolizines from Pyridine, Acetophenone and Chalcone under Solvent‐Free Conditions
Authors: Zhang Xueguo , Wang Peigen , Han Jianwei , Guo Xin , Chen Baohua 
Published: March 2018

AbstractA facile and efficient copper‐catalyzed reaction for the synthesis of indolizines from pyridine, acetophenone and chalcone was developed. The reactions were realized under mild and solvent‐free conditions.
Photo‐responsive Supra‐Amphiphilic Aggregates with Differential Morphology and Fluorescent Property Mediated by the Substituent Position in the Counterions of Bola‐Amphiphiles
Authors: Guo Yongxian , Lu Jie , Kang Qi , Wang Tao , Yu Li 
Published: March 2018

AbstractBased on the ionic self‐assembly (ISA) strategy, disparate morphologies of 4′‐bis(trimethylammoniumhexyloxy)azobenzene dibromide (BTHA)/naphthalene sulfonic acid sodium (NSA) supra‐amphiphilic aggregates were obtained by regulating the substituent position in the counterions, viz. 1D dendritic structures for BTHA/1‐NSA and 2D rhombus plate‐like structures for BTHA/2‐NSA. Nuclear Magnetic Resonance (NMR) and elemental analysis reveal the same molar ratio (1:2) of the supra‐amphiphiles. Fourier transform infrared (FTIR), UV‐vis absorption spectroscopy, and X‐ray diffraction (XRD) measurements demonstrate their distinct molecular arrangement style. The quantum chemistry calculation results based on Gaussian and MOPAC2016 manifest the inner conformation and energy discrepancy of supramolecular materials. With UV light irradiation, the morphology and fluorescence property of the supra‐amphiphilic aggregates changed remarkably. Meanwhile, the supramolecular structures show photo‐stability with alternate UV and visible light irradiation, accompanied with a position shift of the maximum fluorescence intensity, which has potential for application in optical fields. In this work, the substituent position‐effect was unveiled to mediate the morphologies and consequent fluorescence properties for supramolecular materials, which is anticipated to offer a reference for subsequent rational design of functional materials.
Surface Plasmon Resonance of A Bimetallic Nanostructured Film for Enhanced Optical Sensitivity
Authors: Mabe Taylor , Zeng Zheng , Bagra Bhawna , Ryan James , Wei Jianjun 
Published: March 2018

AbstractA bimetallic (Ag/Au) nanoslit film is reported on surface plasmon (SP) generation and refractive index (RI) sensitivity. These were compared to gold devices in transmission surface plasmon resonance (tSPR). The bimetallic films have a primary resonant peak that shifts with periodicity and correlates well with Finite‐Difference Time‐Domain (FDTD) simulation studies. The SPR of bimetallic nanoslit structures is analyzed via a semi‐analytical model. The model enables decomposition and quantitative analysis of SP generation at the aperture under plane‐wave illumination. The nanostructured, metallic, thin films provide flexibility to integrate with microfluidics, allowing for simplified instrumentation and alignment. Calculation and experimentation demonstrate that bimetallic films afford an increase in RI sensitivity due to the addition of silver along with the biocompatibility of gold. The Ag/Au films were found to be non‐diffusing, long‐term stable (over several months), and provided an increase in sensitivity (about 53/RIU) over gold equivalents.
Current‐Induced Concentration Polarization of Nanoporous Media: Role of Electroosmosis
Authors: Yaroshchuk Andriy , Bondarenko Mykola P. 
Published: March 2018

AbstractCurrent‐induced concentration polarization of nanoporous media is explored theoretically by using approach of local thermodynamic equilibrium within nanopore cross‐sections. The problem is solved in quadratures in terms of irreversible thermodynamics. The phenomenological coefficients are further specified by using capillary space‐charge model for straight slit‐like and cylindrical capillaries. This analysis reveals several novel features of current‐induced concentration polarization related to the (electro)osmotic volume transfer. It confirms the previous finding that volume transfer can suppress the limiting‐current phenomena but obtains more accurate criteria for this. In particular, it shows that the critical nanopore size and/or electrolyte concentration depend on the nanoporous‐medium relative thickness. Under no‐limiting‐current conditions, the salt concentration at the interface between nanoporous medium and unstirred layer is a nonmonotone function of current density. This gives rise to unconventional current–voltage characteristics. Moreover, under certain conditions, the analysis predicts the existence of ranges of “prohibited” current densities where the problem does not have 1D stationary solution, which could give rise to a kind of “phase separation” with coexisting zones of different local current densities corresponding to the same voltage. Besides the advanced understanding of current‐induced concentration polarization of nanoporous media, this analysis provides guidelines for the optimization of sample preconcentration systems in (bio)chemical microanalysis.
Ultrathin 2D Zirconium Metal–Organic Framework Nanosheets: Preparation and Application in Photocatalysis
Authors: He Ting , Ni Bing , Zhang Simin , Gong Yue , Wang Haiqing , Gu Lin , Zhuang Jing , Hu Wenping , Wang Xun 
Published: March 2018

AbstractSynthesizing ultrathin 2D metal–organic framework nanosheets in high yields has received increasing research interest but remains a great challenge. In this work, ultrathin zirconium‐porphyrinic metal–organic framework (MOF) nanosheets with thickness down to ≈1.5 nm are synthesized through a pseudoassembly–disassembly strategy. Owing to the their unique properties originating from their ultrathin thickness and highly exposed active sites, the as‐prepared ultrathin nanosheets exhibit far superior photocatalysis performance compared to the corresponding bulk MOF. This work highlights new opportunities in designing ultrathin MOF nanosheets and paves the way to expand the potential applications of MOFs.
Promoting the Direct H2O2 Generation Catalysis by Using Hollow Pd–Sn Intermetallic Nanoparticles
Authors: Zhang Junbo , Shao Qi , Zhang Ying , Bai Shuxing , Feng Yonggang , Huang Xiaoqing 
Published: March 2018

AbstractAlthough direct hydrogen (H2) oxidation to hydrogen peroxide (H2O2) is considered as a promising strategy for direct H2O2 synthesis, the desirable conversion efficiency remains formidable challenge. Herein, highly active and selective direct H2 oxidation to H2O2 is achieved by using hollow Pd–Sn intermetallic nanoparticles (NPs) as the catalysts. By tuning the catalytic solvents and catalyst supports, the efficiency of direct H2 oxidation to H2O2 can be optimized well with the hollow Pd2Sn NPs/P25 exhibiting H2O2 selectivity up to 80.7% and productivity of 60.8 mol kgcat−1 h−1. In situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption results confirm the different surface atom arrangements between solid and hollow Pd–Sn NPs. X‐ray photoelectron spectra results show that the higher efficiency of Pd2Sn NPs/P25 is due to its higher content of metallic Pd and higher ratio of Snx+, which benefit H2O2 production and selectivity.
Nanohybrids with Magnetic and Persistent Luminescence Properties for Cell Labeling, Tracking, In Vivo Real‐Time Imaging, and Magnetic Vectorization
Authors: Teston Eliott , Maldiney Thomas , Marangon Iris , Volatron Jeanne , Lalatonne Yoann , Motte Laurence , Boisson‐Vidal Catherine , Autret Gwennhael , Clément Olivier , Scherman Daniel , Gazeau Florence , Richard Cyrille 
Published: March 2018

AbstractOnce injected into a living organism, cells diffuse or migrate around the initial injection point and become impossible to be visualized and tracked in vivo. The present work concerns the development of a new technique for therapeutic cell labeling and subsequent in vivo visualization and magnetic retention. It is hypothesized and subsequently demonstrated that nanohybrids made of persistent luminescence nanoparticles and ultrasmall superparamagnetic iron oxide nanoparticles incorporated into a silica matrix can be used as an effective nanoplatform to label therapeutic cells in a nontoxic way in order to dynamically track them in real‐time in vitro and in living mice. As a proof‐of‐concept, it is shown that once injected, these labeled cells can be visualized and attracted in vivo using a magnet. This first step suggests that these nanohybrids represent efficient multifunctional nanoprobes for further imaging guided cell therapies development.
RETRACTED: Thermoresponsive PEG‐Coated Nanotubes as Chiral Selectors of Amino Acids and Peptides
Authors: Kameta Naohiro , Dong Jiuchao , Yui Hiroharu 
Published: March 2018

AbstractA series of nanotubes with a dense layer of short poly(ethylene glycol) (PEG) chains on the inner surface are prepared by means of a coassembly process using glycolipids and PEG derivatives. Dehydration of the PEG chains by heating increases the hydrophobicity of the nanotube channel and fluorescent‐dye‐labeled amino acids are extracted from bulk solution. Rehydration of the PEG chains by cooling results in back‐extraction of the amino acids into the bulk solution. Because of the supramolecular chirality of the nanotubes, amino acid enantiomers can be separated in the back‐extraction procedure, which is detectable with the naked eye as a change in fluorescence as the amino acids are released from the nanotubes. The efficiency and selectivity of the chiral separation are enhanced by tuning the chemical features and inner diameter of the nanotube channels. For example, compared with wide nanotube channels (8 nm), narrow nanotube channels (4 nm) provide more effective electrostatic attraction and hydrogen bond interaction environments for the transporting amino acids. Introduction of branched alkyl chains to the inner surface of the nanotubes enables chiral separation of peptides containing hydrophobic amino acids. The system described here provides a simple, quick, and on‐site chiral separation in biological and medical fields.
The value of ultrasound in the investigation of ingested foreign bodies in children
Authors: Piotto Lino , Gent Roger 
Published: March 2018

AbstractIntroductionAlthough the use of radiography to locate and track radiopaque ingested foreign bodies in children is very sensitive, it may not be very specific. Using ultrasound, we can often not only detect the foreign body but be more precise in its location and movement.MethodsUsing ultrasound, we investigated ingested foreign bodies which did not seem to move on serial radiographs, when there was uncertainty about their location and when they had caused bowel obstruction.ResultsUsing radiography, the exact location of the foreign bodies could often not be determined. Nor could their apparent lack of progression through the alimentary tract be explained. We have found ultrasound to be very successful in overcoming these problems. It has provided accurate localisation of the foreign body and allowed real‐time assessment of any movement with peristalsis.DiscussionA clear advantage of using ultrasound is the avoidance of ionising radiation, which is important in paediatric patients. We have demonstrated that ultrasound has a role when there are complicating factors such as an absence of progressive movement through the alimentary tract and when the foreign body is sharp or radiolucent. In our experience, ultrasound has proven very useful for the planning of surgical removal.
Chondrocranial morphology of Carcharopsis wortheni (Chondrichthyes, Euselachii incertae sedis) based on new material from the Fayetteville Shale (upper Mississippian, middle Chesterian)
Authors: Bronson Allison W. , Mapes Royal H. , Maisey John G. 
Published: March 2018

AbstractThe first known basicranium belonging to Carcharopsis wortheni is described, based on examination of endoskeletal morphology obtained from three‐dimensional reconstructions produced by high‐resolution CT scanning of a previously undescribed specimen. C. wortheni has been described from the late Mississippian (middle Chesterian) Fayetteville Shale based on jaws and teeth, but never before from its cranial anatomy. This specimen has jaw fragments and teeth, associated with the basicranium. The braincase has rounded, low extensions of the occipital region, forming a short lateral occipital shelf, the hypotic lamina is separated from the otic capsule by a continuous metotic fissure, and the postorbital flange is low. Cartilage surrounding the notochordal canal is mineralized, and broken into at least two pieces. Paired, enclosed dorsal aortae are present, which branch into orbital arteries anteriorly, with a midline pit present between the posterior openings for the aortae. Portions of the semicircular canals are visible, with associated ampullae. An improved description of C. wortheni teeth is presented based on CT scanning, including details of tooth vascularization. Carcharopsis is the first Palaeozoic chondrichthyan in which an anaulacorhize‐like vascular network has been recognized. New anatomical data presented here add considerably to our understanding of the phylogenetic relationships of Carcharopsis, and also contribute to the described diversity of Fayetteville Shale vertebrates.
Stepwise extraction, chemical modification, GC–MS separation, and determination of amino acids in human plasma#
Authors: Todua Nino G. , Camara Johanna E. , Murray Jacolin A. , Mikaia Anzor I. 
Published: March 2018

AbstractA method for isolation of enriched fractions of amino acids from human plasma followed by derivatization, gas chromatography separation and mass spectrometry identification is described. The method involves a stepwise extraction of plasma constituents with the use of two solvents: (a) extraction with methanol yields a concentrate of polyols, urea, carbohydrates and most long‐chain saturated and unsaturated aliphatic acids, and (b) further solubilization with water produces mainly a concentrate of amino acids. Chemical modification of amino acids with methyl chloroformate/methanol gives rise to methyl esters of methoxycarbonyl derivatives. The derivatization products are stable and quite suitable for gas chromatography with mass spectrometry analysis. The electron ionization mass spectra of the derivatization products reveal specific fragmentation patterns applicable for structure elucidation. The efficiency of the method is demonstrated by gas chromatography with mass spectrometry identification of 19 amino acids as their methyl esters of methoxycarbonyl derivatives in Standard Reference Material 1950 Metabolites in Frozen Human Plasma.
Short‐term Physiological Response Profiles of Tagged Migrating Adult Sockeye Salmon: A Comparison of Gastric Insertion and External Tagging Methods
Authors: Dick M. , Eliason E. J. , Patterson D. A. , Robinson K. A. , Hinch S. G. , Cooke S. J. 
Published: March 2018

AbstractA variety of electronic tag types are routinely applied to fish to better understand migration biology. However, tagging procedures have the potential to affect the postrelease behaviour and survival of tagged individuals. In this study, wild adult Sockeye Salmon Oncorhynchus nerka from the Harrison River, British Columbia, were radio‐tagged by gastric insertion or external attachment techniques immediately after capture to understand the short‐term physiological response to these two tagging methods. Plasma cortisol, glucose, lactate, sodium, and potassium levels, as well as white muscle lactate and glycogen concentrations, were measured in samples obtained from fish upon capture (0 h) as well as 1 or 4 h after the tagging treatment. The effects of key biological variables, such as sex and proximity to spawn, on the physiological response to the tagging events were also evaluated. Tagging occurred during two distinct time periods representing fish of different maturation states and durations of freshwater residency. Overall, the physiological response to the tagging scenarios was characteristic of the disturbance associated with exhaustive exercise. There were no significant differences detected in the response profiles following gastric or external tagging procedures. This was despite procedural differences such as stomach perforations observed in 68% of the gastric insertions in the late sampling period, and external attachments taking three times longer (43 s) than gastric insertion (15 s). Moreover, the tagged fish showed similar response profiles to control fish that were handled but not tagged. These results suggest that the capture and handling associated with a tagging event induced physiological disturbance, and that the addition of a quick tagging procedure appeared to be nonadditive over the 4‐h assessment period. Sex and proximity to spawn had significant main and interaction effects on some of the physiological response variables, indicating that biological context is important for interpreting physiological assessments in experiments that manipulate exercise and stress responses in migrating adult Pacific salmon.
Comparison of diagnostic accuracy of early screening for pre‐eclampsia by NICE guidelines and a method combining maternal factors and biomarkers: results of SPREE
Authors: Tan M. Y. , Wright D. , Syngelaki A. , Akolekar R. , Cicero S. , Janga D. , Singh M. , Greco E. , Wright A. , Maclagan K. , Poon L. C. , Nicolaides K. H. 
Published: March 2018

ABSTRACTObjectiveTo test the hypothesis that the performance of first‐trimester screening for pre‐eclampsia (PE) by a method that uses Bayes' theorem to combine maternal factors with biomarkers is superior to that defined by current National Institute for Health and Care Excellence (NICE) guidelines.MethodsThis was a prospective multicenter study (screening program for pre‐eclampsia (SPREE)) in seven National Health Service maternity hospitals in England, of women recruited between April and December 2016. Singleton pregnancies at 11–13 weeks' gestation had recording of maternal characteristics and medical history and measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA‐PI), serum placental growth factor (PlGF) and serum pregnancy‐associated plasma protein‐A (PAPP‐A). The performance of screening for PE by the Bayes' theorem‐based method was compared with that of the NICE method. Primary comparison was detection rate (DR) using NICE method vs mini‐combined test (maternal factors, MAP and PAPP‐A) in the prediction of PE at any gestational age (all‐PE) for the same screen‐positive rate determined by the NICE method. Key secondary comparisons were DR of screening recommended by the NICE guidelines vs three Bayes' theorem‐based methods (maternal factors, MAP and PAPP‐A; maternal factors, MAP and PlGF; and maternal factors, MAP, UtA‐PI and PlGF) in the prediction of preterm PE, defined as that requiring delivery < 37 weeks.ResultsAll‐PE developed in 473 (2.8%) of the 16 747 pregnancies and preterm PE developed in 142 (0.8%). The screen‐positive rate by the NICE method was 10.3% and the DR for all‐PE was 30.4% and for preterm PE it was 40.8%. Compliance with the NICE recommendation that women at high risk for PE should be treated with aspirin from the first trimester to the end of pregnancy was only 23%. The DR of the mini‐combined test for all‐PE was 42.5%, which was superior to that of the NICE method by 12.1% (95% CI, 7.9–16.2%). In screening for preterm PE by a combination of maternal factors, MAP and PlGF, the DR was 69.0%, which was superior to that of the NICE method by 28.2% (95% CI, 19.4–37.0%) and with the addition of UtA‐PI the DR was 82.4%, which was higher than that of the NICE method by 41.6% (95% CI, 33.2–49.9%).ConclusionsThe performance of screening for PE as currently recommended by NICE guidelines is poor and compliance with these guidelines is low. The performance of screening is substantially improved by a method combining maternal factors with biomarkers. © 2018 Crown copyright. Ultrasound in Obstetrics & Gynecology © 2018 ISUOG.
Traditionally vs sonographically coached pushing in second stage of labor: a pilot randomized controlled trial
Authors: Bellussi F. , Alcamisi L. , Guizzardi G. , Parma D. , Pilu G. 
Published: March 2018

ABSTRACTObjectiveTo investigate the usefulness of visual biofeedback using transperineal ultrasound to improve coached pushing during the active second stage of labor in nulliparous women.MethodsThis was a randomized controlled trial of low‐risk nulliparous women in the active second stage of labor. Patients were allocated to either coached pushing aided by visual demonstration on transperineal ultrasound of the progress of the fetal head (sonographic coaching) or traditional coaching. Patients in both groups were coached by an obstetrician for the first 20 min of the active second stage of labor and, subsequently, the labor was supervised by a midwife. Primary outcomes were duration of the active second stage and increase in the angle of progression at the end of the coaching process. Secondary outcomes included the incidence of operative delivery and complications of labor.ResultsForty women were recruited into the study. Those who received sonographic coaching had a shorter active phase of the second stage (30 min (interquartile range (IQR), 24–42 min) vs 45 min (IQR, 39–55 min); P = 0.01) and a greater increase in the angle of progression (13.5° (IQR, 9–20°) vs 5° (IQR, 3–9.5°); P = 0.01) in the first 20 min of the active second stage of labor than did those who had traditional coaching. No differences were found in the secondary outcomes between the two groups.ConclusionOur preliminary data suggest that transperineal ultrasound may be a useful adjunct to coached pushing during the active second stage of labor. Further studies are required to confirm these findings and better define the benefits of this approach. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Phosphine poisoning in free‐range local chickens: a case report
Authors: Muraina Issa A. , Oladipo Olusola O. , Akanbi Olatunde B. , Shallmizhili Johnson J. , Gyang Moses D. , Ijale Gabriel O. , Govwang Felix P. , Atiku Aliyu A. 
Published: March 2018

AbstractPhosphine poisoning is rarely reported in poultry, and its diagnosis is a great challenge for veterinary toxicologists and pathologists. A case of phosphine toxicosis in local, free range chickens is reported. Fourteen dead chickens (age ≥6 months old) were presented to the veterinary clinic for necropsy. The history revealed that the chickens were normally fed with guinea corn grains, but were suspected to have been fed boiled rice laced with poison. The clinical signs observed were ruffled feathers, somnolence, anorexia and high mortality. The disease ran a 2‐day course with mortality pattern of four chickens the first day, six overnight and 14 the following day. Necropsy findings showed generalized vascular congestion and haemorrhage in the lungs and visceral organs, with the crop and gizzard filled with guinea corn and rice grains and greenish‐yellow faecal material in the intestinal lumen. The presence of widespread congestion and petechial haemorrhages on visceral organs with the microscopic pulmonary congestion, and diffuse intraparabronchial presence of air sac macrophages, strongly suggested an acute toxic cause of death. Chemical tests on the crop contents of the dead chickens were positive for phosphine gas. This report will contribute to a better understanding of the clinical signs and lesions presented in cases of acute phosphide rodenticide exposure in domestic chickens, with a brief review of the forensic literature.