bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction‐Based Ratiometric Chemosensor for Instant Detection of Cyanide in Water with High Selectivity and Sensitivity
Authors: Lin Qi , Liu Xin , Wei Tai‐Bao , Zhang You‐Ming 
Published: October 2013

AbstractA highly selective chemosensor 1 based on an acylhydrazone group as binding site and naphthalene group as the fluorescence signal group were described, which could instantly detect CN− in water with specific selectivity and high sensitivity. The detection of cyanide was performed via the nucleophilic attack of cyanide anion on the carbonyl group, which could be confirmed by 1H NMR, 13C NMR, ESI‐MS and DFT calculations. The addition of CN− to sensor 1 induced a remarkable color change from colorless to yellow and generated a blue fluorescence, these sense procedure could not interfered by other coexistent competitive anions (F−, Cl−, Br−, I−, AcO−, H2PO4−, HSO4−, ClO4−, SCN−, S2−, NO3− and SO42−). The detection limits were 5.0×10−7 M and 2.0×10−9 M of CN− using the visual fluorescent color changes and fluorescence spectra changes respectively, which is far lower than the WHO guideline of 1.9×10−6 M. Test strips based on sensor 1 were fabricated, which could act as a convenient and efficient CN− test kit to detect CN− in pure water for “in‐the‐field” measurement.
Water‐ and Organo‐Dispersible Gold Nanoparticles Supported by Using Ammonium Salts of Hyperbranched Polystyrene: Preparation and Catalysis
Authors: Gao Lei , Nishikata Takashi , Kojima Keisuke , Chikama Katsumi , Nagashima Hideo 
Published: October 2013

AbstractGold nanoparticles (1 nm in size) stabilized by ammonium salts of hyperbranched polystyrene are prepared. Selection of the R groups provides access to both water‐ and organo‐dispersible gold nanoparticles. The resulting gold nanoparticles are subjected to studies on catalysis in solution, which include reduction of 4‐nitrophenol with sodium borohydride, aerobic oxidation of alcohols, and homocoupling of phenylboronic acid. In the reduction of 4‐nitrophenol, the catalytic activity is clearly dependent on the size of the gold nanoparticles. For the aerobic oxidation of alcohols, two types of biphasic oxidation are achieved: one is the catalyst dispersing in the aqueous phase, whereas the other is in the organic phase. The catalysts are reusable more than four times without loss of the catalytic activity. Selective synthesis of biphenyl is achieved by the homocoupling of phenylboronic acid catalyzed by organo‐dispersible gold nanoparticles.
Selective Transportation of Microdroplets Assisted by a Superhydrophobic Surface with pH‐Responsive Adhesion
Authors: Cheng Zhongjun , Du Ming , Lai Hua , Du Ying , Zhang Naiqing , Sun Kening 
Published: October 2013

AbstractWe report a new strategy to realize the selective transportation of microdroplets assisted by a superhydrophobic surface with pH‐responsive adhesion. On the surface, only basic microdroplets can be pinned and acidic or neutral microdroplets can easily roll off. Therefore, by using the surface as a “mechanical hand”, microdroplets can be transported selectively according to one’s requirements by simply controlling the pH of the solution. The special ability of the surface to achieve selective transportation is ascribed to the following two reasons: 1) superhydrophobicity, which can avoid the wetting problem, and 2) pH‐responsive adhesion, which results from the combined effect of chemical variation of the carboxylic acid group and microstructures on the surface. Furthermore, we also demonstrated a process of selective transportation of microdroplets for applications in droplet‐based microreactors through our surface. The results reported herein advance a new method to realize the selective transportation of microdroplets and we believe that this method could potentially be used in a wide range of applications, such as biomolecular detection and transportation in biochips.
Heterogeneous versus Homogeneous Copper(II) Catalysis in Enantioselective Conjugate‐Addition Reactions of Boron in Water
Authors: Kitanosono Taku , Xu Pengyu , Kobayashi Shū 
Published: October 2013

AbstractWe have developed CuII‐catalyzed enantioselective conjugate‐addition reactions of boron to α,β‐unsaturated carbonyl compounds and α,β,γ,δ‐unsaturated carbonyl compounds in water. In contrast to the previously reported CuI catalysis that required organic solvents, chiral CuII catalysis was found to proceed efficiently in water. Three catalyst systems have been exploited: cat. 1: Cu(OH)2 with chiral ligand L1; cat. 2: Cu(OH)2 and acetic acid with ligand L1; and cat. 3: Cu(OAc)2 with ligand L1. Whereas cat. 1 is a heterogeneous system, cat. 2 and cat. 3 are homogeneous systems. We tested 27 α,β‐unsaturated carbonyl compounds and an α,β‐unsaturated nitrile compound, including acyclic and cyclic α,β‐unsaturated ketones, acyclic and cyclic β,β‐disubstituted enones, acyclic and cyclic α,β‐unsaturated esters (including their β,β‐disubstituted forms), and acyclic α,β‐unsaturated amides (including their β,β‐disubstituted forms). We found that cat. 2 and cat. 3 showed high yields and enantioselectivities for almost all substrates. Notably, no catalysts that can tolerate all of these substrates with high yields and high enantioselectivities have been reported for the conjugate addition of boron. Heterogeneous cat. 1 also gave high yields and enantioselectivities with some substrates and also gave the highest TOF (43 200 h−1) for an asymmetric conjugate‐addition reaction of boron. In addition, the catalyst systems were also applicable to the conjugate addition of boron to α,β,γ,δ‐unsaturated carbonyl compounds, although such reactions have previously been very limited in the literature, even in organic solvents. 1,4‐Addition products were obtained in high yields and enantioselectivities in the reactions of acyclic α,β,γ,δ‐unsaturated carbonyl compounds with diboron 2 by using cat. 1, cat. 2, or cat. 3. On the other hand, in the reactions of cyclic α,β,γ,δ‐unsaturated carbonyl compounds with compound 2, whereas 1,4‐addition products were exclusively obtained by using cat. 2 or cat. 3, 1,6‐addition products were exclusively produced by using cat. 1. Similar unique reactivities and selectivities were also shown in the reactions of cyclic trienones. Finally, the reaction mechanisms of these unique conjugate‐addition reactions in water were investigated and we propose stereochemical models that are supported by X‐ray crystallography and MS (ESI) analysis. Although the role of water has not been completely revealed, water is expected to be effective in the activation of a borylcopper(II) intermediate and a protonation event subsequent to the nucleophilic addition step, thereby leading to overwhelmingly high catalytic turnover.
Iridium and Rhodium Complexes within a Macroreticular Acidic Resin: A Heterogeneous Photocatalyst for Visible‐light Driven H2 Production without an Electron Mediator
Authors: Mori Kohsuke , Kubota Yoshihiko , Yamashita Hiromi 
Published: October 2013

AbstractDirect ion exchange of cyclometalated iridium(III) and tris‐2,2′‐bipyridyl rhodium(III) complexes, of which the former acts as a photosensitizer and the latter as a proton reduction catalyst, within a macroreticular acidic resin has been accomplished with the aim of developing a photocatalyst for H2 production under visible‐light irradiation. Ir LIII‐edge and Rh K‐edge X‐ray absorption fine structure (XAFS) measurements suggest that the Ir and Rh complexes are easily accommodated in the macroreticular space without considerable structural changes. The photoluminescence emission of the exchanged Ir complex due to a triplet ligand charge‐transfer (3LC) and metal‐to‐ligand charge‐transfer (3MLCT) transition near 550 nm decreases with increasing the amount of the Rh complex, thus suggesting the occurrence of an electron transfer from Ir to Rh. The Ir‐Rh/resin catalyst behaves as a heterogeneous photocatalyst capable of both visible‐light sensitization and H2 production in an aqueous medium in the absence of an electron mediator. The photocatalytic activitity is strongly dependent on the amount of the components and reaches a maximum at a molar ratio of 2:1 of Ir/Rh complexes. Moreover, leaching and agglomeration of the active metal complexes are not observed, and the recovered photocatalyst can be recycled without loss in catalytic activity.
Sigma‐2 Receptor Agonists as Possible Antitumor Agents in Resistant Tumors: Hints for Collateral Sensitivity
Authors: Niso Mauro , Abate Carmen , Contino Marialessandra , Ferorelli Savina , Azzariti Amalia , Perrone Roberto , Colabufo Nicola Antonio , Berardi Francesco 
Published: October 2013

AbstractWith the aim of contributing to the development of novel antitumor agents, high‐affinity σ2 receptor agonists were developed, with 6,7‐dimethoxy‐2‐[4‐[1‐(4‐fluorophenyl)‐1H‐indol‐3‐yl]butyl]‐1,2,3,4‐tetrahydroisoquinoline (15) and 9‐[4‐(6,7‐dimethoxy‐1,2,3,4‐tetrahydroisoquinolin‐2‐yl)butyl]‐9H‐carbazole (25) showing exceptional selectivity for the σ2 subtype. Most of the compounds displayed notable antiproliferative activity in human MCF7 breast adenocarcinoma cells, with similar activity in the corresponding doxorubicin‐resistant MCF7adr cell line. Surprisingly, a few compounds, including 25, displayed enhanced activity in MCF7adr cells over parent cells, recalling the phenomenon of collateral sensitivity, which is under study for the treatment of drug‐resistant tumors. All of the compounds showed interaction with P‐glycoprotein (P‐gp), and 15 and 25, with the greatest activity, were able to revert P‐gp‐mediated resistance and reestablish the antitumor effect of doxorubicin in MCF7adr cells. We therefore identified a series of σ2 receptor agonists endowed with intriguing antitumor properties; these compounds deserve further investigation for the development of alternate strategies against multidrug‐ resistant cancers.
Target Hopping as a Useful Tool for the Identification of Novel EphA2 Protein–Protein Antagonists
Authors: Tognolini Massimiliano , Incerti Matteo , Pala Daniele , Russo Simonetta , Castelli Riccardo , Hassan‐Mohamed Iftiin , Giorgio Carmine , Lodola Alessio 
Published: October 2013

AbstractLithocholic acid (LCA), a physiological ligand for the nuclear receptor FXR and the G‐protein‐coupled receptor TGR5, has been recently described as an antagonist of the EphA2 receptor, a key member of the ephrin signalling system involved in tumour growth. Given the ability of LCA to recognize FXR, TGR5, and EphA2 receptors, we hypothesized that the structural requirements for a small molecule to bind each of these receptors might be similar. We therefore selected a set of commercially available FXR or TGR5 ligands and tested them for their ability to inhibit EphA2 by targeting the EphA2‐ephrin‐A1 interface. Among the selected compounds, the stilbene carboxylic acid GW4064 was identified as an effective antagonist of EphA2, being able to block EphA2 activation in prostate carcinoma cells, in the micromolar range. This finding proposes the “target hopping” approach as a new effective strategy to discover new protein–protein interaction inhibitors.
Potential utility of cell sheets derived from the anterior cruciate ligament and synovium fabricated in temperature‐responsive culture dishes
Authors: Mitani Genya , Sato Masato , Yamato Masayuki , Kokubo Mami , Takagaki Tomonori , Ebihara Goro , Okano Teruo , Mochida Joji 
Published: October 2013

AbstractDevelopment of tissue‐engineered materials to treat anterior cruciate ligament (ACL) injury has been limited by the lack of phenotypic markers. We investigated the feasibility of inducing ACL regeneration using cell sheet technology based on the expression of tenomodulin (TNMD) as an early phenotypic marker of ligaments. ACL remnants, the synovium surrounding cruciate ligaments (SCL), the synovium surrounding the infrapatellar fat pads (SIF), and subcutaneous fat tissue (SCF) were obtained from patients undergoing ACL reconstruction or total knee arthroplasty. ACL cell sheets and SCL‐derived cell sheets were fabricated successfully A three‐dimensional bioengineered ACL was generated by combining triple‐layered ACL cell sheets with a bioabsorbable mesh composite. Immunohistochemical examination showed that TNMD was expressed in human ACL fibers, triple‐layered ACL cell sheets, ACL remnants, SCL, and SIF, but not in SCF. Real‐time PCR showed that TNMD mRNA was expressed at substantially higher levels in the ACL, SCL, and SIF than in the SCF. These results suggest that TNMD is a specific marker of the human ACL and that ACL sheets have a phenotype similar to that of the ACL. The greater expression of TNMD in the SCL‐ and SIF‐ suggests that the synovium is a potential cell source for ACL regeneration. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2927–2933, 2014.
CATTLE, DIAMONDS AND INSTITUTIONS: MAIN DRIVERS OF BOTSWANA'S ECONOMIC DEVELOPMENT, 1850 TO PRESENT
Authors: Hillbom Ellen 
Published: October 2013

AbstractThis study investigates the role of political as well as economic institutions, factor endowments and geography as main drivers of change in Botswana's long‐term economic development, from 1850 to the present. The claim that we need to embrace multi‐causal explanations giving equal explanatory value to all mentioned potential drivers is made. Further, in order not to compress history, we should give equal attention to the pre‐colonial, colonial and post‐independence eras. The study leads by example and provides a thorough analysis that enriches our understanding of the country's past and present. Copyright © 2013 John Wiley & Sons, Ltd.
Swallowing pressure and pressure profiles in young healthy adults
Authors: Matsubara Keigo , Kumai Yoshihiko , Samejima Yasuhiro , Yumoto Eiji 
Published: October 2013

Objectives/HypothesisTo measure the swallowing pressure (SP) of normal subjects using a 2.64‐mm‐diameter high‐resolution manometry (HRM) catheter with 36 circumferential sensors.Study DesignRepeated measures with subjects serving as controls.MethodsThirty healthy subjects swallowed water at different temperatures and volumes to examine the maximum SP at the velopharynx, meso‐hypopharynx, upper esophageal sphincter (UES), and cervical esophagus, and the duration of lowered pressure at the UES.ResultsThe maximum SP at any location was unaffected by the volume of water, whereas the maximum SP at the UES and cervical esophagus was affected by the temperature. The duration of lowered SP at the UES was significantly prolonged with 10 versus 2 mL of cold water. The pressure curve in males had two peaks (at the velopharynx and UES), whereas that of females had a single peak at the UES.ConclusionsOur data obtained with 2.64‐mm HRM demonstrated that as the bolus volume is increased, the duration of lowered SP at the UES is prolonged. The higher maximum SP at the velopharynx in males versus females suggests that there may be a gender difference in pressure at the velopharynx that has not been described previously. This implies that it is necessary to take gender differences into consideration when evaluating the etiology of swallowing dysfunction by examining the SP and SP curve. Moreover, the thinner catheter is less invasive and may contribute to obtaining more physiological measurements.Level of Evidence4 Laryngoscope, 124:711–717, 2014
Which factors are associated with trainees' confidence in performing obstetric and gynecological ultrasound examinations?
Authors: Tolsgaard M. G. , Rasmussen M. B. , Tappert C. , Sundler M. , Sorensen J. L. , Ottesen B. , Ringsted C. , Tabor A. 
Published: October 2013

ABSTRACTObjectiveTo explore the association between clinical training characteristics and trainees' level of confidence in performing ultrasound scans independently.MethodsA cross‐sectional e‐survey was distributed to members of the national societies of junior obstetricians/gynecologists in Denmark, Sweden and Norway (n = 973). Multiple linear regression models were used to explore the effect that amount of time spent in specialized ultrasound units and clinical experience had on trainees' confidence in performing ultrasonography independently. Exploratory factor analysis was used to identify factors that contributed to trainees' confidence in performing ultrasonography. Trainees' ultrasound confidence was finally compared with their expected levels of performance.ResultsOf the 682 respondents (response rate 70.1%), 621 met the inclusion criteria. Clinical experience and time spent in specialized ultrasound units were predictors of trainees' confidence in performing ultrasonography independently (P < 0.001). Trainees required more than 24 months of clinical experience and 12–24 days of training in specialized ultrasound units in order to feel confident about performing transvaginal and transabdominal ultrasound scans independently. Three factors were related to ultrasound confidence: technical aspects, image perception and integration of scan into patient care. There were significant differences between trainees' level of confidence and their expected levels of performance (P < 0.001).ConclusionsClinical experience and time spent in specialized ultrasound units were predictors of trainees' confidence in performing ultrasonography independently. Discrepancies between trainees' confidence and their expected levels of performance raised concerns about the adequacy of current ultrasound training programs. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
The gradient flow coupling in the Schrödinger functional
Authors: Fritzsch Patrick , Ramos Alberto 
Published: October 2013

AbstractWe study the perturbative behavior of the Yang-Mills gradient flow in the Schrödinger Functional, both in the continuum and on the lattice. The energy density of the flow field is used to define a running coupling at a scale given by the size of the finite volume box. From our perturbative computation we estimate the size of cutoff effects of this coupling to leading order in perturbation theory. On a set ofNf= 2 gauge field ensembles in a physical volume ofL~ 0.4 fm we finally demonstrate the suitability of the coupling for a precise continuum limit due to modest cutoff effects and high statistical precision.
Hemodynamics of the Reconstructed Gastric Tube During Esophagectomy: Assessment of Outcomes with Indocyanine Green Fluorescence
Authors: Kumagai Youichi , Ishiguro Toru , Haga Norihiro , Kuwabara Koki , Kawano Tatsuyuki , Ishida Hideyuki 
Published: October 2013

AbstractBackgroundConstruction of a gastric tube that is well perfused with blood during esophagectomy is the most important factor in avoiding anastomotic leakage. We clarified the hemodynamics of the reconstructed gastric tube with indocyanine green (ICG) fluorescence.MethodsIn 20 patients undergoing gastric tube reconstruction during esophagectomy, we evaluated blood flow in the gastric tube with ICG fluorescence imaging. We divided the patients into two groups according to the quality of blood flow to the gastric tube—“good” (n = 9) and “sparse or absent” (n = 11)—based on visual assessment of the anastomosis of the right and left gastroepiploic vessels. We measured the time from initial enhancement of the root of the right gastroepiploic artery until enhancement of the most cranial branch of the left gastroepiploic artery and tip of the gastric tube.ResultsThe gastric tube was divisible into three zones according to the dominant arteries present in the greater curvature under ICG fluorescence. The left gastroepiploic artery was enhanced in a direction opposite that of physiological blood flow in all cases. The median period from initial enhancement of the root of the right gastroepiploic artery to the most cranial branch of the left gastroepiploic artery until perfusion up to the tip of the gastric tube did not differ significantly between the “good” and the “sparse or absent” groups (P = 0.24, 0.68)ConclusionsIt is essential to preserve the whole vessel arcade of the greater curvature to achieve good blood perfusion in the gastric tube. The ICG fluorescence method has potential usefulness for evaluation of blood flow in the gastric tube.
Central Role of Relatedness in Alaska Native Youth Resilience: Preliminary Themes from One Site of the Circumpolar Indigenous Pathways to Adulthood (CIPA) Study
Authors: Wexler Lisa , Moses Joshua , Hopper Kim , Joule Linda , Garoutte Joseph 
Published: October 2013

AbstractThis qualitative study of youth resilience takes place in an Alaska Native community, which has undergone rapid, imposed social change over the last three generations. Elders, and successive generations have grown up in strikingly different social, economic and political contexts. Youth narratives of relationships in the context of adolescent growth and development offer insights to better understand culturally‐patterned experience, continuity and change. Local youth and adults shaped the design, implementation and analysis phases of this participatory study. Multiple interviews, totaling 20 older (ages 15–18) and younger (11–14) boys and girls provide accounts of everyday lives and life histories. Although losing close relationships was the most common stressor, many of the participants’ resilience strategies centered on their connections to others. Participants cultivated ‘relatedness’, nurturing relationships that took on kinship qualities. Within these relationships, youth participants acted more responsibly and/or developed a sense of competency and self‐worth because of others’ reliance on them.
A Tensile Deformation Model for In-situ Dendrite/Metallic Glass Matrix Composites
Authors: Qiao J. W. , Zhang T. , Yang F. Q. , Liaw P. K. , Pauly S. , Xu B. S. 
Published: October 2013

AbstractIn-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti46Zr20V12Cu5Be17 exhibit ultimate tensile strength of 1510 MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening) and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify the work-hardening behavior of dendrites and softening of the amorphous matrix. Furthermore, the model can be employed to simulate the tensile behavior of in-situ dendrite/MGMCs.
Weakly supervised learning of semantic colour terms
Authors: Hanwell David , Mirmehdi Majid 
Published: October 2013

Recognition of visual attributes in images allows an image's information content to be expressed textually. This has benefits for web search and image archiving, especially since visual attributes transcend language barriers. Classifiers are traditionally trained using manually segmented images, which are expensive and time consuming to produce. The authors propose a method which uses raw, noisy and unsegmented results of web image searches, to learn semantic colour terms. They use probabilistic graphical models on continuous domain, both for weakly supervised learning, and for segmentation of novel images. Experiments show that the authors methods give better results than the current state of the art in colour naming using noisy, weakly labelled training data.∗Note: Colour figures are available in the online version of this paper.