bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro differentiation potential of human haematopoietic CD34+ cells towards pancreatic β‐cells
Authors: Sunitha Manne Mudhu , Srikanth Lokanathan , Santhosh Kumar Pasupuleti , Chandrasekhar Chodimella , Sarma Potukuchi Venkata Gurunadha Krishna 
Published: August 2016

AbstractHaematopoietic stem cells (HSCs) possess multipotent ability to differentiate into various types of cells on providing appropriate niche. In the present study, the differentiating potential of human HSCs into β‐cells of islets of langerhans was explored. Human HSCs were apheretically isolated from a donor and cultured. Phenotypic characterization of CD34 glycoprotein in the growing monolayer HSCs was confirmed by immunocytochemistry and flow cytometry techniques. HSCs were induced by selection with beta cell differentiating medium (BDM), which consists of epidermal growth factor (EGF), fibroblast growth factor (FGF), transferrin, Triiodo‐l‐Tyronine, nicotinamide and activin A. Distinct morphological changes of differentiated cells were observed on staining with dithizone (DTZ) and expression of PDX1, insulin and synaptophysin was confirmed by immunocytochemistry. Quantitative real‐time polymerase chain reaction (qRT‐PCR) analysis revealed distinct expression of specific β‐cell markers, pancreatic and duodenal homeobox‐1 (PDX1), glucose transporter‐2 (GLUT‐2), synaptophysin (SYP) and insulin (INS) in these differentiated cells compared to HSCs. Further, these cells exhibited elevated expression of INS gene at 10 mM glucose upon inducing with different glucose concentrations. The prominent feature of the obtained β‐cells was the presence of glucose sensors, which was determined by glucokinase activity and high glucokinase activity compared with CD34+ stem cells. These findings illustrate the differentiation of CD34+ HSCs into β‐cells of islets of langerhans.
Impact of analysis interval size on the quality of optical frequency domain imaging assessments of stent implantation for lesions of the superficial femoral artery
Authors: Miki Kojiro , Fujii Kenichi , Kawasaki Daizo , Shibuya Masahiko , Fukunaga Masashi , Imanaka Takahiro , Tamaru Hiroto , Sumiyoshi Akinori , Nishimura Machiko , Horimatsu Tetsuo , Saita Ten , Kobayashi Yuhei , Honda Yasuhiro , Fitzgerald Peter J. , Masuyama Tohru , Ishihara Masaharu 
Published: August 2016

ObjectivesThis study aimed to investigate the influence of analysis interval size on optical frequency domain imaging (OFDI) assessment of stent therapy for lesions of the superficial femoral artery (SFA). Background. No consensus or validating data are available with respect to the methodology of intravascular imaging analysis for the peripheral arteries. Methods. OFDI was performed for 30 SFA lesions, during endovascular therapy and at the 6‐month follow‐up. Initially, lumen and stent borders were traced at 1‐mm axial intervals. Volumes were calculated using a PC‐based software, and the volume index (VI) was defined as the volume divided by the stent length. Two additional OFDI analyses were performed using 2‐mm and 5‐mm intervals, thereby reducing the number of cross‐sectional image frames analyzed. Results. The mean stent length was 89.7 ± 35.2 mm. The mean difference in baseline minimum lumen area (MLA) was 0.4 mm2 between MLA values from the 1‐mm and 2‐mm interval analyses, and 2.2 mm2 between MLA values from the 1‐mm and 5‐mm interval analyses. In volumetric analysis, there were excellent correlations and good agreements for stent, lumen, and neointimal VI measurements obtained on the basis of different analysis intervals. Conclusions. Using large intervals in OFDI analyses of SFA lesions resulted in few differences in measurement variability of volumetric parameters. However, planar analysis for MLA assessment can be susceptible to high variability when large intervals are applied. © 2016 Wiley Periodicals, Inc.
PFO “angioplasty”: The preparation of a very stiff and long tunnel for device closure
Authors: Butera Gianfranco , Piazza Luciane , Heles Mohamed 
Published: August 2016

IntroductionPatent foramen ovale (PFO) closure is a widely performed procedure. Understanding the anatomy is mandatory in order to perform the procedure successfully. The degree of overlap between the septum primum and secundum is called the tunnel. In particular, long and stiff tunnels may prevent the correct positioning of devices that have a fixed distance between the right and left atrial discs.Patients and MethodsWe evaluated retrospectively 361 patients with PFO closure between January 2012 and June 2014 in our institution and were treated due to previous history of ischemic stroke. By TEE, the overlap between septum primum and secundum is usually better seen on the bicaval view that is obtained at 75–90° midesophageal views. Tunnel length and PFO opening were measured. Twelve subjects (median age 35 years; range 30–58 years; three females) showed a long (median 22 mm; range 15–32 mm) and rigid tunnel (median opening 2 mm; range 1–4 mm).ResultsAngioplasty of the tunnel was performed by using peripheral angioplasty balloons with a length ranging from 4 to 8 cm and a diameter between 8 and 12 mm. After angioplasty, the tunnel appeared shorter (12 mm; range 8–16 mm) and less rigid (median opening 8 mm; range 7–12 mm). The following devices were implanted: 25 mm Amplatzer PFO occluder in three patients; 25 mm Gore septal occluder in nine subjects. Median fluoroscopy time was 8 min (range 6–10 min). No complications occurred. At a median follow‐up of 12 months (range 2–18 months), no problems occurred and all subjects but one (trivial residual shunting) showed a complete closure.ConclusionsAngioplasty of a PFO rigid and stiff tunnel is a feasible and safe option. © 2016 Wiley Periodicals, Inc.
Routine invasive versus selective invasive strategies for Non‐ST‐elevation acute coronary syndromes: An Updated meta‐analysis of randomized trials
Authors: Elgendy Islam Y. , Kumbhani Dharam J. , Mahmoud Ahmed N. , Wen Xuerong , Bhatt Deepak L. , Bavry Anthony A. 
Published: August 2016

ObjectivesTo perform an updated systematic review comparing a routine invasive strategy with a selective invasive strategy for patients with non‐ST‐elevation acute coronary syndromes (NSTE‐ACS) in the era of stents and antiplatelet therapy.BackgroundRecent meta‐analyses comparing both strategies have shown conflicting results.MethodsElectronic databases were searched for randomized trials that compared a routine invasive strategy (i.e., routine coronary angiography +/− revascularization) versus a selective invasive strategy (i.e., medical stabilization and coronary angiography +/− revascularization if objective evidence of ischemia or refractory ischemia) in patients with NSTE‐ACS. Summary odds ratios (OR) were primarily constructed using Peto's model.ResultsTwelve trials with 9,650 patients were included. Compared with a selective invasive strategy, a routine invasive strategy was associated with a reduction in the composite of all‐cause mortality or myocardial infarction (MI) [OR: 0.86, 95% confidence interval (CI) 0.77‐0.96] at a mean follow‐up of 39 months, primarily due to a reduction in the risk of MI (OR: 0.78, 95% CI: 0.68‐0.88). The risk of all‐cause mortality was non‐significantly reduced with a routine invasive strategy (OR: 0.88, 95% CI: 0.77‐1.01). The risk of recurrent angina was reduced with a routine invasive strategy (OR: 0.55, 95% CI: 0.49‐0.62), as well as the risk of future revascularization procedures (OR: 0.35, 95% CI: 0.30‐0.39).ConclusionIn patients with NSTE‐ACS, a routine invasive strategy reduced the risk of ischemic events, including the risk of mortality or MI. Routine invasive therapy reduced the risk of recurrent angina and future revascularization procedures. © 2016 Wiley Periodicals, Inc.
Prognostic value of renal function in patients with aortic stenosis treated with transcatheter aortic valve replacement
Authors: Meneguz‐Moreno Rafael A. , Ramos Auristela IO , Siqueira Dimytri , de Castro‐Filho Antonio , Jatene Tannas , Dias Jeronimo Andreia , Le Bihan David , Moreira Adriana , Arrais Magaly , Abizaid Alexandre , Sousa Amanda , Eduardo Sousa J. 
Published: August 2016

ObjectivesThe objectives of the present study were to analyze the variation of renal function after transcatheter aortic valve replacement (TAVR) focused on acute kidney injury (AKI) and its impact on short‐ and mid‐term mortality.BackgroundChanges on renal function after TAVR and their impact on clinical outcomes are incompletely understood until now.MethodsAt two tertiary centers 221 consecutive patients were submitted to TAVR. Kidney injury was defined according to VARC‐2 criteria. Patients were classified according to the presence (group 1) or absence (group 2) of AKI. Creatinine values were collected daily until seventh day after procedure, 1 month, 6 months, and then 1 year after TAVR.ResultsAt baseline, groups were similar, except for EuroSCORE II (8.66% vs. 7.34%, P = 0.02) and glomerular filtration rate (GFR) (39.59 vs. 48.49 mL/min.1.73 m2, P = 0.002). Overall 30 day‐mortality and 1‐year mortality were 6.3% and 14.0%, respectively. Both 30‐day mortality (23.1% vs. 1.2%, P < 0.001) and 1‐year mortality (44.2% vs. 4.7%, P < 0.001) were higher in group 1. After multivariable‐adjusted models, the only independent predictor for AKI after TAVR was baseline GFR (HR: 1.37, 95% CI: 1.08–1.77, P = 0.01). The independent risk factors for 1‐year mortality were AKI (HR: 15.66, 95% CI: 6.07–44.63, P < 0.001), COPD (HR: 3.14, 95% CI: 1.05–9.40, P = 0.04) and aortic regurgitation grade postprocedure ≥ 2 (P = 0.05) also after multivariate analysis.ConclusionsIn this TAVR cohort, baseline GFR was the only independent predictor of AKI, which negatively impacted on 30‐day and 1‐year mortality. © 2016 Wiley Periodicals, Inc.
Development and validation of a simple risk score to predict 30‐day readmission after percutaneous coronary intervention in a cohort of medicare patients
Authors: Minges Karl E. , Herrin Jeph , Fiorilli Paul N. , Curtis Jeptha P. 
Published: August 2016

ObjectivesTo develop a risk model that can be used to identify PCI patients at higher risk of readmission who may benefit from additional resources at the time of discharge.BackgroundA high proportion of patients undergoing PCI are readmitted within 30 days of discharge.MethodsThe sample comprised patients aged ≥65 years who underwent PCI at a CathPCI Registry®‐participating hospital and could be linked with 100% Medicare fee‐for‐service claims between 01/2007 and 12/2009. The sample (n = 388,078) was randomly divided into risk score development (n = 193,899) and validation (n = 194,179) cohorts. We did not count as readmissions those associated with staged revascularization procedures. Multivariable logistic regression models using stepwise selection models were estimated to identify variables independently associated with all‐cause 30‐day readmission.ResultsThe mean 30‐day readmission rates for the development (11.36%) and validation (11.35%) cohorts were similar. In total, 19 variables were significantly associated with risk of 30‐day readmission (P < 0.05), and model c‐statistics were similar in the development (0.67) and validation (0.66) cohorts. The simple risk score based on 14 variables identified patients at high and low risk of readmission. Patients with a score of ≥13 (15.4% of sample) had more than an 18.5% risk of readmission, while patients with a score ≤6 (41.9% of sample) had less than an 8% risk of readmission.ConclusionAmong PCI patients, risk of readmission can be estimated using clinical factors present at the time of the procedure. This risk score may guide clinical decision‐making and resource allocation for PCI patients at the time of hospital discharge. © 2016 Wiley Periodicals, Inc.
Mechanistic Insights into the Oxygen Reduction Reaction on Metal–N–C Electrocatalysts under Fuel Cell Conditions
Authors: Lopes Thiago , Kucernak Anthony , Malko Daniel , Ticianelli Edson A. 
Published: August 2016

AbstractThree different transition metal‐C‐N catalysts are tested under a range of fuel cell conditions. It is found that common features of the polarisation curve can be explained by a change in electrocatalytic mechanism. Utilising a simple model to quantify the change in mechanisms, iR‐free results of the fuel cell experiments are fit and found to be represented by a common set of parameters. The change in mechanism is assumed to be a switch from four‐electron reduction of oxygen to water to a two‐electron reduction to hydrogen peroxide followed by disproportionation of the hydrogen peroxide to water and oxygen. The data is used to estimate a mass specific exchange current density towards the oxygen reduction reaction (ORR) to water in the range 10−11–10−13 A g−1 depending on the catalyst. For the reduction of oxygen to hydrogen peroxide, the mass specific exchange current density is estimated to be in the range 10−2–10−3 A g−1. Utilising the electrokinetic model, it is shown how the mass transport losses can be extracted from the polarisation curve. For all three catalyst layers studied, these mass transport losses reach about 100 mV at a current density of 1 A cm−2. Finally a discussion of the performance and site density requirements of the non‐precious metal catalysts are provided, and it is estimated that the activity towards the ORR needs to be increased by an order of magnitude, and the site density by two/three orders of magnitude to compete with platinum as an ORR electrocatalyst.
Intracellular Hydrogen Peroxide Detection with Functionalised Nanoelectrodes
Authors: Marquitan Miriam , Clausmeyer Jan , Actis Paolo , Córdoba Ainara López , Korchev Yuri , Mark Melanie D. , Herlitze Stefan , Schuhmann Wolfgang 
Published: August 2016

AbstractHydrogen peroxide (H2O2) is one of the most important reactive oxygen species, and it is involved in a number of cellular processes ranging from signal transduction to immune defence and oxidative stress. It is of great interest to intracellularly quantify H2O2 to improve the understanding of its role in disease processes. In this study, we present an amperometric nanosensor for the quantification of H2O2 at the single‐cell level. Deposition of the electrocatalyst Prussian Blue on carbon nanoelectrodes enables selective H2O2 reduction at mild potentials. Owing to their small size and needle‐type shape, these nanoelectrodes can penetrate the membrane of single living cells, causing only minimal perturbation. The nanosensors allow for the monitoring of penetration‐induced oxidative outbursts as well as the uptake of H2O2 from the extracellular environment in single murine macrophages.
Metal Complexes with Azolate‐Functionalized Multidentate Ligands: Tactical Designs and Optoelectronic Applications
Authors: Lu Chin‐Wei , Wang Yang , Chi Yun 
Published: August 2016

AbstractThis review is aimed at updating the recent development on the metal complexes bearing azolate‐containing chelates that have received a growing attention from both the industrial and academic sectors. Particular emphasis is given to the luminescent metal complexes, for which tridentate and multidentate bonding interactions give rise to both higher ligand field strength and better rigidity versus their bidentate counterparts—consequently, this is beneficial to the chemical stability and emission efficiency needed for applications such as organic light‐emitting diodes and bio‐imaging. Their basic designs involve chelates, such as monoanionic 6‐azolyl 2,2′‐bipyridine, dianionic 2,6‐diazolylpyridine, and 2‐azolyl‐6‐phenylpyridine, and the core metal ion spanning from main group elements, such as GaIII and InIII, to the late transition metal ions such as RuII, OsII, IrIII, and PtII and even the lanthanides. Furthermore, the great versatility of these azolate chelates for assembling the robust and emissive metal complexes, provides bright prospect in future optoelectronic investigations.
Efficient Room‐Temperature Methane Activation by the Closed‐Shell, Metal‐Free Cluster [OSiOH]+: A Novel Mechanistic Variant
Authors: Sun Xiaoyan , Zhou Shaodong , Schlangen Maria , Schwarz Helmut 
Published: August 2016

AbstractThe closed‐shell cluster ion [OSiOH]+ is generated in the gas phase and its reactivity towards the thermal activation of CH4 has been examined using Fourier transform‐ion cyclotron resonance (FT‐ICR) mass spectrometry in conjunction with state‐of‐the‐art quantum chemical calculations. Quite unexpectedly at room temperature, [OSiOH]+ efficiently mediates C−H bond activation, giving rise to [SiOH]+ and [SiOCH3]+ with the concomitant formation of methanol and water, respectively. Mechanistic aspects for this unprecedented reactivity pattern are presented, and the properties of the [OSiOH]+/CH4 couple are compared with those of the closed‐shell systems [OCOH]+/CH4 and [MgOH]+/CH4; the last two couples exhibit an entirely different reactivity scenario.
Regio‐ and Stereoselective Aliphatic–Aromatic Cross‐Benzoin Reaction: Enzymatic Divergent Catalysis
Authors: Beigi Maryam , Gauchenova Ekaterina , Walter Lydia , Waltzer Simon , Bonina Fabrizio , Stillger Thomas , Rother Dörte , Pohl Martina , Müller Michael 
Published: August 2016

AbstractThe catalytic asymmetric synthesis of chiral 2‐hydroxy ketones by using different thiamine diphosphate dependent enzymes, namely benzaldehyde lyase from Pseudomonas fluorescens (PfBAL), a variant of benzoylformate decarboxylase from Pseudomonas putida (PpBFD‐L461A), branched‐chain 2‐keto acid decarboxylase from Lactococcus lactis (LlKdcA) and a variant of pyruvate decarboxylase from Acetobacter pasteurianus (ApPDC‐E469G), was studied. Starting with the same set of substrates, substituted benzaldehydes in combination with different aliphatic aldehydes, PfBAL and PpBFD‐L461A selectively deliver the (R)‐ and (S)‐2‐hydroxy‐propiophenone derivatives, respectively. The (R)‐ and (S)‐phenylacetylcarbinol (1‐hydroxy‐1‐phenylacetone) derivatives are accessible in a similar way using LlKdcA and ApPDC‐E469G, respectively. In many cases excellent stereochemical purities (>98 % enantiomeric excess) could be achieved. Hence, the regio‐ and stereochemistry of the product in the asymmetric aliphatic–aromatic cross‐benzoin reaction can be controlled solely by choice of the appropriate enzyme or enzyme variant.
Mechanistic Insight into Heptosyltransferase Inhibition by using Kdo Multivalent Glycoclusters
Authors: Tikad Abdellatif , Fu Huixiao , Sevrain Charlotte M. , Laurent Sophie , Nierengarten Jean‐François , Vincent Stéphane P. 
Published: August 2016

AbstractThe synthesis of unprecedented multimeric Kdo glycoclusters based on fullerene and calix[4]arene central scaffolds is reported. The compounds were used to study the mechanism and scope of multivalent glycosyltransferase inhibition. Multimeric mannosides based on porphyrin and pillar[5]arenes were also generated in a controlled manner. Twelve glycoclusters and their monomeric ligands were thus assayed against heptosyltransferase WaaC, which is an important bacterial glycosyltransferase that is involved in lipopolysaccharide biosynthesis. It was first found that all the multimers interact solely with the acceptor binding site of the enzyme even when the multimeric ligands mimic the heptose donor. Second, the novel Kdo glycofullerenes displayed very potent inhibition (Ki=0.14 μm for the best inhibitor); an inhibition level rarely observed with glycosyltransferases. Although the observed “multivalent effects” (i.e., the enhancement of affinity of a ligand when presented in a multimeric fashion) were in general modest, a dramatic effect of the central scaffold on the inhibition level was evidenced: the fullerene and the porphyrin scaffolds being by far superior to the calix‐ and pillar‐arenes. We could also show, by dynamic light scattering analysis, that the best inhibitor had the propensity to form aggregates with the heptosyltransferase. This aggregative property may contribute to the global multivalent enzyme inhibition, but probably do not constitute the main origin of inhibition.
Ion‐Pair Complexation with Dibenzo[21]Crown‐7 and Dibenzo[24]Crown‐8 bis‐Urea Receptors
Authors: Mäkelä Toni , Kiesilä Anniina , Kalenius Elina , Rissanen Kari 
Published: August 2016

AbstractSynthesis and ion‐pair complexation properties of novel ditopic bis‐urea receptors based on dibenzo[21]crown‐7 (R1) and dibenzo[24]crown‐8 (R2) scaffolds have been studied in the solid state, solution, and gas phase. In a 4:1 CDCl3/[D6]DMSO solution, both receptors clearly show positive heterotropic cooperativity toward halide anions when complexed with Rb+ or Cs+, with the halide affinity increasing in order I−<Br−<Cl−. In solution, the rubidium complexes of both receptors have higher halide affinities compared to the caesium complexes. However, Rb+ and Cs+ complexes of R2 show stronger affinities toward all the studied anions compared to the corresponding cationic complexes of R1. Similar selectivity of the receptors toward the studied ion pairs was also observed also in the gas phase by competition experiments with mass spectrometry. A total of eight crystal structures with different rubidium and caesium halides and oxyanions were obtained in addition to the crystal structure of R2⋅BaCl2. The selectivity observed in solution and in the gas phase is explainable by the conformational differences observed in the crystal structures of ion‐pair complexes with R1 and R2. In the solid state, R1 has an open conformation due to the asymmetric crown‐ether scaffold, whereas R2 has a compact, folded conformation. Computational studies of the ion‐pair complexes of R2 show that the interaction energies of the complexes increase in the order CsI<CsBr<CsCl<RbCl, supporting the selectivity observed in solution and the gas‐phase.
α‐Diamine Nickel Catalysts with Nonplanar Chelate Rings for Ethylene Polymerization
Authors: Liao Heng , Zhong Liu , Xiao Zefan , Zheng Ting , Gao Haiyang , Wu Qing 
Published: August 2016

AbstractA series of novel α‐diamine nickel complexes, (ArNH‐C(Me)‐(Me)C‐NHAr)NiBr2, 1: Ar=2,6‐diisopropylphenyl, 2: Ar=2,6‐dimethylphenyl, 3: Ar=phenyl), have been synthesized and characterized. X‐ray crystallographic analysis showed that the coordination geometry of the α‐diamine nickel complexes is markedly different from conventional α‐diimine nickel complexes, and that the chelate ring (N‐C‐C‐N‐Ni) of the α‐diamine nickel complex is significantly distorted. The α‐diamine nickel catalysts also display different steric effects on ethylene polymerization in comparison to the α‐diimine nickel catalyst. Increasing the steric hindrance of the α‐diamine ligand by substitution of the o‐methyl groups with o‐isopropyl groups leads to decreased polymerization activity and molecular weight; however, catalyst thermal stability is significantly enhanced. Living polymerizations of ethylene can be successfully achieved using 1/Et2AlCl at 35 °C or 2/Et2AlCl at 0 °C. The bulky α‐diamine nickel catalyst 1 with isopropyl substituents can additionally be used to control the branching topology of the obtained polyethylene at the same level of branching density by tuning the reaction temperature and ethylene pressure.