bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methandiide as a Non‐Innocent Ligand in Carbene Complexes: From the Electronic Structure to Bond Activation Reactions and Cooperative Catalysis
Authors: Becker Julia , Modl Tanja , Gessner Viktoria H. 
Published: July 2014

AbstractThe synthesis of a ruthenium carbene complex based on a sulfonyl‐substituted methandiide and its application in bond activation reactions and cooperative catalysis is reported. In the complex, the metal–carbon interaction can be tuned between a RuC single bond with additional electrostatic interactions and a RuC double bond, thus allowing the control of the stability and reactivity of the complex. Hence, activation of polar and non‐polar bonds (OH, HH) as well as dehydrogenation reactions become possible. In these reactions the carbene acts as a non‐innocent ligand supporting the bond activation as nucleophilic center in the 1,2‐addition across the metal–carbon double bond. This metal–ligand cooperativity can be applied in the catalytic transfer hydrogenation for the reduction of ketones. This concept opens new ways for the application of carbene complexes in catalysis.
Heteroscedastic modelling via the autoregressive conditional variance subspace
Authors: Park Jin‐Hong , Samadi S. Yaser 
Published: July 2014

AbstractThe paper deals with nonparametric estimation of the conditional variance of a time series based on a nonlinear autoregressive model in the squared innovation time series, which does not require specification of a model. We introduce a notion called the autoregressive central variance subspace (ACVS) to obtain the information included in the conditional variance of time series data. We use the squared time series to identify the ACVS by a nonparametric kernel method. In addition, we simultaneously estimate the unknown dimension and lag of the ACVS by a modified information criterion. Finally, we investigate the performance of all the estimators including the ACVS through simulations and a real analysis, which suggests implementing a new dimension reduction approach to modelling time series data that exhibits volatility. The Canadian Journal of Statistics 42: 423–435; 2014 © 2014 Statistical Society of Canada
Amphiphilic Bicyclic Peptides as Cellular Delivery Agents
Authors: Oh Donghoon , Darwish Shaban Anwar , Shirazi Amir Nasrolahi , Tiwari Rakesh Kumar , Parang Keykavous 
Published: July 2014

AbstractTwo bicyclic peptides composed of tryptophan and arginine residues were synthesized from monocyclic peptide building blocks and evaluated as cellular delivery agents. [W5G]‐(triazole)‐[KR5] and [W5E]‐(β‐Ala)‐[KR5] containing triazole and β‐alanine linkers improved the cellular delivery of fluorescein (F′)‐labeled phosphopeptide F′‐GpYEEI (F′‐PP) by 7.6‐ and 19.3‐fold, respectively, in human ovarian adenocarcinoma cells. However, parent monocyclic peptide [R5] and monocyclic peptide [WR]4 only enhanced the cellular uptake of the phosphopeptide by only 1.3‐ and 3.7‐fold, respectively. Confocal microscopy showed that the corresponding fluorescein‐labeled bicyclic peptide F′‐[KW4E]‐(β‐Ala)‐[KR5] was localized in the cytosol and nucleus. Studying the cellular uptake of F′‐[KW4E]‐(β‐Ala)‐[KR5] in the presence of endocytosis inhibitors indicated that the clathrin‐ and caveolin‐dependent endocytosis are the main pathways for cellular uptake. The bicyclic peptide was able to improve antiproliferative activity of doxorubicin by 20 %. These data suggest that this bicyclic peptide can be utilized as a new class of cell‐penetrating peptides and cellular delivery tools.
Diaryl‐Substituted Azolylthioacetamides: Inhibitor Discovery of New Delhi Metallo‐β‐Lactamase‐1 (NDM‐1)
Authors: Zhang Yi‐Lin , Yang Ke‐Wu , Zhou Ya‐Jun , LaCuran Alecander E. , Oelschlaeger Peter , Crowder Michael W. 
Published: July 2014

AbstractThe emergence and spread of antibiotic‐resistant pathogens is a global public health problem. Metallo‐β‐lactamases (MβLs) such as New Delhi MβL‐1 (NDM‐1) are principle contributors to the emergence of resistance because of their ability to hydrolyze almost all known β‐lactam antibiotics including penicillins, cephalosporins, and carbapenems. A clinical inhibitor of MBLs has not yet been found. In this study we developed eighteen new diaryl‐substituted azolylthioacetamides and found all of them to be inhibitors of the MβL L1 from Stenotrophomonas maltophilia (Ki<2 μM), thirteen to be mixed inhibitors of NDM‐1 (Ki<7 μM), and four to be broad‐spectrum inhibitors of all four tested MβLs CcrA from Bacteroides fragilis, NDM‐1 and ImiS from Aeromonas veronii, and L1 (Ki<52 μM), which are representative of the B1a, B1b, B2, and B3 subclasses, respectively. Docking studies revealed that the azolylthioacetamides, which have the broadest inhibitory activity, coordinate to the ZnII ion(s) preferentially via the triazole moiety, while other moieties interact mostly with the conserved active site residues Lys224 (CcrA, NDM‐1, and ImiS) or Ser221 (L1).
A New Class of Phase‐Selective Synthetic β‐Amino Acid Based Peptide Gelator: From Mechanistic Aspects to Oil Spill Recovery
Authors: Konda Maruthi , Maity Indrajit , Rasale Dnyaneshwar B. , Das Apurba K. 
Published: July 2014

AbstractThe mechanistic aspects of supramolecular ordering of synthetic β‐amino acid based peptides in different organic solvents and fuel oils are reported. The peptide Boc‐cis‐ACHC‐Aib‐Phe‐OMe (Boc=tert‐butyloxycarbonyl, cis‐ACHC=cis‐2‐aminocyclohexanecarboxylic acid, Aib=α‐amino isobutyric acid, Phe=phenylalanine; 1) is able to entrap various organic solvents and oils, leading to the formation of self‐supporting gels. Spectroscopic studies confirm the turn‐type β‐sheet arrangement of peptide 1 in the gel phase. A morphology study shows that a bundle of nanofibers form from self‐assembled peptide 1. Peptide 1 is capable of entrapping organic or oil layers selectively over the aqueous layer. Furthermore, the phase‐selective gelation behavior of peptide 1 is effectively used as a model study for oil spill recovery from a biphasic mixture of oil and water.
Dithienopyrrole‐/Benzodithiophene‐Based Donor–Acceptor Polymers for Memristor
Authors: Wang Cheng , Liu Gang , Chen Yu , Liu Shanshan , Chen Qibin , Li Runwei , Zhang Bin 
Published: July 2014

AbstractInvited for this month’s cover is the group of Prof. Dr. Yu Chen from East China University of Science and Technology, P. R. China. The cover picture shows fundamental passive circuit elements of resistor, capacitor, inductor and memristor and the correlations between the circuit variables. Read the full text of the article at 10.1002/cplu.201402133
Surface Decoration of ϵ‐Fe2O3 Nanorods by CuO Via a Two‐Step CVD/Sputtering Approach**
Authors: Barreca Davide , Carraro Giorgio , Peeters Daniel , Gasparotto Alberto , Maccato Chiara , Kessels Wilhelmus M. M. , Longo Valentino , Rossi Francesca , Bontempi Elza , Sada Cinzia , Devi Anjana 
Published: July 2014

AbstractIn this paper we report on the first example of Fe2O3/CuO composites fabricated by a two‐step vapor‐phase synthetic strategy. The target route is based on the CVD of Fe2O3 nanorod arrays on Si(100) at 400 °C starting from Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5‐hexafluoro‐2,4‐pentanedionate; TMEDA = N,N,N′,N′‐tetramethylethylenediamine), followed by radio frequency (RF) copper sputtering for various process durations, and final ex‐situ annealing in air. The combined use of complementary structural, morphological, and chemical analyses give evidence of the formation of pure nanocomposite systems, characterized by the presence of the sole ϵ‐Fe2O3 and CuO phases. The unique features of the adopted approach enable an efficient surface decoration of ϵ‐Fe2O3 rods by CuO nanoparticles a few nm in diameter, resulting in an intimate contact between the two oxides, and a CuO content tunable through variations of the sole sputtering time.
Efficient purification of CD4+ lymphocytes from peripheral blood progenitor cell products using affinity bead acoustophoresis
Authors: Lenshof Andreas , Jamal Arshad , Dykes Josefina , Urbansky Anke , Åstrand‐Grundström Ingbritt , Laurell Thomas , Scheding Stefan 
Published: July 2014

AbstractProcessing of peripheral blood progenitor cells (PBPC) for clinical transplantation or research applications aims to effectively isolate or deplete specific cell populations, utilizing primarily magnetic or fluorescence activated sorting methods. Here, we investigated the performance of microfluidic acoustophoresis for the separation of lymphocyte subsets from PBPC, and present a novel method for affinity‐bead‐mediated acoustic separation of cells which can otherwise not be acoustically discriminated. As the acoustic force on a particle depends on particle size, density and compressibility, targeting of cells by affinity specific beads will generate cell‐bead complexes that exhibit distinct acoustic properties relative to nontargeted cells and are, thus, possible to isolate. To demonstrate this, PBPC samples (n = 22) were obtained from patients and healthy donors. Following density gradient centrifugation, cells were labeled with anti‐CD4‐coated magnetic beads (Dynal) and isolated by acoustophoresis and, for comparison, standard magnetic cell sorting technique in parallel. Targeted CD4+ lymphocytes were acoustically isolated with a mean (±SD) purity of 87 ± 12%, compared with 96 ± 3% for control magnetic sorting. Viability of sorted cells was 95 ± 4% (acoustic) and 97 ± 3% (magnetic), respectively. The mean acoustic separation efficiency of CD4+ lymphocytes to the target fraction was 65 ± 22%, compared with a mean CD4+ lymphocyte recovery of 56 ± 15% for magnetic sorting. Functional testing of targeted CD4+ lymphocytes demonstrated unimpaired mitogen‐mediated proliferation capacity and cytokine production. Hematopoietic progenitor cell assays revealed a preserved colony forming ability of nontarget cells post sorting. We conclude that the acoustophoresis platform can be utilized to efficiently isolate bead‐labeled CD4+ lymphocytes from PBPC samples in a continuous flow format, with preserved functional capacity of both target and nontarget cells. These results open up for simultaneous affinity‐bead‐mediated separation of multiple cell populations, something which is not possible with current standard magnetic cell separation technology. © 2014 International Society for Advancement of Cytometry
Large‐scale adaptive divergence in Boechera fecunda, an endangered wild relative of Arabidopsis
Authors: Leamy Larry J. , Lee Cheng‐Ruei , Cousins Vanessa , Mujacic Ibro , Manzaneda Antonio J. , Prasad Kasavajhala , Mitchell‐Olds Thomas , Song Bao‐Hua 
Published: July 2014

AbstractMany biological species are threatened with extinction because of a number of factors such as climate change and habitat loss, and their preservation depends on an accurate understanding of the extent of their genetic variability within and among populations. In this study, we assessed the genetic divergence of five quantitative traits in 10 populations of an endangered cruciferous species, Boechera fecunda, found in only several populations in each of two geographic regions (WEST and EAST) in southwestern Montana. We analyzed variation in quantitative traits, neutral molecular markers, and environmental factors and provided evidence that despite the restricted geographical distribution of this species, it exhibits a high level of genetic variation and regional adaptation. Conservation efforts therefore should be directed to the preservation of populations in each of these two regions without attempting transplantation between regions. Heritabilities and genetic coefficients of variation estimated from nested ANOVAs were generally high for leaf and rosette traits, although lower (and not significantly different from 0) for water‐use efficiency. Measures of quantitative genetic differentiation, QST, were calculated for each trait from each pair of populations. For three of the five traits, these values were significantly higher between regions compared with those within regions (after adjustment for neutral genetic variation, FST). This suggested that natural selection has played an important role in producing regional divergence in this species. Our analysis also revealed that the B. fecunda populations appear to be locally adapted due, at least in part, to differences in environmental conditions in the EAST and WEST regions.
Synthesis and Molecular Structures of Monosubstituted Pentamethylcobaltocenium Cations
Authors: Wolter‐Steingrube Anne , Bugenhagen Bernhard E. C. , Herrmann Carmen , Heck Jürgen 
Published: July 2014

Abstract(Amino‐η5‐cyclopentadienyl)(pentamethyl‐η5‐cyclopentadienyl)cobalt(III) hexafluorophosphate (6PF6) was prepared by a route that started with the synthesis of the zwitterion (oxycarbonyl‐η5‐cyclopentadienyl)(pentamethyl‐η5‐cyclopentadienyl)cobalt(III) (1). The acidification of 1 created the carboxylic acid 2PF6, which was converted into the acyl chloride 3PF6. The reaction with NaN3 afforded the azide 4PF6, which was transformed to the carbamate 5PF6. The hydrolysis of 5PF6 afforded the desired aminocobaltocenium compound 6PF6. The oxidation of 6PF6 yielded the (nitro‐η5‐cyclopentadienyl)(pentamethyl‐η5‐cyclopentadienyl)cobalt(III) cation 7+. For 1, 2+, 4PF6, 6PF6, and 7PF6, X‐ray structure analyses were performed. The electronic structure of 6+ calculated by DFT methods revealed a short C–N bond, which is in agreement with the molecular structure obtained from X‐ray structure analysis. The pKa value of 6PF6 was estimated from aqueous solution. Cyclic voltammetry studies show a reversible one‐electron reduction and an irreversible one‐electron oxidation.
A Concise Synthesis of (2R,3R)‐ and (2R,3S)‐3‐Hydroxypipecolic Acids, and Total Synthesis of (–)‐Deoxoprosopinine and (+)‐2‐epi‐Deoxoprosopinine from D‐Glycals
Authors: Mallick Asadulla , Kumari Nitee , Roy Rashmi , Palanivel Ashokkumar , Vankar Yashwant D. 
Published: July 2014

AbstractShort and efficient formal syntheses of (2R,3R)‐ and (2R,3S)‐3‐hydroxypipecolic acids, and total syntheses of (–)‐deoxoprosopinine and (+)‐2‐epi‐deoxoprosopinine have been achieved starting from D‐glycals. The key steps involved in these syntheses were Ferrier rearrangement, azide reduction, intramolecular cyclization, and Grignard reaction.
Application and Scope of Schreiber's Gold(I)‐Catalyzed α‐Pyrone Synthesis to Ring A Aromatic Podolactones
Authors: Sánchez‐Larios Eduardo , Giacometti Robert D. , Hanessian Stephen 
Published: July 2014

AbstractSchreiber's gold(I)‐catalyzed synthesis of α‐pyrones was adapted to the total synthesis of a ring A aromatic podolactone, urbalactone. The scope of the acetylenic ester partner in the formation of α‐pyrones was studied. The total synthesis features, as key steps, α‐pyrone formation, Friedel–Crafts cyclization, Stille coupling, and a N,N′‐dicyclohexylcarbodiimide/4‐(N,N‐dimethylamino)pyridine lactonization to generate the γ‐lactone. Several α‐pyrone intermediates from this work exhibited in vitro antiproliferative activity against the A2780 ovarian cancer cell line.
Is It an Eating Disorder or Achalasia or Both? A Literature Review and Diagnostic Challenges
Authors: Reas Deborah L. , Zipfel Stephan , Rø Øyvind 
Published: July 2014

AbstractIntroductionAchalasia is a rare oesophageal motility disorder characterized by physical, behavioural and psychosocial features that are strikingly similar to eating disorders (ED).MethodA literature search of PubMed and Google Scholar identified 36 cases of achalasia from 11 countries misdiagnosed as ED between 1980 and 2013.ResultsOn average, the typical misdiagnosed case was an 18‐year‐old female with an average weight loss of 16.2 kg. Vomiting behaviour in achalasia was distinguished by occurring after both solids and liquids, occurring in public, and worsening at night or while lying down, and was associated with pain relief. Manometric investigations of oesophageal functioning in clinical ED samples are few and have shown little evidence of dysmotility.DiscussionAchalasia and ED share numerous clinical features including weight loss and vomiting. Pain associated with swallowing difficulties may lead to an increasingly restricted pattern of eating and food avoidance. Increased awareness of achalasia in ED treatment settings can help facilitate detection of achalasia, thereby reducing treatment delay. © 2014 The Authors. European Eating Disorders Review published by John Wiley & Sons, Ltd.
Medicare Part B Intensity and Volume Offset
Authors: Brunt Christopher S. 
Published: July 2014

SummaryUnder Medicare Part B, adjustments to the fee schedule are made under the assumption that physicians and hospitals make up for fee reductions through increased service provision called ‘volume offsetting’. While historically, researchers have found evidence of volume offsetting, more recent studies have called into question its magnitude and existence. This study is the first to propose and empirically evaluate an alternative hypothesis of offsetting, namely the alteration of billed or provided services as a means of ‘intensity offsetting’. Evaluating both forms of offsetting, it finds strong evidence of intensity offsetting and little to no evidence of volume offsetting. Simulating a 10% reduction in the Medicare fee schedule, this study estimates that across different procedures between 22% and 59% of a fee reduction will be offset through alterations in service intensity. Copyright © 2014 John Wiley & Sons, Ltd.
The electrochemical production of boric acid
Authors: Yakar Elbeyli İffet , Turan Abdullah Zahid , Kalafatoğlu İ. Ersan 
Published: July 2014

AbstractBACKGROUNDBoric acid (H3BO3) was electrochemically produced from borax pentahydrate (Na2B4O7.5H2O) using membrane electrolysis, and a flow diagram of the production process was developed. The effect of different catholyte concentrations (10, 20 and 30% aqueous NaOH) and current densities (1.2, 1.8 and 2.9 kA m−2) on current efficiency was studied. The electrical power consumption per ton of boric acid produced was calculated and the qualities of boric acid products were determined.RESULTSThe current efficiency ranged between 94% and 74% depending on operating conditions. Optimum process conditions for electrochemical boric acid production were determined to be 1.8 kA m−2 current density and 20% aqueous NaOH catholyte concentration. In these conditions, the specific energy consumption for 1 ton of boric acid produced was calculated at 2000 kWh (i.e. specific energy consumption 2000 kWh ton−1 at 7.5 V and 1.8 kA m−2).CONCLUSIONSThe production of boric acid by an electrochemical method is more attractive than the current commercial process and other production methods described in the literature. The process is environment friendly since it does not generate solid waste, and oxygen is produced instead of chlorine as in the well‐known chlor‐alkali process. © 2014 Society of Chemical Industry
Chemical profile and antiacetylcholinesterase, antityrosinase, antioxidant and α‐glucosidase inhibitory activity of Cynometra cauliflora L. leaves
Authors: Ado Muhammad Abubakar , Abas Faridah , Ismail Intan Safinar , Ghazali Hasanah M , Shaari Khozirah 
Published: July 2014

AbstractBACKGROUNDThe aim of the current study was (i) to evaluate the bioactive potential of the leaf methanolic extract of Cynometra cauliflora L., along with its respective hexane, dichloromethane, ethyl acetate (EtOAc), n‐butanol (n‐BuOH) and aqueous fractions, in inhibiting the enzymes α‐glucosidase, acetylcholinesterase (AChE) and tyrosinase as well as evaluating their antioxidant activities. (ii) In addition, in view of the limited published information regarding the metabolite profile of C. cauliflora, we further characterized the profiles of the EtOAc and n‐BuOH fractions using liquid chromatography–diode array detection–electrospray ionization–tandem mass spectrometry.RESULTSThe leaf methanolic extract of C. cauliflora exhibited potent inhibition of all three enzymes and high antioxidant activity. The bioactivity was found to be concentrated in the EtOAc and n‐BuOH fractions. A total of 18 compounds were identified in these bioactive fractions, comprising a procyanidin trimer, procyanidin tetramer, procyanidin hexamer, taxifolin pentoside, catechin, vitexin, isovitexin, kaempferol hexoside, quercetin pentoside, quercetin hexoside, apigenin‐6‐C‐glucoside‐8‐C‐glucoside, kaempferol–coumaroyl hexoside and isorhamnetin hexoside.CONCLUSIONThe results indicated that C. cauliflora, the leaves in particular, is a rich source of bioactive compounds and could be beneficial for further development of high‐value phytomedicinal preparations and functional food products. © 2014 Society of Chemical Industry
Dispersive liquid–liquid microextraction combined with non‐aqueous capillary electrophoresis for the determination of imazalil, prochloraz and thiabendazole in apples, cherry tomatoes and grape juice
Authors: Xu Lina , Luan Feng , Liu Huitao , Gao Yuan 
Published: July 2014

AbstractBACKGROUNDFruit and vegetables are frequently treated with fungicides to reduce possible spoilage. As a result, fungicide residues may be accumulated in derived products. This important group of chemical compounds has been heavily regulated because of their potential toxicity. Therefore, a simple and rapid method to determine fungicides is desired.RESULTSA simple non‐aqueous capillary electrophoresis (NACE) method based on dispersive liquid–liquid microextraction (DLLME) has been proposed for the determination of imazalil, prochloraz and thiabendazole fungicides in fruits and juice samples. Separation buffer consisted of a methanol–acetonitrile mixture (35:65, v/v) containing 30 mmol L−1 ammonium chloride and 0.5% phosphoric acid. The optimum DLLME conditions were 80 µL trichloromethane as extraction solvent, 0.5 mL tetrahydrofuran as disperser solvent, sample solution pH at 6.0, 5% (w/v) NaCl and 10 s extraction time. Recoveries obtained for various samples ranged from 72% to 102%, with relative standard deviation lower than 6.4%. The limits of detection ranged from 0.47 to 0.72 µg kg−1.CONCLUSIONThe proposed method takes the advantages of DLLME and NACE. It is rapid, accurate, sensitive and reproducible for the determination of imazalil, prochloraz and thiabendazole in fruit samples. © 2014 Society of Chemical Industry