bluuebunny/crossref_metadata_2025_split huggingface dataset:
Central tolerance spares the private high‐avidity CD4+ T‐cell repertoire specific for an islet antigen in NOD mice
Authors: Serre Laurent , Fazilleau Nicolas , Guerder Sylvie 
Published: April 2015

Although central tolerance induces the deletion of most autoreactive T cells, some autoreactive T cells escape thymic censorship. Whether potentially harmful autoreactive T cells present distinct TCRαβ features remains unclear. Here, we analyzed the TCRαβ repertoire of CD4+ T cells specific for the S100β protein, an islet antigen associated with type 1 diabetes. We found that diabetes‐resistant NOD mice deficient for thymus specific serine protease (TSSP), a protease that impairs class II antigen presentation by thymic stromal cells, were hyporesponsive to the immunodominant S100β1‐15 epitope, as compared to wild‐type NOD mice, due to intrathymic negative selection. In both TSSP‐deficient and wild‐type NOD mice, the TCRαβ repertoire of S100β‐specific CD4+ T cells though diverse showed a specific bias for dominant TCRα rearrangements with limited CDR3α diversity. These dominant TCRα chains were public since they were found in all mice. They were of intermediate‐ to low‐avidity. In contrast, high‐avidity T cells expressed unique TCRs specific to each individual (private TCRs) and were only found in wild‐type NOD mice. Hence, in NOD mice, the autoreactive CD4+ T‐cell compartment has two major components, a dominant and public low‐avidity TCRα repertoire and a private high‐avidity CD4+ T‐cell repertoire; the latter is deleted by re‐enforced negative selection.
A Simple and Cost‐Effective Method for the Regioselective Deuteration of Phenols
Authors: Zhan Miao , Xu Ruixue , Tian Ye , Jiang Hongxia , Zhao Lifeng , Xie Yongmei , Chen Yuanwei 
Published: April 2015

AbstractA highly effective and operationally simple method for the deuteration of phenols using NaOH as a catalyst and D2O as the deuterium source is presented. A high regioselectivity for the ortho and/or para hydrogens relative to the oxygen atom was achieved, as well as a high degree of deuterium incorporation. The method also has a high functional‐group tolerance, and allowed the deuteration of complex pharmaceutically interesting substrates.
Selective Incorporation of Fluorine in Pyrazoles
Authors: Sloop Joseph C. , Holder Cory , Henary Maged 
Published: April 2015

AbstractPyrazoles are highly essential heterocyclic structures prevalent in biologically active products used widely throughout various disciplines of chemical industry‐including medicine and agriculture. The efficacy of these pyrazole species is enhanced through the introduction of fluorine and corresponding functionalities; therefore, synthetic methods for the fluorination of these structures is highly appealing which follows the overall trend of increasing interest in fluorination chemistry. Toward assimilating the known techniques for fluorine incorporation to the pyrazole heterocyclic structure we have reviewed both the new and traditional synthetic approaches to the assembly of functionalized pyrazole derivatives. Specifically, efficient synthetic methods and regioselective incorporation of fluorine and fluorine containing functional groups into different pyrazole ring systems are examined.
Synthesis of Boron‐ and Silicon‐Containing Amino Acids through Copper‐Catalysed Conjugate Additions to Dehydroalanine Derivatives
Authors: Bartoccini Francesca , Bartolucci Silvia , Lucarini Simone , Piersanti Giovanni 
Published: April 2015

AbstractA copper‐based catalytic technique for the regioselective hydroboration and hydrosilylation of dehydroalanine derivatives has been developed. This method introduces synthetically versatile boron and silicon groups, while simultaneously performing a catalytic anti‐Markovnikov hydrofunctionalization of dehydroalanines and dehydropeptides for the synthesis of amino acids and peptides bearing unnatural side‐chains. The products obtained were expediently converted into valuable nonproteinogenic amino acid building blocks for polypeptide synthesis.
Electrochemical Oxidation of Desipramine Drug in the Presence of 4,6‐Dimethylpyrimidine‐2‐thiol Nucleophile in Aqueous Acidic Medium
Authors: Tammari Esmail , Nezhadali Azizollah , Lotfi Shahram 
Published: April 2015

AbstractElectrochemical oxidation of desipramine (DES) has been studied in the presence of 4,6‐dimethylpyrimidine‐2‐thiol (DMPT) as nucleophile in acidic medium by means of cyclic voltammetry, controlled‐potential electrolysis and spectroscopic data, as diagnostic techniques. Voltammetric studies of electro‐oxidation of desipramine were realized in a range of pH 1.0 to 8.0 in the absence and presence of DMPT. The results indicate the participation of the product of electrochemical oxidation of desipramine in the reaction with DMPT with ECEC electrochemical mechanism. However, the voltammetry and coulometry results imply existence of a catalytic (EC′) electrochemical mechanism in parallel with ECEC electrochemical mechanism. The product has been characterized by IR, 1H NMR, 13C NMR and MS methods.
Carbon‐Based Electrodes for Sensitive Electroanalytical Determination of Aminonaphthalenes
Authors: Zavazalova Jaroslava , Ghica Mariana Emilia , Schwarzova‐Peckova Karolina , Barek Jiri , Brett Christopher M. A. 
Published: April 2015

AbstractThe electroanalytical performance of bare glassy carbon electrodes (GCE) for the determination of 1‐aminonaphthalene (1‐AN) and 2‐aminonaphthalene (2‐AN) was compared with GCE modified by a Nafion permselective membrane or multiwalled carbon nanotubes and with other types of carbon‐based materials, carbon film and boron doped diamond. Nafion‐modified GCE gave the highest sensitivity and lowest detection limit (0.4 µmol L−1) for differential pulse voltammetric determination of 1‐AN. Electrochemical impedance spectroscopy gave information about the processes at the electrode surface. Simultaneous determination of 1‐AN and 2‐AN in a mixture at GCE and their determination in model samples of river water is presented.
Electrodeposition of reduced graphene oxide on a Pt electrode and its use as amperometric sensor in microchip electrophoresis
Authors: Lucca Bruno Gabriel , de Lima Fábio , Coltro Wendell K. T. , Ferreira Valdir Souza 
Published: April 2015

This report describes the development and application of a novel graphene‐modified electrode to be used as amperometric sensor in microchip electrophoresis (ME) devices. The modified electrode was achieved based on electroreduction of graphene oxide on an integrated Pt working electrode of a commercial ME device. The surface modification was characterized by SEM and cyclic voltammetry techniques. The results indicated that graphene sheets were successfully deposited exhibiting higher surface conductivity and greater electrode sensitivity. The performance of the modified electrode for the amperometric detection on ME devices has been demonstrated by the separation and detection of an anionic mixture containing iodide and ascorbate. The graphene‐modified electrode provided significantly higher sensitivity (896.7 vs. 210.9 pA/μM for iodide and 217.8 vs. 127.8 pA/μM for ascorbate), better separation efficiencies (3400 vs. 700 plates/m for iodide and 10 000 vs. 2400 plates/m for ascorbate), enhanced peak resolutions (1.6 vs. 1.0), and LODs (1.5 vs. 5.3 μM for iodide and 3.1 vs. 7.3 μM for ascorbate) in comparison with the unmodified Pt electrode. The proposed amperometric sensor was successfully applied for the analysis of ascorbic acid (through its anionic form) in a commercial medicine sample, and the results achieved were in agreement with the value provided by the supplier. Based on the data here presented, the modified graphene electrode shows great promise for ME applications.
Concentrated Production and Conditional Heavy Tails in Commodity Returns
Authors: Merener Nicolas 
Published: April 2015

AbstractI study the impact of commodity production concentration on the occurrence of extreme commodity returns. I explore this issue in a sample of 22 agricultural, mineral and energy commodities of global scope that are liquidly traded through futures at the most important exchanges. I find that measures of production concentration such as the Herfindahl index computed on national shares of global output, or the market share of the top three producers, had significant and positive effect on measures of extreme returns during 1995–2012, as implied by daily return kurtosis or the shape parameter of the distribution of extreme returns. Volatility persistence appears unlikely to generate the cross sectional kurtosis observed empirically unless heavy tailed conditional returns are also included in the dynamics. The results are economically significant and robust to the inclusion of controls for inventories, futures liquidity, and country size. These findings are consistent with a simple mechanism of aggregation of globally distributed local supply shocks that impact global supply and hence commodity prices. © 2015 Wiley Periodicals, Inc. Jrl Fut Mark 36:46–65, 2016
Psychoactive prescribing for older people—what difference does 15 years make?
Authors: Hughes Lloyd D. , Cochrane Lynda , McMurdo Marion E. T. , Guthrie Bruce 
Published: April 2015

ObjectiveThe objective of the study was to review prescribing of psychoactive medications for older residents of the Tayside region of Scotland.MethodsThe analysis used community prescribing data in 1995 and 2010 for all older residents in Tayside. For each psychoactive drug class, the name of the most recently prescribed drug and the date prescribed were extracted. The relative risk (RR) and 95% confidence intervals (CI) for patients receiving psychoactive medication in 2010 were compared with those for patients in 1995. Psychoactive prescribing was analyzed by year, age, gender, and deprivation classification. The chi‐squared test was used to calculate statistical significance.ResultsTotal psychoactive prescribing in people over the age of 65 years has increased comparing 1995 with 2010. Antidepressant [RR = 2.5 (95% CI 2.41–2.59) p < 0.001] and opioid analgesia [RR = 1.21 (1.19–1.24) p < 0.001] prescriptions increased between 1995 and 2010. Hypnotics/anxiolytic [RR = 0.69 (0.66–0.71) p < 0.001] and antipsychotic [RR = 0.83 (0.77–0.88) p < 0.001] prescriptions decreased between 1995 and 2010. An increase in psychoactive prescribing is particularly marked in lower socioeconomic groups. Patients in the least affluent fifth of the population had RR = 1.25 (1.20–1.29) [p < 0.001] of being prescribed one to two psychoactive medications and RR = 1.81 (1.56–2.10) [p < 0.001] of being prescribed three or more psychoactive medications in 2010 compared with those in 1995. The RRs for the most affluent fifth were RR = 1.14 (1.1–1.19) [p < 0.001] and RR = 1.2 (1.01–1.42) [p < 0.001] for one to two, and three or more medications, respectively.ConclusionPsychoactive medication prescribing has increased comparing 1995 with 2010, with increases disproportionately affecting patients in lower socioeconomic groups. The availability of new psychoactive drugs, safety concerns, and economic factors may explain these increases. Copyright © 2015 John Wiley & Sons, Ltd.
Estimating the Dynamics and Persistence of Financial Networks, with an Application to the Sterling Money Market
Authors: Giraitis Liudas , Kapetanios George , Wetherilt Anne , ŽIKEŠ Filip 
Published: April 2015

SummaryWe propose a novel methodology for dynamic econometric modelling of large financial networks subject to persistence, structural changes and sparsity. We estimate bivariate dynamic Tobit‐type models for each pair of banks, allowing for deterministic or stochastic time‐varying parameters, and then aggregate across all bank pairs. To tackle the high dimensionality of the model, we construct a few lagged variables that efficiently summarize the position of a bank pair in the network. We propose a simple and computationally easy kernel‐based local maximum likelihood estimator of the time‐varying parameters of the model and establish its asymptotic properties. We then apply the model to the time series of daily overnight money market network in the UK 2003–2012. The results show that our model can successfully accommodate the numerous structural breaks arising from changes to the monetary framework and captures well the dynamics of the interbank lending relationships in this period. Copyright © 2015 John Wiley & Sons, Ltd.
Factor‐Based Identification‐Robust Interference in IV Regressions
Authors: Kapetanios Georges , Khalaf Lynda , Marcellino Massimiliano 
Published: April 2015

SummaryRobust methods for instrumental variable inference have received considerable attention recently. Their analysis has raised a variety of problematic issues such as size/power trade‐offs resulting from weak or many instruments. We show that information reduction methods provide a useful and practical solution to this and related problems. Formally, we propose factor‐based modifications to three popular weak‐instrument‐robust statistics, and illustrate their validity asymptotically and in finite samples. Results are derived using asymptotic settings that are commonly used in both the factor and weak‐instrument literature. For the Anderson–Rubin statistic, we also provide analytical finite‐sample results that do not require any underlying factor structure. An illustrative Monte Carlo study reveals the following. Factor‐based tests control size regardless of instruments and factor quality. All factor‐based tests are systematically more powerful than standard counterparts. With informative instruments and in contrast to standard tests: (i) power of factor‐based tests is not affected by k even when large; and (ii) weak factor structure does not cost power. An empirical study on a New Keynesian macroeconomic model suggests that our factor‐based methods can bridge a number of gaps between structural and statistical modeling. Copyright © 2015 John Wiley & Sons, Ltd.
Optimization of silk films as substrate for functional corneal epithelium growth
Authors: Jia Liang , Ghezzi Chiara E. , Kaplan David L. 
Published: April 2015

AbstractThe corneal epithelium is the first cellular barrier to protect the cornea. Thus, functional tissue engineering of the corneal epithelium is a strategy for clinical transplantation. In this study, the optimization of silk films (SFs) as substrates for functional human corneal epithelium growth was investigated with primary human corneal epithelial cells on SFs, poly‐D‐lysine (PDL) coated SFs, arginine‐glycine‐aspartic acid (RGD) modified SFs and PDL blended SFs. PDL coated SFs significantly promoted cell adhesion at early phases in comparison to the other study groups, while PDL blended SF significantly promoted cell migration in a “wound healing” model. All film modifications promoted cell proliferation and viability, and a multi‐layered epithelium was achieved in 4 weeks of culture. The epithelia formed were tightly apposed and maintained an intact barrier function against rose bengal dye penetration. The results suggested that a differentiated human corneal epithelium can be established with primary corneal epithelial cells on SFsin vitro, by optimizing SF composition with PDL. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 431–441, 2016.
Adhesive and sealant interfaces for general surgery applications
Authors: Scognamiglio Francesca , Travan Andrea , Rustighi Isabella , Tarchi Paola , Palmisano Silvia , Marsich Eleonora , Borgogna Massimiliano , Donati Ivan , de Manzini Nicolò , Paoletti Sergio 
Published: April 2015

AbstractThe main functions of biological adhesives and sealants are to repair injured tissues, reinforce surgical wounds, or even replace common suturing techniques. In general surgery, adhesives must match several requirements taking into account clinical needs, biological effects, and material features; these requirements can be fulfilled by specific polymers. Natural or synthetic polymeric materials can be employed to generate three‐dimensional networks that physically or chemically bind to the target tissues and act as hemostats, sealants, or adhesives. Among them, fibrin, gelatin, dextran, chitosan, cyanoacrylates, polyethylene glycol, and polyurethanes are the most important components of these interfaces; various aspects regarding their adhesion mechanisms, mechanical performance, and resistance to body fluids should be taken into account to choose the most suitable formulation for the target application. This review aims to describe the main adhesives and sealant materials for general surgery applications developed in the past decades and to highlight the most important aspects for the development of future formulations. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 626–639, 2016.
Cancellous bone healing around strontium‐doped hydroxyapatite in osteoporotic rats previously treated with zoledronic acid
Authors: Li Yunfeng , Shui Xueping , Zhang Li , Hu Jing 
Published: April 2015

AbstractBisphosphonates (BPs) are potent anti‐osteoporotic agents. Strontium‐doped hydroxyapatite (HA) (SrHA) has been reported to increase bone density and improve trabecular microarchitecture in osteoporotic animals. But information about the effect of SrHA on the surrounding bone tissue in osteoporotic animals previously on BPs treatment is limited. We hypothesize that SrHA will induce increased bone density in the vicinity of the material when compared to HA, even in osteoporotic animals previously treated with BPs. HA and 10%SrHA (HA with 10 mol % calcium substituted by strontium) implants were prepared and characterized by scanning electronic microscopy (SEM), X‐ray photoemission spectroscopy (XPS), and X‐ray diffraction (XRD). Osteoporotic animal model was established by bilateral ovariectomy. Twelve weeks later, all OVX rats accepted subcutaneous injection of zoledronic acid (ZOL) at the dose of 1.5 μg/kg weekly for another twelve weeks. Subsequently, rod‐shaped HA and SrHA implants were inserted in the distal femur of the OVX animals previously treated with ZOL. Eight weeks after implantation, specimens were harvested for histological and micro‐computed tomography (micro‐CT) analysis. Compared to HA, 10%SrHA raised the percent bone volume by 32.7%, the mean trabecular thickness by 36.5%, the mean trabecular number by 34.3%, the mean connectivity density by 38.4%, while the mean trabecular separation showed no significant difference. 10%SrHA also increased the bone area density by 36.3% in histological analysis. Results from this study indicated that 10%SrHA increased bone density and improved trabecular microarchitecture around implants in osteoporotic animals previously treated with ZOL when compared to HA. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 476–481, 2016.
Application of ZnO‐Al2O3 Nanocomposite as Nanocatalyst for Photodegradation of Acid Violet 5B
Authors: Karami Hassan , Karimi Mohammad Ali , Jokar Raheleh 
Published: April 2015

AbstractZnO‐Al2O3 nanocomposite (ZANC) is used as nanocatalyst for photodegradation of acid violet 5B (AV5B) as an industrial dye. The experimental data shows that the degradation of AV5B is accelerated by ZANC and UV light. The effects of various parameters such as pH, hydrogen peroxide and ethanol are investigated on the photodegradation efficiency. Photocatalytic degradation rate of AV5B is increased by ethanol and hydrogen peroxide. Based on the kinetic studies, the rate constant of the photodegradation reaction is estimated 2.829 × 10‐1 min‐1.
Photocatalytic Activity of TiO2 Nanofibers with Doped La Prepared by Electrospinning Method
Authors: Ma Yan‐Ting , Li Shu‐Dan 
Published: April 2015

AbstractLa‐TiO2 nanofibers are prepared by a sol‐gel assisted electrospinning method. The structure and morphology of La‐TiO2 nanofibers are characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis shows that the weight percentage of anatase and rutile in the 1.5 mol% La‐TiO2 nanofibers calcined at 600 °C is about 8:2, which is similar to P‐25. The XRD data of La‐TiO2 nanofibers with different La content shows that La3+ dopant has a great inhibition on TiO2 phase transformation. The photocatalytic activity of the as‐prepared La‐TiO2 nanofibers is evaluated by photocatalytic decolorization of Methylene Blue (MB) aqueous solution. The results show that the 1.5 mol% La‐TiO2 nanofibers calcined at 600 °C exhibit high photocatalytic activity, indicating that 600 °C and 1.5 mol% are the appropriate calcination temperature and optimal molar ratio of La to Ti, respectively.
A Highly Efficient Tandem Knoevenagel/Michael Reaction Using Mohr’s Salt Hexahydrate as a Green and Powerful Catalyst: Selective Synthesis of Benzylpyrazolocoumarins on Water
Authors: Eskandari Khalil , Karami Bahador , Khodabakhshi Saeed , Farahi Mahnaz 
Published: April 2015

AbstractIn this work, new, efficient, and environmentally adapted synthesis of benzylpyrazolocoumarins in one‐pot is introduced. From tri‐component reaction of a wide range of aryl aldehydes, 4‐hydroxycoumarin, and 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one on water, benzylpyrazolocoumarins with good to excellent yields in a green procedure were synthesized. The highly efficient role of ferrous ammonium sulfate hexahydrate (Mohr’s salt) as a new green catalyst in this synthesis is obviously demonstrated. This novel procedure is an effective, cheap and environmentally adapted route to the synthesis of benzylpyrazolocoumarin derivatives. The crude products recrystallized to afford the crystalline pure product. This novel procedure has some advantages such as high efficiency, simplicity, high rate and environmental safety.
Nanomagnetic‐supported Sulfonic Acid: Simple and Rapid Method for the Synthesis of α,α′‐Bis‐(substituted‐benzylidene) Cycloalkanones
Authors: Amoozadeh Ali , Kolvari Eskandar , Koukabi Nadiya , Otokesh Somayeh 
Published: April 2015

AbstractNanomagnetic‐supported sulfonic acid is found to be a powerful and reusable heterogeneous catalyst for the rapid synthesis of α,α′‐bis‐(substituted‐benzylidene)cycloalkanones under conventional heating and solvent free conditions. High yield, simple work up and easy recovery of the catalyst are the most obvious advantages of this procedure.
Adsorption of 4‐Chloro‐2‐methylphenoxy Acetic Acid (MCPA) from Aqueous Solution onto Cu‐Fe‐NO3 Layered Double Hydroxide Nanoparticles
Authors: Nejati Kamellia , Davari Soheila , Rezvani Zolfaghar , Dadashzadeh Mahin 
Published: April 2015

AbstractThe nanoparticles of Cu‐Fe‐NO3 layered double hydroxide (LDH) were prepared with Cu/Fe molar ratio of 2:1 by a thermal process and co‐precipitation method at pH 9 and were characterized by X‐ray powder diffraction (XRPD), thermal gravimetric analysis (TGA), atomic adsorption spectroscopy (AAS) and fourier infrared spectroscopy (FT‐IR). The size and morphology of nanoparticles were examined by transmission electron microscopy (TEM). Cu‐Fe‐NO3‐LDH was studied as a potential adsorbent of the acid herbicide MCPA [(4‐chloro‐2‐methylphenoxy) acetic acid] as function of pH, contact time and temperature. The results showed high and rapid adsorption of MCPA on the LDH. The characterization of the adsorption products by XRD indicates that the intercalation of MCPA between the LDH layers has not occurred and surface adsorption has happened. The adsorption kinetic was tested for pseudo‐first‐order, pseudo‐second‐order, elovich and intra‐particle diffusion kinetic models and rate constants were calculated. Freundlich and Langmuir isotherm models were applied to experimental equilibrium data obtained from the measurements of pesticide adsorption. Langmuir isotherm slightly better fitted to the experimental data than that of Freundlich. In the adsorption experiments, the Gibbs free energy ΔG0 values, the enthalpy ΔH0, and entropy ΔS0 were determined.