bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exciton Dynamics in Semiconductor Nanocrystals
Authors: Wheeler Damon A. , Zhang Jin Z. 
Published: April 2013

AbstractThis review article provides an overview of recent advances in the study and understanding of dynamics of excitons in semiconductor nanocrystals (NCs) or quantum dots (QDs). Emphasis is placed on the relationship between exciton dynamics and optical properties, both linear and nonlinear. We also focus on the unique aspects of exciton dynamics in semiconductor NCs as compared to those in bulk crystals. Various experimental techniques for probing exciton dynamics, particularly time‐resolved laser methods, are reviewed. Relevant models and computational studies are also briefly presented. By comparing different materials systems, a unifying picture is proposed to account for the major dynamic features of excitons in semiconductor QDs. While the specific dynamic processes involved are material‐dependent, key processes can be identified for all the materials that include electronic dephasing, intraband relaxation, trapping, and interband recombination of free and trapped charge carriers (electron and hole). Exciton dynamics play a critical role in the fundamental properties and functionalities of nanomaterials of interest for a variety of applications including optical detectors, solar energy conversion, lasers, and sensors. A better understanding of exciton dynamics in nanomaterials is thus important both fundamentally and technologically.
Clinical and genetic study of a family with a paternally inherited 15q11–q13 duplication
Authors: Marini Carla , Cecconi Antonella , Contini Elisa , Pantaleo Marilena , Metitieri Tiziana , Guarducci Silvia , Giglio Sabrina , Guerrini Renzo , Genuardi Maurizio 
Published: April 2013

AbstractInterstitial chromosome 15q11–q13 duplications are associated with developmental delay, behavioral problems and additional manifestations, including epilepsy. In most affected individuals the duplicated chromosome is maternally derived, whereas paternal inheritance is more often associated with a normal phenotype. Seizures have not been described in patients with paternal dup 15q11–q13. We describe a family with five individuals in three generations with a paternally‐inherited 15q11–q13 duplication, four of whom exhibited abnormal phenotypic characteristics, including seizures. The 18‐year‐old female proband presented with moderate intellectual disability, obesity, and epilepsy. Her brother manifested learning disability and behavioral problems. They both inherited the 15q11–q13 dup from their father who had a normal phenotype. Their paternal uncle and grandfather also had the duplication and were reported to have had seizures. Array‐CGH and MLPA analyses showed that the duplication included the TUBGCP5, CYFIP1, MKRN3, MAGEL2, NDN, SNRPN, UBE3A, ATP10A, GABRB3, GABRA5, GABRG3, and OCA2 genes. This report provides evidence for intrafamilial phenotypic variability of paternal dup 15q11–q13, ranging from normal to intellectual disability and seizures, and potentially expanding the phenotype of paternal 15q11–q13 interstitial duplications. © 2013 Wiley Periodicals, Inc.
Electrochemical grafting of 4‐phenoxybenzoic acid units onto oxidized carbon fibers as a first step for high temperature composites
Authors: Soulis Spyridon , Triantou Despina , Simitzis Johannis 
Published: April 2013

ABSTRACTThe electropolymerization of 4‐phenoxybenzoic acid (4‐PBA) onto carbon fibers (CFs) was studied as a way to synthesize coated CFs with grafted poly(para‐phenyl ether ketone) (p‐PEK) and enhance their wettability by matrices such as PEK or PEEK. Since the pristine CFs were not electrochemically active enough, a proper electrochemical oxidation treatment using sulfuric acid was applied, capable of creating oxygen‐containing groups onto their surface. The groups formed in the oxidized CFs were electron acceptors and their amount was quasi‐quantitatively evaluated based on their ability to absorb dye from aqueous solutions. The graft electropolymerization of 4‐PBA onto the CFs electrode was achieved at anodic potentials using cyclic voltammetry (CV). The grafted coating had a thickness of up to 0.35 μm. The materials were characterized using FTIR, NMR, SEM, and TGA. A possible reaction mechanism is proposed, for the grafting of 4‐PBA units onto the carboxyl groups of the treated CFs. The coated CFs were more thermally stable compared to the treated CFs without grafting. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1466–1478, 2013
Preparation, characterization, and release properties of hydrogels based on hyaluronan for pharmaceutical and biomedical use
Authors: Roig‐Roig Ferran , Solans Conxita , Esquena Jordi , García‐Celma María José 
Published: April 2013

ABSTRACTHyaluronic acid (HA) is a natural polysaccharide that is widely distributed in the human body. Its physicochemical properties and high biocompatibility make it a good candidate for biomedical and pharmaceutical uses. In the present work, we report HA‐based hydrogels that could be applied as drug delivery systems or as implants for the treatment of joint diseases. We use butanediol diglycidyl ether as a chemical crosslinker to obtain HA hydrogels. Using a new dissolution tester and ketoprofen (KP) as a model drug, we study the release properties of the hydrogels. We obtain homogeneous and transparent hydrogels with high strength and elasticity. The swelling ratio (SR) depends on the crosslinker concentration and pH of the medium. We also reveal differences between the release profile of KP from swollen and unswollen hydrogels. The characteristics and differences in KP release profiles depending on the SR suggest the possibility of obtaining controlled release from HA‐based hydrogels. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1377‐1382, 2013
Preparation and characterization of high‐performance poly(ether ether ketone) fibers with improved spinnability based on thermotropic liquid crystalline poly(aryl ether ketone) copolymer
Authors: Luan Jiashuang , Zhang Shuling , Zhang Mei , Geng Zhi , Wang Yang , Wang Guibin 
Published: April 2013

ABSTRACTHigh‐performance poly(ether ether ketone) (PEEK) fibers were prepared by melt‐spinning in the presence of thermotropic liquid crystalline poly(aryl ether ketone) copolymer (FPAEKLCP). The rheological and mechanical properties, birefringence, orientation, and crystallization of the resulting PEEK/FPAEKLCP fibers were characterized by using a melt flow indexer, capillary rheometer, single fiber electronic tensile strength tester, polarized light microscopy (PLM), and wide‐angle X‐ray diffraction (WAXD), respectively. The results indicate that the melt viscosity of PEEK significantly reduced by introducing FPAEKLCP, followed by the improvements in the spinnability and the quality of as‐spun fibers. The tensile properties of PEEK/FPAEKLCP fibers mainly depend on the content of FPAEKLCP, drawing temperature, drawing ratio, and annealing processes. Moreover, the tensile strength and modulus of PEEK/FPAEKLCP fibers are obviously higher than those of neat PEEK fibers under the same processing conditions. This should be attributed to an enhancement in the orientation and crystallization of PEEK compounded with FPAEKLCP. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1406‐1414, 2013
A multifunctional luminescent europium photostabilizer based on a novel hindered amine ligand and phenanthroline
Authors: Wu Jiajie , Feng Jiachun 
Published: April 2013

ABSTRACTA novel hindered amine ligand, mono‐2,2,6,6‐tetramethyl‐4‐piperidyl‐succinate (MTPS), has been designed to chelate europium(III) ion with 1,10‐phenanthroline (Phen) as a coligand to prepare polymer photostabilizer. The luminescent property of the stabilizer and its efficiency of protecting polymer matrix from photodegradation have also been investigated. Under UV excitation, the stabilizer has red light emission in both ethanol solution and polypropylene (PP) matrix. The PP sheets containing the stabilizer display significantly improved photostability, which may be attributed to MTPS which scavenges radical, as well as Phen which makes the complex dissipate the absorbed ultraviolet light in a harmless manner. These preliminary results demonstrate that the introduction of the stabilizer can endow polymer matrices not only excellent photoluminescent properties but also improved photostability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1399‐1405, 2013
The biotransformation of oleuropein in rats
Authors: Lin Peiyan , Qian Weidong , Wang Xiaoying , Cao Li , Li Shaofen , Qian Tianxiu 
Published: April 2013

ABSTRACTA highly sensitive and specific LC‐MS/MS method was developed to investigate thein vivobio‐transformation of oleuropein in rat. Rat feces and urine samples collected after oral administration were determined by liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative‐ion mode. The assay procedure involves a simple liquid–liquid extraction of parent oleuropein and the metabolite from rat feces and urine with ethyl acetate. Chromatographic separation was operated with 0.1% formic acid aqueous and methanol in gradient program at a flow rate of 0.50 mL/min on an RP‐C18column with a total run time of 31 min. This method was successfully applied to simultaneous determination of oleuropein and its metabolites in rat feces and urine. De‐glucosylation, hydrolysis, oxygenation and methylation were found to comprise the major metabolic pathway of oleuropein in rat gastrointestinal tract and three metabolites were absorbed into the blood circulatory system within 24 h after oral administration. Copyright © 2013 John Wiley & Sons, Ltd.
5′‐Trityl‐Substituted Thymidine Derivatives as a Novel Class of Antileishmanial Agents: Leishmania infantum EndoG as a Potential Target
Authors: Casanova Elena , Moreno David , Gigante Alba , Rico Eva , Genes Carlos Mario , Oliva Cristina , Camarasa María‐José , Gago Federico , Jiménez‐Ruiz Antonio , Pérez‐Pérez María‐Jesús 
Published: April 2013

AbstractTwo series of 5′‐triphenylmethyl (trityl)‐substituted thymidine derivatives were synthesized and tested against Leishmania infantum axenic promastigotes and amastigotes. Several of these compounds show significant antileishmanial activity, with IC50 values in the low micromolar range. Among these, 3′‐O‐(isoleucylisoleucyl)‐5′‐O‐(3,3,3‐triphenylpropanoyl)thymidine displays particularly good activity against intracellular amastigotes. Assays performed to characterize the nature of parasite cell death in the presence of the tritylthymidines indicated significant alterations in mitochondrial transmembrane potential, an increase in superoxide concentrations, and also significant decreases in DNA degradation during the cell death process. Results point to the mitochondrial nuclease LiEndoG as a target for the action of this family of compounds.
The influence of adjuvant radiotherapy dose on overall survival in patients with resected pancreatic adenocarcinoma
Authors: Hall William A. , Colbert Lauren E. , Liu Yuan , Gillespie Theresa , Lipscomb Joseph , Hardy Claire , Kooby David A. , Prabhu Roshan S. , Kauh John , Landry Jerome C. 
Published: April 2013

BACKGROUNDAdjuvant radiotherapy (A‐RT) for patients with resected pancreatic adenocarcinoma (PAC) is controversial. In the current study, the authors aim to determine whether there is an association between overall survival (OS) and A‐RT dose.METHODSNational Cancer Data Base (NCDB) data were obtained for all patients who received A‐RT for resected PAC from 1998 through 2002. Univariate and multivariate survival analyses were performed along with Kaplan‐Meier estimates for A‐RT levels < 40 grays (Gy), 40 Gy to < 50 Gy, 50 Gy to < 55 Gy, and ≥ 55 Gy.RESULTSA total of 1385 patients met the inclusion criteria. The median age of the patients was 64 years (range, 29 years‐87 years). All patients underwent surgical resection and A‐RT with or without chemotherapy. A total of 231 patients were diagnosed with stage I disease, 273 were diagnosed with stage II disease, 734 were diagnosed with stage III disease, and 126 were diagnosed with stage IVA disease (according to the fifth edition of the American Joint Committee on Cancer); 21 were found to have an unknown stage of disease. The median A‐RT dose was 45 Gy (range, 1.63 Gy‐69 Gy). The median OS was 21 months (95% confidence interval [95% CI], 19 months‐23 months). On multivariate analysis, an A‐RT dose < 40 Gy (hazards ratio [HR], 1.30 [95% CI, 1.03‐1.66]; P = .031), an A‐RT dose of 40 Gy to < 50 Gy (HR, 1.17 [95% CI, 1.00‐1.37]; P = .05), and an A‐RT dose ≥ 55 Gy (HR, 1.44 [95% CI, 1.08‐1.93]; P = .013) predicted worse OS compared with the reference category of 50 Gy to < 55 Gy.CONCLUSIONSA‐RT doses of < 40 Gy, 40 Gy to < 50 Gy, and ≥ 55 Gy were found to be associated with an inferior OS. The dose of A‐RT delivered appears to influence OS and a prospective study evaluating the addition of optimally delivered A‐RT for patients with resected PAC is needed. Cancer 2013;119:2350–2357. © 2013 American Cancer Society.
Providing QoS strategies and cloud‐integration to web servers by means of aspects
Authors: Giunta Rosario , Messina Fabrizio , Pappalardo Giuseppe , Tramontana Emiliano 
Published: April 2013

SummaryThe main responsibilities of a web server are to listen from the communication channel and to prepare replies to requests. Additional responsibilities include adapting processing activities, for example, through scheduling or request filtering, so as to satisfy Quality of Service (QoS) requirements. Typical QoS‐related concerns address behavioural constraints (e.g. response time bounds, satisfiable by scheduling the most urgent requests first) and resource monitoring, for optimal use. Although such concerns are spread across several web server components, they should be handled separately from communication‐related ones, for the sake of modularity.For this purpose, we advocate recourse to aspect‐oriented programming and illustrate it by showing how a QoS‐related layer can be smoothly superimposed on top of a well‐known, unmodified, web server Jigsaw. As part of the provided support, requests are assessed and partitioned into those that can be appropriately handled by using local resources and those needing further resources. For the latter requests, cloud‐based resources are gathered. Aspect‐orientation enables new QoS‐related code to be separated from web server modules so as to keep existing code unaltered, while runtime behaviour is modified with the measures needed to handle QoS concerns. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis of Chiral Spirocyclopentenyl‐β‐lactams through Phosphane‐Catalyzed [3+2] Annulation of Allenoates with 6‐Alkylidenepenicillanates
Authors: Santos Bruna S. , Pinho e Melo Teresa M. V. D. 
Published: April 2013

AbstractThe first examples of phosphane‐catalyzed [3+2] annulation of allenoates to 6‐alkylidenepenicillanates leading to chiral spirocyclopentenyl‐β‐lactams are reported. The synthesis of this new type of β‐lactams involved the generation of either two or three consecutive stereogenic centers, including a quaternary chiral center. Although the reported methodology is highly diastereoselective, the regioselectivity is dependent on the nature of the methylenepenicillanate derivative and on the nature of the allenoate γ‐substituent.
A Genetically Encodable Ligand for Transfer Hydrogenation
Authors: Mayer Clemens , Hilvert Donald 
Published: April 2013

AbstractSimple tripeptides are shown here to be versatile ligands for iridium‐catalyzed transfer hydrogenations affording large acceleration effects. A water‐soluble iridium complex with Gly‐Gly‐Phe, for example, catalyzes the reduction of diverse ketones, aldehydes, and imines by formate with turnover frequencies rivaling or outperforming those of established ligand systems. Regioselective reduction of coenzyme NAD+ to NADH illustrates the potential utility of this system for biotechnological applications. Because peptides are genetically encodable, they represent an attractive class of foldamer ligands for creating artificial metalloenzymes.
Ultrahigh Durable PtPd/C Nanowire Networks Catalyst Synthesized by Modified Phase Transfer Method for Methanol Oxidation
Authors: Chu Y.‐Y. , Wang Z.‐B. , Cao J. , Gu D.‐M. , Yin G.‐P. 
Published: April 2013

AbstractA novel PtPd/C nanowire catalyst with interconnected network and fewer great grain boundaries has been successfully prepared by templateless and modified phase‐transfer method using cetyltrimethylammonium bromide as a capping in ethylene glycol solution by microwave‐assisted process. Its structure, composition, and morphology are characterized by X‐ray diffraction, energy dispersive analysis of X‐ray, and transmission electron microscopy, respectively. The electrochemical measurements demonstrate that the highly dispersed and uniform PtPd/C nanowire networks catalyst has a significantly higher electrocatalytic activity and durability for the methanol oxidation as compared to solid solution PtPd/C. The greatly improved durability of PtPd/C nanowire networks catalyst is mainly a consequence of the unique interconnected network structure with fewer grain boundaries, which provide more facile pathway for the electron transfer, and inhibit the particle growth and agglomeration, as well as prevent the particles embedded in the microporous of carbon support to enhance the Pt utilization.
The semidiurnal tide in the middle atmosphere of Mars
Authors: Kleinböhl Armin , John Wilson R. , Kass David , Schofield John T. , McCleese Daniel J. 
Published: April 2013

AbstractAtmospheric thermal tides are global oscillations in atmospheric fields that are subharmonics of a solar day. While atmospheric tides on Earth are mainly relevant in the upper atmosphere, on Mars, they dominate temperature variations and winds throughout the atmosphere. Observations and model simulations to date have suggested that the migrating diurnal tide is the predominant mode in the Martian atmosphere, and that the semidiurnal tide is only relevant in the tropical middle atmosphere during conditions of high dust loading. New comprehensive observations by the Mars Climate Sounder in a geometry that allows coverage of multiple local times show that the semidiurnal tide is a dominant response of the Martian atmosphere throughout the Martian year. The maximum semidiurnal amplitude of ~ 16 K is found at southern winter high latitudes, which makes it the largest tidal amplitude observed in the Martian middle atmosphere outside of dust storm conditions. The semidiurnal tide can be successfully modeled due to recent advances of Mars General Circulation Models (MGCMs) that include the radiatively active treatment of water ice clouds. Tidal forcing occurs through absorption of radiation by aerosols and points to the vertical structure of dust and clouds and their radiative effects as being essential for our understanding of the thermal structure and the general circulation of the Martian atmosphere. As with terrestrial GCMs trying to quantify mechanisms affecting climate, future Mars modeling efforts will require microphysical schemes to control aerosol distributions, and vertically and temporally resolved measurements of temperature and aerosols will be essential for their validation.
USING IN‐LINE RESERVOIR OPERATIONAL STRATEGY TO IMPROVE DEZ MAIN IRRIGATION CANAL PERFORMANCE
Authors: Hashemy S. M. , Monem M. J. , Isapoor S. , van Overloop P. J. 
Published: April 2013

ABSTRACTIn this study an in‐line storage strategy is applied to improve the existing operational performance of an upstream‐controlled 13‐pool irrigation canal. Three pools in the upstream, middle and downstream sections of the main canal are considered as in‐line reservoirs. Decentralized proportional‐integral (PI) controllers are designed to regulate their upstream water levels based on a mixed control method. Each regulator is coupled to its upstream in‐line reservoir. The objectives of the controlled system are keeping the upstream water level of each regulator at the target levels; reducing delay times of flow travelling in the canal and compensating for mismatches between upstream supply and downstream demands. Existing and proposed operational methods are compared, using the hydrodynamic modelling package Sobek, considering a severe and sudden increasing– decreasing flow condition. In this case study, the water level profiles and controller performance indicators imply that in‐line storage in the main canal decreases water level deviations in most of the pools in the range of 24–57 % in comparison with the current operation. Moreover, using in‐line reservoirs decreases the delay times especially in the downstream part of the canal. Copyright © 2013 John Wiley & Sons, Ltd.
Hepatoprotective effects of syringin on fulminant hepatic failure induced by D‐galactosamine and lipopolysaccharide in mice
Authors: Gong Xia , Zhang Li , Jiang Rong , Wang Chang‐Dong , Yin Xin‐Ru , Wan Jing‐Yuan 
Published: April 2013

ABSTRACTThe prognosis for fulminant hepatic failure (FHF) still remains extremely poor with a high mortality and, therefore, better treatments are urgently needed. Syringin, a main active substance isolated from Eleutherococcus senticosus, has been reported to exhibit immunomodulatory and anti‐inflammatory properties. In this study, we investigated the effects and underlying mechanisms of syringin on lipopolysaccharide (LPS) and D‐galactosamine (D‐GalN)‐induced FHF in mice. Mice were administered syringin (10, 30 and 100 mg kg–1, respectively) intraperitoneally (i.p) 30 min before LPS/D‐GalN then mortality and liver injury were evaluated subsequently. We found that syringin dose‐dependently attenuated LPS/D‐GalN‐induced FHF, as indicated by reduced mortality, inhibited aminotransferase and malondialdehyde (MDA) content, an increased glutathione (GSH) concentration and alleviated pathological liver injury. In addition, syringin inhibited LPS/D‐GalN‐induced hepatic caspase‐3 activation and hepatocellular apoptosis, myeloperoxidase (MPO) activity and intercellular adhesion molecule‐1 (ICAM‐1) expression, as well as hepatic tissues tumor necrosis factor‐alpha (TNF‐α) production and NF‐κB activation in a dose‐dependent manner. These experimental data indicate that syringin might alleviate the FHF induced by LPS/D‐GalN through inhibiting NF‐κB activation to reduce TNF‐α production. Copyright © 2013 John Wiley & Sons, Ltd.
Biodegradable weft‐knitted intestinal stents: Fabrication and physical changes investigation in vitro degradation
Authors: Li Gang , Li Yi , Lan Ping , Li Jiashen , Zhao Zheng , He Xiaowen , Zhang Jing , Hu Hong 
Published: April 2013

AbstractBiodegradable stents can alleviate intestinal obstruction and stenosis in patients. The objective of this study was to develop a biodegradable polydioxanone (PDO) stent using weft‐knitting technology and then investigate its biodegradation behaviors in vitro. PDO monofilament with linear density of 100 ± 10 tex was knitted into a tubular stent using a tubular weft‐knitting machine. The physical and mechanical properties were evaluated according to the British standard BS EN 13895:2003 and ISO 7198:1998. The biodegradation behaviors of PDO weft‐knitted stent in a phosphate buffer solution (pH = 6.8 ± 0.2, 37 ± 0.5°C) were then investigated. The results showed that the stent maintained more than 60% of its original radial force above 12 weeks. During the 16 weeks of degradation, weight, crystallization, and pH change indicated the degradation medium was diffused into the chain segments of low molecular weight due to the rupture of ester bonds in the monofilament. Fourier transform infrared spectroscopy results demonstrated that the chemical structure of PDO polymer is stable during the in vitro degradation. In conclusion, this biodegradable stent can find valuable applications in treatment of intestinal obstruction and stenosis clinically. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 982–990, 2014.