bluuebunny/crossref_metadata_2025_split huggingface dataset:
2,8-Dihydroxyadenine Urolithiasis. Case Report and Literature Review
Authors: Arancio Matteo , Ranzoni Stefania , Delsignore Alessandro , Landi Giuseppe , Maffei Nicola , Marcato Maurizio , Mina Alessandro , Martinengo Carlo 
Published: May 2011

Introduction 2,8-Dihydroxyadenine (DHA) urolithiasis is a rare type of urinary stone disease secondary to deficiency of adenine phosphoribosyltransferase (APRT) activity, a rare, inherited autosomal recessive disease with an incidental rate from 0.4 to 1.2%. The prevalence is higher among Japanese than other ethnic groups. APRT normally catalyzes the conversion of adenine to adenosine monophosphate and its deficiency results in 2,8-dihydroxyadenine (2,8-DHA) accumulation. This compound is extremely insoluble and its crystallization can lead to stone formation and renal failure. We report the case of 2,8-dihydroxyadenine (DHA) urolithiasis in a 52-year-old male patient. Material and Methods In December 2008 a 52-year-old Caucasian man was admitted to our hospital with sudden pain in the left lumbar region. Abdominal X-ray did not show any radiopaque urinary stone. I.V. pielography showed a radiolucent left lumbar ureteral (0.6 mm) and renal (1.5 cm) stone. After therapy with tamsulosin, the ureteral stone was excreted. Successful ESWL treatment was performed for renal stone. He presented a clinical history of several episodes of bilateral renal colic and two prior ESWL treatment for radiolucent stones. Chemolitholysis was never successful. Results Stone analysis by infrared spectroscopy and microscopic examination of urine reveal typical 2,8-DHA crystals. APRT deficiency was detected in the hemolysate of erythrocyte. Partial deficiency of APRT in the patient's relatives showed heterozygosity of the enzyme defect. Allopurinol therapy successfully prevented further stone formation. 20 months later the patient remains stone free. Conclusion Two types of deficit are commonly distinguished, depending on the level of residual APRT activity. Type I is complete enzyme deficiency. Type II shows residual activity in cell lysates, but enzyme activity is not demonstrable in intact cells. About 78% of the Japanese patients belong to type II. The diagnosis of the disease is based on stone analysis by infrared spectroscopy or microscopic examination of urine, which may reveal typical 2,8-DHA crystals. Molecular approach can identify mutations, which are responsible of this inherited disease. Excessive water intake, restriction of foods with high adenine contents and administration of allopurinol are useful treatments. APRT deficiency is a rare disease but we can consider this pathology in case of recurrent radiolucent stones after chemolitolysis.
Heterogeneous Transparent Ultrathin Films with Tunable‐Color Luminescence Based on the Assembly of Photoactive Organic Molecules and Layered Double Hydroxides
Authors: Yan Dongpeng , Lu Jun , Wei Min , Qin Shenghui , Chen Li , Zhang Shitong , Evans David G. , Duan Xue 
Published: May 2011

AbstractMulticolor luminescent films have great potential for use in optoelectronics, solid‐state light‐emitting materials, and optical devices. This work describes a systematic investigation of the ordered assembly of two‐ (blue/green, blue/orange, red/blue, red/green) and three‐color (blue/red/green) light‐emitting ultrathin films (UTFs) by using different photofunctional anions [bis(N‐methylacridinium)@polyvinylsulfonate ion pairs and anionic derivatives of poly(p‐phenylene), poly(phenylenevinylene), and poly(thiophene)] and Mg‐Al‐layered double hydroxide nanosheets as building blocks. The rational combination of luminescent components affords precise control of the emission wavelengths and intensity, and multicolored luminescent UTFs can be precisely tailored covering most of the visible spectral region. The assembly process of the UTFs and their luminescence properties, as monitored by UV–vis absorption and fluorescence spectroscopy, resulted in a gradual change in luminescence color in the selected light‐emitting spectral region upon increasing the number of deposition cycles. X‐ray diffraction demonstrates that the UTFs are periodic layered structures involving heterogeneous superlattices associated with individual photoactive anion–LDH units. These UTFs also exhibit well‐defined multicolor polarized fluorescence with high polarization anisotropy, and the emissive color changes with polarization direction. Therefore, this work provides a way of fabricating heterogeneous UTFs with tunable‐color luminescence as well as polarized multicolor emission, which have potential applications in the areas of light displays and optoelectronic devices.
Electrochemically Induced High Capacity Displacement Reaction of PEO/MoS2/Graphene Nanocomposites with Lithium
Authors: Xiao Jie , Wang Xiaojian , Yang Xiao‐Qing , Xun Shidi , Liu Gao , Koech Phillip K. , Liu Jun , Lemmon John P. 
Published: May 2011

AbstractNanocomposites comprised of poly(ethylene oxide), molybdenum disulfide, and graphene were prepared by the hydrolysis of lithiated molybdenum disulfide in an aqueous solution of PEO and graphene. Structural analysis by XRD shows the nanocomposites are disordered with an expansion of ∼6 Å in the interlayer spacing. During the first discharge, the nanocomposites electrochemically dissociates irreversibly into Li2S and Mo and are able to continously cycle as Li2S +Mo/Lix ↔ S + Mo + Lix+2 as shown by XRD of the discharged electrodes at different depth of discharge (DOD), cyclic voltammetry (CV), and high resolution TEM. A significant increase of the reversible capacity is found in as‐prepared MoS2/PEO/graphene composite. The results suggest a new electro‐interaction between lithium and molybdenum metal that only occurs in the nanoregime and is enhanced by PEO. The addition of 2 wt% of graphene to the nanocomposites greatly increases the rate capability with rates as high as 10000mA g−1 yielding > 250mAh g−1 and recovering to > 600 mAhr g−1 at 50mA g−1.
Distribution of Y‐chromosome q lineages in native americans
Authors: Bisso‐Machado Rafael , Jota Marilza S. , Ramallo Virginia , Paixão‐Côrtes Vanessa R. , Lacerda Daniela R. , Salzano Francisco M. , Bonatto Sandro L. , Santos Fabrício R. , Bortolini Maria Cátira 
Published: May 2011

AbstractObjectives:This investigation was performed to identify and evaluate the distribution of all 15 Y‐chromosome lineages belonging to the Q clade in a sample of natives from South America.Methods:One hundred and forty‐eight individuals from 20 Native American populations, as well as 24 Asian samples including Eskimos, were tested with 18 biallelic loci that can identify all currently known lineages of the Y‐Chromosome Q clade. Sequencing was performed in part of the sample (∼180,000 nucleotides, which detected, for instance, several downstream markers related to the Q1a3a lineage).Results:No new mutation was found and Q1a3a was consistently found in high frequencies in all populations, followed at a much lower frequency by Q1a3*, while Q1a3a derived‐lineages are probably population/tribe/region‐specific.Conclusion:The number of basal Y chromosome lineages in North America is apparently higher than in South America due probably to a bottleneck during the South American colonization and/or more recent Circum‐Arctic gene flow. Am. J. Hum. Biol., 2011. © 2011 Wiley‐Liss, Inc.
Solvothermal synthesis of organically modified α‐zirconium phosphate‐based polystyrene nanocomposites and thermal stability
Authors: Zhang Rui , Hu Yuan 
Published: May 2011

AbstractPolystyrene/α‐zirconium phosphate (PS/OZrP) nanocomposites were prepared based on the organically modified α‐ZrP(OZrP) with hexadecyltrimethyl ammonium bromide (C16) by solvothermal technique and solution refluxing. The structure of the PS/OZrP composites was characterized by X‐ray diffraction and high‐resolution electronic microscopy. The thermal behaviors of the composites obtained were investigated by thermogravimetric analysis. The maximum decomposition temperatures (Tmax) of PS/OZrP nanocomposites prepared by solvothermal method increased gradually from 431 to 458°C with the increase of the OZrP loading from 0 to 20 wt %, and the amounts of the charred residue at 600°C (char wt %) had a remarkable increase from 1.6 to 17.1 wt %, respectively. Moreover, the TG results of the nanocomposites prepared by solvothermal method have more obvious enhancement in the thermal stabilities and especially in the amount of charred residue at 600°C (char wt %), which has a double increase from 4.2 to 8.5 wt % at the content of 10 wt % OZrP than by solution refluxing. All results suggested that the solvothermal method is an effective way for the preparation of PS/OZrP nanocomposites with the intercalated nanostructure, which led to the obviously improved thermal stability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122:593–598, 2011
Weltrekord am Gotthard — ein Jahrhunderttunnel‐Bau
Authors: Caminada Paul 
Published: May 2011

AbstractAm 15. Oktober 2010 wurden in der Oströhre zwischen Sedrun und Faido die letzten Meter des 57 km langen Basistunnels der Gotthardstrecke durchbrochen. Der Anlass wurde als Großereignis gefeiert und von zahlreichen TV‐ und Radiostationen weltweit übertragen: An diesem Tag wurde der längste Tunnel der Welt durchschlagen. Der Süden und der Norden des Alpenkamms rücken einander näher, und die Verbindungen ins Land, wo die Zitronen blühen, werden kürzer, die Zusammenarbeit in Handel und Wirtschaft einfacher. Ein Wunderwerk, wie auch schon geschrieben wurde, ist der Gotthard‐Basistunnel nicht: Für Wissenschaft, Ingenieurwesen und Handwerk ist er das Ergebnis einer stetigen Arbeit, einer aufwendigen Vorbereitung und Planung, eines enormen Aufwands an Material und Maschinen. Kurz und gut: eine ultrateure Investition für europäische direkte und leistungsfähige Verkehrsverbindungen durch die Zentralalpen der Schweiz. Zweifellos ist es ein Pionierwerk der Bergbau‐ und Eisenbahntechnik, aber nur ein kleiner, unbedeutender “Kratzer” in der Geologie und Tektonik dieses Gebirgsmassivs. Dank dieser gewaltigen Untertagbauten bleiben die Naturschönheit der Alpen, unsere Umwelt und Lebensqualität bewahrt. Vom Gotthard, Kurzbezeichnung für Sankt Gotthard oder San Gottardo, fließt das Wasser in die vier Himmelsrichtungen und verbindet die Alpen mit bedeutenden abendländischen Kulturkreisen. Der Berg verdankt seinen Namen dem heiligen Gotthard (Godehard), dem deutschen Bischof von Hildesheim (10./11. Jh.). Er soll auf dem Gotthardpass ein Wunder vollbracht haben, weshalb ihm zu Ehren ein Hospiz errichtet wurde.
Hinterlüftete Vorhangfassaden aus Textilbeton
Authors: Kulas Christian , Schneider Maike , Will Norbert , Grebe Reiner 
Published: May 2011

AbstractDer innovative Verbundwerkstoff textilbewehrter Beton (kurz: Textilbeton) erschließt neue Anwendungsgebiete im Betonbau und bietet im Fassadenbau zahlreiche Vorteile. Durch die Verwendung nicht‐korrodierender technischer Textilien aus alkaliresistentem Glas oder Carbon können die Betondeckungen minimiert werden, und es entstehen extrem schlanke Betonbauteile. Durch die Verwendung eines sogenannten Feinbetons mit Korngrößen bis zu 8 mm in Kombination mit speziellen Nachbehandlungstechniken entstehen architektonisch anspruchsvolle und hochwertige Sichtbetonoberflächen. Anhand mehrerer kürzlich abgeschlossener Anwendungsprojekte wird in dem Artikel das Potential hinterlüfteter Textilbetonfassaden aufgezeigt, die Elementflächen von über 12 m2 bei nur 30 mm dicken Plattenspiegeln aufweisen.Ventilated façade structures made of textile reinforced concrete — structural behavior and construction. The innovative composite material textile reinforced concrete (TRC) opens up new application areas in structural concrete engineering and has advantages especially in the field of façade engineering. By using non‐corrosive technical textiles made of alkali‐resistant glass or carbon, the concrete covers can be minimized resulting in extreme slender concrete members. The used fine‐grained concrete with maximum grain‐sizes of 8 mm in combination with special curing techniques en ables high‐quality fair faced concrete surfaces. The potential of TRC façades has been demonstrated by several projects employing TRC panels with areas over 12 m2 and a thickness of only 30 mm.
Prediction and analysis of protein methylarginine and methyllysine based on Multisequence features
Authors: Hu Le‐Le , Li Zhen , Wang Kai , Niu Shen , Shi Xiao‐He , Cai Yu‐Dong , Li Hai‐Peng 
Published: May 2011

AbstractProtein methylation, one of the most important post‐translational modifications, typically takes place on arginine or lysine residue. The reversible modification involves a series of basic cellular processes. Identification of methyl proteins with their sites will facilitate the understanding of the molecular mechanism of methylation. Besides the experimental methods, computational predictions of methylated sites are much more desirable for their convenience and fast speed. Here, we propose a method dedicated to predicting methylated sites of proteins. Feature selection was made on sequence conservation, physicochemical/biochemical properties, and structural disorder by applying maximum relevance minimum redundancy and incremental feature selection methods. The prediction models were built according to nearest the neighbor algorithm and evaluated by the jackknife cross‐validation. We built 11 and 9 predictors for methylarginine and methyllysine, respectively, and integrated them to predict methylated sites. As a result, the average prediction accuracies are 74.25%, 77.02% for methylarginine and methyllysine training sets, respectively. Feature analysis suggested evolutionary information, and physicochemical/biochemical properties play important roles in the recognition of methylated sites. These findings may provide valuable information for exploiting the mechanisms of methylation. Our method may serve as a useful tool for biologists to find the potential methylated sites of proteins. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 763‐771, 2011.
The effects of shear flow on protein structure and function
Authors: Bekard Innocent B. , Asimakis Peter , Bertolini Joseph , Dunstan Dave E. 
Published: May 2011

AbstractProtein molecules are subjected to potentially denaturing fluid shear forces during processing and in circulation in the body. These complex molecules, involved in numerous biological functions and reactions, can be significantly impaired by molecular damage. There have been many studies on the effects of hydrodynamic shear forces on protein structure and function. These studies are reviewed and the implications to bioprocessing and pathophysiology of certain diseases are discussed. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 733‐745, 2011.
Topography of the recurrent laryngeal nerve in relation to the thyroid artery, Zuckerkandl tubercle, and Berry ligament in Kenyans
Authors: Kaisha W. , Wobenjo A. , Saidi H. 
Published: May 2011

AbstractInjury to the recurrent laryngeal nerve (RLN) is an important but avoidable complication of thyroidectomy. This complication may be avoided by the identification of the nerve facilitated by important landmarks found along its course. The setting for this work is the Human Anatomy Laboratory of the University of Nairobi. The aim of this work is to determine the topographic relationship of the RLN with the inferior thyroid artery (ITA), the tubercle of Zuckerkandl (TZ), and the ligament of Berry (LB) in a Kenyan population. The relationship between the nerve and the above landmarks was determined during dissection of 146 right and left thyroid lobes. One right side of the neck had a nonrecurrent nerve. Of the specimens where relationship was determined, the nerve was anterior to the ITA in 37% of cases and posterior in 51.4%. In relation to the LB, 45.3% were superficial (dorsolateral). The TZ was clearly delineated in 86 of the 146 specimens. No nerve traversed the tubercle. The RLN exhibited variations similar to those in other populations. The TZ when present was a reliable landmark to the nerve. Clin. Anat. 24:853–857, 2011. © 2011 Wiley‐Liss, Inc.
Recent Advances in Amine Synthesis by Catalytic Hydroaminomethylation of Alkenes
Authors: Crozet Delphine , Urrutigoïty Martine , Kalck Philippe 
Published: May 2011

AbstractCarbon–carbon coupling catalyzed by transition metals represents a powerful synthetic method to have an access to organic molecules, especially when they present a significant complexity. The strategy to transform abundant and not expensive reactants into products of pharmaceutical interest by the appropriate catalytic way is of fundamental interest, provided that high conversion rates and selectivities can be gained. During the past decade, considerable progress has been made to transform a simple alkene into an aldehyde by carbonylation, to condense it with an NH function‐containing molecule present in the medium, and to hydrogenate the resulting imine or enamine into the relevant amine. Rhodium complexes are able to catalyze this series of reactions and be an efficient synthetic tool to produce rather sophisticated amines in one‐pot reactions under mild conditions of pressure and temperature. In the future, the production of various amines required by the industry of fine chemicals looks attractive by means of this catalytic method.
Quantitative characterisation of mixing in stirred tank reactors with mean age distribution
Authors: Liu Minye 
Published: May 2011

AbstractA new method is developed to characterise impeller mixing performance of a stirred tank reactor with mean age distribution. The spatial distribution of mean age reveals the non‐uniform distribution of local blend time. The mean age frequency function is found to scale with impeller speed and the ratio of the impeller diameter to the tank diameter. A blend time is defined from the mean age frequency function and this blend time is found to agree very well with the blend time correlations in literature. This method can be used to predict blend time in a stirred tank reactor using CFD with only a small fraction of the CPU time required by the current method of solving the time dependent tracer scalar equation. With this method, CFD can be efficiently used for practical reactor analysis, design, and scale‐up.
Formulation of activated carbons and evaluation of methane storage by compression and adsorption
Authors: Sales D. C. S. , Martins R. G. , Jaguaribe E. F. , Abreu C. A. M. 
Published: May 2011

AbstractActivated carbons were produced from coconut shells by chemical activation using H3PO4 (CAQ1) and ZnCl2 (CAQ2), and used as adsorbents for natural gas storage. CAQ1 presented a wider pore size distribution than CAQ2. Storage evaluations were made in a semi‐pilot unit (0.5–4.0 MPa and 298–313 K). According to the used reactant, at 313 K and 3.0 MPa, the adsorptive capacities were 0.060 g/g (CAQ2) and 0.092 g/g (CAQ1). The shortest storage time to charge the tank to 4.0 MPa was obtained by CAQ2 (3.1 min), compared to CAQ1 (3.4 min), due to its higher specific heat capacity. © 2011 Canadian Society for Chemical Engineering
Applying nanofluid to a rotary disc contactor to investigate breakage phenomenon
Authors: Molavi Hoda , Bahmanyar Amir , Khoobi Nafiseh , Bahmanyar Hossein 
Published: May 2011

AbstractFive different nanofluids have been prepared by use of two‐step procedure, in which SiO2 nanoparticles with different volume fractions and hydrophobicities have been dispersed in butyl acetate as base fluid by applying ultrasonication method. Three different methods have been used to evaluate the nanofluids' stability: conventional sedimentation method, particle size analyser and UV‐Vis spectrophotometric. As a quite novel research, these nanofluids were applied to a Rotary Disc Contactor with 91 mm diameter and 12 rotating discs to investigate breakage probability and the first critical rotor speed. The effects of nanoparticles' volume fraction and hydrophobicity, as well as rotor speed, mother drop size and continuous phase height on the breakage phenomenon have been studied. © 2011 Canadian Society for Chemical Engineering
Different positions of tropomyosin isoforms on actin filament are determined by specific sequences of end‐to‐end overlaps
Authors: Śliwińska Małgorzata , Żukowska Magdalena , Borys Danuta , Moraczewska Joanna 
Published: May 2011

AbstractTropomyosins are dimeric rod‐like proteins which polymerize along actin filaments and regulate interactions with other actin‐binding proteins. Homologous sequences responsible for the binding of tropomyosin to consecutive actin monomers repeat along tropomyosin and are called actin‐binding periods. In this work, the localization of tropomyosin isoforms on actin alone and on actin–myosin complex was evaluated by measuring Förster resonance energy transfer (FRET) distances between a donor (AEDANS) attached to either the N‐terminal actin‐binding period 1 or to the central actin‐binding period 5 and an acceptor (DABMI) bound to actin's Cys374. The recombinant α‐tropomyosin isoforms – TM2, TM5a, and TM1b9a, used in this study, had various amino acid sequences of the N‐ and C‐termini forming the end‐to‐end overlap. Although the sequences of actin‐binding period 5 of the three isoforms were identical, the donor–acceptor distances calculated for each isoform varied between 38.6 and 41.5 Å. Differences in FRET distances between the three tropomyosin isoforms labeled in actin‐binding period 1 varied between 34.8 and 40.2 Å. Rigor binding of myosin heads to actin increased all measured distances. The degree and cooperativity of myosin‐induced shift was different for each of the isoforms and actin‐binding periods. The structural differences correlate with cooperative regulation of actin‐activated S1 ATPase by the three tropomyosins. The results indicate that amino acid sequences of the end‐to‐end overlap determine specific orientation of tropomyosin isoform on actin. This can be important for steric and cooperative regulation of the actin filament and determine functional specificity of multiple tropomyosin isoforms present in eucaryotic cells. © 2011 Wiley‐Liss, Inc.
Structure–Activity Studies of RFamide Peptides Reveal Subtype‐Selective Activation of Neuropeptide FF1 and FF2 Receptors
Authors: Findeisen Maria , Rathmann Daniel , Beck‐Sickinger Annette G. 
Published: May 2011

AbstractSelectivity is a major issue in closely related multiligand/multireceptor systems. In this study we investigated the RFamide systems of hNPFF1R and hNPFF2R that bind the endogenous peptide hormones NPFF, NPAF, NPVF, and NPSF. By use of a systematic approach, we characterized the role of the C‐terminal dipeptide with respect to agonistic properties using synthesized [Xaa 7]NPFF and [Xaa 8]NPFF analogues. We were able to identify only slight differences in potency upon changing the position of Arg 7, as all modifications resulted in identical behavior at the NPFF1R and NPFF2R. However, the C‐terminal Phe 8 was able to be replaced by Trp or His with only a minor loss in potency at the NPFF2R relative to the NPFF1R. Analogues with shorter side chains, such as α‐amino‐4‐guanidino butyric acid ([Agb 7]NPFF) or phenylglycine ([Phg 8]NPFF), decreased efficacy for the NPFF1R to 25–31 % of the maximal response, suggesting that these agonist–receptor complexes are more susceptible to structural modifications. In contrast, mutations to the conserved Asp 6.59 residue in the third extracellular loop of both receptors revealed a higher sensitivity toward the hNPFF2R receptor than toward hNPFF1R. These data provide new insight into the subtype‐specific agonistic activation of the NPFF1 and NPFF2 receptors that are necessary for the development of selective agonists.