bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel combinative Raman and SEM mapping method for the detection of exfoliation of graphite in electrodes at very positive potentials
Authors: Hintennach Andreas , Novák Petr 
Published: April 2011

AbstractThe random exfoliation at very positive potentials (>5 V vs Li/Li+) of graphite (used as a conductive component in positive electrodes of lithium‐ion batteries) was investigated with in situ Raman microscopy and post mortem scanning electron microscopy (SEM). A novel semiautomated computational method for the data analysis of both characterization methods was developed to correlate Raman and SEM information with good lateral resolution, in order to locate exfoliated graphite particles. Proof is given that the exfoliating particles detected via the semiautomatic in situ Raman microscopy mappings correctly describes exfoliated areas, as confirmed via post mortem SEM pictures. Copyright © 2011 John Wiley & Sons, Ltd.
Loss of p53 in esophageal squamous cell carcinoma and the correlation with survival: Analyses of gene mutations, protein expression, and loss of heterozygosity in Japanese patients
Authors: Egashira Akinori , Morita Masaru , Yoshida Rintaro , Saeki Hiroshi , Oki Eiji , Sadanaga Noriaki , Kakeji Yoshihiro , Tsujitani Shun‐ichi , Maehara Yoshihiko 
Published: April 2011

AbstractBackgroundA high frequency of p53 protein expression or gene mutation has been reported in the early stages of esophageal squamous cell carcinoma (ESCC), and thus loss of p53 function is thought to be very important in esophageal carcinogenesis. However, there is controversy surrounding the correlation between p53 dysfunction and ESCC tumor progression. The complexity arises from the different modalities, such as mutation analysis, immunohistochemistry, and the detection of loss of heterozygosity (LOH) at the p53 genomic locus.MethodsIn this study, we comprehensively analyzed p53 gene mutation, p53 protein expression, and LOH at 17p13 in 94 surgically resected Japanese cases of ESCC.ResultsThe frequency of p53 gene mutation was 60.6%. The rate of positive p53 protein expression was 56.4%. The frequency of LOH at 17p13 was 67.5%. There was a statistically significant correlation between the presence of a gene mutation and LOH, whereas, there was no significant correlation between gene mutation and protein expression.ConclusionsDespite the importance of loss of p53 function in esophageal carcinogenesis, none of the examined parameters, either singly or combined, correlated with overall survival. Taken together, p53 function is a primary target for esophageal carcinogenesis but there is no apparent correlation with the malignant phenotype in ESCC. J. Surg. Oncol. 2011;104:169–175. © 2011 Wiley‐Liss, Inc.
Simultaneous determination of catecholamines and their metabolites related to Alzheimer's disease in human urine
Authors: Liu Lili , Li Qing , Li Naijing , Ling Junhong , Liu Ran , Wang Yixiang , Sun Lixin , Chen Xiao Hui , Bi Kaishun 
Published: April 2011

AbstractA simple and specific high‐performance liquid chromatography method coupled with fluorescence detection (HPLC‐FL) has been developed for the simultaneous determination of L‐3,4‐dihydroxyphenylalanine, norepinephrine, dopamine, epinephrine and 3,4‐dihydroxyphenylacetic acid in human urine. The samples were derivatized by 1,2‐diphenylethylenediamine with isoprenaline as internal standard. The factors affecting the fluorescence yield were investigated, including the reaction and separation conditions. The catecholamine derivatives were separated on a Kromasil C18 column with methanol and sodium acetate buffer as mobile phase. The limits of detection for all catecholamines ranged from 0.2 to 1.1 ng/mL. The linear ranges were from 2.5 to 200 ng/mL except 3,4‐dihydroxyphenylacetic acid from 5 to 200 ng/mL. The intra‐ and interday RSDs for all catecholamines were 1.0–8.0 and 2.1–14%, respectively. The method was successfully applied to determine the catecholamines in human urine from 14 Alzheimer's disease patients and 14 healthy volunteers. It was concluded that the mean levels of catecholamines in urine of Alzheimer's disease patients were all lower than those in healthy volunteers. The cluster analysis and independent samples T‐test were used to distinguish the Alzheimer's disease patients and healthy volunteers.
Evaluation of Chinese medicinal herbs fingerprinting by HPLC‐DAD for the detection of toxic aristolochic acids
Authors: Heaton James , Whiley Luke , Hong Yingzi , Mary Sebastian Chinnu , William Smith Norman , Legido‐Quigley Cristina 
Published: April 2011

AbstractAristolochic acids are known to contribute to various renal disorders; therefore, expanding the availability of analytical methodology to detect these compounds is important in order to assess the quality of Chinese herbal medicines in which they can be found. Twelve medicinal herbal samples were procured from various sources and extracted in duplicate prior to a “fingerprint” analysis using conventional HPLC‐DAD. Multivariate analysis was performed on the entire chromatographed fingerprints. The resulting output was a partial least‐square discriminant analysis model, which was able to evaluate the potential presence of aristolochic acids I and II as well as providing an individual herbal “fingerprint”. The results of this study provide evidence that the presence of aristolochic acids contained within certain herbal extractions could be detected using a simple method, although some limitations apply to this method for quality control, since newly detected samples for aristolochic acid (positives) will need further confirmation with purity checks or MS hyphenation.
Does Cue competition reduce conditioned liking of brands and products?
Authors: Walther Eva , Ebert Irena , Meinerling Katrin 
Published: April 2011

AbstractThe present studies investigated whether the visual co‐presentation of a brand name and a product visual increases or decreases the acquisition of liking toward these stimuli in a conditioning paradigm. In Study 1, participants were presented with an elemental brand name, an elemental product visual, or a compound of both stimuli, along with liked faces. Results indicated that the mere pairing with the liked face led to increased liking in the elemental condition, but not in the compound condition (i.e., cue competition). Study 2 showed that this effect is due to the divided attention toward the compound, but not due to competition among conditioned stimuli (CSs) to predict the unconditioned stimulus (US). © 2011 Wiley Periodicals, Inc.
Amyotrophic lateral sclerosis patients' self‐reported satisfaction with assistive technology
Authors: Gruis Kirsten L. , Wren Patricia A. , Huggins Jane E. 
Published: April 2011

AbstractIntroduction:Assistive devices are prescribed for amyotrophic lateral sclerosis (ALS) patients with motor deficits, but little is known about their perceived benefit. Therefore, we assessed ALS patients' satisfaction with commonly prescribed devices.Methods:A telephone survey of 63 ALS patients from a single multidisciplinary clinic was conducted to assess the frequency of use, perceived usefulness, and satisfaction with 33 assistive devices.Results:Of those assistive technologies used “often or always” by ≥20% of respondents, arm rails by the toilet, elevated toilet seat, shower seat, shower bars, and slip‐on shoes were ranked very highly for both usefulness and satisfaction. The ankle brace for ambulation, transfer board, speaker phone, and electronic seating controls were also ranked highly. The button hook, dressing stick, and long‐handled reaching tool received low ratings for both usefulness and satisfaction.Conclusions:ALS patients reported high usefulness and satisfaction levels with all bathroom adaptive devices and certain low‐technology devices. Muscle Nerve, 2011
Positive afferent feedback to the human soleus muscle during quiet standing
Authors: Van Doornik Johan , Azevedo Coste Christine , Ushiba Junichi , Sinkjær Thomas 
Published: April 2011

AbstractIntroduction:In this study we investigated the mechanisms responsible for soleus muscle contraction during quiet standing.Methods:Subjects stood on a platform that was randomly moved forward or downward or rotated around the ankle.Results:Downward perturbation caused a short‐latency drop in averaged rectified soleus electromyography (SOL EMG). SOL drop increased monotonically with downward acceleration amplitude. Ischemia above the knee abolished or diminished this drop. Ischemia above the ankle had no diminishing effect. Vibration of the Achilles tendon had a diminishing effect on the amplitude of SOL responses.Conclusions:The short‐latency drop in SOL observed for downward perturbation might be due to a decrease in positive afferent feedback due to the sudden decrease in body weight. This implies the existence of an ongoing afferent feedback loop toward the SOL motoneuron pool from force‐sensitive receptors. Both Ia and Ib afferents probably play a role in the responses observed. Muscle Nerve, 2011
Construct validity of a questionnaire to measure the type of fluid intake and type of urinary incontinence
Authors: Arya Lily A. , Heidi Harvie , Cory Lori , Segal Saya , Northington Gina M. 
Published: April 2011

AbstractObjective: to determine the reproducibility and construct validity of the Questionnaire Based Voiding Diary (QVD) for measuring the type and volume of fluid intake and the type of urinary incontinence.Methods: 250 women completed the QVD, a 48‐hour bladder diary and underwent complete urogynecologic evaluation to determine a final clinical diagnosis. The questionnaire was re‐administered after a 2‐week period with no change in treatment, and 2‐3 months later following treatment of urinary symptoms.Results: The reproducibility of the fluid intake, output, fluid intake behavior and urinary symptom subscales of the QVD was 0.68‐0.92. Correlation of the fluid intake scale of the QVD with the 48‐hour voiding diary for determining the type and volume of fluid intake was high (r = 0.65‐0.83, P < 0.01). High correlations were noted between the fluid intake behavior scale and urinary frequency (r = 0.82, P < .01), urgency (r = 0.77, P < .01) and urge incontinence (r = 0.71, P < .01). The median total fluid intake and mean urinary symptom score was significantly lower in responders (2074 mL, 10.2 ± 3.3) than non‐responders (2347 mL, 18.5 ± 4.6). As compared to the final clinical diagnosis, the sensitivity, specificity and positive likelihood ratio of the QVD for the diagnosis of predominant stress urinary incontinence are 86%, 66% and 2.6 and for predominant urge incontinence 82%, 79% and 4.0 respectively.Conclusion: The QVD provides clinically meaningful information on the type and volume of fluid intake and the type of urinary incontinence at the initial office visit. Neurourol. Urodynam. Neurourol. Urodynam. 30: 1597–1602, 2011. © 2011 Wiley Periodicals, Inc.
Semidefinite relaxation approximation for multivariate bi‐quadratic optimization with quadratic constraints
Authors: Ling Chen , Zhang Xinzhen , Qi Liqun 
Published: April 2011

SUMMARYIn this paper, we consider the NP‐hard problem of finding global minimum of quadratically constrained multivariate bi‐quadratic optimization. We present some bounds of the considered problem via approximately solving the related bi‐linear semidefinite programming (SDP) relaxation. Based on the bi‐linear SDP relaxation, we also establish some approximation solution methods, which generalize the methods for the quadratic polynomial optimization in (SIAM J. Optim. 2003; 14:268–283). Finally, we present a special form, whose bi‐linear SDP relaxation can be approximately solved in polynomial time. Copyright © 2011 John Wiley & Sons, Ltd.
Computational (solute–solvent cluster + PCM) study of medium effects on the experimental 13C and 1H NMR chemical shifts of lactones and lactams
Authors: Faska N. , Auhmani A. , Esseffar M. , Abboud J. L‐M. 
Published: April 2011

AbstractSolvent effects on the 1H and 13C NMR chemical shifts of some lactones: β‐propiolactone, γ‐butyrolactone, δ‐valerolactone and ε‐caprolactone, as well as lactams: azetidin‐2‐one, pyrrolidin‐2‐one, δ‐valerolactam and ε‐caprolactam have been investigated and discussed in a wide range of solvents. The experimental results were compared with density functional calculations using a large basis set. Solvent effects were computed by means of an integrated approach including the polarizable continuum model and an optimum number of explicit solvent molecules surrounding the solute. The agreement between computed and experimental chemical shifts fully validates our integrated approach. In order to quantify and elucidate the origin of the solvent effects on the 1H and 13C chemical shifts of the selected compounds, a multi‐linear regression analysis has been carried out using the empirical Kamlet–Abboud–Taft solvatochromic parameters. It has been found that there is a good correlation between the solvent‐induced chemical shifts of 13C and the π* scale of solvent dipolarity polarizability. 1H chemical shifts are affected mainly by the dipolarity–polarizability and the basicity of the solvent. An excellent agreement has been obtained between the calculated and the experimental data. Copyright © 2011 John Wiley & Sons, Ltd.
Cyclic voltammetry of nitrophenyl N‐glycosides on mercury electrode
Authors: Gubica Tomasz , Stroka Jadwiga , Temeriusz Andrzej , Kańska Marianna 
Published: April 2011

AbstractTen nitrophenyl N‐glycosides have been studied electrochemically in neutral (at pH 7) water–organic solutions by cyclic voltammetry using static mercury drop electrode. For all compounds under investigation the two electrochemical processes have been observed: the four‐electron irreversible reduction of their nitro groups to the corresponding phenylhydroxylamine derivatives, as well as the two‐electron quasi‐reversible process between phenylhydroxylamine and nitroso derivatives. For three compounds the additional electrochemical processes have been also observed, which can be connected with the formation of azoxybenzene derivatives. The potentials of both redox processes: a two‐electron quasi‐reversible RNHOH/RNO (Ef) and four‐electron irreversible RNO2/RNHOH (Epc(I)) systems have been determined and discussed according to crystal structures of selected compounds. Ef and Epc(I) depended strongly on the positive mesomeric effect (caused by glycosidic nitrogen atom), as well as on the intramolecular hydrogen bond between electroactive nitro group and the hydrogen atom at the glycosidic atom observed in N‐o‐nitrophenyl‐2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosylamine. Moreover, the chirality of selected reactants has had the pronounced effect on the Epc(I). Copyright © 2011 John Wiley & Sons, Ltd.
The role of alkane dithiols in controlling polymer crystallization in small band gap polymer:Fullerene solar cells
Authors: Agostinelli Tiziano , Ferenczi Toby A. M. , Pires E. , Foster Samuel , Maurano Andrea , Müller Christian , Ballantyne Amy , Hampton Mark , Lilliu Samuele , Campoy‐Quiles Mariano , Azimi Hamed , Morana Mauro , Bradley Donal D. C. , Durrant James , Macdonald J. Emyr , Stingelin Natalie , Nelson Jenny 
Published: April 2011

AbstractThe effect of the addition of 1,8‐octanedithiol (ODT) during processing on the microstructure of blend films of poly[2,6‐(4,4‐bis‐(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)] (PCPDTBT) and [6,6]‐phenyl‐C71 butyric acid methyl ester ([70]PCBM) is studied. Grazing incidence X‐ray diffraction and absorption spectroscopy show that the crystalline order of PCPDTBT increases when ODT is introduced in the solution phase either to neat polymer systems or to blends with [70]PCBM. The increased crystalline order is accompanied by less dispersive hole transport in the polymer, and leads to a more efficient formation of a percolating fullerene network within the blend. This contributes to an increase in photocurrent generation. However, the bimolecular recombination rate as determined from photovoltage transients increases upon addition of ODT, limiting the power conversion efficiency to values well below those expected from the energy levels of PCPDTBT. We propose some explanations for this increase in bimolecular recombination, based also on variable angle spectroscopic ellipsometry measurements. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Structures of segments of α‐synuclein fused to maltose‐binding protein suggest intermediate states during amyloid formation
Authors: Zhao Minglei , Cascio Duilio , Sawaya Michael R. , Eisenberg David 
Published: April 2011

AbstractAggregates of the protein α‐synuclein are the main component of Lewy bodies, the hallmark of Parkinson's disease. α‐Synuclein aggregates are also found in many human neurodegenerative diseases known as synucleinopathies. In vivo, α‐synuclein associates with membranes and adopts α‐helical conformations. The details of how α‐synuclein converts from the functional native state to amyloid aggregates remain unknown. In this study, we use maltose‐binding protein (MBP) as a carrier to crystallize segments of α‐synuclein. From crystal structures of fusions between MBP and four segments of α‐synuclein, we have been able to trace a virtual model of the first 72 residues of α‐synuclein. Instead of a mostly α‐helical conformation observed in the lipid environment, our crystal structures show α‐helices only at residues 1–13 and 20–34. The remaining segments are extended loops or coils. All of the predicted fiber‐forming segments based on the 3D profile method are in extended conformations. We further show that the MBP fusion proteins with fiber‐forming segments from α‐synuclein can also form fiber‐like nano‐crystals or amyloid‐like fibrils. Our structures suggest intermediate states during amyloid formation of α‐synuclein.
Novel, fluorescent, SSB protein chimeras with broad utility
Authors: Liu Juan , Choi Meerim , Stanenas Adam G. , Byrd Alicia K. , Raney Kevin D. , Cohan Christopher , Bianco Piero R. 
Published: April 2011

AbstractThe Escherichia coli single‐stranded DNA binding protein (SSB) is a central player in DNA metabolism where it organizes genome maintenance complexes and stabilizes single‐stranded DNA (ssDNA) intermediates generated during DNA processing. Due to the importance of SSB and to facilitate real‐time studies, we developed a dual plasmid expression system to produce novel, chimeric SSB proteins. These chimeras, which contain mixtures of histidine‐tagged and fluorescent protein(FP)‐fusion subunits, are easily purified in milligram quantities and used without further modification, a significant enhancement over previous methods to produce fluorescent SSB. Chimeras retain the functionality of wild type in all assays, demonstrating that SSB function is unaffected by the FPs. We demonstrate the power and utility of these chimeras in single molecule studies providing a great level of insight into the biochemical mechanism of RecBCD. We also utilized the chimeras to show for the first time that RecG and SSB interact in vivo. Consequently, we anticipate that the chimeras described herein will facilitate in vivo, in vitro and single DNA molecule studies using proteins that do not require further modification prior to use.
Tat peptide‐calmodulin binding studies and bioinformatics of HIV‐1 protein–calmodulin interactions
Authors: McQueen Peter , Donald Lynda J. , Vo Thach N. , Nguyen Dung H. , Griffiths Heather , Shojania Shaheen , Standing Kenneth G. , O'Neil Joe D. 
Published: April 2011

AbstractThe human immunodeficiency virus type 1 (HIV‐1) genome encodes 18 proteins and 2 peptides. Four of these proteins encode high‐affinity calmodulin‐binding sites for which direct interactions with calmodulin have already been described. In this study, the HIV‐1 proteome is queried using an algorithm that predicts calmodulin‐binding sites revealing seven new putative calmodulin‐binding sites including residues 34–56 of the transactivator of transcription (Tat). Tat is a 101‐residue intrinsically disordered RNA‐binding protein that plays a central role in the regulation of HIV‐1 replication. Interactions between a Tat peptide (residues 34–56), melittin, a well‐characterized calmodulin‐binding peptide, and calmodulin were examined by direct binding studies, mass spectrometry, and fluorescence. The Tat peptide binds to both calcium‐saturated and apo‐calmodulin with a low micromolar affinity. Conformational changes induced in the Tat peptide were determined by circular dichroism, and residues in calmodulin that interact with the peptide were identified by HSQC NMR spectroscopy. Multiple interactions between HIV‐1 proteins and calmodulin, a highly promiscuous signal transduction hub protein, may be an important mechanism by which the virus controls cell physiology. Proteins 2011; © 2011 Wiley‐Liss, Inc.
The size‐Ramsey number of trees
Authors: Dellamonica Domingos 
Published: April 2011

AbstractGiven a graph G, the size‐Ramsey number
$\hat r(G)$
is the minimum number m for which there exists a graph F on m edges such that any two‐coloring of the edges of F admits a monochromatic copy of G.In 1983, J. Beck introduced an invariant β(·) for trees and showed that
$\hat r(T) = \Omega (\beta (T))$. Moreover he conjectured that $\hat r(T) = \Theta (\beta (T))$. We settle this conjecture by providing a family of graphs and an embedding scheme for trees. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2011
Zur erforderlichen Größe von Zinkdurchlauföffnungen feuerverzinkter Hohlprofilkonstruktionen
Authors: Feldmann Markus , Schäfer Dirk 
Published: April 2011

AbstractEin Element zur Vermeidung von Verzug und Rissbildung beim Feuerverzinken ist die Wahl einer möglichst großen Eintauchgeschwindigkeit. Deswegen wurde hierfür ein Mindestwert von vE ≥ 0,8 m/min in der neuen DASt‐Ri 022 vorgeschrieben. Insbesondere bei Hohlprofilkonstruktionen hängt die Einhaltung dieses Mindestwertes stark von Größe und Anzahl der Zinkdurchlauföffnungen ab; und es hat sich herausgestellt, dass die bisherigen Regelungen zur Größe und Anordnung dieser Öffnungen nicht ausreichen. Hier setzt das Ziel der vorgestellten Untersuchungen an, nämlich Regeln für Art und Größe von Zinkdurchlauföffnungen zu entwickeln, die eine ausreichend große Eintauchgeschwindigkeit zur Vermeidung exzessiver Spannungs‐Dehnungszustände als Mitverursacher von Verzug und Rissbildung gewährleisten. Die Herleitungen bauen auf den Gesetzen der Hydraulik auf und werden mit Versuchen erprobt. Ergebnis ist ein einfacher und nachvollziehbarer Algorithmus zur Bestimmung von Größe und Verteilung von Zinkdurchlauföffnungen in Hohlprofilkonstruktionen, die auf die Vermeidung von Verzug und Rissbildung wie auch auf einen schnelleren Verzinkungsvorgang ausgerichtet sind. Daraus wird ein Bemessungsvorschlag in Form einer einfachen Tabelle abgeleitet.Required Size of ventilation openings of hot‐dip galvanized hollow sections. In order to avoid distortion and cracking during hotdip galvanizing a relatively high immersion speed should be chosen. For instance, in the new German standard to avoid cracking during hot‐dip galvanizing DASt‐Ri 022 a dipping speed of vE ≥ 0,8 m/min has been proposed. Especially for elements with hollow sections the dipping speed is strongly dependant on the size of the ventilation openings. However, it was found that the current rules on size and distribution of these openings are not sufficient. Therefore, the aim of the research described hereafter was to find out rules for size and distribution of ventilation openings that enable a safe galvanizing by providing enough freedom for a quick immersion. Basis of the derivations are the rules of hydraulics that furthermore are verified by experiments of the immersion of hollow sections. The results yield into a simple and reasonable algorithm to determine size and distribution of ventilation openings of hollow sections, contributing to a distortion‐ and crack‐free structure. Finally a proposal in form of design a sheet is made available.