bluuebunny/crossref_metadata_2025 huggingface dataset:
Cd2Ge2O6 nanowires grown by a simple hydrothermal route
Authors: Pei L. Z. , Yang Y. , Pei Y. Q. , Yuan C. Z. , Duan T. K. , Zhang Q.‐F.
Published: April 2011

Cd2Ge2O6 nanowires have been synthesized by a simple hydrothermal route in the absence of any surfactants. The diameter and length of the Cd2Ge2O6 nanowires with flat tips are 30‐300 nm and several dozens of micrometers, respectivley. X‐ray diffraction and high‐resolution transmission electron microscopy results show that the nanowires are composed of monoclinic Cd2Ge2O6 phase. The growth condition dependence results show that the formation of the Cd2Ge2O6 nanowires undergoes three morphological changes from spherical particles to nanorods, and finally to nanowires. The photoluminescence spectrum of the Cd2Ge2O6 nanowires exhibits three fluorescence emission peaks centered at 422 nm, 490 nm and 528 nm showing the potential application for optical devices. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Automated detection of rare‐event pathogens through time‐gated luminescence scanning microscopy
Authors: Lu Yiqing , Jin Dayong , Leif Robert C. , Deng Wei , Piper James A. , Yuan Jingli , Duan Yusheng , Huo Yujing
Published: April 2011

Many microorganisms have a very low threshold (<10 cells) to trigger infectious diseases, and, in these cases, it is important to determine the absolute cell count in a low‐cost and speedy fashion. Fluorescent microscopy is a routine method; however, one fundamental problem has been associated with the existence in the sample of large numbers of nontarget particles, which are naturally autofluorescent, thereby obscuring the visibility of target organisms. This severely affects both direct visual inspection and the automated microscopy based on computer pattern recognition. We report a novel strategy of time‐gated luminescent scanning for accurate counting of rare‐event cells, which exploits the large difference in luminescence lifetimes between the lanthanide biolabels, >100 μs, and the autofluorescence backgrounds, <0.1 μs, to render background autofluorescence invisible to the detector. Rather than having to resort to sophisticated imaging analysis, the background‐free feature allows a single‐element photomultiplier to locate rare‐event cells, so that requirements for data storage and analysis are minimized to the level of image confirmation only at the final step. We have evaluated this concept in a prototype instrument using a 2D scanning stage and applied it to rare‐event Giardia detection labeled by a europium complex. For a slide area of 225 mm2, the time‐gated scanning method easily reduced the original 40,000 adjacent elements (0.075 mm × 0.075 mm) down to a few “elements of interest” containing the Giardia cysts. We achieved an averaged signal‐to‐background ratio of 41.2 (minimum ratio of 12.1). Such high contrasts ensured the accurate mapping of all the potential Giardia cysts free of false positives or negatives. This was confirmed by the automatic retrieving and time‐gated luminescence bioimaging of these Giardia cysts. Such automated microscopy based on time‐gated scanning can provide novel solutions for quantitative diagnostics in advanced biological, environmental, and medical sciences. © 2011 International Society for Advancement of Cytometry
Time‐domain equalizer for multicarrier systems in impulsive noise
Authors: Tan Yee Chieh , Ramli Nordin Bin , Chuah Teong Chee
Published: April 2011

In multicarrier communication systems, a time‐domain equalizer (TEQ) can be applied to shorten the channel impulse response and to eliminate inter‐symbol interference (ISI). However, the presence of impulsive noise in the channel may paralyze the operation of TEQs and subsequently lead to poor error performance. In this paper, a multicarrier receiver that incorporates a constant false alarm rate algorithm and an iterative estimation technique (CFAR‐IET) in conjunction with a TEQ is proposed to increase the robustness of the receiver against impulsive noise. Furthermore, an improved version of the CFAR‐IET‐TEQ scheme, which uses the buffering, sorting, removing and amplitude averaging (BSRA) processes, is presented. Performance comparisons of the proposed schemes with the existing Gaussian‐optimized schemes are made. Simulation results show that the BSRA‐IET‐TEQ scheme is an effective approach to reduce symbol error rate (SER) in impulsive channels while performing satisfactorily in Gaussian channels. Copyright © 2011 John Wiley & Sons, Ltd.
Significantly Enhanced CO2/CH4 Separation Selectivity within a 3D Prototype Metal–Organic Framework Functionalized with OH Groups on Pore Surfaces at Room Temperature
Authors: Chen Zhenxia , Xiang Shengchang , Arman Hadi D. , Li Peng , Zhao Dongyuan , Chen Banglin
Published: April 2011

A new three‐dimensional microporous metal–organic framework (MOF) Zn(BDC‐OH)(DABCO)0.5·(DMF)2(H2O) (UTSA‐25; H2BDC‐OH = 2‐hydroxybenzenedicarboxylic acid, DABCO = 1,4‐diazabicyclo[2.2.2]octane) with functional–OH groups on the pore surfaces was solvothermally synthesized and structurally characterized. UTSA‐25 features a three‐dimensional structure with 3D intercrossed channels of about 7.5 × 7.5, 3.2 × 4.7, and 3.2 × 4.7 Å2, respectively. The small pores and the functional –OH groups on the pore surfaces within the activated UTSA‐25a have enabled their strong interactions with CO2 of adsorption enthalpy of 22.5 kJ mol–1, which is higher than that of 17.5 kJ mol–1 in the original MOF Zn(BDC)(DABCO)0.5 without the functionalized –OH groups. Accordingly, CO2/CH4 separation selectivities in UTSA‐25a of 17.2 and 12.5 at 273 and 296 K, respectively, are much higher than those of 4.4 and 3.7 in Zn(BDC)(DABCO)0.5, thus highlighting UTSA‐25a as a very promising porous material for industrially important CO2/CH4 separation.
A Series of MnIII4MnII8 Single‐Molecule Magnets Mediated by Intra‐ and Intermolecular Interactions
Authors: Leng Ji‐Dong , Dian Long‐Yang , Liu Jun‐Liang , Tong Ming‐Liang
Published: April 2011

The solvothermal reaction of manganese(II) acetylacetonate [Mn(acac)2], 1,1,1‐tris(hydroxymethyl)ethane (H3thme), 1,1,1‐tris(hydroxymethyl)propane (H3thmp), and (CH3)3CCO2H leads to a series of mixed‐valence MnIII4MnII8clusters, [MnIII4MnII8(μ5‐O)2(μ3‐OMe)2(thme)4(Me3CCO2)10(H2O)2] (1), [MnIII4MnII8(μ5‐O)2(μ3‐OMe)2(thme)4(Me3CCO2)10(MeOH)2] (2), [MnIII4MnII8(μ5‐O)2(μ3‐OMe)2(thmp)4(Me3CCO2)10(H2O)2] (3), and [MnIII4MnII8(μ5‐O)2(μ3‐OMe)2(thmp)4(Me3CCO2)10(MeOH)2] (4). The MnIII4MnII8 cores of the complexes can be described as a central rhomboid [Mn4O6] layer sandwiched by two [Mn4O7] layers. Alternating current (AC) magnetization studies reveal that complexes 1–4 possess the S = 4 spin ground state and behave as single‐molecule magnets (SMMs). All four of the compounds clearly show slow magnetic relaxation behavior, but out‐of‐phase AC peaks above 1.8 K were only obtained for 3 and 4, thereby revealing that the ground‐state anisotropy of four Mn12 clusters are effectively modified by intra‐ and intermolecular interactions by substituting the tripodal ligands and terminal ligands.
SiFA‐Modified Phenylalanine: A Key Compound for the Efficient Synthesis of 18F‐Labelled Peptides
Authors: Iovkova Ljuba , Könning Daniel , Wängler Björn , Schirrmacher Ralf , Schoof Sebastian , Arndt Hans‐Dieter , Jurkschat Klaus
Published: April 2011

Both the racemic and the stereoselective synthesis of the silicon‐modified amino acid p‐(tBu2FSi)C6H4CH2(NH2)COOH (SiFA‐phenylalanine, 6) and its derivatives p‐(tBu2FSi)C6H4CH2(NHBoc)COOH (10) and p‐(tBu2FSi)C6H4CH2(NHFmoc)COOH (11) are reported. The latter two compounds are valuable building blocks for the convenient introduction of silicon‐based fluoride acceptors (SiFAs) into peptides by solid‐phase peptide syntheses (SPPS). As prove of principle, the Tyr3‐octreotate derivatives 12, 13 and 14 were prepared by using standard protocols of the solid‐phase peptide synthesis (SPPS). They were labelled with 18F‐fluorine by isotopic exchange in radiochemical yields of up to 70 % (with radiochemical purity ranging between 92 and 99 %). The incorporation of 18F‐fluorine into the SiFA‐modified amino acid 6 was studied as the latter may also serve as a tracer in PET. After purification, [18F]‐6 showed a remarkable stability in an isotonic solution. Also reported is the molecular structure, as determined by single‐crystal X‐ray diffraction analysis, of p‐(tBu2FSi)C6H4CHCH[C(O)OMe]NHC(O)OCH2Ph (8), which serves as a precursor for the stereoselective synthesis of compound 6.
Effects of urban air pollutants on elemental accumulation and identification of oxidative stress biomarkers in the transplanted lichen Pseudovernia furfuracea
Authors: Oztetik Elif , Cicek Arzu
Published: April 2011

Determining the origins of heavy metals, their accumulation, and their detoxification mechanisms constitutes a major problem in understanding environmental pollution in urban areas. The objective of this study was to detect the relative air quality in Eskisehir city center (Turkey) through the transplanted epiphytic lichen Pseudovernia furfuracea as a biomonitor of the concentrations of some heavy metals accumulated and to describe their toxic effects on lichen physiology during the study period of one year. The influence of heavy metal accumulations on macroelement levels were also examined. In addition to analysis of B, K, Ca, P, S, Al, Fe, Mg, Mn, Ni, Zn, Pb, and Cu, total soluble proteins and oxidative stress parameters through glutathione (GSH) contents and glutathione S-transferase (GST) activities were also determined. Results indicate that, although the heavy metal concentrations were found to be gradually increased from the unpolluted control zone to the city center, the concentrations of macroelements S and Ca were higher in the polluted area. However, B, K, Mg, and P elements were found to be higher in the unpolluted area than in the polluted zones. It seems that heavy metals induce oxidative stress in lichens; we found enhancement of GSH concentrations and GST activity. Most probably, the expected destruction in this organism was reduced by the intervention of antioxidant capacity. Therefore, this report confirms the fact that the epiphytic lichen P. furfuracea is a good model for biomonitoring atmospheric quality for a long-term transplantation study, and oxidative stress parameters stand out as a tool for an early environment assessment of other physiological parameters. Environ. Toxicol. Chem. 2011; 30:1629–1636. © 2011 SETAC
A method for overcoming the surface tension time step constraint in multiphase flows II
Authors: Sussman M.
Published: April 2011

A method for overcoming the surface tension time step constraint is presented. The algorithm presented in this work is an improvement on the work presented by Sussman and Ohta (SIAM J Sci Comput 2009). In this work, the method of Sussman and Ohta is extended in order to treat problems with contact angle dynamics. Furthermore, this work presents a more efficient method for computing volume‐preserving motion by mean curvature than the method presented previously. The new method is tested on the following four 2D problems: (1) 3D axisymmetric (r−z) surface tension driven zero gravity droplet oscillation, (2) measurement of the magnitude of parasitic currents for a droplet on a substrate initialized in static equilibrium, (3) relaxation of a 2D droplet on a substrate to static shape, and (3) relaxation of a 2D bubble on a substrate to static shape. Copyright © 2011 John Wiley & Sons, Ltd.
Copy number profiling in von hippel‐lindau disease renal cell carcinoma
Authors: Shuib Salwati , Wei Wenbin , Sur Hariom , Morris Mark R. , McMullan Dominic , Rattenberry Eleanor , Meyer Esther , Maxwell Patrick H. , Kishida Takeshi , Yao Masahiro , Latif Farida , Maher Eamonn R.
Published: April 2011

Germline mutations in the VHL tumor suppressor gene cause von Hippel‐Lindau (VHL) disease and somatic VHL mutations occur in the majority of clear cell renal cell carcinoma (cRCC). To compare copy number abnormalities (CNAs) between cRCC from VHL patients and sporadic cRCC cases without detectable somatic VHL mutations, we analyzed 34 cRCC with Affymetrix 250K arrays. To increase the power of the study, we then combined our results with those of a previously published study and compared CNAs in VHL and non‐VHL related cRCC using the genomic identification of significant targets in cancer (GISTIC) program. In VHL, cRCC GISTIC analysis identified four statistically significant regions of copy number gain and four statistically significant regions of deletion that occurred in >10% of tumors analyzed. Sporadic cRCC without detectable VHL mutations had, on average, more copy number abnormalities than VHL cRCC though the most common regions of loss/gain (e.g., 3p and 14q loss and 5q gain) were present in both tumor sets. However, CNAs on chromosome arms 7p (gain) and 8p (loss) were only detected in VHL RCC. Although individual copy number abnormality peaks contained clear candidate cancer genes in some cases (e.g., the 3p loss peak in VHL cRCC contained only six genes including VHL), most peaks contained many genes. To date, only a minority of the candidate genes included in these peaks have been analyzed for mutation or epigenetic inactivation in cRCC but TNFRSF10C and DUSP4 map to the 8p region deleted in VHL cRCC and TP53 and HIF2A (EPAS1) mapped to CNA loss and gain peaks (chromosomes 17 and 2, respectively) detected in sporadic VHL wild‐type cRCC. © 2011 Wiley‐Liss, Inc.
The miR‐15a‐miR‐16‐1 locus is homozygously deleted in a subset of prostate cancers
Authors: Porkka Kati P. , Ogg Erinn‐Lee , Saramäki Outi R. , Vessella Robert L. , Pukkila Heidi , Lähdesmäki Harri , van Weerden Wytske M. , Wolf Maija , Kallioniemi Olli P. , Jenster Guido , Visakorpi Tapio
Published: April 2011

MicroRNAs (miRNAs) are small, non‐coding RNAs that negatively regulate the expression of protein coding genes. In this study, we screened highly informative prostate cancer cell lines and xenografts (n = 42) for miRNA gene copy number and expression changes. The expression profiling showed distinction between cell lines and xenografts as well as between androgen sensitive and independent models. Only a few copy number alterations that were associated with expression changes were identified. Most importantly, the miR‐15a‐miR‐16‐1 locus was found to be homozygously deleted in two samples leading to the abolishment of miR‐15a, but not miR‐16, expression. miR‐16 is also expressed from another genomic locus. Mutation screening of the miR‐15a‐miR‐16‐1 gene in the model systems as well as clinical samples (n = 50) revealed no additional mutations. In conclusion, our data indicate that putative tumor suppressors, miR‐15a and miR‐16‐1, are homozygously deleted in a subset of prostate cancers, further suggesting that these miRNAs could be important in the development of prostate cancer. © 2011 Wiley‐Liss, Inc.
Hematocrit and C‐reactive protein predict treatment response times in ADAMTS13‐deficient thrombotic microangiopathy
Authors: Samia Noelle I. , Friedman Kenneth D. , Gottschall Jerome L. , Raife Thomas J.
Published: April 2011

Thrombotic microangiopathy (TMA) syndromes are a heterogeneous group of microvascular syndromes that are typically treated with plasma exchange and other adjunctive therapies. Important pathogenic factors, such as ADAMTS13 deficiency, define distinct subsets of TMA. New treatments for TMA are being explored that are hypothesized to bring about remission more quickly. However, the existing factors that influence response to treatment time are poorly understood. We hypothesized that common laboratory parameters available at the time of treatment initiation might correlate with the number of days of plasma exchange required to induce remission. We therefore retrospectively compared pretreatment platelet counts, hematocrit levels, and C‐reactive protein (CRP) levels to the number of days of plasma exchange treatment in 27 ADAMTS13‐deficient TMA patients and 25 non‐ADAMTS13‐deficient patients that achieved remission. Using quantile regression analysis, we observed that in ADAMTS13‐deficient patients, higher initial hematocrit levels significantly correlated with shorter treatment response times. In addition, for ADAMTS13‐deficient patients, elevated levels of CRP correlated directly with longer response times. Higher platelet counts were associated with a nonsignificant trend toward shorter response times. In non‐ADAMTS13‐deficient TMA patients no significant correlations were observed. Our results suggest that when conducting clinical trials of adjunctive treatments for TMA, clinical data, including ADAMTS13 levels, pretreatment hematocrit levels, and CRP levels may be informative in interpreting response to treatment times. J. Clin. Apheresis, 2011. © 2011 Wiley‐Liss, Inc.
Effect of Na+, Mg2+, and Zn2+ chlorides on the structural and thermodynamic properties of water/n‐heptane interfaces
Authors: Rodríguez‐Ropero Francisco , Fioroni Marco
Published: April 2011

The effect on the structural and thermodynamic properties in water/n‐heptane interfaces on addition of NaCl, MgCl2, and ZnCl2 has been examined through five independent 100‐ns molecular dynamics simulations. Results indicate that the interfacial thickness within the framework of the capillary‐wave model decreases on addition of electrolytes in the order Na+ < Mg2+ < Zn2+, whereas the interfacial tension increases in the same order. Ionic density profiles and self‐diffusion coefficients are strongly influenced by the strength of the first hydration shell, which varies in the order Na+ < Mg2+ < Zn2+. On the other hand, the Cl− behavior, that is, diffusion and solvation sphere, is influenced by its counterion. Accordingly, cations are strongly expelled from the interface, which is especially remarkable for the small divalent cations. This fact alters the water geometry near the interface and in a lesser extent n‐heptane order and number of hydrogen bonds per water molecule close to the interface. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
A forgotten social science? Creating a place for linguistics in the historical dialogue
Authors: Martin‐Nielsen Janet
Published: April 2011

The post–World War II era was one of great triumph for American linguists—and yet linguistics is all but absent from the historical literature on postwar social science. This paper aims to illuminate this curious situation: to understand its provenance, evaluate its merits, and contextualize it broadly. I argue that the historiographic lacuna results from two factors: (1) the opt‐out of linguists from the wider American social science community, and (2) historical‐developmental and ‐orientational factors that stand linguistics apart from the social science mainstream. The resultant isolation of linguistics has led to a parallel isolation in the historical literature. Ultimately, this paper poses a pivotal and timely question: How is the postwar social science space construed within the existing historiographic framework, and how should it be construed in order to maximize understanding? I propose a rethink of the received historiography centered on intellectual transformations and cross‐disciplinary integration. © 2011 Wiley Periodicals, Inc.
Regio‐ and stereoselective synthesis of 1‐benzopyrano[2,3‐b]pyrrolo[2,3‐d]pyridines: A microwave‐accelerated intramolecular [3+2] cycloaddition reaction of azomethine ylide
Authors: Maiti Sourav , Lakshmykanth T. M. , Panja Suman Kalyan , Mukhopadhyay Ranjan , Datta Ayan , Bandyopadhyay Chandrakanta
Published: April 2011

Regio‐ and stereoselective syntheses of tetracyclic compounds having chromone, pyrrolidine, and piperidine rings have been accomplished by an intramolecular [3+2] cycloaddition reaction involving azomethine ylide. The reactions were carried out thermally as well as by irradiation with microwave. The latter process accelerates the reaction. The selectivities were investigated by density functional theory computation. J. Heterocyclic Chem., (2011).
Complexes of iron(III) and chromium(III) salen and salophen Schiff bases with bridging 1,3,5‐triazine derived multidirectional ligands
Authors: Koç Ziya Erdem
Published: April 2011

A new synthetic route for preparing multidirectional ligands was developed by using 2,4,6‐trichloro‐1,3,5‐triazine (cyanuric chloride) as core. The reaction included the selective substitutions of 4‐aminobenzoic acid onto three chlorides of the triazine ring via a stepwise manner at 1:1, 1:2, or 1:3 equiv. and 0, 25, 130°C, respectively. An efficient synthesis of a novel class of “multidirectional ligands” has been developed based on high‐yielding chloride substitutions of 2,4,6‐trichloro‐1,3,5‐triazine by amines. Sixteen new mono‐, di‐, tri‐, and tetra‐nuclear Fe(III) and Cr(III) complexes involving tetradenta Schiff bases N,N′‐bis(salicylidene)ethylenediamine‐(salenH2) or bis(salicylidene)‐o‐phenylenediamine‐(salophenH2) with two new 1,3,5‐triazine derived multidirectional ligands were synthesized and characterized by means of elemental analysis, 1H NMR, FT‐IR spectroscopy, LC‐MS analysis, AAS, thermal analysis, and magnetic susceptibility measurements. The complexes were also characterized as low‐spin distorted octahedral Fe(III) and Cr(III) bridged by carboxylic acids. It was understood that the [{Fe(salen)/(salophen)}2O] and [{Cr(salen)/(salophen)}2O] containing compounds could be represented by the electronic structure of te and te. J. Heterocyclic Chem., (2011).
Stochastic simulation of rainfall in the semi‐arid Limpopo basin, Botswana
Authors: Kenabatho P. K. , McIntyre N. R. , Chandler R. E. , Wheater H. S.
Published: April 2011

The application of spatial‐temporal stochastic rainfall models to semi‐arid or arid areas is expected to be particularly challenging because of the high variability of rainfall, sparse rain gauge networks with significant periods of missing rainfall and potential data quality issues. In this article, a generalized linear model (GLM) has been fitted to daily rainfall data from the period 1975–1999 for 13 gauges in a 7660 km2 sub‐basin of the Limpopo basin in Botswana, with the objective of exploring applicability of the GLM for infilling historic records and for climate change analysis. Several relevant statistics of rainfall space‐time variability were used to analyse model performance, including use of an independent validation period and sites that were not used in the fitting. The GLM was considered to simulate rainfall adequately for the purpose of sub‐basin‐scale water resource studies, although the model uncertainty is high. The main factors affecting rainfall space‐time variability were found to be seasonality, autocorrelation of daily rainfall, altitude, latitude and longitude. Addition of large‐scale drivers of rainfall (pressure, humidity and temperature) further improved representation of inter‐annual variability, and this link to large‐scale climate potentially facilitates downscaling of global climate model outputs. Although the model was locally sensitive to data quality issues, there was no evidence that these issues affected sub‐basin scale analysis. Copyright © 2011 Royal Meteorological Society
Spatio‐temporal variation of daily extreme temperatures over Turkey
Authors: Toros Hüseyin
Published: April 2011

Extreme (maximum and minimum) temperature records are analysed for search of spatio‐temporal variation patterns in regional climate change throughout Turkey based on 165 stations, as many stations as possible, and as far back as possible, in the period 1961–2008. The main purpose is to better understand the possibility of annual trends during the warm and cold periods. Homogeneity and Mann‐Kendall trend test methodologies are applied in order to identify statistically significant trends at each station. It is observed that there is a significant warming in both annual maximum and minimum temperature records. Increasing trends in warm period are comparatively stronger than cold periods so far as the maximum temperatures are concerned. There are also increasing trends in annual minimum temperature during warm periods with almost no change in minimum temperatures of cold periods. The observations indicate that the temperature began to increase in the beginning of the 1980s. Nine stations are chosen from different geographical regions in order to compare monthly average temperature values of 1961–1984 with 1985–2008 and a marked increase was observed on extreme temperatures in these stations. Copyright © 2011 Royal Meteorological Society
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

The 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

Background

A 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.

Methods

In this study, we comprehensively analyzed p53 gene mutation, p53 protein expression, and LOH at 17p13 in 94 surgically resected Japanese cases of ESCC.

Results

The 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.

Conclusions

Despite 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

A 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

Aristolochic 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

The 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

Introduction:

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

Introduction:

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

Objective: 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

In 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

Solvent 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

Ten 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

The 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

Aggregates 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

The 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

The 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.
Inhibitory Effects of Isolated Compounds from Black Coloured Rice Bran on the Complement Classical Pathway
Authors: Moon Hyung‐In , Lee Jai‐Heon , Lee Young‐Choon , Kim Soo‐Ki
Published: April 2011

The present study evaluated the anticomplement effects of isolated compounds from black coloured rice bran in the classical pathway of the complement system. Using column chromatography, three compounds: oryzafuran, quercetin and protocatechuic acid, were isolated and evaluated for in vitro anticomplement activity. Oryzafuran showed the most potent inhibitory activity against the complement system, with 50% inhibitory concentration (IC50) values of 126.2 µg/mL. This is the first report of anticomplement activity of isolated compounds from black coloured rice bran. Copyright © 2011 John Wiley & Sons, Ltd.
The size‐Ramsey number of trees
Authors: Dellamonica Domingos
Published: April 2011

Given 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