bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of preparation conditions on the fluorescence properties of Eu(Sal)3Phen
Authors: Yang Cheng , Liu Li , Gao Yi , Zhang Wan , Zhang Xiujuan , Zhang Liqun 
Published: January 2006

AbstractThe influence of the synthesis conditions (method and sequence of adding reagents, reaction temperature, stirring rate) on the luminescence performance of the rare earth ternary complex compound europium‐salicylic acid‐(1,10‐phenanthroline) [Eu(Sal)3Phen] was studied. We show that the method and sequence of adding reagents greatly affects the luminescence properties of the products. Within the range of synthesis temperatures (30–70°C), the complex has a better luminescence performance at the lower temperature. However, performance decreased when the temperature decreased to 20°C. Increase of stirring rate led to better performance in the range 200–700 r.p.m. Infrared (IR) spectroscopy, scanning electron microscopy (SEM) and wide‐angle X‐ray diffraction (WAXD) were utilized to characterize the structure and morphology of Eu(Sal)3Phen. The studies demonstrate that the crystallization of the product increased with increasing luminescence of the product. Therefore, it is proposed that increasing the crystallization of the product will enhance its luminescence performance. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of tetracycline, chlortetracycline and oxytetracycline by flow injection with inhibitory chemiluminescence detection using copper(II) as a probe ion
Authors: Han Suqin , Liu Erbao , Li Hua 
Published: January 2006

AbstractThis paper reports an indirect flow‐injection (FI) method for the determination of the tetracycline drugs (TCs), tetracycline (TC), chlortetracycline (CTC) and oxytetracycline (OTC), using copper(II) as a probe ion. The method was based on the inhibition caused by these TCs to the copper(II)‐catalysed chemiluminescence (CL) reaction between luminol and H2O2. The CL reaction was induced on‐line and injection of the sample produced negative peaks as a result of the copper(II) complexation or displacement by the analytes. The height of the peaks was proportional to the drug concentration in the sample. The choice of the catalyst ion, the concentration of luminol, H2O2 and copper(II) are discussed. The linear range was 3.6 × 10−8–1.0 × 10−5, 1.1 × 10−7–1.0 × 10−5 and 1.9 × 10−7–1.0 × 10−5 mol/L for TC, CTC and OTC, respectively. The detection limit was 5.0 × 10−9 mol/L for TC, 1.0 × 10−8 mol/L for CTC and 2.0 × 10−8 mol/L for OTC (3σ), respectively. The method was applied to the determination of TCs in pharmaceutical preparations and human urine with recoveries in the range 95–105%. Copyright © 2006 John Wiley & Sons, Ltd.
ω‐Hydrazino Linear Polyethylenimine: A Monoconjugation Building Block for Nucleic Acid Delivery
Authors: Pons Bénédicte , Mouhoubi Lila , Adib Abdennaji , Godzina Przemyslaw , Behr Jean‐Paul , Zuber Guy 
Published: January 2006

AbstractNonviral gene therapy requires efficient vectors that are able to deliver nucleic acids inside the targeted cell nucleus. Developing new tools for the synthesis of supramolecular vectors with improved transfection efficiency and better biodistribution is therefore a crucial issue. Here we describe the synthesis of a 140‐mer linear polyethylenimine (L‐PEI) terminated at one end by a highly nucleophilic hydrazine residue. This cationic polymer, whose backbone is well known for its remarkable gene‐delivery efficiency, constitutes a building block for ω‐regioselective conjugation to molecules through the formation of stable linkages such as the hydrazone bonds. To demonstrate the potential of the ω‐hydrazino linear polyethylenimine, human serum transferrin, a ligand that is well know to improve gene‐delivery systems, was used as a model of sensitive material. The blood protein was oxidized to generate an aldehyde function and was subsequently conjugated to hydrazino PEI. The new polyethylenimine–transferrin (PEI–Tf) vector was purified and was shown to condense plasmid DNA into compact superstructures compatible with cellular uptake. Finally, the cellular‐binding and gene‐delivery properties of PEI/DNA polyplexes incorporating different quantities of transferrin were evaluated by FACS analysis and luciferase assay.
Difficult retrieval of the EPI filterwire with a 5 French FR4 coronary catheter following carotid stenting
Authors: Ganim Rick P. , Muench Andreas , Giesler Gregory M. , Smalling Richard W. 
Published: January 2006

AbstractCarotid angioplasty and stenting with an embolic protection device is emerging as a reasonable alternative to carotid endarterectomy in high‐risk patients. The deployment and retrieval of these devices, however, can be problematic. We describe a case where a 5 Fr FR4 coronary catheter was used to retrieve an EPI Filterwire device following carotid stenting. © 2006 Wiley‐Liss, Inc.
Competition of Proton and Electron Transfers in Gas‐Phase Reactions of Hydrogen‐Containing Dications CHX2+ (X=F, Cl, Br, I) with Atoms, Nonpolar and Polar Molecules
Authors: Roithová Jana , Herman Zdenek , Schröder Detlef , Schwarz Helmut 
Published: January 2006

AbstractThe competition between proton and electron transfer in reactions of mass‐selected dications CHX2+ (X=F, Cl, Br, and I) with rare gas atoms (Ne, Ar, Kr, and Xe) and selected molecular reagents (N2, O2, CO, H2O, and HCl) is studied in the gas phase. In the ion–molecule reactions of CHX2+ dications with atoms and nonpolar molecules, it is the energy balance of electron transfer that acts as the decisive factor: when the exothermicity of electron transfer exceeds 2 eV, this process predominates at the expense of bond‐forming proton transfer. In marked contrast, the reactions between these triatomic dications and polar molecules are governed for the benefit of the thermochemically more favored products resulting from proton transfer.
Can Substituted Cyclopentadiene Become Aromatic or Antiaromatic?
Authors: Stanger Amnon 
Published: January 2006

AbstractCyclopentadiene derivatives with electronegative (F, Cl) or electropositive (H3Si, Me3Si) bis‐5,5‐substituents were studied at the B3LYP/6‐311G* level of theory. It was found that there is no special stabilization or destabilization for any of the derivatives; the energetic effects that were previously attributed to aromatic stabilization or antiaromatic destabilization are the result of interactions in the reference systems. A nucleus‐independent chemical shift (NICS) scan study at the HF‐GIAO/6‐311+G* theoretical level of these and similar derivatives suggest that they all show different magnitudes of diamagnetic ring current. None of the derivatives shows a paramagnetic ring current. Thus, cyclopentadienes are neither aromatic nor antiaromatic. It is also concluded that a diamagnetic ring current is perhaps necessary but certainly not a sufficient condition for aromaticity. The NICS scan procedure describes the type of ring current in the system, whereas a single isotropic NICS value (i.e., NICS(1)) may wrongly assign the type of ring current. It is shown that neither NICS(1) nor the NICS scan procedure can be used as a single aromaticity criterion.
Triheterocyclic Thiadiazepine Derivatives of Pharmacological Interest: Synthesis of 2‐Aryl‐4‐[p‐(2,3‐dihydro‐5‐methyl‐2‐oxo‐1,3,4‐oxadiazol‐3‐yl)phenyl]‐6‐(un)substituent‐1′′,2′′,4′′‐triazolo[3′′,4′′‐b]‐1′,3′,4′‐thiadiazepine
Authors: Kamble Ravindre , Sudha Belagur 
Published: January 2006

AbstractSynthesis of novel thiadiazepine derivatives based on the reactivity of 4‐acetylphenylsydnone (1) was reported. The structures of the newly synthesized compounds have been proved by their physical, analytical, IR, 1H NMR, 13C NMR and mass spectral data.
A population‐based survey of prostate‐specific antigen testing among California men at higher risk for prostate carcinoma
Authors: Spencer Benjamin A. , Babey Susan H. , Etzioni David A. , Ponce Ninez A. , Brown E. Richard , Yu Hongjian , Chawla Neetu , Litwin Mark S. 
Published: January 2006

AbstractBACKGROUNDDespite the lack of evidence demonstrating a survival benefit from prostate‐specific antigen (PSA) screening, its use has become widespread, organizations have encouraged physicians to discuss early detection of prostate carcinoma, and two higher risk groups have been recognized. In the current study, the authors examined whether African‐American men and men who had a family history of prostate carcinoma underwent PSA testing preferentially, and patterns of test use were examined according to age, race, and other factors.METHODSData regarding self‐reported PSA test use in the past year among men age 50 years and older without a history of prostate carcinoma (n = 8713 men) were analyzed from the 2001 California Health Interview Survey.RESULTSThe overall rate of PSA use was 43.0%. Older age, higher socioeconomic status, having a usual source of healthcare, and a family history of prostate carcinoma were the strongest predictors of testing. Higher risk African‐American men age 50 years and older were no more likely to be tested than white men. Men at higher risk who had a family history of prostate carcinoma were more likely to have been tested than men who had no such family history.CONCLUSIONSRates of PSA use among higher risk men who had a family history of prostate carcinoma were higher compared with the rates among men without such a family history. However, PSA testing rates among higher risk African‐American men were no different than the rates among lower risk white men, suggesting that some risk factors for prostate carcinoma (but not others) are associated with preferential testing. Testing in all groups was associated with access to care variables, highlighting the importance of removing barriers to preventive healthcare services. Cancer 2006. © 2006 American Cancer Society.
Threshold‐based admission control for a multimedia Grid: analysis and performance evaluation
Authors: Zhang Yang , Cao Jiannong , Chen Xiaolin , Lu Sanglu , Xie Li 
Published: January 2006

AbstractIn a Grid‐based services system facing a large number of requests with different services and profits significance, there is always a trade‐off between the system profits and the Quality of Service (QoS). In such systems, admission control plays an important role: the system has to employ a proper strategy to make admission control decisions and reserve resources for the coming requests thus to achieve greater profits without violating the QoS of the requests already admitted. In this paper, we introduce three essential admission control strategies with threshold on resource reservation and a newly proposed strategy with layered threshold. Through comprehensive theoretical analyses and extensive simulations, we demonstrate that the strategy with layered threshold is more efficient and flexible than the existing strategies for Grid‐based multimedia services systems. Copyright © 2006 John Wiley & Sons, Ltd.
GPGC: a Grid‐enabled parallel algorithm of geometric correction for remote‐sensing applications
Authors: Zhou Haifang , Yang Xujun , Liu Hengzhu , Tang Yu 
Published: January 2006

AbstractChinaGrid is an important project sponsored by the China Ministry of Education, aiming to provide high‐performance services in a Grid computing environment. In this paper, one of the applications offered by ChinaGrid, parallel remote‐sensing image processing, is described. Geometric correction is a basic step during the processing of remote‐sensing imagery, which is traditionally a computation‐intensive and communication‐intensive application if in parallel mode. In order to move this application into a Grid, a new Grid‐enabled parallel algorithm of geometric correction is proposed, called GPGC. GPGC changes the frequent and fine‐grain communication mode of the existing parallel method into a delayed but concentrated exchanging mode by computing an irregular local output area. This change means no communication or synchronization happens during resampling that occupies most of the execution time. To prove its efficiency, the complexity of GPGC is analyzed in theory. Finally, performance testing of GPGC and its application in ChinaGrid are given. Experimental results show that our algorithm is more suitable for a Grid platform, excelling the old method in both performance and salability. Copyright © 2006 John Wiley & Sons, Ltd.
Spontaneous crystallization of sodium chloride from aqueous‐ethanol solutions – Part 2: Mechanism of aggregation and coalescence of crystals
Authors: Linnikov Oleg D. 
Published: January 2006

AbstractPublished data on aggregation kinetics of sodium chloride crystals at its spontaneous crystallization from supersaturated aqueous‐ethanol solutions were analysed. It was found that the crystals coalesced through contact nucleus‐bridges between them according to the mechanism proposed by Polak. The kinetics of aggregation were described by the Smoluchowski equation for coagulation of colloidal particles. The kinetic coefficient of aggregation process depended on supersaturation, temperature of solution and other characteristics of the system. The specific surface energy of sodium chloride 0.95 mJ/m2 was found. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron‐phonon short‐range interactions mobility and p‐ to n‐type conversion in TlGaS2 crystals
Authors: Qasrawi A. F. , Gasanly N. M. 
Published: January 2006

AbstractThe conductivity type conversion from p ‐ to n ‐type at a critical temperature of 315 K in TlGaS2 crystals is observed through the Hall effect measurements in the temperature range of 200–350 K. The analysis of the temperature‐dependent electrical resistivity, Hall coefficient and carrier concentration data reveals the extrinsic type of conduction with donor impurity levels that behave as acceptor levels when are empty. The data analysis allowed the calculation of hole and electron effective masses of 0.36m 0 and 0.23m 0, respectively. In addition, the temperature‐dependent Hall mobility is found to decrease with temperature following a logarithmic slope of ∼1.6. The Hall mobility in the n ‐region is limited by the electron‐phonon short‐range interactions scattering with an electron‐phonon coupling constant of 0.21. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical study of top illuminated planar SiC PIN ultraviolet detectors
Authors: Wei Jiang 
Published: January 2006

AbstractIt is the first time that the idea of planar PIN structure ultraviolet (UV) detection has been demonstrated on SiC EPI wafers. By using this structure, the surface illuminated device has no efficiency‐bandwidth trade‐off problem, also can be easily integrated as an array device which can solve the low signal issue in normal edge illuminated device due to small device area with no sacrificial of high bandwidth. The performance of SiC PIN photodetectors is analyzed based on a serial of process parameters and device structures. The calculated results show the correlations of dark current, photocurrent, bandwidth (BW) with PIN structures and fabrication processes. Speed and optoelectronics performances were carefully considered for real implementations under theoretical conditions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structure and conformation study of N‐methyl‐t‐3‐methyl‐r‐2, c‐6‐diphenylpiperidin‐4‐one thiosemicarbazone
Authors: Sampath N. , Ponnuswamy M. N. , Nethaji M. 
Published: January 2006

AbstractThiosemicarbazones are having the ability to bind with metal and inhibit the enzyme ribonucleoside diphosphate reductase (RDR), an enzyme which is involved in the synthesis of DNA precursors in the mammalian cells. The title compound N‐methyl‐t‐3‐methyl‐r‐2, c‐6‐diphenylpiperidin‐4‐one thiosemicarbazone (NMMDPT), CCDC 218052, was prepared using Mannich reaction and characterized by X‐ray diffraction methods. The crystal data are: C20H24N4S; M.W = 352.49, triclinic, space group P$ \bar 1 $, a = 8.467(2) Å, b = 10.228(2) Å, c = 12.249(2) Å; α = 92.595(3)°, β = 104.173(3)°, γ =113.628(3)°; V = 930.0(3) Å3, Z = 2, Dcal = 1.259 Mgm–3, µ = 0.184 mm–1, λ (MoKα)= 0.71073 Å, final R1 and wR2 are 0.0470 and 0.1052, respectively. The piperidine rings adopt chair conformation. The planar phenyl rings are oriented equatorially at 2,6‐positions of the piperidine ring. The molecular packing can be viewed as dimers held together by two N–H…S types of intermolecular hydrogen bonds. Weak C–H…π interactions also support the stability of the molecules in the crystal in addition to van der Waals forces. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Single‐cell analysis of siRNA‐mediated gene silencing using multiparameter flow cytometry
Authors: Chan Steven M. , Olson Janelle A. , Utz Paul J. 
Published: January 2006

AbstractBackground:Use of synthetic short interfering RNAs (siRNAs) to study gene function has been limited by an inability to selectively analyze subsets of cells in complex populations, low and variable transfection efficiencies, and semiquantitative assays for measuring protein down‐regulation. Intracellular flow cytometry can overcome these limitations by analyzing populations at the single‐cell level in a high‐throughput and quantitative fashion. Individual cells displaying a knockdown phenotype can be selectively interrogated for functional responses using multiparameter analysis.Methods:Lck‐specific siRNA was delivered into Jurkat T cells or peripheral blood mononuclear cells (PBMCs) to suppress endogenous Lck expression. Transfected cells were fluorescently stained for intracellular Lck and analyzed using multiparameter flow cytometry. The Lcklo Jurkat subpopulation was selectively analyzed for CD69 up‐regulation and phospho‐states of signaling proteins following T‐cell receptor (TCR) stimulation. Surface expression levels of CD4 and CD8 on transfected CD3+ gated PBMCs were correlated with intracellular Lck levels.Results:A subpopulation of Jurkat cells with reduced levels of Lck was clearly resolved from cells with wildtype levels of Lck. Both CD69 up‐regulation and ZAP70 phosphorylation were suppressed in Lcklo cells when compared with those in Lckhi cells upon TCR stimulation. Knockdown of intracellular Lck in primary T lymphocytes reduced surface expression of CD4 in a dose‐dependent manner.Conclusions:Multiparameter flow cytometry is a powerful technique for the quantitative analysis of siRNA‐mediated protein knockdown in complex hard‐to‐transfect cell populations. © 2005 Wiley‐Liss, Inc.
Direct Simultaneous Determination of α‐ and β‐Naphthol Isomers at GC‐Electrode Modified with CNTs Network Joined by Pt Nanoparticles Through Derivative Voltammetry
Authors: Wang Xiao‐Gang , Wu Qing‐Sheng , Ding Ya‐Ping 
Published: January 2006

AbstractThe semi‐derivative technique was adopted to improve the resolution and surfactant was added to sample solution to enhance the sensitivity, α‐ and β‐naphthol isomers could be determined directly and simultaneously at glassy carbon electrode modified with carbon nanotubes network joined by Pt nanoparticles. In 0.1 mol L−1 HAc‐NaAc buffer solution (pH 5.8), the linear calibration ranges were 1.0×10−6 to 8.0×10−4 mol L−1 for both α‐ and β‐naphthols, with detection limits of 5.0×10−7 for α‐ and 6.0×10−7 mol L−1 for β‐naphthol. The amount of naphthol isomers in artificial wastewater has been tested with above method, and the recovery was from 98% to 103%.
Electrochemical Approach to the Radical Anion Formation from 2′‐Hydroxy Chalcone Derivatives
Authors: Quintana‐Espinoza P. , Yáñez C. , Escobar C. A. , Sicker D. , Araya‐Maturana R. , Squella J. A. 
Published: January 2006

AbstractThree 2′‐hydroxy chalcone derivatives were electrochemically reduced to the radical anion by a reversible one‐electron transfer followed by a chemical dimerization reaction. Under suitable conditions of the medium, the one‐electron reduction produces very well resolved cyclic voltammograms due to the formation of the radical anion. By using appropriately the wide versatility of the cyclic voltammetric technique, was possible to study the generation of the radical anion and its stability.
Isochromosome breakpoints on 17p in medulloblastoma are flanked by different classes of DNA sequence repeats
Authors: Mendrzyk Frank , Korshunov Andrey , Toedt Grischa , Schwarz Frank , Korn Bernhard , Joos Stefan , Hochhaus Andreas , Schoch Claudia , Lichter Peter , Radlwimmer Bernhard 
Published: January 2006

AbstractMedulloblastoma is a highly malignant embryonal tumor of the cerebellum that accounts for 20%–25% of all intracranial pediatric tumors. The most frequent chromosomal rearrangement in medulloblastoma is isochromosome 17, or i(17q). Its frequency suggests that it serves an important role in tumor pathogenesis, possibly mediated by the disruption or permanent activation of a gene at the breakpoint. To address this question, we performed a detailed analysis of chromosome 17 DNA copy number from 18 medulloblastomas previously shown to carry an apparent i(17q). We identified two breakpoint regions, one well within band 17p11.2 (n = 16) and a second within the pericentromeric region (n = 2). To map the breakpoints more precisely, we constructed a tiling‐path matrix‐CGH array covering chromosomal band 17p11.2 to the centromere and utilized it to delineate two small breakpoint intervals mapping at Mb 19.0 and 21.7 in seven of the medulloblastomas and in nine hematological neoplasias with i(17q). The former interval contains two breakpoint clusters that each colocalize with a pair of head‐to‐head inverted DNA sequence repeats, and the latter maps close to a region of α‐satellite repeats. No consensus coding sequence localizes in these regions. Together, these data strongly suggest that the effects of i(17q) in medulloblastoma are mediated by gene‐dosage effects of genes on 17p or 17q rather than by the disruption or deregulation of a “breakpoint” gene. Furthermore, we identified artifacts introduced in DNA copy number data by cross‐hybridization of low‐copy repeat sequences and discuss the challenge these can pose in the interpretation of diagnostic microarrays. © 2006 Wiley‐Liss, Inc.
Amplification of CDK4 and MDM2 in malignant melanoma
Authors: Muthusamy Viswanathan , Hobbs Cara , Nogueira Cristina , Cordon‐Cardo Carlos , McKee Phillip H. , Chin Lynda , Bosenberg Marcus W. 
Published: January 2006

AbstractAmplification of the 12q13–15 region is a common event in several human tumors including liposarcomas, gliomas, and osteosarcomas. We have demonstrated high‐level amplification of 12q14 in a subset of uncultured malignant melanomas (3 of 53). High‐resolution mapping of the amplicon using quantitative PCR revealed a bipartite amplicon consisting of a primary 50‐kb amplicon centered on CDK4 and a secondary amplicon centered on MDM2, without amplification of the intervening 11 Mb of genomic DNA. Analysis of mRNA and protein levels in melanomas with 12q14 amplification demonstrated overexpression of target genes CDK4 and MDM2 without loss of CDKN2A‐P16 (P16INK4A) or CDKN2A‐P14ARF (P14ARF) expression, important regulators of the RB1 and TP53 pathways, which are commonly lost or mutated in melanoma. These results suggest that coamplification of CDK4 and MDM2 may substitute for loss of P16INK4A and P14ARF function in a subset of melanomas. © 2006 Wiley‐Liss, Inc.