bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel chiroptical analysis of hemoglobin by surface enhanced resonance Raman optical activity spectroscopy
Authors: Brazhe Nadezda A. , Brazhe Alexey R. , Sosnovtseva Olga V. , Abdali Salim 
Published: January 2010

AbstractThe metalloprotein hemoglobin (Hb) was studied using surface enhanced resonance Raman spectroscopy (SERRS) and surface enhanced resonance Raman optical activity (SERROA). The SERROA results are analyzed and compared with the SERRS, and the later to the resonance Raman (RRS) performed on Hb. The SERRS measurements careful optimization, with respect to the concentration and volume ratio of the analyte to colloids, enables for the first time SERROA of this molecule. We observed that the most intense SERROA signals were attributed the ν4, ν20, and ν21 vibrations, which are sensitive to the redox state of the heme's iron ion, and to the presence of its sixth site, bound to exogenous ligand; O2, NO or CO. However, in this study, the SERROA signals corresponding to these vibrations appear more sensitive to the Hb oxygen‐binding properties than they appear in the SERRS or RRS. Moreover, the SERROA signal of Hb has successfully been monitored as a function of time, and was observed to be stable for 4–5 min. To our knowledge, the SERROA results of Hb, and its comparison to SERRS and RRS, are here reported for the first time. Chirality 21:E307–E312, 2009. © 2010 Wiley‐Liss, Inc.
Ru‐catalyzed Asymmetric Hydrogenation of Aryl Ketones Using Tetrazole Derived NH2‐hybrid Ligand
Authors: Bie Fusheng , Li Yuehui , Cao Weiguo , Sanboval Christian A. 
Published: January 2010

AbstractReadily available chiral hybrid NH2/tetrazole ligand [(S)‐TEA, 1] in combination with Ru‐BINAP or Ru‐DIOP complexes catalyzes the asymmetric hydrogenation of a number of simple ketones with moderate enantioselectivity (up to 72% ee). The tetrazole functionality results in reversal of the typically observed chiral‐induction for related systems and allows for hydrogenation to be uncharacteristically conducted in (non‐protic) THF solvent. The observed catalyst performance is sensitive to the reaction conditions employed and the particular compounds involved. The origins of such features are considered to derive from the added functionality provided by the tetrazole moiety in 1, which due to its modular nature provides a good basis for further development.
Theoretical Study of Origin of Triple Fluorescences of a Squaraine Dye, Bis[4‐(N,N‐dimethylamino)phenyl]squaraine
Authors: Mang Chaoyong , Zhou Jun , Liu Caiping , Wu Kechen 
Published: January 2010

AbstractA new scheme of photo‐fluorescent emission origin, described as S0 (relaxed state)→Sn (Frank‐Condon state)→ Sm (relaxed state)→S0 (Frank‐Condon state), is presented to explain the multiple fluorescent emissions of squaraine dyes observed experimentally according to the configuration interaction singles calculations of relaxed excited states of a model compound, bis[4‐(N,N‐dimethylamino)phenyl]squaraine (SQ). It is exhibited that all triple fluorescent emissions of SQ have their significant origin in vertical electron transitions of different relaxed excited states. In addition, some important absorption peaks appearing in higher energy region are most likely to be responsible for the higher energy band observed in solid states of many squaraine dyes.
Conduction in BaO‐ and MgO‐doped LaGaO3
Authors: Chen Cheng , Wang Wenbao , Ma Guilin 
Published: January 2010

AbstractA series of La0.90Ba0.10Ga1−xMgxO3−α (x=0.20, 0.25 and 0.30) ceramics with a perovskite‐type orthorhombic structure were prepared by the conventional solid‐state reaction. Their conduction was studied in wet hydrogen, wet air and dry air atmospheres by various electrochemical methods including AC impedance spectroscopy, isotope effect, electrochemical hydrogen pumping, steam concentration cells and oxygen concentration cells from 873 to1273 K. Proton conduction was confirmed directly by an electrochemical hydrogen‐pumping experiment. The hydrogen evolution rates coincided with theoretical ones calculated from Faraday's law, indicating that in hydrogen atmosphere the charge carriers were predominantly protons. Isotope effect confirmed the ceramic samples possessed proton conduction under water vapor‐containing atmosphere. In wet air atmosphere, the samples were found to be mixed (proton+oxide ion+hole) conductors, and in dry air atmosphere to be mixed (oxide ion+hole) conductors. These results were different from the reports that BaO‐ and MgO‐doped LaGaO3 ceramics were mixed conductors of oxide ion and electron hole in O2 and air; whereas they were oxide ion conductors in N2 and H2 atmospheres.
Hydrothermal Synthesis, Crystal Structures of Three New Metal(II) Complexes with 1‐Adamantaneacetic Acid
Authors: Geng Xiaohong , Kong Lichun , Zheng Jufang , Feng Yunlong , Su Hong 
Published: January 2010

AbstractThree new complexes constructed by 1‐adamantaneacetic acid (HL), [Zn2L4]n (1), [MnL2(4,4′‐bipy)(H2O)2]n· 2n(HL) (2) and MnL2(2,2'‐bipy)(H2O)2 (3), have been hydrothermally synthesized. X‐ray single crystal diffraction analyses reveal that both 1 and 2 are infinite 1D chains along b axis. 2 and 3 have an octahedral coordination and show the supramolecular structures which are formed on the basis of the connectivity of intermolecular hydrogen bonds. The deprotonated L− ligands coordinate the M(II) atoms with many coordination modes in the title complexes.
Structure, DNA Binding Studies of Complex {[Cu(phen)(py)(H2O)2]·2H2O}n
Authors: Gao Enjun , Shi Qunzhi , Liu Lei , Zhu Mingchang , Shi Chunyue , Zhang Wanzhong 
Published: January 2010

AbstractA copper(II) complex of type {[Cu(phen)(py)(H2O)2]·2H2O}n (where phen=1,10‐phenanthroline, py=pyridine‐3,4‐dicarboxylate) has been synthesized by a normal temperature volatilization method and structurally determined by single‐crystal X‐ray crystallography. The crystal belongs to monoclinic system, space group P2(1)/c with the crystal cell parameters of a=7.5258(4) Å, b=12.3184(7) Å, c=21.0000(12) Å, α=90.00°, β=98.0720(10) °, γ=90.00°, V=1927.53(19) Å3 and Z=4. The final reliability factors are R=0.0398 and wR=0.1138 for 3771 reflections with I>2δ(I0). Its mode of interaction with DNA and the binding constants have been determined by fluorescence, ultraviolet spectra and viscometry.
Cluster Analysis and QSAR Study of Some Anti‐hepatitis B Virus Agents Comprising 4‐Aryl‐6‐chloro‐quinolin‐2‐ones and 5‐Aryl‐7‐chloro‐1,4‐benzodiazepines
Authors: Li Zuguang , Chen Kexian , Xie Haiying , Wang Yan , Dong Fengchao 
Published: January 2010

AbstractChronic hepatitis B virus (HBV) infection has caused a global health crisis by infecting more than 400 million people, constituting the ninth leading cause of death in the world. There is an urgent demand for antiviral agents to effectively inhibit HBV infection based on the development of drug resistance and increasing infected numbers. Quantitative structure‐activity relationship (QSAR) models were developed for a series of potent anti‐hepatitis B virus agents comprising 4‐aryl‐6‐chloro‐quinolin‐2‐ones and 5‐aryl‐7‐chloro‐1,4‐benzodiazepines using Cerius2 4.10 software. The best 2D‐QSAR model (r2=0.952 and r2pred=0.989) constructed by the genetic function approximation (GFA) methodology indicates that the activity was mainly governed by E‐State‐keys (S_sssN and S_sCl), electronic descriptor (LUMO), thermodynamic descriptor (Foct) and conformational descriptor (Energy). 3D‐QSAR models were developed based on steric and electrostatic interactions by molecular field analysis (MFA) to investigate the substitutional requirements for the favorable receptor‐drug interaction, showing that electrostatic interactions is crucial for the activity. The models derived can provide a preliminary valuable guidance for continuing search for novel potent anti‐hepatitis B virus agents prior to synthesis.
Synthesis of Novel Imines Containing Indolizine Moiety
Authors: Liu Weiwei , Zhao Yueqiang , Gu Xiang , Fan Rijing , Hu Hongwen 
Published: January 2010

AbstractReaction of 2‐phenylindolizine‐3‐carbothialdehyde with amine derivatives provides a new, mild and efficient synthesis of a series of heterocyclic imines. The corresponding structures of products were established by IR, 1H NMR, MS and elemental analysis. And the reaction mechanisms was also discussed.
Spectrophotometric Determination of Human Immunoglobulin G Based on Enlargement of Gold Nanoparticles
Authors: Deng Xinyu , Gao Dejiang , Liang Fanghui , Jin Danhong , Tian Yuan , Chen Yanhua , Yu Aiming , Zhang Hanqi 
Published: January 2010

AbstractBased on the sandwich immunoreaction and enlargement of colloidal gold, a simple spectrophotometric determination of human immunoglobulin G (IgG) was developed. The sandwich immunoreaction among the goat‐anti‐human IgG, the human IgG and goat‐anti‐human IgG labeled with colloidal gold was completed on the surface of 96 well clear polystyrene high bind stripwell(tm) microplate. The immobilized colloidal gold was enlarged by the reaction of 0.01% HAuCl4 with 0.4 mmol·L−1 NH2OH·HCl. A common UV‐Vis spectrophotometer was employed to measure the absorption of the colloidal gold enlarged. The absorption signal of colloidal gold is proportional to the logarithm of human IgG concentration ranging from 5.0×10−9 to 2.0×10−5 g·mL−1, which is comparable with those obtained by other immunoassays. In the proposed method, the immobilized colloidal gold can be easily enlarged and a new absorption band is present at about 620 nm, which makes the signal be recorded with a common medical analyzer. This spectrophotometric determination can be made in a common laboratory without the well‐trained technician and the special equipment.
Electrocatalytic Oxidation of Nitrite at Gold Nanoparticle‐ polypyrrole Nanowire Modified Glassy Carbon Electrode
Authors: Li Jing 
Published: January 2010

AbstractA novel chemically modified electrode based on the dispersion of gold nanoparticles on polypyrrole nanowires has been developed to investigate the oxidation behavior of nitrite using cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques. The diffusion coefficient (D), electron transfer coefficient (α) and charge transfer rate constant (k) for the oxidation of nitrite were determined. The modified electrode exhibited high electrocatalytic activity toward the oxidation of nitrite. The catalytic peak current was found to be linear with nitrite concentrations in the range of 8.0×10−7−2.5×10−3 mol·L−1 with a detection limit of 1.0×10−7 mol·L−1 (s/n=3). The proposed method was successfully applied to the detection of nitrite in water samples with obtained satisfactory results. Additionally, the sensor also showed excellent sensitivity, anti‐interference ability, reproducibility and stability properties.
Synthesis and Antimicrobial Activity of Novel Iminophosphocin Derivatives
Authors: Koteswara rao Valasani , Subba reddy Sanapalli , Dada peer Echchukattula , Janardhan rao Alahari , Naga raju Chamarthi 
Published: January 2010

AbstractIminophosphocins 8a–8e and 9a–9e were synthesized in four‐step reactions via Staudinger reaction. 3‐(Bromomethyl)‐1,2,3,4,5‐pentahydro‐3λ5‐naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐one (3) was prepared by reacting tris(bromomethyl)phosphineoxide (1) with 1,8‐diaminonaphthalene (2) in the presence of triethylamine (TEA) in dry tetrahydrofuran (THF), and treated with L‐valine methyl ester (4) and bis(2‐chloroethyl)amine (5) in the presence of TEA in dry THF to get 3‐methyl‐2‐[(3‐oxo‐1,2,3,4,5‐pentahydro‐3λ5‐naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐yl)methylamino]butanoate (6) and 3‐[di(2‐chloroethyl)aminomethyl]‐1,2,3,4,5‐pentahydro‐3λ5‐ naphtho[1,8‐f,g][1,5,3]diazaphosphocin‐3‐one (7). The compounds 6 and 7 were treated with trichlorosilane (SiCl3H) in dry tetrahydrofuran (THF) to form the trivalent P(III) intermediates 8 and 9, which were further treated with various alkyl azides in dry THF in 55–60°C to afford the title compounds 8a–8e and 9a–9e. Their structures were established by multi‐nuclear NMR and mass spectra. All the newly synthesized compounds were found to possess moderate anti‐microbial activity.
A Simple One‐pot Synthesis of Indeno[2,1‐f]quinolin‐3‐one Derivatives under Microwave Irradiation
Authors: Peng Juhua , Jia Runhong , Xu Yajuan , Tu Shujiang , Ma Ning , Zhang Ge 
Published: January 2010

AbstractA series of new indeno[2,1‐f]quinolin‐3(2H)‐one derivatives were synthesized by a reaction of aromatic aldehyde with Meldrum's acid (2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione) and 9H‐fluoren‐2‐amine under microwave irradiation without catalyst in glacial acetic acid. This reaction has notable advantages of short reaction time, high yield and convenient operation.
Highly Concise Synthesis of 3'‐"Up"‐ethynyl‐5'‐methylbicyclo‐ [3.1.0]hexyl Purine and Pyrimidine Nucleoside Derivatives Using Rhodium(II) Carbenoid Cycloaddition and Highly Diastereoselective Grignard Reaction
Authors: Yang Zunhua , Kim Kyung Ran , Park Ah‐Young , Lee Hyung‐Rock , Kang Jin‐Ah , Kim Won Hee , Chun Pusoon , Gong Ping , Lee Boeun , Jeong Lak Shin , Moon Hyung Ryong 
Published: January 2010

AbstractSynthesis of north‐5'‐methylbicyclo[3.1.0]hexyl purine and pyrimidine nucleosides with an ethynyl group at C‐3' position has been successfully accomplished by a facile method. Methylbicyclo[3.1.0]hexanone (±)‐5 having three contiguous chiral centers was remarkably simply constructed only by four steps containing a carbenoid insertion reaction in the presence of rhodium(II) acetate dimer and CuSO4, giving a correct relative stereochemistry of the generated three chiral centers. Upon Grignard reaction of (±)‐5 with ethynylmagnesium bromide, exclusive diastereoselectivity was observed. Condensation of glycosyl donor (±)‐9 with purine nucleobase afforded only the desired N9‐alkylated nucleoside, while condensation with pyrimidine, N3‐benzoylated uracil gave the desired N1‐alkylated nucleoside (±)‐13 with the undesired O2‐alkylated nucleoside (±)‐14. Probably, (±)‐14 would be formed due to steric hindrance caused upon approaching for N1‐alkylation.
PPA‐SiO2 as a Heterogeneous Catalyst for Efficient Synthesis of 2‐Substituted‐1,2,3,4‐tetrahydro‐4‐quinazolinones under Solvent‐free Conditions
Authors: Shaterian Hamid Reza , Oveisi Ali Reza 
Published: January 2010

AbstractSilica‐supported polyphosphoric acid (PPA‐SiO2) catalyzed efficiently the reaction of anthranilamide with aryl aldehydes or ketones under solvent‐free conditions to afford the corresponding 1,2,3,4‐tetrahydro‐4‐quinazolinone derivatives. This work consistently has the advantages of excellent yields, short reaction time, simple experimental and work‐up procedures. The heterogeneous catalyst could be recovered and recycled for several times without any loss of its activity.
Copper(I) Oxide Catalyzed Formation of CS Bond Mediated by N,N′‐Type Ligand
Authors: Feng Yisi , Zhao Xiaoyang , Wang Jueyu , Zheng Fayin , Xu Huajian 
Published: January 2010

Abstract1,10‐Phenanthroline, a simple and cheap N,N′‐type ligand, was found to work well as the ligand of CS coupling catalyzed by Cu2O. The corresponding coupling products were synthesized in good to excellent yields (75%–99%) in DMSO at 80°C. A variety of aryl halides and thiols were investigated and satisfactory results were obtained.
Synthesis and Characterization of Novel Trifluoromethylphenyl Silane Monomers
Authors: Li Zhanxiong , Du Liping , Tang Songqing , Wang Changyao 
Published: January 2010

AbstractUsing 3,5‐bis(trifluoromethyl)bromobenzene and methyltrimethoxysilane or tetraethoxysilane as raw materials, novel trifluoromethylphenyl silanes were synthesized via Grignard reaction and substitution reaction, and the molecular structure of silane products was characterized by NMR, FT‐IR, MS techniques and elemental analysis. The reaction result showed that the reactivity of Grignard reagent was different in THF and diethyl ether when subjected to substitution reaction, which gave three products with different substitution degree. According to the current work, mono‐, di‐ and tri‐substituted product can be obtained selectively from the same reactants by controlling the reaction condition.
Calculation and Measurement of Terahertz Active Normal Modes in Crystalline PETN
Authors: Burnett Andrew D. , Kendrick John , Cunningham John E. , Hargreaves Michael D. , Munshi Tasmin , Edwards Howell G. M. , Linfield Edmund H. , Davies A. Giles 
Published: January 2010

AbstractThe terahertz frequency spectrum of pentaerythritol tetranitrate (PETN) is calculated using Discover1with the COMPASS2force field, CASTEP[3]and PWscf.4The calculations are compared to each other and to terahertz spectra (0.3–3 THz) of crystalline PETN recorded at 4 K. A number of analysis methods are used to characterise the calculated normal modes.
Fractal dimension of cell clusters in effusion cytology
Authors: Sharma Nidhi , Dey Pranab 
Published: January 2010

AbstractIn this study, the fractal dimension (FD) of the ball‐like tight clusters of known metastatic adenocarcinoma cells is compared with the tight cell clusters of the benign cells in the effusion fluid to find out the role of FD in differentiating malignant from benign cluster in effusion. A total of 68 and 72 images of cluster of cells from 12 cases of benign and 13 cases of metastatic pleural and peritoneal effusion were studied for FD. The mean FD of the cluster of cells of benign and malignant effusion was 1.4801 ± 0.23260 and 1.7175 ± 0.09006, respectively. Mann–Whitney U‐test showed significant difference of FD between the cell clusters of malignant and benign effusion cases (P < 0.0001). Cytological features along with the measurement of FD of cell clusters in effusion cytology may be helpful in differentiating benign from malignant cases. Diagn. Cytopathol. 2010;38:866–868. © 2010 Wiley‐Liss, Inc.
Should fine‐needle aspiration cytology be the first choice diagnostic modality for assessment of all nonpalpable breast lesions? The experience of a breast cancer screening center in Alexandria, Egypt
Authors: Abdel‐Hadi Mona , Abdel‐Hamid Gehane F. , Abdel‐Razek Naglaa , Fawzy Rawia K. 
Published: January 2010

AbstractFine‐needle aspiration cytology (FNAC) of breast masses has been replaced by ultrasound‐guided core‐needle biopsy (USG‐CNB) in many countries. However, in Egypt, breast FNAC continues to play the major role in diagnosing breast masses. In this prospective study, we evaluated the efficacy of USG‐FNACs performed at a breast cancer screening center by comparing the FNAC results with the corresponding definitive histological examination outcome. We also investigated the role that CNB can play as a complementary diagnostic tool for FNAC in selected cases. A total of 229 consecutive nonpalpable breast masses were included in this study. Each FNAC was placed into one of four categories: 3.5% nondiagnostic, 13.5% benign, 12.3% atypical/suspicious (indeterminate), and 70.7% malignant. The overall diagnostic accuracy was 98.9%, with a specificity and sensitivity of 99.3 and 96.7%, respectively. The overall positive predictive values and negative predictive values were 99.3 and 96.7%, respectively. Only 37 masses (16%) were converted to CNB, with the indeterminate cytology being the most common cause (54%) for this conversion. Two cases demonstrating the superior benefit of FNAC over CNB are illustrated. Although we started the study by reserving CNB as a first choice to assess microcalcifications without architectural distortion, we ended the study by deciding to perform combined FNAC and CNB for this type of lesions. In conclusion, aiming to maximize the preoperative diagnosis of cancer, it would be cost efficient and time saving to use FNAC as a first‐line investigation to benefit from the wealth of cytological information yielded, followed by CNB in selected cases. Diagn. Cytopathol. 2010;38:880–889. © 2010 Wiley‐Liss, Inc.
Screening for testosterone abuse in male athletes using the measurement of urinary LH, a revision of the paradigm
Authors: Goebel Catrin , Howe Christopher J. , Ho Ken K. , Nelson Anne , Kazlauskas Rymantas , Trout Graham J. 
Published: January 2010

AbstractThe primary screening method for the detection of doping by athletes using synthetic versions of endogenous steroids such as testosterone relies on measurement of the ratio of testosterone (T) to epitestosterone (E) in urine. In 2005 the World Anti‐Doping Agency (WADA) lowered the T/E value at which samples undergo further investigation from six to four. This has resulted in a large increase in the number of athletes with naturally elevated T/E ratios undergoing investigation without a corresponding increase in the number of proven doping offences involving testosterone.Our objective was to develop a new simple screening protocol that can, with high probability, not only distinguish athletes whose natural T/E values exceed four from those whose T/E values have been elevated by testosterone doping but also detect those athletes with naturally low T/E values that do not exceed four despite being administered testosterone.Testosterone (250 mg Sustanon) was administered weekly to a group of 47 young adult males for five weeks in a double‐blind placebo controlled study and urine samples collected. The samples were analysed for steroid concentrations using GC/MS and for luteinizing hormone (LH) by immunoassay.The elevation of T/E that occurred in all subjects was accompanied by a significant reduction in urinary LH concentrations to levels that are rare in normal subjects.The appropriate measurement of urinary LH, with the measurement of T/E values, can markedly improve the efficiency of detection of doping with testosterone by male athletes, particularly those who have low natural T/E ratios. Copyright © 2010 John Wiley & Sons, Ltd.
IFN‐γ‐receptor signaling ameliorates transplant vasculopathy through attenuation of CD8+ T‐cell‐mediated injury of vascular endothelial cells
Authors: Bolinger Beatrice , Engeler Daniel , Krebs Philippe , Miller Simone , Firner Sonja , Hoffmann Matthias , Palmer Douglas C. , Restifo Nicholas P. , Tian Yinghua , Clavien Pierre‐Alain , Ludewig Burkhard 
Published: January 2010

AbstractOcclusive transplant vasculopathy (TV) is the major cause for chronic graft rejection. Since endothelial cells (EC) are the first graft cells encountered by activated host lymphocytes, it is important to delineate the molecular mechanisms that coordinate the interaction of EC with activated T cells. Here, the interaction of CD8+ T cells with Ag‐presenting EC in vivo was examined using a transgenic heart transplantation model with β‐galactosidase (β‐gal) expression exclusively in EC (Tie2‐LacZ hearts). We found that priming with β‐gal peptide‐loaded DC failed to generate a strong systemic IFN‐γ response, but elicited pronounced TV in both IFN‐γ receptor (IFNGR)‐competent, and ifngr−/− Tie2‐LacZ hearts. In contrast, stimulation of EC‐specific CD8+ T cells with β‐gal‐recombinant mouse cytomegalovirus (MCMV‐LacZ) in recipients of ifngr+/+ Tie2‐LacZ hearts did not precipitate significant TV. However, MCMV‐LacZ infection of recipients of ifngr−/− Tie2‐LacZ hearts led to massive activation of β‐gal‐specific CD8 T cells, and led to development of fulminant TV. Further analyses revealed that the strong systemic IFN‐γ “storm” associated with MCMV infection induced upregulation of programmed death‐1 ligand 1 (PD‐L1) on EC, and subsequent attenuation of programmed death‐1 (PD‐1)‐expressing EC‐specific CD8+ T cells. Thus, IFNGR signaling in ECs activates a potent peripheral negative feedback circuit that protects vascularized grafts from occlusive TV.