bluuebunny/crossref_metadata_2025_split huggingface dataset:
High performance liquid chromatographic enantioseparation of chiral bridged polycyclic compounds on chiralcel OD‐H and chiralpak OT(+)
Authors: Peluso Paola , Cossu Sergio , Moretto Flavio , Marchetti Mauro 
Published: July 2008

AbstractThe HPLC enantiomeric separation of 29 racemic bridged polycyclic compounds was examined on commercially available Chiralcel OD‐H and Chiralpak OT(+) columns. The separations were evaluated under normal‐phase mode (hexane containing mobile phase) for Chiralcel OD‐H and under normal‐phase as well as under reversed‐phase mode (pure MeOH, temperature 5°C) for Chiralpak OT(+). Almost all compounds were resolved either on Chiralcel OD‐H or on Chiralpak OT(+), in some cases on both. The use of trifluoroacetic acid (TFA), as modifier of the hexanic mobile phase, had a beneficial effect on the enantioseparation of some polar and acidic compounds on Chiralcel OD‐H. The influence of small chemical structural modifications of the analytes on the enantioseparation behavior is discussed. A structure–retention relationship has been observed on both stationary phases. This chromatographic evaluation may provide some information about the chiral recognition mechanism: in the case of Chiralcel OD‐H, hydrogen bonding, π‐π and distereoselective repulsive are supposed to be the major analyte‐CSP interactions. In the case of Chiralpak OT(+), a reversed‐phase enantioseparation could take place through hydrophobic interactions between the aromatic moiety of the analytes and the chiral propeller structure of the CSP. The synthesis of some unknown racemic bromobenzobicyclo[2.2.1] analytes is also described. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
L‐Selectin‐deficient SJL and C57BL/6 mice are not resistant to experimental autoimmune encephalomyelitis
Authors: Uboldi Chiara , Döring Axinia , Alt Carsten , Estess Pila , Siegelman Mark , Engelhardt Britta 
Published: July 2008

AbstractL‐selectin has been suggested to play a role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. Here we demonstrate that L‐selectin–/– SJL mice are susceptible to proteolipid protein (PLP)‐induced EAE because the compromised antigen‐specific T cell proliferation in peripheral lymph nodes is fully compensated by the T cell response raised in their spleen. Transfer of PLP‐specific T cells into syngeneic recipients induced EAE independent of the presence or absence of L‐selectin on PLP‐specific T cells or in the recipient. Leukocyte infiltration into the central nervous system parenchyma was detectable independent of the mode of disease induction and the presence or absence of L‐selectin. In addition, we found L‐selectin–/– C57BL/6 mice to be susceptible to myelin oligodendrocyte glycoprotein‐induced EAE. Taken together, we demonstrate that in SJL and C57BL/6 mice L‐selectin is not required for EAE pathogenesis. The apparent discrepancy of our present observation to previous findings, demonstrating a role of L‐selectin in EAE pathogenesis in C57BL/6 mice or myelin‐basic protein (MBP)‐specific TCR‐transgenic B10.PL mice, may be attributed to background genes rather than L‐selectin and to a unique role of L‐selectin in EAE pathogenesis in MBP‐TCR‐transgenic mice.
Hydrogen Bonding and Anion Binding in Structures of Tris(pyrazolyl)boratenickel(II) and Phosphate Esters
Authors: Santana M. Dolores , López‐Banet Luisa , García Gabriel , García Luís , Pérez José , Liu Malva 
Published: July 2008

AbstractThis paper presents the syntheses, crystal structures and spectroscopic properties of a series of nickel(II) complexes containing hydrotris(3,5‐dimethylpyrazolyl)borate and phosphate esters: [Tp*Ni(Hpz*)2(L)][(RO)2PO2] [R = Et, Bu; L = H2O (1), (BuO)2P(O)OH (2)] and [Tp*Ni(Hpz*)(H2O)2][(EtO)2PO2] (5) {Tp* = hydrotris(3,5‐dimethylpyrazolyl)borate, Hpz* = 3,5‐dimethylpyrazole}. The complexes [Ni(Tp*)2] (3) and [(Tp*Ni)2(μ‐pz*)(μ‐OH)](4) were also prepared and fully characterized. X‐ray crystallographic studies of 1 and 2 reveal that the pyrazole moieties are hydrogen bonded to the guest phosphate ester anion. In complex 5, the phosphate anion is hydrogen‐bonded by two O–H groups of the water molecules. Their behavior in solution was investigated by 1D and 2D 1H NMR spectroscopic techniques. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Lanthanide Complexes of 2,2′,2″‐(10‐{[Hydroxy(phenyl)phosphoryl]methyl}‐1,4,7,10‐tetraazacyclododecan‐1,4,7‐triyl)triacetic Acid: Structural Characterisation of Intermediates from the Proposed Complexation Mechanism in the Systems of LnIII‐dota‐Type Ligands
Authors: Vojtíšek Pavel , Rohovec Jan , Klimentová Jana 
Published: July 2008

AbstractThe crystal and molecular structures of ten lanthanide complexes of H4do3aPPh [2,2′,2″‐(10‐{[hydroxy(phenyl)phosphoryl]methyl}‐1,4,7,10‐tetraazacyclododecan‐1,4,7‐triyl)triacetic acid] are presented here. These complexes constitute a new type of coordination compounds within the Ln‐dota family. They represent an intermediate stage on the way from the ligand to the classical in‐cavity complexes. The important role of intramolecular H‐bonds for the process was observed. These intermediate complexes in the solid state form several isostructural groups with the different coordination polyhedra (square antiprisma or dodecahedron) of lanthanide ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Copper Zeolites as Green Catalysts for Multicomponent Reactions of Aldehydes, Terminal Alkynes and Amines: An Efficient and Green Synthesis of Propargylamines
Authors: Patil Meghshyam K. , Keller Murielle , Reddy Benjaram M. , Pale Patrick , Sommer Jean 
Published: July 2008

AbstractCuI‐modified zeolites, especially CuI‐USY, have proved to be very efficient catalysts in multicomponent reactions, allowing for a solvent‐free synthesis of propargylamines from aldehydes, amines, and terminal alkynes. With a heterogeneous catalyst and in the absence of solvent, this process is among the greenest ever reported. A mechanism has been proposed for this three‐component reaction.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Aryl Trialkylsilyl Ketenes: Acid‐Catalyzed Synthesis from 1‐Aryl‐2‐diazo‐2‐trialkylsilylethanones and Their Conversion into 3‐Silyl‐1‐silyloxyallenes
Authors: Bucher Stefan M. , Brückmann Ralf , Maas Gerhard 
Published: July 2008

AbstractAryl‐substituted α‐silyl α‐diazo ketones are readily transformed into aryl silyl ketenes in the presence of a catalytic amount of triflic acid. Thus, a convenient method to prepare these silyl ketenes becomes available, which combines two steps, silylation of an aryl diazomethyl ketone and acid‐induced Wolff rearrangement of the formed α‐silyl α‐diazo ketone, in a one‐pot procedure. It appears that the trialkylammonium salt, which is formed in the silylation step, can also catalyze the Wolff rearrangement, but distinctly more slowly than the proton acid. The silyl ketenes react smoothly with α‐silyl α‐diazo ketones to form 3‐silyl‐1‐silyloxyallenes in fairly good yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Electrochemical Characterization of Self‐Assembled Monolayer of a Novel Manganese Tetrabenzylthio‐Substituted Phthalocyanine and Its Use in Nitrite Oxidation
Authors: Matemadombo Fungisai , Griveau Sophie , Bedioui Fethi , Nyokong Tebello 
Published: July 2008

AbstractManganese phthalocyanine MnPc(SPh)4 has been synthesized and used to form self assembled monolayers on gold electrodes. The well packed SAM monolayer was characterized by analyzing the blocking of a number of Faradic processes by cyclic voltammetry, evaluating the electrical characteristics of the modified electrode by electrochemical impedance and imaging the modified surface by electrochemical scanning microscopy. Finally, MnPc(SPh)4‐SAM modified electrode displayed an electrocatalytic behavior toward the oxidation of nitrite.
The Fabrication and Characterization of a Bismuth Nanoparticle Modified Boron Doped Diamond Electrode and Its Application to the Simultaneous Determination of Cadmium(II) And Lead(II)
Authors: Toghill Kathryn E. , Wildgoose Gregory G. , Moshar Amir , Mulcahy Chris , Compton Richard G. 
Published: July 2008

AbstractWe report the simultaneous electroanalytical determination of Pb2+ and Cd2+ by square‐wave anodic stripping voltammetry (SWASV) using a bismuth nanoparticle modified boron doped diamond (Bi‐BDD) electrode. Bi deposition was performed in situ with the analytes, from a solution of 0.1 mM Bi(NO3)3 in 0.1 M HClO4 (pH 1.2), and gave detection limits of 1.9 μg L−1 and 2.3 μg L−1 for Pb(II) and Cd(II) respectively. Pb2+ and Cd2+ could not be detected simultaneously at a bare BDD electrode, whilst on a bulk Bi macro electrode (BiBE) the limits of detection for the simultaneous determination of Pb2+ and Cd2+ were ca. ten times higher.
Dynamically coated silica monolith with ionic liquids for capillary electrochromatography
Authors: Tian Yun , Feng Rui , Liao Liping , Liu Hanlan , Chen Hao , Zeng Zhaorui 
Published: July 2008

AbstractAn ionic liquid, 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([BMIM][BF4]) was introduced as dynamic coating of a silica monolithic column for capillary electrochromatography of phenols and nucleoside monophosphates. The run‐to‐run and column‐to‐column repeatability of migration time for six phenols were satisfactory on this column with relative standard deviation values less than 0.90 and 4.31%, respectively. Anodic electroosmotic flow (EOF) was observed, which increased with the increase of [BMIM][BF4] concentration within 120 mM and when [BMIM][BF4] concentration was above 120 mM, EOF leveled off due to the saturation of [BMIM][BF4] on the monolith. Efficient separation of phenols and nucleoside monophosphates on this dynamically coated monolithic column was obtained, compared with a dynamically coated fused‐silica column and unmodified silica monolithic column. The retention behavior of uncharged phenols is mainly manipulated by hydrophobic interactions due to the presence of butyl groups, and that of nucleoside monophosphates is governed by the electrostatic attraction mechanism based on the interaction between positively charged [BMIM][BF4] moieties and negatively charged phosphate groups. In addition, silica matrix also contributes to the separation resolution.
Comparative study of the biosorption of cadmium(II), chromium(III), and lead(II) by olive stone
Authors: Hernáinz F. , Calero M. , Blázquez G. , Martín‐Lara M.A. , Tenorio G. 
Published: July 2008

AbstractThis research focuses on potential of using olive stone as a low‐cost biosorbent, for cadmium, chromium, and lead removal from aqueous solutions in a batch system as a function of pH, contact time, and temperature. Experimental data were tested in terms of biosorption kinetics using pseudo‐second‐order kinetic model. The results showed that the biosorption processes of the three metal ions followed well pseudo‐second‐order kinetics at 25, 40, and 60°C and for a metal initial concentration of 10 mg/L. The activation energy of biosorption (E) was determined as 7.09 kJ/mol for Cd(II), 12.39 kJ/mol for Cr(III), and 10.29 kJ/mol for Pb(II) indicating that the biosorption of these metal ions was taken place mainly by physical interactions. The equilibrium biosorption was also studied at these temperatures applying Sips isotherm model. Using the Sips constant, b, the thermodynamic parameters were calculated. The values of these parameters showed that the biosorption of Cd(II), Cr(III), and Pb(II) ions by olive stone was feasible and spontaneous and reflected the endothermic nature of the process for the removal of Cr(III) and Pb(II) except Cd(II). © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Where will China go? A viewpoint based on an analysis of the challenges of resource supply and pollution
Authors: Yuan Zengwei , Jiang Weili , Liu Beibei , Bi Jun 
Published: July 2008

AbstractRelying on the multiple inputs of natural resource and energy, as well as the transformation from a centrally planned economy to a market‐based economy and open policy, China made a great economic growth in the last few decades and became one of the most important world economic powers. However, the rapid economic growth has engendered serious natural resource depletion and pollution. Pollution and ecological degradation are becoming essential obstacles for China's further growth. Under the situation, the concept of circular economy (CE) was promoted in China as a new development strategy to alleviate the shortage of resource supply by improving the resource productivity and the eco‐efficiency of production and consumption, which will accelerate the economic transformation from economic growth to economic development. The difference of the two modes is that economic growth relies on a continuing increase of resource inputs while economic development relies on the improvement of efficiency (resource productivity and eco‐efficiency). © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Hall effects for MHD Oldroyd 6‐constant fluid flows using finite element method
Authors: Sajid M. , Mahmood R. , Hayat T. , Siddiqui A. M. 
Published: July 2008

AbstractThis paper numerically investigates the influence of Hall current on the steady flows of an Oldroyd 6‐constant fluid between concentric cylinders. The flow analysis has been performed by employing finite element method. Two flow problems are considered. These problems have been recently solved by Rana et al. (Chaos, Solitons and Fractals, in press). Here the main equation governing the flow problems in (Chaos, Solitons and Fractals, in press) is corrected first and then used in the simulation. Finally, the interesting observations are obtained by plotting graphs. Copyright © 2008 John Wiley & Sons, Ltd.
Direct Electrochemistry of CueO and Its Mutants at Residues to and Near Type I Cu for Oxygen‐Reducing Biocathode
Authors: Miura Y. , Tsujimura S. , Kurose S. , Kamitaka Y. , Kataoka K. , Sakurai T. , Kano K. 
Published: July 2008

AbstractCueO, a multi‐copper oxidase (MCO) occurring in Escherichia coli, catalyses a four‐electron reduction of O2 in a direct electron transfer (DET) mechanism with very high electrocatalytic activity on carbon aerogel electrodes. However, the overpotential of CueO is greater than that in other MCOs. By understanding the redox properties of CueO, we attempted to reduce this overpotential. Direct electrochemistry of CueO on carbon aerogel electrodes showed a pair of redox waves derived from the type I (T1) Cu site with a redox potential ($E {^{\circ \prime} \atop {\rm T1}} $) of 0.28 V versus Ag|AgCl at pH 5.0. Dependence of $E {^{\circ \prime} \atop {\rm T1}} $ on pH suggests the participation of proton transfer and acid–base equilibrium of some amino acid residue. The shape of the catalytic current is consistent with the T1 site being an inlet of electrons in the DET bioelectrocatalysis of O2, in which case the overpotential could be reduced by shifting $E {^{\circ \prime} \atop {\rm T1}} $ towards the positive potential. To achieve this, we created mutants of CueO at M510, which is the axial ligand of the T1 Cu, and at D439, which forms a hydrogen bond with His443 coordinated with the T1 Cu. Two mutants, M510L and D439A, successfully reduced the overpotential.
Pretreatment prediction of virological response to peginterferon plus ribavirin therapy in chronic hepatitis C patients using viral and host factors
Authors: Shirakawa Haruaki , Matsumoto Akihiro , Joshita Satoru , Komatsu Michiharu , Tanaka Naoki , Umemura Takeji , Ichijo Tetsuya , Yoshizawa Kaname , Kiyosawa Kendo , Tanaka Eiji 
Published: July 2008

Abstract

The interferon sensitivity determining region (ISDR) of the hepatitis C virus (HCV) and T-helper type 1 and type 2 (Th1/Th2) ratio were analyzed along with other host and viral factors for their ability to predict the response of patients with chronic hepatitis C to pegylated interferon alpha-2b (Peg-IFN) and ribavirin (RBV) combination therapy. A total of 120 chronic hepatitis C patients with genotype 1 HCV and high baseline viral loads who were to undergo combination therapy scheduled for 48 weeks were enrolled. Sustained virologic response (SVR) was achieved in 54 (45%) of the 120 patients. The pretreatment factors significantly associated with SVR by logistic regression analysis were ISDR mutant [odds ratio (OR) = 86.0,

P

= 0.0008], Th1/Th2 ratio ≤ 15.5 (OR = 9.6,

P

= 0.0021), body weight 59 kg, and neutrophil count 2,300/μL. A logistic regression model to estimate SVR before combination therapy was constructed using these four factors. Patients fell into three groups when plotted according to estimated and actual SVR rates: actual SVR rate was 91% (32/35) in the high sensitivity group, 41% (15/37) in the intermediate sensitivity group, and 15% (7/48) in the low sensitivity group. Rapid or early virological responses were seen in 80% of patients with high sensitivity and who achieved SVR but were found in only 40% of patients with intermediate or low sensitivity. Null- and very late virological responses were quite rare in the high sensitivity group. In conclusion, a logistic regression model that includes the sequence of ISDR of the HCV, Th1/Th2 ratio, body weight, and neutrophil count can be useful for accurately predicting actual SVR rate before combination therapy. (Hepatology 2008;48:1753-1760.)
Thymidylate synthase genotyping is more predictive for therapy response than immunohistochemistry in patients with colon cancer
Authors: Gosens Marleen J. , Moerland Elna , Lemmens Valery P. , Rutten Harm T. , Tan‐Go Ivonne , van den Brule Adriaan J. 
Published: July 2008

AbstractThymidylate synthase (TS) is a potentially valuable marker for therapy response since it is the molecular target of 5‐fluorouracil (5‐FU). TS can be analyzed at the DNA (gene polymorphisms and amplification) and protein level (immunohistochemistry). This study investigated the predictive role of TS at the DNA and protein levels in patients with N+colon cancer (n= 38). Tumor and normal tissues were genotyped using PCR for variable number of tandem repeats (VNTR), a single nucleotide polymorphism (SNP) in the 3R allele and a 6 bp deletion (1494del6) in theTSgene. Tumor tissues were additionally analyzed for loss of heterozygosity (VNTR polymorphism). A newly developed real time PCR assay was used to detect the presence ofTSgene amplifications in tumor tissues. VNTR analysis in normal tissue was significantly associated with distant tumor recurrence (8% for 2R/2Rvs.52% for patients carrying a 3R allele,p= 0.038) and cancer‐specific survival (p= 0.021). IHC was not found to be significantly associated with patients' outcome. No correlations betweenTSgene polymorphisms and IHC were found. However,TSgene amplification was correlated with a strong IHC staining intensity. In conclusion, this study indicates that DNA based analysis is more predictive for patients' outcome than TS IHC. © 2008 Wiley‐Liss, Inc.
Sustainable water saving: new concept of modern agricultural water saving, starting from development of Xinjiang's agricultural irrigation over the last 50 years
Authors: Ruisen Zhong , Xinguang Dong , Yingjie Ma 
Published: July 2008

AbstractThis paper analyses first the state of water land exploitation and water saving irrigation in Xinjiang over the last 50 years. A fairly severe situation of water resources utilization exists in Xinjiang, and so agricultural water saving provides an important way of solving the problem. Taking a comprehensive view of development of agricultural irrigation in Xinjiang over the last 50 years, surface irrigation and new high water‐saving technologies have both been present. Despite these two kinds of irrigation technologies, it is difficult to realize the effect of water saving and increasing production using the former, which is an engineering water‐saving mode using a canal anti‐seepage technique. To some degree, it inhibits ecological water use. The latter, which is an agronomic water‐saving mode laying emphasis on crop growth mechanisms, can realize the effect of water saving and increasing production. But, on the other hand, it is unable to improve soil characteristics. On the contrary, it might even aggravate soil salinization. Therefore, both engineering water saving and agronomic water saving must reconsider the sustainability of water saving. Can it realize reasonable water resources allocation of the whole watershed? Can it realize sustainable utilization of water resources in the whole watershed? This paper advances a new concept of modern agricultural water saving – sustainable water saving – which is different from real water saving. Copyright © 2008 John Wiley & Sons, Ltd.
Antitumor properties of a sulfated polysaccharide from the red seaweed Champia feldmannii (Diaz‐Pifferer)
Authors: Lins Kézia O. A. L. , Bezerra Daniel P. , Alves Ana Paula N. N. , Alencar Nylane M. N. , Lima Michael W. , Torres Valeska M. , Farias Wladimir R. L. , Pessoa Cláudia , de Moraes Manoel O. , Costa‐Lotufo Letícia V. 
Published: July 2008

AbstractIn recent years, much attention has been focused on polysaccharides isolated from natural sources. The aim of this study was to investigate the in vitro and in vivo antitumor properties of a sulfated polysaccharide isolated from the seaweed C. feldmannii (Cf‐PLS). Hematological, biochemical and histopathological analyses were performed in order to evaluate the toxicological aspects related to Cf‐PLS treatment. Its effects on the immunological system were also investigated. The Cf‐PLS did not show any significant in vitro cytotoxicity at the experimental exposure levels that were used, but showed in vivo antitumor effect. The inhibition rates of sarcoma 180 tumor development were 48.62 and 48.16% at the doses of 10 and 25 mg kg−1, respectively. In addition, Cf‐PLS was also able to increase the response elicited by 5‐fluorouracil (5‐FU) from 48.66 to 68.32%. The histopathological analysis of liver and kidney showed that both organs were moderately affected by Cf‐PLS‐treatment. Neither enzymatic activity of alanine aminotransferase nor urea or creatinine levels were significantly altered. In hematological analysis, leucopeny was observed after 5‐FU treatment, but this effect was prevented when the treatment was associated with the Cf‐PLS. It was also demonstrated that Cf‐PLS acts as an immunomodulatory agent, raising the production of specific antibodies, and increasing the production of OVA‐specific antibodies. It also induced a discreet hyperplasia of lymphoid folicules of the white pulp in the spleen of treated mice. In conclusion, Cf‐PLS has some interesting anticancer activity that could be associated with its immunostimulating properties. Copyright © 2008 John Wiley & Sons, Ltd.