bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atropisomeric Discrimination in New RuII Complexes Containing the C2‐Symmetric Didentate Chiral Phenyl‐1,2‐bisoxazolinic Ligand
Authors: Sala Xavier , Plantalech Elena , Romero Isabel , Rodríguez Montserrat , Llobet Antoni , Poater Albert , Duran Miquel , Solà Miquel , Jansat Susanna , Gómez Montserrat , Parella Teodor , Stoeckli‐Evans Helen , Benet‐Buchholz Jordi 
Published: January 2006

AbstractA new family of RuII complexes containing the tridentate meridional 2,2′:6′,2′′‐terpyridine (trpy) ligand, a C2‐symmetric didentate chiral oxazolinic ligand 1,2‐bis[4′‐alkyl‐4′,5′‐dihydro‐2′‐oxazolyl]benzene (Phbox‐R, R = Et or iPr), and a monodentate ligand, of general formula [Ru(Y)(trpy)(Phbox‐R)]n+ (Y = Cl, H2O, py, MeCN, or 2‐OH‐py (2‐hydroxypyridine)) have been prepared and thoroughly characterized. In the solid state the complexes have been characterized by IR spectroscopy and by X‐ray diffraction analysis in two cases. In solution, UV/Vis, cyclic voltammetry (CV), and one‐dimensional (1D) and two‐dimensional (2D) NMR spectroscopy techniques have been used. We have also performed density functional theory (DFT) calculations with these complexes to interpret and complement experimental results. The oxazolinic ligand Phbox‐R exhibits free rotation along the phenyloxazoline axes. Upon coordination this rotation is restricted by an energy barrier of 26.0 kcal mol−1 for the case of [Ru(trpy)(Phbox‐iPr)(MeCN)]2+ thus preventing its potential interconversion. Furthermore due to steric effects the two atropisomers differ in energy by 5.7 kcal mol−1 and as a consequence only one of them is obtained in the synthesis. Subtle but important structural effects occur upon changing the monodentate ligands that are detected by NMR spectroscopy in solution and interpreted by using their calculated DFT structures.
Noncovalent Synthesis in Aqueous Solution and Spectroscopic Characterization of Multi‐Porphyrin Complexes
Authors: Gulino Fabio G. , Lauceri Rosaria , Frish Limor , Evan‐Salem Tamar , Cohen Yoram , De Zorzi Rita , Geremia Silvano , Di Costanzo Luigi , Randaccio Lucio , Sciotto Domenico , Purrello Roberto 
Published: January 2006

AbstractThe interactions of the tetracationic meso‐tetrakis(N‐methyl‐4‐pyridyl)porphyrin (H2TMPyP) and its metallo derivatives (MTMPyP) (where M=copper(II), zinc(II), and gold(III) with the octa‐anionic form (at neutral pH) of 5,11,17,23‐tetrasulfonato‐25,26,27,28‐tetrakis(hydroxycarbonylmethoxy)calix[4]arene (C4TsTc) lead to a series of complex species whose stoichiometry and porphyrin sequence can be easily tuned. Crystallographic, spectroscopic, and diffusion NMR studies converge towards a common picture in which a central 1:4 porphyrin/calixarene unit serves as a template for the formation of more complex species. These species arise by successive, stepwise addition of single porphyrin molecules above and below the plane of the 1:4 central core to ultimately give a 7:4 complex. Noticeably, the stoichiometry of the various complex species corresponds to the actual concentration ratio of porphyrins and calixarenes in solution allowing the stoichiometry of these species to be easily tuned. This behavior and the remarkable stability of these species allow homo‐porphyrin and hetero‐(metallo)porphyrin species to be formed with control of not only the stoichiometry but also the sequence of the porphyrin array. The flexibility and ease of this approach permit, in principle, the design and synthesis of porphyrin arrays for predetermined purposes. For example, we have shown that it is very easy to design and obtain mixed porphyrin species in which a foreseen photoinduced electron‐transfer is indeed observed.
Micelle‐to‐Vesicle Transition Induced by Organic Additives in Catanionic Surfactant Systems
Authors: Yin Haiqing , Lei Sheng , Zhu Shengbao , Huang Jianbin , Ye Jianpin 
Published: January 2006

AbstractA micelle‐to‐vesicle transition (MVT) induced by the addition of a series of apolar hydrocarbons (n‐butylbenzene, n‐hexane, n‐octane, and n‐dodecane) to the catanionic surfactant system n‐dodecyltriethylammonium bromide/sodium n‐dodecylsulfate (DTEAB/SDS) has been investigated for the first time by means of rheology and turbidity measurements, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Interestingly, a MVT can take place within certain micellar regions, which are dependent on the structure and chain length of the hydrocarbon. However, these hydrocarbons are unable to induce a MVT in another catanionic surfactant system, namely, n‐dodecyltriethylammonium bromide/sodium n‐dodecylsulfonate (DTEAB/SDSO3), in which the molecular interactions are weaker than in the DTEAB/SDS system. On the other hand, polar additives, such as n‐octanol and n‐octylamine, exhibit much higher efficiency and activity in inducing MVT than hydrocarbons in both DETAB/SDS and DTEAB/SDSO3. Moreover, DLS, TEM, and time‐resolved fluorescence quenching (TRFQ) results demonstrate that the ratio of vesicles to micelles in the system can be actively controlled by addition of polar additives. Possible mechanisms for the above phenomena are presented, and the potential application of controllable micelle/vesicle systems in the synthesis of tailored bimodal mesoporous materials is discussed.
Electrodeposition and Properties of an Amorphous Ni‐W‐B Alloy before and after Heat Treatment
Authors: Yang Fang‐Zu , Ma Zhao‐Hai , Huang Ling , Xu Shu‐Kai , Zhou Shao‐Min 
Published: January 2006

AbstractTo strengthen the properties of Ni‐W alloy, dimethylamine borane (DMAB) was added to an alloy Ni‐W electrolyte solution and a ternary Ni‐W‐B alloy was electrodeposited. The electrodeposition, crystallographic structure, surface morphology, heat treatment and corrosion resistance, of the alloy were studied by DSC, XRD, SEM and electrochemical techniques. The results showed that the structure of the alloy was greatly affected by the cooperation of boron compound. DSC experiment combined with X‐ray diffractometry indicated that the obtained Ni‐W‐B alloy was still in amorphous structure although W content in the alloy was decreased by the addition of DMAB. After heat treatment at 400 °C for 1 h, the microhardness was increased from 612 to 947 kg·mm−2 that was comparative to Cr coating. The appearance of the as‐plated coating was in fine and slice grains and kept almost no change after heat treatment. In w=0.03 NaCl solution the as‐plated coating presented very good corrosion resistance. After the coating was heat‐treated its corrosion resistance was enhanced.
Theoretical Studies on Electronic Spectra and Second‐order Nonlinear Optical Properties of Glucosyl Substituted Barbituric Acid Derivatives
Authors: Feng Jing‐Dong , Yan Li‐Kai , Su Zhong‐Min , Kan Yu‐He , Lan Ya‐Qian , Liao Yi , Zhu Yu‐Lan 
Published: January 2006

AbstractAM1 semi‐empirical method was used to optimize the barbituric acid derivatives substituted with glucosyl B1–5(series B), and the thiobarbituric acid derivatives substituted with glucosyl T1–5 (seriesT). Based on the optimized structures, INDO/CI method was adopted to calculate the electronic spectra. Meanwhile, the second‐order nonlinear optical (NLO) coefficients βμ were calculated with the sum‐over‐state (SOS) formula. The results show that when the number of glucosyl units was increased, |βμ| values of the barbituric and thiobarbituric acid derivatives were both enhanced, especially for thiobarbituric acid derivatives. It indicates that non‐conjugated substituted group could also improve NLO properties of materials when the number of repeated units was increased. Additionally, the absorption bands appearing in UV area are consistent with the proper change of the number of glucosyl units, and consequently it can be concluded that the high transparencies of all systems were scarcely varied.
Image Contrast Inversion of a Solvent Cast SEBS Film
Authors: Han Xia , Xu Jian , Liu Hong‐Lai , Hu Ying 
Published: January 2006

AbstractThe image contrast inversion was investigated in detail when soft polymeric materials were imaged with tapping mode atomic force microscopy (TM‐AFM). Solvent cast film of polystyrene‐block‐poly(ethylene/butylene)‐block‐polystyrene (SEBS) triblock copolymers was used as a model system in this study, which showed phase separation domains with a size of several tens of nanometers. AFM contrast reversal process, through positive image, to an intermediary and till negative image, could be clearly seen in height images of the soft block copolymer using different tapping force. The higher tapping force would lead to not only contrast inversion, but also the different size of the microdomains and different roughness of the images. Moreover, contrast inversion was explained on the basis of attractive and repulsive contributions to the tip‐sample interaction and indentation of the soft domains.
Synthesis and Crystal Structure of a New Oxovanadium(V)Multicomponent Complex with Acylhydrazone and Benzoylhydrazine
Authors: Zhou Yin‐Zhuang , Chen Rui‐Jin , Tu Shu‐Jie , Lu Xiao‐Ming 
Published: January 2006

AbstractA new oxovanadium(V) complexwith the mixed ligand of 2‐oxopropionic acid benzoylhydrazone (C10H10N2O3) and benzoylhydrazine (C7H8N2O), VO(C7H7N2O)(C10H9N2O3), has been synthesized. Its structure was determined by single crystal X‐ray diffraction analysis. The crystal belongs to monoclinic system with space group P21/n and cell parameters: a=1.1136(4) nm, b=0.6217(2) nm,c=2.6038(9) nm,β=97.182(6)(, V=1.7887(11) nm3, Z=4, F(000)=836, Mr407.28, Dc=1.512 g/cm3, μ(Mo Kα)=0.592 mm−1, R1=0.0445, wR2=0.1203. Vanadium atom is 6‐coordinated by carboxyl and carbonyl O atoms and N atom of one tridentate C10H10N2O3 to form two stable five‐membered rings with the same edge, and the other coordinated atoms of N and O come from one bidentate benzoylhydrazine C7H8N2O. The title complex has a six‐coordinated V center [VO(N2O3)] with a distorted octahedral arrangement. In the crystal lattice, there are hydrogen bonding interactions between two molecules.
Synthesis of N‐Alkylhexahydroazepine by One‐step Catalytic Alkylation and Hydrogenation of Caprolactam
Authors: Du Jun‐Ming , Shen Wei , Xu Hua‐Long 
Published: January 2006

AbstractA new synthetic method for the preparation of N‐alkylhexahydroazepine by one‐step catalytic alkylation and hydrogenation of caprolactam has been developed. Alkylated caprolactam was firstly synthesized by catalytic alkylation of caprolactam with alcohol and then directly hydrogenated into N‐alkylhexahydroazepine over Cu‐ZnO/γ‐Al2O3 catalyst.
Facile Microwave Assisted Liquid Phase Deposition Process to TiO2 Nanocrystallines
Authors: Zhang Liu‐Xue , Liu Peng , Su Zhi‐Xing 
Published: January 2006

AbstractAnatase nanoparticles were successfully prepared via a facile microwave assisted liquid phase deposition (MW‐LPD) process with hexafluorotitanate ammonium (NH4)2TiF6 as precursor. Compared with the conventional LPD processes, the MW‐LPD technique could provide high yield quickly and crystallinity in a diluted precursor solution at a low temperature. The products were characterized by XRD and TEM. Their photocatalytic activities were also investigated by the photodegradation of methylene blue (MB) as a model molecule.
Effect of Penicillin G Potassium Salt on the Physicochemical Properties of SDS Aqueous Solution and the Release of the Salt in SDS/n‐C5H11OH/H2O System
Authors: Qian Jun‐Hong , Lu Yi‐Ying , Guo Rong 
Published: January 2006

AbstractThe effects of penicillin potassium salt (PenK) on the solubility, Krafft temperature TK, critical micelle concentration CMC of SDS micelle and the phase behavior of SDS/n‐C5H11OH/H2O system were studied. The partial phase diagrams of SDS/PenK/H2O system at different temperatures were determined. The release amounts of PenK in SDS/n‐C5H11OH/H2O system and the distribution coefficient of PenK between micelle and water were measured by UV‐Vis spectroscopy. The results show that in the presence of PenK, the CMC of SDS was decreased while the TK of SDS was increased and the solubility of SDS in both water and SDS/n‐C5H11OH/H2O oil in water (O/W) microemulsion was decreased, but increased in water in oil (W/O) microemulsion. SDS micelles and SDS/n‐C5H11OH/H2O O/W microemulsion could accelerate the release rate of PenK. The addition of SDS and water could both increase the release rate of PenK, whereas the presence of n‐C5H11OH reduced the release rate of PenK. The above results were related to the electrostatic repulsion between PenK and SDS.
Kinetic Investigation of Thermal Decomposition Reactions of Podophyllotoxin and Its Derivatives
Authors: Wen Pu‐Hong , Feng Guo‐Dong , Zheng Jian‐Bin 
Published: January 2006

AbstractThe thermal behavior and thermal decomposition kinetic parameters of podophyllotoxin (1) and 4 derivatives, picropodophyllin (2), deoxypodophyllotoxin (3), β‐apopicropodophyllin (4), podophyllotoxone (5) in a temperature‐programmed mode have been investigated by means of DSC and TG‐DTG. The kinetic model functions in differential and integral forms of the thermal decomposition reactions mentioned above for first stage were established. The kinetic parameters of the apparent activation energy Ea and per‐exponential factor A were obtained from analysis of the TG‐DTG curves by integral and differential methods. The most probable kinetic model function of the decomposition reaction in differential form was (1−α)2 for compounds 1–3, (2/3)·α−1/2 for compound 4 and (1/2)(1−α)·[−ln (1−α)]−1 for compound 5. The values of Ea indicated that the reactivity of compounds 1–5 was increased in the order: 5<4<2<1<3. The values of the entropy of activation ΔS≠, enthalpy of activation ΔH≠ and free energy of activation ΔG≠of the reactions were estimated. The values of ΔG≠indicated that the thermal stability of compounds 1–3with the same f(α) was increased in the order: 2<3<1.
Effects of Ultrasonic Treatment on the Structure and Electrochemical Performances of Spherical β‐Ni(OH)2
Authors: Zhou Huan‐Bo , Zhou Zhen‐Tao 
Published: January 2006

AbstractA method of ultrasonic treatment (UST) was first used to modify the structure and electrochemical performance of nickel hydroxide for the active material of nickel series alkaline batteries. The experimental results showed that UST was an effective method to improve the electrochemical performance of β‐Ni(OH)2such as specific discharge capacity, discharge potential, electrochemical reversibility and oxygen evolution over‐potential. The results of electrochemical impedance spectroscopy, powder X‐ray diffraction and particle size distribution indicated that the improvement of the performance of β‐Ni(OH)2 through UST was attributed to the reduction of the charge‐transfer resistance (Rt) and the diffusion impedance (Zw), which resulted from the decrease of the crystallite and particle size and the increase of interlayer spacing. Diffusion coefficient of proton DH of ultrasonic treated β‐Ni(OH)2gained by CV tests was 1.13×10−11cm2/s, and the average discharge specific capacity of ultrasonic treated β‐Ni(OH)2 electrode was 301 mAh/g.
Antimicrobial Properties and Toxicity of Anthraquinones by Microcalorimetric Bioassay
Authors: Wu Yan‐Wen , Ouyang Jie , Xiao Xiao‐He , Gao Wen‐Yuan , Liu Yi 
Published: January 2006

AbstractThe growth thermogenic curves of Staphylococcus aureus and Tetrahymena thermophila affected by 1,8‐dihydroxyanthraquinone, emodin and rhein were determined quantitatively by microcalorimetry. The inhibitory effects of the three anthraquinones (AQ) on S.aureus revealed that the sequence of antimicrobial activity of those was rhein>emodin>1,8‐dihydroxyanthraquinone. The toxicity of the three AQ on T. thermophila indicated that all the tested AQ were toxic to the tested protozoa and the hydroxyl and carboxyl substituted at different position of anthraquinone ring resulted in the enhancement of toxicity.
Linear Expression of the Mathematical Relationship between Electroosmotic Mobility and Buffer Concentration
Authors: Xu Xu , Gao Jian‐Ping , Bao Xiao‐Ling 
Published: January 2006

AbstractIt was believed that electroosmotic mobility μeo is inversely proportional to the square root of the ionic strength I. But the linear relationship for regression analysis was expressed differently in different papers. The paper studied the linear expression of the mathematical relationship between μeo and c (background buffer concentration) by mathematical transform and real experimental data. μeo values of fused silica capillary were determined in four buffer systems. Their experimental conditions were controlled carefully for decreasing temperature difference ΔT and pH difference ΔpH in 50 µm ID capillary, in which no double layer overlap existed. The linear relationship between the reciprocal of electroosmotic mobility and the square root of concentration (or ionic strength) was derived by mathematical method. The regression analysis of experimental data was shown to well correspond to the relationship. The constants in regression equation could be well defined and the calculated results were acceptable.
Synthesis and Mesomorphic Properties of Chiral Mesogens Bearing Fluorinated Alkyl Terminal Tails
Authors: Qin Chuan , Rong Guo‐Bin , Chen Bao‐Quan , Wen Jian‐Xun 
Published: January 2006

AbstractTen chiral mesogenic compounds containing fluorinated alkyl terminal tails were prepared and characterized by IR, NMR, MS. The phase transition behavior was investigated by DSC and polarized optical microscope. Two‐ring liquid crystal compounds exhibited no mesogenic phase or only a monotropic smectic A phase. The longer fluorinatd alkyl chain on the three‐ring was advantageous to the formation of smectic phase. The mesogens with chiral center located between fluorinated tail and mesogenic core exhibited chiral smectic C phase and other smectic phases when the alkoxyl adhering to the other side of the mesogenic core was of intermediate length.
Evaluation of complete disease remission in acute myeloid leukemia
Authors: Bacher Ulrike , Kern Wolfgang , Schoch Claudia , Schnittger Susanne , Hiddemann Wolfgang , Haferlach Torsten 
Published: January 2006

AbstractBACKGROUNDDifferent diagnostic methods add information to define complete remission (CR) in patients with acute myeloid leukemia (AML). The detection of minimal residual disease (MRD) for predicting prognosis and for therapeutic planning still are under discussion.METHODSThe authors studied 216 patients with AML at the time of initial diagnosis and during follow‐up and correlated cytomorphology, interphase fluorescence in situ hybridization (FISH), and flow cytometry results to evaluate response status. They further tested the prognostic impact of those results, especially in patients who achieved a morphologic CR.RESULTSInterphase FISH was found to be correlated significantly with the clinical course at the time of complete cytomorphologic remission and was more reliable than morphology for defining CR. Furthermore, interphase FISH was correlated with immunophenotyping results at all times during follow‐up.CONCLUSIONSThe current results indicated that interphase FISH may be used as a valid MRD parameter in patients with AML. Multiparameter immunophenotyping for MRD also was correlated strongly with the clinical course, and the authors suggest integrating such immunophenotyping into the routine diagnostic panel at the time of diagnosis and during the clinical course in patients with AML. Cancer 2006. © 2006 American Cancer Society.
Phase III study of PSC‐833 (valspodar) in combination with vincristine, doxorubicin, and dexamethasone (valspodar/VAD) versus VAD alone in patients with recurring or refractory multiple myeloma (E1A95)
Authors: Friedenberg William R. , Rue Montserrat , Blood Emily A. , Dalton William S. , Shustik Chaim , Larson Richard A. , Sonneveld Pieter , Greipp Philip R. 
Published: January 2006

AbstractBACKGROUNDPreliminary studies have shown valspodar (PSC‐833: Novartis Pharmaceuticals, East Hanover, NJ) to be a potent inhibitor of multidrug resistance (MDR), one cause of resistance to chemotherapy. An international randomized control study (Phase III) evaluated the use of vincristine, doxorubicin, and dexamethasone (VAD) with (n= 46) and without (n= 48) valspodar in the treatment of patients with recurring or refractory multiple myeloma.METHODSPatients with documented recurrence or refractory myeloma were stratified based on prior treatment exposure and creatinine and randomized. Because of interaction of valspodar with vincristine and doxorubicin, the doses of these drugs were reduced compared with the VAD‐alone arm, and the doxorubicin was further reduced in the last 15 patients when given with valspodar based on pharmacokinetic and toxicity studies.RESULTSThere were no complete or near‐complete responses. There were 29% partial responses (PRs) in the VAD‐alone arm and 44% with valspodar (P= 0.2). Median progression‐free survival was 7 months with VAD alone and 4.9 months with valspodar (P= 0.50). Subjective response was 19% with VAD alone and 17% with valspodar (P= 1.0). Median survival with VAD alone was 18.5 months and 15.3 with the addition of valspodar (P= 0.055). Toxicity of Grade 3 or greater was higher (P< 0.0001) in the valspodar arm (89%) compared with the VAD‐alone arm (58%). The reduction of doxorubicin dose reduced toxicity but not significantly (P= 0.11).CONCLUSIONThe addition of the MDR‐modulating agent valspodar to VAD did not improve treatment outcome. Toxicity was increased in the valspodar‐treated group compared with VAD alone. Cancer 2006. © 2006 American Cancer Society.
Adjuvant chemotherapy in muscle‐invasive bladder carcinoma
Authors: Ruggeri Enzo Maria , Giannarelli Diana , Bria Emilio , Carlini Paolo , Felici Alessandra , Nelli Fabrizio , Gallucci Michele , Cognetti Francesco , Pollera Camillo Francesco 
Published: January 2006

AbstractBACKGROUNDThe treatment of muscle‐invasive bladder carcinoma should include both the eradication of local disease and the elimination of potential micrometastases. To date, the ‘gold standard’ treatment for muscle invasive bladder carcinoma has been recognized to be radical cystectomy. Adjuvant chemotherapy (AC) has the advantage of being administered to patients with known prognostic factors of recurrence. A pooled analysis was used to verify whether AC is able to increase the disease‐free survival (DFS) and overall survival (OS) of patients with muscle‐invasive bladder carcinoma who had undergone radical cystectomy.METHODSAll published randomized Phase III studies were considered eligible and a literature‐based pooled analysis was accomplished. DFS and OS were the endpoints. Event‐based relative risk ratio (RR) and 95% confidence intervals (95% CI) were derived. Combined effect estimation was computed with a fixed‐ and a random‐effect model. A heterogeneity test was applied as well.RESULTSFive trials were collected. All were evaluable for OS (350 patients) and four of these also were evaluable for DFS (273 patients). A significant benefit from AC was noted both in OS (RR, 0.74; 95% CI, 0.62–0.88 [P = 0.001]) and DFS (RR, 0.65; CI 0.54–0.78, [P < 0.001]). No significant heterogeneity was found.CONCLUSIONSAlthough the results of the analysis favor the use of AC, larger studies are needed to identify the role of AC in the treatment of muscle‐invasive bladder carcinoma. Ongoing trials (European Organization for Research and Treatment of Cancer [EORTC]/Southwest Oncology Group [SWOG] and the Italian Multicentric Study) can help to better identify patients who can benefit from this approach. Cancer 2006. © 2006 American Cancer Society.