bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Modeling of Interactions of the Benzolactam‐V8 Modulators with the Cys2 Domain of Protein Kinase Cδ
Authors: HUANG Li‐Li , MA Da‐Wei , XIA Zong‐Xiang 
Published: October 2007

AbstractMolecular modeling of interactions of four 7‐ or 8‐substituted benzolactam‐V8 (BLV) molecules with the cys2 activator‐binding domain of protein kinase C (PKCδ) was carried out using molecular docking program Autodock. The docked models reveal that the hydroxymethyl group at the C(5) atom of the eight‐membered ring of each BLV is bound at the bottom of the binding groove of the cys2 domain of PKCδ. The BLV molecules make hydrogen bonds and hydrophobic interactions with PKCδ, which are similar to those in the crystal structure of the cys2 domain of PKCδ in complex with phorbol 13‐acetate. BLV‐1 does not contain a long side chain that is hydrophobic and necessary for membrane insertion, so that it would not be a potent modulator of PKCδ. The other three BLV molecules have long side chains substituted at C(7) or C(8) atoms, and it was predicted, based on the docking results, that they had the PKCδ‐binding affinity in the order of BLV‐2>BLV‐4>BLV‐3, and BLV‐2 would be a potent activator of PKCδ.
Is There a Minimum Electrophilicity Principle in Chemical Reactions?
Authors: NOORIZADEH Siamak 
Published: October 2007

AbstractFor 25 simple reactions, the changes of the hardness (Δη), polarizability (Δα) and electrophilicity index (Δω) and their cube‐roots (Δη1/3, Δα1/3, Δω1/3) were calculated. It is shown that although the Maximum Hardness and Minimum Polarizability Principles are not valid for all reactions, but in most cases Δω1/3<0, whereas we always find Δω<0. Our observation implies to this fact that for those chemical reactions in which the number of moles decreases or at least remains constant, the most stable species (reactants or products) have the lowest sum of electrophilicities. In other words "the natural direction of a chemical reaction is toward a state of minimum electrophilicity". This fact may be called Minimum Electrophilicity Principle (MEP).
Nitrogen‐rich 6‐(3,5‐Dimethylpyrazol‐1‐yl)‐3‐(2,4,6‐trinitro‐anilino)‐1,2,4,5‐tetrazin: Synthesis, Crystal Structure and Thermal Property
Authors: PAN Wan‐Long , HUANG Kun‐Lin , TANG Wang , XU Yan‐Qing , HU Chang‐Wen 
Published: October 2007

Abstract6‐(3,5‐Dimethylpyrazol‐1‐yl)‐3‐(2,4,6‐trinitroanilino)‐1,2,4,5‐tetrazin (1) has been synthesized and characterized by 1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X‐ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities (>1.55 g·cm−3) and good thermal stabilities (Td>220 °C). The intrermolecular hydrogen bonds construct the P‐ and M‐helices from organic molecules and may contribute to the high melting points.
Sorption Removal of Pb(II) from Solution by Uncalcined and Calcined MgAl‐Layered Double Hydroxides
Authors: ZHANG Shu‐Qin , HOU Wan‐Guo 
Published: October 2007

Abstract Layered double hydroxide (LDH) with a Mg/Al molar ratio of 1:1 was synthesized by using a co‐precipitation method and its calcined product (CLDH) was obtained by calcination of the MgAl‐LDH at 500 °C. The sorption removal of Pb2+ from solution was investigated, finding that both LDH and CLDH show good sorption ability and they could be used as a new type of environmental sorbent for the removal of Pb2+ from water. The sorption kinetics and the sorption isotherms of Pb2+ on both LDH and CLDH can be described by the pseudo‐second order kinetics and Freundlich isotherm, respectively, under the studied conditions. The sorption amounts of Pb2+ on LDH and CLDH are independent of pH in a pH range of about 3–10. The presence of NaNO3 may inhibit the sorption ofPb2+ on LDH while hardly affect that on CLDH. The sorption mechanism of Pb2+ on LDH and CLDH may be attributed to the surface precipitation and the surface complex adsorption. The surface complex adsorption may be further distinguished to the chemical binding adsorption forming the inner‐sphere surface complexes and the electrostatic binding adsorption forming the outer‐sphere surface complexes. The sorption mechanism of Pb2+ on LDH may be attributed to the surface precipitation and the electrostatic binding adsorption, while that on CLDH may be attributed to the surface precipitation and the chemical binding adsorption.
Theoretical Study of the Low‐Lying Excited States of Butoxy Radicals and Non‐Radiative Decay Routes
Authors: LIN Ling , ZU Li‐Li , FANG Wei‐Hai , YU Jian‐Guo , LIU Ruo‐Zhuang 
Published: October 2007

AbstractThe potential energy surfaces for the butoxy radical dissociation into R·+O on the six low‐lying electronic states have been determined with the combined CASSCF and MR‐CI methods. The isomerization reactions between the different conformers of 1‐ and 2‐butoxy radicals at the X̃ and B̃ states have been also investigated with the MP2, B3LYP, and CASSCF methods. The non‐radiative decay mechanisms of butoxy radicals at the B̃ state have been characterized with the computed potential energy surfaces and intersections. Supported by recent LIF experimental results, it was predicted that the t‐butoxy radical would predissociate via the B̃/ C̃ intersection. As to 1‐ and 2‐butoxy radicals, the relative energies of the transition states for the isomerization reactions between conformers at the B̃ state are much lower than those of the B̃/C̃ intersections, resulting in the predominance of the isomerization in the decay of the B̃ state for 1‐ and 2‐butoxy radicals.
Molecular Dynamics Simulation of the Self‐assembled Monolayers of 1‐Adamantanethiolate and Its Derivatives on Au(111) Surfaces
Authors: ZHOU Jun‐Hong , ZHU Rui‐Xin , SHI Liang‐Wei , ZHANG Tao , CHEN Min‐Bo 
Published: October 2007

AbstractThe self‐assembled monolayers (SAMs) of 1‐adamantanethiolate and its derivatives on Au(111) surface were investigated. Density functional theory (DFT) calculation indicates that the most stable configuration for absorption is at the face centered cubic (fcc)‐bridge site. Canonical ensemble molecular dynamics (MD) simulations were carried out to study the structures and energies of the SAMs. The ordered structures of the SAMs were analyzed by means of radial distribution function and the relative stability of the SAMs was compared. It was concluded by the comparison of various contributions to the SAM formation energy that the formation of the SAMs was determined by the intermolecular nonbonding interaction and the chemical bonding interaction of sulfur and gold.
Theoretical Studies on Reaction Mechanism of CH3SO with NO
Authors: LI Xiao‐Yan , MENG Ling‐Peng , ZHENG Shi‐Jun 
Published: October 2007

AbstractThe potential energy surface (PES) of CH3SO radical with NO reaction has been studied at MP2/6‐311G(2df,p) and QCISD/6‐311G(2df,p) levels. Geometries of the reactants, transition states (TS) and products were optimized at B3LYP/6‐311G (d,p) level. The geometries of the transition states were found for the first time. The calculated results show that the reaction can proceed via singlet‐state or triplet‐state PES. Because of the high energy barrier of triplet surface, the singlet surface reactions are dominant. The topological analysis of electron density shows that there are two kinds of structural transition states (the bifurcation‐type ring structure transition state and the T‐shaped conflict structure transition state) in the titled reaction. The total electronic density of the reactants, TS and products and the spin electronic density on the triplet surface were also discussed in this paper.
Aggregate Formed by a Cationic Fluorescence Probe
Authors: TIAN Juan , SANG Da‐Yong , JI Guo‐Zhen 
Published: October 2007

AbstractThe aggregation behavior of a cationic fluorescence probe 10‐(4,7,10,13,16‐pentaoxa‐1‐azacyclooctadecyl‐ methyl)anthracen‐9‐ylmethyl dodecanoate (1) was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.
Electronic Properties of Two Series of Blue‐Emitting Conjugated Oligomers and Polymers Based on Cyanostilbene: A Quantum Chemistry Study
Authors: YANG Li , FENG Ji‐Kang , REN Ai‐Min 
Published: October 2007

AbstractOne of the drawbacks of the electroluminescence (EL) polymers is that they are usually much better at accepting and transporting holes than electrons due to their inherent richness of π‐electrons. One approach improving electron injection and transport in conjugated polymers is to incorporate moieties with high electron affinities. In this theoretical work, to gain an insight into the chemical structure‐property relationships was aimed by controllable modification of the main chain structures. Two cyanovinylene derivatives with 2,7‐fluorenylene and p‐phenylene moieties in the main chains, namely, poly{(2,5‐dimethoxy‐p‐phenylene‐1,4‐ylene)‐alt‐[1,2‐bis(p‐phenylene)‐1‐ cyanovinylene]} (PPhCN) and poly{[9,9‐dimethyl‐2,7‐fluorenylene]‐alt‐[1,2‐bis(p‐phenylene)‐1‐cyanovinylene]} (PFCN), were studied employing density functional theory (DFT) and time dependent density functional theory (TD‐DFT) with B3LYP functional. The electronic properties of the neutral molecules, extrapolated ionization potentials (IP) and electron affinities (EA), and energy gaps were investigated in comparison with pristine poly(2,7‐ fluorenylene). From comparison with poly(2,7‐fluorenylene) (PF), the 1,2‐bis(p‐phenylene)‐1‐cyanovi‐ nylene unit was found to be a good electron‐withdrawing moiety for electronic materials and the incorporation of 1,2‐bis(p‐ phenylene)‐1‐cyanovinylene resulted in a narrow band gap and a red shift of both the absorption and photoluminescence emission peaks. Most importantly, the LUMO energies of PFCN are around 1 eV lower than those of PF, which results in the decrement of EA about 0.9 eV, indicating that the 1,2‐bis(p‐phenylene)‐1‐cyanovinylene unit has significantly improved the electron‐accepting properties of the copolymer PFCN. Substitution of 2,5‐dimeth‐ oxy‐p‐phenylene for 9,9‐dimethyl‐2,7‐fluorenylene induced larger band gaps and thus a blue‐shift in absorption and emission peaks, which can be attributed to the better conjugated backbone in PFCN.
Preparation and Characterization of Mesoporous Ce0.5Zr0.5O2 Mixed Oxide
Authors: FENG Sheng‐Sheng , GU Ying‐Ying , LI Jin‐Lin , SONG Feng‐Xuan 
Published: October 2007

AbstractMesoporous (MSU) Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of the pH value on the formation of mesostructure and the thermal stability of the material has been evaluated. The products were characterized by transmission electron microscopy, powder X‐ray diffraction and nitrogen adsorption‐desorption measurements. The results showed that the as‐prepared Ce0.5Zr0.5O2 mixed oxide possessed a specific surface area of 163.3 m2·g−1, which had a cubic fluorite‐type structure and possessed specific surface areas of 148.4 and 62.4 m2·g−1 after calcination at 500 and 800 °C for 2 h, respectively. The material showed excellent thermal stability.
A New 4.0‐Generation Dendrimer Phosphorescence Labeling Reagent and Its Application to Determination of Trace Alkaline Phosphatase by Affinity Adsorption Solid Substrate‐room Temperature Phosphorimetry
Authors: LI Zhi‐Ming , LIU Jia‐Ming , CHEN Xiao‐Hua , YANG Min‐Lan , CHEN Xin‐Hua , SHI Xiu‐Mei 
Published: October 2007

AbstractA Triton X‐100‐4.0G‐D (4.0G‐D refers to a 4.0‐generation dendrimer) was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption (AA) reactions (direct method and sandwich method) were carried out between the labeling product of Triton X‐100‐4.0G‐D‐Wheat germ agglutinin (WGA) and alkaline phosphatase (ALP), the product of AA reaction preserved the good characteristics of room temperature phosphorescence (RTP) of 4.0G‐D and ΔIP of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate‐room temperature phosphorimetry (AA‐SS‐RTP) was established on the basis of WGA labeled with the Triton X‐100‐4.0G‐D. The detection limits were 0.20 ag·spot−1 (corresponding concentration: 5.0×10−16 g·mL−1, namely 5.0×10−18 mol·L−1) for a direct method and 0.14 ag·spot−1 (corresponding concentration: 3.5×10−16 g·mL−1, namely 3.5×10−18 mol·L−1) for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully applied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme‐linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA‐SS‐RTP was discussed.
Selective Pre‐concentration and Solid Phase Extraction of Mercury(II) from Natural Water by Silica Gel‐loaded (E)‐N‐(1‐Thien‐2′‐ylethylidene)‐1,2‐phenylenediamine Phase
Authors: MOGHIMI Ali 
Published: October 2007

AbstractSilica gel‐loaded (E)‐N‐(1‐thien‐2′‐ylethylidene)‐1,2‐phenylenediamine (TEPDA) phase was synthesized based on physical adsorption approaches. The stability of a chemically modified TEPDA especially in concentrated hydrochloric acid that was then used as a recycling and preconcentration reagent allowed the further uses of silica gel‐loaded immobilized TEPDA phase. The application of this silica gel‐loaded phase to sorption of a series of metal ions was performed by using different controlling factors such as the pH of the metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing silica gel‐loaded TEPDA phases. Hg(II) was found to exhibit the highest affinity towards extraction by these silica gel‐loaded TEPDA phases. The pronounced selectivity was also confirmed by the determined distribution coefficients (Kd) of all the metal ions, showing the highest value reported for mercury(II) extraction by the silica gel immobilized TEPDA phase. The potential applications of the silica gel immobilized TEPDA phase to selective extraction of mercury(II) from aqueous solution were successfully accomplished and preconcentration of low concentration of Hg(II) (30 pg·mL−1) from natural tap water with a preconcentration factor of 200 for Hg(II) off‐line analysis was conducted by cold vapor atomic absorption analysis.
Synthesis of Diphenyl α‐(Dipropoxyphosphoramido)alkylphosphonates
Authors: CUI Zhan‐Wei , ZHANG Jian‐Feng , MIAO Zhi‐Wei , CHEN Ru‐Yu 
Published: October 2007

AbstractA convenient method has been developed for the synthesis of diphenyl α‐(dipropoxyphosphoramido)alkyl‐ phosphonates under mild conditions, namely the reaction of dipropyl phosphoramidate (1) with a para‐ (un)substituted benzaldehyde or cyclicketone (2) and triphenyl phosphite (3) by a one‐pot procedure with the aid of acetyl chloride.
ZrOCl2 Catalysed Chemoselective Conversion of Aldehydes to geminal‐Diacetates and Their Cleavage: A Mild and Efficient Method
Authors: NAGARAJ Adki , SANJEEVA REDDY Cherkupally 
Published: October 2007

AbstractZrOCl2 was found to be an effective Lewis acid catalyst for the solventless chemoselective conversion of aldehydes into geminal‐diacetates in high yields at room temperature. Regeneration of the aldehydes from the acetals was also achieved using the same catalyst in water. The beneficial effect of microwave irradiation on the reaction was also described. Other advantages are the very low loading of catalyst, high yields achieved even on a gram scale, and considerably shortened reaction time compared to the conventional method.
Solvent‐free Knoevenagel Condensations over TiO2
Authors: HOSSEINI‐SARVARI Mona , SHARGHI Hashem , ETEMAD Samane 
Published: October 2007

AbstractA study involving the scope of substrates in the Knoevenagel reaction under SFC has been conducted. Reactivity trends favored formation of the condensation product using both electron deficient and rich aryl aldehydes. A recycling study confirmed that the reaction medium could be used multiple times affording, with each run, the desired condensation product in excess of 95% conversion.
A Simple One‐pot Synthesis of 3,5‐Dicyano‐1,2‐dihydropyrid‐2‐ones in Aqueous Media
Authors: ZHUANG Qi‐Ya , XU Jia‐Ning , TU Shu‐Jiang , JIA Run‐Hong , ZHANG Jun‐Yong , LI Chun‐Mei , ZHOU Dian‐Xiang 
Published: October 2007

AbstractA simple and clean synthesis of 3,5‐dicyano‐1,2‐dihydropyrid‐2‐ones by a one‐pot three‐component reaction of malononitrile, aromatic aldehydes and 2‐cyanoacetamide or 2‐cyanothioacetamide has been achieved in an aqueous solution with potassium carbonate as a base under microwave irradiation without a phase transfer reagent. This protocol has the advantages of short reaction time (5–8 min) and convenient work‐up.
Synthesis and Characterization of Poly(butylene adipate‐co‐ terephthalate) Catalyzed by Rare Earth Stearates
Authors: ZHU Kui , ZHU Wei‐Pu , GU Yan‐Bo , SHEN Zhi‐Quan , CHEN Wei , ZHU Gui‐Xiang 
Published: October 2007

AbstractRare earth (Nd, Y, La, Dy) stearates have been synthesized and used as single component catalysts for the polycondensation of dimethyl terephthalate, adipic acid and 1,4‐butanediol for the first time preparing biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) with high molecular weight. The microstructures of PBAT were characterized by 1H NMR spectra. The PBAT exhibits good mechanical properties such as high tensile strength (ca. 20 MPa) and long break elongation (>700%).
Molten‐salt Synthesis and Properties of ZnS with Hexagonal Prism Morphology
Authors: LIU Jin‐Song , JI Guang‐Bin , LI Zi‐Quan , CAO Jie‐Ming , ZHENG Ming‐Bo , KE Xing‐Fei 
Published: October 2007

AbstractZnS with hexagonal prism morphology has been synthesized successfully by molten‐salt method with ZnS nanoparticles as precursors, and the ZnS nanoparticles were prepared by one‐step solid‐state reaction of Zn(CH3COO)2·2H2O with Na2S·9H2O at ambient temperature. Crystal structure and morphology of the product were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy and HRTEM. Ultraviolet‐visible optical absorption spectrum of the ZnS hexagonal prism shows a distinct red shift from that of bulk ZnS crystals and photoluminescence spectrum exhibits strong emissions at 380 and 500 nm, respectively. Further experiments were designed and the formation mechanism of the ZnS hexagonal prism has been also discussed in brief.
Alkoxymethylenephosphonate Analogues of (Lyso)phosphatidic Acid Stimulate Signaling Networks Coupled to the LPA2Receptor
Authors: Gajewiak Joanna , Tsukahara Ryoko , Tsukahara Tamotsu , Yu Shuanxing , Lu Yiling , Murph Mandi , Mills Gordon B. , Tigyi Gabor , Prestwich Glenn D. 
Published: October 2007

AbstractAn efficient stereocontrolled synthesis afforded alkoxymethylenephosphonate (MP) analogues of lysophosphatidic acid (LPA) and phosphatidic acid (PA). The pharmacological properties of MP‐LPA and MP‐PA analogues were characterized for LPA receptor subtype‐specific agonist and antagonist activity using Ca2+‐mobilization assays in RH7777 cells expressing the individual LPA1–LPA3receptors and CHO cells expressing LPA4. In addition, activation of a PPARγ reporter gene construct expressed in CV‐1 cells was assessed. These metabolically stabilized LPA analogues exhibited an unexpected pattern of partial agonist/antagonist activity for the LPA G‐protein‐coupled receptor family and the intracellular LPA receptor PPARγ. Analogues were compared with 18:1 LPA for activation of downstream signaling in HT‐29 colon cancer cells, which exclusively express LPA2, and both SKOV3 and OVCAR3 ovarian cancer cells, which express LPA1, LPA2, and LPA3. Unexpectedly, reverse phase protein arrays showed that four MP‐LPA and MP‐PA analogues selectively activated downstream signaling in HT‐29 cells with greater potency than LPA. In particular, the oleoyl MP‐LPA analogue strongly promoted phosphorylation and activation of AKT, MEK, and pS6 in HT‐29 cells in a concentration‐dependent manner. In contrast, the four MP‐LPA and MP‐PA analogues were equipotent with LPA for pathway activation in the SKOV3 and OVCAR3 cells. Taken together, these results suggest that the MP analogues may selectively activate signaling via the LPA2receptor subtype, while simultaneously suppressing signaling through the LPA1and LPA3subtypes.
Interferon‐α and 5‐fluorouracil combination therapy after palliative hepatic resection in patients with advanced hepatocellular carcinoma, portal venous tumor thrombus in the major trunk, and multiple nodules
Authors: Nagano Hiroaki , Miyamoto Atsushi , Wada Hiroshi , Ota Hideo , Marubashi Shigeru , Takeda Yutaka , Dono Keizo , Umeshita Koji , Sakon Masato , Monden Morito 
Published: October 2007

AbstractBACKGROUND.The authors reported previously the beneficial effects of interferon (IFN)‐α/5‐fluorouracil (5‐FU) combination therapy for patients with advanced hepatocellular carcinoma (HCC) who have tumor thrombi in the major portal branches. In this report, the authors describe the results from IFN/5‐FU chemotherapy for patients who underwent palliative hepatic resection for advanced HCC with tumor thrombus in the main trunk of the portal vein and multiple nodules in the whole liver. In addition, they evaluated the correlation between the response to such therapy and expression of IFN‐α type 2 receptor (IFNAR2).METHODS.From October 1999 to December 2004, 30 patients with advanced HCC, tumor thrombi in the main trunk of the portal vein, and multiple nodules in the whole liver (Vp4 and grade 3 intrahepatic metastases) were recruited for this study. They underwent palliative hepatic resection followed by at least 2 courses of IFN/5‐FU. IFNAR2 expression levels were determined by immunohistochemistry.RESULTS.No major treatment‐related complications were noted. An objective response was noted in 10 patients (33.3%) and included a complete response in 6 patients (20%), a partial response in 4 patients (13.3%), no response in 1 patient (3.3%), and progressive disease in 19 patients (63.4%). IFNAR2 expression was detected in 20 of 30 patients (66.7%). There was a significant difference in overall survival between patients with positive and negative IFNAR2 expression cases (P < .0025), and a significant correlation was observed between IFNAR2 expression and response to IFN/5‐FU combination therapy (P = .0199).CONCLUSIONS.Adjunct IFN/5‐FU therapy is a promising modality for patients with advanced HCC, tumor thrombi in the major trunk, and multiple nodules after palliative hepatic resection. The results from this study indicated that the response to such therapy seemed to be correlated with IFNAR2 expression. Cancer 2007. © 2007 American Cancer Society.