bluuebunny/crossref_metadata_2025 huggingface dataset:
Hybrids of hybrids: nano‐scale combinations of polyphosphazenes with other materials
Authors: Allcock Harry R.
Published: March 2010

Although more than 700 different polyphosphazenes are known, with a wide range of physical and chemical properties, a further expansion of materials properties can be accomplished by combining these macromolecules with other materials such as organic polymers, ceramics or semiconductors. These combinations lead to uses in the fields of biomedicine, energy generation and energy storage, and the formation of nano‐particles such as micelles. This article is a review of recent developments in the author's laboratory to combine polyphosphazenes with other materials in order to generate new combinations of useful properties. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and characterization of poly(n‐undecyl isocyanate)/polyaniline polyblend
Authors: Li Yu‐Jen , Ho Ko‐Shan , Lo Wan‐Ting , Yang Shin‐Shiao , Chao Liang , Chang Yu‐Chen , Han Yu‐Kai , Hsieh Tar‐Hwa , Huang Ying‐Jie
Published: March 2010

Poly(n‐undecyl isocyanate) (PUDIC)/n‐dodecylbenzenesulfonic acid (DBSA)‐doped polyaniline (PANIDBSA) polyblend was prepared and the effect of the H‐bonding between these two polymers on the compatibility, conjugation chain length of PANIDBSA, and helixity of PUDIC in the polyblend system were studied. The monomer and polymer were characterized by NMR spectra and the polyblend was analyzed by FTIR, UV–vis spectra, and wide‐angle X‐ray diffraction. It was found when the blend composition of the PUDIC was higher than 10%, the WAXD patterns demonstrated lower angle shifting for the peaks at around 2θ = 2–2.5°, referring to the distance between the layers of the layered structure of PANIDBSA crystalline with increasing PUDIC, indicating the expansion of the layered structure of PANIDBSA. The FTIR spectra illustrated the presence of an absorption peak at 1700 cm−1 shift to higher wave number with PUDIC due to its H‐bonding with PANIDBSA. The UV–vis spectra of PANIDBSA described a blue‐shift of the λmax with PUDIC, indicating that the presence of PUDIC in the polyblend system can interrupt and decrease the conjugation chain length of PANIDBSA. The optical activity of the helical PUDIC decreased notably with the presence of PANIDBSA, resulting from the reversed helical effect (de‐nature) of H‐bonding. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and gas permeation properties of a single layer PDMS membrane
Authors: Sadrzadeh Mohtada , Shahidi Kazem , Mohammadi Toraj
Published: March 2010

In this work, a new polydimethylsiloxane (PDMS) membrane was synthesized and its sorption, diffusion, and permeation properties were investigated using H2, N2, O2, CH4, CO2, and C3H8 as a function of pressure at 35°C. PDMS, as a rubbery membrane, was confirmed to be more permeable to more condensable gases such as C3H8. The synthesized PDMS membrane showed much better gas permeation performance than others reported in the literature. Based on the sorption data of this study and other researchers' works, some valuable parameters such as Flory‐Huggins (FH) interaction parameters, χ, etc., were calculated and discussed. The concentration‐averaged FH interaction parameters of H2, N2, O2, CH4, CO2, and C3H8 in the synthesized PDMS membrane were estimated to be 2.196, 0.678, 0.165, 0.139, 0.418, and 0.247, respectively. Chemical similarity of O2, CH4, and C3H8 with backbone structure of PDMS led to lower χ values or more favorable interactions with polymer matrix, particularly for CH4. Regular solution theory was applied to verify correctness of evaluated interaction parameters. Local effective diffusion coefficient of C3H8 and CO2 increased with increasing penetrant concentration, which indicated the plasticization effect of these gases over the range of penetrant concentration studied. According to high C3H8/gas ideal selectivity values, the synthesized PDMS membrane is recommended as an efficient membrane for the separation of organic vapors from noncondensable gases. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Some comparative aspects of particle formation and rate of reaction in emulsion polymerization of vinyl acetate and butyl acrylate
Authors: Jahanzad Fatemeh
Published: March 2010

The comparative study of monomers, in terms of particle formation and rate of polymerization, facilitates the interpretation of the results from the corresponding copolymerization runs and can be considered as a preliminary step toward formulation of copolymerization reactions. Batch emulsion homopolymerization of vinyl acetate (VA) and butyl acrylate (BA), as model monomers with a wide water solubility disparity, were carried out to investigate the effects of variations in the monomer concentration, electrolyte concentration, reaction volume, and surfactant type on the kinetics of polymerization. With sodium lauryl sulfate as surfactant, VA emulsion polymerization produced more particles than BA at a lower monomer concentration, but fewer particles at a higher monomer concentration. At a lower VA concentration, a depressed growth for newly formed particles during interval III contributed to the formation of a large number of particles. The application of aerosol MA and OT surfactants improved the stability of polyvinyl acetate (PVA) particles so that a larger number of polymer particles was obtained for VA, in comparison with BA. BA emulsion polymerization showed little sensitivity to electrolyte concentrations and reaction volumes within the range studied. The colloidal stability of PVA particles was found to be quite sensitive toward the aforementioned variables. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
High‐strength biodegradable poly(vinyl alcohol)/fly ash composite films
Authors: Nath Dilip Chandra Deb , Bandyopadhyay Sri , Boughton Philip , Yu Aibing , Blackburn Darryl , White Chris
Published: March 2010

We prepared biodegradable composite films of poly(vinyl alcohol) (PVA) and fly ash (FA) spanning 5, 10, 15, 20, and 25 wt % concentrations by casting aqueous solutions. The tensile strengths of the composite films were increased proportionally via the addition of FA. The strength of the film was enhanced by 193% with 20% FA compared to the neat PVA control. Further addition of FA deviated from the linear trend. The moduli of the composites also increased proportionally with FA addition to 212% at 20 wt % FA addition compared to the control. The percentage strain at break exponentially decreased with the addition of FA. In the dynamic mechanical behavior, the storage and loss moduli both increased with FA content. The tan δ peaks corresponding to the glass‐transition temperature shifted 5–10°C higher above the control sample (73°C). This shift was attributed to a reduction in the mobility of PVA segments because they were anchored by the FA surface. The reductions in mobility manifested in strong interfacial interactions were indicative of hydrogen bonding. Broadening and reduction in the intensities of the stretching and bending peaks of OH, CH and CO of PVA in the Fourier transform infrared spectra were observed. This suggested that hydrogen bonding was active between the functional groups in the FA and PVA chains. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
New copper phthalocyanine oligomers for high dielectric constant polymer films
Authors: Saha Rituparna , Mandal Braja K.
Published: March 2010

We report here the synthesis of two new oligomeric copper phthalocyanine (CuPc) derivatives by esterification of the corresponding carboxylic acids with tri(ethylene glycol) monomethyl ether. The solubility of these derivatives in N,N′‐dimethylformamide (DMF) enabled us to perform dielectric studies with poly(vinylidene fluoride‐trifluoroethylene) P(VDF‐TrFE), acting as the host polymer matrix. The highest room temperature dielectric constant achieved is 94 at 100 Hz, compared with 12 for the base polymer host matrix. Thermogravimetric analyzes of the polymer films showed that they are thermostable at 100°C for a long period of time. Scanning electron microscopy (SEM) images of the films have also been analyzed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of acryloyloxy guar gum
Authors: Shenoy Mohan A. , D'Melo Dawid John
Published: March 2010

Guar gum is a galactomannan commonly used as a viscosity modifier in the food, pharmaceutical, and cosmetics industry. The aim of this study was to synthesize acryloyloxy guar gum via a Schotten‐Bauman reaction in aqueous media. The reaction products were characterized using FTIR, C13‐NMR, wide angle X‐ray diffraction techniques to ascertain the effect of acrylation on the structure of guar gum. The acrylation of guar gum was found to be limited to the primary hydroxyl groups on the guar gum molecule. The maximum degree of substitution (DS) was found to be 0.56, which was observed after 3 h of reaction. Since the reaction was carried out in an aqueous medium after 3 h of reaction the DS of the derivatised guar gum was found to decrease, because of hydrolysis of the formed ester linkages. The ester content and intrinsic viscosity of the derivatised guar gums were also evaluated. Thermal analysis showed that a higher DS resulted in products with lower thermal stability and there was no evidence of reaction via the acrylate groups on heating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Mechanical properties and sliding wear behavior of potassium titanate whiskers‐reinforced poly(ether ether ketone) composites under water‐lubricated condition
Authors: Xie Guang‐You , Zhong Ying‐Jie , Sui Guo‐Xin , Yang Rui
Published: March 2010

Polyetheretherketone (PEEK) composites reinforced with potassium titanate whiskers (PTW) were compounded using a twin‐screw extruder followed by injection molding. The effects of PTW on the mechanical properties, crystallization performances and wear behaviors of PEEK under water lubrication have been investigated. It was denoted that the yield strength, Young's modulus, and microhardness of the composites increased with increasing whisker content, but the elongation at break and the impact strength showed decreasing trend. It was revealed that the inclusion of PTW could effectively reduce the friction coefficient and enhance the wear resistance of the PEEK. The DSC tests showed that the crystallinity of the composite slightly decreased with the addition of PTW, which might imply that the crystallinity of PEEK was not the dominant factor that influenced the wear properties of the composites. The enhancement on the wear resistance was attributed to the reinforced effect of PTW on PEEK. The wear mechanism changed from fatigue wear into mild abrasive wear when the PTW was added into PEEK. The lowest wear rate 9.3 × 10−8 mm3/Nm was achieved at 10 wt % PTW content. However, excessive whiskers would cause severe abrasive wear to the composite. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of crosslinked phenolic‐typed beads by dispersion polycondensation of 2‐phenoxyethanol with formaldehyde
Authors: Ji Chunnuan , Shi Jingxi , Sun Changmei , Qu Rongjun , Wang Chunhua , Sun Yanzhi
Published: March 2010

A novel dispersion polymerization of 2‐phenoxyethanol (PE) with formaldehyde for the preparation of crosslinked phenolic‐typed beads (CPBs) is reported. Monodisperse CPBs with particle sizes in the range 400–700 μm were obtained. The dispersion polymerization of PE with formaldehyde was conducted with hydroxyethyl cellulose, concentrated sulfuric acid, and formic acid as a stabilizer, catalyst, and solvent, respectively. The effects of reaction variables, including the polymerization temperature, agitation rate, molar ratio of formaldehyde to 2‐phenoxyethanol (F/P), stabilizer concentration, and amount of the catalyst on the particle size, particle size distribution, and morphology, were investigated. Particularly, CPBs of a size 604 μm and a narrow particle size distribution (polydispersity index = 1.193) were prepared under the following conditions: polymerization temperature = 60°C, agitation rate = 700 rpm, stabilizer concentration = 2.5%, F/P = 3 : 1, and amount of catalyst = 8 mL. The resulting CPBs were characterized by scanning electron microscopy and laser particle analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of poly[N′‐(2‐cyanoacetyl)acrylohydrazide] and its copolymers with styrene and N‐phenylacrylamide: Characterization, complexation, thermal stability, swelling, and morphology
Authors: A. Elassar Abdel‐Zaher , El‐Sayed Ahmed E. M. , Ahmed Fared S.
Published: March 2010

N′‐(2‐cyanoacetyl)acrylohydrazide (CAH) was obtained with the treatment of 2‐cyanoacetohydrazide with acryloyl chloride in acetonitrile. The obtained acrlyoyl derivative was transferred to the corresponding polymer, poly[N′‐(2‐cyanoacetyl)acrylohydrazide] (PCAH), through treatment with 2,2′‐azobisisobutyronitrile at 75°C. Copolymers with styrene or N‐phenyl acrylamide monomers were synthesized with different ratios. The structures of these polymers were characterized with elemental analysis and spectral data. The morphology, metal uptake, and ion selectivity of the polymers were studied. In addition, the swelling behavior of the polymer and metallopoymer complexes at different times of drying was also investigated. Thermogravimetric analysis of the polymer and polymer complexes under air reflected that PCAH–Pb was the most stable, followed by PCAH, PCAH–Hg, PCAH–Cu, PCAH–Ni, and PCAH–Co. A similar stability with little difference was reported under nitrogen. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Properties of copper phthalocyanine blue encapsulated with a copolymer of styrene and maleic acid
Authors: Fu Shaohai , Ding Lei , Xu Changhai , Wang Chunxia
Published: March 2010

Copper phthalocyanine blue was encapsulated with a copolymer of styrene and maleic acid (PSMA) via a phase‐separation technique, and a PSMA‐encapsulated pigment dispersion was prepared. The effects of the additive on the stability of the dispersion were studied. Scanning electron microscopy photographs revealed that the particles in the PSMA‐encapsulated pigment dispersion were more uniform than those in a PSMA‐dispersed pigment dispersion. X‐ray photoelectron spectroscopy provided evidence that the PSMA‐encapsulated pigment acquired abundant carboxylic groups that could improve its wettability to water. Moreover, the results also indicated that the PSMA‐encapsulated pigment dispersion had improved color strength, its stability could be greatly influenced by the pH value and ion strength, and its apparent viscosity changed little with an increase in the shear rate. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rheological modeling of fracture in plug‐assisted vacuum thermoforming
Authors: Hosseini H. , Berdyshev B. V. , Mehrabani‐Zeinabad A.
Published: March 2010

The fracture of polymeric sheets is one of the practical problems occurring during plug‐assisted vacuum thermoforming. This defect can occur during both the plug‐assist and vacuum‐forming stages. This article focuses on two issues: (1) the origins of fracture creation and (2) the determination of the process parameters needed for removal of the defect. The results of our work not only lead to an understanding of the cause of this problem but also enable us to calculate the parameters that affect the fracture of polymeric sheets during plug‐assisted vacuum thermoforming. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of nanozirconia on the thermal stability of poly(methyl methacrylate) prepared by in situ bulk polymerization
Authors: Wang Xinlong , Wu Lianghu , Li Jin
Published: March 2010

Nanozirconia (nano‐ZrO2) was prepared by the sol–gel method and incorporated into poly(methyl methacrylate) (PMMA) by the in situ bulk polymerization of methyl methacrylate. The structure of the nano‐ZrO2 was confirmed by X‐ray diffraction (XRD), transmission electron microscopy, and Fourier transform infrared (FTIR) spectroscopy. The structure of the nano‐ZrO2 nanocomposites were studied by differential scanning calorimetry, FTIR spectroscopy, XRD, and scanning electron microscopy, and the results show that there were interactions between the nanoparticles and the polymer. The influence of the nano‐ZrO2 on the thermal stability of PMMA was investigated by thermogravimetric analysis (TGA). The results indicate that nano‐ZrO2 enhanced the thermal stability of the PMMA/nano‐ZrO2 nanocomposites. The effects of the heating rate in dynamic measurements (5–30°C/min) on kinetic parameters such as apparent activation energy (Ea) in TGA both in nitrogen and air were investigated. The Kissinger method was used to determine Ea for the degradation of pure PMMA and the PMMA/nano‐ZrO2 nanocomposites. The kinetic results show that the values of Ea for the degradation of the nanocomposites were higher than that of pure PMMA in air. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and application of a new vinyl copolymer superplasticizer
Authors: Lu Sheng‐Hua , Liu Gang , Ma Yan‐Fen , Li Fang
Published: March 2010

A new vinyl graft copolymer superplasticizer was synthesized by copolymerization of polyethylene glycol acrylate (PEGAA), polyethylene glycol biester of maleic acid and citric acid (PEGMC), acrylic acid (AA), sodium allylsulphonate (SAS), and methyl acrylate (MA). The effects of the vinyl monomers' molar ratio, initiator, reaction temperature, and reaction time on its application properties were investigated. The results show that the new vinyl graft copolymer superplasticizer has excellent application properties when the molar ratio of PEGAA, PEGMC, AA, SAS, and MA is 0.5 : 0.10 : 0.20 : 0.05 : 0.03 and the initiator ammonium persulfate [(NH4)2S2O8, APS] is 0.8 wt % at 80°C for 3 h. The vinyl monomers' conversion is 98.7%. The applied results show that the water‐reducing ratio and retardation solidification time of the superplasticizer reach 33.5% and 4 h, respectively. The applied concrete has excellent mechanical properties. Its molecular structure was characterized by nuclear magnetic resonance, Fourier transform infrared spectra, and gel permeation chromatography. It is characteristic of the new vinyl graft copolymer superplasticizer that citric acid (CA) and MA are introduced into the copolymer molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Atmospheric pressure plasma enhanced synthesis of flame retardant cellulosic materials
Authors: Totolin Vladimir , Sarmadi Majid , Manolache Sorin O. , Denes Ferencz S.
Published: March 2010

Flame retardant cellulosic materials have been produced using a silicon dioxide (SiO2) network coating. SiO2 network armor was prepared through hydrolysis and condensation of the precursor tetraethyl orthosilicate (TEOS), prior coating the substrates, and was cross linked on the surface of the substrates using atmospheric pressure plasma (APP) technique. Because of protection effects of the SiO2 network armor, the cellulosic based fibers exhibit enhanced thermal properties (characterized by TGA and DSC) and improved flame retardant (proven by ASTM D1230‐99). Furthermore, the surface analysis (XPS and SEM) confirmed the presence of the SiO2 network attached to the substrates even after intense ultrasound washes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A review of factors influencing user satisfaction in information retrieval
Authors: Al‐Maskari Azzah , Sanderson Mark
Published: March 2010

The authors investigate factors influencing user satisfaction in information retrieval. It is evident from this study that user satisfaction is a subjective variable, which can be influenced by several factors such as system effectiveness, user effectiveness, user effort, and user characteristics and expectations. Therefore, information retrieval evaluators should consider all these factors in obtaining user satisfaction and in using it as a criterion of system effectiveness. Previous studies have conflicting conclusions on the relationship between user satisfaction and system effectiveness; this study has substantiated these findings and supports using user satisfaction as a criterion of system effectiveness.
X‐ and H‐Shape Two Dimensional Conjugated Oligomers with Anthracene as the Node
Authors: Cui Weibin , Fu Yingying , Qu Yao , Tian Hongkun , Zhang Jingping , Xie Zhiyuan , Geng Yanhou , Wang Fosong
Published: March 2010

X‐ and H‐shape two‐dimensional (2D) conjugated oligomers (X‐ and H‐mers) and relevant model compounds have been synthesized through the introduction of different conjugated segments at the 9,10 and 2,6‐positions of anthracene, and their properties were studied in detail. Comparing with the model compounds, the X‐ and H‐mers are featured with broader absorption spectra and narrower energy bandgaps. Computational studies on the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) also indicate that these X‐ and H‐mers are 2D conjugated. Solution processed bulk heterojunction (BHJ) solar cells with [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) as the acceptor material exhibited the power conversion efficiency (PCE) up to 0.53 %.
Exact controllability of wave equations with variable coefficients coupled in parallel
Authors: Wu Jieqiong , Li Shengjia , Chai Shugen
Published: March 2010

In this paper, we investigate exact controllability for coupled wave equations which have variable coefficients principal part. Observability inequality is obtained by using Riemannian geometry method and Carleman estimates. Furthermore, the exact controllability result is established with Dirichlet boundary controls when T>T0, where the lower bound T0 for the control time T is different from that obtained in the constant coefficient principal part case.

Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Rapid construction and characterization of synthetic antibody libraries without DNA amplification
Authors: Ge Xin , Mazor Yariv , Hunicke‐Smith Scott P. , Ellington Andrew D. , Georgiou George
Published: March 2010

We report on a simple method to rapidly generate very large libraries of genes encoding mutant proteins without the use of DNA amplification, and the application of this methodology in the construction of synthetic immunoglobulin variable heavy (VH) and light (Vκ) libraries. Four high quality, chemically synthesized polynucleotides (90–140 bases) were annealed and extended using T4 DNA polymerase. Following electroporation, >109 transformants could be synthesized within 1 day. Fusion to β‐lactamase and selection on ampicillin resulted in 3.7 × 108 VH and 6.9 × 108 Vκ clones highly enriched for full‐length, in‐frame genes. High‐throughput 454 DNA sequencing of >250,000 VH and Vκ genes from the pre‐ and post‐selection libraries revealed that, in addition to the expected reduction in reading‐frame shifts and stop codons, selection for functional expression also resulted in a statistical decrease in the cysteine content. Apart from these differences, there was a good agreement between the expected and actual diversity, indicating that neither oligonucleotide synthesis nor biological constrains due to protein synthesis of VH/Vκ‐β‐lactamase fusions introduce biases in the amino acid composition of the randomized regions. This methodology can be employed for the rapid construction of highly diverse libraries with the near elimination of PCR errors in invariant regions. Biotechnol. Bioeng. 2010; 106: 347–357. © 2010 Wiley Periodicals, Inc.
Preparation and Characterization of a Bifunctional Aldolase/Kinase Enzyme: A More Efficient Biocatalyst for CC Bond Formation
Authors: Iturrate Laura , Sánchez‐Moreno Israel , Oroz‐Guinea Isabel , Pérez‐Gil Jesús , García‐Junceda Eduardo
Published: March 2010

A bifunctional aldolase/kinase enzyme named DLF has been constructed by gene fusion through overlap extension. This fusion enzyme consists of monomeric fructose‐1,6‐bisphosphate aldolase (FBPA) from Staphylococcus carnosus and the homodimeric dihydroxyacetone kinase (DHAK) from Citrobacter freundii CECT 4626 with an intervening linker of five amino acid residues. The fusion protein was expressed soluble and retained both kinase and aldolase activities. The secondary structures of the bifunctional enzyme and the parental enzymes were analyzed by circular dichroism (CD) spectroscopy to study the effect of the covalent coupling of the two parent proteins on the structure of the fused enzyme. Because S. carnosus FBPA is a thermostable protein, the effect of the fusion on the thermal stability of the bifunctional enzyme has also been studied. The proximity of the active centers in the fused enzyme promotes a kinetic advantage as the 20‐fold increment in the initial velocity of the overall aldol reaction indicates. Experimental evidence supports that this increase in the reaction rate can be explained in terms of substrate channeling.
ChemInform Abstract: Investigations in the Systems Sr—As—O—X (X: H, Cl): Preparation and Crystal Structure Refinements of the Anhydrous Arsenates(V) Sr3(AsO4)2, Sr2As2O7, α‐ and β‐SrAs2O6, and of the Apatite‐Type Phases Sr5(AsO4)3OH and Sr5(AsO4)3Cl.
Authors: Weil Matthias , Dordevic Tamara , Lengauer Christian L. , Kolitsch Uwe
Published: February 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vibrational and Thermodynamic Properties of 2,2′,4,4′,6,6′‐Hexanitroazobenzene and Its Derivatives: A Density Functional Theory Study
Authors: Liu Yan , Gong Xuedong , Wang Guixiang , Wang Lianjun , Xiao Heming
Published: March 2010

HNAB (2,2′,4,4′,6,6′‐hexanitroazobenzene) and its derivatives have been optimized to obtain their molecular geometries and electronic structures by using density functional theory at the B3LYP/6‐31G* level. Their IR spectra have been computed and assigned by vibrational analysis. The strongest peaks are attributed to the NO asymmetric stretching of nitro groups. Its central position moves towards higher frequency as the number of nitro groups increases. It is obvious that there is hydrogen‐bonding between amino and nitro groups in amino derivatives. Based on the frequencies scaled by 0.96 and the principle of statistical thermodynamics, the thermodynamic properties have been evaluated, which are linearly related with the temperature, as well as the number of nitro and amino groups, respectively, obviously showing good group additivity. And the thermodynamic functions for the nitro derivatives increase much more than those for the amino derivatives with the increase of the number of substituents. The values of heat of formation (HOF) for the nitro derivatives increase gradually with n, while those of the amino derivatives decrease smoothly with n.
Atom‐economy Synthesis of N‐Substituted Carbamate from Urea Derivative and Dimethyl Carbonate Catalyzed by La/SiO2: Characterization and Activity
Authors: Guo Xiaoguang , Shang Jianpeng , Li Jian , Wang Liguo , Ma Yubo , Shi Feng , Deng Youquan
Published: March 2010

A series of silica gel immobilized lanthanum catalysts were prepared for the atom‐economy synthesis of N‐substituted carbamates from urea derivatives and dimethyl carbonate. The La/SiO2 catalysts with lanthanum loadings varied from 1.3 wt% to 8.5 wt% were characterized by AES, BET, XRD, TEM, FT‐IR, XPS and TPD. According to the characterization, lanthanum species with particle sizes of 5–10 nm on the surface of silica gel were formed. The catalysts were all amorphous and the surface areas were 336.5–530.2 m2/g. NH3‐TPD analysis showed that all samples exhibited similar acid strength with different acid amounts. FT‐IR measurement indicated that the component of lanthanum species on the catalyst surface were La(OH)3, LaOOH and hydrated La2O3. Also, the peak value of the absolute amount of LaOOH was obtained with 4.3 wt% lanthanum loading. The BET surface area decreased dramatically when the lanthanum loading was above 4.3 wt%. In consideration of the results obtained from the catalytic reactions, it could be concluded that LaOOH was the possible active species and high surface area was important for the high catalytic activity.
Catalytic Performances of Binder‐free ZSM‐5 Catalysts for Dehydration of Crude Methanol to Dimethyl Ether
Authors: Wang Jing , Cheng Xiaowei , Guo Juan , Chen Xiaocheng , He Heyong , Long Yingcai
Published: March 2010

A series of binder‐free ZSM‐5 catalysts and a binder‐containing catalyst were prepared and characterized with X‐ray diffraction (XRD), X‐ray fluorescence (XRF), 27Al magic‐angle spinning (MAS) nuclear magnetic resonance (NMR), N2 sorption and ammonia temperature‐programmed deposition (TPD) methods. The catalytic activity and selectivity in the dehydration of crude methanol to dimethyl ether (DME) were evaluated in a fixed‐bed reactor for the catalysts. The outstanding structural characters such as high zeolite contents, sufficiently open channels and richness in mesopores have been proved on these binder‐free catalysts. The influence of the solid‐acidity, which is closely related to the framework silica alumina ratio (SAR) of the catalysts, on the catalytic properties has been discussed. A binder‐free catalyst with a better potential in application has been selected for its high activity and selectivity, long life‐time and non‐sensitivity to water contents in the feed. The reason for its excellent performance of the catalyst was discussed.
Interaction between (1,1′‐Binaphthalene)‐2,2′‐diol and Lecithin Liposome
Authors: Chen Liuhua , Gan Lihua , An Shenjing , Zhu Dazhang , Xu Zijie , Hao Zhixian , Chen Longwu
Published: March 2010

The interaction between (1,1′‐binaphthalene)‐2,2′‐diol (BINOL) and lecithin liposome was studied by UV‐Vis, fluorescence and 1H NMR spectroscopies. BINOL can obviously associate with lecithin liposome and the preferential binding site of BINOL with lecithin liposome is located in the headgroup region. The hydrogen bond and electrostatic interaction should exist in BINOL/liposome system, which restricts intra‐annular rotation of naphthol moieties. Therefore, the fluorescence intensity of BINOL increases when a small quantity of liposome is added into the system. The partition coefficient KD between the lecithin liposome and the aqueous phase is 310.9. With the increase of BINOL concentration, the micropolarity (I1/I3) and membrane fluidity of liposome decreased, while the viscosity of membrane increased.
Star‐shaped Organic Molecules That Comprise a 1,3,5‐Trisubstituted Benzene Core and Three Oligoaryleneethynylene Arms as Light‐emitting Materials
Authors: Liu Yanling , Feng Jikang , Ran Xueqin , Ren Aimin
Published: March 2010

Star‐shaped rigid molecules that comprise a 1,3,5‐trisubstitued benzene core and three oligoaryleneethynylene arms have great potential application in organic light‐emitting devices (OLEDs). Their optical and electronic properties are tuned by the star‐shaped molecular size. To reveal the relationship between the properties and structures, we perform a systemic investigation for these organic molecules. The ground and excited state molecules are studied using density functional theory (DFT), the ab initio HF, and the single excitation configuration interaction (CIS), respectively. And the electronic absorption and emission spectra are investigated with time‐dependent density functional theory (TDDFT) and Zerner's intermediate neglect of differential overlap (ZINDO) methods. The results show that the HOMOs, LUMOs, energy gaps, ionization potentials (IP), electron affinities (EA), absorption and emission spectra are controlled by the star‐shaped molecular size, which favor the hole and electron injection into OLEDs. With increasing the molecular conjugated length, the absorption and emission spectra exhibit red shifts to some extent and are in good agreement with the experimental ones. Also, the calculated emission spectra range from 330 to 440 nm. All the calculated show that the star‐shaped molecules are promising as blue light emitting materials
Mixed Ligand Palladium(II) Complex with NS‐Bidentate S‐Allyldithiocarbazate Schiff Base: Synthesis, Spectral Characterization, Crystal Structure and Decoding Intermolecular Interactions with Hirshfeld Surface Analysis
Authors: Takjoo Reza , Takjoo Rozita , Yazdanbakhsh Mohammad , Aghaei kaju Amir , Chen Yaguang
Published: March 2010

A new mixed ligand palladium(II) complex with bidentate NS‐donor chelate, [PdCl(PPh3)L] (L: S‐allyl β‐N‐(benzylidene)dithiocarbazate), has been prepared and characterized using single crystal X‐ray diffraction and spectroscopic (electronic, IR, 1H NMR and 13C NMR) techniques. The shorter PdP bond distance, 2.255(7) Å, than the sum of the single bond radii for palladium and phosphorus (2.41 Å), showed partial double bond character. Visualizing and exploring the crystal structure using Hirshfeld surface analysis showed the presence of π··· π, N··· π, CH··· π, Cl···H and weak CH···S interactions as most important intermolecular interactions in the crystal lattice, which are responsible to extension of the supramolecular network of the compound and stabilization of the crystal structure.
Rhodium‐catalyzed Asymmetric Ring‐opening Reactions of N‐Boc‐azabenzonorbornadiene with N‐Substituted Piperazine Nucleophiles
Authors: Wu Yuhua , Yang Dingqiao , Zeng Heping , Xie Lei , Wu Lihuan , Mo Haihong , Zuo Xiongjun
Published: March 2010

Asymmetric ring‐opening reactions of N‐Boc‐azabenzonorbornadiene with N‐substituted piperazine nucleophiles in the presence of 5 mol% of [Rh(COD)Cl]2 and 10 mol% of chiral ligand, (R,S)‐PPF‐P‐t‐Bu2, gave the corresponding 1,2‐diamine product in moderate to excellent yields (up to 95%) with reasonable enantiomeric excesses (up to 70% ee). The results showed that the nature of ligands had significant influence on the yields and the enantiomeric excesses.
Synthesis and Pharmacological Evaluation of Some Novel Imidazo[2,1‐b][1,3,4]thiadiazole Derivatives
Authors: Kumar Parvin
Published: March 2010

Synthesis of bis‐1,3‐{6′‐arylimidazo[2,1‐b][1,3,4]thiadiazol‐2‐yl}‐1,2,2‐trimethylcyclopentane (3), bis‐1,3‐{thiadiazolo[2′,3′:2,1]imidazo[4,5‐b]quinoxalinyl}‐1,2,2‐trimethylcyclopentane (5) has been achieved by the reaction of bis‐(5′‐amino‐1′,3′,4′‐thiadiazolyl)‐1,2,2‐trimethylcyclopentane with α‐haloketones, 2,3‐dichloroquinoxaline respectively. Bromination of compound 3 furnished bis‐1,3‐{5′‐bromo‐6′‐arylimidazo[2,1‐b][1,3,4]thiadiazol‐2‐yl}‐1,2,2‐trimethylcyclopentane (4). The structural assignment of these compounds was supported by IR, 1H NMR and elemental analysis data. The antimicrobial, anti‐inflammatory and antifungal activities of some of the compounds have also been evaluated.
Al(H2PO4)3 as an Efficient and Reusable Catalyst for One‐pot Three‐component Synthesis of α‐Amino Phosphonates under Solvent‐free Conditions
Authors: Maghsoodlou Malek Taher , Habibi‐Khorassani Sayyed Mostafa , Heydari Reza , Hazeri Nourollah , Sajadikhah Seyed Sajad , Rostamizadeh Mohsen
Published: March 2010

Synthesis of α‐amino phosphonates is described under solvent‐free conditions at 100°C from reaction between aldehydes and amines in the presence of trialkyl phosphites using Al(H2PO4)3 as an efficient and reusable heterogeneous catalyst. The advantages of this procedure are short reaction time, flexibility and having high to excellent yields.
Copper(II) and 2,2′‐Biimidazole‐promoted Novel Reaction of 4,4,4‐Trifluoro‐1‐phenylbutane‐1,3‐diones with Iodobenzene Diacetate
Authors: Zhou Chunmei , Zeng Runsheng , Zou Jianping
Published: March 2010

A new and efficient way was developed to carry out the reaction of 4,4,4‐trifluoro‐1‐phenylbutane‐1,3‐dione with iodobenzene diacetate under the assistance of Cu(II) and 2,2′‐biimidazole at a low temperature in excellent yield. 2‐Acetoxyacetophenone was obtained unexpectedly.
Template‐synthesized Protein Nanotubes with Controlled Size Based on Layer‐by‐layer Method
Authors: Tao Caihong , Yang Shengrong , Zhang Junyan
Published: March 2010

The protein nanotubes fabricated by a layer‐by‐layer deposition method using the porous alumina membrane as the template were described. The combination of the template method and the layer‐by‐layer assembly technique for the fabrication of protein nanotubes presented simplicity and versatility. The nanotubes composed of two kinds of proteins (bovine serum albumin and hemoglobin lyophilized bovine erythrocytes) with different sizes could be synthesized through this method. The outside diameter of the obtained nanotubes was determined by the diameter of the pores of the template. And the wall thickness of the protein nanotubes increased with the increase of the number of protein layers that made up of the walls of nanotubes. Such biodegradable nanotubes with good biocompatibility should be useful for in vivo applications.
Detachment of the basal body from the sperm tail is not required to organize functional centrosomes during Drosophila embryogenesis
Authors: Riparbelli Maria Giovanna , Callaini Giuliano
Published: March 2010

The formation of the zygotic spindle at fertilization requires in most animals the central contribution of the sperm‐inherited basal body that recruits maternal cytoplasmic components to assemble a functional centrosome. Although as a general rule the entire sperm enters the egg during fertilization, the fate of the sperm basal body during further development is not clear. We have found that the sperm centriole remains linked to the apical end of the sperm tail through early development and is able to duplicate and recruit maternal components to assemble functional centrosomes. The basal body, therefore, needs not to be detached from the sperm tail to perform its centriole function during organization of the centrosome. By cellularization and early gastrulation the sperm centriole has lost both these capabilities. The persistence of the sperm axoneme and its close association with its centriole during development presents a paradox. If the sperm centriole is a true basal body, then the widespread idea that cells with a primary cilium must resorb the axoneme and transform the basal body into a centriole to enable proper mitosis will have to be re‐examined. © 2010 Wiley‐Liss, Inc.
Circulating biomarkers for vascular endothelial growth factor inhibitors in renal cell carcinoma
Authors: Zurita Amado J. , Jonasch Eric , Wu Hua‐Kang , Tran Hai T. , Heymach John V.
Published: March 2010

In recent years, there has been significant progress in the clinical development and application of antiangiogenic therapies in renal cell carcinomas, particularly inhibitors of the vascular endothelial growth factor (VEGF) pathway. Despite this progress, no validated methods are currently available for identifying which patients are most likely to respond to treatment or experience toxic effects, selecting the optimal dose, or determining whether the intended molecular target has been effectively inhibited. However, recent studies have suggested that some of the biomarkers currently under investigation in clear cell renal cell carcinoma for VEGF pathway inhibitors are promising. These biomarkers include circulating proangiogenic factors and receptors; markers of hypoxia and endothelial damage; and cellular populations in peripheral blood, such as circulating endothelial cells. Further preclinical and translational validation studies are still needed to determine their practical utility in the clinical setting. Cancer 2009;115(10 suppl):2346‐54. © 2009 American Cancer Society.
Innovations and challenges in renal cancer: Summary statement from the Third Cambridge Conference
Authors: Atkins Michael B. , Bukowski Ronald M. , Escudier Bernard J. , Figlin Robert A. , Hudes Gary H. , Kaelin William G. , Linehan W. Marston , McDermott David F. , Mier James W. , Pedrosa Ivan , Rini Brian I. , Signoretti Sabina , Sosman Jeffrey A. , Teh Bin Tean , Wood Christopher G. , Zurita Amado J. , King Laura
Published: March 2010

The Third Cambridge Conference on Innovations and Challenges in Renal Cancer, a symposium held in Cambridge, Massachusetts, June 27‐28, 2008, and chaired by Michael B. Atkins, was convened to discuss the current state of knowledge in the field, critique new data, stimulate communication among those involved in basic and clinical research, and offer recommendations for further study. Four main topics were discussed: genetics and molecular biology of renal cell cancer, staging and prognosis, systemic therapy, and correlative science and biomarkers in stage IV disease. The conference format combined brief presentations with extended periods of discussion. The conclusions and recommendations are summarized in this paper and presented in more detail in the individual papers that follow. Cancer 2009;115(10 suppl):2247‐51. © 2009 American Cancer Society.
Hereditary kidney cancer
Authors: Linehan W. Marston , Pinto Peter A. , Bratslavsky Gennady , Pfaffenroth Elizabeth , Merino Maria , Vocke Cathy D. , Toro Jorge R. , Bottaro Donald , Neckers Len , Schmidt Laura S. , Srinivasan Ramaprasad
Published: March 2010

Kidney cancer is not a single disease; it is comprised of several different types of cancer, each with a different histology, with a different clinical course, caused by a different gene, and responding differently to therapy. The VHL gene is the gene for the hereditary cancer syndrome, von Hippel‐Lindau, as well as for the common form of sporadic, noninherited, clear cell kidney cancer. Understanding the VHL‐hypoxia inducible factor (HIF) pathway has provided the foundation for the development of several agents targeting this pathway, such as sunitinib, sorafenib, and temsirolimus. Hereditary papillary renal carcinoma (HPRC) is a hereditary renal cancer syndrome in which affected individuals are at risk for the development of bilateral, multifocal, type 1 papillary renal cell carcinoma. The genetic defect underlying HPRC is MET, the cell surface receptor for hepatocyte growth factor. Mutations of MET also have been identified in a subset of tumors from patients with sporadic type 1 papillary renal cell carcinoma (RCC). Clinical trials targeting the MET pathway are currently underway in patients with HPRC and in patients with sporadic (nonhereditary) papillary kidney cancer. The BHD gene (also known as folliculin or FLCN) is the gene for Birt‐Hogg‐Dube syndrome, an autosomal‐dominant genodermatosis associated with a hereditary form of chromophobe and oncocytic, hybrid RCC. Preclinical studies are underway targeting the BHD gene pathway in preparation for clinical trials in Birt‐Hogg‐Dube and sporadic chromophobe RCC. Patients with hereditary leiomyomatosis RCC (HLRCC) are at risk for developing cutaneous and uterine leiomyomas and a very aggressive type of RCC. HLRCC is characterized by germline mutation of the Krebs cycle enzyme, fumarate hydratase (FH). Studies of the tricarboxylic acid cycle and the VHL‐HIF pathways have provided the foundation for therapeutic approaches in patients with HLRCC‐associated kidney cancer as well as other hereditary and sporadic forms of RCC. Cancer 2009;115(10 suppl):2252‐61. Published 2009 by the American Cancer Society.
The current state of brachytherapy nomograms for patients with clinically localized prostate cancer
Authors: Nguyen Carvell T. , Zelefsky Michael J. , Kattan Michael W.
Published: March 2010

For men diagnosed with clinically localized prostate cancer, definitive therapy with radical prostatectomy, external beam radiation therapy, or brachytherapy offers a high chance of cure. Currently, there are insufficient data to recommend 1 treatment approach over another, leaving physicians and patients to decide based on their own biases and preferences. Prediction tools, such as nomograms and probability tables, have been created as decision aids to facilitate patient counseling and decision making. Nomograms in particular can assess the therapeutic efficacy of a given therapy by providing individualized estimates of the risk of failure after treatment. The authors performed a comprehensive literature review to identify nomograms assessing the efficacy of brachytherapy in patients with clinically localized prostate cancer, and found a paucity of such models. Analysis of currently available brachytherapy nomograms reveals suboptimal predictive power compared with models based on other treatment modalities. The purpose of this review is to spur development of new and more accurate prediction tools for predicting outcomes after brachytherapy, offering physicians and patients the opportunity to equally assess the efficacy of all available treatment modalities for clinically localized prostate cancer. Cancer 2009;115(13 suppl):3121–7. © 2009 American Cancer Society.
Decision support systems for morphology‐based diagnosis and prognosis of prostate neoplasms
Authors: Montironi Rodolfo , Cheng Liang , Lopez‐Beltran Antonio , Mazzucchelli Roberta , Scarpelli Marina , Bartels Peter H.
Published: March 2010

Recent advances in computer and information technologies have allowed the integration of both numeric and non‐numeric data, that is, descriptive, linguistic terms. This has led at 1 end of the spectrum of technology development to machine vision based on image understanding and, at the other, to decision support systems. This has had a significant impact on our capability to derive diagnostic and prognostic information from histopathological material with prostate neoplasms. Cancer 2009;115(13 suppl):3068–77. © 2009 American Cancer Society.
Prediction of sexual function after radical prostatectomy
Authors: Briganti Alberto , Capitanio Umberto , Chun Felix K.‐H. , Karakiewicz Pierre I. , Salonia Andrea , Bianchi Marco , Cestari Andrea , Guazzoni Giorgio , Rigatti Patrizio , Montorsi Francesco
Published: March 2010

Radical prostatectomy (RP) is a commonly used procedure in the treatment of clinically localized prostate cancer. For this report, the authors critically analyzed the factors associated with recovery of erectile function after surgery. A systematic review of the literature using the Medline and CancerLit databases was conducted. Keywords for the literature search included prostate cancer, radical prostatectomy, erectile dysfunction, impotence, treatment, and prophylaxis. Accurate patient selection (based on patient age, preoperative erectile function, and comorbidity profile) and adequate surgical technique (ie, the preservation of neurovascular bundles) were the major determinants of postoperative erectile function. Moreover, better results were achieved when an appropriate pharmacologic treatment using either oral or local approaches was given. Therefore, the authors concluded that, if patients are stratified correctly according to preoperative, intraoperative, and postoperative factors, then a satisfactory functional recovery may be expected after surgery. For these reasons, an ideal multivariate model predicting the restoration of erectile function after surgery should include patient, surgeon, and postsurgical treatment variables. The authors also concluded that the stratification of patients with regard to their risk of developing erectile dysfunction after surgery was feasible based on several parameters, which should be taken into account for correct patient treatment and counseling. To address this objective, accurate tools for predicting the likelihood of complete functional recovery after surgery are needed. Cancer 2009;115(13 suppl):3150–9. © 2009 American Cancer Society.