bluuebunny/crossref_metadata_2025 huggingface dataset:
Combined Evaluation of Matrix Metalloproteinases and their Inhibitors has Better Clinical Utility in Oral Cancer
Authors: Singh Ragini D. , Nilayangode Haridas , Patel Jayendra B. , Shah Franky D. , Shukla Shilin N. , Shah Pankaj M. , Patel Prabhudas S.
Published: February 2011

Background

Oral cancer is a major health hazard worldwide with increasing incidence and mortality. Cervical lymph node metastasis is a major determinant of outcome in oral cancer. The matrix metalloproteinase (MMP) system is critically involved in invasion and metastasis. Assessment of MMPs and tissue inhibitors of MMPs (TIMPs) in certain combinations might have better clinical efficacy given their potential role in the metastatic process.

Aim

Plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 in 50 controls and 75 oral cancer patients (nonmetastatic, n=54; metastatic, n=21) were evaluated to assess their investigative value and role in predicting the behavior of this malignancy.

Methods

The plasma concentrations of MMP-2, MMP-9, TIMP-1 and TIMP-2 were quantified by ELISA. The best 2- and 3-marker combinations were calculated using the statistical software mROC. The diagnostic values for all the biomolecules as single markers and their combinations were estimated using the measures of diagnostic accuracy, i.e. the area under the ROC curve and the sensitivity and specificity at cutoff limits with the highest diagnostic accuracy and at the 95% limits of sensitivity and specificity, respectively.

Results

MMP-9, TIMP-1 and TIMP-2 were significantly elevated (p=0.000, p=0.013 and p=0.005, respectively) in oral cancer patients. MMP-9 emerged as the best single statistically significant marker in plasma for oral cancer detection. It showed an increase in diagnostic performance when tested in combination with MMP-2 and TIMP-2. The median plasma MMP-9 levels were elevated in both the metastatic and nonmetastatic groups compared with controls (p<0.004 and p<0.007, respectively).

Conclusion

The results indicated that plasma MMP and TIMP levels in relevant combinations may facilitate clinical decision-making for improved management of oral cancer patients and may provide important data for selecting patients for treatment with drugs that interfere with MMP and TIMP activities.
Linear Estimation of Stationary Autoregressive Processes
Authors: Dianat Reza , Marvasti Farokh
Published: February 2011

Consider a sequence of an th-order Autoregressive (AR) stationary discrete-time process and assume that at
least consecutive neighboring samples of an unknown sample are available. It is not important that the neighbors
are from one side or are from both the left and right sides. In this paper, we find explicit solutions for the optimal linear
estimation of the unknown sample in terms of the neighbors. We write the estimation errors as the linear combination
of innovation noises. We also calculate the corresponding mean square errors (MSE). To the best of our knowledge,
there is no explicit solution for this problem. The known solutions are the implicit ones through orthogonality equations.
Also, there are no explicit solutions when fewer than samples are available. The order of the process () and the
feedback coefficients are assumed to be known.
Hydroformylation – Homogeneous
Authors: Ungváry Ferenc
Published: February 2011

Transition‐metal‐catalyzed olefin hydroformylation in homogeneous systems is reviewed.
Photoconduction: Very Large Photoconduction Enhancement Upon Self‐Assembly of a New Triindole Derivative in Solution‐Processed Films (Adv. Funct. Mater. 4/2011)
Authors: Gallego‐Gómez Francisco , García‐Frutos Eva M. , Villalvilla José M. , Quintana José A. , Gutierrez‐Puebla Enrique , Monge Angeles , Díaz‐García María A. , Gómez‐Lor Berta
Published: February 2011

A new carbazole‐related small molecule exhibiting self‐assembly into ordered nanostructures in solution‐processed cast films has been synthesized and its charge‐photogeneration and ‐transport properties have been investigated. Large photoconductivity was measured in the amorphous state while an enormous improvement in the photoconduction properties was observed when the molecules spontaneously organized. Photocurrents increased upon self‐assembly by up to four orders of magnitude, mostly due to the drastic enhancement of the charge photogeneration. A greatly favorable arrangement of the aromatic cores in the resulting nanostructures, which were characterized by X‐ray analysis, may explain these improvements. Photocurrents of mA cm−2, on/off ratios of 104 and quantum efficiencies of unity at low field and light intensity, which are among the best values reported to date, along with the simplicity of fabrication, give this readily‐available organic system great potential for use in plastic optoelectronic devices.
Regiodiverse Three‐Component Synthesis of Arenes
Authors: Danz Michael , Hilt Gerhard
Published: February 2011

A ruthenium‐catalyzed enyne metathesis reaction followed by a cobalt‐catalyzed Diels–Alder reaction and oxidation of the dihydroaromatic intermediate generates the two regioisomeric aromatic products in good overall yields in a one‐pot procedure. The regiochemistry of the cycloaddition can be controlled by the ligand choice on the cobalt catalyst to generate the product with the 1,3,5‐ or the 1,2,4‐substitution pattern predominantly. The high functional group tolerance was used to generate bifunctionalized building blocks and finally an unprecedented regioselective Scholl reaction is described.
Synthesis, characterization, and photophysical properties of novel poly(p‐phenylene vinylene) derivatives with conjugated thiophene as side chains
Authors: Ding Tianpeng , Zhao Bin , Shen Ping , Lu Junjian , Li Hui , Tan Songting
Published: February 2011

Two novel poly(p‐phenylene vinylene) (PPV) derivatives with conjugated thiophene side chains, P1 and P2, were synthesized by Wittig‐Horner reaction. The resulting polymers were characterized by 1H‐NMR, FTIR, GPC, DSC, TGA, UV–Vis absorption spectroscopy and cyclic voltammetry (CV). The polymers exhibited good thermal stability and film‐forming ability. The absorption spectra of P1 and P2 showed broader absorption band from 300 to 580 nm compared with poly[(p‐phenylene vinylene)‐alt‐(2‐methoxy‐5‐octyloxy‐p‐phenylene vinylene)] (P3) without conjugated thiophene side chains. Cyclic voltammograms displayed that the bandgap was reduced effectively by attaching conjugated thiophene side chains. This kind of polymer appears to be interesting candidates for solar‐cell applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Experimental observations of time‐dependent behaviors for polycarbosilane melt
Authors: Cheng Xuan , Bai Xuewei , Li Junjie , Chen Huizhen , Zhang Ying
Published: February 2011

The distinct characteristics of thixotropic and viscoelastic phenomena of polycarbosilane (PCS) melt were reported first time based on experimental observations. The PCS was synthesized according to the Yajima process with the number of average molecular weight being ∼ 1170, followed by an appropriate preshear treatment to remove air bubbles encountered during the heating or pressing process of PCS specimens. A series of shear thixotropic loop, start‐up, and step‐down rate measurements were carried out at 280°C to systematically examine the time‐dependent behaviors of PCS melt. It was found that the PCS melt was nonlinear complex fluid with a strong time‐dependent in viscoelasticity and apparent thixotropy. Compared with the conventional high‐density polyethylene, the shear stress–shear time responses of PCS melt were more susceptible to the changes of shear rate, shear time, and standing time because of the nature of low‐molecular‐weight polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Physicomechanical studies and solvent resistance analysis of melt‐blended novel ethylene‐1‐octene elastomer and ethylene‐co‐acrylic acid interpenetrating network hybrids
Authors: Gupta Baisali , Banerjee Deepanjan , Goswami Luna , Bandyopadhyay Abhijit
Published: February 2011

Polar modification of poly(ethylene‐co‐octene) (POE) elastomer was carried out with a relatively new approach. Poly(ethylene‐co‐acrylic acid) (EAA) was taken as the modifier and POE with a calculated amount of EAA were coextruded with dicumyl peroxide (DCP; used as a crosslinker). The majority of the compositions showed the existence of a crosslinked EAA phase inside POE, although increasing DCP concentrations and extrusion temperatures were possibly capable of crosslinking either of the phases, as observed with a model composition. All of the samples were soft and light in nature. The best composition was the one that contained 13.3 wt % EAA; that composition showed excellent surface polarity and superior mechanical properties. Detailed solvent swelling experiments also yielded the best results for that particular composition. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of the glycerol content and temperature on the rheology of native and acetylated starches during and after gelatinization
Authors: Morán Juan I. , Cyras Viviana P. , Giudicessi Silvana L. , Erra‐Balsells Rosa , Vázquez Analía
Published: February 2011

Native potato starch was acetylated and characterized. The influence of this chemical modification on different properties of the starch was studied. The characterization included the molecular weight, thermal properties, crystallinity, amylose content, swelling behavior, and pasting and rheological properties. The chemical modification induced small changes in the crystallinity of the starch and a reduction in the gelatinization heat and in the range of temperatures at which it took place. The amylose content was determined for acetylated and native potato starches. The swelling of native granules was higher than the swelling of acetylated potato starch. Regarding pasting behavior, the native and acetylated starches responded in similar ways to changes in the temperature and glycerol content. Finally, the acetylated starch was less pseudoplastic than the native starch. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Development of new concepts for the control of polymerization processes: Multiobjective optimization and decision engineering. II. Application of a Choquet integral to an emulsion copolymerization process
Authors: Camargo Mauricio , Morel Laure , Fonteix Christian , Hoppe Sandrine , Hu Guo‐Hua , Renaud Jean
Published: February 2011

In polymer industry, engineers seek to obtain polymers with prescribed end‐use properties, high productivities, and low cost. Thus, the optimization of a manufacturing process with all those goals and constraints belongs to a problem domain that aims to achieve the best trade‐off possible. This article concerns the optimization of the batch emulsion polymerization of styrene and α‐methylstyrene. An accurate model was developed to describe the complete patterns of the emulsion polymerization. Key parameters of the model were identified on the basis of batch experimental data. The model was then used to simulate, under several operating conditions, the polymerization rate, the overall conversion of monomers, and the number and weight‐average molecular weights. Amulticriteria optimization approach based on an evolutionary algorithm and the concept of dominance from the Pareto frontier theory was used. Last, a decision aid system based on the Choquet integral was proposed to determine the optimal operating conditions with the preferences of the decision maker taken into account. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Poly(aryl ether ketone)s with bromomethyl groups: Synthesis and quaternary amination
Authors: Ma Wenjia , Zhao Chengji , Lin Haidan , Zhang Gang , Na Hui
Published: February 2011

A series of bromomethylated poly(arylene ether ketone)s (PAEKs) with different contents of bromine tethered to the benzyl groups were successfully synthesized and characterized in this work. For this purpose, poly(arylene ether ketone) with 3,3′,5,5′‐tetramethyl‐4,4′‐dihydroxybipheny moiety (PAEK‐TM) was prepared by the aromatic nucleophilic polycondensation, and then the PAEK‐TM has benzylic methyl groups that were converted to bromomethyl groups by a radical reaction using N‐bromosuccinimide. Then, the bromomethylbenzyl groups in the membrane was converted to quaternary ammonium moieties in TMPAEK‐NOH. 1H‐NMR measurements were used to characterize and confirm the structures of the resulting PAEK‐x‐BrTM and TMPAEK‐NBr derivatives (x refers to the molar percentage of bromine introduced per repeating units). TGA analysis showed that PAEK‐x‐BrTM exhibited a very low‐decomposition temperature at about 200°C corresponding to the CBr bond cleavage. The hydroxide conductivity of TMPAEK‐NOH membrane was 8 mS cm−1 at room temperature, while the water uptake of TMPAEK‐NOH membrane was 22.3% at 20°C and 32.6% at 60°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology, dynamic mechanical, and electrical properties of bio‐based poly(trimethylene terephthalate) blends, part 1: Poly(trimethylene terephthalate)/poly(ether esteramide)/polyethylene glycol 400 bis(2‐ethylhexanoate) blends
Authors: Kobayashi Toshikazu , Wood Barbara A. , Blackman Gregory S. , Takemura Akio
Published: February 2011

Bio‐based PTT and PTT blends with PEEA of two different ion contents (275 ppm Na and 3515 ppm Na) and PEG 400 bis (2‐ethylhexanoate) were prepared by melt processing. The blends were characterized by differential scanning calorimetry, dynamic mechanical analysis, transmission electron microscopy, and atomic force microscopy. Electro‐static performance was also investigated for those PTT blends since PEEA is known as an ion conductive polymer. Here we confirmed that PEG 400 bis (2‐ethylhexanoate) improves the static decay performance of PTT/PEEA blends. DMA strongly suggests that PEG 400 bis (2‐ethylhexanoate) and PEEA are miscible pairs, and PEG 400 bis (2‐ethylhexanoate) selectively goes into the PEEA phase rather than the PTT phase, which lowers the Tg of PEEA. Besides topographic analysis of morphology and phase separation, tunneling atomic force microscopy was also applied to see if we can observe the surface directly for the static dissipative material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Study on crystallization kinetics of LDPE filled with CaCO3 of different size and size distribution
Authors: Zhang Jun , Fang Jue , Han Bing , Zhou Ninglin , Wu Juan , Ma Zhen‐Mao , Mo Hong , Shen Jian
Published: February 2011

The thermoplastic filled with the different size distribution fillers was a new method for improving processability of thermoplastic composites. In our former study, we found that the melt torque of low‐density polyethylene (LDPE) composites, which were filled with 30 wt % the effective size distribution CaCO3, evidently decreased. In this article, two sizes of CaCO3, 600 meshes and 2500 meshes, were blended by different proportions and were filled into LDPE matrix with 30 wt %. Crystal process, isothermal crystallization kinetics, and nonisothermal crystallization kinetics of a series of composites were characterized by differential scanning calorimeter (DSC). The results showed that composites filled with the effective size distribution CaCO3 leaded to the lower melting and crystallization temperature, the more wide crystallization temperature area, while their the crystallization rate constant (k) of isothermal crystallization kinetics decreased and their Avrami exponents (n) and crystallization half‐life (t1/2) of isothermal crystallization kinetics increased compared with those of the composites filled with the single size CaCO3. Nonisothermal crystallization kinetics had the similar results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Novel diphenyl thioether‐bridged binuclear metallocenes of Ti and Zr for synthesis of polyethylene with broad molecular weight distribution
Authors: Nie Yujing , Sun Junquan , Yin Wenxia , Wang Lincai , Shi Zuyun , Schumann Herbert
Published: February 2011

Two diphenyl thioether‐bridged binuclear metallocenes of Ti and Zr, [(C5H5)Cl2MC5H4CH2(p‐C6H4)]2S [M = Ti (1) and Zr (2)], have been synthesized by treating the dilithium salts of the corresponding ligand [(C5H5CH2(p‐C6H4)]2S with two equivalents of C5H5TiCl3 and C5H5ZrCl3(DME), respectively, in toluene at 0°C. Both new complexes have been characterized by 1H‐NMR spectroscopy and elemental analysis. Homogeneous ethylene polymerization using both complexes was performed in the presence of methylaluminoxane (MAO). The influences of molar ratio of [MAO]/[Cat], concentration of the catalysts, time, and temperature have been studied systematically. The catalytic activity of 1 is higher than that of the corresponding oxygen‐bridged catalyst [(C5H5)Cl2TiC5H4CH2(p‐C6H4)]2O. The catalytic activity of 2 is at least two times higher than that of 1 under any tested polymerization conditions. The melting points of polyethylene (PE) produced by 1 and 2 are higher than 130°C, indicating a highly linear and highly crystalline PE. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synergistic effect on crystalline structure of polyvinylidene fluoride nanocomposites with multiwalled carbon nanotube loading by a twin screw extruder
Authors: Kang Dong Jin , Pal Kaushik , Bang Dae Suk , Kim Jin Kuk
Published: February 2011

Polyvinylidene fluoride (PVDF)/multiwalled carbon nanotube (MWCNT) composites were prepared by using twin screw extruder at various (0–5 wt %) MWCNT loadings. Field Emission Scanning Electron Microscope (FESEM) micrographs showed a relatively good dispersion and random distribution of MWCNT in PVDF matrix. The physical and dielectric properties increased gradually with the increase in MWCNT content but the thermal stability decreased. The DSC result revealed the increase in crystallinity of the PVDF matrix. Wide angle X‐Ray diffraction (WAXD) result showed a large shoulder at 2θ of 20.78° with increasing in MWCNT content. The experimental percolation threshold for the surface resistance of PVDF/MWCNT composites were estimated and clearly observed at 4 wt % of MWCNT loading. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology of polyurethanes at various length scale: The influence of chain structure
Authors: Mishra Abhinay , Maiti Pralay
Published: February 2011

Micro‐structural investigation of polyurethanes (PUs) with different chain structure has been reported. Polarized optical microscopic studies of aliphatic polyurethanes demonstrate the development of micro clusters with increasing hard segment content (HSC) and crystallization. DSC and XRD results support the crystalline and amorphous nature of aliphatic and aromatic PUs, respectively. Self‐assembled biphasic morphology is discernible in aliphatic polyurethane while nanometer size domains are observed in aromatic PUs. The dimension of micro‐domain has been measured by using AFM and established its size as independent of hard segment content. The self‐assembly is greater for higher HSC aliphatic PUs leading to the formation of bigger domain while the meager hydrogen bond formation restricts the domain size of aromatic polyurethanes. Segmented morphology of surface as well as in bulk of aliphatic polyurethanes is evident from SEM and TEM images and grows with increasing HSC. In contrast, homogeneous and amorphous nature has been observed for aromatic PUs. In situ segregation of phases in aliphatic PUs have been captured through light transmittance and optical images which is categorically absent in aromatic polyurethane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Biodegradable and photocurable multiblock copolymers with shape‐memory properties from poly(ε‐caprolactone) diol, poly(ethylene glycol), and 5‐cinnamoyloxyisophthalic acid
Authors: Nagata Minoru , Inaki Kunihito
Published: February 2011

Biodegradable and photocurable multiblock copolymers of various compositions were synthesized by the high‐temperature solution polycondensation of poly(ε‐caprolactone) (PCL) diols of molecular weight (Mn) = 3000 and poly(ethylene glycol)s (PEG) of Mn = 3000 with a dichloride of 5‐cinnamoyloxyisophthalic acid (ICA) as a chain extender, followed by irradiation by a 400 W high‐pressure mercury lamp (λ > 280 nm) to form a network structure. The gel contents increased with photocuring time, reaching a level of over 90% after 10 min for all copolymers without a photoinitiator. The thermal and mechanical properties of the photocured copolymers were examined by DSC and tensile tests. In cyclic thermomechanical tensile tests, the photocured ICA/PCL/PEG copolymer films showed good shape‐memory properties at 37–60°C, with both shape fixity ratio and shape recovery ratio over 90% at a maximum tensile strain of 100–300%. The water absorption of these copolymers and their rate of degradation in a phosphate buffer solution (pH 7.0) at 37°C increased significantly with increasing PEG content. The novel photocured ICA/PCL/PEG multiblock copolymers are potentially useful in biomedical applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermosensitive soy protein/poly(n‐isopropylacrylamide) interpenetrating polymer network hydrogels for drug controlled release
Authors: Liu Yong , Cui Yingde
Published: February 2011

A series of the thermosensitive interpenetrating polymer network hydrogels composed of soy protein and poly(N‐isopropylacrylamide) were successfully prepared. The structure and properties were systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. It was found that the hydrogels had good miscibility and high porosity, and the volume phase transition temperatures of the hydrogels were around 32°C. The release behavior and the release mechanism of a model protein, bovine serum albumin (BSA), were also investigated in detail. The results indicated that the release behavior of BSA had strong temperature dependence and the release percentage of BSA could be controlled by modulating the amount of soy protein or crosslinking agent. The analysis of the release mechanism revealed that the Fickian diffusion controlled release was dominant under the experimental conditions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Poly (styrene‐n‐butyl acrylate‐methyl methacrylate)/silica nanocomposites prepared by emulsion polymerization
Authors: Rong Qianping , Zhu Aiping , Zhong Tao
Published: February 2011

Poly (styrene‐n‐butyl acrylate‐methyl methacrylate) (PSBM)/silica nanocomposite was prepared by emulsion polymerization in the presence of oleic acid surface modified nanosilica. The structure, morphology, size, and size distribution were characterized by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and dynamics laser scattering. The chemical bond was formed between PSBM and nanosilica revealed by FTIR and TEM studies. The composite particles with an averaged diameter ranging from 30 to 80 nm have the core‐shell structure. The effect of silica content on the glass transition temperature Tg, pyrolyze temperature, and rheological behavior of PSBM composites was systematically investigated. The results indicated that the addition of nanosilica could effectively inhibit chain movement, and improved the pyrolyze temperature of PSBM. The steady viscosity and dynamic modulus were strongly dependent on the content and distribution of nanosilica in PSBM nanocomposites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Monitoring nonisothermal crystallization of thermoplastic polymers using a quartz crystal resonator
Authors: Kim Byoung Chul , Maeda Kouji , Kim Young Han
Published: February 2011

A new monitoring device for the nonisothermal crystallization of thermoplastic polymers, polyethylene, polypropylene, polystyrene, and polyamide, is developed utilizing a quartz crystal resonator, and its performance is evaluated by comparing the measurements with the results of DSC thermoanalysis and microscopic observation. The experimental results of four different polymers indicate that the variation of resonant freency of the quartz crystal resonator is a good means to monitor the crystallization process. Though the measurements of melting and crystallization are close to the DSC outcome, more deviation is observed with the new device. The change in crystalline morphology during the crystallization process is also detected from the slope changes of the frequency decrease. In comparison with the microscopic observation of polymer films, it is found that the processes of nucleation and crystal growth in nonisothermal crystallization can be explained with the variation of the resonant frequency of the quartz crystal resonator. In addition, crystallization kinetics is modeled with the Avrami equation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Hydrolytic degradation of poly(ethylene terephthalate) in a pyrolytic two step process to obtain benzene rich oil
Authors: Grause Guido , Handa Tomohiko , Kameda Tomohito , Mizoguchi Tadaaki , Yoshioka Toshiaki
Published: February 2011

Poly(ethylene terephthalate) (PET) was degraded in a two step process to obtain a valuable oil, consisting mainly of benzene. First, PET was hydrolyzed in a steam atmosphere at 450°C, and the resulting terephthalic acid was decarboxylized in the presence of CaO. By separating the two fundamental reactions of this degradation process, the hydrolysis reaction and decarboxylation, the amount of residue was reduced, and the amount of benzene obtained increased. It was found that the best results were obtained at a decarboxylation temperature of 700°C, with a yield of 48% benzene. At lower temperatures, the terephthalic acid was adsorbed at the catalyst without decarboxylation; at higher temperatures, large amounts of char were formed due to pyrolytic reactions. Unlike solvolysis processes, no solvent is used in this process; in effect eliminating the expense of processing waste liquids. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and properties of novel dicyanate with low dielectric and water absorption performance
Authors: Zhang Zhongyun , Yu Ruobing , Wang Fan , Wang Jialiang , Jiao Yangsheng
Published: February 2011

The 1,4‐bis (3,5‐dimethyl‐4‐cyanatobenzyl) benzene (BBZCy) was synthesized successfully by the reaction of 1,4‐bis (3,5‐dimethyl‐4‐hydroxybenzyl)benzene(BBZ) with cyanogen chloride in the presence of triethylamine at −5–0°C. Its structure was confirmed by means of FTIR, elemental analysis, MS, and 1H NMR spectra. The monomer of BBZCy was cured by itself or cured with catalysts to form sym‐triazine structure. Thermal properties of cured BBZCy were studied using DSC, DMA, TMA, and TGA. Compared with the commercial bisphenol A dicyanate resin (BADCy), the cured BBZCy resin exhibited a lower dielectric constant (2.66 at 1 GHz), a lower dissipation factor (0.0054 at 1 GHz), lower water absorption (0.8% at 100 h), less thermal stability, and lower glass transition temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Role of choline formate ionic liquid in the polymerization of vinyl and methacrylic monomers
Authors: Sundar D. Sathish , Vijayaraghavan R. , Subramaniam J. , Surianarayanan M. , Mandal A. B
Published: February 2011

Polymerizations of vinyl and methacrylate monomers (2‐hydroxyethyl methacrylate, styrene, and methyl methacrylate) were carried out in a choline formate ionic liquid at room temperature without the addition of peroxide‐based initiators. Choline formate acted as both an initiator and a solvent and produced high‐molecular‐weight polymers. Gel permeation chromatography and electron paramagnetic resonance measurements indicated that the polymerizations predominantly occurred by a free‐radical mechanism. This method of polymerization provides an alternate route to eliminate the use of toxic initiators and solvents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and Biological Evaluation of 2′‐Oxo‐2,3‐dihydro‐3′H‐ spiro[chromene‐4,5′‐[1,3]oxazolidin]‐3′yl]acetic Acid Derivatives as Aldose Reductase Inhibitors
Authors: Rapposelli Simona , Da Settimo Federico , Digiacomo Maria , La Motta Concettina , Lapucci Annalina , Sartini Stefania , Vanni Michael
Published: February 2011

Aldose reductase (ARL2) is the first enzyme in the polyol pathway which catalyzes the NADPH‐dependent reduction of glucose to sorbitol. Its involvement on diabetic complications makes this enzyme a challenge therapeutic target widely investigated to limit and/or prevent them. On this basis, a limited series of 4‐spiro‐oxazolidinone‐benzopyran derivatives (1–7) were synthesized to evaluate them as potential ARL2 inhibitors. The activity was determined spectrophotometrically by monitoring the oxidation of NADPH catalyzed by ALR2. Within the series of compounds, the 4‐methoxy derivative 1b showed to be the most active compound, exhibiting inhibitory levels in the submicromolar range. In addition, the activity against the aldehyde reductase isoform (ARL1) was also evaluated. Unlike sorbinil (reference drug) that lack of selectivity towards the two enzyme all the tested compounds resulted to be devoid of ARL1 inhibitory activity (IC50 > 10 µM), thus proving to be selective.
Rituximab treatment induces the expression of genes involved in healing processes in the rheumatoid arthritis synovium
Authors: Gutierrez‐Roelens I. , Galant C. , Theate I. , Lories R. J. , Durez P. , Nzeusseu‐Toukap A. , Van den Eynde B. , Houssiau F. A. , Lauwerys B. R.
Published: February 2011

Objective

Rituximab displays therapeutic benefits in the treatment of patients with rheumatoid arthritis (RA) resistant to tumor necrosis factor (TNF) blockade. However, the precise role of B cells in the pathogenesis of RA is still unknown. We undertook this study to investigate the global molecular effects of rituximab in synovial biopsy samples obtained from anti‐TNF–resistant RA patients before and after administration of the drug.

Methods

Paired synovial biopsy samples were obtained from the affected knee of anti‐TNF–resistant RA patients before (time 0) and 12 weeks after (time 12) initiation of rituximab therapy. Total RNA was extracted, labeled according to standard Affymetrix procedures, and hybridized on GeneChip HGU133 Plus 2.0 slides. Immunohistochemistry and quantitative real‐time reverse transcriptase–polymerase chain reaction experiments were performed to confirm the differential expression of selected transcripts.

Results

According to Student's paired t‐tests, 549 of 54,675 investigated probe sets were differentially expressed between time 0 and time 12. Pathway analysis revealed that genes down‐regulated between time 0 and time 12 were significantly enriched in immunoglobulin genes and genes involved in chemotaxis, leukocyte activation, and immune responses (Gene Ontology annotations). In contrast, genes up‐regulated between time 0 and time 12 were significantly enriched in transcripts involved in cell development (Gene Ontology annotation) and wound healing (Gene Set Enrichment Analysis). At baseline, higher synovial expression of immunoglobulin genes was associated with response to therapy.

Conclusion

Rituximab displays unique effects on global gene expression profiles in the synovial tissue of RA patients. These observations open new perspectives in the understanding of the biologic effects of the drug and in the selection of patients likely to benefit from this therapy.
Self‐Assembly and Aggregate‐Induced Enhanced Emission of Amphiphilic Fluorescence Dyes in Water and in the Solid State
Authors: Hirose Takashi , Higashiguchi Kenji , Matsuda Kenji
Published: February 2011

1‐Cyano‐1,2‐bis(biphenyl)ethene (CNBE) derivatives with a hexa(ethylene glycol) group as an amphiphilic side chain were synthesized and the self‐assembling character and fluorescence behavior were investigated. The amphiphilic derivatives showed aggregate‐induced enhanced emission (AIEE) in water and in the solid state. The fluorescence quantum yield increased as the rigidity of the aggregates increased (i.e., in ethyl acetate<in water<in the solid state). As determined from measurements of fluorescence spectra, fluorescence quantum yields, and fluorescence lifetimes, a key factor for the enhanced emission is suppression of the nonradiative decay process arising from restricted molecular motion. Additionally, the difference in the emission rate constant is not negligible and can be used to interpret the difference in fluorescence quantum yield in water and in the solid state.
Facile Preparation of Homo‐ and Hetero‐Dimetallic Complexes with a 4‐Phosphino‐Substituted NHC Ligand. Toward the Design of Multifunctional Catalysts
Authors: Mendoza‐Espinosa Daniel , Donnadieu Bruno , Bertrand Guy
Published: February 2011

A series of bimetallic complexes have been synthesized that are supported by a 4‐phosphino‐substituted NHC ligand. The use of this stable ligand reduces the number of synthetic steps and allows for a wide range of metal combinations to be introduced into the complexes.
Stabilization of nonlinear networked probabilistic interval delay systems with sensor random packet dropout
Authors: Zhang Yong , Fang Huajing , Wang Baoxian
Published: February 2011

In this paper, the problem of stabilization for nonlinear networked systems with probabilistic interval delay and sensor random packet dropout is investigated. By employing the information of probabilistic distribution of time‐varying delay and considering random sensor packet dropout with compensation, the nonlinear stochastic delayed system model is established. Based on the obtained model, by choosing an appropriate Lyapunov function and utilizing a new discrete Jensen‐type inequality, sufficient conditions are derived to obtain the relation of the maximum allowable delay bound, delay interval occurrence rate and packet dropout rate to the stochastic stability of nonlinear networked control systems. Two kinds of design procedures for output feedback controller are also presented in terms of solving corresponding linear matrix inequalities. Numerical examples are provided to illustrate the effectiveness and applicability of proposed techniques.

Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Intraseasonal variability in the South American monsoon system
Authors: Ferreira Solange Aragão , Gan Manoel Alonso
Published: February 2011

The active and break periods of the South America monsoon system (SAMS) were determined based on a monsoon rainfall index (MRI) for the three wettest months. The precipitation composite for active cases shows a pattern similar to the average summer rainfall. The wind circulation composite presents a strong northwesterly flow from the western Amazon to southeastern Brazil. During the active (break) periods, an intense (weak) moisture flux convergence occurs over the Amazon basin, southeastern and central‐western Brazil. The intense moisture convergence over these regions during the active periods is a typical feature of the South Atlantic convergence zone (SACZ) system. Copyright © 2011 Royal Meteorological Society
Power calculation for gravitational radiation: oversimplification and the importance of time scale
Authors: Whiting A.B.
Published: February 2011

A simplified formula for gravitational‐radiation power is examined. It is shown to give completely erroneous answers in three situations, making it useless even for rough estimates. It is emphasised that short timescales, as well as fast speeds, make classical approximations to relativistic calculations untenable (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The solar photospheric abundance of zirconium
Authors: Caffau E. , Faraggiana R. , Ludwig H.‐G. , Bonifacio P. , Steffen M.
Published: February 2011

Zirconium (Zr), together with strontium and yttrium, is an important element in the understanding of the Galactic nucleosynthesis. In fact, the triad Sr‐Y‐Zr constitutes the first peak of s‐process elements. Despite its general relevance not many studies of the solar abundance of Zr were conducted. We derive the zirconium abundance in the solar photosphere with the same CO5BOLD hydrodynamical model of the solar atmosphere that we previously used to investigate the abundances of C‐N‐O. We review the zirconium lines available in the observed solar spectra and select a sample of lines to determine the zirconium abundance, considering lines of neutral and singly ionised zirconium. We apply different line profile fitting strategies for a reliable analysis of Zr lines that are blended by lines of other elements. The abundance obtained from lines of neutral zirconium is very uncertain because these lines are commonly blended and weak in the solar spectrum. However, we believe that some lines of ionised zirconium are reliable abundance indicators. Restricting the set to Zr II lines, from the CO5BOLD 3D model atmosphere we derive A (Zr) = 2.62 ± 0.06, where the quoted error is the RMS line‐to‐line scatter (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elemental abundance analyses with DAO spectrograms: XXXIII. β UMa (A0mA1 IV‐V), α Dra (A0 III), π Dra (A2 IIIs), and κ Cep (B9 III)
Authors: Adelman S.J. , Yu K. , Gulliver A.F.
Published: February 2011

This paper presents extended analyses of β UMa (A0mA1 IV‐V), α Dra (A0 III), π Dra (A2 IIIs), and κ Cep (B9 III) which have previously been studied in this series. α Dra is a metal‐poor star while κ Cep has solar abundances. Both β UMa and π Dra are Am stars. Whenever possible, more accurate and precise gf values replace older values. High S/N (200+) and high dispersion Dominion Astrophysical Observatory spectrograms to the red of previously obtained spectra supplement the observations. The derived rotational velocities are 45, 25, 26, and 23 km s–1, respectively. These LTE fine analyses use the ATLAS9 and the WIDTH9 programs of R. L. Kurucz. The results of the extended and the previous analyses are in good agreement. Thus in the past decade a significant improvement in the system of gf values has not been achieved although for many lines there have been changes. The use of additional regions has increased the quality of some results (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Composite spectra: XVII. 12 Comae, a member of the Coma open cluster
Authors: Griffin R.E.M. , Griffin R.F.
Published: February 2011

The components of binary stars offer the potential to examine the predictions of stellar‐evolution theory with particularly tight constraints. Those constraints are further tightened when the binary belongs to a cluster whose properties have been well determined independently. 12 Comae presents both advantages, belonging as it does to the Coma Cluster, Melotte 111. The orbit of 12 Comae has an eccentricity of nearly 0.6 and a period of 13 months. By a process of subtraction we separate the spectra of the component stars, derive a precise double‐lined orbit solution, and by modelling the photometry we extract the individual stellar photometric and physical properties, ages and rotation. By fitting theoretical evolutionary tracks to the positions of the stars in the H‐R diagram we confirm their individual masses, and derive a ZAMS of ∼0.65 Gyr, which accords well with measurements published for the cluster itself. We show that the primary of 12 Comae is an evolving giant of spectral type ∼G7 and mass 2.6 M⊙, while its secondary (whose spectrum could be isolated particularly cleanly) is an A3 dwarf which has a mass of 2.05 M⊙ and has commenced its evolution away from the main sequence. There is evidence that both stars are slightly metal‐weak (–0.25 < [Fe/H] < 0.0), well in keeping with analyses of other members of this cluster (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First detection of a magnetic field in the fast rotating runaway Oe star ζ Ophiuchi
Authors: Hubrig S. , Oskinova L.M. , Schöller M.
Published: February 2011

The star ζ Ophiuchi is one of the brightest massive stars in the northern hemisphere and was intensively studied in various wavelength domains. The currently available observational material suggests that certain observed phenomena are related to the presence of a magnetic field. We acquired spectropolarimetric observations of ζ Oph with FORS 1 mounted on the 8‐m Kueyen telescope of the VLT to investigate if a magnetic field is indeed present in this star. Using all available absorption lines, we detect a mean longitudinal magnetic field 〈Bz〉all = 141 ± 45 G, confirming the magnetic nature of this star. We review the X‐ray properties of ζ Oph with the aim to understand whether the X‐ray emission of ζ Oph is dominated by magnetic or by wind instability processes (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of increasing swelling and anionic charges on the enzymatic hydrolysis of organosolv‐pretreated softwoods at low enzyme loadings
Authors: Del Rio Luis F. , Chandra Richard P. , Saddler John N.
Published: February 2011

Organosolv‐pretreated Lodgepole pine substrates were physically and chemically treated to increase their hydrophilicity and swelling as these are two substrate attributes which have been shown to improve cellulolytic hydrolysis. Surprisingly, mechanical treatment of the organosolv‐treated substrates by PFI‐mill refining did not significantly increase hydrolysis yields despite decreases in particle size and crystallinity and increases in swelling. However, sulfonation of the substrate did, significantly, increase enzymatic hydrolysis at loadings of both 5 and 2.5 FPU g−1 cellulose (from 80% to 95% and from 35% to 80%, respectively). In addition, sulfonation resulted in an increase in the amount of free enzymes detected during the course of hydrolysis to a maximum of 80% after 72 h. This suggested that the beneficial effects of sulfonation were primarily due to a decrease in the non‐specific binding of the cellulases to the lignin. Biotechnol. Bioeng. 2011; 108:1549–1558. © 2011 Wiley Periodicals, Inc.
Enzymatic transformations of cellulose assessed by quantitative high‐throughput fourier transform infrared spectroscopy (QHT‐FTIR)
Authors: Corgié Stéphane C. , Smith Hanna M. , Walker Larry P.
Published: February 2011

Enzymatic hydrolysis of bacterial microcrystalline cellulose was performed with the thermophile enzyme system of Thermobifida fusca Cel5A (a classical endocellulase), Cel6B (a classical exocellulase), Cel9A (a processive endoglucanase), and a synergistic mixture of endo‐ and exocellulases. Different concentrations of enzymes were used to vary the extent of hydrolysis. Following standardization, the concentration of cellulose was directly correlated to the absorbance of the cellulose signals. Crystallinity indexes (Lateral Order Index (LOI), Total Crystallinity Index, Hydrogen Bonding Index), allomorphic composition, conversion of specific atomic bonds (including the β‐glucosidic bonds) were extracted from the spectral data obtained by QHT‐FTIR. By quantifying the disruption of the H‐bonding in complement to the sugar production, a more dynamic and complex picture of the role of cellulases in the hydrolysis of cellulose was demonstrated. The disruption of the H‐bonding within the cellulose matrix appears as a quantifiable activity of the enzymes which was not correlated with the production of sugars in solution. The results also demonstrate that Cel9A activities from the cellulose transformation standpoint were partially similar to the activities of the synergistic mixture. In addition, Cel9A preferentially degraded the Iα fraction of the crystalline cellulose while the Cel5A and Cel6B synergistic mixture preferentially degraded the Iβ fraction. Biotechnol. Bioeng. 2011; 108:1509–1520. © 2011 Wiley Periodicals, Inc.
Chemostat‐based transcriptional analysis of growth rate change and BCL‐2 over‐expression in NS0 cells
Authors: Krampe Britta , Fagan Ailís , Gaora Peadar Ó. , Al‐Rubeai Mohamed
Published: February 2011

We investigated the transcriptional response of NS0 cells undergoing controlled nutrient growth change in continuous chemostat culture using mouse microarrays. A 50% reduction in growth rate resulted in detectable alterations in the expression of 29 genes in NS0 cells. Notably, expression of genes in three major biological processes, namely transcriptional, translational, and protein processing functions, were modified. To further elucidate the advantage of the chemostat environment for establishment of “omic” data sets, an expression profile of the over‐expressed gene bcl‐2 in NS0 cells was probed. Functional analysis revealed that the underlying altered molecular mechanism was particularly associated with G1 cell cycle progression, protein synthesis, and apoptosis. Importantly, these findings agreed with the physical function of the cells. Despite an increase in survival rate, bcl‐2 over‐expression resulted in a decrease of specific productivity, glucose consumption, oxygen uptake rate and intracellular protein content, indicating a lower energy generating metabolism. Further, a prolongation of G1 cell cycle phase was evident on lowering the growth rate. Overall, the application of microarray analysis to chemostat‐grown cultures offers an excellent combination for the interpretation of transcriptomic profiles to elucidate the molecular mechanisms during nutrient growth change and bcl‐2 over‐expression. Biotechnol. Bioeng. 2011; 108:1603–1615. © 2011 Wiley Periodicals, Inc.
Application of a dense gas technique for sterilizing soft biomaterials
Authors: Karajanagi Sandeep S. , Yoganathan Roshan , Mammucari Raffaella , Park Hyoungshin , Cox Julian , Zeitels Steven M. , Langer Robert , Foster Neil R.
Published: February 2011

Sterilization of soft biomaterials such as hydrogels is challenging because existing methods such as gamma irradiation, steam sterilization, or ethylene oxide sterilization, while effective at achieving high sterility assurance levels (SAL), may compromise their physicochemical properties and biocompatibility. New methods that effectively sterilize soft biomaterials without compromising their properties are therefore required. In this report, a dense‐carbon dioxide (CO2)‐based technique was used to sterilize soft polyethylene glycol (PEG)‐based hydrogels while retaining their structure and physicochemical properties. Conventional sterilization methods such as gamma irradiation and steam sterilization severely compromised the structure of the hydrogels. PEG hydrogels with high water content and low elastic shear modulus (a measure of stiffness) were deliberately inoculated with bacteria and spores and then subjected to dense CO2. The dense CO2‐based methods effectively sterilized the hydrogels achieving a SAL of 10−7 without compromising the viscoelastic properties, pH, water‐content, and structure of the gels. Furthermore, dense CO2‐treated gels were biocompatible and non‐toxic when implanted subcutaneously in ferrets. The application of novel dense CO2‐based methods to sterilize soft biomaterials has implications in developing safe sterilization methods for soft biomedical implants such as dermal fillers and viscosupplements. Biotechnol. Bioeng. 2011; 108:1716–1725. © 2011 Wiley Periodicals, Inc.