bluuebunny/crossref_metadata_2025 huggingface dataset:
Homocysteine‐lowering therapy or antioxidant therapy for bone loss in Parkinson's disease
Authors: Lee Seung Hun , Kim Mi Jung , Kim Beom‐Jun , Kim Sung Reul , Chun Sail , Ryu Jin Sook , Kim Ghi Su , Lee Myoung Chong , Koh Jung‐Min , Chung Sun Ju
Published: November 2009

We investigated whether homocysteine (Hcy)‐ lowering therapy or an antioxidant prevented bone loss in Parkinson's disease (PD) patients taking levodopa. Forty‐two PD patients with low bone mineral density (BMD) taking levodopa were randomly assigned to Hcy‐lowering therapy (5 mg folate and 1500 μg vitamin B12 daily), α‐lipoic acid (α‐LA) therapy (1200 mg daily), or control groups. Primary outcomes were BMD changes from baseline to 12 months. Secondary outcomes were changes in Hcy level, and C‐telopeptide (CTX) levels at 12 months. Forty‐one patients completed the study. Hcy‐lowering therapy resulted in significantly greater BMD changes at the lumbar spine (4.4%), total femur (2.8%), and femur shaft (2.8%) than control (P = 0.005–0.023). BMD changes in the α–LA therapy group were similar to those of the control group, but changes at the trochanter (4.6%) were significantly greater in the α–LA therapy group than in the control group after adjustment for body mass index changes. Hcy concentrations decreased to 35.2% ± 13.4% in the Hcy‐lowering therapy group, but increased in other groups. Serum CTX levels at 12 months tended to be lower in the Hcy‐lowering group (0.442 ± 0.024 ng/mL) than control group (0.628 ± 0.039 ng/mL) (P = 0.159). This small trial suggests that Hcy‐lowering therapy may prevent bone loss in PD patients taking levodopa. © 2009 Movement Disorder Society
Obstacle avoidance to elicit freezing of gait during treadmill walking
Authors: Snijders Anke H. , Weerdesteyn Vivian , Hagen Yolien J. , Duysens Jacques , Giladi Nir , Bloem Bastiaan R.
Published: November 2009

Freezing of gait (FOG) is a common and disabling feature of Parkinson's disease (PD). Detailed pathophysiological studies are hampered by the fact that FOG episodes are difficult to elicit in a gait laboratory. We evaluated whether the need to avoid sudden obstacles on a treadmill can provoke FOG. We included 21 PD patients (15 with self‐reported off‐period FOG). Patients were tested in the off‐state. FOG during overground walking was assessed using a standardized gait trajectory and axial 360° turns. Subsequently, patients walked on a motorized treadmill with suddenly appearing obstacles that necessitated compensatory stepping. Performance was videotaped, and presence of FOG was scored visually by two independent raters. Thirteen patients showed FOG during overground walking. During treadmill walking, obstacle avoidance was associated with 13 unequivocal FOG episodes in eight patients, whereas only one patient froze during undisturbed treadmill walking (Wilcoxon z = −2.0, P = 0.046). FOG episodes elicited by obstacle avoidance were brief (typically <1 s). Almost all episodes were provoked when subjects had a longer available response time. In conclusion, suddenly appearing obstacles on a treadmill can elicit FOG in a controlled laboratory setting. However, the moving treadmill and the obstacle both act as cues, which apparently help to immediately overcome the provoked FOG episode. This may limit the ecological validity of this new approach. © 2009 Movement Disorder Society
β‐Sitosterol exhibits anti‐inflammatory activity in human aortic endothelial cells
Authors: Loizou Stella , Lekakis Ioannis , Chrousos George P. , Moutsatsou Paraskevi
Published: November 2009

β‐Sitosterol, normally present in vegetable‐containing diets, comprises an important component of cholesterol controlling functional foods. It has been associated with cardiovascular protection, exerting its effect mainly through increasing the antioxidant defense system and effectively lowering the serum cholesterol levels in humans. However, its anti‐inflammatory effect on endothelium is unknown. Attachment of leukocytes to the vascular endothelium and the subsequent migration of cells into the vessel wall are early events in atherogenesis, this process requiring the expression of endothelial adhesion molecules. We examined the effect of β‐sitosterol (0.1–200 μM) on (i) the expression of vascular adhesion molecule 1 and intracellular adhesion molecule 1 by cell ELISA and (ii) the attachment of monocytes (U937 cells) in tumor necrosis factor‐α (TNF‐α)‐stimulated human aortic endothelial cells (HAECs) by adhesion assay. The effect on nuclear factor‐kB phosphorylation was also examinedviaa cell‐based ELISA kit. Results showed that β‐sitosterol inhibits significantly vascular adhesion molecule 1 and intracellular adhesion molecule 1 expression in TNF‐α‐stimulated HAEC as well as the binding of U937 cells to TNF‐α‐stimulated HAEC and attenuates the phosphorylation of nuclear factor‐kB p65. This study extends existing data regarding the cardioprotective effect of β‐sitosterol and provides new insights into understanding the molecular mechanism underlying the beneficial effect of β‐sitosterol on endothelial function.
Measurement of caffeic and ferulic acid equivalents in plasma after coffee consumption: Small intestine and colon are key sites for coffee metabolism
Authors: Renouf Mathieu , Guy Philippe A. , Marmet Cynthia , Fraering Anne‐Lise , Longet Karin , Moulin Julie , Enslen Marc , Barron Denis , Dionisi Fabiola , Cavin Christophe , Williamson Gary , Steiling Heike
Published: November 2009

Previous studies on coffee examined absorption of phenolic acids (PA) in the small intestine, but not the contribution of the colon to absorption. Nine healthy volunteers ingested instant soluble coffee (∼335 mg total chlorogenic acids (CGAs)) in water. Blood samples were taken over 12 h, and at 24 h to assess return to baseline. Many previous studies, which used glucuronidase and sulfatase, measured only PA and did not rigorously assess CGAs. To improve this, plasma samples were analyzed after full hydrolysis by chlorogenate esterase, glucuronidase and sulfatase to release aglycone equivalents of PA followed by liquid–liquid extraction and ESI‐LC‐ESI‐MS/MS detection. Ferulic, caffeic and isoferulic acid equivalents appeared rapidly in plasma, peaking at 1–2 h. Dihydrocaffeic and dihydroferulic acids appeared in plasma 6–8 h after ingestion (Tmax=8–12 h). Substantial variability in maximum plasma concentration and Tmax was also observed between individuals. This study confirms that the small intestine is a significant site for absorption of PA, but shows for the first time that the colon/microflora play the major role in absorption and metabolism of CGAs and PA from coffee.
Cucurbitacin B induces G2 arrest and apoptosis via a reactive oxygen species‐dependent mechanism in human colon adenocarcinoma SW480 cells
Authors: Yasuda Shusuke , Yogosawa Shingo , Izutani Yasuyuki , Nakamura Yoshitaka , Watanabe Hirotsuna , Sakai Toshiyuki
Published: November 2009

Cucurbitacin B (cucB) is a triterpenoid constituent of Cucurbitaceae vegetables and a promising phytochemical for cancer prevention. However, the mechanism of anti‐tumor activity of cucB remains unknown, especially in colon cancers. Here, we demonstrate for the first time that cucB inhibited growth of human colon cancer SW480 cells through a reactive oxygen species (ROS)‐dependent mechanism. CucB induced G2 phase arrest and apoptosis in a dose‐dependent manner. At the molecular level, cucB reduced the expression of cyclin B1 and cdc25C proteins and activated caspases in SW480 cells. On the other hand, the state of phosphorylation of signaling transducer and activator of transcription 3 (STAT3) was unchanged. We found that cucB increased intracellular ROS levels, and N‐acetylcysteine, a well‐known antioxidant, reduced the changes in expression of the molecules, and suppressed both G2 arrest and apoptosis. These results suggested that cucB induced G2 arrest and apoptosis through a STAT3‐independent but ROS‐dependent mechanism in SW480 cells.
Theoretical and experimental 1H, 13C and 15N NMR studies of N‐alkylation of substituted tetrazolo[1,5‐a]pyridines
Authors: Berionni Guillaume , Pégot Bruce , Goumont Régis
Published: November 2009

The 15N as well as 1H and 13C chemical shifts of nine substituted tetrazolopyridines and their corresponding tetrazolopyridinium salts have been determined by using NMR spectroscopy at the natural abundance level of all nuclei in CD3CN. In this paper, we report, for the first time, the N‐alkylation reaction of electron deficient tetrazolopyridines. The treatment of tetrazolopyridines 5–13 with one equivalent of trialkyloxonium tetrafluoroborate leads to a mixture of two isomers, i.e. N3‐ and N2‐alkyl tetrazolo[1,5‐a]pyridinium salts. It has been observed that the N3‐isomer is always the major isomer, except in the case of the CF3 substituent, where the two isomers are obtained in the same amount. The quaternary tetrazolopyridinium nitrogen N3 is shielded by around 100 ppm (parts per million) with respect to the parent tetrazolopyridine. Experimental data are interpreted by means of density functional theory (DFT) calculations, including solvent‐induced effects, within the conductor‐like polarizable continuum model (CPCM). Good agreements between theoretical and experimental 1H, 13C and 15N NMR were found. The combination of multinuclear magnetic resonance spectroscopy with gauge including atomic orbital (GIAO) DFT calculations is a powerful tool in the structural elucidation for both neutral and cationic heterocycles and in the determination of the orientation of N‐alkylation of tetrazolopyridines. Copyright © 2009 John Wiley & Sons, Ltd.
Finite deformation formulation for embedded frictional crack with the extended finite element method
Authors: Liu Fushen , Borja Ronaldo I.
Published: November 2009

We reformulate an extended finite element (FE) framework for embedded frictional cracks in elastoplastic solids to accommodate finite deformation, including finite stretching and rotation. For the FE representation, we consider a Galerkin approximation in which both the trial and weighting functions adapt to the current contact configuration. Contact and frictional constraints employ two Kuhn–Tucker conditions, a contact/separation constraint nesting over a stick/slip constraint for the case when the crack faces are in frictional sliding mode. We integrate finite deformation bulk plasticity into the formulation using the multiplicative decomposition technique of nonlinear continuum mechanics. We then present plane strain simulations demonstrating various aspects of the extended FE solutions. The mechanisms considered include combined opening and frictional sliding in initially straight, curved, and S‐shaped cracks, with and without bulk plasticity. To gain further insight into the extended FE solutions, we perform mesh convergence studies focusing on both the global and the local responses of structures with cracks, including the distribution of the normal component of traction on the crack faces. Copyright © 2009 John Wiley & Sons, Ltd.
Factors associated with medicine use among children aged under 12 years—a population survey in Finland
Authors: Hämeen‐Anttila Katri , Lindell‐Osuagwu Leena , Sepponen Kati , Vainio Kirsti , Halonen Pirjo , Ahonen Riitta
Published: November 2009

Purpose

The goal was to determine the prevalence of medicine use and to provide population‐based information on factors associated with medicine use, including prescribed and over‐the‐counter (OTC) medicines, in children aged under 12 years.

Methods

A cross‐sectional population survey of a random sample of children aged under 12 years (n = 6000) was carried out in Finland in spring 2007, with a response rate of 67%. A questionnaire was sent to their parents. Current use of medicines prescribed by a physician and use of OTC medicines during the preceding two days were the main outcome measures.

Results

The prevalence of current prescribed medicine use was 17%, and the 2‐day prevalence of OTC medicine use 17% (vitamins excluded). The use of prescribed medicines was higher among children with illnesses diagnosed by a physician. Additionally, predictors for the use of prescribed medicines were young age among boys, health status worse than good, and the use of any prescribed medicines by a parent. The predictors for the use of OTC medicines by the child were young age and fairly good to poor health status, and the use of OTC medicines by a parent. However, children with any illnesses diagnosed by a physician were less likely to use OTC medicines.

Conclusions

A considerable proportion of children use prescription and OTC medicines in Finland. Young age and health‐related factors, morbidity and health status, and parental medicine use predicted children's medicine use. Further studies are needed to examine the association between parents' and children's medicine use. Copyright © 2009 John Wiley & Sons, Ltd.
Right‐wing authoritarianism, Big Five and perceived threat to safety
Authors: Dallago Francesca , Roccato Michele
Published: November 2009

Using structural equations modelling, we performed a secondary analysis of the data collected by the Italian Observatory of the North West (Italian national sample, N = 976) to investigate the direct, mediated and moderated relations connecting the Big Five personality factors and perceived personal and societal threat to safety with right‐wing authoritarianism (RWA). Openness, Conscientiousness and perceived societal threat to safety exerted additive effects on RWA; the relation between Openness and RWA was partially mediated by societal threat to safety and that between societal threat to safety and RWA was moderated by Openness. Limitations and possible developments of this research are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of electron beam irradiation on the crystallization of silk fibroin fiber‐reinforced poly(ε‐caprolactone) biocomposites
Authors: Qiao Xiuying , Li Wei , Sun Kang , Chen Xiaodong
Published: November 2009

In the medical industry, ionizing radiation has attracted increasing interest in recent years for the sterilization of biomedical materials due to its high effectiveness at relatively low cost and simple operation. In the study reported here, silk fibroin (SF) fiber was used to prepare novel reinforced poly(ε‐caprolactone) (PCL) biocomposites, and the effect of electron beam irradiation on both non‐isothermal and isothermal crystallization kinetics of the SF/PCL biocomposites was investigated. The models of Ozawa treatment, Avrami analysis and regime theory of crystal growth are applicable for describing the non‐isothermal and isothermal crystallization kinetics of the irradiated PCL and SF/PCL composites. Compared with non‐irradiated PCL and SF/PCL composites, the irradiated specimens exhibit the same crystallization regime (regime II) and similar lateral surface free energy (σ), except for smaller fold surface free energy (σe) and work of chain folding (q). The crosslinked PCL network formed in the irradiation process can act as a nucleation agent and accelerate the primary crystallization of PCL. However, the restriction effect of the crosslinked PCL network on the molecular chain mobility will reduce the overall crystallization rate of PCL, and this restriction effect appears stronger in the non‐isothermal crystallization process than in the isothermal crystallization process. Copyright © 2009 Society of Chemical Industry
Ethylene–propylene copolymer/ordered polysilsesquioxane nanocomposites prepared via organic acid‐ or base‐catalyzed binary silica water‐crosslinking reactions
Authors: Adachi Kenta , Hirano Tomoyuki , Kasai Paul H , Nakamae Katsuhiko , Iwabuki Hitoshi , Murakami Koji
Published: November 2009

In situ silica sol–gel‐derived organic–inorganic hybrid materials, which comprise a vinyltrimethoxysilane‐grafted ethylene–propylene copolymer (EPR‐g‐VTMS) and n‐hexyltrimethoxysilane (HTMS), were successfully prepared in the presence of an organic acid and base catalyst. Benzenesulfonic acid and aniline were selected as the organic acid and base catalyst, respectively, to examine the progress and effect of progressive changes in the silane water‐crosslinking reaction of EPR‐g‐VTMS/HTMS composites. The water‐crosslinked EPR‐g‐VTMS/HTMS composites were characterized by means of attenuated total reflectance Fourier transform infrared spectroscopy, gel content, solid‐state 29Si cross‐polarization/magic‐angle spinning NMR, wide‐angle X‐ray scattering, tensile strength and field‐emission scanning electron microscopy measurements. These results revealed that the type of catalyst has a substantial influence on the nature of siloxane bonds and eventually the physical tensile properties of the water‐crosslinked EPR‐g‐VTMS/HTMS composites, which can be explained mainly from knowledge of the traditional acid‐ and base‐catalyzed silica sol–gel reaction. Moreover, an in‐depth analysis of the aniline‐catalyzed composites indicated the formation of ladder‐type poly(n‐hexylsilsesquioxane)s and the presence of a highly ordered structure with a thickness equal to the length of two n‐hexyl groups in all‐trans conformation. We demonstrate potential for the future design of highly ordered silicate‐based organic–inorganic hybrid nanocomposites. Copyright © 2009 Society of Chemical Industry
Origin of significant solvent effects on 1J(CC) spin–spin coupling in some acetylenes: hydrogen bonding and solvent polarity
Authors: Biedrzycka Zenobia , Kamieńska‐Trela Krystyna , Witanowski Michał
Published: November 2009

It is demonstrated that some acetylenes, those of the RCCH structure, display anomalously high sensitivity to solvent effects of their 1J(CC) coupling while RCCR acetylenes fail to show that. The solvent‐induced variation in the latter coupling does not exceed 3 Hz; this seems to be the upper limit of variation of any J(CC) and J(CH) coupling in the molecular system studied which included: acetylene (in 13 solvents), phenylacetylene (in 12 solvents), 1‐phenylpropyne, and 2‐hexyne (two solvents each), and the only exceptions are 1J(CC) in acetylene, which is shown to vary within about 13 Hz, and that in phenylacetylene where the range amounts to about 8 Hz. These apparent anomalies are explained in the present study in terms of two effects of prime importance, solvent polarity and the solute‐to‐solvent hydrogen bonds where the CH moiety in RCCH acetylenes acts as a donor of hydrogen bonds to acceptor sites in the solvent concerned. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of well‐defined PNIPAM‐b‐(PEA‐g‐P2VP) double hydrophilic graft copolymer via sequential SET‐LRP and ATRP and its “schizophrenic” Micellization behavior in aqueous media
Authors: Feng Chun , Li Yongjun , Yang Dong , Li Yaogong , Hu Jianhua , Zhai Sujuan , Lu Guolin , Huang Xiaoyu
Published: November 2009

A series of well‐defined double hydrophilic graft copolymers, consisting of poly(N‐isopropylacrylamide)‐b‐poly(ethyl acrylate) backbone and poly(2‐vinylpyridine) side chains, were synthesized by successive single‐electron‐transfer living radical polymerization (SET‐LRP) and atom transfer radical polymerization (ATRP). The backbone was prepared by sequential SET‐LRP of N‐isopropylacrylamide and 2‐hydroxyethyl acrylate at 25 °C using CuCl/tris(2‐(dimethylamino)ethyl)amine as the catalytic system. The obtained diblock copolymer was transformed into the macroinitiator by reacting with 2‐chloropropionyl chloride. Next, grafting‐from strategy was used for the synthesis of poly(N‐isopropylacrylamide)‐b‐[poly(ethyl acrylate)‐g‐poly(2‐vinylpyridine)] double hydrophilic graft copolymer. ATRP of 2‐vinylpyridine was initiated by the macroinitiator at 25 °C using CuCl/hexamethyldiethylenetriamine as the catalytic system. The synthesis of both the backbone and the side chains are controllable. Thermo‐ and pH‐responsive schizophrenic micellization behaviors were investigated by 1H NMR, fluorescence spectroscopy, dynamic light scattering, and transmission electron microscopy. Unimolecular micelles with PNIPAM‐core formed in acidic environment (pH = 2) with elevated temperature (T ≥ 32 °C), whereas the aggregates turned into spheres with PEA‐g‐P2VP‐core accompanied with the lifting of pH values (pH ≥ 5.3) at room temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 15–23, 2010
Making “smart polymers” smarter: Modern concepts to regulate functions in polymer science
Authors: Börner Hans G. , Kühnle Hans , Hentschel Jens
Published: November 2009

This highlight summarizes recent attempts and advances of macromolecular sciences to abstract the biological concept of regulation and import it into synthetic polymer systems. The differences of “responsive switching” exploited in smart polymers and “regulation” present in the biological world of proteins are evident. Therefore, the biomimetic regulation might advance the possibilities of polymer science beyond these of established “smart polymers” and makes precise regulation of functions through signaling events, signal transduction and even complex regulative circuits possible. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1–14, 2010
A minimal amount of acrylonitrile turns the nitroxide‐mediated polymerization of methyl methacrylate into an almost ideal controlled/living system
Authors: Nicolas Julien , Brusseau Ségolène , Charleux Bernadette
Published: November 2009

Nitroxide‐mediated controlled/living free‐radical polymerization of methyl methacrylate initiated by the SG1‐based alkoxyamine BlocBuilder was successfully performed in bulk at 80–99 °C with the help of a very small amount of acrylonitrile (AN, 2.2–8.8 mol %) as a comonomer. Well‐defined PMMA‐rich P(MMA‐co‐AN) copolymers were prepared with the number‐average molar mass, Mn, in the 6.1–32 kg mol−1 range and polydispersity indexes as low as 1.24. Incorporation of AN in the copolymers was demonstrated by 1H and 13C NMR spectroscopy, and its effect on the chain thermal properties was evaluated by DSC and TGA analyses. Investigation of chain‐end functionalization by an alkoxyamine group was performed by means of 31P NMR spectroscopy and chain extensions from a P(MMA‐co‐AN)‐SG1 macroinitiator. It demonstrated the very high proportion of SG1‐terminated polymer chains, which opened the door to block copolymer synthesis with a high quality of control. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 34–47, 2010
Photoresponsive oil sorbers
Authors: Kulawardana Erandimala U. , Neckers Douglas C.
Published: November 2009

A photoresponsive oil sorber (POS) with a hydrophobic, photoresponsive core and shell has been synthesized via suspension polymerization. Lauryl acrylate, isodecyl acrylate, and tert‐butylstyrene were used as monomers, 4‐(methacrylamino)azobenzene (Azo‐M) used as photoresponsive monomer, and bis(methacryloylamino)azobenzene (Azo‐CL‐M) used as photoresponsive surface crosslinker. The POS prefers nonpolar solvents. It absorbed 15 times its dry weight in toluene, 19 times its dry weight in chloroform, and 16 times its dry weight in dichloromethane. Rapid and photoresponsive desorption of solvent (86% of solvent expulsed in 30 min) was characteristic. POS is an excellent gasoline absorber rapidly increasing its body weight in its presence. The new POS is less dense than water, and can potentially be used for cleaning oil spills on water. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 55–62, 2010
Copolymerization of vinylidene fluoride and acrylic acid in supercritical carbon dioxide
Authors: Firetto Vanessa , Scialdone Onofrio , Silvestri Giuseppe , Spinella Alberto , Galia Alessandro
Published: November 2009

The free‐radical copolymerization of vinylidene fluoride (VDF) and acrylic acid (AA) was carried out in supercritical carbon dioxide using both precipitation and dispersion techniques in the presence of an ammonium carboxylate perfluoropolyether compound. Formation of a copolymer was confirmed by variable contact time CP MAS NMR spectroscopy. Macromolecular matrices were significantly enriched in AA with respect to the initial feed composition and we found that the nonfluorinated monomer has a much higher reactivity ratio with respect to VDF. The cumulative concentration, crystallinity, and water affinity of the synthesized copolymers could be modified changing the initial feed composition, the density of the polymerization mixture, the specific interfacial area of the polymer phase, and the polymerization time. The solubility of the macromolecular product in water was greatly affected by its composition. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 109–121, 2010
Investigation of nitrogen‐rich energetic polymers based on alkylbridged bis‐(1‐methyl‐tetrazolylhydrazines)
Authors: Klapötke Thomas M. , Sproll Stefan M.
Published: November 2009

Nitrogen‐rich energetic polymers were synthesized by the polyaddition reaction of 1,2‐bis(5‐monomethylhydrazinyl‐1H‐tetrazolyl)ethane (1a), 1‐methyl‐1,2‐bis(5‐monomethylhydrazinyl‐1H‐tetrazolyl)ethane (1b), and 1,4‐bis(5‐mono‐methylhydrazinyl‐1H‐tetrazolyl)butane (1c) with hexamethylene diisocyanate. The experiments showed that neither a polymerization from solution or bulk was possible. Therefore, a new method for the polymerization of tetrazolyl hydrazines had to be developed. The formed polymers were characterized by vibrational spectroscopy (IR) and elemental analysis. The energetic properties were investigated by bomb calorimetric measurements along with calculations using the EXPLO5 software. The thermal stability was investigated by DSC measurements. The properties render the polymers into promising compounds regarding an application as energetic binder. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 122–127, 2010
Microwave‐assisted derivatization of cellulose in an ionic liquid: An efficient, expedient synthesis of simple and mixed carboxylic esters
Authors: Possidonio Shirley , Fidale Ludmila C. , El Seoud Omar A.
Published: November 2009

Microwave (MW)‐assisted cellulose dissolution in ionic liquids (ILs) has routinely led either to incomplete biopolymer solubilization, or its degradation. We show that these problems can be avoided by use of low‐energy MW heating, coupled with efficient stirring. Dissolution of microcrystalline cellulose in the IL 1‐allyl‐3‐methylimidazolium chloride has been achieved without changing its degree of polymerization; regenerated cellulose showed pronounced changes in its index of crystallinity, surface area, and morphology. MW‐assisted functionalization of MCC by ethanoic, propanoic, butanoic, pentanoic, and hexanoic anhydrides has been studied. Compared with conventional heating, MW irradiation has resulted in considerable decrease in dissolution and reaction times. The value of the degree of substitution (DS) was found to be DSethanoate > DSpropanoate > DSbutanoate. The values of DSpentanoate and DShexanoate were found to be slightly higher than DSethanoate. This surprising dependence on the chain length of the acylating agent has been reported before, but not rationalized. On the basis of the rate constants and activation parameters of the hydrolysis of ethanoic, butanoic, and hexanoic anhydrides in aqueous acetonitrile (a model acyl transfer reaction), we suggest that this result may be attributed to the balance between two opposing effects, namely, steric crowding and (cooperative) hydrophobic interactions between the anhydride and the cellulosic surface, whose lipophilicity has increased, due to its partial acylation. Four ethanoate‐based mixed esters were synthesized by the reaction with a mixture of the two anhydrides; the ethanoate moiety predominated in all products. The DS is reproducible and the IL is easily recycled. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 48: 134–143, 2010
Phosphorus ligands for iron(III)‐mediated ATRP of styrene via generation of activators by monomer addition
Authors: He Dan , Xue Zhigang , Khan Mohd Yusuf , Noh Seok Kyun , Lyoo Won Seok
Published: November 2009

Styrene polymerization via generation of activators by monomer addition (GAMA) for atom transfer radical polymerization (ATRP) has been examined extensively with bulk FeX3 and FeX2 at 110 °C in conjunction with various phosphorus‐bearing ligands. It was found that GAMA possesses advantages over normal ATRP. Most importantly, narrower polydispersity index (PDI) values were observed from the styrene polymerizations with Fe(III) over those with Fe(II). Every instance of 2‐(diphenylphosphino)‐N,N′‐dimethyl‐[1,1′‐biphenyl]‐2‐amine and 2‐(diphenylphosphino) pyridine with the Fe(III) system were controlled excellently without addition of any radical initiator or reducing agent additives. Initiator type was found to exert a significant factor to influence on the controllability of polymerization. The initiation of 1‐phenylethyl chloride and methyl‐2‐chloropropionate gave rise to formation of polymers with narrow PDI (1.05–1.20), whereas those from 1‐phenylethyl bromide increased to 1.35. The GAMA of bulk styrene exhibited the best performance in terms of both rate and controllability compared with toluene and anisole. Both formation of block copolymer from the macroinitiator and efficient perturbation of polymerization with 2,2,6,6‐tetramethylpiperidine 1‐oxyl provided firm evidence to support the living and radical characteristics for the GAMA of styrene. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 144–151, 2010
Grafting polymer chains bearing an N‐succinimidyl activated ester end‐group onto primary amine‐coated silica particles and application of a simple, one‐step approach via nitroxide‐mediated controlled/living free‐radical polymerization
Authors: Parvole Julien , Ahrens Lucas , Blas Hélène , Vinas Jérôme , Boissière Cédric , Sanchez Clément , Save Maud , Charleux Bernadette
Published: November 2009

In a first part, the alkoxyamine initiator derived from BlocBuilder® based on the nitroxide SG1 and bearing an N‐succinimidyl ester function was used to synthesize a variety of well‐defined polymers with the activated ester group at the α‐end. The grafting of those polymer chains onto primary‐amine functionalized Stöber silica particles was performed in soft conditions at room temperature and was studied as a function of the polymer chain length, the type of solvent, and the concentrations of both polymer and amine. Polymer grafting densities were mainly in the 0.1–0.2 chain nm−2 range. To increase the grafting density in simple experimental conditions, a direct one‐step method was then proposed: the primary‐amine modified silica, the N‐succinimidyl ester functionalized alkoxyamine, and the monomer were all introduced into the reaction medium at once. This technique allowed grafting and chain growth to take place simultaneously at the polymerization temperature (i.e., 120 °C for styrene), in a single step, and produced hybrid particles with very high grafting density, up to 0.9 chain nm−2, and long polymer chains. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 173–185, 2010
Dicarboxylic imide‐substituted poly(p‐phenylene vinylenes) with high electron affinity
Authors: Qu Hemi , Luo Jing , Zhang Xiaojie , Chi Chunyan
Published: November 2009

Synthesis of n‐type organic semiconductors with high electron mobilities, good environmental stability, and good processability is an urgent task in current organic electronics. This is because most of π‐conjugated materials are p‐type and prefer to transport positive hole carriers. In this article, a series of new dicarboxylic imide‐substituted poly(p‐phenylene vinylenes) (DI‐PPVs) were first synthesized. They exhibited a high electron affinity of 3.60 eV and thus are able to transport electrons. The polymers showed tunable solubility in common organic solvents and high chemical and thermal stability. They remain rigidity of the PPV backbone, and strong interchain π‐stacking was observed in thin films by X‐ray diffraction measurement. All these suggested that these polymers could serve as good candidates as n‐type semiconductors in organic electronic devices such as n‐channel field‐effect transistors and all polymer‐based solar cells. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 186–194, 2010
Thermophysical analysis of SU8‐modified microstructures created by visible light lithography
Authors: Rodriguez Ponce Daniel , Lozano Karen , Eubanks Thomas , Harb Ahmad , Ferrer Domingo , Lin Yuankun
Published: November 2009

SU8 has been modified with photoinitiators Rose Bengal, H‐NU 470 and H‐NU 535, to conduct visible light lithography. The thermophysical properties of the lithographically transformed modified SU8 photoresins were investigated. The influence of the concentration of visible light photosensitizer and photoinitiator as well as exposure time to visible laser on thermal stability and curing kinetics were analyzed. Significant differences in the thermophysical properties were observed in these three photoinitiator groups of modified SU8 photoresins. These results provide with usable quantitative information regarding resin formulation to optimize lithography processing parameters, and therefore, the ultimate properties of lithographically formed microstructures. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 47–54, 2010
Cold crystallization behavior of polyamide 6 in PS‐g‐PA6 graft copolymers
Authors: Shi Dean , Wang Xiao‐Yang , Shi Hengchong , Yin Jing‐Hua , Li Robert K. Y. , Hu Guo‐Hua
Published: November 2009

TEM micrographs show that the PA grafts of PS‐g‐PA6 graft copolymers, which are obtained directly by extracting homo‐PA6 out from the homo‐PA6/PS‐g‐PA6 blends, are in the form of wormlike structure. The wormlike PA6 domains can shrink into droplets after annealing at 250 °C for 15 min. The diameter of the droplet determined by TEM and SAXS is in the range of 50–60 nm. This article reports on a unique crystallization behavior of the PA6 grafts in PS‐g‐PA6 graft copolymers. In a DSC cooling scan, PA6 grafts do not crystallize from the melt with a cooling rate of 10 °C/min. However, there is a cold crystallization peak around 65 °C in the subsequent heating scan. This cold crystallization phenomenon, which has not yet been reported in the literature till now, follows well the homogeneous nucleation mechanism and is depressed at relatively slow cooling rates (2 °C/min) or even completely eliminated after annealing within a specific temperature range. It may be caused by the slow diffusion or transport rate of the less flexible PA6 grafts to the crystal fronts when crystallization takes place around its glass transition temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 65–73, 2010
Human prostate sphere‐forming cells represent a subset of basal epithelial cells capable of glandular regeneration in vivo
Authors: Garraway Isla P. , Sun Wenyi , Tran Chau P. , Perner Sven , Zhang Bao , Goldstein Andrew S. , Hahm Scott A. , Haider Maahum , Head Christian S. , Reiter Robert E. , Rubin Mark A. , Witte Owen N.
Published: November 2009

BACKGROUND

Prostate stem/progenitor cells function in glandular development and maintenance. They may be targets for tumor initiation, so characterization of these cells may have therapeutic implications. Cells from dissociated tissues that form spheres in vitro often represent stem/progenitor cells. A subset of human prostate cells that form prostaspheres were evaluated for self‐renewal and tissue regeneration capability in the present study.

METHODS

Prostaspheres were generated from 59 prostatectomy specimens. Lineage marker expression and TMPRSS‐ERG status was determined via immunohistochemistry and fluorescence in situ hybridization (FISH). Subpopulations of prostate epithelial cells were isolated by cell sorting and interrogated for sphere‐forming activity. Tissue regeneration potential was assessed by combining sphere‐forming cells with rat urogenital sinus mesenchyme (rUGSM) subcutaneously in immunocompromised mice.

RESULTS

Prostate tissue specimens were heterogeneous, containing both benign and malignant (Gleason 3–5) glands. TMPRSS‐ERG fusion was found in approximately 70% of cancers examined. Prostaspheres developed from single cells at a variable rate (0.5–4%) and could be serially passaged. A basal phenotype (CD44+CD49f+CK5+p63+CK8−AR−PSA−) was observed among sphere‐forming cells. Subpopulations of prostate cells expressing tumor‐associated calcium signal transducer 2 (Trop2), CD44, and CD49f preferentially formed spheres. In vivo implantation of sphere‐forming cells and rUGSM regenerated tubular structures containing discreet basal and luminal layers. The TMPRSS‐ERG fusion was absent in prostaspheres derived from fusion‐positive tumor tissue, suggesting a survival/growth advantage of benign prostate epithelial cells.

CONCLUSION

Human prostate sphere‐forming cells self‐renew, have tissue regeneration capability, and represent a subpopulation of basal cells. Prostate 70: 491–501, 2010. © 2009 Wiley‐Liss, Inc.
Androgen receptor CAG repeat length is not associated with the risk of incident symptomatic benign prostatic hyperplasia: Results from the prostate cancer prevention trial
Authors: Kristal Alan R. , Price Douglas K. , Till Cathee , Schenk Jeannette M. , Neuhouser Marian L. , Ockers Sandy , Lin Daniel W. , Thompson Ian M. , Figg William D.
Published: November 2009

BACKGROUND

To examine whether androgen receptor (AR) CAG repeat length was associated with the risk of incident benign prostatic hyperplasia (BPH).

METHODS

A nested case‐control study of 416 BPH cases and 527 controls drawn from Prostate Cancer Prevention Trial placebo‐arm participants who were free of BPH at baseline. BPH was assessed over 7 years and was defined as receipt of medical or surgical treatment, two scores > 14 on the International Prostate Symptom Score (IPSS), or two increases in IPSS ≥ 5 with at least one score ≥ 12.

RESULTS

Compared to men with AR repeat length ≤ 19, the covariate‐adjusted odds ratios [95% CI] were 1.07 [0.73, 1.57] and 0.90 [0.55, 1.45]) for repeat length 20–24 and ≥25, respectively. There was a weak association of AR repeat length with baseline serum testosterone (T) (Spearman r = 0.09, p < 0.02); however, control for or stratification by T did not change study results. Further, results did not differ when stratified by body mass index or baseline concentration of 3α‐diol glucoronide, and were similar for all BPH definitions.

CONCLUSIONS

There were no associations of AR CAG repeat length and BPH risk. Knowledge of AR CAG repeat length provides no clinical useful information for the prevention of symptomatic BPH. Prostate 70: 584–590, 2010. © 2009 Wiley‐Liss, Inc.
Hepsin cooperates with MYC in the progression of adenocarcinoma in a prostate cancer mouse model
Authors: Nandana Srinivas , Ellwood‐Yen Katharine , Sawyers Charles , Wills Marcia , Weidow Brandy , Case Thomas , Vasioukhin Valeri , Matusik Robert
Published: November 2009

BACKGROUND

Hepsin is a cell surface protease that is over‐expressed in more than 90% of human prostate cancer cases. The previously developed Probasin‐hepsin/Large Probasin‐T antigen (PB‐hepsin/LPB‐Tag) bigenic mouse model of prostate cancer demonstrates that hepsin promotes primary tumors that are a mixture of adenocarcinoma and neuroendocrine (NE) lesions, and metastases that are NE in nature. However, since the majority of human prostate tumors are adenocarcinomas, the contribution of hepsin in the progression of adenocarcinoma requires further investigation.

METHODS

We crossed the PB‐hepsin mice with PB‐Hi‐myc transgenic mouse model of prostate adenocarcinoma and characterized the tumor progression in the resulting PB‐hepsin/PB‐Hi‐myc bigenic mice.

RESULTS

We report that PB‐hepsin/PB‐Hi‐myc bigenic mice develop invasive adenocarcinoma at 4.5 months. Further, histological analysis of the 12‐ to 17‐month‐old mice revealed that the PB‐hepsin/PB‐Hi‐myc model develops a higher grade adenocarcinoma compared with age‐matched tumors expressing only PB‐Hi‐myc. Consistent with targeting hepsin to the prostate, the PB‐hepsin/PB‐Hi‐myc tumors showed higher hepsin expression as compared to the age‐matched myc tumors. Furthermore, endogenous expression of hepsin increased in the PB‐Hi‐myc mice as the tumors progressed.

CONCLUSIONS

Although we did not detect any metastases from the prostates in either the PB‐hepsin/PB‐Hi‐myc or the PB‐Hi‐myc mice, our data suggests that hepsin and myc cooperate during the progression to high‐grade prostatic adenocarcinoma. Prostate 70: 591–600, 2010. © 2009 Wiley‐Liss, Inc.
NMR characterization of an engineered domain fusion between maltose binding protein and TEM1 β‐lactamase provides insight into its structure and allosteric mechanism
Authors: Wright Chapman M. , Majumdar Ananya , Tolman Joel R. , Ostermeier Marc
Published: November 2009

RG13 is a 72 kDa engineered allosteric enzyme comprised of a fusion between maltose binding protein (MBP) and TEM1 β‐lactamase (BLA) for which maltose is a positive effector of BLA activity. We have used NMR spectroscopy to acquire [15N, 1H]‐TROSY‐HSQC spectra of RG13 in the presence and absence of maltose. The RG13 chemical shift data was compared to the published chemical shift data of MBP and BLA. The spectra are consistent with the expectation that the individual domain structures of RG13 are substantially conserved from MBP and BLA. Differences in the spectra are consistent with the fusion geometry of MBP and BLA and the maltose‐dependent differences in the kinetics of RG13 enzyme activity. In particular, the spectra provide evidence for a maltose‐dependent conformational change of a key active site glutamate involved in deacylation of the enzyme‐substrate intermediate. Proteins 2010. © 2009 Wiley‐Liss, Inc.
UV and X‐ray structural studies of a 101‐residue long Tat protein from a HIV‐1 primary isolate and of its mutated, detoxified, vaccine candidate
Authors: Foucault Marine , Mayol Katia , Receveur‐Bréchot Véronique , Bussat Marie‐Claire , Klinguer‐Hamour Christine , Verrier Bernard , Beck Alain , Haser Richard , Gouet Patrice , Guillon Christophe
Published: November 2009

The 101‐residue long Tat protein of primary isolate 133 of the human immunodeficiency virus type 1 (HIV‐1), wt‐Tat133 displays a high transactivation activity in vitro, whereas the mutant thereof, STLA‐Tat133, a vaccine candidate for HIV‐1, has none. These two proteins were chemically synthesized and their biological activity was validated. Their structural properties were characterized using circular dichroism (CD), fluorescence emission, gel filtration, dynamic light scattering, and small angle X‐ray scattering (SAXS) techniques. SAXS studies revealed that both proteins were extended and belong to the family of intrinsically unstructured proteins. CD measurements showed that wt‐Tat133 or STLA‐Tat133 underwent limited structural rearrangements when complexed with specific fragments of antibodies. Crystallization trials have been performed on the two forms, assuming that the Tat133 proteins might have a better propensity to fold in supersaturated conditions, and small crystals have been obtained. These results suggest that biologically active Tat protein is natively unfolded and requires only a limited gain of structure for its function. Proteins 2010. © 2009 Wiley‐Liss, Inc
Genomics, evolution, and crystal structure of a new family of bacterial spore kinases
Authors: Scheeff Eric D. , Axelrod Herbert L. , Miller Mitchell D. , Chiu Hsiu‐Ju , Deacon Ashley M. , Wilson Ian A. , Manning Gerard
Published: November 2009

Bacterial spore formation is a complex process of fundamental relevance to biology and human disease. The spore coat structure is complex and poorly understood, and the roles of many of the protein components remain unclear. We describe a new family of spore coat proteins, the bacterial spore kinases (BSKs), and the first crystal structure of a BSK, YtaA (CotI) from Bacillus subtilis. BSKs are widely distributed in spore‐forming Bacillus and Clostridium species, and have a dynamic evolutionary history. Sequence and structure analyses indicate that the BSKs are CAKs, a prevalent group of small molecule kinases in bacteria that is distantly related to the eukaryotic protein kinases. YtaA has substantial structural similarity to CAKs, but also displays distinctive features that broaden our understanding of the CAK group. Evolutionary constraint analysis of the protein surfaces indicates that members of the BSK family have distinct clade‐conserved patterns in the substrate binding region, and probably bind and phosphorylate distinct targets. Several classes of BSKs have apparently independently lost catalytic activity to become pseudokinases, indicating that the family also has a major noncatalytic function. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Recent progress of highly efficient in vivo biological screening for novel agrochemicals in China
Authors: Li Baoju , Yuan Huizhu , Fang Jichao , Tao Liming , Huang Qingchun , Qian Xuhong , Fan Zhijin
Published: November 2009

This paper describes the recent progress of in vivo biological screening for pesticides in China. According to the criteria, including the severity of damage caused by pests and the economic value of the crops, the investigated insects, pathogens, herbs and other species in the agricultural field were selected as the main screening targets for pesticides. Corresponding in vivo microscreening methods have been established and applied in the pesticide screening procedure, which has higher reproducibility, a shorter time and greater efficiency that offset the drawbacks of conventional methods for pesticide screening. Copyright © 2009 Society of Chemical Industry
Effectiveness of five insecticides for the control of adults and young stages of Cacopsylla melanoneura (Förster) (Hemiptera: Psyllidae) in a semi‐field trial
Authors: Baldessari Mario , Trona Federica , Angeli Gino , Ioriatti Claudio
Published: November 2009

BACKGROUND: Cacopsylla melanoneura (Förster) is a vector of Candidatus Phytoplasma mali, the causal agent of one of the most serious diseases in European apple orchards, apple proliferation (AP). The aim of this study was to evaluate the toxicity of five insecticides from different chemical groups (carbamates, chitin inhibitors, insect growth regulators, organophosphates and pyrethroids) towards overwintered adults and young stages of C. melanoneura under semi‐field conditions.

RESULTS: The organophosphate chlorpyrifos and the pyrethroid etofenprox caused higher mortality of overwintered adults than diflubenzuron, fenoxycarb and abamectin, with mortality values exceeding 90%. All the pesticides tested reduced the number of progeny per female and, except for abamectin, were highly effective against young stages, with a long‐lasting effect.

CONCLUSION: An integrated management of the vector is currently required to prevent the spread of AP. The reference insecticides, chlorpyrifos and etofenprox, have a strong toxicity and persistence against all stages of the vector. In apple orchard IPM programmes, the chitin inhibitors and the insect growth regulators could be part of an alternative and more sustainable strategy for the control of C. melanoneura owing to their effectiveness against immature stages. Copyright © 2009 Society of Chemical Industry