bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of a new dust uplift scheme in the Met Office Unified Model™
Authors: Ackerley D. , Highwood E. J. , Harrison M. A. J. , McConnell C. L. , Joshi M. M. , Walters D. N. , Milton S. F. , Greed G. , Brooks M. E.
Published: May 2009

Aeolian mineral dust aerosol is an important consideration in the Earth's radiation budget as well as a source of nutrients to oceanic and land biota. The modelling of aeolian mineral dust has been improving consistently despite the relatively sparse observations to constrain them. This study documents the development of a new dust emissions scheme in the Met Office Unified Model™ (MetUM) based on the Dust Entrainment and Deposition (DEAD) module. Four separate case studies are used to test and constrain the model output. Initial testing was undertaken on a large dust event over North Africa in March 2006 with the model constrained using AERONET data. The second case study involved testing the capability of the model to represent dust events in the Middle East without being re‐tuned from the March 2006 case in the Sahara. While the model is unable to capture some of the daytime variation in AERONET AOD there is good agreement between the model and observed dust events. In the final two case studies new observations from in situ aircraft data during the Dust Outflow and Deposition to the Ocean (DODO) campaigns in February and August 2006 were used. These recent observations provided further data on dust size distributions and vertical profiles to constrain the model. The modelled DODO cases were also compared to AERONET data to make sure the radiative properties of the dust were comparable to observations. Copyright © 2009 Royal Meteorological Society and Crown Copyright
A method for using weather radar data to test cloud resolving models
Authors: May Peter T. , Lane Todd P.
Published: May 2009

A simple method for extracting useful metrics to characterize cloud fields from volumetric radar data is described along with the use of these metrics to evaluate the performance of cloud resolving models. This method involves the calculation of a ‘Statistical Coverage Product’, where the fraction of a grid of radar data covered by various reflectivity thresholds and microphysical classifications is calculated, along with profiles of maximum reflectivity, areas of convective and stratiform rain, and the amounts of rainfall in these categories. The application of this method is illustrated, whereby radar observation and a cloud resolving model simulation are compared for a tropical island thunderstorm near Darwin, Australia. Copyright © 2009 Royal Meteorological Society
Sensitivity analysis of leaf wetness duration within a potato canopy
Authors: Jacobs A.F.G. , Heusinkveld B.G. , Kessel G.J.T. , Holtslag A.A.M.
Published: May 2009

A description and analysis is given of a wetness duration experiment, carried out in a potato field in the centre of the Netherlands in September 2005. The observations are used to design and evaluate a within‐canopy dew model which provides the leaf wetness distribution within the canopy caused by dew processes and by precipitation. This within‐canopy dew model consists of three layers (bottom, centre, top) each with equal contribution to the leaf area index. The model results compared favourably with experimental evidence. The sensitivity of the dew and precipitation interception on the amount of free water and the duration of the leaf wetness was analysed by varying the leaf area index and some important weather variables. The findings suggest that the leaf area index affects the amount of free water, but is barely sensitive to leaf wetness duration. Wind speed has hardly any effect on the amount of free water collection as well as on leaf wetness duration. The net radiation, however, appears to be sensitive to the amount of collected free water as well as the leaf wetness duration. Copyright © 2009 Royal Meteorological Society
Characterization of 2,5‐diaryl‐1,3,4‐oxadiazolines by multinuclear magnetic resonance and density functional theory calculations. Investigation on a case of very remote Hammett correlation
Authors: Cerioni Giovanni , Maccioni Elias , Cardia Maria Cristina , Vigo Sara , Mocci Francesca
Published: May 2009

Two series of 2,5‐diaryl‐1,3,4‐oxadiazolines have been studied by multinuclear magnetic resonance and density functional theory calculations. A full NMR spectroscopic characterization has been performed and excellent remote Hammett correlations (σp or $\sigma_{\rm {p}}^{+}$) have been found for para substitution in the two aryl rings through at least 11 bonds, notwithstanding the presence in the path of atoms that should act as insulators and a lack of correlation for some of the intermediate atoms. The computational investigation on the electronic delocalization, performed with the ACID (anisotropy of the induced current density) method, reveals indeed that electrons are delocalized in almost the entire molecule despite the presence of the insulators. Copyright © 2009 John Wiley & Sons, Ltd.
Establishment of trophectoderm and inner cell mass lineages in the mouse embryo
Authors: Marikawa Yusuke , Alarcón Vernadeth B.
Published: May 2009

The first cell lineage specification in mouse embryo development is the formation of trophectoderm (TE) and inner cell mass (ICM) of the blastocyst. This article is to review and discuss the current knowledge on the cellular and molecular mechanisms of this particular event. Several transcription factors have been identified as the critical regulators of the formation or maintenance of the two cell lineages. The establishment of TE manifests as the formation of epithelium, and is dependent on many structural and regulatory components that are commonly found and that function in many epithelial tissues. Distinct epithelial features start to emerge at the late 8‐cell stage, but the fates of blastomeres are not fixed as TE or ICM until around 32‐cell stage. The location of blastomeres at this stage, that is, external or internal of the embryo, in effect defines the commitment towards the TE or ICM lineage, respectively. Some studies implicate the presence of a developmental bias among blastomeres at 2‐ or 4‐cell stage, although it is unlikely to play a decisive role in the establishment of TE and ICM. The unique mode of cell lineage specification in the mouse embryo is further discussed in comparison with the formation of initial cell lineages, namely the three germ layers, in non‐mammalian embryos. Mol. Reprod. Dev. 76: 1019–1032, 2009. © 2009 Wiley‐Liss, Inc.
Oogenesis specific genes (Nobox, Oct4, Bmp15, Gdf9, Oogenesin1 and Oogenesin2) are differentially expressed during natural and gonadotropin‐induced mouse follicular development
Authors: Monti Manuela , Redi CarloAlberto
Published: May 2009

Using a semi‐quantitative, single‐cell sensitive RT‐PCR method, we studied the expression of oogenesis specific genes (Nobox, Oct4, Bmp15, Gdf9, Oogenesin1 and Oogenesin2) in single oocytes collected from primordial, primary, secondary, preantral and antral follicles during natural and gonadotropin‐induced mouse follicular development. We compared the number of transcripts of these genes, showing that they are differentially expressed, both in natural conditions and under gonadotropin‐induction throughout the assessed developmental stages. Our data show a clear increase in the number of transcripts between the primordial until the preantral stages, with the exception of the Oogenesin1 transcripts under gonadotropin‐induction. The number of transcripts starts decreasing at the antral stage and proceeds until the metaphase II stage, with values very similar to those obtained for the primordial oocytes in both analyzed conditions. Under exogenous gonadotropin‐induction, oocyte recruitment to ovulation at the preantral stage is marked by an increase in Nobox and Oogenesin2 gene expression that is concomitant with a decrease in Oogenesin1 gene expression. Oocytes that are able to proceed into whole embryo development show a tight regulation of Nobox and Oct4 expression at the antral stage. A parallel immunocytochemical study at the protein level corroborates these findings. Mol. Reprod. Dev. 76: 994–1003, 2009. © 2009 Wiley‐Liss, Inc.
Bladder neck closure and suprapubic tube placement in a debilitated patient population
Authors: Ginger Van Anh T. , Miller Jane L. , Yang Claire C.
Published: May 2009

Aims

Bladder neck closure (BNC) with suprapubic tube (SPT) placement is a method of bladder management for patients with neurogenic bladders (NGB). We evaluated our experience at one institution.

Methods

We conducted a retrospective chart review of patients who received BNC with SPT placement from 1999 to 2008.

Results

Twenty‐nine patients (24 females and 5 males, average age 53.4 ± 9.6 years) underwent BNC with SPT placement. Cause of NGB was multiple sclerosis (48%), spinal injury (28%), or myelodysplasia (17%). All but one were dependent on caregivers for activities of daily living. Preoperative urodynamics studies were performed on 23 patients. Retropubic BNC was performed in 26 of 29 patients. Two females had a transvaginal approach, and one male had a perineal approach. Early (<90 days) postoperative complication rate was 52%. Persistent urine leakage was present in eight patients: two peristomal leakage and six urethral leakage. All three non‐retropubic BNC had postoperative fistulas (P = 0.01). Catheter complications were associated with seven of the eight urinary leaks (P = 0.01).

Conclusions

BNC with SPT is a method of bladder management in the NGB population, particularly suited to those with a low functional status. Fistula rates are significantly higher with non‐retropubic BNC (P = 0.01). Poor catheter care in the postoperative period is associated with postoperative urinary leakage (P = 0.01). Neurourol. Urodynam. 29:382–386, 2010. © 2009 Wiley‐Liss, Inc.
An unfitted finite element method using discontinuous Galerkin
Authors: Bastian Peter , Engwer Christian
Published: May 2009

In this paper we present a new approach to simulations on complex‐shaped domains. The method is based on a discontinuous Galerkin (DG) method, using trial and test functions defined on a structured grid. Essential boundary conditions are imposed weakly via the DG formulation. This method offers a discretization where the number of unknowns is independent of the complexity of the domain.

We will show numerical computations for an elliptic scalar model problem in ℝ2 and ℝ3. Convergence rates for different polynomial degrees are studied. Copyright © 2009 John Wiley & Sons, Ltd.
Space–time meshfree collocation method: Methodology and application to initial‐boundary value problems
Authors: Netuzhylov Hennadiy , Zilian Andreas
Published: May 2009

A novel space–time meshfree collocation method (STMCM) for solving systems of non‐linear ordinary and partial differential equations by a consistent discretization in both space and time is proposed as an alternative to established mesh‐based methods. The STMCM belongs to the class of truly meshfree methods, i.e. the methods that do not have any underlying mesh, but work on a set of nodes only without any a priori node‐to‐node connectivity. Instead, the neighbouring information is established on‐the‐fly. The STMCM is constructed using the Interpolating Moving Least‐squares technique, which allows a simplified implementation of boundary conditions due to fulfillment of the Kronecker delta property by the kernel functions, which is not the case for the major part of other meshfree methods.

The method is validated by several examples ranging from interpolation problems to the solution of PDEs, whereas the STMCM solutions are compared with either analytical or reference ones. Copyright © 2009 John Wiley & Sons, Ltd.
Dynamic‐spatial management of coastal aquifers
Authors: Kan Iddo , Leizarowitz Arie , Tsur Yacov
Published: May 2009

We analyze the management of a coastal aquifer under seawater intrusion (SWI) using distributed control methods. The aquifer's state is taken as the water head elevation (vis‐à‐vis sea level, say), which varies with time and in space since extraction, natural recharge and lateral water flows vary with time and in space. The water head, in turn, induces a temporal‐spatial SWI process, which changes the volume of fresh water in the aquifer. Under reasonable conditions we show that the optimal state converges to a steady‐state process that is constant in time. We characterize the optimal steady‐state process in terms of a standard control problem (in space) and offer a tractable algorithm to solve for it. Copyright © 2009 John Wiley & Sons, Ltd.
Shear induced clay organo‐modification: application to plasticized starch nano‐biocomposites
Authors: Chivrac Frédéric , Pollet Eric , Avérous Luc
Published: May 2009

The present paper reports the successful development of a straightforward clay organo‐modification protocol named “Shear Induced Clay Organo‐modification” process, or SICO. To develop such a fast process, natural montmorillonite has been organo‐modified with cationic starch (surfactant) under shearing. According to the obtained results, this process allows the preparation of a pre‐exfoliated montmorillonite, organo‐modified by cationic starch (OMMT‐CS). Then, the OMMT‐CS has been dispersed into different plasticized starch‐based plastics, varying the polysaccharide botanical source, to obtain nano‐biocomposites displaying an exfoliated morphology. To establish the efficiency of this protocol and highlight this nano‐structuration, uniaxial tensile tests have been performed on these materials. The mechanical properties have been compared with those obtained with nano‐biocomposites elaborated with OMMT‐CS prepared with the conventional and efficient Exfoliation/Adsorption technique. Since comparable properties are obtained, we assume that the SICO process is a powerful technique to easily and quickly organo‐modify the montmorillonite clay and to obtain exfoliated nano‐biocomposites. Copyright © 2009 John Wiley & Sons, Ltd.
Nanofibrous polyaniline thin film prepared by plasma‐induced polymerization technique for detection of NO2 gas
Authors: Tiwari Ashutosh , Kumar Rajendra , Prabaharan Mani , Pandey Ravi R. , Kumari Premlata , Chaturvedi Anurag , Mishra A. K.
Published: May 2009

A nanofibrous polyaniline (PANI) thin film was fabricated using plasma‐induced polymerization method and explored its application in the fabrication of NO2 gas sensor. The effects of substrate position, pressure, and the number of plasma pulses on the PANI film growth rate were monitored and an optimum condition for the PANI thin film preparation was established. The resulting PANI film was characterized with UV–visible spectrophotometer, FTIR, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The PANI thin film possessed nanofibers with a diameter ranging from 15 to 20 nm. The NO2 gas sensing behavior was studied by measuring the change in electrical conductivity of PANI film with respect to NO2 gas concentration and exposure time. The optimized sensor exhibited a sensitivity factor of 206 with a response time of 23 sec. The NO2 gas sensor using nanofibrous PANI thin film as sensing probe showed a linear current response to the NO2 gas concentration in the range of 10–100 ppm. Copyright © 2009 John Wiley & Sons, Ltd.
Sustained first remission in an adolescent with hepatosplenic T‐cell lymphoma treated with T‐cell leukemia induction, nucleoside analog‐based consolidation, and early hematopoietic stem cell transplant
Authors: Schafer Eric , Chen Allen , Arceci Robert J.
Published: May 2009

Hepatosplenic T‐cell lymphoma (HTCL) is a rare malignancy. Prognosis is poor with only a few case reports of long‐term survivors. While HTCL universally involves the bone marrow, the condition has been most often treated with multimodal lymphoma specific chemotherapy. We report a durable, sustained first remission in an adolescent treated for HTCL who received induction therapy according to a high risk T‐cell leukemia regimen, a nucleoside analog‐based consolidation, and allogeneic transplantation associated with GVHD. Pediatr Blood Cancer 2009;53:1127–1129. © 2009 Wiley‐Liss, Inc.
Effects of TEOS contents on swelling behaviors and mechanical properties of thermosensitive hybrid gels
Authors: Huang Wei‐Jen , Lee Wen‐Fu
Published: May 2009

A series of organic‐inorganic hybrid thermosensitive gels with three different structures and different contents of tetraethoxysilane (TEOS) were prepared from N‐isopropylacrylamide (NIPAAm), and N,N′‐methylene‐bis‐acrylamide (NMBA) and TEOS [N‐IPN]; NIPAAm, 3‐(trimethoxysilyl) propyl methacrylate (TMSPMA) as coupling agent and TEOS [NT‐IPN]; and NIPAAm, TMSPMA and TEOS [NT‐semi‐IPN] by emulsion polymerization and sol‐gel reaction in this study. The effect of TEOS content on the swelling behavior, mechanical properties, and morphologies of the present gels was investigated. Results showed that the properties of the gels would be affected by the gel networks such as IPN or semi‐IPN, existence of TMSPMA as the bridge chain between networks, and content of TEOS. The NT‐semi‐IPN gel had higher swelling ratio because poly (NIPAAm) moiety in the semi‐IPN gels was not restricted by NMBA network. However, the IPN gels such as N‐IPN and NT‐IPN had good mechanical properties and lower swelling ratio, but had bad thermosensitivity due to the addition of coupling agent, TMSPMA, into the gel system that resulted in denser link between organic and inorganic components. Increasing TEOS content would also reduce the thermosensitivity of the hybrid gels. The morphology showed that IPN gels had partial aggregation (siloxane domain) and showed some denser phases. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
The turning point on plots of log ϕ and log t of Mo's equation
Authors: Song Jian‐bin , Mo Zhi‐shen , Lu Chun‐hua , Ren Min‐qiao , Zhang Qiu‐ping , Liu Yu‐jian , Ni Ya‐ru , Xu Zhong‐zi
Published: May 2009

BACKGROUND: Mo's equation based on the Avrami equation and Ozawa equation has been successfully used in non‐isothermal crystallization kinetics by many researchers. However, in recent years we have found that plots of log ϕ–log t of Mo's equation are not straight lines, but there appears a turning point at ϕ = 7 °C min−1 or so. The aim of this article is to analyze in detail the reason for the occurrence of this turning point by studying the non‐isothermal crystallization of poly(vinylidene fluoride) (PVDF) using differential scanning calorimetry.

RESULTS: A turning point at about 7 °C min−1 appeared on plots of log ϕ–log t. The cooling rate where the turning point occurred showed little change with increasing relative crystallinity, but the temperature decreased. It is noted that this turning‐point temperature is lower than transition temperature of regime I → II reported for PVDF.

CONCLUSION: We deemed that the occurrence of turning points on plots of log ϕ–log t of Mo's equation can be ascribed to the different crystallization regimes based on the Hoffman nucleation theory, and presumed that the turning point corresponded to transition of regime I → II. Finally, we considered that Mo's equation should be analyzed using two beelines, instead of one beeline. Copyright © 2009 Society of Chemical Industry
Synthesis and optoelectronic properties of liquid‐crystalline copolymers based on fluorene and triphenylamine‐containing oligo(p‐phenylenevinylene) derivatives for white light emission
Authors: Li Hui , Wang Lei , Zhao Bin , Shen Ping , Tan Songting
Published: May 2009

A series of novel liquid‐crystalline copolymers based on fluorene and triphenylamine‐containing oligo(p‐phenylenevinylene) derivatives have been synthesized according to the Suzuki polymerization method. The structures, optical and electrochemical properties of the copolymers were characterized by 1H NMR, 13C NMR, GPC, UV–vis, photoluminescence (PL) spectroscopy, and cyclic voltammetry (CV), respectively. The thermotropic phase behavior of the copolymers was investigated by using differential scanning calorimetry (DSC) and polarized optical microscope (POM). All of the copolymers exhibit thermally liquid crystalline properties and represent the characteristic Schlieren textures in a wide temperature range. The effects of the concentrations and chain length of the oligo(phenylenevinylene) units on the thermal properties, liquid crystalline, photo‐ and electroluminescent properties of the copolymers have been investigated in details. Among the copolymers‐based devices with a configuration of ITO/PEDOT:PSS/polymers/Ca/Al, the device based on PF‐LOPV05 exhibits the lowest turn‐on voltage of 3 V and the maximum brightness of 210 cd/m2 at 8.3 V. A single layer device based on the blend of PF/PF‐LOPV05 emits white electroluminescence with CIE coordinates of (0.30, 0.35) at 8 V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3296–3308, 2009
Locally sulfonated poly(ether sulfone)s with highly sulfonated units as proton exchange membrane
Authors: Matsumoto Kazuya , Higashihara Tomoya , Ueda Mitsuru
Published: May 2009

Novel locally sulfonated poly(ether sulfone)s with highly sulfonated units were successfully synthesized for fuel cell applications. Poly(ether sulfone)s were prepared by the nucleophilic substitution of bis(4‐fluorophenyl) sulfone with 1,2,4,5‐tetrakis([1,1′‐biphenyl]‐2‐oxy)‐3,6‐bis(4‐hydroxyphenoxy)benzene and bis(4‐hydroxyphenyl) sulfide, followed by oxidation using m‐chloroperoxybenzoic acid. The desired highly sulfonated units were easily introduced by postsulfonation and each one had ten sulfonic acid groups. The sulfonated polymers gave tough, flexible, and transparent membranes by solvent casting. The high contrast in polarity between highly sulfonated units and hydrophobic poly(ether sulfone) units enabled the formation of defined phase‐separated structures and well‐connected proton paths. The sulfonated polymers exhibited excellent proton conductivity over a wide range of relative humidities. The proton conductivity of the sulfonated polymer with an ion exchange capacity value of 2.38 mequiv/g was comparable to that of Nafion 117 even at 30% relative humidity. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3444–3453, 2009
Direct patterning of poly(amic acid) and low‐temperature imidization using a crosslinker, a photoacid generator, and a thermobase generator
Authors: Ogura Tomohito , Higashihara Tomoya , Ueda Mitsuru
Published: May 2009

A positive‐type photosensitive polyimide (PSPI) based on poly(amic acid) (PAA), a crosslinker 1,1,1‐tris{4‐[2‐(vinyloxy)ethoxy]phenyl}ethane (TVPE), a photoacid generator (PAG) (5‐propylsulfonyloxyimino‐5H‐thiophen‐2‐ylidene)‐2‐(methylphenyl)acetonitrile (PTMA), and a thermobase generator (TBG) t‐butyl 2,6‐dimethylpiperidine‐1‐carboxylate (BDPC) has been developed as a promising material in microelectronics. The PAA was prepared from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐oxydianiline (ODA) in dimethyl sulfoxide (DMSO). The PSPI, consisting of PAA (69 wt %), TPVE (21 wt %), PTMA (3 wt %), and BDPC (7 wt %), showed high sensitivity of 21 mJ/cm2 and a high contrast of 6.8 when it was exposed to a 436‐nm line (g‐line), postbaked at 90 °C for 5 min, and developed with 1.69 wt % TMAHaq. A clear positive image of 8 μm line and space pattern was printed on film, which was exposed to 50 mJ/cm2 of g‐line by a contact printing mode and fully converted to the corresponding polyimide (PI) pattern on heating at 200 °C, confirmed by FTIR spectroscopy. Thus, this system will be a good candidate for next generation PSPIs. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3362–3369, 2009
Frontal polymerization synthesis and characterization of Konjac glucomannan‐graft‐acrylic acid polymers
Authors: Li Jing , Zhang Xia , Chen Jian , Xia Jun , Ma Meihu , Li Bin
Published: May 2009

Konjac glucomannan‐graft‐acrylic acid polymers, used as superabsorbent polymers (SAPs), were synthesized by frontal polymerization (FP). The features of front propagation including front velocity and maximum temperature (Tmax) were influenced by the amount of glucomannan, initiator, and environment temperature. The graft copolymer was characterized by FTIR, DSC, and SEM. The amount of crosslinking agent mainly determined the crosslinking degree of SAPs that would affect the water absorbency and microstructure. Water absorbency of SAP was also investigated and most of them displayed high water absorption rate. The aforementioned results allow us to conclude that FP can be considered as a promising method to fabricate SAP for its excellent advantages. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3391–3398, 2009
Low band gap copolymers based on thiophene and quinoxaline: Their electronic energy levels and photovoltaic application
Authors: Peng Qiang , Xu Jun , Zheng Wenxu
Published: May 2009

Low band gap conjugated copolymers containing donor (thiophene)‐acceptor (quinoxaline, Qx) were synthesized via Stille coupling polymerization. The resulting copolymers were characterized by 1H NMR, element analysis, GPC, TGA, and DSC. UV‐vis spectra indicated that the increase in the content of quinoxaline units increased the interaction strengthen of the polymer main chains and caused a red‐shift in the optical absorbance. Cyclic voltammetry was used to estimate energy levels of the lowest unoccupied molecular orbit (LUMO) and the highest occupied molecular orbit (HOMO), and the band gap (Eg) of the copolymers. The basic electronic structures of the copolymers were also studied by density‐functional theory (DFT) calculations. Both the experimental and calculation results indicated an increase in the HOMO energy level with increasing the content of quinoxaline units, whereas the corresponding change in the LUMO energy level is much smaller. Polymer photovoltaic cells (PVCs) were fabricated with the structure of ITO/PEDOT:PSS (30 nm)/active layer (80 nm)/Ca (8 nm)/Al(140 nm). The results show that the introduction of a proper amount of electron‐acceptor groups in the polymer main chains induces an extension of the absorption spectra and improves the photovoltaic properties of the copolymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3399–3408, 2009
Photochemistry and initiation behavior of phenylethynyl onium salts as cationic photoinitiators
Authors: Höfer Michael , Liska Robert
Published: May 2009

Phenyl(phenylethynyl)iodonium hexafluorophosphate and diphenyl(phenylethynyl)sulfonium hexafluorophosphate were synthesized for application as cationic photoinitiators using simple, straightforward methods. Quantification of the purity of the counterion was determined by FTIR analysis with subsequent mathematical peak deconvolution. Photodecomposition products for direct irradiation were determined in steady state photolysis experiments yielding diphenyl sulfide and phenyl(phenylethynyl) sulfide or iodobenzene, respectively, as main products. Heterolytic cleavage was proposed as main photodecomposition pathway because low yields of phenylacetylene radical recombination products and no photoproducts generated by phenyl radicals, including benzene, were detected. High activity as photoinitiators was verified by photo‐DSC experiments in direct irradiation and in photosensitized initiation using 9,10‐dibutylanthracene, 2‐isopropylthioxanthone, and surprisingly also benzophenone as sensitizers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3419–3430, 2009
Synthesis of stimuli‐responsive macroazoinitiators and their use as an inistab toward hairy polymer latex particles
Authors: Fujii Syuji , Kakigi Yuichi , Suzaki Motomichi , Yusa Shin‐Ichi , Muraoka Masahiro , Nakamura Yoshinobu
Published: May 2009

Stimuli‐responsive macroazoinitiators with central azo unit have been synthesized by atom transfer radical polymerization (ATRP) of 2‐(dimethylamino)ethyl methacrylate or 2‐(diethylamino)ethyl methacrylate in 2‐propanol at 25 °C. The mean degree of polymerization of the polymer chains besides the azo group was fixed between 25 and 60. 1H NMR, gel permeation chromatography, UV‐Vis spectrophotometer, and surface tensiometer were used to characterize the stimuli‐responsive macroazoinitiators in terms of their chemical structure, molecular weight, polydispersity, and pH‐responsive behavior, respectively. Eventually, dispersion polymerization of styrene using the poly[2‐(diethylamino)ethyl methacrylate] (PDEA) macroazoinitiator as an inistab (initiator + stabilizer) in 2‐propanol medium was conducted. Near‐monodisperse 98 nm polystyrene (PS) latex particles with pH‐responsive PDEA hair were successfully synthesized. The PS latex particles with the PDEA hair can be dispersed in acidic aqueous media where the PDEA hair was protonated and was solvated, and can be flocculated in basic aqueous media where the PDEA hair was deprotonated and was precipitated. This dispersion‐flocculation cycle was reversible. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3431–3443, 2009
Intermolecular interactions on amine‐cured epoxy matrices with different crosslink densities. Influence on the hole and specific volumes and the mechanical behavior
Authors: Blanco M. , Ramos J. A. , Goyanes S. , Rubiolo G. , Salgueiro W. , Somoza A. , Mondragon I.
Published: May 2009

The architecture of an epoxy matrix was modified by curing the resin with mono‐/diamine mixtures having identical chemical structures. Both hole volume and specific volume variations were studied by positron annihilation lifetime spectroscopy and pressure‐volume‐temperature/density measurements, respectively. The average hole volume of the networks at room temperature slightly increased when the monoaminic chain extender content increased. The increment in the intermolecular interactions between functional groups of the networks chains, due to the less hindered nitrogen introduced by the monoamine, appears to be the responsible for the observed behavior. Besides, only small variations on the specific volume were observed on increasing the monoamine content, which points out that for a cured epoxy system, the chemical structure of the curing agent is mainly responsible for chain packing in the networks. On the other hand, intermolecular interactions between chains were considered as the key factor for fixing stiffness and strength. Thus, it was observed that the increase of the intermolecular interactions with the monoamine content produced a decrease in the sub‐Tg small‐range cooperative motions, which increased the low‐deformation mechanical properties at temperatures between β and α relaxations. This conclusion could be applied to previous investigations with epoxy matrices not fully crosslinked (nonstoichiometric or noncompletely cured formulations). Finally, it was found that fracture properties do not significantly depend either on the hole volume or on the intermolecular interactions. Fracture properties are more dependent on the crosslink density and the glass transition temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1240–1252, 2009
Proton conductivity survey of the acid doped copolymers based on 4‐vinylbenzylboronic acid and 4(5)‐vinylimidazole
Authors: Sezgin Aslihan , Akbey Ümit , Graf Robert , Bozkurt Ayhan , Baykal Abdülhadi
Published: May 2009

In this work, poly(4‐vinylbenzylboronic acid‐co‐4(5)‐vinylimidazole) (poly(4‐VBBA‐co‐4‐Vim)) copolymers were synthesized by free‐radical copolymerization of the monomers 4‐VBBA and 4‐Vim at various monomer feed ratios. The copolymers were characterized by 1H MAS NMR and 11B MQ‐MAS NMR methods and the copolymer composition was determined via elemental analysis. The membrane properties of these copolymers were investigated after doping with phosphoric acid at several stoichiometric ratios. The proton exchange reaction between acid and heterocycle is confirmed by FTIR. Thermal properties of the samples were investigated via thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The morphology of the copolymers was characterized by x‐ray diffraction, XRD. The temperature dependence of proton conductivities of the samples was investigated by means of impedance spectroscopy. Proton conductivity of the copolymers increased with the doping ratio and reached to 0.0027 S/cm for poly(4‐VBBA‐co‐4‐Vim)/2H3PO4 in the anhydrous state. The boron coordination in the copolymer was determined by 11B MQ‐MAS experiment and the coexistence of three and four coordinated boron sites was observed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1267–1274, 2009
Stress relaxation under large step equibiaxial elongation for low‐density polyethylene
Authors: Okamoto Kenzo , Yamaguchi Masayuki
Published: May 2009

The stress relaxation under large step equibiaxial elongation for low‐density polyethylene with long‐chain branches revealed that the time‐strain separability holds in relaxation modulus GB(t, εB), and damping function hB(εB) exhibits weaker equibiaxial elongational strain εB dependence than that predicted by the Doi–Edwards theory without the independent alignment approximation. Dependencies of damping function h(γ) for step shear deformation and hB(εB) on stretch ratio α of polymer contour length and orientation of a polymer chain in direction of the maximum orientation were evaluated, and it was found that the α dependencies of h(γ) and hB(εB) are different, whereas dependencies of h(γ) and hB(εB) on the orientation coincide fairly well. These results indicate that the damping is dominated by the chain orientation rather than α. This implies that withdrawal of long‐chain branches into tube of a backbone chain occurs when the orientation of the long‐chain branches is large and friction force against the branch point withdrawal is small. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1275–1284, 2009
Deformation of elastomeric polyolefin spherulites
Authors: Wang H. P. , Chum S. P. , Hiltner A. , Baer E.
Published: May 2009

The ethylene‐octene block copolymers in this study consist of long crystallizable sequences with low comonomer content alternating with rubbery amorphous blocks with high comonomer content. The crystallizable blocks form lamellae that organize into space‐filling spherulites even when the fraction of crystallizable block is so low that the crystallinity is only 7%. These unusual spherulites are highly elastic and recover from strains as high as 300%. This new class of thermoplastic elastomers is fundamentally different from conventional elastomeric olefin copolymers that depend on isolated, fringed micellar‐like crystals to provide the junctions for the elastomeric network. The elastomeric block copolymers are shown to be unique in that a hierarchical organization of space‐filling lamellar spherulites provides the junctions for the elastomeric network. The deformation of the elastic spherulites is readily studied with small angle light scattering, wide angle X‐ray diffractograms, and atomic force microscopy. At strains in excess of 300%, the spherulites break up into a fibrillar structure following lamellar deformation processes that are similar to those established for high density ethylenic polymers. The crystalline transformation produces a stiffer elastomer that exhibits complete recovery on subsequent loadings. Similar experiments on elastomeric random ethylene‐octene copolymers where fringed micellar crystals provide the physical crosslinks that connect the rubbery, amorphous chain segments reveal significant differences. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1313–1330, 2009
Development and Characterisation of a Microwave‐heated Atmospheric Plasma Torch
Authors: Leins Martina , Alberts Lukas , Kaiser Mathias , Walker Matthias , Schulz Andreas , Schumacher Uwe , Stroth Ulrich
Published: May 2009

Among other applications, microwave plasma sources at atmospheric pressure are used for the decomposition of halogenated volatile organic compounds (VOC). The presented microwave plasma torch is based on an axially symmetric resonator. Simulations of the electric field distribution, Eigen frequency analyses and measurements of the resonant frequency resulted in an improved design. Microwaves of 2.45 GHz are fed into this cavity resulting in a sufficiently high electric field for ignition and maintaining stable plasma. The characterisation of the plasma is made with optical emission spectroscopy. The decomposition of VOC was analysed with FTIR‐spectroscopy, a mass spectrometer and an FID.
Effect of Cold Forming on Low‐Temperature Plasma Nitriding and Carburizing Characteristics of Austenitic Stainless Steel
Authors: Egawa Motoo , Matsuda Yasushi , Ueda Nobuhiro , Sone Takumi , Tsujikawa Masato , Nakata Kazuhiro
Published: May 2009

The cold‐rolled specimen of AISI304 and AISI316 were plasma nitrided and carburized at low temperature, and the S‐phase layers formed on the surface were investigated. In nitriding on AISI304 and AISI316, the thicknesses of the nitrided layers increased with an increase in rolling reduction. In plasma carburizing, on both steels, the thicknesses of the carburized layers were almost unchanged as the rolling reduction increased. In the nitriding, the growth of the S‐phase layer was accelerated by the deformation structure. However, in the carburizing, the growth of S‐phase layer was almost constant as the rolling reduction increased.
Sequence determinants of thermodynamic stability in a WW domain—An all‐β‐sheet protein
Authors: Jäger Marcus , Dendle Maria , Kelly Jeffery W.
Published: May 2009

The stabilities of 66 sequence variants of the human Pin1 WW domain have been determined by equilibrium thermal denaturation experiments. All 34 residues composing the hPin1 WW three‐stranded β‐sheet structure could be replaced one at a time with at least one different natural or non‐natural amino acid residue without leading to an unfolded protein. Alanine substitutions at only four positions within the hPin1 WW domain lead to a partially or completely unfolded protein—in the absence of a physiological ligand. The side chains of these four residues form a conserved, partially solvent‐inaccessible, continuous hydrophobic minicore comprising the N‐ and C‐termini. Ala mutations at five other residues, three of which constitute the ligand binding patch on the concave side of the β‐sheet, significantly destabilize the hPin1 WW domain without leading to an unfolded protein. The remaining mutations affect protein stability only slightly, suggesting that only a small subset of side chain interactions within the hPin1 WW domain are mandatory for acquiring and maintaining a stable, cooperatively folded β‐sheet structure.
Conformational changes in redox pairs of protein structures
Authors: Fan Samuel W. , George Richard A. , Haworth Naomi L. , Feng Lina L. , Liu Jason Y. , Wouters Merridee A.
Published: May 2009

Disulfides are conventionally viewed as structurally stabilizing elements in proteins but emerging evidence suggests two disulfide subproteomes exist. One group mediates the well known role of structural stabilization. A second redox‐active group are best known for their catalytic functions but are increasingly being recognized for their roles in regulation of protein function. Redox‐active disulfides are, by their very nature, more susceptible to reduction than structural disulfides; and conversely, the Cys pairs that form them are more susceptible to oxidation. In this study, we searched for potentially redox‐active Cys Pairs by scanning the Protein Data Bank for structures of proteins in alternate redox states. The PDB contains over 1134 unique redox pairs of proteins, many of which exhibit conformational differences between alternate redox states. Several classes of structural changes were observed, proteins that exhibit: disulfide oxidation following expulsion of metals such as zinc; major reorganisation of the polypeptide backbone in association with disulfide redox‐activity; order/disorder transitions; and changes in quaternary structure. Based on evidence gathered supporting disulfide redox activity, we propose disulfides present in alternate redox states are likely to have physiologically relevant redox activity.
High‐energy water sites determine peptide binding affinity and specificity of PDZ domains
Authors: Beuming Thijs , Farid Ramy , Sherman Woody
Published: May 2009

PDZ domains have well known binding preferences for distinct C‐terminal peptide motifs. For most PDZ domains, these motifs are of the form [S/T]‐W‐[I/L/V]. Although the preference for S/T has been explained by a specific hydrogen bond interaction with a histidine in the PDZ domain and the (I/L/V) is buried in a hydrophobic pocket, the mechanism for Trp specificity at the second to last position has thus far remained unknown. Here, we apply a method to compute the free energies of explicit water molecules and predict that potency gained by Trp binding is due to a favorable release of high‐energy water molecules into bulk. The affinities of a series of peptides for both wild‐type and mutant forms of the PDZ domain of Erbin correlate very well with the computed free energy of binding of displaced waters, suggesting a direct relationship between water displacement and peptide affinity. Finally, we show a correlation between the magnitude of the displaced water free energy and the degree of Trp‐sensitivity among subtypes of the HTRA PDZ family, indicating a water‐mediated mechanism for specificity of peptide binding.
Structural and biochemical analyses of YvgN and YtbE from Bacillus subtilis
Authors: Lei Jian , Zhou Yan‐Feng , Li Lan‐Fen , Su Xiao‐Dong
Published: May 2009

Bacillus subtilis is one of the most studied gram‐positive bacteria. In this work, YvgN and YtbE from B. subtilis, assigned as AKR5G1 and AKR5G2 of aldo‐keto reductase (AKR) superfamily. AKR catalyzes the NADPH‐dependent reduction of aldehyde or aldose substrates to alcohols. YvgN and YtbE were studied by crystallographic and enzymatic analyses. The apo structures of these proteins were determined by molecular replacement, and the structure of holoenzyme YvgN with NADPH was also solved, revealing the conformational changes upon cofactor binding. Our biochemical data suggest both YvgN and YtbE have preferential specificity for derivatives of benzaldehyde, such as nitryl or halogen group substitution at the 2 or 4 positions. These proteins also showed broad catalytic activity on many standard substrates of AKR, such as glyoxal, dihydroxyacetone, and DL‐glyceraldehyde, suggesting a possible role in bacterial detoxification.
NMR‐based characterization of a refolding intermediate of β2‐microglobulin labeled using a wheat germ cell‐free system
Authors: Kameda Atsushi , Morita Eugene‐Hayato , Sakurai Kazumasa , Naiki Hironobu , Goto Yuji
Published: May 2009

In patients with dialysis‐related amyloidosis, β2‐microglobulin (β2‐m) is a major structural component of amyloid fibrils. It has been suggested that the partial unfolding of β2‐m is a prerequisite to the formation of amyloid fibrils, and that the folding intermediate trapped by the non‐native trans‐Pro32 isomer leads to the formation of amyloid fibrils. Although clarifying the structure of this refolding intermediate by high resolution NMR spectroscopy is important, this has been made difficult by the limited lifetime of the intermediate. Here, we studied the structure of the refolding intermediate using a combination of amino acid selective labeling with wheat germ cell‐free protein synthesis and NMR techniques. The HSQC spectra of β2‐ms labeled selectively at either phenylalanine, leucine, or valine enabled us to monitor the structures of the refolding intermediate. The results suggested that the refolding intermediate has an overall fold and cores similar to the native structure, but contains disordered structures around Pro32. The fluctuation of the β‐sheet regions especially the last half of the βB strand and the first half of the βE strand, both suggested to be important for amyloidogenicity, may transform β2‐m into an amyloidogenic structure.
Regulation of PSA secretion and survival signaling by calcium‐independent phopholipase A2β in prostate cancer cells
Authors: Nicotera Thomas M. , Schuster David P. , Bourhim Mustapha , Chadha Kailash , Klaich Gary , Corral David A.
Published: May 2009

BACKGROUND

Serum prostate specific antigen (PSA) levels in prostate cancer patients serve as a useful biomarker for diagnosing and monitoring prostate cancer. Recently, secreted PSA has been characterized as an autocrine survival factor through activation of Akt and induction of AR. In the normal prostate, PSA is secreted in the lumen of prostatic ducts to lyse proteins in the seminal coagulum.

METHODS

However, the mechanism for constitutive PSA secretion from benign prostate and its transport across the prostate‐blood barrier into serum are unknown. Regulation of peptide secretion by iPLA2‐β has been reported in non‐prostatic tissue and in prostate tissue iPLA2‐β is reported to be under androgen regulation. We investigated whether iPLA2 plays a role for in PSA secretion by comparing iPLA2 activity and expression in normal prostate epithelial RWPE‐1 cells and in LNCaP prostate cancer cells. Expression of the two active iPLA2‐β mRNA splice variants, LH‐iPLA2 and SH‐iPLA2, were increased and the inhibitory ankyrin‐iPLA2 isoform was markedly reduced in LNCaP cells as compared to normal prostate epithelial RWPE‐1 cells.

RESULTS

These changes are consistent with a higher enzymatic activity in LNCaP cells. The iPLA2‐β‐specific inhibitor BEL inhibited PSA secretion and induced apoptosis in LNCaP cells. iPLA2 knockdown using SiRNA inhibited PSA secretion, downregulated AR and induced apoptosis. Exogenous PSA suppressed BEL‐induced apoptosis and neutralizing anti‐PSA antibody blocked the survival effect of PSA.

CONCLUSIONS

These data indicate that iPLA2‐β participates in regulating PSA secretion and supports the concept that secreted PSA provides an autocrine survival function in LNCaP cells. Prostate 69:1270–1280, 2009. © 2009 Wiley‐Liss, Inc.
Serum adiponectin, C‐peptide and leptin and risk of symptomatic benign prostatic hyperplasia: Results from the prostate cancer prevention trial
Authors: Schenk Jeannette M. , Kristal Alan R. , Neuhouser Marian L. , Tangen Catherine M. , White Emily , Lin Daniel W. , Thompson Ian M.
Published: May 2009

BACKGROUND

Recent epidemiologic studies have identified obesity as a risk factor for benign prostatic hyperplasia (BPH). We examined whether adiponectin, leptin, and C‐peptide were associated with incident, symptomatic BPH and whether these factors mediate the relationship between obesity and BPH risk.

METHODS

Data are from Prostate Cancer Prevention Trial placebo arm participants who were free of BPH at baseline. Incident BPH (n = 698) was defined as treatment, two International Prostate Symptom Score (IPSS) values > 14, or an increase of ≥5 in IPSS from baseline documented on at least two occasions plus at least one score ≥12. Controls (n = 709) were selected from men reporting no BPH treatment or IPSS > 7 during the 7‐year trial. Baseline serum was analyzed for adiponectin, C‐peptide, and leptin concentrations.

RESULTS

Neither C‐peptide nor leptin was associated with BPH risk. The odds ratio [95% CI] contrasting highest to lowest quartiles of adiponectin was 0.65[0.47, 0.87] Ptrend = 0.004. Findings differed between levels of physical activity: there was a strong inverse association between adiponectin and BPH among moderately/very active men OR = 0.43 [0.29, 0.63], and no association among sedentary/minimally active men OR = 0.92 [0.65, 1.30] Pinteraction = 0.005. Adiponectin concentrations explained only a moderate amount of the relationship between obesity and BPH risk.

CONCLUSIONS

High adiponectin concentrations were associated with reduced risk of incident, symptomatic BPH. This association was limited to moderately/very active men; suggesting the relationship between obesity and BPH involves a complex interaction between factors affecting glucose uptake and insulin sensitivity. However, adiponectin is likely not the only mechanism through which obesity affects BPH risk. Prostate 69:1303–1311, 2009. © 2009 Wiley‐Liss, Inc.