bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity of Immobilized Trypsin in the Layer Structure of Polyelectrolyte Microcapsules (PEMC)
Authors: Garbers Eike , Mitlöhner Rita , Georgieva Radostina , Bäumler Hans 
Published: September 2007

AbstractPolyelectrolyte microcapsules composed by using the LbL technique on stabilized RBC as templates were coated with up to ten layer pairs of trypsin/PSS or trypsin/alginate. The trypsin layer growth was confirmed by particle electrophoresis, confocal laser scanning microscopy, flow cytometry, and protein determination according to Lowry. In the coating series with trypsin/PSS, the amount of immobilized enzyme was larger than that with trypsin/alginate. The enzyme immobilization led to activity reduction of up to 90% compared to that of the same enzyme amount in the solution. No significant differences between the activities of trypsin immobilized in combination with PSS and with alginate were found.magnified image
Application and New Developments in Polymer‐Dispersed Liquid Crystal Simulation Studies
Authors: Jeon Young Jae , Bingzhu Yin , Rhee June Tak , Cheung David L. , Jamil Muhammad 
Published: September 2007

AbstractPolymer‐dispersed liquid crystals (PDLCs) represent an important new class of materials with electro‐optic applications such as flexible displays, large‐area devices projection displays, electrically switchable windows, etc. On considering such applications of these materials, many studies have been performed on the experimental side. Similarly, research on the simulation side for the PDLCs is of the fundamental interest too. The present article contains a short review on the present and past simulation studies of PDLCs. Various molecular simulation approaches applied to PDLC systems by different groups are reviewed here. In addition some new findings of the bulk phases are also extensively described.magnified image
Effect of Concentration Gradient on the Morphology Development in Polymer Solutions Undergoing Thermally Induced Phase Separation
Authors: Jiang Bai Tao , Chan Philip K. 
Published: September 2007

AbstractAnisotropic porous polymeric materials fabricated from the phase separation method via spinodal decomposition are used in various practical engineering applications. We studied the formation of anisotropic porous polymeric materials numerically, by imposing an initial linear concentration gradient across a model polymer solution. The initial concentration gradient is placed at three different regions of the polymer sample for comparison purposes. All the simulation results are in good agreement with published experimental observations, which are reported from the applications of porous polymeric membranes. The structure development shows that an anisotropic porous morphology forms when an initial linear concentration gradient is applied to the model polymer solution.magnified image
Contraversive eye deviation during stimulation of the subthalamic region
Authors: Sauleau Paul , Pollak Pierre , Krack Paul , Pélisson Denis , Vighetto Alain , Benabid Alim‐Louis , Tilikete Caroline 
Published: September 2007

AbstractContraversive eye deviation (CED) is most often observed intraoperatively during subthalamic nucleus implantation for Parkinson's disease and considered to result from wrong electrode positioning. We report on a woman, bilaterally implanted in the subthalamic nucleus for severe Parkinson's disease disclosing long‐lasting CED only when the stimulators were activated separately. Clinical examination and eye movements recording in this patient showed that CED occurred when stimulation was applied at the site and at similar intensity used for the best antiparkinsonian effect. These results suggest that the subthalamic area may be involved in orienting movements, either through the subthalamic nucleus itself or the fibers from the Frontal Eye Fields. Interestingly, this report shows that CED may be corrected by bilateral stimulation and that CED may not necessarily implicate electrode repositioning. © 2007 Movement Disorder Society
Complete 1H and 13C assignments of the four major saponins from Dioscorea villosa (wild yam)
Authors: Hayes Patricia Y. , Lambert Lynette K. , Lehmann Reg , Penman Kerry , Kitching William , De Voss James J. 
Published: September 2007

AbstractComplete 1H and 13C spectral assignments for the four major steroidal saponins isolated by methanolic extraction of the roots of Dioscorea villosa, collected in North Carolina, United States (in summer and autumn), are presented in this paper. The structures were determined by a combination of 1H, 13C and 2D NMR techniques and were found to be ((3β,25R)‐26‐(β‐D‐glucopyranosyloxy)‐22‐methoxyfurost‐5‐en‐3‐yl‐O‐β‐D‐glucopyranosyl‐(1 → 3)‐O‐β‐D‐glucopyranosyl‐(1 → 4)‐O‐[α‐L‐rhamnopyranosyl‐(1 → 2)]‐β‐D‐glucopyranoside (1) (or methyl parvifloside), ((3β,25R)‐26‐(β‐D‐glucopyranosyloxy)‐22 methoxyfurost‐5‐en‐3‐yl‐O‐α‐L‐rhamnopyranosyl‐(1 → 2)‐O‐[β‐D‐gluco‐ pyranosyl‐(1 → 4)]‐β‐D‐glucopyranoside (2) (or methyl protodeltonin), (3β,25R)‐spirost‐5‐en‐3‐yl‐O‐β‐D‐glucopy ranosyl‐(1 → 3)‐O‐β‐D‐glucopyranosyl‐(1 → 4)‐O‐[α‐L‐rhamnopyranosyl‐(1 → 2)]‐β‐D‐glucopyranoside (3) (or Zingiberensis saponin I) and (3β,25R)‐spirost‐5‐en‐3‐yl‐O‐α‐L‐rhamnopyranosyl‐(1 → 2)‐O‐[β‐Ds‐glucopyranosyl ‐(1 → 4)]‐β‐D‐glucopyranoside (4) (or deltonin). Copyright © 2007 John Wiley & Sons, Ltd.
Constitutive heterochromatin during mouse oogenesis: The pattern of histone H3 modifications and localization of HP1α and HP1β proteins
Authors: Meglicki Maciej , Zientarski Maciej , Borsuk Ewa 
Published: September 2007

AbstractCentromeres are the fragments of DNA that are responsible for proper chromosome segregation. They consist of centromeric chromatin surrounded by blocks of pericentric heterochromatin, playing an important role in centromere function. In somatic cells, the pericentric domains have a specific pattern of epigenetic modifications of core histones and contain specific pericentric proteins. These features are probably more important for the centromere function than the sequence of the centromeric DNA itself. In somatic cells, the HP1α and HP1β proteins are indispensable for constitutive heterochromatin formation and maintenance. We have analyzed the localization of these proteins in the primordial, growing, fully‐grown, and maturing mouse oocytes. Additionally, we have analyzed post‐translational modifications of histone H3, which can influence HP1α and HP1β association with the heterochromatin. We showed that the regions of constitutive heterochromatin have a distinct pattern of histone H3 acetylation and di‐, and trimethylation of its lysine 9. We demonstrated that HP1β protein was present in pericentric chromatin domains in primordial oocytes, growing (transcriptionally active) oocytes, and in fully‐grown oocytes, and was released to the cytoplasm after germinal vesicle breakdown. In contrast, the HP1α was never detected in primordial oocytes, was first detected in pericentric heterochromatin in growing oocytes, dissociated from pericentric heterochromatin in fully‐grown oocytes, and it was never detected in maturing oocytes. The presence of HP1α and HP1β proteins on the heterochromatin of transcriptionally active oocytes and their absence in transcriptionally silent oocytes suggest that they are necessary for the repression of RNA synthesis in heterochromatin domains of transcribing oocytes. Mol. Reprod. Dev. 75: 414–428, 2008. © 2007 Wiley‐Liss, Inc.
Lower‐bound limit analysis by using the EFG method and non‐linear programming
Authors: Chen Shenshen , Liu Yinghua , Cen Zhangzhi 
Published: September 2007

AbstractIntended to avoid the complicated computations of elasto‐plastic incremental analysis, limit analysis is an appealing direct method for determining the load‐carrying capacity of structures. On the basis of the static limit analysis theorem, a solution procedure for lower‐bound limit analysis is presented firstly, making use of the element‐free Galerkin (EFG) method rather than traditional numerical methods such as the finite element method and boundary element method. The numerical implementation is very simple and convenient because it is only necessary to construct an array of nodes in the domain under consideration. The reduced‐basis technique is adopted to solve the mathematical programming iteratively in a sequence of reduced self‐equilibrium stress subspaces with very low dimensions. The self‐equilibrium stress field is expressed by a linear combination of several self‐equilibrium stress basis vectors with parameters to be determined. These self‐equilibrium stress
basis vectors are generated by performing an equilibrium iteration procedure during elasto‐plastic incremental analysis. The Complex method is used to solve these non‐linear programming sub‐problems and determine the maximal load amplifier. Numerical examples show that it is feasible and effective to solve the problems of limit analysis by using the EFG method and non‐linear programming. Copyright © 2007 John Wiley & Sons, Ltd.
Boundary value problems defined on stochastic self‐similar multiscale geometries
Authors: Soare M. A. , Picu R. C. 
Published: September 2007

AbstractA method for solving elasticity problems defined on composite bodies with a stochastic multiscale microstructure is presented. It is considered that the composite is made from two types of materials with different elastic moduli. One of these is taken as the matrix, while the other forms the inclusions. The inclusions form a stochastic fractal with a finite, but potentially large, number of scales and are randomly distributed within the matrix. The method presented here leads to the statistics of the solution, i.e. the mean and the variance of the stress and displacement fields. It is based on the stochastic finite element method (spectral approach, second‐order technique) and on scaling properties of the spatial distribution of inclusions over the problem domain. This scaling allows for a simple formulation of the multiscale problem and leads to significant computation cost savings, especially when the fractal has a large number of relevant scales. Several examples are presented and used to verify the proposed method against computationally intensive classical finite element models in which the mesh is refined down to the scale of the finest inclusions. Copyright © 2007 John Wiley & Sons, Ltd.
Electrical and humidity sensing properties of synthesized hydrophosphoric acid doped polyaniline
Authors: Sonawane Yogesh S. , Kulkarni M. V. , Kale B. B. , Aiyer R. C. 
Published: September 2007

AbstractH3PO4 doped polyaniline was synthesized by a single‐step chemical polymerization method using ammonium persulfate as an oxidizing agent. The material characterization was done by SEM, UV–vis spectroscopy and thermogravimetric analysis (TGA). The pellets of the synthesized material were used to study the electrical properties, using a four‐probe method. The room temperature electrical conductivity is found to be 0.2201 S/cm. The electrical resistance in response to the varying humid environment (ranging between 20 and 100% RH) is recorded to evaluate the sensitivity of the H3PO4 polyaniline samples toward humidity. The resistance of the samples is found to vary by three orders of magnitude for 20–100% RH and is found to decrease with increasing humidity. The response and recovery time are observed to be 12–14 and 26–30 sec, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
A study of starch addition on burst effect and diameter of polyurethane microspheres containing theophylline
Authors: Emami Shahriar Hojjati , Orang Fariba , Mahmoudi Morteza , Rafienia Mohammad 
Published: September 2007

AbstractTheophylline was encapsulated in polyurethane prepared with hexamethylene diisocyanate (HMDI), polycaprolactone (PCL) (MW = 530 and 2000 g/mol) diols, and starch as polyols and butanediol as chain extender. Polyurethane microspheres were prepared in two reactors; after polyurethane preparation by mixing PCL/starch, HMDI and theophylline in the first reactor, microspheres formation was achieved by transferring the reaction mixture to an aqueous medium (moving at 5000 rpm) of the second reactor. Fourier transform infrared (FTIR) was employed to confirm polyurethane formation during the course of reactions. FTIR spectrum revealed bands at 1729–1733 cm−1 and 3340–3347 cm−1 which indicates carbonyl and NH of amine groups, respectively. Scanning electron microscopy (SEM) was used to study the morphology of the samples. SEM confirmed the formation of microspheres with spherical morphology. Particle size investigation with optical microscopy revealed a size distribution of 8–70 µm. Controlled release of theophylline from the microspheres was performed in phosphate buffered saline (PBS) at pH = 7.4 and monitored with a ultraviolet (UV) spectrometer at 274 nm. Drug release profiles showed that starch addition reduced the release rate around 24% for microspheres prepared from PCL with a molecular weight of 2000 g/mol and it had negligible effect on a molecular weight of 530 g/mol. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation, morphology and electrical conductivity of polyaniline/polyoxyalkylene–montmorillonite exfoliated nanocomposites
Authors: Salahuddin N. , Ayad M. M. , Ali M. 
Published: September 2007

AbstractPolyaniline (PANI)/organoclay exfoliated nanocomposites containing different organoclay contents (14–50 wt%) were prepared. PANI emeraldine base (EB) and oligomeric PANI (o‐PANI) were intercalated into montmorillonite (MMT) modified by four types of polyoxyalkylene diamine or triamine (organoclay) using N‐methyl pyrolidinone (NMP) as a solvent in the presence of 0.1 M HCl. o‐PANI and EB have been synthesized by oxidative polymerization of aniline using ammonium peroxydisulfate (APS). Infrared absorption spectra (IR) confirm the electrostatic interaction between negatively charged surface of MMT and positively charged sites in PANI. X‐ray diffraction (XRD) studies disclosed that the d001 spacing between interlamellar surface disappeared at low content of the organoclay. The morphology of these materials was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrical conductivities of the PANI‐organoclay and o‐PANI‐organoclay nanocomposites were 1.5 × 10−3–2 × 10−4 and 9.5 × 10−7–1.8 × 10−9 S/cm, respectively depending on the ratio of PANI. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis and characterization of tercopolymers derived from ε‐caprolactone, trimethylene carbonate, and lactide
Authors: Jia Yongtang , Shen Xinyuan , Gu Xiaohua , Dong Jiong , Mu Chunxiao , Zhang Yuqing 
Published: September 2007

AbstractA series of tri‐components copolymers with different molar ratios were synthesized via bulk ring‐opening copolymerization of trimethylene carbonate (TMC), L‐lactide (LLA), and ε‐caprolactone (ε‐CL), using stannous octoate as catalyst. The sequence structure of the tercopolymer chain was characterized by 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and gel permeation chromatography (GPC). The results showed that although block sequence of the corresponding monomers still existed in the tercopolymer chain, the random tercopolymers were ultimately obtained due to the transesterification during polymerization. For the samples TP1 and TP2, longer sequence of LLA existed in the molecular chains. The thermal properties of tercopolymers were investigated by differential scanning calorimetry (DSC) and the mechanical properties of the resulting copolymers were studied by using a tensile tester. The results indicated that the properties of these copolymers could be adjusted by changing the compositions of the copolymers. The resulting tercopolymers are expected to have potential uses as nerve regeneration and other biomedicine materials. Copyright © 2007 John Wiley & Sons, Ltd.
Glomerular and tubular induction of the transcription factor c‐Jun in human renal disease
Authors: De Borst MH , Prakash J , Melenhorst WBWH , van den Heuvel MC , Kok RJ , Navis G , van Goor H 
Published: September 2007

AbstractThe transcription factor c‐Jun regulates the expression of genes involved in proliferation and inflammation in many cell types but its role in human renal disease is largely unclear. In the current study we investigated whether c‐Jun activation is associated with human renal disease and if c‐Jun activation regulates pro‐inflammatory and pro‐fibrotic genes in renal cells. Activation of c‐Jun was quantified by scoring renal expression of phosphorylated c‐Jun (pc‐Jun) in control human renal tissue and in biopsies from patients with various renal diseases (diabetic nephropathy, focal glomerulosclerosis, hypertension, IgA nephropathy, membranous glomerulopathy, minimal change disease, membranoproliferative glomerulonephritis, systemic lupus erythematosus, acute rejection, and Wegener's granulomatosis); this was correlated with parameters of renal damage. Furthermore, we studied the functional role of c‐Jun activation in human tubular epithelial cells (HK‐2) stimulated with TGF‐β. Activated c‐Jun was present in nuclei of glomerular and tubular cells in all human renal diseases, but only sporadically in controls. Across the diseases, the extent of pc‐Jun expression correlated with the degree of focal glomerulosclerosis, interstitial fibrosis, cell proliferation, kidney injury molecule‐1 (Kim‐1) expression, macrophage accumulation, and impairment of renal function. In HK‐2 cells, TGF‐β induced c‐Jun activation after 1 h (+40%, p < 0.001) and 24 h (+160%, p < 0.001). The specific c‐Jun N‐terminal kinase (JNK) inhibitor SP600125 abolished c‐Jun phosphorylation at all time points and blunted TGF‐β‐ or BSA‐induced procollagen‐1α 1 and MCP‐1 gene expression in HK‐2 cells. We conclude that in human renal disease, the transcription factor c‐Jun is activated in glomerular and tubular cells. Activation of c‐Jun may be involved in the regulation of inflammation and/or fibrosis in human renal disease. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Classification of commercial Catuaba samples by NMR, HPLC and chemometrics
Authors: Daolio Cristina , Beltrame Flávio L. , Ferreira Antonio G. , Cass Quezia B. , Cortez Diógenes Aparício Garcia , Ferreira Márcia M. C. 
Published: September 2007

AbstractFor over a century, Catuaba has been used in Brazilian folk medicine as an aphrodisiac even though the identity of the plant material employed is often uncertain. The species recommended by the Brazilian Pharmacopeia is Anemopaegma arvense (Bignoniaceae), but many other plants, regionally known as Catuaba, are commercialised. Frequently, the quality control of such a complex system is based on chemical markers that do not supply a general idea of the system. With the advent of the metabolomics approach, a global analysis of samples becomes possible. It appears that 1H‐NMR is the most useful method for such application, since it can be used as a wide‐spectrum chemical analysis technique. Unfortunately, the generated spectra is complex so a possible approach is to look at the metabolite profile as a whole using multivariate methods, for example, by application of principal component analysis (PCA). In the present paper, we describe for the first time a proton high‐resolution magic angle spinning nuclear magnetic resonance (1H‐HR‐MAS NMR) method coupled with PCA for the metabolomic analysis of some commercial Catuaba samples, which provided a reduction in the time required for such analysis. A comparative study of HPLC, HR‐MAS and liquid‐NMR techniques is also reported. Copyright © 2007 John Wiley & Sons, Ltd.
Morphological and fractal studies of polypropylene/poly(ethene‐1‐octene) blends during melt mixing using scanning electron microscopy
Authors: Xu Xinhua , Zhu Tianbing , Zhu Lin , Song Na , Sheng Jing 
Published: September 2007

AbstractBACKGROUND: Polymer blending creates new materials with enhanced mechanical, chemical or optical properties, with the exact properties being determined by the type of morphology and the phase dimension of the blend. In order to control blend properties, morphology development during processing needs to be understood. The formation and evolution of polypropylene/poly(ethylene‐1‐octene) (PP/POE) blend morphology during blending are qualitatively represented by a series of time‐dependent scanning electron microscopy (SEM) patterns. The area diameter and its distribution of dispersed phase domains are discussed in detail. In order to characterize the formation and evolution of phase morphology quantitatively, two fractal dimensions, Ds and Dd, and their corresponding scaling functions are introduced to analyze the SEM patterns.RESULTS: The evolution of the area diameter indicates that the major reduction in phase domain size occurs during the initial stage of melt mixing, and the domain sizes show an increasing trend due to coalescence with increasing mixing times. The distribution in dispersed phase dimension obeys a log‐normal distribution, and the two fractal dimensions are effective to describe the phase morphology: Ds for dispersed phase dimension and Dd for the distribution in it.CONCLUSIONS: The fractal dimensions Ds and Dd can be used quantitatively to characterize the evolutional self‐similarity of phase morphology and the competition of breakup and coalescence of dispersed phase domains. It is shown that the fractal dimensions and scaling laws are useful to describe the phase morphology development at various mixing times to a certain extent. Copyright © 2007 Society of Chemical Industry
Experience and predictors of symptoms, distress and health‐related quality of life over time in postmenopausal women with recurrent breast cancer
Authors: Kenne Sarenmalm Elisabeth , Öhlén Joakim , Odén Anders , Gaston‐Johansson Fannie 
Published: September 2007

AbstractThe purpose of this study was to explore the symptom experience and predictors of distress and quality of life over time in women with recurrent breast cancer. Fifty‐six women completed questionnaires at the diagnosis of recurrence, 1 month, 3 and 6 months after recurrence. A majority of women reported multiple, concurrent and distressing symptoms such as lack of energy, difficulty sleeping, pain, worry and problems with sexual interest or activity during the recurrent breast cancer trajectory. The highest level of symptom burden and distress and decreased quality of life was reported 3 months after recurrence. Although distress declined and quality of life improved over time, patients reported persistent symptoms. Of the patients at increased risk of vulnerability to distress were women who experienced multiple and concurrent symptoms. Other risk factors were co‐morbidity, prehistory of anxiety and depression and progressive or terminal disease. Fatigue, pain and depression explained 68–72% of the variance in distress. Distress explained 44–46% of the variance in quality of life. These findings suggest that symptoms are important contributors to the distress experience, and that distress has a severe impact on quality of life. The care of women with recurrent breast cancer must be based upon the awareness of critical factors that exacerbate the vulnerability to distress throughout the disease trajectory. Copyright © 2007 John Wiley & Sons, Ltd.