bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the architecture and environment on polymeric molecular assemblies of novel amphiphilic diblock copolynorbornenes with narrow polydispersity via living ring‐opening metathesis polymerization
Authors: Liaw Der‐Jang , Huang Ching‐Cheng , Kang En‐Tang 
Published: March 2006

AbstractDiblock copolymers of 5‐(methylphthalimide)bicyclo[2.2.1]hept‐2‐ene (NBMPI) and 1,5‐cyclooctadiene were synthesized by living ring‐opening metathesis polymerization with a well‐defined catalyst {RuCl2(CHPh)[P(C6H11)3]2}. Unhydrogenated diblock copolymers showed two glass transitions due to poly(NBMPI) and polybutadiene segments, such as two glass‐transition temperatures at −86.5 and 115.3 °C for poly1a and −87.2 and 115.3 °C for poly1b. However, only one melting temperature could be observed for hydrogenated copolymers, such as 119.8 °C for poly2a and 121.7 °C for poly2b. The unhydrogenated diblock copolymer with the longer poly(NBMPI) chain (poly1a; temperature at 10% mass loss = 400 °C) exhibited better thermal stability than the one with the shorter poly(NBMPI) chain (poly1b; temperature at 10% mass loss = 385 °C). Two kinds of hydrogenated diblock copolymers, poly2a and poly2b, exhibited relatively poor solubility but better thermal stability than unhydrogenated diblock copolymers because of the polyethylene segments. Poly[(hydrochloride quaternized 2‐norbornene‐5‐methyleneamine)‐b‐butadiene]‐1 (poly3a) was obtained after the hydrolysis and quaternization of poly1a. Dynamic light scattering measurements indicated that the hydrodynamic diameters of the cationic copolymer (poly3a) in water (hydrodynamic diameter = 1580 nm without salt), methanol/water (4/96 v/v; hydrodynamic diameter = 1500 nm without salt), and tetrahydrofuran/water (4/96 v/v; hydrodynamic diameter = 1200 nm without salt) decreased with increasing salt (NaCl) concentration. The effect of temperature on the hydrodynamic diameter of hydrophobically modified poly3a was also studied. The inflection point of the hydrodynamic diameter of poly3a was observed at various polymer concentrations around 30 °C. The critical micelle concentration of hydrophobically modified poly3a was observed at 0.018 g dL−1. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2901–2911, 2006
Effect of 1‐hexene comonomer on polyethylene particle growth and copolymer chemical composition distribution
Authors: Smit Madri , Zheng Xuejing , Brüll Robert , Loos Joachim , Chadwick John C. , Koning Cor E. 
Published: March 2006

AbstractAn investigation of the polymer particle growth characteristics and polymer molecular weight and composition distributions in ethylene homopolymerization and ethylene/1‐hexene copolymerization has been carried out with a catalyst comprising a zirconocene and methylaluminoxane immobilized on a silica support. The presence of 1‐hexene leads to higher productivity and easier fragmentation of the support during particle growth. Crystallization analysis fractionation and gel permeation chromatography analysis of ethylene/1‐hexene copolymers prepared at different polymerization times reveals a broadening of the chemical composition distribution with increasing polymerization time as a result of the gradual formation of a relatively high‐molecular‐weight, ethylene‐rich fraction. The results are indicative of significant monomer diffusion effects in both homopolymerization and copolymerization. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2883–2890, 2006
Reversible addition–fragmentation chain transfer polymerization of methyl methacrylate in emulsion
Authors: Luo Yingwu , Cui Xiufeng 
Published: March 2006

AbstractTheoretical simulations showed that for controlled/living radical polymerization in an emulsion system, some of the earliest born particles could be superswollen to a size close to 1 μm. We hypothesized that the superswelling of these particles would lead to colloidal instability. Under the guidance of the simulation results, reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization of methyl methacrylate (MMA) was carried out. Experimental results showed that increasing the initiation rate, surfactant level, and targeted molecular weight could improve the colloidal stability of the RAFT polymerization of MMA in an emulsion. The experimental results were in full accord with the theoretical predictions. The poor control of the molecular weight and polydispersity index was found to have a close relationship with the colloidal instability. For the first time, we demonstrated that RAFT polymerization could successfully be implemented with little coagulum, good control of the molecular weight, and a low polydispersity index with the same process used for traditional emulsion polymerization but with higher surfactant levels and initiation rates. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44:2837–2847, 2006
Detailed microscopic study of the full zipA:FtsZ interface
Authors: Moreira I.S. , Fernandes P.A. , Ramos M.J. 
Published: March 2006

AbstractProtein–protein interaction networks are very important for a wide range of biological processes. Crystallographic structures and mutational studies have generated a large number of information that allowed the discovery of energetically important determinants of specificity at intermolecular protein interfaces and the understanding of the structural and energetic characteristics of the binding hot spots. In this study we have used the improved MMPB/SA (molecular mechanics/Poisson‐Boltzmann surface area) approach that combining molecular mechanics and continuum solvent permits to calculate the free energy differences upon alanine mutation. For a better understanding of the binding determinants of the complex formed between the FtsZ fragment and ZipA we extended the alanine scanning mutagenesis study to all interfacial residues of this complex. As a result, we present new mutations that allowed the discovery of residues for which the binding free energy differences upon alanine mutation are higher than 2.0 kcal/mol. We also observed the formation of a hydrophobic pocket with a high warm spot spatial complementarity between FtsZ and ZipA. Small molecules could be designed to bind to these amino acid residues hindering the binding of FtsZ to ZipA. Hence, these mutational data can be used to design new drugs to control more efficiently bacterial infections. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Modeling and functional analysis of AEBP1, a transcriptional repressor
Authors: Lyons Peter J. , Mattatall Neil R. , Ro Hyo‐Sung 
Published: March 2006

AbstractAdipocyte enhancer binding protein 1 (AEBP1) is a transcriptional repressor of the aP2 gene, which encodes the adipocyte lipid binding protein and is involved in the differentiation of preadipocytes into mature adipocytes. It is an isoform of aortic carboxypeptidase‐like protein (ACLP), which is a part of the extracellular matrix. AEBP1 and ACLP contain a conserved carboxypeptidase domain which is critical for the function of AEBP1 as a transcriptional repressor. Homology modeling and multiple alignment of AEBP1 homologues were performed to identify putative domains and critical residues that were then deleted or mutated in mouse AEBP1. Expression of wild‐type and mutant AEBP1 proteins in CHO cells was performed, and their function in transcriptional repression was assayed by luciferase assay. All deletion forms of AEBP1 were able to repress transcription driven by the aP2 promoter. The DNA binding domain of AEBP1 was mapped by electrophoretic mobility shift assays to a region of the C‐terminus rich in basic residues. However, wild‐type AEBP1 was not able to interact strongly with DNA, suggesting that AEBP1 might function predominantly as a corepressor, independent of DNA binding. AEBP1 was also found to interact with Ca2+/calmodulin through this basic region, suggesting another mechanism of functional regulation. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Three real‐space discretization techniques in electronic structure calculations
Authors: Torsti T. , Eirola T. , Enkovaara J. , Hakala T. , Havu P. , Havu V. , Höynälänmaa T. , Ignatius J. , Lyly M. , Makkonen I. , Rantala T. T. , Ruokolainen J. , Ruotsalainen K. , Räsänen E. , Saarikoski H. , Puska M. J. 
Published: March 2006

AbstractA characteristic feature of the state‐of‐the‐art of real‐space methods in electronic structure calculations is the diversity of the techniques used in the discretization of the relevant partial differential equations. In this context, the main approaches include finite‐difference methods, various types of finite‐elements and wavelets. This paper reports on the results of several code development projects that approach problems related to the electronic structure using these three different discretization methods. We review the ideas behind these methods, give examples of their applications, and discuss their similarities and differences. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recent progress with large‐scale ab initio calculations: the CONQUEST code
Authors: Bowler D. R. , Choudhury R. , Gillan M. J. , Miyazaki T. 
Published: March 2006

AbstractWhile the success of density functional theory (DFT) has led to its use in a wide variety of fields such as physics, chemistry, materials science and biochemistry, it has long been recognised that conventional methods are very inefficient for large complex systems, because the memory requirements scale as N 2 and the cpu requirements as N 3 (where N is the number of atoms). The principles necessary to develop methods with linear scaling of the cpu and memory requirements with system size (𝒪(N ) methods) have been established for more than ten years, but only recently have practical codes showing this scaling for DFT started to appear. We report recent progress in the development of the Conquest code, which performs 𝒪(N ) DFT calculations on parallel computers, and has a demonstrated ability to handle systems of over 10000 atoms. The code can be run at different levels of precision, ranging from empirical tight‐binding, through ab initio tight‐binding, to full ab initio , and techniques for calculating ionic forces in a consistent way at all levels of precision will be presented. Illustrations are given of practical Conquest calculations in the strained Ge/Si(001) system. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lagrange‐function approach to real‐space order‐N electronic‐structure calculations
Authors: Varga Kálmán , Pantelides S. T. 
Published: March 2006

AbstractThe Lagrange functions are a family of analytical, complete, and orthonormal basis sets that are suitable for efficient, accurate, real‐space, order‐N electronic‐structure calculations. Convergence is controlled by a single monotonic parameter, the dimension of the basis set, and computational complexity is lower than that of conventional approaches. In this paper we review their construction and applications in linear‐scaling electronic‐structure calculations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional studies of molecular magnets
Authors: Postnikov Andrei V. , Kortus Jens , Pederson Mark R. 
Published: March 2006

AbstractAfter a general introduction into the field of molecular magnets the discussion focuses on a more specific description of their most important representative species, single‐molecule magnets incorporating transition metal ions. We overview traditional model approaches for the phenomenological description of such systems and outline some ways used to parameterize the corresponding models from experiment and from first‐principle calculations. The latter can be either multi‐determinantal quantum chemical schemes or those based on the density functional theory. In particular we discuss Heisenberg exchange parameters and magnetic anisotropy constants. As a practical example, an introduction into problems and properties of some single‐molecule magnets which gained much attention within last years, namely Mn12‐acetate, “Fe8” and “V15” systems, is given. This introduction into systems is followed by a critical comparison of calculation schemes based on the density functional theory that are particularly well suited for the study of molecular magnets. For the above systems we select some benchmark results, obtained by different methods. Finally, we outline our recent progress in the study of other single‐molecule magnets, including six‐membered “ferric wheels”, “ferric stars” and “Ni4” molecules, which we studied with the use of first‐principles methods Siesta and NRLMOL. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of mouse Sim2 gene on the cell cycle of PC12 cells
Authors: Meng Xianfang , Shi Jing , Peng Bin , Zou Xiaojing , Zhang Chun 
Published: March 2006

AbstractSim2 gene plays an important role in the pathogenesis of Down syndrome (DS). To observe the effect of mouse Sim2 (mSim2) on the cell cycle of PC12 cells in vitro and explore the role of Sim2 in the pathogenesis of DS, we cloned the full open reading frame of mSim2 into the pcDNA3 vector and transfected it into PC12 cells, before analysing the effect of mSim2 on the cell cycle. A eukaryotic expression vector of mSim2 (pcDNA3‐mSim2) was successfully constructed. There was notable expression of mSim2 mRNA in the cells transfected with pcDNA3‐Sim2. Flow cytometry showed that there were more cells in G0/G1 phase in the Sim2‐transfected cells than that in the controls (P < 0.01), and significantly fewer in G2/M phase (P < 0.01). The mRNA and protein expressions of cyclin E decreased in the Sim2‐transfected cells, while p27 expression increased significantly (P < 0.01). It is concluded that Sim2 may play an important role in the pathogenesis of DS by inhibiting the cell cycle, which is related to the decreased expression of cyclin E and increased expression of p27.
EDAC fixation increases the demonstrability of biogenic amines in the unicellular Tetrahymena: A flow cytometric and confocal microscopic comparative analysis
Authors: Csaba G. , Kovács P. , Pállinger É. 
Published: March 2006

AbstractEarlier experiments demonstrated the presence of hormones of the higher ranked animals in Tetrahymena. In the present experiments two fixatives, paraformaldehyde, which is commonly used and a carbodiimide, EDAC that was recommended by Panula et al. for the immunocytochemistry of histamine, are compared in Tetrahymena for the demonstration of histamine and serotonin by using flow cytometry and confocal microscopy. Both hormone levels were significantly higher after EDAC fixation; serotonin almost doubled and histamine was more than fivefold. The confocal microscopic pictures were clearer and the hormones' localization was easier. The results support earlier observations on the presence of these hormones in Tetrahymena and points to the advantage of EDAC fixation for demonstrating these hormones immunocytochemically.
Newly developed primary culture of rat visceral adipocytes and their in vitro characteristics
Authors: Shimizu Kyoko , Sakai Masato , Ando Mamiko , Chiji Hideyuki , Kawada Teruo , Mineo Hitoshi , Taira Toshio 
Published: March 2006

AbstractWe have recently developed a primary culture system for visceral adipocytes (VAs) using stomal‐vascular cells (SVCs) isolated from the mesenteric fat tissue of male Sprague—Dawley rats of 3–5 weeks of age. Modified Dulbecco's modified Eagle medium (DMEM)/F12 containing 17 μM pantothenic acid, 33 μM biotin, 100 μM ascorbic acid, 1 μM octanoic acid, 50 nM triiodothyronine, 10 μg/ml insulin, 10% newborn calf serum (NCS), 100 units/ml penicillin and 100 μg/ml streptomycin was used as a basal culture medium, which did not contain any synthetic compounds usually used to promote adipogenesis, such as indomethacin, dexamethasone, or peroxisome proliferator‐activated receptor (PPAR)‐γ agonists. The SVCs differentiated and proliferated efficiently, and formed a confluent monolayer in 3 days. The VAs accumulated lipids droplets in their cytoplasm at ∼7 days. The differentiation rate from applied SVCs to mature adipocytes was >80% per culture. Adiponectin concentration in the medium increased from Day 5 to Day 7. Application of lipid emulsion stimulated maturation of the SVCs into VAs, as well as subsequent lipid accumulation. Norepinephrine (2 × 10−5 mM) reduced the size of lipid particles and decreased triglyceride (TG) content in the matured adipocytes at 30 min. These results indicate that the new culture system is sufficient to maintain the physiological activity of visceral adipose tissue similar to that in vivo, making it an appropriate and useful tool for basic and applied research on obesity.
Post-traumatic stress reactions of children and adolescents exposed to the Athens 1999 earthquake
Authors: Giannopoulou Ioanna , Strouthos Marios , Smith Patrick , Dikaiakou Anastasia , Galanopoulou Vasiliki , Yule William 
Published: March 2006

AbstractThis study was undertaken 6–7 months after the 1999 Athens earthquake with the aim of exploring the differences in post-traumatic stress disorder (PTSD), anxiety and depression symptoms between a group of children exposed to earthquake with a group of children not exposed to it, but with both groups potentially exposed to the same levels of post-earthquake adversities. The study included 2037 children, aged 9–17 years, who were assessed with self-completed questionnaires. The directly exposed group (N = 1752) had significantly higher anxiety and PTSD scores than the indirectly exposed group (N = 284), but no significant group differences were found in depression scores. Girls in both groups reported significantly more PTSD, anxiety and depressive symptoms than boys. Younger children reported significantly more PTSD and anxiety symptoms than the older ones. No significant interactions were found between direct exposure to earthquake, age group and gender. The severity of PTSD symptoms was most strongly predicted by greater perceived threat during the earthquake, whereas depression was most strongly predicted by the level of post-earthquake adversity. The severity of anxiety symptoms was most strongly predicted by female gender. These findings are discussed in relation to the need for screening and intervention following earthquake events.
Effects of atypical and typical antipsychotic treatments on sexual function in patients with schizophrenia: 12-month results from the Intercontinental Schizophrenia Outpatient Health Outcomes (IC-SOHO) study
Authors: Dossenbach Martin , Dyachkova Yulia , Pirildar Sebnem , Anders Martin , Khalil Afaf , Araszkiewicz Aleksander , Shakhnovich Tamara , Akram Aly , Pecenak Jan , McBride Margaret , Treuer Tamas 
Published: March 2006

AbstractPurposeSexual dysfunction in patients with schizophrenia can reduce quality of life and treatment compliance. This report will compare the effects of selected atypical and typical antipsychotics on sexual function in a large, international population of outpatients with schizophrenia who were treated over 1 year.Subjects and methodsOutpatients with schizophrenia, who initiated or changed antipsychotic treatment, and entered this 3-year, prospective, observational study were classified according to the monotherapy prescribed at baseline: olanzapine (N = 2638), risperidone (N = 860), quetiapine (N = 142) or haloperidol (N = 188).ResultsBased on patient perception, the odds of experiencing sexual dysfunction during 1 year of therapy was significantly lower for patients treated with olanzapine and quetiapine when compared to patients who received risperidone or haloperidol (all P ≤ 0.001). Females on olanzapine (14%) or quetiapine (8%) experienced a lower rate of menstrual irregularities, compared to females on risperidone (23%) or haloperidol (29%). Significant discordance was evident between patient reports and psychiatrist perception of sexual dysfunction, with psychiatrists underestimating sexual dysfunction (P ≤ 0.001).ConclusionsThese findings indicate clinically relevant differences exist in the sexual side effect profiles of these selected antipsychotics. These factors should be considered when selecting the most appropriate treatment for outpatients with schizophrenia.
Public attitudes towards mental patients: a comparison between Novosibirsk, Bratislava and German cities
Authors: Schomerus Georg , Matschinger Herbert , Kenzin Denis , Breier Peter , Angermeyer Matthias C. 
Published: March 2006

AbstractPurpose– It is commonly assumed that reforms in the sector of psychiatric care have contributed to reducing the stigma attached to mental illness. In order to examine whether a relation between the psychiatric care set-up and stigmatisation of the patients exists we compared public attitudes towards mental patients in three countries at differing stages of progress in psychiatric reform.Methods– Population surveys on public attitudes towards mental patients were conducted in Novosibirsk (Russia) and Bratislava (Slovakia). The data were compared with those from a population survey that had recently been carried out in Germany. In all three surveys the same sampling procedure and fully structured interview were used. Public attitude towards mental patients was elicited using a perceived devaluation-discrimination measure.Results– Psychiatric patients face considerable rejection in all three locations in question. Overall, the degree of perceived devaluation and discrimination was similar in all countries with a significant, but marginal tendency towards stronger devaluation of mental patients in Germany.Conclusion– Our results do not support a strong relationship between psychiatric reform and mental illness stigma.
Resistance in Enterobacteriaceae: Results of a Multicenter Surveillance Study, 1995-2000
Authors: Friedland Ian , Stinson Lue , Ikaiddi Margaretmary , Harm Sandra , Woods Gail L. 
Published: March 2006

AbstractObjectives:To assess changes over time in susceptibility of Enterobacteriaceae from patients in ICUs, compare susceptibility rates of isolates from patients in ICUs with those from inpatients outside ICUs, and explore phenotypic patterns of cross-resistance and co-resistance.Design:From 1995 to 2000, centers participating in the ICU Surveillance Study tested 100 to 200 consecutive nosocomial gram-negative bacilli by broth microdilution.Setting:Each year, 42 to 97 U.S. hospitals tested isolates.Results:In all years, imipenem was the most potent agent tested, followed by amikacin and ertapenem. Extended-spectrum beta-lactam and monobactam agents had good activity against Escherichia coli and Klebsiella species, but limited activity against Enterobacter species. Susceptibility to imipenem and amikacin did not fluctuate during the analysis period, whereas susceptibility to ceftazidime, ceftriaxone, and ciprofloxacin decreased 2% to 5%. The decline was most pronounced for susceptibility of Escherichia coli to ciprofloxacin: 98.7% of ICU isolates were susceptible in 1995 versus 93.2% in 2000. Susceptibility of ICU isolates was lower than that of non-ICU isolates, except for ciprofloxacin, for which the reverse was true. Cross-resistance was common among extended-spectrum cephalosporins and penicillins, but uncommon between imipenem and ertapenem. Only imipenem and ertapenem remained highly active against Enterobacteriaceae with a phenotype suggesting possible production of an extended-spectrum beta-lactamase and those with a phenotype suggesting possible Amp C hyperproduction.Conclusions:Imipenem was the most active agent against nosocomial Enterobacteriaceae. Susceptibility to ciprofloxacin decreased from 1995 to 2000, particularly in Escherichia coli, and, in contrast to other agents, was lower among non-ICU isolates.