bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of aromatic polyethersulfone‐based graft copolyacrylates via ATRP catalyzed by FeCl2/isophthalic acid
Authors: Zhu Shenmin , Xiao Guyu , Yan Deyue 
Published: August 2002

AbstractThe atom transfer radical polymerization (ATRP) catalyzed by the FeCl2/isophthalic acid system was used for the preparation of novel aromatic polyethersulfone (PSF)‐based graft copolymers in N,N‐dimethylformamide (DMF), such as aromatic PSF‐graft‐poly(methyl methacrylate), aromatic PSF‐graft‐polymethylacrylate, and aromatic PSF‐graft‐poly(butyl acrylate). The route consisted of two steps. The first step included the chloromethylation of aromatic PSF, and the second step involved the ATRP of acrylate monomers using chloromethylated aromatic PSF as the macroinitiator and FeCl2/isophthalic acid as the catalyst in DMF. Characterization data by gel permeation chromatography, DSC, IR, 1H NMR, and thermogravimetric analysis confirmed that the graft copolymerization was successful. Only one glass‐transition temperature (Tg) was observed for aromatic PSF‐graft‐poly(methyl methacrylate), and two Tg's were detected for aromatic PSF‐graft‐methyl acrylate and aromatic PSF‐graft‐poly(butyl acrylate). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2943–2950, 2001
Modeling of the optical anisotropy of a dye polarizer
Authors: Han S. E. , Hwang I. S. 
Published: August 2002

AbstractA new model has been developed to account for the dependence of the optical anisotropy of a dye polarizer on the dye concentration. The effect of the dye concentration has been studied through an examination of the changes in the orientation distribution of the polymer. The model takes into account the intrinsic optical anisotropy of the dichroic dye, the polymer orientation, the polymer orientation distribution, and the dye orientation with respect to the polymer. It is assumed that (1) the orientation distribution function of the polymer segments can be expressed as an elliptical distribution function and that (2) the free rotation of each dye molecule on its axis is suppressed because of the attraction force between the dye molecules and the polymer chains. The pseudo‐order parameter, which takes into account the aforementioned assumptions, determines the relation between single‐piece transmittance and polarizing efficiency. The orientation distribution of the polymer molecules in the experiment and its effect on the optical performance of a polarizer are quantitatively determined. The model predicts that the effect of the orientation distribution becomes more significant as the polymer chains are oriented more highly. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1363–1370, 2002
Open spaces and molecular motions in carbon‐black‐ and silica‐loaded SBR investigated using positron annihilation
Authors: Uedono A. , Fukui S. , Muramatsu M. , Ubukata T. , Kimura S. , Tanigawa S. 
Published: August 2002

AbstractLifetime spectra of positrons were measured for styrene–butadiene rubber (SBR) vulcanizates filled with carbon black (CB) or silica. At temperatures between 10 and 420 K, no large difference between the size of the open spaces in the CB/SBR vulcanizate and that in the specimen without the filler was observed. Above the glass‐transition temperature (Tg = 230 K), the same was true for the silica/SBR vulcanizate. Below Tg, however, the size of the open spaces was reduced by the incorporation of silica as a result of the suppression of local molecular motions in the SBR. The density of the open spaces was reduced by the incorporation of the fillers. However, above 400 K it started to increase in the silica/SBR vulcanizate. For the CB/SBR vulcanizate, the introduction of open spaces was well suppressed, even at 420 K. © 2001 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 39: 835–842, 2001
Ionic conductivities of solid polymer electrolytes: The effect of pressure
Authors: Ahn Woo Young , Bae Young Chan 
Published: August 2002

AbstractA molecular thermodynamic model based on the theory of melting point depression, the Adam–Gibbs configurational entropy model, and the lattice fluid model was developed to interpret the ionic conductivities of solid polymer electrolytes with various pressures. Quantitative descriptions according to the proposed model are in good agreement with the experimental data for the given systems. Our results show that an eutectic point moves toward a higher Tm and lower weight fraction of salt, and the ionic conductivity significantly decreases with pressure. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1484–1491, 2001
An NMR study of mobility in a crystalline side‐chain comblike polymer
Authors: Giotto Marcus , Azar David , Gosselin Jaimie , Inglefield Paul T. , Jones Alan A. 
Published: August 2002

AbstractCarbon‐13 spin–lattice relaxation times are measured for poly(octadecyl acrylate) above and below the melting point of the crystalline side chains. The chain backbone has long spin–lattice relaxation times below the melting point that shorten by more than an order of magnitude as the melting point range is traversed. Below the melting point, the backbone is nearly immobilized with spin–lattice relaxation changing very slowly with temperature. Above the melting point, the shorter spin–lattice relaxation times are typical of a rubber above the glass transition and decrease with increasing temperature. The methylene groups in the side chain are quite mobile well below the melting point, indicating fairly rapid anisotropic motion within the crystal. The methyl group at the end of the chain and the adjacent methylene group have longer spin–lattice relaxation times, indicating the greatest side‐chain mobility at the end, which is in the middle of the crystal structure. The side‐chain carbon adjacent to the carbonyl group is as mobile as the majority of the side‐chain carbon, indicating side‐chain mobility extends to all of the side‐chain CH2 groups. The abrupt transition in the mobility of the backbone is not typical of the amorphous phase in a semicrystalline polymer where the backbone units can crystallize. The close proximity of every backbone segment to the crystalline domain locks backbone segmental motion below the melting point. Melting and crystallization of the side chains switch segmental motion of the backbone on and off. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1548–1552, 2001
Medical students' attitudes towards breaking bad news: an empirical test of the World Health Organization model
Authors: De Valck C. , Bensing J. , Bruynooghe R. 
Published: August 2002

AbstractThe literature regarding breaking bad news distinguishes three disclosure models: non‐disclosure, full‐disclosure and individualized disclosure.In this study, we investigated the relations between attitudes regarding disclosure of bad news and global professional attitudes regarding medical care in a sample of medical students (n=88). The Attitudes towards Breaking Bad News Questionnaire was developed and factor analysed to provide a valid and reliable instrument to measure attitudes regarding disclosure of bad news. The results indicate a preference for an individualized, patient‐centred disclosure model in male and female students. Regarding the global professional attitudes, female students appear more humane‐oriented than male students.Second, the relationship between global professional attitudes and attitudes regarding breaking bad news was examined by means of correlational and cluster analysis. The inter‐relationship between global professional attitudes and attitudes regarding bad news is poor. Results of the cluster analysis, however, suggest that the sample can be divided into subsamples representing different disclosure clusters on the basis of specific combinations of global professional attitudes regarding medical care and attitudes regarding breaking bad news. The results are discussed in view of the theoretical framework proposed by the World Health Organization (WHO) in their training module on communication of bad news. Copyright © 2001 John Wiley & Sons, Ltd.
Predictors of a normal chest x‐ray in respiratory syncytial virus infection
Authors: Kneyber Martin C.J. , Moons Karel G.M. , de Groot Ronald , Moll Henriëtte A. 
Published: August 2002

AbstractRespiratory syncytial virus (RSV) accounts for the majority of lower respiratory tract infections (LRTI) in infants and young children. A chest x‐ray is frequently performed in infants with LRTI caused by RSV. The aim of this study was to develop and validate a prediction model to estimate the probability for a normal chest x‐ray in children with RSV infection. For this purpose, easy obtainable diagnostic parameters were used. This prediction model may be applied to decide which patients do not require a chest x‐ray. The data of 287 children admitted with RSV infection or diagnosed as such in the outpatient department of the Sophia Children's Hospital between 1992–1996 were studied. The derivation set comprised 232 patients (1992–1995), and the validation set contained 55 patients (1995–1996). A chest x‐ray was designated as normal when atelectasis, hyperinflation, or pulmonary infiltrates were absent. In order to develop a prediction model, patient history and clinical and laboratory variables were consecutively entered into a logistic regression model according to the diagnostic workup that was practiced at the time. Variables with P ≤ 0.10 were retained in the model. The predictive accuracy of the multivariable models was examined using the area under receiver operating curve (ROC‐area).In 202 (87%) patients from the derivation set, a chest x‐ray was performed. A normal chest x‐ray could be predicted by increasing age, increasing birth weight, presence of rhinitis, absence of retractions, and increasing arterial oxygen saturation. The ROC‐area was 0.80 in the derivation and validation sets. This prediction model was transformed into a score chart.In conclusion, a normal chest x‐ray can accurately be predicted, using a model including easily obtainable patient characteristics, and clinical and laboratory variables. This model may be a useful tool in deciding whether or not to perform a chest x‐ray in patients with RSV infections. Pediatr Pulmonol. 2001; 31:277–283. © 2001 Wiley‐Liss, Inc.
Early chest radiographs in very low birth weight babies receiving corticosteroids for lung disease
Authors: Clark Philip W. , Bloomfield Frank H. , Harding Jane E. , Teele Rita L. 
Published: August 2002

AbstractWe set out to determine whether chest radiographs obtained in premature infants between 9–16 days of age are predictive for the development of chronic lung disease of the newborn (CLD). This was a prospective cohort study. The study included 40 babies who were enrolled in a randomized trial of corticosteroid therapy for the prevention of CLD. Chest radiographs were obtained for clinical indications between 9–16 and 25–35 days of age. All chest radiographs were assessed by a single pediatric radiologist who was unaware of the treatment allocation and who used a previously published scoring system devised by Weinstein et al. [Pediatr Pulmonol 1994;18:284–289].The radiographic score at 9–16 days correlated well with the radiographic score at 25–35 days of age (correlation coefficient, 0.69, P ≤ 0.001). The scores at 9–16 days were significantly higher in those babies who had CLD at 28 days postnatal age (PNA) (P = 0.03) and at 36 weeks postmenstrual age (PMA) (P = 0.002). Using a receiver‐operator characteristic curve, we have determined that for a radiographic score of 3 or greater at 9–16 days, the sensitivity for CLD was 0.64, and specificity was 0.84.We conclude that a chest radiograph taken between 9–16 days may help predict which at‐risk preterm infants will develop CLD. Pediatr Pulmonol. 2001; 31:297–300. © 2001 Wiley‐Liss, Inc.
Inspiratory resistive load detection in children with life‐threatening asthma
Authors: Davenport Paul W. , Kifle Yemiserach 
Published: August 2002

AbstractThe detection of inspiratory resistive (R) loads was studied in nonasthmatic children (NA), asthmatic children (A), and children with a history of life‐threatening asthma (LTA). It was hypothesized that the LTA children would have a reduced ability to detect added mechanical loads as measured by the Weber fraction, which assesses the resistive load detection threshold (ΔR50/R0). Subjects were separated from the investigator, were seated in a soundproofed room, and breathed through a nonrebreathing valve with the inspiratory port connected to the loading manifold. The subject's inspiratory baseline resistance (Raw) was measured by the interrupter method. Ten magnitudes of R loads and no‐load were presented randomly 10 times each for a single inspiration. The loads were presented in three trials. Subjects pressed a button if they detected the presence of a load. The ΔR50 was determined from the % detection‐ΔR curve. R0 was the sum of the subject's Raw and the minimal resistance of the apparatus.The ΔR50/R0 for children with life‐ threatening asthma was significantly greater than for asthmatic and nonasthmatic children.The increased ΔR50/R0 suggests that children with LTA are at risk of life‐threatening asthma attacks, in part because it requires a greater change in resistance above their baseline resistance before they sense an increased mechanical load such as presented to them by bronchoconstriction during an asthmatic attack. Pediatr Pulmonol. 2001; 32:44–48. © 2001 Wiley‐Liss, Inc.
Churg‐Strauss syndrome revealed by acute abdominal pain
Authors: Berlioz M. , Triolo V. , Sirvent N. , Albertini M. 
Published: August 2002

AbstractWe describe a 10‐year‐old girl with Churg‐Strauss syndrome, who presented with acute abdominal pain, bloody diarrhea, and pulmonary infiltrates. She had a 6‐year history of severe asthma. Bronchoalveolar lavage showed marked eosinophilia. She responded well to high‐dose intravenous corticosteroid pulse therapy for 3 consecutive days, followed by oral steroids without developing major side effects. This case should remind pediatricians of the rare existence of this vasculitis in children. Relapse is not uncommon, and long‐term careful supervision is necessary. Pediatr Pulmonol. 2001; 32:92–94. © 2001 Wiley‐Liss, Inc.
Beclomethasone diproprionate reduced airway inflammation without adrenal suppression in young children with cystic fibrosis: A pilot study†‡
Authors: Wojtczak Henry A. , Kerby Gwendolyn S. , Wagener Jeffrey S. , Copenhaver Steven C. , Gotlin Ronald W. , Riches David W.H. , Accurso Frank J. 
Published: August 2002

AbstractInhaled corticosteroids are commonly used in cystic fibrosis (CF), but there are few studies evaluating their safety in young children. We, therefore, prospectively administered beclomethasone diproprionate (BDP) to 12 clinically stable young children with CF to examine the safety of this therapy with respect to adrenal suppression and airway infection. To determine potential mechanisms of corticosteroid action in CF, we also examined airway markers of inflammation before and after inhaled steroid treatment. BDP 210 μg twice a day was given via spacer for 2 months. Twelve‐hour serum and urine cortisols and response to low‐dose synthetic ACTH cortisol stimulation were assessed. Bronchoalveolar lavage fluid (BALF) was examined pre‐ and posttreatment with BDP by quantitative bacteriology and indices of airway inflammation, including levels of total neutrophils, neutrophil elastase‐α‐1 antiprotease complexes (NEAP), CA 19‐9 mucin‐associated antigen, interleukin‐8 (IL‐8), and macrophage IL‐8 mRNA.Following 2 months of treatment, serum and urine cortisol levels were unchanged. Response to low‐dose ACTH cortisol stimulation was not significantly decreased at 30 min. Posttreatment BALF bacterial density was not statistically different from pretreatment; however, one patient who was initially culture negative became culture‐positive with Hemophilus influenzae. BALF total neutrophil counts, corrected for epithelial lining fluid dilution, were decreased to approximately one third of pretreatment values (P = 0.03). NEAP and CA 19‐9 mucin‐associated antigen demonstrated similar decreases. BALF IL‐8 levels and macrophage IL‐8 mRNA levels were not statistically changed.These findings suggest that treatment with BDP 420 μg per day for 2 months in young children with CF does not affect urine and blood cortisol, causes no decrease in adrenal reserve, and does not result in a clinically significant increase in airway infection. In addition, the fall in bronchoalveolar lavage fluid inflammatory markers following BDP suggests possible modulation of neutrophil influx into the CF airway and provides justification for further studies of inhaled corticosteroids in CF. Pediatr Pulmonol. 2001; 32:293–302. © 2001 Wiley‐Liss, Inc.
Mutation analysis of the p51 gene and correlation between p53, p73, and p51 expressions in prostatic carcinoma
Authors: Takahashi Hiroyuki , Fukutome Kazuo , Watanabe Masatoshi , Furusato Masakuni , Shiraishi Taizo , Ito Haruo , Suzuki Hiroyoshi , Ikawa Shuntaro , Hano Hiroshi 
Published: August 2002

AbstractBACKGROUNDp73 and p51 are genes possessing amino‐acid similarities to p53. We previously found no mutation in p73 in prostatic carcinoma, but did find abnormal expression of the gene. Involvement of these genes in prostatic carcinogenesis is still poorly understood.METHODSMutation analysis of the p51 gene and allelotyping of 3q28, on which p51 lies, were performed. Expression of p53, p73, and p51 was examined using reverse transcription–polymerase chain reaction, and expression levels were compared.RESULTSNo mutation in p51 was found (0/55 cases). Loss of heterozygosity at 3q28 was detected in 6 of 28 cases (21.8%). By expression analysis we found that in p53, 4 of 38 cases (10.5%) showed downregulation. No cases showed upregulation of p53. In contrast, p73 and p51 were downregulated in 42.1 and 39.5% of cases, respectively, and upregulated in 31.5 and 34.2% of cases, respectively. Expression levels of p51 corresponded with those of p73 in 25 of 38 cases (65.8%).CONCLUSIONSSomatic mutations in p73 and p51 are not important in prostatic carcinogenesis. These genes may be associated with tumors by expression levels and may have roles in addition to tumor suppresson. Prostate 47:85–90, 2001. © 2001 Wiley‐Liss, Inc.
GDEP, a new gene differentially expressed in normal prostate and prostate cancer†
Authors: Olsson Pär , Bera Tapan K. , Essand Magnus , Kumar Vasantha , Duray Paul , Vincent James , Lee Byungkook , Pastan Ira 
Published: August 2002

AbstractBACKGROUNDThe database of human expressed sequence tags (dbEST) is a potential source for the identification of tissue specific genes. The database contains sequences that originate from cDNA libraries from different tissues cell types and tumors.METHODSComputer based analysis identified a cluster of sequence homologous ESTs, containing ESTs derived only from human prostate cDNA libraries. The tissue specificity was examined by multiple tissue RNA dot blots and RT‐PCR. The new RNA transcript was characterized using northern blot analysis, RACE‐PCR, and a ribonuclease protection assay.RESULTSWe have identified a gene differentially expressed in prostate using EST database analysis and experimental studies. We name the gene GDEP for gene differentially expressed in prostate. The major GDEP transcript is about 520 bp long. GDEP RNA was detected in nine prostate tissue samples, four normal and five cancer. Expression in prostate epithelial cells was established by in situ hybridization. Weak expression was detected in the prostate cancer cell line LNCaP. In vitro transcription/translation indicate that the RNA encodes a small 34 amino acid protein. The major transcript consists of two exons with one large intron (> 15 kb). The GDEP gene was mapped to chromosome 4q21.1 by radiation hybrid mapping.CONCLUSIONSOur data proves that tissue specific genes can be identified by EST database mining. The prostate specificity of GDEP expression indicates that GDEP may be useful in the diagnosis or treatment of prostate cancer. Prostate 48:231–241, 2001. Published 2001 Wiley‐Liss, Inc.
Role of endogenous transforming growth factor β (TGFβ) 1 in prostatic stromal cells*
Authors: Bretland Amanda J. , Reid Sheilagh V. , Chapple Christopher R. , Eaton Colby L. 
Published: August 2002

AbstractBACKGROUNDIn this study, defined culture conditions were used to examine the effects of recombinant TGFβ1 on prostatic stromal cells and to determine the role of endogenous TGFβ produced by these cells.METHODSCells were grown +/− recombinant TGFβ1 and cell population sizes in replicate cultures determined. In other experiments, TGFβ1 production by prostatic stromal cells was examined and the effects of neutralization of this activity on cell population sizes and apoptosis evaluated.RESULTSAt > 1 ng/ml, TGFβ1 reduced cell population sizes while at 0.01 ng/ml cell numbers were increased cf. controls. Stromal cells produced up to 10 ng/ml/48 hr of latent TGFβ1 of which < 0.2% was biologically active. When cells were treated with anti‐TGFβ1 antibodies, cell numbers decreased cf. controls and the proportion of apoptotic cells increased.CONCLUSIONSThese observations suggest that TGFβ1 is an autocrine factor made by prostatic stromal cells in which it inhibits apoptosis at the activity levels produced. Prostate 48:297–304, 2001. © 2001 Wiley‐Liss, Inc.
Structure and cooperativity of a T‐state mutant of histidine decarboxylase from Lactobacillus 30a
Authors: Worley Scott , Schelp Elisabeth , Monzingo Arthur F. , Ernst Stephen , Robertus Jon D. 
Published: August 2002

AbstractHistidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth. HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH. The X‐ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate‐binding site. The HDC trimer has also been shown to exhibit cooperative kinetics at neutral pH, that is, histidine can trigger a T‐state to R‐state transition. The D53,54N mutant of HDC has an elevated Km, even at low pH, indicating that the enzyme assumes the low activity T‐state. We have solved the structures of the D53,54N mutant at low pH, with and without the substrate analog histidine methyl ester (HME) bound. Structural analysis shows that the apo‐D53,54N mutant is in the inactive or T‐state and that binding of the substrate analog induces the enzyme to adopt the active or R‐state. A mechanism for the cooperative transition is proposed. Proteins 2002;46:321–329. © 2002 Wiley‐Liss, Inc.
Kinetic nonoptimality and vibrational stability of proteins
Authors: Cieplak Marek , Hoang Trinh Xuan 
Published: August 2002

AbstractScaling of folding times in Go models of proteins and of decoy structures with the Lennard–Jones potentials in the native contacts reveal power law trends when studied under optimal folding conditions. The power law exponent depends on the type of native geometry. Its value indicates lack of kinetic optimality in the model proteins. In proteins, mechanical and thermodynamic stabilities are correlated. Proteins 2001;44:20–25. © 2001 Wiley‐Liss, Inc.