bluuebunny/crossref_metadata_2025 huggingface dataset:
Grid‐connected photovoltaic systems: the Brazilian experience and the performance of an installation
Authors: Ferreira de Oliveira Sérgio Henrique , Zilles Roberto
Published: August 2002

Just as in several other countries, the Brazilian experience of installing in place solar photovoltaic technology was first aimed at meeting the needs of rural areas. More recently, the effects of the international trend towards grid‐connected photovoltaic systems are beginning to be felt in Brazil. In less than five years, the first four grid‐connected photovoltaic systems have been installed, and other projects are in progress. This work presents the overall characteristics of the first four systems and the technical performance achieved by one of them, with an annual production in the range of 1500 kW h/kWp. Copyright © 2001 John Wiley & Sons, Ltd.
Radical stabilization energy as a measure of the spectral properties and reactivity trends in homologous groups
Authors: Finkelshtein E. I.
Published: August 2002

The existence of linear relationships has been demonstrated between stretching frequencies of R—H, RO—H, CH3CON(R)—H and R—OX (X = H for alcohols and O for peroxy radicals) bonds and radical stabilization energies, Es(R·), of related radicals. The correlation equations of Es(R·) and R—H bond dissociation energies (BDE), D(R—H), with the above stretching frequencies were obtained. From the equations the D(R—H) values for different hydrocarbons were calculated and compared with the experimental data. The mean difference between calculated and experimental values for saturated hydrocarbons is 2.3 kJ mol−1. The greater differences for some unsaturated hydrocarbons are discussed and explained. The BDEs calculated from the D(R—H = f (ν) equations may be regarded as the best. The IR spectra of menthol, menadione, 3‐methylpent‐2‐en‐4‐yn‐1‐ol and retinol were recorded in solution and the Es(R·) values of the corresponding radicals and the D(R—H) values of the related C—H bonds in the parent hydrocarbons were estimated for the first time. It is also shown that the radical stabilization energy may be used to estimate the reactivity of organic compounds in free radical reactions. One may conclude that the stabilization energy of the radicals of many organic compounds could be estimated from the vibrational spectra. The Es(R·) itself is a useful quantity for predicting kinetic and spectral properties of organic compounds. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and characterization of new aromatic tweezers and complex formation with tropylium ion in 1,2‐dichloroethane
Authors: Lämsä Markku , Kiviniemi Sari , Kettukangas Eeva‐Riitta , Nissinen Maija , Pursiainen Jouni , Rissanen Kari
Published: August 2002

A series of benzene and pyridine tweezers bearing phenyl, naphthyl and anthryl receptor units was prepared and characterized. The x‐ray crystal structure of the 1,3‐bis(9‐methanolanthracene)methylbenzene ligand (5) is reported. UV–visible and NMR spectroscopy were used to investigate the host–guest chemistry of the new ligands in complexation with tropylium tetrafluoroborate as a model aromatic cationic guest in 1,2‐dichloroethane. The appearance of coloured charge‐transfer absorption bands demonstrates the complex formation with a tropylium ion. The enlargement of aryl receptor size from phenyl and naphthyl to anthryl increases the stability of complexes. Electron donor–acceptor interactions are an important driving force for complexation by molecular tweezers. The results are discussed and compared with those of previously studied systems containing crown ethers and podands. The bisanthracenes 5 and 1,3‐bis(9‐methanolanthracene)methylpyridine (6) are especially interesting in displaying both complexation ability and intramolecular cycloaddition via charge‐transfer excitation. Copyright © 2001 John Wiley & Sons, Ltd.
Tautomerism in 4‐substituted 1‐phenyl‐3‐methyl‐pyrazolin‐5‐ones—a theoretical ab initio and 13C NMR study
Authors: Kleinpeter E. , Koch A.
Published: August 2002

The tautomeric equilibria between the CH, OH and NH forms in a series of 4‐substituted 1‐phenyl‐3‐methyl‐pyrazolin‐5‐ones have been studied using ab initio calculations at various levels of theory and comparison made with the experimental results obtained from NMR measurements. Quantitative comparison of both the relative energies and the 13C chemical shifts of the tautomers constituting the tautomeric equilibria were made by calculation of both sets of parameters. The influence of the solvent was included by employing various models of the self‐consistent reaction field theory. Initially, the solvent was included in the calculations by applying a continuum of differing polarity over the surface of isolated tautomers (self‐consistent isodensity polarized continuum model method), then later by assuming formation of an adduct between the solute and the solvent (thereby simulating effectively the hydrogen bonding in the OH and NH tautomers) and finally by calculating dimer or trimer complexes of the various tautomers. In this manner, the agreement between the theoretically calculated and the experimentally determined tautomeric equilibria was improved significantly. The theoretically calculated 13C chemical shifts of the tautomers were found to be viable for the assignment of the tautomers, particularly the preferred tautomer in the OH/NH equilibrium, which remains fast on the NMR time scale even at low temperatures. Copyright © 2001 John Wiley & Sons, Ltd.
Tetraalkylalkene vertical ionization potentials revisited
Authors: Nelsen Stephen F. , Reinhardt Laurie A.
Published: August 2002

The vertical ionization potentials for three tetra‐α‐branched‐alkyl‐substituted alkenes (13–15) are reported, compared with literature data for other tetralkylalkenes, and the values discussed with reference to AM1 semiempirical and B3LYP density functional calculations. Copyright © 2001 John Wiley & Sons, Ltd.
(Thiocarbonyl‐α‐thio)carboxylic acid derivatives as transfer agents in reversible addition–fragmentation chain‐transfer polymerizations
Authors: Farmer Steven C. , Patten Timothy E.
Published: August 2002

Ethyl S‐(thiobenzoyl)thioacetate, ethyl S‐thiobenzoyl‐2‐thiopropionate, and S‐(thiobenzoyl)thioglycolic acid were used as chain‐transfer agents for the reversible addition–fragmentation chain‐transfer (RAFT) polymerizations of styrene, methyl methacrylate, and butyl acrylate. Of these polymerizations, only those of styrene and butyl acrylate with any of the transfer agents showed molecular weight control corresponding to controlled/living polymerizations. The best molecular weight control was observed for the polymerizations of styrene and butyl acrylate with ethyl (S)‐thiobenzoyl‐2‐thiopropionate. Semiempirical PM3 calculations were performed for the investigation of the relative heats of reaction of the chain‐transfer equilibria between the aforementioned chain‐transfer agents and dimer radicals of the three monomers. The molecular weight control of the polymerizations correlated with the stability trend of the leaving‐group radical of the chain‐transfer agent. This relatively simple computational model offered some value in determining which transfer agents would show the best molecular weight control in RAFT polymerizations. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 555–563, 2002; DOI 10.1002/pola.10143
Poly(pentamethylcyclopentasiloxane). I. Synthesis and characterization
Authors: Kurian P. , Kennedy J. P. , Kisluik A. , Sokolov A.
Published: August 2002

We have discovered that pentamethylcyclopentasiloxane (D5H) can be readily polymerized into poly(pentmethylcyclopentasiloxane) (PD5) with a Pt (Karstedt) catalyst in the presence of water in bulk or in solution at 100 °C and that the product is a solid with extraordinary properties. The polymerization starts with the oxidation of the SiH groups by water into an intermediate containing SiOH groups (SiH + H2O → SiOH + H2), which is followed immediately by the condensation (2SiO → SiOSi) of D5H rings into complex aggregates of cyclosiloxane moieties. According to Raman spectroscopy, an average of three of the five SiH functionalities are converted, and the final product contains only a negligible number of SiOH groups. The melting and glass‐transition temperatures of the monomer are exceptionally low: Tm,D5H = −137.6 ± 1 and Tg,D5H = −152 ± 2 °C. The polymer exhibits an unprecedented combination of properties: it is a stiff and brittle solid, is insoluble in common solvents, does not exhibit a melting endotherm but has an extremely low glass transition (Tg,PD5 = −151 ± 0.5 °C), and is thermally stable up to at least 700 °C. Brillouin scattering indicates very slow variation of the relaxation time with temperature, a property characteristic of strong glass‐forming systems such as silica glass. This characteristic may account for the unique combination of properties of the new polymer: an extremely low glass‐transition temperature combined with solidlike properties even at ambient temperature (more than twice its glass‐transition temperature). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1285–1292, 2002
Synthesis and characterization of novel polyimides bearing a side chain composed of stilbene mesogen and undecyl spacer and the alignment ability of nematic liquid‐crystal molecules
Authors: Park J. H. , Sohn B.‐H. , Jung J. C. , Lee S. W. , Ree M.
Published: August 2002

Four different polyimides with side chains containing undecyl spacers and 4‐fluorostilbene mesogen end groups were prepared, and their structures and the controllability of the liquid‐crystal (LC) alignment with rubbing were investigated. From X‐ray scattering and differential scanning calorimetry data, pyromellitic dianhydride (PMDA)‐, benzophenone‐3,3′,4,4′‐tetracarboxylic dianhydride (BTDA)‐, and 4,4′‐oxydi(phthalic anhydride) (ODPA)‐based polyimides were shown to have layered structures and short‐range ordering. Pretilt angles of LCs on the rubbed surfaces were 1–9°, depending on the rubbing density and backbone. In particular, the long undecyl spacers caused the mesogenic stilbene end groups to lie next to the main chain, resulting in a reduction in the pretilt angles. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1800–1809, 2001
One‐step preparation of polyurethane dispersions by miniemulsion polyaddition
Authors: Tiarks Franca , Landfester Katharina , Antonietti Markus
Published: August 2002

The application of the miniemulsion process to synthesize polyurethane dispersions with diameters of about 200 nm in a one‐step procedure, free of molecular weight restrictions, is described. With IR and NMR spectroscopy, it is shown that the reaction of the diisocyanate with the diol is the main reaction, whereas the reaction with water is only a side reaction. Differential scanning calorimetry measurements and transmission electron microscopy are used to characterize both polymer and latex properties. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2520–2524, 2001
Synthesis, characterization, and biodegradability of novel regular‐network polyester‐amines based on 1,1,1‐triethanolamine
Authors: Nagata Minoru , Morooka Takashi , Sakai Wataru , Tsutsumi Naoto
Published: August 2002

Regular‐network polyester‐amines were prepared from 1,1,1‐triethanolamine (YN) and various dicarboxylic acids [HOOC(CH2)n−2COOH, n = 6–14]. A prepolymer prepared by melt polycondensation was cast from dimethylformamide solution and postpolymerized at 220 °C in a nitrogen flow for various periods of time to form a network. The resultant films were transparent, flexible, and insoluble in organic solvents. The network polyester‐amines obtained were characterized by infrared absorption spectra, wide‐angle X‐ray diffraction analysis, density, DSC, and thermomechanical analysis. The biodegradation experiments for the network polyester‐amine films were carried out in enzymatic solution with Rhizopus delemar or Pseudomonas cepacia lipase and in an activated sludge. The degree and rate of biodegradation were estimated by the weight loss of the films. After incubation in Rhizopus delemar lipase solution for 24 h, weight loss was hardly observed for YN6–7, whereas it increased greatly for YN8–13 (13–51 g/m2), and then it decreased rapidly for YN14. The methylene‐chain dependence of degradation was essentially the same as in the case of network polyesters from glycerol and various aliphatic dicarboxylic acids reported previously. Psedomonas cepacia lipases also degraded YNn films, but the rate of degradation was much slower than Rhizopus delemar lipase. In the exposure to activated sludge for 30 days, the network polyester films with medium methylene‐chain lengths (YN7–11) showed the lager weight loss, as in the case of the enzymatic degradation, whereas the rate of biodegradation was much slower than that of the enzymatic degradation with Rhizopus delemar lipase. The effect of the protonation of the film with hydrochloric acid on the enzymatic degradation was also examined. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2896–2903, 2001
Synthesis of aromatic polyethersulfone‐based graft copolyacrylates via ATRP catalyzed by FeCl2/isophthalic acid
Authors: Zhu Shenmin , Xiao Guyu , Yan Deyue
Published: August 2002

The 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

A 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

Lifetime 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

A 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

Carbon‐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

The 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

Respiratory 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

We 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

The 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

We 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

Inhaled 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

BACKGROUND

p73 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.

METHODS

Mutation 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.

RESULTS

No 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%).

CONCLUSIONS

Somatic 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

BACKGROUND

The 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.

METHODS

Computer 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.

RESULTS

We 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.

CONCLUSIONS

Our 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

BACKGROUND

In 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.

METHODS

Cells 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.

RESULTS

At > 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.

CONCLUSIONS

These 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

Histidine 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

Scaling 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.
Helix‐coil transition of PrP106–126: Molecular dynamic study
Authors: Levy Yaakov , Hanan Eilat , Solomon Beka , Becker Oren M.
Published: August 2002

A set of 34 molecular dynamic (MD) simulations totaling 305 ns of simulation time of the prion protein‐derived peptide PrP106–126 was performed with both explicit and implicit solvent models. The objective of these simulations is to investigate the relative stability of the α‐helical conformation of the peptide and the mechanism for conversion from the helix to a random‐coil structure. At neutral pH, the wild‐type peptide was found to lose its initial helical structure very fast, within a few nanoseconds (ns) from the beginning of the simulations. The helix breaks up in the middle and then unwinds to the termini. The spontaneous transition into the random coil structure is governed by the hydrophobic interaction between His111 and Val122. The A117V mutation, which is linked to GSS disease, was found to destabilize the helix conformation of the peptide significantly, leading to a complete loss of helicity approximately 1 ns faster than in the wild‐type. Furthermore, the A117V mutant exhibits a different mechanism for helix‐coil conversion, wherein the helix begins to break up at the C‐terminus and then gradually to unwind towards the N‐terminus. In most simulations, the mutation was found to speed up the conversion through an additional hydrophobic interaction between Met112 and the mutated residue Val117, an interaction that did not exist in the wild‐type peptide. Finally, the β‐sheet conformation of the wild‐type peptide was found to be less stable at acidic pH due to a destabilization of the His111–Val122, since at acidic pH this histidine is protonated and is unlikely to participate in hydrophobic interaction. Proteins 2001;45:382–396. © 2001 Wiley‐Liss, Inc.
Aversion of the feral pigeon and the house sparrow to pellets and sprouts treated with commercial formulations of methyl anthranilate
Authors: Moran Shmuel
Published: August 2002

Two methyl anthranilate formulations, ReJex‐iT® TP‐40 and AG‐36, were tested as bird‐repelling agents for animal feed and vegetable sprouts, respectively. Feral pigeons (Columba livia) and house sparrows (Passer domesticus) are important pests of animal husbandry and field crops in Israel. In each 4‐day experiment, four birds were held together in an aviary, and were offered four trays or dishes with animal feed or cauliflower sprouts in four corners of the cage. The trays and dishes were transposed daily in a Latin square sequence. Pigeons consumed significantly more untreated feed than treated feed. When no alternative untreated food was offered, there was no significant repellency. Treatment of animal feed with TP‐40 to give 2.0 ml methyl anthranilate kg−1 or less had no repellent effect on sparrows. Concentrations of 4.0 ml kg−1 or more repelled the sparrows significantly. When no untreated feed was presented, pigeons and sparrows preferred the lowest concentration of methyl anthranilate presented. When AG‐36 was tested on vegetable sprouts, the sparrows tended significantly to avoid the highest concentration used—14.5 ml methyl anthranilate litre−1 spray. The inter‐specific differences between the birds indicate that the efficacy of methyl anthranilate formulations as a repellent has to be specified for every species. This study did not determine (1) the possibility of developing habituation, (2) the behaviour of birds under natural conditions in the field, or (3) the influence of the feeding behaviour of a sympatric bird species on the repellency of methyl anthranilate to other species.

© 2001 Society of Chemical Industry
Viability and stability of biological control agents on cotton and snap bean seeds
Authors: Elliott Monica L , Jardin Elizabeth A Des , Batson William E , Caceres Jacobo , Brannen Philip M , Howell Charles R , Benson D Michael , Conway Kenneth E , Rothrock Craig S , Schneider Raymond W , Ownley Bonnie H , Canaday Craig H , Keinath Anthony P , Huber Donald M , Sumner Donald R , Motsenbocker Carl E , Thaxton Peggy M , Cubeta Marc A , Adams Pamela D , Backman Paul A , Fajardo Julius , Newman Melvin A , Pereira Roberto M
Published: August 2002

Cotton and snap bean were selected for a multi‐year, multi‐state regional (south‐eastern USA) research project to evaluate the efficacy of both commercial and experimental bacterial and fungal biological control agents for the management of damping‐off diseases. The goal for this portion of the project was to determine the viability and stability of biological agents after application to seed. The biological seed treatments used included: (1) Bacillaceae bacteria, (2) non‐Bacillaceae bacteria, (3) the fungus Trichoderma and (4) the fungus Beauveria bassiana. Seed assays were conducted to evaluate the following application factors: short‐term (≤3 months) stability after seed treatment; quality (ie isolate purity); compatibility with chemical pesticides and other biocontrol agents; application uniformity between years and plant species. For the bacterial treatments, the Bacillaceae genera (Bacillus and Paenibacillus) maintained the greatest population of bacteria per seed, the best viability over time and the best application uniformity across years and seed type. The non‐Bacillaceae genera Burkholderia and Pseudomonas had the least viability and uniformity. Although Beauveria bassiana was only evaluated one year, the seed fungal populations were high and uniform. The seed fungal populations and uniformity for the Trichoderma isolates were more variable, except for the commercial product T‐22. However, this product was contaminated with a Streptomyces isolate in both the years that it was evaluated. The study demonstrated that Bacillaceae can be mixed with Trichoderma isolates or with numerous pesticides to provide an integrated pest control/growth enhancement package.

© 2001 Society of Chemical Industry
Baseline toxicity of several pesticides to Hyaliodes vitripennis (Say) (Hemiptera: Miridae)
Authors: Bostanian Noubar J , Larocque Nancy , Chouinard Gérald , Coderre Daniel
Published: August 2002

Hyaliodes vitripennis (Say) is a univoltine indigenous predacious mirid. It has been reported in several orchards where IPM programmes are used. It is a generalist, and feeds on phytophagous mites in addition to other arthropods. In Quebec, a foliar application of imidacloprid, deltamethrin or lambda‐cyhalothrin is used at least once per season to manage arthropod pests such as leafhoppers and leaf‐eating caterpillars. Meanwhile, several applications of metiram, flusilazole, myclobutanil and mancozeb are made to control apple scab [Venturia inaequalis (Cooke) Winter]. In laboratory trials, comparison of lethal concentrations of the three insecticides against H vitripennis nymphs and adults showed no significant difference. However, when lethal concentrations were compared between two growth stages for each insecticide, a significant difference was noted between adults and nymphs treated with lambda‐cyhalothrin, adults being more susceptible than nymphs. No such difference could be detected for imidacloprid or deltamethrin. When LC50 values were compared with the manufacturer's label rates, deltamethrin and imidacloprid were toxic to the nymphs and adults, and lambda‐cyhalothrin was slightly toxic to the nymphs and moderately toxic to the adults. Among the fungicides evaluated in the laboratory, myclobutanil showed moderate toxicity to adults at the manufacturer's label rate. The remaining fungicides had no toxic effects to adults or nymphs, even at four times the manufacturer's label rate.

© 2001 Society of Chemical Industry
Predominant torsional forms adopted by oligopeptide conformers in solution: parameters for molecular recognition
Authors: Marshall Neil J. , Grail Barry M. , Payne John W.
Published: August 2002

In this paper, we describe the predominant conformational forms adopted by tripeptides and higher oligopeptides in aqueous solution. About 50 tripeptides and almost 20 higher oligopeptides (4–6 residues) were subjected to conformational analysis using SYBYL Random Search. As with dipeptides (Grail BM, Payne JW. J. Peptide Sci. 2000; 6: 186–199), both tripeptides and higher oligopeptides were found to occupy relatively few combinations of psi–phi space that were distinct from those associated with predominant protein secondary structures (e.g. helices and β‐sheets). Again, the preferred psi (ψ) values for the first residue (i−1) were in sectors encompassed by the ranges from +150° to ±180°, +60° to +90° and −60° to −90°, which were combined with preferred phi (ϕ) values for the second residue (i) in sectors with ranges from −150° to ±180°, −60° to −90° and +30° to +60°. It was notable that tripeptides and, to a greater extent, higher oligopeptides adopted an initial psi (ψ) (Tor2) from +150° to ±180°. For tripeptides, their N–C distances (distance between N‐terminal nitrogen and C‐terminal carbon atoms) distribute about 6.5 Å to give shorter, ‘folded’ conformers that are similar in length to dipeptides, and longer, ‘extended’ conformers that are distinct. Furthermore, for higher oligopeptides, their N–C distances did not increment in relation to their increasing number of residues and short, ‘folded’ conformers were still present. These findings have a bearing upon the recognition of these molecules as substrates for widely distributed peptidases and peptide transporters. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd.
Risk assessment and management of offshore structures
Authors: G Bea Robert
Published: August 2002

During the past 30 years, reliability‐based risk assessment and management processes have been developed and applied in assessing and maintaining the integrity of a worldwide infrastructure of offshore structure systems. These systems are characterized as a combination of structures, hardware/equipment, operating personnel, organizations, environments and the interfaces between these components. Background on current and future trends in development of comprehensive programs to help improve the quality and reliability of offshore structure systems are outlined. The importance and characteristics of human and organizational factors are discussed. A combination of proactive, reactive and interactive approaches have been developed that employ three strategies to achieve desirable quality and reliability: reduce likelihood of malfunctions, increase detection and correction of malfunctions, and decrease the effects and consequences of malfunctions. System robustness and fail‐safe design are key elements of the third strategy.
Inhibitory effects of aromatic herbs on lipid peroxidation and protein oxidative modification of mice brain homogenate by copperin vitro
Authors: Toda Shizuo
Published: August 2002

Several aromatic herbs were inferred to have inhibitory effects on the generation of oxygen free radicals. It has been demonstrated that free radicals produced by copper produce lipid peroxidation and protein oxidative modification in the brain. The results presented here showed that several aromatic herbs, Caryophylli flos, Cinnamomi cortex, Foeniculi fructus and Zedoariae rhizoma, have inhibitory effects on lipid peroxidation or protein oxidative modification of mice brain homogenate produced by copper in vitro. Copyright © 2001 John Wiley & Sons, Ltd.
What's new?
Authors: Bohaychuk Wendy
Published: August 2002

The What's New? section in the Quality Assurance Journal aims to draw your attention to items of importance to QA professionals. Each item will be linked to the relevant internet address which you might add to your ‘favorites’ folders. If there is any other new information which should be brought to the attention of readers, please let us know by e‐mailing gcrpc@compuserve.com Copyright © 2001 John Wiley & Sons, Ltd.