bluuebunny/crossref_metadata_2025_split huggingface dataset:
Training subspecialty nurses in developing countries: Methods, outcome, and cost
Authors: Wilimas Judith A. , Donahue Nora , Chammas Georgette , Fouladi Maryam , Bowers Lynne J. , Ribeiro Raul C. 
Published: June 2003

AbstractBackgroundAs infections are controlled in developing countries, other pediatric subspeciality programs such as oncology become increasingly important. A major impediment to the development of such programs is a lack of trained nurses. Therefore, education of pediatric subspecialty nurses becomes a priority.ProcedureWe describe three models we have used for education of pediatric oncology nurses: a short series of classes or lectures with additional training of key nurses, an expanded 12 week series of classes at centers combining didactic and clinical instruction and a regional residential school offering regular 12 week courses in theory and clinical practice.ResultsCost analysis showed that the cost per nurse trained was, respectively, $3,700; $4,350; and $5,500. Early effectiveness indicators show that retention rates are high, home institutions are satisfied, and nurses trained shared their knowledge with other nurses and improved nursing practices.ConclusionsPrograms to teach subspecialty nursing in developing countries are effective and can improve medical care. Such programs should be based on past experience and evaluated as to cost and effectiveness. Med Pediatr Oncol 2003;41:136–140. © 2003 Wiley‐Liss, Inc.
Role of radiosurgery in craniopharyngiomas: A preliminary report
Authors: Amendola Beatriz E. , Wolf Aizik , Coy Sammie R. , Amendola Marco A. 
Published: June 2003

AbstractPurposeThe purpose of this retrospective review is to evaluate our experience using radiosurgery in the management of craniopharyngiomas.Materials and MethodsFourteen patients, 6 males and 8 females, ages ranging from 3 to 44 years of age, were treated with radiosurgery from February 1994 through December 2000 for primary or recurrent craniopharyngioma. There were two adults and 12 children. All patients were treated with the Leksell Gamma units Model U or C. The mean minimum dose was 14 Gy ranging from 11 to 20 Gy and the mean maximum dose was 29 Gy ranging from 24 to 40 Gy. Volume of treatment ranged from 0.1 to 26.5 cm3. The dose to critical structures was below 8 Gy to the optic chiasm and below 14 Gy to the brain stem. One of the 14 patients had previous conventional radiation therapy.ResultsAll patients are alive and with out evidence of recurrent disease 6–86 months after treatment. Only two patients required retreatment.ConclusionsAlthough craniopharyngioma is a benign tumor, its location makes even advanced microsurgical techniques difficult to perform. Radiosurgery obviates the shortcomings of surgical resection near the hypothalamic‐pituitary axis without the morbidity of open surgery. Med Pediatr Oncol 2003;41:123–127. © 2003 Wiley‐Liss, Inc.
Electronic and geometric structures of Sin– and Sin+ (n = 2–10) clusters and in comparison with Sin
Authors: Li Bao‐xing , Cao Pei‐lin , Zhou Xu‐yan 
Published: June 2003

AbstractUsing full‐potential linear‐muffin‐tin‐orbital molecular‐dynamics (FP‐LMTO‐MD) method, we have studied the geometric and electronic structures of ionic Si2–10 clusters. The structures we obtained include not only all the most stable structures reported previously, but also some new structures. Our calculations show that the ground state structure of negative Si8– cluster ion is a new structure with C2v, which is different from that reported before. In addition, we have also found that the ground state structure of positive Si+10 cluster ion is a tricapped pentagonal bipyramid with Cs symmetry, which has been not reported previously. As for their electronic structures, these charged silicon clusters show 0.5–2.5 eV of energy gaps between the lowest unoccupied energy level and the highest occupied energy level. The gaps for cationic silicon clusters are closer to those of their corresponding neutral clusters, but many of the gaps for the anionic clusters are not.
Orientation effects on the magnetic properties of a pair Cr6 and V6 atomic clusters embedded in bulk Fe
Authors: Alvarado‐Leyva P. G. , Dorantes‐Dávila J. 
Published: June 2003

AbstractThe magnetic and electronic properties of a pair Cr6 and V6 atomic clusters embedded in bulk Fe are determined by using a realistic spd‐band Hubbard‐like model. The spin density distribution is calculated self‐consistently in the unrestricted Hartree–Fock approximation. The local magnetic moments μ(i) and the density of electronic states ρi(ε) are obtained at various atoms i of the cluster and of the surrounding Fe matrix. We consider two different orientations between the clusters, or better still the axis of symmetry of the clusters: collinear (C) and non‐collinear (NC). For all the cases studied the interface magnetic coupling between cluster and matrix moments is antiparallel. The Fe moments close to the cluster are slighty reduced, and the μ(i) of Cr and V atoms at the interface are often much larger than the Cr bulk moments (e.g. μ(i) = –1.39μB for Cr6 in Fe in both orientations). We compare the results with the corresponding results for just one Cr6 and V6 atomic cluster embedded in bulk Fe.
Some universal relations between the gap and thermodynamic functions plausible for various models of superconductors
Authors: Gonczarek Ryszard , Krzyzosiak Mateusz 
Published: June 2003

AbstractIt is proven that there exist some universal relations between the energy gap and the differences of the thermodynamic potential, entropy, specific heat and critical magnetic field for many two‐ and three‐dimensional models of superconductivity with spin‐singlet Cooper pairs forming s or d or g etc. states. The obtained formulae make it possible to derive thermodynamic functions and, in particular, the superconducting specific heat and the critical magnetic induction in the whole temperature range 0 ≤ T ≤ Tc employing the form of Δ(T) only. The inverse formula allowing us to find Δ(T), when the temperature dependence of the specific heat difference is known, is also presented. The results are referred to some obtained within the McMillan formalism, and some remarks on the application of the present formulae to the t–J model are given.
Effects of stoichiometries on the positron distribution in Si1–x–yGexCy alloys
Authors: Soudini B. , Bensaâd Z. , Abid H. , Sehil M. 
Published: June 2003

AbstractThe effect of alloying on the positron distribution in Si1–x–yGexCy alloys is reported. Our computations of the thermalized positron densities are based on the independent particle method coupled with the empirical pseudopotential method to derive the positron and electron wave functions, respectively. Initial results show a clear symmetrical positron charge distribution relative to the bond centre, a quite similar situation that was found in the IV groups. Since the minimum band gaps were found to be very sensitive to the carbon as well as the germanium concentration variations, this has an immediate consequence on the positron densities, where we find a deviation from linearity. This illustrative result was an indication of the alloying effect in this system (bowing effect).
Prevalence of extra‐oesophageal manifestations in gastro‐oesophageal reflux disease: an analysis based on the ProGERD Study
Authors: Jaspersen D. , Kulig M. , Labenz J. , Leodolter A. , Lind T. , Meyer‐Sabellek W. , Vieth M. , Willich S. N. , Lindner D. , Stolte M. , Malfertheiner P. 
Published: June 2003

SummaryBackground and aims: Gastro‐oesophageal reflux disease (GERD) can be associated with a variety of extra‐oesophageal disorders (EED) such as chronic cough, asthma, laryngeal disorder or chest pain. The aim of the study was to estimate and compare the prevalence of EED in a population with symptomatic GERD presenting as either erosive reflux disease (ERD) or non‐erosive reflux disease (NERD).Methods: Baseline data were collected from a prospective, multicentre, open cohort study (ProGERD) in which patients will be followed for 5 years after initial treatment with esomeprazole. Within the framework of this trial, all patients underwent gastroscopy and filled out a questionnaire designed to assess EED. The influence of potential prognostic factors on the prevalence of EED was analysed by multivariate (stepwise logistic regression) analysis.Results: 6215 patients (3303 male, 2912 female; mean age 54 years) presenting with heartburn were included. EED was detected in 32.8% of all patients. The proportion was significantly higher (P = 0.0002) in ERD patients (34.9%) than in NERD patients (30.5%). As judged from the multivariate analysis, female gender, age, oesophagitis of LA grade C/D, duration of GERD disease greater than 1 years and smoking were significantly associated with EED. ERD patients with oesophagitis of LA grade A or B did not have a significantly higher risk of EED than patients with NERD.Conclusions: Patients with GERD have a high probability of experiencing EED, which may be associated with a number of prognostic factors such as duration and severity of GERD. Extra‐oesophageal disorders are slightly, but statistically, more prevalent in ERD than in NERD patients.
NOD2/CARD15 gene polymorphisms and Crohn's disease in the Chinese population
Authors: Leong R. W. L. , Armuzzi A. , Ahmad T. , Wong M. L. , Tse P. , Jewell D. P. , Sung J. J. Y. 
Published: June 2003

SummaryBackground: Crohn's disease affects people world‐wide, but the incidence in Asia is lower than in Western countries. This difference may be due to genetic and/or environmental factors. Three single nucleotide polymorphisms (SNPs) of the NOD2/CARD15 gene have been identified to be independently associated with the development of Crohn's disease in Caucasians. Whether these SNPs are involved in the pathogenesis of Crohn's disease in the Chinese population is unknown.Aim: To determine if NOD2/CARD15 gene polymorphisms are found in Chinese patients with Crohn's disease.Methods: Sixty‐five consecutive Chinese Crohn's disease patients had genotyping performed using sequence‐specific PCR directed against the wild‐type and the Arg702Trp, Gly908Arg and 3020insC variants of the NOD2/CARD15 gene. Controls consisted of 63 patients with ulcerative colitis and 70 patients with dyspepsia.Results: None of the patients with Crohn's disease had heterozygous or homozygous SNP variants. Similarly none of the ulcerative colitis or dyspeptic controls had these SNPs.Conclusion: The three previously described SNPs associated with the development of Crohn's disease in Caucasians are not found in Chinese patients with Crohn's disease.
Land contamination and urinary abnormalities: cause for concern?
Authors: Staples B , Howse M L P , Mason H , Bell G M 
Published: June 2003

Aims:To determine the prevalence of proteinuira and enzymuria among a cohort of subjects exposed to hexachlorobutadiene (HCBD) in their homes and to determine whether there was a change in observed effects when exposure ceased.Methods:Residents underwent a health check, which included a panel of urinary markers of both glomerular and tubular origin, within two months of cessation of long term exposure to HCBD and again at least 10 months after exposure ceased. Analysis of the results was performed to determine if there was any early evidence of renal effects, and to ascertain whether changes in these parameters occurred after exposure to HCBD ceased.Results:Tubular proteinuria and enzymuria were increased in the initial health check and significantly decreased after the residents had left their homes for about 10 months. As the early renal tubular markers improved when exposure ceased it is anticipated that the long term nephrotoxic risk will be minimal, but the carcinogenic risk remains unknown.Conclusions:Results show there was a renal effect which improved when subjects left their homes. This suggests there was a local environmental factor responsible for the observations. This is consistent with the predicted toxicological effects of HCBD from animal studies.
Work related and individual predictors for incident neck pain among office employees working with video display units
Authors: Korhonen T , Ketola R , Toivonen R , Luukkonen R , Häkkänen M , Viikari-Juntura E 
Published: June 2003

Aims:To investigate work related and individual factors as predictors for incident neck pain among office employees working with video display units (VDUs).Methods:Employees in three administrative units of a medium sized city in Finland (n = 515) received mailed questionnaires in the baseline survey in 1998 and in the follow up survey in 1999. Response rate for the baseline was 81% (n = 416); respondents who reported neck pain for less than eight days during the preceding 12 months were included into the study cohort as healthy subjects (n = 232). The follow up questionnaire 12 months later was completed by 78% (n = 180). Incident neck cases were those reporting neck pain for at least eight days during the preceding 12 months.Results:The annual incidence of neck pain was 34.4% (95% CI 25.5 to 41.3). Poor physical work environment and poor placement of the keyboard increased the risk of neck pain. Among the individual factors, female sex was a strong predictor. Smoking showed a tendency for an increased risk of neck pain. There was an interaction between mental stress and physical exercise, those with higher mental stress and less physical exercise having especially high risk.Conclusion:In the prevention of neck disorders in office work with a high frequency of VDU tasks, attention should be given to the work environment in general and to the more specific aspects of VDU workstation layout. Physical exercise may prevent neck disorders among sedentary employees.
Exposure to nitroaromatic explosives and health effects during disposal of military waste
Authors: Letzel S , Göen Th , Bader M , Angerer J , Kraus T 
Published: June 2003

Aims:To investigate the exposure to dinitrotoluene (DNT) and trinitrotoluene (TNT) and the resulting effects in workers which occur during the disposal of military waste.Methods:Eighty two employees from a mechanical plant in Germany were studied, of whom 51 were regularly exposed to ammunition containing TNT and DNT, 19 occasionally, and 12 not at all.Results:Air analyses yielded maximum concentrations of 20 μg/m3for 2,4-DNT and 3250 μg/m3for 2,4,6-TNT, respectively. The maximum concentrations in the urine of workers regularly exposed amounted to 5.0 μg/l of 2,4,6-TNT, 1464.0 μg/l of 2-amino-4,6-dinitrotoluene, 6693.0 of μg/l 4-amino-2,6-dinitrotoluene, 2.1 μg/l of 2,4-DNT, 95.0 μg/l of 2,4-dinitrobenzoic acid, and 3.6 μg/l of 2,6-DNT. There was a highly significant linear correlation between the urinary concentrations of the two main metabolites of TNT, 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene. In 63 persons TNT or DNT or metabolite concentrations above the analytical detection limit were found in urine. These persons reported more frequently symptoms like bitter taste, burning eyes, and discoloration of the skin and hair than persons (n = 19) without detectable TNT and/or DNT exposure.Conclusion:During the disposal of military waste containing relevant TNT and DNT, exposure can occur of occupational-medical relevance. Biological monitoring is suitable for the early detection of possible adverse effects at workplaces exposed to TNT. Protective measures should be improved, together with adequate occupational-medical surveillance of persons exposed to nitroaromatic explosives. Further studies are necessary to exclude possible long term effects.
Surfactant interactions with P(AM–AA–BPAM) hydrophobically modified polyelectrolytes
Authors: Ye L. , Huang Ronghua , Hoffman H. 
Published: June 2003

AbstractThe interactions of hydrophobically modified polyelectrolytes poly(acrylamide–sodium acrylic acid–N‐(4‐butyl)phenylacrylamide [P(AM‐AA‐BPAM)] with anionic (sodium dodecyl sulfate), cationic (cetyl trimethylammonium bromide), and nonionic (tetradecyldimethyl‐aminoxid) surfactants were studied via solution rheology, surface tension, and atomic force microscopy measurements. Viscosity measurements indicated that the intermolecular association of the polymer was greatly enhanced by the interaction with the surfactants, especially the oppositely charged surfactants with both a hydrophobic association and an electrostatic attraction. The greatest viscosity increase was realized with the addition of such oppositely charged surfactants. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2664–2671, 2003
Prediction of the molecular‐weight dependence of mutual diffusion coefficients in polymer‐solvent systems
Authors: Vrentas J. S. , Vrentas C. M. 
Published: June 2003

AbstractThe ability of a proposed theory to describe the molecular weight dependence of mutual diffusion coefficients for polymer–solvent systems is examined by comparison with experimental measurements. Good agreement between experiment and theory was observed for two very different polymer molecular weights. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2778–2779, 2003
Effects of sunshine UV irradiation on the tensile properties and structure of ultrahigh molecular weight polyethylene fiber
Authors: Huapeng Zhang  , Shi Meiwu , Zhang Jianchun , Wang Shanyuan 
Published: June 2003

AbstractThis study investigated sunlight‐simulated ultraviolet (UV) beam irradiation on the tensile properties and structure of ultrahigh molecular weight polyethylene (UHMWPE) fibers. The tensile results showed that after 300 h sunlight UV irradiation, the tensile properties of the UHMWPE fibers were obviously degraded. Investigation of morphology revealed that the crystallinity was slightly increased, whereas the overall orientation and molecular weight of the fibers were decreased. SEM observations indicated that the degradation process was nonuniform throughout the fiber and a change from a ductile to a brittle fracture mechanism was found after UV irradiation. DMA results showed two β‐relaxations and one α‐relaxation in the original single filament, and UV irradiation led to the increased intensity of the high‐temperature β‐relaxation and the lowered position of the low‐temperature β‐relaxation. This indicated that irradiation‐induced molecular scission and branching were located primarily in the amorphous and the interface areas of the fiber. Changes in the thermal behavior were also examined by DSC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2757–2763, 2003
Intrinsic viscosity dependence on polymer molecular weight and fluid temperature
Authors: Rushing T. S. , Hester R. D. 
Published: June 2003

AbstractExperimental solution intrinsic viscosity responses to temperature and polymer molecular weight variations were used to test the modeling capability of a simplified intrinsic viscosity equation. The multiple linear equation contains three parameters that are related to the thermodynamic properties of a polymer solution. Simple linear regression was used to produce an intrinsic viscosity equation containing unique fitted parameters for each of three solutions. These parameters describe the polymer coil size at unperturbed conditions and the polymer coil expansion capabilities of the solvent as a function of fluid temperature and molecular weight. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2831–2835, 2003
Radiation and conduction heat transfer coupled with liquid water transfer, moisture sorption, and condensation in porous polymer materials
Authors: Wang Z. , Li Y. , Zhu Q. Y. , Luo Z. X. 
Published: June 2003

AbstractA new one‐dimensional mathematical model to simulate the complex coupled heat and moisture transfer in porous polymer materials is presented. The new model takes into account effects of multiple involved processes such as radiation and conduction heat transfer, liquid capillary action, moisture sorption, and condensation. The technique of volume of fraction (VOF) is used to model the dynamic distribution of moisture in different phases, that is, vapor and liquid. The finite volume method (FVM) is used to develop the numerical computational scheme to solve the model. The temperature change on the fabric surface derived from the computational results of the model is compared with experimental measurements with reasonable agreement between the two. Further numerical simulations were carried out to investigate the complex interactions and coupling effects among the various heat and moisture‐transfer processes involved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2780–2790, 2003
Synthesis, characterization, and electro‐optical properties of a soluble conjugated polymer containing an oxadiazole unit in the main chain
Authors: Zhang Su‐Yang , Kong Fan , Sun Rong , Yuan Ren‐Kuan , Jiang Xi‐Qun , Yang Chang‐Zheng 
Published: June 2003

AbstractA novel copolymer, poly{[2,5‐diphenylene‐1,3,4‐oxadiazole‐vinylene]‐alt‐[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene]}(MEH‐OPPV) containing a high‐electron‐affinity unit of aromatic oxadiazole in the main chain is synthesized through the Wittig condensation reaction. The obtained copolymer is easily soluble in conventional organic solvents. The structure of the copolymer was characterized by Fourier transform infrared, 1H nuclear magnetic resonance, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and ultraviolet‐visible and photoluminescence spectroscopy. The TGA result indicates that the copolymer has very high thermal stability (stable up to 310°C in nitrogen), while DSC investigation demonstrates that the glass transition temperature (Tg) is 143°C, which might be a merit for the long‐life operation of light‐emitting devices. The absorption spectrum of film sample of the copolymer reveals two peaks at 310 and 370 nm, respectively, and the edge absorption corresponds to a band gap of 2.46 eV. A single‐layer light‐emitting diode device ITO/MEH‐OPPV/Al is successfully fabricated. The device emits visible yellowish‐green light above the bias voltage of 4.0 V under ambient condition. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2618–2623, 2003
Graft copolymerization of methyl methacrylate onto gelatin using KMnO4‐H2SO4 redox system
Authors: Keleş Havva , Saçak Mehmet 
Published: June 2003

AbstractThe graft copolymerization of methyl methacrylate onto gelatin was studied using KMnO4‐H2SO4 redox system. The maximum graft yield of 64.5% was obtained at the potassium permanganate concentration of 2.00 × 10−3 mol/L and the optimum temperature of 50°C. Activation energy was calculated as 18.6 kcal/mol at the temperature interval of 40–70°C. The results of the thermogravimetric analysis showed that the degradation temperature of gelatin increased as a result of grafting. Moreover, some changes in the properties of methyl methacrylate‐grafted samples were also observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2836–2844, 2003