bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoluminescence of doped ZnS nanoparticles under hydrostatic pressure
Authors: Li G. H. , Su F. H. , Ma B. S. , Ding K. , Xu S. J. , Chen W. 
Published: November 2004

AbstractThe pressure dependence of the photoluminescence from ZnS:Mn2+, ZnS:Cu2+, and ZnS:Eu2+ nanoparticles were investigated under hydrostatic pressure up to 6 GPa at room temperature. Both the orange emission from the 4T1 – 6A1 transition of Mn2+ ions and the blue emission from the DA pair transition in the ZnS host were observed in the Mn‐doped samples. The measured pressure coefficients are –34.3(8) meV/GPa for the Mn‐related emission and –3(3) meV/GPa for the DA band, respectively. The emission corresponding to the 4f65d1 – 4f7 transition of Eu2+ ions and the emission related to the transition from the conduction band of ZnS to the t2 level of Cu2+ ions were observed in the Eu‐ and Cu‐doped samples, respectively. The pressure coefficient of the Eu‐related emission was found to be 24.1(5) meV/GPa, while that of the Cu‐related emission is 63.2(9) meV/GPa. The size dependence of the pressure coefficients for the Mn‐related emission was also investigated. The Mn emission shifts to lower energies with increasing pressure and the shift rate (the absolute value of the pressure coefficient) is larger in the ZnS:Mn2+ nanoparticles than in bulk. Moreover, the absolute pressure coefficient increases with the decrease of the particle size. The pressure coefficients calculated based on the crystal field theory are in agreement with the experimental results. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐pressure X‐ray structural study of BeO and ZnO to 200 GPa
Authors: Mori Y. , Niiya N. , Ukegawa K. , Mizuno T. , Takarabe K. , Ruoff A. L. 
Published: November 2004

AbstractWe have carried out high‐pressure X‐ray structural studies of BeO and ZnO up to 200 GPa to find the phase transition of BeO from the wurzite to the NaCl structure and that of ZnO from the NaCl to the CsCl structure, which are expected theoretically. The phase transition of BeO occurred at 137 GPa, which is in good agreement with the theoretical value of 139 GPa. The wurzite phase persisted up to 175 GPa. The bulk modulus of BeO at zero pressure is determined to be 223 GPa by the Birch's equation. As previously reported, the ZnO sample transformed from the wurzite structure to the NaCl structure at 9.1 GPa. Extending the pressure range up to 202 GPa no phase transition to the CsCl structure occurred. The bulk modulus of the NaCl structure was determined to be 194 GPa. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of charge‐transfer effects in regioselectivity
Authors: Korchowiec Jacek 
Published: November 2004

AbstractThe energy‐partitioning scheme was used to study the regioselectivity problem. As a model system, Diels–Adler (DA) reaction was considered. It is shown that charge‐transfer (CT) energy is not responsible for experimentally observed trends in regioselectivity. However, it is the only contribution to the overall interaction energy that depends regularly on the type of substituents attached to reactant molecules. The main factors governing the orientation in DA reaction are deformation and Heitler–London energies. We have also demonstrated that the clear relationship between CT energy and the amount of charge transferred from one to another reactant exists for reactive systems that differ only in the substitution pattern. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Density functional calculations of 19F and 235U NMR chemical shifts in uranium (VI) chloride fluorides UF6−nCln: Influence of the relativistic approximation and role of the exchange‐correlation functional
Authors: Schreckenbach Georg 
Published: November 2004

AbstractRelativistic density functional theory (DFT) has been applied to the calculation of the 19F nuclear magnetic resonance (NMR) chemical shifts of the title compounds. It is shown that, while large‐core effective core potentials (ECP) fail completely for the calculation of ligand NMR chemical shifts in uranium compounds, small‐core ECPs are a valid relativistic method for this purpose. In an earlier study of the same systems, certain differences between theory and experiment had been observed, for instance, in the relative chemical shift of the A4 and X sites in UF5Cl. The reason for these deviations has been investigated further in the current paper. By comparing different relativistic methods, it is shown that the relativistic approximation is not responsible for these deviations. The role of the approximation to the exchange‐correlation (XC) functional of DFT has been probed, and generalized gradient approximations (GGA) as well as hybrid DFT methods have been investigated. None of these methods corrects the mentioned errors. It is argued that the neglect of environmental factors (solvent effects) remains as a possible error source, although the approximate XC functional appears to be the more likely cause of the problem. 235U NMR shieldings and chemical shifts have been calculated, and the trends predicted earlier have been confirmed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Building teacher identity with urban youth: Voices of beginning middle school science teachers in an alternative certification program
Authors: Proweller Amira , Mitchener Carole P. 
Published: November 2004

AbstractTeacher identity development and change is shaped by the interrelationship between personal biography and experience and professional knowledge linked to the teaching environment, students, subject matter, and culture of the school. Working from this framework, this study examines how beginning teacher interns who are part of an alternative route to teacher certification construct a professional identity as science educators in response to the needs and interests of urban youth. From the teacher interns, we learn that crafting a professional identity as a middle‐level science teacher involves creating a culture around science instruction driven by imagining “what can be,” essentially a vision for a quality and inclusive science curriculum implicating science content, teaching methods, and relationships with their students. The study has important implications for the preparation of a stronger and more diverse teaching force able to provide effective and inclusive science education for all youth. It also suggests the need for greater attention to personal and professional experience and perceptions as critical to the development of a meaningful teacher practice in science. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 1044–1062, 2004
Environment, Quality of Life, and Urban Growth in the New Economy
Authors: Hirschhorn Joel S. 
Published: November 2004

AbstractSooner or later, most environmental professionals will be affected by the national smart growth movement, which addresses suburban sprawl and urban revitalization. Environmental sustainability is at the heart of more sustainable economic growth—which means growth that does not sacrifice quality of life for economic prosperity. This article summarizes the findings of a recent report on the linkage between growth and quality of life in the new economy, with a special emphasis on the role of governors. © 2001 John Wiley & Sons, Inc.
Novel and therapeutic effect of caffeic acid and caffeic acid phenyl ester on hepatocarcinoma cells: complete regression of hepatoma growth and metastasis by dual mechanism
Authors: Chung Tae‐Wook , Moon Sung‐Kwon , Chang Young‐Chae , Ko Jeong‐Heon , Lee Young‐Choon , Cho Gun , Kim Soo‐Hyun , Kim Jong‐Guk , Kim Cheorl‐Ho 
Published: November 2004

ABSTRACTOur previous studies have clearly shown that the angiogenic enzymes, matrix metalloproteinase (MMP) ‐2/9, are directly involved in human hepatic tumorigenesis and metastasis and suggest that the MMP‐2/9 inhibitors, which have dual inhibitory activi¬ties on enzyme activity and transcription, represent the best candidates for achieving tumor regression. Many anti‐cancer drugs have strong cellular cytotoxicity and side effects, indicating that strong anti‐cancer drugs that have no or minimal cytotoxicity and side effects need to be developed. The specific aim of the present study was to develop powerful anti‐cancer drugs with specific tumor regression and anti‐metastatic potential having the dual inhibitory activities of specific MMP‐2 and ‐9 enzyme activities and gene transcription at the molecular level. Caffeic acid (CA), a strong and selective MMP‐9 activity and transcription inhibitor, was isolated from the plant Euonymus alatus and its derivative, caffeic acid phenethyl ester (CAPE), was synthesized. CA and CAPE selectively inhibited MMP‐2 and ‐9 but not ‐1, ‐3, ‐7, or cathepsin K. Treatment of HepG2 cells with CA (100 μg/mL) and CAPE (5 μg/mL) suppressed phorbol 12‐myristate 13‐acetate (PMA) ‐in¬duced MMP‐9 expression by inhibiting the function of NF‐κB, but not AP‐1. We confirmed that CA and CAPE suppressed the growth of HepG2 tumor xenografts in nude mice in vivo. The subcutaneous and oral administrations of CA and CAPE significantly reduced the liver metastasis. These results confirm the therapeutic potential of the compounds and suggest that the antimetastatic and anti‐tumor effects of CA and CAPE are mediated through the selective suppression of MMP‐9 enzyme activity and transcriptional down‐regulation by the dual inhibition of NF‐κB as well as MMP‐9 catalytic activity.—Chung, T.‐W., Moon, S.‐K., Chang, Y.‐C., Ko, J.‐H., Lee, Y.‐C., Cho, G., Kim, S.‐H., Kim, J.‐G., Kim, C.‐H. Novel and therapeutic effect of caffeic acid and caffeic acid phenyl ester on hepatocarcinoma cells: complete regression of hepatoma growth and metastasis by dual mechanism. FASEBJ. 18, 1670–1681 (2004)
Multiple Genetic Processes Result in Heterogeneous Rates of Evolution within the Major Cluster Disease Resistance Genes in Lettuce[W]
Authors: Kuang Hanhui , Woo Sung-Sick , Meyers Blake C. , Nevo Eviatar , Michelmore Richard W. 
Published: November 2004

AbstractResistance Gene Candidate2 (RGC2) genes belong to a large, highly duplicated family of nucleotide binding site–leucine rich repeat (NBS-LRR) encoding disease resistance genes located at a single locus in lettuce (Lactuca sativa). To investigate the genetic events occurring during the evolution of this locus, ∼1.5- to 2-kb 3′ fragments of 126 RGC2 genes from seven genotypes were sequenced from three species of Lactuca, and 107 additional RGC2 sequences were obtained from 40 wild accessions of Lactuca spp. The copy number of RGC2 genes varied from 12 to 32 per genome in the seven genotypes studied extensively. LRR number varied from 40 to 47; most of this variation had resulted from 13 events duplicating two to five LRRs because of unequal crossing-over within or between RGC2 genes at one of two recombination hot spots. Two types of RGC2 genes (Type I and Type II) were initially distinguished based on the pattern of sequence identities between their 3′ regions. The existence of two types of RGC2 genes was further supported by intron similarities, the frequency of sequence exchange, and their prevalence in natural populations. Type I genes are extensive chimeras caused by frequent sequence exchanges. Frequent sequence exchanges between Type I genes homogenized intron sequences, but not coding sequences, and obscured allelic/orthologous relationships. Sequencing of Type I genes from additional wild accessions confirmed the high frequency of sequence exchange and the presence of numerous chimeric RGC2 genes in nature. Unlike Type I genes, Type II genes exhibited infrequent sequence exchange between paralogous sequences. Type II genes from different genotype/species within the genus Lactuca showed obvious allelic/orthologous relationships. Trans-specific polymorphism was observed for different groups of orthologs, suggesting balancing selection. Unequal crossover, insertion/deletion, and point mutation events were distributed unequally through the gene. Different evolutionary forces have impacted different parts of the LRR.
A prospective, randomized‐controlled pilot study of ursodeoxycholic acid combined with mycophenolate mofetil in the treatment of primary sclerosing cholangitis
Authors: Sterling R. K. , Salvatori J. J. , Luketic V. A. , Sanyal A. J. , Fulcher A. S. , Stravitz R. T. , Contos M. J. , Mills A. S. , Shiffman M. L. 
Published: November 2004

SummaryBackground : Ursodeoxycholic acid has been ineffective in the treatment of primary sclerosing cholangitis. Because the pathogenesis of primary sclerosing cholangitis is related to immune destruction of bile duct epithelium, several immune suppressive agents have been evaluated. Mycophenolate mofetil is a potent immunosuppressant that is now widely used in organ transplantation.Aim : In this pilot study to determine if mycophenolate mofetil when combined with ursodeoxycholic acid could prevent evidence of clinical progression and improve the biochemical, histological and/or cholangiographic features of primary sclerosing cholangitis compared with patients treated with ursodeoxycholic acid alone.Methods : Twenty‐five patients with well‐defined primary sclerosing cholangitis were randomized to ursodeoxycholic acid (13–15 mg/kg/day) with or without mycophenolate mofetil (1000 mg b.d.). Cholangiography and liver biopsy were performed at study entry and after 2 years of treatment. Symptoms, clinical features of liver disease and biochemical tests were monitored at 3‐month intervals.Results : The mean age 44 years, 58% male, 84% Caucasian and 64% had ulcerative colitis. After 2 years, there were no differences in laboratory values, histological stage or cholangiograms between patients treated with ursodeoxycholic acid alone and those treated with mycophenolate mofetil + ursodeoxycholic acid.Conclusions : Mycophenolate mofetil combined with ursodeoxycholic acid does not appear to provide additional benefit compared with standard doses of ursodeoxycholic acid alone in the treatment of primary sclerosing cholangitis.
A single dose of ranitidine 150 mg modulates oesophageal acid sensitivity in patients with functional heartburn
Authors: Rodriguez‐Stanley S. , Ciociola A. A. , Zubaidi S. , Proskin H. M. , Miner P. B. 
Published: November 2004

SummaryBackground : The rapid onset and symptomatic response to histamine‐2 receptor antagonists prior to the pharmacological effect on acid secretion suggests a different mechanism of action.Aim : To determine if ranitidine decreases oesophageal sensitivity to chemical and mechanical stimulation, potentially via oesophageal histamine receptors.Methods : A total of 18 patients with functional heartburn received oral ranitidine 150 mg b.d. or placebo for 7 consecutive days in a double‐blind randomized crossover design and underwent Barostat balloon distention and Bernstein acid infusion on study day 1 (90 min postdose) and study day 7. First sensation and pain were recorded and pain severity was rated on a 5‐point Likert scale and a 100 mm visual analogue scale. Least square mean values were generated and one‐tailed t‐tests were performed.Results : After a single dose of ranitidine 150 mg, time to pain with oesophageal acid infusion was increased by 29% (P < 0.05) and visual analogue scale and Likert scores were decreased by 20% (P < 0.06) and 23% (P < 0.02), respectively compared with placebo. After 1 week of ranitidine, positive alterations in sensory parameters persisted. Balloon distention sensory parameters were not altered by ranitidine.Conclusions : Ranitidine significantly decreased oesophageal sensitivity to acid. Failure of ranitidine to improve balloon sensory parameters supports existence of multiple sensory pathways in the oesophagus.
Behaviour of the bowel wall during the first year after surgery is a strong predictor of symptomatic recurrence of Crohn's disease: a prospective study
Authors: Parente F. , Sampietro G. M. , Molteni M. , Greco S. , Anderloni A. , Sposito C. , Danelli P. G. , Taschieri A. M. , Gallus S. , Bianchi Porro G. 
Published: November 2004

SummaryBackground : Recurrences after surgery for Crohn's disease are frequent and unpredictable. To date, there is little agreement as to which factors increase a patient risk of early recurrence.Aim : To assess whether the post‐operative behaviour of diseased bowel walls, as determined by ultrasound, may be a useful predictor of relapse.Methods : A total of 127 Crohn's disease patients were monitored after surgery by means of bowel ultrasound as well as by clinical and laboratory evaluations for a median follow‐up of 41.0 months. Bowel wall thickness of diseased loops measured at ultrasound during follow‐up was compared with the presurgery values. Multivariable survival analysis was performed to elucidate predictors of early post‐operative recurrence. Receiver operating characteristic curves were also constructed taking into account bowel wall thickness for selecting Crohn's disease patients with high risk of clinical/surgical recurrence.Results : The estimated 5 years survival probability of symptomatic Crohn's disease recurrence were 90% and 33%, respectively for unchanged/worsened bowel wall thickness vs. improved bowel wall thickness at 12 months from surgery. The hazard ratio for unchanged/worsened bowel wall thickness at 12 months was 8.9 (95% CI: 3.4–23.2). Receiver operating characteristic curve identified a bowel wall thickness > 6.0 mm at 12 months from surgery as directly associated with the risk of having a Crohn's disease recurrence (hazard ratio was 6.5, 95% CI: 2.8–15.4).Conclusions : Systematic ultrasound follow‐up of diseased bowel walls after conservative surgery allows the early identification of patients at high risk of clinical/surgical recurrence.
Evaluation of the clinical value of pharmacists’ modifications of prescription errors
Authors: Buurma Henk , De Smet Peter A. G. M. , Leufkens Hubert G. M. , Egberts Antoine C. G. 
Published: November 2004

AimsOur objective was to examine the clinical value of pharmacists’ interventions to correct prescription errors.MethodsIn this study, we reviewed a random sample of prescriptions that had been modified in pharmacies. These prescriptions were collected on one predetermined day between 25th February and 12th March 1999 from 141 Dutch community pharmacies. Each prescription modification was evaluated by a panel of reviewers, including representatives of five groups of health care professionals. After generally rating each modification as positive, negative, or neutral, the reviewers assessed its outcome (in terms of prevention of an adverse drug reaction [ADR], an improvement in effectiveness, both, or other), the probability and importance of improvements in effectiveness and/or the probability and seriousness of an ADR in the case of a nonintervention. Our analyses included 144 interventions from the first general assessment and a selection of 90 consistently rated ‘positive’ interventions (from all assessments).ResultsOn average, one in 200 prescriptions (0.49%) was found to have been positively modified by Dutch community pharmacists. About half of these interventions (49.8%) were aimed at preventing ADRs; 29.2% were rated as a positive modification in the effectiveness of pharmacotherapy and 8.6% affected both effectiveness and ADR. Reviewers’ ratings varied widely between different categories of drug‐related problems (DRPs). The impact of individual interventions (n = 83) varied, and for 53% of these interventions it was estimated to be relatively high.ConclusionsPharmacists’ interventions led to modification of prescriptions for an array of DRPs. Such interventions can contribute positively to the quality of pharmacotherapy. By extrapolating our data, we estimated a daily occurrence of approximately 2700 positive interventions in all Dutch pharmacies (1.6 per pharmacy per day). Reviewers rated the impact of interventions on a patient's health as significant in a substantial number of cases.
Effect of oral linezolid on the pressor response to intravenous tyramine
Authors: Cantarini Mireille V. , Painter Catherine J. , Gilmore Elaine M. , Bolger Catherine , Watkins Claire L. , Hughes Andrew M. 
Published: November 2004

AimsTo investigate the effect of monoamine oxidase A inhibition from a single oral dose of linezolid on the pressor response to intravenous (i.v.) tyramine, using positive and negative controls to validate the methodology.MethodsThis placebo‐controlled, three‐period crossover study was conducted in 12 healthy male volunteers. Each volunteer received either one oral dose of moclobemide (300 mg), linezolid (600 mg), or placebo tablet followed by an i.v. tyramine pressor test until an increase in systolic blood pressure of at least 30 mmHg above baseline occurred. Each study day was separated by a 7‐day washout period. The dose of tyramine required to raise the blood pressure by 30 mmHg (TYR30) was calculated for each oral treatment by linear interpolation between log‐transformed doses of i.v. tyramine. The influence of body mass index (BMI) on TYR30 was also investigated.ResultsThe tyramine sensitivity factor (ratio of the geometric least square mean TYR30 for placebo and active oral treatment) was 1.8 [90% confidence interval (CI) 1.6, 2.0, P < 0.0001] for linezolid and 2.1 (90% CI 1.8, 2.4, P < 0.0001) for the positive control moclobemide. BMI had a statistically significant effect on TYR30.ConclusionsThere was a significant difference in the pressor response to i.v. tyramine between linezolid and placebo. Moclobemide (positive control) and linezolid have a similar pressor response to i.v. tyramine. The statistically significant effect of BMI on TYR30 underlines the advantage of within‐individual comparisons of treatments in order to reduce variability and provide more accurate treatment estimates.