bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transition‐metal‐templated synthesis of rotaxanes and catenanes: From small molecules to polymers
Authors: Kern Jean‐Marc , Sauvage Jean‐Pierre , Bidan Gerard , Divisia‐Blohorn Bernadette 
Published: October 2003

AbstractThis article provides an overview of the fundamental principles of the synthesis of metallocatenanes and metallorotaxanes. It also describes the synthesis and properties of electronic conducting polymers—polypyrrole and polythiophene—built around metallocatenanes and metallorotaxanes. The particular properties of this new class of polymers, including the possibility of transmetallation reactions being performed with them and the observation of electronic coupling between the metal centers and the conducting matrix, are discussed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3470–3477, 2003
Amphiphilic and hydrophobic surface patterns generated from hyperbranched fluoropolymer/linear polymer networks: Minimally adhesive coatings via the crosslinking of hyperbranched fluoropolymers
Authors: Gan Daoji , Mueller Anja , Wooley Karen L. 
Published: October 2003

AbstractHyperbranched fluoropolymers (HBFPs), based on benzyl ether linkages and having a large number of pentafluorophenyl chain ends, were crosslinked by a reaction with diamino‐terminated poly(ethylene glycol) (PEG) or diamino‐terminated poly(dimethyl siloxane) (PDMS) to form hyperbranched–linear copolymer networks of different compositions, structures, and properties. The crosslinking reactions involved the nucleophilic aromatic substitution of the pentafluorophenyl para‐fluorines of HBFP by the amine functionalities of the respective telechelic linear segments. The contact angles, differential scanning calorimetry, thermogravimetric analysis, tensile measurements, and atomic force microscopy (AFM) were used to characterize the resulting network film samples. The surface wettability of the crosslinked materials was affected by the nature and amount of the linear polymer crosslinking agent employed. Amphiphilic polymer networks were formed by the incorporation of diamino‐terminated PEG as a crosslinker, whereas diamino‐terminated PDMS produced polymer networks of a hydrophobic character. The mechanical properties improved upon crosslinking, as measured by tensile testing. The mechanical integrity of the films was also found to improve upon crosslinking, as measured by AFM machining protocols. The AFM images revealed topographical morphologies that appeared to be the result of phase segregation of HBFP from PEG or PDMS; the dimensions of the phase‐segregated domains were dependent on the stoichiometry of HBFP to the linear polymer and the thickness of the coating. As the content of PEG increased, fouling by human fibrinogen, used as a model protein, decreased. Further studies are in progress to determine the effects of the surface composition, morphology, and topography on the biofouling characteristics. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3531–3540, 2003
Some of Sam Greenhouse's contributions to statistical methods
Authors: Gail Mitchell H. 
Published: October 2003

AbstractI briefly survey some areas of Sam Greenhouse's contributions to statistical methods before focusing on three examples. These examples illustrate Sam's ability to identify problems of practical importance and to make valuable contributions to their solutions. Many of his papers continue to provide important guidance and insight because he dealt with issues of enduring practical importance. Published in 2003 by John Wiley & Sons, Ltd.
The use of the ‘reverse Cornfield inequality’ to assess the sensitivity of a non‐significant association to an omitted variable
Authors: Yu Binbing , Gastwirth Joseph L. 
Published: October 2003

AbstractUnlike randomized experimental studies, investigators do not have control over the treatment assignment in observational studies. Hence, the treated and control (non‐treated) groups may have widely different distributions of unobserved covariates. Thus, if observational data are analysed as if they had arisen from a controlled study, the analyses are subject to potential bias. Sensitivity analysis is a technique for assessing whether the inference drawn from a study could be altered by a moderate ‘imbalance’, between the distribution of the covariates in different groups. In this paper, we examine the sensitivity analysis of the test of proportions in 2 × 2 tables from a new perspective: ‘could a non‐significant result have occurred because the treated group has a higher prevalence of an unobserved risk factor?’. The study was motivated by an analysis of the studies concerning with the possible effect of spermicide use on birth defects that were cited in a legal decision. Copyright © 2003 John Wiley & Sons, Ltd.
Estimating population size and duplication rates when records cannot be linked
Authors: Laska Eugene M. , Meisner Morris , Wanderling Joseph , Siegel Carole 
Published: October 2003

AbstractThe capture‐recapture approach to estimating the size of a population is a well‐studied area of statistics. The number of distinct individuals, NA and NB, on each of two lists, A and B, and the number common to both lists, NAB, are used to form an estimate of the binomial probability of being on one of the lists, which then allows an estimate to be made of the size of the population. Critical to the method is an accurate count of NAB. We consider situations in which this count is not available. Such problems arise in a variety of behavioural health contexts in which the need for protection of privacy may prevent sharing identifying information, so it is not possible to specifically match an individual who appears on one list with an individual on the other. Suppose that the birth dates and/or other demographics of individuals on each list are known. We introduce two methods for estimating the duplication rates and the size of the population. Conditioning on the set β of birth dates of those on list B, NA and NB, the maximum likelihood estimators (MLEs) and their variance are derived. The MLEs are based on the proportion of individuals on list A whose birth dates fall in β. This approach is particularly useful if list B itself contains duplicates. The second model utilizes the full sample distribution of the birth dates. We generalize this approach to accommodate multiple demographic characteristics. The approaches are applied to the problem of estimating duplication rates and the population size of veterans who have mental illness in Kings County, NY. The data are lists of those receiving service from the Veterans Administration system and from providers funded or certified by the New York State Office of Mental Health. Copyright © 2003 John Wiley & Sons, Ltd.
Long distance nitrogen air pollution effects on lichens in Europe
Authors: van Herk C. M. , Mathijssen-Spiekman E. A. M. , de Zwart D. 
Published: October 2003

AbstractThe epiphytic lichen flora of 25 European ICP-IM monitoring sites, all situated remote from air pollution sources, was statistically related to measured levels of SO2 in air, NH4+, NO3− and SO42− in precipitation, annual bulk precipitation, and annual average temperature. Significant regression models were calculated for eleven acidophytic species. Several species strong negative correlation with nitrogen compounds. At concentrations as low as 0·3 mg N l−1 in precipitation, a decrease of the probability of occurrence is observed for Bryoria capillaris, B. fuscescens, Cetraria pinastri, Imshaugia aleurites and Usnea hirta. The observed pattern correlations strongly suggests a key role of NH4+ in determining the species occurrence, additional role of NO3− cannot be ruled out. Some species show a distinct response to current of SO2 well. It may be concluded that long distance nitrogen air pollution has strong influence the occurrence of acidophytic lichen species.
A new species of Arctomia from Sichuan Province, China
Authors: Jørgensen P. M. 
Published: October 2003

AbstractArctomia teretiuscula sp. nov. (Arctomiaceae) is described from Sichuan Province, China. A minutely coralloid, bryophilous cyanolichen, it is a further example of the biogeographical link between the lichen biotas of the Himalayan region and the Arctic. A key to the three accepted species of Arctomia is provided.
Responses of moist non‐acidic arctic tundra to altered environment: productivity, biomass, and species richness
Authors: Gough Laura , Hobbie Sarah E. 
Published: October 2003

In arctic Alaska, researchers have manipulated air temperature, light availability, and soil nutrient availability in several tundra communities over the past two decades. These communities responded quite differently to the same manipulations, and species responded individualistically within communities and among sites. For example, moist acidic tundra is primarily nitrogen (N)‐limited, whereas wet sedge tundra is primarily phosphorus (P)‐limited, and the magnitude of growth responses varies across sites within communities. Here we report results of four years of manipulated nutrients (N and/or P) and/or air temperature in an understudied, diverse plant community, moist non‐acidic tussock tundra, in northern Alaska. Our goals were to determine which factors limit above‐ground net primary productivity (ANPP) and biomass, how community composition changes may affect ecosystem attributes, and to compare these results with those from other communities to determine their generality.Although relative abundance of functional groups shifted in several treatments, the only significant change in community‐level ANPP and biomass occurred in plots that received both N and P, driven by an increase in graminoid biomass and production resulting from a positive effect of adding N. There was no difference in community biomass among any other treatments; however, some growth forms and individual species did respond. After four years no one species has come to dominate the treatment plots and species richness has not changed. These results are similar to studies in dry heath, wet sedge, and moist acidic tundra where community biomass had the greatest response to both N and P and warming results were more subtle. Unlike in moist acidic tundra where shrub biomass increased markedly with fertilization, our results suggest that in non‐acidic tundra carbon sequestration in plant biomass will not increase substantially under increased soil nutrient conditions because of the lack of overstory shrub species.
Synergistic Effect of Interleukin‐1α and Ceramide Analogue on Production of Prostaglandin E2 and F2α by Endometrial Stromal Cells
Authors: KAWANO YASUSHI , NAKAMURA SATOMI , FUKUDA JUNICHIRO , MIYAKAWA ISAO 
Published: October 2003

PROBLEM: Prostaglandins (PGs) are synthesized in the endometrium. Our objective was to evaluate interleukin (IL)‐1α‐induced production of PGE2 and PGF2α in endometrial stromal cells (ESC) following treatment with ceramide analogues.
METHODS OF STUDY: ESC were obtained from human uterine endometrium by enzymic digestion and filtration. ESC were treated with IL‐1α, IL‐1 receptor antagonist (ra), C2‐ceramide and C6‐ceramide. The concentrations of PGE2 and PGF2α in media were determined using ELISA. The induction of prostaglandin H synthase (PGHS)‐2 mRNA was also ascertained by reverse transcription‐polymerase chain reaction (RT‐PCR).
RESULTS: The production of PGE2 and PGF2α was significantly increased by IL‐1α and suppressed by IL‐1 ra, in a dose‐dependent manner. PGF2α production was further increased by treatment with the combination of IL‐1α and C2‐ceramide as compared with IL‐1α treatment alone. There was no significant difference in PGE2 production between cells treated with IL‐1α and C2‐ceramide and those treated with IL‐1α alone. Both PGE2 and PGF2α production were significantly increased by treatment with IL‐1α and C6‐ceramide as compared with IL‐1α treatment alone. Treatment of ESC with IL‐1α stimulated PGHS‐2 mRNA. PGHS‐2 mRNA was decreased when IL‐1 ra was added to the IL‐1α‐stimulated cells.
CONCLUSIONS: These results suggest that IL‐1α stimulates the production of PGE2 and PGF2α by a mechanism that involves the sphingomyelin‐ceramide system, and thus that ceramide may be important in increasing the production of PGE2 and PGF2α in the human endometrium.
Attentional shifts to smoking cues in smokers
Authors: Waters Andrew J. , Shiffman Saul , Bradley Brendan P. , Mogg Karin 
Published: October 2003

ABSTRACTAims  Many theories of addiction assume that responses to drug cues maintain drug use and precipitate relapse. There is evidence that measures derived from experimental cognitive psychology yield important information about cue reactivity. We used a pictorial version of the visual probe task to evaluate: (i) whether minimally deprived smokers attend differentially to smoking cues (attentional bias); (ii) whether this bias is related to self‐reported craving and dependence; and (iii) whether it predicted outcome in a subsequent cessation attempt.Design  Participants took part in a structured smoking cessation program. Each participant completed the visual probe task roughly 2 weeks before quitting while non‐deprived.Setting  A research smoking cessation clinic.Participants  141 heavy smokers seeking treatment for smoking cessation.Measurements  The computerized attentional bias measure and self‐reported urge were taken in a laboratory session. Participants also monitored their smoking and craving on electronic diaries both when smoking ad libitum and for up to 6 weeks post‐cessation.Findings  Participants were faster and more accurate in responding to a visual probe that replaced a smoking picture than to a neutral picture, indicating that they showed attentional bias towards the smoking cues. Attentional bias on the first half of the task correlated with pre‐task craving, indicating that the bias may tap motivational processes, but it did not predict outcome in smoking cessation.Conclusions  The visual probe task can add useful information about attentional responses to drug cues. Further work is required to uncover the theoretical significance and utility of this measure.
Abuse and dependence potential for the non‐benzodiazepine hypnotics zolpidem and zopiclone: a review of case reports and epidemiological data
Authors: Hajak G. , Müller W. E. , Wittchen H. U. , Pittrow D. , Kirch W. 
Published: October 2003

ABSTRACTAims  The non‐benzodiazepine hypnotics zolpidem and zopiclone, which are indicated for short‐term treatment of insomnia, were considered originally by physicians as almost devoid of abuse and dependence potential. Several recent publications, however, have suggested that both agents carry a significant risk of abuse. To substantiate and re‐evaluate this situation, the world literature was reviewed for cases of dependence of both agents; these cases were analysed in order to identify certain underlying patterns, if evident.Methods  A systematic review based on a Medline literature search was conducted including the years 1966–2002 to assemble all available clinical case reports that were analysed for typical features of abuse and dependence according to prespecified criteria. Only case reports were of interest, and clinical studies were excluded. No limitations as to language or publication year were applied. The terms ‘zolpidem’, ‘zopiclone’ and ‘abuse’, ‘dependence’, ‘addiction’, ‘withdrawal’ and ‘intoxication’ were used to identify relevant publications. Potentially relevant citations were retrieved and assessed for inclusion independently by two authors.Results  A total of 36 cases for zolpidem were identified, most of them reported in recent years, and 22 cases for zopiclone. Both sexes were involved to a similar extent; and cases were reported in all age groups. In extreme cases, dose increases reached a factor of 30–120 above the recommended doses. The majority of patients had a history of former drug or alcohol abuse and/or other psychiatric conditions.Conclusion  On the basis of world‐wide prescription numbers, which are approximately twofold higher for zolpidem (1 338 774 000 tablets from June 2001 to June 2002 in Europe, Japan and United States) than for zopiclone (664 897 000 tablets during the same period in Europe and Japan), the relative incidence of reported dependence similar for both drugs and remarkably lower than that of benzodiazepines used for the treatment of disturbed sleep. The findings offer the conclusion that zolpidem and zopiclone are relatively safe drugs. However, as both drugs are psychotropic drugs, patients with a history of abuse or dependence and those with psychiatric diseases seem to be at increased risk of abuse of these agents.
The cigar as a drug delivery device: youth use of blunts
Authors: Soldz Stephen , Huyser Dana Joy , Dorsey Elizabeth 
Published: October 2003

ABSTRACTAims  Blunts are hollowed‐out cigars used to smoke marijuana (and perhaps other substances) in the United States. We investigated rates of blunt use; whether cigar use reported in surveys may actually be blunt use; the relationship of blunt to cigar use; characteristics of blunt users; brands of cigars used to make blunts; and drugs added to blunts.Design  A school‐based survey of youth, the Cigar Use Reasons Evaluation (CURE).Setting  Eleven schools across Massachusetts.Participants  A total of 5016 students in grades 7–12.Measurements  CURE items assessing blunt, cigar and cigarette use, brands used to make blunts, drugs added to blunts and demographics were used.Findings  Life‐time blunt use was reported by 20.0% of the sample, with use greater among high school (25.6%) than middle school (11.4%) students, and among males (23.7%) than females (16.6%). Self‐reported cigar use rates were not influenced strongly by blunt use being misreported as cigar use. In a multivariate model, blunt use was associated with male gender, higher grade in school, lower GPA, truancy, lower school attachment, not living in a two‐parent family, being of ‘other’ race/ethnicity and current use of both cigarettes and cigars. ‘Phillies’ was the most popular brand of cigar for making blunts, used by 59.$% of users. ‘Garcia y Vega’ (18.0%) was the second most popular. Twenty‐eight per cent of blunt users had added drugs other than marijuana to blunts.Conclusions  The use of blunts as a drug delivery device is a serious problem. Efforts to address it will require the cooperation of the tobacco control and substance abuse prevention systems.
Longitudinal study on the prevalence of benzodiazepine (mis)use in a prison: importance of the analytical strategy
Authors: Borrey D. , Meyer E. , Duchateau L. , Lambert W. , Van Peteghem C. , Leenheer A. P. De 
Published: October 2003

ABSTRACTAims  This study evaluates the suitability of gas chromatographic‐mass spectrometric (GC‐MS) analysis to follow‐up the extent of benzodiazepine (mis)use in a Belgian prison population and compares it to other analytical strategies (e.g. screening followed by confirmation of the positive samples).Design and participants  From February to August 1998, 598 persons were jailed of which 188 (31.4% of the incoming detainees) volunteered to be screened. Urine samples (530 in total) were collected on the day of arrival and after 14, 30 and 90 days of imprisonment.Measurements  All samples were screened by EMIT® for benzodiazepines and analysed subsequently by GC‐MS.Findings  EMIT® screening yielded 117 (22.1%) positive samples, a number which increased to 174 (32.8%) after GC‐MS analysis. Of these 174 GC‐MS positive samples, 119 (68.4%) contained one benzodiazepine while for the remaining samples multiple benzodiazepine (mis)use could be demonstrated. A significant increase in benzodiazepine (mis)use was indicated only from day 0 to day 14 based on the GC‐MS results but not on the immunoassay results, even when the latter were complemented with GC‐MS analysis of the positively screened samples. The GC‐MS data also demonstrated that benzodiazepines are mainly (mis)used by subjects on benzodiazepine prescription as almost 50% of these subjects took additional non‐prescribed benzodiazepines. During GC‐MS analysis other drugs were co‐extracted unintentionally and chromatographed and 23.9% of the volunteers were positive for illegal drugs on the day of arrival.Conclusion  Immunoassay results yield an underestimation of the problem of benzodiazepine (mis)use in prison due to the high false negative rate. GC‐MS analysis of all samples therefore is the recommended strategy for this type of longitudinal study as it yields more correct and detailed information than the immunoassay results.
Clinical drug monitoring by microdialysis: application to levodopa therapy in Parkinson's disease
Authors: O'CONNELL MARK T. , TISON FRANÇOIS , QUINN NIALL P. , PATSALOS PHILIP N. 
Published: October 2003

1We describe the first application of microdialysis to monitor the pharmacokinetics of a drug in the blood of man. 2The aims of the study were to ascertain patient acceptability and tolerability of a new microdialysis probe and to assess its accuracy in determining the pharmacokinetics of levodopa and its principal plasma metabolite 3‐O‐methyldopa (3‐OMD). 3Eight patients with parkinsonism on chronic levodopa therapy were investigated. 4After an overnight fast, a flexible microdialysis probe, perfused with isotonic saline, was inserted into a forearm vein and a blood sampling cannula was inserted in a forearm vein of the other arm. After ingestion of a levodopa preparation (Madopar Dispersible}}rm), dialysate was collected over 5 or 10 min periods and blood samples were taken every 15 or 30 min for 2–6 h. 5Dialysate drug profiles were similar to those of plasma, and levodopa and 3‐OMD concentrations exhibited significant (P<0.001) correlation with those observed in the corresponding plasma samples. 6The mean (±s.d.) blood dialysate concentrations for levodopa and 3‐OMD were 36.1±9.2% and 43.4±8.4% respectively of the plasma content. 7The tolerability of the probe was excellent, and all eight patients found it preferable to conventional blood sampling. 8Microdialysis of blood is less invasive than frequent intermittent direct blood sampling, and can readily be used to continuously monitor levodopa pharmacokinetics. In a clinical setting, a combination of drug monitoring by this technique together with clinical evaluation of motor function can be used to optimize levodopa treatment in patients with Parkinson's disease.