bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of drugs in mothers of offspring with neural‐tube defects
Authors: Medveczky Erika , Puhó Erzsébet , Czeizel E. Andrew 
Published: July 2004

AbstractObjectiveTo study the risk of maternal drugs use during pregnancy in the origin of isolated neural‐tube defects (NTD).Materials and methods1202 cases with NTD, 38 151 population controls without any defects and 22 475 patient controls with other defects were compared in the population‐based data set of the Hungarian Case‐Control Surveillance of Congenital Abnormalities (HCCSCA), 1980–1996. The HCCSCA contains 542 drugs, however only those drugs were evaluated which included five or more mothers in the NTD group. Drugs with the same chemical structures were combined. In addition, only drug use in the second month of pregnancy was evaluated because it is the critical period for NTD. Of course, it is necessary to exclude different biases, mainly recall bias at the evaluation of these drugs. Of 121 chemicals, only oxytetracycline, carbamazepine and valproic acid had some association with NTD. High doses of exogenous oestrogens, clomiphene, chorionic gonadotropin, lynesterol and ergotamine also seemed to have some indirect association with NTD because their exposures occurred more frequently before the critical period of NTD due to maternal infertility.ConclusionOur findings suggest that drugs used during pregnancy do not appear to substantially contribute to the occurrence of isolated NTD but some drugs have a role in the origin of these defects. Copyright © 2004 John Wiley & Sons, Ltd.
Predictors of herbal medicine use in a Swedish health practice
Authors: Al‐Windi Ahmad 
Published: July 2004

AbstractObjectiveThe aim of this study was to characterise users of herbal medicines and assess the effect of socio‐demographic characteristics, perceived health and chronic disease on the use of herbal medicine in a multi‐ethnic Swedish health practice population.MethodsA questionnaire was completed by 1433 (out of a total of 1776) patients aged 16 years and above who visited the Jordbro Health Centre (JHC) in Stockholm, Sweden, between 14 January and 30 June 2002. The results were linked to computerised medical records.ResultsAltogether 320 (22.3%) of this patient population used some form of herbal medicine. The bivariate analysis showed that the use of herbal medicine were more common among patients aged 45–64 years, females, high educated, patients born in Nordic countries or Europe compared to other age groups, males, low educated, patients born outside Europe and without chronic disease. In the logistic regression analysis when the effects of confounders were taken into account, females, high educated patients and patients with chronic disease had higher odds for use of herbal medicine than males, low educated and patients without chronic disease. The odds ratios (ORs) and 95% confidence interval (95% CI) were 1.95 (1.40–2.76) for female as compared with male patients; 2.10 (1.49–2.97) for subjects with a high level of education compared with subjects with a low educational level and 1.62 (1.15–2.29) for subjects with chronic disease compared with subjects without chronic disease. The common diagnoses were musculo‐skeletal, respiratory and circulatory disorders, signs and symptoms and external causes according to the International Classification of Diseases (ICD10). There were no significant differences between users and non‐users of herbal medicine regarding the number of consultations with any physician or the general practitioner (GP), contacts with the health care centre, use of prescribed medicines or number of days of sick leave during the past year.ConclusionFemales, well‐educated patients and patients with chronic disease had higher odds for use of herbal medicine than others irrespective of other socio‐demographic characteristics, and herbal medicine was seen to be used independently of conventional medicine. Copyright © 2003 John Wiley & Sons, Ltd.
Agreement between GPRD smoking data: a survey of general practitioners and a population‐based survey
Authors: Lewis James D. , Brensinger Colleen 
Published: July 2004

AbstractBackgroundCigarette smoking is a common habit that is associated with many diseases. Smoking is often an important confounding variable in pharmacoepidemiological studies. The General Practice Research Database (GPRD) is widely used in pharmacoepidemiological research. In this study, we compare data recorded in the GPRD with the smoking history obtained from direct query of general practitioners (GPs) and from a population‐based survey.MethodsWe completed a mailed survey of GPs caring for a random sample of 150 patients with inflammatory bowel disease. The survey asked the GP to categorize the patients smoking status on a specified date. These results were then compared to the data recorded in the GPRD. Smoking status of 225 308 randomly selected GPRD patients without inflammatory bowel disease was compared to the results of a population‐based household survey.ResultsCompleted surveys with usable data were received from GPs on 136 of the 150 patients (91%). The sensitivity and positive predictive value of the database for current smoking were 78% (95% CI: 52–94) and 70% (95% CI: 46–88) respectively. The sensitivity and positive predictive value of former smoking were 53% (95% CI: 28–77) and 60% (95% CI: 32–84) respectively. Current and former smoking rates in the GPRD were 79% and 29% respectively of expected rates according to the population‐based survey .ConclusionsCurrent smoking is more completely recorded in the GPRD than former smoking. These data need to be considered when planning GPRD studies where smoking is an important exposure variable. Copyright © 2003 John Wiley & Sons, Ltd.
Current fluctuations of polymeric chains
Authors: Walczak Kamil 
Published: July 2004

AbstractCoherent electron transport is investigated in a molecular device made of a polymeric chain sandwiched between two metallic electrodes. The molecular system is described by a simple Hückel model, while the coupling to the electrodes is treated in a broad energy band approach. Transport characteristics and noise power are calculated in two response regimes: linear and non‐linear. A strong dependence is shown of the shot noise on (i) the length of the polymeric chain and (ii) the strength of the molecule‐to‐electrode coupling. In particular, a detailed discussion of Poissonian to sub‐Poissonian crossover in the noise spectra is included. An algorithm is presented that allows one to calculate the lowest possible level of current fluctuations (due to the Pauli exclusion principle) in designing molecular devices. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multiplexed hybridizations of positively charge‐tagged peptide nucleic acids detected by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Bauer Oliver , Guerasimova Anna , Sauer Sascha , Thamm Sabine , Steinfath Matthias , Herwig Ralf , Janitz Michal , Lehrach Hans , Radelof Uwe 
Published: July 2004

AbstractPeptide nucleic acid (PNA) is a novel class of DNA analogues in which the entire sugar‐phosphate backbone is replaced by a pseudopeptide counterpart. Owing to its neutral character and the consequent lack of electrostatic repulsion, PNA exhibits very stable heteroduplex formation with complementary nucleic acid that is essentially ionic strength independent and enables hybridization under minimum salt conditions. This feature as well as its superior ion stability and easy ionization compared to DNA renders PNA very attractive for hybridization‐based matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) applications. We have developed an approach to DNA characterization that takes advantage of multiplexed PNA hybridizations analyzed by MALDI‐TOFMS. Our motivation was the further development of oligonucleotide fingerprinting, an efficient technique for cDNA and genomic DNA library characterization. Through positive ‘charge‐tagging’ of PNA the efficiency of detection in MALDI‐TOFMS was considerably enhanced permitting an unparalleled degree of multiplexing. Results from the simultaneous hybridization of 21 charge‐tagged PNA hexamer oligonucleotides showed that genomic DNA and cDNA clones are successfully characterized on the basis of their hybridization profiles. The degree of multiplexing achieved may render a significant increase in throughput and hence efficiency of oligonucleotide fingerprinting possible. Copyright © 2004 John Wiley & Sons, Ltd.
Electrospray ionization mass spectrometry in the structural characterization of some diphenyllead(IV) thiosemicarbazonates
Authors: Casas José S. , García‐Tasende María S. , Sordo José , Taboada Carmen , Tubaro Michela , Traldi Pietro , Vidarte María J. 
Published: July 2004

AbstractThe behavior in electrospray ionization mass spectrometry (ESI‐MS) conditions of some complexes formed by Pb(C6H5)2(OAc)2 with salicylaldehyde, 2‐ketobutyric acid, pyridine‐2‐carbaldehyde, 2‐acetylpyridine, and 2‐benzoylpyridine thiosemicarbazones, was studied in detail with the aid of collisional experiments performed by ion trap. The homoleptic complexes of tridentate thiosemicarbazonate dianions (TSC2−) lose the phenyl groups first, destabilizing the high oxidation state of the metal and leading to Pb(II) complexes in which the TSC2− ligand or a part of it remains coordinated to the metal. The main difference among the complexes derives from the presence of a carboxylate group on the 2‐ketobutyric acid thiosemicarbazonato ligand, which probably interacts with a Na+ cation leading to ESI‐generated [M+Na]+ species. In the absence of the carboxylate group, the production of abundant protonated molecules is observed. These different behaviors have been rationalized from the structural point of view. The heteroleptic mononuclear complexes, including thiosemicarbazonate and AcO− monoanions in the coordination sphere, do not yield intact ionized molecular species, and the most abundant ESI‐generated ion is due to AcO− loss. The spectrum of the binuclear heteroleptic complex formed by the salicylaldehyde thiosemicarbazonate monoanion is conditioned by the weak bonding interaction displayed by the acetate bridge. MSn experiments yield important information on the relative ligand–Pb bond strengths. This work forms part of the search for chelating agents that can be used for effective chemotherapy of organolead poisoning. Copyright © 2004 John Wiley & Sons, Ltd.
Surface‐activated chemical ionization ion trap mass spectrometry in the analysis of amphetamines in diluted urine samples
Authors: Cristoni Simone , Bernardi Luigi Rossi , Gerthoux Piermario , Gonella Elisabetta , Mocarelli Paolo 
Published: July 2004

AbstractA new ionization method, named surface‐activated chemical ionization (SACI), was employed for the analysis of five amphetamines (3,4‐methylenedioxyamphetamine (MDA), 3,4‐methylenedioxymethamphetamine (MDMA), 3,4‐methylenedioxyethylamphetamine (MDE), amphetamine and methamphetamine) by ion trap mass spectrometry. The results so obtained have been compared with those achieved by using atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) using the same instrument, clearly showing that SACI is the most sensitive of the three. The limit of detection and linearity range for SACI were compared with those obtained using APCI and ESI, showing that the new SACI approach provides the best results for both criteria. SACI was used to analyze MDA, MDMA MDE, amphetamine and methamphetamine in four urine samples, and the quantitation results are compared with those achieved using ESI. Copyright © 2004 John Wiley & Sons, Ltd.
N2O influence on isotopic measurements of atmospheric CO2
Authors: Sirignano Carmina , Neubert Rolf E. M. , Meijer Harro A. J. 
Published: July 2004

AbstractIn spite of extensive efforts, even the most experienced laboratories dealing with isotopic measurements of atmospheric CO2 still suffer from poor inter‐laboratory consistency. One of the complicating factors of these isotope measurements is the presence of N2O, giving rise to mass overlap in the isotope ratio mass spectrometer (IRMS). The aim of the experiment reported here has been twofold: first, the re‐establishment of the correction for ‘mechanical’ interference of N2O in the IRMS, along with its variability and drift, and the best way to quantitatively determine the correction factors. Second, an investigation into secondary effects, i.e. the influence of N2O admitted with the CO2 sample on the “cross contamination”1 between sample and (pure CO2) working gas. To make the suspected effects better detectable, isotopically enriched CO2 gas with different concentrations of N2O has been measured for the first time. No evidence of secondary effects was observed, from which we conclude that N2O is not a major player in the inter‐laboratory consistency problems. Still, we also found that the determination of the ‘mechanical’ N2O correction needs to be very carefully determined for each individual IRMS, and should be periodically re‐determined. We show that the determination of the correction should be performed using CO2/N2O mixtures with concentration ratios around that of the atmosphere, as the extrapolation from pure gas end member behaviour will give erroneous results due to non‐linearities. For our IRMS, a VG SIRA series II, we find a correction of 0.23‰ for δ45CO2 and 0.30‰ for δ46CO2 of atmospheric samples, (with 0.85‰ mixing ratio). This implies that the relative ionisation efficiency (E) value associated with this machine is 0.75. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of N2O on the isotopic composition of air‐CO2 samples
Authors: Ghosh Prosenjit , Brand Willi A. 
Published: July 2004

AbstractThe ionisation efficiencies of N2O vs. CO2 as well as their ratios were measured in detail introducing clean N2O and CO2 into the electron impact ion source of an isotope ratio mass spectrometer. Changes in the ionisation efficiency ratio (IER) were found for different electron energy settings and compared with the ratios of literature ionisation cross‐section values for pure N2O and CO2. To establish the influence of mixtures of N2O and CO2 in a mass spectrometer, artificial air mixtures were prepared by mixing different amounts of N2O and CO2 from well‐calibrated spike cylinders with CO2‐free air. The mixing ratios varied from 8–512 ppb for N2O and from 328–744 ppm for CO2. With these mixtures the effects of varying N2O concentrations on apparent CO2 isotope ratios in air samples were determined. After applying a mass balance correction the δ13C results were consistent within small error margins. The data seemed almost independent from a particular choice for the IER of N2O vs. CO2 in the correction algorithm. For δ18O a small effect of the ionisation efficiency ratio of N2O vs. CO2 was found. Several sets of calculations were made varying the IER between 0.88 and 0.62. The dependence of δ18O was the smallest with an adopted IER of 0.68–0.72 in the mass balance correction equation for isotopic analysis of CO2 in air. For high‐precision measurements of the CO2 stable isotope ratios in air samples a careful assessment of the mass spectrometer performance is necessary. Different ion sources, even different ion source settings, alter the IER of N2O vs. CO2 which is used in the N2O correction algorithm. Preferably, the specific mass spectrometric behaviour should be established with clean N2O/CO2 mixtures or with air mixtures covering a larger range of N2O concentrations. Copyright © 2004 John Wiley & Sons, Ltd.
De Bruijn cycles for covering codes
Authors: Chung Fan , Cooper Joshua N. 
Published: July 2004

AbstractA de Bruijn covering code is a q‐ary string S so that every q‐ary string is at most R symbol changes from some n‐word appearing consecutively in S. We introduce these codes and prove that they can have size close to the smallest possible covering code. The proof employs tools from field theory, probability, and linear algebra. Included is a table of the best known bounds on the lengths of small binary de Bruijn covering codes, up to R = 11 and n = 13, followed by several open questions in this area. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
A web‐based learning system with the framework of linking explanations of related knowledge to web pages
Authors: Mitsuhara Hiroyuki , Ochi Youji , Yano Yoneo 
Published: July 2004

AbstractIn exploratory learning using Web pages, the learner tries to understand a visited page by recalling and applying related knowledge. The learner also refers to and applies explanations of the related knowledge if access is possible. The expectation is that the knowledge used in understanding various pages will be organized and integrated, and will be stabilized in the memory. The purpose of this study is to develop a WBL (Web‐based learning) system that assists such knowledge stabilization. The authors consider that the most fundamental knowledge stabilization assistance consists of helping the learner refer to and apply explanations of related knowledge from the visited page. Consequently, this paper proposes a framework in which related knowledge is linked to Web pages, and presents a WBL system based on such a framework. The effectiveness of the proposed system is investigated through an experiment. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(10): 102–113, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10517
Feasibility study of convenient automatic identification system of medical articles using LF‐band RFID in hospital
Authors: Hosaka Ryosuke 
Published: July 2004

AbstractThe number of medical accidents has recently been increasing in patient environments in Japan. Most of these accidents are ascribed to errors by nurses. Among these, however, are cases that could have been prevented by appropriate management of medical articles. In the patient environment, the patient is placed at the center, and medical articles are in a dependency relation to the patient. An accident may arise if such a dependency is not fulfilled. This paper proposes the use of low‐frequency‐band RFID tags in order to monitor the patient environment. In the proposed method, tags are attached to the patient and all related medical articles. By monitoring the tags at any time by wireless communications, mistaken inclusion of articles related to other patients can be avoided. In this system, tags are automatically identified, which avoids placing an extra burden on the nurses and other medical professionals. In this study, the identification performance of RFID tags is improved and the feasibility of their use as a practical system is verified by an experiment in an environment simulating an actual site. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(10): 74–82, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10581
Design of agent‐based middleware for flexible connection control
Authors: Konno Susumu , Kitagata Gen , Suganuma Takuo , Sugawara Kenji , Kinoshita Tetsuo 
Published: July 2004

AbstractControlling connections between operating networks in an extranet according to various requests from users or applications creates a huge load for network administrators. In response to this problem, the authors herein propose a type of agent‐based middleware for dynamically configuring and providing network services based on requests assigned from applications. In addition, they describe a method of designing this agent‐based middleware and construct an experimental system that incorporates it to show the effectiveness of the proposed technique through experiments using the system. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(10): 50–62, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10656
Autonomous development of relationships among web servers for facilitating information utilization
Authors: Sato Shin‐ya , Harada Masanori , Kazama Kazuhiro 
Published: July 2004

AbstractA Web server can play a role as an agent for people who create information, and Web servers with related information can be searched by the agent in order to facilitate efficient information utilization on the Web. Web servers exchange information with other servers and select which ones to keep or abandon, resulting in an increase in the links with servers with greater relevance. As a result, a community, a group of Web servers that are mutually linked, is created. A Web server community can be used as a place for various forms of information utilization and exchange, such as meta‐searches and contents syndication. In this paper, the authors propose an algorithm for creating communities after evaluating the meaning of facilitating information utilization via a community. They then verify the validity of their idea through simulations. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(10): 40–49, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10659
A method of estimation of magnetic resonance spectroscopy using complex‐valued neural networks
Authors: Morita Naoyuki , Konishi Osamu 
Published: July 2004

AbstractMRS (magnetic resonance spectroscopy) consists of collecting the nuclear magnetic resonance (NMR) spectrum of the metabolites in the living body and estimating it. In the field of MRS, we usually get an NMR spectrum by applying the Fourier transform to the real part of the NMR signal [free induction decay (FID) signal], which is a complex‐valued signal. We must then measure the area of the spectral peak to estimate metabolites in the living body from the spectrum. A curve fitting technique is used for that measurement. However, this technique is not suitable for large quantities of data processing, because human intervention is necessary and is laborious. For this reason, an automatic method of estimating an NMR spectrum is required in the field of MRS. In this paper, we propose a method of estimation of an NMR spectrum by using a Hopfield complex‐valued neural network and try to estimate the spectrum automatically. In addition, we consider damping state of the NMR signal and devise a method called sequential extension of section (SES). It is shown that the estimation precision of the spectrum improves when SES is used. Furthermore, SES is found to reduce the local minimum problem in Hopfield neural networks. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(10): 14–22, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10705
Stock identification of Mediterranean horse mackerel (Trachurus mediterraneus) using morphometric and meristic characters
Authors: Turan Cemal 
Published: July 2004

Abstract
Morphologic differentiation among stocks of Mediterranean horse mackerel, Trachurus mediterraneus, throughout the Black, Marmara, Aegean and Eastern Mediterranean Seas, was investigated using morphometric and meristic characters. Discriminant function analysis of both morphometric and meristic characters suggested that there is restricted migration of mackerel among the adjacent seas. Overlapping of four Black sea samples on the discriminant space in morphometric and meristic characters suggested that there is one self-recruiting population in the area. The Marmara sea samples were the most isolated samples from all others for both morphometric and meristic characters, which may indicate existence of a distinguishable mackerel stock in the area. The sample from the Aegean Sea was grouped with one geographically close Mediterranean sample based on morphometrics, and separated from all other Mediterranean samples based on meristic characters, suggesting some degree of intermingling between these areas. Examination of the contribution of each morphometric variable to canonical functions indicated that differences among samples seemed to be associated with the anterior part of the body. In meristic analyses, highest contributions to canonical functions were associated with the number of gill rakers and pectoral fin rays.