bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of 7‐methylguanine using isotope dilution and gas chromatography/electron‐capture negative chemical ionization mass spectrometry
Authors: Chiang Su‐Yin , Huang Tai‐Hung , Uang Shi‐Nian , Wu Hong‐Dar Isaac , Wei Yi‐Chiech , Lin Hui‐Yi , Swenberg James A. , Wu Kuen‐Yuh 
Published: June 2005

AbstractThis paper presents results obtained for in vivo endogenous and exogenous 7‐methylguanine (7‐MG) analyzed using a method incorporating gas chromatography with electron‐capture negative chemical ionization mass spectrometry and isotope dilution (GC/EC‐ID‐MS). 13C4‐Labeled 7‐MG was synthesized to serve as an internal standard to improve accuracy of quantitation, and was used to analyze 7‐MG in livers of control mice and dacarbazine‐treated mice. The results confirm that 7‐MG in tissue DNA can be measured using this GC/EC‐ID‐MS method with excellent sensitivity and specificity. Administration of 0, 30, and 60 mg/kg dacarbazine to mice led to dose‐dependent increases in the formation of 7‐MG. The results indicate that this method could be applied to the analysis of endogenous and exogenous 7‐MG in human tissues for future molecular epidemiology studies on potential health effects caused by methylating agents. Copyright © 2005 John Wiley & Sons, Ltd.
Some fundamental and technical aspects of the quantitative analysis of pharmaceutical drugs by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: Sleno Lekha , Volmer Dietrich A. 
Published: June 2005

AbstractThe purpose of the present paper was to study some of the underlying physical and technical aspects of high‐throughput quantitative matrix‐assisted laser desorption/ionization (MALDI) of small drug molecules. A prototype MALDI‐triple quadrupole instrument equipped with a high repetition rate laser was employed. Initially, the detection limits and dynamic ranges for the quantitation of four drugs (quinidine, danofloxacin, ramipril and nadolol) were determined. Internal standards were carefully chosen for each of these analytes in terms of structure similarity and fragmentation pathways. Three organic matrices were tested for these assays, resulting in different crystallization behaviors and measurement reproducibilities. α‐Cyano‐4‐hydroxycinnamic acid yielded the best results and was subsequently employed for the quantitative determination of all four analytes. Further experiments considered the role of laser energy and pulse rate on the ablated areas as well as ion signals. Light microscope and scanning electron microscope images allowed the examination of the ablated area of the MALDI spots. The images showed convincing evidence that the ablated area was virtually void of crystals after analysis, with no preferential removal of material in the center of the laser's path. Average values for the amount of material ablated were determined to be 3.9 ± 0.5% of the total spot size, and as low as 19.5 attomoles of analyte were detectable for our most sensitive analyte, ramipril. It was calculated that, under these assay conditions, it was possible to accurately quantify less than 1 femtomole of all analytes with the use of appropriately pure internal standards. These studies showed very promising results for the quantitative nature of MALDI for small molecules with molecular weights less than 500 Da. Copyright © 2005 John Wiley & Sons, Ltd.
Intact human holo‐transferrin interaction with oxaliplatin
Authors: Zhao Yuan‐Yuan , Mandal Rupasri , Li Xing‐Fang 
Published: June 2005

AbstractWe report the interaction of intact human holo‐transferrin (holo‐Tf) with oxaliplatin (an anticancer drug), and the characterization of a complex composed of (1:1) intact holo‐Tf and the parent oxaliplatin molecule using nanoelectrospray ionization quadrupole time‐of‐flight mass spectrometry (nanoESI‐QTOF‐MS). The molecular weight of this complex was determined to be 80 077 Da, which was an increase of 397 mass units compared to the protein alone (79 680 Da), suggesting that a parent drug molecule was bound to the intact protein. We further examined the interaction between the intact protein and oxaliplatin using size‐exclusion high‐performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS). The protein complex and free oxaliplatin were separated by HPLC and quantitatively determined by simultaneous monitoring of both 195Pt and 56Fe using ICPMS. The HPLC/ICPMS detected both Pt and Fe signals at retention time of 2.6 min, identifying the protein–drug complex. The Fe signal at 2.6 min did not change with the increase in incubation time of the reaction mixture containing holo‐Tf and oxaliplatin, while the Pt signal at the same retention time increased over time, further demonstrating that the formation of this complex does not affect the protein‐bound Fe. The binding constant of the (1:1) intact human holo‐Tf–oxaliplatin complex was determined to be 7.7 × 105 M−1. Both nanoESI‐MS and HPLC/ICPMS results support that the holo‐Tf and parent oxaliplatin molecules form complexes through non‐covalent binding, suggesting that holo‐Tf may be a useful carrier for oxaliplatin delivery. Copyright © 2005 John Wiley & Sons, Ltd.
Negative gas‐phase ion chemistry of GeH4: a quadrupole ion trap study
Authors: Operti Lorenza , Rabezzana Roberto , Turco Francesca , Vaglio Gian Angelo 
Published: June 2005

AbstractGas‐phase anion/molecule reactions of germanium hydride were studied by quadrupole ion trap (QIT) mass spectrometry. Under chemical ionization (CI) conditions and with a sample pressure of about 5.0 × 10−5 Torr, clustering reactions proceed up to the formation of Ge5H ion clusters. With increasing cluster size, the most abundant ion species are those with the lowest content of hydrogen. Reaction sequences obtained by ion isolation were determined for primary, secondary and tertiary germane ions, and reaction enthalpies were calculated for reactions of primary ions. Ion/neutral condensation processes followed by single and double dehydrogenation are by far the most important reactions; moreover, isotope scrambling is observed for almost every reactant ion. These results are in good agreement with previously published data and indicate that germane negative ions are quite efficient in formation and growth of ionic clusters, which can be considered suitable precursors of amorphous solid hydrogenated germanium used in the semiconductor field. Copyright © 2005 John Wiley & Sons, Ltd.
Liquid chromatography/electrospray ionization mass spectrometry method for the quantification of valproic acid in human plasma
Authors: Ramakrishna N. V. S. , Vishwottam K. N. , Manoj S. , Koteshwara M. , Santosh M. , Chidambara J. , Kumar B. Ravi 
Published: June 2005

AbstractA simple, sensitive and rapid liquid chromatography/electrospray ionization mass spectrometry (LC/ESI‐MS) method was developed and validated for the quantification of valproic acid, an antiepileptic drug, in human plasma using benzoic acid as internal standard (IS). Following solid‐phase extraction, the analytes were separated using an isocratic mobile phase on a reversed‐phase C18 column and analyzed by MS in the single ion monitoring mode using the respective [M–H]− ions, m/z 143 for valproic acid and m/z 121 for the IS. The assay exhibited a linear dynamic range of 0.5–60 µg/mL for valproic acid in human plasma. The lower limit of quantification was 500 ng/mL with a relative standard deviation of less than 10%. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The average absolute recoveries of valproic acid and the IS from spiked plasma samples were 96.1 ± 4.2 and 95.6 ± 2.7%, respectively. A run time of 4.5 min for each sample made it possible to analyze more than 250 human plasma samples per day. The validated method has been successfully used to analyze human plasma samples for application in pharmacokinetic, bioavailability and bioequivalence studies. Copyright © 2005 John Wiley & Sons, Ltd.
A gas chromatographic/mass spectrometric method for tracing the microbial conversion of glucose into amino sugars in soil
Authors: He Hongbo , Xie Hongtu , Zhang Xudong , Wang Yanhong , Wu Yeye 
Published: June 2005

AbstractAmino sugars in soils are heterogeneous and have been used as microbial residue biomarkers to investigate the microbial contribution to soil organic matter. However, it is not clear what the available carbon source is and how glucose is utilized for the synthesis of soil amino sugars. This paper presents a new gas chromatography/mass spectrometry (GC/MS) approach for the identification of 13C incorporation into three amino sugars, D‐glucosamine, D‐galactosamine, and muramic acid, in soil incubated with U‐13C‐glucose. Method evaluation showed that the chemical ionization (CI) mode was suitable for all these amino sugars, but that electron impact (EI) mode was applicable only to glucosamine and galactosamine. The 13C conversion rate was estimated based on the abundance ratio of the ions corresponding to the masses of the ions F + n and F (where n is the skeleton carbon number in the fragment ions F of the amino sugars) and calculated as atom percentage excess. The reproducibility of the method was excellent and clearly adequate for the present purpose. In addition, the new approach is highly accurate as tested with mixtures of U‐13C‐glucose and natural glucose. Copyright © 2005 John Wiley & Sons, Ltd.
Removal of metabolite interference during liquid chromatography/tandem mass spectrometry using high‐field asymmetric waveform ion mobility spectrometry
Authors: Kapron James T. , Jemal Mohammed , Duncan Glenn , Kolakowski Beata , Purves Randy 
Published: June 2005

AbstractThe effect of metabolite interference during liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of an amine drug was investigated using FAIMS (high‐Field Asymmetric waveform Ion Mobility Spectrometry). The selected reaction monitoring (SRM) transition used for the drug exhibited an interference due to in‐source conversion of the N‐oxide metabolite to generate an ion isobaric with the drug. The on‐line FAIMS device removed the metabolite interference before entrance to the mass spectrometer. FAIMS was used to demonstrate the relative accuracy and precision of drug analysis even in the presence of a co‐eluting metabolite that may undergo in‐source conversion. Copyright © 2005 John Wiley & Sons, Ltd.
On the random 2‐stage minimum spanning tree
Authors: Flaxman Abraham D. , Frieze Alan , Krivelevich Michael 
Published: June 2005

AbstractIt is known [A. M. Frieze, Discrete Appl Math 10 (1985), 47–56] that if the edge costs of the complete graph Kn are independent random variables, uniformly distributed between 0 and 1, then the expected cost of the minimum spanning tree is asymptotically equal to $\zeta(3)=\sum_{i=1}^{\infty}i^{-3}$. Here we consider the following stochastic two‐stage version of this optimization problem. There are two sets of edge costs cM: E → ℝ and cT: E → ℝ, called Monday's prices and Tuesday's prices, respectively. For each edge e, both costs cM(e) and cT(e) are independent random variables, uniformly distributed in [0, 1]. The Monday costs are revealed first. The algorithm has to decide on Monday for each edge e whether to buy it at Monday's price cM(e), or to wait until its Tuesday price cT(e) appears. The set of edges XM bought on Monday is then completed by the set of edges XT bought on Tuesday to form a spanning tree. If both Monday's and Tuesday's prices were revealed simultaneously, then the optimal solution would have expected cost ζ(3)/2 + o(1). We show that, in the case of two‐stage optimization, the expected value of the optimal cost exceeds ζ(3)/2 by an absolute constant ε > 0. We also consider a threshold heuristic, where the algorithm buys on Monday only edges of cost less than α and completes them on Tuesday in an optimal way, and show that the optimal choice for α is α = 1/n with the expected cost ζ(3) − 1/2 + o(1). The threshold heuristic is shown to be sub‐optimal. Finally we discuss the directed version of the problem, where the task is to construct a spanning out‐arborescence rooted at a fixed vertex r, and show, somewhat surprisingly, that in this case a simple variant of the threshold heuristic gives the asymptotically optimal value 1 − 1/e + o(1). © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Summary of ISO/TC 201 standard: XV. ISO 20341:2003—Surface chemical analysis—secondary ion mass spectrometry—method for estimating depth resolution parameters with multiple delta‐layer reference materials
Authors: Moon D. W. 
Published: June 2005

AbstractThis International Standard specifies procedures for estimating three depth resolution parameters, via the leading‐edge decay length, the trailing‐edge decay length and Gaussian broadening, in SIMS depth profiling using multiple delta‐layer reference materials. This International Standard is not applicable to delta‐layers where the chemical and physical state of the near‐surface region, modified by the incident primary ions, is not in the steady state. Copyright © 2005 John Wiley & Sons, Ltd.
Disability Rights, Prenatal Diagnosis and Eugenics: A Cross‐Cultural View
Authors: Raz Aviad E. 
Published: June 2005

AbstractThis paper considers the disability rights critique of genetic testing in the context of different communities and the issue of nondirectiveness. Despite the wide usage of genetic diagnosis in Israel, no public debate has emerged there concerning disability rights and prenatal testing. The common attitude that emerged from interviews with Israeli representatives of organizations “of’’ and “for’’ people with genetic diseases and congenital disabilities can be described as a two‐fold view of disability: support of genetic testing during pregnancy, and support of the disabled person after birth. This two‐fold view is explained as a secular construction situated in legal, economic and cultural contexts. The paper concludes by considering the implications of the “two‐fold view’’ of disability for the profession of genetic counseling. It is argued that awareness of the existence of conflicting views among clients—such as the view of the ‘disability critique’ as well as of the “two‐fold view of disability’’—should strengthen the significance of nondirectiveness.
Proliferative feeder cells support prolonged expansion of human embryonic stem cells
Authors: Xie Chang‐Qing , Lin Ge , Yuan Ding , Wang Jian , Liu Tian‐Cheng , Lu Guang‐Xiu 
Published: June 2005

AbstractLong‐term proliferation of human embryonic stem (hES) cells is currently achieved by co‐culturing with mitotically inactive primary mouse embryonic fibroblasts (mEFs), which serve as feeder cells. This study explores the possibility that proliferative mEFs can be used as feeder cells to maintain the prolonged expansion of hES cells. All undifferentiated hES cell clumps were re‐plated on six different densities of proliferative mEFs. hES colonies cultured on 1 × 105–5 × 105 proliferative mEFs amplified over 130 days of continuous culture and remained undifferentiated, as did those cultured on mitotically inactive mEFs. This suggests that certain densities of proliferative mEFs can maintain the propagation of hES cells, which may be helpful for identifying the cytokines and adhesion molecules that are required for their self‐renewal.
Evidence that erythrocytes are highly susceptible to exercise oxidative stress: FT‐IR spectrometric studies at the molecular level
Authors: Petibois Cyril , Déléris Gérard 
Published: June 2005

AbstractWe tested the hypothesis that usual exercise oxidative stress strongly affects erythrocytes viability. A 120‐min physical exercise with progressive intensity was used as a model of oxidative stress. FT‐IR spectrometry was used to determine structural changes in erythrocyte contents (phospholipids, proteins, lactate, and glucose) from blood samples taken every 20 min. Carbonyl formation from amino acid residues (P = 0.03) and hemoglobin unfolding (P = 0.01) could be identified as main protein denaturation markers during oxidative stress. Higher unsaturation level (P = 0.001) in phospholipids fatty acyl chains were also observed while VO2 increased (P < 0.05). The increase in lactacidosis affected primarily hemoglobin unfolding (P = 0.02). Finally, two distinct cellular events occurred during oxidative stress: 1—phospholipids peroxidation correlated to VO2, but lactacidosis and hemoconcentration remained secondary factors; 2—hemoglobin denaturation was mainly observed through unfolding and carbonylation, and lactacidosis and hemoconcentration were important contributing factors.
Teacher reports of ADHD symptoms in Italian children at the end of first grade
Authors: Mugnaini Daniele , Masi Gabriele , Brovedani Paola , Chelazzi Chiara , Matas Marzenka , Romagnoli Caterina , Zuddas Alessandro 
Published: June 2005

AbstractObjective:To determine the prevalence of teacher-rated ADHD symptoms in Italian first-graders.Method:1891 first-graders aged 6.6–7.4 years were evaluated using a 34-item DSM-IV-referenced ADHD teacher rating questionnaire which included all the 18 DSM-IV ADHD diagnostic criteria, some Oppositional-Defiant Disorder (ODD), Conduct Disorder (CD), depression and anxiety symptoms, and questions about the child's social and scholastic impairment.Results:Criteria for ADHD were met in 7.1% (n = 135) of the subjects (10.4% males and 3.8% females), 3.5% with the Inattentive subtype, 2.3% with the Hyperactive/Impulsive subtype and 1.3% with a Combined subtype. Internalizing (depression and/or anxiety) symptoms were reported in 25.9% of the subjects with ADHD symptoms, 17% showed externalizing symptoms (ODD or CD), and 12.6% showed both. Comorbid symptoms were 10 times more frequent than in subjects without ADHD symptoms. Inattentive subtype and scholastic impairment were more frequent in females, Hyperactive/Impulsive subtype and social impairment were more frequent in males.Conclusions:Even though the real prevalence of ADHD in first graders is presumably lower than that found in the present study, this screening procedure might allow detecting those children who could benefit from referral for more comprehensive assessments.
Negative evidences in association between apolipoprotein E polymorphism and panic disorder
Authors: Martínez-Barrondo S. , Sáiz P.A. , Morales B. , García-Portilla M.P. , Coto E. , Álvarez V. , Bascarán M.T. , Bousoño M. , Bobes J. 
Published: June 2005

AbstractThe aim is to investigate the association between apolipoprotein E (ApoE) and panic disorder (PD). Genotyping 92 PD patients [Diagnostic Statistic Manual IV (DSM IV) criteria] and 174 controls no differences were found between both groups. Variation in the ApoE-gene was not associated with the development of PD.
Remotely Sensed: A Topography of the Global Sex Trade
Authors: Biemann Ursula 
Published: June 2005

Voluntarily or not, women are moved in great numbers from Manila to Nigeria, from Burma to Thailand, and from post-socialist countries to Western Europe: female geobodies in the flow of global capitalism. The recently released 53-minute video essay Remote Sensing by the Swiss artist and video director Ursula Biemann traces the routes and reasons of women who migrate into the global sex industry. Taking a geographical approach to trafficking, the video develops a particular visual language generated by new media and satellite technologies, which traces the migration of women in the age of digital images. All stills are taken from the video that was shot in the Philippines, Thailand, California, and the German–Czech border.
Autobiography, the dangers of knowledge and Genet's suspect reader
Authors: Boyle Claire 
Published: June 2005

Abstract

Genet's autobiographical work is noticeably resistant to providing its reader with a conventional autobiographical account of the author's life and self.
Notre-Dame-des-Fleurs
writes the self principally through its fantasies;
Journal du voleur
reveals a reluctant autobiographical narrator. My article argues that Genet's determination not to supply the traditional ingredients of autobiography stems from his insights as a prisoner into the means by which deviant, anti-social individuals are made to conform to society's demands. I suggest that Genet is conscious of how the regime of ‘haute surveillance’ in prison aims to correct the unacceptable practices of the prisoner by exposing them knowingly to a constant watchful gaze, which should instil obedience. In this insight, Genet foreshadows Michel Foucault's theorizations in
Surveiller et punir
on the workings of the prison system. Foucault states that the watchful gaze allows knowledge to be amassed about the prisoner: once reduced to the known and the predictable, a prisoner's behaviour is no longer a threat and he can be disciplined and subjectified. I argue that Genet's treatment of his reader and aversion to autobiographical conventions reflect a determination to avoid subjectification, and to continue acting as an irritant to his society.
High birthweight and shoulder dystocia: the strongest risk factors for obstetrical brachial plexus palsy in a Swedish population‐based study
Authors: Margareta Mollberg , Henrik Hagberg , Börje Bager , Håkan Lilja , Lars Ladfors 
Published: June 2005

Background.  Obstetrical brachial plexus palsy (OBPP) is a serious form of neonatal morbidity.Objective.  The aim of this work was to study the incidence of OBPP and to analyze its risk factors.Methods.  This is a population‐based retrospective case–control study. All deliveries recorded in the Swedish Medical Birth Registry between 1987 and 1997 (n = 1 213 987) were investigated. Cases (n = 2399) with OBPP were compared to all other cases.Results.  The incidence of OBPP increased from 0.17 in 1987 to 0.27% in 1997 (p = 0.002). During the same time period, the mean birthweight increased from 3483 to 3525 g. Birthweight increasing from 4000 g was associated with a progressive rise in OBPP risk. Other significant risk factors associated with the injury were shoulder dystocia, breech presentation in vaginal delivery, operative vaginal delivery, diabetes mellitus, induction of labor, protracted active phase, secondary arrest of dilatation, and epidural anesthesia. Cesarean section was associated with a decreased risk of OBPP. If 5000 g is chosen as cut‐off for cesarean section, 85% of the infants in this weight class are underestimated using ultrasonography. Approximately, 331 abdominal deliveries have to be performed to avoid one case of OBPP.Conclusions.  Shoulder dystocia and infant birthweight of 4500 g and more are the strongest risk factors for OBPP in a Swedish population.