bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of the degradome of Isp‐1, a major intracellular serine protease of Bacillus subtilis, by two‐dimensional gel electrophoresis and matrix‐ assisted laser desorption/ionization‐time of flight analysis
Authors: Lee Ah Young , Goo Park Sung , Kho Chang Won , Young Park Sun , Cho Sayeon , Lee Sang Chul , Lee Do Hee , Myung Pyung Keun , Park Byoung Chul
Published: November 2004

Intracellular serine protease‐1 (Isp‐1) is a major intracellular serine protease of Bacillus subtilis, whose functions still remain largely unknown. Furthermore, physiological substrates are yet to be determined. To identify Isp‐1 substrates, we digested extract obtained from an Isp‐1 deficient Bacillus mutant with purified Isp‐1 and examined eliminated or decreased spots by two‐dimensional gel and matrix‐assisted laser desorption/ionization‐time of flight analyses. Proteins degraded by Isp‐1, termed the Isp‐1 degradome, are involved in a variety of cellular functions such as DNA packing, genetic competence, and protein secretion. From the degradome we selected ClpC and EF‐Tu as putative Isp‐1 substrates and studied their in vitro degradation. ClpC and EF‐Tu contain putative cleavage sites for Isp‐1. N‐terminal sequencing of in vitro proteolytic fragments of ClpC and EF‐Tu revealed that these sites are indeed recognized and cleaved by Isp‐1. Moreover, the cellular levels of ClpC and EF‐Tu were dramatically reduced at the late stationary phase, where the expression level of Isp‐1 was greatly increased. These results suggest that the regulated proteolysis of ClpC by Isp‐1 plays an important role in the stationary phase adaptive response. This degradomic approach could provide a powerful tool for finding physiological substrates of many proteolytic enzymes whose functions remain to be determined.
Is it functional?
Authors: Pixton Katherine L.
Published: November 2004

This report describes the first scientific meeting of the British Society for Proteome Research (BSPR), which was organised jointly with the European Bioinformatics Institute (EBI) and held in July 2004. The focus of the conference was functional proteomics with an emphasis on possible clinical application. The main subjects described here are: the need to simplify samples, the use of biological fluids verses tissue, consideration of biological and experimental variation and the creation of databases to achieve menaingful functional analysis.
Identification of target proteins of N‐acetylglucosaminyl‐transferase V and fucosyltransferase 8 in human gastric tissues by glycomic approach
Authors: Kim Yong‐Sam , Hwang Soo Young , Oh Sejeong , Sohn Hosung , Kang Hye‐Yeon , Lee Jeong‐Hwa , Cho Eun‐Wie , Kim Jin‐Young , Yoo Jong Shin , Kim Nam‐Soon , Kim Cheorl‐Ho , Miyoshi Eiji , Taniguchi Naoyuki , Ko Jeong Heon
Published: November 2004

To understand better the mechanism underlying gastric cancer and search for potential markers for gastric cancer prognosis, the proteomic analysis of gastric cancer tissues was conducted using two‐dimensional gel electrophoresis and lectin blot, followed by electrospray ionization‐mass spectrometry. These approaches permitted identification of glyco‐ or putative glycosylated proteins which may be associated with tumorigenesis. The proteins identified include molecules involved in sugar metabolism, signal transduction, proteolysis, and stress, as well as several unknown proteins, which were aberrantly glycosylated as evidenced by the L‐phytohemagglutinin blot.
Proteome analysis of red deer antlers
Authors: Park Hee Jin , Lee Do Hee , Park Sung Goo , Lee Sang Chul , Cho Sayeon , Kim Ha Kun , Kim Jae Jong , Bae Hyunsu , Park Byoung Chul
Published: November 2004

Deer antlers are the only mammalian organs capable of repeated regeneration. Although antlers are known to develop from pedicles, which arise from antlerogenic cells of cranial periosteum, their developmental process is not fully elucidated. For example, while endocrine and environmental factors influence the antler development, it is still unclear which signaling pathways are involved in the transduction of such stimuli. To study the developmental process of antlers and identify proteins functioning in their growth, we have established proteome maps of red deer (Cervus elaphus) antlers. With two‐dimensional gel electrophoresis and matrix‐assisted laser desorption/ionization mass spectrometry, we analyzed more than 800 protein spots and identified ∼ 130 individual proteins derived from the growing tip of antlers. The overall profile of the antler proteome was dissimilar to those of other types of tissue. Also comparison of proteomes derived from proximal bony tissue and the growing tip of antlers revealed substantial differences. Moreover several cell growth or signaling‐related proteins are expressed exclusively in the growing tip, suggesting that these proteins function in the growth and differentiation of antlers. Currently, using the antler proteome maps, we are actively searching for the regulatory factor(s) that may control the antler development.
Zooming in: Fractionation strategies in proteomics
Authors: Stasyk Taras , Huber Lukas A.
Published: November 2004

The recent development of mass spectrometry, i.e., high sensitivity, automation of protein identification and some post‐translational modifications (PTMs) significantly increased the number of large‐scale proteomics projects. However, there are still considerable limitations as none of the currently available proteomics techniques allows the analysis of an entire proteome in a single step procedure. On the other hand, there are several successful studies analyzing well defined groups of proteins, e.g., proteins of purified organelles, membrane microdomains or isolated proteins with certain PTMs. Coupling of advanced separation methodologies (different prefractionation strategies, such as subcellular fractionation, affinity purification, fractionation of proteins and peptides according to their physicochemical properties) to highly sensitive mass spectrometers provides powerful means to detect and analyze dynamic changes of low abundant regulatory proteins in eukaryotic cells on the subcellular level. This review summarizes and discusses recent strategies in proteomics approaches where different fractionation strategies were successfully applied.
Substituted propenyl end groups as reactive intermediates in radical polymerization
Authors: Yamada Bunichiro , Oku Fuminori , Harada Takahiro
Published: November 2004

The addition of propagating radicals of methyl acrylate (MA) and styrene (St) to CH2C(CO2CH3)CH2 and CH2C(C6H5)CH2 ω‐end groups of poly(methyl methacrylate) (PMMA) and polystyrene (PSt) was investigated. The end groups were as reactive as MA and St toward the poly(methyl acrylate) (PMA) and PSt radicals, respectively. The adduct radical derived from the two types of PMMA end groups and PMA radicals underwent β fragmentation exclusively to yield PMMA radicals and end groups bound to PMA chains. The addition of PSt radicals to PMMA with CH2C(CO2Me)CH2 end groups resulted in adduct radicals that underwent β fragmentation and addition to St or coupling with PSt radicals. Adduct radicals formed by the addition of PMA radicals to both types of end groups of PSt exclusively formed CC bond by coupling with PMA radicals to form branched structures or by addition to MA monomer to give a copolymer. The fate of the adduct radicals was highly dependent on the type of polymer chain and the substituent bound to the end group. Steric congestion of the adduct radical arising from the α‐methyl group of the PMMA chain was considered to be crucial for fragmentation to expel the PMMA radical. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 645–654, 2003
Synthesis and properties of new ultraviolet–blue‐emissive fluorene‐based aromatic polyoxadiazoles with confinement moieties
Authors: Yang Nam Choul , Park Young Hoon , Suh Dong Hack
Published: November 2004

Three families of fluorene–oxadiazole‐based polymers with confinement moieties have successfully been prepared by the two‐step method for polyoxadiazole synthesis. These polymers show good solubility in common organic solvents, high thermal stability, and strong violet and blue photoluminescence in solution and as films, respectively. Their low‐lying highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels originate from the electron deficiency of an oxadiazole moiety, and this suggests that they may be useful for blue‐emitting and electron‐transport/hole‐blocking layers in electroluminescent devices. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 674–683, 2003
Latent solid‐phase extraction with thermoresponsive soluble polymers
Authors: Gonzalez Sergio O. , Furyk Steven , Li Chunmei , Tichy Shane E. , Bergbreiter David E. , Simanek Eric E.
Published: November 2004

The use of soluble thermoresponsive polymers to sequester or scavenge hydrophobic guest molecules from dilute aqueous solutions on heating is described. In these studies, a homopolymer of N‐isopropylacrylamide was shown to sequester 46–83% of a soluble monochlorotriazine from 0.1–10 ppm aqueous solutions when heating above this polymer's lower critical solution temperature (LCST). Substitution of the reactive piperidine‐containing 20:1 copolymer poly(N‐isopropylacrylamide)‐c‐poly[N‐4‐(acrylamidomethyl)piperidine] for this unreactive polymer led to >98% scavenging of these same triazines when heating above this reactive polymer's LCST. The monochlorotriazine guests studied included the herbicide atrazine and two dye‐labeled analogues of this herbicide. In one case, an atrazine analogue was designed so as to contain a dansyl group for fluorescence analysis. In the second case, an atrazine analogue was labeled with a methyl red group to facilitate visual and spectrophotometric analysis. Atrazine concentrations were measured with liquid chromatography–mass spectrometry. The enhanced efficiency of the reactive piperidine‐containing copolymer scavenger in removing triazines from solution is attributed to covalent bond formation by nucleophilic aromatic substitution of the chlorine of the monochlorotriazines by the piperidine nucleophile on the copolymer. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6309–6317, 2004
Non‐transition metal‐catalyzed living radical polymerization of vinyl chloride initiated with iodoform in water at 25 °C
Authors: Percec Virgil , Popov Anatoliy V. , Ramirez‐Castillo Ernesto , Coelho Jorge F. J. , Hinojosa‐Falcon Luis A.
Published: November 2004

Non‐transition metal‐catalyzed living radical polymerization (LRP) of vinyl chloride (VC) in water at 25–35 °C is reported. This polymerization is initiated with iodoform and catalyzed by Na2S2O4. In water, S2Odissociates into SOthat mediates the initiation and reactivation steps via a single electron transfer (SET) mechanism. The exchange between dormant and active propagating species also includes the degenerative chain transfer to dormant species (DT). In addition, the SO2released from SOduring the SET process can add reversibly to poly(vinyl chloride) (PVC) radicals and provide additional transient dormant ∼SOradicals. This novel LRP proceeds mostly by a combination of competitive SET and DT mechanisms and, therefore, it is called SET‐DTLRP. Telechelic PVC with a number‐average molecular weight (Mn) = 2,000–55,000, containing two active ∼CH2CHClI chain ends and a higher syndiotacticity than the commercial PVC were obtained by SET‐DTLRP. This PVC is free of structural defects and exhibits a higher thermal stability than commercial PVC. SET‐DTLRP of VC is carried out under reaction conditions related to those used for its commercial free‐radical polymerization. Consequently, SET‐DTLRP is of technological interest both as an alternative commercial method for the production of PVC with superior properties as well as for the synthesis of new PVC‐based architectures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6267–6282, 2004
Acceleration of the single electron transfer–degenerative chain transfer mediated living radical polymerization (SET–DTLRP) of vinyl chloride in water at 25 °C
Authors: Percec Virgil , Popov Anatoliy V. , Ramirez‐Castillo Ernesto , Weichold Oliver
Published: November 2004

The accelerated single electron transfer–degenerative chain transfer mediated living radical polymerization (SET–DTLRP) of vinyl chloride (VC) in H2O/tetrahydrofuran (THF) at 25 °C is reported. This process is catalyzed by sodium dithionite (Na2S2O4)‐sodium bicarbonate (NaHCO3). Electron transfer cocatalysts (ETC) 1,1′‐dialkyl‐4,4′‐bipyridinum dihalides or alkyl viologens were also employed in this polymerization. The resulting poly(vinyl chloride) (PVC) has a number‐average molecular weight (Mn) = 2,000–12,000, no detectable amounts of structural defects, and both active chloroiodomethyl and inactive chloromethyl chain ends. The molecular weight distribution of PVC obtained isMw/Mn= 1.5. The surface active agents afford the final polymers as a powder and provide an acceleration of the rate of polymerization. The role of ETC is to accelerate the single electron transfer (SET) step, whereas THF enhances the degenerative chain transfer (DT) step. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6364–6374, 2004
Effect of sample preparation on the glass‐transition of thin polystyrene films
Authors: Fakhraai Z. , Sharp J. S. , Forrest J. A.
Published: November 2004

We have investigated the effect of sample preparation on the glass‐transition temperature (Tg) of thin films of polystyrene (PS). By preparing and measuring the glass‐transition temperature Tg of multilayered polymer films, we are able to assess the contribution of the spincoating process to the reduced Tg values often reported for thin PS films. We find that it is possible to determine a Tg even on the first heating cycle, and that by the third heating cycle (a total annealing time of 15 min at T = 393 K) the Tg value has reached a steady state. By comparing multilayered versus single layered films we find that the whole Tg depends only on the total film thickness, and not on the thickness of the individual layers. These results strongly suggest that the spincasting process does not contribute significantly to Tg reductions in thin polymer films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4503–4507, 2004
Side‐chain crystallization behavior of graft copolymers consisting of amorphous main chain and crystalline side chains: Poly(methyl methacrylate)‐graft‐poly(ethylene glycol) and poly(methyl acrylate)‐graft‐poly(ethylene glycol)
Authors: Inomata Katsuhiro , Nakanishi Eiji , Sakane Yasuo , Koike Masao , Nose Takuhei
Published: November 2004

Graft copolymers consisting of amorphous main chain, poly(methyl methacrylate) (PMMA), or poly(methyl acrylate) (PMAc), and crystalline side chains, poly(ethylene glycol) (PEG), have been prepared by copolymerization of PEG macromonomers with methyl methacrylate or methyl acrylate (MMAxor MACx, respectively). Because of the compatibility of PMMA/PEG and PMAc/PEG, from small‐angle X‐ray scattering results, the main and side chains in graft copolymers were suggested to be homogeneous in the molten state. Differential scanning calorimetry (DSC) cooling scans revealed that PEG side chains for graft copolymers with large PEG fractions were crystallized when the sample was cooled, with a cooling rate of 10 °C/min. The spherulite pattern observed by a polarized optical microscope suggested the growth of PEG crystalline lamellae. Crystallization of PEG in MMAxwas more restrained than in MACx. From these results, we have concluded that the crystallization behavior of the grafted side chains is strongly influenced by the glass transition of a homogeneously molten sample as well as dilution of the crystallizable chains. Domain spacings for isothermally crystallized graft copolymers were described by interdigitating chain packing in crystalline–amorphous lamellar structure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 79–86, 2005
Menopausal symptoms in women with breast cancer: Prevalence and treatment preferences
Authors: Hunter Myra S , Grunfeld Elizabeth A , Mittal Sangeeta , Sikka Pooja , Ramirez Amanda‐Jane , Fentiman Ian , Hamed Hisham
Published: November 2004

Menopausal symptoms are common and problematic for women receiving adjuvant treatment for breast cancer and management presents a challenge. This cross‐sectional descriptive study aimed to investigate the experience of menopausal symptoms, current management and treatment preferences of 113 patients with breast cancer. These women (who were prescribed tamoxifen and were on average 3 years post‐diagnosis) were recruited from a breast unit database. They completed the Hot Flush and Night Sweats Questionnaire (HFNSQ), the Women's Health Questionnaire (WHQ) and subscales of the EORTC‐QLQ‐C30 and the BR23, as well as questions about treatments. Forty‐four of this sample were also interviewed. The prevalence of hot flushes and night sweats was 80 and 72%, respectively (average 30 per week). Having more problematic hot flushes and night sweats were associated with more anxiety and sleep problems (WHQ), and with poorer emotional and social functioning and worse body image (EORTC‐QLQ‐C30). The women had used a range of treatments for menopausal symptoms but there was often no evidence for the efficacy for many of these treatments. Strongest preferences were for non‐medical treatments, particularly vitamins and herbal remedies and cognitive behavioural therapy (CBT). The evidence for the effectiveness of the former is weak, whereas CBT has been shown to reduce menopausal symptoms, but needs to be evaluated in a population of women who have been treated for breast cancer. Copyright © 2004 John Wiley & Sons, Ltd.
Relationship between local structural entropy and protein thermostabilty
Authors: Chan Chen‐Hsiung , Liang Han‐Kuen , Hsiao Nai‐Wan , Ko Ming‐Tat , Lyu Ping‐Chiang , Hwang Jenn‐Kang
Published: November 2004

We developed a technique to compute structural entropy directly from protein sequences. We explored the possibility of using structural entropy to identify residues involved in thermal stabilization of various protein families. Examples include methanococcal adenylate kinase, Ribonuclease HI and holocytochrome c551. Our results show that the positions of the largest structural entropy differences between wild type and mutant usually coincide with the residues relevant to thermostability. We also observed a good linear relationship between the average structural entropy and the melting temperatures for adenylate kinase and its chimeric constructs. To validate this linear relationship, we compiled a large dataset comprised of 1153 sequences and found that most protein families still display similar linear relationships. Our results suggest that the multitude of interactions involved in thermal stabilization may be generalized into the tendency of proteins to maintain local structural conservation. The linear relationship between structural entropy and protein thermostability should be useful in the study of protein thermal stabilization. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Computational studies and peptidomimetic design for the human p53–MDM2 complex
Authors: Zhong Haizhen , Carlson Heather A.
Published: November 2004

The interaction between human p53 and MDM2 is a key event in controlling cell growth. Many studies have suggested that a p53 mimic would be sufficient to inhibit MDM2 to reduce cell growth in cancerous tissue. In order to design a potent p53 mimic, molecular dynamics (MD) simulations were used to examine the binding interface and the effect of mutating key residues in the human p53–MDM2 complex. The Generalized Born surface area (GBSA) method was used to estimate free energies of binding, and a computational alanine‐scanning approach was used to calculate the relative effects in the free energy of binding for key mutations. Our calculations determine the free energy of binding for a model p53–MDM2 complex to be −7.4 kcal/mol, which is in very good agreement with the experimentally determined values (−6.6–−8.8 kcal/mol). The alanine‐scanning results are in good agreement with experimental data and calculations by other groups. We have used the information from our studies of human p53–MDM2 to design a β‐peptide mimic of p53. MD simulations of the mimic bound to MDM2 estimate a free energy of binding of −8.8 kcal/mol. We have also applied alanine scanning to the mimic–MDM2 complex and reveal which mutations are most likely to alter the binding affinity, possibly giving rise to escape mutants. The mimic was compared to nutlins, a new class of inhibitors that block the formation of the p53–MDM2 complex. There are interesting similarities between the nutlins and our mimic, and the differences point to ways that both inhibitors may be improved. Finally, an additional hydrophobic pocket is noted in the interior of MDM2. It may be possible to design new inhibitors to take advantage of that pocket. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Albanian immigrants in Lecce and Modena: narratives of rejection, survival and integration
Authors: King Russell , Mai Nicola
Published: November 2004

The Albanian exodus to Italy was one of the most dramatic European migration events of the 1990s. Initially welcomed, by the summer of 1991 an intensely negative sociocultural stereotype of Albanian migrants had been installed by certain politicians and the media in Italy. They were condemned as disorganised and prone to criminality; and this stigmatisation became more entrenched as the decade passed. Based on in‐depth interviews and other field observations, this paper examines how Albanian migrants in two contrasting places in Italy have fared in terms of negotiating their way around these stereotypes, and of integrating within the local social and economic environments, specifically in relation to work, housing and social space. Lecce in the southern region of Apulia is the principal area of migrant arrival and a zone of passage as well as of settlement; however, it is one of Italy's poorest provinces. Modena, in the north of Italy, is one of the country's richest cities. The broad picture is that Albanian migrants are economically better integrated in Modena, but do not participate much in the social and cultural life of the city; whereas in Lecce, social contact with local people is more intense, but labour market success is more limited, above all because of the narrow range of employment on offer. Three key factors conditioning the process of differential integration of the migrants are their legal status, their access to network‐based support, and the socio‐economic and institutional settings encountered in each local context of immigration. Copyright © 2004 John Wiley & Sons, Ltd.
Variation in Reliability and Quality
Authors: O'Connor Patrick D. T.
Published: November 2004

Engineering products are characterized by many parameters, such as weight, dimensions, electrical and mechanical parameters, power consumption, flow rates, and son on. Products are used in a range of conditions, such as temperature, humidity, vibration, power supply values, and so on. In practical situations of manufacture, test and operation these are all subject to variation. How these variations can affect manufacturing, operation and reliability can, in theory, be assessed using statistical methods. This tutorial explains the nature of variation as it affects engineering products, and describes how variation should be dealt with in design, manufacture and test. Copyright © 2004 John Wiley & Sons, Ltd.
Generalized Linear Model‐based Control Charts for Discrete Semiconductor Process Data
Authors: Skinner Katina R. , Montgomery Douglas C. , Runger George C.
Published: November 2004

In previous simple cases generalized linear model (GLM)‐based control charts have been shown to be very effective in detecting shifts in multivariate counts when input variables are measurable. This paper studies the effectiveness of GLM‐based control charts on more complicated data sets with multiple inputs and outputs whose relationships are varied. Results show that the GLM‐based charts were most effective in detecting changes in the means of overdispersed counts (when compared with counts with normal dispersion). The GLM‐based charts were more effective than multiple C charts in detecting changes in the means of counts when multiple complicated relationships exist. Copyright © 2004 John Wiley & Sons, Ltd.
Insight into the Bioactivity and Metabolism of Human Glucagon Receptor Antagonists from 3D‐QSAR Analyses
Authors: Chen HaiFeng , Yao Xiaojun , Petitjean Michel , Xia Hairong , Yao JianHua , Panaye A. , Doucet J. P. , Fan BoTao
Published: November 2004

Descriptors, such as logP, the number of hydrogen bond donors, the number of hydrogen bond acceptors, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) combined with fields of CoMFA and CoMSIA to construct models for hyperglycemia decrease activity and metabolism of human glucagon receptor antagonists. The results reveal that including logP, HOMO and LUMO energies is meaningful for QSAR/QSMR model. The models were validated by using a test set of structural diverse compounds that had not been included in the CoMFA and CoMSIA models. Support Vector Machines (SVM) have been used to select the suitable additional descriptors to construct 3D‐QSAR/QSMR models. A key factor to mention is that activity and metabolism models simultaneously. These in silico ADME models are helpful in making quantitative prediction of inhibitory activities and rates of metabolism before resorting in vitro and in vivo experimentation.
Rapid determination of five probe drugs and their metabolites in human plasma and urine by liquid chromatography/tandem mass spectrometry: application to cytochrome P450 phenotyping studies
Authors: Yin Ophelia Q. P. , Lam Sherry S. L. , Lo Cindy M. Y. , Chow Moses S. S.
Published: November 2004

A liquid chromatography/mass spectrometry method, for rapid determination of five cytochrome P450 (CYP) probe drugs and their relevant metabolites in human plasma and urine, is described. The five specific probe substrates/metabolites, caffeine/paraxanthine (CYP1A2), tolbutamide/4‐hydroxytolbutamide/carboxytolbutamide (CYP2C9), omeprazole/5‐hydroxyomeprazole (CYP2C19), debrisoquine/5‐hydroxydebrisoquine (CYP2D6) and midazolam/1′‐hydroxymidazolam (CYP3A), together with the internal standards (phenacetin and paracetamol), in plasma and urine, were extracted using solid‐phase extraction. The chromatography was performed using a C18 column with an isocratic mobile phase consisting of acetonitrile and 0.1% formic acid in water (70:30). The triple‐quadrupole mass spectrometer was operated in both positive and negative modes, and multiple reaction monitoring was used for quantification. The method was validated over the concentration ranges 0.05–5 μg/mL for caffeine and paraxanthine, 0.02–2 μg/mL for tolbutamide, 0.1–20 μg/mL for 4‐hydroxytolbutamide, carboxytolbutamide, debrisoquine and 5‐hydroxydebrisoquine, 5–2500 ng/mL for omeprazole and 5‐hydroxyomeprazole, and 1–100 ng/mL for midazolam and 1′‐hydroxymidazolam. The intra‐ and inter‐day precision were 0.3–13.7% and 1.9–14.3%, respectively, and the accuracy ranged from 93.5–107.2%. The lower limit of quantification varied between 1 and 100 ng/mL. The present method provides a robust, fast and sensitive analytical tool for the five‐probe drug cocktail, and has been successfully applied to a clinical phenotyping study in 16 subjects. Copyright © 2004 John Wiley & Sons, Ltd.
Matrix‐assisted and polymer‐assisted laser desorption/ionization time‐of‐flight mass spectrometric analysis of low molecular weight polystyrenes and polyethylene glycols
Authors: Woldegiorgis Andreas , Löwenhielm Peter , Björk Anders , Roeraade Johan
Published: November 2004

Recently, matrices based on oligomers of dioxin and thiophene (polymer‐assisted laser desorption/ionization (PALDI)) have been described for mass spectrometric (MS) analysis of low molecular weight compounds (Woldegiorgis A, von Kieseritzky F, Dahlstedt E, Hellberg J, Brinck T, Roeraade J. Rapid Commun. Mass Spectrom. 2004; 18: 841–852). In this paper, we report the use of PALDI matrices for low molecular weight polymers. An evaluation with polystyrene and polyethylene glycol showed that no charge transfer ionization occurs. Ionization is mediated through metal ion adduction. Comparison of matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) data for two very low molecular weight polymers with data obtained from size‐exclusion chromatography (SEC) revealed a systematic difference regarding mean molecular weight and dispersity. Further, the mass spectra obtained with PALDI matrices had a higher signal‐to‐noise ratio than the spectra obtained with conventional matrices. For polymers with higher molecular weights (>1500 Da), the conventional matrices gave better performance. For evaluation of the MALDI spectra, three non‐linear mathematical models were evaluated to model the cumulative distributions of the different oligomers and their maximal values of Mw, Mn and PDI. Models based on sigmoidal or Boltzmann equations proved to be most suitable. Objective modeling tools are necessary to compare different sample and instrumental conditions during method optimization of MALDI analysis of polymers, since the bias between MALDI and SEC data can be misleading. Copyright © 2004 John Wiley & Sons, Ltd.
Tandem (quadrupole‐time‐of‐flight) electrospray mass spectrometry of oligo(vinyl acetates) with isopropylol or (1‐hydroxyethyl)‐2‐oxyisopropanyl end groups
Authors: Collins Steven , Rimmer Stephen
Published: November 2004

Poly(vinyl acetates) with either isopropylol or (1‐hydroxyethyl)‐2‐oxyisopropanyl end groups were analysed by tandem mass spectrometry using a quadrupole‐time‐of‐flight (Q‐TOF) instrument. Random scission along the polymer backbone was not observed. Instead the initial scissions were derived from the cleavage of end‐group species. The resultant macrocations were subject to further elimination reactions that eventually produced polyene macrocations. A smaller fraction of the initial macrocations also reacted by loss of ketene and this reaction produced macrocations containing vinyl alcohol units. Copyright © 2004 John Wiley & Sons, Ltd.
Water quality before and after dam building on a heavily polluted river in semi‐arid Algeria
Authors: Taleb Amina , Belaidi Nouria , Gagneur James
Published: November 2004

The impact of the construction and management of a reservoir on a polluted stream in a semi‐arid region has been highlighted using physico‐chemical indicators. The Tafna river (Algeria) collects heavily polluted wastewater from the town of Maghnia and from several factories. Organic pollution comes from domestic sewage and from food industries. Ore treatment industries discharge very acidic wastewater. Temperature, pH, conductivity, chloride, dissolved oxygen, biological oxygen demand (BOD), and nitrogen compounds have been surveyed between 1996 and 2001, before and after the construction of the dam. The change in each parameter is compared between sites located upstream and downstream from the dam.

The spatio‐temporal evolution of the organic pollution indicators was highlighted by ANOVA and principal component analysis. By enhancing sedimentation of the organic matter, the reservoir makes possible a significant decline in the BOD downstream of the dam, but increases NH4 concentration at the downstream sites. The pollution is diluted during high flows and dam releases. Conversely, during low flow periods, mineralization of organic matter is higher in the lower Tafna. Copyright © 2004 John Wiley & Sons, Ltd.
Movements of wild atlantic salmon parr in relation to peaking flows below a hydropower station
Authors: Berland G. , Nickelsen T. , Heggenes J. , Økland F. , Thorstad E. B. , Halleraker J.
Published: November 2004

Movements of 20 radio‐tagged wild Atlantic salmon (Salmo salar) parr were studied 1.3 km downstream of a hydropower station. Ten parr were free‐ranging and ten were restricted to an area near the river bank by a 75 m2 rectangular containment pen that was flooded at high flow, but dry at low flow except for a small refuge at the low end. The positions of contained parr were continuously recorded within a four‐cell uniform grid by continuous data logging, while free‐ranging fish were positioned by manual tracking four times per day. River discharge was manipulated to run five pseudo‐replicated series of three step changes from 30 to 70 to 110 m3 s−1, with slow (2 h) and rapid (0 h) increase and decrease in discharge, as well as during day and night. No differences in movements or home ranges (mean 2770 m2 ± 1759 SD) were detected related to manipulated discharge variations or time of day or night for the free‐ranging parr. No free‐ranging parr were stranded during rapid flow reductions. In the containment pen, the parr distributed themselves relatively evenly among the cells. They moved significantly more at changing than at stable flows. In the containment pen, most of the fish that were stranded were observed during rapid flow reductions at night. Rapid reductions in water flow may cause increased mortality in large parr in shallow habitats if movements are restricted; however, rapid fluctuations did not appear to influence movements or cause stranding by free‐ranging Atlantic salmon parr, which moved considerable distances regardless of discharge. Copyright © 2004 John Wiley & Sons, Ltd.
X‐ray photoelectron spectroscopy analysis of the stability of platinized catalytic electrodes in dye‐sensitized solar cells
Authors: Wang Guiqiang , Lin Yuan , Xiao XuRui , Li XuePing , Wang Weibo
Published: November 2004

The stability of platinized catalytic electrodes prepared by thermal decomposition of hexachloroplatinic acid was investigated. The platinum on the electrode did not dissolve in the presence of the electrolyte containing an iodide/triiodide redox couple, even under anodic bias. The electrocatalytic activity of platinized catalytic electrodes sealed in a cell with oxygen‐free electrolyte did not decrease within 23 weeks. However, the charge transfer resistance value of platinized catalytic electrodes increased tenfold when the electrodes were heated at 150° for 15 min in air during the sealing process and doubled when the electrodes were reused. The XPS analysis results showed that part of the platinum catalyst on the surface of the electrode was transformed to Pt[II] and Pt[IV] during the thermal sealing process, which led to the decrease of catalytic activity of the platinized catalytic electrodes for the reduction of triiodide. A large amount of inactive iodine absorbed on the surface of the reused electrode, which was confirmed by XPS, also decreased the electrocatalytic activity of the electrodes. The electrocatalytic activity of reused electrodes can be recovered by heating again at 390 °C or removing the platinum oxide and inactive iodine by the electrochemical method. Copyright © 2004 John Wiley & Sons, Ltd.
The use of quantile regression in health care research: a case study examining gender differences in the timeliness of thrombolytic therapy
Authors: Austin Peter C. , Tu Jack V. , Daly Paul A. , Alter David A.
Published: November 2004

Investigators are frequently interested in determining patient and system characteristics associated with delays in the provision of essential medical treatment. Investigators have typically used either multiple linear regression or Cox proportional hazards models to assess the impact of patient and system characteristics on the timeliness of medical treatment. A drawback to the use of these two methods is that they allow, at best, a partial exploration of how a distribution of delays in treatment or of waiting times changes with patient characteristics. In contrast, quantile regression models allow one to assess how any quantile of a conditional distribution changes with patient characteristics. We illustrate the utility of quantile regression by examining gender differences in the delivery of thrombolysis in patients with an acute myocardial infarction. We demonstrate that richer inferences can be drawn through the use of quantile regression. Females were more likely to experience delays in treatment compared to males. Furthermore, gender had a greater impact upon those patients who had the greatest delays in treatment. Investigators who want to determine how a distribution of delays in treatment or of waiting times changes with patient or system characteristics should consider complementing their analyses with the use of quantile regression. Copyright © 2004 John Wiley & Sons, Ltd.
On simultaneous assessment of sensitivity and specificity when combining two diagnostic tests
Authors: Tang Man‐Lai
Published: November 2004

Diagnostic tests are seldom adopted in isolation. Few tests have high sensitivity and specificity simultaneously. In these cases, one can increase either the sensitivity or the specificity by combining two component tests under either the ‘either positive’ rule or the ‘both positive’ rule. However, there is a tradeoff between sensitivity and specificity when these rules are applied. We propose three statistical procedures to simultaneously assess the sensitivity and specificity when combining two component tests. Measurements of interest include rate difference and rate ratio. Our empirical results demonstrate that (i) the asymptotic test procedures for both measurements and approximate test procedure for rate difference possess inflated type I error rate; (ii) the exact test procedures for both measurements possess deflated type I error rate; and (iii) the approximate (unconditional) test procedure for rate ratio becomes an reliable alternative and nicely controls the actual type I error rate in small to moderate sample sizes. Moreover, the approximate (unconditional) test procedure is computationally less intensive than the exact (unconditional) test procedure. We illustrate our methodologies with a real example from a residual nasopharyngeal carcinoma (RNP) study. Copyright © 2004 John Wiley & Sons, Ltd.
Study of the Thermoplastic Wheat Starch Cationisation Reaction under Molten Condition
Authors: Ayoub Ali , Berzin Françoise , Tighzert Lan , Bliard Christophe
Published: November 2004

This paper deals with the functionalization of thermoplastic wheat starch with cationic groups under the action of thermo‐mechanical energy. Two reagents, leading to the same reactive species, are used: 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride and 2‐epoxypropyltrimethylammonium chloride. An experimental study and a theoretical approach for reactive extrusion operations were carried out in a bench‐top twin‐screw microcompounder. The theoretical model developed is in satisfactory agreement with the experimental results obtained in the molten state, with low water content. Reaction kinetic studies, performed at different temperatures between 100 and 140°C, show that starch cationisation follows a second order reaction, with rate constants following the Arrhenius law. The obtained results allow calculation of the values of activation energy. The analysis of the thermoplastic unmodified and modified cationic starches by size exclusion chromatography (SEC) shows a decrease of the excluded fraction, which is attributed to the effect of the thermo‐mechanical melting process. The X‐ray diffraction spectra typical of molten starches were obtained.
Studies on the composition of ancient Indian punch‐marked silver coins
Authors: Vijayan V. , Rautray T. R. , Nayak P. K. , Basa D. K.
Published: November 2004

Punch‐marked coins are the oldest known numismatic objects used in ancient India. Seven punch‐marked silver coins were analysed by using the non‐destructive multi‐elemental PIXE technique. A 3 MeV proton beam from a pelletron accelerator was used for irradiation of these samples to obtain the spectral data and GUPIX software was employed to derive the elemental concentrations. The results reveals that silver, copper, gold and lead are significant constituents of the punch‐marked silver coins and there are also traces of elements such as Ti, Cr, Mn, Fe, Co, Ni, As and Y, which seems to imply that PIXE can be used effectively for the non‐destructive quantitative analysis of ancient coins. Copyright © 2004 John Wiley & Sons, Ltd.
Spectrum function of polarizer‐scattered x‐ray tube radiation
Authors: Kitov B. I.
Published: November 2004

An equation was derived to calculate the x‐ray tube spectrum from a massive anode and scattered from a homogeneous flat target. The spectrum function of molybdenum anode radiation scattered from a boron carbide polarizer was calculated. Copyright © 2004 John Wiley & Sons, Ltd.
Nitric oxide synthase inhibition impairs myocardial efficiency and ventriculo‐arterial matching in acute ischemic heart failure
Authors: Nordhaug Dag , Steensrud Tor , Aghajani Ebrahim , Korvald Christian , Myrmel Truls
Published: November 2004

Background and aims:

The effect of nitric oxide (NO) manipulation in acute heart failure has not been sufficiently investigated. Therefore, we assessed the impact of NO‐synthase (NOS) inhibition on left ventricular (LV) function and energetics as well as overall hemodynamics, in a porcine model of acute ischemic LV failure.

Methods:

Acute heart failure was induced by left coronary artery microembolization in fourteen anesthetized pigs. LV pressure–volume relationships and mechanical work (PVA) were assessed 30 min after stable heart failure, using pressure‐conductance catheters. Myocardial oxygen consumption (MVO2) was determined from coronary flow and coronary arteriovenous oxygen difference. Microembolization led to a significant decrease in cardiac output, arterial pressure and LV systolic and diastolic performance. Animals were then randomized to a control group (n=7) or to receive 15 mg/kg Nω‐Nitro‐l‐arginine‐metyl ester (n=7), an inhibitor of NO synthase (NOS).

Results:

Measurements 15 min later revealed that NOS inhibited animals had significantly reduced cardiac output (1.53±0.45 vs. 2.13±0.49 l/min, P=0.003) and stroke work (1054±461 vs. 1296±348 mmHg ml, P=0.03), and also displayed a significant increase in the slope of the MVO2–PVA relationship (2.57±0.53 vs. 1.92±0.15, P=0.008), i.e. an inefficient chemomechanical coupling. NOS inhibition did not alter contractility, diastolic function or arterial pressure, but afterload was significantly increased compared to controls (arterial elastance 6.03±1.48 vs. 2.74±0.34 mmHg/ml, P=0.009).

Conclusion:

Inhibition of NOS in experimental acute heart failure increased afterload without altering left ventricular systolic and diastolic function. Consequently, cardiac output was reduced. Furthermore, mechanoenergetic efficiency was severely impaired. NOS inhibition in acute heart failure and cardiogenic shock warrants further investigations.
The value of the electrocardiogram and chest X‐ray for confirming or refuting a suspected diagnosis of heart failure in the community
Authors: Fonseca Cândida , Mota Teresa , Morais Humberto , Matias Fernando , Costa Catarina , Oliveira António G. , Ceia Fátima ,   on behalf of the EPICA Investigators
Published: November 2004

Background

There is a common assumption that a normal ECG or a normal heart size on chest X‐ray virtually rules out a diagnosis of heart failure.

Aims

To assess the value of the electrocardiogram and chest X‐ray in identifying patients with chronic heart failure in the community.

Methods and results

This study was a secondary analysis of data prospectively collected at the time of patient's enrolment in the EPICA study, an epidemiological study of the prevalence of heart failure in Portugal. A total of 6300 subjects were clinically evaluated. Patients who presented with symptoms or signs of heart failure, and/or were receiving diuretics for chronic heart failure (CHF) had a chest X‐ray, ECG, and echocardiogram. The diagnosis of heart failure was confirmed in 551 cases. Patients with right atrial enlargement, atrial flutter, atrial fibrillation, 2nd degree‐Mobitz I atrioventricular block, 1st degree atrioventricular block, left bundle branch block, lung interstitial oedema, and bilateral pleural effusion were more likely to be diagnosed with heart failure. For the diagnosis of heart failure, in the Portuguese population aged over 25 years, an abnormal electrocardiogram had an estimated sensitivity of 81%, and negative predictive value of 75%; an abnormal chest X‐ray had an estimated sensitivity of 57%, and negative predictive value of 83%. Twenty five percent of patients with CHF had a normal ECG or chest X‐ray.

Conclusion

Our results show that electrocardiographic and roentgenographic features are not sufficient to allow heart failure to be reliably predicted in the community and support the recommendation that all patients with suspected heart failure should undergo echocardiography.
Reducing postpartum hemorrhage in Africa
Authors: Lazarus J.V. , Lalonde A.
Published: November 2004

Postpartum hemorrhage (PPH) is the leading cause of maternal mortality in sub‐Saharan Africa. This is being addressed by leading professional organizations, which point to the importance of a skilled attendant at birth. But they also emphasize that the active management of the third stage of labor is proven to reduce the incidence of PPH. In low‐income settings, the prostaglandin misoprostol should be considered as it is low‐cost, stable at room temperature and easy to administer.
Chronic
idiopathic thrombocytopenic purpura (ITP): molecular mechanisms and implications
for therapy
Authors: Andersson Per-Ola , Wadenvik Hans
Published: November 2004

Chronic idiopathic thrombocytopenic purpura (ITP) is an immune-mediated disorder in which platelets are prematurely destroyed in the reticuloendothelial system by platelet autoantibodies. However, it is becoming clear that the pivotal process of the humoral immune response in the pathogenesis of the disorder is a complex interaction between antigen-presenting cells, T cells and B cells. Furthermore, it is increasingly evident that regulatory T cells play an important role and that T-cell-mediated cytotoxicity contributes to the destruction of platelets in ITP. Different new approaches to immunotherapy in chronic ITP have been explored, including use of anti-CD20, anti-CD154 and anti-CD52 antibodies. So far, these therapies have been antigen-nonspecific and the risk of general immunosuppression is a concern. Thus, improving our understanding of the interaction and relative contribution of humoral and cell-mediated mechanisms is essential for developing antigen-specific immunotherapies for the treatment of this disorder. This review aims to elucidate the current status of knowledge of the cellular and humoral immune components of chronic ITP, together with the implications of this knowledge for therapy.