bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical fitness and the stress process
Authors: Ensel Walter M. , Lin Nan
Published: December 2003

In the current paper we focus on the role of physical fitness in the life stress process for both psychological and physical well‐being. The major research question posed in the current study is: Does physical fitness deter distress in a model containing the major components of the life stress process? That is, do individuals who exercise show higher levels of well‐being than those that do not exercise? Is this relationship independent of the stress they experience and the resources they possess? Using data from a representative community sample, the current study finds that physical fitness is directly related to both psychological and physical distress. The more a person exercises, the less psychological and physical symptoms he or she manifests. Physical fitness is associated with decreased distress. This finding holds up, even when stressors and psychosocial resources are included in the model. While physical fitness was not found to mediate the effects of stressors on distress, there was some evidence of a moderating effect of fitness in the stressor–distress relationship, both for psychological and for physical distress. That is, fitness served to buffer the effects of stressors on both psychological and physical distress. In addition, physical fitness is associated with psychological resources that, in turn, are associated with lower levels of distress. The more a person exercises, the greater the self‐esteem. Thus, in addition to directly deterring distress, physical fitness was found to have the potential to indirectly deter distress through its positive association with the level of psychological resources (i.e., self‐esteem) that individuals possess. These and other findings are discussed in the context of the life stress paradigm. Implications for future stress research are presented. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 81–101, 2004.
Change in sense of community: An empirical finding
Authors: Loomis Colleen , Dockett Kathleen H. , Brodsky Anne E.
Published: December 2003

This study investigated changes in students' psychological sense of community (SOC) under two conditions of external threat against their urban, historically Black, public nonresidential university in a U.S. mid‐Atlantic city. Two independent stratified random samples (N = 801 and N = 241) consisting of undergraduate and graduate women (61%) and men (39%)—predominantly of color—averaging 29 years of age completed the Sense of Community Index (SCI; Perkins, Florin, Rich, Wandersman, & Chavis, 1990). During the first assessment there was an external threat to the university community that was not present 20 months later during the second assessment. In this cross‐sectional design, an analysis of covariance (ANCOVA) revealed support for the hypothesis that SOC would be higher when a threat was present than when it was absent ( p < .01). © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 1–8, 2004.
Neighborhoods and neighbors: Do they contribute to personal well‐being?
Authors: Farrell Susan J. , Aubry Tim , Coulombe Daniel
Published: December 2003

The present study examined the relationship between characteristics of neighborhoods (with set physical boundaries and relatively homogeneous populations) and personal well‐being as mediated by sense of community and neighboring behavior. A randomly selected representative sample of 345 residents living in non‐apartment dwellings in Winnipeg, Canada, completed a mail survey that included created measures of neighboring and sense of community and the General Health Questionnaire. Results demonstrated that sense of community mediates the relationship between neighborhood stability (as defined by the marital status and mobility) and residents' well‐being. The frequency of engaging in neighboring behavior was not directly predictive of residents' sense of personal well‐being, but was predictive of increased sense of community. Consistent with previous research, findings highlight the importance of building a sense of community among residents in a neighborhood. Implications of findings for neighborhood planning are discussed. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 9–25, 2004.
Prediction of gas chromatographic retention times of capillary columns of different inside diameters
Authors: Aryusuk Kornkanok , Krisnangkura Kanit
Published: December 2003

The retention times (t R) of n‐alkanes (C16–C22) eluted from capillary columns of different diameters are accurately predicted by using the equation proposed by Krisnangkura et al. (J. Chromatogr. Sci. 1997, 35, 329–332). The numerical values of four thermodynamically related constants (a, b, c, and d) of the BP‐1 (100% dimethylpolysiloxane) capillary column (0.32 mm ID×25 m, film thickness, 0.25 μm) are –6.169, –0.512, 226.98, and 410.30, respectively. For columns of the same stationary phase but of different inside diameters and film thickness, accurate tR values can be predicted by using the same numerical values of the last three constants but the first constant (a) is changed by the difference in the natural logarithm of the column phase ratios (β). All the derived numerical values of each column were tested with FAMEs and with n‐alkanes in temperature‐programmed GC (TPGC). All the predicted tR values agree well with the experimental values. About 77% of the TPGC data have errors lower than 0.5% and the largest value is –1.04%.
Simultaneous determination of digoxin and digitoxin by micellar electrokinetic chromatography and application to drug formulations
Authors: Tseng Hsiu‐Hui , Wu Hsin‐Lung , Lin Shun‐Jin , Chen Su‐Hwei
Published: December 2003

A simple micellar electrokinetic chromatographic method is described for simultaneous determination of digoxin and digitoxin. The simultaneous analysis of digoxin and digitoxin was performed in Tris buffer (10 mM; pH 9) with 90 mM sodium dodecyl sulfate and 10% isopropyl alcohol as an anionic surfactant and organic modifier. Under these conditions, good separation with high efficiency is achieved in short analysis times. Several parameters affecting the separation of the drugs were studied, including the pH and concentrations of the Tris buffer and sodium dodecyl sulfate. The linear range of the method for the determination of digoxin and digitoxin was over 0.01–0.3 mg/mL; the detection limit (signal to noise ratio = 3; injection 3.5 kPa 3 s) was 4 and 6 μg/mL, respectively. Application of the proposed method to the determination of digoxin in commercial tablets and in injections proved to be feasible.
Increased size‐sorting performance in gravitational SPLITT by using a pinched sample inlet design
Authors: Moon Myeong Hee , Kang Dukjin , Kwon So‐Yeon , Lee Seungho
Published: December 2003

Split‐flow thin fractionation is a continuous, flow‐assisted separation technique for sorting macromolecules and particulate matter on a preparative scale. On reducing the thickness of the sample inlet conduit of a gravitational split‐flow thin fractionation channel, size‐sorting performance is found to increase since particles that are continuously fed into the channel can be more rapidly compressed toward the upper wall of the channel. Experiments are carried out by measuring the number percentage of particles eluted at each outlet as a function of different thickness values of the sample inlet conduit. The effects that the total thickness of the gravitational split‐flow thin fractionation channel and the sample feed concentration have on the size‐fractionation performance are examined with the goal of determining the best pinched sample inlet, gravitational split‐flow thin fractionation channel design.
Determination of moutan tannins by high‐performance liquid chromatography and capillary electrophoresis
Authors: Wu Ya‐Ting , Huang Wen‐Ying , Lin Ta‐Chen , Sheu Shuenn‐Jyi
Published: December 2003

Cortex Moutan (Radicis Cortex Moutan), the dried root bark of Paeonia moutan and P. spp., contains a series of water‐soluble tannins. With the eight components, 1 4,6‐di‐O‐GG (4,6‐di‐O‐galloyl‐D‐glucose), 2 1,2,3,6‐tetra‐O‐GG, 3 1,2,3,4,6‐penta‐O‐GG, 4 1,3,4,6‐tetra‐O‐GG, 5 3,4,6‐tri‐O‐GG, 6 1,3,6‐tri‐O‐GG, 7 3,6‐di‐O‐GG, and 8 1,2,6‐tri‐O‐GG, as marker substances, a rapid and efficient method of analysis based on HPLC and CE was developed. Using a phosphate eluent, a 5C18‐MS separating column, and a detection wavelength of 280 nm, HPLC was successfully used to analyze the eight constituents within 60 min. The analysis can be completed within 50 min, using the MEKC mode with a buffer composed of borate, SDS, and isopropanol, and a detection wavelength of 210 nm. The detection limit for the marker substances varied from 0.04 to 0.93 μg/mL for the HPLC method and 0.02 to 0.36 μg/mL for the CE method.
Sensitive analyses of agricultural chemicals by capillary electrochromatography
Authors: Starkey Jason A. , Abrantes Shirley , Mechref Yehia , Novotny Milos V.
Published: December 2003

Capillary electrochromatography using a monolithic matrix was employed to develop a rapid and highly efficient separation methodology for the analyses of mixtures of agrochemical importance. Using this method, ppm‐ppb detection limits for urea, carbamate, and phenoxy acid herbicides were achieved without a preconcentration technique. The detection limits were further decreased to low‐ppb levels for the same class of compounds using an on‐column preconcentration technique.
Selectivity tuning of cyclodextrin derivatives by specific substitution
Authors: Junge Melanie , König Wilfried A.
Published: December 2003

A new, highly enantioselective cyclodextrin derivative combining the properties of heptakis(6‐O‐tert‐butyldimethylsilyl‐2,3‐di‐O‐methyl)‐β‐cyclodextrin and heptakis(2,3‐di‐O‐acetyl‐6‐O‐tert‐butyldimethylsilyl)‐β‐cyclodextrin was prepared by exchanging a methyl group for an acetyl substituent in a single glucose unit of heptakis(6‐O‐tert‐butyldimethylsilyl‐2,3‐di‐O‐methyl)‐β‐cyclodextrin. A comparative evaluation of the separation capabilities showed that the enantioselectivity of both “parent” cyclodextrin derivatives is transferred to the new chiral stationary phase.
Impact of water/PDMS phase ratio, volume of PDMS, and sampling time on Stir Bar Sorptive Extraction (SBSE) recovery of some pesticides with different KO/W
Authors: Bicchi Carlo , Cordero Chiara , Rubiolo Patrizia , Sandra Pat
Published: December 2003

In Stir Bar Sorptive Extraction (SBSE) organic analytes are enriched from aqueous samples by sorption onto a thick film of polydimethylsiloxane (PDMS) coated on a glass‐enveloped magnet. Sampled analytes are recovered by thermodesorption (TDS) and analysed on‐line by cGC‐MS. This study evaluates the SBSE recovery as a function of KO/W, the phase ratio (β), PDMS volume (20, 40, and 110 μL), sample volumes (4, 10, 100, and 1000 mL), and sampling time (0.67, 1, 2, 4, 5, 6, and 24 h) for three pesticides with different KO/W [parathion methyl (KO/W: 7.24×102), β‐endosulfan (KO/W: 6.8×103), and buprofezin (KO/W: 2.0×104)]. Experimental recoveries with SBSE in reasonable sampling times were found to be mainly conditioned by β, which must be as low as possible either by operating on small sample volumes or by using stir bars coated with high PDMS volume when samples of relatively large volume are analysed.
Analysis of intermediates from polycyclic aromatic hydrocarbon biodegradation
Authors: Copper Christine L.
Published: December 2003

A major difficulty in assessing bioremediation in hydrocarbon impacted field sites is the determination of the extent and products of contaminant biodegradation. Previously, various analytical techniques, including mass spectrometry and chromatography, have been used to characterize components in mixtures resulting from biodegradation. In this work, the applicability of capillary electrophoresis (CE) to this area of research is demonstrated. CE methods were optimized for analysis of compounds that are known metabolites of polycyclic aromatic hydrocarbon (PAH) biodegradation.
Micellar liquid chromatography of polycyclic aromatic hydrocarbons: Alkylpyridinium chloride as mobile phase modifier and selective fluorescence quencher
Authors: Mao Chunfeng , McGill Kelly E. , Tucker Sheryl A.
Published: December 2003

The dual role of alkylpyridinium chlorides, cetylpyridinium chloride (CPC) and dodecylpyridinium chloride (DDPC), as micellar mobile phase modifiers and selective fluorescence quenching agents of polycyclic aromatic hydrocarbons (PAHs), in micellar liquid chromatographic separation of PAHs is reported. The replacement of 0.037 M cetyltrimethylammonium chloride in the aqueous mobile phase with CPC/DDPC quencher greatly simplifies the observed fluorescence‐detected chromatograms, facilitating PAH identification. The resulting chromatograms are similar to those obtained from the conventional approach – pyridinium chloride quencher in an acetonitrile mobile phase. To quantify the quenching, the (F0 /F – 1) values from the Stern‐Volmer equation are calculated from the chromatograms and compared. The feasibility of using CPC or DDPC as a dual reagent under isocratic and gradient conditions is shown.
Weight approximations in multi‐attribute decision models
Authors: Roberts Ron , Goodwin Paul
Published: December 2003

The use of surrogate weights based on rankings has been proposed as a method for avoiding difficulties associated with the elicitation of weights in multi‐attribute decision analysis. When the simple multiattribute rating technique using swings (SMARTS) method is being employed it has been suggested that rank order centroid (ROC) weights are the best surrogate weights to use. This study shows that ROC weights are appropriate to use as a substitute for original weights that are constrained to sum to a fixed total (usually 1 or 100) as used in the point allocation method. If, however, the original weights are determined without any initial restrictions, as in the direct rating method, and are then normalized, which is the common procedure in SMARTS analysis, then the ROC weights do not provide the best approximations to the original weights. This paper shows how to obtain rank order distribution (ROD) weights that provide a better approximation than the ROC approach to unrestricted original weights. The paper also shows that, as the number of attributes in a decision problem increases, the ROD weights approximate to the more easily calculated rank sum weights. Copyright © 2003 John Wiley & Sons, Ltd.
Towards statistical multicriteria decision modelling: a first approach
Authors: De Smet Yves , Springael Johan , Kunsch Pierre
Published: December 2003

Many real life situations result from decisions taken by a very large number of decision makers. Among them, we may cite road traffic congestion, crowding during shopping, equity market behaviour, distribution of holiday destinations, etc. Furthermore, these decisions often depend on the optimisation of several conflicting criteria. In this paper, we introduce a new multicriteria tool based on Markov chains to model and manage these macroscopic phenomena. Finally, the road traffic congestion problem will be considered to illustrate the applicability of our approach. Copyright © 2003 John Wiley & Sons, Ltd.
Attribute‐based differentiation of alternatives
Authors: Keisler Jeffrey M.
Published: December 2003

An intermediate step is introduced to the dialogue decision process for decision analysis. Alternatives are refined after they have been generated within a strategy table but before they are subject to more detailed evaluation. Two or more judges create a subjective mapping from alternatives to attributes that will later be mapped to criteria. In strategy tables, each of the alternative strategies consists of a coherent set of choices made across several decisions that are to be coordinated. These strategic alternatives are modified so as to increase their differentiation in the attribute space, rather than in the decision space alone. When criteria weights are unknown, the best alternative from the modified set may be superior to the best alternative from the original set. Furthermore, analysis of the resulting alternatives may yield a better mapping of the value response surface for the action space, in the sense that this mapping leads to eventual construction of a higher value alternative. Results are reported for a consulting engagement incorporating the proposed step. Copyright © 2003 John Wiley & Sons, Ltd.
Neuronal glial interaction in different neurological diseases studied by ex vivo13C NMR spectroscopy
Authors: Sonnewald Ursula , Kondziella Daniel
Published: December 2003

Nuclear magnetic resonance spectroscopy (NMRS) has been used extensively for several decades to elucidate metabolic pathways in biological systems and has led to new insights into cerebral metabolism. Many of these insights have been gained by NMRS using in vitro models, such as tissue extracts, cell cultures or brain slices. Extracts of cells or tissue provide an excellent basis for metabolic studies and facilitate the interpretation of in vivo spectra. 13C NMRS is at present mostly used for in vitro or animal studies. Conclusions from the epilepsy models presented in this review are that turnover of metabolites is time‐dependant in kainate‐injected rats with limbic seizures. Early and only temporarily enhanced astrocytic activity is followed by altered metabolism in neurons with an increased turnover of important amino acids such as GABA and glutamate. However, pentylenetetrazole (PTZ) kindling affects astrocytes in younger and glutamatergic neurons in older animals. In the presence of PTZ, phenobarbital decreases labeling of most metabolites in all cell types, except GABAergic neurons, from both labeled precursors in the younger animals. However, in older animals only GABAergic neurons are affected by phenobarbital, as indicated by an increase in GABA labeling. In kaolin‐induced hydrocephalus it was shown that astrocyte metabolism is disturbed in the early phase, particularly in the cerebrum. These alterations continue into the chronic period. Only then do the first signs of neuronal metabolic impairment appear, which might explain why dementia is a prominent clinical feature in patients with chronic hydrocephalus. Copyright © 2003 John Wiley & Sons, Ltd.
Toward dynamic isotopomer analysis in the rat brain in vivo: automatic quantitation of 13C NMR spectra using LCModel
Authors: Henry Pierre‐Gilles , Öz Gülin , Provencher Stephen , Gruetter Rolf
Published: December 2003

The LCModel method was adapted to analyze localized in vivo 13C NMR spectra obtained from the rat brain in vivo at 9.4 T. Prior knowledge of chemical‐shifts, J‐coupling constants and J‐evolution was included in the analysis. Up to 50 different isotopomer signals corresponding to 10 metabolites were quantified simultaneously in 400 μl volumes in the rat brain in vivo during infusion of [1,6‐13C2]glucose. The analysis remained accurate even at low signal‐to‐noise ratio of the order of 3:1. The relative distribution of isotopomers in glutamate, glutamine and aspartate determined in vivo in 22 min was in excellent agreement with that measured in brain extracts. Quantitation of time series of 13C spectra yielded time courses of total 13C label incorporation into up to 16 carbon positions, as well as time courses of individual isotopomer signals, with a temporal resolution as low as 5 min (dynamic isotopomer analysis). The possibility of measuring in vivo a wealth of information that was hitherto accessible only in extracts is likely to expand the scope of metabolic studies in the intact brain. Copyright © 2003 John Wiley & Sons, Ltd.
Reflections on the application of 13C‐MRS to research on brain metabolism
Authors: Morris Peter , Bachelard Herman
Published: December 2003

The power of 13C‐MRS lies in its unique chemical specificity, enabling detection and quantification of metabolic intermediates which would not be so readily monitored using conventional radiochemical techniques. Examples from animal studies, by examination of tissue extracts from the whole brain, brain slices and cultured cells, include observation of intermediates such as citrate and triose phosphates which have yielded novel information on neuronal/glial relationships. The use of 13C‐labelled acetate as a specific precursor for glial metabolism provided evidence in support of the view that some of the GABA produced in the brain is derived from glial glutamine. Such studies have also provided direct evidence on the contribution of anaplerotic pathways to intermediary metabolism. Analogous studies are now being performed on the human brain, where 13C‐acetate is used to quantitate the overall contribution of glial cells to intermediary metabolism, and use of 13C‐glucose enables direct calculation of rates of flux through the TCA (FTCA) and of the glutamate–glutamine cycle (FCYC), leading to the conclusion that the rate of glial recycling of glutamate accounts for some 50% of FTCA. The rate of 0.74 μmol min−1 g−1 for FTCA is compatible with PET rates of CMRglc of 0.3–0.4 μmol min−1 g−1 (since each glucose molecule yields two molecules of pyruvate entering the TCA). Our brain activation studies showed a 60% increase in FTCA, which is very similar to the increases in CBF and in CMRglc observed in PET activation studies. Copyright © 2003 John Wiley & Sons, Ltd.
Clinical experience with 13C MRS in vivo
Authors: Ross Brian , Lin Alexander , Harris Kent , Bhattacharya Pratip , Schweinsburg Brian
Published: December 2003

13C MRS was installed on a clinical scanner at 1.5 T in order to facilitate integrated MR examinations of human brain disorders. Using a simplified protocol, (1‐13C) glucose and/or (1‐13C) acetate were administered orally or by intravenous infusion. 13C spectra of diagnostic quality were acquired in more than 100 consecutive studies. Novel 13C neurochemical data contributed to the understanding of Alzheimer's, Canavan's, mitochondrial and hepatic encephalopathy, epilepsy and normal brain development. 13C MRS uncovered hitherto unknown disorders of NAA‐synthesis, glutamate neurotransmission, TCA‐cycle and glycolysis. Despite low inherent signal‐to‐noise, natural abundance 13C MRS showed diagnostic promise. 13C MRS is feasible in a clinical setting, at reasonable cost in neonates, children, adults and elderly patients. Copyright © 2003 John Wiley & Sons, Ltd.
An improvement of the EDI method in linear elastic fracture mechanics by means of an a posteriori error estimator in G
Authors: Giner E. , Fuenmayor F. J. , Tarancón J. E.
Published: December 2003

In this paper, an error estimator that quantifies the effect of the finite element discretization error on the computation of the stress intensity factor in linear elastic fracture mechanics is presented. In order to obtain the proposed estimator, a shape design sensitivity analysis (SDSA) is applied to the fracture mechanics problem. Following this approach, one of the most efficient post‐processing techniques for computing the strain energy release rate G, the well‐known EDI method, may be interpreted as a continuum method of the SDSA. The proposed error estimator is based on the recovery of the gradient fields and its reliability has been checked by means of numerical problems, yielding very good estimations of the true error. The new estimator remarkably improves the results given by a previous error estimator, which is based on a discrete analytical approach of SDSA. As a consequence, the combination of the new error estimator and the result given by the EDI method provides a much more accurate estimation of G. Copyright © 2003 John Wiley & Sons, Ltd.
Using prices to help obtain human‐improvement results
Authors: Colvin Terrence R.
Published: December 2003

An increased focus on major, lasting human‐improvement results and their prices may help to generate significant increases in value for service recipients and society. This chapter presents a vision and a case for pricing selected human‐improvement results, and describes methods that may allow these prices to be developed.
Differential protein expressions induced by adenovirus‐mediated p16 gene transfer into Balb/c nude mouse
Authors: Park Misun , Kang Hoil , Lim Sinae , Lee Choon‐Taek , Kim Okhee
Published: December 2003

To evaluate the safety of adenovirus‐mediated gene transfer, we investigated differential protein expression after transducing adenoviral vector containing the p16INK4a tumor suppressor gene (Ad5CMV‐p16) into Balb/c nude mice. We found that adenovirus‐mediated p16INK4a gene transfer inhibited experimental lung metastasis, and that the intratumoral injection of Ad5CMV‐p16 resulted in regression of A549 cell xenografted tumors in Balb/c nude mice. We investigated changes in protein expression after intratumoral injection of Ad5CMV‐p16 or Ad5CMV (1010 plaque‐forming units) into A549 cell xenografted Balb/c nude mice by two‐dimensional gel electrophoresis /matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. Compared with the control (serum‐free medium treated tumor cells) Ad5CMV‐p16 gene transfer changed the expression of 29 proteins including heterogeneous nuclear ribonucleoprotein, protein phosphatase 2, 14‐3‐3 zeta protein, alpha‐tubulin, and glutathione‐S‐transferase P1. Moreover, both Ad5CMV‐p16 and Ad5CMV up‐regulated the expression of glutathione‐S‐transferase P1. In addition, Ad5CMV‐p16 gene transfer did not seem to increase the expression of tumorigenicity‐related protein in Balb/c nude mice. Further studies will be needed to investigate the effect of Ad5CMV‐p16 on normal human cells and tissues for safety evaluation. These results suggest that the p16 gene seems to have an important role in apoptosis as well as in cell cycle arrest in non‐small cell lung cancer.
Proteome analysis of rat pancreatic acinar cells: Implication for cerulein‐induced acute pancreatitis
Authors: Yu Ji Hoon , Yun Shin Young , Lim Joo Weon , Kim Hyeyoung , Kim Kyung Hwan
Published: December 2003

Cerulein pancreatitis was shown to be one of the best characterized models for acute pancreatitis. High doses of cerulein induce a dysregulation of the digestive enzyme production and cytoplasmic vacuolization and the death of acinar cells, edema formation, and an infiltration of inflammatory cells into the pancreas, which are similar symptoms shown in human acute pancreatitis. The present study aims to determine the differentially expressed proteins in cerulein‐treated pancreatic acinar cells as an in vitro model for acute pancreatitis. Pancreatic acinar AR42J cells were treated with 10−8 M cerulein for 24 h. The changed protein patterns separated by two‐dimensional electrophoresis using pH gradients of 5–8 were conclusively identified by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry analysis of the peptide digests. Five differentially expressed proteins (heat shock protein 90, mitochondrial ATP synthase beta chain precursor, tubulin beta chain, 3‐mercaptopyruvate sulfurtransferase, mitochondrial ATP synthase subunit D) were identified in cerulein‐treated AR42J cells. These proteins are related to cellular stress such as reactive oxygen species, cytoskeletal function, and cell signaling. In conclusion, the differentially expressed proteins will provide valuable information to understand the pathophysiologic mechanism of acute pancreatitis and may be useful for prognostic indices of acute pancreatitis.
Mass spectrometry and tandem mass spectrometry analysis of rat mitochondrial ATP synthase: Up‐regulation in pancreatic acinar cells treated with cerulein
Authors: Yu Ji Hoon , Yun Shin Young , Lim Joo Weon , Kim Hyeyoung , Kim Kyung Hwan
Published: December 2003

Mitochondrion is a vulnerable intracellular target to reactive oxygen species (ROS). ROS have been considered to be important regulators of the pathogenesis of pancreatitis. This study aims to determine whether ROS induces mitochondrial damage by monitoring the expression level of mitochondrial ATP synthase as the key molecular component in mitochondria associated with cellular damage. Pancreatic acinar AR42J cells were treated with cerulein which induces symptoms similar to that associated with human acute pancreatitis. Proteins were separated by two‐dimensional electrophoresis using pH gradients of 5–8 and identified using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometer (MS), quadrupole time‐of‐flight MS and MS/MS with nano‐electrospray. Following cerulein treatment, mitochondrial ATP synthase beta chain was highly expressed compared to nontreated cell. The protein was identified by its pI of 5.2 and molecular weight (56 354 Da) with 27 matched peptides. Among the MS spectrum, precursor ions m/z 488.28, 544.81, 631.82, 693.34, 718.38, 729.41, 801.40, 809.39, 825.94, and 994.52 were further identified using MS/MS and confirmed the isolated protein to be mitochondrial ATP synthase beta chain. In conclusion, cerulein‐induced oxidative injury may result in the induction of mitochondrial ATP synthase, which may act as an adaptive pathophysiological process in the pancreas.
Pattern analysis of serum proteome distinguishes renal cell carcinoma from other urologic diseases and healthy persons
Authors: Won Yonggwan , Song Ho‐Jun , Kang Taek Won , Kim Jung‐Ja , Han Byoung‐Don , Lee Seung‐won
Published: December 2003

Despite having a relatively low incidence, renal cell carcinoma (RCC) is one of the most lethal urologic cancers. For successful treatment including surgery, early detection is essential. Currently there is no screening method such as biomarker assays for early diagnosis of RCC. Surface‐enhanced laser desorption/ionization‐time of flight mass spectrometry (SELDI‐TOF) is a recent technical advance that can be used to identify biomarkers for cancers. In this study, we investigated whether SELDI protein profiling and artificial intelligence analysis of serum could distinguish RCC from healthy persons and other urologic diseases (nonRCC). The SELDI‐TOF data was acquired from a total of 36 serum samples with weak cation exchange‐2 protein chip arrays and filtered using ProteinChip software. We used a decision tree algorithm c4.5 to classify the three groups of sera. Five proteins were identified with masses of 3900, 4107, 4153, 5352, and 5987 Da. These biomarkers can correctly separate RCC from healthy and nonRCC samples.
Monitoring protein expression by proteomics: Human plasma exposed to benzene
Authors: Joo Won‐A , Kang Mee‐Jeong , Son Won‐kyu , Lee Hyun‐Ju , Lee Do‐Youn , Lee Eunil , Kim Chan‐Wha
Published: December 2003

Low levels and long term exposure to benzene is associated with hematotoxicity including aplastic anemia, acute myelogenous leukemia, and lymphoma. Current biomonitoring methods such as urinary phenol, S‐phenylmercapturic acid, and trans‐trans muconic acid were found to be unreliable as analytical methods to detect benzene exposure. Therefore, to search for a specific protein for biomonitoring benzene exposure, we investigated plasma proteins from workers (n = 50) at a printing company who were exposed to benzene, by two‐dimensional gel electrophoresis. The protein profiles are significantly different (p 〈 0.05) between benzene exposed and unexposed groups, as identified by matrix‐assisted laser desorption ionization/time of flight mass spectrometry and confirmed by Western blot analyses. T cell receptor β chain (TCR β), FK506‐binding protein, and matrix metalloproteinase‐13 were expressed only in benzene exposed workers. In addition, interleukin‐4 receptor α chain and T cell surface glycoprotein CD1b precursor were found to be up‐regulated in the plasma of benzene exposed workers. When we treated Jurkat cells with benzene (10 μM–10 mM), TCR β expression was increased in the membrane more than 6–9‐fold compared to untreated cells. In addition, the amount of TCR β released into the culture media, at benzene concentrations greater than 50 μM, increased up to 10 mM. Therefore, TCR β levels in plasma could be used as a biomarker and a possible therapeutic target for benzene exposure.
Establishment of a two‐dimensional electrophoresis map forNeospora caninumtachyzoites by proteomics
Authors: Lee Eung Goo , Kim Jae Hoon , Shin Yong Seung , Shin Gee Wook , Suh Myung Deuk , Kim Dae Yong , Kim Yong Hwan , Kim Gon Sup , Jung Tae Sung
Published: December 2003

Expressed proteins and antigens fromNeospora caninumtachyzoites were studied by two‐dimensional gel electrophoresis and immunoblot analysis combined with matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. Thirty‐one spots corresponding to 20 different proteins were identified fromN. caninumtachyzoites by peptide mass fingerprinting. Six proteins were identified from aN. caninumdatabase (NTPase, 14‐3‐3 protein homologue, NcMIC1, NCDG1, NcGRA1 and NcGRA2), and 11 proteins were identified in closely related species using theT. gondiidatabase (HSP70, HSP60, pyruvate kinase, tubulin α‐ and β‐chain, putative protein disulfide isomerase, enolase, actin, fructose‐1,6‐bisphosphatase, lactate dehydrogenase and glyceradehyde‐3‐phosphate dehydrogenase). One hundred and two antigen spots were observed using pH 4–7 IPG strips on immunoblot profiles. Among them, 17 spots corresponding to 11 antigenic proteins were identified from aN. caninumprotein map. This study involved the construction of in‐depth protein maps forN. caninumtachyzoites, which will be of value for studies of its pathogenesis, drug and vaccine development, and phylogenetic studies.
Characterization of a bovine pregnancy‐associated protein using two‐dimensional gel electrophoresis, N‐terminal sequencing and mass spectrometry
Authors: Pyo Jaehoon , Hwang Sun‐Il , Oh Jisun , Lee So‐Jin , Kang Sun‐Cheol , Kim Jong‐Sang , Lim Jinkyu
Published: December 2003

Bovine pregnancy‐associated protein (bPAP) isolated from pregnant bovine urines by two‐dimensional electrophoresis (2‐DE) was characterized by N‐terminal sequencing, internal sequencing, and mass spectrometric analyses using matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry and tandem mass spectrometry. Database search using the amino acid sequences and the peptide mass profiles showed that the protein is a novel bovine pregnancy‐associated protein of which the N‐terminus has a high similarity to collagen alpha. The protein has a molecular mass of 21 kDa and a pI of 6.1. The expression profiles of the protein from the urine of 30 pregnant and 20 nonpregnant cows characterized by 2‐DE indicated that the expression of bPAP during pregnancy increased to over nmol from the pmol level basal expression of bPAP at the nonpregnant state with < 3% of false negatives and < 10% of false positives. Using the peptide sequence information, polyclonal antibodies against the bPAP protein were generated. The purified polyclonal antibodies against the peptide sequences of bPAP detected the 21 kDa protein on the blots of pregnant cow urine by Western blot analysis. In addition, analysis showed that the expression of bPAP in the urine is associated with pregnancy, but that the urine concentration of bPAP is not correlated with the duration of the pregnancy.
Proteome analysis of hairy root from Panax ginseng C. A. Meyer using peptide fingerprinting, internal sequencing and expressed sequence tag data
Authors: Kim Seung Il , Kim Jin Young , Kim Eun A. , Kwon Kyung‐Hoon , Kim Kyung‐Wook , Cho Kun , Lee Jeong Hwa , Nam Myung Hee , Yang Deok‐Chun , Yoo Jong Shin , Park Young Mok
Published: December 2003

As an initial step to the comprehensive proteomic analysis of Panax ginseng C. A. Meyer, protein mixtures extracted from the cultured hairy root of Panax ginseng were separated by two‐dimensional polyacrylamide gel electrophoresis (2‐DE). The protein spots were analyzed and identified by peptide finger printing and internal amino acid sequencing by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry (MALDI‐TOF MS) and electrospray ionization quadrupole‐time of flight mass spectrometry (ESI Q‐TOF MS), respectively. More than 300 protein spots were detected on silver stained two‐dimensional (2‐D) gels using pH 3–10, 4–7, and 4.5–5.5 gradients. Major protein spots (159) were analyzed by peptide fingerprinting or de novo sequencing and the functions of 91 of these proteins were identified. Protein identification was achieved using the expressed sequence tag (EST) database from Panax ginseng and the protein database of plants like Arabidopsis thaliana and Oryza sativa. However, peptide mass fingerprinting by MALDI‐TOF MS alone was insufficient for protein identification because of the lack of a genome database for Panax ginseng. Only 17 of the 159 protein spots were verified by peptide mass fingerprinting using MALDI‐TOF MS whereas 87 out of 102 protein spots, which included 13 of the 17 proteins identified by MALDI‐TOF MS, were identified by internal amino acid sequencing using tandem mass spectrometry analysis by ESI Q‐TOF MS. When the internal amino acid sequences were used as identification markers, the identification rate exceeded 85.3%, suggesting that a combination of internal sequencing and EST data analysis was an efficient identification method for proteome analysis of plants having incomplete genome data like ginseng. The 2‐D patterns of the main root and leaves of Panax ginseng differed from that of the cultured hairy root, suggesting that some proteins are exclusively expressed by different tissues for specific cellular functions. Proteome analysis will undoubtedly be helpful for understanding the physiology of Panax ginseng.
Synthesis and characterization of new segmented polyurethanes with side‐chain, liquid‐crystalline chain extenders
Authors: Huang Fang‐Jung , Wang Tzong‐Liu
Published: December 2003

Liquid‐crystalline, segmented polyurethanes with methoxy–biphenyl mesogens pendant on the chain extender were synthesized by the conventional prepolymer technique and esterification reaction. Two, side‐chain, liquid‐crystalline (SCLC) polyurethanes with mesogens having spacers of six and eight methylene units were prepared. The structures of the mesogenic units and SCLC polyurethanes were confirmed by Fourier transform infrared spectroscopy and 1H NMR. Polymer properties were also examined by solubility tests, water uptakes, and inherent viscosity measurements. Differential scanning calorimetry studies indicated that the transition temperature of the isotropic to the liquid‐crystalline phase decreased with increasing spacer length. Wide‐angle X‐ray diffraction (WAXD) studies revealed the existence of liquid‐crystalline phases for both SCLC polyurethanes. Polarized optical microscopic investigations further confirmed the thermotropic liquid‐crystalline behaviors and nematic mesophases of both samples. Thermogravimetric analysis displayed better thermal stabilities for both SCLC polymers and indicated that the presence of mesogenic side chains may increase the thermal stability of segmented polyurethanes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 290–302, 2004
Thermoplastic poly(ester‐imide)s derived from anhydride‐terminated polyester prepolymer and diisocyanate
Authors: Banu P. , Radhakrishnan Ganga
Published: December 2003

The phase‐separation behavior of thermoplastic poly(ester‐imide) [P(E‐I)] multiblock copolymers, (A‐B)n, was investigated by a stepwise variation of the imide content. All the multiblock copolymers were synthesized by solution polycondensation with dimethylformamide as a solvent. P(E‐I)s were prepared with anhydride‐terminated polyester prepolymer and diisocyanates. Polyester prepolymers were prepared by the reaction of pyromellitic dianhydride and two different polyols [poly(tetramethylene oxide glycol) (PTMG) and polycaprolactone diol (PCL)]. Structural determination was done with Fourier transform infrared spectroscopy and Fourier transform NMR, and the molecular weight was determined by gel permeation chromatography. The effect of the imide content on the thermal properties of the synthesized P(E‐I)s was investigated by thermogravimetric analysis and differential scanning calorimetry. The polymers were also characterized for static and dynamic mechanical properties. Thermal analysis data indicated that the polymers based on PTMG were stable up to 330 °C in nitrogen atmosphere and exhibited phase‐separated morphology. Polymers based on PCL showed multistage decomposition, and the films derived from them were too fragile to be characterized for static and dynamic mechanical properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 341–350, 2004
Mechanism of the anionic polymerization of methyl methacrylate initiated by tetramethylammonium–triphenylmethide in tetrahydrofuran
Authors: Warner William N. , Hu Jinbo , Surya Prakash G. K. , Olah George A. , Hogen‐Esch Thieo E.
Published: December 2003

A tetramethylammonium (TMA)–triphenylmethide (TPM) initiator generated in situ by the reaction of trimethyltriphenylmethylsilane with tetramethylammonium fluoride in tetrahydrofuran was found to have greater stability than the corresponding tetrabutylammonium or tetrahexylammonium derivatives. The predominant mode of degradation of TMA–TPM was found to be the TMA‐mediated methylation of TPM anions. The initiation of methyl methacrylate by TMA–TPM in tetrahydrofuran at −78 °C was demonstrated to produce quantitative yields of poly(methyl methacrylate) with polydispersities of less than 1.1. Although the initiator efficiencies were low (9–40%) because of relatively slow initiation on the polymerization timescale, the initiation appeared to be rapid enough to give relatively narrow molecular weight distributions. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 237–244, 2004
Synthesis of random terpolymers and determination of reactivity ratios of N‐carboxyanhydrides of leucine, β‐benzyl aspartate, and valine
Authors: Wamsley Andrea , Jasti Bhaskara , Phiasivongsa Pasit , Li Xiaoling
Published: December 2003

The copolymerization and terpolymerization of leucine‐N‐carboxyanhydride, β‐benzyl aspartate‐ N‐carboxyanhydride, and valine‐N‐carboxyanhydride in dioxane, initiated with triethylamine, were investigated to determine the random nature of the terpolymer composition for potential applications as targeting drug delivery carriers. 1H NMR was used to obtain the actual monomer compositions of the polymers. The reactivity ratio of each monomer was determined with Fineman–Ross, Kelen–Tüdös, and nonlinear least‐squares curve‐ fitting methods. The product of the estimated reactivity ratios from the monomers in the binary copolymerizations indicated that random polymers were predominantly formed. On the basis of the reactivity ratios determined from the binary copolymers, Alfrey–Goldfinger equations were used to estimate the compositions of the terpolymers. There was no statistical difference between the actual monomer compositions and the calculated compositions of the terpolymers; this validated the reactivity ratios estimated by Fineman–Ross, Kelen–Tüdös, and nonlinear least‐squares curve‐ fitting methods. Therefore, the poly(leucine‐β‐Bzl‐ aspartate‐valine) synthesized in this study was primarily a random terpolymer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 317–325, 2004
Poly[(2‐alkoxy‐5‐methyl‐1,3‐phenylene vinylene)‐alt‐(phenylene vinylene)] derivatives with different contents ofcis‐ andtrans‐olefins: The effect of the olefin bond geometry and conjugation length on luminescence
Authors: Liao Liang , Ding Liming , Karasz Frank E. , Pang Yi
Published: December 2003

Poly[(2‐alkyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(1,3‐phenylenevinylene)]s (8) and poly[(2‐alkyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(1,4‐phenylenevinylene)]s (10) were synthesized by the Wittig reaction to provide materials containing 45–62%cis‐vinylene bonds. The optical characteristics of8and10were compared with those of their respective isomers,3and4, thecis‐vinylene contents of which were significantly lower (9–16%). Although a greater fraction ofcis‐CHCH linkages caused the absorption maximum (λmax) of8and10to be slightly blueshifted (by ∼3–6 nm) from that of3and4, the impact of the vinylene bond geometry appeared to be negligible on their fluorescence spectra. The fluorescence quantum efficiencies of8and10were estimated to be approximately 0.25 and 0.72, respectively. Both8(λmax≈ 445 or 462 nm) and10(λmax≈ 480 or 506 nm) were electroluminescent, showing effective color tuning by the controlled insertion ofm‐phenylene moieties. The external electroluminescence quantum efficiencies were determined to be 4.26 × 10−3% for8and 0.63% for10. Thecis/trans‐vinylene bond ratio had a great impact on the electroluminescence device performance of8but a much smaller impact on the performance of10. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 303–316, 2004
Diffusion and partition coefficients of small organic solvents in molten miscible polymer blends: Correlations with thermodynamic interactions
Authors: Popovska‐Pavlovska F. , Raka Lj.
Published: December 2003

The transport properties of small organic molecules in molten poly(vinyl chloride) (PVC)/atactic poly(methyl methacrylate) (PMMA) blends and their homopolymers were studied with inverse gas chromatography. The elution profiles resulting from various organic solvents and different experimental conditions were used for measuring diffusion and partition coefficients. With the van Deemter equation and retention volumes at infinite dilution, diffusion coefficients of 10−7 to 10−8 cm2/s and partition coefficients of 10–50 were calculated. The dependence of the diffusion and partition coefficients on experimental variables such as the blend concentration, temperature, and solute nature was examined. The presence of PMMA in PVC blends affected the sorption behavior of the PVC matrix up to a certain concentration. Beyond that, it was hard to derive any composition–diffusivity dependence. On the contrary, the diffusion and partition coefficients were greatly influenced by changes in the temperature and by the nature of the solute. For those solutes (e.g., chlorinated hydrocarbons) showing stronger interactions with polymer blends (higher negative values for the Flory–Huggins interaction parameter χ1(23)), higher diffusion and partition coefficients were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 267–279, 2004
Morphology and fracture behavior of toughening‐modified poly(vinyl chloride)/organophilic montmorillonite composites
Authors: Wan Chao Ying , Zhang Yong , Zhang Yin Xi , Qiao Xiu Ying , Teng Guo Min
Published: December 2003

Toughening‐modified poly(vinyl chloride) (PVC)/organophilic montmorillonite (OMMT) composites with an impact‐modifier resin (Blendex 338) were prepared by melt intercalation, and their microstructures were investigated with wide‐angle X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The mechanical properties of the PVC composites were examined in terms of the content of Blendex and OMMT, and the fracture toughness was analyzed with a modified essential work of fracture model. Intercalated structures were found in the PVC/OMMT composites with or without Blendex. Either Blendex or OMMT could improve the elongation at break and notched impact strength of PVC at proper contents. With the addition of 30 phr or more of Blendex, supertough behavior was observed for PVC/Blendex blends, and their notched impact strength was increased more than 3319% compared with that of pristine PVC. Furthermore, the addition of OMMT greatly improved both the toughness and strength of PVC/Blendex blends, and the toughening effect of OMMT on PVC/Blendex blends was much larger than that on pristine PVC. Blendex and OMMT synergistically improved the mechanical properties of PVC. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 286–295, 2004