bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Enzyme Biosensor Based on ISFETs for Quantitative Analysis of Serine Proteinases
Authors: Biloivan Olga A. , Dzyadevych Sergiy V. , Boubriak Olga A. , Soldatkin Alexey P. , El'skaya Anna V. 
Published: September 2004

AbstractA new potentiometric biosensor allowing quantitative determination of the proteinases through their esterase activity has been developed. The biosensor, specific for ester artificial substrates of serine proteinases has been fabricated using a pH‐sensitive field effect transistor (pH‐FET) and an immobilized complex of trypsin and α2‐macroglobulin. It has been shown that created biosensor is able to determine the activity of the soluble trypsin in the range of 0.1–30 U/mL (substrate BAEE). The relative standard deviation for the trypsin determination was approximately 3%. The operation stability of the biosensor was no less than 12 h (40 measurements). The response of the biosensor stored at +4 °C was stable for 30 days.
Modelling of the Potentiometric Response of ENFETs Based on Enzymatic Multilayer Membranes
Authors: Aouni F. , Mlika R. , Martelet C. , Ouada H. Ben , Jaffrezic‐Renault N. , Soldatkin A. P. 
Published: September 2004

AbstractBased on the modified site‐binding model, the response of urea‐sensitive enzymatic field effect transistors (ENFETs) is fitted. The effect of two types of surface sites (silanol and amine sites) and of additional polymeric permselective membrane on the sensitivity of the biosensor is discussed. It is found that the dependence of the slope of the sensor response versus pUrea, on the buffer concentration and on the diffusion of the urea in the enzymatic membrane can be translated by a parameter α that depends on the membrane composition. Moreover, the enhancement of the sensor sensitivity by deposition of additional permselective membranes can be illustrated by a parameter δ that depends on the association of additional permselective membranes and a buffer; the higher values of parameter δ are obtained with a Nafion membrane associated with a phosphate buffer.
Non‐self‐overlapping structured grid generation on an n‐sided surface
Authors: Wang Charlie C. L. , Tang Kai 
Published: September 2004

AbstractMost existing meshing algorithms for a 2D or shell figure requires the figure to have exactly four sides. Generating structured grids in the n‐sided parametric region of a trimmed surface thus usually requires to first partition the region into four‐sided sub‐regions. We address the automatic structured grid generation problem in an n‐sided region by fitting a planar Gregory patch so that the partition requirement is naturally avoided. However, self‐overlapping may occur in some portions of the algebraically generated grid; this severely limits its usage in most of engineering and scientific applications where a grid system with no self‐intersecting is strictly required. To solve the problem, we use a functional optimization approach to move grid nodes in the u−v domain of the trimmed surface to eliminate the self‐overlapping. The derivatives of a Gregory patch, which are extremely difficult to compute analytically, are not required in our method. Thus, our optimization algorithm compares favourably at least in terms of speed with some other mesh optimization algorithms, such as the elliptic PDE method. In addition, to overcome the difficulty of guessing a good initial position of every grid node for the conjugate gradient method, a progressive optimization algorithm is incorporated in our optimization. Experiment results are given to illustrate the usefulness and effectiveness of the presented method. Copyright © 2004 John Wiley & Sons, Ltd.
Estimating the demand for health care with panel data: a semiparametric Bayesian approach
Authors: Jochmann Markus , León‐González Roberto 
Published: September 2004

AbstractThis paper is concerned with the problem of estimating the demand for health care with panel data. A random effects model is specified within a semiparametric Bayesian approach using a Dirichlet process prior. This results in a very flexible distribution for both the random effects and the count variable. In particular, the model can be seen as a mixture distribution with a random number of components, and is therefore a natural extension of prevailing latent class models. A full Bayesian analysis using Markov chain Monte Carlo simulation methods is proposed. The methodology is illustrated with an application using data from Germany. Copyright © 2004 John Wiley & Sons, Ltd.
Anthocyanin‐ and hydrolyzable tannin‐rich pomegranate fruit extract modulates MAPK and NF‐κB pathways and inhibits skin tumorigenesis in CD‐1 mice
Authors: Afaq Farrukh , Saleem Mohammad , Krueger Christian G. , Reed Jess D. , Mukhtar Hasan 
Published: September 2004

AbstractChemoprevention has come of age as an effective cancer control modality; however, the search for novel agent(s) for the armamentarium of cancer chemoprevention continues. We argue that agents capable of intervening at more than one critical pathway in the carcinogenesis process will have greater advantage over other single‐target agents. Pomegranate fruit extract (PFE) derived from the tree Punica granatum possesses strong antioxidant and antiinflammatory properties. Pomegranate fruit was extracted with acetone and analyzed based on matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry and found to contain anthocyanins, ellagitannins and hydrolyzable tannins. We evaluated whether PFE possesses antitumor‐promoting effects. We first determined the effect of topical application of PFE to CD‐1 mice against 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced conventional markers and other novel markers of skin tumor promotion. We found that topical application of PFE (2 mg/mouse) 30 min prior to TPA (3.2 nmole/mouse) application on mouse skin afforded significant inhibition, in a time‐dependent manner, against TPA‐mediated increase in skin edema and hyperplasia, epidermal ornithine decarboxylase (ODC) activity and protein expression of ODC and cyclooxygenase‐2. We also found that topical application of PFE resulted in inhibition of TPA‐induced phosphorylation of ERK1/2, p38 and JNK1/2, as well as activation of NF‐κB and IKKα and phosphorylation and degradation of IκBα. We next assessed the effect of skin application of PFE on TPA‐induced skin tumor promotion in 7,12‐dimethylbenz(a)anthracene‐initiated CD‐1 mouse. The animals pretreated with PFE showed substantially reduced tumor incidence and lower tumor body burden when assessed as total number of tumors per group, percent of mice with tumors and number of tumors per animal as compared to animals that did not receive PFE. In TPA‐treated group, 100% of the mice developed tumors at 16 weeks on test, whereas at this time in PFE‐treated group, only 30% mice exhibited tumors. Skin application of PFE prior to TPA application also resulted in a significant delay in latency period from 9 to 14 weeks and afforded protection when tumor data were considered in terms of tumor incidence and tumor multiplicity. The results of our study provide clear evidence that PFE possesses antiskin‐tumor‐promoting effects in CD‐1 mouse. Because PFE is capable of inhibiting conventional as well as novel biomarkers of TPA‐induced tumor promotion, it may possess chemopreventive activity in a wide range of tumor models. Thus, an in‐depth study to define active agent(s) in PFE capable of affording antitumor‐promoting effect is warranted.
Increased endothelial uptake of paclitaxel as a potential mechanism for its antiangiogenic effects: Potentiation by Cox‐2 inhibition
Authors: Merchan Jaime R. , Jayaram Deepa R. , Supko Jeffrey G. , He Xiaoying , Bubley Glenn J. , Sukhatme Vikas P. 
Published: September 2004

AbstractPaclitaxel has antiangiogenic properties, but the mechanisms for the enhanced sensitivity of endothelial cells (ECs) to this drug are not established. The aims of our study were to compare the distribution of paclitaxel into ECs with other cell types, to assess the effects of low doses of paclitaxel on Cox‐2 expression and to determine the combined effects of paclitaxel and Cox‐2 inhibitors on angiogenesis in vitro and in patients with cancer. Upon exposure to low (5 nM) concentrations of [3H]‐paclitaxel, uptake of radioactivity was more than 5 times higher in ECs than other cell types. Exposing human umbilical vein ECs to low nanomolar (1–50 nM) concentrations of paclitaxel enhanced Cox‐2 expression more than 2‐fold, as measured by ELISA. Combined treatment with paclitaxel and the Cox‐2 inhibitor NS‐398 resulted in increased antiendothelial effects as compared to each agent alone. To assess the biologic effects of the combined treatment in vivo, 4 cancer patients were treated with a prolonged intravenous infusion of paclitaxel (10 mg/m2/day) and the Cox‐2 inhibitor celecoxib (400 mg p.o. BID), and plasma angiogenic activity and drug levels were measured. The treatment was well tolerated, providing steady‐state concentrations of paclitaxel in plasma near 10 nM and potent plasma antiendothelial effects were observed. These findings suggest that antiangiogenic effects of paclitaxel may be due its preferential accumulation in ECs. Low dose paclitaxel in combination with a Cox‐2 inhibitor is an attractive antiangiogenic and antitumor strategy that deserves further evaluation in clinical trials.
Sequence‐ and schedule‐dependent enhancement of zoledronic acid induced apoptosis by doxorubicin in breast and prostate cancer cells
Authors: Neville‐Webbe Helen L. , Rostami‐Hodjegan Amin , Evans Catherine A. , Coleman Robert E. , Holen Ingunn 
Published: September 2004

AbstractWe investigated whether the combination of zoledronic acid and doxorubicin induced apoptosis of breast and prostate cancer cell lines, and if synergistic interaction was present. We investigated whether the levels of cell death altered depending on the sequence in which the drugs were administered and the possible mechanism of action responsible for the increased cell death following combined treatments. Breast and prostate cancer cells were treated with zoledronic acid alone, doxorubicin alone, or drugs in sequence (doxorubicin before, after, or with zoledronic acid), and the levels of apoptotic death were determined by evaluation of nuclear morphology. We found that clinically relevant concentrations of doxorubicin and zoledronic acid induced sequence‐ and schedule‐dependent apoptosis of breast and prostate cancer cells. For maximal apoptosis, cells had to be pretreated for 24 hr with doxorubicin before immediate treatment with zoledronic acid for 1 hr. This observation is a characteristic feature of cell cycle phase‐specific synergistic effect. Replacing zoledronic acid with the nonnitrogen‐containing bisphosphonate clodronate did not induce increased apoptosis. Induction of apoptosis was mainly via inhibition of the mevalonate (MVA) pathway, as addition of the MVA pathway intermediary geranylgeraniol inhibited the induction of apoptosis by doxorubicin followed by zoledronic acid. In conclusion, combined treatment of breast and prostate cancer cell lines with clinically relevant doses of doxorubicin and zoledronic acid induces apoptosis in a synergistic fashion. These findings may have relevance for the clinical setting, particularly breast cancer patients receiving these drugs in the adjuvant setting.
Independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer in Taiwan
Authors: Lee Chien‐Hung , Lee Jang‐Ming , Wu Deng‐Chyang , Hsu Hon‐Ki , Kao Ein‐Long , Huang Hsiao‐Ling , Wang Tsu‐Nai , Huang Meng‐Chuan , Wu Ming‐Tsang 
Published: September 2004

AbstractA multicenter case‐control study was conducted in northern and southern Taiwan to clarify the independent and combined effects of alcohol intake, tobacco smoking and betel quid chewing on the risk of esophageal cancer. A total of 513 patients with newly diagnosed and histopathologically confirmed squamous cell carcinoma of the esophagus and 818 gender, age and study hospital‐matched controls were included. We found a significant dose‐response relationship between the duration and intensity of consumption of the 3 substances and the development of this neoplasm in this site. Although the amount of alcohol consumed had a stronger effect on the risk of esophageal cancer than the number of years it was consumed, however, the number of years one smoked had a stronger effect on the risk than the amount of cigarettes consumed. The strongest risk factor of esophageal cancer was alcohol intake, with highest risk (OR = 13.9) being for those who consumed more than 900 g/day‐year. Combined exposure to any 2 of 3 substances brought the risks up to 8.8–19.7 fold and, to all 3 substances, to 41.2‐fold. A multiplicative interaction effect for alcohol drinkers who smoked on cancer risk was detected, whereas an additive interaction effect was found among drinkers who chewed. The combined effect of all 3 substances accounted for 83.7% of the attributable fraction of contracting esophageal cancer in this population. In conclusion, these results suggest that the intensity and the length of time alcohol and tobacco are used play different roles in the etiology of esophageal cancer. Alcohol separately interacts with tobacco and betel quid in a differently synergistic way in determining the development of this site of cancer.
Thermal risks from LED‐ and high‐intensity QTH‐curing units during polymerization of dental resins
Authors: Bouillaguet Serge , Caillot Guillaume , Forchelet Jacques , Cattani‐Lorente Maria , Wataha John C. , Krejci Ivo 
Published: September 2004

AbstractThe aim of this study was to test the ability of an infrared (IR) camera to assess temperature changes and distributions in teeth below restorations when quartz‐tungsten‐halogen (QTH) and light‐emitting diode (LED) curing lights were used to photopolymerize the restorative material. Our hypothesis was that the higher power density and broader spectral distribution of the QTH source would cause greater increases in tooth temperature than the LED source, and that these differences would be best demonstrated with the IR camera. Cavities were prepared on human third molars and restored with a resin composite restorative material. The material was light‐cured using three light‐curing sources using several exposure times. The external (outside the tooth) and internal (inside the pulp chamber) temperature changes during polymerization of the composite material were recorded over 360 s with thermocouples and an IR camera. Using thermocouples the maximum increase in external temperature (+17.7°C) was reported for the Swiss Master light after 20 s of curing time while the minimum temperature rise (+7.8°C) was reported for the Freelight 2. Whereas a 2.6°C increase in internal temperature was observed after curing 20 s with the Freelight 2, 7.1°C was reported after 60 s of light exposure to Astralis 10. Infrared images showed similar trends in external–internal rises in temperature as the thermocouples, although temperatures measured by the IR were generally higher. These results indicate that the higher power density QTH sources caused greater increases in tooth temperatures than the LED source and that thermocouples may underestimate the heat applied to the tooth. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 72B: 260–267, 2005
Electrotransfer of human IL‐1Ra into skeletal muscles reduces the incidence of murine collagen‐induced arthritis
Authors: Jeong Jae‐Gyun , Kim Jong‐Mook , Ho Seong‐Hyun , Hahn Woong , Yu Seung Shin , Kim Sunyoung 
Published: September 2004

AbstractBackgroundIt has previously been demonstrated that high levels of gene expression in skeletal muscles can be achieved after direct in vivo electrotransfer of naked plasmid DNA. The purpose of this study is to examine the potential of in vivo electroporation of plasmid DNA encoding human IL‐1Ra for the prevention of murine collagen‐induced arthritis (CIA).MethodsDBA/1 mice were injected in gastrocnemius muscles with plasmid DNA followed by in vivo electroporation. To uncover the optimum conditions of gene transfer, various electric field strengths and different amounts of plasmid DNA were applied. Calf muscles around the injected areas were investigated with histological methods for damage to muscle tissue. The levels of human IL‐1Ra expression in the injected area and also in the serum were determined with ELISA for human IL‐1Ra. Based on these data, the effects of electrotransfer of plasmid DNA were tested using the murine CIA model. DBA/1 mice were immunized with bovine collagen type II at the base of the tail. On day 21, mice were given a booster injection with the same antigen. Mice were divided into two groups on day 26. One group of mice received plasmid containing the IL‐1Ra cDNA sequence, while control mice were given plasmid lacking the IL‐1Ra coding sequence. The incidence of arthritis was evaluated by macroscopic analysis, histological analysis, and the levels of inflammatory cytokines.ResultsIL‐1Ra expression increased as a function of the electrical field strength and the amount of DNA. 200 V/cm (eight pulses; 20 ms per pulse; 1 Hz) and 15 µg of plasmid DNA per mouse were found to be optimum for gene transfer. After in vivo electroporation, gene expression in both muscle and serum increased gradually, reaching a peak value on day 10. Significant levels of human IL‐1Ra expression were maintained for 20 days. Macroscopic analysis showed that the onset of CIA was significantly inhibited by direct electrotransfer of plasmid DNA encoding human IL‐1Ra. Histological analysis of knee joints showed that the incidence of arthritis in knee joints was also prevented. The levels of mouse IL‐1β and IL‐12 in paws were significantly lower in the group treated with IL‐1Ra than those in the control group.ConclusionsThese results demonstrate that direct electrotransfer of plasmid containing the human IL‐1Ra cDNA sequence to skeletal muscle can reduce the incidence of CIA in mice. Copyright © 2004 John Wiley & Sons, Ltd.
Gender, extra‐firm mobility, and compensation attainment in the United States and Hong Kong
Authors: Lam Simon S. K. , Dreher George F. 
Published: September 2004

AbstractUsing data from 739 U.S. managers and professionals and 593 Hong Kong Chinese managers and professionals we examined the moderating effects of gender on the relationship between changing employers and compensation attainment. While there were no gender‐based compensation differences early in the careers of these individuals (in 1991), large pay differences favoring men were observed in 1999 only among those who had followed an external labor market strategy. These results demonstrate that this phenomenon is not isolated to labor markets of the United States and strengthen the view that much of the observed pay differential favoring men has its origins in extra‐firm mobility, not intra‐firm gender discrimination. Copyright © 2004 John Wiley & Sons, Ltd.
Voluntary employee turnover: combining variables from the ‘traditional’ turnover literature with the theory of planned behavior
Authors: van Breukelen Wim , van der Vlist René , Steensma Herman 
Published: September 2004

AbstractIn this study we tried to answer the question of whether the three predictors from the theory of planned behavior provide a satisfactory explanation for intentions and behaviors in the context of voluntary employee turnover. We examined whether variables which have traditionally played a prominent role in the study of turnover, i.e., job satisfaction, organizational commitment, age, and tenure, were capable of explaining additional variance in turnover intentions and voluntary turnover. We conducted a longitudinal study in which 296 respondents serving as professionals in the Royal Netherlands Navy completed a questionnaire. Half a year later they were asked to answer a second identical questionnaire; data were obtained from 202 participants who answered all relevant questions in both questionnaires. Their actual behavior (staying versus leaving) was registered during a 2‐year period following the completion of the first questionnaire. Behavioral intentions proved to be the best predictor of turnover in which the effects of all other variables were accounted for. Job satisfaction and tenure explained a significant proportion of the variance in intentions after the effects of the predictors from the theory of planned behavior had been taken into account. The results are discussed in relation to theoretical, methodological, and practical issues. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of Fe compounds on nutrient uptake by plants grown in sand media with different pH
Authors: Ylivainio Kari , Jaakkola Antti , Aksela Reijo 
Published: September 2004

AbstractThe effect of soil and foliar application of different iron (Fe) compounds (FeSO4, Fe‐EDTA, Fe‐EDDS, and Fe‐EDDHA) on nutrient concentrations in lettuce (Lactuca sativa cv. Australian gelber) and ryegrass (Lolium perenne cv. Prego) was investigated in a greenhouse pot experiment using quartz sand as growth medium. Soil application was performed in both the acidic and alkaline pH range, and foliar application to plants grown in the alkaline sand only. Lettuce growth was depressed by Fe deficiency in the alkaline sand, whereas the treatments had no effect on ryegrass growth. Soil‐applied Fe compounds raised the Fe concentrations in lettuce. This was especially true for the Fe chelates, which also increased yields. Soil‐applied Fe compounds had no statistically significant effect on Fe concentrations in ryegrass. Concentrations of manganese (Mn) in lettuce were equally decreased by all soil‐applied chelates. In the alkaline sand, soil application of Fe‐EDDHA elevated copper (Cu) and depressed zinc (Zn) concentrations in lettuce. The chelates increased Zn concentration in ryegrass. Foliar application of Fe‐EDDS increased Fe concentrations in lettuce and in ryegrass most. Fe‐EDDHA depressed Mn and Zn concentrations in lettuce more than other Fe compounds, suggesting the existence of another mechanism, in addition to Fe, that transmits a corresponding signal from shoot to roots with an impact on uptake of micronutrients.
Plant availability of catch crop sulfur following spring incorporation
Authors: Eriksen Jørgen , Thorup‐Kristensen Kristian , Askegaard Margrethe 
Published: September 2004

AbstractCatch crops might reduce sulfate leaching and thereby increase the overall sulfur (S)‐use efficiency in crop rotations. At two experimental sites in Denmark (a sandy loam and a coarse sand), S uptake of catch‐crop species was measured. Furthermore, net release of S following incorporation of this material (S contents 0.13%–1.03%, C:S ratios of 40–329, and lignin contents of 1%–10.8%) was investigated in a pot experiment with spring barley in sandy soil. The catch crops showed huge differences in their ability to sequester S. The best catch crops (legumes on sandy loam), sequestered 10–12 kg S ha–1, and the poorest catch crops (ryegrass and sorrel on coarse sand) sequestered less than 3 kg S ha–1. The S‐mineralization rates were highest for crucifers (57%–85% of total S added) and lowest for legumes (up to 46% of total S added). Differences can partly be explained by the C:S ratio, whereas no significant relationship was found with the lignin content of the incorporated catch crops. Catch crops may help to avoid S deficiency and increase synchrony between plant demand and available soil S in a crop rotation. However, the release of S will not fulfil the need of S‐demanding crops and even for cereals, the mineralization will most often only make a contribution. In the case of legume catch crops, it is advisable to use a supplemental S source.