bluuebunny/crossref_metadata_2025_split huggingface dataset:
Midgut proteases from Mamestra configurata (Lepidoptera: Noctuidae) larvae: Characterization, cDNA cloning, and expressed sequence tag analysis
Authors: Hegedus Dwayne , Baldwin Doug , O'Grady Michael , Braun Lorraine , Gleddie Steve , Sharpe Andrew , Lydiate Derek , Erlandson Martin 
Published: April 2003

AbstractThe activities of digestive protease within the midgut of Mamestra configurata (bertha armyworm) larvae were examined using specific substrates and protease inhibitors. The bulk of the activity was associated with serine proteases comprising trypsin‐, chymotrypsin‐, and elastase‐like enzymes. At least 10–15 serine protease isozymes were detected using one‐dimension gelatin gel electrophoresis. Cysteine or aspartic protease activities were not present; however, amino‐ and carboxypeptidase activities were associated with the midgut extract. Midgut proteases were active in the pH range of 5.0–12.0 with peaks at pH 7.5 and 11.0. In general, the middle region of the midgut exhibited a higher pH (approximately 8.0) than either the posterior or anterior regions (approximately 7.3–7.7). Moulting larvae possessed a neutral gut pH that was 0.5–1.5 units below that of feeding larvae. Degenerate PCR and expressed sequence tag (EST)‐based approaches were used to isolate 30 distinct serine protease encoding cDNAs from a midgut‐specific cDNA library including 8 putative trypsins, 9 chymotrypsins, 1 elastase, and 12 whose potential activities could not be determined. cDNAs encoding three amino‐ and two carboxypeptidases were also identified. Larvae feeding upon artificial diet containing 0.2% soybean trypsin inhibitor experienced a significant delay in development. Arch. Insect Biochem. Physiol. 53:30–47, 2003. © 2003 Wiley‐Liss, Inc.
The connection between the research of a university and counts of links to its web pages: An investigation based upon a classification of the relationships of pages to the research of the host university
Authors: Thelwall Mike , Harries Gareth 
Published: April 2003

AbstractResults from recent advances in link metrics have demonstrated that the hyperlink structure of national university systems can be strongly related to the research productivity of the individual institutions. This paper uses a page categorization to show that restricting the metrics to subsets more closely related to the research of the host university can produce even stronger associations. A partial overlap was also found between the effects of applying advanced document models and separating page types, but the best results were achieved through a combination of the two.
Type/Token‐Taken informetrics
Authors: Egghe Leo 
Published: April 2003

AbstractType/Token‐Taken informetrics is a new part of informetrics that studies the use of items rather than the items itself. Here, items are the objects that are produced by the sources (e.g., journals producing articles, authors producing papers, etc.). In linguistics a source is also called a type (e.g., a word), and an item a token (e.g., the use of words in texts). In informetrics, types that occur often, for example, in a database will also be requested often, for example, in information retrieval. The relative use of these occurrences will be higher than their relative occurrences itself; hence, the name Type/Token‐Taken informetrics. This article studies the frequency distribution of Type/Token‐Taken informetrics, starting from the one of Type/Token informetrics (i.e., source–item relationships). We are also studying the average number μ* of item uses in Type/Token‐Taken informetrics and compare this with the classical average number μ in Type/Token informetrics. We show that μ* ≥ μ always, and that μ* is an increasing function of μ. A method is presented to actually calculate μ* from μ, and a given α, which is the exponent in Lotka's frequency distribution of Type/Token informetrics. We leave open the problem of developing non‐Lotkaian Type/Token‐Taken informetrics.
Adapting measures of clumping strength to assess term‐term similarity
Authors: Bookstein Abraham , Kulyukin Vladimir , Raita Timo , Nicholson John 
Published: April 2003

AbstractAutomated information retrieval relies heavily on statistical regularities that emerge as terms are deposited to produce text. This paper examines statistical patterns expected of a pair of terms that are semantically related to each other. Guided by a conceptualization of the text generation process, we derive measures of how tightly two terms are semantically associated. Our main objective is to probe whether such measures yield reasonable results. Specifically, we examine how the tendency of a content bearing term to clump, as quantified by previously developed measures of term clumping, is influenced by the presence of other terms. This approach allows us to present a toolkit from which a range of measures can be constructed. As an illustration, one of several suggested measures is evaluated on a large text corpus built from an on‐line encyclopedia.
Relevant term suggestion in interactive web search based on contextual information in query session logs
Authors: Huang Chien‐Kang , Chien Lee‐Feng , Oyang Yen‐Jen 
Published: April 2003

AbstractThis paper proposes an effective term suggestion approach to interactive Web search. Conventional approaches to making term suggestions involve extracting co‐occurring keyterms from highly ranked retrieved documents. Such approaches must deal with term extraction difficulties and interference from irrelevant documents, and, more importantly, have difficulty extracting terms that are conceptually related but do not frequently co‐occur in documents. In this paper, we present a new, effective log‐based approach to relevant term extraction and term suggestion. Using this approach, the relevant terms suggested for a user query are those that co‐occur in similar query sessions from search engine logs, rather than in the retrieved documents. In addition, the suggested terms in each interactive search step can be organized according to its relevance to the entire query session, rather than to the most recent single query as in conventional approaches. The proposed approach was tested using a proxy server log containing about two million query transactions submitted to search engines in Taiwan. The obtained experimental results show that the proposed approach can provide organized and highly relevant terms, and can exploit the contextual information in a user's query session to make more effective suggestions.
A novel method for discovering fuzzy sequential patterns using the simple fuzzy partition method
Authors: Chen Ruey‐Shun , Hu Yi‐Chung 
Published: April 2003

AbstractSequential patterns refer to the frequently occurring patterns related to time or other sequences, and have been widely applied to solving decision problems. For example, they can help managers determine which items were bought after some items had been bought. However, since fuzzy sequential patterns described by natural language are one type of fuzzy knowledge representation, they are helpful in building a prototype fuzzy knowledge base in a business. Moreover, each fuzzy sequential pattern consisting of several fuzzy sets described by the natural language is well suited for the thinking of human subjects and will help to increase the flexibility for users in making decisions. Additionally, since the comprehensibility of fuzzy representation by human users is a criterion in designing a fuzzy system, the simple fuzzy partition method is preferable. In this method, each attribute is partitioned by its various fuzzy sets with pre‐specified membership functions. The advantage of the simple fuzzy partition method is that the linguistic interpretation of each fuzzy set is easily obtained. The main aim of this paper is exactly to propose a fuzzy data mining technique to discover fuzzy sequential patterns by using the simple partition method. Two numerical examples are utilized to demonstrate the usefulness of the proposed method.
HelpfulMed: Intelligent searching for medical information over the internet
Authors: Chen Hsinchun , Lally Ann M. , Zhu Bin , Chau Michael 
Published: April 2003

AbstractMedical professionals and researchers need information from reputable sources to accomplish their work. Unfortunately, the Web has a large number of documents that are irrelevant to their work, even those documents that purport to be “medically‐related.” This paper describes an architecture designed to integrate advanced searching and indexing algorithms, an automatic thesaurus, or “concept space,” and Kohonen‐based Self‐Organizing Map (SOM) technologies to provide searchers with fine‐grained results. Initial results indicate that these systems provide complementary retrieval functionalities. HelpfulMed not only allows users to search Web pages and other online databases, but also allows them to build searches through the use of an automatic thesaurus and browse a graphical display of medical‐related topics. Evaluation results for each of the different components are included. Our spidering algorithm outperformed both breadth‐first search and PageRank spiders on a test collection of 100,000 Web pages. The automatically generated thesaurus performed as well as both MeSH and UMLS—systems which require human mediation for currency. Lastly, a variant of the Kohonen SOM was comparable to MeSH terms in perceived cluster precision and significantly better at perceived cluster recall.
Pharmacokinetic profile of a modified release formulation of trimetazidine (TMZ MR 35 mg) in the elderly and patients with renal failure
Authors: Barré J. , Ledudal P. , Oosterhuis B. , Brakenhoff J.P.G. , Wilkens G. , Sollie F.A.E. , Tran D. 
Published: April 2003

AbstractObjectives – To study the effect of age and renal function on the pharmacokinetic profile of a modified release tablet of trimetazidine (TMZ MR 35 mg) administered twice daily.Methods– Study 1: Twelve healthy elderly subjects (CLcreat 72±8 ml/min, 72±4 years mean±SD) and eight young volunteers (CLcreat 134±18 ml/min, 25±8 years) received TMZ MR 35 mg b.i.d. (eight doses). Study 2: eight patients with severe renal failure (CLcreat. 17±5 ml/min, 54±10 years), five patients with moderate renal failure (CLcreat. 39±6 ml/min, 54±15 years) and eight volunteers (CLcreat. 104±17 ml/min, 53±9 years) received TMZ MR 35 mg b.i.d. (patients: ten doses, volunteers: eight doses). Serial blood and urine samples were obtained following administration of the last dose in each study. TMZ plasma and urine concentrations were determined by gas chromatography (NPD‐detector). The resulting data were analysed using standard non‐compartmental pharmacokinetic methods.Results– Study 1: Elimination half‐life of TMZ was significantly longer and renal clearance significantly lower in the elderly subjects. Study 2: In patients with either moderate or severe renal failure, exposure (AUC0–24) was significantly increased and renal clearance (CLR) was significantly decreased. Significant correlations were observed between CLcreat and CLR (r=0.94) and between CLcreat and AUC0–24 (r=−0.94).Conclusion – With repeated administration of TMZ MR 35 mg b.i.d., a decrease in CLcreat is directly related to a decrease in CLR and results in an increase in exposure to TMZ. Copyright © 2003 John Wiley & Sons, Ltd.
Impact of solutol HS 15 on the pharmacokinetic behaviour of colchicine upon intravenous administration to male Wistar rats
Authors: Bittner Beate , González Roberto Carlos Bravo , Walter Isabelle , Kapps Martin , Huwyler Jörg 
Published: April 2003

AbstractIn the current investigation, the alkaloid colchicine was administered intravenously to male Wistar rats both as a solution in isotonic sodium chloride (NaCl 0.9%, control group) and in NaCl 0.9%:Solutol HS 15 (95:5) at 1.5 mg/kg. At predetermined time points, plasma and urine were collected from the animals and analysed for colchicine and its demethylated metabolites by LC/MS‐MS.In the presence of Solutol HS 15, colchicine clearance (CI) was significantly decreased and its maximum plasma concentration (cmax) was significantly increased as compared to the control group (CI: 15.6±7.0 ml/min/kg vs 34.3±2.3 ml/min/kg; cmax 3055.1±587.4 h vs 1260.1±223.7 h; p<0.05). Moreover, the amount of parent colchicine excreted into urine was markedly increased in the Solutol HS 15 treated group (41.50±3.23 vs 1.17±0.41% of total dose; p<0.05). By contrast, there was no statistically significant difference but a trend to lower values only in the volume of distribution (Vd 13.3±2.2 l/h vs 31.4±17.7 l/h, p=0.35). The half‐lives for the first (t1/2 1stphase. 0.21±0.02 h vs 0.20±0.03 h) and second phase (t1/2 2ndphase. 18.5±6.9 h vs 18.3±7.7 h) did not differ significantly in dependence on the dosing vehicle. The free fraction in rat plasma (FF), the blood/plasma (λ) and erythrocyte/plasma concentration ratios (Ke) were not significantly changed in the presence of different concentrations of Solutol HS 15 compared with surfactant‐free incubations (overall means: 72.25±0.50% for FF, 0.80±0.02 for λ, 0.46±0.04 for Ke). In vitro, in rat hepatocytes, the clearance of colchicine was significantly reduced at 0.003% Solutol HS 15 present in the incubation medium (0.86±0.15 μl/min/10−6 cells vs 1.46±0.06 μl/min/10−6 cells). As colchicine exhibits a comparatively high aqueous solubility, an impact of Solutol HS 15 on the solubility of the alkaloid is very unlikely to be a reason for the observed effect. Therefore, our results indicate that the most likely reasons for the changed pharmacokinetic behaviour of colchicine in the presence of Solutol HS 15 are alterations of metabolism and/or transport as well as distribution and elimination processes. Copyright © 2003 John Wiley & Sons, Ltd.
Pharmacokinetics of an ultralong sustained‐release theophylline formulation when given twice daily in elderly patients with chronic obstructive pulmonary disease: Monitoring implications
Authors: Armijo Juan A. , Sánchez Blanca M. , Peralta F. Galo , González‐Ruiz Mario , Cuadrado Antonio , Verdejo Asunción , Cos María A. de , Arjona Rafael 
Published: April 2003

AbstractThe steady‐state pharmacokinetics of an ultralong sustained release formulation of theophylline (Unilong®) twice daily (bid) in elderly hospitalized patients suffering from chronic obstructive pulmonary disease (COPD) have been studied in order to establish guidelines for monitoring. The study was carried out in 37 patients (33 men), aged 60–87 years. Samples were collected from 0 to 12 h after the morning dose on day 9 of treatment with 250 mg bid (n=25) or 375 mg bid (n=12). Considerable variability in apparent clearance (range 0.33–1.49 ml/min per kg of ideal body weight), Cssmin/D (range 0.28–1.86), Cssmax/D (range 0.65–2.33) and (Cssmax–Cssmin)/Cssavg (range 0.18–0.80) was observed. There was no significant correlation between the patient's age and apparent clearance within this elderly population. The concentration‐to‐dose ratio and the relationship between the steady‐state plasma concentration at different times during the dosage interval and Cssavg are described. It is concluded that the interpatient variability in peak‐trough fluctuation of this formulation was higher than that described in healthy volunteers by other investigators, and that the apparent clearance did not decrease with age within this elderly population with COPD. The importance of theophylline monitoring is emphasized and rules to estimate Cssavg and Css5h from Css0h when only a single sample obtained before the morning dose is available are given. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of procaine hydrochloride using flow injection inhibitory chemiluminescence
Authors: Li Nianbing , Chi Yuwu , Wang Jian , Duan Jianping , Chen Guonan 
Published: April 2003

AbstractA new flow injection chemiluminescent method has been developed for the determination of procaine hydrochloride, based on the inhibition of the chemiluminescence reaction of luminol–hydrogen peroxide by procaine hydrochloride. The influence of several surfactants and β‐cyclodextrin on the chemiluminescence intensity were studied. It was found that β‐cyclodextrin enhanced the decrease in chemiluminescence intensity. The method is simple, convenient and sensitive, with a detection limit (3 σ) of 0.08 µg/mL. The decreased chemiluminescence intensity is linear, with the concentration of procaine hydrochloride in the range 0.2–100.0 µg/mL and 100.0–400.0 µg/mL. The relative standard deviation for 10 repeated measurements were 4.5% and 3.4% for 1.0 and 20.0 µg/mL procaine hydrochloride, respectively. The method has been successfully applied to the determination of procaine hydrochloride in injection solutions of this drug. Copyright © 2003 John Wiley & Sons, Ltd.
Comparison of the spectral emission of lux recombinant and bioluminescent marine bacteria
Authors: Thouand Gérald , Daniel Philippe , Horry Habib , Picart Pascal , Durand Marie José , Killham Ken , Knox Oliver GG , DuBow Michael S , Rousseau Michel 
Published: April 2003

AbstractThe purpose of the present paper was to study the influence of bacteria harbouring the luciferase‐encoding Vibrio harveyi luxAB genes upon the spectral emission during growth in batch‐culture conditions. In vivo bioluminescence spectra were compared from several bioluminescent strains, either naturally luminescent (Vibrio fischeri and Vibrio harveyi) or in recombinant strains (two Gram‐negative Escherichia coli::luxAB strains and a Gram‐positive Bacillus subtilis::luxAB strain). Spectral emission was recorded from 400 nm to 750 nm using a highly sensitive spectrometer initially devoted to Raman scattering. Two peaks were clearly identified, one at 491–500 nm (± 5 nm) and a second peak at 585–595 (± 5 nm) with the Raman CCD. The former peak was the only one detected with traditional spectrometers with a photomultiplier detector commonly used for spectral emission measurement, due to their lack of sensitivity and low resolution in the 550–650 nm window. When spectra were compared between all the studied bacteria, no difference was observed between natural or recombinant cells, between Gram‐positive and Gram‐negative strains, and growth conditions and growth medium were not found to modify the spectrum of light emission. Copyright © 2003 John Wiley & Sons, Ltd.
Transient formation of the oxo–iron(IV) porphyrin radical cation during the reaction of iron(III) tetrakis‐5,10,15,20‐(N‐methyl‐4‐pyridyl)porphyrin with hydrogen peroxide in aqueous solution
Authors: Saha Tapan Kumar , Karmaker Subarna , Tamagake Keietsu 
Published: April 2003

AbstractThe reaction of iron(III) tetrakis‐5,10,15,20‐(N‐methyl‐4‐pyridyl)porphyrin (Fe(III)TMPyP) with hydrogen peroxide (H2O2) and the catalytic activity of the reaction intermediates on the luminescent peroxidation of luminol in aqueous solution were studied by using a double‐mixing stopped‐flow system. The observed luminescence intensities showed biphasic decay depending on the conditions. The initial flashlight decayed within <1 s followed by a sustained emission for more than 30 s. Computer deconvolution of the time‐resolved absorption spectra under the same conditions revealed that the initial flashlight appeared during the formation of the oxo–iron(IV) porphyrin, TMPyPFe(IV) = O, which is responsible for the sustained emission. The absorption spectra 0.0–0.5 s did not reproduce well by a simple combination of the two spectra of Fe(III)TMPyP and TMPyPFe(IV) = O, indicating that transient species was formed at the initial stage. Addition of uric acid (UA) caused a significant delay in the initiation of the luminol emission as well as in the formation of the TMPyPFe(IV) = O. Both of them were completely diminished in the presence of UA equimolar with H2O2, while mannitol had no effect at all. The delay of the light emission as well as the appearance of TMPyPFe(IV) = O was directly proportional to the [UA]0 but other kinetic profiles were not changed significantly. Based on these observations and the kinetic analysis, we confirmed the involvement of the oxo–iron(IV) porphyrin radical cation, (TMPyP)·+Fe(IV) = O, as an obligatory intermediate in the rate‐determining step of the overall reaction, Fe(III)TMPyP + H2O2 → TMPyPFe(IV) = O, with a rate constant of k = 4.3 × 104/mol/L/s. The rate constants for the reaction between the (TMPyP)·+Fe(IV) = O and luminol, and between the TMPyPFe(IV) = O and luminol were estimated to be 3.6 × 106/mol/L/s and 1.31 × 104/mol/L/s, respectively. Copyright © 2003 John Wiley & Sons, Ltd.
Interaction of aromatic compounds with Photobacterium leiognathi luciferase: fluorescence anisotropy study
Authors: Kudryasheva N. S. , Nemtseva E. V. , Visser A. J. W. G. , van Hoek A. 
Published: April 2003

AbstractThe time‐resolved and steady‐state fluorescence techniques were employed to elucidate possible interactions of four aromatic compounds (anthracene, POPOP, MSB and 1,4‐naphthalendiol) with bacterial luciferase. Fluorescence spectra and fluorescence anisotropy decays of these compounds were studied in ethanol, water–ethanol solutions and in the presence of bacterial luciferase. Shifts of fluorescent spectra and differences in rotational correlation times are interpreted in terms of weak (hydrophobic) interactions of the molecules with the enzyme. These interactions suggest the feasibility of intermolecular energy transfer by an exchange resonance mechanism with a collision‐interaction radius as a way of excitation of these compounds in the reaction catalysed by bacterial luciferase. Copyright © 2003 John Wiley & Sons, Ltd.
Measurement of adenine nucleotides in plasma
Authors: Gorman Mark W. , Marble David R. , Ogimoto Kayoko , Feigl Eric O. 
Published: April 2003

AbstractThe goal of this study was to identify the most important variables affecting bioluminescent ATP, ADP and AMP measurements in plasma and to develop an assay that takes these variables into account. Blood samples were drawn from conscious dogs. A ‘stop solution’ containing EDTA was prepared, which greatly retarded plasma ATP degradation by chelating Mg+2 and Ca+2 that are co‐factors for many ATPases. Stop solution and blood were mixed using a two‐syringe withdrawal system. Samples were centrifuged twice in order to remove red blood cells, and ATP was measured in the supernatant using the firefly luciferase assay. Sample pH was adjusted to the optimal range (7.75–7.95) and Mg2+ (necessary for the luciferase reaction) was added back to the sample within the luminometer 2 s prior to luciferase addition. Four assay tubes were prepared for each plasma sample, containing standard additions of 0–15 pmol added ATP, in order to quantify native plasma ATP content. In separate plasma/stop solution samples ADP + ATP was measured after converting ADP to ATP via the pyruvate kinase reaction, and AMP + ADP + ATP was measured after addition of both myokinase and pyruvate kinase. Addition of forskolin and isobutylmethylxanthine (IBMX) to the stop solution to inhibit platelets resulted in lower ATP concentrations. Measurement of ATP and haemoglobin from lysed erythrocytes revealed that haemolysis exerts a strong influence on plasma ATP concentration that must be taken into account. Copyright © 2003 John Wiley & Sons, Ltd.