bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid determination method of caffeine and application to monitoring of caffeine‐assisted chemotherapy
Authors: Kawahara Masami , Kagiyama Hiromi , Kanazawa Yoshimitsu , Tsuchiya Hiroyuki , Tomita Katsuro , Yokogawa Koichi , Miyamoto Ken‐ichi 
Published: February 2004

AbstractCaffeine‐assisted chemotherapy for bone and soft tissue tumours is very effective. However, high serum caffeine concentrations cause severe side effects, so monitoring of the serum level during therapy is important. For this purpose, a rapid determination method was established by high‐performance liquid chromatography after solid‐phase extraction. This method can measure caffeine and its three major metabolites in serum samples within 8 min. The mean serum caffeine concentrations of patients were 34.6±7.8, 54.5±11.9 and 73.0±12.8 μg/ml at 24, 48 and 72 h, respectively, after the start of a 1500 mg/m2/day continuous infusion for 72 h. The distribution volume of caffeine was 0.65±0.23 l/kg, and the total body clearance was 0.025±0.011 l/h/kg, which was one‐third of the reported low dose clearance. The appropriate infusion rate was calculated to avoid severe side effects in the final phase of the infusion by using a one‐compartment constant infusion model based on the serum levels measured at 24 and 48 h. Caffeine clearance did not correlate with the metabolite/caffeine ratio in serum at any time. It is concluded that individual monitoring with this method for the purpose of dose adjustment is useful for avoiding the side effects of caffeine‐assisted chemotherapy. Copyright © 2004 John Wiley & Sons, Ltd.
Evaluation of pharmacokinetics, brain levels and protein binding of centpropazine in rats
Authors: Bhattaram Venkatesh Atul , Paliwal Jyoti K. , Gupta Ram C. 
Published: February 2004

AbstractThe pharmacokinetics of centpropazine (CNPZ), an antidepressant, was studied in rats. CNPZ was administered to groups of rats (n=3 to 5) via oral (40 mg/kg), intravenous (5 mg/kg), intraperitoneal (5 mg/kg) and intraduodenal (4 and 8 mg/kg) routes. The AUCs of CNPZ were estimated and the bioavailabilities were calculated. CNPZ was characterized by a short elimination half‐life (39.5 min), a high clearance (118 ml/min/kg) and a relatively large volume of distribution (1945 ml/kg) after intravenous administration. After oral administration CNPZ exhibited a very low oral bioavailability (∼0.2%). The total first pass effect (Egit+liver) was calculated as 98.7%. The bioavailability of CNPZ was similar when administered by intraduodenal and oral routes. CNPZ readily penetrated into the brain and reached Cmax by 30 min post oral dosing. About 92.0%±0.8% of the drug was bound to serum proteins. Low oral bioavailability of CNPZ following oral administration is likely due to its metabolism by intestinal mucosa and liver. Copyright © 2004 John Wiley & Sons, Ltd.
Pharmacokinetics of HEPP, a new anticonvulsant, in healthy subjects and rabbits after multiple doses
Authors: González‐Esquivel Dinora F. , Pérez M Rodolfo , Cook Helgi Jung 
Published: February 2004

AbstractIn the present study the pharmacokinetics of D,L‐3hydroxy‐3‐phenylpropionamide (HEPP) a new anticonvulsant compound was studied after multiple dose administration in healthy male volunteers and in rabbits. The study in humans involved the oral administration of 375mg of HEPP b.i.d. for 7 consecutive days. The study in rabbits explored doses of 30mg/kg intraperitoneal (i.p.) given once daily for 6 days. In both studies pharmacokinetic (PK) profiles were characterized after the first dose and after the last multiple dose. Plasma HEPP concentrations were measured by HPLC. Pharmacokinetic parameters were calculated by noncompartmental methods. The results in humans as well as in rabbits showed that after multiple doses the AUC values decreased and CL/F values were significantly increased, which could be due to an induction process in the metabolic disposition of the drug. Copyright © 2004 John Wiley & Sons, Ltd.
In vitro dissolution and in vivo oral absorption of methylphenidate from a bimodal release formulation in healthy volunteers
Authors: Wang Yanfeng , Lee Lucy , Somma Russell , Thompson Glenn , Bakhtiar Ray , Lee James , Rekhi Gurvinder Singh , Lau Henry , Sedek Greg , Hossain Mohammad 
Published: February 2004

AbstractPurpose—The objective of this study was to evaluate the in vitro dissolution and in vivo absorption of D,L‐threo‐methylphenidate (MPH) from a novel bimodal release formulation (Ritalin® LA capsule) compared with an immediate‐release formulation (Ritalin IR tablet) in healthy volunteers.Methods—The bimodal release formulation contains 50% of the dose in the immediate‐release (IR) beads and 50% in polymethacrylate‐coated, delayed‐release (DR) beads. To better understand the impact of dissolution from the DR beads on oral absorption of MPH, three Ritalin LA formulations with different dissolution profiles for the DR beads (referred to as slow‐, medium and fast‐release formulations) were prepared, and tested together with the immediate‐release formulation in 18 healthy male and female volunteers after a single oral dose under fasted conditions. The rate and extent of oral absorption of MPH were evaluated based on the overall Cmax, tmax and AUC values, as well as the Cmax, tmax and AUC values for each individual peak of the bimodal plasma concentration‐time profile. The in vivo absorption‐time profile was also examined by deconvolution.Results—All three Ritalin LA formulations demonstrated similar bimodal plasma concentration–time profiles with two peak concentrations observed at ∼2 and ∼6 h post dose, mimicking that of Ritalin IR tablets given 4 h apart. Deconvolution results showed that the absorption of MPH was biphasic, with a rapid absorption phase between 0 to ∼2 h, and a somewhat slower second absorption between ∼3–6 h, consistent with the in vitro bimodal release characteristics of Ritalin LA formulation. The three Ritalin LA formulations were bioequivalent to one another based on the overall Cmax and AUC values and the corresponding values describing the first and second peaks, although their in vitro dissolution profiles for the DR beads were different. Compared with Ritalin IR, the Ritalin LA formulation demonstrated a similar rate of absorption for the first peak, a lower second Cmax and a higher trough concentration between peaks, as well as similar overall plasma AUC.Conclusions—Following a single oral drug administration, Ritalin LA demonstrated a two‐peak plasma concentration–time profile, similar to that of the IR formulation given 4 h apart, but with less fluctuation in the plasma concentration–time profile. The in vivo biphasic absorption of MPH appeared to be well correlated with the bimodal dissolution characteristics of this new Ritalin LA formulation, and some changes in the dissolution profiles for the DR beads appeared not to affect the overall bioavailability of MPH in humans. Copyright © 2004 John Wiley & Sons, Ltd.
Photoinduced Interactions Between Oxidized and Reduced Lipoic Acid and Riboflavin (Vitamin B2)
Authors: Lu Changyuan , Bucher Götz , Sander Wolfram 
Published: February 2004

AbstractAs a powerful natural antioxidant, lipoic acid (LipSS) and its reduced form dihydrolipoic acid (DHLA) exert significant antioxidant activities in vivo and in vitro by deactivation of reactive oxygen and nitrogen species (ROS and RNS). In this study the riboflavin (RF, vitamin B2) sensitized UVA and visible‐light irradiation of LipSS and DHLA was studied employing continuous irradiation, fluorescence spectroscopy, and laser flash photolysis (LFP). Our results indicate that LipSS and DHLA quench both the singlet state (1RF*) and the triplet state (3RF*) of RF by electron transfer to produce the riboflavin semiquinone radical (RFH.) and the radical cation of LipSS and DHLA, respectively. The radical cation of DHLA is rapidly deprotonated twice to yield a reducing species; the radical anion of LipSS (LipSS.−). When D2O was used as solvent, it was confirmed that the reaction of LipSS with 3RF* consists of a simple electron‐transfer step, while loss of hydrogen occurs in the case of DHLA oxidation. Due to the strong absorption of RFH. and the riboflavin ground state, the absorption of the radical cation and the radical anion of LipSS can not be observed directly by LFP. N,N,N′,N′‐tetramethyl‐p‐phenylenediamine (TMPD) and N,N,N′,N′‐tetramethyl benzidine (TMB) were added as probes to the system. In the case of LipSS, the addition resulted in the formation of the radical cation of TMPD or TMB by quenching of the LipSS radical cation. If DHLA is the reducing substrate, no formation of probe radical cation is observed. This confirms that LipSS.+ is produced by riboflavin photosensitization, and that there is no oxidizing species produced after DHLA oxidization.
Synthesis of Silver and Gold Nanoparticles by a Novel Electrochemical Method
Authors: Ma Houyi , Yin Bingsheng , Wang Shuyun , Jiao Yongli , Pan Wei , Huang Shaoxin , Chen Shenhao , Meng Fanjun 
Published: February 2004

AbstractSpherical silver and gold nanoparticles with narrow size distributions were conveniently synthesized in aqueous solution by a novel electrochemical method. The technological keys to the electrochemical synthesis of monodispersed metallic nanoparticles lie in the choice of an ideal stabilizer for the metallic nanoclusters and the use of a rotating platinum cathode. Poly(N‐vinylpyrrolidone) (PVP) was chosen as the stabilizer for the silver and gold clusters. PVP not only protects metallic particles from agglomeration, but also promotes metal nucleation, which tends to produce small metal particles. Using a rotating platinum cathode effectively solves the technological difficulty of rapidly transferring the (electrochemically synthesized) metallic nanoparticles from the cathode vicinity to the bulk solution, avoiding the occurrence of flocculates in the vicinity of the cathode, and ensuring the monodispersity of the particles. The particle size and particle size distribution of the silver and gold nanoparticles were improved by adding sodium dodecyl benzene sulfonate (SDBS) to the electrolyte. The electrochemically synthesized nanoparticles were characterized by TEM and UV/Vis spectroscopy.
Performance evaluation of TCP session considering long‐range dependence of RTT
Authors: Hagiwara Tatsuya , Matsuda Takahiro , Yamamoto Miki 
Published: February 2004

AbstractRecent research has shown that long‐range dependence is found not only in network traffic volume, but also in the propagation delay time of packets. The round‐trip propagation time of packets, which is known as the round‐trip time (RTT), is one of the most important parameters for determining TCP performance. The ability to understand its characteristics can contribute to an improvement in TCP performance. Therefore, in this paper, to determine the impact of the long‐range dependence of the RTT on TCP performance, the authors looked at the two congestion control phases known as congestion avoidance and slow start in TCP window control and used computer simulations to evaluate performance. First, the evaluation related to the impact on the congestion avoidance phase showed that higher long‐range dependence and larger transfer files caused greater variability in the file transfer completion time. Next, the evaluation related to the impact on the slow start phase, which evaluated the impact of the long‐range dependence of the RTT on the TCP retransmission timeout (RTO), showed that higher long‐range dependence causes unnecessary timeouts, which end up causing the resending of packets that have not actually been lost, to occur more frequently. The authors also performed investigations for mitigating the impact of the long‐range dependence of the RTT and made a number of modifications to the existing RTO estimation algorithm to show that TCP performance can be improved. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(6): 52–60, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10073
Synchronous CSMA/CD on PTMP access networks
Authors: Kobayashi Hiroshi , Ozawa Kazuyoshi , Kamura Koichirou , Moriya Osamu 
Published: February 2004

AbstractIn order to realize high‐speed Internet access on PTMP access networks such as bidirectional CATV, the Synchronous CSMA/CD method has been developed. The main points are that, when multiple packets collide, the collision state always starts from the head of the colliding packets by synchronizing the arrival of the packets at the hub device with the predetermined timing, and that the hub device always monitors the access status of the uplink and broadcasts the status through the downlink. As a result, the CSMA/CD method can be applied to PTMP networks, and the maximum network length can be arbitrarily set without dependence on the minimum packet length. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(6): 43–51, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10074
Beat interference suppression techniques by means of transmission diversity and adaptive equalization
Authors: Kubo Hiroshi , Okazaki Akihiro , Tanada Kazuo , Murakami Keishi 
Published: February 2004

AbstractIn this paper, we discuss techniques for transmitting signals over the same frequency by synchronizing multiple base stations in order to achieve both high communication quality and excellent spectral efficiency in broadcast (P‐MP: Point to Multipoint) communication (single‐frequency, multistation simultaneous transmission). Specifically, in this paper, we propose a communication technique that uses the concept of transmission diversity and converts beat interference to intersymbol interference to suppress beat interference, which becomes a problem in single‐frequency, multistation simultaneous transmission. The proposed technique features (1) controlling the transmit timing or waveform of the signal transmitted from each base station, and (2) using an adaptive equalizer to compensate for intersymbol interference produced during transmission. Finally, we assume a high‐speed Rayleigh fading environment in addition to a beat interference environment in computer simulations and demonstrate the effectiveness of the proposed technique when maximum likelihood sequence estimation based on per‐survivor processing is adopted. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(6): 12–21, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10167
Production of a Laccase and Decrease of the Phenolic Content in Canola Meal during the Growth of the Fungus Pleurotus ostreatus in Solid State Fermentation Processes
Authors: Hu J. , Duvnjak Z. 
Published: February 2004

AbstractSolid state fermentation of canola meal was carried out with the fungus Pleurotus ostreatus DAOM 197961, which is a producer of laccase. The aim of this study was to examine the effects of moisture content, inoculum size, homogenisation of inoculum and particle size of canola meal on the growth of the fungus, the production of a laccase and the decrease of the content of sinapic acid esters (SAE) in a solid state process. The results showed that the optimum moisture content, which was varied in the media between 50% and 75%, for the growth and enzyme production was 60%. The initial rate of SAE content decrease was faster in the media with 70% and 75% moisture than in those with lower moisture levels. In the study of the effects of inoculum concentration in the range of 1.1 mg to 5.5 mg/g of the medium, it was found that larger amounts of biomass and enzyme were produced in the media with inoculum concentrations from 1.1 mg to 3.3 mg/g of the medium than in the media with a higher inoculum concentration. The final and approximately the same concentrations of SAE were reached at the same time regardless of the inoculum concentration. Considering that the fungus formed pellets under the conditions at which it was grown during the inoculum preparation, it was necessary to break them by homogenisation prior to their utilisation as an inoculum. The homogenisation was carried out during a period between 15&#129;s and 200&#129;s. Although higher biomass concentrations and enzyme activities were obtained in the media which were inoculated with the inoculum homogenised for 15&#129;s and 30&#129;s, the maximum enzyme activities and biomass concentrations were reached in the media inoculated with the inoculum, which was homogenised for 120&#129;s and 200&#129;s. The time of inoculum homogenisation did not influence the kinetics of the SAE decrease. When the effects of the particle size of canola meal on the process were studied, it was found that larger particles of the meal in the solid media were more favourable for the production of the biomass and enzyme, and for a faster decrease of the SAE content than those of smaller sizes. From the obtained results it can be concluded that the tested variables have a significant influence on the growth of the fungus Pleurotus ostreatus DAOM 197961, the production of laccase and the decrease of the SAE content in canola meal. The data could be useful for the development of a solid state process for the production of laccase and for the decrease of the phenolics content in canola meal.
Carbon Dioxide Emission in Relation to the Growth of Geotrichum candidum in Solid Cultures
Authors: Couzon S. , Couriol C. , Amrane A. , Prigent Y. 
Published: February 2004

AbstractGeotrichum candidum plays an important role in the ripening of Camembert‐type cheeses. However, the direct measurement of the biomass concentration is rather tedious and, therefore, the development of alternative methods for monitoring the growth on solid media would be very useful. For this purpose, a non‐structured model was previously developed to describe the CO2 emission during the growth of G. candidum in liquid cultures. The CO2 production was assumed to be partially associated with growth: a part resulted from growth and the remaining from cellular maintenance. This model has also been validated in solid cultures on peptone‐lactate based medium. The coefficients for growth‐associated and non‐growth‐associated production were found to be 0.301 and 0.123 per day, respectively. Therefore, the CO2 production may be a non‐destructive and useful tool to monitor fungal growth in solid cultures. In the case of mixed cultures of both fungi (Geotrichum candidum and Penicillium camembertii) involved in the ripening of Camembert cheeses, CO2 emission can be related to the total viable biomass, while ammonia and volatile sulphur compounds can be linked to G. candidum biomass. Indeed, it was previously shown that Penicillium camembertii released only very low amounts of both compounds.
New Developments in Chemical Engineering for the Production of Drug Substances
Authors: Behr A. , Brehme V.A. , Ewers Ch.L.J. , Grön H. , Kimmel T. , Küppers S. , Symietz I. 
Published: February 2004

AbstractThe pharmaceutical industry is moving towards a profitability gap between increasing costs and decreasing prices. Finally, management has understood that mergers and acquisitions, high throughput screening, and biotechnology alone will not save the companies' earnings. Therefore, classical approaches like the optimization of production technologies for drug substances, that might help to increase profitability, are receiving increasing attention. This paper shows how the combination of innovative components will guide the way to very efficient and cost‐effective production. The first component is the design and manufacturing of production facilities. The second component is a process streamlining of the production process. The key technologies discussed here are process control and miniplant technology. For these technologies a brief outlook on future trends is given.
Test of Porous Ceramic Material for the Immobilisation of Predominant Nitrifying Bacteria and for the Improvement of the AAO Process
Authors: Lee J.M. , Choi I.S. , Wiesmann U. 
Published: February 2004

AbstractThe efficiency of nitrification in a fixed bed reactor was compared to that found in an activated sludge reactor to determine their sensitivity to changing loads and lower temperatures. Two structurally identical lab‐scale systems, using the anaerobic/anoxic/aerobic (AAO) process to remove nitrogen and phosphorus simultaneously, were operated in parallel with secondary clarifiers and sludge return. The first aerobic system was operated as an activated sludge reactor, the second system as a fixed bed reactor. The aerobic fixed bed reactor was filled with porous ceramic materials for the immobilisation of predominantly nitrifying bacteria. The removal efficiencies of 99 % NH4+‐N, 90 % DOC, and 98 % PO43–‐P for normal loads of 0.11 g/L d DOC, 0.06 g/L d NH4+‐N, and 0.0054 g/L d PO43–‐P were achieved for both systems. However, the system with an aerobic fixed bed reactor was characterised by the following advantages over the system with an activated sludge reactor: a shorter time to reach almost complete nitrification, a higher nitrification rate at higher loads of NH4+‐N and a lower sensitivity of nitrification at lower temperatures down to 12 °C.
Visualization of Differential Gene Expression – Using Fluorescence‐Based cDNA‐AFLP
Authors: Gigliotti S. , Hausman J.‐F. , Evers D. 
Published: February 2004

AbstractcDNA‐AFLP is one of the techniques developed to study differentially expressed genes. This recent technique is advantageous because it does not need prior sequence knowledge and is reliable due to highly stringent PCR conditions.The traditional cDNA‐AFLP method uses radioactively labelled products and is characterised by high sensitivity and resolution. Here, the use of Cy5‐labelled primers to detect products on polyacrylamide gels is reported. This non‐radioactive method, based on fluorescence, is shown to be faster and the recovery of interesting bands is easier.The study of the differential gene expression of the interaction between potato and Phytophthora infestans was used for the valuation of this method.Different gene expression profiles – such as up‐regulation, down‐regulation or point expression – were obtained. Moreover, this technique was shown to be highly reproducible.
Improving the Production of Ectomycorrhizal Fungus Mycelium in a Bioreactor by Measuring the Ergosterol Content
Authors: Carrillo C. , Díaz G. , Honrubia M. 
Published: February 2004

AbstractThe cultivation of some ectomycorrhizal fungi growing in bioreactors under submerged aerobic conditions was modified by regulating the cultivation parameters and determining the optimum duration of the process. For this goal, the active mycelium was determined by quantifying its ergosterol content.Lactarius deliciosus(strain LDF5) andSuillus mediterraneensis(strain 35 AM) were cultivated in a BRAUN Biostat®B bioreactor under the following fermentation conditions: 23 °C, pH 5.5, 60&#146;% dissolved oxygen, 100 rpm stirring, and 1.2‐‐2 L/min air flow. In addition, several cultivation conditions were assayed forL. deliciosus. During the fermentation cycle, samples were taken at different times. Ergosterol was extracted and quantified using high‐performance liquid chromatography (HPLC). The quantity of ergosterol inL. deliciosusincreased with the age of the culture up to 4.7 μg/mg (17‐day‐old culture). In the case ofS. mediterraneensis, this quantity increased up to day 11 of the cultivation, and then it decreased. Three days after the addition of fresh medium, a maximum of 8.9 μg/mg was reached. On the other hand, the highest ergosterol content inL. deliciosus(6.3 μg/mg) was obtained using MMN medium with the addition of agar.