| 1. |
- Cho, Jeong-woo, 1978-, et al.
(författare)
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Dynamic Buffer Management Scheme Based on Rate Estimation in Packet-Switched Networks
- 2002
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Ingår i: Computer Networks. - : Elsevier. - 1389-1286 .- 1872-7069. ; 39:6, s. 769-787
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Tidskriftsartikel (refereegranskat)abstract
- While traffic volume of real-time applications is rapidly increasing, current routers do not guarantee minimum QoS values of fairness and drop packets in random fashion. If routers provide a minimum QoS, resulting less delays, more fairness, and smoother sending rates, TCP-friendly rate control (TFRC) can be adopted for real-time applications. We propose a dynamic buffer management scheme that meets the requirements described above, and can be applied to TCP flow and to data flow for transfer of real-time applications. The proposed scheme consists of a virtual threshold function, an accurate and stable per-flow rate estimation, a per-flow exponential drop probability, and a dropping strategy that guarantees fairness when there are many flows. Moreover, we introduce a practical definition of active flows to reduce the overhead coming from maintaining per-flow states. We discuss how proposed scheme motivates real-time applications to adopt TFRC.
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| 2. |
- Doerner, K, et al.
(författare)
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high performance computing in the optimization of software test plans
- 2002
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Ingår i: Optimization and Engineering. - 1389-4420 .- 1573-2924. ; 3:1, s. 67-87
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Tidskriftsartikel (refereegranskat)abstract
- Statistical software testing is an increasingly popular method in the software development cycle. An exact modeling of the usage profiles of a software system is an indispensable prerequisite for statistical testing. Recently, new techniques for obtaining optimal usage profiles even the presence of rarely used critical functions have been introduced. Although these techniques deliver unbiased dependability estimates with a single model (instead of using multiple models as it is the current practice) their applicability is hampered by their prohibitive computational complexity.
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| 3. |
- Espvall, Majen, et al.
(författare)
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Social networks of women with undefined musculoskeletal disorder
- 2002
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Ingår i: Social Work in Health Care. - : Taylor & Francis. - 0098-1389 .- 1541-034X. ; 36:1, s. 77-91
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to investigate social integration among, and the availability of social support for, female patients with undefined musculoskeletal disorder compared to women with coronary heart disease. The aim was to elucidate the importance of a clear diagnosis for the social network relationships of these female patients. For the measurement of social support two instruments were used: an abbreviated version of the Interview Schedule for Social Interaction and a condensed version of the Interpersonal Support Evaluation List. After adjustment for age, marital and employment status, significant differences can be recognized between the two groups of patients: MSD-patients interact with fewer people and receive less emotional support. Implications for social work practice and issues for future research are presented.
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| 4. |
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| 5. |
- Norlin, Anna, et al.
(författare)
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Investigation of Interfacial Capacitance of Pt, Ti and TiN Coated Electrodes by Electrochemical Impedance Spectroscopy
- 2002
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Ingår i: Biomolecular Engineering. - 1389-0344 .- 1878-559X. ; 19:2-6, s. 67-71
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical processes at the electrode-electrolyte (body fluid) interface are of ultimate importance for stimulating/sensing electrode function. A high electrode surface area is desirable for safe stimulation through double-layer charging and discharging. Pt and Pt-Ir alloys have been the most common electrode materials. The use of TiN coating as the surface layer on the electrode has found increasing interest because of its metal-like conductivity, excellent mechanical and chemical properties, and the fact that it can be deposited with a high surface area. In this work, electrochemical impedance spectroscopy (EIS), which is a sensitive and non-destructive technique and widely used for characterization of electrical properties of electrode-electrolyte interfaces, was applied to investigate pure Pt and Ti, and TiN coated electrodes exposed to a phosphate-buffered-saline (PBS) solution. Platinized Pt and Ti were also studied for comparison. The capacitance value of the electrodes in PBS was obtained through quantitative analysis of the EIS spectra. The results reveal that the capacitance of the TiN coated electrodes with a rough surface is several hundreds times higher than that of a smooth Pt surface. Platinization of Ti can also increase the capacitance to the same extent as platina. EIS has been shown to be a powerful technique for characterization of stimulating/sensing electrodes.
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| 6. |
- Caudle, Kelly E, et al.
(författare)
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Incorporation of Pharmacogenomics into Routine Clinical Practice : the Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline Development Process
- 2014
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Ingår i: Current drug metabolism. - : Bentham Science Publishers Ltd.. - 1389-2002 .- 1875-5453. ; 15:2, s. 209-217
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Tidskriftsartikel (refereegranskat)abstract
- The Clinical Pharmacogenetics Implementation Consortium (CPIC) publishes genotype-based drug guidelines to help clinicians understand how available genetic test results could be used to optimize drug therapy. CPIC has focused initially on well-known examples of pharmacogenomic associations that have been implemented in selected clinical settings, publishing nine to date. Each CPIC guideline adheres to a standardized format and includes a standard system for grading levels of evidence linking genotypes to phenotypes and assigning a level of strength to each prescribing recommendation. CPIC guidelines contain the necessary information to help clinicians translate patient-specific diplotypes for each gene into clinical phenotypes or drug dosing groups. This paper reviews the development process of the CPIC guidelines and compares this process to the Institute of Medicine's Standards for Developing Trustworthy Clinical Practice Guidelines.
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| 7. |
- Darwich, A. S., et al.
(författare)
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Interplay of Metabolism and Transport in Determining Oral Drug Absorption and Gut Wall Metabolism : A Simulation Assessment Using the "Advanced Dissolution, Absorption, Metabolism (ADAM)" Model
- 2010
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Ingår i: Current drug metabolism. - : Bentham Science Publishers Ltd.. - 1389-2002 .- 1875-5453. ; 11:9, s. 716-729
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Forskningsöversikt (refereegranskat)abstract
- Bioavailability of orally administered drugs can be influenced by a number of factors including release from the formulation, dissolution, stability in the gastrointestinal (GI) environment, permeability through the gut wall and first-pass gut wall and hepatic metabolism. Although there are various enzymes in the gut wall which may contribute to gut first pass metabolism, Cytochrome P450 (CYP) 3A has been shown to play a major role. The efflux transporter P-glycoprotein (P-gp; MDR1/ABCB1) is the most extensively studied drug efflux transporter in the gut and might have a significant role in the regulation of GI absorption. Although not every CYP3A substrate will have a high extent of gut wall first-pass extraction, being a substrate for the enzyme increases the likelihood of a higher first-pass extraction. Similarly, being a P-gp substrate does not necessarily pose a problem with the gut wall absorption however it may reduce bioavailability in some cases (e. g. when drug has low passive permeability). An on-going debate has focused on the issue of the interplay between CYP3A and P-gp such that high affinity to P-gp increases the exposure of drug to CYP3A through repeated cycling via passive diffusion and active efflux, decreasing the fraction of drug that escapes first pass gut metabolism (F-G). The presence of P-gp in the gut wall and the high affinity of some CYP3A substrates to this transporter are postulated to reduce the potential for saturating the enzymes, thus increasing gut wall first-pass metabolism for compounds which otherwise would have saturated CYP3A. Such inferences are based on assumptions in the modelling of oral drug absorption. These models should be as mechanistic as possible and tractable using available in vitro and in vivo information. We review, through simulation, this subject and examine the interplay between gut wall metabolism and efflux transporters by studying the fraction of dose absorbed into enterocytes (F-a) and F-G via systematic variation of drug characteristics, in accordance with the Biopharmaceutics Classification System (BCS) within one of the most physiological models of oral drug absorption currently available, respectively ADAM. Variables studied included the intrinsic clearance (CLint) and the Michaelis-Menten Constant (K-m) for CYP3A4 and P-gp (CLint-CYP3A4 and Km-CYP3A4, CLint-P-gp and Km-P-gp). The impact of CYP3A4 and P-gp intracellular topography were not investigated since a well-stirred enterocyte is assumed within ADAM. An increased CLint-CYP3A4 resulted in a reduced F-G whereas an increase in CLint-P-gp resulted in a reduced F-a, but interestingly decreased F-G too. The reduction in F-G was limited to certain conditions and was modest. Non-linear relationships between various parameters determining the permeability (e. g. P-app, CLint-P-gp, and Km-P-gp) and gut wall metabolism (e. g. CLint-CYP3A4, Km-CYP3A4) resulted in disproportionate changes in F-G compared to the magnitude of singular effects. The results suggest that P-gp efflux decreases enterocytic drug concentration for drugs given at reasonably high dose which possess adequate passive apparent permeability (high P-app), by de-saturating CYP3A4 in the gut resulting in a lower F-G. However, these findings were observed only in a very limited area of the parameters space matching very few herapeutic drugs (a group with very high metabolism, high turn-over by efflux transporters and low F-a). The systematic approach in this study enabled us to recognise the combination of parameter values where the potential interplay between metabolising enzymes and efflux transporters is expected to be highest, using a realistic range of parameter values taken from an intensive literature search.
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| 8. |
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| 9. |
- Hedlund, E, et al.
(författare)
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Cytochrome P450 in the brain; a review
- 2001
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Ingår i: Current drug metabolism. - : Bentham Science Publishers Ltd.. - 1389-2002. ; 2:3, s. 245-263
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Korkina, L., et al.
(författare)
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The chemical defensive system in the pathobiology of idiopathic environment-associated diseases
- 2009
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Ingår i: Current drug metabolism. - 1389-2002 .- 1875-5453. ; 10:8, s. 914-931
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Forskningsöversikt (refereegranskat)abstract
- Chemical defensive system consisting of bio-sensoring, transmitting, and responsive elements has been evolved to protect multi-cellular organisms against environmental chemical insults (xenobiotics) and to maintain homeostasis of endogenous low molecular weight metabolites (endobiotics). Both genetic and epigenetic defects of the system in association with carcinogenesis and individual sensitivity to anti-tumor therapies have been intensely studied. Recently, several non-tumor human pathologies with evident environmental components such as rather rare functional syndromes (multiple chemical sensitivity, chronic fatigue, Persian Gulf, and fibromyalgia now collectively labeled as idiopathic environmental intolerances) and common diseases (vitiligo and systemic lupus erythematosus) have become subjects of the research on the impaired metabolism and detoxification of xenobiotics and endogenous toxins. Here, we collected and critically reviewed epidemiological, genetic, and biochemical data on the involvement and possible role of cytochrome P450 super family enzymes, glutathione-S-transferase isozymes, catechol-O-methyl-transferase, UDP-glucuronosyl transferases, and proteins detoxifying inorganic and organic peroxides (catalase, glutathione peroxidase, and peroxiredoxin) in the above pathologies. Genetic predisposition assessed mainly by single nucleotide polymorphism and gene expression analyses revealed correlations between defects in genes encoding xenobiotic-metabolizing and/or detoxifying enzymes and risk/severity of these syndromes/diseases. Proteome analysis identified abnormal expression of the enzymes. Their functions were affected epigenetically leading to metabolic impairment and, as a consequence, to the negative health outcomes shared by some of these pathologies. Data obtained so far suggest that distinct components of the chemical defensive system could be suitable molecular targets for future pathogenic therapies.
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