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排序方式: 共有302条查询结果,搜索用时 10 毫秒
1.
2.
C Altman A Ladouch MJ Briantais T Rason E Martin L Jacques C Buffet 《Canadian Metallurgical Quarterly》1995,24(15):708-710
OBJECTIVES: Antral gastritis is frequent in alcoholics. The role of H. pylori in the pathogenesis of gastritis in these patients is not well known. The aim of our study was to study the role of H. pylori and cirrhosis in the pathogenesis of antral gastritis in alcoholic patients. METHODS: Seventy-nine patients were included in the study. All underwent upper gastrointestinal tract endoscopy with antral biopsies, independently of the presence of abdominal pain, and had serological examination for H. pylori antibodies. RESULTS: Cirrhosis and gastritis were present in 50 and 40 patients respectively, H. pylori serological assay and histological identification of the bacterium were positive in 35 (44%) and 19 (24%) patients respectively. Discrepancy between the 2 tests were observed more frequently in cirrhotic patients. A positive serology with a negative histologic examination for H. pylori was present for 18 cirrhotic and 4 noncirrhotic patients (p < 0.05). A gastritis without evidence of H. pylori was more frequent in cirrhotic than in noncirrhotic patients. H. pylori was histologically present in 11 of 29 cirrhotic patients and in 8 of the 11 noncirrhotic patients with a gastritis (p < 0.05). CONCLUSIONS: Discrepancies between histological examination and H. pylori serology in patients with cirrhosis might be due to the inhospitable environment for H. pylori in case of portal hypertension; the positive serology could be in relation with a past infection. 相似文献
3.
Carl Bruch Stephanie Altman Mishkat Al-Moumin Jessica Troell Elana Roffman 《国际水资源开发杂志》2007,23(4):595-624
For millennia, countries in the Middle East and North Africa (MENA) region have developed laws, regulations and other rules to govern their scarce water. These laws have been updated in recent years. This review of the legal frameworks (including regulations, decrees and other rules) reveals both progress and gaps in managing water quality, water quantity and procedural aspects. Of note, while the general frameworks are usually in place, in many instances the necessary details are lacking to give effect to the goals. However, in some instances the legal frameworks governing water lack certain key principles or approaches. In order to effectively meet the growing demands on their water resources, MENA countries will need to further strengthen and develop their legal frameworks. 相似文献
4.
We proposed a design methodology for improved thermophoretic probes that can sample particles with high spatial resolution. A bending vibration analysis for the instantaneous motion of a probe has been done together with direct observation of the probe motion and flow disturbance for systematic study of the effect of different designs on particle sampling. Direct observation of the motion of thermophoretic sampling probes revealed that the probe with a low stiffness would result in inaccurate particle sampling. Based on these, the thermophoretic sampling probe was modified to minimize probe vibration and flow disturbance and this modified design was confirmed to sample particles with higher spatial resolution than the original one by examining transmission electron microscope (TEM) images of particles collected in a flame. 相似文献
5.
Phenotypic analysis of antigen-specific T lymphocytes 总被引:4,自引:0,他引:4
JD Altman PA Moss PJ Goulder DH Barouch MG McHeyzer-Williams JI Bell AJ McMichael MM Davis 《Canadian Metallurgical Quarterly》1996,274(5284):94-96
Identification and characterization of antigen-specific T lymphocytes during the course of an immune response is tedious and indirect. To address this problem, the peptide-major histocompatability complex (MHC) ligand for a given population of T cells was multimerized to make soluble peptide-MHC tetramers. Tetramers of human lymphocyte antigen A2 that were complexed with two different human immunodeficiency virus (HIV)-derived peptides or with a peptide derived from influenza A matrix protein bound to peptide-specific cytotoxic T cells in vitro and to T cells from the blood of HIV-infected individuals. In general, tetramer binding correlated well with cytotoxicity assays. This approach should be useful in the analysis of T cells specific for infectious agents, tumors, and autoantigens. 相似文献
6.
JC Wyatt S Paterson-Brown R Johanson DG Altman MJ Bradburn NM Fisk 《Canadian Metallurgical Quarterly》1998,317(7165):1041-1046
OBJECTIVE: To evaluate the effectiveness of an educational visit to help obstetricians and midwives select and use evidence from a Cochrane database containing 600 systematic reviews. DESIGN: Randomised single blind controlled trial with obstetric units allocated to an educational visit or control group. SETTING: 25 of the 26 district general obstetric units in two former NHS regions. SUBJECTS: The senior obstetrician and midwife from each intervention unit participated in educational visits. Clinical practices of all staff were assessed in 4508 pregnancies. INTERVENTION: Single informal educational visit by a respected obstetrician including discussion of evidence based obstetrics, guidance on implementation, and donation of Cochrane database and other materials. MAIN OUTCOME MEASURES: Rates of perineal suturing with polyglycolic acid, ventouse delivery, prophylactic antibiotics in caesarean section, and steroids in preterm delivery, before and 9 months after visits, and concordance of guidelines with review evidence for same marker practices before and after visits. RESULTS: Rates varied greatly, but the overall baseline mean of 43% (986/2312) increased to 54% (1189/2196) 9 months later. Rates of ventouse delivery increased significantly in intervention units but not in control units; there was no difference between the two types of units in uptake of other practices. Pooling rates from all 25 units, use of antibiotics in caesarean section and use of polyglycolic acid sutures increased significantly over the period, but use of steroids in preterm delivery was unchanged. Labour ward guidelines seldom agreed with evidence at baseline; this hardly improved after visits. Educational visits cost pound860 each (at 1995 prices). CONCLUSIONS: There was considerable uptake of evidence into practice in both control and intervention units between 1994 and 1995. Our educational visits added little to this, despite the informal setting, targeting of senior staff from two disciplines, and donation of educational materials. Further work is needed to define cost effective methods to enhance the uptake of evidence from systematic reviews and to clarify leadership and roles of senior obstetric staff in implementing the evidence. 相似文献
7.
Eitan Altman 《Discrete Event Dynamic Systems》2009,19(1):115-136
We consider in this paper a class of vector valued processes that have the form Y
n + 1 = A
n
( Y
n
) + B
n
. B
n
is assumed to be stationary ergodic and A
n
is assumed to have a divisibility property. This class includes linear stochastic difference equations as well as multi-type
branching processes (with a discrete or with a continuous state space). We derive explicit expressions for the probability
distribution as well as for the two first moments of state vectors at the stationary regime. We then apply this approach to
derive two formalisms to describe the infinite server queue. The first is based on a branching process approach adapted to
phase type service time distributions. The second is based on a linear stochastic difference equation and is adapted to independent
and generally distributed service times with bounded support. In both cases we allow for generally distributed arrival process
(not necessarily i.i.d. nor Markovian).
Eitan Altman Since 1990, Dr. Altman has been a researcher at INRIA (National research institute in informatics and control) in Sophia-Antipolis, France. He has served on the editorial boards of several scientific journals: WINET, COMNET, JDEDS, SIAM (SICON), Stochastic Models, and Journal of Economy Dynamic and Control (JEDC). Has been plenary speaker, (co)chairman of the program committee and general chair of various international conferences. Has received the best paper award in several conferences. His main interests are application of control, game theory and bio-inspired paradigms to networking. 相似文献
Eitan AltmanEmail: |
Eitan Altman Since 1990, Dr. Altman has been a researcher at INRIA (National research institute in informatics and control) in Sophia-Antipolis, France. He has served on the editorial boards of several scientific journals: WINET, COMNET, JDEDS, SIAM (SICON), Stochastic Models, and Journal of Economy Dynamic and Control (JEDC). Has been plenary speaker, (co)chairman of the program committee and general chair of various international conferences. Has received the best paper award in several conferences. His main interests are application of control, game theory and bio-inspired paradigms to networking. 相似文献
8.
Biological processes have produced the ultimate intelligent system (humans), and now we are trying to understand biology (and ourselves) by building intelligent systems. Intelligent systems research in biology strives to understand how living systems perform difficult tasks routinely (ranging from molecular phenomena such as protein-folding to organism-level phenomena such as cognition). The definition of intelligent systems in biology can lead to hours of debate. Some say that all high-performance systems that do something difficult with (or to) biological data should be considered intelligent systems. Others insist that the term intelligent system should be reserved for systems using the methods typically associated with modem AI. 相似文献
9.
Susan J. Altman Richard P. Jensen Malynda A. Cappelle Andres L. Sanchez Randy L. Everett Howard L. Anderson Lucas K. McGrath 《Desalination》2012
A pilot study was conducted to determine whether membrane treatment on a side stream of recirculating cooling-tower water could reduce overall water usage and discharge. The treated permeate was returned to the cooling tower while the concentrate was discharged to the sanitary sewer. Flow rates, pressures and water chemistry were monitored. The pilot demonstrated potential substantial water savings. Maximum make-up water and discharge reduction were 16% and 49%, respectively. As high as possible permeate recovery is needed to maximize water conservation. Silica scaling on the membranes limited water savings in this pilot. Development of membranes with a solute-rejection capacity less than the 92% average of the membranes used in the pilot would assist in optimizing water savings. Decreased water outlays compensated for the additional energy used by membrane treatment. Scaling control is critical for economic operation. 相似文献
10.
BioWar: scalable agent-based model of bioattacks 总被引:2,自引:0,他引:2
Carley K.M. Fridsma D.B. Casman E. Yahja A. Altman N. Li-Chiou Chen Kaminsky B. Nave D. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2006,36(2):252-265
While structured by social and institutional networks, disease outbreaks are modulated by physical, economical, technological, communication, health, and governmental infrastructures. To systematically reason about the nature of outbreaks, the potential outcomes of media, prophylaxis, and vaccination campaigns, and the relative value of various early warning devices, social context, and infrastructure, must be considered. Numerical models provide a cost-effective ethical system for reasoning about such events. BioWar, a scalable citywide multiagent network numerical model, is described in this paper. BioWar simulates individuals as agents who are embedded in social, health, and professional networks and tracks the incidence of background and maliciously introduced diseases. In addition to epidemiology, BioWar simulates health-care-seeking behaviors, absenteeism patterns, and pharmaceutical purchases, information useful for syndromic and behavioral surveillance algorithms. 相似文献