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排序方式: 共有3763条查询结果,搜索用时 15 毫秒
841.
SA Cleaver P Warren M Kern CK Hurley C Raffoux J Keller U Kiesel V Koza E Marry A Mitterschiffthaler M Nakamura CT Okah U Persson T Radde-Stepaniak L Ranson J Raymond M do Rosario Sancho M Varla-Leftherioti T Wiegand JM Winterhager DG Woodfield 《Canadian Metallurgical Quarterly》1997,20(8):621-629
In October 1995 the World Marrow Donor Association (WMDA) was restructured in order to facilitate its primary function of establishing guidelines in relation to international bone marrow and blood stem cell transplants -- transplants in which the donor is in one country and the patient is in another country. Five new working groups were established -- Donor Registries, Ethics, Quality Assurance, Finances, and Stem Cells. This paper, prepared by members of the Donor Registries Working Group, in consultation with the Quality Assurance Working Group, provides recommendations for the 'donor work-up'. This term covers events that start when the definitive donor has been identified, includes the harvesting (collection) and transportation of the stem cell product and ends when the product reaches the transplant centre. The paper includes examples of the documentation intended to ensure compliance with the recommendations at all key points in the sequence. 相似文献
842.
M Lorberboym F Wallach L Estok RE Mosesson M Sacher CK Kim J Machac 《Canadian Metallurgical Quarterly》1998,39(8):1366-1369
Skeletal metastatic lesions arising from gastric cancer are uncommon and usually of the osteolytic type. In order to gain a better understanding of its radiological spectrum, we report two atypical cases of skeletal metastases from gastric adenocarcinoma presenting with unusual radiographic, CT and scintigraphic features. In one patient multiple ossifying skeletal muscle metastases and bone metastases with spiculated periosteal reaction occurred as a presenting manifestation of the malignant disease. The other patient developed widespread osteosclerotic metastases with a superscan pattern on bone scintigraphy. 相似文献
843.
Covalent antithrombin-heparin complexes with high anticoagulant activity. Intravenous, subcutaneous, and intratracheal administration 总被引:1,自引:0,他引:1
A Chan L Berry H O'Brodovich P Klement L Mitchell B Baranowski P Monagle M Andrew 《Canadian Metallurgical Quarterly》1997,272(35):22111-22117
Although heparin has been used clinically for prophylaxis and treatment of thrombosis, it has suffered from problems such as short duration within compartments in vivo that require long term anticoagulation. A covalent antithrombin-heparin complex has been produced with high anticoagulant activity and a long half-life relative to heparin. The product had high anti-factor Xa and antithrombin activities compared with noncovalent mixtures of antithrombin and heparin (861 and 753 units/mg versus 209 and 198 units/mg, respectively). Reaction with thrombin was rapid with bimolecular and second order rate constants of 1.3 x 10(9) M-1 s-1 and 3.1 x 10(9) M-1 s-1, respectively. The intravenous half-life of the complex in rabbits was 2.6 h as compared with 0.32 h for similar loads of heparin. Subcutaneous injection of antithrombin-heparin resulted in plasma levels (peaking at 24-30 h) that were still detectable 96 h post-injection. Given the increased lifetime in these vascular and intravascular spaces, use of the covalent complex in the lung was investigated. Activity of antithrombin-heparin instilled into rabbit lungs remained for 48 h with no detection of any complex systemically. Thus, this highly active agent has features required for pulmonary sequestration as a possible treatment for thrombotic diseases such as respiratory distress syndrome. 相似文献
844.
Pitts Raymond C.; West J. Paige; Hapke Deana M.; Morgan Drake; Dykstra Linda A.; Picker Mitchell J. 《Canadian Metallurgical Quarterly》1996,4(4):389
Lever pressing by rats (Rattus norvegicus) was maintained under a fixed-ratio 20 schedule of food presentation. Response rate-decreasing effects of the opioid compounds fentanyl, U50,488, butorphanol, and nalorphine were examined alone and in combination with the irreversible, μ-selective opioid antagonist β-funaltrexamine (β-FNA) antagonized the rate-decreasingly effects of both fentanyl and butorphanol. β-FNA was more potent and the duration of antagonism was greater, against butorphanol than against fentanyl. β-FNA also antagonized the effects of the higher nalorphine doses: however, lower doses of nalorphine, which were without effect alone, decreased response rates in the presence of β-FNA. The dose–effect curve for U50,488 was shifted leftward in the presence of β-FNA. These data suggest that, β-FNA may be useful in assessing μ-receptor activity related to the effects of opioids on rate of operant behavior and the efficacy with which opioids produce these effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
845.
La Greca Annette M.; Silverman Wendy K.; Vernberg Eric M.; Prinstein Mitchell J. 《Canadian Metallurgical Quarterly》1996,64(4):712
The authors examined symptoms of posttraumatic stress in 3rd–5th grade children during the school year after Hurricane Andrew. From a conceptual model of the effects of traumatic events, 442 children were evaluated 3, 7, and 10 months postdisaster with respect to (a) their exposure to traumatic events during and after the disaster, (b) their preexisting demographic characteristics, (c) the occurrence of major life stressors, (d) the availability of social support, and (e) the type of coping strategies used to cope with disaster-related distress. Although symptoms of posttraumatic stress disorder (PTSD) declined over time, a substantial level of symptomatology was observed up to 10 months after the disaster. All 5 factors in the conceptual model were predictive of children's PTSD symptoms 7 and 10 months postdisaster. Findings are discussed in terms of the potential utility of the model for organizing thinking about factors that predict the emergence and persistence of PTSD symptoms in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
846.
Examines certain anatomical peculiarities of the cat visual system and summarizes some of the parallels (e.g., possession of stereopsis) and differences (e.g., in various spatial thresholds) between the perceptual abilities of cats and humans. These similarities and the larger number of parallels between the 2 species that can be drawn during development, reinforce the validity of choosing the cat for study of the mechanisms that underlie human visual development. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
847.
848.
Computational techniques for the verification of hybrid systems 总被引:5,自引:0,他引:5
Tomlin C.J. Mitchell I. Bayen A.M. Oishi M. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(7):986-1001
Hybrid system theory lies at the intersection of the fields of engineering control theory and computer science verification. It is defined as the modeling, analysis, and control of systems that involve the interaction of both discrete state systems, represented by finite automata, and continuous state dynamics, represented by differential equations. The embedded autopilot of a modern commercial jet is a prime example of a hybrid system: the autopilot modes correspond to the application of different control laws, and the logic of mode switching is determined by the continuous state dynamics of the aircraft, as well as through interaction with the pilot. To understand the behavior of hybrid systems, to simulate, and to control these systems, theoretical advances, analyses, and numerical tools are needed. In this paper, we first present a general model for a hybrid system along with an overview of methods for verifying continuous and hybrid systems. We describe a particular verification technique for hybrid systems, based on two-person zero-sum game theory for automata and continuous dynamical systems. We then outline a numerical implementation of this technique using level set methods, and we demonstrate its use in the design and analysis of aircraft collision avoidance protocols and in verification of autopilot logic. 相似文献
849.
We have evaluated the prevalence and the characteristics of exercise-induced asthma (EIA) in a group of 71 patients with a prior history of mild, moderate or severe asthma (42 males and 29 females), aged 6-16 years-old. Measurements of the forced expiratory volume in 1 second (FEV1) were obtained before and at regular intervals up to 8 hours following exercise. As a control, the same patients were evaluated at similar time intervals on another day when they had not been submitted to an exercise challenge. Using pre-exercise FEV1 values as the reference, 32 patients (45.1%) had a positive exercise challenge, defined as a fall in FEV1 value equal to or greater than 15% from baseline following exercise. Among the patients with a positive exercise challenge, the majority (23/32, 71.8%) had an immediate response alone, with no significant changes in FEV1 within the 8-hour follow-up. However, a subgroup of patients (9/32, 28.1%) had both an immediate and a late-phase response to exercise. During the control day, no significant fall in FEV1 were observed. In keeping with previous investigations, no correlation was found between a history of EIA and a positive exercise challenge in the present study. Positive exercise challenges were found more frequently among patients with moderate and severe asthma than patients with mild asthma. 相似文献
850.
CK Sinha AN Gangopadhyay SP Sahoo SC Gopal DK Gupta SP Sharma 《Canadian Metallurgical Quarterly》1997,12(2-3):186-187
A new variant of esophageal atresia (EA) with tracheoesophageal fistula (TEF) associated with duodenal atresia is reported. The TEF was between the lower pouch and the trachea, with a cystic dilatation in the midportion. The tracheal end of the fistula was obstructed by a membranous septum at both ends of a cystic dilatation, leading to a diagnosis of pure EA (gasless abdomen). After the lower pouch was opened beyond the cystic dilatation, 100 ml nonbilious fluid was obtained. A laparotomy revealed a type III atresia of the first part of the duodenum. 相似文献