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排序方式: 共有6787条查询结果,搜索用时 15 毫秒
41.
N Benito A Nú?ez M de Górgolas J Esteban T Calabuig MC Rivas ML Fernández Guerrero 《Canadian Metallurgical Quarterly》1997,157(14):1577-1580
BACKGROUND: Fever is commonly observed in patients with human immunodeficiency virus (HIV) disease and frequently eludes diagnosis. The role of bone marrow biopsy in the diagnosis of fever of unknown origin in patients infected with HIV remains controversial. PATIENTS AND METHODS: One hundred twenty-three consecutive patients with 137 episodes of fever lasting 10 or more days without diagnosis after 1 week of hospitalization were evaluated by bone marrow biopsy. RESULTS: Overall, a specific diagnosis was achieved in 52 episodes by means of culture and histopathological examination (diagnostic yield, 37.9%). Three types of disease were found: mycobacterial infections (n = 36, 69% of documented episodes), including 18 patients with disseminated tuberculosis and 14 with Mycobacterium avium-intracellulare complex infections; non-Hodgkin lymphomas (n = 12, 23%); and visceral leishmaniasis (n = 4, 8%). Although bone marrow cultures were more sensitive than microscopic examination with special stains for the diagnosis of mycobacterial infections, the pathological examination of bone marrow led to a more rapid diagnosis of disease. In addition, the histopathological examination of bone marrow alone led to the diagnosis of a specific condition in 43 episodes (31.3% of all episodes). CONCLUSIONS: Bone marrow biopsy is a useful procedure for the diagnosis of fever in patients with advanced HIV disease, particularly in areas where tuberculosis and leishmaniasis are prevalent. Involvement of the marrow may be the first indication of the existence of extranodal non-Hodgkin lymphoma. For Mycobacterium avium-intracellulare complex infection, blood cultures were more sensitive than bone marrow biopsy. 相似文献
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Vicente Rodríguez Montequín Francisco Ortega Fernández Nicolás Abajo de Martínez Juan Antonio González Rodríguez 《JOM Journal of the Minerals, Metals and Materials Society》2002,54(7):46-50
This research summary discusses the application of neural networks, evolutionary strategies, and other artificial intelligence
techniques in the modeling and optimization of the models used for temperature, rolling force, and torque calculation in heavy
plate milling. 相似文献
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The electrochemical performance of non-graphitized petroleum cokes has been improved by mild oxidation using hydrogen peroxide, a procedure used for the first time in these materials. For this purpose, various carbonisation temperatures and H2O2 treatments were tested. For low sulfur content cokes, the aqueous oxidative treatment significantly increases the capacity values above 372 mAh/g during the first cycles. In contrast, cokes with a sulfur content of ca. 5%, did not shown a real improvement. The former results have been interpreted in terms of an effective oxidation of the particles surface, which removes unorganized carbon, where lithium can be irreversibly trapped. Moreover, a stable and less resistive passivating layer grows during the first discharge of lithium, as revealed by impedance spectroscopy. Therefore, chemical procedures, as mild oxidation, open an interesting field of research for the improvement of disordered carbons as anode materials in lithium ion batteries. 相似文献
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AE Pérez Rodríguez L Expósito Rivas O Rodríguez Leyva A Goyenechea Hernández 《Canadian Metallurgical Quarterly》1992,44(2):145-148
A discussion is carried out about the experiences with the application of rimantadine and amantadine to patients with influenza. The basic general results consisted in the fact that 2 of the 74 patients treated had a high cure percent (> 68.0%) within the first 72 hours after using the drug. No new diseased were found among the 40 contacts to whom chemoprophylaxis was applied. There were only 3.9% adverse reactions among the total number of people treated with amantadine. 相似文献
49.
Speciation of the semivolatile hydrocarbon engine emissions from sunflower biodiesel 总被引:1,自引:0,他引:1
Biodiesel fuel is a very attractive alternative to conventional fuel and its effects in the engine performance and regulated emissions have been widely studied. However, the impact on unregulated individual compounds or chemical characteristics of exhaust emissions is not fully characterized. In this paper, the semivolatile fractions of the exhaust emissions of biodiesel blends and conventional fuel have been speciated. The results show great differences between the compounds emitted, especially regarding oxygenated and aromatic species. Likewise, there is a clear relationship between speciated hydrocarbons and other important emissions such as total hydrocarbons (HC), particulate matter (PM), volatile organic fraction (VOF) and mean particle diameter (Dm) of PM. 相似文献
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This review aims to summarize the current state of research concerning the interaction of electrodes with liposomes suspended in solutions. Main attention is given to the complex mechanism of adhesion and spreading of liposomes on mercury electrodes. That mechanism can be studied with the help of chronoamperometry, where each adhesion-spreading event appears as a capacitive current spike. Integration of these spikes produces charge versus time transients that can be modeled and simulated, revealing the details of the multi-step adhesion-spreading process. Whereas the number of spikes per time mirrors the macro-kinetics, the analysis of the time behavior of each spike mirrors the micro-kinetics of each adhesion-spreading event. The reviewed studies show that this approach provides a new tool to study the properties of liposome membranes. The adhesion-spreading of liposomes on mercury electrodes has strong similarities to the process of vesicle fusion, which makes these studies a biomimetic model allowing one to deduce the effects of foreign molecules in bilayer membranes. 相似文献