首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   601篇
  免费   0篇
化学工业   8篇
金属工艺   1篇
建筑科学   6篇
能源动力   8篇
轻工业   2篇
一般工业技术   3篇
冶金工业   572篇
自动化技术   1篇
  2024年   1篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2015年   1篇
  2014年   1篇
  2013年   5篇
  2011年   1篇
  2010年   1篇
  2009年   4篇
  2008年   1篇
  2006年   1篇
  2004年   2篇
  2003年   4篇
  2001年   1篇
  1999年   20篇
  1998年   164篇
  1997年   97篇
  1996年   83篇
  1995年   25篇
  1994年   39篇
  1993年   40篇
  1992年   8篇
  1991年   5篇
  1990年   11篇
  1989年   14篇
  1988年   14篇
  1987年   10篇
  1986年   6篇
  1985年   8篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1977年   9篇
  1976年   16篇
  1975年   1篇
排序方式: 共有601条查询结果,搜索用时 156 毫秒
61.
Leukemia has rarely been reported as a late complication of 131I therapy, occurring mostly after cumulative doses of 800 mCi. We observed two cases of acute myeloid leukemia (AML) after 131I therapy for hyperthyroidism and thyroid carcinoma, respectively. The first patient was a 45-year-old woman treated with a single dose of 27 mCi 131I for hyperthyroidism. She developed AML (FAB M2) 14 months after receiving 131I; the second patient was a 44-year-old man affected by refractory thyroid carcinoma who received a total dose of 1 Ci 131I plus radiotherapy and developed AML (FAB M6) 8 years after the first exposure to 131I. Although it is a very rare event, the occurrence of leukemia after 131I treatment should be kept in mind, considering the widespread use of 131I, particularly in the treatment of hyperthyroidism, and the unfavorable outcome of secondary leukemia.  相似文献   
62.
OBJECTIVE: To determine whether incubator home care is desirable and feasible. DESIGN: Inventory. SETTING: Four neonatal units representative of the type of care in general hospitals in the Netherlands. METHOD: The relevant data on all infants with a birth weight < or = 2000 g admitted in the last 3 months of 1996 to one of four hospitals were analysed. Conditions for incubator home care were determined (e.g. absence of need for special care, vital function monitoring or nasogastric tube feeding). RESULTS: Forty-nine infants were enrolled. Mean hospital stay was 28.7 days in an incubator plus 19.7 days in a cot. When infants were placed in a cot they usually still needed tube feeding and monitoring of vital functions and sometimes parenteral nutrition, medication or extra oxygen which made home discharge impossible. Therefore a pilot study of actual home care could not be carried out. CONCLUSION: Although early home discharge is very desirable for newborn infants, the number of infants eligible for incubator home care is so small that further attempts to organise it are not useful.  相似文献   
63.
64.
Our previous studies have shown that monoclonal antibodies (MAbs) to Blastocystis hominis react mainly with carbohydrate epitopes, while 1 MAb (1D5) reacts specifically with a protein of 30.5 kDa. In the present study, 3 monoclonal antibodies (1D5, 1E7 and 4F7) were used in immunogold localization. 1E7 and 4F7 were found to react primarily with the surface coat, while 1D5 was plasma membrane-specific. In the presence of complement, only 1D5 exhibited a cytotoxic effect on B. hominis whereas 1E7 and 4F7 did not, suggesting that the surface coat of B. hominis could serve as an immunological barrier against host antibodies. Using a recently described agar plating method, only 1D5 exhibited significant (P < 0.01) complement-independent cytotoxicity to B. hominis, inhibiting colony growth at low concentrations. Parasites that had been exposed to 1D5 were morphologically smaller than those that were not exposed to this MAb. Colonies that grew in the presence of 1D5 were isolated and grown in liquid medium containing increasing amounts of the cytotoxic MAb. Two clones that grew well in liquid medium containing 1D5 were also able to develop into colonies in soft agar. This study has shown that the 30.5 kDa protein found on the plasma membrane of B. hominis is a functionally important protein and that not all cells within a certain population would be susceptible to the cytotoxic effects of 1D5. These findings suggest that a heterogenous population exists in continuously maintained cultures of B. hominis.  相似文献   
65.
66.
Tolerance is thought to occur when Ag is presented to T cells in the absence of costimulatory interactions from APC accessory molecules. Of the professional APC, the resting B cell may be the main tolerizing cell in vivo. We have analyzed several aspects of activation of naive transgenic CD4 cells stimulated with resting or activated B cells presenting peptide Ag. Similar results were obtained with stimulation from peptide presenting fibroblast APC lacking or expressing B7-1 with intracellular adhesion molecule-1. TCR ligation with little or no accessory molecule coreceptor engagement induced efficient blastogenesis; up-regulation of CD25, CD44, CD69, CD95 and CD71; and down-regulation of CD62L over a 48-h period. Accessory molecule help enhanced the expression of CD25, CD44, CD69, and CD71, but to very modest degrees. Only two molecules, CD40 ligand and IL-2, were found to be extremely dependent on accessory molecule help, with little or no expression evident with peptide presented on resting B cells or class II-positive fibroblasts. T cells induced on resting B cells expanded minimally over 3 days, and this was followed by extensive cell death and hyporesponsiveness of the resulting cells. These studies suggest that under tolerizing conditions, such as Ag presentation by resting B cells, much of the naive CD4 response is induced efficiently. Partial activation, however, may be the overall result due to the lack of CD40 ligand expression, which may regulate costimulatory activity in APC and, in turn, may contribute to limiting the production of IL-2 required for T cell expansion and survival.  相似文献   
67.
68.
We have recently proposed a computational model of the N. gonorrhoeae pilus fiber based on the high resolution X-ray crystal structure of the component protein pilin, combined with available biophysical and genetic data [Parge et al. (1995) Nature 378, 32-38]. In parallel, we have used anti-peptide antibodies to distinguish buried and exposed regions of pilin within the assembled fiber [Forest et al. (1996) Infect. Immun. 64, 644-652]. This mini-review addresses the properties of the current pilus model and the locations of end-exposed epitopes. The fiber forms a three-layered structure of coiled conserved alpha helices surrounded by beta-sheet, with the hypervariable region as the most highly exposed portion. Overall the pilus model developed from diffraction and antibody mapping is expected to be representative of type-4 pili with general implications for type-4 assembly, function, and interactions with other proteins and cell membranes.  相似文献   
69.
An emerging body of research on the physical and sexual abuse of seriously mentally ill (SMI) women documents a high incidence and prevalence of victimization within this population. While causal links are not well understood, there is convergent evidence that victimization of SMI women is associated with increased symptom levels, HIV-related risk behaviors, and such comorbid conditions as homelessness and substance abuse. These abuse correlates may influence chronicity, service utilization patterns, and treatment alliance. This article reviews the research literature on the prevalence, symptomatic and behavioral correlates, and treatment of abuse among SMI women, particularly women with schizophrenia. Within each topic, we discuss relevant research findings, limitations of available studies, and key questions that remain unanswered. We also discuss mechanisms that may underlie the relationship between trauma and schizophrenia-spectrum disorders. We conclude by outlining directions for future research in this area.  相似文献   
70.
OBJECTIVE: The effects of fluvoxamine, a selective serotonin (5-HT) reuptake inhibitor antidepressant, on the pharmacokinetics and pharmacodynamics of buspirone, a non-benzodiazepine anxiolytic agent, were investigated. METHODS: In a randomized, placebo-controlled, two-phase cross-over study, ten healthy volunteers took either 100 mg fluvoxamine or matched placebo orally once daily for 5 days. On day 6, 10 mg buspirone was taken orally. Plasma concentrations of buspirone and its active metabolite, 1-(2-pyrimidinyl)-piperazine (1-PP), were measured up to 18 h and the pharmacodynamic effects of buspirone up to 8 h. RESULTS: The total area under the plasma buspirone concentration-time curve was increased 2.4-fold (P < 0.05) and the peak plasma buspirone concentration 2.0-fold (P < 0.05) by fluvoxamine, compared with placebo. The half-life of buspirone was not affected. The ratio of the total area under the plasma concentration-time curve of 1-PP to that of buspirone was decreased from 7.4 [6.3 (SD)] to 4.4 (3.6) by fluvoxamine (P < 0.05). The results of the six pharmacodynamic tests remained unchanged. CONCLUSION: Fluvoxamine moderately increased plasma buspirone concentrations and decreased the production of the active 1-PP metabolite of buspirone. The mechanism of this interaction is probably inhibition of the CYP3A4-mediated first-pass metabolism of buspirone by fluvoxamine. However, this pharmacokinetic interaction was not associated with impairment of psychomotor performance and it is probably of limited clinical significance.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号