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   1305篇
  免费   0篇
综合类   1篇
化学工业   17篇
金属工艺   1篇
建筑科学   1篇
能源动力   10篇
轻工业   2篇
武器工业   1篇
无线电   2篇
一般工业技术   6篇
冶金工业   1261篇
自动化技术   3篇
  2013年   1篇
  2011年   4篇
  2010年   5篇
  2009年   2篇
  2008年   4篇
  2007年   10篇
  2006年   4篇
  2005年   6篇
  2004年   1篇
  2003年   2篇
  2000年   1篇
  1999年   43篇
  1998年   401篇
  1997年   256篇
  1996年   159篇
  1995年   72篇
  1994年   60篇
  1993年   86篇
  1992年   9篇
  1991年   15篇
  1990年   11篇
  1989年   8篇
  1988年   8篇
  1987年   10篇
  1986年   13篇
  1985年   13篇
  1983年   2篇
  1982年   5篇
  1981年   7篇
  1980年   9篇
  1979年   1篇
  1978年   2篇
  1977年   16篇
  1976年   54篇
  1975年   1篇
  1966年   3篇
  1955年   1篇
排序方式: 共有1305条查询结果,搜索用时 15 毫秒
171.
PURPOSE: To assess the efficacy of percutaneous embolization with an alcoholic solution of zein in the treatment of aneurysmal bone cysts. MATERIALS AND METHODS: Eighteen patients with aneurysmal bone cysts were treated percutaneously with alcoholic zein. The cysts were in the lower limb (n = 7), upper limb (n = 5), pelvis (n = 3), cervical spine (n = 2), and mandible (n = 1). All patients were symptomatic, three had previously undergone surgery. Percutaneous embolization was performed with fluoroscopic or computed tomographic guidance with the patient under general anesthesia. Clinical and imaging follow-up lasted 18 months to 4 years. RESULTS: Percutaneous embolization was performed in 16 cases. In two cases, cystograms showed marked venous drainage and thus embolization was not attempted. Six patients underwent repeat embolization. Complications consisted of a local transitory inflammatory reaction (n = 5), aseptic osteitis (n = 1), and a small pulmonary infarct without sequelae (n = 1). Relief of symptoms was achieved in all patients except one, who underwent surgery. At imaging, improvement was total in 13 cases (87%) and partial in two cases (13%). No recurrence was noted during follow-up. CONCLUSION: Percutaneous embolization of aneurysmal bone cysts with alcoholic zein should be considered a reliable alternative to surgery, especially in cases with a difficult surgical approach or cases of postsurgical recurrence.  相似文献   
172.
A social marketing approach used both qualitative and quantitative methods to develop a hygiene behaviour intervention in rural north-east Thailand. Behaviours were preselected from a previous study and the intervention was designed to promote hand washing, especially before feeding a baby, cooking, eating, and after defaecation or cleaning a baby's bottom, and dish washing immediately after eating. A bacteriological indicator (enumerating faecal streptococci using a finger impression technique) was developed to measure changes in hand washing behaviour and observation (spot checks) of dirty dishes to indicate dish washing practice. There was a significant improvement in both behaviours and a significant reduction in diarrhoeal disease as a result of the intervention. Furthermore, both indicators were retrospectively found to be positively related to diarrhoeal disease incidence. However, receiving and being able to recall the intervention messages was not necessarily sufficient to ensure behaviour change, as some adults found it difficult to change old habits. Villages showing the greatest improvement tended to have a stronger sense of community than others and to have more people actively involved in the intervention.  相似文献   
173.
Defining the chronology and severity of cell damage in an evolving lesion after ischemia is important for understanding the underlying mechanisms in the development of therapeutic intervention. In the present study, we used a combination of histological and immunocytochemical methods to evaluate cell responses from 30 min to 48 h after permanent occlusion of the middle cerebral artery (MCAO) in the rat. Specific immunocytochemical markers clearly revealed acute early responses in neurons (neurofilament protein 200), astrocytes (glial fibrillary acidic protein), and microglia/macrophages (OX-42 and ED-1) such as enlarged, convoluted neuronal processes, and disintegration of glia. Progressive topographic changes in the developing lesion, pinpointed by immunolabeling, indicated the severity and extension of the cell damage. Proliferation and hypertrophy of astrocytes and microglia around the infarct, and contralaterally, occurred 24-48 h after MCAO and coincided with mass necrosis and infiltration of neutrophils and macrophages into the core. These observations corroborate the suggestion that the inflammatory process is involved in the progression of the infarct.  相似文献   
174.
Two-dimensional gel electrophoresis databases have been generated for a range of tissue cell and fluid types, from a number of species. A major difficulty in the development of such databases is the large number of proteins present in even a single cell type (> 10,000) and the low levels of many of these proteins. One approach to overcome these difficulties is to fractionate the cell into its organelles and generate individual databases for each subcellular component. This has the added advantage of assigning a cellular location to each protein identified. Here we report the development of a two-dimensional gel electrophoresis database of lysosomal proteins.  相似文献   
175.
176.
177.
CONTEXT: Irritable bowel syndrome (IBS) is a common functional bowel disorder for which there is no reliable medical treatment. OBJECTIVE: To determine whether Chinese herbal medicine (CHM) is of any benefit in the treatment of IBS. DESIGN: Randomized, double-blind, placebo-controlled trial conducted during 1996 through 1997. SETTING: Patients were recruited through 2 teaching hospitals and 5 private practices of gastroenterologists, and received CHM in 3 Chinese herbal clinics. PATIENTS: A total of 116 patients who fulfilled the Rome criteria, an established standard for diagnosis of IBS. INTERVENTION: Patients were randomly allocated to 1 of 3 treatment groups: individualized Chinese herbal formulations (n = 38), a standard Chinese herbal formulation (n = 43), or placebo (n = 35). Patients received 5 capsules 3 times daily for 16 weeks and were evaluated regularly by a traditional Chinese herbalist and by a gastroenterologist. Patients, gastroenterologists, and herbalists were all blinded to treatment group. MAIN OUTCOME MEASURES: Change in total bowel symptom scale scores and global improvement assessed by patients and gastroenterologists and change in the degree of interference in life caused by IBS symptoms assessed by patients. RESULTS: Compared with patients in the placebo group, patients in the active treatment groups (standard and individualized CHM) had significant improvement in bowel symptom scores as rated by patients (P=.03) and by gastroenterologists (P=.001), and significant global improvement as rated by patients (P=.007) and by gastroenterologists (P=.002). Patients reported that treatment significantly reduced the degree of interference with life caused by IBS symptoms (P=.03). Chinese herbal formulations individually tailored to the patient proved no more effective than standard CHM treatment. On follow-up 14 weeks after completion of treatment, only the individualized CHM treatment group maintained improvement. CONCLUSION: Chinese herbal formulations appear to offer improvement in symptoms for some patients with IBS.  相似文献   
178.
The molecular events involved in apoptosis induced by ionizing radiation remain unresolved. In this paper we show that the cleavage of fodrin to a 150 kDa fragment is an early proteolytic event in radiation-induced apoptosis in the Burkitts' Lymphoma cell line BL30A and requires 100 microM zVAD-fmk for inhibition. Caspases-1, -3, -6 and -7 were shown to cleave fodrin to the 150 kDa fragment in vitro and all were inhibited by 10 microM zVAD-fmk. We also show that the in vitro cleavage of fodrin by calpain is inhibited by 100 microM zVAD-fmk as was the calpain-mediated hydrolysis of casein. We demonstrate that calpain is activated within 15 min after radiation exposure, concomitant with the cleavage of fodrin to the 150 kDa fragment whereas caspase-3 is activated at 2 h correlating with the cleavage of fodrin to the 120 kDa fragment. These results support a role for calpain in the early phases of the radiation-induced apoptosis pathway, upstream of the caspases.  相似文献   
179.
180.
Clinical trials of new anticancer therapies form an important part of the research activity of the Cancer Research Campaign (United Kingdom), and quality-of-life (QOL) end points are being increasingly used in the evaluation of new treatment approaches. The Campaign has a unique policy of supporting a broad range of scientific and clinical research, including psychosocial studies, and thus QOL research is generated in a variety of clinical settings. The focus of interest for the Cancer Research Campaign lies in QOL design and assessment rather than the routine application of QOL protocols. Clinical investigators are free to adopt in individual approach, but the Campaign operates a strict peer-review system in protocol assessment. Some standardization of approach is being achieved through consensus of opinion and wide collaboration, both nationally and internationally.  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