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   292篇
  免费   3篇
电工技术   2篇
综合类   1篇
机械仪表   1篇
建筑科学   1篇
能源动力   2篇
轻工业   1篇
无线电   1篇
冶金工业   279篇
自动化技术   7篇
  2021年   1篇
  2015年   2篇
  2014年   1篇
  2011年   2篇
  2006年   2篇
  2005年   4篇
  2002年   1篇
  2001年   1篇
  1999年   5篇
  1998年   88篇
  1997年   43篇
  1996年   26篇
  1995年   23篇
  1994年   17篇
  1993年   18篇
  1992年   2篇
  1991年   6篇
  1990年   1篇
  1989年   3篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1982年   1篇
  1981年   4篇
  1980年   6篇
  1978年   2篇
  1977年   4篇
  1976年   24篇
排序方式: 共有295条查询结果,搜索用时 15 毫秒
81.
PCR amplification technology for the detection of epizootic hemorrhagic disease virus (EHDV) ribonucleic acid in cell culture and clinical specimens was developed. With oligoribonucleotide primers selected from genome segment 10 of EHDV serotype 1 (EHDV-1), which codes for two nonstructural proteins (NS3 and NS3a), the PCR-based assay resulted in a 535-bp PCR product. RNAs from North American EHDV-1 prototype, EHDV-2 prototype, and a number of EHDV field isolates, including the Central African isolates of EHDV-5 and EHDV-318 propagated in cell cultures, were detected by this PCR-based assay. The specific 535-bp PCR products were visualized onto agarose gels, and the identity of the PCR products was confirmed by chemiluminescent hybridization with a 352-bp internal probe. The sensitivity of the EHDV PCR assay was increased by chemiluminescent hybridization; by this EHDV-NS3 PCR, 10 fg of EHDV RNA was detected (equivalent to 600 viral particles). Amplification product was not detected when the PCR-based assay was applied to RNAs from North American bluetongue virus prototype serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cells; or unfractionated blood from calves and deer that were EHDV seronegative and virus isolation negative. The described EHDV PCR-based assay with primers derived from segment 10 of EHDV-1 resulted in detection of EHDV RNA from blood and tissues collected from calves and deer with natural and experimental EHDV infections and provides a valuable tool to study the epidemiology of EHDV infection in susceptible ruminants.  相似文献   
82.
83.
In the present study the contribution of rat liver endothelial cells (EC) and Kupffer cells (KC) in the clearance of human (hu) C1q in rats was investigated. In untreated rats and rats depleted from KC the clearance kinetics and the tissue distribution of hu C1q were measured. In untreated rats, the clearance of hu C1q occurred in a monophasic manner with a half-life of 66 +/- 26.7 min. The clearance of hu C1q in KC-depleted rats was delayed significantly (p < 0.001) and occurred with a half-life of 217 +/- 78.8 min. Fifteen min after injection, 11 +/- 3.5% of hu C1q was found in the liver of untreated rats and 8 +/- 1.4% was found in the liver of KC-depleted rats. The percentage non-trichloroacetic acid precipitable activity in the circulation, as a measure for degradation of C1q, reached a level of 11.6 +/- 5.6% at 240 min in untreated rats compared with 4.6 +/- 5.8% in KC-depleted rats. Double immunofluorescence staining 5 min after administration of C1q in untreated rats, revealed that C1q was associated with KC and EC in the liver. Fifteen minutes after i.v. injection of hu C1q, there was an uptake of C1q in the hepatocytes. In KC-depleted rats, 5 min after administration of hu C1q, C1q was bound to the EC. Fifteen minutes after injection, C1q was also found in the hepatocytes. Electron microscopical studies revealed that C1q binds to EC, and that it is internalized in the hepatocytes and KC. The clearance of hu C1q in untreated rats was inhibited by preadministration of high concentrations of bovine C1q. These data show that rats depleted from KC are able to bind, internalize and degrade C1q, and that EC may play a role in the handling of C1q and C1q bound to immune complexes.  相似文献   
84.
The use of primary chemotherapy represents a novel approach being used with increasing frequency in the management of early breast cancer. Many studies now testify to the usefulness of this modality in increasing the frequency of breast conservation. The acceptance of high-risk breast cancer as a systemic, and therefore predominantly medical rather than a surgical, disease suggests, however, that its role is likely to be far more reaching. While some trials have so far suggested the possibility of a survival benefit for this approach, definitive conclusions are not yet possible and await the final mature results from several large randomized studies. Even if such studies do not show a large extra benefit for primary chemotherapy over existing adjuvant treatment, the use of the primary tumour as an in vivo model of individual chemosensitivity and the identification of molecular markers as early predictors of response, suggest that this approach will become an integral part of the modern multidisciplinary management of early breast cancer.  相似文献   
85.
In the past, urologic complications contributed greatly to spinal cord injury mortality. With improved evaluation and treatment, this is no longer the case. Treatment should be guided by urodynamic data gathered after the resolution of spinal shock symptoms. Goals of treatment are to facilitate voiding, reduce incontinence, and prevent renal damage. Indwelling catheters are almost never indicated for long-term treatment of the neurogenic bladder. Commonly used treatments include intermittent catheterization, condom catheter drainage with sphincter ablation, and pharmaceutical manipulation. Electrical stimulation of sacral nerve roots shows promise for future therapy.  相似文献   
86.
The authors have studied the process of revascularization of free transplants of growth zones of the bones transplanted heterotopically from greater trochanter of the femur onto the chest. The X-ray and histological data have shown the ingrowth of the vessels into autotransplants from the side of soft tissues of the recipient bed responsible for the growth of the epiphyseal cartilage.  相似文献   
87.
88.
Pharmacologic therapy is an important part of the treatment armamentarium for urogynecologic disorders. Current and future research will determine the utility of such therapy as medications with fewer side effects and more targeted efficacy are developed.  相似文献   
89.
90.
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