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   184篇
  免费   22篇
  206篇
  2018年   2篇
  2016年   4篇
  2015年   5篇
  2014年   4篇
  2013年   3篇
  2012年   6篇
  2011年   3篇
  2010年   2篇
  2009年   4篇
  2008年   4篇
  2007年   6篇
  2006年   8篇
  2004年   4篇
  2003年   2篇
  2002年   4篇
  2001年   3篇
  2000年   6篇
  1998年   3篇
  1996年   5篇
  1995年   2篇
  1993年   3篇
  1992年   5篇
  1991年   4篇
  1990年   4篇
  1989年   3篇
  1987年   4篇
  1986年   5篇
  1985年   8篇
  1984年   5篇
  1983年   9篇
  1982年   6篇
  1981年   3篇
  1980年   3篇
  1979年   8篇
  1978年   3篇
  1975年   3篇
  1974年   9篇
  1973年   5篇
  1972年   4篇
  1971年   4篇
  1970年   3篇
  1969年   6篇
  1968年   2篇
  1967年   4篇
  1959年   1篇
  1949年   1篇
  1940年   1篇
  1938年   1篇
  1933年   1篇
  1932年   1篇
排序方式: 共有206条查询结果,搜索用时 0 毫秒
1.
Mirror carp were infected with Ichthyophthirius multifiliis (Fouquet) under standardized conditions. The size and number of parasites at selected sites on the body were recorded during the course of the infection. Initial exposure to 40 mature parasites resulted in a mild infection with 100% recovery after 18 days. Recovered fish did not appear to be carriers of the parasite. Exposure to 400 parasites resulted in 100% mortality between 22–25 days. The growth rate of the parasite was linear. Parasites were more numerous in the dorsal surface of the fish than in the lateral or ventral surface. The increase in parasite numbers during the disease was greater in the gills than in the skin.  相似文献   
2.
3.
Cervicofacial rhytidectomy   总被引:1,自引:0,他引:1  
  相似文献   
4.
5.
DL-alpha-Difluoromethylornithine, an inhibitor of polyamine biosynthesis, was tested for its ability to synchronize Plasmodium falciparum. Asynchronous cultures were pretreated with sorbitol and incubated for 28-30 hr. Then, when cultures consisted of mainly schizont stage parasites, DL-alpha-difluoromethylornithine was added to the growth medium for another 38-47 hr of incubation. Putrescine was added to parasites arrested at the early trophozoite stage. This resulted in a synchronous resumption of growth. After 19 hr, 83% of parasites were at the schizont stage. After 30 hr, more than 98% of the parasites were in the ring form stage. Furthermore, the transformation of early trophozoites to schizonts occurred within 3 hr, with a slight reduction in parasitemia. Synchrony was maintained for 4-5 biological cycles as confirmed also by flow fluorimetry. It appears that this new approach to synchronize P. falciparum cultures is simple, reproducible, and effective.  相似文献   
6.
During the period spanning the years 1973 to 1981, 4,764 women visited the Gynecology Out-Patient Clinics and Colposcopy Unit of the Nahariyya Hospital to be examined colposcopically and cytologically (and histologically whenever indicated) for precancerous and cancerous lesions of the cervix. Of these women, 2,614 (55%) were referred because of symptoms of cervical pathology and 2,150 (45%) for other (prophylactic) reasons. The subdivision of all women according to their demographic backgrounds afforded a comparison of the findings in Israeli-born Jewesses with those of foreign-born Jewesses and non-Jewish females living in the same geographic area of the Western Galilee district of Israel. Despite the low prevalence of cervical cancer in Jewesses throughout the world, the preliminary report of our pilot study demonstrated that the percentage rates of all degrees of dysplasia/cervical intraepithelial neoplasia (CIN I, II and III) of the uterine cervix of Israeli-born Jewesses was 5.4% in patients with cervical pathology and 3.24% in noncervical-pathology patients. These rates were the highest recorded for any of the demographic groups: 2.06% and 0.33%, respectively, in Moslem women; 1.23% in Christian women with cervical pathology; 2.38% and 1.78%, respectively, in European/American-born Jewesses; and 1.63% and 0.48%, respectively, in Asian/African-born Jewesses. The highest proportion of CIN lesions occurred in the 15- to 30-year-old age groups. Of 100 CIN lesions found in all patients, 45 were cytohistologically associated with the cells of condylomatous lesions. Of 36 patients in whom cervical squamous-cell carcinoma lesions were detected, 18 (50%) were staged (FIGO) as carcinoma in situ (stage 0); the remainder were in stages IA, IB, IIA and IIB, with none in stages III or IV.  相似文献   
7.
8.
9.
We have shown in an initial animal study that omentum will adequately vascularize a skin flap and allow transfer of this tissue composite for use in surgical reconstruction of the breast. Based on this experimental procedure, a technique employing a two-stage operation has been developed and used in 21 female patients in reconstruction of the breast after radical mastectomy. In the first stage, the omentum, attached to one gastroepiploic artery and vein, is exteriorized to the subcutaneous tissue of the lower abdominal wall. In the second stage, the distal omentum, now vascularizing the overlying skin and soft tissue, is moved as a secondary island flap to the anterior chest wall to complete the breast reconstruction. In all but 1 of our 21 patients who have been followed for 1 to 8 years, reconstruction of large defects, including the chest wall, breast mound, and infraclavicular axillary fold depression, was performed without use of a prosthesis. In one patient, there was complete necrosis of the flap due to vascular impairment; there were three instances of delayed healing and a significant but partial loss of the flap in one patient. All complications were encountered in the first 10 patients of the series during the time the technique was being refined.  相似文献   
10.
The involvement of anion channels in the mechanism of the acrosome reaction (AR) was investigated. The AR was induced by Ca2+ or by addition of the Ca2+ ionophore A23187. The occurrence of AR was determined by following the release of acrosin from the cells. In order to investigate the role of anion channels in the AR, several anion-channel inhibitors were tested, mainly DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonic acid). Other blockers, like SITS (4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid), furosemide, probenecid and pyridoxal 5-phosphate, were also tested. We found that DIDS binds covalently to sperm plasma membrane in a time- and concentration-dependent manner. Maximal binding occurs after 2 h with 0.3 mM DIDS. DIDS and SITS inhibit AR in a concentration-dependent manner. The IC50 of DIDS and SITS in the presence of A23187 is 0.15 and 0.22 mM, respectively. Tributyltin chloride (TBTC), an Cl-/OH- exchanger, partially overcomes DIDS inhibition of the AR. HCO3- is required for a maximal acrosin release and Ca(2+)-uptake, in the presence or absence of A23187. It is known that HCO3- activates adenylate cyclase and therefore, increases the intracellular level of cAMP. The inhibition of the AR by DIDS decreases from 95 to 50% when (dibutyryl cyclic AMP (dbcAMP) was added, i.e., HCO3- is no longer required while elevating the level of cAMP in an alternative way. Moreover, we show that the stimulatory effect of HCO3- on Ca(2+)-uptake is completely inhibited by DIDS. We conclude that DIDS inhibits AR by blocking anion channels, including those that transport HCO3- into the cell.  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