全文获取类型
收费全文 | 764篇 |
免费 | 60篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 13篇 |
妇产科学 | 20篇 |
基础医学 | 82篇 |
口腔科学 | 11篇 |
临床医学 | 48篇 |
内科学 | 184篇 |
皮肤病学 | 4篇 |
神经病学 | 30篇 |
特种医学 | 59篇 |
外科学 | 35篇 |
综合类 | 22篇 |
预防医学 | 89篇 |
眼科学 | 58篇 |
药学 | 36篇 |
中国医学 | 3篇 |
肿瘤学 | 129篇 |
出版年
2022年 | 8篇 |
2021年 | 9篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 10篇 |
2015年 | 17篇 |
2014年 | 21篇 |
2013年 | 23篇 |
2012年 | 38篇 |
2011年 | 29篇 |
2010年 | 15篇 |
2009年 | 16篇 |
2008年 | 32篇 |
2007年 | 27篇 |
2006年 | 29篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 27篇 |
2002年 | 22篇 |
2001年 | 13篇 |
2000年 | 25篇 |
1999年 | 17篇 |
1998年 | 29篇 |
1997年 | 21篇 |
1996年 | 16篇 |
1995年 | 22篇 |
1994年 | 8篇 |
1993年 | 18篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 18篇 |
1989年 | 14篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 15篇 |
1985年 | 9篇 |
1983年 | 8篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 7篇 |
1957年 | 6篇 |
1954年 | 5篇 |
排序方式: 共有825条查询结果,搜索用时 15 毫秒
1.
2.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence. 相似文献
3.
4.
F. R. VOGELPOEL R. J. VAN KOOIJ E. R. TE VELDE J. VERHOEF 《International journal of andrology》1990,13(2):81-86
Isolated sperm from normo-, oligo- and astheno-spermic men were incubated for 20 h in medium supplemented with 8% heat-inactivated or untreated human serum, and in medium with heated or untreated serum deficient in complement factor C3. Before and after incubation, sperm motility was assessed by means of a computer-assisted semen analyser. The results did not show significant differences between the motility of sperm incubated in heated or untreated serum. It is concluded that heating of homologous serum is not necessary for preserving sperm motility and in some cases may even be disadvantageous. 相似文献
5.
Low-dose aspirin for migraine prophylaxis 总被引:3,自引:0,他引:3
The Physicians' Health Study is a randomized, double-blind, placebo-controlled trial that studied low-dose aspirin (325 mg every other day) therapy among 22,071 US male physicians aged 40 to 84 years. Annual follow-up questionnaires requested information on the occurrence of numerous medical conditions including migraine. At the end of 60 months, morbidity follow-up was 99.7% complete, and the reported consumption of aspirin or other platelet-active drugs was 86% in the aspirin group and 14% in the placebo group. Of those randomized to aspirin, 661 (6.0%) reported migraine at some time after randomization, as compared with 818 (7.4%) of those allocated to the placebo group, representing a statistically significant 20% reduction in recurrence rate. The rate of self-report of ordinary headache was similar in the two groups. These data indicate that migraine is mediated, at least in part, by the effects of platelets and suggest that low-dose aspirin should be considered for prophylaxis among those with a history of established migraine. 相似文献
6.
O. B. Eden J. S. Lilleyman S. Richards M. P. Shaw J. Peto 《British journal of haematology》1991,78(2):187-196
During the 1970s, despite apparently similar treatment, the prognosis for children with lymphoblastic leukaemia (ALL) improved more in some countries, notably the United States and West Germany, than in others. To find out why, the first phase of the United Kingdom (UK) Medical Research Council (MRC) childhood ALL trial, UKALL VIII, was designed to see whether similar results to the United States Children's Cancer Study Group (CCSG) could be obtained in the U.K. using an identical protocol (CCG 162). Protocol 162 was one of a series of regimens devised by the American Children's Cancer Study Group in the 1970s and was used specifically for their average risk patients (all children with ALL with an initial white cell count up to 50 x 10(9)/l except those aged 3-6 years with white cell counts under 10 x 10(9)/l). One arm (1A) of their study was adopted by the MRC for all children in the U.K. aged 0-14 years with confirmed ALL. Eight hundred and twenty-nine consecutive patients were entered between 1980 and 1984. The first 199 patients formed a single arm study as per the original protocol 162 (arm 1A), but the subsequent 630 children were randomized to receive or not two doses of daunorubicin on the first 2 d of induction. This randomization was an attempt to answer the important question as to whether event-free survival was influenced by the use of four rather than three induction agents. A second randomization between 2 and 3 years continuing therapy was also introduced at this stage as it had been by the CCSG in their protocol. With a minimum follow up period of more than 5 years, disease-free survival for the whole group is 55%, a considerable improvement on all previous UKALL trials. Results for patients directly comparable with those in CCSG 162 ('average risk' patients) and their American counterparts were similar. Daunorubicin was associated with more early deaths but improved disease-free survival for those achieving remission. More children relapsed who stopped treatment after 2 years than those who continued for 3, but this was balanced by increased treatment mortality in the third year. The fact that for UKALL VIII the results were similar to those of the CCSG suggests that previous MRC protocols were not sufficiently sustained and intensive, particularly during the maintenance phase of treatment.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
7.
8.
Image-directed percutaneous biopsies with a biopsy gun 总被引:3,自引:0,他引:3
Core tissue for histologic study is believed by many pathologists to be more diagnostic than material from needle aspiration. Recently, a biopsy "gun" has been introduced, which simplifies core biopsies. With this device, 182 biopsies of multiple anatomic sites were performed with ultrasonic, computed tomographic, and fluoroscopic guidance and 18-gauge needles. High-quality histopathologic specimens were obtained in 177 of the biopsies, and diagnostic target tissue was obtained in 167. Only three significant complications occurred: one bleeding complication that required transfusion and two cases of pneumothorax that necessitated placement of chest tubes. The biopsy gun eliminated the disjointed movements of conventional "skinny" needle biopsies, and none of the samples demonstrated significant "crush" artifact or obscuring blood, problems that are commonly associated with manual biopsy techniques. Patient discomfort was decreased with this system compared with that of manual biopsies, and the total procedure time was reduced. Because of these distinct advantages, the authors now use the biopsy gun exclusively for all percutaneous biopsies and recommend that other institutions consider the use of this biopsy method. 相似文献
9.
10.
目的观察去甲硫氨酸全肠外营养对大鼠血清氨基酸谱等的影响.方法 Wistar大鼠24只,随机分为含甲硫氨酸(+MetTPN,n=12)和去甲硫氨酸全肠外营养2组(-MetTPN,n=12),分别给予相应的TPN支持.治疗7d后,每组随机抽取6只大鼠处死,检测血清FAA(HPLC法)、肝肾功能和全血常规,同时作心、肺、肝、肾组织病理学检查.两组其余大鼠继续原TPN治疗,观察生存期.结果 -MetTPN组大鼠血清游离Met、Cys明显降低,Asp、Glu、Ser等显著增高;大鼠体重下降;血清总蛋白和白蛋白水平下降;血常规和肾功能未见明显异常;组织学检查见肝细胞轻度肿胀,细胞核仁增粗,心肺肾未见明显异常;平均生存18d.对照组上述检查未见异常,除一只大鼠因导管并发症于TPN第16d死亡,其余大鼠全部存活.结论 -MetTPN一周可致大鼠血清游离Met、Cys明显降低和Asp、Glu、Ser等显著增高,及轻度肝功能改变;随着-MetTPN时间延长,出现严重的代谢紊乱和器官功能障碍导致死亡. 相似文献