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   3225642篇
  免费   252880篇
  国内免费   5624篇
耳鼻咽喉   47329篇
儿科学   102601篇
妇产科学   89569篇
基础医学   459890篇
口腔科学   92946篇
临床医学   289749篇
内科学   626786篇
皮肤病学   66706篇
神经病学   265593篇
特种医学   128302篇
外国民族医学   1170篇
外科学   490272篇
综合类   74191篇
现状与发展   2篇
一般理论   1202篇
预防医学   255119篇
眼科学   75985篇
药学   243209篇
  5篇
中国医学   6006篇
肿瘤学   167514篇
  2018年   32078篇
  2016年   27266篇
  2015年   30994篇
  2014年   44204篇
  2013年   67596篇
  2012年   91588篇
  2011年   97082篇
  2010年   57124篇
  2009年   54461篇
  2008年   92505篇
  2007年   99230篇
  2006年   100361篇
  2005年   98009篇
  2004年   94543篇
  2003年   91175篇
  2002年   90208篇
  2001年   146348篇
  2000年   151226篇
  1999年   128155篇
  1998年   37338篇
  1997年   33626篇
  1996年   33577篇
  1995年   32339篇
  1994年   30433篇
  1993年   28290篇
  1992年   103701篇
  1991年   100903篇
  1990年   98179篇
  1989年   94891篇
  1988年   88162篇
  1987年   86733篇
  1986年   82404篇
  1985年   78910篇
  1984年   59645篇
  1983年   51098篇
  1982年   31000篇
  1981年   27552篇
  1980年   25844篇
  1979年   56311篇
  1978年   39813篇
  1977年   33719篇
  1976年   31879篇
  1975年   34087篇
  1974年   41461篇
  1973年   39506篇
  1972年   37349篇
  1971年   34577篇
  1970年   32461篇
  1969年   30460篇
  1968年   28200篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
931.
932.
933.
Is atrial fibrillation an inflammatory disorder?   总被引:2,自引:0,他引:2  
I read with great interest the excellent review on the influenceof inflammation in the pathogenesis of atrial fibrillation (AF)by Boos   相似文献   
934.
935.
936.
Interferon-alpha (IFN-alpha) has proved effective in the treatment of hemangiomas, hemangioblastomas, and Kaposi's sarcoma. To investigate the ability of IFNs to inhibit angiosarcoma, we used two transformed murine endothelial cell lines that form angiosarcomas in vivo. SVR and MS1-VEGF cell lines express oncogenic H-ras or vascular endothelial growth factor (VEGF), respectively. IFN-alpha1,8, which is active against murine and human cells, inhibited SVR and MS1-VEGF proliferation in vitro by 40% at 10(3) U/mL (p = 0.028). In vivo, IFN-alpha1,8 inhibited SVR tumor volume by 71% (p = 0.047) and MS1-VEGF volume by 79% (p = 0.003). Tumor-induced angiogenesis was decreased in SVR tumors by 52% (p = 0.005) and in MS1-VEGF tumors by 58% (p = 0.001). Sera from IFN-alpha1,8-treated mice bearing either SVR or MS1-VEGF tumors demonstrated a 5-fold increase in IP-10/CXCL10 (p = 0.001), an IFN-induced antiangiogenic protein. Both recombinant IP-10 and IFN-alpha1,8 inhibited human umbilical vein endothelial cell (HUVEC) vessel formation in the fibrin gel assay, a three-dimensional culture model of angiogenesis, by 56% at 25 ng/mL and 50% at 1.2 ng/mL, respectively (p < 0.001). An IP-10 blocking antibody restored vessel formation to 80% of untreated controls (p = 0.001). Given the magnitude of the in vivo response, these data suggested that the antitumor effects of IFN-alpha1,8 were likely mediated through angiogenesis inhibition rather than solely by direct inhibition of tumor cell proliferation.  相似文献   
937.
This study examined the ability of PCR to amplify Leishmania DNA, stored on Giemsa-stained slides, from American cutaneous leishmaniasis (ACL) patients. In total, 475 slides stored for up to 36 years were obtained from an outpatient clinic in a Brazilian ACL-endemic region, and Leishmania DNA was amplified from 395 (83.2%) of the DNA samples using primers specific for the minicircle kinetoplast DNA. Restriction fragment length polymorphism analysis of these amplicons demonstrated that Leishmania (Viannia) braziliensis was the only species present in these samples. The results demonstrated that archived Giemsa-stained slides can provide a Leishmania DNA source for performing clinical and epidemiological studies of leishmaniasis.  相似文献   
938.
939.
OBJECTIVE: To assess the effects of adding combined estradiol/norethisterone acetate therapy (CENT) to goserelin acetate treatment (GA) of dysfunctional uterine bleeding (DUB) in perimenopausal women. METHODS: In a randomized, placebo-controlled, double-blind trial followed by an open follow-up study, 31 perimenopausal women with DUB were recruited from gynecological outpatient departments of two Dutch hospitals and randomized for treatment with either GA/placebo or GA/CENT for 6 months followed by 18 months of GA/CENT for all. The main outcome measures were abdominal pain, number of bleeding days, double-layer endometrial thickness (DET), Greene climacteric score (GCS), visual analog scale for well-being, bone mineral density (BMD) and mammographic density (BI-RAD score). RESULTS: Abdominal pain, number of bleeding days and DET decreased in both groups, the between-group difference in decrease not being statistically significant. GCS initially showed significant improvement in the GA/CENT group. BMD decreased significantly in the GA/placebo group (-4.1%) compared with the GA/CENT group (-0.3%). Another 18 months of GA/CENT did not result in a lasting difference in BMD between groups. BI-RAD scores did not differ significantly between or within the two groups. CONCLUSIONS: Adding CENT to GA treatment for DUB in perimenopausal women initially prevented BMD loss and improved climacteric complaints, while having no negative impact on vaginal bleeding, abdominal pain or BI-RAD scores. However, prolonged treatment did not result in a lasting prevention of bone loss.  相似文献   
940.
The aim of this study was to assess the incidence and risk factors of pelvic fractures as a result of radiation therapy in women with gynecological cancer. We retrospectively reviewed 3530 female patients treated at our institute between 1980 and 1998 with megavoltage radiation with or without brachytherapy for cancer in the pelvic area. Eligible were patients with vulvar, vaginal, cervical, endometrial, and fallopian tube cancer. Median follow-up was 88 months (range 0-240). Emphasis was put on treatment-related and patient-related risk factors. Of the eligible 3155 patients, 15 developed symptomatic bone fracture caused by osteoradionecrosis, which makes an overall incidence of 0.44% The diagnosis was based on anamnesis, clinical course, and X-ray or computed tomography images. Median time of onset was 44 months (range 6-197). All patients had pain as the first symptom. The only independent predictive factor for developing osteoradionecrosis seemed to be preexistent osteoporosis. Other risk factors that are related to osteoporosis include higher age, postmenopausal status, or steroid treatment. We did not find any significant treatment-related predictive factor for pelvic osteoradionecrosis. Patients with osteoporosis are probably at the highest risk for developing osteoradionecrotic fractures after pelvic radiotherapy. More studies are needed to find out other endogenous predictive factors.  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