全文获取类型
收费全文 | 19994篇 |
免费 | 1307篇 |
国内免费 | 172篇 |
专业分类
耳鼻咽喉 | 225篇 |
儿科学 | 416篇 |
妇产科学 | 198篇 |
基础医学 | 2519篇 |
口腔科学 | 352篇 |
临床医学 | 1567篇 |
内科学 | 5396篇 |
皮肤病学 | 483篇 |
神经病学 | 1337篇 |
特种医学 | 811篇 |
外科学 | 2854篇 |
综合类 | 247篇 |
一般理论 | 21篇 |
预防医学 | 1281篇 |
眼科学 | 394篇 |
药学 | 1271篇 |
中国医学 | 64篇 |
肿瘤学 | 2037篇 |
出版年
2023年 | 109篇 |
2022年 | 197篇 |
2021年 | 443篇 |
2020年 | 292篇 |
2019年 | 388篇 |
2018年 | 452篇 |
2017年 | 439篇 |
2016年 | 487篇 |
2015年 | 539篇 |
2014年 | 679篇 |
2013年 | 845篇 |
2012年 | 1350篇 |
2011年 | 1327篇 |
2010年 | 816篇 |
2009年 | 663篇 |
2008年 | 1222篇 |
2007年 | 1367篇 |
2006年 | 1231篇 |
2005年 | 1256篇 |
2004年 | 1137篇 |
2003年 | 1167篇 |
2002年 | 1112篇 |
2001年 | 358篇 |
2000年 | 320篇 |
1999年 | 348篇 |
1998年 | 227篇 |
1997年 | 213篇 |
1996年 | 181篇 |
1995年 | 160篇 |
1994年 | 123篇 |
1993年 | 102篇 |
1992年 | 223篇 |
1991年 | 176篇 |
1990年 | 184篇 |
1989年 | 158篇 |
1988年 | 119篇 |
1987年 | 103篇 |
1986年 | 75篇 |
1985年 | 83篇 |
1984年 | 67篇 |
1983年 | 64篇 |
1982年 | 47篇 |
1981年 | 38篇 |
1980年 | 43篇 |
1979年 | 53篇 |
1978年 | 45篇 |
1977年 | 46篇 |
1973年 | 40篇 |
1972年 | 40篇 |
1970年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
11.
Mamoru Uemura MD Masahiko Higashiyama MD Jiro Okami MD Kazuyuki Oda MD Koji Takami MD Ken Kodama MD 《General thoracic and cardiovascular surgery》2006,54(2):289-292
We present a case of intrapulmonary metastasis developing 18 years after complete resection of thymoma. An 8 mm nodule in the lower lobe of the left lung was noted on chest X-ray in a 76-year-old woman who had undergone complete resection of Masaoka’s stage II thymoma 18 years earlier. Since the nodule grew to 17 mm during a 2-year follow-up, wedge resection was performed. The lesion was histologically diagnosed as an intrapulmonary metastasis from thymoma. Extremely late recurrence after complete resection of thymoma is discussed. 相似文献
12.
13.
Paul Steinbok Ken Poskitt D. Douglas Cochrane O. Olof Flodmark 《Child's nervous system》1991,7(1):16-20
Enhanced and non-enhanced computed tomography (CT) brain scans were performed within 72 h of surgery on 21 children in whom brain tumors had been resected totally or subtotally, and scans were repeated at varying intervals thereafter. Biopsies of the resection margins were performed in 12 patients at the end of the surgical procedure. The immediate CT scan showed enhancement in the resection margin in 13 of the 21 patients and in 9 of the 13, the enhancement disappeared on follow-up scans. There was discordance between the results of immediate CT scan examination and the biopsies of the resection margins in 7 of the 12 cases. The advantages and disadvantages of an immediate postoperative scan versus a more delayed CT scan are discussed. 相似文献
14.
15.
16.
17.
Marijuana components suppress induction and cytolytic function of murine cytotoxic T cells in vitro and in vivo. 总被引:3,自引:0,他引:3
T W Klein Y Kawakami C Newton H Friedman 《Journal of toxicology and environmental health》1991,32(4):465-477
Killer lymphocytes play a major role in host defense against tumors and infectious diseases. Previously, we reported that delta-9-tetrahydrocannabinol (THC) and II-hydroxy-delta-9-tetrahydrocannabinol (II-hydroxy-THC) suppressed the cytolytic activity of cultured natural killer (NK) cells. Also, we showed that the drugs appeared to be affecting a stage in the killing process subsequent to the binding of the killer cell to the target cell. In the present report, we have extended these studies to an examination of the effect of cannabinoids on the activity of cytotoxic T lymphocytes (CTLs). The cytolytic activity of CTLs generated by cocultivation with either allospecific stimulators or TNP-modified-self stimulators were suppressed by both THC and II-hydroxy-THC treatment. Allospecific CTLs generated in vivo were also inhibited by an in vitro exposure to either THC or II-hydroxy-THC, and the sensitivity of these cells to drug effects appeared to be greater than the sensitivity of the in vitro generated CTLs. Suppression of cytolytic function by THC and II-hydroxy-THC was maximal after a 4-h drug treatment, suggesting that the drug effects were inducible and therefore required a finite period of time to develop maximally. As seen in previous studies involving NK cells, drug treatment of mature CTLs appears to have little effect on the binding capacity of these cells for the target. However, the maximal killing capacity of the cells and the frequency of CTLs were significantly reduced by drug treatment. In addition to suppressing the cytolytic activity of mature effector CTLs, we also show that drug treatment inhibits both the proliferation of lymphocytes responding to an allogeneic stimulus and the maturation of these lymphocytes to mature CTLs. Similarly, CTL activity developing in vivo could be inhibited by THC injection. These results suggest that CTLs are inhibited by cannabinoids by at least two mechanisms. First, the cytolytic activity of mature killers is suppressed at some point beyond the binding to the target cell. Second, the cannabinoids appear to suppress the normal development of these mature effector cells from less mature precursor cells. 相似文献
18.
Paul Roderick Ruth Davies Chris Jones Terry Feest Steve Smith Ken Farrington 《Nephrology, dialysis, transplantation》2004,19(3):692-701
BACKGROUND: The demand for renal replacement therapy (RRT) in England has risen steadily, although from a lower base than many other developed countries. Predicting the future demand for RRT and the impact of factors such as the acceptance rate, transplant supply and patient survival, is required in order to inform the planning of such services. METHODS: A discrete event simulation model estimates the future demand for RRT in England in 2010 for a range of scenarios. The model uses current prevalence and current and projected future acceptance rates, survival rates and the transitions between modalities to predict future patient numbers. National population and mortality data, published literature and data from the UK Renal Registry and UK Transplant, are used to estimate unmet need for RRT, the impact of changing demography and incidence of Type 2 diabetes, patient haemodialysis (HD) survival and transplant supply. RESULTS: By 2010 the predicted prevalence will have increased from about 30,000 in 2000 to between 42 and 51,000 (900-1000 p.m.p.), an average annual growth of 4.5-6%. Changing transplant supply has a small effect on overall numbers but changes the proportion of patients with functioning graft by up to 8%. Even with an optimistic increase in transplant supply (11% p.a. for 5 years), numbers on HD will continue to rise substantially, especially in the elderly. The factors most influencing future patient numbers are the acceptance rate and dialysis survival. CONCLUSION: This model predicts a substantial growth in the RRT population to 2010 to a rate approaching 1000 p.m.p., particularly in the elderly and those on HD, with a steady state not being reached for at least 25 years. 相似文献
19.
Yoshinori Igarashi Naoki Okano Ken Ito Takahiko Mimura Kazumasa Miki 《Digestive endoscopy》2007,19(Z1):S109-S114
A 69‐year‐old man was admitted to Toho University Omori Medical Center complaining of icterus. Abdominal computed tomography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were suspicious of cholangioma of inferior bile duct. Peroral cholangioscopy using narrow band imaging (NBI) was performed and it was possible to diagnose the mucosal spread lesions of cholangioma. Histological findings reflected the endoscopic findings. Mucosal spread lesions of cholangiocarcinoma were successfully diagnosed using the CHF‐B260 for NBI. 相似文献
20.
Yutaka Senga Seiichiro Ozono Hayakazu Nakazawa Satoshi Nagamori Ken Marumo Shigeo Horie Tetsuro Onishi Noriomi Miyao Masahiro Nakao Tatsuo Igarashi Tomoyasu Tsushima Michihiko Hasegawa Masaru Murai the Japanese Society of Renal Cancer 《International journal of urology》2007,14(4):284-288
OBJECTIVE: A joint study was undertaken by the Japanese Society of Renal Cancer to investigate the present status of partial nephrectomy in Japan and to speculate about what may be the indications for partial nephrectomy in patients with renal cell carcinoma. METHODS: Data were tabulated for 469 patients from participating medical institutions and various clinical factors were investigated with regard to disease progression (local recurrence and distant metastasis). RESULTS: Disease progression was observed in 21 patients (4.5%). No significant relation to disease progression was observed for sex, laterality, tumor histology, grade and tumor size. Although patients with solitary tumors displayed excellent prognosis irrespective of tumor diameter, patients with multiple tumors displayed a high likelihood of disease progression. Patients older than 77 years old and patients with imperative indication were found to have a poorer prognosis. CONCLUSION: In patients with solitary tumors, partial nephrectomy can be actively performed, even if the patient displays elective indications and the tumor is >4 cm in diameter. In patients displaying multiple tumors with imperative indications, the decision whether to perform partial nephrectomy should be made by the patients and their physicians after considering the impact on curability and the quality of life. 相似文献