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   12572篇
  免费   639篇
  国内免费   52篇
耳鼻咽喉   224篇
儿科学   152篇
妇产科学   155篇
基础医学   1504篇
口腔科学   430篇
临床医学   771篇
内科学   2731篇
皮肤病学   190篇
神经病学   1070篇
特种医学   797篇
外科学   2313篇
综合类   55篇
预防医学   311篇
眼科学   236篇
药学   816篇
中国医学   19篇
肿瘤学   1489篇
  2023年   53篇
  2022年   123篇
  2021年   224篇
  2020年   138篇
  2019年   214篇
  2018年   266篇
  2017年   198篇
  2016年   235篇
  2015年   188篇
  2014年   303篇
  2013年   351篇
  2012年   601篇
  2011年   599篇
  2010年   343篇
  2009年   280篇
  2008年   542篇
  2007年   559篇
  2006年   620篇
  2005年   542篇
  2004年   519篇
  2003年   474篇
  2002年   549篇
  2001年   469篇
  2000年   480篇
  1999年   457篇
  1998年   195篇
  1997年   148篇
  1996年   126篇
  1995年   110篇
  1994年   101篇
  1993年   85篇
  1992年   306篇
  1991年   273篇
  1990年   292篇
  1989年   304篇
  1988年   262篇
  1987年   263篇
  1986年   231篇
  1985年   209篇
  1984年   142篇
  1983年   97篇
  1981年   52篇
  1979年   81篇
  1978年   59篇
  1977年   50篇
  1973年   46篇
  1972年   48篇
  1971年   49篇
  1970年   47篇
  1969年   54篇
排序方式: 共有10000条查询结果,搜索用时 710 毫秒
61.
PURPOSE: We assessed the feasibility of utilizing three-dimensional (3D) phase sensitive inversion recovery (IR) images for preoperatively determining deep brain stimulator position. METHODS: We measured geometric distortion with a grid phantom and evaluated images of 3 volunteers to determine optimum imaging parameters for 3D phase sensitive IR. RESULTS: Geometric distortion measured less than 1.0%. Respective inversion and recovery times, which provided high T(1) contrast between the subthalamic nucleus and adjacent tissue, were 200 and 4000 ms. In studies of 3 volunteers and 2 patients, the subthalamic nucleus was clearly depicted in 3D phase sensitive IR images. The measured coordinates of the subthalamic nucleus agreed well with those calculated by conventional estimation from midpoint of the anterior and posterior commissure. CONCLUSION: Three-dimensional phase sensitive inversion recovery was useful in visualizing the subthalamic nucleus for effective deep brain stimulation.  相似文献   
62.
In the present case, a patient in whom limb apraxia and asymmetrical parkinsonism developed suggesting corticobasal degeneration, is reported. Neuropathologic examination revealed numerous tufted astrocytes in the precentral cortex in addition to the characteristic pathologic findings of PSP. Therefore, on the basis of clinicopathologic features, atypical progressive supranuclear palsy was diagnosed. In addition, the brain tissue of the present patient was investigated with an antibody specific for four‐repeat tau (4R‐tau). In the precentral cortex, numerous tau‐positive tufted astrocytes, pretangles, and threads were positive for 4R‐tau. Using a confocal microscopy we demonstrated that tufted astrocytes positive for 4R‐tau were adjacent to astrocytes positive for GFAP. The present findings suggest that accumulation of four‐repeat tau in astrocytes is a degenerative process rather than a reactive process.  相似文献   
63.
64.
A rare case of primary linitis plastica carcinoma of the colon seen in a 44 year old Japanese man is described herein. The patient had a complete obstruction of the descending colon and was treated with a loop colostomy followed shortly afterward by a left hemicolectomy. At the time of the second operation, the entire thickness of the colonic wall was found to be infiltrated by cancer cells, however, the other intraabdominal organs were free of cancerous involvement. The histopathological diagnosis made at this time was primary linitis plastica carcinoma of the descending colon. Nine months later, the patient developed an intestinal obstruction and relaparotomy revealed diffuse peritoneal dissemination. Two years after the first operation, upper GI films and a gastrofiberscopic examination revealed gastric involvement. The patient died 28 months after his initial operation, and autopsy revealed widespread metastases in the peritoneal surface, paraaortic lymph nodes, small intestine, remaining colon and stomach.  相似文献   
65.
Neural responses in the dorsal motor nucleus of the vagus (DMV) to topical administrations of sodium and portal infusions of hypertonic saline were investigated electrophysiologically by using multibarrel electrodes in anesthetized rats. Of 102 neurons that showed antidromic response to electrical stimulation of the ventral gastric vagus or the accessory celiac vagus, 51 neurons increased and 13 neurons decreased their discharge rates in response to the electrophoretic administration of sodium. The other 38 neurons did not respond to this stimulation. The portal infusion of hypertonic saline elicited neural responses of some DMV neurons whose axons are involved into either the ventral gastric or the accessory celiac vagus. Further, effects of the topical administration and the portal infusion of hypertonic saline were examined on 33 neurons. Typical response was characterized by an increase in discharge rate responding to both of the portal infusion and the topical administration. In conclusion, the DMV neurons receiving the afferent inputs from hepatoportal osmoreceptors may have an enteroceptor function detecting the change in osmotic pressure of their environment.  相似文献   
66.
Pulmonary aspergillosis associated with old tuberculosis is generally resistant to treatment. Thus, if patients are treated only with conservative therapy, their condition continues to deteriorate due to repetitive hemoptysis, and may even become critical. Surgical treatment is required for these patients; however, it is extremely difficult to resect the lesion due to severe adhesions to the chest wall and vascular proliferation surrounding the lesion. We performed preoperative arterial embolization, achieving good results in three patients with hemoptysis caused by pulmonary aspergillosis. The feeding arteries were embolized using microcoils and/or gelatin sponges, and a lobectomy was safely carried out in all patients. We concluded that preoperative arterial embolization is a safe and effective technique to prevent massive hemorrhage occurring at the time of surgery. This work was presented at the 11th Annual Meeting of the Japanese Association for Chest Surgery, held in Kyoto, Japan, May 13–14, 1994  相似文献   
67.
68.
This study examines the pulmonary hemodynamics during reimplantation and rejection following unilateral lung transplantation in dogs. Nineteen mongrel dogs were divided into three groups according to the method of treatment used: group 1 (n = 6) underwent modified autotransplantation of the left lung; group 2 (n = 6), allotransplantation without immunosuppression; and group 3 (n = 7), allotransplantation with immunosuppression. The pulmonary arterial blood flow and ventilation scores, assessed by chest X-rays, were measured for 2 weeks postoperatively. Pulmonary blood flow to the transplanted lung decreased slightly in group 1, whereas in group 2, it decreased sharply from the 3rd postoperative day (POD) and was almost completely absent by the 14th POD. In group 3, it decreased by 28% on the 1st POD but recovered gradually to 37% by the 14th POD. Ventilation scores were the same among the three groups on the 1st POD but in group 2, they decreased rapidly from the 3rd POD. This change correlated well with that of the pulmonary arterial (PA) flow, although the ventilation score changed after the PA flow did. In conclusion, rejection was reflected earlier and more distinctly by the changes in PA flow than by chest X-rays.  相似文献   
69.
Case 1: A 48-year-old male with stage 4 penile cancer is reported. We used peplomycin (PEP) and cisplatinum (CDDP) for preoperative chemotherapy. Chemotherapy was effective. Radical surgery with bilateral inguinal lymphadenectomy was done and skin defect was covered with a skin flap. Case 2: A 61-year-old male with stage 4 penile cancer underwent radical surgery after modified MBD therapy with methotrexate (MTX), PEP and CDDP. Emasculation with skin resection and inguinal and pelvic lymphadenectomy were performed. The skin defect was deep and wide. It was covered with a glacilis myocutaneous skin flap. Distal end of the flap became necrotic. It was covered with tensor fascia lata myocutaneous flap. Seventeen patients with penile cancer were treated between 1972 and 1990 at Mie University Hospital. Nine patients were in stage 1, 4 stage 2, 1 stage 3, 3 stage 4. Treatment consisted of surgery (3), surgery+chemotherapy (10), surgery+chemotherapy+irradiation (2), chemotherapy+irradiation (1), and surgery+irradiation(1). Cancer death was observed in 2 cases (stage 2), 2 patients died of other diseases, 10 are alive, and 3 patients were lost to follow up.  相似文献   
70.
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