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   520篇
  免费   19篇
  国内免费   7篇
耳鼻咽喉   9篇
儿科学   19篇
妇产科学   11篇
基础医学   79篇
口腔科学   5篇
临床医学   21篇
内科学   191篇
皮肤病学   7篇
神经病学   10篇
特种医学   2篇
外科学   49篇
综合类   1篇
预防医学   22篇
药学   40篇
中国医学   1篇
肿瘤学   79篇
  2023年   5篇
  2022年   3篇
  2021年   14篇
  2020年   9篇
  2019年   17篇
  2018年   16篇
  2017年   12篇
  2016年   16篇
  2015年   11篇
  2014年   12篇
  2013年   17篇
  2012年   31篇
  2011年   25篇
  2010年   18篇
  2009年   14篇
  2008年   34篇
  2007年   23篇
  2006年   24篇
  2005年   29篇
  2004年   30篇
  2003年   23篇
  2002年   27篇
  2001年   8篇
  2000年   10篇
  1999年   15篇
  1998年   4篇
  1997年   4篇
  1996年   6篇
  1995年   2篇
  1993年   2篇
  1992年   6篇
  1991年   3篇
  1990年   6篇
  1989年   10篇
  1988年   10篇
  1987年   9篇
  1986年   9篇
  1985年   6篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1980年   3篇
  1979年   2篇
  1978年   1篇
  1977年   3篇
  1973年   4篇
  1971年   3篇
  1970年   1篇
  1969年   2篇
  1966年   1篇
排序方式: 共有546条查询结果,搜索用时 15 毫秒
61.
We investigated the correlation between the frequency of numerical aberrations of chromosome 17 and clinicopathological features of gastric cancer. The copy number of chromosome 17 was examined with fluorescence in-situ hybridization (FISH) in frozen specimens from 100 primary gastric cancers. Chromosomal numerical aberrations were diagnosed as chromosomal loss (single signal) or gain (triple or more signals), in each cell. The frequency of numerical aberrations of chromosome 17 correlated significantly with the depth of invasion (P < 0.01), lymph node metastasis (P < 0.0001), lymphatic invasion (P < 0.001), and venous invasion (P < 0.01). Numerical aberrations of chromosome 17 were associated with lymph node metastasis in 32 early gastric cancers. Multiple regression analysis identified the depth of invasion and numerical aberrations of chromosome 17 as independent significant determinants of lymph node metastasis. Our findings suggest that alterations in chromosome 17 may be linked with tumor progression in primary gastric cancer. Our results also indicate that numerical aberrations of chromosome 17 detected by FISH provide important information about the malignant potential (in particular, lymph node metastasis) of primary gastric cancer. (Received Feb. 22, 1998; accepted July 24, 1998)  相似文献   
62.
More than 10(4) plaque-forming units (pfu)/ml of HIV are inactivated during the alcohol fractionation step from plasma to fraction (Fr)-II+III, greater than 10(4) pfu/ml is inactivated from Fr-II+III to Fr-II and greater than 10(4) pfu/ml is inactivated during the polyethylene glycol (PEG) fractionation process from Fr-II+III to intravenous IgG (IVIG). The total inactivation rate from plasma to IVIG via Fr-II+III or Fr-II was calculated to be greater than 10(8) or 10(12), respectively. The PEG fractionation method produces an intact and unmodified IVIG. In addition, the PEG fractionation method at a low ionic strength was found to be effective for the elimination of greater than 10(5) units of other viruses, including hepatitis B, vesicular stomatitis and Sindbis viruses.  相似文献   
63.
Background  To clarify the oncological outcome of rectal well-differentiated neuroendocrine tumors (W/D NETs), we examined the clinicopathological characteristics and prognosis of patients with this neoplasm. Materials and methods  A total of 23 patients who underwent surgical treatment with lymph node dissection for rectal W/D NETs between 1973 and 2007 were reviewed. Results  Median tumor size measured preoperatively was 13 mm (range, 4–25 mm), and the median number of dissected lymph nodes was 16 (range, 1–46). The incidence of lymph node metastasis was 61% (14 of 23 cases). The smallest W/D NETs with lymph node metastasis was 10 mm in diameter. All the patients without lymph node metastasis survived without recurrence. Among 11 patients who had only regional lymph node metastasis, only one developed liver metastasis and died 13 months after initial surgery. Among three patients with lateral pelvic lymph node metastasis, two survived more than 5 years, although two had liver metastasis. Conclusions  Because the incidence of lymph node metastasis is very high in patients with rectal W/D NETs greater than 10 mm in diameter, radical surgery is required. In this series, the outcome of rectal W/D NETs patients with lateral pelvic lymph node metastasis was better than expected.  相似文献   
64.
Spontaneous perforation of a choledochal cyst with ensuing pseudocyst formation is a very rare complication. We report the development of a pseudocyst adjacent to a choledochal cyst in a very low-birth-weight infant at 2 months of age. Elective excision of the choledochal cyst and biliary tract reconstruction were successfully performed 2 months later when the infant weighed 3 kg. Delayed primary repair may be a viable alternative treatment for low-birth-weight infants with choledochal cysts.  相似文献   
65.
A clinicopathological study of 9 cases presenting axillary mass alone was reported. Histological diagnosis revealed 3 occult breast cancers, 2 apocrine gland adenocarcinomas of the skin, a carcinoma and a fibroadenoma in the axillary accessory breast, a neurogenic tumor in the axilla, and a benign lymphadenopathy. There were no clinical characteristics helpful in preoperative differential diagnosis. As the axilla includes the main lymphatic routes from the breast, the axillary tail of the breast and accessory breast, breast-associated tumors should be kept in mind in the management of patients with axillary mass as a sole clinical feature.  相似文献   
66.
The effects of intraperitoneal administration of OK-432 on tumor cells in ascites, in relation to the infiltration of effector cells and on the immune responses of the host, particularly, with regard to immune suppressive mechanisms, were investigated in 25 patients with cancerous ascites. The effects of OK-432 depended on frequency of the repeated and continuous administrations through a tube placed in the peritoneum during laparotomy. Infiltrations of neutrophils and lymphocytes were observed in the ascites within a short period after the administration and monocyte infiltration followed. Disappearance of tumor cells correlated well with the infiltration of these cells. No marked changes in the proliferative responses of peripheral blood lymphocytes were noted and decreases in serum inhibitory factor levels in sera were observed in patients given larger doses of OK-432. A marked reduction in Concanavalin-A-induced suppressor cell activities was observed after OK-432 administration. OK-432 administration probably leads to a disappearance of tumor cells by enhancing peritoneal effector cell activities and by inhibiting the induction of suppressor cell activities, in a dose dependent manner.  相似文献   
67.
Twenty-five elderly women (those 70 years or older) with borderline and malignant ovarian tumors during the past 20 years were reviewed clinico-pathologically in comparison with 160 younger women (those 69 years or younger). The following results were obtained: 1) The incidence rate of elderly women for all patients of borderline and malignant ovarian tumors was 13.5%, and did not tend to increase in the past several years. 2) The rate that the elderly woman visited first at the other department excepting the department of obstetrics and gynecology was 36%, and which was statistically higher than that of the younger woman (p less than 0.01). 3) Fifty-two % of elderly patients had some complications and the incidence was significantly higher than that (23.1%) of younger patients (p less than 0.005). 4) Histopathologically in elderly patients, 9 patients (36%) were of serous cystadenocarcinoma and 17 patients (68%) were of malignant epithelial tumor (primary ovarian cancer and malignant Brenner tumor). 5) Of elderly patients, 8 (47.1%) were in Stage III and IV, and it was higher incidence than that (33.3%) of younger patients. In advanced cases, the histological grades became more poorly. 6) The survival rate of elderly patients in Stage III and IV was significantly lower than that in Stage I and II. The various treatment for Stage III and IV patients did not demonstrate the correlation in prognosis. In contrast, the survival rate for the group treated surgically in Stage I and II was significantly higher than that of non-surgical group (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
68.
69.
70.
We designed and synthesized small-molecule activator protein-1 (AP-1) inhibitors based on a three-dimensional (3D) pharmacophore model that we had previously derived from a cyclic decapeptide exhibiting AP-1 inhibitory activity. New AP-1 inhibitors with a 1-thia-4-azaspiro[4.5]decane or a benzophenone scaffold, which inhibit the DNA-binding and transactivation activities of AP-1, were discovered using a "lead hopping" procedure. An additional investigation of the benzophenone analogues confirmed the reliability of the pharmacophore model, its utility to discover AP-1 inhibitors, and the potency of the benzophenone derivatives as a lead series.  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