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   5585篇
  免费   247篇
  国内免费   14篇
耳鼻咽喉   42篇
儿科学   68篇
妇产科学   76篇
基础医学   675篇
口腔科学   271篇
临床医学   384篇
内科学   1029篇
皮肤病学   80篇
神经病学   318篇
特种医学   207篇
外科学   1093篇
综合类   21篇
预防医学   125篇
眼科学   25篇
药学   445篇
中国医学   19篇
肿瘤学   968篇
  2023年   22篇
  2022年   28篇
  2021年   85篇
  2020年   47篇
  2019年   70篇
  2018年   95篇
  2017年   79篇
  2016年   83篇
  2015年   81篇
  2014年   106篇
  2013年   131篇
  2012年   204篇
  2011年   229篇
  2010年   132篇
  2009年   118篇
  2008年   223篇
  2007年   247篇
  2006年   244篇
  2005年   247篇
  2004年   237篇
  2003年   258篇
  2002年   232篇
  2001年   229篇
  2000年   236篇
  1999年   189篇
  1998年   80篇
  1997年   59篇
  1996年   73篇
  1995年   59篇
  1994年   66篇
  1993年   54篇
  1992年   177篇
  1991年   155篇
  1990年   132篇
  1989年   144篇
  1988年   121篇
  1987年   119篇
  1986年   106篇
  1985年   106篇
  1984年   63篇
  1983年   57篇
  1982年   17篇
  1981年   20篇
  1979年   38篇
  1978年   23篇
  1977年   21篇
  1973年   19篇
  1972年   24篇
  1970年   22篇
  1969年   18篇
排序方式: 共有5846条查询结果,搜索用时 15 毫秒
71.
The present study was undertaken to determine whether chemoimmunotherapy using activated killer cells is better than chemotherapy alone for cancer patients with peritoneal carcinomatosis. Thirty-one cancer patients received adoptive immunotherapy by activated killer cells and chemotherapy by anticancer drugs selected by a chemosensitivity test (chemoimmunotherapy group), and another 31 cancer patients received chemotherapy (chemotherapy group). The regimen of chemotherapy was determined by the results of a chemosensitivity test in both groups. The clinical effects including response rate and survival were assessed. Five patients (16.1%) achieved complete response (CR), and 17 patients (54.8%) partial response (PR) in the chemoimmunotherapy group (response rate: 22/31 patients = 71.0%), whereas 4 patients (12.9%) achieved CR, and 5 patients (16.1%) PR in the chemotherapy group (response rate: 9/31 patients = 29.0%). The response rate was higher in chemoimmunotherapy group than in chemotherapy group (p<0.05). However, no difference was observed in survival between the two groups. Therefore, it is necessary to develop methods to induce more potent killer cells for adoptive immunotherapy.  相似文献   
72.
A new material, an emulsion of poly(vinyl acetate) was experimentally developed and clinically used to overcome several disadvantages in currently used liquid embolisation materials. The emulsion microparticles, 0.3–0.7 m in size, possessed cationic charge on the surface and hence aggregated immediately on contact with fluids containing anions. This inert polymer has the advantage that it does not induce a deleterious reaction in living tissue. Moreover, its medium is water and it is not adhesive, like the cyanoacrylates. Several concentrations of emulsion were injected into the renal arteries of dogs. For the investigation of tissue reactions and the possibility of recanalisation, the emulsion was injected into rats both subcutaneously and into the renal arteries. The renal artery injections in dogs showed adequate radiopacity and consistent complete occlusion. The lower the concentration of the emulsion, the smaller the arteries which could be occluded. Even at very low concentrations, however, venous occlusion did not occur. Histological study of the embolised rat kidney revealed no detectable damage in the vessel wall and no recanalisation for up to 6 months. The subcutaneously injected PVAc emulsion elicited mononuclear cell infiltration and gradual centripetal fibrosis, without any deleterious effect on the surrounding tissue. A cerebral arteriovenous malformation (AVM) was embolised using the material. Histology of the resected nidus showed findings similar to those in the animal experiments.  相似文献   
73.
74.
Cultivated T24 cells derived from a human bladder cancer were inoculated into the chorioallantoic membrane vein of chick embryos. Hyperthermic treatment was performed following injection of anticancer agents 3 days after the inoculation of the T24 cells. DNA samples were obtained from the livers of the chick embryos, and the polymerase chain reaction technique was used to amplify a DNA fragment specific to the human -globin gene. The Southern hybridization method was used to evaluate the inhibitory effects of anticancer agents in combination with/without hyperthermia on T24 cells metastasized to the liver. The hyperthermia exerted an inhibitory effect on the growth of the T24 cells in the livers of the chick embryos, and this was dependent on the thermal dose. The antitumor effects of hyperthermia performed at 42.5° C for 20 min and at 43.0° C for 10 min were evidenced by 69.2% an 82.0% inhibition of the growth of the metastasized T24 cells, respectively, as compared with the growth of untreated T24 cell. Hyperthermia performed at 42.5° C for 10 min alone produced 26.7% tumor growth inhibition, and these conditions for hyperthermia were subsequently used as a criterion for evaluating the effects of its combination with various anticancer agents. Adriamycin (20 g/egg) alone, mitomycin C (10 g/egg) alone, carboplatin (10 g/egg) alone, and cisplatin (10 g/egg) alone produced 13.5%, 58.9%, 27.3%, and 29.1% tumor growth inhibition, respectively. Adriamycin and mitomycin C applied in combination with hyperthermia showed additive inhibitory effects on the growth of the metastasized T24 cells in this chick embryo model.  相似文献   
75.
We analyzed association between p53 and/or Rb expression and clinicopathologic variables or Ag-NOR counts, and then ascertained whether p53 and/or Rb expression would be useful for estimating prognosis in 81 breast cancer patients. Positive p53 expression was significantly associated with post-menopausal status, axillary lymph node metastases and Ag-NOR counts, whereas low level Rb expression was significantly associated with tumor size. Moreover, the combination of p53 and Rb expression was significantly associated with Ag-NOR counts, although there was no significant association between p53 and Rb expression. In the univariate study, p53 expression as well as age and axillary lymph node metastases were significantly associated with survival, whereas Rb expression was not. In the multivariate study, p53 and/or Rb expression did not provide independent prognostic information, although axillary lymph node metastases was an important factor affecting survival. Our findings suggest that p53 and/or Rb expression may reflect tumor proliferation of breast cancer, but the prognostic value of such assays is limited.  相似文献   
76.
The relationship between nm23 expression, HPA staining, and other clinicopathological variables, i.e., axillary (AX) and internal mammary lymph node (IMN) metastases was assessed, and their prognostic values were analyzed. Positive HPA staining was found to be significantly correlated with tumor size, and with AX and IMN metastases, whereas negative nm23 expression was significantly correlated with AX and IMN metastases. A univariate study revealed that overall survival was correlated significantly with tumor size, AX and IMN metastases, and HPA staining, whereas nm23 expression did not appear to be a significant prognostic factor. In a multivariate study, only AX and IMN metastases were significant prognostic factors. When AX and IMN metastases were excluded from the Cox model, however, only HPA staining had independent prognostic value for survival. In this study, therefore, it may be concluded that HPA staining was more closely correlated with AX and IMN metastases, and with survival than nm23 expression.  相似文献   
77.
Although breast conserving treatment (BCT) has become the standard therapy for early breast cancer, breast removal is still recommended for patients with a tumor beneath the nipple or with Paget’s disease. We have employed transposition of a latissimus dorsi myocutaneous (LD-MC) flap after wide local excision of a tumor with the nipple-areola complex. A new nipple-areola complex was reconstructed on the LD-MC flap after breast irradiation. Utilizing reconstructive techniques, BCT will likely become the treatment of choice for more patients with early breast cancer.  相似文献   
78.
An 82-year-old black woman with a history of hepatocellular carcinoma presented with gastrointestinal bleeding. Barium enema and fibrocolonoscopy revealed a 4-cm polypoid mass at the level of the ascending colon with evidence of active bleeding. Biopsies of the lesion proved it to be metastatic hepatocellular carcinoma. Exploratory laparotomy revealed no further dissemination of the tumor, and the patient underwent an ileocolectomy. The serosal side of the colonic lesion was free from tumor, and there was no peritoneal implantation, direct extension, or lymph node involvement. This case represents an extremely rare presentation of metastatic hepatocellular carcinoma.  相似文献   
79.
A 32-year-old man consulted Osaka National hospital with chief complaints of dysuria and macrohematuria. DIP and CT revealed that the right kidney deviated to the lower pole of the left kidney and they fused together. The right ureter crossed over the supine. The calcified shadow existed in the lower end of the left ureter with cobra head image. He had no external anomalies. Under diagnosing crossed fused kidney (inverted L shaped) complicated the left ureterocele with a stone, transurethral incision of ureterocele (TUI) was performed. We made transverse incision and extracted stone, 7 mm in size (calcium oxalate 96% and calcium phosphate 4%). Three months later after the operation, IVP, CG and VCG revealed the down-sized ureterocele and no VUR. Crossed renal ectopia complicated many anomalies about 50%. Among them anomalies of the urinary tract was most frequent about 30%. But crossed renal ectopia with ureterocele wasn't reported so far in Japanese literature.  相似文献   
80.
BACKGROUND/PURPOSE: The N-myc amplification status in neuroblastoma has been evaluated previously for the whole tumor by the Southern blot method. The aim of this study is to evaluate the effectiveness of the fluorescence in situ hybridization (FISH) method to analyze N-myc amplification in neuroblastoma and compare the findings with those using the Southern blot method. METHODS: In 26 neuroblastoma primary tumors and metastatic lesions, the N-myc amplification status was evaluated by both the Southern blot method and FISH method. RESULTS: Of the 22 samples with no N-myc amplification using Southern blot, no cells with N-myc amplification using FISH were present in 21 of the samples. However, one metastatic liver lesion showed 16% of the nuclei to display more than 10 copies of N-myc based on FISH analysis. In the 4 remaining samples with N-myc amplification using the Southern blot method (17 copies, 15 copies, 6 copies, and 3 copies), the rates of cells with more than 10 copies of N-myc based on a FISH analysis were 79%, 68%, 94%, and 9%, respectively. CONCLUSIONS: The FISH method can detect more accurately N-myc amplification than the Southern blot method either when the rate of cells with N-myc amplification is low or intratumor heterogeneity is present.  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