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   6831篇
  免费   435篇
  国内免费   47篇
耳鼻咽喉   169篇
儿科学   290篇
妇产科学   69篇
基础医学   966篇
口腔科学   97篇
临床医学   612篇
内科学   1321篇
皮肤病学   259篇
神经病学   707篇
特种医学   462篇
外科学   1175篇
综合类   28篇
一般理论   5篇
预防医学   235篇
眼科学   102篇
药学   338篇
中国医学   8篇
肿瘤学   470篇
  2023年   38篇
  2022年   65篇
  2021年   141篇
  2020年   84篇
  2019年   137篇
  2018年   159篇
  2017年   115篇
  2016年   158篇
  2015年   218篇
  2014年   215篇
  2013年   331篇
  2012年   486篇
  2011年   463篇
  2010年   308篇
  2009年   257篇
  2008年   423篇
  2007年   473篇
  2006年   404篇
  2005年   382篇
  2004年   373篇
  2003年   343篇
  2002年   327篇
  2001年   130篇
  2000年   119篇
  1999年   116篇
  1998年   73篇
  1997年   76篇
  1996年   49篇
  1995年   49篇
  1994年   41篇
  1993年   46篇
  1992年   42篇
  1991年   46篇
  1990年   39篇
  1989年   31篇
  1988年   33篇
  1987年   47篇
  1986年   37篇
  1985年   28篇
  1984年   23篇
  1983年   26篇
  1982年   26篇
  1980年   16篇
  1979年   21篇
  1978年   22篇
  1977年   24篇
  1976年   24篇
  1975年   29篇
  1974年   21篇
  1972年   16篇
排序方式: 共有7313条查询结果,搜索用时 15 毫秒
991.
BACKGROUND: Ovarian small cell carcinoma of the hypercalcemic type is a rare neoplasm that is associated with a poor prognosis. The objective of the current study was to investigate the clinicopathologic features of this tumor and to develop preliminary diagnostic and therapeutic guidelines. METHODS: Between 1994 and 2005, 11 girls (ages 9-22 years) who were registered on the German Maligne Keimzelltumoren studies and the Kiel Pediatric Tumor Registry were analyzed. Prior to histopathologic review, 8 patients had been misdiagnosed with either germ cell tumor or juvenile granulosa cell tumor. RESULTS: According to the International Federation of Gynecologic Oncology, 4 patients had Stage IA disease, 3 patients had Stage IC disease, and 4 patients had Stage III disease. After resection, 4 patients were followed without additional therapy, and all 4 patients developed recurrent disease after 3 to 11 months. Seven patients received adjuvant chemotherapy during first-line treatment. One patient with Stage III disease received additional regional deep hyperthermia. During first-line treatment, high-dose chemotherapy was received by 4 patients who achieved a complete response (CR) after conventional chemotherapy. All 4 of those patients remained in CR for 7 to 73 months, whereas the other 3 patients developed recurrent disease. Salvage treatment after recurrence or tumor progression consisted of surgery and chemotherapy. One patient received high-dose chemotherapy in 2nd CR and remained in 2nd CR. In total, 5 patients remained alive with no evidence of disease. CONCLUSIONS: Patients with ovarian small cell carcinoma of the hypercalcemic type require multiagent chemotherapy during first-line treatment. High-dose chemotherapy may be used to consolidate the therapeutic success.  相似文献   
992.
993.
BACKGROUND: Her 2/neu gene amplification has been reported in several types of cancer. Monoclonal antibodies against the Her 2/neu receptor are used as a treatment in e.g. metastatic breast cancer. AIM: The aim of this study was to determine the frequency of additional Her 2/neu gene copies in relations to the number of chromosome 17 centromeres of patients with Sézary syndrome. METHODS: Fluorescence in situ hybridization (FISH) with probes specific for the Her 2/neu gene locus and the centromere of chromosome 17 was performed on nuclei from peripheral blood cells of 9 patients with Sézary syndrome. For analysis of Her 2/neu protein expression immunostaining was performed. In addition, FISH was used to analyze distribution of typical lymphocytes on cryo-cut sections of affected skin of two patients. RESULTS: 7/9 cases showed additional Her 2/neu gene copies in relation to the number of chromosome 17 centromeres. 4/5 cases with additional Her 2/neu gene copies in which immunostaining was performed expressed Her 2/neu protein. On cryo-cut sections atypical lymphocytes with additional Her 2/neu gene copies were detected in the dermis as well as in the epidermis of affected skin. DISCUSSION: These data suggest that Her 2/neu might be involved in the pathogenesis of Sézary syndrome and that Her 2/neu might be a promising target for antitumor therapy in a subgroup of patients.  相似文献   
994.
995.
996.
997.
The potent inflammatory mediator histamine is released from activated mast cells in interstitial cystitis (IC). Here, we report on the histamine receptor subtypes involved in the intracellular calcium response of cultured smooth muscle cells (cSMC). Fura-2 was used to monitor the calcium response in cSMC, cultured from human detrusor biopsies. The distribution of histamine receptor subtypes was addressed by immunocytochemistry in situ and in vitro. Histamine stimulated a maximum of 92% of the cells (n=335), being more effective than carbachol (70%, n=920). HTMT (H1R-agonist), dimaprit (H2R) and MTH (H3R) lead to significant lower numbers of reacting cells (60, 48 and 54%). Histamine receptor immunoreactivity (H1R, H2R, H3R, H4R) was found in situ and in vitro. Histamine-induced calcium increase is mediated by distinct histamine receptors. Thus, pre-therapeutic evaluation of histamine receptor expression in IC patients may help to optimize therapy by using a patient-specific cocktail of subtype-specific histamine receptor antagonists.  相似文献   
998.
Emergence agitation may occur after general anesthesia with volatile anesthetics in children. We designed this study to examine the emergence behavior of children undergoing ear-nose-throat surgery after sevoflurane induction and desflurane maintenance versus both sevoflurane induction and maintenance using a recently published Pediatric Anesthesia Emergence Delirium (PAED) scale. In 38 premedicated children aged 12 mo to 7 yr mask induction with sevoflurane was performed and they were randomly assigned to receive either sevoflurane (n = 19) or desflurane (n = 19) for maintenance of general anesthesia. Time to tracheal extubation, modified Aldrete score, emergence behavior, recovery complications, and pain scores were assessed. The PAED scale showed a significant advantage for desflurane (6 [0-15] versus 12 [2-20], maximum total score of 20 for severe agitation). Time to extubation was significantly shorter with desflurane than with sevoflurane (5.4 +/- 1.4 versus 13.4 +/- 1.8 min). The modified Aldrete score on arrival in the postanesthesia care unit (PACU) was significantly lower in children receiving sevoflurane for maintenance. Time to discharge from PACU to normal ward and the incidence of adverse effects were not significantly different between the groups. In conclusion, the use of desflurane for maintenance of anesthesia after sevoflurane induction in children is associated with less severe emergence agitation and faster emergence times.  相似文献   
999.
BACKGROUND: For years ABO-incompatible kidney transplantations were preferentially performed in Japanese centers. In order to overcome the increased risk of humoral rejections, patients were treated with multiple sessions of plasmapheresis, intensified immunosuppressive therapy and splenectomy before transplantation. Despite good long-term results regarding patient and organ survival rates, increased morbidity during the early post-transplant period prevented a broad application of this method. Recently, a new protocol including the anti-CD20-antibody (Ab) rituximab and blood group-specific immunoadsorption instead of splenectomy and plasmapheresis was published with excellent short-term results. METHODS: From April 2004 to September 2005, 11 patients were prepared for ABO-incompatible transplantation. All patients received 375 mg/m2 rituximab intravenous 3 to 4 weeks before transplantation. Immunosuppressive therapy consisted of tacrolimus, mycophenolate mofetil and prednisone and was started at least 7 days before transplantation. Intravenous immunoglobulins (0.5 g/kg) were administered the day before transplantation. Immunoglobulin G (IgG)-anti-A or -B Ab titers before starting immunoadsorption treatment ranged between 1 : 4 and 1 : 1024. Immunoadsorption treatment was started in parallel with immunosuppressive medication and was continued until the anti-A or anti -B Ab titers (IgG and IgM) were lowered to the aimed pre-transplant threshold of <1 : 8. During the early postoperative period, additional immunoadsorption treatments were performed, if the titers increased again above 1 : 8 (days 0 to 7) or 1 : 16 (days 8 to 14), respectively. RESULTS: Transplantation could be conducted in eight of 11 patients (two females, six males, mean recipient age 52+/-11 yr). The mean follow-up was 7.0 months (range 4 to 17). The blood group constellation was A1 to 0 in four cases, A2 to 0 in two cases, B to A in one case, and A1 to B in another case, respectively. On average, each patient received seven immunoadsorption treatments. All transplants showed primary function and no humoral rejections occurred. Three of our 11 patients showed rapid increases of isoagglutinin titers after each immunoadsorption treatment and thus could not be transplanted. One patient died 4 months after transplantation with a functioning graft due to sepsis secondary to pseudomembranous enterocolitis. The mean creatinine value of the remaining seven patients now is 1.6 mg/dl. SUMMARY: The use of antigen-specific immunoadsorption and an immunosuppressive regimen consisting of a conventional triple immunosuppressive therapy has shown excellent short-term results. The immunoadsorption treatment using antigen-specific columns is highly effective and even patients with high isoagglutinin titers can be transplanted. This protocol is an option for end-stage renal disease patients who have no blood group-compatible donor.  相似文献   
1000.
BACKGROUND: Antigen-specific immunoadsorption combined with rituximab offers the possibility for ABO-incompatible kidney transplantation without splenectomy. PATIENT AND METHOD: An 8-year-old mentally retarded girl with steroid-resistant nephrotic syndrome and focal segmental glomerulosclerosis due to mitochondriopathy poorly tolerated hemodialysis. Paternal blood group A1B was incompatible with blood group B of the child. Therefore, we decided to perform the first ABO-incompatible renal transplantation in a child in Germany using antigen-specific immunoadsorption. Rituximab (1 x 375 mg/m2) was administered 2 weeks before the first immunoadsorption (Glycosorb) ABO A-column). Triple-drug immunosuppression (tacrolimus, mycophenolate mofetil and prednisolone) was simultaneously started with immunoadsorption. Initial tacrolimus levels were targeted between 15 and 20 ng/ml. Before transplantation, six immunoadsorptions were applied on days -9, -7, -4, -3, -2 and -1. Intravenous immunoglobulin (0.5 g/kg) was administered preoperatively. After transplantation, three immunoadsorptions were performed on days +4, +6 and +8. RESULTS: Before transplantation, antibody (Ab) titers against paternal erythrocytes (20 degrees C) were reduced from 1 : 64 to 1 : 4 by six antigen-specific immunoadsorptions. After transplantation, we performed three more immunoadsorptions and the Ab titers were stable between 1 : 1 and 1 : 8. One, 2 and 8 months later we observed increases in the Ab titer up to 1 : 32 requiring no change in immunosuppressive therapy. No side effects of immunoadsorption were observed. The girl had excellent initial graft function with a serum creatinine of 55 to 70 micromol/l. Two weeks after transplantation, graft biopsy showed no signs of rejection; there was focal positivity for C4d only. Twelve months after transplantation, renal function was stable, with a serum creatinine of 117 micromol/l. Episodes of rejection or severe infections were absent. CONCLUSION: ABO-incompatible transplantation using antigen-specific immunoadsorption and rituximab may serve as a suitable alternative for children urgently needing renal transplantation and missing a blood group-compatible donor.  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