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   1615篇
  免费   72篇
  国内免费   4篇
耳鼻咽喉   17篇
儿科学   31篇
妇产科学   34篇
基础医学   213篇
口腔科学   6篇
临床医学   121篇
内科学   403篇
皮肤病学   18篇
神经病学   115篇
特种医学   167篇
外科学   235篇
综合类   26篇
预防医学   55篇
眼科学   26篇
药学   58篇
中国医学   5篇
肿瘤学   161篇
  2024年   2篇
  2023年   13篇
  2022年   29篇
  2021年   55篇
  2020年   31篇
  2019年   42篇
  2018年   52篇
  2017年   38篇
  2016年   53篇
  2015年   41篇
  2014年   47篇
  2013年   67篇
  2012年   100篇
  2011年   101篇
  2010年   56篇
  2009年   54篇
  2008年   87篇
  2007年   99篇
  2006年   77篇
  2005年   68篇
  2004年   100篇
  2003年   72篇
  2002年   88篇
  2001年   26篇
  2000年   33篇
  1999年   32篇
  1998年   15篇
  1997年   12篇
  1996年   11篇
  1995年   12篇
  1994年   13篇
  1993年   13篇
  1992年   18篇
  1991年   18篇
  1990年   15篇
  1989年   9篇
  1988年   12篇
  1987年   6篇
  1986年   12篇
  1985年   19篇
  1984年   12篇
  1983年   8篇
  1981年   3篇
  1980年   7篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1974年   2篇
  1969年   1篇
  1968年   1篇
排序方式: 共有1691条查询结果,搜索用时 15 毫秒
11.
12.
Gonadotropin-releasing hormoen (Gn-RH) analogs have been used in the therapy of the endocrine-dependent cancers including the repductive tract-originated tumors. Gn-RH receptor and its transmembrane signaling pathways have been demonstrated in a high proportion of these tumors. The demonstration of existence of receptors for a hormone can better predict hormonal dependency, and might be a first step towards an effective hormonal treatment. These findings suggest the merit of further therapeutic investigations of Gn-RH analogs alone or in combination with traditional therapies in the management of Gn-RH receptor-positive tumors.  相似文献   
13.
Liver regeneration in a patient with fulminant hepatic failure (FHF) who underwent living-related partial liver transplantation (LRLT) was investigated regarding hepatic growth factors. The patient was a 16-yr-old Japanese male who developed severe subacute FHF. LRLT was performed using an extended left lobe of the ABO matched patient's mother. In the recipient, the pre-transplant levels of both plasma hepatocyte growth factor (HGF) and transforming growth factor (TGF)-beta were extremely high and rapidly decreased following the liver replacement. The liver volume evaluated using a CAT scan increased 195% after 2 wk in graft liver and 110% after 2 wk in the hepatectomized donor. The explanted liver (FHF liver), the liver from donor (normal liver), and the graft liver [the 3rd post-transplant day (POD 3)] were all investigated immunohistochemically. FHF liver: No liver regeneration was observed [proliferative cell nuclear antigen (PCNA) labeling index (L.I.): 0%]. In the liver, both HGF in the hepatocytes and c-met on the membrane of the hepatocytes were positive. TGF-beta was positive in the hepatocytes and no apoptosis was detected by the TUNEL method. Donor liver (POD 0): Few PCNA stained hepatocytes were detected. No HGF was detected but c-met was clearly detected on the cell membrane of the hepatocytes. Neither TGF-beta nor apoptosis was detected. Graft liver (POD 3): The PCNA L.I. was conspicuous at 40%. HGF was positive in non-parenchymal cells and c-met was positive in the cytoplasm of the hepatocytes. TGF-beta was negative while apoptosis was positive in the zone 3 hepatocytes. In conclusion, these findings suggested that the liver of the patient with FHF did not respond to liver regenerative stimulus, in part, through involvement of inhibitor TGF-beta. On POD 3, the transplanted graft was in a vigorous regenerative status in comparison to that in the hepatectomized donor. The HGF/c-met system is thought to be involved in the mechanism of regeneration. Intrahepatic apoptosis was detected in the graft on the 3rd post-transplant day probably due to transient ischemia in the liver, which was not related to the Fas/Fas-ligand system.  相似文献   
14.
We encountered eight rare cases of myonephropathic metabolic syndrome (MNMS) which developed as a complication of the femoral arterial cannulation (FAC) during cardiopulmonary bypass (CPB). Seven were boys ranging in age from 4–17 years, and all had undergone open heart surgery using CPB with a hemodilution technique. These eight corresponded to 1.9 per cent of the 420 patients treated with CPB before June, 1974. The pump priming fluid used was either Ringer’s lactate solution alone or that containing a small amount of colloidal solution. Duration of CPB ranged from 52 min to 2 hrs and 42 min, but the FAC period was more than 3 hrs in each case. Acute renal failure occurred in 3 and 2 required peritoneal dialysis. Severe respiratory insufficiency occurred in 2 and one died 3 months after the operation. The most effective means to prevent the development of MNMS seems to be the local cooling of the cannulated limb during FAC. MNMS did not occur in 444 cases of CPB with FAC after July 1974, and here local cooling was applied in all cases.  相似文献   
15.
Recently, bioartificial liver (BAL) treatment was reported to provide beneficial effects for patients with fulminant hepatic failure (FHF). Some success in experimental or clinical trials has been reported; however, the evaluation of BAL efficacy remains unclear, especially in comparison with other treatments for FHF. The purpose of this study was to compare the efficacy between BAL and plasma exchange (PE) in experimentally induced FHF in pigs. Pigs undergoing hepatic devascularization (HD) were placed into the following groups: no treatment (control; n = 6), BAL treatment (BAL; n = 5), and plasma exchange (PE; n = 5). Each treatment was initiated 6 h after HD and lasted for 4 h. BAL treatment significantly improved liver functions in FHF pigs. The decrease in cerebral perfusion pressure was also significantly suppressed in the pigs with BAL, and their survival time was prolonged compared with the results in pigs with PE. The effects of BAL outperform those of PE in the treatment of experimental FHF model.  相似文献   
16.
17.
We constructed a question and answer system for direct delivery of E-mail queries from the general public to the proper hospital representative and with which the system administrator can monitor E-mail replies. The system consists of two sub-systems; one is an E-mail questionnaire sub-system that automatically delivers E-mail queries to the proper person and an E-mail reply monitor sub-system with which the system administrator can monitor the E-mail replies. The monitor system compares the origin address of the E-mail reply and the destination address on a questionnaire filled out at the time the query is made. In a test of the system, 56 queries were received in 31 days, with 37 replied to. The interval from receipt of an E-mail query to reply was calculated. Nineteen replies were submitted within 2 days.  相似文献   
18.
We report a case of adenosquamous carcinoma of the stomach that produced granulocyte-colony stimulating factor (G-CSF). The patient, who had an admission diagnosis of advanced gastric cancer, had marked leukocytosis without evidence of infection. After leukemia and metastatic leukemoid reaction were excluded by bone marrow examination, a G-CSF-producing cancer was suspected as the cause of the abnormally elevated serum G-CSF level. The resected stomach tumor was histologically diagnosed as adenosquamous carcinoma; positive expression of G-CSF by tumor cells was shown with immunohistochemical detection, which confirmed the preoperative diagnosis. Recurrent disease in the liver and lymph nodes, accompanied by leukocytosis and re-elevation of serum G-CSF, developed just 3 months after the curative gastrectomy and adjuvant chemotherapy. All of the recurrent disease was resected, restoring normal levels of serum G-CSF. The patient survived for almost 2 years after the initial surgery with extensive chemotherapy, including weekly treatment with paclitaxel, before finally succumbing to liver failure secondary to extensive liver metastasis.  相似文献   
19.
 The effects of changing from a full-day to a half-day shift work before a night duty shift on physiological and psychological functions during the night shift were investigated in 12 healthy unmarried nurses working on the same ward of a university hospital. Three shift patterns, i.e., a day shift following a day shift, a night shift following a day shift, and a night shift following a half-day shift, were studied in terms of physical activity level, sympathetic and parasympathetic activity levels, cortisol, prolactin, NK cell activity, and changes in mood states. The change to the half-day shift increased the duration of sleep before night duty by about 86 min and brought wake-up times forward by about 1 h, resulting in increases in rest and time before work. In addition, the change was revealed to reduce the influence of reversed-phase circadian rhythms on autonomic nervous activity during the night shift. The score for sleepiness was significantly lower at 0500 hours following a half-day shift. There were some marginal but not significant differences in the scores reflecting the degree of vigor, tiredness and irritation during the night shift. Although the prolactin concentration was significantly decreased at the start of the night shift after the half-day shift, there was no difference in cortisol concentration or NK cell activity between the usual night shift after a day shift and the night shift after the half-day shift. The half-day shift was not observed to cause any marked change in the fixed biorhythms of these nurses. The cortisol and NK cell activity levels were low during the night shift, suggesting that the night shift itself is a high stress level, which is prejudicial to biodefense. Received: 1 August 1995/Accepted: 8 March 1996  相似文献   
20.
[Purpose] In this study, we investigated the preoperative and early postoperative health-related quality of life in patients who underwent surgical treatment for gastrointestinal cancer and also the factors that affect postoperative health-related quality of life. [Participants and Methods] The study included 198 patients who underwent elective surgery for gastrointestinal cancer (129 males and 69 females, age: 65.4 ± 11.8 years). Health-related quality of life was evaluated using the Short-Form 36-Item Health Survey version 2 at the following time points: 1–2 days preoperatively (baseline) and 4 weeks postoperatively. [Results] Compared with baseline levels, physical functioning, bodily pain, vitality, as well as physical, social, and emotional role functioning significantly decreased 4 weeks postoperatively. In contrast, compared with baseline levels, mental health significantly improved 4 weeks postoperatively. Physical functioning and general health evaluated 4 weeks postoperatively were significantly associated with income, baseline health-related quality of life, and the 6-minute walk test. [Conclusion] It is important to consider baseline income and health-related quality of life and increase postoperative exercise capacity to improve health-related quality of life in patients who undergo surgical treatment for gastrointestinal cancer.  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