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   2058篇
  免费   98篇
  国内免费   26篇
耳鼻咽喉   3篇
儿科学   73篇
妇产科学   21篇
基础医学   262篇
口腔科学   21篇
临床医学   148篇
内科学   491篇
皮肤病学   26篇
神经病学   168篇
特种医学   23篇
外科学   341篇
综合类   8篇
预防医学   153篇
眼科学   84篇
药学   107篇
中国医学   7篇
肿瘤学   246篇
  2024年   7篇
  2023年   10篇
  2022年   37篇
  2021年   60篇
  2020年   38篇
  2019年   47篇
  2018年   40篇
  2017年   37篇
  2016年   42篇
  2015年   63篇
  2014年   48篇
  2013年   100篇
  2012年   115篇
  2011年   126篇
  2010年   70篇
  2009年   49篇
  2008年   108篇
  2007年   113篇
  2006年   125篇
  2005年   140篇
  2004年   122篇
  2003年   105篇
  2002年   133篇
  2001年   41篇
  2000年   43篇
  1999年   43篇
  1998年   22篇
  1997年   12篇
  1996年   15篇
  1995年   9篇
  1994年   12篇
  1993年   17篇
  1992年   23篇
  1991年   28篇
  1990年   23篇
  1989年   17篇
  1988年   23篇
  1987年   23篇
  1986年   11篇
  1985年   6篇
  1984年   9篇
  1983年   19篇
  1982年   6篇
  1980年   6篇
  1979年   6篇
  1974年   3篇
  1973年   4篇
  1972年   3篇
  1968年   3篇
  1966年   3篇
排序方式: 共有2182条查询结果,搜索用时 15 毫秒
51.
Hyperthermia is a promising anti-cancer treatment in which the tissue temperature is increased to 42–45 °C, and which is often used in combination with chemotherapy or radiation therapy. Our aim in the present work was to examine the feasibility of combination therapy for oral cancer with cisplatin and hyperthermia generated with ferucarbotran (Resovist®; superparamagnetic iron oxide) in an alternating magnetic field (AMF). First, we established that administration of ferucarbotran at the approved dosage for magnetic resonance imaging provides an iron concentration sufficient to increase the temperature to 42.5 °C upon exposure to AMF. Then, we examined the effect of cisplatin combined with ferucarbotran/AMF-induced hyperthermia on cultured human oral cancer cells (HSC-3 and OSC-19). Cisplatin alone induced apoptosis of cancer cells in a dose-dependent manner, as is well known. However, the combination of cisplatin with ferucarbotran/AMF was significantly more effective than cisplatin alone. This result suggests that it might be possible to reduce the clinically effective dosage of cisplatin by administering it in combination with ferucarbotran/AMF-induced hyperthermia, thereby potentially reducing the incidence of serious cisplatin-related side effects. Further work seems justified to evaluate simultaneous thermo-chemotherapy as a new approach to anticancer therapy.  相似文献   
52.
Hepatitis B virus X (HBX) protein plays a crucial role in carcinogenesis, but its mechanism is unclear. The involvement of ataxia telangiectasia mutated (ATM) kinase in the enhanced redox system was investigated by examining the phosphorylation level of ATM in HBX gene-transfected cells and in transgenic mice following redox system manipulation by treatment with hydrogen peroxide (H2O2) or antioxidant. Western blotting and immunostaining showed that phospho-ATM was significantly increased by HBX both in vitro (3.2-fold; p<0.05) and in vivo (4-fold; p<0.05), and this effect was abrogated by antioxidant treatment. The level of PKC-δ in HBX-expressing cells was increased 3.5-fold compared to controls. Nuclear localized NF-E2-related factor 2 (Nrf2) was increased in HBX-expressing cells exposed to H2O2, but remained at lower levels after the treatment with rottlerin, KU55933, or caffeine. The levels of anti-oxidant molecules were increased in HBX expressing cells and in transgenic mice, indicating that HBX stimulates the Nrf2-mediated redox system. The levels of intracellular reactive oxygen species (ROS) were significantly increased in HBX-expressing cells treated with hydrogen peroxide in the presence of ATM inhibitor KU55933 or caffeine. Treatment of HBX-expressing cells with KU55933 or caffeine before the exposure to H2O2 increased the ratio of cell apoptosis to 33 ± 4% (p<0.05) and 22 ± 4% (p<0.05), respectively. Collectively, HBX stimulates the ATM-mediated PKC-δ/Nrf2 pathway, and maintains the enhanced activity of the redox system. Therefore, manipulating ATM kinase activity might be a useful strategy for treating HBX-induced carcinogenesis.  相似文献   
53.
A 21-year-old Japanese man without known diabetes mellitus had abdominal pain. The diagnosis was ketoacidosis and hypertriglyceridemia-induced acute pancreatitis. He had polydipsia and polyuria and had habitually drunk several soft drinks every day for two years. After hospitalization, despite adequate liquid intake, dehydration remained with hypotonic polyuria. Further examinations revealed the coexistence of central diabetes insipidus (CDI), possibly caused by lymphocytic infundibulo-neurohypophysitis, based on anti-rabphilin-3A antibody positivity. Although CDI had been undiagnosed for two years, over-consumption of sugar-rich soft drinks to ease thirst caused ketoacidosis, hypertriglyceridemia, and acute pancreatitis. There are no previous reports of this three-part combination of symptoms caused by CDI.  相似文献   
54.
Journal of Neuro-Oncology - This study aimed to investigate the preoperative predictive factors affecting return to work in patients with gliomas in the left cerebral hemisphere undergoing awake...  相似文献   
55.
Analysis of anticancer immunity aids in assessing the prognosis of patients with breast cancer. From 250 operated breast cancers, we focused on serum levels of C‐C motif chemokine ligand 5 (CCL5), which is involved in cancer immune reactions. Serum levels of CCL5 were measured using a cytometric bead‐based immunoassay kit and CCL5 expression in cancer cells was determined using immunohistochemical staining. In addition, mRNA in cancer and stromal cells was analyzed by microdissection and comparison with the public dataset. Disease‐free survival (DFS) of patients with high CCL5 levels (cut‐off, 13.87 ng/mL; n = 192) was significantly better than those with low CCL5 levels (n = 58; hazard ratio, 0.20; 95% confidence interval, 0.10‐0.39; P < .0001). An improved overall survival was observed in patients with high CCL5 levels compared to those with low CCL5 levels (P = .024). On the contrary, high immunohistochemical expression of CCL5 in cancer cells was significantly associated with decreased DFS. As serum CCL5 levels did not correlate with CCL5 expression in cancer cells and the relative expression of mRNA CCL5 was elevated in stromal cells in relation to cancer cells, serum CCL5 might be derived not from cancer cells, but from stromal cells. Expression of CCL5 in serum, but not in cancer cells, might contribute to improved patient prognosis mediating through not only immune reaction, but through other mechanisms. Determination of circulating CCL5 levels could be useful for predicting patient prognosis.  相似文献   
56.
57.
58.
The surgical techniques and clinical results of quadrantectomy as a form of breast-conserving surgery are described. A quadrantectomy is a breast-conserving technique including wide resection and tumorectomy. A quadrantectomy is designed to remove an anatomic segment of breast tissue (duct-lobular system). It has the advantage of greater surgical curability than other conserving techniques in cases with ductal spread, because breast cancer arising in the terminal duct often spreads in the duct-lobular system. However, quadrantectomy poses some cosmetic problems due to the large volume of breast tissue excised. Additionally, quadrantectomy has failed to show better results in local recurrence rates compared with wide resection. Therefore quadrantectomy should be limited to breast cancer with segmental and wide ductal spread. It is important to determine the surgical technique that compromises between local curability and cosmetic results for each patient with breast cancer.  相似文献   
59.
AIM:To compare hemorrhoidectomy with a bipolar electrothermal device or hemorrhoidectomy using an ultrasonically activated scalpel.METHODS:Sixty patients with grade Ⅲ or Ⅳ hemorrhoids were prospectively randomized to undergo closed hemorrhoidectomy assisted by bipolar diathermy(group 1) or hemorrhoidectomy with the ultrasonic scalpel(group 2).Operative data were recorded,and patients were followed at 1,3,and 6 wk to evaluate complications.Independent assessors were assigned to obtain postoperative pain scores,oral analgesic requirement and satisfaction scores.RESULTS:Reduced intraoperative blood loss median 0.9 mL(95% CI:0.8-3.7) vs 4.6 mL(95% CI:3.8-7.0),P = 0.001 and a short operating time median 16(95% CI:14.6-18.2) min vs 31(95% CI:28.1-35.3) min,P < 0.0001 was observed in group 1 compared with group 2.There was a trend towards lower postoperative pain scores on day 1 group 1 median 2(95% CI:1.8-3.5) vs group 2 median 3(95% CI:2.6-4.2),P = 0.135.Reduced oral analgesic requirement during postoperative 24 h after operation median 1(95% CI:0.4-0.9) tablet vs 1(95% CI:0.9-1.3) tablet,P = 0.006 was observed in group 1 compared with group 2.There was no difference between the two groups in the degree of patient satisfaction or number of postoperative complications.CONCLUSION:Bipolar diathermy hemorrhoidectomy is quick and bloodless and,although as painful as closed hemorrhoidectomy with the ultrasonic scalpel,is associated with a reduced analgesic requirement immediately after operation.  相似文献   
60.
(1) Background: Protein stimulates the secretion of glucagon (GCG), which can affect glucose metabolism. This study aimed to analyze the metabolic effect of a high-protein diet (HPD) in the presence or absence of proglucagon-derived peptides, including GCG and GLP-1. (2) Methods: The response to HPD feeding for 7 days was analyzed in mice deficient in proglucagon-derived peptides (GCGKO). (3) Results: In both control and GCGKO mice, food intake and body weight decreased with HPD and intestinal expression of Pepck increased. HPD also decreased plasma FGF21 levels, regardless of the presence of proglucagon-derived peptides. In control mice, HPD increased the hepatic expression of enzymes involved in amino acid metabolism without the elevation of plasma amino acid levels, except branched-chain amino acids. On the other hand, HPD-induced changes in the hepatic gene expression were attenuated in GCGKO mice, resulting in marked hyperaminoacidemia with lower blood glucose levels; the plasma concentration of glutamine exceeded that of glucose in HPD-fed GCGKO mice. (4) Conclusions: Increased plasma amino acid levels are a common feature in animal models with blocked GCG activity, and our results underscore that GCG plays essential roles in the homeostasis of amino acid metabolism in response to altered protein intake.  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