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   552篇
  免费   50篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   31篇
妇产科学   10篇
基础医学   73篇
口腔科学   1篇
临床医学   75篇
内科学   123篇
神经病学   33篇
特种医学   43篇
外科学   80篇
综合类   26篇
预防医学   35篇
眼科学   1篇
药学   12篇
肿瘤学   59篇
  2022年   6篇
  2021年   11篇
  2020年   6篇
  2019年   7篇
  2018年   8篇
  2017年   10篇
  2016年   14篇
  2015年   15篇
  2014年   21篇
  2013年   22篇
  2012年   27篇
  2011年   25篇
  2010年   24篇
  2009年   17篇
  2008年   13篇
  2007年   22篇
  2006年   25篇
  2005年   14篇
  2004年   5篇
  2003年   8篇
  2002年   11篇
  2001年   7篇
  1999年   10篇
  1998年   20篇
  1997年   19篇
  1996年   17篇
  1995年   15篇
  1994年   13篇
  1993年   9篇
  1992年   5篇
  1991年   6篇
  1990年   7篇
  1989年   10篇
  1988年   12篇
  1987年   16篇
  1986年   18篇
  1985年   5篇
  1984年   12篇
  1983年   9篇
  1982年   7篇
  1980年   5篇
  1979年   11篇
  1978年   3篇
  1977年   10篇
  1974年   9篇
  1973年   3篇
  1972年   8篇
  1971年   4篇
  1970年   4篇
  1969年   3篇
排序方式: 共有603条查询结果,搜索用时 15 毫秒
91.
Afatinib is an oral, ErbB family blocker, which covalently binds and irreversibly blocks all kinase-competent ErbB family members. This phase II, open-label, single-arm study explored afatinib activity in human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients progressing after trastuzumab treatment. Patients had stage IIIB/IV HER2-positive metastatic breast cancer, with progression following trastuzumab or trastuzumab intolerance and an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2. Patients received 50 mg afatinib once-daily until disease progression. Primary endpoint was objective response rate (Response Evaluation Criteria in Solid Tumors 1.0), with tumor assessments every 8 weeks. Forty-one patients were treated. Patients had received a median of three prior chemotherapy lines (range, 0-15) and 68.3% had received trastuzumab for >1 year. Four patients (10% of 41 treated; 11% of evaluable patients) had partial response. Fifteen patients (37% of 41) had stable disease as best response and 19 (46% of 41) achieved clinical benefit. Median progression-free survival was 15.1 weeks (95% confidence interval [CI]: 8.1-16.7); median overall survival was 61.0 weeks (95% CI: 56.7-not evaluable). Most frequent common terminology criteria for adverse events grade 3 treatment-related adverse events were diarrhea (24.4%) and rash (9.8%). Afatinib monotherapy was associated with promising clinical activity in extensively pretreated HER2-positive breast cancer patients who had progressed following trastuzumab treatment.  相似文献   
92.
Mounting evidence suggests that bone marrow-derived cells (BMDC) contribute to tumor growth, angiogenesis, and metastasis. In acute reactions to cancer therapy, several types of BMDCs are rapidly mobilized to home tumors. Although this host reaction to therapy can promote tumor regrowth, its contribution to metastasis has not been explored. To focus only on the effects of chemotherapy on the host, we studied non-tumor-bearing mice. Plasma from animals treated with the chemotherapy paclitaxel induced angiogenesis, migration, and invasion of tumor cells along with host cell colonization. Lesser effects were seen with the chemotherapy gemcitabine. Conditioned medium from BMDCs and plasma from chemotherapy-treated mice each promoted metastatic properties in tumor cells by inducing matrix metalloproteinase-9 (MMP9) and epithelial-to-mesenchymal transition. In mice in which Lewis lung carcinoma cells were injected intravenously, treatment with paclitaxel, but not gemcitabine or vehicle, accelerated metastases in a manner that could be blocked by an MMP9 inhibitor. Moreover, chimeric mice reconstituted with BMDC where MMP9 activity was attenuated did not support accelerated metastasis by carcinoma cells that were pretreated with chemotherapy before their introduction to host animals. Taken together, our findings illustrate how some chemotherapies can exert prometastatic effects that may confound treatment outcomes.  相似文献   
93.
94.
95.
96.
The vertebrate immune system monitors whether an organism is invaded by pathogens. Therefore, each cell has to prove itself as healthy. This is achieved by presenting fragments of intracellular protein degradation products on the surface, i.e., each cell displays peptides on specialised proteins known as major histocompatibility complex (MHC) class I proteins. A displayed peptide has to pass certain constraints before its presentation: It has to be excised out of a protein, translocated into the endoplasmic reticulum (ER) and fit into the binding groove of a MHC molecule. In theory, alteration of the cellular protein profile by mutation or infection should force pathogen-specific T-cells to take action via recognition of foreign peptide bound to MHC class I molecules on the cell surface. Unfortunately, pathogens and tumours have evolved many ways to affect antigen presentation and to escape from immune response. Understanding the exact mechanisms of antigen presentation, i.e., protein cleavage and peptide binding by MHC molecules, would allow their manipulation by drugs and lead to the re-establishment of the correct antigen presentation pathway. This review will summarise current knowledge of the mechanisms of antigen presentation and discuss putative targets for therapeutic treatment as well as for vaccination strategies.  相似文献   
97.
Long-term disability following high-voltage electric hand injuries   总被引:3,自引:0,他引:3  
Fifty-eight patients who sustained high-voltage electric hand injuries over a ten-year period were reviewed to determine the incidence of long-term disability. Patients were divided into two groups, depending on whether or not they had sustained a current or noncurrent injury. Follow-up ranged between three months and nine years, with an average of 29.5 months. In Group A' (current group), 34 patients had 52 hand injuries. In this group, 21 patients required operative intervention to relieve vascular or neurologic compression. Thirty percent of explored limbs were subsequently amputated. Of the remaining extremities, 42% had normal function while 58% had diminished or greatly diminished function. There were 24 patients in Group B (noncurrent group) with 35 hand injuries. Function was diminished in 23%, greatly diminished in 14%, and absent in 3% of cases. The amputation rate and the residual functional deficit in Group A concurs with those of previously reported series. Although there is a significant inevitable morbidity after noncurrent injuries, many patients may benefit from nerve/muscle conduction studies and physical therapy.  相似文献   
98.
Fong  LY; Farber  JL; Magee  PN 《Carcinogenesis》1998,19(9):1591-1596
Previous work has shown that sustained increased and decreased cell proliferation, induced by dietary zinc deficiency and caloric restriction respectively, influence the course of N- nitrosomethylbenzylamine (NMBA)-induced esophageal carcinogenesis in rats. The present study considered whether the increased cell proliferation and esophageal tumor incidence induced by zinc deficiency are reversed upon zinc replenishment. Weanling rats were maintained initially on a deficient diet containing 4 p.p.m. zinc. After 5 weeks, carcinogen-treated animals were given six intragastric doses of NMBA (2 mg/kg twice weekly). Controls were untreated. After the second NMBA dose, the rats were divided into three dietary groups. One group was continued on the deficient diet, while the other two groups were switched to diets containing either 75 or 200 p.p.m. zinc, with half of the members in each group fed ad libitum and half pair-fed with deficient rats. NMBA-untreated controls were similarly replenished. At various time points, esophageal cell proliferation was assessed in five animals from each group by immunohistochemical detection of cells in S phase, with in vivo 5-bromo-2'deoxyuridine labeling. At 11 weeks after the first dose, esophageal tumor incidence was greatly reduced, from 100% in the deficient group to 26 and 14% respectively in the replenished groups fed ad libitum 75 and 200 p.p.m. zinc and to 14 and 11% respectively in the replenished groups pair-fed 75 and 200 p.p.m. zinc. In addition, the number of tumors per esophagus was reduced from 9.93 +/- 4.25 in deficient rats, to a range of 0.11 +/- 0.31-0.30 +/- 0.54 in replenished animals. Following zinc replenishment, esophageal cell proliferation, as measured by labeling index (LI), the number of labeled cells and the total number of cells, was markedly decreased in NMBA-untreated and -treated esophagi as compared with those in corresponding deficient esophagi. Thus, the esophageal cell proliferation induced by zinc deficiency is reversed by zinc replenishment and replenished animals have a markedly lower incidence of esophageal tumors.   相似文献   
99.
With use of a quantitative limulus assay, the levels of circulating endotoxins were examined in a population of burn patients with injuries covering 1% to 88% of the total body surface area (TBSA). In cases in which the injury was less than 20% TBSA, the increases in endotoxins were only 35% as compared with those of normal controls. As the extent of injury increased, the levels of endotoxins also increased: burns between 21% and 40% TBSA showed average increases of over 350% and burns in excess of 40% showed increases of 500%. The relationship between burn size and total endotoxin burden was significant (p = less than 0.01). Time-course studies indicated that in most cases, peak endotoxin levels occurred 3 to 4 days after injury. The data also showed that there was no relationship between the age of the patient and the extent of the endotoxin increase.  相似文献   
100.
Delirium is the most common mental disorder at older age in hospitals after acute admission. The pathogenesis of delirium is largely unknown. Hyperactivity of the hypothalamic‐pituitary‐adrenal axis, leading to increased cortisol levels, has been suggested to play a role in the development of delirium. The effects of cortisol, the most important glucocorticoid (GC) in humans, are mainly mediated by the GC receptor (GR). Several polymorphisms in the GR gene that alter the GC sensitivity are known. The aim of this study was to study the role of these GR polymorphisms in delirium in elderly patients. Patients aged 65 years and older admitted to the medical department or scheduled for hip surgery were included. Delirium was diagnosed using the Confusion Assessment Method. Five single nucleotide polymorphisms in the GC receptor gene were genotyped and haplotypes were constructed. Delirium was associated with impaired cognitive (P < 0.001) and functional function (P < 0.001), as well as with older age (P < 0.001). Homozygous carriers of haplotype 4, characterized by the presence of the BclI and TthIIII minor alleles, had a 92% decreased risk of developing delirium (P = 0.02), independent of age, cognitive, and functional state. Homozygous carriage of the BclI‐TthIIII haplotype of the GR gene is related to a reduced risk of developing delirium. This suggests that altered GC signaling may be involved in the pathogenesis and development of delirium in the elderly. © 2011 Wiley‐Liss, Inc.  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