全文获取类型
收费全文 | 82295篇 |
免费 | 4508篇 |
国内免费 | 180篇 |
专业分类
耳鼻咽喉 | 984篇 |
儿科学 | 1839篇 |
妇产科学 | 1721篇 |
基础医学 | 11036篇 |
口腔科学 | 3213篇 |
临床医学 | 6360篇 |
内科学 | 20135篇 |
皮肤病学 | 1824篇 |
神经病学 | 7223篇 |
特种医学 | 1940篇 |
外科学 | 10820篇 |
综合类 | 378篇 |
一般理论 | 33篇 |
预防医学 | 7248篇 |
眼科学 | 1531篇 |
药学 | 5632篇 |
中国医学 | 311篇 |
肿瘤学 | 4755篇 |
出版年
2024年 | 50篇 |
2023年 | 500篇 |
2022年 | 323篇 |
2021年 | 1271篇 |
2020年 | 771篇 |
2019年 | 1368篇 |
2018年 | 2485篇 |
2017年 | 1602篇 |
2016年 | 1685篇 |
2015年 | 2245篇 |
2014年 | 2358篇 |
2013年 | 3352篇 |
2012年 | 7143篇 |
2011年 | 7354篇 |
2010年 | 3324篇 |
2009年 | 2439篇 |
2008年 | 6180篇 |
2007年 | 6393篇 |
2006年 | 6341篇 |
2005年 | 6104篇 |
2004年 | 5515篇 |
2003年 | 5042篇 |
2002年 | 4785篇 |
2001年 | 1684篇 |
2000年 | 2158篇 |
1999年 | 1103篇 |
1998年 | 275篇 |
1997年 | 210篇 |
1996年 | 202篇 |
1995年 | 192篇 |
1994年 | 154篇 |
1993年 | 150篇 |
1992年 | 176篇 |
1991年 | 173篇 |
1990年 | 120篇 |
1989年 | 112篇 |
1988年 | 81篇 |
1987年 | 70篇 |
1986年 | 88篇 |
1985年 | 105篇 |
1984年 | 129篇 |
1983年 | 83篇 |
1982年 | 105篇 |
1981年 | 88篇 |
1980年 | 95篇 |
1979年 | 57篇 |
1978年 | 54篇 |
1977年 | 46篇 |
1976年 | 49篇 |
1974年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
A. B. Soares P. R. Faria L. A. Magna M. E. P. Correa C. A. de Sousa O. P. Almeida M. L. Cintra 《Journal of oral pathology & medicine》2005,34(6):368-373
BACKGROUND: Graft-vs.-host disease (GVHD) is the major cause of morbidity and mortality in patients undergoing allogeneic Bone Marrow Transplantation (BMT). The aim of our study was to identify the most relevant histological features for diagnosis of chronic Graft-vs.-Host Disease (cGVHD) in oral mucosa and minor salivary glands of 25 patients, as well as to evaluate the immunophenotype of the inflammatory cells. METHODS: Sixteen patients that were submitted to allogeneic BMT but did not present cGVHD were selected as a control group. The sections were studied on H & E and CD68, CD45, CD4, CD8, CD20 staining. RESULTS: The most frequent histologic findings in oral mucosa at the day of diagnosis of cGVHD were: hydropic degeneration of the basal layer of the epithelium, apoptotic bodies, lymphocytic infiltration, and focal or total cleavage between the epithelial and connective tissue. In the labial salivary glands (LSG), lymphocytic infiltration, acinar loss and fibrosis were the main alterations. Cytotoxic CD8-T cells and macrophages were predominant both in the epithelium and connective tissue, as well as in minor salivary glands. CONCLUSIONS: Histological features were useful in the diagnosis of oral cGVHD. It is suggested that CD8-T cells and macrophages play important role in the pathogenesis of the disease. 相似文献
73.
74.
75.
Carmen Guillén Ponce María Pilar Garrido López María José Molina Garrido Gema Muñoz Molina Alfredo Carrato 《Clinical & translational oncology》2007,9(1):53-55
Pituitary metastases of solid tumours are infrequent, specially as a first manifestation. When they happen, they are usually
due to breast or lung cancer and are asymptomatic or produce diabetes insipidus. It is very strange that they produce hormonal
deficiency.
We present a case report of a bronchogenic adenocarcinoma in a 65-year-old man which began with panhypopituitarism, diabetes
insipidus and visual alterations. Magnetic resonance imaging revealed a large sellar mass, with clivus infiltration and invading
the right cavernous sinus. The biopsy result was adenocarcinoma metastases from lung cancer. 相似文献
76.
Paulo Cezar Galv?o do Amaral Euler de Medeiros ázaro Filho Thales Delmondes Galv?o Ettinger Eric Junior Galeno Egydio José de Magalh?es Neto Fabrício Mascarenhas Edvaldo Fahel 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2006,10(3):355-358
BACKGROUND: Randomized studies demonstrate that laparoscopic appendectomy yields better results compared with open techniques. We sought to identify factors that determine an extended hospital stay among patients undergoing laparoscopic appendectomy. METHODS: This was a prospective study including 669 patients undergoing laparoscopic appendectomy. We analyzed variables that can predict the length of hospital stay. RESULTS: Of 669 patients undergoing laparoscopic appendectomy, 141 stayed in the hospital for > or = 5 days (Group 1), and 97 stayed in the hospital for < or = 1 day after surgery (Group 2). The univariate analysis demonstrated that fever (P<0.0001), nausea and vomiting (P=0.060), leukocytosis (P<0.0001), gangrened or perforated intraoperative appearance of the appendix (P<0.0001), and appendix position behind the ileocecal junction (P<0.001) were related to a longer hospital stay. The multivariate analysis through logistical regression showed that the factors independently and significantly associated with an extended hospital stay were presurgical fever, appendix position behind the ileocecal junction, and intraoperative gangrened or perforated appearance of the appendix. CONCLUSION: Fever, appearance, and position of the appendix are factors related to an extended hospital stay. 相似文献
77.
José Ignacio Bilbao Mercedes Arias Jesús María Longo Pedro Luis Alejandre María Teresa Betés Arlette María Elizalde 《Cardiovascular and interventional radiology》1997,20(2):149-153
Percutaneous embolization of large portosystemic collaterals was performed in three patients following placement of a transjugular
intrahepatic portosystemic shunt in order to improve hepatopetal portal flow. Improved hepatic portal perfusion was achieved
in these cases, thereby theoretically reducing the risk of chronic hepatic encephalopathy. 相似文献
78.
Paclitaxel is an antineoplastic agent derived from the bark of the Pacific yew tree that has activity against many tumors including breast and ovarian carcinomas. In the past, its extravasation quality has been considered to be a local irritant; however, recent reports suggest that the agent may be a vesicant. A patient experienced a delayed vesicant reaction to a paclitaxel extravasation that resulted in severe necrosis. No acute symptoms were reported at the time of extravasation from the 24-hour peripheral paclitaxel infusion. However, on day 11 the patient complained of severe and progressive pain at the site of extravasation. The site was erythematous and had areas of central necrosis requiring debridement and closure by a plastic surgeon. Because paclitaxel possesses vesicant characteristics, health care professionals should be aware of its potential extravasation hazard. Prolonged peripheral infusions should be avoided or administered with extreme caution. 相似文献
79.
For the treatment of intraabdominal infection, single-agent antimicrobial regimens such as β-lactams with good antianaerobic activity are frequent alternatives to combination regimens such as aminoglycosides or aztreonam plus an antianaerobic agent such as clindamycin or metronidazole. The major issues in selecting a regimen are relative efficacy, potential for adverse drug effects, and cost. Single agents are clearly equivalent to combinations in preventing infectious complications after penetrating abdominal trauma and in treating established intraabdominal infections of mild to moderate severity or in relatively low-risk patients. A few trials demonstrated their equivalency in patients at high risk of mortality, although experience is limited. Single-agent regimens may reduce the risks of adverse drug effects compared with combination regimens, but they are not always less expensive. 相似文献
80.
A rapid and sensitive method for measuring monooxygenase activities in hepatocytes cultured in 96-well plates 总被引:3,自引:0,他引:3
Summary Measurement of biotransformation activities in cells is of great importance for drug metabolism and toxicologic studies. It is currently done by measuring the enzymatic activities in partially purified microsomes. In the present work we report on a rapid, easy, sensitive, and reproducible fluorimetric assay for quantifying cytochrome P450-dependent monooxygenase activities (P450IA1, P450IIB1) in hepatocytes cultured in 96-well plates. The procedure involves the direct determination of enzymatic activities in intact hepatocytes while avoiding cell homogenization, thereby permitting use of a the reduced number of cells and allowing cultured cells to be used in later experiments. Substrates (7-ethoxyresorufin, 7-pentoxyresorufin) are added to culture medium and metabolized by hepatocytes. After enzymatic deconjugation, the fluorescent resorufin present in culture medium is quantified by means of a microplate fluorimetric reader. Major advantages of this technique, as compared to other available methods, are: a) no cell disruption is required; b) activity can be measured with a very small number of cells; c) rapid processing time; and d) possibility of performing repeated assays with the same cell monolayer. 相似文献