全文获取类型
收费全文 | 113319篇 |
免费 | 5910篇 |
国内免费 | 349篇 |
专业分类
耳鼻咽喉 | 1729篇 |
儿科学 | 3933篇 |
妇产科学 | 3122篇 |
基础医学 | 14933篇 |
口腔科学 | 3340篇 |
临床医学 | 8176篇 |
内科学 | 27079篇 |
皮肤病学 | 3922篇 |
神经病学 | 9480篇 |
特种医学 | 2759篇 |
外国民族医学 | 30篇 |
外科学 | 15350篇 |
综合类 | 645篇 |
一般理论 | 24篇 |
预防医学 | 9943篇 |
眼科学 | 1985篇 |
药学 | 7344篇 |
中国医学 | 383篇 |
肿瘤学 | 5401篇 |
出版年
2023年 | 760篇 |
2022年 | 1421篇 |
2021年 | 3008篇 |
2020年 | 1605篇 |
2019年 | 2803篇 |
2018年 | 3507篇 |
2017年 | 2331篇 |
2016年 | 2464篇 |
2015年 | 2464篇 |
2014年 | 3704篇 |
2013年 | 5106篇 |
2012年 | 7024篇 |
2011年 | 7325篇 |
2010年 | 4243篇 |
2009年 | 3852篇 |
2008年 | 5750篇 |
2007年 | 5898篇 |
2006年 | 5791篇 |
2005年 | 5834篇 |
2004年 | 5293篇 |
2003年 | 5009篇 |
2002年 | 4780篇 |
2001年 | 3353篇 |
2000年 | 3446篇 |
1999年 | 2900篇 |
1998年 | 984篇 |
1997年 | 740篇 |
1996年 | 645篇 |
1995年 | 565篇 |
1994年 | 457篇 |
1993年 | 441篇 |
1992年 | 1346篇 |
1991年 | 1324篇 |
1990年 | 1198篇 |
1989年 | 1042篇 |
1988年 | 932篇 |
1987年 | 907篇 |
1986年 | 844篇 |
1985年 | 803篇 |
1984年 | 579篇 |
1983年 | 517篇 |
1979年 | 505篇 |
1978年 | 354篇 |
1975年 | 371篇 |
1974年 | 415篇 |
1973年 | 434篇 |
1972年 | 378篇 |
1971年 | 357篇 |
1970年 | 355篇 |
1969年 | 352篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
102.
J Sabán J L Rodríguez-García J Gil J R País S Medina 《The Netherlands journal of medicine》1991,39(5-6):350-352
The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient. 相似文献
103.
To determine the therapeutic activity on regional myocardial function of nifedipine intravenous administration (0.16 mg/kg) during short term myocardial induced ischemia, we used 6 mongrel dogs anesthetized and intubated those who we have implanted 3 pairs of ultrasonic crystals in the subendocardial layer. Utilizing an open chest canine model we performed total 1 minute and partial 2 minutes 30 seconds alternative obstructions, controlled with electromagnetic flowmeters in the anterior descending (AD) and circumflex (Cx) coronary arteries before and after drug administration. During the 70-80% obstructions we have shown a significant improvement in segment shortening, reduced by ischemia, in the ischemic and peri-ischemic zone. The ischemic markers, per cent increment of end diastolic length (% IEDL) and per cent increment of end systolic length (% IESL), have shown significant improvement during partial obstructions in the ischemic and peri-ischemic zone. After total obstructions the improvement on regional myocardial function is less marked and limited to ischemic zone. 相似文献
104.
105.
Gunnar Franzn Olav G. Klausen Ronald T. Grenko John Carstensen Bo Nordenskjld 《The Laryngoscope》1991,101(6):669-673
A retrospective study was performed on 20 patients with adenoid cystic carcinomas of major salivary glands to see if DNA. patterns correlated with their prognoses. Fourteen tumors were found to be DNA. diploid; 6 were DNA aneuploid. Histologically, all DNA-aneu-ploid tumors had solid components, compared with only 5 of the DNA-diploid tumors. All of the DNA-aneuploid tumors recurred, in contrast to only 2 of the DNA-diploid tumors; the difference was highly significant (P<0.001). All of the patients with no recurrences had DNA-diploid tumors. In our study, DNA measurements of adenoid cystic carcinomas gave statistically significant information about prognosis and correlated to histological grading. We propose that evaluation of DNA content may be performed before planning the treatment of adenoid cystic carcinomas. 相似文献
106.
BACKGROUND: Intraarterial chemotherapy of oral and oropharyngeal cancer with cisplatin (cis-diamminedichloroplatinum [II]) has experienced a revival in the last decade. Side-effects of the therapy were very low with concomitant systemic infusion of the neutralizing agent sodium thiosulphate. The requisite dose of the chemotherapeutic agent which safely leads to apoptosis of oral cancer cells has not yet been assessed in vitro, nor has the combination of cisplatin and sodium thiosulphate been examined for the potential reduction of cytotoxicity in oral cancer cells. STUDY DESIGN: In a panel of two tongue squamous cancer cell lines and an oesophageal cancer cell line as control and comparison, cisplatin (0.2-10 microgram/ml) was combined with sodium thiosulphate (0-0.5 mg/ml). RESULTS: 10 microgram/ml of cisplatin proved to be 100% antiproliferative, while any additional concentration of sodium thiosulphate decreased this effect. At the maximum dose of cisplatin, a sodium thiosulphate/cisplatin concentration relation of less than 6:1 still effected cytotoxic activity of >80%. An increase of cisplatin concentration led to higher cytotoxicity irrespective of sodium thiosulphate concentration. The oesophageal cell line was more sensitive to cisplatin and to sodium thiosulphate than the tongue cell lines. CONCLUSIONS: In this study, it was found that high concentrations of cisplatin are necessary in oral cancer to reach cytotoxic levels which support high-dose intraarterial chemotherapy by which these levels might be reached. A sodium thiosulphate/cisplatin concentration ratio within the tumour of less than 6:1 may be allowed without compromising the cytotoxic activity of cisplatin. 相似文献
107.
The right gastroepiploic artery (GEA) was used as a pedicled conduit for direct coronary artery revascularization in 20 patients presenting with more or less exhausted saphenous vein resources. The early angiographic patency of the GEA conduit appears to be satisfactory when it is connected to the right coronary artery system. A distinct disadvantage of GEA grafting is the necessity to enter the abdominal cavity, which may lead to probably rare and as yet unrecognized morbidity. Future abdominal surgery may injure the GEA conduit unless its topographic relations to the prepyloric antrum, liver and diaphragm are properly recognized. The surgeon must then be prepared to encounter antegastric, retrogastric, antehepatic, transhepatic and retrohepatic routes of the redirected intraabdominal artery. The present paper addresses this problem. Preoperative angiography of the celiac trunk and superior mesenteric artery may be helpful in decision-making when a patient reports or records show that a graft has been harvested from the abdominal cavity. 相似文献
108.
109.
J Martín de Pablos M Santano Domínguez A Blanco Yun J Sánchez Calero 《Revista española de enfermedades digestivas》1992,82(3):189-191
We report a case of a primary gastric Burkitt's lymphoma in a 8-year-old child, which first symptoms were abdominal pain, dysphagia, melena and a constitutional syndrome. The differential characteristics of this case are its peculiar gastric infiltration and the existence of oesophageal extension, which is very infrequent among this kind of tumors. 相似文献
110.
F. A. Calvo O. Abuchaibe I. Azinovic E. Tangco J. Aristu R. Martínez F. Pardo J. Alvarez-Cienfuegos J. M. Berián 《European radiology》1992,2(1):29-34
Thirty patients with malignant tumours in the upper abdomen underwent surgery and intraoperalive radiation (IORT), using electron beam, to: the surgical bed, residual or unresected tumour. The technical aspects and results of this treatment are described. Renal, adrenal, bile duct and gastrointestinal tumours were treated. along with several other lesions. The surgical procedure consisted in 10 cases simply of exposure of the tumour for IORT and in 20 the tumour was resected. The TORT dose ranged from 10 to: 20 Gv. In 13 patients, external beam radiation was also given to: residual tumour or to: areas of high risk for recurrence. Chemotherapy was given to: 10 patients. Tolerance to: the combined treatment was acceptable; with few complications related to: IORT.The median follow-up and survival time 23 months (range 4-more than 70 months). Local tumour control rate (or tumour stabilisation) is 90%. Distant metastases developed in 19 patients (63%). The actuarial survival rate for the group projected at 70 months (maximum follow-up) is 37%. IORT in useful in the management of tumours arising in the upper abdominal organs, for palliation surgery or when resectability of the tumour is in doubt. Indications for IORT include patients with uncommon tumours of the upper abdomen who are not be candidates for standardised cancer treatment.Presented at the European Congress of Radiology, Vienna, September 15–20,1991 相似文献