全文获取类型
收费全文 | 2227084篇 |
免费 | 155531篇 |
国内免费 | 4041篇 |
专业分类
耳鼻咽喉 | 32854篇 |
儿科学 | 70882篇 |
妇产科学 | 62288篇 |
基础医学 | 315501篇 |
口腔科学 | 66053篇 |
临床医学 | 195040篇 |
内科学 | 424488篇 |
皮肤病学 | 51228篇 |
神经病学 | 177002篇 |
特种医学 | 87690篇 |
外国民族医学 | 595篇 |
外科学 | 339314篇 |
综合类 | 48939篇 |
现状与发展 | 7篇 |
一般理论 | 712篇 |
预防医学 | 158141篇 |
眼科学 | 53272篇 |
药学 | 171549篇 |
9篇 | |
中国医学 | 5172篇 |
肿瘤学 | 125920篇 |
出版年
2018年 | 22765篇 |
2017年 | 18252篇 |
2016年 | 20710篇 |
2015年 | 22555篇 |
2014年 | 30800篇 |
2013年 | 46808篇 |
2012年 | 62346篇 |
2011年 | 66435篇 |
2010年 | 39035篇 |
2009年 | 36307篇 |
2008年 | 62875篇 |
2007年 | 67963篇 |
2006年 | 68463篇 |
2005年 | 65858篇 |
2004年 | 63526篇 |
2003年 | 61370篇 |
2002年 | 59897篇 |
2001年 | 106754篇 |
2000年 | 110131篇 |
1999年 | 91972篇 |
1998年 | 24789篇 |
1997年 | 22237篇 |
1996年 | 21623篇 |
1995年 | 20275篇 |
1994年 | 18824篇 |
1993年 | 17722篇 |
1992年 | 69861篇 |
1991年 | 67445篇 |
1990年 | 66283篇 |
1989年 | 64334篇 |
1988年 | 59309篇 |
1987年 | 58169篇 |
1986年 | 55420篇 |
1985年 | 52695篇 |
1984年 | 39260篇 |
1983年 | 33338篇 |
1982年 | 19629篇 |
1979年 | 36930篇 |
1978年 | 26009篇 |
1977年 | 22844篇 |
1976年 | 20526篇 |
1975年 | 23254篇 |
1974年 | 27434篇 |
1973年 | 26726篇 |
1972年 | 25394篇 |
1971年 | 23804篇 |
1970年 | 22325篇 |
1969年 | 21462篇 |
1968年 | 19816篇 |
1967年 | 17775篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
G K Freeman 《The British journal of general practice》1989,39(321):145-147
The influence of receptionists on continuity of care in four group practices was examined. Twenty two receptionists were observed making 543 appointments and afterwards were interviewed about their personal priority for continuity of care. One of the practices ran a personal list system. It was found that the personal list practice attracted more requests for a specific doctor and time which were then more difficult to satisfy. Most receptionists thought it was important that patients should see the same doctor but their influence seemed to be small compared with that of the doctor as expressed in practice policies. Marked variation in demand for individual doctors was seen in two of the practices without a personal list system. 相似文献
993.
H Ku?nierczyk J Matuszyk C Radzikowski 《Archivum immunologiae et therapiae experimentalis》1989,37(5-6):547-556
The alkylating agent ifosfamide synthesized according to own method at the Institute of Pharmaceutical Industry, Warsaw, was compared in biological evaluations with Holoxan (Asta-Werke's ifosfamide). No significant differences between tested compounds were found in respect of acute toxicity and antitumor activity in experimental systems in mice. 相似文献
994.
Michael K. Gardner Elaine Clark Mary Ann C. Bowman Patrick J. Miller 《Alcoholism, clinical and experimental research》1989,13(4):508-511
This study investigated analogical reasoning abilities of alcoholics who had been abstinent from alcohol for at least 1 year. Their performance was compared to that of nonalcoholic controls matched as a group for education, age, and gender. Solution times and error rates were modeled using a regression model. Results showed a nonsignificant trend for alcoholics to be faster, but more error prone, than controls. The same componential model applied to both groups, and fit them equally well. Although differences have been found in analogical reasoning ability between controls and alcoholics immediately following detoxification, we find no evidence of differences after extended periods of sobriety. 相似文献
995.
Maternal factors influencing development of embryos from mice superovulated with gonadotropins 总被引:5,自引:0,他引:5
In NMRI mice superovulation with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) increased mating rate, number of implantation sites, rate of advanced and delayed resorptions, as well as retarded sternebral ossification and cleft palate. On day 3 of gestation in preimplantation embryos, cell number and mitotic index were lower after superovulation than after spontaneous ovulation. However, when preimplantation embryos from superovulated and control females were transferred on day 3 of pregnancy to pseudopregnant recipients (10 embryos per female) no differences could be detected between the two groups of fetuses at term. The results of the embryo transfer experiments indicate that abnormal embryonic development after superovulation with gonadotropins is predominantly induced by effects of the hormone treatment on the maternal uterine environment. 相似文献
996.
Thiarubrine A, a dithiacyclohexadiene polyine from the roots of Chaenactis douglasii, and a related dithiacyclohexadiene from Rudbeckia hirta exhibit strong light-independent antibacterial and antifungal activity. This activity is enhanced by exposure to visible light. Visible light also converts the compounds to the corresponding thiophenes. These are antibiotic only when irradiated with UV-A. Dithiacyclohexadienes are the first polyines to exhibit such complex mechanisms of toxicity towards microorganisms. 相似文献
997.
Addison's disease is rarely caused by metastatic cancer. We report a unique case of hypoadrenalism owing to metastatic transitional cell carcinoma of the bladder. The relevant literature is reviewed. 相似文献
998.
999.
K Takeuchi O Furukawa H Tanaka H Nishiwaki S Okabe 《Japanese journal of pharmacology》1987,44(2):163-170
The effects of hemorrhagic shock (HE) on duodenal pH, acid-neutralizing capacity and mucosal tolerance to acid were investigated in anesthetized rats, and they were compared with those of indomethacin. HE was performed by bleeding from the carotid artery to reduce arterial blood pressure to about 55 mmHg (3 ml of bleeding per 200 g of body weight), and indomethacin was given s.c. in a dose of 5 mg/kg. Duodenal pH was determined in the outflow from the proximal duodenum (1.7 cm) which was perfused with 10(-4) M HCl, and acid-neutralizing capacity was measured by back-titration of the perfusate to pH 4.0 with 10 mM HCl. Under these conditions, duodenal pH was kept at around 6.0 as the result of neutralization in the loop (approximately 8 microEq/hr). Both HE and indomethacin significantly decreased the pH and acid-neutralizing capacity. Administration of 16,16-dimethyl prostaglandin E2 (16-dmPGE2: 30 micrograms/kg, s.c.) significantly increased both pH and acid-neutralizing capacity in normal and indomethacin-treated rats, but failed to affect these parameters in rats under HE conditions. When the duodenal loop was perfused with 50 mM HCl for 1.5 hr, both HE and indomethacin induced extensive damage in the mucosa. Pretreatment with 16-dmPGE2 significantly reduced the formation of duodenal lesions induced by indomethacin but not by HE. These results suggest that HE as well as indomethacin impaired duodenal acid-neutralizing capacity to reduce the tolerance to acid of the mucosa. The deleterious effects of HE on the mucosa may be mainly due to a decreased mucosal blood flow, but not due to a deficiency of endogenous prostaglandins. 相似文献
1000.
ABSTRACT. A 54-year-old profoundly mentally retarded female patient with phenylketonuria and a severe behaviour problem was treated with a restricted protein and high energy diet. After several weeks of dietary intervention the patient's behaviour improved significantly. 相似文献