全文获取类型
收费全文 | 2454402篇 |
免费 | 185754篇 |
国内免费 | 5022篇 |
专业分类
耳鼻咽喉 | 34399篇 |
儿科学 | 81412篇 |
妇产科学 | 70754篇 |
基础医学 | 353333篇 |
口腔科学 | 68404篇 |
临床医学 | 215457篇 |
内科学 | 483396篇 |
皮肤病学 | 55410篇 |
神经病学 | 196991篇 |
特种医学 | 93427篇 |
外国民族医学 | 794篇 |
外科学 | 370284篇 |
综合类 | 54376篇 |
现状与发展 | 4篇 |
一般理论 | 760篇 |
预防医学 | 191697篇 |
眼科学 | 56550篇 |
药学 | 180232篇 |
2篇 | |
中国医学 | 5380篇 |
肿瘤学 | 132116篇 |
出版年
2018年 | 27377篇 |
2017年 | 20437篇 |
2016年 | 22932篇 |
2015年 | 25982篇 |
2014年 | 35930篇 |
2013年 | 54172篇 |
2012年 | 74588篇 |
2011年 | 79362篇 |
2010年 | 46495篇 |
2009年 | 43599篇 |
2008年 | 74231篇 |
2007年 | 79309篇 |
2006年 | 80156篇 |
2005年 | 78092篇 |
2004年 | 74905篇 |
2003年 | 71745篇 |
2002年 | 70071篇 |
2001年 | 114489篇 |
2000年 | 117367篇 |
1999年 | 98446篇 |
1998年 | 28058篇 |
1997年 | 25208篇 |
1996年 | 25338篇 |
1995年 | 23981篇 |
1994年 | 22072篇 |
1993年 | 20739篇 |
1992年 | 76423篇 |
1991年 | 74006篇 |
1990年 | 72157篇 |
1989年 | 69540篇 |
1988年 | 64214篇 |
1987年 | 62981篇 |
1986年 | 59446篇 |
1985年 | 56726篇 |
1984年 | 42830篇 |
1983年 | 36723篇 |
1982年 | 22090篇 |
1981年 | 19649篇 |
1979年 | 39305篇 |
1978年 | 27788篇 |
1977年 | 23463篇 |
1976年 | 22318篇 |
1975年 | 23824篇 |
1974年 | 28404篇 |
1973年 | 27383篇 |
1972年 | 25864篇 |
1971年 | 23797篇 |
1970年 | 22471篇 |
1969年 | 21275篇 |
1968年 | 19993篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Tauseef Ahmed Alan Yagoda Howard I. Scher Cora Sternberg Robin C. Watson 《Investigational new drugs》1986,4(2):171-174
Summary Deaza-aminopterin is a folate analog which is transported more rapidly than methotrexate into cells and appears to be more active than methotrexate against human and animal tumor in vitro. Fifteen patients with advanced urothelial tract cancer were given deaza-aminopterin 30–37.5 mg/m2 IV QW. In responding patients drug was given QOW after 4–6 consecutive doses. Doses were escalated or de-escalated by 7.5 mg/m2 depending on toxicity. Twelve patients had received prior chemotherapy which included methotrexate in nine. Three patients achieved a partial remission lasting 1, 3, and 3 months respectively: all responders had previously failed methotrexate after an initial response to a methotrexate containing regimen. None of the six patients who were methotrexate naive responded to deaza-aminopterin; 3 subsequently received methotrexate without response. Mild mucositis was universal and in 5 was severe. Six patients had an increase in liver transaminases probably secondary to anti-folate hepatotoxicity. Other toxicities included diarrhea, nausea, skin rash and fever. Further studies are needed to define the precise efficacy of deaza-aminopterin in patients with urothelial tract cancers. 相似文献
992.
993.
The effect of proteases inhibitors, epsilon-amino-caproic acid and gordox, on reproduction of rotavirus SA-11 in MA-104 cells was studied by enzyme immunoassay. These inhibitors were shown to exert an inhibiting effect on rotavirus reproduction. 相似文献
994.
The possible reversal by calcium of the inhibitory action of verapamil on the atrioventricular (AV) node was investigated in anesthetized, atropinized dogs, with cardiac pacing. The His bundle potentials were recorded by endocavitory electrode and the AV node effective refractory period measured by the extrastimulus method. Calcium infusion was effective against the impairment of AV nodal conduction induced by verapamil, provided it remained moderate: the gradual rise in the plasma calcium concentration counteracted the effects of an infusion of verapamil on conduction time and effective refractory period in the AV node, as long as it did not exceed 5 mmol/L. However, beyond this level, calcium appeared less and less capable of reversing the effects of verapamil. Thus, the protective action of calcium had a bell-shaped dose-response curve, with the optimum at 5 mmol/L. This biphasic influence is consistent with the opposite opinions previously given concerning the antagonism between calcium and calcium blockers, depending on whether hypercalcemia brought into play was mild or major. In any case, the prominent role played by calcium in the slow inward current in the AV node accounts for the antagonism, observed in vivo, between calcium and verapamil. The pacemaker activity of the sinoatrial (SA) node was less influenced by both calcium blocker and calcium. 相似文献
995.
Haemophilus influenzae vaccine containing polyribosyl ribitol phosphate (PRP) or PRP covalently linked to diphtheria toxoid (PRP-D) was given to 94 healthy infants 17 to 22 months of age at the same time, but not at the same site, as a diphtheria-tetanus-pertussis booster. Systemic reactions were similar in the two vaccine groups and resembled those expected with the diphtheria-tetanus-pertussis injection alone. Six (13%) and seven (14%) of the PRP and PRP-D recipients, respectively, had minor local reactions to the Haemophilus vaccine. Among the 77 children who were not already naturally immune (ie, anti-PRP antibody concentration of less than or equal to 0.15 micrograms of protein per milliliter) before vaccination, PRP-D was significantly more effective than PRP in inducing protective levels of antibody. Only 15 (43%) of the 35 nonimmune PRP recipients achieved a concentration of greater than or equal to 0.15 microgram/mL and only seven (20%) reached a concentration greater than or equal to 1.0 micrograms/mL following vaccination. In contrast, 34 (81%) of the 42 nonimmune recipients of PRP-D had a concentration of greater than or equal to 0.15 microgram/mL following vaccine and 32 (62%) had a concentration of greater than or equal to 1.0 micrograms/mL (P less than or equal to .001). These results suggest that more than one-half of nonimmune 18-month-old infants will not respond to PRP with protective levels of antibody. In light of the current data, recommendation for revaccination at 24 months of age for those immunized at any younger age is appropriate. 相似文献
996.
J G Classé 《Journal of the American Optometric Association》1986,57(1):66-71
In establishing the liability of optometrists for negligence the courts have applied the same standard of care that is imposed upon other health care professionals, holding that optometrists must employ the minimum degree of skill, care and learning that is ordinarily exhibited by members of the profession who are in good standing. The leading cases establishing this standard have involved glaucoma, retinal detachment, and intraocular tumors. Optometrists have also been held liable under product liability law for injuries caused by ophthalmic lenses, which illustrates the trend toward strict liability. Other cases have involved the doctrine of informed consent. 相似文献
997.
Bromocriptine (0.5 mg/kg) and apomorphine (0.03 mg/kg) exert moderate aphrodisiac effect in sexually sluggish rats. This effect appears rapidly and reaches its peak within 24 h. Amphetamine (2 mg/kg) acts similarly but with a more rapid onset and offset of the effect. A single dose of (-)deprenyl, a selective inhibitor of MAO-B, exerts a much more potent effect in this test. 相似文献
998.
Defecation dynamics and behavior profiles in encopretic children 总被引:2,自引:0,他引:2
The social competence and behavioral profiles of 38 encopretic children were evaluated, and the social competence and behavioral ratings were correlated with physiologic abnormalities found during anorectal manometric and EMG evaluation and with treatment outcome. When defecation was studied, 66% of encopretic children were not able to defecate rectal balloons and 63% were not able to relax the external anal sphincter during defecation attempts. Total social competence and behavior problem scores were not different for boys able and unable to defecate balloons. Total social competence scores were significantly lower in girls unable to defecate balloons than in those able to (P less than .006), whereas behavior problem scores were similar in girls able to and unable to defecate. We found that persistence of encopresis at 6-month and 12-month follow-up was not related to the social competence (P greater than .2) or behavioral scores (P greater than .2) but was significantly related to the inability to defecate (P less than .01) and to the inability to relax the external sphincter during defecation attempts (P less than .03). 相似文献
999.
1000.
F C Martin 《The Practitioner》1987,231(1431):848-852