全文获取类型
收费全文 | 3451364篇 |
免费 | 248004篇 |
国内免费 | 6135篇 |
专业分类
耳鼻咽喉 | 47027篇 |
儿科学 | 112633篇 |
妇产科学 | 94009篇 |
基础医学 | 498811篇 |
口腔科学 | 98302篇 |
临床医学 | 313705篇 |
内科学 | 664409篇 |
皮肤病学 | 77039篇 |
神经病学 | 272428篇 |
特种医学 | 129174篇 |
外国民族医学 | 693篇 |
外科学 | 518346篇 |
综合类 | 76025篇 |
现状与发展 | 14篇 |
一般理论 | 1255篇 |
预防医学 | 267497篇 |
眼科学 | 82722篇 |
药学 | 254848篇 |
13篇 | |
中国医学 | 7545篇 |
肿瘤学 | 189008篇 |
出版年
2021年 | 26898篇 |
2019年 | 27781篇 |
2018年 | 39066篇 |
2017年 | 29480篇 |
2016年 | 32933篇 |
2015年 | 37187篇 |
2014年 | 52409篇 |
2013年 | 78209篇 |
2012年 | 107878篇 |
2011年 | 114356篇 |
2010年 | 68231篇 |
2009年 | 64011篇 |
2008年 | 106796篇 |
2007年 | 113793篇 |
2006年 | 115060篇 |
2005年 | 111054篇 |
2004年 | 106819篇 |
2003年 | 102394篇 |
2002年 | 98845篇 |
2001年 | 163016篇 |
2000年 | 167351篇 |
1999年 | 140358篇 |
1998年 | 39870篇 |
1997年 | 34854篇 |
1996年 | 35048篇 |
1995年 | 33251篇 |
1994年 | 30573篇 |
1993年 | 28585篇 |
1992年 | 108242篇 |
1991年 | 105204篇 |
1990年 | 101938篇 |
1989年 | 98357篇 |
1988年 | 90196篇 |
1987年 | 88287篇 |
1986年 | 83049篇 |
1985年 | 79481篇 |
1984年 | 59009篇 |
1983年 | 50282篇 |
1982年 | 29365篇 |
1979年 | 53684篇 |
1978年 | 37852篇 |
1977年 | 31787篇 |
1976年 | 30144篇 |
1975年 | 32053篇 |
1974年 | 38828篇 |
1973年 | 37182篇 |
1972年 | 34707篇 |
1971年 | 32632篇 |
1970年 | 30277篇 |
1969年 | 28628篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
J A Scatina D R Hicks M Kraml M N Cayen 《Xenobiotica; the fate of foreign compounds in biological systems》1989,19(9):991-1002
1. The disposition of AY-30,068 (I), a new tetrahydrocarbazole analgesic drug, was studied in mice, rats, dogs, rhesus monkeys, and man. 2. Oral doses of the 14C-labelled drug in aqueous solution were well absorbed in rodents, but absorption of oral doses of the crystalline drug in dogs was poor. Due to the virtual absence of serum metabolites in rats and dogs, the bioavailability of I was nearly identical to the extent of absorption. Although a small first-pass effect was observed in mice, unchanged I represented a major portion of serum radioactivity. 3. A linear increase in the serum concentrations of I occurred at doses between 0.05 and 25 mg/kg in rats, 0.1 and 50 mg/kg in dogs, and 1-160 mg in man. In rhesus monkeys given a 0.5 mg/kg oral dose, the Cmax and AUC of I were similar to values obtained following a corresponding dose in dogs. 4. After i.v. administration of a 1.0 mg/kg dose the terminal elimination half-life (t1/2 beta) of I was 4 h in mice and 9-10 h in rats and dogs. In rodents, dogs, and several human subjects, the elimination of I was interrupted by secondary peaks. Enterohepatic circulation was confirmed in bile duct cannulated rats, where the t1/2 beta of I was decreased to 2.4 h. In rodents the serum clearance and apparent volume of distribution of I were 0.04-0.2 l/kg.h and 0.5-0.8 l/kg, respectively, and 0.6 l/kg.h and 9.8 l/kg in dogs. 5. In rodents and dogs dosed with 14C-labelled I, radioactivity was excreted almost entirely in the faeces. No unchanged I was detected in rat bile, while about 70% of the radioactivity corresponded to conjugates of parent drug. 相似文献
993.
Serum aminogram changes were prospectively studied in 95 patients with enteric fistula and intraabdominal infection who was under total parenteral nutrition (TPN) therapy with Anfuming 14s. In patients with sepsis and starvation, the aminogram showed remarkably low total free amino acids before TPN therapy. In 81 survivors, free amino acids increased gradually to normal in 2 weeks after use of TPN and in 14 dead cases increased rapidly to a significantly higher peak at terminal stage. Both in survivors and nonsurvivors, phenylalanine level remained high during the study. In response to infection, proline was also elevated but to a lesser degree; the ratio of branched chain amino acid (BCAA) to aromatic amino acid (AAA) was lower than normal and the decrease of arginine was parallel to the severity of infection. We conclude that the ideal amino acids preparation for the starvated and septic patients should be high in BCAA and arginine but low in phenylalanine, administration of inappropriate exogenous amino acids in decompensated metabolic septic patients may bring about more harm than benefit, and in septic patients that the levels of serum phenylalanine and proline are elevated persistently along with the decrease of arginine level is a useful prognostic indication. 相似文献
994.
995.
996.
997.
J. Saßmannshausen N. Bornfeld A. Kluge W. Sauerwein F. Härting A. Wessing 《International ophthalmology》1989,13(4):243-251
Advanced malignant melanomas of the uvea unsuited for an eye salvaging approach require enucleation of the tumor containing eye. A series of 68 patients is reported who underwent enucleation combined with insertion of a spherical dura-encased implant after 30 Gray pre-irridiation therapy of the orbit. Postoperative results with special attention to cosmetic outcome and motility of the prosthesis suggest that the insertion of an orbital implant should be preferred to the enucleation with no implant. 相似文献
998.
Fatal and non-fatal stingray envenomation 总被引:2,自引:0,他引:2
A fatality occurred in a previously healthy 12-year-old boy after a penetrating chest injury from a stingray barb. The injury occurred under freak circumstances. Death was a result of cardiac tamponade which was secondary to venom-induced, localized myocardial necrosis and spontaneous perforation, six days after the direct penetration of the right ventricle by the barb. Three other cases of less serious stingray envenomation are described which illustrate the significant localized morbidity that may occur without immediate wound exploration and toilet after adequate anaesthesia. We also report a study of a series of 100 minor stingray envenomations which, when treated, resulted in no morbidity. It is possible that local infiltration with 1% plain lignocaine may have a direct counteraction against stingray venom that remains in the wound area. Stingray venom has insidious, but powerful, localized tissue necrosing properties in humans. 相似文献
999.
The contractile response of isolated guinea pigs common bile ducts (CBD) to transmural electrical stimulation and the effects of morphine and naloxone was studied. Contractile responses increased as a function of stimulus frequency. In the absence of naloxone morphine inhibited the contractile response to electrical stimulation in a dose-dependent manner. Naloxone prevented the inhibitory effect of morphine on the contractile response to electrical stimulation. We conclude that smooth muscle of the CBD in guinea pig is functional and can contribute to biliary motility, and that opiate receptors exist in nerve elements in the CBD. 相似文献
1000.
Dihydroxyacetone (DHA), a browning agent, protects photosensitive rats and humans against long ultraviolet radiation (UVA, 320-400 nm) and visible (blue) light. The photoprotective efficacy of DHA and structurally similar compounds was assessed as prevention of edema in the paws of psoralen-sensitized rats, after exposure to blacklight fluorescent lamps. Methylglyoxal produced a yellow-brown color and provided nearly the same protection as DHA, whereas monohydroxyacetone did not color the skin and afforded little or no protection. Glyceraldehyde provided a moderate amount of protection, which was enhanced by prior exposure of the agent to alkaline pH. A solution of 5-hydroxymethylfurfuraldehyde was yellow and provided minimal protection by staining the skin rather than browning it. We conclude that the ability to produce a brown color in skin is a useful criterion for screening compounds for photoprotective efficacy against UVA radiation. 相似文献