全文获取类型
收费全文 | 1744630篇 |
免费 | 139259篇 |
国内免费 | 2919篇 |
专业分类
耳鼻咽喉 | 23637篇 |
儿科学 | 57322篇 |
妇产科学 | 49717篇 |
基础医学 | 248512篇 |
口腔科学 | 52116篇 |
临床医学 | 149457篇 |
内科学 | 346003篇 |
皮肤病学 | 37983篇 |
神经病学 | 141811篇 |
特种医学 | 68301篇 |
外国民族医学 | 475篇 |
外科学 | 260177篇 |
综合类 | 40389篇 |
现状与发展 | 3篇 |
一般理论 | 571篇 |
预防医学 | 140646篇 |
眼科学 | 40441篇 |
药学 | 132660篇 |
3篇 | |
中国医学 | 3485篇 |
肿瘤学 | 93099篇 |
出版年
2018年 | 19248篇 |
2017年 | 14487篇 |
2016年 | 15719篇 |
2015年 | 18178篇 |
2014年 | 24160篇 |
2013年 | 36613篇 |
2012年 | 51671篇 |
2011年 | 54324篇 |
2010年 | 31110篇 |
2009年 | 28788篇 |
2008年 | 50653篇 |
2007年 | 53529篇 |
2006年 | 53925篇 |
2005年 | 52305篇 |
2004年 | 51090篇 |
2003年 | 48663篇 |
2002年 | 47474篇 |
2001年 | 79245篇 |
2000年 | 82390篇 |
1999年 | 69472篇 |
1998年 | 18366篇 |
1997年 | 16743篇 |
1996年 | 16711篇 |
1995年 | 16385篇 |
1994年 | 15352篇 |
1993年 | 14467篇 |
1992年 | 57169篇 |
1991年 | 55371篇 |
1990年 | 54188篇 |
1989年 | 52250篇 |
1988年 | 48567篇 |
1987年 | 47850篇 |
1986年 | 45613篇 |
1985年 | 44123篇 |
1984年 | 32932篇 |
1983年 | 28387篇 |
1982年 | 16575篇 |
1981年 | 14837篇 |
1979年 | 31580篇 |
1978年 | 21814篇 |
1977年 | 18471篇 |
1976年 | 17362篇 |
1975年 | 18395篇 |
1974年 | 22551篇 |
1973年 | 21757篇 |
1972年 | 19884篇 |
1971年 | 18770篇 |
1970年 | 17232篇 |
1969年 | 16270篇 |
1968年 | 14993篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Dermal absorption of the insecticide lindane was determined following topical application of ring 14C-labeled lindane to the tail of Sprague-Dawley rats. The tail was tested as a practical alternative to the rat mid-dorsal (back) region, and the data obtained were compared to those with rat back and with those of rhesus monkeys in our previous reports. There was no significant difference between total percentage urinary 14C recovery for rats dosed on the tail with occlusive tail covers (52 +/- 6.2%; t1/2 = 2.7 d) compared to those with nonocclusive covers (55 +/- 4.4%; t1/2 = 2.9 d). Neither the total percentage urinary recovery nor the t1/2 values obtained for the rat tail and rat back models differed significantly. Carbon-14 activity was still detectable in urine samples taken after 72 d post-treatment. However, an extensive tissue analysis failed to demonstrate 14C activity persisting at 72 d, with the exception of trace levels detected in blood serum and tail tissue. Advantages of the rat tail model are highlighted. 相似文献
992.
European Surgery - Es werden in einer retrospektiven Studies die Ergebnisse von 101 Patienten, welche wegen einer komplizierten Kolondivertikulitis in den Jahren 1965 bis 1978 operiert wurden, den... 相似文献
993.
994.
995.
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
996.
997.
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
998.
A long-term clinical and therapeutic study was performed in 47 patients with mesangial IgA glomerulonephritis. The male to
female ratio was 2.9∶1. An episode of gross haematuria or the incidental discovery of asymptomatic microscopic haematuria
with associated mild proteinuria heralded the apparent onset of renal disease. At the onset of observation 18 patients (38.2%)
had high blood pressure. Other 17 patients developed hypertension during observation. Anaemia was uncommon. No essential abnormalities
in serum protein and lipid patterns were found. Twenty-nine patients (61.6%) had higher levels of serum immunoglobulins—most
frequently of IgA (42.5%). Twenty-two patients had low serum C3 levels (46.8%). The percentage of patients with renal failure increased from 21.2 to 36.1 during observation. Male sex, hypertension,
proteinuria higher than 2 g/24 h, elevated ESR, high serum IgA levels, longer duration of the disease and older age of patients
suggest an unfavourable outcome. Long-term treatment with a combination of azathioprine/acenocumarol, or indomethacin, or
levamisole has no effect on the clinical manifestation and evolution. 相似文献
999.
VECURONIUM AND ATRACURIUM IN PATIENTS WITH END-STAGE RENAL FAILURE: A Comparative Study 总被引:2,自引:0,他引:2
LEPAGE J. Y.; MALINGE M.; COZIAN A.; PINAUD M.; BLANLOEIL Y.; SOURON R. 《British journal of anaesthesia》1987,59(8):1004-1010
Twenty patients with end-stage renal failure, undergoing kidneytransplantation, were assigned randomly to receive either vecuroniumor atracurium under evoked twitch tension control. The cumulative-dosetechnique was used to obtain 95% twitch depression (vecuronium:initial bolus 15 µg kg1, increments 6 µgkg1; atracurium: initial bolus 100 µg kg1,increments 40 µg kg1). Using ED95 values derivedfrom the log-probit dose-response curves, vecuronium was 4.6times more potent than atracurium. The durations of action ofthe initial cumulativedoses (from end of injection of the lastincrement to 25% recovery) were 11.1± 3.3 min for vecuroniumand 16.2±3.9 min for atracurium (P < 0.05). In termsof duration of action of the maintenance doses (vecuronium one-quarterof the total incremental dose; atracurium one-third) some cumulationwas observed with vecuronium (interaction time x treatment;cumulation ratio 1.46 ±0.31 v. 0.98±0.10 for atracurium,P< 0.001). After 2 h of surgery, the mean recovery times(25% to 75% twitch height) did not differ (18.5±2.8 minand 16.7±4.4 min). It is concluded that vecuronium mightbe less safe than atracurium in patients with end-stage renalfailure undergoing prolonged operations. 相似文献
1000.
Phase I study of high-dose cytosine arabinoside and etoposide in patients with advanced malignancies
Bayard L. Powell Hyman B. Muss Robert L. Capizzi Mary E. Caponera Douglas R. White Patricia J. Zekan James N. Atkins Don V. Jackson Jr. Frederick Richards II John B. Craig Julia M. Cruz Charles L. Spurr 《Cancer chemotherapy and pharmacology》1987,19(3):250-252
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182 相似文献