全文获取类型
收费全文 | 2999篇 |
免费 | 376篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 83篇 |
妇产科学 | 299篇 |
基础医学 | 229篇 |
口腔科学 | 61篇 |
临床医学 | 931篇 |
内科学 | 520篇 |
皮肤病学 | 82篇 |
神经病学 | 60篇 |
特种医学 | 253篇 |
外科学 | 252篇 |
综合类 | 89篇 |
一般理论 | 1篇 |
预防医学 | 169篇 |
眼科学 | 48篇 |
药学 | 135篇 |
中国医学 | 29篇 |
肿瘤学 | 120篇 |
出版年
2023年 | 51篇 |
2022年 | 29篇 |
2021年 | 47篇 |
2020年 | 61篇 |
2019年 | 79篇 |
2018年 | 104篇 |
2017年 | 120篇 |
2016年 | 106篇 |
2015年 | 125篇 |
2014年 | 142篇 |
2013年 | 172篇 |
2012年 | 129篇 |
2011年 | 177篇 |
2010年 | 149篇 |
2009年 | 143篇 |
2008年 | 104篇 |
2007年 | 118篇 |
2006年 | 89篇 |
2005年 | 76篇 |
2004年 | 72篇 |
2003年 | 74篇 |
2002年 | 55篇 |
2001年 | 55篇 |
2000年 | 40篇 |
1999年 | 70篇 |
1998年 | 100篇 |
1997年 | 112篇 |
1996年 | 107篇 |
1995年 | 98篇 |
1994年 | 70篇 |
1993年 | 50篇 |
1992年 | 31篇 |
1991年 | 35篇 |
1990年 | 15篇 |
1989年 | 44篇 |
1988年 | 41篇 |
1987年 | 27篇 |
1986年 | 37篇 |
1985年 | 34篇 |
1984年 | 16篇 |
1983年 | 18篇 |
1982年 | 20篇 |
1981年 | 12篇 |
1980年 | 15篇 |
1979年 | 12篇 |
1978年 | 17篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1975年 | 18篇 |
1974年 | 8篇 |
排序方式: 共有3389条查询结果,搜索用时 15 毫秒
1.
2.
D Van Neste† RM Trüeb‡ 《Journal of the European Academy of Dermatology and Venereology》2006,20(5):578-583
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials. 相似文献
3.
Circulating immune complex levels in patients with schistosomiasis and complications 总被引:3,自引:0,他引:3
A M Ghanem F N Boctor S Bassily H Shaheen A Ahmed L Garges 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1987,81(5):773-777
Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera. 相似文献
4.
Extracorporeal membrane oxygenation for the circulatory support of children after repair of congenital heart disease 总被引:1,自引:0,他引:1
M D Klein K W Shaheen G C Whittlesey W W Pinsky E Arciniegas 《The Journal of thoracic and cardiovascular surgery》1990,100(4):498-505
We have treated 39 infants and children with congenital heart disease with extracorporeal membrane oxygenation during the past 5 years. Thirty-six were treated for low cardiac output or pulmonary vasoreactive crisis after repair of congenital heart defects. Twenty-two (61%) survived. Most patients were cannulated from the neck via the right internal jugular vein and the right common carotid artery. Six patients were cannulated from the chest, including three who had separate drainage of the left side of the heart with a left atrial cannula. Two of these patients survived and were the only survivors of the nine patients cannulated in the operating room because they could not be weaned from cardiopulmonary bypass after open cardiac operations. We also reviewed 312 patients (the predictor study series) having open cardiac operations before the availability of extracorporeal membrane oxygenation; 27 of these patients died. Data were collected at 1 and 8 hours postoperatively to determine if any parameters might predict early mortality. With these parameters used as criteria, patients who went on extracorporeal membrane oxygenation were as sick as those who died before extracorporeal membrane oxygenation was available. The most common complication was bleeding related to heparinization. The mean transfusion requirement in survivors was 1.50 +/- 1.13 ml/kg/hr, 5.63 +/- 7.0 ml/kg/hr in the nonsurvivors, and 7.46 +/- 8.29 ml/kg/hr in those cannulated in the operating room because they could not be weaned from bypass. Four children had intracranial hemorrhage, and two of them died. There was one late death. Nine of the 22 survivors are entirely normal. All survivors who do not have Down's syndrome are considered to have normal central nervous system function. We conclude that extracorporeal membrane oxygenation can improve survival in patients with both pulmonary artery hypertension and low cardiac output after operations for congenital heart disease. 相似文献
5.
A young woman was bitten on the shoulder by a female Steatoda nobilis spider, in Worthing on the south coast of England. She noticed intense radiating pain, local sweating (indicating parasympathetic stimulation) and feverishness. This immigrant species from the Canary Islands has established itself along the south coast of England in recent years. Like the related Mediterranean species S. paykulliana, S. nobilis may be of medical importance and deserves further study. 相似文献
6.
V Schleyer† S Radakovic-Fijan‡ S Karrer† T Zwingers§ A Tanew‡ M Landthaler† RM Szeimies† 《Journal of the European Academy of Dermatology and Venereology》2006,20(7):823-828
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile. 相似文献
7.
8.
9.
M Wood J Uetrecht J M Phythyon S Shay B J Sweetman O Shaheen A J Wood 《Anesthesia and analgesia》1986,65(5):481-488
Because the H2-receptor antagonist cimetidine has been shown to inhibit drug metabolism, the effects of cimetidine on anesthetic metabolism and toxicity were investigated in a rat model. Cimetidine decreased inorganic plasma fluoride production after methoxyflurane administration both in 21% oxygen (P less than 0.001) and in 100% oxygen (P less than 0.001). Phenobarbital produces an increased fluoride formation after methoxyflurane anesthesia, and this fluoride formation is also reduced by cimetidine (P less than 0.005). There was no significant difference between the plasma fluoride levels in rats anesthetized with halothane or enflurane. Although cimetidine inhibited the in vivo defluorination of methoxyflurane, fluoride levels were still within the nephrotoxic range, and cimetidine is not likely to play a role as part of a preanesthetic regimen that would permit the increased clinical use of methoxyflurane. Cimetidine also inhibited the oxidative metabolism of halothane; cimetidine decreased (P less than 0.05) trifluoroacetic acid concentrations after halothane anesthesia in 21% oxygen and in 100% oxygen and decreased (P less than 0.05) bromide concentrations after halothane anesthesia in 100% oxygen. Trifluoroacetic acid levels were less (P less than 0.02) after halothane anesthesia in 14% oxygen as compared with 100% oxygen, indicating a reduction in oxidative metabolism under hypoxic conditions. However, bromide concentrations were maximal after halothane anesthesia in 21% oxygen, and significantly (P less than 0.001) less after halothane anesthesia in 14% and 100% oxygen. Bromide production, therefore, seems to be inhibited by both hypoxia and hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.