全文获取类型
收费全文 | 9333篇 |
免费 | 635篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 105篇 |
儿科学 | 237篇 |
妇产科学 | 244篇 |
基础医学 | 1278篇 |
口腔科学 | 738篇 |
临床医学 | 795篇 |
内科学 | 2279篇 |
皮肤病学 | 256篇 |
神经病学 | 909篇 |
特种医学 | 133篇 |
外科学 | 938篇 |
综合类 | 54篇 |
一般理论 | 2篇 |
预防医学 | 799篇 |
眼科学 | 179篇 |
药学 | 505篇 |
中国医学 | 47篇 |
肿瘤学 | 527篇 |
出版年
2024年 | 16篇 |
2023年 | 145篇 |
2022年 | 275篇 |
2021年 | 482篇 |
2020年 | 283篇 |
2019年 | 400篇 |
2018年 | 433篇 |
2017年 | 302篇 |
2016年 | 351篇 |
2015年 | 405篇 |
2014年 | 506篇 |
2013年 | 595篇 |
2012年 | 823篇 |
2011年 | 829篇 |
2010年 | 431篇 |
2009年 | 328篇 |
2008年 | 606篇 |
2007年 | 518篇 |
2006年 | 392篇 |
2005年 | 392篇 |
2004年 | 336篇 |
2003年 | 283篇 |
2002年 | 215篇 |
2001年 | 82篇 |
2000年 | 58篇 |
1999年 | 65篇 |
1998年 | 43篇 |
1997年 | 25篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 14篇 |
1993年 | 19篇 |
1992年 | 42篇 |
1991年 | 53篇 |
1990年 | 31篇 |
1989年 | 22篇 |
1988年 | 23篇 |
1987年 | 22篇 |
1986年 | 15篇 |
1985年 | 17篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1966年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
N Scopinaro E Gianetta D Friedman G F Adami E Traverso B Vitale M Castagnola G Semino M Summa V Bachi 《Gastroenterology Clinics of North America》1987,16(3):529-531
Biliopancreatic diversion is a very effective method for weight reduction. In some instances it is too effective and needs to be revised. 相似文献
2.
3.
Enrico Bertino Carolina Bisson Claudio Martano Alessandra Coscia Claudio Fabris Giovanna Monti Tiziana Testa Amedeo Conti 《Pediatric allergy and immunology》2006,17(7):484-488
AIM: A positive correlation between maternal and cord-blood IgE levels is well documented for total IgEs, but not for specific IgEs. The difficulty in detecting specific cord-blood IgEs is due to their low concentrations, which hinder their dosage by low-sensitivity methods. The study aimed to correlate maternal and foetal specific IgEs against individual cow's milk proteins, detected by highly sensitive and specific techniques. METHODS: Cow's milk specific IgE detection was performed by chemiluminescence on 52 specimens of maternal and cord blood after cow's milk protein separation by 1D and 2D gel electrophoresis. Cow's milk protein (CMP) antigens were identified by mass spectrometry techniques. RESULTS: Specific IgEs for CMPs were found in 25/52 (48.1%) of maternal sera and in 19/52 (37%) of cord-blood sera. In order of decreasing frequency, the proteins found were BSA, IgG heavy chain, caseins and, in a single case, b-lactoglobulin. Positive cord-blood sera in all cases corresponded to a positive maternal result, and maternal and foetal immunoreactivity patterns were closely correlated. Moreover, in no case was there a positive cord-blood response with a negative maternal response. CONCLUSION: The study demonstrates a close relationship between maternal and cord-blood specific IgE patterns. The phenomenon observed could provide a model to elucidate the general production method of foetal IgEs, which might only be produced in the presence of both the corresponding maternal IgE and the related allergen. 相似文献
4.
S L Clark D J Vitale S D Minton R A Stoddard P L Sabey 《American journal of obstetrics and gynecology》1987,157(2):294-295
Fetal hydrops secondary to cystic adenomatoid malformation was detected in a second-trimester fetus. In utero thoraco-amniotic shunt placement resulted in resolution of the hydrops. At term, there was no evidence of pulmonary hypoplasia. 相似文献
5.
6.
Giammanco GM Vitale G Mansueto S Capra G Caleca MP Ammatuna P 《Journal of clinical microbiology》2005,43(12):6027-6031
A retrospective analysis by molecular-sequence-based techniques was performed to correctly identify the etiological agent of 24 Mediterranean spotted fever cases occurring in Western Sicily, Italy, from 1987 to 2001. Restriction analysis of a 632-bp PCR-amplified portion of the ompA gene allowed presumptive identification of five clinical isolates as belonging to Rickettsia conorii subsp. israelensis, the etiological agent of Israeli spotted fever (ISF). The remaining 19 rickettsial isolates were Rickettsia conorii subsp. conorii, the only pathogenic rickettsia of the spotted fever group reported in Italy until the present. Sequence analysis of the ompA gene confirmed the identification of all the R. conorii subsp. israelensis isolates and demonstrated that rickettsiosis caused by R. conorii subsp. israelensis can be traced back to 1991 in Sicily. The recorded clinical data of the five ISF patients support the idea that these strains could correlate to more-severe forms of human disease. Three of five patients experienced severe disease, and one of them died. 相似文献
7.
Vitale C Cornoldi A Gebara O Silvestri A Wajngarten M Cerquetani E Fini M Ramires JA Rosano GM 《Menopause (New York, N.Y.)》2005,12(5):552-558
OBJECTIVE: The lack of a beneficial long-term cardiovascular effect of hormone therapy and the early incidence of cardiovascular adverse events observed in recent randomized studies have been related to a heightened inflammatory effect of hormone therapy. DESIGN: We evaluated the effect of different postmenopause therapies on inflammatory markers and endothelial function in 205 postmenopausal women before and after therapy. RESULTS: all postmenopausal women, estrogens alone increased plasma levels of C-reactive protein (CRP) but decreased all other markers of inflammation including interleukin-6 (IL-6) (CRP: +75% +/- 11%, intracellular adhesion molecule: -21% +/- 4%, vascular cell adhesion molecule: -15% +/- 6%, E-selectin: -18% +/- 4%, s-thrombomodulin -10.5% +/- 3.7%, IL-6 -14% +/- 6%; percent changes, P < 0.01 compared with baseline). Raloxifene and tibolone did not significantly affect the overall inflammatory milieu. In a minority of patients, estrogen-progestogen associations and tibolone increased IL-6 levels and induced unfavorable changes on inflammation markers (CRP: +93% +/- 8%, intracellular adhesion molecule: -3% +/- 2%, vascular cell adhesion molecule: -5% +/- 2%, E-selectin: +6% +/- 2%, s-thrombomodulin: +5% +/- 2%, IL-6: +12% +/- 4%; percent changes compared with baseline). Patients with increased IL-6 levels were older and had a longer time since menopause. In all patients except those with increased IL-6 levels, hormone therapy improved endothelial function, whereas tibolone and raloxifene did not significantly change endothelial function compared with baseline. A worsening of endothelial function was detected in patients with increased IL-6 levels during therapy. CONCLUSIONS: Postmenopausal hormone therapy is associated with decreased vascular inflammation; however, in patients with a longer time since menopause, postmenopause hormone therapy may increase inflammation and worsen endothelial function. These unfavorable vascular effects may be detected by an elevation in IL-6 levels and by a lack of improvement in endothelial function. 相似文献
8.
9.
Plasma glucose and lactate, hepatic glycogen and epididymal adipose tissue lipogenesis and lipolysis were studied in Wistar audiogenic rats (WARs), a genetic model of epilepsy, under three experimental conditions, i.e., before, 3 min after and 10 min after seizures induced by intense sound exposure. Plasma glucose increased 3 min after the seizure onset and rose to a peak after 10 min. Hepatic glycogen decreased significantly in susceptible audiogenic rats compared to nonepileptic controls, even before sound stimulation. A marked ( approximately 10-fold) rise was observed in plasma lactate levels 3 and 10 min after the seizures compared to the response of the control group. Lipogenic activity showed a marked decrease even after stimulation with 25 ng/ml insulin. Based on these results, WARs showed reduced isoproterenol-stimulated lipolysis compared to control animals, whereas basal levels only differed significantly at 10 min after seizure activity. In conclusion, it can be inferred from these results that (a) the increase in plasma glucose after stimulation might result from sequential interaction of autonomic activation at seizure onset; (b) excessive muscular activity was at least partially responsible for the steady rise in plasma lactate concentrations; (c) audiogenic seizures, which increase adrenergic activity, induce desensitization of the beta-adrenergic lipolytic pathway in epididymal adipose tissue; (d) genetic selection for audiogenic seizure susceptibility results in pronounced alterations at multiple levels of metabolic regulation. 相似文献
10.
Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl(-1)) leaching solution, employed in a copper production plant, was investigated. The iron-oxidizing bacteria able to grow in the leaching solution were enriched by several batch cultivations and, after serial dilution, an abundant bacterial strain was isolated. This strain, called LA, exhibited a relatively constant rate of iron-oxidation in media containing sulfate ions at concentrations ranging from 10 to 150 gl(-1). Culture collection strains of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans showed limited abilities to grow at sulfate ion concentrations higher than 70 gl(-1). In spite of its tolerance to high sulfate concentrations, strain LA was as sensitive to NaCl as A. ferrooxidans. Comparative sequence analysis of the 16S rRNA gene of strain LA indicated that it is phylogenetically related to strains described as Leptospirillum ferrooxidans. Bacterial community DNA restriction patterns of 16S rRNA genes suggested that strain LA was a minor component of the bacterial population present in leaching solution, but is abundant in ore leached with this solution. 相似文献