全文获取类型
收费全文 | 1566篇 |
免费 | 123篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 36篇 |
妇产科学 | 34篇 |
基础医学 | 136篇 |
口腔科学 | 73篇 |
临床医学 | 109篇 |
内科学 | 472篇 |
皮肤病学 | 32篇 |
神经病学 | 158篇 |
特种医学 | 56篇 |
外科学 | 163篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 153篇 |
眼科学 | 17篇 |
药学 | 176篇 |
中国医学 | 9篇 |
肿瘤学 | 40篇 |
出版年
2022年 | 14篇 |
2021年 | 28篇 |
2020年 | 17篇 |
2019年 | 18篇 |
2018年 | 21篇 |
2017年 | 24篇 |
2016年 | 30篇 |
2015年 | 30篇 |
2014年 | 47篇 |
2013年 | 48篇 |
2012年 | 78篇 |
2011年 | 73篇 |
2010年 | 53篇 |
2009年 | 52篇 |
2008年 | 43篇 |
2007年 | 64篇 |
2006年 | 52篇 |
2005年 | 67篇 |
2004年 | 64篇 |
2003年 | 62篇 |
2002年 | 46篇 |
2001年 | 39篇 |
2000年 | 52篇 |
1999年 | 35篇 |
1998年 | 21篇 |
1997年 | 27篇 |
1996年 | 19篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 12篇 |
1992年 | 35篇 |
1991年 | 31篇 |
1990年 | 22篇 |
1989年 | 50篇 |
1988年 | 32篇 |
1987年 | 37篇 |
1986年 | 45篇 |
1985年 | 46篇 |
1984年 | 33篇 |
1983年 | 41篇 |
1982年 | 21篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 13篇 |
1977年 | 13篇 |
1975年 | 7篇 |
1974年 | 11篇 |
1973年 | 13篇 |
1972年 | 7篇 |
1970年 | 7篇 |
排序方式: 共有1692条查询结果,搜索用时 15 毫秒
81.
82.
Cabral FR Priel MR Silva Araujo BH Brito Torres L de Lima E Gurgel do Vale T Pereira F Alves de Amorim H Abrão Cavalheiro E Amado Scerni D Naffah-Mazzacoratti Mda G 《Developmental neuroscience》2011,33(6):469-478
Malnutrition during the earliest stages of life may result in innumerable brain problems. Moreover, this condition could increase the chances of developing neurological diseases, such as epilepsy. We analyzed the effects of early-life malnutrition on susceptibility to epileptic seizures induced by the pilocarpine model of epilepsy. Wistar rat pups were kept on a starvation regimen from day 1 to day 21 after birth. At day 60, 16 animals (8 = well-nourished; 8 = malnourished) were exposed to the pilocarpine experimental model of epilepsy. Age-matched well-nourished (n = 8) and malnourished (n = 8) rats were used as controls. Animals were video-monitored over 9 weeks. The following behavioral parameters were evaluated: first seizure threshold (acute period of the pilocarpine model); status epilepticus (SE) latency; first spontaneous seizure latency (silent period), and spontaneous seizure frequency during the chronic phase. The cell and mossy fiber sprouting (MFS) density were evaluated in the hippocampal formation. Our results showed that the malnourished animals required a lower pilocarpine dose in order to develop SE (200 mg/kg), lower latency to reach SE, less time for the first spontaneous seizure and higher seizure frequency, when compared to well-nourished pilocarpine rats. Histopathological findings revealed a significant cell density reduction in the CA1 region and intense MFS among the malnourished animals. Our data indicate that early malnutrition greatly influences susceptibility to seizures and behavioral manifestations in adult life. These findings suggest that malnutrition in infancy reduces the threshold for epilepsy and promotes alterations in the brain that persist into adult life. 相似文献
83.
Pedro M. Costa Sandra Caeiro Mário S. Diniz Jorge Lobo Marta Martins Ana M. Ferreira Miguel Caetano Carlos Vale T. Ángel DelValls Maria H. Costa 《Ecotoxicology (London, England)》2009,18(8):988-1000
Juvenile Solea senegalensis were exposed to fresh sediments from three stations of the Sado estuary (Portugal) in 28-day laboratory assays. Sediments revealed distinct levels of total organic matter, fine fraction, redox potential, trace elements (arsenic, cadmium, chromium, copper, nickel, lead and zinc) and organic contaminants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls and a pesticide: dichloro diphenyl trichloroethane). Organisms were surveyed for contaminant bioaccumulation and induction of two hepatic biochemical biomarkers: metallothionein (MT) and cytochrome P450 (CYP1A), as potential indicators of exposure to metallic and organic contaminants, respectively. Using an integrative approach it was established that, although bioaccumulation is in general accordance with sediment contamination, lethality and biomarker responses are not linearly dependent of the cumulative concentrations of sediment contaminants but rather of their bioavailability and synergistic effects in organisms. It is concluded that metals and organic contaminants modulate both MT and CYP1A induction and it is suggested that reactive oxygen species may be the link between responses and effects of toxicity. 相似文献
84.
Silvia Pereira Martin L. Saker Micaela Vale Vitor M. Vasconcelos 《Bulletin of environmental contamination and toxicology》2009,83(1):81-84
The effects of aqueous extracts from Microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: Festuca rubra L., Lolium perenne L., and Lactuca sativa L. There was a clear inhibition of root growth for L. sativa exposed to strains containing microcystins (5.9–56.4 μg L−1). The strain that produced the most pronounced effects contained the lowest concentration of microcystin suggesting that other cellular compounds may also affect growth. 相似文献
85.
Idiopathic Localised Bladder Amyloidosis is arare cause of haematuria and urinary tractsymptoms. A review of the literature highlightsthe varied presentations and the appropriateinvestigations for this condition, withemphasise on the exclusion of a secondarycause. In addition, the range of treatmentoptions is fully discussed. Our report on a 65-yearold gentleman illustrates that a highindex of suspicion is required for itsdiagnosis. Furthermore, conservative managementcan be an effective strategy in selectedpatients. 相似文献
86.
Spina MG Merlo-Pich E Akwa Y Balducci C Basso AM Zorrilla EP Britton KT Rivier J Vale WW Koob GF 《Psychopharmacology》2002,160(2):113-121
RATIONALE: Corticotropin-releasing factor (CRF) and urocortin (Ucn) belong to the CRF-related family, share a high degree of structural homology and bind to CRF receptors. However, compared with CRF, Ucn was shown to display either weaker or similar anxiogenic-like effects in vivo. OBJECTIVE: To compare the anxiogenic-like responses of rats injected intracerebroventricularly (ICV) with different doses of either rat/human CRF (r/hCRF) or rat Ucn (rUcn) at different intervals after injection. METHODS: Rats were tested on three validated paradigms of emotional behavior [i.e. elevated plus-maze (EPM), defensive withdrawal (DW) and conflict test (CT)] 5 and 30 min after treatment. RESULTS: In the EPM test only r/hCRF, but not rUcn, produced anxiogenic-like effects at the dose of 1.0 microg, when the peptides were injected 5 min before testing. At 30 min after injection, both peptides caused a significant reduction of open arms exploration, rUcn being effective at 0.01 microg. In the DW test both peptides were equally potent in decreasing the exploratory behavior and increasing the time spent in the chamber at the dose of 1.0 microg when tested 30 min after injection. In the CT both rUcn (0.25-1.0 microg) and r/hCRF (0.75-1.0 microg) decreased significantly the responding in the punished component. However, rUcn reduced food responding also in the unpunished component possibly due to its powerful anorectic activity. CONCLUSIONS: Comparison of anxiogenic-like activities of r/hCRF and rUcn at doses up to 1.0 microg revealed striking differential effects that depended on the time of testing after ICV peptide injection, and on the paradigm of anxiety used. These results suggest that the onset of r/hCRF and rUcn actions related to behavioral responses to anxiety is likely to depend on brain peptide-specific mechanisms including binding properties to CRF-receptors, differential distribution to specific functional brain sites and the distribution and effectiveness of binding-protein interactions. 相似文献
87.
88.
The international collaborative study of maternal phenylketonuria: status report 1994 总被引:1,自引:0,他引:1
R Koch HL Levy R Matalon B Rouse WB Hanley F Trefz C Azen EG Friedan F de la Cruz F Güttler PB Acosta 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(S407):111-119
Neonatal screening for phenylketonuria (PKU) has created a problem as females with PKU are reaching child-bearing age. Surveys have revealed that maternal phenylalanine blood concentrations greater than 1200 μmol/l are associated with fetal microcephaly, congenital heart defects and intrauterine growth retardation. It is estimated that as many as 3000 hyperphenylalaninemic females may be at risk of producing these fetal abnormalities. To examine this problem, the international maternal PKU collaborative study was developed to evaluate the efficacy of a phenylalanine-restricted diet in reducing fetal morbidity. Preliminary findings have indicated that phenylalanine restriction should begin before conception for females with PKU planning a pregnancy. Dietary control should maintain maternal blood phenylalanine levels between 120 and 360 μmol/l and should provide adequate energy, protein, vitamin and mineral intake. Pregnant hyperphenylalaninemic females who achieved metabolic control after conception or by the 10th week of pregnancy had a better offspring outcome than anticipated. The results of 402 pregnancies are reviewed. 相似文献
89.
A 4 year old girl treated with a standard chemotherapy protocol for acute lymphoblastic leukaemia developed hepatic candidosis during the consolidation phase. This relapsed after a prolonged course of amphotericin B and flucytosine. An eight week course of liposomal amphotericin produced a marked clinical improvement which was sustained for one year. A subsequent relapse was associated with transformation to myelodysplastic leukaemia. 相似文献
90.
Vale J 《Current medical research and opinion》2000,16(Z1):s63-s67
There is little evidence to support a link between benign prostatic hyperplasia (BPH) and erectile dysfunction (ED). Any apparent relationship may reflect the fact that both are common conditions with a similar gender and age distribution. However, the surgical treatment of BPH (e.g. TURP or open prostatectomy) may cause ED as a postoperative complication in some patients. Similarly, the medical treatment of BPH with finasteride may be associated with ED (< 5% in one study). However, alpha-blockade is not associated with this side-effect. 相似文献