全文获取类型
收费全文 | 2647篇 |
免费 | 188篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 142篇 |
妇产科学 | 45篇 |
基础医学 | 234篇 |
口腔科学 | 56篇 |
临床医学 | 331篇 |
内科学 | 804篇 |
皮肤病学 | 21篇 |
神经病学 | 118篇 |
特种医学 | 244篇 |
外科学 | 289篇 |
综合类 | 43篇 |
预防医学 | 193篇 |
眼科学 | 19篇 |
药学 | 120篇 |
1篇 | |
中国医学 | 7篇 |
肿瘤学 | 190篇 |
出版年
2023年 | 8篇 |
2022年 | 9篇 |
2021年 | 34篇 |
2020年 | 32篇 |
2019年 | 35篇 |
2018年 | 39篇 |
2017年 | 33篇 |
2016年 | 40篇 |
2015年 | 50篇 |
2014年 | 56篇 |
2013年 | 88篇 |
2012年 | 99篇 |
2011年 | 83篇 |
2010年 | 89篇 |
2009年 | 95篇 |
2008年 | 94篇 |
2007年 | 82篇 |
2006年 | 105篇 |
2005年 | 97篇 |
2004年 | 91篇 |
2003年 | 83篇 |
2002年 | 89篇 |
2001年 | 78篇 |
2000年 | 75篇 |
1999年 | 81篇 |
1998年 | 103篇 |
1997年 | 107篇 |
1996年 | 103篇 |
1995年 | 73篇 |
1994年 | 64篇 |
1993年 | 56篇 |
1992年 | 59篇 |
1991年 | 44篇 |
1990年 | 37篇 |
1989年 | 63篇 |
1988年 | 68篇 |
1987年 | 65篇 |
1986年 | 35篇 |
1985年 | 50篇 |
1984年 | 35篇 |
1983年 | 41篇 |
1982年 | 26篇 |
1981年 | 25篇 |
1980年 | 21篇 |
1979年 | 16篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 14篇 |
1974年 | 8篇 |
排序方式: 共有2861条查询结果,搜索用时 15 毫秒
11.
Reduced glutathione (GSH) is mutagenic in Salmonella in thepresence of -glutamyltranspeptidase (GGT), with the highestresponse obtained in strain TA102. Reduced cysteinylglycine,one of the products of GGT metabolism of GSH, is mutagenic inthe absence of GGT. In strain TA102, GSH mutagenesis was dependenton molecular oxygen, enhanced by iron, inhibited by EDTA, desferrioxaminemesylate, mannitol, butylated hydroxyanisole, peroxidase andcatalase, but not by superoxide dismutase. Binding of GSH orits GGT-dependent metabolites to DNA in vitro was not detected.This is consistent with a model of an indirect mechanism ofmutagenesis, i.e. cleavage of GSH by GGT, followed by facileauto-oxidation of the resulting cysteinylglycine, with the productionof free radicals which lead to the (pen)ultimate mutagen, H2O2. 相似文献
12.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献
13.
Hendrickx J; Dams E; Coucke P; Lee P; Fernandes J; Willems PJ 《Human molecular genetics》1996,5(5):649-652
X-linked liver glycogenosis type II (XLG II) is a recently described X-
linked liver glycogen storage disease, mainly characterized by enlarged
liver and growth retardation. These clinical symptoms are very similar to
those of XLG I. In contrast to XLG I patients, however, XLG II patients do
not show an in vitro enzymatic deficiency of phosphorylase kinase (PHK).
Recently, mutations were identified in the gene encoding the liver alpha
subunit of PHK (PHKA2) in XLG I patients. We have now studied the PHKA2
gene of four unrelated XLG II patients and identified four different
mutations in the open reading frame, including a deletion of three
nucleotides, an insertion of six nucleotides and two missense mutations.
These results indicate that XLG II is due to mutations in PHKA2. In
contrast to XLG I, XLG II is caused by mutations that lead to minor
structural abnormalities in the primary structure of the liver alpha
subunit of PHK. These mutations are found in a conserved RXX(X)T motif,
resembling known phosphorylation sites that might be involved in the
regulation of PHK. These findings might explain why the in vitro PHK
enzymatic activity is not deficient in XLG II, whereas it is in XLG I.
相似文献
14.
15.
16.
Bianciardi P Fasanella A Foglia Manzillo V Trotta T Pagano A Sorino S Gradoni L Oliva G 《Parasitology research》2004,93(6):486-492
We evaluated the efficacy of enrofloxacin, alone or combined with metronidazole, against Leishmania infantum. The in vitro activity of this fluoroquinolone was assessed using two different methods: a direct test aimed at assessing the drug activity on the parasite, and an indirect test aimed at evaluating the drug effect on macrophage killing, lymphomonocyte activation and nitric oxide production. An in vivo test was also performed on 36 dogs with leishmaniasis, subdivided into three groups, one treated with enrofloxacin, another with enrofloxacin plus metronidazole, and a control group with meglumine antimoniate. The direct test did not show any action of enrofloxacin on the parasite, while the indirect testing showed an enhancement of macrophage killing and an increase in nitric oxide production. These findings show that enrofloxacin does not exert a direct anti-leishmanial activity in vitro. However, on the basis of the positive immunostimulation results shown in vitro and the clinical improvement, particularly of the cutaneous lesions, obtained in several dogs in the in vivo trial, the use of enrofloxacin in association with a specific anti-leishmanial drug can be proposed in the therapeutic protocol of canine leishmaniasis. 相似文献
17.
18.
19.
L1 knockout mice show dilated ventricles, vermis hypoplasia and impaired exploration patterns 总被引:8,自引:3,他引:8
Fransen E; D'Hooge R; Van Camp G; Verhoye M; Sijbers J; Reyniers E; Soriano P; Kamiguchi H; Willemsen R; Koekkoek SK; De Zeeuw CI; De Deyn PP; Van der Linden A; Lemmon V; Kooy RF; Willems PJ 《Human molecular genetics》1998,7(6):999-1009
L1 is a neural cell adhesion molecule mainly involved in axon guidance and
neuronal migration during brain development. Mutations in the human L1 gene
give rise to a complex clinical picture, with mental retardation,
neurologic abnormalities and a variable degree of hydrocephalus. Recently,
a transgenic mouse model with a targeted null mutation in the L1 gene was
generated. These knockout (KO) mice show hypoplasia of the corticospinal
tract. Here we have performed further studies of these KO mice including
magnetic resonance imaging of the brain, neuropathological analysis and
behavioral testing. The ventricular system was shown to be abnormal with
dilatation of the lateral ventricles and the 4th ventricle, and an altered
shape of the Sylvius aqueduct. Additionally, the cerebellar vermis of the
KO mice is hypoplastic. Their exploratory behavior is characterized by
stereotype peripheral circling reminiscent of that of rodents with induced
cerebellar lesions.
相似文献
20.
PJ Hallam P. Mannucci A. Tripodi D. Bevan B. Lawsen L. Tengborn A. Wacey DN Coopel 《Clinical genetics》1998,54(3):231-233
Hallam PJ, Mannucci P, Tripodi A, Bevan D, Laursen B, Tengborn L, Wacey A, Cooper DN. Three novel PROC gene lesions causing protein C deficiency. Clin Genet 1998: 54: 231–233. 0 Munksgaard, 1998
Missense mutations. three of them novel (Am210→Val, Asn248→ Ile, Ah355→Val), were found in the protein c ( PROC ) genes of 7 patients with inherited protein C deficiency associated with venous thrombosis. Comparison with the phenotypic effects of mutations in the analogous residues of factor IX causing hdernophilia B and the use of molecular modelling has provided explanations as to how these lesions might alter either the structure, function or secretion of the protein C molecules encoded. 相似文献
Missense mutations. three of them novel (Am210→Val, Asn248→ Ile, Ah355→Val), were found in the protein c ( PROC ) genes of 7 patients with inherited protein C deficiency associated with venous thrombosis. Comparison with the phenotypic effects of mutations in the analogous residues of factor IX causing hdernophilia B and the use of molecular modelling has provided explanations as to how these lesions might alter either the structure, function or secretion of the protein C molecules encoded. 相似文献