全文获取类型
收费全文 | 229篇 |
免费 | 16篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 14篇 |
妇产科学 | 2篇 |
基础医学 | 28篇 |
口腔科学 | 8篇 |
临床医学 | 20篇 |
内科学 | 61篇 |
皮肤病学 | 1篇 |
神经病学 | 4篇 |
特种医学 | 47篇 |
外科学 | 10篇 |
预防医学 | 29篇 |
眼科学 | 1篇 |
药学 | 8篇 |
中国医学 | 1篇 |
肿瘤学 | 8篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 11篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 7篇 |
2005年 | 9篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1973年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有245条查询结果,搜索用时 15 毫秒
41.
42.
Primary cavitating lung carcinomas have not previously been described with spontaneous pneumothorax as the presenting manifestation. Two patients whose pneumothoraces resulted in the initial diagnosis of a primary cavitary lung carcinoma are described. Pathologic evidence of vascular invasion suggests tumor necrosis with secondary rupture into the pleural space as a likely mechanism for pneumothorax. 相似文献
43.
44.
45.
46.
We compared the phenotype of two common mouse models, C-57BL/6J (C57), which carries only the Ren-1c gene, and 129/SvJ (Sv-129), with both Ren 1d and Ren-2. We hypothesized two renin gene Sv-129 would have increased blood pressure and the renin-angiotensin system would be more influential in regulating renal function compared with one renin gene mice. Sv-129 consistently had higher blood pressure than C-57, whether conscious (128 versus 108 mm Hg, P<0.001) or anesthetized (102 versus 88 mm Hg, P<0.001). Plasma renin concentration in both conscious and anesthetized C-57 mice was 3- to 4-fold higher than in Sv-129 (P<0.05), whereas renal cortical renin content was 2.5-fold higher (P<0.005). Renal blood flow and renal vascular resistance were the same in C-57 and Sv-129. Exogenous angiotensinogen produced identical pressor and renal vasoconstrictor responses in both strains. Blocking AT1 receptors with losartan reduced blood pressure by 19 mm Hg in both strains. Nitric oxide synthase inhibition by l-NAME increased blood pressure by 29 mm Hg in C-57 and 35 mm Hg in Sv-129 mice, but the decrease in renal blood flow was 30% less in C-57 (P<0.025). We conclude that Sv-129 mice with two renin genes have higher blood pressure but lower plasma and renal renin than C-57 mice with one renin gene. Renin substrate may limit angiotensin II production in the mouse. In Sv-129, the influence of nitric oxide on renal but not systemic resistance may be exaggerated. Renin from Ren-2 may act independently of normal renin control mechanisms. 相似文献
47.
AM Innes KM Boycott EG Puffenberger D Redl IM MacDonald AE Chudley C Beaulieu R Perrier T Gillan A Wade JS Parboosingh 《Clinical genetics》2010,78(5):424-431
Innes AM, Boycott KM, Puffenberger EG, Redl D, MacDonald IM, Chudley AE, Beaulieu C, Perrier R, Gillan T, Wade A, Parboosingh JS. A founder mutation in BBS2 is responsible for Bardet‐Biedl syndrome in the Hutterite population: utility of SNP arrays in genetically heterogeneous disorders. Bardet‐Biedl syndrome (BBS) is a multisystem genetically heterogeneous disorder, the clinical features of which are largely the consequence of ciliary dysfunction. BBS is typically inherited in an autosomal recessive fashion, and mutations in at least 14 genes have been identified. Here, we report the identification of a founder mutation in the BBS2 gene as the cause for the increased incidence of this developmental disorder in the Hutterite population. To ascertain the Hutterite BBS locus, we performed a genome‐wide single nucleotide polymorphism (SNP) analysis on a single patient and his three unaffected siblings from a Hutterite family. The analysis identified two large SNP blocks that were homozygous in the patient but not in his unaffected siblings, one of these regions contained the BBS2 gene. Sequence analysis and subsequent RNA studies identified and confirmed a novel splice site mutation, c.472‐2A>G, in BBS2. This mutation was also found in homozygous form in three subsequently studied Hutterite BBS patients from two different leuts, confirming that this is a founder mutation in the Hutterite population. Further studies are required to determine the frequency of this mutation and its role, if any, in the expression of other ciliopathies in this population. 相似文献
48.
Enhanced release of prostaglandins contributes to flow-induced arteriolar dilation in eNOS knockout mice. 总被引:9,自引:0,他引:9
D Sun A Huang C J Smith C J Stackpole J A Connetta E G Shesely A Koller G Kaley 《Circulation research》1999,85(3):288-293
Nitric oxide and prostaglandins were shown to contribute to the endothelial mediation of flow-induced dilation of skeletal muscle arterioles of rats. Thus, we hypothesized that flow-induced dilation and its mediation are altered in gracilis muscle arterioles of mice deficient in the gene for endothelial nitric oxide synthase (eNOS-KO) compared with control wild-type (WT) mice. Gracilis muscle arterioles ( approximately 80 micrometer) of male mice were isolated, then cannulated and pressurized in a vessel chamber. The increases in diameter elicited by increases in perfusate flow from 0 to 10 microq/min were similar in arterioles from eNOS-KO (n=28) and WT (n=22) mice ( approximately 20 micrometer at 10 microL/min flow). Removal of the endothelium eliminated flow-induced dilations in vessels of both strains of mice. N(omega)-nitro-L-arginine (L-NNA, 10(-4) mol/L) significantly inhibited flow-induced dilation in arterioles of WT mice by approximately 51% but had no effect on responses of arterioles from eNOS-KO mice. Indomethacin (INDO, 10(-5) mol/L) inhibited flow-induced dilation of WT mice by approximately 49%, whereas it completely abolished this response in arterioles of eNOS-KO mice. Simultaneous administration of INDO and L-NNA eliminated flow-induced responses in arterioles of WT mice. Dilations to carbaprostacyclin were similar at concentrations of 10(-8) and 3x10(-8) mol/L but decreased significantly at 10(-7) mol/L in arterioles of eNOS-KO compared with those of WT mice. These findings demonstrate that, despite the lack of nitric oxide mediation, flow-induced dilation is close to normal in arterioles of eNOS-KO mice because of an enhanced release of endothelial dilator prostaglandins and suggest that this vascular adaptation may contribute to the regulation of peripheral resistance in eNOS-KO mice. 相似文献
49.
Paulsson AK McMullen KP Peiffer AM Hinson WH Kearns WT Johnson AJ Lesser GJ Ellis TL Tatter SB Debinski W Shaw EG Chan MD 《中国神经肿瘤杂志》2013,(1):52-52
PURPOSE: We investigate the patterns of failure in the treatment of glioblastoma(GBM) based on clinical target volume(CTV) margin size,dose delivered to the site of initial failure,and the use of temozolomide and intensity-modulated radiotherapy(IMRT).METHODS: Between August 2000 and May 2010,161 patients with GBM were treated with radiotherapy with or without concurrent temozolomide.Patients were treated with CTV expansions that ranged from 5 to 20 mm using a shrinking field technique.Patterns of failure and time to progression and overall survival were compared based on CTV margin,use of temozolomide,and use of IMRT.Kaplan Meier analysis was used to estimate survival times,and χ test was used for comparison of cohorts.RESULTS: For patients treated with 5-,10-,and 15-to 20-mm CTV,79%,77%,and 86% experienced failures in the 60 Gy volume,respectively.Forty-eight percent,55%,and 66% of patients with 5-,10-,and 15-to 20-mm CTV experienced failures in the 46 Gy volume,respectively.There was no statistical difference between patients treated with 5-,10-,15-to 20-mm margins with regard to 60 Gy failure(P=0.76),46 Gy failure(P=0.51),or marginal failure(P=0.73).Eighty percent of patients receiving temozolomide experienced failures in the 60 Gy volume.There was no increased likelihood of marginal failures in patients receiving IMRT(P =0.97).CONCLUSIONS: Modern treatment techniques including use of concurrent temozolmide,limited CTV margin size,and IMRT have not greatly changed the patterns of failure of GBM. 相似文献
50.
Inhibitory synaptogenesis in mouse somatosensory cortex 总被引:4,自引:3,他引:1
It is widely believed that inhibitory synapses are not present or present
in only small numbers in the rodent cerebral cortex during the early
postnatal period when the cortex is being innervated by thalamocortical
fibers. Quantitative electron microscopy was carried out on the
posteromedial barrel subfield of mouse somatosensory cortex from postnatal
day 4 (P4) when thalamocortical innervation of the barrels is becoming
established, through to sexual maturity (>P32), and in adulthood. Both
asymmetrical (putatively excitatory) and symmetrical (putatively
inhibitory) synapses were present in all layers from P4. The symmetrical
synapses were immunoreactive for GABA at all ages. There was a progressive
increase in both asymmetrical and symmetrical synapses up to P32, density
in all layers increasing 16-fold, with the production of asymmetrical
synapses leading and greatly outstripping that of symmetrical. From P32 to
P120, the oldest age studied, synaptic numbers declined by 18% to 13 times
the P4 level, but this affected predominantly layers II/III, IV and V, and
mainly involved asymmetrical synapses. The relative percentage of
asymmetrical to symmetrical synapses from P4 to P8 was 57%/43% but at P32
it was 89.5%/10.5% and in adulthood 85.4%/14.6%. These data indicate that
inhibitory synaptogenesis in the rodent cortex begins earlier than
previously thought, a basis for inhibition being present from the earliest
period. Pruning of all synapses occurs well after thalamocortical
innervation is established and inhibitory synapses are less affected by the
pruning process.
相似文献