全文获取类型
收费全文 | 2307篇 |
免费 | 120篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 168篇 |
妇产科学 | 35篇 |
基础医学 | 205篇 |
口腔科学 | 67篇 |
临床医学 | 224篇 |
内科学 | 575篇 |
皮肤病学 | 56篇 |
神经病学 | 96篇 |
特种医学 | 372篇 |
外国民族医学 | 1篇 |
外科学 | 223篇 |
综合类 | 24篇 |
预防医学 | 98篇 |
眼科学 | 18篇 |
药学 | 138篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 147篇 |
出版年
2022年 | 6篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 17篇 |
2018年 | 39篇 |
2017年 | 29篇 |
2016年 | 37篇 |
2015年 | 45篇 |
2014年 | 49篇 |
2013年 | 85篇 |
2012年 | 45篇 |
2011年 | 52篇 |
2010年 | 62篇 |
2009年 | 97篇 |
2008年 | 46篇 |
2007年 | 71篇 |
2006年 | 72篇 |
2005年 | 63篇 |
2004年 | 45篇 |
2003年 | 57篇 |
2002年 | 55篇 |
2001年 | 49篇 |
2000年 | 53篇 |
1999年 | 46篇 |
1998年 | 109篇 |
1997年 | 120篇 |
1996年 | 123篇 |
1995年 | 84篇 |
1994年 | 85篇 |
1993年 | 99篇 |
1992年 | 45篇 |
1991年 | 45篇 |
1990年 | 37篇 |
1989年 | 70篇 |
1988年 | 54篇 |
1987年 | 49篇 |
1986年 | 46篇 |
1985年 | 46篇 |
1984年 | 35篇 |
1983年 | 23篇 |
1982年 | 24篇 |
1981年 | 35篇 |
1980年 | 20篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1977年 | 26篇 |
1976年 | 20篇 |
1975年 | 12篇 |
1972年 | 10篇 |
1969年 | 6篇 |
排序方式: 共有2452条查询结果,搜索用时 15 毫秒
21.
22.
MJ Hwang A Bhangu CE Webster DM Bowley MX Gannon SS Karandikar 《Annals of the Royal College of Surgeons of England》2014,96(5):343-347
Introduction
In 2009 the Department of Health instructed McKinsey & Company to provide advice on how commissioners might achieve world class National Health Service productivity. Asymptomatic inguinal hernia repair was identified as a potentially cosmetic procedure, with limited clinical benefit. The Birmingham and Solihull primary care trust cluster introduced a policy of watchful waiting for asymptomatic inguinal hernia, which was implemented across the health economy in December 2010. This retrospective cohort study aimed to examine the effect of a change in clinical commissioning policy concerning elective surgical repair of asymptomatic inguinal hernias.Methods
A total of 1,032 patients undergoing inguinal hernia repair in the 16 months after the policy change were compared with 978 patients in the 16 months before. The main outcome measure was relative proportion of emergency repair in groups before and after the policy change. Multivariate binary logistic regression was used to adjust the main outcome for age, sex and hernia type.Results
The period after the policy change was associated with 59% higher odds of emergency repair (3.6% vs 5.5%, adjusted odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.03–2.47). In turn, emergency repair was associated with higher odds of adverse events (4.7% vs 18.5%, adjusted OR: 3.68, 95% CI: 2.04–6.63) and mortality (0.1% vs 5.4%, p<0.001, Fisher’s exact test).Conclusions
Introduction of a watchful waiting policy for asymptomatic inguinal hernias was associated with a significant increase in need for emergency repair, which was in turn associated with an increased risk of adverse events. Current policies may be placing patients at risk. 相似文献23.
MJ Ramdass P Harnarayan N Mooteeram A Nath V Naraynsingh S Budhooram T Dookie R Henry 《Annals of the Royal College of Surgeons of England》2014,96(2):121-126
Introduction
This study aimed to determine whether ethnic differences show different patterns of arterial disease in the lower limb.Methods
A prospective analysis of 100 consecutive patients with 160 lower limb arteriograms was performed looking at the pattern of disease with relation to ethnicity in Trinidad and Tobago.Results
There were 53 male and 47 female patients with an age range of 43–90 years (mean: 66 years). Of the 100 patients, 45 were of East Indian descent, 36 of Afro-Caribbean descent, 14 of mixed descent and 5 had other backgrounds. There were 32 smokers and 69 diabetics.The most commonly affected artery in East Indians was the anterior tibial artery (ATA, 70%) followed by the peroneal artery (60%), superficial femoral artery (SFA, 60%), posterior tibial artery (PTA, 57%) and tibioperoneal trunk (TPT, 39%). In Afro-Caribbeans, the most commonly affected artery was the ATA (79%) followed by the PTA (74%), peroneal artery (66%) and TPT (55%). The mixed group showed the PTA (85%) to be most diseased followed by the peroneal artery (75%), ATA (70%), SFA (70%), dorsalis pedis artery (DPA, 60%) and TPT (50%). Overall, the most diseased vessel in all groups was the ATA (73%) followed by the PTA (66%), peroneal artery (64%), SFA (59%), TPT (46%), DPA (38%), popliteal artery (31%) and medial plantar artery (MPA, 29%), with the proximal vessels not being affected severely.Conclusions
Ethnic divisions were only statistically significant (p<0.05) with East Indians showing worse disease in the profunda femoris artery and Afro-Caribbeans showing worse disease in the PTA, DPA and MPA. This suggests that environmental factors may play a significant role in the disease process including smoking and dietary factors rather than purely genetics. 相似文献24.
25.
26.
27.
28.
Changes in intracellular Ca2+ concentrations [( Ca2+]i) in platelets stimulated with aggregating agents were measured with the fluorescent indicator dye quin 2. Ca2+ influx, but not intracellular mobilization, in response to adenosine diphosphate (ADP), platelet aggregating factor (PAF-acether), and sodium arachidonate was significantly inhibited by monoclonal antibodies against the glycoprotein (GP) IIb-IIIa complex; inhibition of thrombin-stimulated influx was inhibited to a lesser extent and reached statistical significance only at thrombin concentrations of 0.1 U/mL and below. Anti-GP Ib and HLA-ABC monoclonal antibodies had no effect on Ca2+ influx in response to any agonist. Thrombasthenic platelets gave normal [Ca2+]i responses to ADP and thrombin, which were not inhibited by an anti-GP IIb-IIIa antibody. It is suggested that Ca2+ influx in response to weak agonists occurs predominantly via a channel closely adjacent to the GP IIb-IIIa complex, but that higher concentrations of thrombin and A23187 also stimulate influx via another pathway. 相似文献
29.
Peripheral blood lymphocytes (PBLs) from multiple myeloma patients are defective in both proportion and absolute numbers of OKT4+ cells and have a normal proportion but reduced absolute number of OKT8+ cells. To assess the functional capabilities of the T cells in myeloma patients, we cloned the T cells in PBLs using limiting dilution conditions in which 100% of OKT4+ and OKT8+ T cells in normal PBLs are able to form a clone. In contrast, the OKT8+ cells from PBLs of five of seven multiple myeloma patients were severely compromised in their clonogenic potential; only 7% to 25% of OKT8+ T cells appeared to give rise to a clone. Clonogenic potential of the OKT4+ cells in patients was more nearly normal. Analysis of two multiple myeloma patients with abnormally low numbers of T cells in PBLs revealed the existence of abnormalities in the progenitors of T cell clones. In both patients, two to three times as many T cell clones were observed as would have been expected based on the number of PBLs cultured at limiting dilution, indicating that OKT4-8- cells in PBLs are capable of giving rise to OKT4+ and, at lower frequency, to OKT8+ clonal progeny in vitro. We conclude that purely quantitative assessment of T cell subsets should be interpreted with caution, since proportionately normal numbers of OKT8+ cells in patient PBLs are seriously compromised in their ability to give rise to clonal progeny in vitro, and since there appears to be a OKT4-8- population of T cells in PBLs that are committed to become OKT4+ or OKT8+ T cells, but are unable to do so in vivo. 相似文献
30.
Peripheral circulatory effects of insulin in diabetes 总被引:1,自引:0,他引:1
Peripheral circulatory effects of insulin were studied in the diabetic patients with and without autonomic neuropathy. Forearm blood flow, calf venous volume and calf venous distensibility were measured by strain gauge plethysmography. In the diabetic patients with autonomic neuropathy, mean blood pressure fell from 96 +/- 5 to 88 +/- 5 mmHg after an intravenous injection of 4 U of monocomponent insulin (p less than 0.001). Forearm vascular resistance decreased from 53.99 +/- 8.29 to 45.88 +/- 7.76 mmHg X ml-1 X 100ml-1 X min-1 after insulin (p less than 0.01). Insulin increased calf venous volume from 1.20 +/- 0.19 to 2.23 +/- 0.44 ml/100ml (p less than 0.05) and calf venous distensibility from 0.039 +/- 0.004 to 0.082 +/- 0.016 ml/mmHg (p less than 0.05). In contrast, in the diabetic patients without autonomic neuropathy, there were no significant changes in the mean blood pressure, forearm vascular resistance, calf venous volume and calf venous distensibility. Symptoms of hypoglycaemia did not occur in any patient. These results suggest that insulin has a vasodilator action on both resistance and capacitance vessels, which may be one of the main factors in insulin-induced hypotension. 相似文献