全文获取类型
收费全文 | 2292篇 |
免费 | 298篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 98篇 |
妇产科学 | 68篇 |
基础医学 | 229篇 |
口腔科学 | 138篇 |
临床医学 | 332篇 |
内科学 | 465篇 |
皮肤病学 | 118篇 |
神经病学 | 146篇 |
特种医学 | 165篇 |
外科学 | 314篇 |
综合类 | 107篇 |
现状与发展 | 30篇 |
一般理论 | 1篇 |
预防医学 | 163篇 |
眼科学 | 28篇 |
药学 | 86篇 |
中国医学 | 3篇 |
肿瘤学 | 92篇 |
出版年
2024年 | 18篇 |
2023年 | 183篇 |
2022年 | 17篇 |
2021年 | 25篇 |
2020年 | 60篇 |
2019年 | 39篇 |
2018年 | 69篇 |
2017年 | 49篇 |
2016年 | 52篇 |
2015年 | 70篇 |
2014年 | 97篇 |
2013年 | 92篇 |
2012年 | 82篇 |
2011年 | 97篇 |
2010年 | 110篇 |
2009年 | 119篇 |
2008年 | 73篇 |
2007年 | 116篇 |
2006年 | 73篇 |
2005年 | 60篇 |
2004年 | 65篇 |
2003年 | 64篇 |
2002年 | 54篇 |
2001年 | 53篇 |
2000年 | 41篇 |
1999年 | 53篇 |
1998年 | 54篇 |
1997年 | 56篇 |
1996年 | 51篇 |
1995年 | 52篇 |
1994年 | 40篇 |
1993年 | 42篇 |
1992年 | 35篇 |
1991年 | 24篇 |
1990年 | 24篇 |
1989年 | 38篇 |
1988年 | 35篇 |
1987年 | 35篇 |
1986年 | 19篇 |
1985年 | 27篇 |
1984年 | 14篇 |
1982年 | 15篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1978年 | 13篇 |
1976年 | 19篇 |
1975年 | 15篇 |
1974年 | 13篇 |
1968年 | 10篇 |
1967年 | 11篇 |
排序方式: 共有2609条查询结果,搜索用时 15 毫秒
61.
Evidence that thrombocytopenia observed in humans treated with orally bioavailable glycoprotein IIb/IIIa antagonists is immune mediated 总被引:3,自引:0,他引:3
Billheimer JT Dicker IB Wynn R Bradley JD Cromley DA Godonis HE Grimminger LC He B Kieras CJ Pedicord DL Spitz SM Thomas BE Zolotarjova NI Gorko MA Hollis GF Daly RN Stern AM Seiffert D 《Blood》2002,99(10):3540-3546
Glycoprotein (GP) IIb/IIIa antagonists are effective therapeutic agents, but elicit thrombocytopenia with a frequency that approaches 2%. Here, we provide evidence that thrombocytopenia in humans treated with the GP IIb/IIIa antagonist roxifiban is immune mediated. Two patients underwent conversion to a highly positive drug-dependent antibody (DDAB) status temporally associated with thrombocytopenia. Despite the continued presence of DDABs, the fall in platelet count was reversed by discontinuation of drug treatment, pointing to the exquisite drug dependency of the immune response. DDABs appear to bind to neoepitopes in GP IIb/IIIa elicited on antagonist binding. This information was used to develop an enzyme-linked immunosorbent assay (ELISA) for DDAB using solid-phase GP IIb/IIIa. A high level of specificity is indicated by the observation that DDAB binding is dependent on the chemical structure of the GP IIb/IIIa antagonist and that only 2% to 5% of human blood donors and 5% of chimpanzees present with pre-existing DDABs. Furthermore, none of 108 nonthrombocytopenic patients from the phase II roxifiban study showed an increase in antibody titer. Absorption of thrombocytopenia plasma with platelets reduced the DDAB ELISA signal, indicating that the test detects physiologically relevant antibodies. Screening patients for pre-existing or increasing DDAB titer during treatment with GP IIb/IIIa antagonists may reduce the incidence of drug-induced thrombocytopenia. 相似文献
62.
Effects of Enteral Nutrition on the Barrier Function of the Intestinal Mucosa and Dopamine Receptor Expression in Rats With Traumatic Brain Injury 下载免费PDF全文
Background: Impaired intestinal mucosal barrier (IMB) function is common in traumatic brain injury (TBI), but dopamine receptors (DRs) change in intestinal mucosa after TBI, and effects of enteral nutrition (EN) and supplements on IMB function remain unclear. Our purpose was to study the effects of EN and supplements on intestinal mucosal permeability (IMPB) and the expression of DRs DRD1 and DRD2 in the intestinal mucosa of rats with TBI. Methods: Forty‐eight rats were divided into 8 groups; control, animals with TBI, dopamine group, animals with TBI treated with dopamine antagonist, EN alone, or EN combined with glutamine, probiotics, or a combination of probiotics and glutamine daily after TBI. Results: The IMPB was improved in the glutamine, probiotics, and combination groups. Including probiotics improved IMPB more than adding glutamine, and bacterial translocation in the intestines after TBI was reduced in the probiotics and combination groups (all Ps < .01). TBI led to elevated DRD1 and DRD2 mRNA and protein levels, which were reduced in the DA antagonist, glutamine, probiotics, and combination groups. DRD2 mRNA and protein levels in the probiotics and combination groups were decreased more than in the DA antagonist group (all Ps < .01). The increased IMPB after TBI correlated with increased DRD1 and DRD2 levels in the rat intestinal mucosa. Conclusion: EN supplemented with probiotics or combining glutamine and probiotics lowers the increased IMPB, bacterial translocation, and DRD1 and DRD2 mRNA and protein expression in rat intestinal mucosa caused by TBI. 相似文献
63.
Intrathoracic lymphoblastic lymphoma (LBL) is classically of T‐cell lineage, but these cases of pleural B‐cell LBL suggest that this is not always the case. Despite the clinical challenges involved every attempt should be made to secure a biopsy and histological diagnosis, as we move into an era of lineage‐directed therapies. 相似文献
64.
GCH1 attenuates cardiac autonomic nervous remodeling in canines with atrial‐tachypacing via tetrahydrobiopterin pathway regulated by microRNA‐206 下载免费PDF全文
65.
Effect of body mass index and fat distribution on insulin sensitivity, secretion, and clearance in nonobese healthy men. 总被引:8,自引:0,他引:8
C Walton I F Godsland A J Proudler C V Felton V Wynn 《The Journal of clinical endocrinology and metabolism》1992,75(1):170-175
The effects of variation in body mass index (BMI; kg/m2) and body fat topography on insulin sensitivity, secretion, and clearance were determined in a group of 146 nonobese nondiabetic males. Volunteers underwent an i.v. glucose tolerance test, with determination of plasma glucose, insulin, and C-peptide levels. BMI was taken as a measure of overall adiposity, while skinfold thickness ratios were used to assess the centrality of fat distribution and the localization of central fat within the trunk. Measurements of insulin sensitivity, secretion, and clearance were obtained by mathematical modelling of the i.v. glucose tolerance test concentration profiles. Increasing BMI and centrality of fat distribution had no significant effect on glucose tolerance, but were independently associated with diminished insulin sensitivity and increased insulin secretion. The elevation in secretion occurred almost entirely during the second phase of pancreatic insulin release. These results show that the variations in insulin sensitivity and secretion that have often been reported in obesity are also present in a group within the normal range of BMI. However, the absence of any decrease in hepatic uptake, also reported in the obese, indicates that this might be an additional mechanism recruited to maintain glycemic control at higher levels of adiposity. Localization of central fat in the lower trunk was correlated with elevated first phase insulin secretion, but no concomitant change in insulin sensitivity. There may, therefore, be a direct effect of the distribution of central fat on insulin secretion. 相似文献
66.
David Crook Raymond Bruce Melek Worthington Dayid Mulcahy MRCP David Patterson FRCP Victor Wynn FRCP 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》1992,6(6):633-639
Summary Changes in plasma concentrations of high density lipoproteins (HDL) and triglycerides may partly explain the ability of cholesterol-lowering drugs to decrease the incidence of coronary heart disease. We measured the response of fasting plasma lipids, lipoproteins, and apolipoproteins in 46 subjects with Type IIa hypercholesterolemia treated with simvastatin for 3 months. The initial dose of simvastatin (10 mg/day) was subsequently increased up to 40 mg/day if the plasma cholesterol concentration had not fallen below 5.2 mmol/l. Plasma concentrations of HDL cholesterol and of the apolipoproteins AI and AII were increased by simvastatin. The increase in HDL cholesterol (9%) was due to increases in both subfractions (HDL2 17%; HDL3 7%), changes that would be consistent with a beneficial effect on cardiovascular risk. Simvastatin decreased plasma triglyceride concentrations by 25%. Plasma total cholesterol concentrations fell by 35% after 3 months of treatment; this fall was proportional to the initial concentration and was due almost entirely to a 45% fall in low density lipoprotein cholesterol. In contrast, plasma concentrations of lipoprotein Lp(a) were not affected by simvastatin. 相似文献
67.
An apparently anomalous relationship between insulin and C-peptide concentrations in their initial response to intravenous glucose. 总被引:1,自引:0,他引:1
C Walton I F Godsland A J Proudler C V Felton V Wynn 《Metabolism: clinical and experimental》1992,41(11):1210-1214
Intravenous glucose tolerance tests (IVGTTs) with determination of plasma glucose, insulin, and C-peptide concentrations were performed in 136 men and 154 women. It was found that in 4% of men and 12% of women the plasma concentration of insulin exceeded that of C-peptide during the initial response to glucose. Subjects exhibiting this phenomenon had lower fasting and post-glucose C-peptide concentrations than those who did not; however, there were no statistically significant differences in glucose or insulin concentrations. The phenomenon was age-related, being absent from individuals aged 35 years and under, while in older age groups it appeared to be more prevalent in women than in men, suggesting an additional effect of menopause. However, in three follow-up IVGTTs performed in a subgroup of postmenopausal women over a period of 18 months, the phenomenon failed to recur in any of the individuals who first exhibited it, although it did occur in others. Our observations suggest the existence of an age-related but intermittent decrease in pancreatic insulin secretion, which does not lead to any significant change in plasma insulin concentrations, possibly as a result of reduced hepatic uptake of insulin. One consequence appears to be an excess of insulin over C-peptide during the early part of the IVGTT, which is probably related to the different distributional kinetics of the two peptides. 相似文献
68.
Nynke D Scherpbier-de Haan Gerald MM Vervoort Chris van Weel Jozé CC Braspenning Jan Mulder Jack FM Wetzels Wim JC de Grauw 《The British journal of general practice》2013,63(617):e798-e806
Background
Chronic kidney disease (CKD) is highly prevalent in patients with diabetes or hypertension in primary care. A shared care model could improve quality of care in these patientsAim
To assess the effect of a shared care model in managing patients with CKD who also have diabetes or hypertension.Design and setting
A cluster randomised controlled trial in nine general practices in The Netherlands.Method
Five practices were allocated to the shared care model and four practices to usual care for 1 year. Primary outcome was the achievement of blood pressure targets (130/80 mmHg) and lowering of blood pressure in patients with diabetes mellitus or hypertension and an estimated glomerular filtration rate (eGFR)<60ml/min/1.73m2.Results
Data of 90 intervention and 74 control patients could be analysed. Blood pressure in the intervention group decreased with 8.1 (95% CI = 4.8 to 11.3)/1.1 (95% CI = −1.0 to 3.2) compared to −0.2 (95% CI = −3.8 to 3.3)/−0.5 (95% CI = −2.9 to 1.8) in the control group. Use of lipid-lowering drugs, angiotensin-system inhibitors and vitamin D was higher in the intervention group than in the control group (73% versus 51%, 81% versus 64%, and 15% versus 1%, respectively, [P = 0.004, P = 0.01, and P = 0.002]).Conclusion
A shared care model between GP, nurse practitioner and nephrologist is beneficial in reducing systolic blood pressure in patients with CKD in primary care. 相似文献69.
Stavros M Stivaros Robert Alston Neville B Wright Kate Chandler Denise Bonney Robert F Wynn Andrew M Will Maqsood Punekar Sean Loughran John-Paul Kilday Detlev Schindler Leena Patel Stefan Meyer 《The British journal of radiology》2015,88(1056)
Objective:
Fanconi anaemia (FA) is an inherited disease associated with congenital and developmental abnormalities resulting from the disruption of a multigenic DNA damage response pathway. This study aimed to define the MRI appearances of the brain in patients with FA in correlation with their genetic and clinical features.Methods:
A review of the brain MRI in 20 patients with FA was performed. Pituitary size and frequencies of the radiological findings of individuals with FA and age-matched controls were determined.Results:
Abnormalities were identified in 18 (90%) patients with FA, the commonest being a small pituitary (68%, p < 0.01 females and p < 0.001 males). In five cases (25%, p = 0.02), the pituitary morphology was also abnormal. Posterior fossa abnormalities were seen in six cases (30%, p = 0.01) including Chiari I malformation (n = 3), Dandy–Walker variant (n = 2) and cerebellar atrophy (n = 2). Six patients (30%, p = 0.01) had morphological structural variation of the corpus callosum (CC).Conclusion:
The incidence of central nervous system (CNS) abnormalities in FA is higher than previously reported, with a midline predominance that points to impact in the early stages of CNS development. MRI brain imaging is important for endocrine assessment and pre-transplant evaluation and can make an important contribution to clinical decision-making.Advances in knowledge:
The incidence of brain structural abnormalities in FA is higher than previously reported, with abnormalities of the posterior fossa, CC and pituitary being common. There is an association with gender and reduction in pituitary size which does not strongly correlate with biochemically evident endocrine abnormality. 相似文献70.