全文获取类型
收费全文 | 3749篇 |
免费 | 198篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 157篇 |
儿科学 | 215篇 |
妇产科学 | 36篇 |
基础医学 | 372篇 |
口腔科学 | 153篇 |
临床医学 | 342篇 |
内科学 | 660篇 |
皮肤病学 | 42篇 |
神经病学 | 531篇 |
特种医学 | 66篇 |
外科学 | 485篇 |
综合类 | 19篇 |
一般理论 | 4篇 |
预防医学 | 288篇 |
眼科学 | 70篇 |
药学 | 172篇 |
中国医学 | 1篇 |
肿瘤学 | 336篇 |
出版年
2023年 | 16篇 |
2022年 | 33篇 |
2021年 | 53篇 |
2020年 | 39篇 |
2019年 | 48篇 |
2018年 | 73篇 |
2017年 | 51篇 |
2016年 | 89篇 |
2015年 | 70篇 |
2014年 | 89篇 |
2013年 | 198篇 |
2012年 | 204篇 |
2011年 | 221篇 |
2010年 | 125篇 |
2009年 | 144篇 |
2008年 | 227篇 |
2007年 | 242篇 |
2006年 | 206篇 |
2005年 | 255篇 |
2004年 | 252篇 |
2003年 | 224篇 |
2002年 | 218篇 |
2001年 | 36篇 |
2000年 | 34篇 |
1999年 | 42篇 |
1998年 | 58篇 |
1997年 | 48篇 |
1996年 | 36篇 |
1995年 | 43篇 |
1994年 | 40篇 |
1993年 | 42篇 |
1992年 | 44篇 |
1991年 | 31篇 |
1990年 | 26篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 25篇 |
1985年 | 25篇 |
1984年 | 20篇 |
1983年 | 39篇 |
1982年 | 44篇 |
1981年 | 15篇 |
1980年 | 26篇 |
1979年 | 16篇 |
1978年 | 19篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1972年 | 10篇 |
排序方式: 共有3949条查询结果,搜索用时 15 毫秒
41.
42.
Noriaki Moriyama Teemu Laakso Peter Raivio Sebastian Dahlbacka Eeva-Maija Kinnunen Tatu Juvonen Antti Valtola Annastiina Husso Maina P. Jalava Tuomas Ahvenvaara Tuomas Tauriainen Jarkko Piuhola Asta Lahtinen Matti Niemelä Timo Mäkikallio Marko Virtanen Pasi Maaranen Markku Eskola Mika Laine 《The Canadian journal of cardiology》2021,37(1):37-46
BackgroundThe data on acute kidney injury (AKI) in patients without chronic kidney disease (CKD) after transcatheter aortic valve replacement (TAVR) are limited. The study sought to compare the incidence of AKI and its impact on 5-year mortality after TAVR and surgical aortic valve replacement (SAVR) in patients without CKD.MethodsThis registry included data from 6463 consecutive patients who underwent TAVR or SAVR. CKD was defined as estimated glomerular filtration rate <60 mL/min/1.73 m2. AKI was defined according to the Kidney Disease Improving Global Outcomes criteria. For sensitivity analysis, propensity-score matching between TAVR and SAVR was performed.ResultsThe study included 4555 consecutive patients (TAVR, n = 1215 and SAVR, n = 3340) without CKD. Propensity-score matching identified 542 pairs. Patients who underwent TAVR had a significantly lower incidence of AKI in comparison to those who underwent SAVR (unmatched 4.7% vs 16.4%, P < 0.001, multivariable analysis: odds ratio, 0.29, 95% confidence interval [CI], 0.20-0.41; matched 5.9% vs 19.0%, P < 0.001). Patients with AKI had significantly increased 5-year mortality compared with those without AKI (unmatched 36.0% vs 19.1%, log-rank P < 0.001; matched 36.3% vs 24.0%, log-rank P < 0.001). The adjusted hazard ratios for 5-year mortality were 1.58 (95% CI, 1.20-2.08) for AKI grade 1, 3.27 (95% CI, 2.09-5.06) for grade 2, and 4.82 (95% CI, 2.93-8.04) for grade 3.ConclusionsTAVR in patients without CKD was associated with a significantly less frequent incidence of AKI compared with SAVR. AKI significantly increased the risk of 5-year mortality after either TAVR or SAVR, and increasing severity of AKI was incrementally associated with 5-year mortality. 相似文献
43.
Five-year trend in serum HDL-lipoprotein cholesterol in the Finnish population aged 25-64 years. A suggestion of an increase 总被引:1,自引:0,他引:1
V V Salomaa M Jauhiainen P Pietinen H J Korhonen L Kartovaara E Vartiainen J Tuomilehto 《Atherosclerosis》1991,86(1):39-48
High density lipoprotein cholesterol (HDLC) was measured in the population surveys carried out in Finland in 1982 and 1987. The mean (+/- SD) of HDLC for men aged 25-64 years was 1.23 +/- 0.32 mmol/l in 1982 and 1.30 +/- 0.33 mmol/l in 1987, the increase being 5.7%. Respective values in women were 1.46 +/- 0.33 mmol/l and 1.58 +/- 0.35 mmol/l, an increase of 8.2%. The increase was significantly greater in women than in men (P less than 0.001). The prevalence of low HDLC (less than or equal to 0.9 mmol/l) fell from 13.5 to 9.6% in men and from 3.2 to 1.4% in women. Factors associated with low HDLC were the history of ischemic heart disease (IHD), diabetes and hypertension in both sexes and the positive family history of IHD in women. Subjects with low HDLC also had higher body mass index (BMI), waist-hip ratio and serum total cholesterol (TC) concentration than subjects with normal HDLC. Changes in BMI, waist-hip ratio, alcohol intake, leisure time physical activity, prevalence of smoking or in the dietary variables recorded, did not explain the increase in HDLC. 相似文献
44.
Antibodies to human heat shock protein 60, hypertension and dyslipidemia. A study of joint effects on coronary risk 总被引:3,自引:0,他引:3
Kervinen H Huittinen T Vaarala O Leinonen M Saikku P Manninen V Mänttäri M 《Atherosclerosis》2003,169(2):339-344
OBJECTIVE: High IgA-class (but not IgG-class) Anti-Heat-shock-protein 60 antibody level is a predictor of coronary risk in dyslipidemic middle-aged men. In this paper we studied the joint effects of high Anti-Hsp60-antibody level and the classical coronary risk factors. METHODS: We used nested case-control design and logistic regression analyses. The cases consisted of 233 middle-aged men with myocardial infarction or coronary death during 8.5-year follow-up in Helsinki Heart Study, a coronary primary prevention study with gemfibrozil. The controls were subjects without coronary events, matched for drug treatment and the geographical area. RESULTS: The relative coronary risks (Odds Ratios (ORs); 95% confidence interval) were 1.41 (0.96-2.05) for high IgA-class Anti-Hsp60 antibody level and 1.98 (1.35-2.90) for hypertension, defined as mean arterial pressure >114 mmHg. With simultaneous occurrence of high Anti-Hsp60 antibody level and hypertension, the ORs were 2.32 (1.26-4.27) for systolic and 2.99 (1.63-5.48) for diastolic hypertension. Similar patterns of joint effects were found between high Anti-Hsp60 antibody and lipoprotein cholesterol levels as well as antibodies against oxidized low-density lipoprotein. CONCLUSIONS: Our results suggest that, while high IgA-class Anti-Hsp60 antibody level predicts coronary risk, the effect is modest without simultaneous occurrence of other classical risk factors. 相似文献
45.
Blomgren K Alho OP Ertama L Huovinen P Korppi M Mäkelä M Penttilä M Pitkäranta A Savolainen S Varonen H Suonpää J;Finnish Society of Otorhinolaryngology committee 《Scandinavian journal of infectious diseases》2005,37(4):245-250
These clinical practice guidelines aim at providing assistance mainly to primary health care physicians for the diagnosis and management of acute sinusitis. Despite the huge impact of upper respiratory infections, criteria for diagnoses are often vague, and physicians are often uncertain of their diagnoses. This is not surprising, as the sole definition of acute sinusitis is somewhat confusing, not to mention the existing discrepancies between treatments, even among specialists. The Finnish Society of Otorhinolaryngology has set up a committee to evaluate existing data on acute sinusitis and to formulate these guidelines. The committee comprised Finnish experts in adult and paediatric otorhinolaryngology, clinical microbiology, radiology, paediatrics, and epidemiology. Recommendations given are based on the principles of evidence-based medicine, with the level of evidence presented. 相似文献
46.
Is there any link between insulin resistance and inflammation in established preeclampsia? 总被引:5,自引:0,他引:5
Kaaja R Laivuori H Pulkki P Tikkanen MJ Hiilesmaa V Ylikorkala O 《Metabolism: clinical and experimental》2004,53(11):1433-1435
Both insulin resistance and inflammation may contribute to the onset of preeclampsia. They also could be interrelated. We studied the relationship between inflammatory cytokines and markers of insulin resistance. During their third trimester, 22 proteinuric preeclamptic women and 16 normotensive controls underwent intravenous glucose tolerance test (minimal model). Preeclamptic women were more insulin-resistant (P = .009), and they had higher levels of serum soluble tumor necrosis alpha receptor II (TNFalpha RII) (P = .002), triglycerides (P = .006), uric acid (P = .001), and leptin (P = .002) than did the controls. However, the study groups did not differ in serum TNFalpha, C-reactive protein (CRP), interleukin-6 (IL-6), sex hormone-binding globulin (SHBG), and high-density lipoprotein-2 (HDL(2))-cholesterol. In multiple regression analysis only SHBG (P = .01) and triglycerides (P = .0036) were associated with insulin sensitivity independently of body mass index (BMI), weight gain, HDL(2)-cholesterol, CRP, TNFalpha, and TNFalpha RII, IL-6, and leptin. We conclude that insulin resistance and the inflammatory markers studied were not associated in established preeclampsia. 相似文献
47.
Virtanen I Korhonen M Petäjäniemi N Karhunen T Thornell LE Sorokin LM Konttinen YT 《The Journal of clinical endocrinology and metabolism》2003,88(10):4960-4966
Laminin has been proposed to influence the function of human adrenal cortex. We have studied the distribution of laminin (Ln) chains using immunofluorescence in human fetal and adult adrenal cortex. In the fetal gland Ln alpha2- and alpha5-chains were weakly expressed in the definitive zone, whereas Ln alpha4-, beta1-, and gamma1-chains occurred around vessels. In the adult gland, Ln alpha2-, alpha5-, and gamma1-chains were found in epithelial basement membranes (BM) in all cortical zones, Ln alpha4-chain in vessels, Ln beta1-chain in outer zone, and Ln beta2-chain in the two inner zones of the cortex, respectively. Among the integrins in adult gland, integrin alpha(3)-subunit was confined to basal surfaces of cortical cells, alpha(6) to vessels, alpha(1) to the stroma, and alpha(2) diffusely to epithelial cells. Lutheran glycoprotein and dystroglycan occurred in the fetal gland diffusely in the definitive zone and throughout the epithelium in the adult. The isoform composition of BM of the adult adrenal gland is distinct, with Ln-2 and -10 in BM of the outer zone and Ln-4 and -11 in BM of the two inner zones. The results suggest that integrin alpha(3)beta(1) and Lutheran are candidate receptors for Ln-10 and -11, whereas dystroglycan probably binds Ln-2 and -4. 相似文献
48.
Kalle Hakala Pekka Luukkonen Matti Vuoristo Heikki Järvinen Tatu A. Miettinen 《Journal of hepatology》1997,26(6):1306-1312
Background: Previous studies suggest only minor changes in bile acid metabolism after panproctocolectomy with ileal pouch construction.Aims/Methods: To investigate these changes further, we studied cholesterol absorption and serum, biliary and fecal non-cholesterol sterols and lipids in 12 ileal pouch patients and 10 controls.Results: In patients, cholesterol absorption was markedly reduced and was associated with low serum total and LDL cholesterol and LDL triglyceride levels, but surprisingly, cholesterol synthesis, as indicated by sterol-balance data or serum cholesterol precursor levels, was within low normal limits. The high proportions of serum plant sterol to cholesterol, particularly that of campesterol, were not related to cholesterol absorption, but were attributable to a markedly reduced biliary cholesterol secretion. Interestingly, in these patients the fractional absorption of campesterol was normal, whereas that of sitosterol, like cholesterol, was reduced and was positively related to the intestinal influx of cholesterol. The patients' serum cholestanol proportion was normal, but the proportion of the cholestanol formed during intestinal passage was significantly reduced (17.9% vs 65.2% in controls).Conclusions: Thus ileal pouch patients are characterized by sterol malabsorption, lowered serum total and LDL-cholesterol levels, but unexpectedly without any increase in cholesterol synthesis. The lack of high serum cholestanol, shown earlier frequently in unoperated patients with ulcerative colitis, may indicate reversible cholestasis, a finding deserving further exploration. 相似文献
49.
Petri M. Leukkunen Ekta Rani Assa Aravindh Sasikala Devi Harishchandra Singh Graham King Matti Alatalo Wei Cao Marko Huttula 《RSC advances》2020,10(60):36930
P25 comprising of mixed anatase and rutile phases is known to be highly photocatalytically active compared to the individual phases. Using a facile wet chemical method, we demonstrate a ternary nanocomposite consisting of Ni and Ag nanoparticles, decorated on the surface of XTiO2 (X: P25, rutile (R)) as an efficient visible-light-driven photocatalyst. Contrary to the current perspective, RTiO2-based Ni–Ag–RTiO2 shows the highest activity with the H2 evolution rate of ∼86 μmol g−1 W−1 h−1@535 nm. Together with quantitative assessment of active Ni, Ag and XTiO2 in these ternary systems using high energy synchrotron X-ray diffraction, transmission electron microscopy coupled energy dispersive spectroscopy mapping evidences the metal to semiconductor contact via Ag. The robust photocatalytic activity is attributed to the improved visible light absorption, as noted by the observed band edge of ∼2.67 eV corroborating well with the occurrence of Ti3+ in Ti 2p XPS. The effective charge separation due to intimate contact between Ni and RTiO2via Ag is further evidenced by the plasmon loss peak in Ag 3d XPS. Moreover, density functional theory calculations revealed enhanced adsorption of H2 on Ti8O16 clusters when both Ag and Ni are simultaneously present, owing to the hybridization of the metal atoms with d orbitals of Ti and p orbitals of O leading to enhanced bonding characteristics, as substantiated by the density of states. Additionally, the variation in the electronegativity in Bader charge analysis indicates the possibility of hydrogen evolution at the Ni sites, in agreement with the experimental observations.Robust photocatalytic activity of Ni–Ag–RTiO2 is attributed to the improved visible light absorption and effective charge separation due to intimate contact between Ni and RTiO2via Ag, as evidenced by Ti3+ in Ti 2p XPS and energy dispersive mapping. 相似文献
50.