全文获取类型
收费全文 | 1055篇 |
免费 | 50篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 14篇 |
妇产科学 | 31篇 |
基础医学 | 122篇 |
口腔科学 | 15篇 |
临床医学 | 47篇 |
内科学 | 268篇 |
皮肤病学 | 4篇 |
神经病学 | 75篇 |
特种医学 | 39篇 |
外科学 | 142篇 |
综合类 | 6篇 |
预防医学 | 109篇 |
眼科学 | 20篇 |
药学 | 121篇 |
中国医学 | 2篇 |
肿瘤学 | 73篇 |
出版年
2023年 | 4篇 |
2021年 | 48篇 |
2020年 | 21篇 |
2019年 | 10篇 |
2018年 | 20篇 |
2017年 | 13篇 |
2016年 | 22篇 |
2015年 | 27篇 |
2014年 | 29篇 |
2013年 | 36篇 |
2012年 | 47篇 |
2011年 | 57篇 |
2010年 | 41篇 |
2009年 | 20篇 |
2008年 | 58篇 |
2007年 | 52篇 |
2006年 | 56篇 |
2005年 | 62篇 |
2004年 | 54篇 |
2003年 | 70篇 |
2002年 | 61篇 |
2001年 | 19篇 |
2000年 | 26篇 |
1999年 | 24篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1992年 | 17篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 4篇 |
1975年 | 7篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1971年 | 8篇 |
1970年 | 4篇 |
1968年 | 4篇 |
1967年 | 8篇 |
1966年 | 9篇 |
排序方式: 共有1107条查询结果,搜索用时 265 毫秒
21.
Arkadiusz Koszarny Maria Majdan Magdalena Dryglewska Jacek Tabarkiewicz 《Reumatologia》2015,53(2):61-68
Objectives
The aim of the study was to investigate the prevalence of selected organ-specific autoantibodies in rheumatoid arthritis (RA) and primary Sjögren''s syndrome (pSS) patients, and discuss their clinical significance.Material and methods
The study included 121 RA and 30 pSS patients. Sera were tested for the presence of autoantibodies to thyroid peroxidase (anti-TPO), thyroglobulin (anti-TG), TSH receptor (TRAbs), mitochondrial antigen M2 (AMA-M2-3E) and gliadin-analogous fusion peptides (anti-GAF(3X)) using the ELISA method. Non-organ-specific antibodies were determined: rheumatoid factor in IgM class, anti-citrullinated peptide antibodies and antinuclear antibodies. The occurrence of antibodies was also examined with regards to RA activity.Results
The following autoantibodies were detected in RA patients: anti-TPO – 13 (10.7%), anti-TG – 6 (5%), AMA-M2-3E – 3 (2.5%), anti-GAF(3X) – 5 (4.1%). The respective levels of these autoantibodies in pSS patients were 3 (10%), 2 (6.7%), 4 (13.3%) and 2 (6.7%). Polyautoimmunity was confirmed in 34 RA patients (including 20 cases of autoimmune thyroid disease [AITD]) and in 6 pSS patients (6 cases of AITD). When RA patients were divided into anti-TPO positive and anti-TPO negative groups, we found a statistically significant relationship between groups regarding age and hemoglobin concentration. In pSS patients the anti-TPO positive group was less likely to use immunosuppressive drugs as compared with the anti-TPO negative group. Anti-TPO was significantly more frequently detected in RA + AITD vs. RA, RA + SS + AITD vs. RA and in pSS + AITD vs. pSS patients.Conclusions
Organ-specific autoantibodies are relatively frequently observed in patients with RA and pSS. Their presence is connected with the clinical picture of the diseases. 相似文献22.
23.
Structurally Specific Heparan Sulfates Support Primitive Human Hematopoiesis by Formation of a Multimolecular Stem Cell Niche 总被引:7,自引:3,他引:7
Gupta Pankaj; Oegema Theodore R. Jr; Brazil Joseph J.; Dudek Arkadiusz Z.; Slungaard Arne; Verfaillie Catherine M. 《Blood》1998,92(12):4641-4651
Stem cell localization, conservation, and differentiation isbelieved to occur in niches in the marrow stromal microenvironment. Ourrecent observation that long-term in vitro human hematopoiesis requiresa stromal heparan sulfate proteoglycan (HSPG) led us to hypothesizethat such HSPG may orchestrate the formation of the stem cell niche. Wecompared the structure and function of HS from M2-10B4, ahematopoiesis-supportive cell line, with HS from a nonsupportive cellline, FHS-173-We. Long-term culture-initiating cell (LTC-IC)maintenance was enhanced by PG from supportive cells but not by PG fromnonsupportive cells (P < .005). The supportive HS weresignificantly larger and more highly sulfated than the nonsupportiveHS. Specifically, supportive HS contained higher 6-O-sulfation on theglucosamine residues. In agreement with these observations, purified6-O-sulfated heparin and highly 6-O-sulfated bovine kidney HS similarlymaintained LTC-IC. In contrast, completely desulfated heparin,N-sulfated heparin, and unmodified heparin did not support LTC-ICmaintenance. Moreover, the supportive HS promoted LTC-IC maintenancebut not differentiation of CD34+/HLA-DRcells into colony-forming cells (CFCs) and mature bloodcells. The supportive HS but not the nonsupportive HS bound bothcytokines and matrix components critical for hematopoiesis, includinginterleukin-3 (IL-3), macrophage inflammatory protein-1 (MIP-1),and thrombospondin (TSP). Significantly more CD34+ cellsadhered directly to immobilized O-sulfated heparin than to N-sulfatedor desulfated heparin. Thus, hematopoiesis-supportive stromal HSPGpossessing large, highly 6-O-sulfated HS mediate the juxtaposition ofhematopoietic progenitors with stromal cells, specific growth-promoting(IL-3) and growth-inhibitory (MIP-1 and platelet factor 4 [PF4])cytokines, and extracellular matrix (ECM) proteins such as TSP. Weconclude that the structural specificity of stromal HSPG thatdetermines the selective colocalization of cytokines and ECM componentsleads to the formation of discrete niches, thereby orchestrating thecontrolled growth and differentiation of stem cells. These findings mayhave important implications for ex vivo expansion of and gene transferinto primitive hematopoietic progenitors. 相似文献
24.
Stawicki S Jasik M Roik M Kosior D Scisło P Kochanowski J Dembe K Krakowiecki A Karnafel W Opolski G 《Polskie Archiwum Medycyny Wewn?trznej》2003,110(3):989-996
Last decade brought great development in the treatment of patients with heart failure (HF). General use of angiotensin-converting-enzyme inhibitors (ACE-I) in patients with asymptomatic left ventricular dysfunction or with HF significantly reduced morbidity and mortality. The aim of this study was to assess how the specialists from Cardiology Department and Gastroenterology Department think that heart failure should be managed, how they implement their knowledge and if it is consistent with the recommendation of European Society of Cardiology (ESC) and whether differences exists in practice between specialists. In the first phase the specialists, cardiologists and diabetologists, answered the questions about the management of different stages of HF. In second phase we analysed medical documentation of 345 patients aged between 38 and 98 years, hospitalised in Cardiology and Gastroenterology Departments from October 2000 to February 2002 by reason of coronary artery disease, hypertension and dilated cardiomyopathy. In the third phase we compared the knowledge of heart failure management from questionnaire and its implementation, the compliance with ESC recommendation and finally whether differences in clinical practice exist between cardiologist and diabetologists. RESULTS: ACE-I were prescribed in all NYHA classes of HF. In over 50% patients in II NYHA class to 94% in IV NYHA class in Cardiology Department. Differences between the Departments in prescribing of ACE-I were observed. Beta-blockers (BB) were used with the same frequency in all NYHA classes, more often in Cardiology Department. Frequency of the administration of digoxin, diuretics, aldosterone receptor blocker was increasing starting with II NYHA class. The highest compliance between declarations from questionnaire and clinical practice concerned the use of BB and ACE-I combination. 相似文献
25.
Marek Strzala Arkadiusz Stanula Grzegorz G?ab Jacek Glodzik Andrzej Ostrowski Marcin Kaca Leszek Nosiadek 《Journal of Sports Science and Medicine》2015,14(1):110-117
The aim of this study was to investigate somatic properties and physiological capacity, and analyze kinematic parameters in the 200 m breaststroke swimming race. Twenty-seven male swimmers participated in the study. They were 15.7±1.98 years old. Their average height was 1.80 ± 0.02 m and lean body mass (LBM) was 62.45 ± 8.29 kg. Physiological exercise capacity was measured in two separate 90 sec. all-out tests, one for the arms and second for legs. During the tests total work of arm cranking (TWAR) and cycling (TWLG) as well as peak of VO2 for arm (VO2peakAR) and leg (VO2peakLG) were measured. The underwater swimmers body movements were recorded during the all-out swimming 200m breaststroke speed test using an underwater camera installed on a portable trolley. The swimming kinematic parameters and propulsive or non-propulsive movement phases of the arms and legs as well as average speed (V200), surface speed (V200surface) and swimming speed in turn zones (V200turns) were extracted. V200surface was significantly related to the percentage of leg propulsion and was shown to have large effect on VO2peakLG in the Cohen analysis. V200turns depended significantly on the indicators of physiological performance and body structure: TWAR, VO2peak LG and LBM, LBM, which in turn strongly determined the measured results of TWAR, TWLG, VO2peakAR and VO2peakLG. The V200turns and V200surface were strongly associated with V200, 0.92, p < 0.001 and 0.91, p < 0.001 respectively. In each lap of the 200m swimming there was an increased percentage of propulsion of limb movement observed simultaneously with a reduction in the gliding phase in the breaststroke cycles.
Key points
- This study investigated the influence of the selected indicators of somatic properties and physiological capacity as well kinematic and coordination parameters on breaststroke swimming.
- In this observations the body’s functional capacity have an important impact on achieving good breaststroke swimming results, the V200 was moderately associated on VO2peakLG, moreover, separate V200turns depended with VO2peakLG and on LBM and TWAR.
- The speed of surface breaststroke swimming - V200surface similarly as V200turns had a very strong influence on the end result of V200 , 0.91, p<0.001 and 0.92, p<0.001 respectively.
- The ability to swim fast on the surface (V200surface) was positively and significantly associated with the percentage time of propulsion generation -LP in the breaststroke cycle.
26.
Smoking is one of the most important risk factors of atherosclerosis and ischaemic heart disease. Endothelial dysfunction is a pathological result of smoking. The aim of the study was to examine the influence of cigarette smoking on biochemical parameters of endothelial function in persons with angiographically confirmed coronary arteries atherosclerosis. The study group included 117 men: 55 patients (mean age 58.8 +/- 10.4) with ischaemic heart disease and 62 healthy subjects (mean age 47.1 +/- 9.3) of control group. In all patients blood lipid concentrations, biochemical parameters of endothelial function (nitric oxide, endothelin-1, sICAM, selectin-E), and inflammation parameters (interleukin-1 beta, interleukin-6) were measured. In a group of smoking patients both: with atherosclerosis and in control subjects nitric oxide (NO) concentrations in serum were decreased in comparison to nonsmokers. In patients with diagnosed coronary arteries atherosclerosis interleukin-6 and sICAM concentrations were increased in comparison to non-smokers. It is concluded that cigarette smoking activates or maintains inflammatory reaction in vessels with atherosclerotic changes. 相似文献
27.
Gruchala M Ciećwierz D Wasag B Targoński R Dubaniewicz W Nowak A Sobiczewski W Ochman K Romanowski P Limon J Rynkiewicz A 《American heart journal》2003,145(1):125-131
Background There is growing evidence from recent studies that atrial natriuretic peptide (ANP) plays an important part in coronary blood flow regulation and in atherosclerosis. Transition T2238→C in the atrial natriuretic peptide (ANP) precursor gene, which leads potentially to the translation of ANP with 2 additional arginines, has been suggested to be associated with salt-sensitive hypertension. According to our knowledge, this study is the first to look for the potential association of the ScaI ANP gene polymorphism with the history of nonfatal myocardial infarction and the extent of coronary artery disease (CAD).Methods The study was performed in 847 consecutive, white patients (719 men and 128 women) with significant coronary artery stenosis confirmed by means of elective coronary angiography (at least 1 coronary artery with ≥50% lumen narrowing). Screening for the T2238→C substitution was performed by means of polymerase chain reaction of genomic DNA, followed by ScaI digestion and agarose gel electrophoresis.Results We found a significant association of the A2A2 ScaI ANP genotype with a higher incidence of positive history of nonfatal myocardial infarction (odds ratio 1.85, 95% CI 1.33-2.58) and multiple-vessel CAD (odds ratio 1.45, 95% CI 1.02-2.06). The ScaI ANP genotype distribution did not differ with age, sex, body mass index, plasma lipids, hypertension, diabetes mellitus, and family history of CAD in studied groups.Conclusions Our results suggest that the ScaI ANP polymorphism may be associated with nonfatal myocardial infarction and the extent of CAD. However, the precise mechanism of this association remains to be determined. (Am Heart J 2003;145:125-31.) 相似文献
28.
Amanda Bartkowiak Arkadiusz Zarzycki Slawomir Kac Marcin Perzanowski Marta Marszalek 《Materials》2020,13(22)
Nanotechnology is a very attractive tool for tailoring the surface of an orthopedic implant to optimize its interaction with the biological environment. Nanostructured interfaces are promising, especially for orthopedic applications. They can not only improve osseointegration between the implant and the living bone but also may be used as drug delivery platforms. The nanoporous structure can be used as a drug carrier to the surrounding tissue, with the intention to accelerate tissue–implant integration as well as to reduce and treat bacterial infections occurring after implantation. Titanium oxide nanotubes are promising for such applications; however, their brittle nature could be a significantly limiting factor. In this work, we modified the topography of commercially used titanium foil by the anodization process and hydrothermal treatment. As a result, we obtained a crystalline nanoporous u-shaped structure (US) of anodized titanium oxide with improved resistance to scratch compared to TiO2 nanotubes. The US titanium substrate was successfully modified with hydroxyapatite coating and investigated for bioactivity. Results showed high bioactivity in simulated body fluid (SBF) after two weeks of incubation. 相似文献
29.
30.
This publication presents an assessment of the influence of a surface treatment such as shot-peening on the fatigue life of a compressor blade exposed to resonant vibrations. As part of the work, a geometric model of the blade was developed, and a numerical modal and fatigue analysis were performed. The fatigue analysis was based on the Manson–Coffin–Basquin and Ramberg–Osgood models. Additionally, the location of the highest equivalent stresses was established. Based on the results of the strength analysis, two points were identified where a fatigue crack may potentially occur. As part of the work, the influence of different values of residual stresses on the results of the fatigue life was determined. The obtained results were compared to the literature values of fatigue life for this blade. A secondary objective of the study was to determine the size of the grains at various points of the blade, as well as the thickness of the layer plasticized as a result of peening. The relationship between the location of the highest values of the equivalent stresses and the thickness of the plasticized layer was determined. An explanation of the effect of shot-peening on the increase in the fatigue life of the blade was proposed. 相似文献