全文获取类型
收费全文 | 3240篇 |
免费 | 193篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 271篇 |
妇产科学 | 209篇 |
基础医学 | 259篇 |
口腔科学 | 163篇 |
临床医学 | 293篇 |
内科学 | 741篇 |
皮肤病学 | 53篇 |
神经病学 | 256篇 |
特种医学 | 73篇 |
外科学 | 404篇 |
综合类 | 51篇 |
预防医学 | 131篇 |
眼科学 | 152篇 |
药学 | 182篇 |
中国医学 | 10篇 |
肿瘤学 | 167篇 |
出版年
2024年 | 5篇 |
2023年 | 56篇 |
2022年 | 120篇 |
2021年 | 194篇 |
2020年 | 114篇 |
2019年 | 125篇 |
2018年 | 146篇 |
2017年 | 108篇 |
2016年 | 127篇 |
2015年 | 130篇 |
2014年 | 150篇 |
2013年 | 213篇 |
2012年 | 249篇 |
2011年 | 266篇 |
2010年 | 162篇 |
2009年 | 99篇 |
2008年 | 201篇 |
2007年 | 209篇 |
2006年 | 179篇 |
2005年 | 169篇 |
2004年 | 128篇 |
2003年 | 108篇 |
2002年 | 89篇 |
2001年 | 21篇 |
2000年 | 12篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1966年 | 1篇 |
1936年 | 2篇 |
1923年 | 1篇 |
排序方式: 共有3452条查询结果,搜索用时 15 毫秒
1.
2.
Increased arterial stiffness in young normotensive patients with Turner syndrome: associations with vascular biomarkers 下载免费PDF全文
3.
Berrin Leblebici Nur Turhan Mehmet Adam Mahmut Nafiz Akman 《Journal of wound, ostomy, and continence nursing》2007,34(4):407-411
OBJECTIVE: We sought to measure the incidence of pressure ulcer development at a university health center in Turkey, and to determine whether the Waterlow Pressure Sore Risk (PSR) Scale score predicted pressure ulcer development, stage, or number of ulcers. DESIGN: We prospectively evaluated patients who were hospitalized at our university-based medical center. SETTING AND SUBJECTS: We analyzed data from 22,834 patients hospitalized at the Baskent University Adana Teaching and Medical Research Center in Ankara, Turkey from January 1, 2004 to December 31, 2004, including 360 patients who developed pressure ulcers. INSTRUMENTS: The Waterlow PSR Scale was used to assess pressure ulcer risk. In addition, age, sex, the ward or unit in which the patient was hospitalized, reason for hospitalization, and location and stage of ulcers were collected on a data form designed specifically for this study. METHODS: A single nurse physiotherapist assessed all patients daily during their hospitalization. When a pressure ulcer was diagnosed by the nurse physiotherapist, a physician staged the pressure ulcers based on the US National Pressure Ulcer Advisory Panel (NPUAP) staging system. RESULTS: Three hundred sixty out of 22,834 patients developed 1 or more pressure ulcers, resulting in an incidence rate of 1.6%. Most ulcers (59.2%) occurred in patients hospitalized in the intensive care unit (n = 213). A positive correlation between the Waterlow PSR Scale score and number of ulcers per patient (r: 0.178, P < .01) was identified. No significant correlation was found linking Waterlow PSR Scale score and ulcer stage or the development of a single ulcer. CONCLUSION: We found significantly lower pressure ulcer incidence rates than those commonly reported in the literature, which we believe is principally attributable to short hospital stays and a strong emphasis on preventive nursing care. While high Waterlow PSR scale Scores correlated positively with development of multiple ulcers, this did not predict ulcer stage or the presence of a single pressure ulcer. 相似文献
4.
5.
6.
Qadri F Raqib R Ahmed F Rahman T Wenneras C Das SK Alam NH Mathan MM Svennerholm AM 《Clinical and diagnostic laboratory immunology》2002,9(2):221-229
Investigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected with Vibrio cholerae O1 and V. cholerae O139. The levels of nonspecific mediators of the innate defense system, i.e., prostaglandin E(2) (PGE(2)), leukotriene B(4) (LTB(4)), and lactoferrin (Lf), as well as myeloperoxidase (MPO), were elevated at the acute stage of the disease in stools obtained from both O1- and O139-infected adults and children. In the systemic compartment, the levels of Lf were increased after onset of disease, which in children remained elevated up to convalescence compared to the healthy controls. Increased concentrations of C-reactive protein were seen in the sera of adult cholera patients at the acute stage of infection. Elevated levels of the nitric oxide (NO*) metabolites (nitrite and nitrate [NO(2)(-) and NO(3)(-)]) were detected in plasma but not in urine. The activity of the scavenger of reactive oxygen species, superoxide dismutase, was higher in the plasma of adults immediately after the onset of disease, suggesting that an active scavenging of reactive oxygen species was taking place. The concentration of 8-iso-prostaglandin F(2 alpha) remained unchanged in the systemic and mucosal compartments in the study subjects. After the recovery of patients from cholera, the concentration of the majority of the metabolites decreased to baseline levels by day 30 after the onset of infection. Immunohistochemical staining showed increased tissue expression of MPO, Lf, and inducible nitric oxide synthase at the acute stage in the duodenal biopsies of adults and rectal biopsies obtained from children with cholera. Very little difference was seen in the levels of the different inflammatory mediators in patients infected with V. cholerae O1 or the encapsulated V. cholerae O139. In summary, these results suggest that elevated concentrations of Lf, MPO, PGE(2), LTB(4), and NO*, as well as other metabolites, during the acute stage of the disease indicate that the innate defense system, as well as the inflammatory process, is activated in both adults and pediatric patients infected with V. cholerae O1 and O139. 相似文献
7.
Increased Levels of Inflammatory Mediators in Children and Adults Infected with Vibrio cholerae O1 and O139 下载免费PDF全文
Firdausi Qadri Rubhana Raqib Firoz Ahmed Taufiqur Rahman Christine Wenneras Swadesh Kumar Das Nur Haque Alam Minnie M. Mathan Ann-Mari Svennerholm 《Clinical and Vaccine Immunology : CVI》2002,9(2):221-229
Investigations were carried out to study the production of factors associated with the innate immune response in the systemic and mucosal compartments in adults and children infected with Vibrio cholerae O1 and V. cholerae O139. The levels of nonspecific mediators of the innate defense system, i.e., prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and lactoferrin (Lf), as well as myeloperoxidase (MPO), were elevated at the acute stage of the disease in stools obtained from both O1- and O139-infected adults and children. In the systemic compartment, the levels of Lf were increased after onset of disease, which in children remained elevated up to convalescence compared to the healthy controls. Increased concentrations of C-reactive protein were seen in the sera of adult cholera patients at the acute stage of infection. Elevated levels of the nitric oxide (NO·) metabolites (nitrite and nitrate [NO2− and NO3−]) were detected in plasma but not in urine. The activity of the scavenger of reactive oxygen species, superoxide dismutase, was higher in the plasma of adults immediately after the onset of disease, suggesting that an active scavenging of reactive oxygen species was taking place. The concentration of 8-iso-prostaglandin F2α remained unchanged in the systemic and mucosal compartments in the study subjects. After the recovery of patients from cholera, the concentration of the majority of the metabolites decreased to baseline levels by day 30 after the onset of infection. Immunohistochemical staining showed increased tissue expression of MPO, Lf, and inducible nitric oxide synthase at the acute stage in the duodenal biopsies of adults and rectal biopsies obtained from children with cholera. Very little difference was seen in the levels of the different inflammatory mediators in patients infected with V. cholerae O1 or the encapsulated V. cholerae O139. In summary, these results suggest that elevated concentrations of Lf, MPO, PGE2, LTB4, and NO·, as well as other metabolites, during the acute stage of the disease indicate that the innate defense system, as well as the inflammatory process, is activated in both adults and pediatric patients infected with V. cholerae O1 and O139. 相似文献
8.
Combination of reverse transcriptase PCR analysis and immunoglobulin M detection on filter paper blood samples allows diagnostic and epidemiological studies of measles 下载免费PDF全文
9.
Thrombopoietin receptor (Mpl) expression by megakaryocytes in myeloproliferative disorders 总被引:2,自引:0,他引:2
The thrombopoietin receptor (Mpl) is involved in the pathogenesis of chronic myeloproliferative disorders (CMPD). In this study, we determined Mpl expression by bone marrow cells and megakaryocytes in CMPD by applying laser microdissection, real-time RT-PCR, and immunohistochemistry. Mpl mRNA expression was significantly increased up to 9-fold in total bone marrow cells (p < 0.001) and up to 4-fold in megakaryocytes in chronic myeloproliferative disorders (n = 73) compared to normal controls (n = 26, p = 0.01). Immunohistochemistry revealed heterogeneous Mpl expression by megakaryocytes in CMPD with a stronger accentuation in idiopathic myelofibrosis (IMF) in comparison to polycythaemia vera (PV) and essential thrombocythemia (ET). In addition to megakaryocytes, the erythropoietic lineage was prominently labelled by Mpl antiserum, with considerably stronger staining in polycythaemia vera. We conclude that, in CMPD, megakaryocytes and erythroid cells exhibit increased Mpl expression levels which may contribute to the sustained proliferation of both cell lineages in CMPD. 相似文献
10.
Ateş A Düzgün N Ulu A Tiryaki AO Akar N 《Pathophysiology of haemostasis and thrombosis》2003,33(3):157-163
OBJECTIVES: Beh?et's disease (BD) is a chronic inflammatory disorder of still unknown etiology, characterized by endothelial cell injury/dysfunction and thrombosis and/or aneurysm of large blood vessels. Thrombophilia may play a role in the pathogenesis of thrombosis in BD. The common inherited gene defects, factor V (FV) 1691A (Leiden) and prothrombin (PT) 20210A, are known risk factors for thrombosis. The FV 4070G polymorphism was shown to influence circulating FV levels and to contribute to the activated protein C resistance phenotype. The aim of the study was to evaluate the role of FV 1691A, FV 4070G and PT 20210A gene mutations in Turkish BD patients with and without venous thrombosis. METHODS: Seventy-one patients with BD (27 with venous thrombosis) and 91 healthy subjects were included in the study. FV 1691A, FV 4070G, and PT 20210A mutations were determined by a method based on PCR-RFLP. RESULTS: The frequency of FV 1691A heterozygous mutation in BD patients with venous thrombosis (25.9%) was significantly higher than that in healthy subjects (8.8%; OR = 3.63; 95% CI 1.18-11.2). Although the frequency of this mutation in patients with venous thrombosis was higher than that in the patients without venous thrombosis (11.4%), the difference did not reach a statistically significant level (OR = 2.73; 95% CI 0.77-9.70). In BD patients with thrombosis, the frequencies of FV 4070G and PT 20210A were not significantly different compared to the BD patients without venous thrombosis and healthy subjects. CONCLUSIONS: Our results suggest that the FV 1691A, FV 4070G, and PT 20210A mutations are unlikely to play an important role in the pathogenesis of thrombosis in patients with BD. 相似文献