全文获取类型
收费全文 | 903篇 |
免费 | 45篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 28篇 |
妇产科学 | 22篇 |
基础医学 | 165篇 |
口腔科学 | 10篇 |
临床医学 | 65篇 |
内科学 | 219篇 |
皮肤病学 | 6篇 |
神经病学 | 92篇 |
特种医学 | 46篇 |
外科学 | 101篇 |
预防医学 | 40篇 |
眼科学 | 3篇 |
药学 | 62篇 |
肿瘤学 | 76篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 12篇 |
2021年 | 21篇 |
2020年 | 13篇 |
2019年 | 26篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 21篇 |
2015年 | 26篇 |
2014年 | 30篇 |
2013年 | 42篇 |
2012年 | 75篇 |
2011年 | 66篇 |
2010年 | 30篇 |
2009年 | 40篇 |
2008年 | 66篇 |
2007年 | 66篇 |
2006年 | 49篇 |
2005年 | 43篇 |
2004年 | 60篇 |
2003年 | 46篇 |
2002年 | 35篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 15篇 |
1998年 | 13篇 |
1997年 | 16篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1976年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有954条查询结果,搜索用时 0 毫秒
61.
Recent studies show that healthy subjects and patients with moderate hypertension have different pressor responses to hyperventilation, depending on their sympathoadrenergic reactivity. In the present study, we investigated whether a different response to the hyperventilation test is related to differences in the daily blood pressure profiles recorded with noninvasive ambulatory monitoring. Forty-five healthy subjects and 67 patients with essential hypertension of grades 1 and 2 (Joint National Committee VI and World Health Organization) were investigated. Healthy subjects and hypertensive patients responding to hyperventilation with an increase in systolic blood pressure had, during daytime ambulatory blood pressure assessment, peak systolic blood pressure values (146.0+/-5.0 mm Hg, 182.2+/-9.0 mm Hg, respectively) similar to the hyperventilation peak systolic blood pressure values (147.2+/-3.5 mm Hg, 183.0+/-4.7 mm Hg, respectively). Hypertensive patients responding to hyperventilation with a decrease in blood pressure showed clinic systolic blood pressure values (178.4+/-3.2 mm Hg) higher than daytime average ambulatory systolic blood pressure (155.2+/-7.1 mm Hg; P<0.01). Our results indicate that a hyperventilation test yields information on daily peak blood pressure values in healthy subjects and hypertensive patients when it induces a pressor increase and can identify hypertensive patients with the so-called "white coat effect" when it induces a pressor decrease. 相似文献
62.
Roselli M Mineo TC Basili S Mariotti S Martini F Bellotti A Ambrogi V Spila A D'Alessandro R Gazzaniga PP Guadagni F Ferroni P 《Thrombosis and haemostasis》2003,89(1):177-184
Platelet activation, commonly found in lung cancer patients, may cause the release of angiogenic factors, such as vascular endothelial growth factor (VEGF-A). The present study was designed to investigate whether plasma VEGF-A levels were associated to different stages of non-small cell lung cancer (NSCLC). Moreover, sP-selectin, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complex (TATc) and D-dimer levels were measured to test the hypothesis of an involvement of platelet and coagulation activation in tumor angiogenesis. VEGF-A, sP-selectin, F1+2, TATc and D-dimer levels were elevated in 65 patients with NSCLC, particularly in metastatic patients. sP-selectin (p <0.003) and F1+2 (p <0.005) levels were independently associated to VEGF-A. In addition, patients with positive levels of both sP-selectin and F1+2 had the highest levels of VEGF-A. In conclusion, our findings support the hypothesis that thrombin generation might induce platelet activation and VEGF-A release in NSCLC. 相似文献
63.
Maria Fiorella Contarino MD Elles Berger‐Plantinga MD Elisabeth M.J. Foncke MD Katja Ritz MSc Jonke Mellema MD Frank Baas PhD Johannes D. Speelman MD PhD Marina A.J. Tijssen MD PhD 《Movement disorders》2008,23(14):1998-2003
We describe a large family with a primary focal dystonia from a small Dutch village on a former island. Twenty‐four individuals spanning three generations were examined by two movement‐disorder neurologists. Two other movement‐disorder neurologists evaluated the videos independently. Subjects were classified as “affected,” “possibly affected,” or “not affected.” A diagnosis was defined if all the neurologists agreed on the definition. Eight definitely affected and four possibly affected subjects were detected. Clinical presentation consisted of mild cranio‐cervical‐brachial dystonia. Mean age at onset was 45.5 years (range, 39–56). Mean BFMDRS motor score was 4.4 (range, 1–8). Mean TWSTRS score (part I) was 11.3 (range, 8–23). Mutations in DYT1 gene and in the ε‐sarcoglycan (SGCE) genes were not detected. We could not find linkage to the dominant DYT6, DYT7, DYT13, or the recessive DYT16 loci. The identification and accurate clinical evaluation of large dystonia families not linked to known genes is crucial for further advancement in molecular genetic characterization of focal dystonia. © 2008 Movement Disorder Society 相似文献
64.
65.
66.
67.
Nicholas G. Moon Fiorella Mazzini Allison M. Pekkanen Emily M. Wilts Timothy E. Long 《Macromolecular chemistry and physics.》2018,219(16)
The monomer isosorbide diacrylate (iSDA) and commercially available dithiols allowed access to a range of biosourced, degradable polymers. Altering the dithiol identity significantly affected the glass transition Tgs of the polymer products; however, polymers did not exhibit Tgs above room temperature. Incorporating the comonomer N,N′‐methylene bisacrylamide provided mechanical reinforcement through hydrogen bonding, resulting in soft, pliable materials. Differential scannin calorimetry (DSC) and variable‐temperature fourier‐transform infrared (FTIR) spectroscopy indicated that increases in mechanical integrity resulted from hydrogen bonding. Dynamic mechanical analysis (DMA) revealed materials that exhibited suitable moduli and service windows at body temperature. Biological evaluation demonstrated favorable cytotoxicity and cell attachment, rendering these materials potential candidates as novel scaffold materials for tissue growth. 相似文献
68.
69.
Glutathione metabolism and antioxidant enzymes in patients affected by nonalcoholic steatohepatitis 总被引:4,自引:0,他引:4
Nobili V Pastore A Gaeta LM Tozzi G Comparcola D Sartorelli MR Marcellini M Bertini E Piemonte F 《Clinica chimica acta; international journal of clinical chemistry》2005,355(1-2):105-111
BACKGROUND: Oxidative stress and accumulation of excessive fat in the liver may underlie the pathophysiology of nonalcoholic steatohepatitis (NASH). Given that glutathione blood metabolism may represent an indicator of tissue oxidative status, we analysed the blood profile of various forms of glutathione in children with NASH, and we evaluated the presence of systemic oxidative stress by calculating the oxidised/reduced glutathione ratio (GSSG/GSH). Furthermore, we analysed the catalytic activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione transferase (GST), and glutathione reductase (GR) in blood of patients. METHODS: Blood samples were obtained from 21 children with NASH and 28 controls. Total, reduced, oxidised, and protein-bound glutathione concentrations were determined by reversed-phase liquid chromatography with fluorescence detection. Antioxidant enzymes were spectrophotometrically assayed by using specific substrates. RESULTS: Our findings showed a 1.5-fold increase of GSSG in patients, resulting in a significant rise of the GSSG/GSH ratio. SOD, GPx, and GR activities were not significantly different in NASH respect to controls, whereas GST, which provides the second defence line against oxidative stress, was 17.8% increased. CONCLUSIONS: Our data demonstrate an impairment of glutathione metabolism and antioxidant enzyme activities in blood of patients with NASH, supporting a consistent role of free radical cytotoxicity in the pathophysiology of the disease. 相似文献
70.
Hsu EB Casani JA Romanosky A Millin MG Singleton CM Donohue J Feroli ER Rubin M Subbarao I Whyne DM Snodgrass TD Kelen GD 《Prehospital and disaster medicine》2007,22(3):214-218
INTRODUCTION: In recent years, government and hospital disaster planners have recognized the increasing importance of pharmaceutical preparedness for chemical, biological, radiological, nuclear, and explosive (CBRNE) events, as well as other public health emergencies. The development of pharmaceutical surge capacity for immediate use before support from the (US) Strategic National Stockpile (SNS) becomes available is integral to strengthening the preparedness of local healthcare networks. METHODS: The Pharmaceutical Response Project served as an independent, multidisciplinary collaboration to assess statewide hospital pharmaceutical response capabilities. Surveys of hospital pharmacy directors were conducted to determine pharmaceutical response preparedness to CBRNE threats. RESULTS: All 45 acute care hospitals in Maryland were surveyed, and responses were collected from 80% (36/45). Ninety-two percent (33/36) of hospitals had assessed pharmaceutical inventory with respect to biological agents, 92% (33/36) for chemical agents, and 67% (24/36) for radiological agents. However, only 64% (23/36) of hospitals reported an additional dedicated reserve supply for biological events, 67% (24/36) for chemical events, and 50% (18/36) for radiological events. More than 60% of the hospitals expected to receive assistance from the SNS within < or = 48 hours. CONCLUSIONS: From a pharmaceutical perspective, hospitals generally remain under-prepared for CBRNE threats and many expect SNS support before it realistically would be available. Collectively, limited antibiotics and other supplies are available to offer prophylaxis or treatment, suggesting that hospitals may have insufficient pharmaceutical surge supplies for a large-scale event. Although most state hospitals are improving pharmaceutical surge capabilities, further efforts are needed. 相似文献