全文获取类型
收费全文 | 704篇 |
免费 | 56篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 22篇 |
妇产科学 | 5篇 |
基础医学 | 104篇 |
口腔科学 | 18篇 |
临床医学 | 100篇 |
内科学 | 187篇 |
皮肤病学 | 8篇 |
神经病学 | 28篇 |
特种医学 | 35篇 |
外科学 | 54篇 |
综合类 | 9篇 |
预防医学 | 77篇 |
眼科学 | 13篇 |
药学 | 55篇 |
中国医学 | 5篇 |
肿瘤学 | 39篇 |
出版年
2023年 | 18篇 |
2022年 | 15篇 |
2021年 | 28篇 |
2020年 | 23篇 |
2019年 | 27篇 |
2018年 | 15篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 16篇 |
2014年 | 31篇 |
2013年 | 30篇 |
2012年 | 48篇 |
2011年 | 55篇 |
2010年 | 36篇 |
2009年 | 27篇 |
2008年 | 48篇 |
2007年 | 41篇 |
2006年 | 39篇 |
2005年 | 35篇 |
2004年 | 30篇 |
2003年 | 23篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 16篇 |
1998年 | 18篇 |
1997年 | 19篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1948年 | 1篇 |
1934年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有767条查询结果,搜索用时 15 毫秒
61.
Experimental intrahepatic portacaval anastomosis: use of expandable Gianturco stents 总被引:2,自引:0,他引:2
Original Gianturco expandable stents and their modifications were used to create an experimental intrahepatic portacaval anastomosis (EIPCA) in 30 young domestic swine without portal hypertension. The study focused on the design of a suitable stent, the technique of its application, and the evaluation of short-term patency of the EIPCA. A stent with a 2.5-cm-long body and wire skirts on both ends was most suitable for EIPCA creation. Well-positioned stents shunted most of the portal blood in the inferior vena cava circulation and remained patent for 4-6 weeks. Ingrowth of liver parenchyma and abundant proliferation of the intima and connective tissue inside the stent lumen in these rapidly growing animals gradually decreased EIPCA patency, and thrombus formation with diminished blood flow closed them completely. 相似文献
62.
63.
In this paper we compare several approaches to identifying certain key respiratory control parameters relying on data normally
available from non-invasive measurements. We consider a simple model of the respiratory control system and describe issues
related to numerical estimates of key parameters involved in respiratory function such as central and peripheral control gains,
transport delay, and lung compartment volumes. The combination of model-specific structure and limited data availability influences
the parameter estimation process. Methods for studying how to improve the parameter estimation process are examined including
classical and generalized sensitivity analysis, and eigenvalue grouping. These methods are applied and compared in the context
of clinically available data. These methods are also compared in conjunction with specialized tests such as the minimally
invasive single-breath CO2 test that can improve the estimation, and the enforced fixed breathing test, which opens the control loop in the system.
The analysis shows that it is impossible to estimate central and peripheral gain simultaneously without usage of ventilation
measurement and a controlled perturbation of the respiratory system, such as the CO2 test. The numerical results are certainly model dependent, but the illustrated methods, the nature of the comparisons, and
protocols will carry over to other models and data configurations. 相似文献
64.
Matthew W. Knuiman Hien T.V. Vu Helen C. Bartholomew 《Australian and New Zealand journal of public health》1998,22(7):747-753
Coronary heart disease (CHD) is a multifactorial disease and CHD risk should be estimated by assessing all cardiovascular risk factors simultaneously. Simply adding up the number of factors with 'at risk' values fails to identify high-risk subjects with multiple risk factors at moderately elevated values. A more efficient approach is to use a quantitative multivariate risk score. A number of overseas studies have produced CHD risk scoring systems for men. There are few risk scores developed for women and no CHD risk scores have been developed from Australian data. This study used data on CHD risk factors and morbidity/mortality follow-up for the 1978 Busselton Health Survey participants to provide age-specific estimates of absolute risk of CHD hospitalisation or death, and to develop multivariate CHD risk scoring systems for men and women. The scores are based on age, blood pressure, anti-hypertensive medication, total and HDL cholesterol, smoking, diabetes, left ventricular hypertrophy and previous history of CHD. The generalisability and applicability of these risk estimation systems to Australian populations in the late 1990s is discussed. 相似文献
65.
66.
67.
Laura M. Ellwein Hien T. Tran Cheryl Zapata Vera Novak Mette S. Olufsen 《Cardiovascular Engineering》2008,8(2):94-108
The complexity of mathematical models describing the cardiovascular system has grown in recent years to more accurately account
for physiological dynamics. To aid in model validation and design, classical deterministic sensitivity analysis is performed
on the cardiovascular model first presented by Olufsen, Tran, Ottesen, Ellwein, Lipsitz and Novak (J Appl Physiol 99(4):1523–1537,
2005). This model uses 11 differential state equations with 52 parameters to predict arterial blood flow and blood pressure.
The relative sensitivity solutions of the model state equations with respect to each of the parameters is calculated and a
sensitivity ranking is created for each parameter. Parameters are separated into two groups: sensitive and insensitive parameters.
Small changes in sensitive parameters have a large effect on the model solution while changes in insensitive parameters have
a negligible effect. This analysis was successfully used to reduce the effective parameter space by more than half and the
computation time by two thirds. Additionally, a simpler model was designed that retained the necessary features of the original
model but with two-thirds of the state equations and half of the model parameters. 相似文献
68.
急性呼吸窘迫综合征(acute respiraory distress syndrome,ARDS)是一种常见的严重肺功能紊乱的肺部并发症。常并发于脓毒血症、创伤和抽吸术等严重损伤后。ARDS的发生及死亡率可因发生ARDS损伤类型的不同而有差别,提示ARDS的发病机制和预后因临床风险因素而不同。最近,对重症病人进 相似文献
69.
Denise A. Hien Aimee N. C. Campbell Therese Killeen Mei-Chen Hu Cheri Hansen Huiping Jiang Mary Hatch-Maillette Gloria M. Miele Lisa R. Cohen Weijin Gan Stella M. Resko Michele DiBono Elizabeth A. Wells Edward V. Nunes 《AIDS and behavior》2010,14(2):421-430
Women in drug treatment struggle with co-occurring problems, including trauma and post-traumatic stress disorder (PTSD), which can heighten HIV risk. This study examines the impact of two group therapy interventions on reduction of unprotected sexual occasions (USO) among women with substance use disorders (SUD) and PTSD. Participants were 346 women recruited from and receiving treatment at six community-based drug treatment programs participating in NIDA’s Clinical Trials Network. Participants were randomized to receive 12-sessions of either seeking safety (SS), a cognitive behavioral intervention for women with PTSD and SUD, or women’s health education (WHE), an attention control psychoeducational group. Participants receiving SS who were at higher sexual risk (i.e., at least 12 USO per month) significantly reduced the number of USO over 12-month follow up compared to WHE. High risk women with co-occurring PTSD and addiction may benefit from treatment addressing coping skills and trauma to reduce HIV risk. 相似文献
70.
Nguyen HP Li L Gatson JW Maass D Wigginton JG Simpkins JW Schug KA 《Journal of pharmaceutical and biomedical analysis》2011,54(4):830-837
Estrogens are known to exhibit neuroprotective effects on the brain. Their importance in this regard and in others has been emphasized in many recent studies, which increases the need to develop reliable analytical methods for the measurement of estrogen hormones. A heart-cutting two-dimensional liquid chromatography separation method coupled with electrospray ionization-tandem mass spectrometry (ESI-MS/MS) has been developed for simultaneous measurement of four estrogens, including estriol (E3), estrone (E1), 17β-estradiol (17β-E2), and 17α-estradiol (17α-E2), in human cerebrospinal fluid (CSF). The method was based on liquid-liquid extraction and derivatization of estrogens with dansyl chloride to enhance the sensitivity of ESI-based detection in conjunction with tandem mass spectrometry. Dansylated estriol and estrone were separated in the first dimension by an amide-C18 column, while dansylated 17β- and 17α-estradiol were resolved on the second dimension by two C18 columns (175 mm total length) connected in series. This is the first report of a method for simultaneous quantification of all four endogenous estrogen compounds in their dansylated form. The detection limits for E1, 17α-E2, 17β-E2, and E3 were 19, 35, 26, and 61pg/mL, respectively. Due to matrix effects, validation and calibration was carried out in charcoal-stripped CSF. The precision and accuracy were more than 86% for the two E2 compounds and 79% for E1 and E3 while the extraction recovery ranged from 91% to 104%. The method was applied to measure estrogens obtained in a clinical setting, from the CSF of ischemic trauma patients. While 17β-estradiol was present at a significant level in the CSF of some samples, other estrogens were present at lower levels or were undetectable. 相似文献