全文获取类型
收费全文 | 93794篇 |
免费 | 7654篇 |
国内免费 | 4659篇 |
专业分类
耳鼻咽喉 | 1143篇 |
儿科学 | 1303篇 |
妇产科学 | 999篇 |
基础医学 | 11951篇 |
口腔科学 | 1776篇 |
临床医学 | 10020篇 |
内科学 | 14149篇 |
皮肤病学 | 2009篇 |
神经病学 | 5130篇 |
特种医学 | 4556篇 |
外国民族医学 | 21篇 |
外科学 | 10013篇 |
综合类 | 12131篇 |
现状与发展 | 28篇 |
一般理论 | 9篇 |
预防医学 | 6031篇 |
眼科学 | 2838篇 |
药学 | 9961篇 |
67篇 | |
中国医学 | 4110篇 |
肿瘤学 | 7862篇 |
出版年
2024年 | 196篇 |
2023年 | 1086篇 |
2022年 | 2787篇 |
2021年 | 3949篇 |
2020年 | 2739篇 |
2019年 | 2596篇 |
2018年 | 2850篇 |
2017年 | 2667篇 |
2016年 | 2949篇 |
2015年 | 4324篇 |
2014年 | 5271篇 |
2013年 | 5318篇 |
2012年 | 7890篇 |
2011年 | 8178篇 |
2010年 | 5324篇 |
2009年 | 4615篇 |
2008年 | 5830篇 |
2007年 | 5542篇 |
2006年 | 5211篇 |
2005年 | 4621篇 |
2004年 | 3553篇 |
2003年 | 3443篇 |
2002年 | 2924篇 |
2001年 | 2009篇 |
2000年 | 1720篇 |
1999年 | 1499篇 |
1998年 | 861篇 |
1997年 | 766篇 |
1996年 | 639篇 |
1995年 | 599篇 |
1994年 | 552篇 |
1993年 | 374篇 |
1992年 | 470篇 |
1991年 | 422篇 |
1990年 | 383篇 |
1989年 | 339篇 |
1988年 | 251篇 |
1987年 | 250篇 |
1986年 | 196篇 |
1985年 | 152篇 |
1984年 | 88篇 |
1983年 | 79篇 |
1982年 | 57篇 |
1981年 | 55篇 |
1980年 | 50篇 |
1979年 | 65篇 |
1978年 | 56篇 |
1975年 | 44篇 |
1974年 | 35篇 |
1973年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Ho-Chul Jung Sung-Bin Chon Won Sup Oh Dong-Hyun Lee Ho-Jin Lee 《The American journal of tropical medicine and hygiene》2015,92(2):256-261
Scrub typhus usually presents as acute undifferentiated fever. This cross-sectional study included adult patients presenting with acute undifferentiated fever defined as any febrile illness for ≤ 14 days without evidence of localized infection. Scrub typhus cases were defined by an antibody titer of a ≥ fourfold increase in paired sera, a ≥ 1:160 in a single serum using indirect immunofluorescence assay, or a positive result of the immunochromatographic test. Multiple regression analysis identified predictors associated with scrub typhus to develop a prediction rule. Of 250 cases with known etiology of acute undifferentiated fever, influenza (28.0%), hepatitis A (25.2%), and scrub typhus (16.4%) were major causes. A prediction rule for identifying suspected cases of scrub typhus consisted of age ≥ 65 years (two points), recent fieldwork/outdoor activities (one point), onset of illness during an outbreak period (two points), myalgia (one point), and eschar (two points). The c statistic was 0.977 (95% confidence interval = 0.960–0.994). At a cutoff value ≥ 4, the sensitivity and specificity were 92.7% (79.0–98.1%) and 90.9% (86.0–94.3%), respectively. Scrub typhus, the third leading cause of acute undifferentiated fever in our region, can be identified early using the prediction rule. 相似文献
2.
This retrospective study aimed to evaluate radiation-induced pneumonitis (RIP) and a related condition that we define in this report—prolonged minimal RIP (pmRIP)—after stereotactic body radiotherapy (SBRT) for Stage I primary lung cancer in patients with chronic obstructive pulmonary disease (COPD). We assessed 136 Stage I lung cancer patients with COPD who underwent SBRT. Airflow limitation on spirometry was classified into four Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades, with minor modifications: GOLD 1 (mild), GOLD 2 (moderate), GOLD 3 (severe) and GOLD 4 (very severe). On this basis, we defined two subgroups: COPD-free (COPD −) and COPD-positive (COPD +). There was no significant difference in overall survival or cause-specific–survival between these groups. Of the 136 patients, 44 (32%) had pmRIP. Multivariate analysis showed that COPD and the Brinkman index were statistically significant risk factors for the development of pmRIP. COPD and the Brinkman index were predictive factors for pmRIP, although our findings also indicate that SBRT can be tolerated in early lung cancer patients with COPD. 相似文献
3.
4.
5.
6.
7.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
8.
9.
Recent studies have reported an association between gastroesophageal reflux disease (GERD) and atrial fibrillation (AF). The objective of the present study was to evaluate whether AF is one of the risk factors for GERD occurrence.In this hospital-based, retrospective, case–control study, the patients were classified into 2 groups. The patients diagnosed with new AF were assigned to the AF group (n = 1612); those diagnosed without AF and GERD were assigned to the control group (n = 1612). The subjects in the control group were selected from outpatients of total healthcare center without a history of AF or GERD, and matched for age and gender. We evaluated the incidence of GERD and risk factors for GERD occurrence between the 2 groups.The number of patients experiencing occurrence of GERD during the follow-up period was significantly higher in the AF group than those in the control group, respectively (129 patients vs 98 subjects, P = 0.037). The incidence of GERD was significantly higher in the AF group than in the control group by Kaplan–Meier analysis with log-rank test (P = 0.008). The AF group''s adjusted hazard ratio of GERD occurrence against that of the control group was 1.37 (95% confidence interval [CI]: 1.16–1.57; P = 0.009) according to Cox''s proportional hazard model.The presence of AF appears to increase the incidence of GERD and may be considered a risk factor for the development of GERD. Further, large prospective and cohort studies will be required to better establish the correlation of GERD with AF. 相似文献
10.
Three‐Dimensional Echocardiographic Evaluation of Mitral Apparatus during Preload Manipulation in Patients with Hypertrophic Cardiomyopathy 下载免费PDF全文
Hyemoon Chung M.D. Ji Hyun Yoon M.D. Young Won Yoon M.D. Ph.D. Ji Young Chung B.N. Jung‐Joon Cha M.D. Jong‐Youn Kim M.D. Ph.D. Pil‐Ki Min M.D. Ph.D. Byoung‐Kwon Lee M.D. Ph.D. Bum‐Kee Hong M.D. Ph.D. Se‐Joong Rim M.D. Ph.D. Hyuck Moon Kwon M.D. Eui‐Young Choi M.D. Ph.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(8):1261-1269