全文获取类型
收费全文 | 56209篇 |
免费 | 3923篇 |
国内免费 | 1198篇 |
专业分类
耳鼻咽喉 | 348篇 |
儿科学 | 1193篇 |
妇产科学 | 1511篇 |
基础医学 | 4951篇 |
口腔科学 | 968篇 |
临床医学 | 6214篇 |
内科学 | 8619篇 |
皮肤病学 | 421篇 |
神经病学 | 1962篇 |
特种医学 | 1928篇 |
外国民族医学 | 9篇 |
外科学 | 5260篇 |
综合类 | 8739篇 |
现状与发展 | 1篇 |
预防医学 | 9376篇 |
眼科学 | 349篇 |
药学 | 5626篇 |
109篇 | |
中国医学 | 1828篇 |
肿瘤学 | 1918篇 |
出版年
2024年 | 113篇 |
2023年 | 784篇 |
2022年 | 1611篇 |
2021年 | 2243篇 |
2020年 | 2185篇 |
2019年 | 1842篇 |
2018年 | 1912篇 |
2017年 | 1810篇 |
2016年 | 1927篇 |
2015年 | 1909篇 |
2014年 | 3912篇 |
2013年 | 3921篇 |
2012年 | 3688篇 |
2011年 | 3834篇 |
2010年 | 2876篇 |
2009年 | 2593篇 |
2008年 | 2534篇 |
2007年 | 2650篇 |
2006年 | 2207篇 |
2005年 | 1965篇 |
2004年 | 1666篇 |
2003年 | 1408篇 |
2002年 | 1208篇 |
2001年 | 1048篇 |
2000年 | 933篇 |
1999年 | 843篇 |
1998年 | 687篇 |
1997年 | 706篇 |
1996年 | 633篇 |
1995年 | 565篇 |
1994年 | 547篇 |
1993年 | 419篇 |
1992年 | 446篇 |
1991年 | 385篇 |
1990年 | 337篇 |
1989年 | 312篇 |
1988年 | 268篇 |
1987年 | 217篇 |
1986年 | 206篇 |
1985年 | 278篇 |
1984年 | 234篇 |
1983年 | 147篇 |
1982年 | 207篇 |
1981年 | 173篇 |
1980年 | 160篇 |
1979年 | 130篇 |
1978年 | 102篇 |
1977年 | 98篇 |
1976年 | 91篇 |
1975年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
目的:分析应用多序列联合的检查方式对超早期脑梗死患者的临床诊断意义.方法:对应用多序列磁共振检查(包括T1W成像、T2W成像、DW成像、FLAIR成像及MRA成像)的超早期脑梗死患者共30例进行回顾性分析,分析成像对超早期脑梗死患者检出的敏感性及MRA分级与梗死面积的关系.结果:DW检出率明显高于其他3种成像的检出率(P<0.05),而T1W成像、T2W成像及FLAIR成像检出率比较差异无统计学意义(P>0.05).MRA动脉显像分级与梗死面积呈正向直线相关,MRA动脉显像分级越高,出现大面积脑梗死越多.结论:多序列联合的检查对超早期脑梗死患者的检出率高,且可对梗死面积进行初步的预测. 相似文献
993.
994.
Systolic longitudinal strain correlates with visual assessment of regional left ventricular function during dobutamine stress echocardiography and discriminates the segments with induced contractility impairment
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
995.
996.
Manasawee Srisuttayasathien Tarinee Manchana 《Taiwanese journal of obstetrics & gynecology》2021,60(1):56-59
ObjectivesAdherence to follow-up is crucial for cervical intraepithelial neoplasia grade 1 (CIN1) because these women have a chance of progression to high-grade premalignant cervical lesions and cervical cancer. This study aimed to evaluate the rate of adherence to follow-up in women who were initially diagnosed with CIN 1 over a period of 24 months and to evaluate the regression and progression rate of CIN 1.Material and methodsOf 1050 women who visited a colposcopy clinic from October 2013 through March 2017, 138 with histologically proven as CIN 1 were recruited. Adherence to follow-up, the regression and progression rate of CIN 1 were retrospectively assessed.ResultsOf the 138 women, 86 (62.3%) followed regularly until the study endpoint at 24 months. During the study period, 10 women received ablative treatment. The regression rate in women who had surveillance with cervical cytology was 69.7%, persistent disease of 18.4%, and progression to CIN 2–3 of 11.8%. In contrast, 80% of women who received ablative treatment had regression, 20% of them had persistent disease but none had progression.ConclusionsNearly 40% of women with CIN 1 were lost to follow-up at 24 months. Adherence to the follow-up should be emphasized to all women. Intensive interventions to improve adherence and clinical outcome might be an option, particularly among women with poor compliance. 相似文献
997.
Hua Qin Brendan T Keenan Diego R Mazzotti Fernando Vaquerizo-Villar Jan F Kraemer Niels Wessel Sergio Tufik Lia Bittencourt Peter A Cistulli Philip de Chazal Kate Sutherland Bhajan Singh Allan I Pack Ning-Hung Chen Ingo Fietze Thorarinn Gislason Steven Holfinger Ulysses J Magalang Thomas Penzel 《Sleep》2021,44(5)
Study ObjectivesPatients with obstructive sleep apnea (OSA) exhibit heterogeneous heart rate variability (HRV) during wakefulness and sleep. We investigated the influence of OSA severity on HRV parameters during wakefulness in a large international clinical sample.Methods1247 subjects (426 without OSA and 821 patients with OSA) were enrolled from the Sleep Apnea Global Interdisciplinary Consortium. HRV parameters were calculated during a 5-minute wakefulness period with spontaneous breathing prior to the sleep study, using time-domain, frequency-domain and nonlinear methods. Differences in HRV were evaluated among groups using analysis of covariance, controlling for relevant covariates.ResultsPatients with OSA showed significantly lower time-domain variations and less complexity of heartbeats compared to individuals without OSA. Those with severe OSA had remarkably reduced HRV compared to all other groups. Compared to non-OSA patients, those with severe OSA had lower HRV based on SDNN (adjusted mean: 37.4 vs. 46.2 ms; p < 0.0001), RMSSD (21.5 vs. 27.9 ms; p < 0.0001), ShanEn (1.83 vs. 2.01; p < 0.0001), and Forbword (36.7 vs. 33.0; p = 0.0001). While no differences were found in frequency-domain measures overall, among obese patients there was a shift to sympathetic dominance in severe OSA, with a higher LF/HF ratio compared to obese non-OSA patients (4.2 vs. 2.7; p = 0.009).ConclusionsTime-domain and nonlinear HRV measures during wakefulness are associated with OSA severity, with severe patients having remarkably reduced and less complex HRV. Frequency-domain measures show a shift to sympathetic dominance only in obese OSA patients. Thus, HRV during wakefulness could provide additional information about cardiovascular physiology in OSA patients.Clinical Trial Information: A Prospective Observational Cohort to Study the Genetics of Obstructive Sleep Apnea and Associated Co-Morbidities (German Clinical Trials Register - DKRS, DRKS00003966) https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003966 相似文献
998.
ObjectiveTo analyze adherence to treatment of tuberculosis infection and to identify risk factors for its compliance.DesignAn observational historical cohort study.SettingHospital Universitari Sant Joan d’Alacant (Alicante).ParticipantsAll patients with a tuberculin skin test (TST) done during tuberculosis contact tracing during 6 years.ResultsWe included 764 tuberculosis contacts in the analysis. 59.7% of the 566 patients who completed the contact tracing, had tuberculosis infection (TI). Of the patients with TI, 45.6% had not started treatment for tuberculosis infection (TTBI). Factors associated with not starting TTBI were: age (36-65 years, RR: 5.8; 95% CI: 1.2-27.5, and > 65 years, RR: 11.3; 95% CI: 2.0-64.0), the social relationship with TB case (RR: 2.2; 95% CI 1.2-3.8), and the TST reaction (≥ 15 mm; RR: 0.5; 95% CI: 0.3-0.9). The completion rate for TTBI was 80.4% among people who started therapy. The treatment regimen was associated with greater compliance to TTBT (7-9H, RR: 12.7; 95% CI: 1.5-107.3).ConclusionsThe treatment compliance rate of Tuberculosis infection was high among people who started therapy. Almost a half of the contacts with TI did not start treatment, and associated factors were: age, social relationship, and the TST reaction. The treatment regimen was associated with greater compliance. It is important to know the factors associated with adherence to treatment of TI in each health area, and focus efforts on risk groups; thereby approaching the global control of tuberculosis. 相似文献
999.
目的探讨不同抗菌药物给药途径治疗脑出血患者微创钻颅置管外引流术后颅内感染的临床疗效。方法选择2009年1月-2013年6月72例脑出血行微创钻颅置管外引流术后颅内感染患者为研究对象,将36例行全身给药+腰穿后鞘内注射为A组,25例行全身给药+腰大池引流+鞘内注射为B组,11例行全身给药+脑脊液生理盐水置换为C组,比较3组患者治疗前后脑脊液常规指标差异,治疗期间不同时点脑脊液中的药物浓度以及患者的临床效果。结果 3组患者治疗后颅内压、脑脊液各项指标平均值恢复正常,颅内压值从高到低依次为C、A、B组,差异有统计学意义(F=12.341,P<0.05),C组氯化钠含量较A、B两组低,差异有统计学意义(F=4.621,P<0.05);B组患者治疗后不同时点脑脊液中药物浓度均为最高,C组明显低于A、B两组,差异有统计学意义(P<0.05);3组患者各项指标恢复时间中B组时间最短,C组最长,差异有统计学意义(P<0.05);3组均无明显不良反应发生。结论鞘内抗菌药物注射结合全身抗感染治疗能有效治疗颅内感染,其中腰大池置管引流比多次腰穿更能保证脑脊液中药物浓度,缩短治疗时间。 相似文献
1000.
目的 调查国内永久起搏器围术期预防性应用抗生素现状.方法 设计调查问卷,并于2012年1月至3月通过电子邮件将问卷发至各中心负责人.若回复的资料有疑问或不确定,通过电话、电子邮件或专门调查人上门等方式进行资料核对,获得准确信息.结果 共收到135个中心回复的有效调查表.112个中心(82.9%)在术前(含术中)预防性应用了抗生素,14个(10.4%)中心仅术后预防应用,9个中心(6.7%)术前术后均未预防应用抗生素.79.2%的中心选用头孢一代或二代或青霉素类抗生素,其余中心分别使用了头孢三代(6.7%)和喹诺酮类(2.2%)抗生素.74.1%的中心选择在术前0.5 ~2.0 h开始应用抗生素,3.7%在术中应用;其余中心分别在术前3~6 h(5.2%)和术后(10.3%)才开始应用.术后抗生素持续使用时间也各不相同:7.9%仅术前应用1次,13.5%持续应用超过72 h,其余99个中心(78.6%)抗生素应用持续时间在24 ~ 72 h.35.6%的中心术中应用抗生素液冲洗囊袋,其中大多数(81.3%)选择庆大霉素注射液稀释冲洗囊袋.结论 心脏起搏器围术期抗生素应用仍不规范,是否应用抗生素、抗生素选择种类、开始时机以及持续时间均因中心而不同.大多数中心都在术前预防性应用了抗生素,并选择抗菌谱覆盖金黄色葡萄球菌的β内酰胺类抗生素.但术后应用抗生素的持续时间和抗生素液冲洗囊袋的有效性还有待进一步研究. 相似文献