全文获取类型
收费全文 | 81989篇 |
免费 | 3300篇 |
国内免费 | 786篇 |
专业分类
耳鼻咽喉 | 504篇 |
儿科学 | 1301篇 |
妇产科学 | 964篇 |
基础医学 | 8333篇 |
口腔科学 | 3718篇 |
临床医学 | 6519篇 |
内科学 | 16896篇 |
皮肤病学 | 1596篇 |
神经病学 | 6028篇 |
特种医学 | 2302篇 |
外国民族医学 | 1篇 |
外科学 | 13973篇 |
综合类 | 4503篇 |
现状与发展 | 2篇 |
一般理论 | 5篇 |
预防医学 | 6793篇 |
眼科学 | 1612篇 |
药学 | 5567篇 |
20篇 | |
中国医学 | 2608篇 |
肿瘤学 | 2830篇 |
出版年
2023年 | 1177篇 |
2022年 | 1890篇 |
2021年 | 3409篇 |
2020年 | 2296篇 |
2019年 | 6329篇 |
2018年 | 6489篇 |
2017年 | 4048篇 |
2016年 | 1400篇 |
2015年 | 1389篇 |
2014年 | 2844篇 |
2013年 | 2837篇 |
2012年 | 1951篇 |
2011年 | 2288篇 |
2010年 | 1932篇 |
2009年 | 1621篇 |
2008年 | 1730篇 |
2007年 | 1655篇 |
2006年 | 1365篇 |
2005年 | 1156篇 |
2004年 | 935篇 |
2003年 | 942篇 |
2002年 | 672篇 |
2001年 | 683篇 |
2000年 | 550篇 |
1999年 | 547篇 |
1998年 | 357篇 |
1997年 | 355篇 |
1996年 | 320篇 |
1995年 | 313篇 |
1994年 | 261篇 |
1993年 | 243篇 |
1992年 | 253篇 |
1991年 | 213篇 |
1990年 | 188篇 |
1989年 | 183篇 |
1988年 | 164篇 |
1986年 | 143篇 |
1985年 | 2912篇 |
1984年 | 3455篇 |
1983年 | 2912篇 |
1982年 | 3382篇 |
1981年 | 3073篇 |
1980年 | 2561篇 |
1979年 | 2547篇 |
1978年 | 2093篇 |
1977年 | 1564篇 |
1976年 | 2009篇 |
1975年 | 1525篇 |
1974年 | 1331篇 |
1973年 | 1279篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
《Journal of the American College of Surgeons》2020,230(4):463-473
- Download : Download high-res image (281KB)
- Download : Download full-size image
102.
103.
104.
Tau Ming Liew 《Journal of the American Medical Directors Association》2019,20(8):1054.e11-1054.e20
ObjectivesEarly diagnosis of cognitive impairment is increasingly emphasized in the literature to facilitate timely preventive interventions. Although bedside cognitive tests such as the Montreal Cognitive Assessment (MoCA) are widely used for such early diagnostic purposes, they may not have comparable performance to a full neuropsychological battery (FNB) in diagnosing early cognitive impairment. This study investigated whether a small subset of neuropsychological tests can be added on to MoCA to match its performance to that of the FNB in discriminating mild cognitive impairment and dementia (MCI/dementia) from normal cognition.DesignCross-sectional diagnostic study.SettingAlzheimer's Disease Centers across the United States.ParticipantsOlder participants (≥50 years) who completed MoCA and the FNB (N = 9187).MeasuresThe study sample was split into two: the derivation sample (n = 1837) was used to develop a brief neuropsychological battery that best discriminated MCI/dementia (using the best-subset approach with 10-fold cross-validation); while the validation sample (n = 7350) verified its actual performance in discriminating MCI/dementia.ResultsA 3-item neuropsychological battery was identified, comprising MoCA, Benson Complex Figure Recall, and Craft Story 21 Delayed Recall. It had excellent performance in discriminating MCI/dementia from normal cognition (area under the receiver operating characteristic curve [AUROC] 90.0%, 95% confidence interval [CI] 89.2%-90.7%), which was comparable to that of the FNB (AUROC 88.4%, 95% CI 87.6%-89.2%). By contrast, MoCA alone had significantly worse AUROC (86.9%, 95% CI 86.0%-87.7%) than that of the FNB.Conclusions/ImplicationsUsing rigorous methods, this study developed a brief neuropsychological battery that maintained the brevity of a bedside cognitive test, while rivaling the diagnostic performance of an FNB in early cognitive impairment. This brief battery offers a viable alternative when the FNB is needed but cannot be feasibly administered in nonspecialty clinics. It can have a wider health systems effect of improving patients’ access to accurate diagnosis in early cognitive impairment and facilitating timely interventions to delay the progression of cognitive impairment. 相似文献
105.
MR评价垂体腺瘤质地及与其胶原含量的关系 总被引:4,自引:1,他引:3
目的利用MR测量垂体腺瘤不同质地的信号强度,并分析其与肿瘤胶原含量间的关系。方法57例经手术证实的垂体腺瘤标本,术前均行MR检查,根据术中肿瘤硬度分为质地韧组(8例)与质地软组(49例),标本行天狼猩红染色检测其胶原含量。结果纤维化与非纤维化组T1WI瘤体/灰质信号强度比分别为1.31±0.31、1.16±0.26;T1WI瘤体/白质信号强度比分别为1.01±0.25、0.91±0.18,两组间差异无统计学意义(P(0.05);T1+WI瘤体/灰质信号强度比分别为1.83±0.28、1.84±0.51;T1+WI瘤体/白质信号强度比分别为1.56±0.24、1.46±0.37,两组间差异无统计学意义(P(0.05);T2WI瘤体/灰质信号强度比分别为1.15±0.26、1.57±0.46(P(0.05);T2WI瘤体/白质信号强度比分别为1.48±0.39、2.10±0.61,两组间有统计学意义(P(0.01);胶原含量分别为20.03%±7.99%、7.87%±4.82%,两组间有统计学意义(P<0.01);且T2WI瘤体/灰质、T2WI瘤体/白质与胶原含量呈显著负相关(r=-0.531、r=-0.726,P均(0.01)。结论术前MR可以预测垂体腺瘤的质地;其中以T2WI瘤体/白质为预测指标为最佳。胶原含量影响垂体腺瘤质地,MRI上T2WI可以反映其胶原含量的多少。 相似文献
106.
N Simelela 《International journal of gynaecology and obstetrics》2006,94(3):292-300
Preventing unintended pregnancies through access to modern family planning could avert 20-35% of maternal deaths, saving the lives of more than 100,000 women each year. Obstacles to wider access still exist, but they may be overcome by overt policy commitment to reproductive health services, partnership between stakeholders, community involvement and quality programs. 相似文献
107.
Baher Husain Christian Kuehne Christian Waydhas Ulrike Lewan Claudia Ose Dieter Nast-Kolb Steffen Ruchholtz 《European Journal of Trauma》2006,32(6):548-554
Abstract
Background: Does there exist a difference in the outcome of severely injured children and severely injured healthy adults?
Methods: The data of 1,566 severely injured patients, treated between May 1998 and December 2002 in our emergency department of the
University Essen/Germany, were analyzed. Patients with an injury severity score (ISS) > 24 were included in the present study.
Patients younger as 18 (17) years were located to the children group c. Patients aged 18 and up to the age of 54 were included
in the adult group a.
Results: Fifty-four children and 252 adults met the selection criteria. ISS and the Glasgow coma scale (GCS) before intubation were
not statistically different in both groups. Seriously injured children stayed significantly shorter on the intensive care
unit, required significantly less ventilator days. Furthermore, the incidence of single organ failure (SOF) and multiple organ
failure (MOF) was significantly lower in the children group. Mortality in the children group (29.6%) was lower than that in
the adult group (33.7%). There was no death due to MOF in the children group as compared to 2.4% (n = 6) in the adults.
Conclusion: The incidence of SOF and MOF was significantly lower in the children group although there was no difference in ISS, GCS and
injury patterns. The prognosis of severely injured children was found to be better than those of adults. Moreover, there was
no death due to MOF in the children group. 相似文献
108.
对血清蛋白白球比值参考范围的修改及其临床应用 总被引:1,自引:0,他引:1
李学军 《实用医药杂志(山东)》2006,23(1):34-35
目的探讨血清蛋白白球比值(A/G)的参考范围和A/G在计算过程中产生的误差对临床应用的影响。方法①选取健康查体人员统计其A/G参考范围;②从理论上分析A/G计算误差的存在。结果①以统计结果的2s置信区间作为A/G的参考范围是1.1~2.2;②A/G计算值的误差会远大于相应总蛋白和白蛋白的测定误差。结论A/G较合适的参考范围为1.1~2.2,并且在临床应用中仍可根据实际情况降低其范围的下限。 相似文献
109.
Abstract Migraine without aura is typically considered a female condition. The purpose of this study was to determine if there have
been any changes in the female-to-male ratio of the disease over time. We included in the study all patients with migraine
without aura (n=3457) referred to the Parma University Headache Centre between 1976 and 1995. They were divided into subgroups with respect
to gender and year-range of onset of migraine (before 1960, in the 1960s, in the 1970s, in the 1980s, and between 1990 and
1995). Gender ratio ranged from 3.6:1 (in patients with onset before 1960) to 2.8:1 (in patients with onset in the 1980s),
with no statistically significant changes during the observation period. 相似文献
110.
镍铬合金烤瓷修复体394件中远期修复效果回顾性分析 总被引:2,自引:1,他引:1
目的:了解镍铬合金烤瓷修复体的中远期修复效果。方法:对我科1995年7月~2005年3月具有完整病历记载并能正常复诊的312例(394件)镍铬合金烤瓷修复体的临床资料进行了回顾性分析。结果:镍铬合金烤瓷修复体3年以上成功率为96.2%,5年以上成功率为92.9%,牙龈炎症、松动脱落、瓷崩是镍铬合金烤瓷修复体失败的3种主要表现。结论:为确保镍铬合金烤瓷修复体的中远期疗效,应从适应证的选择、固位体的设计、基牙制备、烤瓷工艺等方面严格把关。 相似文献