全文获取类型
收费全文 | 48879篇 |
免费 | 3964篇 |
国内免费 | 573篇 |
专业分类
耳鼻咽喉 | 436篇 |
儿科学 | 2282篇 |
妇产科学 | 561篇 |
基础医学 | 4932篇 |
口腔科学 | 838篇 |
临床医学 | 4919篇 |
内科学 | 3513篇 |
皮肤病学 | 326篇 |
神经病学 | 17144篇 |
特种医学 | 965篇 |
外国民族医学 | 1篇 |
外科学 | 2249篇 |
综合类 | 4477篇 |
一般理论 | 3篇 |
预防医学 | 3907篇 |
眼科学 | 243篇 |
药学 | 3958篇 |
15篇 | |
中国医学 | 1316篇 |
肿瘤学 | 1331篇 |
出版年
2024年 | 52篇 |
2023年 | 964篇 |
2022年 | 1234篇 |
2021年 | 2068篇 |
2020年 | 2109篇 |
2019年 | 1881篇 |
2018年 | 1833篇 |
2017年 | 1962篇 |
2016年 | 1930篇 |
2015年 | 1749篇 |
2014年 | 3636篇 |
2013年 | 4653篇 |
2012年 | 2735篇 |
2011年 | 3165篇 |
2010年 | 2584篇 |
2009年 | 2680篇 |
2008年 | 2611篇 |
2007年 | 2252篇 |
2006年 | 1952篇 |
2005年 | 1569篇 |
2004年 | 1334篇 |
2003年 | 1191篇 |
2002年 | 975篇 |
2001年 | 790篇 |
2000年 | 610篇 |
1999年 | 547篇 |
1998年 | 498篇 |
1997年 | 436篇 |
1996年 | 362篇 |
1995年 | 353篇 |
1994年 | 305篇 |
1993年 | 261篇 |
1992年 | 258篇 |
1991年 | 242篇 |
1990年 | 213篇 |
1989年 | 183篇 |
1988年 | 188篇 |
1987年 | 144篇 |
1986年 | 94篇 |
1985年 | 151篇 |
1984年 | 121篇 |
1983年 | 83篇 |
1982年 | 117篇 |
1981年 | 64篇 |
1980年 | 56篇 |
1979年 | 51篇 |
1978年 | 34篇 |
1977年 | 40篇 |
1976年 | 31篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
Major depressive disorder is a serious and common neuropsychiatric disorder that affects more than 350 million people worldwide. Electroconvulsive therapy is the oldest and most effective treatment available for the treatment of severe major depressive disorder. Electroconvulsive therapy modifies structural network changes in patients with major depressive disorder and schizophrenia. And it can also affect neuroinflammatory responses and may have neuroprotective effects. Electroconvulsive therapy plays an irreplaceable role in the treatment of major depressive disorder. 相似文献
2.
3.
4.
目的 探究注意缺陷多动障碍(ADHD)患儿血清25羟基维生素D[25(OH)D]、微量元素表达水平及临床意义。方法 选取2019年4月至2020年11月本院诊治的84例ADHD患儿进行研究(ADHD组),依据ADHD分型标准将患儿分为注意缺陷为主型组(28例)、多动为主型组(33例)、混合型组(23例),并选取同期84例体检健康儿童进行对照研究(对照组)。采用高效液相色谱-串联质谱法检测所有受试儿童血清25(OH)D水平;检测血清铁(Fe)、磷(P)、镁(Mg)、钙(Ca)、铜(Cu)、锌(Zn)、铅(Pb)水平;Pearson法分析ADHD患儿血清25(OH)D水平与Cu、Zn、Pb水平的相关性;Logistic回归分析ADHD发生的影响因素;受试者工作特征(ROC)曲线分析血清25(OH)D、Zn、Pb水平对ADHD的诊断价值。结果 ADHD组血清25(OH)D、Cu、Zn水平均显著低于对照组(P<0.05),Pb水平显著高于对照组(P<0.05);注意缺陷为主型组、多动为主型组、混合型组患儿血清25(OH)D、Fe、P、Mg、Ca、Cu、Zn、Pb水平比较,差异无统计学意义(P>0.05);ADHD患儿血清25(OH)D水平与Cu、Zn水平均呈正相关(P<0.05),与Pb水平呈负相关(P<0.05);25(OH)D、Zn是影响ADHD发生的保护因素(P<0.05),Pb是影响ADHD发生的危险因素(P<0.05);血清25(OH)D、Zn、Pb水平诊断ADHD的曲线下面积(AUC)分别为0.773、0.770、0.772,截断值分别为21.01 ng/mL、16.05 μmol/L、50.69 μg/L,相应灵敏度分别为82.1%、77.4%、63.1%,特异度分别为67.9%、71.4%、88.1%;三者联合诊断ADHD的AUC为0.883,其灵敏度、特异度分别为81.0%、81.0%。结论 ADHD患儿血清25(OH)D、Cu、Zn水平降低,Pb水平升高,25(OH)D、微量元素水平与ADHD患儿类型无关,25(OH)D、Zn、Pb联合有助于临床筛查ADHD患儿。 相似文献
5.
6.
《Vaccine》2022,40(30):4038-4045
PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion.MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster.ResultsAmong 110 participants, 56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed.ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals. 相似文献
7.
8.
9.
Background and aimThe effects of physical activity and exercise on gaming disorder severity in individuals with gaming disorder are unknown. The present study aimed to address the empirical gap in the current literature by comparing the effects of virtual reality-based training (VRT) and aerobic training (AT) exercise programs on gaming disorder severity, physical activity, physical fitness, and anxiety versus control group.Materials and methodsForty-four young male adults (18–28 years) with gaming disorder and a sedentary lifestyle were included in the study. The primary outcomes of the study were changes in gaming disorder severity and physical activity, and secondary outcomes included changes in physical fitness and anxiety levels. The participants were randomly assigned to VRT (n = 15), AT (n = 14) and control (n = 15) groups. Training sessions were performed at 50–70% of the maximal heart rate. Exercise programs consisted of 6 weeks of training 3 times a week for 30 min.ResultsThere was a decrease in the severity of gaming disorder as well as an increase in the level of physical activity in the VRT and AT exercise groups compared to the control group. In addition, a reduction was observed in the gaming time and sedentary time in both exercise groups versus control group. VRT group experienced greater improvements in physical fitness parameters than the AT group.ConclusionVRT and AT were effective in reducing gaming time and the severity of gaming disorder in individuals with gaming disorder. The therapeutic effects of VRT and AT can be used for reducing the severity of gaming disorder. 相似文献
10.
《Gait & posture》2022
BackgroundVisually induced dizziness can develop as a sequala of a vestibular disorder and is characterized by symptoms of nausea, dizziness, and imbalance in rich visual environments such as supermarkets and shopping malls. To date the mechanisms underlying visually induced dizziness are poorly understood.Research questionWhat are the characteristics of visual fixations and postural sway in adults with visually induced dizziness compared to healthy adults when exposed to increasingly complex visual environments?MethodsWe recruited 20 adults with visually induced dizziness and 20 healthy adults to this cross-sectional exploratory study. Participants were instructed to maintain gaze on letters projected on a large screen with backgrounds of differing visual complexity. The number of visual refixations, movement of the centre of pressure, and movement of the head and body centres of mass were recorded.ResultsAdults with visually induced dizziness showed a significantly higher number of visual refixations (F= 10.592, p < 0.01), and increased mean velocity of head and body centres of mass movement (F= 14.034, p < 0.01 and F= 6.553, p < 0.05 respectively) compared to healthy adults.SignificanceAdults with visually induced dizziness exhibited visual fixational instability and increased postural and head sway compared to healthy adults. This was mainly observed in conditions with complex and moving backgrounds. This may account for reports from adults with visually induced dizziness of worsening symptoms in busy environments. The results from the study may assist in guiding intervention development to reduce symptoms of visually induced dizziness. 相似文献