全文获取类型
收费全文 | 58910篇 |
免费 | 5960篇 |
国内免费 | 4212篇 |
专业分类
耳鼻咽喉 | 541篇 |
儿科学 | 757篇 |
妇产科学 | 881篇 |
基础医学 | 6330篇 |
口腔科学 | 911篇 |
临床医学 | 7848篇 |
内科学 | 8111篇 |
皮肤病学 | 565篇 |
神经病学 | 3038篇 |
特种医学 | 2031篇 |
外国民族医学 | 30篇 |
外科学 | 6157篇 |
综合类 | 10711篇 |
现状与发展 | 11篇 |
一般理论 | 4篇 |
预防医学 | 4066篇 |
眼科学 | 1654篇 |
药学 | 6518篇 |
59篇 | |
中国医学 | 3843篇 |
肿瘤学 | 5016篇 |
出版年
2024年 | 223篇 |
2023年 | 999篇 |
2022年 | 2416篇 |
2021年 | 3414篇 |
2020年 | 2576篇 |
2019年 | 2216篇 |
2018年 | 2146篇 |
2017年 | 2218篇 |
2016年 | 1933篇 |
2015年 | 3034篇 |
2014年 | 3566篇 |
2013年 | 3413篇 |
2012年 | 4794篇 |
2011年 | 5033篇 |
2010年 | 3294篇 |
2009年 | 2572篇 |
2008年 | 3148篇 |
2007年 | 2990篇 |
2006年 | 2895篇 |
2005年 | 2943篇 |
2004年 | 1770篇 |
2003年 | 1621篇 |
2002年 | 1442篇 |
2001年 | 1194篇 |
2000年 | 1066篇 |
1999年 | 1083篇 |
1998年 | 667篇 |
1997年 | 665篇 |
1996年 | 507篇 |
1995年 | 470篇 |
1994年 | 406篇 |
1993年 | 266篇 |
1992年 | 340篇 |
1991年 | 317篇 |
1990年 | 281篇 |
1989年 | 218篇 |
1988年 | 226篇 |
1987年 | 166篇 |
1986年 | 152篇 |
1985年 | 103篇 |
1984年 | 54篇 |
1983年 | 44篇 |
1982年 | 22篇 |
1981年 | 29篇 |
1980年 | 27篇 |
1979年 | 24篇 |
1978年 | 13篇 |
1977年 | 10篇 |
1971年 | 8篇 |
1970年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Xiuqin Li Hongze Wang Qingnian Chen Zhiqin Li Chao Liu Shengnan Yin Zhengchen You 《Fundamental & clinical pharmacology》2019,33(6):621-633
Felbamate is an anticonvulsant used in the treatment of epilepsy. In this study, we investigated the antidepressant‐like actions of felbamate in mice. The effects of felbamate were first assessed using the forced swimming test (FST) and tail suspension test (TST), and then investigated in the chronic unpredictable mild stress (CUMS) and chronic social defeat stress (CSDS) models of depression. The changes in the hippocampal brain‐derived neurotrophic factor (BDNF) signaling cascade after chronic stress and felbamate treatment were also examined. It was found that felbamate exhibited antidepressant‐like activities in the FST and TST without affecting the locomotor activity of mice. Felbamate was also effective in both the CUMS and CSDS models of depression. Moreover, felbamate administration fully restored the decreased hippocampal BDNF signaling pathway in both the CUMS‐stressed and CSDS‐stressed mice. Collectively, felbamate has antidepressant‐like actions in mice involving the hippocampal BDNF system. 相似文献
993.
目的探索let-7d-3p和miRNA-21-5p在二氧化硅(SiO_2)诱导的大鼠纤维化肺组织中的差异表达及其意义。方法 SPF级Wistar雄性大鼠随机分为对照组和模型组,每组30只,采用一次性气管内灌注1 ml SiO_2悬浊液建立大鼠矽肺模型,对照组大鼠相同方法灌注1ml灭菌生理盐水。分别于染尘后1、7、14、21、28 d采集各组大鼠肺组织,每组取6只,对3只大鼠肺组织进行病理学观察,另外3只采用miRNA微阵列芯片技术筛选肺组织中差异表达的miRNA,通过miRNA芯片筛选结合反转录定量聚合酶链式反应(RT-qPCR)验证let-7d-3p和miRNA-21-5p在两组间的表达水平,对let-7d-3p和miRNA-21-5p进行靶基因预测并进行GO(gene ontology)富集分析和KEGG(kyoto encyclopedia of genes and genomes)通路分析。结果对照组大鼠1、7、14和21 d Masson染色均可见正常肺组织,未发现胶原纤维,28 d大鼠肺间质和支气管周围仅有少量纤细的胶原分布;模型组大鼠1 d和7 d未发现胶原纤维,14 d染色可见较多以淋巴细胞为主的炎症细胞浸润,未见明显纤维组织,21 d和28 d模型组大鼠肺间质内可见大片状密集的胶原纤维沉积,在肉芽组织、支气管及血管壁周围胶原蛋白增生明显。模型组中let-7d-3p的表达水平均显著下调,miRNA-21-5p表达水平均显著上调,与对照组相比差异均有统计学意义(P0.05)。结论模型组中let-7d-3p和miRNA-21-5p表达变化明显,可能与早期矽肺的发生发展有关。 相似文献
994.
目的探讨突变等位基因肿瘤异质性(MATH)在甲状腺乳头状癌(PTC)中的临床意义。
方法从癌症基因图谱公共数据集下载并预处理PTC肿瘤测序数据及临床资料数据,分析MATH与PTC临床病理特征的相关性,使用Kaplan-Meier法进行生存分析,验证MATH对PTC患者的预后价值。
结果PTC患者中MATH值为2.57~93.72,平均29.45±16.19;将≥29.45者纳入高MATH组,<29.45者纳入低MATH组。高MATH组与低MATH组的患者年龄、性别、临床分期、BRAF基因型差异无统计学意义(P>0.05)。MATH不是PTC患者总体生存期(OS)的显著预测因素(P=0.4595);在BRAF突变型PTC患者中,高MATH者的OS低于低MATH者(P=0.0252),而在BRAF野生型PTC患者中,高MATH者的OS高于低MATH者(P=0.0495)。
结论MATH可在BRAF突变型和野生型亚组中可预测PTC患者的预后及指导临床治疗。 相似文献
995.
996.
BaiHang Chen Chao Chen ZeTian Yang PeiZhen Huang Hang Dong ZhanPeng Zeng 《Foot and Ankle Surgery》2019,25(1):63-70
Background
To compare the efficacy between fixation with suture-button and screw in the treatment of syndesmotic injuries: a meta-analysis.Methods
We comprehensively searched PubMed, Embase, and the Cochrane Library and performed a meta-analysis of randomized controlled trials (RCTs) and retrospective comparative studies (RTCs). We performed using Review Manager 5.2.Results
Three RCTs and six retrospective studies were conducted, including a total of 397 patients. The significant differences of the fixation of suture-button were reported for AOFAS scores (at 3, 6 and 12 months follow-up), full-weight time, reoperation, malreduction and the rate of failure of fixation. There were no significant differences between the groups regarding complications of infection, VAS, OMAS, range of motion, TFCS, TFO and MCS.Conclusions
Neither the functional outcome nor complications significantly differed between the fixation methods, but suture-button might lead to a quicker return to work. This analysis needs to be confirmed and updated by larger sample data and rigorously designed RCTs. 相似文献997.
Pi-Yu Chao Su-Yi Lin Kuan-Hung Lin Yu-Fen Liu Ju-Ing Hsu Chi-Ming Yang Jun-You Lai 《Nutrients》2014,6(5):2115-2130
The objectives of this study were to identify the antioxidants and antioxidant axtivity in 27 of Taiwan’s indigenous vegetables. Lycium chinense (Lc), Lactuca indica (Li), and Perilla ocymoides (Po) contained abundant quercetin (Que), while Artemisia lactiflora (Al) and Gynura bicolor (Gb) were rich in morin and kaempferol, respectively. Additionally, Nymphoides cristata (Nc) and Sechium edule (Se)-yellow had significantly higher levels of myricetin (Myr) than other tested samples. Cyanidin (Cyan) and malvidin (Mal) were abundant in Gb, Abelmoschus esculentus Moench (Abe), Po, Anisogonium
esculentum (Retz.) Presl (Ane), Ipomoea batatas (Ib)-purple, and Hemerocallis fulva (Hf)-bright orange. Relatively high levels of Trolox equivalent antioxidant capacity (TEAC), oxygen radical absorption capacity (ORAC), and 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenger were generated from extracts of Toona sinensis (Ts) and Po. Significant and positive correlations between antioxidant activity and polyphenols, anthocyanidins, Que, Myr, and morin were observed, indicating that these phytochemicals were some of the main components responsible for the antioxidant activity of tested plants. The much higher antioxidant activity of Po, Ts, and Ib (purple leaf) may be related to their higher Cyan, Que, and polyphenol content. 相似文献
998.
目的 调查芜湖市主城区大气 PM2.5中多环芳烃(PAHs)污染特征及其人群健康风险。方法 2020年6月至2021年5月,每月10至16日采集芜湖市主城区大气PM2.5样品,检测和分析其中16种优先控制PAHs浓度及组成特征,并利用特征比值法和物质结构判断PM2.5中PAHs来源,采用US EPA健康风险模型评估其人群健康风险。结果 大气PM2.5浓度均值为49.2μg/m3,范围为7~151μg/m3;16种PAHs均有不同程度检出,总浓度均值为6.85ng/m3,范围为0.13~31.62ng/m3;PM2.5与16种PAHs各月份日均浓度变化存在相关性(R=0.867,P<0.001);16种PAHs季节变化为冬季>秋季>春季>夏季,构成均以4~6 环为主;大气PM2.5中PAHs主要来源为机动车排放和燃煤。PM2.5中16种PAHs的总致癌风险值(Risk)为2.20×10-7,低于1×10-6,致癌风险可忽略;非致癌风险危害商值(HQ)为0.49,小于1,非致癌健康风险低。结论 芜湖市主城区大气PM2.5中PAHs污染较轻,无明显健康风险。 相似文献
999.
Chuan-Chia Chang Yu-Chen Kao Che-Yi Chao Nian-Sheng Tzeng Hsin-An Chang 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2021,24(1):40
BackgroundWe previously showed the efficacy of bi-anodal transcranial direct current stimulation (tDCS) over the prefrontal cortex (PFC) regions with extracephalic reference placement in improving negative symptoms in schizophrenia. In this ancillary investigation, the effects of this intervention on insight levels, other clinical outcomes, and cardio-respiratory and autonomic functions were examined and the potential of biomarkers for treatment response was explored.MethodsSchizophrenia patients were randomly allocated to receive 10 sessions of bi-anodal tDCS over the PFC regions with extracephalic reference placement (2 mA, 20 minutes, twice daily for 5 weeks) or sham stimulation. We examined, in 60 patients at baseline, immediately after stimulation and at follow-up visits, the insight levels, other clinical outcomes, blood pressure, respiratory rate, heart rate, and heart rate variability.ResultsInsight levels as assessed by the abbreviated version of the Scale to Assess Unawareness in Mental Disorder in schizophrenia awareness of the disease, positive and negative symptoms dimensions, and beliefs about medication compliance as assessed by Medication Adherence Rating Scale were significantly enhanced by active stimulation relative to sham. No effects were observed on cognitive insight, other clinical outcomes, or cardio-respiratory and autonomic functions. Heart rate variability indices as biomarkers were not associated with the clinical response to the intervention.ConclusionsOur results provide evidence for bi-anodal tDCS over the PFC regions with extracephalic reference placement in heightening the levels of insight into the disease and symptoms, as well as beliefs about medication compliance in schizophrenia, without impacting other clinical outcomes and cardio-respiratory/autonomic functions. 相似文献
1000.
目的 观察let-7家族微RNA抑制剂(anti-let-7)对支气管哮喘(简称哮喘)小鼠气道炎性反应的影响,并探讨let-7参与哮喘形成的机制.方法 32只小鼠按随机数字法分为4组(n=8),即正常对照组(A组)、哮喘组(B组)、干预对照组(C组)和干预组(D组).其中B、C和D组用鸡卵蛋白(OVA)免疫,建立哮喘模型,A组以生理盐水替代OVA处理.D组小鼠激发前注射anti-let-7以抑制内源性let-7表达,C组小鼠注射乱序siRNA对照.比较各组小鼠支气管肺泡灌洗液(BALF)的细胞计数,肺组织中let-7e以及BALF中白细胞介素-10(IL-10)含量;体外用anti-let-7转染肺癌细胞A549,并检测细胞中let-7e表达和细胞培养上清中IL-10的含量;荧光素酶报告法检测let-7e是否直接靶向IL-10.结果 与A组相比,B组和C组小鼠BALF中细胞总数和嗜酸粒细胞数显著增加[(20.32±5.33)×109/L和(24.74±6.69)×109/L比(7.12± 1.88)×109/L,(6.45±2.5)×109/L和(7.12±2.66)×109/L比(0.04±0.01)×109/L,均P<0.01];肺组织中let-7e水平明显升高(分别为3.83倍和3.27倍,均P<0.01).与C组比较,D组BALF中细胞总数和嗜酸粒细胞数明显减少[(13.85±3.74)× 109/L比(24.74±6.69)×109/L,(2.15±1.13)×109/L比(7.12±2.66)×109/L,均P<0.05];肺组织中let-7e显著降低[(0.45±0.22)比(3.28±0.45),P<0.01],同时BALF中IL-10水平明显升高[(4.68±0.85)比(1.70±0.29),P<0.01].此外,在肺癌细胞A549 中转染anti-let-7,let-7e表达显著下降[(0.22±0.03)比(1.00±0.11),P<0.01],同时培养上清中IL-10明显上升[(2.58±0.35)比(1.00±0.15),P<0.01].体外let-7e过表达显著降低IL-10报告载体的荧光素酶活性[(0.59±0.06)比(1.00±0.03),P<0.01],而对突变的IL-10报告载体没有抑制作用.结论 anti-let-7对哮喘小鼠气道炎性反应具有明显的抑制作用,其作用机制可能与let-7直接靶向并抑制IL-10有关. 相似文献