全文获取类型
收费全文 | 2258550篇 |
免费 | 164350篇 |
国内免费 | 18298篇 |
专业分类
耳鼻咽喉 | 31124篇 |
儿科学 | 64298篇 |
妇产科学 | 60011篇 |
基础医学 | 319680篇 |
口腔科学 | 63083篇 |
临床医学 | 205485篇 |
内科学 | 431277篇 |
皮肤病学 | 44741篇 |
神经病学 | 170855篇 |
特种医学 | 88221篇 |
外国民族医学 | 576篇 |
外科学 | 344432篇 |
综合类 | 76328篇 |
现状与发展 | 57篇 |
一般理论 | 529篇 |
预防医学 | 157127篇 |
眼科学 | 53623篇 |
药学 | 179896篇 |
197篇 | |
中国医学 | 16549篇 |
肿瘤学 | 133109篇 |
出版年
2021年 | 23332篇 |
2019年 | 20240篇 |
2018年 | 26858篇 |
2017年 | 21476篇 |
2016年 | 22723篇 |
2015年 | 28743篇 |
2014年 | 37940篇 |
2013年 | 49067篇 |
2012年 | 68541篇 |
2011年 | 73785篇 |
2010年 | 43686篇 |
2009年 | 39646篇 |
2008年 | 65648篇 |
2007年 | 69506篇 |
2006年 | 70743篇 |
2005年 | 69382篇 |
2004年 | 63129篇 |
2003年 | 60945篇 |
2002年 | 59044篇 |
2001年 | 106514篇 |
2000年 | 110212篇 |
1999年 | 94189篇 |
1998年 | 26474篇 |
1997年 | 23929篇 |
1996年 | 23514篇 |
1995年 | 22036篇 |
1994年 | 20457篇 |
1993年 | 18312篇 |
1992年 | 71831篇 |
1991年 | 69658篇 |
1990年 | 67929篇 |
1989年 | 66007篇 |
1988年 | 61116篇 |
1987年 | 59538篇 |
1986年 | 56277篇 |
1985年 | 53610篇 |
1984年 | 39136篇 |
1983年 | 33641篇 |
1982年 | 18940篇 |
1979年 | 36004篇 |
1978年 | 24839篇 |
1977年 | 21448篇 |
1976年 | 19586篇 |
1975年 | 21535篇 |
1974年 | 25692篇 |
1973年 | 24469篇 |
1972年 | 23371篇 |
1971年 | 21871篇 |
1970年 | 20540篇 |
1969年 | 19677篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Lei Yang You-Ling Shi Yan Ma Wei-Wei Ren Guang-Ming Pang Jiao Liu 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2022,130(1):43-52
Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis. 相似文献
12.
Weina Cheng Yazhi Wang Jingxian Liu Xiaofei Li Ming Yu Cancan Duan Liu Liu Jianyong Zhang 《Journal of applied toxicology : JAT》2022,42(6):970-980
Cantharidin (CTD) is an effective antitumor agent. However, it exhibits significant hepatotoxicity, the mechanism of which remains unclear. In this study, biochemical and histopathological analyses complemented with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabolomic analysis of bile acids (BAs) were employed to investigate CTD-induced hepatotoxicity in rats. Sixteen male and female Sprague–Dawley rats were randomly divided into two groups: control and CTD (1.0 mg/kg) groups. Serum and liver samples were collected after 28 days of intervention. Biochemical, histopathological, and BA metabolomic analyses were performed for all samples. Further, the key biomarkers of CTD-induced hepatotoxicity were identified via multivariate and metabolic pathway analyses. In addition, metabolite–gene–enzyme network and Kyoto Encyclopedia of Genes and Genomes pathway analyses were used to identify the signaling pathways related to CTD-induced hepatotoxicity. The results revealed significantly increased levels of biochemical indices (alanine aminotransferase, aspartate aminotransferase, and total bile acid). Histopathological analysis revealed that the hepatocytes were damaged. Further, 20 endogenous BAs were quantitated via UHPLC-MS/MS, and multivariate and metabolic pathway analyses of BAs revealed that hyocholic acid, cholic acid, and chenodeoxycholic acid were the key biomarkers of CTD-induced hepatotoxicity. Meanwhile, primary and secondary BA biosynthesis and taurine and hypotaurine metabolism were found to be associated with the mechanism by which CTD induced hepatotoxicity in rats. This study provides useful insights for research on the mechanism of CTD-induced hepatotoxicity. 相似文献
13.
Timothy J. Cordingley Mark A.G. Wilson Kathryn M. Weston 《Health & social care in the community》2022,30(1):353-359
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children. 相似文献
14.
15.
16.
Tengzhi Liu Kathrine Røe Redalen Morten Karlsen 《Journal of labelled compounds & radiopharmaceuticals》2022,65(7):191-202
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies. 相似文献
17.
18.
19.
20.
Stepanova E. S. Makarenkova L. M. Chistyakov V. V. Rybakov Yu. L. Gukasov V. M. Fedotcheva T. A. Parshin V. A. Votyakov V. A. Shimanovskii N. L. 《Pharmaceutical Chemistry Journal》2019,52(12):1016-1020
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was... 相似文献