全文获取类型
收费全文 | 102182篇 |
免费 | 10543篇 |
国内免费 | 2796篇 |
专业分类
耳鼻咽喉 | 746篇 |
儿科学 | 1550篇 |
妇产科学 | 1206篇 |
基础医学 | 19379篇 |
口腔科学 | 2657篇 |
临床医学 | 6342篇 |
内科学 | 14682篇 |
皮肤病学 | 1875篇 |
神经病学 | 11087篇 |
特种医学 | 2820篇 |
外国民族医学 | 27篇 |
外科学 | 8149篇 |
综合类 | 10122篇 |
预防医学 | 3966篇 |
眼科学 | 1042篇 |
药学 | 16687篇 |
33篇 | |
中国医学 | 3951篇 |
肿瘤学 | 9200篇 |
出版年
2023年 | 1771篇 |
2022年 | 2419篇 |
2021年 | 3746篇 |
2020年 | 4111篇 |
2019年 | 4271篇 |
2018年 | 3975篇 |
2017年 | 4097篇 |
2016年 | 3737篇 |
2015年 | 4232篇 |
2014年 | 6306篇 |
2013年 | 6552篇 |
2012年 | 5835篇 |
2011年 | 7021篇 |
2010年 | 5619篇 |
2009年 | 5658篇 |
2008年 | 5588篇 |
2007年 | 4762篇 |
2006年 | 4086篇 |
2005年 | 3769篇 |
2004年 | 3183篇 |
2003年 | 2829篇 |
2002年 | 2104篇 |
2001年 | 1786篇 |
2000年 | 1455篇 |
1999年 | 1303篇 |
1998年 | 1042篇 |
1997年 | 1088篇 |
1996年 | 977篇 |
1995年 | 1104篇 |
1994年 | 1019篇 |
1993年 | 967篇 |
1992年 | 759篇 |
1991年 | 681篇 |
1990年 | 586篇 |
1989年 | 497篇 |
1988年 | 474篇 |
1987年 | 473篇 |
1986年 | 571篇 |
1985年 | 779篇 |
1984年 | 741篇 |
1983年 | 581篇 |
1982年 | 579篇 |
1981年 | 488篇 |
1980年 | 449篇 |
1979年 | 374篇 |
1978年 | 229篇 |
1977年 | 190篇 |
1976年 | 197篇 |
1975年 | 121篇 |
1974年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
临床上子宫切除术为妇科常见手术,包括开腹子宫切除术、腹腔镜下子宫切除术和经阴道子宫切除术。临床书写手术名称与ICD手术编码有所区别,并不能完全反应出编码所需的要素。编码时容易错编和漏编。根据ICD-9-CM-3手术分类规则,子宫切除术的手术编码以手术入路、术式、手术切除范围等方面为轴心进行分类,分别为经腹子宫次全切除术68.3、经腹子宫全部切除术68.4、经阴道子宫切除术68.5、经腹根治性子宫切除术68.6和经阴道根治性子宫切除术68.7等术式。实际工作中,编码员应准确掌握手术编码的分类轴心,应结合不同案例分析,阅读手术记录明确了手术的入路、术式、手术切除范围等相关信息,尤其是手术的切除范围、是否伴有临近器官的切除和是否伴有淋巴结的清扫等,从而提高子宫切除术编码的准确性与完整性。 相似文献
2.
《Research in social & administrative pharmacy》2022,18(9):3694-3698
In this paper, we argue that understanding and addressing the problem of poor-quality medical products requires a more interdisciplinary approach than has been evident to date. While prospective studies based on rigorous standardized methodologies are the gold standard for measuring the prevalence of poor-quality medical products and understanding their distribution nationally and internationally, they should be complemented by social science research to unpack the complex set of social, economic, and governance factors that underlie these patterns. In the following sections, we discuss specific examples of prospective quality surveys and of social science studies, highlighting the value of cross-sector partnerships in driving high-quality, policy-relevant research in this area. 相似文献
3.
4.
5.
目的研究喉癌肿瘤相关成纤维细胞(CAFs)外泌体表达下调的miRNA-656-3p对喉癌细胞生长和侵袭能力的影响以及丹参酮ⅡA对其调控作用。方法将CAFs外泌体miRNA-656-3p表达上调,制备外泌体上清,检测其对喉癌细胞体外增殖、侵袭能力及细胞周期的影响。检测中药提取物丹参酮ⅡA是否具有类似的上调CAFs外泌体miRNA-656-3p表达的作用,其作用后的CAFs外泌体上清是否具有类似的抑制喉癌增殖和侵袭能力的功效。结果过表达miR-656-3p的CAFs外泌体上清能抑制喉癌细胞的体外增殖和侵袭能力,抑制CCND2的表达,并将喉癌细胞阻滞在G0/G1期。而丹参酮ⅡA也可以上调CAFs外泌体中miR-656-3p的表达水平,其作用后的CAFs外泌体能发挥类似的抑制喉癌细胞体外增殖和侵袭的功效。结论喉癌CAFs外泌体miRNA-656-3p的表达下调促进喉癌细胞的生长和侵袭能力,丹参酮ⅡA可上调CAFs外泌体miR-656-3p的表达,通过后者抑制喉癌细胞的生长和侵袭能力。 相似文献
6.
Qi Zhang Shuang Wu Qianqian Xiao Chenping Kang Hong Hu Xiaohong Hou Xuetao Wei Weidong Hao 《Journal of applied toxicology : JAT》2022,42(4):588-599
Obesogens are a subset of endocrine disruptor chemicals (EDCs) that cause obesity. The typical EDC 4-nonylphenol (4-NP) has been identified as an obesogen. However, the in vitro effects of 4-NP on adipogenesis remain unclear. In this study, 3T3-L1 preadipocytes and C3H/10T1/2 mesenchymal stem cells (MSCs) were used to investigate the influence of 4-NP on adipogenesis. The differentiation protocols for 3T3-L1 preadipocytes and C3H/10T1/2 MSCs took 8 and 12 days, respectively, beginning at Day 0. In differentiated 3T3-L1 preadipocytes, 20 μM 4-NP decreased cell viability on Days 4 and 8. Exposure to 4-NP inhibited triglyceride (TG) accumulation and adipogenic marker expression on Days 0–8, but the inhibitory effects were weaker on Days 2–8. The protein expression of pSTAT3 or STAT3 decreased on Days 0–8 and 2–8. Conversely, 4-NP promoted TG accumulation and the adipogenic marker expression in C3H/10T1/2 adipocytes. The opposing effects were attributed to physiological differences between the two cell lines. The 3T3-L1 preadipocytes are dependent on mitotic clonal expansion (MCE) to drive differentiation, while C3H/10T1/2MSCs and human preadipocytes are not. Additionally, 4-NP downregulated β-catenin expression in C3H/10T1/2 adipocytes. Accordingly, we hypothesized that 4-NP promotes adipogenesis. The role of the canonical Wnt pathway in the promotion of adipogenesis by 4-NP requires further validation. This study provides new insights into the mechanisms and appropriate risk management of 4-NP. 相似文献
7.
《Saudi Pharmaceutical Journal》2022,30(10):1486-1496
IntroductionPreclinical studies have demonstrated the possible anticancer effects of statins, but the synergistic effect of concomitant statin use with standard chemotherapy protocols in patients with breast cancer has not yet been investigated.AimThe current study aimed to evaluate the efficacy of concomitant pitavastatin use with neoadjuvant chemotherapy protocols in patients with breast cancer.MethodsThis study was a randomized controlled clinical trial. A total of 70 adult female patients with pathologically-proven invasive breast cancer were randomized to receive or not receive pitavastatin (2 mg) oral tablets once daily concomitantly with standard neoadjuvant chemotherapy protocols for 6 months. The primary outcomes of this study were changes in tumor size and changes to the Ki67 index. In addition, secondary outcomes were changes in cyclin D1 and cleaved caspase-3 serum levels. This study was registered at ClinicalTrials.gov (Identifier: NCT04705909).ResultsPatients in the pitavastatin group showed significantly higher median (IQR) reductions in tumor size [?19.8 (?41.5, 9.5)] compared to those in the control group [?5.0 (?15.5, 0.0), p = 0.0009]. The change in Ki67 from baseline to the end of therapy was similar between the two groups (p = 0.12). By the end of therapy, the cyclin D1 levels in the pitavastatin group were significantly decreased [median (IQR) change of ? 10.0 (?20.2, ?2.9) from baseline], whereas the control group showed an increase in cyclin D1 levels [14.8 (4.1, 56.4)]. The median (IQR) caspase?3 was elevated in the pitavastatin group 1.6 (0.2, 2.2), and decreased in the control group (?0.2 (?1.1, 0.0), p = 0.0002).Subgroup analysis of the pitavastatin group revealed that patients with positive human epidermal growth receptor 2 (HER2) had higher median (IQR) reductions in Ki67 [?35.0 (?70.0, ?12.5)] than those with negative HER2 [2.5 (?15.0, 10.0), p = 0.04]. All patients who achieved a complete pathological response (n = 9) exhibited an HER2-neu positive receptor at baseline.ConclusionConcomitant use of pitavastatin with standard neoadjuvant chemotherapy protocols may improve neoadjuvant chemotherapy responses in patients with breast cancer. 相似文献
8.
9.
10.
目的 探讨影响1-羟基-2-氧-1,8-萘啶-3-甲酰胺类HIV整合酶链转移抑制剂(integrase strand transfer inhibitors, INSTIs)抗整合酶链转移(integrase strand transfer, INST)活性的主要微观结构因素。方法 采用遗传函数逼近法构建了10个1-羟基-2-氧-1,8-萘啶-3-甲酰胺类INSTIs的二维定量构效关系(2d-quantitative structure-activity relationship, 2D-QSAR)模型,从中优选出最优模型,并据此探析影响抑制剂抗INST活性的主要微观结构因素。结果 最优2D-QSAR模型的非交叉验证相关系数R2为0.8555,留一法交叉验证相关系数Q2loo为0.7761,外部交互验证相关系数R2ext为0.94,表明所建模型具有较好的统计学意义和稳定性。结论 1-羟基-2-氧-1,8-萘啶-3-甲酰胺类INSTIs的抗INST活性主要与描述符JX、Dipole_mag、Jurs_PNSA_1和Strain_Energy相关,可为抑制剂的进一步合理设计提供理论依据。 相似文献