全文获取类型
收费全文 | 19558篇 |
免费 | 1886篇 |
国内免费 | 861篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 383篇 |
妇产科学 | 115篇 |
基础医学 | 2170篇 |
口腔科学 | 248篇 |
临床医学 | 1450篇 |
内科学 | 2222篇 |
皮肤病学 | 183篇 |
神经病学 | 478篇 |
特种医学 | 523篇 |
外国民族医学 | 3篇 |
外科学 | 741篇 |
综合类 | 3312篇 |
预防医学 | 1632篇 |
眼科学 | 185篇 |
药学 | 5913篇 |
7篇 | |
中国医学 | 1910篇 |
肿瘤学 | 800篇 |
出版年
2024年 | 34篇 |
2023年 | 356篇 |
2022年 | 407篇 |
2021年 | 875篇 |
2020年 | 681篇 |
2019年 | 718篇 |
2018年 | 790篇 |
2017年 | 875篇 |
2016年 | 943篇 |
2015年 | 821篇 |
2014年 | 1208篇 |
2013年 | 2121篇 |
2012年 | 1061篇 |
2011年 | 1184篇 |
2010年 | 888篇 |
2009年 | 757篇 |
2008年 | 819篇 |
2007年 | 802篇 |
2006年 | 781篇 |
2005年 | 725篇 |
2004年 | 629篇 |
2003年 | 552篇 |
2002年 | 445篇 |
2001年 | 474篇 |
2000年 | 403篇 |
1999年 | 302篇 |
1998年 | 253篇 |
1997年 | 238篇 |
1996年 | 262篇 |
1995年 | 259篇 |
1994年 | 224篇 |
1993年 | 210篇 |
1992年 | 189篇 |
1991年 | 168篇 |
1990年 | 138篇 |
1989年 | 119篇 |
1988年 | 86篇 |
1987年 | 79篇 |
1986年 | 58篇 |
1985年 | 78篇 |
1984年 | 54篇 |
1983年 | 35篇 |
1982年 | 44篇 |
1981年 | 32篇 |
1980年 | 26篇 |
1979年 | 19篇 |
1978年 | 22篇 |
1977年 | 13篇 |
1976年 | 20篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Lipid nanoparticles (LNPs) are becoming popular as a means of delivering therapeutics, including those based on nucleic acids and mRNA. The mRNA-based coronavirus disease 2019 vaccines are perfect examples to highlight the role played by drug delivery systems in advancing human health. The fundamentals of LNPs for the delivery of nucleic acid- and mRNA-based therapeutics, are well established. Thus, future research on LNPs will focus on addressing the following: expanding the scope of drug delivery to different constituents of the human body, expanding the number of diseases that can be targeted, and studying the change in the pharmacokinetics of LNPs under physiological and pathological conditions. This review article provides an overview of recent advances aimed at expanding the application of LNPs, focusing on the pharmacokinetics and advantages of LNPs. In addition, analytical techniques, library construction and screening, rational design, active targeting, and applicability to gene editing therapy have also been discussed. 相似文献
2.
目的 对比研究朝鲜淫羊藿酸性多糖酯化还原前后的理化特性,并探讨其改善油酸诱导的肝癌HepG2细胞脂质堆积活性的差异。方法 采用高效凝胶渗透色谱法测定朝鲜淫羊藿酸性多糖(EFPA)的均一性和分子量,高效液相色谱法测定EFPA和酯化还原后朝鲜淫羊藿酸性多糖(EFPA-R)的单糖组成;采用油酸(OA)处理HepG2细胞诱导建立脂质蓄积模型,不同浓度EFPA与EFPA-R(10、30、100、300 μg·mL-1)分别和OA共同作用于细胞24 h,采用CCK-8试剂盒测定细胞存活率,油红O染色观察细胞内脂滴蓄积情况,并采用试剂盒测定细胞内总胆固醇(TC)、甘油三酯(TG)含量。结果 EFPA为成分均一的多糖组分,分子量为125.8 kDa,由甘露糖、葡萄糖、半乳糖、葡萄糖醛酸和阿拉伯糖组成,摩尔比为1.7∶7.4∶1.4∶1.8∶1.0,葡萄糖占比最大,EFPA-R由甘露糖、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为0.8∶10.6∶2.1∶1.0;在10-300 μg·mL-1范围内,EFPA和EFPA-R对HepG2细胞的抑制作用较弱,作为给药浓度;与空白组相比,模型组细胞中TC、TG含量显著升高(P < 0.01),细胞内红色脂滴显著增多,与模型组相比,EFPA可显著降低细胞中TC、TG含量(P < 0.01),明显减少细胞内红色脂滴(P < 0.05或P < 0.01),EFPA-R干预后细胞则无明显变化。结论 EFPA可明显改善HepG2细胞脂质堆积情况,且呈现剂量依赖性,而半乳糖醛酸(GalA)的存在可能是其抑制HepG2细胞脂质蓄积的关键因素。 相似文献
3.
4.
5.
Sounak Gupta Rafael E. Jimenez Loren Herrera-Hernandez Christine M. Lohse R. Houston Thompson Stephen A. Boorjian Bradley C. Leibovich John C. Cheville 《Mayo Clinic proceedings. Mayo Clinic》2021,96(6):1470-1489
ObjectiveTo study the clinical features and identify unique renal neoplasia subtypes and their prognostic implications in individuals with tuberous sclerosis complex (TSC).Patients and MethodsThe Mayo Clinic nephrectomy registry included 37 patients with TSC diagnosed between 1970 and 2018. Four additional patients were identified from the pathology consultation and autopsy files. All available renal tumors were further characterized using immunohistochemistry and fluorescence in situ hybridization. Clinicopathologic features and follow-up were obtained from the medical record. The American Association for Cancer Research Project GENIE registry was accessed using cBioPortal for molecular profiling of angiomyolipoma (AML).ResultsA total of 276 renal tumors from 41 patients were analyzed. Renal tumors were classified into 9 distinct morphological subtypes, with AML predominating (238 [86%]). Interestingly, all these tumors acted in a benign fashion except one renal cell carcinoma with clear cells and fibromyomatous stroma and one epithelioid AML that metastasized. Molecular profiling studies revealed that epithelioid AMLs were enriched for alterations of TP53, RB1, and ATRX. Eight patients died of direct complications of TSC, including 3 of end-stage renal disease. To date, none have died of a renal epithelial neoplasm.ConclusionThe identification of unique renal neoplasia subtypes may provide important clues to establish a diagnosis of TSC, and in the somatic setting, this finding has important implications for accurate prognostication. These tumors tend to be indolent, and only 2 of 276 tumors in our study exhibited metastatic behavior. Our results support multidisciplinary management with a focus on preservation of renal function. 相似文献
6.
7.
《Saudi Pharmaceutical Journal》2022,30(5):595-604
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation. 相似文献
8.
目的:探讨健脾益肝方对非酒精性脂肪性肝病(NAFLD)患者脂肪分布及脂代谢的影响。方法:将80例NAFLD患者随机分为对照组和治疗组各40例。两组患者均在多学科联合管理下给予个体化的饮食、运动等生活方式指导,治疗组患者在此基础上加用健脾益肝方,疗程均为3个月。通过生物电阻抗技术测量患者治疗前后脂肪质量及分布,定期监测肝肾功能、血脂指标。比较两组患者肥胖、脂肪分布、血脂指标变化。结果:治疗组患者有效率为97.5%,明显高于对照组的82.5%,差异有统计学意义(P<0.05);治疗组患者BMI、BFP、WHR、TC、TG及LDL-C水平明显低于对照组,差异有统计学意义(均P<0.05);治疗组患者躯干及内脏脂肪沉积改善明显优于对照组,差异有统计学意义(均P<0.05)。结论:生活方式干预联合健脾益肝方治疗NAFLD患者能显著改善患者的肥胖及脂代谢紊乱,并且与躯干和内脏脂肪质量的下降密切相关。 相似文献
9.
10.