全文获取类型
收费全文 | 38718篇 |
免费 | 4102篇 |
国内免费 | 2679篇 |
专业分类
耳鼻咽喉 | 541篇 |
儿科学 | 550篇 |
妇产科学 | 230篇 |
基础医学 | 3151篇 |
口腔科学 | 637篇 |
临床医学 | 4839篇 |
内科学 | 4221篇 |
皮肤病学 | 629篇 |
神经病学 | 1554篇 |
特种医学 | 1504篇 |
外国民族医学 | 6篇 |
外科学 | 3670篇 |
综合类 | 9243篇 |
现状与发展 | 12篇 |
一般理论 | 1篇 |
预防医学 | 3702篇 |
眼科学 | 725篇 |
药学 | 4402篇 |
62篇 | |
中国医学 | 3410篇 |
肿瘤学 | 2410篇 |
出版年
2024年 | 209篇 |
2023年 | 662篇 |
2022年 | 1653篇 |
2021年 | 2053篇 |
2020年 | 1750篇 |
2019年 | 1165篇 |
2018年 | 1329篇 |
2017年 | 1406篇 |
2016年 | 1177篇 |
2015年 | 1886篇 |
2014年 | 2449篇 |
2013年 | 2609篇 |
2012年 | 3566篇 |
2011年 | 3860篇 |
2010年 | 2960篇 |
2009年 | 2526篇 |
2008年 | 2652篇 |
2007年 | 2394篇 |
2006年 | 2079篇 |
2005年 | 1724篇 |
2004年 | 1176篇 |
2003年 | 1091篇 |
2002年 | 803篇 |
2001年 | 608篇 |
2000年 | 474篇 |
1999年 | 293篇 |
1998年 | 137篇 |
1997年 | 128篇 |
1996年 | 113篇 |
1995年 | 97篇 |
1994年 | 77篇 |
1993年 | 44篇 |
1992年 | 49篇 |
1991年 | 49篇 |
1990年 | 35篇 |
1989年 | 48篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 30篇 |
1985年 | 25篇 |
1984年 | 27篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1959年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
101.
YanTing Zhou YuQing Yu Hui Yang Han Yang YanFei Huo Yang Huang XinXia Tian WeiGang Fang 《Cancer science》2022,113(7):2457
Our previous works have indicated that extracellular ATP is an important prometastasis factor. However, the molecular mechanism involved needs to be further studied. We demonstrated that extracellular ATP treatment could upregulate the expression of connective tissue growth factor (CTGF) in both triple‐negative breast cancer (TNBC) cells and endothelial cells (ECs). Extracellular ATP stimulated the migration of TNBC cells and ECs, and angiogenesis of ECs via the P2Y2––YAP‐CTGF axis. Furthermore, we demonstrated that adenosine triphosphate (ATP) stimulated TNBC cell adhesion to ECs and transmigration through the EC layer via CTGF by upregulation of integrin β1 on TNBC cells and VCAM‐1 on ECs. Both apyrase (ATP‐diphosphohydrolase) and CTGF shRNA treatments could inhibit the metastasis of inoculated tumors to lung and liver in a mouse model, and these treated tumors had fewer blood vessels. Collectively, our data indicated that extracellular ATP promotes tumor angiogenesis and the interactions between TNBC cells and ECs through upregulation of CTGF, thereby stimulating TNBC metastasis. The pleiotropic effects of ATP in angiogenesis and cell adhesion suggest that extracellular ATP or CTGF could be an effective target for TNBC therapy. 相似文献
102.
Na Li Xiaolong Ma Jiaqi Zhou Jingjing Deng Chao Gu Chunyuan Fei Linfeng Cao Qi Zhang Feng Tao 《Journal of clinical laboratory analysis》2022,36(7)
IntroductionRapid and accurate pathogen identification is essential for the treatment of pneumonia. Metagenomic next‐generation sequencing (mNGS) is a newly developed technology to obtain microbial nucleic acid sequence information quickly, efficiently, and without bias.MethodsWe performed shotgun metagenomic next‐generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) for pathogen identification in pneumonia in a prospective study with 138 patients from a single center. We compared the results of mNGS with standard methods including culture, staining, and targeted PCR and evaluated the clinical applicability of mNGS.ResultsMost of the patients (128/138, 92.75%) were cured or improved. One patient (1/138, 0.72%) died because of acute gastrointestinal bleeding, and 9 patients (9/138, 6.52%) showed no improvement. mNGS identified more bacteria (53 versus 27), fewer fungi (8 versus 31), and more viruses (16 versus 1) than standard methods. In total, treatment in 34 out of 138 cases (24.64%) was adjusted and optimized because of mNGS results. Positive mNGS results contributed to a definitive diagnosis in 23 cases (16.67%), which helped guide treatment decision by either adjusting the antibiotics without de‐escalation or continuing the empirical treatment. mNGS also confirmed no active infection in 11 cases (7.97%) allowed for antibiotic de‐escalation.ConclusionThis prospective clinical study evaluated the clinical utility of mNGS for the diagnosis of pneumonia and showed that mNGS of BALF provides valuable information for effective treatment. 相似文献
103.
目的 构建Trappin-2的真核表达体系,初步探讨Trappin-2对HaCaT细胞及银屑病跨膜模型增殖的影响.方法 采用DNA重组技术构建Trappin-2的表达载体pIRES2-EGFP-Trappin-2,通过脂质体法转染入宫颈癌HeLa细胞.将Trappin-2高表达上清加入HaCaT细胞及银屑病跨膜模型中,通过3H-TdR掺入法、MTT法、流式细胞术及组化染色Ki67检测对增殖的影响.结果 Trappin-2作用后MTY和cpm值变化率显示Trappin-2可抑制HaCaT细胞的代谢与DNA合成,同时可使HaCaT细胞G2 S期细胞比例下降,而G1期细胞比例增加.Trappin-2可下调银屑病皮损Ki67表达水平.结论 成功将Trappin-2基因转染HeLa细胞,并进行有效表达,初步证实Trappin-2具有抑制HaCaT细胞及银屑病跨膜模型增殖的特性. 相似文献
104.
105.
Jingjing Yan Weidong Fei Qianqian Song Yao Zhu Na Bu Li Wang Mengdan Zhao Xiaoling Zheng 《Drug delivery》2022,29(1):2296
The emerging cell membrane (CM)-camouflaged poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) (CM@PLGA NPs) have witnessed tremendous developments since coming to the limelight. Donning a novel membrane coat on traditional PLGA carriers enables combining the strengths of PLGA with cell-like behavior, including inherently interacting with the surrounding environment. Thereby, the in vivo defects of PLGA (such as drug leakage and poor specific distribution) can be overcome, its therapeutic potential can be amplified, and additional novel functions beyond drug delivery can be conferred. To elucidate the development and promote the clinical transformation of CM@PLGA NPs, the commonly used anucleate and eukaryotic CMs have been described first. Then, CM engineering strategies, such as genetic and nongenetic engineering methods and hybrid membrane technology, have been discussed. The reviewed CM engineering technologies are expected to enrich the functions of CM@PLGA for diverse therapeutic purposes. Third, this article highlights the therapeutic and diagnostic applications and action mechanisms of PLGA biomimetic systems for cancer, cardiovascular diseases, virus infection, and eye diseases. Finally, future expectations and challenges are spotlighted in the concept of translational medicine. 相似文献
106.
目的探讨健脾消胀片对大鼠胃酸含量、胃蛋白酶活力及胃肠电活动的影响。方法结扎大鼠幽门与十二指肠结合部造模,测大鼠胃酸含量和胃蛋白酶活力;用EGEG-8D胃肠电图仪记录5 min大鼠胃电图,测量频率和幅值,以观察健脾消胀片对大鼠胃窦电活动、小肠电活动的影响。结果大、中剂量健脾消胀片组可使大鼠胃酸含量显著升高,大剂量健脾消胀片组可使大鼠胃蛋白酶活性显著升高,中剂量健脾消胀片组可使大鼠胃蛋白酶活性明显升高;大、中剂量健脾消胀片组可使大鼠胃窦电活动频率显著升高,小剂量健脾消胀片组可使大鼠胃窦电活动频率明显升高,大、中、小剂量健脾消胀片组可使大鼠胃窦电活动幅值显著升高;大、中、小剂量健脾消胀片组可使大鼠小肠电活动频率和幅值均显著升高。结论健脾消胀片具有消食和胃的临床意义。 相似文献
107.
水蛭注射液的HPLC指纹图谱 总被引:1,自引:0,他引:1
以次黄嘌呤为考察指标,建立了水蛭注射液的HPLC指纹图谱。采用C18柱,流动相为10mmol/L磷酸二氢钾溶液和50%甲醇,梯度洗脱。检测波长为254nm。 相似文献
108.
目的 观察复方丹参滴丸对高脂血症患者红细胞变形性的影响,并探讨其可能的作用机制.方法 选取高脂血症患者100例,完全随机分为单药组和联合组,各50例.单药组予以瑞舒伐他汀钙10 mg/次,每晚1次口服;联合组在单药组基础上给予复方丹参滴丸10粒/次,3次/d口服.8周后检测红细胞变形性、红细胞膜Na+-K+-ATP酶活性及丙二醛含量的变化.结果 ①单药组治疗前TG、TC、LDL-C、HDL-C分别为(2.62±0.53)、(6.5±1.0)、(4.2±0.5)、(1.2±0.3)mmol/L,治疗后分别为(1.45±0.29)、(4.2±1.0)、(2.9±0.4)、(1.7±0.3)mmol/L,治疗前后差异均有统计学意义(P<0.01或P<0.05);联合组治疗前TG、TC、LDL-C、HDL-C分别为(2.51±0.33)、(6.8±1.0)、(4.0±0.5)、(1.1±0.3)mmol/L,治疗后分别为(1.40±0.31)、(4.2±0.9)、(2.8 ±0.5)、(1.7±0.4)mmol/L,治疗前后差异均有统计学意义(P<0.01或P<0.05),治疗后组间差异无统计学意义(P>0.05).②单药组和联合组治疗前红细胞变形指数分别为(56±4)%和(59±6)%,治疗后红细胞变形指数分别为(62±8)%和(69±8)%,组内治疗前后的差异及治疗后组间差异均有统计学意义(均P <0.05).③单药组和联合组治疗前红细胞膜Na+-K+-ATP酶活性分别为(0.57±0.06)和(0.61±0.07) μmol/(mg·min),治疗后分别为(0.81±0.09)和(1.05±0.11) μmol/(mg·min),组内治疗前后的差异及治疗后组间差异均有统计学意义(均P<0.05).④单药组和联合组治疗前血浆丙二醛水平分别为(6.3±0.5)和(6.2±0.7) μmol/L (P <0.05),治疗后分别为(5.6±0.6)和(5.1±0.4)μmol/L,组内治疗前后的差异及治疗后组间差异均有统计学意义(均P<0.05).结论 复方丹参滴丸能有效改善高脂血症患者红细胞变形性,提高红细胞通过微小血管的能力,其机制可能与降低脂质过氧化损伤以及提高红细胞膜Na+-K+-ATP酶活性有关. 相似文献
109.
目的:研究核转录因子NF-κB p65、血管生成素-2、Ki-67和CD31在血管瘤增生及退化组织中的表达情况.方法:采用免疫组织化学方法检测人皮肤血管瘤增生期、退化期及正常皮肤组织中核转录因子p65、血管生成素-2、CD31、Ki-67蛋白的表达水平.结果:增生期血管瘤内皮细胞CD31表达水平高于退化期,差异有显著性(P<0.05);增生期血管瘤内皮细胞核转录因子p65、血管生成素-2表达水平高于退化期及正常皮肤组,差异有显著性(P<0.05);退化期血管瘤内皮细胞核转录因子p65、血管生成素-2表达水平与正常皮肤组织相比,差异无显著性(P>0.05);核转录因子p65与血管生成素-2相关性分析在血管瘤发展过程中呈正相关(P<0.01);核转录因子p65与Ki-67相关性分析在血管瘤发展过程中呈正相关(P<0.01).结论:在血管瘤组织中,核转录因子p65的表达与血管生成素-2和Ki-67的表达呈正相关,提示核转录因子p65可能通过正向调控血管生成素-2的表达而促进血管瘤的形成;核转录因子p65可能成为新的血管瘤病理分型标记物. 相似文献
110.
Mahmoud Omer Hessein Ali Nina Orlovskaya Amelia Ballesteros Vee San Cheong Kari Martyniak Fei Wei Boyce E. Collins Sergey N. Yarmolenko Jackson Asiatico Michael Kinzel Christopher Ngo Jagannathan Sankar Ashley Calder Timothy Gilbertson Teerin Meckmongkol Ranajay Ghosh Melanie Coathup 《Nutrients》2022,14(15)
The influence of diet on the development of osteoporosis is significant and not fully understood. This study investigated the effect of diets of varying lipid profiles and ω-3, ω-6 and ω-9 composition on the structural and mechanical properties of bone. The hypothesis studied was that a diet high in saturated fat would induce osteoporosis and produce an overall increased detrimental bony response when compared with a diet high in unsaturated ω-6, or ω-9. Male C57BL/6J mice were fed either a control diet, 50:50 mix (saturated:unsaturated) high in ω-9 (HFD50:50), a diet high in saturated fat (HSF) or a polyunsaturated fat diet high in ω-6 (PUFA) over an 8-week duration. Tibiae were retrieved and evaluated using DMA, 3-point-bending, histomorphometry, and microCT. Mice fed a HSF diet displayed key features characteristic of osteoporosis. The loss tangent was significantly increased in the HFD50:50 diet group compared with control (p = 0.016) and PUFA-fed animals (p = 0.049). HFD50:50-fed mice presented with an increased viscous component, longer tibiae, increased loss modulus (p = 0.009), and ultimate stress, smaller microcracks (p < 0.001), and increased trabecular width (p = 0.002) compared with control animals. A diet high in ω-9 resulted in an overall superior bone response and further analysis of its role in bone health is warranted. 相似文献