全文获取类型
收费全文 | 32817篇 |
免费 | 2932篇 |
国内免费 | 1119篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 169篇 |
妇产科学 | 143篇 |
基础医学 | 3388篇 |
口腔科学 | 983篇 |
临床医学 | 1511篇 |
内科学 | 1783篇 |
皮肤病学 | 432篇 |
神经病学 | 1549篇 |
特种医学 | 271篇 |
外国民族医学 | 3篇 |
外科学 | 1306篇 |
综合类 | 7844篇 |
现状与发展 | 6篇 |
预防医学 | 533篇 |
眼科学 | 204篇 |
药学 | 1748篇 |
25篇 | |
中国医学 | 13847篇 |
肿瘤学 | 1043篇 |
出版年
2024年 | 129篇 |
2023年 | 318篇 |
2022年 | 811篇 |
2021年 | 1130篇 |
2020年 | 1329篇 |
2019年 | 736篇 |
2018年 | 570篇 |
2017年 | 1167篇 |
2016年 | 1285篇 |
2015年 | 1106篇 |
2014年 | 2932篇 |
2013年 | 2315篇 |
2012年 | 2729篇 |
2011年 | 2873篇 |
2010年 | 2380篇 |
2009年 | 1666篇 |
2008年 | 1579篇 |
2007年 | 1666篇 |
2006年 | 1467篇 |
2005年 | 1253篇 |
2004年 | 1022篇 |
2003年 | 970篇 |
2002年 | 758篇 |
2001年 | 634篇 |
2000年 | 563篇 |
1999年 | 343篇 |
1998年 | 358篇 |
1997年 | 334篇 |
1996年 | 288篇 |
1995年 | 271篇 |
1994年 | 307篇 |
1993年 | 267篇 |
1992年 | 224篇 |
1991年 | 170篇 |
1990年 | 119篇 |
1989年 | 125篇 |
1988年 | 94篇 |
1987年 | 63篇 |
1986年 | 78篇 |
1985年 | 109篇 |
1984年 | 71篇 |
1983年 | 57篇 |
1982年 | 44篇 |
1981年 | 37篇 |
1980年 | 25篇 |
1979年 | 28篇 |
1978年 | 20篇 |
1977年 | 19篇 |
1976年 | 12篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
目的 通过分析特发性肺纤维化急性加重期(AE-IPF)患者证候与血清生物标志物的关系,为中医辨证治疗提供参考。方法 采用观察性研究设计,收集2019年3月至2019年11月三个中心的AE-IPF患者76例,其中痰热壅肺证26例、痰浊阻肺证50例,并纳入健康志愿者10例作为对照。采用ELISA测定患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平,分析与中医证候的相关性。结果 AE-IPF患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平均显著高于健康对照组。血清CCL18、HMGB1、KL-6、MMP-7和SP-D水平在痰热壅肺证和痰浊阻肺证患者间无显著性差异(P>0.05),而血清SP-A水平存在显著性差异(P<0.05)。结论 血清SP-A与AE-IPF证候存在一定的相关性,血清SP-A的浓度升高,与痰热壅肺证关系越密切,反之,血清SP-A浓度降低,则与痰浊阻肺证关系越密切。AE-IPF痰热壅肺证患者的预后可能较痰浊阻肺证患者更差。 相似文献
2.
文题释义:
细胞膜片技术:是在体外接种培养高密度的细胞,使其相互融合生长至100%而形成的透明致密膜状物。该技术不需要胰酶消化即可收集细胞,因此保留了大量的胞外基质、细胞间连接以及细胞-基质连接等结构。目前细胞膜片技术已成为组织工程领域的研究热点,已被推广应用于牙周膜、角膜、心脏、软骨、食管等多种组织器官修复。
成骨细胞:主要由内外骨膜和间充质始祖细胞分化而来,在复杂的骨形成过程中发挥着主要的功能,承担着骨基质的合成、分泌和矿化。骨髓间充质干细胞具有多向分化潜能,能定向分化为成骨细胞,其成骨分化过程可受多种因素的影响,如细胞因子的调控、遗传因素和激素水平等。背景:现阶段骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖、成骨分化的影响和作用机制还尚未可知,如何将生长因子与组织工程细胞膜片技术相整合,最终将其用于骨缺损修复具有重要意义。
目的:探讨单独及联合应用骨形态发生蛋白2和碱性成纤维生长因子2对骨髓间充质干细胞膜片增殖和成骨分化的影响。
方法:体外分离培养鉴定SD大鼠骨髓间充质干细胞并构建细胞膜片,选用不同质量浓度的骨形态发生蛋白2和碱性成纤维生长因子2单独及联合诱导骨髓间充质干细胞膜片,CCK-8法结合碱性磷酸酶活性检测确定2种因子促进膜片增殖和成骨分化的最佳有效质量浓度;然后对骨髓间充质干细胞膜片进行成骨诱导,通过大体及显微镜观察、Vonkossa染色、茜素红染色、RT-PCR检测相关成骨标志物来评估诱导效果。
结果与结论:单独应用骨形态发生蛋白2可增强骨髓间充质干细胞膜片的碱性磷酸酶活性,最佳质量浓度为100 μg/L(P < 0.001),单独应用碱性成纤维生长因子2能加速骨髓间充质干细胞膜片的增殖,最佳质量浓度为20 μg/L(P < 0.001),而联合应用既可以促进膜片增殖又能提高其碱性磷酸酶活性(P < 0.001);经成骨诱导后,4组膜片在形态学上无明显差异,均能诱导骨髓间充质干细胞膜片的成骨分化,其中联合组钙结节最明显(P < 0.001),可显著促进膜片晚期成骨分化并抑制其早期成骨分化,具有明显的协同促进作用(P < 0.001)。结果表明,骨形态发生蛋白2和碱性成纤维生长因子2联合应用时具有协同作用,既可以促进骨髓间充质干细胞膜片增殖,又能显著增强其成骨诱导能力。ORCID: 0000-0003-1918-579X(何惠宇)
中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程 相似文献
3.
4.
目的研究和开发支持中医和现代生物医学本体和术语集的语义标注系统。方法以MedPortal本体库和中医临床术语集等为术语资源库,设计语义标注系统工作流程和功能框架,并开发Web应用系统。结果构建了一个基于Web的中医药文献语义标注系统,支持语料库管理与维护、术语词典管理、语义标注和语义检索等功能,既可以为基于机器学习的信息抽取算法研究提供训练集,又能实现语义层面的多来源数据集成与知识融合。结论该中医药文献语义标注系统设计方案已经过实际项目验证,可为其他同类系统研发提供参考。 相似文献
5.
6.
Rosario Gulias-Cañizo Anell Lagunes-Guillén Arturo González-Robles Erika Sánchez-Guzmán Federico Castro-Muñozledo 《Burns : journal of the International Society for Burn Injuries》2019,45(2):398-412
Background
Since recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns.Materials and methods
Initially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21 days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization.Results
EGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10 μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10 μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21 days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation.Conclusion
This work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy. 相似文献7.
ObjectiveThis study used a prospective cohort study to observe the effect of triple-negative breast cancer on the 2-year disease-free survival rate with or without “TCM formula”.MethodsFrom November 1 st, 2016, the first patient was enrolled in the cohort study. A total of 356 patients were enrolled on January 30, 2019. Among them, 154 cases were followed up for 2 years. During the follow-up, there were 6 cases of shedding, so 6 cases were affected. A total of 148 cases were included in the analysis, including 73 in the exposed group and 75 in the non-exposed group. The exposed group was given “TCM formula” on the basis of standardized treatment, and the non-exposed group was treated with simple triple-negative breast cancer. The two groups visited each of the three months. The interview included safety examination (hematology and imaging). The endpoint was the difference in 2-year invasive disease-free survival between the exposed and non-exposed groups and the safety of the “TCM formula”.ResultsThere were 6 cases of shedding during the experiment and the shedding rate was 3.9 %. The 2-year rate of invasive disease-free survival in the exposed team was 88.7 % and the non-exposed group was 82.5 %. Logistic multivariate regression analysis predicted that “TCM formula” could reduce the disease-related recurrence and metastasis rate by 11 % (OR = 0.89, 95 % CI 0.37−0.956, P<0.05). Through K–M survival analysis, TNBC patients with age ≤35 years and regional lymph node stage N1 may be the benefit group of “TCM formula”(P<0.05). During the study, the incidence of total adverse events was 8.2 % in the exposed group, mainly manifested as stomach discomfort, diarrhea, and hepatocyte damage.Conclusion1. In the exposed group, the two-year rate of invasive disease-free survival increased by 6.2 % compared with the non-exposed group(P>0.05). 2. According to K–M survival analysis, TNBC patients with age ≤35 years and regional lymph node metastasis to N1 may be potential beneficiaries of “TCM formula”. 3. “TCM Formula” is safe and tolerable to most patients. 相似文献
8.
中风病是临床的常见病、多发病。本病病因较多,病情变化迅速,证型繁杂,不同的文献中证候分类差异较大。证候分类的繁杂给临床工作者治疗中风病带来极大不便。本文对以证候要素(内风、内火、痰湿、瘀血、气虚、阴虚)为切入点论治中风病的理论进行探讨,并举例论证其临床疗效。 相似文献
9.
《Biomaterials》2015
The chemical composition, structure and surface characteristics of biomaterials/scaffold can affect the adsorption of proteins, and this in turn influences the subsequent cellular response and tissue regeneration. With magnesium/calcium phosphate cements (MCPC) as model, the effects of magnesium (Mg) on the initial adhesion and osteogenic differentiation of bone marrow stromal cells (BMSCs) as well as the underlying mechanism were investigated. A series of MCPCs with different magnesium phosphate cement (MPC) content (0∼20%) in calcium phosphate cement (CPC) were synthesized. MCPCs with moderate proportion of MPC (5% and 10%, referred to as 5MCPC and 10MCPC) were found to effectively modulate the orientation of the adsorbed fibronectin (Fn) to exhibit enhanced receptor binding affinity, and to up-regulate integrin α5β1 expression of BMSCs, especially for 5MCPC. As a result, the attachment, morphology, focal adhesion formation, actin filaments assembly and osteogenic differentiation of BMSCs on 5MCPC were strongly enhanced. Further in vivo experiments confirmed that 5MCPC induced promoted osteogenesis in comparison to ot her CPC/MCPCs. Our results also suggested that the Mg on the underlying substrates but not the dissolved Mg ions was the main contributor to the above positive effects. Based on these results, it can be inferred that the specific interaction of Fn and integrin α5β1 had predominant effect on the MCPC-induced enhanced cellular response of BMSCs. These results provide a new strategy to regulate BMSCs adhesion and osteogenic differentiation by adjusting the Mg/Ca content and distribution in CPC, guiding the development of osteoinductive scaffolds for bone tissue regeneration. 相似文献
10.
目的 探讨糖尿病前期的中医证型及证素分布特点。方法 检索中国知网、万方及维普三大数据库中收录的自建库以来有关糖尿病前期证型的临床研究文献,对中医证型进行规范整理,建立数据库,提取证素,运用数据挖掘技术中的关联分析、聚类分析探究证素分布规律。结果 共纳入10篇文献,总有效病例1620例,证型经规范处理后整理为18个,主要证型为脾虚痰湿证。共提取证素13个,主要病位证素为脾,主要病性证素为气虚、湿和痰,关联分析显示脾—湿支持度和置信度最高,聚类分析结果可得到3个聚类组。结论 糖尿病前期病位在脾,气虚、脾、痰、湿是常见证素,临床诊治糖尿病前期应注重从脾论治,需辨证施治。 相似文献