全文获取类型
收费全文 | 162614篇 |
免费 | 52319篇 |
国内免费 | 6811篇 |
专业分类
耳鼻咽喉 | 2200篇 |
儿科学 | 5136篇 |
妇产科学 | 1578篇 |
基础医学 | 26241篇 |
口腔科学 | 6700篇 |
临床医学 | 24537篇 |
内科学 | 35710篇 |
皮肤病学 | 8226篇 |
神经病学 | 17795篇 |
特种医学 | 5496篇 |
外国民族医学 | 63篇 |
外科学 | 22117篇 |
综合类 | 16237篇 |
现状与发展 | 30篇 |
一般理论 | 24篇 |
预防医学 | 9541篇 |
眼科学 | 3890篇 |
药学 | 15097篇 |
72篇 | |
中国医学 | 6181篇 |
肿瘤学 | 14873篇 |
出版年
2024年 | 274篇 |
2023年 | 1556篇 |
2022年 | 3533篇 |
2021年 | 6126篇 |
2020年 | 8601篇 |
2019年 | 13795篇 |
2018年 | 13170篇 |
2017年 | 14245篇 |
2016年 | 14668篇 |
2015年 | 16084篇 |
2014年 | 16800篇 |
2013年 | 16527篇 |
2012年 | 10579篇 |
2011年 | 11345篇 |
2010年 | 13315篇 |
2009年 | 8646篇 |
2008年 | 6379篇 |
2007年 | 5528篇 |
2006年 | 5451篇 |
2005年 | 5321篇 |
2004年 | 3570篇 |
2003年 | 3377篇 |
2002年 | 3109篇 |
2001年 | 2801篇 |
2000年 | 2922篇 |
1999年 | 2807篇 |
1998年 | 1728篇 |
1997年 | 1633篇 |
1996年 | 1267篇 |
1995年 | 1097篇 |
1994年 | 926篇 |
1993年 | 630篇 |
1992年 | 742篇 |
1991年 | 626篇 |
1990年 | 565篇 |
1989年 | 487篇 |
1988年 | 398篇 |
1987年 | 344篇 |
1986年 | 255篇 |
1985年 | 195篇 |
1984年 | 93篇 |
1983年 | 76篇 |
1982年 | 42篇 |
1981年 | 46篇 |
1980年 | 29篇 |
1979年 | 30篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 3篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 209 毫秒
11.
12.
13.
Julie Despres Yasmina Ramdani Marine di Giovanni Magalie Bnard Abderrakib Zahid Mait Montero‐Hadjadje Florent Yvergnaux Thibaut Saguet Azeddine Driouich Marie‐Laure Follet‐Gueye 《Experimental dermatology》2019,28(8):922-932
It is well recognized that the world population is ageing rapidly. Therefore, it is important to understand ageing processes at the cellular and molecular levels to predict the onset of age‐related diseases and prevent them. Recent research has focused on the identification of ageing biomarkers, including those associated with the properties of the Golgi apparatus. In this context, Golgi‐mediated glycosylation of proteins has been well characterized. Additionally, other studies show that the secretion of many compounds, including pro‐inflammatory cytokines and extracellular matrix–degrading enzymes, is modified during ageing, resulting in physical and functional skin degradation. Since the Golgi apparatus is a central organelle of the secretory pathway, we investigated its structural organization in senescent primary human dermal fibroblasts using confocal and electron microscopy. In addition, we monitored the expression of Golgi‐related genes in the same cells. Our data showed a marked alteration in the Golgi morphology during replicative senescence. In contrast to its small and compact structure in non‐senescent cells, the Golgi apparatus exhibited a large and expanded morphology in senescent fibroblasts. Our data also demonstrated that the expression of many genes related to Golgi structural integrity and function was significantly modified in senescent cells, suggesting a relationship between Golgi apparatus function and ageing. 相似文献
14.
Jakub Pazdrowski Aleksandra Daczak‐Pazdrowska Adriana Polaska Joanna Ka
mierska Wojciech Barczak Mateusz Szewczyk Pawe Golusiski Zygmunt Adamski Ryszard aba Wojciech Golusiski 《Skin research and technology》2019,25(6):857-861
Radiodermatitis is one of the commonest side effects of radiotherapy. They are usually assessed by semi‐quantitative clinical scores, which are not validated and may be subject to inter‐observer variability. A few previous studies suggested that high‐frequency ultrasonography (HF‐USG) is useful in the assessment of the acute phase of radiation dermatitis in breast cancer patients. (a) To monitor skin changes by HF‐USG during the course of radiotherapy due to head and neck cancers, and (b) to determine whether there is any connection between skin sonograms and the skin scoring criteria. This prospective, observational study includes patients diagnosed with head and neck cancers, treated with radiotherapy or concomitant chemoradiation. The final analysis includes six patients. In every patient, the HF‐USG as well as dermatological assessment (target lesion score—TLS and CACE v. 4.0) were performed 4×: before, in the middle, day after, and 3 months after radiotherapy. There were significant differences between non‐irradiated skin thickness and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P < .0001), as well as between irradiated, unchanged skin thickness (TLS grade 0) and thickness of skin with clinically obvious radiodermatitis (TLS grade 1‐4; P = .0002). There was no significant difference between non‐irradiated and irradiated, unchanged skin thickness (TLS grade 0; P = .9318). In four patients, we demonstrated subepidermal low echogenic band (SLEB). HF‐USG can be useful tool to noninvasive and objective assessment of skin changes during radiotherapy. 相似文献
15.
Jean‐Franois Etter 《Addiction (Abingdon, England)》2019,114(12):2252-2256
16.
17.
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
18.
19.
Ángel Becerra Héctor Trujillo Lucía Valencia Aurelio Rodríguez‐Pérez 《Brazilian Journal of Anesthesiology》2019,69(2):200-203
Background and objectives
A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.Case report
A 41 year‐old woman suffered a car accident. At the emergency department, no abnormalities were found in ECG or chest X‐ray. Abdominal ultrasound revealed the presence of abdominal free liquid and the patient was submitted to urgent exploratory laparotomy. Nevertheless, she persisted suffering arterial hypotension and metabolic acidosis. Looking for the reason of her hemodynamic instability, intraoperative transthoracic echocardiography was performed, finding out the presence of pericardial effusion. Once the cardiac surgeon extracted pericardial clots, patient's situation improved clinically and analytically.Conclusion
Every anesthesiologist should be able to use the intraoperative echocardiography as an effective tool in order to establish the appropriate measures to promote the survival of patients suffering severe trauma. 相似文献20.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3