全文获取类型
收费全文 | 179315篇 |
免费 | 13287篇 |
国内免费 | 4215篇 |
专业分类
耳鼻咽喉 | 1359篇 |
儿科学 | 2519篇 |
妇产科学 | 3089篇 |
基础医学 | 23702篇 |
口腔科学 | 3356篇 |
临床医学 | 12333篇 |
内科学 | 22596篇 |
皮肤病学 | 2184篇 |
神经病学 | 12229篇 |
特种医学 | 6405篇 |
外国民族医学 | 1篇 |
外科学 | 14427篇 |
综合类 | 24304篇 |
现状与发展 | 21篇 |
一般理论 | 8篇 |
预防医学 | 14819篇 |
眼科学 | 2239篇 |
药学 | 25559篇 |
56篇 | |
中国医学 | 12740篇 |
肿瘤学 | 12871篇 |
出版年
2024年 | 253篇 |
2023年 | 2151篇 |
2022年 | 3223篇 |
2021年 | 7469篇 |
2020年 | 6078篇 |
2019年 | 6054篇 |
2018年 | 6121篇 |
2017年 | 6780篇 |
2016年 | 6824篇 |
2015年 | 6366篇 |
2014年 | 7230篇 |
2013年 | 11134篇 |
2012年 | 9029篇 |
2011年 | 10901篇 |
2010年 | 6808篇 |
2009年 | 6997篇 |
2008年 | 8508篇 |
2007年 | 9424篇 |
2006年 | 8938篇 |
2005年 | 8265篇 |
2004年 | 7107篇 |
2003年 | 6366篇 |
2002年 | 5035篇 |
2001年 | 4503篇 |
2000年 | 3775篇 |
1999年 | 3193篇 |
1998年 | 2488篇 |
1997年 | 2599篇 |
1996年 | 2380篇 |
1995年 | 2061篇 |
1994年 | 2004篇 |
1993年 | 1684篇 |
1992年 | 1546篇 |
1991年 | 1459篇 |
1990年 | 1259篇 |
1989年 | 1026篇 |
1988年 | 987篇 |
1987年 | 897篇 |
1986年 | 829篇 |
1985年 | 1208篇 |
1984年 | 967篇 |
1983年 | 729篇 |
1982年 | 751篇 |
1981年 | 617篇 |
1980年 | 599篇 |
1979年 | 478篇 |
1978年 | 297篇 |
1977年 | 260篇 |
1976年 | 243篇 |
1975年 | 186篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
991.
目的 :进一步探讨 MRI增强前后的准备与护理方法。材料与方法 :共增强 833例 ,男 5 85例 ,女 2 4 8例。使用顺磁性造影剂 Gd- DTPA,按 0 .2 m L/kg体重给药。其中双倍量增强 110例 ,增强前认真履行告知义务和签署同意书。发生造影剂外漏者给予鲜马铃薯片外敷。结果 :增强效果达良好以上共 82 5例 ,占 99% ,未发生严重负反应。 3例造影剂外漏 ,鲜马铃薯片外敷后 3h痊愈。结论 :增强前充分细致的准备是保证增强效果的重要因素。认真履行告知义务和签置同意书 ,不仅尊重了病人的权利 ,也是依法行医 ,保证医疗安全的需要 相似文献
992.
目的:提高对足月新生儿窒息缺氧缺血性脑病(简称HIE)头颅CT的临床应用。方法:时80例有明确围产期窒息史和临床症状的患儿进行头颅CT扫描,其中72例进行复查扫描。作治疗前后CT对照并分析预后。结果:80例均有按CT诊断分度标准的轻(33例、占41.2%)、中(28例、占35.0%)、重度(19例、占23.8%)。CT表现,CT诊断阳性率为100%。结论:头颅CT检查能早期、直观、清楚地对足月新生儿窒息反映出脑缺氧缺血性损害及程度和变化。对指导治疗。评估预后有重要意义。 相似文献
993.
Hiroyuki Kumamoto Takahiro Suzuki Kiyoshi Ooya 《Journal of oral pathology & medicine》2002,31(10):605-611
BACKGROUND: To clarify the possible role of nitric oxide (NO) and stress proteins in oncogenesis and cytodifferentiation of odontogenic epithelium. Inducible NO synthase (iNOS) and heat shock proteins (HSPs) were analyzed in ameloblastomas as well as in tooth germs. METHODS: Specimens of seven tooth germs, 36 benign ameloblastomas and five malignant ameloblastomas were examined by immunohistochemistry using antibodies against iNOS and 27-, 60- and 70-kDa HSPs (HSP27, HSP60 and HSP70). RESULTS: Immunoreactivity for iNOS was detected in normal and neoplastic odontogenic epithelial cells and was higher in malignant ameloblastomas than in tooth germs and benign ameloblastomas. HSP27 was expressed constitutively in all odontogenic epithelial cells in tooth germs and benign and malignant ameloblastomas. Expression of HSP60 and HSP70 was detected in normal and neoplastic odontogenic epithelial cells and was prominent in cells neighboring the basement membrane. HSP60 reactivity showed no apparent difference between normal and neoplastic odontogenic epithelium, whereas HSP70 expression was slightly higher in benign and malignant ameloblastomas than in tooth germs. CONCLUSIONS: Activation of iNOS might be associated with malignant potential of epithelial odontogenic tumors. Elevated expression of HSP70 is considered to be involved in neoplastic transformation of odontogenic epithelial cells. 相似文献
994.
目的 :初步探讨 MRI诊断儿童脑白质病变的作用和特异征象。方法 :对 MRI诊断为脑白质病变的病例 4 8例进行观察 ,分析病灶的 MRI征象 ,包括病灶出现的部位、形态、范围及其他合并表现。结果 :1病灶发生的部位 ,多位于双侧侧脑室三角部周围的白质内 ,依次为侧脑室前角周围、半卵圆中心 ,偶见于基底节区等。2形态 :多为小斑片状 ,亦有点线状、小点状。 3范围 :以侧脑室三角部周围白质内发生多见 ,常同时出现于多个部位。 4时常伴有其他合并征象 ,如 ,胼胝体发育不良、畸形或脑室扩大等。结论 :MRI扩展了对儿童脑白质病变的认识 ,是一种较好的手段 相似文献
995.
本文以体外红系祖细胞培养方法。观察白血病细胞相关抑制物对正常红系祖细胞(CFU-E)的抑制作用。10/10例初发未治急性白血病病人的白血病细胞培养液对CFU-E的生长均有抑制,抑制率25.4~67.4%,平均抑制率为44.35%。结果提示,白血病细胞相关抑制物对正常红细胞系造血也有抑制作用。 相似文献
996.
基质金属蛋白酶及其抑制剂在子宫内膜癌的侵袭和转移中发挥着重要的作用。肿瘤的新生血管对肿瘤的发生、发展、转移及预后有着重要作用。微血管密度是衡量血管生成的定量指标。基质金属蛋白酶抑制剂可抑制血管的生成和MMPs对细胞外基质的降解。现将他们与子宫内膜癌的关系综述如下。 相似文献
997.
目的 总结冠状动脉旁路移植术治疗冠心病的体会。 方法 回顾性分析 3 0 6例冠状动脉旁路移植术。男 2 49例 ,女 5 7例。应用体外循环 2 3 4例 ,非体外循环 72例。搭桥数 1~ 6支 人 ,平均 (3 .45± 1.2 5 )支 人。对手术方法、主要并发症和术后处理进行分析总结。结果 二次开胸 5例 (1.6% ) ,低心排综合征 10例 (3 .3 % ) ,应用IABP4例 (1.3 % ) ,肝功能不全 6例 (2 .0 % )。肾功能不全 7例 (2 .3 % ) ,反复发作房颤 2 3例 (7.5 % ) ,肺功能不全 6例(2 .0 % ) ,脑合并症 3例 (1.0 % ) ,胸腔积液 41例 (13 .4% )。死亡 7例 (2 .3 % ) ,其余病人康复出院。结论 合理的选择病人 ,成熟的手术技术 ,良好的心肌保护及术后处理的加强是提高冠状动脉旁路移植术疗效的重要措施。 相似文献
998.
S. Furusho S. Myou M. Fujimura T. Kita M. Yasui K. Kasahara S. Nakao K. Takehara S. Sato 《Clinical and experimental allergy》2006,36(10):1294-1302
BACKGROUND: Adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) are thought to contribute to the airway inflammation and airway hyper-responsiveness (AHR) of allergic asthma. Some differences from allergic asthma have been noted, including airway neutrophilia, and the involvement of ICAM-1 in toluene diisocyanate (TDI) asthma is currently unclear. OBJECTIVE: We utilized mice lacking ICAM-1 expression (ICAM-1(-/-)) to investigate the role of ICAM-1 in airway inflammation and AHR in TDI-induced asthma. METHODS: Male C57BL/6J mice (ICAM-1(+/+)) and ICAM-1(-/-) mice were intranasally sensitized to TDI solution or solvent alone. Airway inflammation, AHR and cytokine secretion were assessed 24 h after challenge by TDI or solvent. The production of antigen-specific IgG and IgE by TDI sensitized and non-sensitized mice was determined. RESULTS: TDI challenge to ICAM-1(+/+) mice induced an increase in airway inflammatory cell numbers, AHR and cytokine secretion of TNF-alpha, macrophage inflammatory protein-2 (MIP-2), IL-4, IL-5 and IFN-gamma into the bronchoalveolar lavage fluid. All these pathophysiological changes were reduced in ICAM-1(-/-) mice. Serum levels of TDI-specific IgG and IgE of ICAM-1(-/-) and ICAM-1(+/+) mice were comparable. CONCLUSION: These results suggest that ICAM-1 plays an essential role in airway inflammation and AHR in TDI-induced asthma. 相似文献
999.
Preexpanded distant "super-thin" intercostal perforator flaps for facial reconstruction without the need for microsurgery. 总被引:1,自引:0,他引:1
F Lu J H Gao R Ogawa H Hykusoku 《Journal of plastic, reconstructive & aesthetic surgery》2006,59(11):1203-1208
BACKGROUND: Concept of the 'super-thin perforator flap' was introduced in 1994 by authors. Since then, various types of 'super-thin perforator flaps' were applied successfully especially for contour sensitive reconstruction such as face and neck. METHODS: Eleven patients requiring large flaps who presented with extensive disfiguring facial scar (male: seven cases, female: four cases). On the consideration of flaps' colour, texture and thickness requirements, the authors selected 'super-thin' anterior intercostal perforator flaps (AICP, range from 4 x 14 cm to 25 cm x 9 cm) for reconstruction purpose. First, tissue expanders (volume range from 800 cc to 1200 cc) were carefully inserted under the AICP. After the flaps were expanded for 2 months, distant scars were removed and the covering super-thinned flaps were transferred into recipient site. Two weeks later, pedicles in the anterior chest were cut down and flaps were transferred to replace all the left scars. RESULTS: Flap were survived without any complications. The colour, texture and thickness of the transferred flap were satisfactory, shrink of flaps were not observed after long term follow-up. The authors present a method of facial reconstruction that has the advantages of creating a large amount of thin tissue of both good colour and texture, without the need of microsurgery and few disadvantages of donor-site morbidity. The disadvantages are three-staged procedures, complications of tissue expansion and uncomfortable compulsory posture for patients. In our opinion, this is an alternative method of choice for reconstructing all large defects in the lower two-thirds of the face. 相似文献
1000.
目的观察病人自控硬膜外镇痛(PCEA)泵治疗难治性腰椎间盘突出症的临床疗效。方法采用临床随机对照的方法,观察组和对照组分别应用病人自控硬膜外镇痛(PCEA)泵和用传统硬膜外注射术进行治疗,并对治疗结果进行统计分析。结果观察组痊愈31例(治愈率68.89%),好转11例(有效率93.33%),对照组痊愈18例(治愈率43.90%),好转16例(有效率82.93%)。两组治愈率比较P=0.019〈0.05,差异有显著性意义,有效率比较P=0.243〉0.05,差异无显著性意义。结论病人自控硬膜外镇痛(PCEA)泵治疗难治性腰椎间盘突出症治愈率要高于传统硬膜外注射术,在药物效应的基础上起液体剥离和持续给药的效果是其可能的作用机制。 相似文献