首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14261篇
  免费   1428篇
  国内免费   1111篇
耳鼻咽喉   70篇
儿科学   180篇
妇产科学   133篇
基础医学   1581篇
口腔科学   326篇
临床医学   1893篇
内科学   2261篇
皮肤病学   156篇
神经病学   812篇
特种医学   499篇
外国民族医学   5篇
外科学   1617篇
综合类   2420篇
现状与发展   4篇
一般理论   1篇
预防医学   974篇
眼科学   426篇
药学   1408篇
  1篇
中国医学   673篇
肿瘤学   1360篇
  2024年   40篇
  2023年   241篇
  2022年   567篇
  2021年   727篇
  2020年   573篇
  2019年   503篇
  2018年   534篇
  2017年   426篇
  2016年   441篇
  2015年   658篇
  2014年   780篇
  2013年   669篇
  2012年   972篇
  2011年   1126篇
  2010年   731篇
  2009年   547篇
  2008年   745篇
  2007年   715篇
  2006年   645篇
  2005年   666篇
  2004年   537篇
  2003年   509篇
  2002年   458篇
  2001年   391篇
  2000年   378篇
  1999年   384篇
  1998年   278篇
  1997年   237篇
  1996年   162篇
  1995年   166篇
  1994年   102篇
  1993年   93篇
  1992年   126篇
  1991年   96篇
  1990年   108篇
  1989年   74篇
  1988年   76篇
  1987年   69篇
  1986年   63篇
  1985年   46篇
  1984年   40篇
  1983年   8篇
  1982年   13篇
  1981年   13篇
  1980年   9篇
  1979年   9篇
  1975年   6篇
  1974年   6篇
  1973年   5篇
  1966年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
沾染液体火箭推进剂时的个人洗消技术进展   总被引:3,自引:0,他引:3  
目的 回顾与分析国内外有关沾染液体火箭推进剂时个人洗消技术和方法的研究资料,提出有效的个人洗消技术和方法,以尽可能地避免染毒或减轻染毒伤员的伤害程度。资料来源与选择 结合我们已进行的有关研究和参加抢救的临床救治体会,并引用国内外公开发表的相关论文及著作。资料引用 论文28篇及3部专著。资料综合主要针对个人洗消技术的有效性与安全性对文献作者采用的方法和指标进行分析和综合。结论 迅速及时地进行有效的洗消,以尽早彻底清除沾染的毒物,是防治液体火箭推进剂中毒的首要措施,可以明显避免或减轻染毒伤员的伤害程度。  相似文献   
12.
胸腰椎爆裂骨折椎管内骨片侵入倾向与对策   总被引:5,自引:0,他引:5  
根据98例中获得随访的39例的X线、CT和MRI(24例)影像学资料,分析胸腰椎爆裂骨折椎管内骨片侵入倾向及对策。将爆裂骨折侵入椎管分为四类八型,宜采用Harrington器械钢丝或椎弓根螺钉钢板轴向撑开系统,使骨折复位,椎管容积恢复,毋需行后路椎管减压。本组取得良好效果。仅对骨片游离型需要切开椎管直接摘除骨片。  相似文献   
13.
Penetration of Schistosoma japonicum cercaria into host skin.   总被引:1,自引:0,他引:1  
The anterior part of Schistosoma japonicum cercaria is a specialized head organ which can slightly stretch out and retract. There are three different types of large unicellular glands in cercarial body, consisting of one head gland, 2 pairs of pre- and 3 pairs of postacetabular glands. These glands differ in position, gross feature, histochemistry and functions. Both polysaccharase and protease activities are demonstrated in the secretions from these glands. Mode of cercarial penetration is described in detail and the penetration is effected by a combination of lytic secretions and mechanical movements. The schematic representation of the process of cercarial penetration is presented. The dynamic distributions of schistosomula in skin at different time intervals after skin penetration in various mammalian hosts are shown. Some newly transformed schistosomula die while penetrating into the skin of 7 mammalian species and the mortality rate varies with the host species, and that can also be affected by the age of cercariae following emergence from the snail. Some physiological aspects between cercariae and newly transformed schistosomula are compared. In contrast to cercariae, schistosomula are saline-adapted and water-intolerant. They were modified histochemically and antigenically.
  相似文献   
14.
椎板后移回植的椎管扩大术治疗椎管狭窄症   总被引:43,自引:0,他引:43  
作者报告棘突劈开、椎板后移回植的椎管扩大术治疗椎管狭窄症182例,使椎管容积扩大34.8%,横径扩大3.8mm,矢径扩大6.1mm。随访2年9个月,优良率86.6%,椎板愈合率96.9%。本文探讨少数椎板迟延愈合的原因和预防措施,如斜切椎板、缝合固定和腰背筋膜与棘上韧带悬吊缝合等。术后卧床10~12周,用石膏型保护。作者认为本法能有效的预防术后脊柱不稳,顽固性腰痛等并发症。  相似文献   
15.
甲氟哌酸药代动力学研究   总被引:3,自引:0,他引:3  
毛伟光  娄建石 《天津医药》1992,20(6):353-355
本文报道国产甲氟哌酸片剂的人体药代动力学研究结果。血、尿药物浓度用微生物打孔法测定。健康志愿者口服甲氟哌酸400mg片剂后,体内药物转运过程符合一室开放模型。甲氟哌酸的血药浓度达峰时间、峰浓度为1.27小时和4.76μg/ml。T_(1/2)Ka和T_(1/2)Ke分别为0.22和10.40小时。研究结果表明,甲氟哌酸吸收快,达峰迅速,血清峰浓度有所提高,消除半衰期长,体内分布广泛,值得在临床推广使用。  相似文献   
16.
Nuclear factor-kappaB (NF-kappaB) plays a key role in inflammation, which is involved in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH). In the present study, we assessed the potential role of NF-kappaB in regulation of cerebral vasospasm. Nuclear factor-kappaB DNA-binding activity was measured in cultured vascular smooth muscle cells (VSMCs) treated with hemolysate and pyrrolidine dithiocarbamate (PDTC, 80 micromol/L), an inhibitor of NF-kappaB. Forty-two rabbits were divided into three groups: control, SAH, and PDTC groups (n=14 for each group). The caliber of the basilar artery was evaluated. Nuclear factor-kappaB DNA-binding activity and the gene expression levels of cytokines and adhesion molecules in the basilar artery were measured. Immunohistochemical study was performed to assess the expression and localization of tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, and myeloperoxidase (MPO). It was observed that NF-kappaB DNA-binding activity was significantly increased by treatment with hemolysate in cultured VSCMs, but this increase was suppressed by pretreatment with PDTC. Severe vasospasm was observed in the SAH group, which was attenuated in the PDTC group. Subarachnoid hemorrhage could induce increases of NF-kappaB DNA-binding activity and the gene expression levels of TNF-alpha, interleukin (IL)-1 beta, ICAM-1, and vascular cell adhesion molecule (VCAM)-1, which were reduced in the PDTC group. Immunohistochemical study demonstrated that the expression levels of TNF-alpha, ICAM-1, and MPO were all increased in the SAH group, but these increases were attenuated in the PDTC group. Our results suggest that NF-kappaB is activated in the arterial wall after SAH, which potentially leads to vasospasm development through induction of inflammatory response.  相似文献   
17.
18.
病案质量整体管理的做法   总被引:3,自引:0,他引:3  
病案质量是衡量临床工作质量的重要标志。目前,因重效益轻质量、重科研轻临床现象突出,致病案质量有所下降。因此,应加强病案质量整体管理,建立医院、科室、个人三级病案质量控制体系;以病案内涵质量为核心内容,制定完善科学的病案质量评价标准;加强岗前培训,抓人员素质的提高;强化病案过程质量管理和终末质量管理,重视病案质量信息反馈作用。  相似文献   
19.
BACKGROUND AND PURPOSE: Birth certificates are a major source of population-based data often used in maternal and child health research, but their value depends upon the level of accuracy of the data. The purpose of this study was to assess the validity of the birth registry data in Taiwan. METHODS: Obstetric records of a total of 2779 infants born at a municipal hospital in Taipei between 1995 and 1997 were abstracted and linked to the Taiwan Birth Registry (TBR). Concordance was presented by agreement percentages for various birth characteristics including gender, birth order, birth weight, and gestational age. Concordance was further assessed using Cohen's k and sensitivity/specificity for both birth weight and gestational age, with both variables categorized according to their customary definitions. RESULTS: Missing data for specific items in the TBR ranged from 0% (gender) to 1.6% (birth order). The birth registry accurately reported all 4 selected items, with the highest and lowest concordance percentage noted for gender (99.0%) and gestational age (88.3%), respectively. The level of agreement indicated by the Cohen's k statistic ranged from 0.92 to 0.96 for birth weight and gestational age when both variables were treated as categorical variables. CONCLUSIONS: The TBR showed a low rate of missing information and high levels of validity for the elements frequently used in maternal and child health research in Taiwan.  相似文献   
20.
探讨周期性双轴力学应变对成骨细胞增殖与分化合成功能的影响。将正常 3月龄雌性 SD大鼠和骨质疏松大鼠颅顶骨分离的成骨细胞分别在含 10 %胎牛血清的 F- 12培养液中培养 ,并接种在双轴力学应变装置中。当细胞生长至亚融合状态 (Subconfluence) ,给细胞施加力学刺激 ,频率为 1Hz,力学刺激分别为 4 0 0、10 0 0、4 0 0 0μ strain;作用时间分别为每天 30 m in,2、4、8h,共加载两天。以未受力学刺激的细胞为对照组 ,受力学刺激的细胞为实验组 ,并进行比较。采用流式细胞技术测定细胞增殖变化 ;采用同位素标记方法检测成骨细胞骨钙素、I型胶原 C端前肽 (PICP)和总蛋白的分泌量。结果表明 :1)在静态培养条件下 ,3ovx组与 3control组比较 ,其细胞功能活性无明显变化 ,但 3ovx组大鼠成骨细胞增殖活性明显增高 ,这与绝经后骨质疏松骨代谢的高转换率相一致。 2 )4 0 0、10 0 0 μstrain力学刺激可以促进 3control组成骨细胞 I型胶原、骨钙素和总蛋白的分泌量增加 ,促进成骨细胞的分化成熟 ;在 10 0 0μstrain力学刺激下 ,成骨细胞合成骨基质的能力增加最为明显。同时 ,在 4 0 0、10 0 0μstrain力学刺激的初期也可以促进成骨细胞的增殖 ,而促进成骨细胞的分化成熟的作用大于促进细胞增殖的作用。 3)在4 0 0 0 μ  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号