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   2761篇
  免费   332篇
  国内免费   33篇
耳鼻咽喉   11篇
儿科学   58篇
妇产科学   113篇
基础医学   496篇
口腔科学   168篇
临床医学   414篇
内科学   496篇
皮肤病学   14篇
神经病学   10篇
特种医学   29篇
外国民族医学   1篇
外科学   53篇
综合类   466篇
现状与发展   1篇
预防医学   239篇
眼科学   12篇
药学   168篇
  2篇
中国医学   84篇
肿瘤学   291篇
  2024年   1篇
  2023年   20篇
  2022年   42篇
  2021年   95篇
  2020年   105篇
  2019年   75篇
  2018年   59篇
  2017年   78篇
  2016年   101篇
  2015年   110篇
  2014年   221篇
  2013年   230篇
  2012年   188篇
  2011年   228篇
  2010年   174篇
  2009年   167篇
  2008年   137篇
  2007年   162篇
  2006年   157篇
  2005年   118篇
  2004年   100篇
  2003年   82篇
  2002年   72篇
  2001年   66篇
  2000年   40篇
  1999年   46篇
  1998年   50篇
  1997年   25篇
  1996年   34篇
  1995年   29篇
  1994年   13篇
  1993年   16篇
  1992年   10篇
  1991年   21篇
  1990年   6篇
  1989年   5篇
  1988年   7篇
  1987年   3篇
  1986年   6篇
  1985年   9篇
  1984年   2篇
  1983年   2篇
  1982年   4篇
  1981年   3篇
  1980年   2篇
  1979年   1篇
  1978年   2篇
  1975年   2篇
排序方式: 共有3126条查询结果,搜索用时 46 毫秒
1.
A 5-year-old boy presented with history of failure to thrive from infancy. There was a history of one sibling death due to similar problems and history of severe abortions in the mother. Routine examination of peripheral smear revealed more than 50% acanthocytes. Based on this tests were streamlined to doing lipid profile and Lipo protein electrophoresis which revealed hypolipidemia and absent Β hypo protein band. Jejuna) mucosal biopsy confirmed the diagnosis of A Beta Lipo proteinemia which revealed lipid laden enterocytes. This case illustrates the importance of simple tests like peripheral smear examination in streamlining further tests in the diagnosis of major diseases.  相似文献   
2.
A cytomorphometric analysis of superficial vaginal cells inwomen in three groups of different types of hormonal concentrationwas made. There were 15 women in each group. Group I was studiedduring a natural cycle, group II under oral contraceptive therapyand group III during an in-vitro fertilization (IVF) stimulationprotocol. Morphometric parameters were measured on an imageanalyser. The area, perimeter and several form factors weremeasured separately for nuclei and cytoplasm. The nucleus:cytoplasmicratio was also determined. The cytoplasmic area was significantlyreduced in group II and was associated with a statisticallysignificant reduction of the nuclear area. The nucleus:cytoplasmicratio appeared significantly increased in group II and reducedin group III. Low oestradiol impregnation obtained with an oralminidosed contraceptive interfered with vaginal cell maturation.High oestradiol concentrations obtained during IVF protocolsinduced marked nuclear pycnosis but did not induce supra-physiologicalcell enlargement. Maximal cell size is genetically regulatedaccording to Driesch's law of volume invariance and hormonalover-stimulation has no effect on cell size. The nucleus:cytoplasmicratio appears to be a powerful parameter reflecting the oppositeeffects of hormones on cell compartments.  相似文献   
3.
TBS诊断系统在宫颈病变中的应用研究   总被引:1,自引:0,他引:1  
目的:对642例查体病人的宫颈涂片进行分析,研究宫颈良性病变和癌前病变及癌变在正常人群中的的发病率。方法:应用TBS系统对兰州市某大型商场30~51岁妇女642例行子宫颈涂片,显微镜下阅片,作出诊断,并对SIL以上的病例行阴道镜下活检术,进行病理检查。结果:正常582例,异常60剜,全部病例中仅1例漏诊。结论:TBS诊断系统与病理和临床诊断趋于一致,具有很高的准确性和适用性。  相似文献   
4.
In some patients with mental retardation, a Q-tip pap smear obtained blindly from the upper vagina may be the only cytologic smear obtainable without subjecting the patient to heavy sedation or to examination under anesthesia. The efficacy of blind Q-tip smears has not been previously determined. Of 31 Q-tip smears obtained from patients with CIN, the Q-tip smear identified the abnormality in 10 (32%) patients. For those patients who will not submit to examination without anesthesia or sedation, routine screening with multiple smears, obtained on an annual basis has the potential to identify many cases of CIN which otherwise would not be identified at all, and in certain patients, this method outweighs the risks of heavy sedation or general anesthesia. Because of the greatly reduced sensitivity of the Q-tip pap, every effort should be made to help the patient and/or her family or guardian to understand the implications and risks of this method. However, if an examination under anesthesia is performed for other indications, a complete gynecologic examination and a direct smear should be obtained at that time.  相似文献   
5.
BACKGROUND: Low-dose allergen challenge (LDAC) may be a useful tool for studying the capacity of allergens to induce airway inflammation in atopic subjects. OBJECTIVE: To evaluate lower airway inflammatory changes following repeated inhalation of very low doses of allergen (VLDAC) in non-asthmatic subjects with allergic rhinitis (NAAR) compared with mild allergic asthmatic subjects (AA). METHODS: Fourteen NAAR and 11 AA were seen out of the pollen season and had skin prick tests with common aeroallergens. Baseline spirometry (S) and methacholine challenge (MC) were done and blood and induced sputum (IS) differential cell counts were obtained. Each subject underwent VLDAC on four consecutive mornings with a relevant allergen. S, MC, and blood and IS samplings were repeated 6 h after the second and fourth VLDAC and one week later. RESULTS: Although there were, as expected, no changes in FEV1 or PC20 in either group, mean percentage eosinophils on IS were significantly increased in NAAR on day 2 of VLDAC and decreased in all but one subject on day 4, with a tendency to return to baseline levels one week later. In AA, there was a non-significant trend for sputum eosinophils to increase on day 2; four subjects showed a decrease of eosinophils on day 4 of VLDAC. There was a correlation between eosinophil cationic protein (ECP) levels and eosinophil counts in NAAR throughout the study. There were no variations in other sputum cells or blood inflammatory cells. CONCLUSION: VLDAC can increase the percentage of eosinophils in IS of NAAR subjects without associated respiratory symptoms nor physiological modifications. A reduction in eosinophilic response despite repeated exposure, more common in NAAR subjects, suggests an adaptation process that needs to be further evaluated.  相似文献   
6.
本文对12例支气管哮喘病人作了22例次支气管肺泡灌洗,其中3例次为重度哮喘发作;8例次为中度发作[1];11例次为缓解期.灌洗方法在一般肺灌洗的基础上经过改良后,12例病人无1例死亡.11例次哮喘发作患者,灌洗后临床症状皆有不同程度改善.11例次缓解期病人,灌洗后皆无不良反应.凡哮喘时间较长者,均能灌洗出较大量脓痰栓.  相似文献   
7.
机械通气病人吸痰吸引负压研究现状   总被引:1,自引:0,他引:1  
蒋丰亦 《护理研究》2006,20(5):387-388
介绍了国内外机械通气病人吸痰时吸引负压的选择。提示护士在机械通气病人护理过程中应根据病人的具体情况合理选择。  相似文献   
8.
李清华  王小军 《现代护理》2006,12(25):2399-2400
目的 采用音乐疗法减轻患儿吸痰时的烦躁、哭闹,减轻氧的消耗,缓解缺氧情况。方法 采用实验性研究设计,选择北京儿童医院ICU病房住院的52名需吸痰患儿为研究对象,选择背景音乐为节奏舒缓的钢琴曲。记录有与无背景音乐时吸痰前后患儿的经皮氧饱和度和心率的变化。结果 对同一患儿进行了干预前后的分析比较,有与无背景音乐下吸痰患儿经皮氧饱和度、心率有显著性差异。结论 音乐疗法对于缓解ICU吸痰患儿缺氧是一种有效干预手段。  相似文献   
9.
介绍魏品康教授治疗脊髓炎后遗症一则,以化痰通络法贯穿始终。  相似文献   
10.
目的:测定肺结核、肺肿瘤及非特异性炎症患者注射结核菌素前后痰巨噬细胞的不同数量变化,由此提供一种新的鉴别诊断方法。方法:皮内注射结核菌素、收集注射前、后痰液,测定痰巨噬细胞在不同时间的数量变化。结果:肺结核病人在结核菌素试验后痰巨噬细胞明显增加,肺部肿瘤及非特异性炎症则无显著性变化。结论:肺部患者测定结核菌素前后痰巨噬细胞变化,可作为菌阴肺结核与肺部肿瘤及非特异性炎症鉴别诊断依据之一。  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