首页 | 官方网站   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   59837篇
  免费   5570篇
  国内免费   4255篇
医药卫生   69662篇
  2024年   238篇
  2023年   936篇
  2022年   2368篇
  2021年   3178篇
  2020年   2353篇
  2019年   1932篇
  2018年   2075篇
  2017年   1835篇
  2016年   1696篇
  2015年   2839篇
  2014年   3406篇
  2013年   2966篇
  2012年   4282篇
  2011年   4750篇
  2010年   3292篇
  2009年   2667篇
  2008年   3184篇
  2007年   3183篇
  2006年   3167篇
  2005年   3053篇
  2004年   2253篇
  2003年   2096篇
  2002年   1707篇
  2001年   1453篇
  2000年   1346篇
  1999年   1366篇
  1998年   918篇
  1997年   865篇
  1996年   636篇
  1995年   667篇
  1994年   557篇
  1993年   327篇
  1992年   369篇
  1991年   334篇
  1990年   289篇
  1989年   248篇
  1988年   203篇
  1987年   198篇
  1986年   133篇
  1985年   114篇
  1984年   65篇
  1983年   37篇
  1982年   22篇
  1981年   27篇
  1980年   8篇
  1979年   22篇
  1977年   1篇
  1976年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
OBJECTIVE: To evaluate the possibility and reliability of the hyoid-sternohyoid graft transfer in the correction of server subglottic laryngotracheal stenosis, and delineate the operation skills and clinical results. METHODS: Seven patients with severe subglottic stenosis underwent laryngotracheal reconstruction using the hyoid grafts with sternohyoid muscle flaps (HG-SHMF). Five of these patients had traumatic subglottic stenosis, one with scar tissue of unknown etiology arising in the subglottic region, another with tracheal narrowing caused by inhalation of hydrochloric acid. RESULTS: All seven patients were successfully decannulated with moderate good voice. The average time from reconstruction to decannulation was 15.4 months. The stent was endoscopically removed with a range of 3 to 22 months; the mean time required for stenting was 9.6 months. Two patients who received additional salvage reconstruction procedures because of graft or stent displacement were extubated with improved voices and satisfactory airway. CONCLUSIONS: The HG-SHMF transfer was a single-stage reconstruction, relatively simple procedure that can restore an adequate airway and a good voice. Patients undergoing laryngotracheal reconstruction with HG-SHMF must have regular, long-term follow-up since graft displacement and recurrent granulation tissue or scar reformation can cause restenosis after an initially successful surgery. This procedure should be used in a large number of patients to further test its reliability.  相似文献   
152.
内镜活检对胃癌组织学分类术前诊断的价值   总被引:6,自引:0,他引:6  
目的 探讨内镜活检对胃癌组织学分类术前诊断的价值。方法 术前对141例胃癌患的内镜活检标本分别根据Lauren分类和世界卫生组织(WHO)分类判断组织学分类,并与手术标本结果对照。结果 内镜活检对胃癌Lauren分类术前诊断的准确率为76.6%。对肠型胃癌诊断的敏感性和特异性分别为85.4%和80.6%。而对弥漫型胃癌则分别为82.7%和80.3%,在59例术前诊断为肠型胃癌的病例中,18例(30.5%)在手术标本中呈弥漫性行生长,而在75例术前诊断为弥漫型胃癌的病例中,仅6例(8.0%)术后诊断为肠型胃癌,内镜活检对胃癌WHO分类术前诊断的准确率为87.2%,其中对乳头状/管状腺癌,黏液腺癌和印戒细胞癌的敏感性分别为91.9%。33.3%和66.7%。结论 内镜活检对胃癌组织学分类的术前诊断具有较高的临床应用价值。  相似文献   
153.
对某院收治的50名地震伤员进行医院感染目标性监测,有效地预防与控制医院感染的发生。通过分类安置伤员,专人目标监测,严格执行消毒隔离制度及手卫生、标准预防措施等,将医院感染发生率降至最低:仅1例重症挤压伤者发生医院感染,医院感染率为2.00%。  相似文献   
154.
公立医院管理与企业管理的比较分析   总被引:1,自引:0,他引:1  
管理就是制定决策,并不等于企业管理。公立医院除了经营目标不同于企业(前者追求社会效益最大化,后者追求利润最大化)以外,其它方面与企业类似。公立医院要保持公益心,讲求社会效益是其管理的最高目标。  相似文献   
155.
Progressive multifocal leukoencephalopathy (PML) is a fetal demyelinating disease in the central nervous system. PML was once a rare disease, but it is now relatively common among AIDS (acquired immunodeficiency syndrome) patients. The immunological state of patients mainly contributes to the pathogenesis of PML. Genetic changes of the etiological agent, however, may also be involved in the development and progression of the disease. The major genetic changes possibly associated with PML include the regulatory region rearrangement and the VP1 loop mutation. Both changes have been identified as genetic changes usually occurring in JCV (JCvirus) DNAs from the brain and cerebrospinal fluid of PML patients. Although it remained to be clarified how these changes are involved in the pathogenesis of PML, accumulating evidence suggests that the VP1 loop mutation is associated with the progression of PML. Here we overview studies (mainly those performed by ourselves) on these genetic changes.  相似文献   
156.
Transient Macular Edema after Laser In-Situ Keratomileusis   总被引:8,自引:0,他引:8  
Purpose: To investigate the macular changes induced by laser in situ keratomileusisc(LASIK) procedure.Methods: Optical Coherence Tomography (OCT) was used to examine 27 eyes of 15LASIK patients before surgery, and 1 day, 1 week, 1 month after surgery.Results: The mean thick iness of neuroepithelial layer of macula was (195 ±24)microns, (178± 16) microns 1 day and 1 month after surgery, respectively, while thebaseline was (174 ± 12) microns. The increase in macular neuroepithelial thickness wascorrelated with the degree of myopia, but not with the duration of suction or thepostoperative BCVA.Conclusion: Mild macular edema is common in the first month following LASIK,especially in high myopia. However, no association with loss of BCVA has beenestablished. Eye Science 2003; 19: 20 - 24.  相似文献   
157.
K Xiong  P Zheng 《针刺研究》1990,15(1):1-5, 12
This review summarized some articles on the effect of the septal area in acupuncture analgesia. The data showed that the pain threshold of animal was increased when septal area was stimulated by electro-acupuncture, and that electrical stimulation of septal area had a marked inhibitory effect on the pain discharges of cells in parafascicular nucleus of thalamus, lateral habenular nucleus, periaqueductal gray and dorsal raphe nucleus. The septal area play an important role in acupuncture analgesia. The majority of the cholinergic neurons in septal area are located in nucleus of the vertical limb of the diagonal band (VDB); gamma-aminobutyric acid of septal area is mainly found in the diagonal band nucleus(td); Dopamine is present in high levels in td and lateral septal nucleus(S1) of septal area; The S1 contain high densities enkephalin-containing neuronal cell bodies and terminals; In addition, substance P and norepinephrine are also high levels in the septal area. These substance above-mentioned have a relations with acupuncture analgesia of septal area. A large number of serotonin-containing neurons are found in the raphe nuclei. The serotonin play an important role in acupuncture analgesia. The serotonin-containing neurons in dorsal raphe nucleus project to S1. The fiber connections of the raphe nuclei with the td are reciprocation. The periaqueductal gray is a important structure on pain modulation. It projects to septal area and receives the fibers from S1. A number of adrenergic neurons are located within the locus coeruleus. The locus coeruleus participate pain modulation and acupuncture analgesia. The neuro-anatomy study demonstrated that locus coeruleus projects to septal area.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
158.
采用辣根过氧化物酶(HRP)逆行示踪与谷氨酸免疫细胞化学结合法对大鼠额叶和枕叶皮质内胼胝体神经元的化学性质进行了研究.结果发现含谷氨酸的胼胝体神经元为大中型锥体细胞,主要分布于皮质Ⅱ/Ⅲ、Ⅴ和Ⅵ层,并有成群分布的倾向.含谷氨酸的胼胝体神经元的数目约占 HRP 标记的胼胝体神经元的17%(额叶)和29%(枕叶).这一结果从形态学上证实,大鼠大脑皮质内相当一部分胼胝体神经元使用谷氨酸作为兴奋性递质。  相似文献   
159.
对20例女性、非妊娠期、生育年龄的寻常型、进行期银屑病患者检测了雌二醇(E_2)、孕酮(P)和睾酮(T)的血清浓度。结果为:卵泡期E_2平均值为84±61.6pg/ml,黄体期E_2平均值为164.9±115pg/ml,均显著高于正常平均值(P值分别为<0.001,<0.005);黄体期P平均值为2.67±4.62ng/ml,显著低于正常平均值(P<0.005);T平均值在正常范围,提示银屑病可能与血清E_2和P浓度有关。  相似文献   
160.
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-23

京公网安备 11010802026262号