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   16283篇
  免费   1124篇
  国内免费   702篇
耳鼻咽喉   73篇
儿科学   93篇
妇产科学   1540篇
基础医学   2880篇
口腔科学   322篇
临床医学   1352篇
内科学   1646篇
皮肤病学   93篇
神经病学   655篇
特种医学   533篇
外国民族医学   4篇
外科学   1232篇
综合类   3232篇
现状与发展   3篇
预防医学   665篇
眼科学   231篇
药学   2222篇
  25篇
中国医学   824篇
肿瘤学   484篇
  2024年   38篇
  2023年   161篇
  2022年   325篇
  2021年   421篇
  2020年   413篇
  2019年   395篇
  2018年   409篇
  2017年   488篇
  2016年   537篇
  2015年   475篇
  2014年   840篇
  2013年   963篇
  2012年   899篇
  2011年   1026篇
  2010年   809篇
  2009年   873篇
  2008年   816篇
  2007年   821篇
  2006年   762篇
  2005年   684篇
  2004年   628篇
  2003年   618篇
  2002年   568篇
  2001年   410篇
  2000年   397篇
  1999年   331篇
  1998年   369篇
  1997年   338篇
  1996年   275篇
  1995年   257篇
  1994年   177篇
  1993年   161篇
  1992年   157篇
  1991年   138篇
  1990年   116篇
  1989年   113篇
  1988年   95篇
  1987年   99篇
  1986年   67篇
  1985年   85篇
  1984年   69篇
  1983年   76篇
  1982年   61篇
  1981年   76篇
  1980年   49篇
  1979年   45篇
  1978年   54篇
  1977年   37篇
  1976年   31篇
  1974年   19篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
2.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.  相似文献   
3.
目的 探讨腹腔镜下子宫双侧动脉阻断术联合清宫术治疗剖宫产瘢痕妊娠疗效及对内分泌的影响.方法 选择2011年1月至2015年12月剖宫产瘢痕妊娠患者57例,其中A组32例患者给予超声引导下清宫术治疗,B组25例患者给予腹腔镜下子宫双侧动脉阻断术联合清宫术治疗,比较两组患者出血量、住院时间、月经复潮时间、术后人绒毛膜促性腺激素(hCG)降至正常时间,并发症情况及术前(T0)、术后第1d(T1)、第3d(T2)神经内分泌激素水平.结果 ①B组患者出血量低于A组,住院时间、月经复潮时间短于A组,比较差异有统计学意义(t出血量=31.85,k院时间=9.36,t月经复t潮时间=16.37,均P<0.05);②B组患者并发症发生率为8.00%,低于A组的15.63%,比较差异有统计学意义(x2=9.35,P<0.05);③B组T1、T2血清COR、β-EP、GLU水平低于A组(CORF交互=17.67,β-EPF交互=132.36,6LUF交互=155.38,均P<0.05).结论 腹腔镜下子宫双侧动脉阻断术联合清宫术治疗剖宫产瘢痕妊娠微创优势明显,安全性高,对内分泌影响较轻.  相似文献   
4.
目的分析米非司酮和宫瘤消胶囊的联合应用对子宫肌瘤的临床治疗效果。方法本研究对象为80例子宫肌瘤患者,收治时间均在2017年3月—2018年3月期间。将上述子宫肌瘤患者随机分成两组,各40例。给予对照组患者口服米非司酮进行治疗,研究组患者在上述治疗的基础上增加宫瘤消胶囊口服治疗,记录2组患者治疗效果,性激素水平及子宫体积及肿瘤体积变化。结果(1)研究组患者的总体有效率显著高于对照组;(2)研究组患者的P、E2、LH及FSH均显著低于对照组;(3)研究组患者子宫体积及肿瘤体积均显著低于对照组。结论米非司酮片和宫瘤消胶囊的联合治疗对子宫肌瘤患者的治疗效果较显著。  相似文献   
5.
Aging alters bladder functions where a decrease in filling, storage and emptying is observed. These changes cause urinary incontinence, especially in women. The aim of this study is to examine how aging affects the intracellular calcium movements due to agonist-induced contractions in permeabilized female rat bladder. Urinary bladder isolated from young and old female Sprague-Dawley rats were used. Small detrusor strips were permeabilized with β-escin. The contractile responses induced with agonists were compared between young and old groups. Carbachol-induced contractions were decreased in permeabilized detrusor from old rats compared to young group. Heparin and ryanodine decreased carbachol-induced contractions in young rats where only heparin inhibited these contractions in olds. Caffeine-induced contractions but not inositol triphosphate (IP3)-induced contractions were decreased in old group compared to youngs. The cumulative calcium response curves (pCa 8–4) were also decreased in old rats. Carbachol-induced calcium sensitization responses did not alter by age where GTP-β-S and GF-109203X but not Y-27632 inhibited these responses. Carbachol-induced contractions decrease with aging in rat bladder detrusor. It can be postulated as IP3-induced calcium release (IICR) is primarily responsible for the contractions in older rats where the decrease in carbachol contractions in aging may be as a result of a decrease in calcium-induced calcium release (CICR), rather than carbachol-induced calcium sensitization.  相似文献   
6.
7.
目的:观察卡托普利(CaP)对自发性高血压大鼠(SHR)血管平滑肌细胞(VSMC)增殖的作用及对原癌基因及抑癌基因的影响。方法:氚-胸腺嘧啶核苷(3H-TdR)参入,电镜,原位来交及Northernblot杂交。结果:CaP在降低SHR血压同时,能减少VSMC的线粒体,粗面内质网及3H-TdR参入量(P<0.01),并能逆转c-fos,c-myc,c-sis原癌基因mRNA表达增强(P<0.05或0.01),p53抑癌基因mRNA表达减弱(P<0.01)。结论:Cap能抑制SHR的VSMC增殖,与癌基因调控的分子生物学机制有关。  相似文献   
8.
9.
10.
'Gliosarcomas' have long been considered to be mixed gliomas and sarcomas. The present study failed to define criteria which clearly delineate 'gliosarcomas' from glioblastoma multiforme and suggests that 'gliosarcomas' should be considered as spindle cell glioblastomas. A total of six cases originally diagnosed as 'gliosarcomas' were compared with four cases of glioblastoma multiforme. No clinical or prognostic features were defined which would clearly separate 'gliosarcomas' from glioblastoma multiforme. Macroscopically, biopsies from 'gliosarcomas' ranged from firm, apparently well-circumscribed tumours to poorly circumscribed lesions with a soft consistency resembling glioblastoma multiforme. Histology revealed a continuous spectrum in which 'gliosarcomas' with large reticulin-rich areas of spindle cells merged with typical glioblastomas containing only small islands of spindle cells and reticulin staining. Immunocytochemistry for glial fibrillary acidic protein (GFAP); S100 protein and alpha-smooth muscle actin (ASMA) showed that the majority of cells in reticulin-poor areas of 'gliosarcoma' and glioblastomas expressed S100 protein and GFAP; many expressed ASMA and some expressed both GFAP and ASMA. Spindle cells in reticulin-rich areas of 'gliosarcomas' and glioblastomas most frequently expressed ASMA but many cells also expressed S100 protein and GFAP; some cells expressed both GFAP and ASMA. The results of this study and a review of the literature suggests that there is a clinical, radiological and pathological continuum with glioblastoma and 'gliosarcoma' at different ends of the spectrum. It is suggested, therefore, that most, if not all, 'gliosarcomas' be redesignated as spindle cell glioblastomas and not be considered as a mixture of glioma and sarcoma.  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