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   244944篇
  免费   40368篇
  国内免费   7988篇
耳鼻咽喉   6211篇
儿科学   6481篇
妇产科学   3977篇
基础医学   15999篇
口腔科学   3266篇
临床医学   38529篇
内科学   62111篇
皮肤病学   8824篇
神经病学   20232篇
特种医学   10222篇
外国民族医学   53篇
外科学   50825篇
综合类   11160篇
现状与发展   92篇
一般理论   24篇
预防医学   12916篇
眼科学   6737篇
药学   10887篇
  67篇
中国医学   4419篇
肿瘤学   20268篇
  2024年   929篇
  2023年   5986篇
  2022年   4716篇
  2021年   7732篇
  2020年   9203篇
  2019年   5426篇
  2018年   10825篇
  2017年   10136篇
  2016年   11450篇
  2015年   12824篇
  2014年   20814篇
  2013年   20624篇
  2012年   13038篇
  2011年   13372篇
  2010年   15100篇
  2009年   17786篇
  2008年   10835篇
  2007年   8883篇
  2006年   11400篇
  2005年   8413篇
  2004年   6315篇
  2003年   4913篇
  2002年   4523篇
  2001年   5919篇
  2000年   5077篇
  1999年   5483篇
  1998年   5004篇
  1997年   4762篇
  1996年   4341篇
  1995年   4146篇
  1994年   2740篇
  1993年   2077篇
  1992年   2074篇
  1991年   1990篇
  1990年   1606篇
  1989年   1668篇
  1988年   1452篇
  1987年   1199篇
  1986年   1179篇
  1985年   969篇
  1984年   703篇
  1983年   632篇
  1982年   574篇
  1981年   459篇
  1980年   400篇
  1979年   382篇
  1978年   366篇
  1977年   421篇
  1975年   302篇
  1972年   321篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
991.
Pietro Rubegni  MD    Sara Poggiali  MD    Aldo Cuccia  MD    Maurizio Biagioli  MD    Michele Fimiani  MD 《Dermatologic surgery》2004,30(12P2):1539-1542
Background. Striated palmoplantar keratoderma or Brunauer-Fohs-Siemens syndrome is a very rare, focal, nonepidermolytic palmoplantar keratoderma with autosomal inheritance. Unlike other palmoplantar keratodermas, no association with visceral or skin cancer has ever been reported.
Objective. We report a case of malignant melanoma arising in the hyperkeratotic lesions on the right heel of a patient with striated palmoplantar keratoderma. The lesion was completely excised; our patient also underwent sentinel lymph node biopsy and then was treated with high-dose interferon adjuvant therapy.
Methods. Sentinel lymph node biopsy incision was made in elliptical fashion, long enough to harvest a full-thickness skin graft to cover the wide local excision defect. The skin graft was defatted by sharp dissection. Several perforations were made in graft and it was secured in place with sutures and bolster dressing.
Results. At follow-up, the grafted skin showed hyperkeratotic changes but no local or systemic signs of the disease was observed.
Conclusion. The association between striated palmoplantar keratoderma and acral melanoma is discussed.  相似文献   
992.
The present study was designed to detect three single nucleotide polymorphisms (SNPs) located on 22q11 that was thought as being of particularly importance for genetic research into schizophrenia. We recruited a total of 176 Chinese family trios of Han descent, consisting of mothers, fathers and affected offspring with schizophrenia for the genetic analysis. The transmission disequilibrium test (TDT) showed that of three SNPs, rs10314 in the 3'-untranslated region of the CLDN5 locus was associated with schizophrenia (chi(2) = 4.75, P = 0.029). The other two SNPs, rs1548359 present in the CDC45L locus centromeric of rs10314 and rs739371 in the 5'-flanking region of the CLDN5 locus, did not show such an association. The global chi-square (chi(2)) test showed that the 3-SNP haplotype system was not associated with schizophrenia although the 1-df test for individual haplotypes showed that the rs1548359(C)-rs10314(G)-rs739371(C) haplotype was excessively non-transmitted (chi(2) = 5.32, P = 0.02). Because the claudin proteins are a major component for barrier-forming tight junctions that could play a crucial role in response to changing natural, physiological and pathological conditions, the CLDN5 association with schizophrenia may be an important clue leading to look into a meeting point of genetic and environmental factors.  相似文献   
993.
994.
995.
996.
The principles of infusion manometry in the measurement of lower esophageal sphincter (LES) pressure were laid down in the mid-1960s by L.D. Harris and his coworkers. Dodds and his colleagues were largely responsible for the improvements and advent of the low-compliance manometry. Using side-hole manometry, it is possible to detect accurate LES pressure that correlates with the strength of the antireflux barrier. The LES pressure as measured by the side-hole manometry, shows respiration-induced pressure oscillations. These pressure oscillations were initially thought to be due to the influence of abdominal and thoracic pressures on the LES. However, it was later pointed out that these pressure oscillations were due to the relative motion of the point pressure sensor (side hole of the manometric catheter) and the LES during respiration. Recent studies suggest that active contraction of the crural diaphragm during inspiration is responsible for the pressure oscillations observed in the cat LES pressure tracings. The use of the sleeve device in the measurement of LES pressure during contraction of the diaphragm has been described recently. Using the principles of manometry and sleeve device, it is now possible to identify two lower esophageal sphincters: the smooth muscle LES, traditionally known as the LES, and crural diaphragm, which we have referred to as the external lower esophageal sphincter. The purpose of the following paper is to summarize the general principles of the infusion manometry in the measurement of intraluminal pressure, specifically the LES pressure. The recently developed technique of detection of the sphincteric function of the crural diaphragm by the sleeve device will be discussed. In the last paragraph the limitations of manometry in detection of the muscular contractile activity are described.  相似文献   
997.
双侧内囊前肢毁损术治疗难治性强迫症疗效及随访研究   总被引:9,自引:0,他引:9  
目的 对难治性强迫症进行双侧内囊前肢毁损术治疗 ,评定手术疗效并进行 2年随访 ,以进一步探索脑外科手术对难治性强迫症的疗效 ,并探讨手术治疗的良好适应症。方法 对 2 8例难治性强迫症患者进行双侧内囊前肢毁损术治疗 ,并分别在手术前、手术后二周、手术后三月、手术后六月、手术后一年、手术后二年进行Y BOCS、HAMA、HAMD量表评定及术后疗效评定。结果  (1)强迫症患者手术后各期Y BOCS评分、HAMA评分与手术前比较均下降 ,有极显著差异 (P <0 .0 0 1) ;(2 )手术后各期Y BOCS的强迫思维评分均有明显下降 (P <0 .0 0 1) ,强迫行为在手术后 1年和 2年 ,与手术前比较无明显改变 (P >0 .0 5 ) ;(3)手术后 2年的总有效率为 5 3.5 % ,明显低于手术后 3月的总有效率 (P <0 .0 1)。结论 采用双侧内囊毁损术有相当的治疗效果 ,对于难治性强迫症患者可作为一种补充治疗手段 ;手术治疗对强迫行为的长期疗效较差 ,以严重的强迫思维为主的难治性强迫症患者为手术更好的适应症。  相似文献   
998.
BACKGROUND: Superficial lymphatic malformations are predominantly developmental malformations of infancy, but they may arise at any age. OBJECTIVE: To describe a patient with a late-onset superficial lymphatic malformation. METHODS: Case report and literature review. RESULTS: A 53-year-old woman was evaluated for a colored lesion that developed spontaneously on the anterior abdominal wall. The lesion was treated by surgical excision. Findings on histopathologic examination of the specimen were consistent with superficial lymphatic malformation. There was no recurrence of the lesion at 4 months after the operation. CONCLUSION: Superficial lymphatic malformations can develop in adults spontaneously without the presence of any predisposing condition. Because the majority of such late-onset malformations reported in the literature are localized lesions similar to the one in our patient, surgical removal with inclusion of subcutaneous tissue usually results in cure without recurrence.  相似文献   
999.
BACKGROUND: Illicit soft-tissue augmentation performed in New York City resulted in an outbreak of Mycobacterium abscessus infection in 2002. OBJECTIVE: To report two cases of women who developed tender, subcutaneous nodules of the face and buttocks after illicit soft-tissue augmentation with a hyaluronic acid derivative. METHODS: Two case reports are presented, and the literature is reviewed. RESULTS: Empiric treatment with clarithromycin (for M. abscessus infection) and prednisone (for foreign body reaction) resulted in clearance of lesions. CONCLUSION: Contaminated or impure material used for soft-tissue augmentation can result in a clustered outbreak of infection or foreign body reaction.  相似文献   
1000.
Intravenous Pyogenic Granuloma of the Hand   总被引:1,自引:0,他引:1  
BACKGROUND: Intravenous pyogenic granuloma is the intravasal counterpart of cutaneous pyogenic granuloma. This rare, benign lesion appears clinically as a subcutaneous nodule usually located in the upper extremity or neck in middle-aged people. It is hard to make an exact diagnosis on clinical basis, and there is a risk of recurrence because of undertreatment. OBJECTIVE: To report a case of an intravenous pyogenic granuloma located in the hand and to describe the clinical and histopathologic features of this rare vascular tumor. METHODS: An operation was performed on a 58-year-old female who presented with a small, painless mass in the right palm, and the pathologic examination revealed an intravenous pyogenic granuloma. CONCLUSION: This rare lesion should be differentiated from a regular pyogenic granuloma and should be excised with the vein segment to avoid recurrence.  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