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   8297篇
  免费   542篇
  国内免费   453篇
耳鼻咽喉   79篇
儿科学   52篇
妇产科学   204篇
基础医学   457篇
口腔科学   110篇
临床医学   626篇
内科学   2032篇
皮肤病学   166篇
神经病学   697篇
特种医学   203篇
外科学   2143篇
综合类   966篇
现状与发展   1篇
预防医学   213篇
眼科学   158篇
药学   430篇
  2篇
中国医学   89篇
肿瘤学   664篇
  2024年   19篇
  2023年   157篇
  2022年   303篇
  2021年   328篇
  2020年   293篇
  2019年   316篇
  2018年   297篇
  2017年   237篇
  2016年   351篇
  2015年   320篇
  2014年   630篇
  2013年   558篇
  2012年   500篇
  2011年   536篇
  2010年   503篇
  2009年   459篇
  2008年   407篇
  2007年   426篇
  2006年   390篇
  2005年   284篇
  2004年   244篇
  2003年   239篇
  2002年   160篇
  2001年   124篇
  2000年   106篇
  1999年   81篇
  1998年   87篇
  1997年   79篇
  1996年   82篇
  1995年   62篇
  1994年   60篇
  1993年   46篇
  1992年   59篇
  1991年   62篇
  1990年   46篇
  1989年   27篇
  1988年   43篇
  1987年   35篇
  1986年   44篇
  1985年   65篇
  1984年   54篇
  1983年   46篇
  1982年   38篇
  1981年   33篇
  1980年   33篇
  1979年   7篇
  1978年   6篇
  1977年   5篇
  1975年   2篇
  1973年   2篇
排序方式: 共有9292条查询结果,搜索用时 15 毫秒
71.
We report a case of a long-term survivor with malignant melanoma of the anus who did not undergo radical surgery. A 71-year-old woman who presented with anal bleeding and anal tumor underwent an excisional biopsy in September 1985. The biopsy specimen was a lobulated, polypoid, pigmented mass 2 cm in diameter, that had been located on the anterior wall of the anus. A satellite nodule 7 mm in diameter was found on the left wall of the anus at the level of the dentate line. Both tumors were histologically diagnosed as malignant melanoma. The primary tumor was 6 mm thick. Melanoma cells were present microscopically at the cut end of the rectum. Because of her history of ischemic heart disease, the patient rejected our recommendation that she undergo radical surgery, and received 10 courses of carboplatin 20 mg intramuscularly and OK-432 10 K.E. (Klinische Einheit) intradermally every week. A single, pigmented metastatic inguinal lymph node developed and was excised in June 1987. A recurrent tumor was detected in the rectum in October 1992, so again we recommended radical surgery. The patient rejected radical surgery again, and received 12 courses of carboplatin 10 mg intramuscularly every 2 weeks. She died of disease at home in July 1993 after surviving for 7 years and 10 months. An autopsy was not performed. This case shows that local excision of the primary lesion may be appropriate to preserve the quality of life of patients with early-stage malignant melanoma of the anus.  相似文献   
72.
Objective: To study the pattern of lymphnode metastasis in carcinoma of esophagus. Methods: 200 cases of resected esophageal cancer specimens were carefully examined pathologically. Lymphnode metastasis, its pathway and extent in relation to pathological changes were analyzed. Results: Lymphnode metastasis was mainly regional and extended vertically in both directions. Leaping-over metastasis was another feature. The deeper invasion by the tumor, the higher frequencies of metastasis development, and vice versa. However, leaping-over metastasis was more likely to occur where tumor invasion was less severe. Conclusion: Owing to the high frequency of lymphnode metastasis in the superior mediastinum and the widely spanned leaping-over metastasis, an operative approach by three incisions through right thoracotomy with excision of the whole segment of esophagus and anastomosis at cervical region was recommended, in order to dissect lymphnodes in the cervical, thoracic and abdominal regions and to leave less or no metastatic lymphnodes behind.  相似文献   
73.
Blood isotone contrast media is considered to be less toxic to vascular and pancreatic duct endothelium than high-osmolar contrast media. In this study we assessed the impact of a low-osmolar contrast agent compared with a blood isotone product on pancreatic damage induced by endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic retrograde sphincterotomy (EST). In a prospective trial 42 consecutive ERCP/EST patients were randomized to receive either iopromid, a low-osmolar non-ionic contrast agent (770 mosmol/kg H2O), or iotrolan, a blood-isotone non-ionic product (320 mosmol/kg H2O). The endoscopies were performed by two experienced endoscopists. Forty patients were included in the study. Blood samples were collected before and 40 min, 2, 4, 6 and 24 h after the endoscopic procedure. Samples were analysed for pancreatic serum enzymes, acute-phase proteins and blood counts. A clinical pain score was investigated. Post-ERCP pancreatitis was diagnosed in 2 patients in the iopromid group and in 5 patients in the iotrolan group. There was no significant difference between groups in the time course of pancreatic serum enzymes, acute-phase proteins or in the pain score. Due to the small number of patients in this study, only stronger differences caused by the two contrast media could have led to statistically significant results. We did not observe statistically significant differences in comparing iotrolan and iopromid concerning ERCP/EST-induced pancreatic damage. Received: 26 February 1999; Revised: 14 May 1999; Accepted: 9 June 1999  相似文献   
74.
目的:探讨胬肉切除联合球结膜瓣转位术技巧及其疗效分析。方法:胬肉切除联合球结膜瓣转位术操作要点:术眼在表麻和浸润麻醉下,彻底切除胬肉及受累及的球筋膜组织。于上方球结膜下注入20g/L利多卡因使球结膜与结膜下组织分离,并作一条与角膜缘平行的带蒂球结膜瓣,将其转位覆盖在巩膜裸露区,并予缝合固定。术后用氯霉素地塞米松眼液滴眼,6~7d拆线。采用此术式治疗翼状胬肉患者379例(386眼),其中原发性翼状胬肉患者373例(380眼),复发性翼状胬肉患者6例(6眼)。结果:手术治愈373例(380眼),治愈率为98.4%;复发6例(6眼),复发率为1.6%。术后复发者经再次作手术,全部治愈。结论:胬肉切除联合球结膜瓣转位术治疗翼状胬肉效果显著,此术式值得推广应用。  相似文献   
75.
We report a favorable outcome following a staged radical excision of an intramedullary low-grade astrocytoma involving the entire spinal cord in a pediatric patient. Although the preoperative neurological status was poor, the eventual outcome was good. This highlights the importance of a good tumor-cord interface that permitted a radical excision of an extensive tumor. Since partial excision followed by radiotherapy usually results in disease progression in patients with low-grade astrocytomas, radical excision and follow-up is probably the treatment of choice.  相似文献   
76.
目的 对比分析宫颈上皮内瘤变(CIN)阴道镜下活检与电环切除术后病理,提高CIN诊断的准确性。方法 回顾性对比分析216例宫颈上皮内瘤变阴道镜下活检与电环切除术后病理,探讨影响两者符合率的相关因素。结果 两者对比,宫颈电环切除术(LEEP)后病理结果与阴道镜下活检相符的74例,升级的18例,降级的124例。阴道镜下检查不满意者活检与电环切除术后病理对比,升级率大于阴道镜下检查满意者,差异有显著性(P〈0.01)。结论 宫颈转化区向宫颈管上移者,要注意宫颈管内的病变。宫颈电环切除术可以部分弥补阴道镜下活检的缺陷,且有治疗作用。  相似文献   
77.
乳腺癌手术保留肋间臂神经的临床价值   总被引:1,自引:0,他引:1  
目的探讨乳腺癌手术腋窝淋巴结清扫时保留肋间臂神经的临床价值。方法84例Ⅰ、Ⅱ、Ⅲa期乳腺癌患者,随机分为两组,试验组(36例)拟行乳腺癌腋窝淋巴结清扫术时保留肋间臂神经,对照组(48例)拟行常规手术切除肋间臂神经。术后对两组患者进行观察并随访。结果试验组术后发生上肢感觉障碍7例(19.4%),而对照组有35例(72.9%),二者比较差异有统计学意义(χ2=23.53,P<0.005);经3~48个月随访均未发现局部复发。结论Ⅰ、Ⅱ、Ⅲa期乳腺癌行腋窝淋巴结清扫术时保留肋间臂神经可以明显减少术后患侧上肢感觉障碍的发生,提高生存质量。  相似文献   
78.
宫颈环形电刀切除术治疗212例宫颈上皮内瘤变价值探讨   总被引:22,自引:0,他引:22  
目的:探讨宫颈环形电刀切除术(LEEP)治疗宫颈上皮内瘤变(CIN)的价值。方法:回顾分析2000年3月至2004年10月212例CIN患者在阴道镜辅助下行宫颈环形电切术的治疗情况。结果:阴道镜下宫颈异常结构处取活检病理结果为CIN者212例行宫颈环形电切术(LEEP),LEEP术后病理检查:宫颈粘膜慢性炎症13例(6.1%)、CINⅠ90例(42.5%)、CINⅡ77例(36.3%)、CINⅢ24例(11.3%),原位癌累及腺体伴早期浸润癌8例(3.8%)。术后195例(92.0%)宫颈标本边缘病理学检查未见CIN病变;术后降级者70例(33.0%),等级者122例(57.5%),升级者20例(9.4%);治愈率达89.2%。结论:LEEP治疗CIN安全有效、简单易行、并发症少、避免了二次手术和过度治疗,能保留患者的生育能力,在治疗的同时能进行诊断。但术后仍需定期和规范的随访以防止宫颈癌的发生和发展。  相似文献   
79.
目的:探讨全直肠系膜切除术治疗中下段直肠癌的临床疗效。方法:回顾性分析采用保留植物神经的全直肠系膜切除术治疗86例中下段直肠癌的临床资料。结果:全组无手术死亡,平均手术时间为126±42min,术中失血平均235.30±189.50ml,发生吻合口瘘2例(2.33%)。术后拔尿管时间3~14d,平均6.23d。术后4周随访,保肛组67例中51例(76.1%)控便能力良好,术后勃起功能障碍发生率24.1%(14/58),射精功能障碍发生率为27.6%(16/58)。随访时间6个月~9年,平均46个月。发生局部复发2例(2.33%)。术后3、5年生存率分别为81.4%和63.2%。结论:全直肠系膜切除术是预防中低位直肠癌的局部复发,提高生活质量的有效措施。直肠癌根治性手术中采用TME手术方法是完全必要的。  相似文献   
80.
AIMS: The objectives of this study were to compare the efficacy of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the response of primary breast carcinoma to neoadjuvant chemotherapy compared to conventional imaging modalities, and to see how surgical outcome was influenced as a result of these findings. METHODS: Thirty-four patients with locally advanced primary breast cancer underwent conventional imaging and DCE-MRI following six cycles of neoadjuvant chemotherapy prior to surgery. Changes in surgical management based on the post-chemotherapy DCE-MRI findings were recorded. RESULTS: Prior to neoadjuvant chemotherapy, 22 of the 34 patients were assessed as requiring mastectomy and the remaining 12 were considered inoperable. Following chemotherapy two patients were still considered inoperable. In 11 of the 34 patients, the final decision to proceed to either mastectomy or non-surgical management was based primarily on pre-treatment disease status or patient choice. DCE-MRI findings, therefore, contributed to the operative decision in 21 of 34 patients. Two of these 21 patients were spared surgery as DCE-MRI demonstrated complete response to chemotherapy and one declined surgery. The remaining 18 were able to undergo wide local excision, with only two patients subsequently requiring mastectomy for involved margins. CONCLUSIONS: DCE-MRI is able to accurately predict those patients suitable for breast conserving surgery following neoadjuvant chemotherapy and should be the imaging modality of choice in assessing the response of patients with primary breast carcinoma to neoadjuvant chemotherapy.  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