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   55376篇
  免费   4893篇
  国内免费   2857篇
耳鼻咽喉   496篇
儿科学   1458篇
妇产科学   607篇
基础医学   4291篇
口腔科学   1696篇
临床医学   6393篇
内科学   12808篇
皮肤病学   1305篇
神经病学   2585篇
特种医学   2198篇
外国民族医学   1篇
外科学   4921篇
综合类   8931篇
现状与发展   11篇
一般理论   4篇
预防医学   6274篇
眼科学   966篇
药学   4054篇
  31篇
中国医学   3052篇
肿瘤学   1044篇
  2024年   196篇
  2023年   1237篇
  2022年   2538篇
  2021年   3173篇
  2020年   2981篇
  2019年   2300篇
  2018年   2133篇
  2017年   2099篇
  2016年   2278篇
  2015年   2073篇
  2014年   4059篇
  2013年   4235篇
  2012年   3372篇
  2011年   3659篇
  2010年   2865篇
  2009年   2700篇
  2008年   2751篇
  2007年   2695篇
  2006年   2295篇
  2005年   1985篇
  2004年   1564篇
  2003年   1408篇
  2002年   1159篇
  2001年   1082篇
  2000年   865篇
  1999年   640篇
  1998年   631篇
  1997年   514篇
  1996年   396篇
  1995年   446篇
  1994年   388篇
  1993年   282篇
  1992年   295篇
  1991年   249篇
  1990年   193篇
  1989年   212篇
  1988年   198篇
  1987年   180篇
  1986年   145篇
  1985年   112篇
  1984年   105篇
  1983年   60篇
  1982年   70篇
  1981年   45篇
  1980年   40篇
  1979年   48篇
  1978年   32篇
  1977年   33篇
  1976年   35篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
妇女围孕期增补叶酸能够有效预防神经管缺陷等疾病的发生。随着对叶酸研究的不断深入,叶酸补充中出现了诸多问题。本文简要综述了叶酸在服用方式以及基础和临床研究中出现的值得讨论、已经引起关注和需要进一步研究探讨的问题,并提出了深入研究叶酸可能的发展趋势。  相似文献   
92.
心血管疾病并发焦虑抑郁症状2050例心理干预治疗分析   总被引:13,自引:1,他引:12  
目的:了解心血管疾病并发焦虑抑郁症状的情况并探讨心理干预等对焦虑抑郁症状的影响。方法:对住院的2050例心血管疾病并发焦虑抑郁症状的患者进行回顾性分析。结果:心血管疾病患者中并发有焦虑抑郁症状者占56%;其常表现为类似心绞痛、左心衰竭症状,可并发有心律失常;高血压病并发有焦虑抑郁患者对血压升高的耐受性差,动态血压检查以非勺型改变者居多;单纯使用心血管药物治疗效果欠佳,心理干预,焦虑抑郁症状严重者结合抗焦虑抑郁药物疗效显著。结论:心血管疾病患者常并发焦虑抑郁症状,心理干预治疗等可有效改善患者的症状。  相似文献   
93.
目的:为了解女职工患妇女病现状,充分认识普查普治必要性。方法:对玉溪市部分女职工进行常规妇科检查、白带多项快染、宫颈荧光筛查、乳腺红外线扫描。结果:女职工患病率74.54%,阴道炎患病率18.67%,宫颈糜烂患病率21,04%,子宫肌瘤占受检人数10.79%,慢性输卵管炎占9.60%,卵巢囊肿占4.3%,乳腺小叶增生患病率为26.86%,乳腺纤维瘤占0.43%,IF荧光宫颈癌筛查3-4分占8.33%。结论:女职工患病率高,提高宣传力度,定期开展妇女病普查普治尤为必要。  相似文献   
94.
Summary Aspergillosis belongs to the group of mycotic diseases of paranasal sinuses. The invasive forms, and particularly the fulminant forms, are potentially fatal. Isolated aspergillosis of the sphenoid sinus or the clivus is a difficult diagnosis, since the often misleading clinical manifestations of this rare disease develop late. These patients become apparent by neurological signs such as cavernous sinus syndrome, pseudotumor of the pituitary or the orbit. Diagnosis is often made intra-operatively or on histological examination. We report a case of invasive aspergillosis uniquely involving the sellar area revealed by clinical features suggesting a pseudotumor of the pituitary. Although such lesions are almost always seen in immune suppressed subjects, in our case, the patient was immune competent and had no past history of sinusitis. The question of whether, and when to perform limited or extensive surgery remains an issue for discussion, owing to the rarity of this disease honed by lack of experience. It depends on several factors: the kind of disease, the immunity, the subtype of invasive fungal sinusitis and the degree of tissue invasion.  相似文献   
95.
Seventeen patients who had undergone extensive small bowel resection were studied for calcium absorption (FACa) and plasma vitamin D metabolites. FACa was measured by a double radio-tracer technique and expressed as percentage of total oral dose. FACa was decreased compared with controls (34%, range: 3-46 v 65%, range: 57-73, P less than 0.01). A positive correlation (r = 0.49, P = 0.05) was found between FACa and the remaining length of small bowel (SBL). As wide variations in both SBL and duration after surgery were observed among the seventeen investigated patients, we were led to individualize less heterogeneous subgroups of patients. Better correlations were found when the patients were divided into two subgroups according to whether the time interval between the resection and the investigation was shorter (r = 0.75, n = 11, P less than 0.02) or longer (r = 0.89, n = 6, P = 0.05) than 2 years. In thirteen patients who had a SBL shorter than 100 cm, a positive correlation was observed between FACa and the time interval after surgery (months): r = 0.65, P less than 0.05. Plasma 1,25 (OH)2D was markedly reduced in the whole group (31 pmol l-1, range: 8-108) compared with controls (103 pmol-1, range: 59-134, P less than 0.01). The present study shows that in extensively small bowel resected patients, calcium absorption is reduced, the alteration being dependent both on the length of the remnant small bowel and on the time after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
96.
目的探讨急性高血压性脑出血患者细胞间粘附分子-1(ICAM-1)在血肿周围脑组织和正常脑组织中的表达及其意义。方法选择30例行开颅手术治疗的急性高血压性脑出血患者,采用免疫组化技术检测ICAM-1在血肿周围脑组织及正常脑组织中的表达。结果实验组血肿周围脑组织可见ICAM-1的表达水平上调,其表达水平明显高于正常脑组织的表达水平(P<0.01)。神经元和血管内皮细胞共同表达ICAM-1,且神经元表达较明显。结论ICAM-1在人类高血压性脑出血血肿周围脑组织的表达水平上调,其表达上调可能参与了血肿周围脑组织的白细胞浸润,最终引发炎性反应和继发性脑损伤。  相似文献   
97.
[目的 ]分析急性脑血管病(ACVD)应激状态的临床特点 ,探讨防治策略及护理对策。 [方法 ]回顾分析 3 62例ACVD病人的临床资料。[结果 ]ACVD病人应激反应的发生率为 47.5 1% ,病死率为 11.88%。 [结论 ]早期明确诊断与治疗 ,并采取措施积极调控机体应激状态 ,加强护理 ,有助于控制病情和促进康复 ,降低病死率。  相似文献   
98.
OBJECTIVES: The study aimed to review the etiologies of patients who underwent surgery for small bowel obstruction (SBO) and to evaluate the risk factors affecting the early postoperative outcomes. MATERIALS AND METHODS: A case series of 430 patients (252 men) with a mean age of 64.5 years, who underwent 437 operations for SBO, were retrospectively reviewed. RESULTS: Peritoneal adhesions and hernia were the most common causes of SBO, contributing 42.3 and 26.8% of all cases, respectively. Strangulation occurred in 27.7% and caused nonviable bowel in 13.0% of obstructing episodes. Old age (age >/= 70 years), female patient, nonadhesive obstruction, and hernia were the independent significant factors associated with bowel strangulation. The 30-day mortality was 6.5%, and the median postoperative hospital stay was 8 days. Old age, the presence of premorbid pulmonary disease, and malignant obstruction were the independent factors associated with operative mortality. The overall complication rate was 35.5%, and old age was the only significant factor associated with postoperative complications. CONCLUSIONS: Surgery for SBO is still associated with significant mortality and morbidity. As old age is significantly associated with an increased incidence of strangulation, operative mortality, and complications, this group of patients should be managed with extra cautions to avoid unfavorable outcome of surgery.  相似文献   
99.
Small bowel transplantation (SBT) is associated with poorly understood enteric dysfunction. The study of SBT in mice is hindered by the technical difficulty of orthotopic SBT in the mouse. Our aim was to develop an easy preparation of extrinsic denervation of the entire jejunoileum in mice as a model of orthotopic SBT. All neurolymphatic tissues accompanying the superior mesenteric artery (SMA) and vein (SMV) were ligated just distal to the middle colic vessels. The SMA and SMV were then stripped of investing adventitia, and the mesentery to jejunum and colon were transected radially. Jejunum and colon were not transected and reanastomosed. To confirm extrinsic denervation 1, 3, and 6 months later, segments of small bowel were stained for protein gene product 9.5 (PGP9.5) and tyrosine hydroxylase (TH). Tyrosine hydroxylase immunoreactive intensity was then quantified using a semiquantitative analysis. Immunohistochemical fluorescence showed persistence of PGP9.5 immunoreactivity confirming enteric nerves in jejunoileum; however, there was no TH immunoreactivity in jejunoileum in denervated mice despite the expected preservation of TH immunoreactivity in the still-innervated duodenum at 1 month. At 3 months, sparse immunoreactivity for TH was present, and by 6 months, reinnervation of TH-containing nerves appeared similar to controls. Quantification of intensity at each time-point further confirmed this trend. This technique in the mouse accomplishes a complete extrinsic denervation of jejunoileum early postoperatively (1 and 3 months); reinnervation occurs by 6 months. This is an easily learned murine model of orthotopic SBT. Presented at the American Gastroenterological Association during Digestive Disease Week in Los Angeles, CA, as a poster presentation on May 23 2006. Abstract published in GastroenterologyE 2006; 130:A604.  相似文献   
100.
肠易激综合征(IBS)是一组持续存在或反复发作的临床症候群,主要症状有腹痛、腹胀、排便习惯改变和大便性状异常、黏液便等,经检查排除可引起这些症状的器质性疾病。临床分为肝木乘脾型腹泻、脾胃虚弱型腹泻、脾肾阳虚型腹泻、肝郁脾虚型便秘四型,根据临床辨证分别施以不同治法,不同方药治疗,有显著疗效。同时,教育患者平时养成良好的饮食卫生习惯,不饮生水,不食生冷瓜果,忌食辛辣、油腻、肥厚之品,保持心情舒畅,怡情悦志,注意保暖,可加强疗效,防止复发。  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