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   8149篇
  免费   701篇
  国内免费   133篇
耳鼻咽喉   87篇
儿科学   144篇
妇产科学   38篇
基础医学   1452篇
口腔科学   154篇
临床医学   1063篇
内科学   841篇
皮肤病学   56篇
神经病学   1126篇
特种医学   489篇
外国民族医学   2篇
外科学   554篇
综合类   682篇
现状与发展   1篇
预防医学   612篇
眼科学   48篇
药学   794篇
  3篇
中国医学   139篇
肿瘤学   698篇
  2023年   98篇
  2022年   186篇
  2021年   273篇
  2020年   276篇
  2019年   283篇
  2018年   299篇
  2017年   306篇
  2016年   316篇
  2015年   317篇
  2014年   553篇
  2013年   556篇
  2012年   448篇
  2011年   512篇
  2010年   439篇
  2009年   395篇
  2008年   389篇
  2007年   445篇
  2006年   368篇
  2005年   263篇
  2004年   212篇
  2003年   216篇
  2002年   169篇
  2001年   146篇
  2000年   126篇
  1999年   100篇
  1998年   85篇
  1997年   72篇
  1996年   67篇
  1995年   50篇
  1994年   49篇
  1993年   47篇
  1992年   51篇
  1991年   54篇
  1990年   37篇
  1989年   25篇
  1988年   51篇
  1987年   38篇
  1986年   51篇
  1985年   66篇
  1984年   52篇
  1983年   42篇
  1982年   63篇
  1981年   42篇
  1980年   44篇
  1979年   45篇
  1978年   31篇
  1977年   42篇
  1976年   33篇
  1974年   30篇
  1973年   25篇
排序方式: 共有8983条查询结果,搜索用时 15 毫秒
101.
将2000~2019年20起我国境内医院空调系统火灾数据进行统计并分析火灾的时间、起火医院的类型和等级、起火部位和点位的特点及产生的原因,希望给同行一些警示。  相似文献   
102.
Obesity is a complex and multifactorial chronic disease with genetic, environmental, physiological and behavioural determinants that requires long-term care. Obesity is associated with a broad range of complications including type 2 diabetes, cardiovascular disease, dyslipidaemia, metabolic associated fatty liver disease, reproductive hormonal abnormalities, sleep apnoea, depression, osteoarthritis and certain cancers. An algorithm has been developed (with PubMed and Medline searched for all relevant articles from 1 Jan 2000–1 Oct 2021) to (i) assist primary care physicians in treatment decisions for non-pregnant adults with obesity, and (ii) provide a practical clinical tool to guide the implementation of existing guidelines (summarised in Appendix 1) for the treatment of obesity in the Australian primary care setting.Main recommendations and changes in managementTreatment pathways should be determined by a person’s anthropometry (body mass index (BMI) and waist circumference (WC)) and the presence and severity of obesity-related complications. A target of 10–15% weight loss is recommended for people with BMI 30–40 kg/m2 or abdominal obesity (WC > 88 cm in females, WC > 102 cm in males) without complications. The treatment focus should be supervised lifestyle interventions that may include a reduced or low energy diet, very low energy diet (VLED) or pharmacotherapy. For people with BMI 30–40 kg/m2 or abdominal obesity and complications, or those with BMI > 40 kg/m2 a weight loss target of 10–15% body weight is recommended, and management should include intensive interventions such as VLED, pharmacotherapy or bariatric surgery, which may be required in combination. A weight loss target of > 15% is recommended for those with BMI > 40 kg/m2 and complications and they should be referred to specialist care. Their treatment should include a VLED with or without pharmacotherapy and bariatric surgery.  相似文献   
103.
目的 计算肝细胞癌、肝转移瘤、肝脏海绵状血管瘤和肝囊肿的病灶/肝脏磁共振信号强度比(SIR),并评价其与病灶性质的关系。方法 随机选择经确诊的肝细胞癌、肝转移瘤、肝海绵状血管瘤和肝囊肿病例共92例(148个病灶)行前瞻性磁共振成像(0.5T)研究。计算4种病灶的SIR,并进行统计学分析。结果 在T1W图像上,肝海绵状血管瘤与恶性肿瘤的SIR值间差异无显著性(t=1.799,P=0.075);质子加权像上,良恶性肿瘤的SIR之间无统计学意义(t=0.691,P=0.491);T2WI上,良性病变的SIR显著高于恶性肿瘤(P<0.01),且4种病变的SIR值与回波时间(TE)之间均存在线性正向相关关系。结论 在T2WI个测得的SIR可用于区分肝脏占位性病灶的性质。  相似文献   
104.
还原型谷胱甘肽治疗尿毒症贫血的初步探讨   总被引:1,自引:0,他引:1  
目的 观察外源性还原型谷胱甘肽对尿毒症贫血的治疗效果。方法 将 42例尿毒症贫血患者随机分为两组。两组患者均给予重组人红细胞生成素 (r- Hu EPO) 30 0 0 U,每周两次皮下注射 ,疗程 12周。治疗组患者同时静脉给予外源性还原型谷胱甘肽 (GSH) 12 0 0 mg,每周两次 ,疗程 12周。于治疗前和治疗后抽静脉血测定血红蛋白 (Hb) ,红细胞 (RBC)和红细胞压积 (HCT)水平。结果  r- Hu EPO治疗后两组患者 HB,RBC和 HCT水平均显著上升 (P<0 .0 1)。 GSH治疗组 Hb,RBC和 HCT水平与对照组比较上升明显 (P<0 .0 5 ) ,治疗组 Hb,RBC和HCT的上升幅度高于对照组 (P<0 .0 5 )。结论 外源性还原型谷胱甘肽能显著提高 r- Hu EPO治疗肾性贫血的疗效 ,GSH可能是治疗尿毒症贫血的有效药物。  相似文献   
105.
BackgroundNon-union is a significant complication of fracture fixation surgery, and can negatively impact a patient’s quality of life. Low intensity pulsed ultrasound (LIPUS) has been used to treat delayed or non-unions previously in the literature. The aim of this study was to determine the success rate of LIPUS treatment in patients with chronic fracture non-unions, and to establish the effect of systemic or local factors on its success.MethodsThis was a retrospective, observational study which included all patients undergoing LIPUS treatment in a single institution. Patients deemed suitable for LIPUS underwent treatment for a period of 6 months from initiation. They were followed up with sequential radiographs to assess union at intervals of 6 weeks, 3 months, 6 months and 1 year. LIPUS treatment was considered to be successful when patients achieved clinical and radiological union, without the need for revision surgery.ResultsA total of 46 patients were included in the study; 8 were lost to follow – up, leaving 38 patients for the final analysis. The mean age of patients was 47.03 ± 19.7 with a male to female ratio of 1.2:1. Union was achieved in 57.89%; the rest underwent revision surgery. There was no significant association between outcomes after LIPUS treatment and patients’ age, gender, smoking status or type of non-union. Patients with a small inter-fragment bone gap were more likely to have a successful outcome after LIPUS (p = 0.041). Time to treatment did not have a statistically significant impact on outcomes after LIPUS. Interestingly, all 6 patients with diabetes in the study managed to achieve union after LIPUS.ConclusionsThis study demonstrates that LIPUS is not successful in a large proportion of patients with established fracture non-unions. However, it does represent a low risk treatment modality as an alternative to revision surgery, especially for patients with diabetes who have a small inter – fragment bone gap. More research in the form of large randomised controlled trials needs to be carried out to further assess the role of LIPUS in the treatment of non-unions.  相似文献   
106.
骨质疏松症是一种与年龄和性别有关的全身性疾病,表现特征为每单位体积的骨量减少,骨强度受损,患者容易骨折,造成生活质量降低。运动疗法相比药物疗法具有经济性、无不良反应等优势,被越来越多人所关注。然而运动疗法的疗效在实际应用过程中并没有完全凸显,主要受运动本身的特点(运动方式、运动强度)以及患者自身条件所影响。目前骨质疏松症的检测方式具有一定的不确定性,患者无法判断经过一段时间运动干预后的真正疗效,从而影响到运动参与的积极性,并且运动干预骨质疏松症的评价指标主要集中在骨密度和骨矿物质含量上,忽视了运动对于人体肌肉功能以及身体机能的影响。另外,骨质疏松症人群的机能状态存在很大差异,因此,想要达到较好的干预效果就需要根据患者特点制定最为合适的运动处方。目前,国内外对运动干预骨质疏松症存在的问题尚缺乏详细的概述,笔者就相关现存问题进行归纳总结,给出建议以供参考,旨在提高运动疗法干预骨质疏松症的效果。  相似文献   
107.
IntroductionReduced port laparoscopic surgery using an umbilical zigzag incision is comparable to conventional multiport laparoscopic surgery. This method is associated with improved cosmesis and decreased wound pain.Presentation of caseA 67-year-old man visited our hospital. He presented emergency room with a chief complaint of right lower abdominal pain by walking. The patient was diagnosed Meckel’s diverticulitis by computed tomography (CT). At first, antibiotics therapy and fasting were performed. Three months later, the patient underwent resection of Meckel’ diverticulum with zigzag transumbilical laparoscopic surgery. The patient’s postoperative course was good, and he rarely felt wound pain. The patient started oral intake three days after surgery, and was discharged 10 days after surgery.DiscussionZigzag transumbilical laparoscopic surgery is very useful for resection of the small intestine. This method is associated with improved cosmesis and decreased wound pain. In the case of Meckel’s diverticulitis, we suggest that interval resection of Meckel’s diverticulum was very useful as it was an operation that could be performed easily.ConclusionReduced port laparoscopic surgery using an umbilical zigzag incision is considered to be an excellent technique in terms of operability and aesthetic outcomes.  相似文献   
108.
贺洋洋 《医疗装备》2021,(4):185-186
高强度聚焦超声(HIFU)是将超声的能量聚集在很小的区域内,通过高热量灼烧病变组织细胞,但不会对周围其他组织产生影响,因此,其被广泛应用于对肿瘤、大脑疾病和血管疾病的治疗中。现阶段,临床正尝试将磁共振引导的HIFU应用于神经外科手术治疗中,如治疗特发性震颤等。该研究简要回顾了HIFU的原理、设备和临床应用,叙述了其在肝脏、乳腺、前列腺、肾脏、子宫肿瘤治疗中的应用效果及应用前景。  相似文献   
109.
Although nicotine is a drug of abuse for millions of smokers, it has been difficult to demonstrate clearly the motivational properties of nicotine with rats using the conditioned place preference (CPP) paradigm. The first experiment attempted to replicate CPPs reported by other researchers using nicotine doses of 0.4, 0.8, and 1.2 mg/kg. There was a trend for all three doses to produce aversions, but it was significant only for the 0.8 mg/kg dose. Exposures to the CS alone extinguished aversions, but a priming dose (0.2 mg/kg) of nicotine given after extinction produced aversions only in animals exposed to 1.2 mg/kg. Experiment 2 tested whether preexposure to morphine or nicotine would sensitize animals to nicotine's reinforcing effects. In this experiment, rats were exposed to either six nicotine (0.6 mg/kg) or morphine (1.0 mg/kg) dosings prior to preference conditioning. Neither preferences nor aversions were observed in any group following subsequent conditioning with 0.6 mg/kg nicotine. The results suggest that previous observations of preference effects may have been due to specific procedural factors or may have depended on negative reinforcement due to stress reduction.  相似文献   
110.
Pharmacokinetics and bioavailability of benperidol were determined in 13 schizophrenic patients after acute administration of 6 mg benperidol as an intravenous (i.v.) bolus injection, orally as liquid, and orally as tablets using a partially randomized cross-over design. Drug plasma levels were determined by high performance liquid chromatography with electrochemical detection and subjected to model independent pharmacokinetic analyses. After i.v. dosing the geometric means (mean-g) were 3.2 min for the distribution half-life, 5.80 h for the elimination half-life (t 1/2), 4.21 l/kg for the distribution volume, 7.50 h for the mean residence time (MRT), and 0.50 l/(h*kg) for the clearance. After oral administration as liquid and as tablet mean-g data for the time lag until the first appearance of measurable plasma concentrations were 0.33 and 1.1 h, mean-g t 1/2 values were 5.5 and 4.7 h, respectively, mean-g t max data were 1.0 h and 2.7 h, mean-g MRT values were 8.44 and 8.84 h, and mean-g C max maxvalues were 10.2 and 7.3 ng/ml. Differences between liquid and tablet administration were statistically significant for time lag,t max, andC max. Mean-g absolute bioavailabilities were computed as 48.6% after liquid and 40.2% after tablet administration respectively. All parameters studied exhibited large intersubject variation. The plasma concentrations of the presumed metabolite reduced benperidol were found to be very low.  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