全文获取类型
收费全文 | 243219篇 |
免费 | 20809篇 |
国内免费 | 5445篇 |
专业分类
耳鼻咽喉 | 2665篇 |
儿科学 | 5375篇 |
妇产科学 | 3319篇 |
基础医学 | 25668篇 |
口腔科学 | 5240篇 |
临床医学 | 26862篇 |
内科学 | 41911篇 |
皮肤病学 | 4388篇 |
神经病学 | 16857篇 |
特种医学 | 10579篇 |
外国民族医学 | 14篇 |
外科学 | 32587篇 |
综合类 | 23466篇 |
现状与发展 | 13篇 |
一般理论 | 109篇 |
预防医学 | 23282篇 |
眼科学 | 4299篇 |
药学 | 19048篇 |
119篇 | |
中国医学 | 8651篇 |
肿瘤学 | 15021篇 |
出版年
2024年 | 568篇 |
2023年 | 2289篇 |
2022年 | 4225篇 |
2021年 | 6861篇 |
2020年 | 5276篇 |
2019年 | 4777篇 |
2018年 | 5728篇 |
2017年 | 5513篇 |
2016年 | 5349篇 |
2015年 | 7350篇 |
2014年 | 9739篇 |
2013年 | 12861篇 |
2012年 | 17758篇 |
2011年 | 18754篇 |
2010年 | 13534篇 |
2009年 | 12610篇 |
2008年 | 15989篇 |
2007年 | 16158篇 |
2006年 | 15357篇 |
2005年 | 14244篇 |
2004年 | 12168篇 |
2003年 | 10943篇 |
2002年 | 10133篇 |
2001年 | 3922篇 |
2000年 | 3028篇 |
1999年 | 2712篇 |
1998年 | 2323篇 |
1997年 | 1955篇 |
1996年 | 1732篇 |
1995年 | 1579篇 |
1994年 | 1380篇 |
1993年 | 1260篇 |
1992年 | 1447篇 |
1991年 | 1313篇 |
1990年 | 1148篇 |
1989年 | 1113篇 |
1988年 | 1035篇 |
1987年 | 989篇 |
1986年 | 992篇 |
1985年 | 961篇 |
1984年 | 1001篇 |
1983年 | 876篇 |
1982年 | 1023篇 |
1981年 | 925篇 |
1980年 | 773篇 |
1979年 | 678篇 |
1978年 | 670篇 |
1977年 | 569篇 |
1976年 | 545篇 |
1974年 | 516篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Sebastian Bonner Thomas Matte Mitchell Rubin Joanne K Fagan Jennifer Ahern David Evans 《The Journal of asthma》2006,43(1):31-35
Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma. 相似文献
12.
【目的】比较不同区域猪晶状体上皮细胞的基因表达在转录组水平上的差异。【方法】解剖显微镜下分离晶状体前囊膜,将附着于其上的上皮细胞分为中央(直径为10.56mm)和周边两部分。分别提取两个样本的总RNAs并经PCR扩增,以Cy3和Cy5分别标记扩增的中央与周边部分的cDNA。与含7548个基因的表达谱芯片杂交,经图像分析,生物信息学处理获得基因表达在转录水平差异的相关信息。【结果】中央与周边区域的猪晶状体上皮细胞在转录组水平共鉴定出952个有效表达的基因点,其中差异表达基因261个.以中央区域为参照,周边上皮细胞mRNA上调137个,下调124个。差异表达基因主要涉及的功能有:细胞周期与凋亡、细胞骨架蛋白及细胞外基质、转录、细胞信号分子等。【结论】中央与周边区域猪晶状体上皮细胞基因表达在转录组水平上差异明显。这类差异呈明显的功能聚类。 相似文献
13.
外科护理学教学中培养学生临床思维能力的探索 总被引:3,自引:0,他引:3
较好的临床思维能力是高护生综合索质的一个重要体现,也是一名优秀的临床护士必须具备的能力。在外科护理学教学中,通过改革课堂教学方法,注重实验教学,加强临床见习,变革考试形式,以培养和提高学生的临床思维能力。 相似文献
14.
Abstract It is well established that thrombolytic therapy increases the risk of secondary intracerebral hemorrhage in ischemic stroke
patients. However, the term “intracerebral hemorrhage” (ICH) covers a wide spectrum from tiny spots of blood to massive space-occupying
hematoma. We will review the etiology and clinical consequences of secondary hemorrhage after thrombolysis in ischemic stroke
patients and discuss the ability of magnetic resonance imaging (MRI) to predict this phenomenon. MRI is a highly sensitive
tool for detection of hemorrhagic transformation after ischemic stroke. The definitions of a so-called symptomatic hemorrhage
after ischemic infarction differ considerably and will also be described. Attributing a causal relationship of a clinical
deterioration to a secondary hemorrhage is not easy and should be only addressed when it exceeds at least 30% of the infarct
volume. In other patients, secondary hemorrhage might be regarded as side effect of reperfusion within the region with the
most severe perfusion deficit. Cerebral microbleeds (CMBs) are a frequent finding in patients with leukoaraiosis and appear
to be a general marker of various types of bleeding- prone small vessel disease and a predictor of recurrent vascular events.
Current data do not support the hypothesis that the detection of CMBs is a useful diagnostic criterion for the exclusion of
patients with CMBs from thrombolytic therapy. However, an increased risk for the rare patients with numerous CMBs can not
be ruled out.
相似文献
15.
Mireille Lavoie rn p hd Thomas De Koninck p hd Danielle Blondeau rn p hd 《Nursing philosophy》2006,7(4):225-234
Abstract The discipline of nursing is still struggling with the differences that need to be clearly defined between the notions of care and nursing care. To be able to clarify this distinction, agreement must first be reached on the meaning of care itself. The present article proposes a conception of care in light of the philosophy of Emmanuel Levinas (1906–1995). This philosopher's thought throws considerable light on the ontology of care, thanks especially to his focus on the deeper implications of human encounter. A profound sense of responsibility towards the other enables Levinas to bring out such dimensions of the concept of care as the relation involved, the feeling of affection, and the interventions. We examine here what these entail regarding nursing care. 相似文献
16.
Pascal Thomas Gilbert Massard Henri Porte Christophe Doddoli Xavier Ducrocq Massimo Conti 《European journal of cardio-thoracic surgery》2006,29(6):880-885
Objective: To investigate on the feasibility, safety, and effectiveness of a new bioabsorbable material for lung staple-line reinforcement. Methods: This prospective open trial included 66 patients (mean age of 56 ± 17 years) who underwent various types of lung resection using staplers with knitted calcium alginate sleeves for buttressing (FOREseal™, Laboratoires Brothier, Nanterre, France) at three academic centers: 29 lobectomies, 22 emphysema surgeries, 15 wedge resections or lung biopsies. Intraoperative air leakage was assessed at a mean respiratory peak pressure of 30 cmH2O, and rated as grade 1, 2, or 3. Persistent air leakage in the postoperative course, as well as any relevant event, was assessed daily. The follow-up period was of 6 months. Results: No technical problem linked to the device occurred. Hemostasis of the cutting edges was completed in all patients. Fifty-six percent of the patients had no intraoperative air leak and 27.3% had grade 1 leaks. Mean postoperative air leaks and thoracic drainage times were 1.9 ± 2.3 days and 6 ± 5.3 days, respectively. In-hospital mortality was nil. There was no empyema. Mean hospital stay was 9.1 ± 6.6 days. At follow-up, one patient underwent lung transplantation, and pathology of the explanted specimen showed the absence of device-related foreign-body inflammation. One patient complained from metalloptysis, and another one, with a metastatic invasive aspergillosis, developed an infectious recurrence that required reoperation. Conclusions: FOREseal is an ergonomic, safe, and promising new material instead of nonabsorbable materials and xenomaterials for staple-line reinforcement. A randomized comparative study is now in progress. 相似文献
17.
18.
19.
Harvey A. Siegal PhD ; Paul J. Draus PhD ; Robert G. Carlson PhD ; Russel S. Falck MA ; Jichuan Wang PhD 《The Journal of rural health》2006,22(2):169-173
CONTEXT: Although the nonmedical use of stimulant drugs such as cocaine and methamphetamine is increasingly common in many rural areas of the United States, little is known about the health beliefs of people who use these drugs. PURPOSE: This research describes illicit stimulant drug users' views on health and health-related concepts that may affect their utilization of health care services. METHODS: A respondent-driven sampling plan was used to recruit 249 not-in-treatment, nonmedical stimulant drug users who were residing in 3 rural counties in west central Ohio. A structured questionnaire administered by trained interviewers was used to collect information on a range of topics, including current drug use, self-reported health status, perceived need for substance abuse treatment, and beliefs about health and health services. FINDINGS: Participants reported using a wide variety of drugs nonmedically, some by injection. Alcohol and marijuana were the most commonly used drugs in the 30 days prior to the interview. Powder cocaine was used by 72.3% of the sample, crack by 68.3%, and methamphetamine by 29.7%. Fair or poor health status was reported by 41.3% of the participants. Only 20.9% of the sample felt they needed drug abuse treatment. Less than one third of the sample reported that they would feel comfortable talking to a physician about their drug use, and 65.1% said they preferred taking care of their problems without getting professional help. CONCLUSIONS: Stimulant drug users in rural Ohio are involved with a range of substances and hold health beliefs that may impede health services utilization. 相似文献
20.
细胞间黏附分子-1在实验性自身免疫性脑脊髓炎大鼠中表达的动态变化及作用 总被引:3,自引:2,他引:1
目的探讨细胞间黏附分子-1(ICAM-1)在实验性自身免疫性脑脊髓炎(EAE)大鼠中表达的动态变化及其作用。方法分别取免疫后第4、6、8、10、12、14、16、18、20天EAE大鼠脑和脊髓制成石蜡切片,行HE染色和ICAM-1半定量免疫组化分析。结果免疫后第8天ICAM-1表达即出现明显上调,早于临床症状的发生;随免疫后时间的延长,ICAM-1表达呈逐渐增高后缓慢下降的变化趋势,并且与EAE大鼠病情评分呈显著正相关(r=0.57,P=0.003)。结论ICAM-1的表达上调可能在EAE发病中具重要作用。 相似文献