全文获取类型
收费全文 | 406829篇 |
免费 | 27616篇 |
国内免费 | 2321篇 |
专业分类
耳鼻咽喉 | 4974篇 |
儿科学 | 9397篇 |
妇产科学 | 8250篇 |
基础医学 | 56127篇 |
口腔科学 | 7834篇 |
临床医学 | 39870篇 |
内科学 | 82921篇 |
皮肤病学 | 7647篇 |
神经病学 | 35819篇 |
特种医学 | 16227篇 |
外国民族医学 | 11篇 |
外科学 | 59282篇 |
综合类 | 5555篇 |
现状与发展 | 5篇 |
一般理论 | 395篇 |
预防医学 | 30662篇 |
眼科学 | 10645篇 |
药学 | 30229篇 |
6篇 | |
中国医学 | 1942篇 |
肿瘤学 | 28968篇 |
出版年
2023年 | 2272篇 |
2022年 | 5050篇 |
2021年 | 10066篇 |
2020年 | 5595篇 |
2019年 | 8697篇 |
2018年 | 10174篇 |
2017年 | 7563篇 |
2016年 | 8963篇 |
2015年 | 11268篇 |
2014年 | 15220篇 |
2013年 | 19846篇 |
2012年 | 30063篇 |
2011年 | 30596篇 |
2010年 | 17499篇 |
2009年 | 15237篇 |
2008年 | 25411篇 |
2007年 | 26110篇 |
2006年 | 25227篇 |
2005年 | 24798篇 |
2004年 | 22882篇 |
2003年 | 20857篇 |
2002年 | 19124篇 |
2001年 | 6437篇 |
2000年 | 5603篇 |
1999年 | 5548篇 |
1998年 | 4323篇 |
1997年 | 3497篇 |
1996年 | 3092篇 |
1995年 | 2925篇 |
1994年 | 2476篇 |
1993年 | 2185篇 |
1992年 | 2814篇 |
1991年 | 2709篇 |
1990年 | 2336篇 |
1989年 | 2196篇 |
1988年 | 2108篇 |
1987年 | 1970篇 |
1986年 | 1947篇 |
1985年 | 1834篇 |
1984年 | 1854篇 |
1983年 | 1673篇 |
1982年 | 1754篇 |
1981年 | 1685篇 |
1980年 | 1472篇 |
1979年 | 1219篇 |
1978年 | 1151篇 |
1977年 | 1019篇 |
1976年 | 923篇 |
1975年 | 767篇 |
1974年 | 828篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
Sung Woo Lee Sung Hyuk Choi Yunsik Hong Wanbae Kim 《European journal of emergency medicine》2006,13(2):117-118
Generally, a computed tomography scan is conducted for the diagnosis of stroke in the emergency department, because these scans are easier and faster in the detection of stroke. If there are no signs of hemorrhage on computed tomography scan, an ischemic stroke is diagnosed and treated accordingly. A magnetic resonance imaging scan may be taken in order to verify ischemic stroke. This process may lead to improper treatment and is time consuming. To address this situation, case studies are presented in which magnetic resonance imaging diffusion-weighted imaging and gradient recalled echo were performed to detect hemorrhagic and ischemic stroke and particularly, subarachnoid hemorrhage, which is undetectable with a computed tomography scan. 相似文献
84.
Lisa A. Lang DDS MS David C. Holmes DDS MS Craig Passon DDS MS Robert M. Trombly DDS JD Jeffrey D. Astroth DDS MSPH Arnold F. Tavel DMD 《Journal of prosthodontics》2003,12(3):206-210
Using complete denture treatment as an introduction to clinical patient care for dental students, the purposes of the Complete Denture Prosthodontics Transition Clinic at the University of Colorado School of Dentistry are to reduce the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience, and to encourage development of student self-confidence and skills. In the 2002 spring semester, faculty at the University of Colorado School of Dentistry initiated the Complete Denture Prosthodontics Transition Clinic for DS-II (second-year) dental students, as an introduction to clinical patient care. Each patient was assigned to a team of two dental students. Three Division of Prosthodontics faculty members staffed each clinic session, providing a student-to-faculty ratio of approximately 6.6:1 and a patient-to-faculty ratio of approximately 3.3:1. All DS-II students in the Class of 2004 delivered their first complete dentures no later than 8 months (average, 184 days) after the last day of the preclinical complete denture prosthodontics course. The time from the diagnostic appointment through the denture placement appointment averaged 39 days for patients treated in this program, compared with an average of 98 days or more for previous classes. The program was successful in achieving the goal of reducing the time lapse between the preclinical complete denture prosthodontics course and the first denture patient experience. 相似文献
85.
Allison J. Cowin PhD ; Nicholas Hatzirodos BSc ; Justin Rigden PhD ; Robert Fitridge FRACS ; David A. Belford PhD 《Wound repair and regeneration》2006,14(4):421-426
High levels of tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, are present in the wound fluid of chronic nonhealing wounds. This leads to increased inflammation, cytokine expression, and ultimately results in impaired wound healing and tissue destruction. Etanercept is a recombinant fusion protein that consists of the soluble TNF receptor (p75) linked to the Fc portion of human IgG1. It is an effective inhibitor of TNF-alpha and has been shown to provide rapid and sustained improvement in rheumatoid arthritis by acting as a soluble receptor binding TNF-alpha and preventing its proinflammatory activities. Therefore, the aim of this study was to determine whether Etanercept could inhibit TNF-alpha activity in chronic wound fluid. Wound fluid was collected from the venous leg ulcers of 16 different patients. The effect of Etanercept on TNF-alpha activity was evaluated using both a TNF-alpha bioassay and an enzyme-linked immunoassay. Etanercept was found to reduce the cytotoxic effect of chronic wound fluid on L929 fibroblasts by approximately 30% and neutralized TNF-alpha binding in the enzyme-linked immunoassay by up to 80%. Direct application of Etanercept to chronic wounds may therefore reduce the inflammatory activity of TNF-alpha, which could reduce the chronicity of venous leg ulcers and thus aid in the healing of these wounds. 相似文献
86.
Background
Both diabetes and obesity syndromes are recognized to promote lumbar vertebral instability, premature osteodegeneration, exacerbate progressive osteoporosis and increase the propensity towards vertebral degeneration, instability and deformation in humans. 相似文献87.
Avninder Dhaliwal Adrienne L West Jonathan D Trobe David C Musch 《Journal of neuro-ophthalmology》2006,26(1):4-10
BACKGROUND: The relationship between the circumstances and severity of closed head injury (CHI) and the clinical and imaging features of cranial nerve 3, 4, and 6 palsies has not been rigorously addressed in a large study. METHODS: Retrospective chart review of 210 consecutive patients with CHI examined at a single tertiary care center from 1987 to 2002. Patients were located by searching the ophthalmology inpatient consultation and neuro-ophthalmology outpatient databases and hospital emergency room billing codes for a diagnosis of traumatic 3, 4, or 6 cranial nerve palsy (Cranial Nerve Injury Group) and a diagnosis of CHI without traumatic 3, 4, or 6 nerve palsy (Control Group). The Cranial Nerve Injury Group was then subdivided into two groups: those with injuries to an individual cranial nerve and those with multiple (including bilateral) cranial nerve injuries. Comparisons between groups were based on age, gender, type of accident, Glasgow Coma Scale (GCS), documented loss of consciousness (LOC), type of ocular injury, presence of systemic injury, need for rehabilitation, physical therapy and cognitive scores, and imaging features. RESULTS: The Cranial Nerve Injury Group had a significantly higher severity of head injury, more CT abnormalities, and worse short-term neurologic outcomes as compared with the Control Group. These trends were also found when each cranial nerve injury subgroup was compared with the Control Group. Those with cranial nerve 3 palsy had the most severe head injury; those with cranial nerve 4 palsy had an intermediate level of head injury; and those with cranial nerve 6 palsy had the lowest level of head injury. There were no consistent associations between the location of the imaging abnormalities and which cranial nerve was damaged. CONCLUSIONS: CHI with palsy of an ocular motor nerve was more severe than CHI without ocular motor nerve palsy, as measured by the GCS, intracranial and skull imaging abnormalities, and a greater frequency of inpatient rehabilitation. Palsy of cranial nerve 3 was associated with relatively more severe CHI than was palsy of cranial nerves 4 or 6. The location of the imaging abnormalities did not correlate with a particular cranial nerve injury. 相似文献
88.
89.
Targeted silencing of disease-associated genes by synthetic short interfering RNA (siRNA) holds considerable promise as a novel therapeutic strategy. However, unmodified siRNA can be potent triggers of the innate immune response, particularly when associated with delivery vehicles that facilitate intracellular uptake. This represents a significant barrier to the therapeutic development of siRNA due to toxicity and off-target gene effects associated with this inflammatory response. Here we show that immune stimulation by synthetic siRNA can be completely abrogated by selective incorporation of 2'-O-methyl (2'OMe) uridine or guanosine nucleosides into one strand of the siRNA duplex. These noninflammatory siRNA, containing less than 20% modified nucleotides, can be readily generated without disrupting their gene-silencing activity. We show that, coupled with an effective systemic delivery vehicle, 2'OMe-modified siRNA targeting apolipoprotein B (apoB) can mediate potent silencing of its target mRNA, causing significant decreases in serum apoB and cholesterol. This is achieved at therapeutically viable siRNA doses without cytokine induction, toxicity, or off-target effects associated with the use of unmodified siRNA. This approach to siRNA design and delivery should prove widely applicable and represents an important step in advancing synthetic siRNA into a broad range of therapeutic areas. 相似文献
90.