全文获取类型
收费全文 | 14027篇 |
免费 | 844篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 455篇 |
妇产科学 | 188篇 |
基础医学 | 2216篇 |
口腔科学 | 500篇 |
临床医学 | 1212篇 |
内科学 | 2732篇 |
皮肤病学 | 355篇 |
神经病学 | 1347篇 |
特种医学 | 565篇 |
外国民族医学 | 3篇 |
外科学 | 2234篇 |
综合类 | 102篇 |
一般理论 | 3篇 |
预防医学 | 804篇 |
眼科学 | 378篇 |
药学 | 843篇 |
中国医学 | 15篇 |
肿瘤学 | 825篇 |
出版年
2022年 | 89篇 |
2021年 | 202篇 |
2020年 | 170篇 |
2019年 | 161篇 |
2018年 | 247篇 |
2017年 | 230篇 |
2016年 | 230篇 |
2015年 | 312篇 |
2014年 | 356篇 |
2013年 | 475篇 |
2012年 | 676篇 |
2011年 | 732篇 |
2010年 | 445篇 |
2009年 | 432篇 |
2008年 | 759篇 |
2007年 | 765篇 |
2006年 | 730篇 |
2005年 | 728篇 |
2004年 | 763篇 |
2003年 | 713篇 |
2002年 | 657篇 |
2001年 | 383篇 |
2000年 | 337篇 |
1999年 | 333篇 |
1998年 | 188篇 |
1997年 | 190篇 |
1996年 | 144篇 |
1995年 | 108篇 |
1994年 | 85篇 |
1993年 | 89篇 |
1992年 | 169篇 |
1991年 | 156篇 |
1990年 | 173篇 |
1989年 | 200篇 |
1988年 | 155篇 |
1987年 | 159篇 |
1986年 | 145篇 |
1985年 | 159篇 |
1984年 | 128篇 |
1983年 | 104篇 |
1982年 | 63篇 |
1980年 | 68篇 |
1979年 | 108篇 |
1978年 | 77篇 |
1977年 | 71篇 |
1975年 | 56篇 |
1974年 | 76篇 |
1973年 | 67篇 |
1972年 | 81篇 |
1970年 | 59篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Marie Warrer Petersen Tine Sylvest Meyhoff Marie Helleberg Maj-Brit Nørregaard Kjær Anders Granholm Carl Johan Steensen Hjortsø Thomas Steen Jensen Morten Hylander Møller Peter Buhl Hjortrup Mik Wetterslev Gitte Kingo Vesterlund Lene Russell Vibeke Lind Jørgensen Klaus Tjelle Thomas Benfield Charlotte Suppli Ulrik Anne Sofie Andreasen Thomas Mohr Morten H. Bestle Lone Musaeus Poulsen Mette Friberg Hitz Thomas Hildebrandt Lene Surland Knudsen Anders Møller Christoffer Grant Sølling Anne Craveiro Brøchner Bodil Steen Rasmussen Henrik Nielsen Steffen Christensen Thomas Strøm Maria Cronhjort Rebecka Rubenson Wahlin Stephan Jakob Luca Cioccari Balasubramanian Venkatesh Naomi Hammond Vivekanand Jha Sheila Nainan Myatra Christian Gluud Theis Lange Anders Perner 《Acta anaesthesiologica Scandinavica》2020,64(9):1365-1375
Introduction
Severe acute respiratory syndrome coronavirus-2 has caused a pandemic of coronavirus disease (COVID-19) with many patients developing hypoxic respiratory failure. Corticosteroids reduce the time on mechanical ventilation, length of stay in the intensive care unit and potentially also mortality in similar patient populations. However, corticosteroids have undesirable effects, including longer time to viral clearance. Clinical equipoise on the use of corticosteroids for COVID-19 exists.Methods
The COVID STEROID trial is an international, randomised, stratified, blinded clinical trial. We will allocate 1000 adult patients with COVID-19 receiving ≥10 L/min of oxygen or on mechanical ventilation to intravenous hydrocortisone 200 mg daily vs placebo (0.9% saline) for 7 days. The primary outcome is days alive without life support (ie mechanical ventilation, circulatory support, and renal replacement therapy) at day 28. Secondary outcomes are serious adverse reactions at day 14; days alive without life support at day 90; days alive and out of hospital at day 90; all-cause mortality at day 28, day 90, and 1 year; and health-related quality of life at 1 year. We will conduct the statistical analyses according to this protocol, including interim analyses for every 250 patients followed for 28 days. The primary outcome will be compared using the Kryger Jensen and Lange test in the intention to treat population and reported as differences in means and medians with 95% confidence intervals.Discussion
The COVID STEROID trial will provide important evidence to guide the use of corticosteroids in COVID-19 and severe hypoxia.4.
Detailed pathological changes of human lumbar facet joints L1–L5 in elderly individuals 总被引:4,自引:1,他引:3
Facet joints play an important role in intervertebral load transmission and are crucial for rotational kinematics. Clinically, the role of facet joints as a possible source of low back pain is seen as controversial and at present is not sufficiently investigated. In this study, human lumbar facet (zygapopyhysial) joints from donors with advanced age were analyzed macroscopically, for degenerative changes. The aim was to determine the extent and morphology of degenerative changes in these joints. Lumbar facet joints (L1–L5) of 32 donors were studied (mean age 80.1±11.2 years). Joint capsules were carefully removed and joint surfaces (5 zones) examined using magnifying glasses and probes. In the result, the majority of facet joints showed cartilage defects of varying extent. Defects were located mostly at the margins of the articular surface, the central zone being relatively well preserved. Defect localization was different between superior (most cartilage defects in superior zone) and inferior (most defects inferiorly) facets. Further, defects were more severe caudal (level of L5) and in older persons. Osteophytes were present in up to 30%, located mostly at the latero-dorsal enthesis of the joint capsule on the superior facet. In conclusion, most margins of the articular facets are subject to degenerative changes in the lumbar spine of elderly persons, the topographical pattern being different in superior and inferior facets. This observation can be explained by the segmental motion patterns during extension/flexion movements of the facets. Sometimes, due to the marginal extension, it is obvious that not all changes can be assessed by CT or MRI. 相似文献
5.
Lei Li Jürgen Bruns Reinhard E. Friedrich Rainer Schmelzle 《European journal of plastic surgery》2006,29(2):93-96
Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile. 相似文献
6.
7.
Depression in Alzheimer's disease: is there a temporal relationship between the onset of depression and the onset of dementia? 总被引:4,自引:0,他引:4
Alzheimer's disease (AD) patients often present with concurrent major depression (MD). To investigate the reasons for this comorbidity, e.g. MD being a risk factor for AD, or both diagnoses having a common neurobiology, the temporal relationship between the first onset of AD and of MD during lifetime was investigated-57 out of 146 AD patients had a lifetime diagnosis of MD. The correlation between the ages at onset of MD and dementia was calculated. The incidence of MD in AD patients in several 5-year-intervals before and after the onset of AD was compared with the average incidence of MD in the present AD sample and with the expected incidence of MD in the general population. No significant correlation between the onset of AD and of MD could be found after controlling for age, gender and the Mini-Mental-State. However, the incidence of MD 5 years before and after the onset of AD significantly exceeded the expected incidences-MD is only partially related to AD. However, the increased incidence of MD within 5 years before and after the onset of dementia may indicate that a common neurobiological process causes cognitive decline and depression in a subsample of AD patients. 相似文献
8.
Andreas Lange Claudia Kistler Tanja B. Jutzi Alexandr V. Bazhin Claus Detlev Klemke Dirk Schadendorf Stefan B. Eichmüller 《Experimental dermatology》2009,18(6):527-535
Abstract: The identification of tumor-specific proteins located at the plasma membrane is hampered by numerous methodological pitfalls many of which are associated with the post-translational modification of such proteins. Here, we present a new combination of detergent fractionation of cells and of subtractive suppression hybridization (SSH) to gain overexpressed genes coding for membrane-associated or secreted proteins. Fractionation of subcellular components by digitonin allowed sequestering mRNA of the rough Endoplasmatic reticulum and thereby increasing the percentage of sequences coding for membrane-bound proteins. Fractionated mRNAs from the cutaneous T-cell lymphoma (CTCL) cell line HuT78 and from normal peripheral blood monocytes were used for SSH leading to the enrichment of sequences overexpressed in the tumor cells. We identified some 21 overexpressed genes, among them are GPR137B, FAM62A, NOMO1, HSP90, SLIT1, IBP2, CLIF, IRAK and ARC. mRNA expression was tested for selected genes in CTCL cell lines, skin specimens and peripheral blood samples from CTCL patients and healthy donors. Several of the detected sequences are clearly related to cancer, but have not yet been associated with CTCL. qPCR confirmed an enrichment of these mRNAs in the rough endoplasmic reticulum fraction. RT-PCR confirmed the expression of these genes in skin specimens and peripheral blood of CTCL patients. Western blotting verified protein expression of HSP90 and IBP2 in HuT78. GPR137B could be detected by immunohistology in HuT78 and in keratinocytes of dysplastic epidermis, but also in sweat glands of healthy skin. In summary, we developed a new technique, which allows identifying overexpressed genes coding preferentially for membrane-associated proteins. 相似文献
9.
10.