全文获取类型
收费全文 | 1182篇 |
免费 | 64篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 66篇 |
妇产科学 | 7篇 |
基础医学 | 139篇 |
口腔科学 | 45篇 |
临床医学 | 99篇 |
内科学 | 227篇 |
皮肤病学 | 41篇 |
神经病学 | 65篇 |
特种医学 | 170篇 |
外国民族医学 | 1篇 |
外科学 | 146篇 |
综合类 | 40篇 |
预防医学 | 84篇 |
眼科学 | 7篇 |
药学 | 70篇 |
中国医学 | 1篇 |
肿瘤学 | 42篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 13篇 |
2017年 | 18篇 |
2016年 | 23篇 |
2015年 | 35篇 |
2014年 | 26篇 |
2013年 | 46篇 |
2012年 | 44篇 |
2011年 | 54篇 |
2010年 | 40篇 |
2009年 | 55篇 |
2008年 | 44篇 |
2007年 | 33篇 |
2006年 | 34篇 |
2005年 | 31篇 |
2004年 | 55篇 |
2003年 | 32篇 |
2002年 | 24篇 |
2001年 | 14篇 |
2000年 | 16篇 |
1999年 | 24篇 |
1998年 | 55篇 |
1997年 | 66篇 |
1996年 | 60篇 |
1995年 | 47篇 |
1994年 | 43篇 |
1993年 | 39篇 |
1992年 | 14篇 |
1991年 | 14篇 |
1990年 | 21篇 |
1989年 | 18篇 |
1988年 | 27篇 |
1987年 | 27篇 |
1986年 | 27篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 19篇 |
1981年 | 4篇 |
1980年 | 9篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 10篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1968年 | 3篇 |
排序方式: 共有1258条查询结果,搜索用时 15 毫秒
81.
Volumetric rendering of MR images 总被引:1,自引:0,他引:1
The authors developed new techniques for three-dimensional display of magnetic resonance (MR) images that preserve soft-tissue definition, are fully automatic, and work with routinely used section thicknesses. MR images are segmented, selectively enhanced, and displayed by means of a volumetric rendering algorithm. These techniques were used to illustrate normal anatomy of the brain, knee, and liver. Three-dimensional rendering of balanced spin-echo images shows the ventricles and extracerebral veins and of T1-weighted images, the sulci and gyri. The large hepatic and portal vessels can be seen with these enhancement techniques. Three-dimensional views of the knee reveal articular surfaces of the tibia and clearly depict menisci and posterior and anterior cruciate ligaments. These techniques make it possible to image multiple soft tissues simultaneously while preserving the detail contained in the original images. Three-dimensional presentation of complex, overlapping anatomic regions is helpful in surgical planning and should lead to improved diagnosis. 相似文献
82.
83.
Anti-Sc1 was detected in a gravida-2 patient at 12 weeks' gestation. At 29 weeks, the antibody was found to be of the IgG3 subclass with a titer of 16, score 36, by the indirect antiglobulin test, and it produced 7 percent lysis by antibody-dependent cellular cytotoxicity (ADCC) assay, a finding that suggested an unaffected fetus. The titer remained constant throughout the pregnancy, as did the IgG subclass and activity in the ADCC assay. At delivery of the full-term infant, the cord hemoglobin was 13.5 g per dL and the direct antiglobulin test was positive (3+) with anti-IgG. The infant did not require transfusion. A sample taken 9 weeks after delivery showed 44 percent lysis in the ADCC assay. The anti-Sc1 titer was 32, score 65. 相似文献
84.
MR Namazi 《Journal of the European Academy of Dermatology and Venereology》2005,19(3):319-322
As the current antipsoriatic medications are commonly associated with deleterious side-effects, a determined search for safer agents, which could be used alone or in combination with current antipsoriatic drugs, would be very imperative. Psoriasis is believed to be characterized by a type 1 cytokine pattern; interferon-gamma, interleukin (IL)-2 and tumour necrosis factor (TNF)-alpha are predominantly expressed in this disorder. Nitric oxide, reactive oxygen species, histamine, leukotriene B4, and decreased [corrected] keratinocyte cyclic adenosine monophosphate/cyclic guanosine monophosphate (cAMP/cGMP) ratio are supposed to play roles in the pathogenesis of this disorder. Based on the immunopathogenesis of psoriasis, this paper introduces three novel, potential treatments for this clinical conundrum: (i) cannabinoids, which exert inhibitory effects on antigen processing and macrophage/T-cell interaction and also on the release of IL-2, TNF-alpha and nitric oxide from immune cells; (ii) loratadine, which is an antihistamine capable of increasing [corrected] the cAMP/cGMP ratio and the production of leukotriene B4; and (iii) allopurinol, which scavenges free radicals, inhibits the production of TNF-alpha, and downregulates the expression of intercellular adhesion molecule-1 and P2X7 receptors on monocytes/macrophages, which are involved in antigen presentation and production of the inflammatory response, respectively. Importantly, allopurinol, especially in combination with cyclosporin, has been shown to be effective against experimental autoimmune uveitis, which, like psoriasis, is a cell-mediated autoimmune disorder. 相似文献
85.
Studies on 24 Wr(a+b+) and 23 Wr(a-b+) blood samples, using anti-Wrb in the enzyme-linked antiglobulin test (ELAT), have shown that Wr(a+b+) red cells bind, on average, a little over half the amount of anti-Wrb bound by Wr(a-b+) red cells. Similarly, ELAT studies using six different anti-Wra and 10 Wr(a+b+) samples, as well as red cells from the original Wr(a+b-) proposita, have shown that Wr(a+b+) red cells bind about half the amount of anti-Wra bound by Wr(a+b-) red cells. Various pitfalls that can arise when the ELAT is used to measure antigen ratios on red cells have been avoided but are described. This conclusive evidence that Wra and Wrb have an antithetical relationship is discussed in light of the knowledge that a ficin-resistant portion of MN sialoglycoprotein (SGP), when carried in liposomes, can inhibit anti-Wrb. It is possible that Wra, Wrb, or both may encode a post-translational change in MN SGP, or production of transferases that glycosylate membrane lipids that affect in situ orientation of MN SGP, or production of protein band 3 that then forms a complex with MN SGP at the red cell membrane surface. 相似文献
86.
Michael G. Fehlings Branko Kopjar Ahmed Ibrahim Lindsay A. Tetreault Paul M. Arnold Helton Defino Shashank Sharad Kale S. Tim Yoon Giuseppe M. Barbagallo Ronald H.M. Bartels Qiang Zhou Alexander R. Vaccaro Mehmet Zileli Gamaliel Tan Yasutsugu Yukawa Darrel S. Brodke Christopher I. Shaffrey Osmar Santos de Moraes Mark B. Dekutoski 《The spine journal》2018,18(4):593-605
Background Context
Degenerative cervical myelopathy (DCM) is a progressive degenerative spine disease and the most common cause of spinal cord impairment in adults worldwide. Few studies have reported on regional variations in demographics, clinical presentation, disease causation, and surgical effectiveness.Purpose
The objective of this study was to evaluate differences in demographics, causative pathology, management strategies, surgical outcomes, length of hospital stay, and complications across four geographic regions.Study Design/Setting
This is a multicenter international prospective cohort study.Patient Sample
This study includes a total of 757 symptomatic patients with DCM undergoing surgical decompression of the cervical spine.Outcome Measures
The outcome measures are the Neck Disability Index (NDI), the Short Form 36 version 2 (SF-36v2), the modified Japanese Orthopaedic Association (mJOA) scale, and the Nurick grade.Materials and Methods
The baseline characteristics, disease causation, surgical approaches, and outcomes at 12 and 24 months were compared among four regions: Europe, Asia Pacific, Latin America, and North America.Results
Patients from Europe and North America were, on average, older than those from Latin America and Asia Pacific (p=.0055). Patients from Latin America had a significantly longer duration of symptoms than those from the other three regions (p<.0001). The most frequent causes of myelopathy were spondylosis and disc herniation. Ossification of the posterior longitudinal ligament was most prevalent in Asia Pacific (35.33%) and in Europe (31.75%), and hypertrophy of the ligamentum flavum was most prevalent in Latin America (61.25%). Surgical approaches varied by region; the majority of cases in Europe (71.43%), Asia Pacific (60.67%), and North America (59.10%) were managed anteriorly, whereas the posterior approach was more common in Latin America (66.25%). At the 24-month follow-up, patients from North America and Asia Pacific exhibited greater improvements in mJOA and Nurick scores than those from Europe and Latin America. Patients from Asia Pacific and Latin America demonstrated the most improvement on the NDI and SF-36v2 PCS. The longest duration of hospital stay was in Asia Pacific (14.16 days), and the highest rate of complications (34.9%) was reported in Europe.Conclusions
Regional differences in demographics, causation, and surgical approaches are significant for patients with DCM. Despite these variations, surgical decompression for DCM appears effective in all regions. Observed differences in the extent of postoperative improvements among the regions should encourage the standardization of care across centers and the development of international guidelines for the management of DCM. 相似文献87.
88.
Trichinella infection and clinical disease 总被引:1,自引:0,他引:1
Clausen MR; Meyer CN; Krantz T; Moser C; Gomme G; Kayser L; Albrectsen J; Kapel CM; Bygbjerg IC 《QJM : monthly journal of the Association of Physicians》1996,89(8):631-636
Trichinellosis is caused by ingestion of insufficiently cooked meat
contaminated with infective larvae of <it>Trichinella</it>
species. The clinical course is highly variable, ranging from no apparent
infection to severe and even fatal disease. We report two illustrative
cases of trichinellosis. Returning to Denmark a few days after having eaten
roasted pork in the Republic of Serbia, a female patient suffered from
severe vomiting, epigastric pain, diarrhoea, and later myalgia, generalized
oedema, and prostration. A biopsy showed heavy infestation with
<it>Trichinella spiralis</it>, 2000 larvae/g of muscle.
Life-threatening cardiopulmonary, renal and central nervous system
complications developed. The patient recovered after several months. Her
husband, who also ate the pork, did not have clinical symptoms, but an
increased eosinophil count and a single larva in a muscle biopsy confirmed
infection. The epidemiology, clinical manifestations, diagnosis, treatment
and prevention of trichinellosis are reviewed.
相似文献
89.
BACKGROUND: JMH is a high-frequency red cell blood group antigen that resides on a 76- to 80-kDa glycosylphosphatidylinositol-linked protein also known as CDw108. Antibodies with JMH specificity are often autoimmune and are usually, if not always, clinically benign. Some individuals with JMH-variant antigen produce alloantibodies to JMH, but little evidence concerning their clinical significance is available. This article reports on two patients who express a JMH-variant antigen and produced alloanti-JMH. STUDY DESIGN AND METHODS: Murine monoclonal antibodies and human antibodies to JMH were used in hemagglutination, radioimmunoassay, and Western blot testing of red cells from two JMH- variant patients; antiserum from one of these patients was also used in biochemical studies. In addition, in vivo survival of JMH-positive red cells was studied in the same patient. RESULTS: Biochemically, both examples of red cells with the JMH-variant phenotype expressed a JMH protein with a molecular weight similar to that of the normal JMH protein. For both patients, family studies suggested an autosomal recessive pattern of inheritance. Survival study demonstrated reduced in vivo red cell survival in one patient. CONCLUSION: JMH-variant phenotypes express a protein of normal molecular weight and are inherited in an autosomal recessive pattern. Furthermore, individuals with this phenotype can produce clinically significant antibodies. 相似文献
90.
Safety of intra‐arterial treatment in acute ischaemic stroke patients on oral anticoagulants. A cohort study and systematic review 下载免费PDF全文