全文获取类型
收费全文 | 887篇 |
免费 | 49篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 39篇 |
妇产科学 | 5篇 |
基础医学 | 98篇 |
口腔科学 | 44篇 |
临床医学 | 82篇 |
内科学 | 176篇 |
皮肤病学 | 40篇 |
神经病学 | 27篇 |
特种医学 | 149篇 |
外国民族医学 | 1篇 |
外科学 | 67篇 |
综合类 | 39篇 |
预防医学 | 92篇 |
眼科学 | 5篇 |
药学 | 47篇 |
中国医学 | 1篇 |
肿瘤学 | 28篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 13篇 |
2016年 | 13篇 |
2015年 | 25篇 |
2014年 | 13篇 |
2013年 | 28篇 |
2012年 | 21篇 |
2011年 | 25篇 |
2010年 | 30篇 |
2009年 | 45篇 |
2008年 | 24篇 |
2007年 | 17篇 |
2006年 | 16篇 |
2005年 | 15篇 |
2004年 | 40篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 13篇 |
2000年 | 14篇 |
1999年 | 26篇 |
1998年 | 54篇 |
1997年 | 62篇 |
1996年 | 56篇 |
1995年 | 42篇 |
1994年 | 40篇 |
1993年 | 37篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 16篇 |
1989年 | 14篇 |
1988年 | 22篇 |
1987年 | 23篇 |
1986年 | 22篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1983年 | 8篇 |
1982年 | 18篇 |
1981年 | 3篇 |
1980年 | 9篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1968年 | 3篇 |
1959年 | 2篇 |
排序方式: 共有945条查询结果,搜索用时 15 毫秒
71.
大鼠脂肪间充质干细胞的成骨分化 总被引:2,自引:2,他引:2
目的:观察大鼠脂肪间充质干细胞经成骨诱导向成骨细胞分化的生物学特性,探讨其作为骨组织工程种子细胞的可行性。方法:实验于2004-07/2006-03在中南大学湘雅医院中心实验室完成主要工作。①取健康SD大鼠双侧腹股沟区脂肪垫,消化法分离出脂肪间充质干细胞,接种入含有体积分数为0.1的新生牛血清的低糖DMEM培养基进行原代培养。②取第3代的脂肪间充质干细胞,用含有体积分数为0.1的新生牛血清、0.1μmol/L地塞米松、50μmol/L抗坏血酸、10mmol/Lβ-甘油磷酸钠的高糖DMEM培养基诱导其向成骨细胞分化。③于3,5,7,10,12,14,21d分别采用倒置显微镜观察细胞形态及增殖情况、Gomori改良钙钴法碱性磷酸酶染色、茜素红S钙结节染色和Ⅰ型胶原免疫细胞化学染色检测脂肪间充质干细胞成骨分化的情况。结果:①脂肪间充质干细胞原代细胞呈成纤维细胞样长梭形外观,传代稳定,细胞形态均一。②经成骨诱导,脂肪间充质干细胞体积增大,呈多角形;成骨诱导14d,Gomori改良钙钴法碱性磷酸酶染色,细胞胞浆内可见浅棕色至棕黑色的颗粒,平均染色阳性率为80%;碱性磷酸酶活性随时间的延长而逐渐增高[3,5,7,10,12,14d依次为(2.43±0.09),(3.60±0.08),(5.01±0.09),(7.75±0.07),(9.59±0.09),(10.94±0.10)μkat/L];成骨诱导21d,钙结节形成明显,茜素红S染色,呈红色结节;成骨诱导7d,Ⅰ型胶原免疫细胞化学染色,细胞胞浆呈棕黄色,胞核经苏木精复染为蓝色。结论:大鼠脂肪间充质干细胞经成骨诱导具有成骨细胞的生物学特性,可作为骨组织工程的种子细胞。 相似文献
72.
73.
74.
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
75.
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
76.
PD Issitt ; MR Combs ; SJ Bredehoeft ; ML Campbell ; M Heimer ; L Joyner ; L Lorentsen ; C Remley ; S Bullock ; J Bumgarner ; et al. 《Transfusion》1993,33(4):284-293
In a retrospective study on samples from 10,000 recently transfused patients, 35 samples were found to contain an antibody that reacted with ficin-treated red cells but was not demonstrable by low-ionic- strength saline solution and indirect antiglobulin test (LISS-IAT). In those 35 patients, the specificity of the antibody was such that each patient would have been transfused with antigen-negative blood had the antibody reacted in LISS-IAT. Tests on red cells from the units already transfused showed that 19 patients had among them received, by chance, 32 antigen-positive and 74 antigen-negative units. The remaining 16 patients had among them received 57 units that were, again by chance, all antigen negative. One patient given antigen-positive blood suffered a delayed transfusion reaction; in two others the antibodies became LISS-IAT active after transfusion. However, similar changes to the LISS- IAT-active state were seen with two antibodies of patients given only antigen-negative blood. Also found in the 10,000 patients were 28 clinically insignificant antibodies, 77 sera in which the antibody was too weak to identify, and 216 autoantibodies that reacted only with ficin-treated red cells. These data support a belief, generally held in the United States but not necessarily elsewhere, that the use of protease-treated red cells for routine pretransfusion tests creates far more work than the accrued benefits justify. 相似文献
77.
GE Signa Twinspeed 1.5T磁共振肝脏扩散加权成像的技术探讨 总被引:8,自引:1,他引:8
目的探讨高场强双梯度磁共振机(GE Signa Twinspeed 1.5T)的肝脏扩散加权成像技术(DWI).方法对20例正常肝脏进行扩散加权成像研究,分别改变重复时间(TR)及扩散敏感系数(b值),测定ADC值、信噪比、图像质量等.结果 b值固定,TR值改变,正常肝组织平均ADC值差异不显著(P>0.05);TR值固定,b值改变,ADC值随b值增大而减小(P<0.05,差异有显著性).b值越大,图像质量越差;b≥800 s/mm2时,图像几乎难以观察.结论 ADC值随b值的增大而减小.行肝脏扩散加权成像时,可适当减小TR值,以缩短扫描时间及患者的屏气时间,减少呼吸运动伪影. 相似文献
78.
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
79.
When red cells (RBCs) are treated with papain, one form of the U antigen, which we have named UPS (U papain-sensitive), is almost completely removed or denatured. A second form, UPR (U papain-resistant), remains unaltered on the treated RBCs. Tests on 42 examples of anti-U showed that two contained only anti-UPS, 19 contained only -UPR, and 21 contained separable -UPS and -UPR. In those sera containing both antibodies, anti-UPR was always the stronger of the two. These findings suggest 1) that UPS is located on the Ss sialoglycoprotein (glycophorin B) at a position distal to a papain-sensitive site or that the cleavage point is within the portion of the SGP that comprises UPS, and 2) that UPR is located between the papain-sensitive site and the RBC membrane. The UPS determinant was not denatured by neuraminidase, L-cysteine, trypsin, ficin, or alpha-chymotrypsin, and it was only partially denatured by pronase. The finding that RBCs treated with para-chloromercuribenzoic acid or para-chloromercuriphenyl sulfonic acid did not react with anti-UPR but did continue to react with anti-UPS suggests that the in situ configuration of UPR, but not UPS, is dependent on the presence of one or more disulfide bonds. RBCs of the S-s-U+(weak) phenotype were shown to carry markedly reduced amounts of both UPS and UPR. 相似文献
80.