全文获取类型
收费全文 | 22170篇 |
免费 | 2175篇 |
国内免费 | 1915篇 |
专业分类
耳鼻咽喉 | 155篇 |
儿科学 | 193篇 |
妇产科学 | 280篇 |
基础医学 | 2835篇 |
口腔科学 | 247篇 |
临床医学 | 3119篇 |
内科学 | 3205篇 |
皮肤病学 | 195篇 |
神经病学 | 1282篇 |
特种医学 | 907篇 |
外国民族医学 | 13篇 |
外科学 | 2087篇 |
综合类 | 3717篇 |
现状与发展 | 5篇 |
一般理论 | 1篇 |
预防医学 | 1497篇 |
眼科学 | 657篇 |
药学 | 2539篇 |
29篇 | |
中国医学 | 1518篇 |
肿瘤学 | 1779篇 |
出版年
2024年 | 73篇 |
2023年 | 394篇 |
2022年 | 975篇 |
2021年 | 1212篇 |
2020年 | 965篇 |
2019年 | 735篇 |
2018年 | 766篇 |
2017年 | 766篇 |
2016年 | 718篇 |
2015年 | 1085篇 |
2014年 | 1344篇 |
2013年 | 1146篇 |
2012年 | 1589篇 |
2011年 | 1907篇 |
2010年 | 1179篇 |
2009年 | 1000篇 |
2008年 | 1169篇 |
2007年 | 1168篇 |
2006年 | 1138篇 |
2005年 | 1162篇 |
2004年 | 728篇 |
2003年 | 702篇 |
2002年 | 563篇 |
2001年 | 486篇 |
2000年 | 512篇 |
1999年 | 530篇 |
1998年 | 325篇 |
1997年 | 350篇 |
1996年 | 267篇 |
1995年 | 250篇 |
1994年 | 213篇 |
1993年 | 127篇 |
1992年 | 133篇 |
1991年 | 93篇 |
1990年 | 95篇 |
1989年 | 87篇 |
1988年 | 76篇 |
1987年 | 74篇 |
1986年 | 59篇 |
1985年 | 28篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1977年 | 1篇 |
1976年 | 7篇 |
1975年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Human granulocyte-macrophage colony-stimulating factor (hGM-CSF): identification of a binding site for a neutralizing antibody. 总被引:2,自引:0,他引:2
E Nice P Dempsey J Layton G Morstyn D F Cui R Simpson L Fabri A Burgess 《Growth factors (Chur, Switzerland)》1990,3(2):159-169
One approach to the localization of functionally active regions of human granulocyte-macrophage colony-stimulating factor (hGM-CSF) is to map the epitopes recognized by neutralizing anti-hGM-CSF monoclonal antibodies. We have defined the epitope recognized by one neutralizing antibody (LMM102) using proteolytic fragments obtained by enzymic digestion of bacterially synthesized hGM-CSF. RP-HPLC fractionation of a tryptic digest resulted in the identification of an immunoreactive "tryptic core" peptide containing 66 amino acids (52% of the protein). Further digestion of this "tryptic core" with S. aureus V8 protease produced a unique immunoreactive hGM-CSF product comprising two peptides, residues 86-93 and 112-127, linked by a disulfide bond between residues 88 and 121. The individual peptides, generated by reduction with dithiothreitol, were not recognized by the antibody. An analog of this peptide has been synthesized chemically and shown to have similar immunoreactivity to the epitope obtained by enzymic digestion. A series of modified peptides has also been synthesized to identify further the region required for antibody recognition. 相似文献
82.
As biodegradable materials, linear polyphosphazenes undergo rapid hydrolysis degradation but exhibit poor mechanical properties. Blending with biodegradable polyesters or inorganic particles strengthen their mechanical properties but give rise to slower degradation rate. To balance the mechanical properties and the degradation rate, micro-crosslinked polyphosphazenes were synthesized in this study. Their glass transition temperatures, mechanical properties, and in vitro degradation behavior were investigated. 2-hydroxyethyl methacrylate (HEMA) was firstly attached to the side chain along with glycine ethyl ester to prepare co-substituted poly(organophosphazene) with pendant ethenyl substituents. The co-substituted poly(organophosphazene) was blended with HEMA or acrylic acid (AA) followed by a free radical polymerization to prepare micro-crosslinked poly(organophosphazenes). The resulting crosslinked polymers showed two separate glass transition temperatures depending on the HEMA or AA feed. Incorporation of crosslinking affected the mechanical properties positively. Crosslinked poly(organophosphazenes) showed an approximately 11-17 fold increase in terms of modulus of elasticity when compared to the linear counterpart. In vitro degradation tests indicated that HEMA-crosslinked polymers hydrolyzed at a retarded rate while AA-crosslinked polymers hydrolyzed at a moderate rate compared to linear polymers. 相似文献
83.
The C4a anaphylatoxin was purified from rat sera activated by heat-aggregated IgG. The anaphylatoxin was isolated by a three-step purification procedure and was judged to be homogeneous based on visualization of a single stained band after electrophoresis on both cellulose acetate membrane strips and on 9% SDS-polyacrylamide gels. Results from Ouchterlony and radioimmunoassay analysis indicated that neither rat C5A nor C3a contaminated the C4a preparation. Rat C4a is a glycoprotein estimated to be 11,000-12,000 mol. wt and contains 76 amino acid residues representing a mol. wt of 8577 and one oligosaccharide unit of 2000-3000 mol. wt. Rat C4a is weakly active in contracting guinea pig ileum at 0.1-1 microM, which is comparable with the activity of human C4a. Both human and bovine C4a are polypeptides free of carbohydrate while rat and presumably mouse C4a are glycoproteins. The complete primary structure of rat C4a anaphylatoxin has been elucidated as follows: (formula; see text) 相似文献
84.
人肝癌组织中p53与HSP70相互作用的初步研究 总被引:7,自引:1,他引:7
目的 :探讨人肝癌中热休克蛋白 70 (HSP70 )与 p5 3的相互作用。方法 :用免疫组织化学染色法 ,从 12例肝癌组织中筛选HSP70与 p5 3均呈阳性表达的标本 ,并以免疫共沉淀法提取之。然后用SDS PAGE及Westernblot分析双阳性标本中两种蛋白的存在形式。结果 :用免疫组织化学法检测到 12例肝癌组织中有 3例为双阳性 ,用抗HSP70mAb免疫共沉淀的样品 ,可检测到 p5 3蛋白。用抗p5 3mAb免疫共沉淀的样品也可检测到HSP70蛋白。结论 :人肝癌中p5 3与HSP70以复合物的形式而存在 ,此可为肝癌的发病机制及免疫治疗的研究提供新的思路 相似文献
85.
Identification of a new locus for autosomal dominant non-syndromic hearing impairment (DFNA7) in a large Norwegian family 总被引:3,自引:0,他引:3
Fagerheim T; Nilssen O; Raeymaekers P; Brox V; Moum T; Elverland HH; Teig E; Omland HH; Fostad GK; Tranebjaerg L 《Human molecular genetics》1996,5(8):1187-1191
Hereditary hearing impairment affects about 1 in 1000 newborns. In most
cases hearing loss is non-syndromic with no other clinical features, while
in other families deafness is associated with specific clinical
abnormalities. Analysis of large families with non-syndromic and syndromic
deafness have been used to identify genes or gene locations that cause
hearing impairment. The present report describes a large Norwegian family
with autosomal dominant non-syndromic, progressive high tone hearing loss
with linkage to 1q21-q23. A maximum LOD score of 7.65 (theta = 0.00) was
obtained with the microsatellite marker D1S196. Analysis of recombinant
individuals maps the deafness gene (DFNA7) to a 22 cM region between D1S104
and D1S466. The region contains several attractive candidate genes. This
report supports the idea of extensive genetic heterogeneity in hereditary
hearing impairment and represents the first localization of a deafness gene
in a Norwegian family.
相似文献
86.
87.
目的 对东营区≥45岁常住居民进行结直肠癌筛查,并探讨初筛阳性者肠镜顺应性及其影响因素,为提高居民结直肠癌筛查工作提供科学依据。方法 采用方便抽样方法选择辖区内2个镇和3个街道的社区卫生服务中心作为结直肠癌筛查志愿者招募点招募≥45岁常住居民为研究对象开展结直肠癌筛查及问卷调查,对初筛阳性者进一步进行肠镜检查,采用描述性分析方法对居民结直肠筛查结果及肠镜顺应性进行分析,并对其影响因素进行单、多因素分析。结果 本研究共纳入1 201人进行分析,男662人,女539人,45~59岁372人,60~69岁495人,70~79岁334人。初筛阳性人数总计371例,其中危险因素初筛阳性154例,FOBT阳性298例,危险因素和FOBT阳性双阳性者81例,初筛阳性率为30.89%。男性(OR=3.177)、黏液血便史(OR=7.683)以及肠道息肉病史(OR=5.008)为结直肠癌初筛阳性的危险因素。371例初筛阳性者中121例完成结肠镜检查,结肠镜检查顺应率为32.61%。性别(OR=2.776)、年龄(OR=0.511、0.433)、婚姻状况(OR=4.267)、文化程度(OR=2.782、3.916)、医疗保险(OR=2.743)是结直肠癌初筛阳性者结肠镜检查顺应性的影响因素。结论 东营市东营区结直肠癌初筛阳性率较高,应加强对存在黏液血便史以及肠道息肉病史男性个体人群的结直肠癌筛查。居民结直肠镜检查顺应性较低,尤其是60岁及以上、非在婚、文化程度较低、无医保的女性个体,可特异性强化对该群体个体的健康教育,提高其结直肠镜顺应性。 相似文献
88.
目的探讨不同类型性染色体型性发育异常(DSD)患者的遗传学改变及临床意义。方法选取西安交通大学第一附属医院356例性染色体型DSD患者进行G显带染色体分析,对其中18例45,X/46,XY嵌合体者进行Y染色体微缺失检测。结果356例染色体型DSD患者中,克氏综合征(KS)210例,Turner综合征(TS)124例,47,XYY综合征8例,47,XXX综合征8例,45,X/46,XY男性3例,Y染色体结构异常3例。18例45,X/46,XY患者中,3例存在微缺失,其中AZFc位点缺失2例,AZFa+b+c位点缺失1例。结论染色体型DSD以克氏综合征最常见,其次为Turner综合征。对45,X/46,XY男性患者进行Y染色体微缺失检测,有助于明确病因和选择更优的辅助生殖技术方案,实现优生优育。 相似文献
89.
90.
雷公藤多甙片加益肾活血法治疗IgM相关性肾小球疾病 总被引:5,自引:0,他引:5
目的探讨IgM相关性肾小球疾病的治疗。方法53例患者分为雷公藤多甙片组(A组)和雷公藤多甙片+中药益肾活血(B组)治疗,疗程2个月。结果两组治疗前后尿蛋白均下降(P<0.05),组间比较则B组降低更明显(P<0.05)。尿红细胞均有减少,A组P>0.05,B组P<0.05;组间比较P<0.05。结论雷公藤多甙片+中药益肾活血法治疗IgM相关性肾小球疾病较单用雷公藤多甙片疗效显著提高。认为辨病辨证相结合组方用药,能够提高疗效。 相似文献