全文获取类型
收费全文 | 7656篇 |
免费 | 583篇 |
国内免费 | 172篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 297篇 |
妇产科学 | 79篇 |
基础医学 | 1468篇 |
口腔科学 | 174篇 |
临床医学 | 385篇 |
内科学 | 808篇 |
皮肤病学 | 109篇 |
神经病学 | 369篇 |
特种医学 | 282篇 |
外科学 | 360篇 |
综合类 | 638篇 |
预防医学 | 2818篇 |
眼科学 | 60篇 |
药学 | 338篇 |
中国医学 | 66篇 |
肿瘤学 | 126篇 |
出版年
2023年 | 87篇 |
2022年 | 167篇 |
2021年 | 241篇 |
2020年 | 223篇 |
2019年 | 232篇 |
2018年 | 223篇 |
2017年 | 221篇 |
2016年 | 180篇 |
2015年 | 221篇 |
2014年 | 273篇 |
2013年 | 320篇 |
2012年 | 269篇 |
2011年 | 319篇 |
2010年 | 254篇 |
2009年 | 324篇 |
2008年 | 324篇 |
2007年 | 382篇 |
2006年 | 310篇 |
2005年 | 244篇 |
2004年 | 198篇 |
2003年 | 207篇 |
2002年 | 238篇 |
2001年 | 285篇 |
2000年 | 251篇 |
1999年 | 232篇 |
1998年 | 113篇 |
1997年 | 143篇 |
1996年 | 141篇 |
1995年 | 123篇 |
1994年 | 129篇 |
1993年 | 84篇 |
1992年 | 105篇 |
1991年 | 69篇 |
1990年 | 91篇 |
1989年 | 78篇 |
1988年 | 102篇 |
1987年 | 75篇 |
1986年 | 88篇 |
1985年 | 72篇 |
1984年 | 79篇 |
1983年 | 71篇 |
1982年 | 64篇 |
1981年 | 63篇 |
1980年 | 63篇 |
1979年 | 55篇 |
1978年 | 60篇 |
1977年 | 74篇 |
1976年 | 112篇 |
1975年 | 70篇 |
1974年 | 53篇 |
排序方式: 共有8411条查询结果,搜索用时 31 毫秒
91.
Matsuyama A Yonemitsu N Hayashida S Watanabe K Sugihara H Inokuchi A 《Pathology international》2003,53(1):46-50
Osteosarcoma is one of the neoplasms that may occur following exposure to radiation. A case of osteosarcoma arising in the craniofacial bone with a short latency period of 3 years after radiotherapy for maxillary squamous cell carcinoma is described. A 64-year-old-man underwent right partial maxillectomy and chemoradiotherapy due to squamous cell carcinoma of his right maxillary sinus. Histologically, the tumor was composed of moderately differentiated squamous cell carcinoma with a component of spindle cell carcinoma. Three years later, osteosarcoma developed in the craniofacial bone within the irradiation field of the first tumor. Detailed histological examination demonstrated that there was no component of osteosarcoma in the first tumor or squamous cell carcinoma in the second tumor. Radiation-induced osteosarcoma usually occurs after a long latency period of more than 10 years after the radiotherapy. In this case, osteosarcoma was possibly a radiation-induced osteosarcoma with a short latency period of 3 years. 相似文献
92.
93.
目的建立人胚胎干细胞无动物源性饲养层培养方法,同时对长时间体外培养的人胚胎干细胞核型变化进行分析。方法人胚胎干细胞系HUES4细胞分别培养于小鼠胚胎成纤维细胞和人包皮成纤维细胞饲养层,并对其干细胞特性进行鉴定;在培养传代过程中,收获P27、P34、P41和P44细胞进行染色体核型分析,P27细胞还进行DNA短串联重复序列多态性分析。结果生长于人包皮成纤维细胞饲养层的HUES4细胞碱性磷酸酶染色以及SSEA-4、TRA-1-60和TRA-1-81抗原阳性,SSEA-1抗原阴性。所检测的4代细胞中均见46,XY/46,XY,t(9;15)(q22;q26)核型嵌合现象,且异常核型百分比随传代次数增加有上升的趋势。结论培养人胚胎干细胞的饲养层细胞可由无动物源性的饲养层细胞替代;长期体外培养有增加细胞染色体核型异常的风险。 相似文献
94.
Luo M Cohen CR Narayansingh MJ Pan S McKinnon L Brunham RC Plummer FA 《Tissue antigens》2004,63(6):609-611
We report a novel DQA1 allele (DQA1*0403N) identified during sequence-based HLA-DQA1 typing of a Kenyan population. The new allele is identical to DQA1*0401 at exon 2 except for a single-nucleotide substitution at codon 53, changing it from lysine to a stop codon (CAA-->TAA). The substitution at codon 53 was confirmed by sequencing two separate polymerase chain reaction products and by sequencing multiple clones obtained following TOPO-TA cloning. The resulting stop codon at position of codon 53 in exon 2 is predicted to produce a non-functional DQA1 alpha-chain. The new allele has been named by the WHO nomenclature committee as DQA1*0403N. This is the first report of a null allele detected in the DQA1 gene. 相似文献
95.
Identification of a new HLA-B*56 variant, B*5614 总被引:6,自引:0,他引:6
In this report, the novel allele B*5614 is presented. The allele was identified in a Chinese individual by sequence-based typing. HLA-B*5614 differs from B*5608 by a single nucleotide at position 277G-->C in exon 2. This results in an amino acid change from Gly to Arg at codon 93. 相似文献
96.
This paper reports on skeletal abnormalities in 38 patients with Apert syndrome. Analysis includes alterations in the shoulders, humeri, elbows, hips, knees, rib cage, and spine (except the cervical spine). Some patients had subacromial dimples and elbow dimples during infancy. Mobility at the glenohumeral joint was limited. Progressive limitation in abduction, forward flexion, and external rotation with growth was virtually a constant finding. The acromioclavicular joint was prominent and sometimes had an angular, pointed appearance clinically. This was often associated with atrophic musculature and winging of the scapulae. Limited elbow mobility was common and usually mild in degree. Decreased elbow extension was most often found with decreased flexion, pronation, and supination occurring less frequently. Limited elbow mobility did not change significantly with growth in contrast to the increasing severity observed in the shoulder joint. Short humeri were a constant finding beyond infancy and genua valga of mild degree were present in many cases. Radiographic examination strongly suggests that the Apert syndrome is characterized by a multiple epiphyseal dysplasia. We found delay in appearance of postnatal ossification centers, particularly in the humeral head, greater tuberosity, capitulum, and radial head. Subsequently, these bones became abnormal in shape. Glenoid dysplasia was observed consistently. The neck of the scapula was very short or absent and the inferior margin of the glenoid cavity was poorly demarcated from the infraglenoid tubercle. The humeral head became oblong in shape with relative prominence of the greater tuberosity which compromised abduction. In the elbow, the capitulum was often small and the radial head was flat in many instances. Subluxation or dislocation of the radial head or angulation of the radial neck was observed in some cases. In the hip joint of some adults, the femoral necks were short and broad with prominence of the greater trochanters. Less common radiographic findings are also discussed. © 1993 Wiley-Liss, Inc. 相似文献
97.
Miguel Urioste María Luisa Martínez-Frías Eva Bermejo Nicols Jimnez Dolores Romero Carmen Nieto Amelia Villa 《American journal of medical genetics. Part A》1994,49(1):94-97
We report on a newborn infant with clinical and radiological manifestations of some type of short rib-polydactyly syndrome who died soon after birth. Chromosomal studies on peripheral blood lymphocytes and chondrocytes demonstrated an apparently balanced pericentric inversion of chromosome 4 (present in the mother also). This association may have occurred by chance but, if not, the chromosomal breakpoints could interrupt the gene responsible for short rib-polydactyly syndromes, or else be related to the mechanism of short rib-polydactyly syndromes. © 1994 Wiley-Liss, Inc. 相似文献
98.
Takeshi Tana Nobuhiro Kamikawaji Christopher J. Savoie Tohru Sudo Yurika Kinoshita T. Sasazuki 《Journal of human genetics》1998,43(1):14-21
Susceptibility to a series of autoimmune diseases is strongly associated with particular HLA class II alleles. Identification
of T cell clones and antigenic epitopes bound by HLA class II molecules involved in autoimmune diseases is critical to understanding
the etiology of these HLA class II-associated diseases. However, establishment of T cell clones in autoimmune diseases is
difficult because the antigenic peptides are unknown. Peptide library methods which include all possible peptide sequences
offer a potentially powerful tool for the detection of cross-reactive antigenic peptides recognized by T cells. Here, we reduced
the number of peptides per mixture by utilizing the known binding motifs of peptides for the HLA-DRB1*0405 molecule and evaluated
the effectiveness of this library design. Each library mixture evoked a strong proliferative response in the unprimed peripheral
blood lymphocytes (PBL) from HLA-DRB1*0405-positive donors but little or no response in the PBL from HLA-DRB1*0405-negative donors. The library also detected antigenic peptides that activated three antigen-specific T cell lines restricted
by HLA-DRB1*0405, with different specificities. The motif-based approach thus presents a powerful method for monitoring T
cells in large, heterogeneous T cell populations and is useful for the identification of the mimic peptide epitopes of T cell
lines and clones.
Received: October 3, 1997 / Accepted: October 23, 1997 相似文献
99.
Mayor NP Cox ST McWhinnie AJ Argüello JR Shaw BE Little AM Madrigal JA Marsh SG 《Tissue antigens》2005,65(1):107-109
We report here the full-length sequence of a novel HLA-A*0301 allele, A*03010103, which differs from A*03010101 by a single nucleotide substitution (G>T) at position 492 within intron 2. The variant was originally identified by Reference Strand-mediated Conformational Analysis (RSCA) and was confirmed by cloning and sequencing. The difference in RSCA mobility between A*03010101 and A*03010103 demonstrates the sensitivity of RSCA to detect single nucleotide polymorphisms. 相似文献
100.
Pelin Sahlén Rapolas Spalinskas Samina Asad Kunal Das Mahapatra Pontus Höjer Anandashankar Anil Jesper Eisfeldt Ankit Srivastava Pernilla Nikamo Anaya Mukherjee Kyu-Han Kim Otto Bergman Mona Ståhle Enikö Sonkoly Andor Pivarcsi Carl-Fredrik Wahlgren Magnus Nordenskjöld Fulya Taylan Isabel Tapia-Páez 《The Journal of allergy and clinical immunology》2021,147(5):1742-1752