全文获取类型
收费全文 | 9580篇 |
免费 | 360篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 129篇 |
妇产科学 | 77篇 |
基础医学 | 1110篇 |
口腔科学 | 161篇 |
临床医学 | 574篇 |
内科学 | 2171篇 |
皮肤病学 | 179篇 |
神经病学 | 963篇 |
特种医学 | 464篇 |
外科学 | 1612篇 |
综合类 | 39篇 |
预防医学 | 253篇 |
眼科学 | 382篇 |
药学 | 787篇 |
中国医学 | 23篇 |
肿瘤学 | 997篇 |
出版年
2023年 | 41篇 |
2022年 | 103篇 |
2021年 | 158篇 |
2020年 | 97篇 |
2019年 | 106篇 |
2018年 | 126篇 |
2017年 | 122篇 |
2016年 | 129篇 |
2015年 | 161篇 |
2014年 | 204篇 |
2013年 | 271篇 |
2012年 | 400篇 |
2011年 | 498篇 |
2010年 | 304篇 |
2009年 | 235篇 |
2008年 | 464篇 |
2007年 | 456篇 |
2006年 | 490篇 |
2005年 | 531篇 |
2004年 | 535篇 |
2003年 | 550篇 |
2002年 | 513篇 |
2001年 | 280篇 |
2000年 | 298篇 |
1999年 | 281篇 |
1998年 | 139篇 |
1997年 | 123篇 |
1996年 | 105篇 |
1995年 | 103篇 |
1994年 | 101篇 |
1993年 | 87篇 |
1992年 | 206篇 |
1991年 | 181篇 |
1990年 | 171篇 |
1989年 | 154篇 |
1988年 | 148篇 |
1987年 | 133篇 |
1986年 | 116篇 |
1985年 | 129篇 |
1984年 | 91篇 |
1983年 | 70篇 |
1982年 | 41篇 |
1981年 | 42篇 |
1980年 | 37篇 |
1979年 | 60篇 |
1978年 | 35篇 |
1977年 | 38篇 |
1975年 | 33篇 |
1974年 | 41篇 |
1973年 | 31篇 |
排序方式: 共有9993条查询结果,搜索用时 15 毫秒
71.
Phylogenetic association of Pneumocystis carinii with the 'Rhizopoda/Myxomycota/Zygomycota group' indicated by comparison of 5S ribosomal RNA sequences 总被引:14,自引:0,他引:14
The cytoplasmic 5S ribosomal RNA (5S rRNA) sequence from Pneumocystis carinii was determined. A sequence comparison matrix of 382 eukaryote 5S rRNA sequences and an evolutionary tree were constructed to establish the phylogenetic position of Pneumocystis. The data suggest that Pneumocystis is associated with the Rhizopoda/Myxomycota/Zygomycota group (= 'Protista fungi') but not with common fungi, such as Ascomycota or Basidiomycota, nor with other protozoa. 相似文献
72.
Noriaki Mitsuda Jun Nakura Lin Ye Tetsuro Miki Toshio Ogihara 《Journal of human genetics》1995,40(3):283-285
Three polymorphic dinucleotide (CA) repeat clones were isolated from a CEPH mega-YAC clone (936F7), and were localized to chromosome 8 using a panel of 13 mouse/human somatic cell hybrids. 相似文献
73.
Seiiohi Sumino Kazuo Nacsashima Tetsuro Shimamine Toshiaki Abe Hideo Tsuneyoshi Satoru Murao 《Pathology international》1983,33(3):629-643
Autopsy findings in a 40-year-old male with heredofamilial amyloidosis and polyneuropathy are reported. He had been suffering from progressive autonomic as well as sensorimotor dysfunctions. Prominent amyloid deposit was found in the kidney, heart, thyroid, and testis, and less in the interstitium and small vessels of almost all organs. The peripheral nerves, some showing prominent hypertrophy, were most severely involved by amyloid deposit in a form of stellate mass, which ultrastructurally consisted of radially arranged amyloid filaments. In the hypertrophied nerves and ganglia, in addition to amyloid, massive accumulation of acid mucopolysaccharide (AMPS) was seen filling up the interstitial space, which was the cause of hypertrophy. Ultrastructurally, AMPS was seen as finely granular substance. An extracted amyloid from the kidney showed 8 nm filament on negative staining and was estimated of having a molecular weight of 14,000. 相似文献
74.
75.
Sakaguchi M Toda M Ebihara T Irie S Hori H Imai A Yanagida M Miyazawa H Ohsuna H Ikezawa Z Inouye S 《The Journal of allergy and clinical immunology》2000,106(3):579-584
BACKGROUND: Most children with anaphylaxis to measles, mumps, and rubella vaccines had shown sensitivity to bovine gelatin that was included in the vaccines. Recently, it was found that bovine type I collagen, which is the main content in the gelatin, is a major allergen in bovine gelatin allergy. Fish meat and skin also contain type I collagen. OBJECTIVE: The present study was designed to investigate IgE antibody to fish gelatin in children with fish allergy. METHODS: Serum samples were taken from patients in 3 groups: (1) 10 patients with fish allergy and specific IgE to fish meat; (2) two patients with allergies to both fish meat and bovine gelatin and specific IgE to fish meat and bovine gelatin; and (3) 15 patients with atopic dermatitis and specific IgE to fish meat. Various fish gelatins (type I collagen) were prepared from fish skin. IgE antibody to fish gelatin was analyzed by using ELISA and immunoblotting. RESULTS: Of 10 patients with fish allergy, 3 had specific IgE to fish gelatin. Of two patients with fish allergy and bovine gelatin allergy, all had specific IgE to fish gelatin. Of 15 patients with atopic dermatitis and specific IgE to fish meat, 5 had specific IgE to fish gelatin. Furthermore, IgE from pooled serum of the patients reacted with both the alpha1 and alpha2 chains of fish type I collagen in immunoblots. There is cross-reactivity among gelatins from various fishes, but there is little cross-reactivity between fish and bovine gelatins. CONCLUSION: Some fish-sensitive patients possessed IgE antibody to fish gelatin. Fish gelatin (type I collagen) might be an allergen in subjects with fish allergy. 相似文献
76.
Multipotent, self-renewing stem and progenitor cells isolated from the mammalian central nervous system (CNS) have been shown to survive as allografts following transplantation to sites throughout the neuraxis. However, studies of this type shed little light upon the immunologic properties of the cells themselves, primarily because little is learned about the intrinsic immunogenic properties of a cell when it is grafted into an immune-privileged site. We have therefore investigated the immunogenic and antigenic properties of CNS progenitor cells by grafting them into a conventional (i.e., non-immune-privileged) site, namely, beneath the kidney capsule. Our results indicate that allogeneic CNS progenitor cells survive at least 4 weeks in a conventional site, during which time they neither sensitize their hosts nor express detectable levels of major histocompatibility complex (MHC) class I or II. These in vivo data are in accord with flow cytometric results showing that CNS progenitor cells do not express MHC class I or class II, either at baseline or upon differentiation in 10% serum. Exposure to interferon gamma, however, reversibly upregulates expression of these key transplantation antigens. Together, these results reveal CNS progenitor cells to possess inherent immune privilege. Since CNS progenitor cell allografts were rejected beneath the kidney capsule following specific sensitization of the host, CNS progenitor cells were able to display alloantigens, albeit not in an immunogenic form. 相似文献
77.
Hiroshi Konomi Hisae Hori Junjiro Sano Hironobu Sunada Ryu-ichiro Hata Sakuhei Fujiwara Yutaka Nagai 《Pathology international》1981,31(4):601-610
Type specific rabbit antibodies to bovine type I, 11, 111, and IV (basement membrane) collagens showing no cross-reaction with other types of collagen were prepared by cross-adsorption and diethylamiuoethyl-cellulose romatography. The antibodies to bovine type I and I11 collagens showed a high cross-reaction with the corresponding human collagens, but those to type I1 and IV collagens did moderate and no cross-reactions with human type I1 and IV collagens, respectively. By using these antibodies, tissue distribution of various types of collagen in normal bovine lung was examined by indirect immunofluorescence microscopy. Both type I and I11 collagens were found to distribute widely in the interstitium of bronchial tree, bronchial
lamina propria and of interlobules as well as alveolar nipples and adventitia of pulmonary arteries. Type I1 collagen was located only in bronchial cartilage. The tissues mainly stained for type 11 collagen were the alveolar interstitium (also stained faintly for type I collagen) and the intima and media of the arteries. Type IV collagen was located in a membranous fashion in alveolar septa and bronchial smooth muscles and subepithelial layers as well as capillaries and the intima and media of arteries. ACTA PATHOL. JPN. 31: 601–610, 1981. 相似文献
lamina propria and of interlobules as well as alveolar nipples and adventitia of pulmonary arteries. Type I1 collagen was located only in bronchial cartilage. The tissues mainly stained for type 11 collagen were the alveolar interstitium (also stained faintly for type I collagen) and the intima and media of the arteries. Type IV collagen was located in a membranous fashion in alveolar septa and bronchial smooth muscles and subepithelial layers as well as capillaries and the intima and media of arteries. ACTA PATHOL. JPN. 31: 601–610, 1981. 相似文献
78.
Lin Ye Jun Nakura Noriaki Mitsuda Asako Takahashi-Fujii Yoshizumi Ishino Ikunoshin Kato Tetsuro Miki Toshio Ogihara 《Journal of human genetics》1996,41(2):257-259
Summary Two polymorphic dinucleotide (CA) repeat dones were isolated from a CEPH mega-YAC clone (844E2), and were localized to chromosome 8 using a panel of 13 mouse/human somatic cell hybrids. 相似文献
79.
Xiaoyan Tang Sadaaki Hori R. Yoshiyuki Osamura Yutaka Tsutsumi 《Pathology international》1995,45(1):34-44
Extensive immunohistochemical analyses of the hyperplastic human palatine tonsil disclosed variegated B cell phenotypes on the lymphoid cells among the crypt epithelium. The reticular epithelial network was evident by cytokeratin immunostaining. The reticular epithelium near the crypt Iumen was positive for Iysozyme. Secretory component was negative, while HLA-DR was frequently expressed. Intramucosal small Iymphocytes, densely distributed in the Iuminal side, consisted mainly of B cells expressing CD19, CD20, CD21, CD22, CD45R, CD74, DBB42, HLA-DR, HLA-DQ, bcl-2 protein and surface lgM. Some B cells revealed mantle zone phenotypes (surface IgD+, CD5+, CD24+, DBA44+, CD10- -, DNA7- -). Cells of germinocyte phenotype (CD10+, DNA7+) were sparsely seen. A good number of intramucosal lymphoid cells were further labeled for CD11b, a phenotype of so-called B-1 cells. Plasma cells were clustered within the basal half. IgG was their major immunoglobulin class, followed by IgA, IgM and lgD classes. A smaller number of T cells (CD2+, CD3+, CD5+, CD45RO+, TCR αβ+) were identified among the epithelium. CD4+ cells predominated over CD8+ cells. TCR γΔ + cells were rare. Macrophages (CD68+), dendritic histio-cytes (S-100 protein+, CD1+), and natural killer cells (CD16+ or CD57+) were also dispersed. Another unique feature of this lymphoepithelial complex was the existence of HLA-DR intramucosal microvasculature, where lymphocyte recirculation was suggested. Proliferating cell nuclear antigen was detected commonly in the epithelial cells but rarely in the lymphoid cells. Possible lymphoepithelial interactions and morphologic similarities to the thymic medulla are discussed. 相似文献
80.
The presence of bradykinin-like polypeptides, kinin-releasing and destroying activity in brain 总被引:2,自引:0,他引:2
S Hori 《The Japanese journal of physiology》1968,18(6):772-787