全文获取类型
收费全文 | 12450篇 |
免费 | 604篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 147篇 |
儿科学 | 186篇 |
妇产科学 | 193篇 |
基础医学 | 1620篇 |
口腔科学 | 251篇 |
临床医学 | 784篇 |
内科学 | 3612篇 |
皮肤病学 | 335篇 |
神经病学 | 896篇 |
特种医学 | 445篇 |
外科学 | 1680篇 |
综合类 | 62篇 |
预防医学 | 287篇 |
眼科学 | 171篇 |
药学 | 1076篇 |
中国医学 | 39篇 |
肿瘤学 | 1321篇 |
出版年
2023年 | 49篇 |
2022年 | 95篇 |
2021年 | 222篇 |
2020年 | 132篇 |
2019年 | 152篇 |
2018年 | 209篇 |
2017年 | 162篇 |
2016年 | 203篇 |
2015年 | 248篇 |
2014年 | 273篇 |
2013年 | 345篇 |
2012年 | 644篇 |
2011年 | 730篇 |
2010年 | 393篇 |
2009年 | 318篇 |
2008年 | 631篇 |
2007年 | 706篇 |
2006年 | 629篇 |
2005年 | 639篇 |
2004年 | 685篇 |
2003年 | 717篇 |
2002年 | 684篇 |
2001年 | 400篇 |
2000年 | 411篇 |
1999年 | 347篇 |
1998年 | 157篇 |
1997年 | 99篇 |
1996年 | 117篇 |
1995年 | 96篇 |
1994年 | 114篇 |
1993年 | 89篇 |
1992年 | 222篇 |
1991年 | 187篇 |
1990年 | 172篇 |
1989年 | 198篇 |
1988年 | 157篇 |
1987年 | 171篇 |
1986年 | 146篇 |
1985年 | 159篇 |
1984年 | 107篇 |
1983年 | 104篇 |
1982年 | 54篇 |
1981年 | 55篇 |
1980年 | 51篇 |
1979年 | 77篇 |
1978年 | 53篇 |
1977年 | 49篇 |
1975年 | 46篇 |
1970年 | 46篇 |
1967年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
111.
Terada Y Imoto I Nagai H Suwa K Momoi M Tajiri T Onda M Inazawa J Emi M 《American journal of medical genetics》2001,103(2):176-180
We performed molecular analysis of a germline interstitial deletion of chromosome 4 [del(4)(q21.22q23)], which had been observed in a male infant manifesting early-onset hepatoblastoma (HBL). The chromosomal anomaly in this child was associated with a unique congenital syndrome including HBL, atrial septal defect, ventricular septal defect, patent ductus arteriosus, mental retardation, and seizures. However, the patient did not exhibit a megalencephaly typical of 4q21-22 deletions. His HBL was associated with an increasing serum alpha-fetoprotein level and rapid growth. To define the chromosomal deletion at the molecular level in this child, we analyzed his lymphoblasts with fluorescence in situ hybridization, using as probes a panel of BAC/PAC genomic clones containing STS markers covering the 4q12-27 region. The analysis revealed that the affected chromosome had an 8-cM deletion within 4q21-q22, flanked by markers D4S2964 and D4S2966. This microdeletion overlaps with the commonly deleted region at 4q21-q22 that was recently defined in adult hepatocellular carcinomas. 相似文献
112.
Yuichi Takeoka Shao-Yuan Chen Richard L. Boyd Koichi Tsuneyama Nobuhisa Taguchi Shinji Morita Hisashi Yago Seishi Suehiro Aftab A. Ansari Leonard D. Shultz M. Eric Gershwin 《Clinical & developmental immunology》1997,5(2):79-89
It is widely accepted that the thymic microenvironment regulates normal thymopoiesis
through a highly coordinated and complex series of cellular and cytokine interactions. A direct
corollary of this is that abnormalities within the microenvironment could be of etiologic
significance in T-cell-based diseases. Our laboratory has developed a large panel of
monoclonal antibodies (mAbs) that react specifically with epithelial or nonepithelial
markers in the thymus. We have taken advantage of these reagents to characterize the
thymic microenvironment of several genetic strains of mice, including BALB/cJ,
C57BL/6J, NZB/BlnJ, SM/J, NOD/Ltz, NOD/Ltz-scid/sz, C57BL/6J-Hcph
me/Hcph me, and
ALY/NscJcl-aly/aly mice, and littermate control animals. We report herein that control
mice, including strains of several backgrounds, have a very consistent phenotypic profile
with this panel of monoclonal antibodies, including reactivity with thymic epithelial cells
in the cortex, the medulla and the corticomedullary junction, and the extracellular matrix.
In contrast, the disease-prone strains studied have unique, abnormal staining of thymic cortex
and medulla at both the structural and cellular levels. These phenotypic data suggest
that abnormalities in interactions between developing thymocytes and stromal cells characterize
disease-prone mice. 相似文献
113.
114.
115.
Role of macrophage migration inhibitory factor in otitis media with effusion in adults 总被引:4,自引:0,他引:4
Kariya S Okano M Aoji K Kosaka M Chikumoto E Hattori H Yuen K Nishioka S Nishioka K Nishizaki K 《Clinical and diagnostic laboratory immunology》2003,10(3):417-422
Otitis media with effusion (OME) is one of the most common ear diseases. Bacterial endotoxins and several inflammatory cytokines appear to be involved in the pathogenesis of OME in children; however, little is known of the immunological aspects of the onset of OME in adults. We sought to determine the presence of macrophage migration inhibitory factor (MIF) as well as interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), RANTES (regulated upon activation, normal T-cell expressed and presumably secreted), and endotoxin in middle ear effusions (MEEs) from adult patients with OME. In addition, the levels of MIF in MEEs from adults and children were compared. MEE was obtained from 95 adults and 11 children. The levels of MIF, IL-1beta, TNF-alpha, and RANTES were determined by enzyme-linked immunosorbent assay, and the concentrations of endotoxin and total protein were determined by the Endospec assay and bicinchoninic acid assay, respectively. MIF was detected in 97.9% of the MEEs from adults, while endotoxin, IL-1beta, TNF-alpha, and RANTES were detected in 96.8, 12.6, 5.3, and 43.9%, respectively. In addition, the level of MIF was significantly higher than those of endotoxin, IL-1beta, and TNF-alpha. A positive correlation between the levels of MIF and endotoxin was observed. MIF and endotoxin were detected in 81.8 and 72.7%, respectively, of the MEEs from the children. The level of MIF was significantly higher in the children, and conversely that of endotoxin was significantly higher in the adults. These results suggest that the interaction between MIF and endotoxin may promote fluid collection in the middle ear, particularly in adults. 相似文献
116.
Murase T Takino H Shimizu S Inagaki H Tateyama H Takahashi E Matsuda H Eimoto T 《Human pathology》2003,34(11):1178-1184
Combined small cell and non-small cell carcinoma is relatively rare in the lung. Examination of the clonal relationship of different components in this type of tumor may give a clue to the rarity. We retrieved 6 such tumors; all 6 had small cell carcinoma and adenocarcinoma components, and 3 had an additional squamous cell carcinoma component. We examined the point mutations in the p53 gene and allelic loss (ie, the loss of heterozygosity [LOH] pattern) of chromosome 3p in each component. p53 mutations were detected in the small cell carcinoma component of 5 tumors and in the non-small cell carcinoma components of 2 tumors. In 1 case, the squamous cell carcinoma component had a p53 mutation locus identical to that in the small cell carcinoma component, but in the other case, the adenocarcinoma component had a different mutation than that in the small cell carcinoma component. Chromosome 3p LOH loci in the squamous cell carcinoma component were present in the small cell carcinoma component in all 3 cases, but some LOH loci were not identical in the small cell carcinoma and adenocarcinoma components in 3 cases. These results suggest that the small cell and squamous cell carcinoma components of combined small cell lung carcinomas have an intimate clonal relationship. On the other hand, the adenocarcinoma component often may be derived from a separate clone or, more likely, undergo a progressive process separate from the squamous cell-small cell carcinoma beginning in a very early stage, that is, before the appearance of p53 and chromosome 3p abnormalities. This tumorigenesis process may explain the relative rarity of combined small cell and non-small cell carcinoma, which occurs primarily in the peripheral lung, an infrequent site of squamous cell carcinoma. 相似文献
117.
Kabashima K Murata T Tanaka H Matsuoka T Sakata D Yoshida N Katagiri K Kinashi T Tanaka T Miyasaka M Nagai H Ushikubi F Narumiya S 《Nature immunology》2003,4(7):694-701
Physical interaction of T cells and dendritic cells (DCs) is essential for T cell proliferation and differentiation, but it has been unclear how this interaction is regulated physiologically. Here we show that DCs produce thromboxane A2 (TXA2), whereas naive T cells express the thromboxane receptor (TP). In vitro, a TP agonist enhances random cell movement (chemokinesis) of naive but not memory T cells, impairs DC-T cell adhesion, and inhibits DC-dependent proliferation of T cells. In vivo, immune responses to foreign antigens are enhanced in TP-deficient mice, which also develop marked lymphadenopathy with age. Similar immune responses were seen in wild-type mice treated with a TP antagonist during the sensitization period. Thus, TXA2-TP signaling modulates acquired immunity by negatively regulating DC-T cell interactions. 相似文献
118.
Renal glomerulogenesis in medaka fish, Oryzias latipes 总被引:2,自引:0,他引:2
Svetlana Fedorova Rieko Miyamoto Tomohiro Harada Sumio Isogai Hisashi Hashimoto Kenjiro Ozato Yuko Wakamatsu 《Developmental dynamics》2008,237(9):2342-2352
We provide an overview of glomerulogenesis in medaka from the embryo to the adult by means of in situ hybridization with the wt1 gene as a marker as well as histology and three-dimensional images. The pronephric glomus starts to develop in the intermediate mesoderm during early somitogenesis, is completed before hatching, and persists throughout the lifetime of the fish. Within 5 days after hatching, mesonephric glomerulus formation begins in the caudomedial end of the pronephric sinus and duct area. The number of glomeruli reaches approximately 200-300 in each kidney within 2 months after hatching. wt1 expression during nephron maturation served as a marker for the formation of the mesenchymal condensate and the nephrogenic body. Existence of mesenchymal condensates and persistence of wt1 expression in the adult kidney suggest that the mesonephros retains precursor cells that may be capable of contributing to neoglomerulogenesis during adulthood. Developmental Dynamics 237:2342-2352, 2008. (c) 2008 Wiley-Liss, Inc. 相似文献
119.
Hisashi Aoki Reiko Tsukahara Kyonosuke Yabe 《European journal of applied physiology》1989,58(4):426-432
Summary The effects of pre-motion silent period (PSP) on dynamic force exertion were studied in ten healthy subjects performing ballistic elbow extensions. The experiments were designed to evaluate the significance of mean differences between the averaged dynamic force curves of two groups: PSP-presence groups and PSP-absence groups. The presence of PSP was judged quantitatively and automatically by means of a newly developed method using statistical analysis. The results indicated that there were two effects of PSP on dynamic force exertion: one was a reducing effect, observed prior to the movement; the other was a reinforcing effect, observed in the first part of the ballistic movement. The duration of the reinforcement was significantly correlated with the duration of the reducing effect of PSP. The findings suggested that the reinforcement of dynamic force may be produced by the pre-stretch of agonistic muscles caused by prior force reduction due to PSP occurrence. The fact that PSP plays an important role in dynamic force exertion suggests that PSP may be incorporated in the central motor control system designed to interrupt the background activity, to stretch the agonist and to reinforce the dynamic force. 相似文献
120.
Simultaneous occurrence of medullary and follicular carcinoma in the same thyroid lobe 总被引:2,自引:0,他引:2
T Tanaka N Yoshimi N Kanai H Mori K Nagai A Fujii S Sakata N Tokimitsu 《Human pathology》1989,20(1):83-86
A rare case of the simultaneous development of medullary and follicular carcinoma of the thyroid gland in a 51-year-old Japanese woman is examined. A preoperative diagnosis was made by needle aspiration cytology. Neoplastic cells of the medullary carcinoma were positive for calcitonin and carcinoembryonic antigen, whereas the tumor cells of the follicular carcinoma were negative for these substances. This case presents evidence that, in rare cases, two malignant epithelial neoplasms of different origins can occur in the same lobe of the thyroid. 相似文献