全文获取类型
收费全文 | 22635篇 |
免费 | 1687篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 789篇 |
妇产科学 | 522篇 |
基础医学 | 3301篇 |
口腔科学 | 328篇 |
临床医学 | 2770篇 |
内科学 | 4983篇 |
皮肤病学 | 479篇 |
神经病学 | 2389篇 |
特种医学 | 384篇 |
外科学 | 2003篇 |
综合类 | 128篇 |
一般理论 | 28篇 |
预防医学 | 2508篇 |
眼科学 | 245篇 |
药学 | 1528篇 |
中国医学 | 43篇 |
肿瘤学 | 1831篇 |
出版年
2024年 | 15篇 |
2023年 | 198篇 |
2022年 | 339篇 |
2021年 | 763篇 |
2020年 | 509篇 |
2019年 | 759篇 |
2018年 | 783篇 |
2017年 | 576篇 |
2016年 | 651篇 |
2015年 | 713篇 |
2014年 | 909篇 |
2013年 | 1189篇 |
2012年 | 1937篇 |
2011年 | 1943篇 |
2010年 | 1036篇 |
2009年 | 872篇 |
2008年 | 1512篇 |
2007年 | 1562篇 |
2006年 | 1539篇 |
2005年 | 1424篇 |
2004年 | 1313篇 |
2003年 | 1163篇 |
2002年 | 1018篇 |
2001年 | 139篇 |
2000年 | 91篇 |
1999年 | 151篇 |
1998年 | 193篇 |
1997年 | 136篇 |
1996年 | 135篇 |
1995年 | 121篇 |
1994年 | 82篇 |
1993年 | 87篇 |
1992年 | 45篇 |
1991年 | 44篇 |
1990年 | 41篇 |
1989年 | 49篇 |
1988年 | 35篇 |
1987年 | 23篇 |
1986年 | 31篇 |
1985年 | 29篇 |
1984年 | 41篇 |
1983年 | 26篇 |
1982年 | 24篇 |
1981年 | 25篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1978年 | 14篇 |
1976年 | 16篇 |
1973年 | 13篇 |
1971年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
151.
Diffuse optical tomography of breast cancer during neoadjuvant chemotherapy: a case study with comparison to MRI 总被引:1,自引:0,他引:1
Choe R Corlu A Lee K Durduran T Konecky SD Grosicka-Koptyra M Arridge SR Czerniecki BJ Fraker DL DeMichele A Chance B Rosen MA Yodh AG 《Medical physics》2005,32(4):1128-1139
We employ diffuse optical tomography (DOT) to track treatment progress in a female subject presenting with locally advanced invasive carcinoma of the breast during neoadjuvant chemotherapy. Three-dimensional images of total hemoglobin concentration and scattering identified the tumor. Our measurements reveal tumor shrinkage during the course of chemotherapy, in reasonable agreement with magnetic resonance images of the same subject. A decrease in total hemoglobin concentration contrast between tumor and normal tissue was also observed over time. The results demonstrate the potential of DOT for measuring physiological parameters of breast lesions during chemotherapy. 相似文献
152.
Filho OG Gordan AN Mello Rde A Neto CS Heinke T 《International journal of surgical pathology》2004,12(2):151-153
Hamartomas were first described by Albrecht in 1904, who defined them as tumor-like malformations in which there was abnormal blending of the normal components of an organ. The myoid hamartoma is a rare benign lesion of the breast and has an uncertain origin, possibly in the walls of the blood vessels, muscularis mammillae of the areolae, and mainly in myoepithelium. We report 3 cases of myoid hamartomas of the breast, with the clinical, radiologic, and histopathological findings, and review the literature. The 3 lesions showed normal breast ducts and lobules, entrapped by a muscular stroma and some foci of mature adipose tissue. The muscular origin of part of the stroma was confirmed by strong reactiveness with smooth-muscle actin. 相似文献
153.
Wong N Hui AB Fan B Lo KW Pang E Leung SF Huang DP Johnson PJ 《Cancer Genetics and Cytogenetics》2003,140(2):124-132
Nasopharyngeal carcinoma (NPC) cell lines and xenografts represent valuable models for functional and therapeutic studies on this common malignancy in Southeast Asia. The karyotypic information in most NPC cell lines and xenografts, however, remains largely unclear to date. We have characterized the chromosomal aberrations in six commonly used human NPC cell lines and xenografts using the molecular cytogenetic technique of comparative genomic hybridization (CGH). Genomic imbalances identified in cell lines were further correlated with structural abnormalities indicated from spectral karyotyping (SKY) analysis. CGH revealed consistent overrepresentations of 8q (six out of six cases) with a smallest overlapping region identified on 8q21.1q22. Other common gains included 7p (4/6 cases), 7q (4/6 cases), 12q (4/6), and 20q (4/6 cases), where minimal overlapping regions were suggested on 7p15p14, 7q11.2q21, and 12q22q24.1. Common losses were detected on 3p12p21 (4/6 cases) and 11q14qter (4/6 cases). Although SKY analysis on cell lines revealed predominantly unbalanced rearrangements, reciprocal translocations that involved chromosome 2 [i.e., t(1;2), t(2;3), and t(2;4)] were suggested. Furthermore, SKY examination illustrated additional breakpoints on a number of apparently balanced chromosomes. These breakpoints included 3p21, 3q26, 5q31, 6p21.1p25, 7p14p22, and 8q22. Our finding of regional gains and losses and breakpoints represents information that may contribute to NPC studies in vitro. 相似文献
154.
Lovering Ruth; Middleton-Price Helen R.; O'Reilly Marie-Anne J.; Genet Sally A.; Parkar Mohammed; Sweatman Angela K.; Bradley Linda D.; Alterman Lesley A.; Malcolm Sue; Morgan Gareth; Levinsky Roland J.; Kinnon Christine 《Human molecular genetics》1993,2(2):139-141
Genetic linkage analysis has been instrumental in mapping thegene for X-linked agammaglobulinemia (XLA) to the proximal longarm of the human X chromosome, to Xq22. Due to the relativerarity of this disease the localization of the gene within Xq22has remained imprecise. We have investigated twenty-nine familiesaffected by XLA and have found no recombinants with the DXS178locus in over 30 informative meioses. DXS178 is now the mostreliable and informative locus for use in pre-natal diagnosisand carrier detection of XLA. In addition, we have identifiednew closely linked proximal and distal flanking markers forXLA, DXS442 and DXS101, respectively. These loci are separatedby 2cM, considerably reducing the extent of DNA within whichthe XLA locus can be contained. This will open up the way formore directed positional cloning efforts for the isolation ofthe XLA gene. 相似文献
155.
Candida albicans expresses a focal adhesion kinase-like protein that undergoes increased tyrosine phosphorylation upon yeast cell adhesion to vitronectin and the EA.hy 926 human endothelial cell line
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Santoni G Lucciarini R Amantini C Jacobelli J Spreghini E Ballarini P Piccoli M Gismondi A 《Infection and immunity》2002,70(7):3804-3815
The signaling pathways triggered by adherence of Candida albicans to the host cells or extracellular matrix are poorly understood. We provide here evidence in C. albicans yeasts of a p105 focal adhesion kinase (Fak)-like protein (that we termed CaFak), antigenically related to the vertebrate p125Fak, and its involvement in integrin-like-mediated fungus adhesion to vitronectin (VN) and EA.hy 926 human endothelial cell line. Biochemical analysis with different anti-chicken Fak antibodies identified CaFak as a 105-kDa protein and immunofluorescence and cytofluorimetric analysis on permeabilized cells specifically stain C. albicans yeasts; moreover, confocal microscopy evidences CaFak as a cytosolic protein that colocalizes on the membrane with the integrin-like VN receptors upon yeast adhesion to VN. The protein tyrosine kinase (PTK) inhibitors genistein and herbimycin A strongly inhibited C. albicans yeast adhesion to VN and EA.hy 926 endothelial cells. Moreover, engagement of alpha v beta 3 and alpha v beta 5 integrin-like on C. albicans either by specific monoclonal antibodies or upon adhesion to VN or EA.hy 926 endothelial cells stimulates CaFak tyrosine phosphorylation that is blocked by PTK inhibitor. A role for CaFak in C. albicans yeast adhesion was also supported by the failure of VN to stimulate its tyrosine phosphorylation in a C. albicans mutant showing normal levels of CaFak and VNR-like integrins but displaying reduced adhesiveness to VN and EA.hy 926 endothelial cells. Our results suggest that C. albicans Fak-like protein is involved in the control of yeast cell adhesion to VN and endothelial cells. 相似文献
156.
Mariano Rocchi Angela Covone Giovanni Romeo Raffaella Faraonio Vittorio Colantuoni 《Somatic Cell and Molecular Genetics》1989,15(2):185-190
The human gene coding for RBP4 has been assigned to 10q2324 using a panel of somatic cell hybrids and in situ hybridization experiments. The mapping of the human RBP1, previously assigned by our group to chromosome 3 using a panel of somatic cell hybrids, was restricted to the region 3q2122 using in situ experiments and Southern blots of genomic DNA from a hybrid retaining a portion of chromosome 3.R.F. is recipient of a Research Grant from A.I.R.C. 相似文献
157.
Matrix metalloproteinase-2, -9, and tissue inhibitor of metalloproteinase-1 in patients with hypertension. 总被引:6,自引:0,他引:6
Giuseppe Derosa Angela D'Angelo Leonardina Ciccarelli Mario N Piccinni Fabio Pricolo Sibilla Salvadeo Lorenza Montagna Alessia Gravina Ilaria Ferrari Simona Galli Sonia Paniga Carmine Tinelli Arrigo F G Cicero 《Endothelium》2006,13(3):227-231
There are conflicting data in the literature regarding the expression pattern of the vascular matrix metalloproteinase (MMP) system and their inhibitors (TIMPs) in human hypertension. The authors hypothesized that MMP-2, MMP-9, and TIMP-1 would be abnormal in hypertension, reflecting alterations in extracellular matrix (ECM) turnover. The authors measured plasma levels and activities of MMP-2, MMP-9, and TIMP-1 in 44 hypertensive patients and 44 controls. MMP-2 levels and activity were significantly higher in hypertensive group (p < .0001). Significant increase was also observed for MMP-9 level and activity (p < .0001) and for TIMP-1 (p < .0001) in hypertensive patients. Plasma levels and activities of MMP-2, MMP-9, and TIMP-1 are increased in hypertensive patients, which may reflect abnormal ECM metabolism. 相似文献
158.
Sanchez AA Johnston DA Myers C Edwards JE Mitchell AP Filler SG 《Infection and immunity》2004,72(1):598-601
Candida albicans must penetrate the endothelial cell lining of the vasculature to invade the deep tissues during a hematogenously disseminated infection. We compared 27 C. albicans mutants with their wild-type parent for their capacity to damage endothelial cells in vitro and cause a lethal infection in mice following tail vein inoculation. Of 10 mutants with significantly impaired capacity to damage endothelial cells, all had attenuated virulence. Therefore, the endothelial cell damage assay can be used as a screen to identify some virulence factors relevant to hematogenously disseminated candidiasis. 相似文献
159.
Multiple pathways of cell invasion are regulated by multiple families of serine proteases 总被引:5,自引:0,他引:5
Del Rosso M Fibbi G Pucci M D'Alessio S Del Rosso A Magnelli L Chiarugi V 《Clinical & experimental metastasis》2002,19(3):193-207
The complex process of tumor invasion requires the coordinated expression and activity of cell-substratum adhesive interactions
and of cell-associated protease systems, which destroy the extracellular matrix (ECM), in order to enable the invading cells
to simultaneously grip and destroy the anatomical barriers that control cell spreading. A number of data indicate that such
a `grip and go' process may be performed by an enlarging series of cell membrane-associated serine proteases and serine protease
receptors, which provide the invasive cells with a functional unit (the protease and its receptor), able to mediate cell-substratum
adhesion through specific receptor domains, to proteolytically degrade ECM and to deliver into the cell signals that up-regulate
the expression either of the protease/receptor complex, or of other adhesion molecules, such as integrins. There is evidence
that some proteases and protease receptor expression are under the control of tumor hypoxia, which is the result of an imbalance
in oxygen supply and demand. The urokinase-type plasminogen activator (u-PA) receptor (u-PAR) is under hypoxic control and
cooperates with other serine proteases of the blood coagulation pathways that may extravasate in the tumor milieu as a result
of hypoxia-simulated increase of vessel permeability. Other serine proteases and their receptors cooperate with the cell-associated
fibrinolytic system to promote cell invasion. Among these, tissue factor and its ligand coagulation factor VII, thrombin and
its protease-activated receptors, and type II trans-membrane serine proteases seem to play a crucial role. This Review takes
into consideration the complex scenario of the single serine proteases and related receptors that are involved in cell invasion,
as well as the protease receptor/adhesion molecule interplay which is necessary to focus the cell surface-driven proteolysis
where adhesion provides a grip to the invading cell.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
160.
Regulation of the antibody response to sheep erythrocytes by monoclonal IgG antibodies 总被引:1,自引:0,他引:1
Ilana Zalcberg Quintana Angela V. Silveira Güran Mller 《European journal of immunology》1987,17(9):1343-1349
Monoclonal antibodies directed against sheep erythrocytes of the isotypes IgG1, IgG2b and IgG2a were used to analyze the specificity of antibody-induced suppression of the immune response. It was first shown that all monoclonals reacted against different antigenic determinants and they all suppressed the immune response to sheep erythrocytes when given shortly after the antigen to more than 50% as compared to 90-96% inhibition obtained with a polyclonal antiserum. Increasing the doses of monoclonals did not increase suppression. However, two different monoclonals administered together caused an additive, but not a synergistic inhibitory effect. No enhancement of the immune response was observed with any of the Ig classes tested. These findings show that four different antigenic determinants on sheep erythrocytes induced the synthesis of corresponding antibodies, with little or no signs of a dominant determinant. Passively administered monoclonal antibodies, even at supraoptimal doses, never suppressed the immune response to the same extent as a polyclonal antiserum, suggesting that each monoclonal only suppressed the synthesis of the corresponding antibody and did not affect antibody synthesis to other determinants. 相似文献