全文获取类型
收费全文 | 31234篇 |
免费 | 1425篇 |
国内免费 | 167篇 |
专业分类
耳鼻咽喉 | 226篇 |
儿科学 | 548篇 |
妇产科学 | 320篇 |
基础医学 | 3751篇 |
口腔科学 | 822篇 |
临床医学 | 1966篇 |
内科学 | 7799篇 |
皮肤病学 | 496篇 |
神经病学 | 2222篇 |
特种医学 | 1417篇 |
外科学 | 5701篇 |
综合类 | 154篇 |
一般理论 | 1篇 |
预防医学 | 1032篇 |
眼科学 | 713篇 |
药学 | 2043篇 |
中国医学 | 65篇 |
肿瘤学 | 3550篇 |
出版年
2023年 | 170篇 |
2022年 | 351篇 |
2021年 | 593篇 |
2020年 | 346篇 |
2019年 | 454篇 |
2018年 | 581篇 |
2017年 | 431篇 |
2016年 | 579篇 |
2015年 | 540篇 |
2014年 | 720篇 |
2013年 | 938篇 |
2012年 | 1555篇 |
2011年 | 1687篇 |
2010年 | 989篇 |
2009年 | 828篇 |
2008年 | 1558篇 |
2007年 | 1705篇 |
2006年 | 1716篇 |
2005年 | 1691篇 |
2004年 | 1627篇 |
2003年 | 1456篇 |
2002年 | 1517篇 |
2001年 | 991篇 |
2000年 | 993篇 |
1999年 | 881篇 |
1998年 | 446篇 |
1997年 | 346篇 |
1996年 | 332篇 |
1995年 | 251篇 |
1994年 | 233篇 |
1993年 | 213篇 |
1992年 | 582篇 |
1991年 | 551篇 |
1990年 | 519篇 |
1989年 | 507篇 |
1988年 | 458篇 |
1987年 | 447篇 |
1986年 | 429篇 |
1985年 | 406篇 |
1984年 | 257篇 |
1983年 | 204篇 |
1982年 | 108篇 |
1981年 | 96篇 |
1979年 | 185篇 |
1978年 | 123篇 |
1977年 | 114篇 |
1973年 | 101篇 |
1972年 | 97篇 |
1970年 | 117篇 |
1969年 | 95篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
991.
Okano H Shiraki K Inoue H Kawakita T Deguchi M Sugimoto K Sakai T Murata K Nakano T Enjoji M 《International journal of molecular medicine》2003,12(6):867-870
PPARgamma is known to induce apoptosis in malignant tumor cells, but the mechanism of this induction is not well understood. We investigated induction of apoptosis with 15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2), a PPARgamma ligand, in cholangio cell carcinoma (CCC) cells (RBE, ETK-1 or HuCCT-1). Apoptosis was induced in RBE and ETK-1 cells with 15d-PGJ2, but not in HuCCT-1 cells, although PPARgamma was expressed in all CCC cells. Apoptosis-related proteins were also expressed, including FLIP, bclx, Apaf-1 and XIAP, but expression levels differed among the three cell lines. RBE cells treated with 15d-PGJ2 showed caspase activation, and it appeared that PPARgamma-induced apoptosis was dependent on caspase activation. However, neither ETK-1 nor HuCCT-1 cells showed significant activation of caspase-8 or -3 with 15d-PGJ2 treatment, raising the possibility of a caspase-independent apoptosis induction pathway. XIAP was down-regulated by 15d-PGJ2 in all three CCC cell lines. Therefore, 15d-PGJ2 induces apoptosis in CCC cells via caspase-dependent or independent pathways. 15d-PGJ2 may also induce down-regulation of XIAP and may promote caspase cascade activation through TNF-family receptor signaling pathways. 相似文献
992.
A gradient micropattern immobilization technique using a photomask was developed to investigate by microscopic observation the effect of the surface concentration of an immobilized thermo-responsive polymer. Poly(N-isopropylacrylamide-co-acrylic acid) was chosen as the thermo-responsive polymer, and was conjugated with 4-azidoaniline to form a photo-reactive thermo-responsive polymer (PIA-Az). The PIA-Az was coated onto a polystyrene plate, and immobilized using UV irradiation in the presence of a gradient micropattern photomask. The immobilization was performed with and without gelatin. Mouse fibroblast STO cells cultured on the plate did not adhere to the surface when PIA-Az had a high surface density, and no cell detachment was observed in any region when the temperature was lowered. However, on the gelatin coimmobilized surfaces, the cells adhered to all surfaces independent of the PIA-Az density, and detached from the high PIA-Az surface density areas when the temperature was lowered. The present technique demonstrates the effect of the surface concentration-dependent immobilization of the molecules. We show that cell detachment can be regulated by perturbating a small part of the cell-immobilized polymer interface. 相似文献
993.
Enkhtuvshin Gereltzul Yoshiyuki Baba Naoto Suda Momotoshi Shiga Maristela Sayuri Inoue Michiko Tsuji Insik Shin Yukio Hirata Kimie Ohyama Keiji Moriyama 《Journal of human genetics》2008,53(10):941-946
This is a report of a 27-year-old woman with an unusual de novo chromosomal abnormality. Mosaicism was identified in peripheral
blood cells examined by standard G-bands by trypsin using Giemsa (GTG) analysis and fluorescence in situ hybridization (FISH)
analysis with chromosome-18 region-specific probes, 46,XX,del(18)(pter → q21.33:)[41], 46,XX,r(18)(::p11.21 → q21.33::)[8],
and 46,XX,der(18)(pter → q21.33::p11.21 → pter)[1]. On the other hand, the karyotype of periodontal ligament fibroblasts was
nonmosaic, 46,XX, der(18)(pter → q21.33::p11.21 → pter)[50]. All cell lines appeared to be missing a portion of 18q (q21.33 → qter).
The pattern of the dup(18p)/del(18q) in the rod configuration raises the possibility of an inversion in chromosome 18 in one
of the parents. However, no chromosomal anomaly was detected in either parent. The most probable explanation is that de novo
rod and ring configurations arose simultaneously from an intrachromosomal exchange. The unique phenotype of this patient,
which included primary hypothyroidism and primary hypogonadism, is discussed in relation to her karyotype. 相似文献
994.
To investigate the neural mechanisms of motion-defined shape processing, we recorded single unit activity in the middle temporal area (MT) while monkeys performed a shape discrimination task under the shape-from-motion (SFM) condition, where a motion cue is critical for shape perception. About 40% of MT neurons responded differentially to shapes under the SFM condition. The differential responses to shapes could not be explained by either the heterogeneous structure of the receptive field or the amount of motion signal. On the other hand, under the shape-from-luminance (SFL) condition, where a luminance cue is critical for shape perception, the proportion of neurons showing differential responses to shapes was smaller than that under the SFM condition and the magnitudes of differential responses themselves were weaker. Thus, the requirement for motion processing for shape perception may facilitate a differential response to shapes under the SFM condition. We compared neuronal activities during the shape discrimination task with those during the direction discrimination task under the SFM condition. Differential responses to shapes were observed more frequently during the shape discrimination task than during the direction discrimination task. Thus, the motion-defined shape processing influenced MT activity. 相似文献
995.
Chondrogenic differentiation of human mesenchymal stem cells on photoreactive polymer-modified surfaces 总被引:2,自引:0,他引:2
Human mesenchymal stem cells (MSCs) were cultured on polystyrene surfaces modified with photoreactive azidophenyl-derivatives of three different chargeable polymers, poly(acrylic acid) (PAAc), polyallylamine (PAAm), and poly(ethylene glycol) (PEG). The MSCs adhered and spread both on a PAAm-modified surface and on PAAc-modified and polystyrene (control) surfaces. However, the cells adhered more easily to the PAAm-modified surface. The MSCs did not attach to the PEG-modified surface and aggregated to form pellets immediately after cell seeding. The cells proliferated on the PAAc-, PAAm-modified and control surfaces with culture time, formed a monolayer, and aggregated to form pellets. The cells in the pellets that formed on the PAAm- and PEG-modified surfaces after 2 weeks culture had a round morphology and the extracellular matrices were positively stained by safranin O and toluidine blue, while those that formed on the PAAc-modified and control surfaces had a spindle, fibroblast-like morphology and were not positively stained by safranin O and toluidine blue. The pellets that formed on the PAAm- and PEG-modified surfaces contained significantly higher levels of sulfated glycosaminoglycans than did those that formed on the PAAc-modified and control surfaces. Type II collagen and cartilage proteoglycan were immunohistologically detected in the pellets that formed on PAAm- and PEG-modified surfaces, but not those that formed on the PAAc-modified and control surfaces. The MSCs cultured on the PAAm- and PEG-modified surfaces expressed a high level of cartilaginous genes encoding type II collagen and aggrecan, while the MSCs cultured on the PAAc-modified and control surfaces did not express these genes. These results suggest that the PAAm-modified surface supported cell adhesion and proliferation and also promoted chondrogenic differentiation of the MSCs. The PAAc-modified and polystyrene surfaces supported cell adhesion and proliferation, but not chondrogenic differentiation. The PEG-modified surfaces did not support cell adhesion, but did promote chondrogenic differentiation. The adhesion, proliferation, and differentiation of the MSCs could be controlled by surface chemistry. 相似文献
996.
Yamada R Sasagawa T Kirumbi LW Kingoro A Karanja DK Kiptoo M Nakitare GW Ichimura H Inoue M 《Journal of medical virology》2008,80(5):847-855
Human papillomavirus (HPV) infection and cervical abnormalities, and their association with human immunodeficiency virus (HIV) infection were studied in 488 women who visited a health center in Nairobi. PCR-based HPV and cervical cytology tests were carried out on all participants, and peripheral CD4+ T cells and plasma HIV RNA were quantitated in HIV positive women. HIV were positive in 32% (155/488) of the women; 77% of these were untreated, and the others had been treated with anti-retroviral drugs within 6 months. Cervical HPV infection was detected in 17% of HIV negative and 49% of HIV positive women. Low-grade squamous intraepithelial lesions were observed in 6.9% of HIV negative and 21% of HIV positive women, while high-grade squamous intraepithelial lesions and cancer were seen in 0.6% and 5.8%, respectively. Multivariate analysis revealed that HIV and HPV infections were associated with each other. Cervical lesions were significantly associated with high-risk HPVs and with HIV infection, depending on HPV infection. HPV infection increased in accordance with lower CD4+ T cell counts and higher HIV RNA levels, and high-grade lesions were strongly associated with high-risk HPV infection and low CD4+ T cell counts. Immunosuppression as a result of HIV infection appears to be important for malignant progression in the cervix. Nationwide prevention of HIV infection and cervical cancer screening are necessary for the health of women in this area. High-risk HPV infection and low CD4+ T cell counts are the risk factors for cervical cancer. 相似文献
997.
Takata Y Inoue H Sato A Tsugawa K Miyatake K Hamada D Shinomiya F Nakano S Yasui N Tanahashi T Itakura M 《Journal of human genetics》2008,53(2):163-173
We conducted population-based association tests for the four selected SNPs (rs2240340/padi4_94, rs7528684/fcrl3_3, rs3792876/slc2F2 and rs2268277/runx1) previously reported to be associated with rheumatoid arthritis (RA). The study population consisted of 950 unrelated Japanese
subjects with RA and 507 controls, none of whom had previously been tested for these variants. Only the SNP rs2240340/padi4_94 was modestly associated with RA [allele odds ratio (OR) 1.22, 95% confidence interval (CI) 1.04–1.43, P = 0.012]. The most significant association effect was found for genotype contrast between minor and major allele homozygotes
(OR 1.53, 95% CI 1.10–2.12, P = 0.010). No other SNPs showed a statistically significant association with RA in our population. Meta-analysis of published
studies and our new data confirmed a highly significant association between PADI4 gene SNPs and increased risk of RA in East Asian populations (allele fixed-effects summary OR 1.31, 95% CI 1.22–1.41, P < 0.0001). We found some evidence for an association of either rs7528684/fcrl3_3 or rs3792876/slc2F2 with RA; however, because the magnitudes of effects were apparently much weaker than those reported in the initial positive
reports, and there were substantial levels of inter-study OR heterogeneity, we concluded that additional studies are needed
to fully understand the present results.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
998.
Marchildon PA Sugiyama T Fukuda Y Peacock JS Asaka M Shimoyama T Graham DY Fukada Y 《Journal of clinical microbiology》2003,41(4):1480-1485
It has been suggested that enzyme immunoassay (EIA) kits validated in one region may yield variable diagnostic performance results in different regions, possibly due to strain-specific differences in antibody responses in different populations. We tested (13)C-urea breath test-characterized serum samples from 109 U.S. patients and 288 Japanese patients using enzyme immunoassay with different preparations of high-molecular-weight cell-associated (HM-CAP) antigens that are conserved across Helicobacter pylori strains. Replicate antigens were prepared from five H. pylori clinical isolates. Eight antigen preparations were evaluated: two of U.S. origin and six of Japanese origin. The accuracies achieved with the eight antigen preparations ranged from 94.4 to 96.3% with the U.S. samples. With the Japanese samples the accuracies achieved ranged from 92.3 to 97.2%. Use of a pool of HM-CAP antigens prepared from isolates from Japan resulted in a higher median enzyme immunoassay value and slightly fewer samples with indeterminate results compared to the results obtained by use of the U.S. standard HM-CAP antigen for H. pylori-positive patients (accuracies, 97.2 and 92.3%, respectively), suggesting that variations in performance between both antigen source and patient population might be reduced by using antigens pooled from several strains. 相似文献
999.
1000.
High Expression of SQSTM1/p62 Protein Is Associated with Poor Prognosis in Epithelial Ovarian Cancer
Reiko Iwadate Jun Inoue Hitoshi Tsuda Masashi Takano Kenichi Furuya Akira Hirasawa Daisuke Aoki Johji Inazawa 《ACTA HISTOCHEMICA ET CYTOCHEMICA》2014,47(6):295-301
High expression of SQSTM1/p62 (p62) protein, which functions as a hub for various cellular signaling pathways, has been detected in several human cancers. However, the clinicopathological impact of high p62 expression is largely unknown in epithelial ovarian cancer (EOC). Here, the expression level of p62 in primary EOCs (n=266) was assessed by immunohistochemistry, and its clinical significance was analyzed. Univariate and multivariate analyses were used to determine the impact of p62 expression on overall survival. p62 was expressed in the cytoplasm (Cyto) and/or nucleus (Nuc) in primary EOCs, and an expression subtype (CytoHigh/NucLow), showing high expression in the cytoplasm but low expression in the nucleus, was significantly correlated with serous carcinoma (P<0.001), advanced stage (P=0.005), presence of residual tumor (P<0.001), and low overall survival rate (P=0.013). Furthermore, in serous carcinomas (n=107), the p62 CytoHigh/NucLow subtype was significantly correlated with low overall survival rate (P=0.019) as an independent factor (P=0.044). Thus, our findings suggest that high expression of cytoplasmic p62 may be a novel prognostic biomarker in EOC, particularly in serous carcinoma. 相似文献