全文获取类型
收费全文 | 3514篇 |
免费 | 203篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 62篇 |
妇产科学 | 21篇 |
基础医学 | 450篇 |
口腔科学 | 61篇 |
临床医学 | 212篇 |
内科学 | 929篇 |
皮肤病学 | 95篇 |
神经病学 | 283篇 |
特种医学 | 221篇 |
外科学 | 557篇 |
综合类 | 24篇 |
预防医学 | 106篇 |
眼科学 | 96篇 |
药学 | 193篇 |
中国医学 | 21篇 |
肿瘤学 | 378篇 |
出版年
2024年 | 4篇 |
2023年 | 23篇 |
2022年 | 77篇 |
2021年 | 141篇 |
2020年 | 79篇 |
2019年 | 106篇 |
2018年 | 116篇 |
2017年 | 83篇 |
2016年 | 89篇 |
2015年 | 97篇 |
2014年 | 153篇 |
2013年 | 171篇 |
2012年 | 253篇 |
2011年 | 274篇 |
2010年 | 170篇 |
2009年 | 131篇 |
2008年 | 208篇 |
2007年 | 220篇 |
2006年 | 214篇 |
2005年 | 198篇 |
2004年 | 168篇 |
2003年 | 191篇 |
2002年 | 156篇 |
2001年 | 42篇 |
2000年 | 38篇 |
1999年 | 30篇 |
1998年 | 26篇 |
1997年 | 33篇 |
1996年 | 25篇 |
1995年 | 26篇 |
1994年 | 19篇 |
1993年 | 13篇 |
1992年 | 28篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1977年 | 4篇 |
1976年 | 4篇 |
1965年 | 2篇 |
1963年 | 2篇 |
1929年 | 2篇 |
排序方式: 共有3742条查询结果,搜索用时 31 毫秒
31.
Kera J Mizuki N Ota M Katsuyama Y Pivetti-Pezzi P Ohno S Inoko H 《Tissue antigens》1999,54(6):565-571
Beh?et's disease has been known to be strongly associated with human leukocyte antigen (HLA) B51, one of the split antigens of HLA-B5. An increased incidence of HLA-B51 in the patient group has also been reported in an Italian population. Since the B51 antigen has been recently identified to comprise nine alleles, B*5101-B*5109, we performed HLA-B51 allele genotyping by the polymerase chain reaction-sequencing based typing (PCR-SBT) method as well as serological HLA-A and -B typing among 21 Italian patients with Beh?et's disease in order to investigate whether there is any correlation of one particular B51-associated allele with Behcet's disease. In addition, HLA class II genotyping was performed by the PCR-restriction fragment length polymorphism (RFLP) method. As a result, only the phenotype frequency of the B51 antigen was found to be significantly increased in the patient group as compared to the ethnically matched control group by the corrected P-value analysis (71.4% in patients vs. 17.9% in controls; chi2 = 14.26, Pc = 0.0042, R.R. = 11.5). In the B51 allele genotyping, 11 out of 15 B51-positive patients were B*5101 and the remaining four were B*5108, whereas all of 5 normal controls were B*5101, showing significant association of each allele with Beh?et's disease. No significant difference was observed between the patient and control groups in the HLA class II allelic distribution. This study revealed a strong association of Beh?et's disease in Italian with B*5108 as well as B*5101, providing important insight into the molecular mechanism underlying an HLA association with Beh?et's disease. 相似文献
32.
Association of gastric epithelial apoptosis with the ability of Helicobacter pylori to induce a neutrophil oxidative burst 总被引:3,自引:0,他引:3
Mizuki I Shimoyama T Fukuda S Liu Q Nakaji S Munakata A 《Journal of medical microbiology》2000,49(6):521-524
Both polymorphonuclear cell infiltration and increased epithelial apoptosis are seen in gastric mucosa in the presence of Helicobacter pylori infection. This study examined the association between bacterial ability to stimulate an oxidative burst in neutrophils and epithelial apoptosis. Biopsy specimens were obtained from 15 patients to detect apoptotic cells by the TUNEL method. H. pylori strains isolated from corresponding stomach biopsy samples were tested for the ability to stimulate an oxidative burst in human neutrophils. Neutrophils were isolated from healthy subjects without H. pylori infection and the oxidative burst was measured by flow cytometry with dichlorofluorescein diacetate. Stimulation with H. pylori increased both the percentage of activated cells and fluorescence intensity. There was a significant positive correlation between the number of epithelial apoptotic cells and fluorescence intensity. Increased neutrophil oxidative burst stimulated by H. pylori may play a role in enhanced gastric mucosal DNA damage and consequent atrophic gastritis and gastric cancer. 相似文献
33.
34.
Fumiyuki Yamasaki Yoshinori Kajiwara Seiji Hama Taro Murakami Toshikazu Hidaka Taiichi Saito Hiroyuki Yoshioka Kazuhiko Sugiyama Kazunori Arita Kaoru Kurisu 《Pathobiology》2007,74(1):22-31
OBJECTIVE: To investigate the mechanism of staurosporine-induced glioma cell death and cell cycle arrest using adenovirus-mediated gene transfection, as well as the function of retinoblastoma (Rb) and genetic instability induced by staurosporine. METHODS: Cell cycle regulation, cell death and nuclear abnormalities induced by staurosporine were examined using an adenovirus vector expressing Rb, p16 or p21 genes in human glioma cell lines. RESULTS: The Rb-defective SF-539 cell line was resistant to staurosporine compared with cell lines expressing intact Rb. SF-539 glioma cells exposed to staurosporine became multinucleated and then died. Multinucleation was prevented in SF-539 cells transfected with the Rb gene, thus decreasing the death rate of these cells. CONCLUSIONS: These results imply that enforced Rb expression protects cells from genomic instability induced by staurosporine regardless of its upstream molecular effects. 相似文献
35.
Oda Y Funasaka K Kitano M Nakama A Yoshikura T 《Environmental and molecular mutagenesis》2004,43(1):10-19
In the present study, we developed a rapid umu-microplate test system that uses the nitroreductase- and O-acetyltransferase-overproducing Salmonella typhimurium strain NM3009 and the O-acetyltransferase-overproducing S. typhimurium strain NM2009 to detect genotoxic activity in small volume samples. The assay was used to test the genotoxicity of several standard mutagens and environmental samples. Exponentially growing cultures of NM3009, NM2009, and the parental strain TA1535/pSK1002 were incubated in 96-well microplates with test chemicals both in the presence and in the absence of rat liver S9. The relative beta-galactosidase activities were then determined colorimetrically using either chlorophenol red-beta-D-galactopyranoside (CPRG) or O-nitrophenyl-beta-D-galactopyranoside (ONPG) as a measure of umuC gene induction activity. The sensitivities of NM3009 without S9 mix and NM2009 with S9 mix to nitroarenes and aromatic amines were up to 24- to 75-fold higher than those of the parent strain. Induction of umuC gene expression was detected more readily with CPRG than ONPG. The umu-microplate assay also detected genotoxicity in organic extracts of particulate matter from air samples collected in Osaka City, Japan. The pattern of the responses suggested that the genotoxic activity of the particulate extract was due primarily to nitrated polycyclic aromatic hydrocarbons. Our results indicate that the umu-microplate assay may be a useful way of carrying out rapid screens for genotoxicity in small-volume environmental samples. 相似文献
36.
Evidence of the monoclonal composition of human endometrial epithelial glands and mosaic pattern of clonal distribution in luminal epithelium 总被引:8,自引:0,他引:8
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tanaka M Kyo S Kanaya T Yatabe N Nakamura M Maida Y Okabe M Inoue M 《The American journal of pathology》2003,163(1):295-301
The endometrium is a highly regenerative tissue that plays a crucial role in implantation. We examined the clonal constitution of glandular cells as well as the luminal epithelium of this unique tissue. Using collagenase-based digestion techniques with microscopic manipulation, we isolated individual human endometrial glands and examined their clonality using a polymerase chain reaction-based assay for nonrandom X chromosome inactivation with an X-linked androgen receptor gene. Most of the glands analyzed were composed of monoclonal populations of epithelial cells and one of the glands exhibited a loss of heterogeneity in the androgen receptor gene. In addition, adjacent glands within a 1-mm(2) area shared clonality, suggesting that clonality of the luminal epithelium is regionally defined. The clonality of endometrium was further confirmed in a study of female mice that harbor the green fluorescent protein gene on either the maternal or paternal X chromosome. Fluorescent microscopy of uterine sections revealed that individual endometrial glands consisted completely of either fluorescent or nonfluorescent cells and that the surface epithelium exhibited a clear boundary between these cell types. These findings suggest that single or multiple stem cells with uniform clonality exist on the bottom of each endometrial gland and genetic alterations occurring in such cells may play a critical role in endometrial carcinogenesis. The possible association between area-specific X inactivation of the endometrial surface and the endometrial receptivity of embryo implantation remains to be clarified. 相似文献
37.
Thrombocytosis in preterm infants: a possible involvement of thrombopoietin receptor gene expression 总被引:2,自引:0,他引:2
Nakayama H Ihara K Hikino S Yamamoto J Nagatomo T Takemoto M Hara T 《Journal of molecular medicine (Berlin, Germany)》2005,83(4):316-320
Transient thrombocytosis is commonly observed in preterm infants after birth, but its physiological mechanism is still unknown. To understand the mechanism of the transient thrombocytosis in preterm infants we firstly evaluated a correlation between platelet counts and thrombopoietin (TPO) levels in preterm infants and next c-mpl mRNA levels on platelets in healthy preterm infants longitudinally during a half-year of life. The mean platelet counts in 45 very low birth weight infants (mean gestational age 27.4±1.8 weeks, mean birth weight 1047±249 g) was 230±71×109/l just after birth and thereafter gradually increased to 579±178×109/l by 5 weeks of age. The platelet counts continued this level for about next 8 weeks. Serum TPO levels soon after birth and at 1 month of age were significantly higher than those at the age of 2–6 months. There was a significant negative correlation between platelet counts and serum TPO values. The c-mpl expression levels on platelets at birth and at 1 month of age tended to be lower than those on platelets from adults, and the c-mpl levels gradually increased through 6 months of age, although they were still lower than those of adults. Our results suggest that low expression of TPO receptor on platelets until 1 month after birth cause a decreased TPO clearance and keep a high level of free TPO in blood, thereby promoting platelet production from megakaryocytes or their progenitors in bone marrow, resulting in the subsequent thrombocytosis in preterm infants. 相似文献
38.
Kasahara K Taguchi T Yamasaki I Kamada M Yuri K Shuin T 《Cancer Genetics and Cytogenetics》2002,137(1):59-63
In this study, we examined nine cases of advanced Japanese prostate cancer by comparative genomic hybridization (CGH) to detect chromosomal imbalances across the entire genome and to identify several new regions likely to contain genes important to the development and progression of this disease. These cases had been previously examined for numerical chromosomal aberrations by fluorescence in situ hybridization (FISH). By CGH, the following regions were found to be over-represented (gains), with fluorescence ratio values higher than the threshold: 4p, 6p, 8q, 11q, 12q, 15q, 16p, 17q, 20, and 21 (>4 cases); underrepresentation (losses) involved: 1q, 4q, 5q, 6q, 13q, 14q, and 22 (>4 cases). The shortest regions of overlap (SRO) of gains were noted at 8q24.1 through q24.3, 12q23, and 17q23 through q24 (>5 cases). The SRO of losses were seen at 5q14 through q21, 6q16.1 through q21, 13q21.3 through q22, and 14q21 (>5 cases). Notably, the gain of chromosomes 8 and 12 by CGH was in agreement with the FISH data, suggesting that the gain of chromosomes 8 and 12 may play an important role in prostate carcinogenesis. The genes on the SRO regions were also discussed in relation to oncogenes and bone metastases. 相似文献
39.
Thom E. Snijders Tom P.C. Schlösser Nathanael D. Heckmann Taro Tezuka Rene M. Castelein Rob P. Stevenson Harry Weinans Arthur de Gast Lawrence D. Dorr 《The Journal of arthroplasty》2021,36(6):2184-2188.e1
BackgroundAnterior and posterior pelvic tilt appears to play a role in total hip arthroplasty (THA) stability. When changing from the standing to the sitting position, the pelvis typically rotates posteriorly while the hips flex and this affects the femoro-acetabular positions. This case-control study compares changes in 3-D acetabular cup orientation during functional pelvic tilt between posterior THA dislocations vs stable THAs.MethodsStanding and sitting 3-D cup orientation was compared between fifteen posterior dislocations vs 233 prospectively followed stable THAs. 3-D cup orientation was calculated using previously validated trigonometric algorithms on biplanar radiographs. Those algorithms combine the angles in the three anatomical planes (coronal inclination, transverse version, and sagittal ante-inclination) in the standing position with the change in sagittal pelvic tilt from standing to sitting to calculate the 3-D orientation in the sitting position.ResultsThe standing cup orientation of the dislocated THAs was only characterized by a lower coronal inclination (P = .039). Compared with the controls, from standing to sitting, they showed less posterior pelvic tilt (P < .001). This led to a significant lower coronal inclination (P < .001) and sagittal ante-inclination (P < .001) in the sitting position but similar transverse version (P = .366).ConclusionsComparing posterior THA dislocations to stable THAs, there is a lower increase of all three orientation angles from standing to sitting. This leads to a decreased sitting coronal inclination and sagittal ante-inclination which may lead to an increased risk of impingement ensued by THA instability. By contrast, the transverse version was not significantly different in both positions. This confirms the importance of biplanar data on functional cup orientation.Level of EvidenceDiagnostic, Level III. 相似文献
40.
Takahiro Miki Tomohiko Nishigami Tsuneo Takebayashi Taro Yamauchi 《Journal of orthopaedic science》2021,26(3):337-342
BackgroundLow back pain (LBP) is a major problem; it causes significant burden, incurs considerable economic and human costs, and adversely affects the quality of life (QoL). Central sensitivity syndrome (CSS) is known as a group of overlapping conditions that share a common pathophysiological mechanism of central sensitization. Previous studies have shown that CSS is present in several disorders. However, it has been studied for people with presurgical LBP. The purpose of the study was to investigate the proportion of patients with CSS for presurgical LBP and to analyse the association of CSS with clinical symptoms and psychological factors.MethodsData of demographics, the central sensitization inventory (CSI), psychological measures, clinical symptoms of 238 patients with presurgical LBP were evaluated. The patients were divided into two groups depending on the CSI scores (≥40 and < 40). The two groups were compared, and the correlation between the CSI scores and other outcomes was analysed. Furthermore, multiple regression analysis was performed to identify factors contributing to the CSI scores.Results13.0% of participants were CSS. All outcomes were significantly different between the groups and significant associations were found between the CSI scores and all other outcomes. In addition, Pain Catastrophizing Scale (PCS) was most significant associated scale for the CSI scores.ConclusionWe found that certain patients had CSS with presurgical LBP. The CSI scores were significantly associated with the majority of the factors. The PCS was the factor with the most influence on the CSI scores. 相似文献