全文获取类型
收费全文 | 9909篇 |
免费 | 408篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 124篇 |
妇产科学 | 138篇 |
基础医学 | 1157篇 |
口腔科学 | 133篇 |
临床医学 | 561篇 |
内科学 | 3042篇 |
皮肤病学 | 238篇 |
神经病学 | 779篇 |
特种医学 | 385篇 |
外科学 | 1375篇 |
综合类 | 26篇 |
一般理论 | 3篇 |
预防医学 | 246篇 |
眼科学 | 143篇 |
药学 | 593篇 |
中国医学 | 19篇 |
肿瘤学 | 1305篇 |
出版年
2024年 | 5篇 |
2023年 | 73篇 |
2022年 | 151篇 |
2021年 | 238篇 |
2020年 | 125篇 |
2019年 | 177篇 |
2018年 | 218篇 |
2017年 | 176篇 |
2016年 | 187篇 |
2015年 | 228篇 |
2014年 | 289篇 |
2013年 | 360篇 |
2012年 | 626篇 |
2011年 | 645篇 |
2010年 | 397篇 |
2009年 | 364篇 |
2008年 | 634篇 |
2007年 | 686篇 |
2006年 | 676篇 |
2005年 | 681篇 |
2004年 | 716篇 |
2003年 | 676篇 |
2002年 | 690篇 |
2001年 | 117篇 |
2000年 | 98篇 |
1999年 | 121篇 |
1998年 | 151篇 |
1997年 | 117篇 |
1996年 | 102篇 |
1995年 | 88篇 |
1994年 | 73篇 |
1993年 | 74篇 |
1992年 | 62篇 |
1991年 | 51篇 |
1990年 | 42篇 |
1989年 | 30篇 |
1988年 | 40篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 18篇 |
1984年 | 21篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1980年 | 14篇 |
1978年 | 12篇 |
1977年 | 5篇 |
1975年 | 8篇 |
1973年 | 8篇 |
1971年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Marushima H Shibata S Asakura T Matsuura T Maehashi H Ishii Y Eda H Aoki K Iida Y Morikawa T Ohkawa K 《International journal of oncology》2011,39(5):1327-1336
In vitro tumor growth in a three-dimensional (3D) architecture has been demonstrated to play an important role in biology not only for developmental organogenesis and carcinogenesis, but also for analyses on reconstitution and maintenance in a variety of biological environments surrounding the cells. In addition to providing architectural similarity to living organisms, 3D culture with a radial flow bioreactor (RFB) can also closely mimic the living hypoxic microenvironment under which specific organogenesis or carcinogenesis occurs. The findings of the present study under the RFB culture conditions show that cancer cells underwent a shift from aerobic to hypoxic energy metabolism, in addition to protein expression to maintain the 3D structure. In RFB-cultured cells, protein stability of hypoxia-inducible factor 1 (HIF1) α, a subunit of HIF1, was increased without upregulation of its mRNA. Under these conditions, PHD2, HIF-prolyl-4-hydroxy-lase 2 and a HIF1 downstream enzyme, were stabilized without affecting the mRNA levels via downregulation of FK506-binding protein 8. PHD2 accumulation, which occurred concomitant with HIF1 stabilization, may have compensated for the lack of oxygen under hypoxic conditions to regulate the HIF levels. 3D-culture-induced overexpression of carbonic anhydrase (another representative HIF downstream enzyme) was found to occur independently of cell density in RFB--cultured cells, suggesting that the RFB provided an adequately hypoxic microenvironment for the cultured cells. From these results, it was hypothesized that the key factors are regulatory molecules, which stabilize and degrade HIF molecules, thereby activating the HIF1 pathway under a hypoxic milieu. 相似文献
992.
993.
Hirata T Osuga Y Takamura M Kodama A Hirota Y Koga K Yoshino O Harada M Takemura Y Yano T Taketani Y 《Endocrinology》2010,151(11):5468-5476
In a novel paradigm of T cell differentiation, type 17 T helper (Th17) cells may play a significant role in endometriosis, a chronic inflammatory disease. However, the mechanism regulating the accumulation of Th17 cells in endometriotic tissues remains unknown. We hypothesized that Th17 cells migrate to endometriotic tissues through an interaction of the chemokine CC chemokine ligand (CCL)20 and its receptor CCR6. Using endometriotic tissues from women with endometriosis, we demonstrated, by flow cytometry, that Th17 cells in endometriotic tissues express CC chemokine receptor (CCR)6. Immunohistochemistry also revealed that CCL20 was expressed in the epithelial cells and stromal cells beneath the epithelium of endometriotic tissues. CCR6+ cells were small and round and scattered in the stroma in which abundant CCL20+ cells were detected. CCL20 caused selective migration of Th17 cells in the peripheral blood in a migration assay. IL-1β, TNF-α, and IL-17A increased the secretion of CCL20 in cultured endometriotic stromal cells. Inhibitors of p38- and p42/44-MAPKs, and stress-activated protein kinase/c-Jun kinase suppressed the secretion of CCL20 increased by IL-1β, TNF-α, and IL-17A. This suggests that the CCL20/CCR6 system is involved in the migration of Th17 cells to endometriotic tissues and that proinflammatory cytokines contribute to the development of endometriosis via up-regulation of CCL20 secretion from endometriotic stromal cells. 相似文献
994.
Etsuko Kobayashi Yasushi Suwazono Mirei Dochi Ryumon Honda Teruhiko Kido 《Bulletin of environmental contamination and toxicology》2009,83(1):102-107
We performed this study to determine whether both eating cadmium (Cd)-polluted rice and drinking and/or cooking with Jinzu
River water are associated with renal tubular dysfunction. A multiple logistic regression analysis of retrospective data indicated
that both factors may contribute to this condition. Estimated threshold values of rice Cd concentration in men were 0.13–0.27 ppm
and 0.09–0.18 ppm in women, without adjustment for use of Jinzu River water. The additional influence of drinking and/or cooking
with Jinzu River water was estimated to be about 0.008 ppm. 相似文献
995.
Kandori A Ogata K Watanabe Y Takuma N Tanaka K Murakami M Miyashita T Sasaki N Oka Y 《Pacing and clinical electrophysiology : PACE》2008,31(4):422-431
Background: The magnetocardiogram (MCG) is a promising medical tool for detecting and visualizing abnormal cardiac electrical activation in heart-disease patients. However, there is no large-scale MCG database of healthy subjects, and there is little knowledge of gender- and age-related influences on MCG data.
Methods and Results: We obtained MCG data from 869 subjects (554 men, 315 women) using a conventional 64-channel MCG system, which covers the whole heart. Electrocardiogram (ECG) data were also obtained; 464 people (268 men, 196 women) were identified as a normal group using ECG data. Time intervals (PQ, QRS, QT, and QTc), current distributions (maximum current vector (MCV), and the total current vector (TCV)) of MCG data of the 464 normal subjects were analyzed to obtain basic MCG parameters.
Although mean values of PQ and QRS intervals of the male subjects were slightly longer than those of the female subjects, no intervals were correlated with gender or age. The correlation between PQ intervals of ECG and those of MCG was better than the correlation between QRS and QT intervals of ECG and those of MCG. Both MCV and TCV angles were much smaller than the electrical-axis angle in ECG. Although TCVs of the QRS and T waves were stable, the women's mean T-wave-TCV angles significantly increased with age. The maximum amplitude of the P wave was about 1.7 pT, and the value of the QRS complex was about 20–25 pT. Moreover, the T-wave amplitude decreases with age.
Conclusion: The MCG standard space-time parameters determined here provide a normal range for MCG parameters. 相似文献
Methods and Results: We obtained MCG data from 869 subjects (554 men, 315 women) using a conventional 64-channel MCG system, which covers the whole heart. Electrocardiogram (ECG) data were also obtained; 464 people (268 men, 196 women) were identified as a normal group using ECG data. Time intervals (PQ, QRS, QT, and QTc), current distributions (maximum current vector (MCV), and the total current vector (TCV)) of MCG data of the 464 normal subjects were analyzed to obtain basic MCG parameters.
Although mean values of PQ and QRS intervals of the male subjects were slightly longer than those of the female subjects, no intervals were correlated with gender or age. The correlation between PQ intervals of ECG and those of MCG was better than the correlation between QRS and QT intervals of ECG and those of MCG. Both MCV and TCV angles were much smaller than the electrical-axis angle in ECG. Although TCVs of the QRS and T waves were stable, the women's mean T-wave-TCV angles significantly increased with age. The maximum amplitude of the P wave was about 1.7 pT, and the value of the QRS complex was about 20–25 pT. Moreover, the T-wave amplitude decreases with age.
Conclusion: The MCG standard space-time parameters determined here provide a normal range for MCG parameters. 相似文献
996.
997.
Associations of objective measures of trauma exposure with psychological sequelae following motor vehicle accidents (MVA) were examined in a Japanese population. Impact and injury severity of 93 MVA victims was assessed using on-the-scene in-depth investigations measured by the Injury Severity Score (ISS), barrier equivalent speed (BES), and change in velocity during the impact (Delta-v). Results showed that ISS, BES, and Delta-v were not related to posttraumatic stress symptoms (PTSS) or psychiatric symptoms at 5 and 14 months after the MVA. Subjective measures (e.g., perceived life risk, persistent medical problems) were significantly related to psychological sequelae. These findings suggest that the objective measures of trauma exposure are not associated directly with PTSS or psychiatric symptoms after an MVA. 相似文献
998.
999.
1000.
Kunisaki C Makino H Takagawa R Oshima T Nagano Y Kosaka T Ono HA Otsuka Y Akiyama H Ichikawa Y Shimada H 《Annals of surgical oncology》2008,15(7):1959-1967
Background The aim of this study was to evaluate the prognostic value of tumor diameter in gastric cancer.
Methods The study group comprised a series of 1215 patients who underwent curative gastrectomy. The appropriate tumor diameter cutoff
value was determined. Prognostic factors were evaluated by univariate and multivariate analyses.
Results The tumor diameter cutoff value was 100 mm. Multivariate analysis showed that tumor site, macroscopic appearance, tumor diameter,
depth of invasion, and presence of lymph node metastasis independently affected prognosis in all patients. Multivariate analysis
of patients with larger tumors identified depth of invasion as an independent prognostic factor. A comparison between patients
with smaller and larger tumors showed marked differences in the survival of those with stage II, IIIA, and IIIB tumors. A
comparison of clinicopathological factors between stage II and III patients revealed that tumors occupying the entire stomach,
ill-defined, undifferentiated, and serosa-penetrating tumors, and peritoneal metastases were far more frequent in patients
with larger tumors.
Conclusions Tumor diameter in gastric cancer is a reliable prognostic factor that might be a candidate for use in the staging system.
To improve outcomes for patients with tumors ≥100 mm in diameter, it is necessary to establish therapeutic strategies for
peritoneal metastasis, particularly in stage II and III tumors. 相似文献