全文获取类型
收费全文 | 912篇 |
免费 | 50篇 |
出版年
2023年 | 3篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 14篇 |
2017年 | 4篇 |
2016年 | 21篇 |
2015年 | 28篇 |
2014年 | 29篇 |
2013年 | 44篇 |
2012年 | 61篇 |
2011年 | 51篇 |
2010年 | 24篇 |
2009年 | 43篇 |
2008年 | 49篇 |
2007年 | 63篇 |
2006年 | 63篇 |
2005年 | 68篇 |
2004年 | 51篇 |
2003年 | 47篇 |
2002年 | 46篇 |
2001年 | 11篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 15篇 |
1990年 | 9篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1967年 | 4篇 |
排序方式: 共有962条查询结果,搜索用时 15 毫秒
41.
42.
Hirotsugu Ohkubo Yoshihiro Kanemitsu Takehiro Uemura Osamu Takakuwa Masaya Takemura Ken Maeno Yutaka Ito Tetsuya Oguri Nobutaka Kazawa Ryuji Mikami Akio Niimi 《PloS one》2016,11(3)
BackgroundAlthough several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.ObjectiveThe purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.MethodsA total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from −950 HU to −701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.ResultsCT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).ConclusionThe measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging. 相似文献
43.
44.
45.
46.
Tissue culture on a chip: Developmental biology applications of self‐organized capillary networks in microfluidic devices 下载免费PDF全文
Organ culture systems are used to elucidate the mechanisms of pattern formation in developmental biology. Various organ culture techniques have been used, but the lack of microcirculation in such cultures impedes the long‐term maintenance of larger tissues. Recent advances in microfluidic devices now enable us to utilize self‐organized perfusable capillary networks in organ cultures. In this review, we will overview past approaches to organ culture and current technical advances in microfluidic devices, and discuss possible applications of microfluidics towards the study of developmental biology. 相似文献
47.
Dinh T. Lam Bui C. Buu Nguyen T. Lang Kinya Toriyama Ikuo Nakamura Ryuji Ishikawa 《Ecology and evolution》2019,9(5):2964-2977
Oryza rufipogon Griff. is a perennial species of wild rice widely distributed along the channels and rivers of the Mekong Delta, Vietnam. This study attempted to find centers of diversity among wild rice populations in this area and their inter‐relationships. The highest genetic diversity was found in the Dong Thap population and the lowest in the Can Tho population. Maternal diversity evaluated using chloroplast INDELs detected ten plastid types, five of which were novel relative to other Asian countries. The mitochondrial genome suggested two unique deletions. One 699‐bp deletion via short tandem repeats was accompanied by another deletion including orf153. All accessions carrying the mitochondrial type were found in a particular plastid type. This unique maternal lineage was confined to specific channels where it showed vigorous vegetative growth in comparison to upstream areas where various maternal lineages and maximum genetic diversity occurred. This area along the Mekong Delta is a center of not only nuclear but also maternal diversity. 相似文献
48.
Takano Y Yamauchi K Hayakawa K Hiramatsu N Kasai A Okamura M Yokouchi M Shitamura A Yao J Kitamura M 《FEBS letters》2007,581(3):421-426
Expression of nephrin, a crucial component of the glomerular slit diaphragm, is downregulated in patients with proteinuric glomerular diseases. Using conditionally immortalized reporter podocytes, we found that bystander macrophages as well as macrophage-derived cytokines IL-1beta and TNF-alpha markedly suppressed activity of the nephrin gene promoter in podocytes. The cytokine-initiated repression was reversible, observed on both basal and inducible expression, independent of Wilms' tumor suppressor WT1, and caused in part via activation of the phosphatidylinositol-3-kinase/Akt pathway. These results indicated a novel mechanism by which activated macrophages participate in the induction of proteinuria in glomerular diseases. 相似文献
49.
Rapid, transient induction of ER stress in the liver and kidney after acute exposure to heavy metal: evidence from transgenic sensor mice 总被引:2,自引:0,他引:2
Hiramatsu N Kasai A Du S Takeda M Hayakawa K Okamura M Yao J Kitamura M 《FEBS letters》2007,581(10):2055-2059
Endoplasmic reticulum (ER) stress-responsive alkaline phosphatase (ES-TRAP) serves as a sensitive indicator for ER stress. In response to heavy metals including cadmium, nickel and cobalt, hepatocytes and renal tubular cells expressing ES-TRAP exhibited ER stress and decreased ES-TRAP activity. In ES-TRAP transgenic mice, acute exposure to cadmium showed rapid, transient decreases in the activity of serum ES-TRAP. It was inversely correlated with the induction of endogenous ER stress markers in the liver and kidney. Our result provides first evidence for the acute, reversible induction of ER stress in vivo after exposure to heavy metal. 相似文献
50.