全文获取类型
收费全文 | 718篇 |
免费 | 69篇 |
专业分类
787篇 |
出版年
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 15篇 |
2016年 | 16篇 |
2015年 | 22篇 |
2014年 | 33篇 |
2013年 | 42篇 |
2012年 | 43篇 |
2011年 | 46篇 |
2010年 | 36篇 |
2009年 | 19篇 |
2008年 | 43篇 |
2007年 | 30篇 |
2006年 | 32篇 |
2005年 | 26篇 |
2004年 | 27篇 |
2003年 | 26篇 |
2002年 | 24篇 |
2001年 | 22篇 |
2000年 | 21篇 |
1999年 | 20篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 10篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 12篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 11篇 |
1984年 | 14篇 |
1981年 | 3篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1939年 | 6篇 |
1938年 | 11篇 |
排序方式: 共有787条查询结果,搜索用时 15 毫秒
31.
Combined observational and experimental data provide limited support for facilitation in lichens 下载免费PDF全文
Måns Svensson Alexandro Caruso Rebecca Yahr Christopher Ellis Göran Thor Tord Snäll 《Oikos》2016,125(2):278-283
It is increasingly recognized that facilitative interactions can shape communities. One of the mechanisms through which facilitation may operate is when one species facilitates the colonization of another through the exchange of shared symbionts. Lichens are symbiotic associations composed of a mycobiont (lichenised‐fungus) and one or two photobionts (algae or cyanobacteria). Different lichen species may have overlapping specificity for photobionts, creating the possibility that facilitation drives lichen community assembly. To investigate whether facilitation occurs in lichens, we combined an observational study (a) with a manipulative field experiment (b). For (a), we quantified the effect of local patch conditions, facilitation and the size of the surrounding metapopulation on colonizations of an epixylic lichen species (Cladonia botrytes) in an area of managed boreal forest. This was done by twice surveying lichens on 293 stumps, located in stands of three age classes. For (b), we treated unoccupied surfaces of 56 cut stumps with algal mixtures of an Asterochloris photobiont and recorded C. botrytes colonizations over three years. In (a), colonization rates of C. botrytes increased with increasing abundance of other lichen species with specificity for Asterochloris photobionts, consistent with an effect of facilitation. However, in the field experiment (b), colonizations of the focal species did not provide support for facilitation. We conclude that our study provides limited support for facilitation in green‐algal lichens, underscoring the importance of combining observational studies with experiments when studying species interactions. 相似文献
32.
Annalisa?Barera Silvio?Buscemi Roberto?Monastero Calogero?Caruso Rosalia?Caldarella Marcello?CiaccioEmail author 《Immunity & ageing : I & A》2016,13(1):14
Background
It is well known that Mediterranean Diet can positively influence the health of each individual, in particular it is know that fibers have an important role. However, in Mediterranean cities most people do not have a close adherence to Mediterranean diet. Thus, in our study, we considered fibers like β-glucans that have been added to pasta with a percentage of 6 %. Our study aimed to evaluate the capacity of β-glucans intake on oxidative stress and inflammation in a cohort of middle aged slightly overweight subjects.Methods
We used a longitudinal study design. The study lasted 30 days during which time, each participant acted with no food restriction. Participants underwent morning fasting blood venous sample for blood chemistry and other biological parameters at the beginning of the study and after 30 days of pasta supplemented with 6 % of β-glucan intake 4 times a week. We performed anthropometric, biochemical, oxidative stress and cytokine analysis at the beginning and the end of study.Results
After the 30 days of pasta intake we obtained a significant decrease of LDL-cholesterol, IL-6 and AGEs levels.Conclusion
The results confirmed a capacity of β-glucans intake to lower oxidative stress. Additional longitudinal observation on community-based cohorts are needed to confirm these data and investigate the biological mechanisms through which effects are induced, and to fully explore the therapeutic potential of β-glucans.33.
34.
Interleukin-13 interferes with CFTR and AQP5 expression and localization during human airway epithelial cell differentiation 总被引:1,自引:0,他引:1
Skowron-zwarg M Boland S Caruso N Coraux C Marano F Tournier F 《Experimental cell research》2007,313(12):2695-2702
Interleukin-13 (IL-13) is a central regulator of Th2-dominated respiratory disorders such as asthma. Lesions of the airway epithelial barrier frequently observed in chronic respiratory inflammatory diseases are repaired through proliferation, migration and differentiation of epithelial cells. Our work is focused on the effects of IL-13 in human cellular models of airway epithelial cell regeneration. We have previously shown that IL-13 altered epithelial cell polarity during mucociliary differentiation of human nasal epithelial cells. In particular, the cytokine inhibited ezrin expression and interfered with its apical localization during epithelial cell differentiation in vitro. Here we show that CFTR expression is enhanced in the presence of the cytokine, that two additional CFTR protein isoforms are expressed in IL-13-treated cells and that part of the protein is retained within the endoplasmic reticulum. We further show that aquaporin 5 expression, a water channel localized within the apical membrane of epithelial cells, is completely abolished in the presence of the cytokine. These results show that IL-13 interferes with ion and water channel expression and localization during epithelial regeneration and may thereby influence mucus composition and hydration. 相似文献
35.
Alexander Bürkle Graziella Caselli Claudio Franceschi Erminia Mariani Paolo Sansoni Angela Santoni Giancarlo Vecchio Jacek M Witkowski Calogero Caruso 《Immunity & ageing : I & A》2007,4(1):4-8
On April 18, 2007 an international meeting on Pathophysiology of Ageing, Longevity and Age-Related Diseases was held in Palermo,
Italy. Several interesting topics on Cancer, Immunosenescence, Age-related inflammatory diseases and longevity were discussed.
In this report we summarize the most important issues. However, ageing must be considered an unavoidable end point of the
life history of each individual, nevertheless the increasing knowledge on ageing mechanisms, allows envisaging many different
strategies to cope with, and delay it. So, a better understanding of pathophysiology of ageing and age-related disease is
essential for giving everybody a reasonable chance for living a long and enjoyable final part of the life. 相似文献
36.
Jung H. Y. Park Mark R. Corkins Jon A. Vanderhoof Nia M. Caruso Marjorie J. Hrbek Beverly S. Schaffer Dorothy H. Slentz Robert H. McCusker Richard G. MacDonald 《Journal of cellular physiology》1996,166(2):396-406
The components of the insulin-like growth factor (IGF) axis and their roles in regulating proliferation and differentiation of the human colon adenocarcinoma cell line, Caco-2, have been investigated. Caco-2 cells proliferated in serum-free medium at 75% the rate observed in medium containing 10% fetal bovine serum. IGF-I (10 nM) increased Caco-2 cell growth in serum-free medium, but not to the rate seen with serum. Multiple IGF-II mRNA species were produced by Caco-2 cells, but IGF-I mRNA was undetectable. Secretion of radioimmunoassayable IGF-II corresponded with steady-state levels of IGF-II mRNA, neither of which was observed to change markedly over the course of 16 days of Caco-2 cell differentiation. Levels of sucrase-isomaltase mRNA, a marker for enterocytic differentiation, increased 12-fold between days 5 and 16 of culture. Northern blotting of total RNA and ligand blot and immunoblot analyses of serum-free conditioned medium revealed that Caco-2 cells produce several IGF binding proteins (IGFBPs), including IGFBP-2, -3, and -4, as well as a 31,000 M, species that was not identified. The pattern of IGFBP secretion changed dramatically during Caco-2 cell differentiation: IGFBP-3 and IGFBP-2 increased 8.5-fold and 5-fold, respectively, whereas IGFBP-4 and the 31,000 M, species decreased 43% and 90%. Caco-2 cell clones stably transfected with a human IGFBP-4 cDNA construct exhibited a 60% increase in steady-state level of IGFBP-4 mRNA, and secreted twice as much IGFBP-4 protein as controls. Moreover, IGFBP-4-overexpressing cells proliferated at only 25% the rate of control cells in serum-free medium, in conjunction with a 70% increase in expression of sucrase-isomaltase. In summary, these studies indicate that a complex IGF axis is involved in autocrine regulation of Caco-2 cell proliferation and differentiation. © 1996 Wiley-Liss, Inc. 相似文献
37.
Sahar Keshvari Berit Genz Ngari Teakle Melanie Caruso Michelle F. Cestari Omkar L. Patkar Brian W. C. Tse Kamil A. Sokolowski Hilmar Ebersbach Julia Jascur Kelli P. A. MacDonald Gregory Miller Grant A. Ramm Allison R. Pettit Andrew D. Clouston Elizabeth E. Powell David A. Hume Katharine M. Irvine 《Disease models & mechanisms》2022,15(4)
38.
Caruso M Maitan MA Bifulco G Miele C Vigliotta G Oriente F Formisano P Beguinot F 《The Journal of biological chemistry》2001,276(48):45088-45097
In L6 skeletal muscle cells and immortalized hepatocytes, insulin induced a 2-fold increase in the activity of the pyruvate dehydrogenase (PDH) complex. This effect was almost completely blocked by the protein kinase C (PKC) delta inhibitor Rottlerin and by PKCdelta antisense oligonucleotides. At variance, overexpression of wild-type PKCdelta or of an active PKCdelta mutant induced PDH complex activity in both L6 and liver cells. Insulin stimulation of the activity of the PDH complex was accompanied by a 2.5-fold increase in PDH phosphatases 1 and 2 (PDP1/2) activity with no change in the activity of PDH kinase. PKCdelta antisense blocked insulin activation of PDP1/2, the same as with PDH. In insulin-exposed cells, PDP1/2 activation was paralleled by activation and mitochondrial translocation of PKCdelta, as revealed by cell subfractionation and confocal microscopy studies. The mitochondrial translocation of PKCdelta, like its activation, was prevented by Rottlerin. In extracts from insulin-stimulated cells, PKCdelta co-precipitated with PDP1/2. PKCdelta also bound to PDP1/2 in overlay blots, suggesting that direct PKCdelta-PDP interaction may occur in vivo as well. In intact cells, insulin exposure determined PDP1/2 phosphorylation, which was specifically prevented by PKCdelta antisense. PKCdelta also phosphorylated PDP in vitro, followed by PDP1/2 activation. Thus, in muscle and liver cells, insulin causes activation and mitochondrial translocation of PKCdelta, accompanied by PDP phosphorylation and activation. These events are necessary for insulin activation of the PDH complex in these cells. 相似文献
39.
Klein RC Siarey RJ Caruso A Rapoport SI Castellino FJ Galdzicki Z 《Journal of neurochemistry》2001,76(6):1663-1669
The trisomy 16 (Ts16) mouse is an animal model for human trisomy 21 (Down's syndrome). The gene encoding the NR2A subunit of the NMDA receptor has been localized to mouse chromosome 16. In the present study, western blot analysis revealed a 2.5-fold increase of NR2A expression in cultured Ts16 embryonic hippocampal neurons. However, this increase did not affect the properties of NMDA-evoked currents in response to various modulators. The sensitivity of NMDA receptors to transient applications of NMDA, spermine, and Zn(2+) was investigated in murine Ts16 and control diploid cultured embryonic hippocampal neurons. Peak and steady-state currents evoked by NMDA were potentiated by spermine at concentrations < 1 mM, and inhibited by Zn(2+) in a dose-dependent and voltage-independent manner. No marked difference was observed between Ts16 and control diploid neurons for any of these modulators with regard to IC(50) and EC(50) values or voltage dependency. Additionally, inhibition by the NR2B selective inhibitor, ifenprodil, was similar. These results demonstrate that NMDA-evoked currents are not altered in cultured embryonic Ts16 neurons and suggest that Ts16 neurons contain similar functional properties of NMDA receptors as diploid control neurons despite an increased level of NR2A expression. 相似文献
40.
Clementi G Caruso A Cutuli VM Prato A Mangano NG Amico-Roxas M 《Life sciences》1999,65(15):PL203-PL208
The antiinflammatory effect of ADM was studied in different models of inflammation and compared to the one of CGRP. Peptides were active against acetic acid-induced peritonitis in the rats. ADM and CGRP exerted the antiinflammatory effect at different doses, 400 and 20 ng/kg respectively, but with different efficacy (ADM >CGRP). This effect was blocked by pretreatment with CGRP (8-37) fragment or with L-NAME. No antiinflammatory activity was evidenced against serotonin- or carrageenin-induced rat paw edema. Our data suggest that ADM exerts antiinflammatory activity in the model characterized by a vascular component. This effect involves CGRP receptors and appears to be mediated by nitric oxide system. 相似文献