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51.
Quinn JM Sims NA Saleh H Mirosa D Thompson K Bouralexis S Walker EC Martin TJ Gillespie MT 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(8):5720-5729
IL-23 stimulates the differentiation and function of the Th17 subset of CD4(+) T cells and plays a critical role in chronic inflammation. The IL-23 receptor-encoding gene is also an inflammatory disease susceptibility gene. IL-23 shares a common subunit with IL-12, a T cell-dependent osteoclast formation inhibitor, and we found that IL-23 also dose-dependently inhibited osteoclastogenesis in a CD4(+) T lymphocyte-dependent manner. When sufficiently enriched, gammadelta T cells also mediated IL-23 inhibition. Like IL-12, IL-23 acted synergistically with IL-18 to block osteoclastogenesis but, unlike IL-12, IL-23 action depended on T cell GM-CSF production. IL-23 did not mediate IL-12 action although IL-12 induced its expression. Male mice lacking IL-23 (IL-23p19(-/-)) had approximately 30% lower bone mineral density and tibial trabecular bone mass (bone volume (BV)/total volume (TV)) than wild-type littermates at 12 wk and 40% lower BV/TV at 26 wk of age; male heterozygotes also had lower bone mass. Female IL-23p19(-/-) mice also had reduced BV/TV. IL-23p19(-/-) mice had no detectable osteoclast defect in trabecular bone but IL-23p19(-/-) had thinner growth plate hypertrophic and primary spongiosa zones (and, in females, less cartilage remnants) compared with wild type. This suggests increased osteoclast action at and below the growth plate, leading to reduced amounts of mature trabecular bone. Thus, IL-23 inhibits osteoclast formation indirectly via T cells in vitro. Under nonpathological conditions (unlike inflammatory conditions), IL-23 favors higher bone mass in long bones by limiting resorption of immature bone forming below the growth plate. 相似文献
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Doudoumis V Tsiamis G Wamwiri F Brelsfoard C Alam U Aksoy E Dalaperas S Abd-Alla A Ouma J Takac P Aksoy S Bourtzis K 《BMC microbiology》2012,12(Z1):S3
BACKGROUND: Wolbachia is a genus of endosymbiotic α-Proteobacteria infecting a wide range of arthropods and filarial nematodes. Wolbachia is able to induce reproductive abnormalities such as cytoplasmic incompatibility (CI), thelytokous parthenogenesis, feminization and male killing, thus affecting biology, ecology and evolution of its hosts. The bacterial group has prompted research regarding its potential for the control of agricultural and medical disease vectors, including Glossina spp., which transmits African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. RESULTS: In the present study, we employed a Wolbachia specific 16S rRNA PCR assay to investigate the presence of Wolbachia in six different laboratory stocks as well as in natural populations of nine different Glossina species originating from 10 African countries. Wolbachia was prevalent in Glossina morsitans morsitans, G. morsitans centralis and G. austeni populations. It was also detected in G. brevipalpis, and, for the first time, in G. pallidipes and G. palpalis gambiensis. On the other hand, Wolbachia was not found in G. p. palpalis, G. fuscipes fuscipes and G. tachinoides. Wolbachia infections of different laboratory and natural populations of Glossina species were characterized using 16S rRNA, the wsp (Wolbachia Surface Protein) gene and MLST (Multi Locus Sequence Typing) gene markers. This analysis led to the detection of horizontal gene transfer events, in which Wobachia genes were inserted into the tsetse flies fly nuclear genome. CONCLUSIONS: Wolbachia infections were detected in both laboratory and natural populations of several different Glossina species. The characterization of these Wolbachia strains promises to lead to a deeper insight in tsetse flies-Wolbachia interactions, which is essential for the development and use of Wolbachia-based biological control methods. 相似文献
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Swartz DD Russell JA Andreadis ST 《American journal of physiology. Heart and circulatory physiology》2005,288(3):H1451-H1460
We engineered implantable small-diameter blood vessels based on ovine smooth muscle and endothelial cells embedded in fibrin gels. Cylindrical tissue constructs remodeled the fibrin matrix and exhibited considerable reactivity in response to receptor- and nonreceptor-mediated vasoconstrictors and dilators. Aprotinin, a protease inhibitor of fibrinolysis, was added at varying concentrations and affected the development and functionality of tissue-engineered blood vessels (TEVs) in a concentration-dependent manner. Interestingly, at moderate concentrations, aprotinin increased mechanical strength but decreased vascular reactivity, indicating a possible relationship between matrix degradation/remodeling, vasoreactivity, and mechanical properties. TEVs developed considerable mechanical strength to withstand interpositional implantation in jugular veins of lambs. Implanted TEVs integrated well with the native vessel and demonstrated patency and similar blood flow rates as the native vessels. At 15 wk postimplantation, TEVs exhibited remarkable matrix remodeling with production of collagen and elastin fibers and orientation of smooth muscle cells perpendicular to the direction of blood flow. Implanted vessels gained significant mechanical strength and reactivity that were comparable to those of native veins. Our work demonstrates that fibrin-based TEVs hold significant promise for treatment of vascular disease and as a biological model for studying vascular development and pathophysiology. 相似文献
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Styliani Geronikolou Stelios Zimeras Constantinos H. Davos Ioannis Michalopoulos Stephanos Tsitomeneas 《PloS one》2014,9(11)
Introduction
The impact of electromagnetic fields on health is of increasing scientific interest. The aim of this study was to examine how the Drosophila melanogaster animal model is affected when exposed to portable or mobile phone fields.Methods/Results
Two experiments have been designed and performed in the same laboratory conditions. Insect cultures were exposed to the near field of a 2G mobile phone (the GSM 2G networks support and complement in parallel the 3G wide band or in other words the transmission of information via voice signals is served by the 2G technology in both mobile phones generations) and a 1880 MHz cordless phone both digitally modulated by human voice. Comparison with advanced statistics of the egg laying of the second generation exposed and non-exposed cultures showed limited statistical significance for the cordless phone exposed culture and statistical significance for the 900 MHz exposed insects. We calculated by physics, simulated and illustrated in three dimensional figures the calculated near fields of radiation inside the experimenting vials and their difference. Comparison of the power of the two fields showed that the difference between them becomes null when the experimental cylinder radius and the height of the antenna increase.Conclusions/Significance
Our results suggest a possible radiofrequency sensitivity difference in insects which may be due to the distance from the antenna or to unexplored intimate factors. Comparing the near fields of the two frequencies bands, we see similar not identical geometry in length and height from the antenna and that lower frequencies tend to drive to increased radiofrequency effects. 相似文献57.
Dimitris Tsaparis Stelios Katsanevakis Christina Stamouli Anastasios Legakis 《Acta theriologica》2008,53(1):87-94
The abundance, density, and habitat use of roe deerCapreolus capreolus (Linnaeus, 1758) and mouflonOvis aries Linnaeus, 1758 were studied in a confined Mediterranean area in Greece with a dung survey based on the faecal accumulation
rate (FAR) technique. Estimated density was modelled with generalized additive models using altitude, habitat type, and slope
as potential covariates. Model selection among the set of candidate models was conducted based on their generalized cross-validation
score. Roe deer had an estimated mean density of 13.9 ind./km2 and the best model included slope and habitat type as covariates. The mean density of mouflon in the study area was 22.1
ind./km2 and the best model used altitude and habitat type as covariates. For both species, the highest densities were encountered
in abandoned cultivations and glades, followed by conifer forests, while the lowest densities were observed in maquis. However,
use of open habitats by mouflon was much greater than it was for roe deer. The strong preference of mouflon (a grazer species)
for open habitats that were abundant with grasses probably reflected food availability and contrasted with the more diverse
habitat use by roe deer (a selective browser). 相似文献
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Improved Performance and Reliability of p‐i‐n Perovskite Solar Cells via Doped Metal Oxides 下载免费PDF全文
Perovskite photovoltaics (PVs) have attracted attention because of their excellent power conversion efficiency (PCE). Critical issues related to large‐area PV performance, reliability, and lifetime need to be addressed. Here, it is shown that doped metal oxides can provide ideal electron selectivity, improved reliability, and stability for perovskite PVs. This study reports p‐i‐n perovskite PVs with device areas ranging from 0.09 cm2 to 0.5 cm2 incorporating a thick aluminum‐doped zinc oxide (AZO) electron selective contact with hysteresis‐free PCE of over 13% and high fill factor values in the range of 80%. AZO provides suitable energy levels for carrier selectivity, neutralizes the presence of pinholes, and provides intimate interfaces. Devices using AZO exhibit an average PCE increase of over 20% compared with the devices without AZO and maintain the high PCE for the larger area devices reported. Furthermore, the device stability of p‐i‐n perovskite solar cells under the ISOS‐D‐1 is enhanced when AZO is used, and maintains 100% of the initial PCE for over 1000 h of exposure when AZO/Au is used as the top electrode. The results indicate the importance of doped metal oxides as carrier selective contacts to achieve reliable and high‐performance long‐lived large‐area perovskite solar cells. 相似文献
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Anastasia Chatzimentor Aggeliki Doxa Stelios Katsanevakis Antonios D. Mazaris 《Global Change Biology》2023,29(7):1809-1821
Rapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life-history characteristics that render them even more susceptible. Impacts on biodiversity have already been reported, however, a systematic risk evaluation of threatened marine populations is lacking. Here, we employ a trait-based approach to assess the risk of 90 threatened marine Mediterranean species to climate change, combining species' exposure to increased sea temperature and intrinsic vulnerability. One-quarter of the threatened marine biodiversity of the Mediterranean Sea is predicted to be under elevated levels of climate risk, with various traits identified as key vulnerability traits. High-risk taxa including sea turtles, marine mammals, Anthozoa and Chondrichthyes are highlighted. Climate risk, vulnerability and exposure hotspots are distributed along the Western Mediterranean, Alboran, Aegean, and Adriatic Seas. At each Mediterranean marine ecoregion, 21%–31% of their threatened species have high climate risk. All Mediterranean marine protected areas host threatened species with high risk to climate change, with 90% having a minimum of 4 up to 19 species of high climate risk, making the objective of a climate-smart conservation strategy a crucial task for immediate planning and action. Our findings aspire to offer new insights for systematic, spatially strategic planning and prioritization of vulnerable marine life in the face of accelerating climate change. 相似文献
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