UV can induce damages on mRNA consistently among different genes.SOS response was more active after UV treatment.Programmed cell death was not found to be more active after UV treatment. The efficacy of ultraviolet (UV) disinfection has been analyzed and validated by numerous studies using culture-based methods, yet the discovery of the viable but nonculturable state necessitates the investigation of UV disinfection based on viability parameters. Paired regulators of the SOS response system, recA-lexA, and the programmed cell death system, mazEF, in Escherichia coli were chosen as the target genes, and the effect of UV irradiation on the mRNAs of the four genes was studied. This research showed that, after UV irradiation, the responses of the mRNAs were highly consistent, with reduction percentages of approximately 60% at 20 mJ/cm2, 70% at 40 mJ/cm2, and 90% at 80 mJ/cm2, and these reductions were believed to be the result of direct UV damage to nucleic acids. After 24 h of dark incubation, recA and lexA were both upregulated but to a lesser extent for repressor lexA; and mazE and mazF were both downregulated. This result implies that UV irradiation induces the dark repair system more actively, and the cells will proceed to death at a rate similar to that associated with natural decay. 相似文献
Solar energy application in a large spectrum has the potential for high-efficiency energy conversion. Though, solar cells can only absorb photon energy of the solar spectrum near their band-gap energy, and the remaining energy will be converted into thermal energy. The use of the thermoelectric generator becomes a necessity for convert this thermal energy dissipated so as to increase efficiency conversion.
This paper analyses the feasibility of photovoltaic-thermoelectric hybrid system and reviews their performance in order to optimize harvested energy. Regarding the thermoelectric effect, a new method of the ambient energy harvesting is presented. This method combines thermoelectric generators and the effects of heat sensitive materials associated to photovoltaic cells in phase change for generating both energy day and night. Experimental measures have been conducted primarily in laboratory conditions for a greater understanding of hybridization phenomena under real conditions and to test the actual performance of devices made. Results show that the hybrid system can generate more power than the simple PV and TEG in environmental conditions. This hybrid technology will highlight the use of renewable energies in the service of the energy production. 相似文献
AbstractThe roles of PM2.5-induced mitochondrial damage and oxidative stress on mast cell degranulation were examined in vitro. Mast cells were treated with suspensions of PM2.5 in Dulbecco’s modified Eagle’s medium at concentrations from 25 to 200?mg/L in the absence or presence of 10?mmol/L N-acetyl-L-cysteine. Biological effects and mitochondrial function were assessed by determining cell viability, β-hexosaminidase release, interleukin-4 secretion, reactive oxygen species generation, adenosine triphosphate production, potential alteration of mitochondrial membrane, and activities of mitochondrial electron transport chain complexes I and III. Exposure of mast cells to PM2.5 induced reduction of adenosine triphosphate production, collapse of mitochondrial membrane potential, and inhibition of the activity of complex III. Co-treatment of mast cells exposed to PM2.5 with N-acetyl-L-cysteine attenuated cytotoxicity and the production of reactive oxygen species, and decreased the release of β-hexosaminidase and interleukin-4. Evidently, PM2.5-induced oxidative stress plays an essential role in mitochondrial toxicity and mast cell activation. 相似文献