Silica fibers are widely used in superhigh velocity radome and antenna windows. The methods of eliminating the agents on the surface silica fibers were sdudied in this paper. SEM was engaged in studying the effects of silica fibers disposed by different methods,and the tensile strength of disposed silica fbers was compared with the originals. The results show that the heat treatment in the high temperature was a useful means to eliminate the agent on the surface of silica fiber, but there was great thermal damage for silica fibers,and the tensile strenth decreased significantly. The combination of volvent treatment and heat tratment could eliminate the agent on tht surface of silica fibers completely,and the tensile strength retained more, which was a good means to eliminate the agents on the surface of silica fiber.
Artemisinin is a secondary metabolite extracted from Artemisia annua. As an effective antimalarial component certified by WHO, artemisinin has extensive economical values. Numerous studies about transcription factors positively regulating artemisinin biosynthesis have been published while negative regulators are rarely reported. In the present study, we identified AaMYB15 as the first R2R3-MYB that negatively regulates artemisinin biosynthesis in A. annua. Experimental evidences showed that AaMYB15 is a transcription factor within nucleus and predominantly expressed in glandular secretory trichomes (GSTs) in A. annua where artemisinin is synthesized and accumulated. The expression of AaMYB15 was induced by dark and JA treatment. Overexpression of AaMYB15 led to a significant decline in the expression levels of key enzyme genes ADS, CYP, DBR2, and ALDH1 and a significant decrease in the artemisinin contents of transgenic A. annua. AaMYB15 directly bound to the promoter of AaORA, a reported positive regulator of artemisinin biosynthesis in JA signaling pathway, to repress its transcriptional activity, thus downregulating the expression levels of downstream key enzyme genes and negatively regulating the artemisinin biosynthesis. Our study provides candidate gene for improvement of A. annua germplasm and new insights into the artemisinin biosynthesis regulation network mediated by light and JA.
Abstract Spectral irradiance scale in the wavelength range from 250 nm to 2500 nm was realized at National Institute of Metrology on the basis of a large area tungsten carbide–carbon (WC–C) high temperature fixed point blackbody, which is composed of a 14 mm diameter WC–C fixed point cell and a variable temperature blackbody BB3500MP as a furnace. A series of 1000 W FEL tungsten halogen lamps were used as transfer standards. The new spectral irradiance scale was compared with the scale based on a variable-temperature blackbody BB3500M, and the divergence between these two methods varied from −0.66% to 0.79% from 280 nm to 2100 nm. The measurement uncertainty of spectral irradiance scale based on fixed-point blackbody was analyzed, and the expanded uncertainty was estimated as 3.9% at 250 nm, 1.4% at 280 nm, 0.43% at 400 nm, 0.27% at 800 nm, 0.25% at 1000 nm, 0.62% at 1500 nm, 0.76% at 2000 nm, and 2.4% at 2500 nm respectively. In the range from 300 nm to 1000 nm the fixed-point scale was improved obviously: the uncertainty decreased by more than 25% compared to the uncertainty based on the variable temperature blackbody. Below 300 nm, the uncertainty became higher because the signal to noise ratio was poor. Above 1100 nm, the contribution of temperature measurement to the uncertainty of spectral irradiance decreases, therefore the uncertainties of two methods are almost at the same level. The fixed-point blackbody was also used to realize the correlated colour temperature and distribution temperature of a tungsten filament lamp, the deviation from the variable temperature blackbody method was −0.5 K and −2.9 K, respectively.
Based on preparing high purity powdered lithium ion-sieve precursor LiMn2O4, using lithium carbonate and manganese carbonate as raw materials, through roasting at high temperature of 800°C, laminar lithium ion-sieve precursor was prepared by commixing poly (vinyl chloride) (PVC) and powdered precursor in DMF (N, N-dimethylformamide) as solvent, and then powder and lithium ion-sieve flat sheet membrane was obtained through washing with HCl solution respectively. Their adsorption capacity and morphology was also characterized. The results show that both powdered lithium ion-sieve and laminar one have high adsorption capacity and selectivity for Li in solutions, and the effect of their retest is good. All these can provide a good foundation for the further study on lithium ion-sieve flat sheet membrane and lithium extraction from seawater.
Background: Hirsuteine is an alkaloid compound that can inhibit the proliferative activity of several cancer cell types in vitro, yet no prior reports have explored its ability to inhibit non-small cell lung cancer (NSCLC) growth. As such, herein, we sought to explore the antiproliferative activity of hirsuteine when used to treat human NSCLC A549 and NC I-H1299 cells across a range of tested concentrations (0–25 μM) and to explore the mechanisms underlying its therapeutic efficacy.Methods: The effects of hirsuteine on cell viability was examined via CCK-8 and colony formation assays, while apoptosis was assessed through Hoechst 33,258 staining and flow cytometry. Cell cycle progression was additionally evaluated via propidium iodide staining, while Western blotting and real-time quantitative polymerase chain reaction (qPCR) method were conducted to assess the levels of proteins and genes associated with apoptosis and cell cycle progression, respectively.Results: Hirsuteine markedly suppressed the proliferation of A549 and NCI-H1299 cells in a dose and time-dependent fashion and induced clear changes in cell morphology, resulting in G0-G1 phase cell cycle arrest that was related to the downregulation of Cyclin E and CDK2. Hirsuteine additionally induced robust apoptosis of A549 and NCI-H1299 cells and Bcl-2 downregulation together with the upregulation of Bax, Apaf1, cytoplasmic cytochrome C, cleaved caspase-3 and cleaved caspase-9, together driving this apoptotic cell death.Conclusion: Hirsuteine can effectively suppress the growth of human NSCLC A549 and NCI-H1299 cells and induce apoptotic death in a dose-dependent fashion in vitro , emphasizing the promising of this alkaloid compound as a potent anticancer treatment that warrants study as a treatment for human NSCLC patients.
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