61 research outputs found
The effects of aB-crystallin on mitochondrial death pathway during hydrogen peroxide induced apoptosis
aB-crystallin, a major small heat shock protein, has recently been shown to exert inhibitory effects on apoptosis, while the responsible mechanisms remain largely unknown. In the present study, we discovered that aB-crystallin protected mouse myoblast C2C12 cells against oxidative stress-induced apoptosis. During hydrogen peroxide-induced apoptosis, aBcrystallin showed that it decreased the redistribution level of phosphatidylserine (PS), reduced the release of cytochrome C and Smac/Diablo from mitochondria into cytoplasm, and decreased the cleavage of Bid. Interestingly, immunoprecipitation experiments with anti-aBcrystallin and anti-myc-tag antibodies demonstrated respectively an interaction between aBcrystallin and p53 during hydrogen peroxide induced apoptosis. Both the NH2-terminal and COOH-terminal regions of aB-crystallin could interact with p53, suggesting two domains of aB-crystallin are necessary for the interaction. Electrophoresis mobility shift assay (EMSA) and luciferase assay further demonstrated that aB-crystallin inhibited the upregulation of the DNA-binding, as well as the transactivation activity of p53 induced by hydrogen peroxide. Our results show that aB-crystallin has a protective role in oxidative stress induced apoptosis by interference with the mitochondrial death pathway
Astronomical function and date of the Taosi observatory
The Taosi site in Xiangfen County, Shanxi Province, may be the capital of the King Yao. Archeologists recently discovered a large semi-circular stamped-earth platform, II FJT1, which has a clear and definite pounded-earth central core together with a curved wall perforated by twelve gaps. The platform is said to be an ancient observatory used to determine the seasons by watching the sunrise. Each feature of II FJT1 was precisely measured and the data are reproduced in this paper. An astronomical analysis of slots E2 and E12 was carried out using the azimuths of the slots' centerlines and the vertical angle of the mountain ridge opposite, above which the sun rises. The results show that at present the sun is close to the two slots but does not exactly enter them at summer and winter solstice sunrise. Using 14C analysis archeologists dated the site to about 2100 BC. Because of the secular change in the obliquity of the ecliptic, at that date on the summer solstice the half-risen sun would have appeared inside slot E12 just to the right of the centerline, and on the winter solstice the sun would have been exactly on the centerline of slot E2. This result provides compelling proof that II FJT1 is an ancient observatory
Assessment of Economic Recovery in Hebei Province, China, under the COVID-19 Pandemic Using Nighttime Light Data
The COVID-19 pandemic has presented unprecedented disruptions to human society worldwide since late 2019, and lockdown policies in response to the pandemic have directly and drastically decreased human socioeconomic activities. To quantify and assess the extent of the pandemic’s impact on the economy of Hebei Province, China, nighttime light (NTL) data, vegetation information, and provincial quarterly gross domestic product (GDP) data were jointly utilized to estimate the quarterly GDP for prefecture-level cities and county-level cities. Next, an autoregressive integrated moving average model (ARIMA) model was applied to predict the quarterly GDP for 2020 and 2021. Finally, economic recovery intensity (ERI) was used to assess the extent of economic recovery in Hebei Province during the pandemic. The results show that, at the provincial level, the economy of Hebei Province had not yet recovered; at the prefectural and county levels, three prefectures and forty counties were still struggling to restore their economies by the end of 2021, even though these economies, as a whole, were gradually recovering. In addition, the number of new infected cases correlated positively with the urban NTL during the pandemic period, but not during the post-pandemic period. The study results are informative for local government’s strategies and policies for allocating financial resources for urban economic recovery in the short- and long-term
Study on Influencing Factors of Active Silicon Content Determination in Gibbsite
This paper mainly studies the factors affecting the determination of active silicon content in gibbsite. Active silicon is an important index of gibbsite. A method for the determination of active silicon in gibbsite was established by inductively coupled plasma atomic emission spectrometry (ICP-AES). The sample pretreatment conditions were optimized, and the optimal sample weight, sample dissolution conditions, sodium hydroxide concentration and volume, constant volume, shaking frequency and boiling time were determined. The results show that the pressure dissolution sample can get better detection results. The recovery of the method is 99.13%~100.70%, the detection limit is 0.02 mg/L, and the relative standard deviation is 0.0191%. The method is simple, rapid, reproducible and accurate, which can be used for the determination of active silicon content in gibbsite
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