Objective: Sarcopenia causes loss of skeletal muscle and function, thus seriously affecting the physical function and quality of life in the elderly. This article discusses the specific molecular mechanism and amelior...Objective: Sarcopenia causes loss of skeletal muscle and function, thus seriously affecting the physical function and quality of life in the elderly. This article discusses the specific molecular mechanism and ameliorating effects of Tudangshen(TDS) on sarcopenia in elderly rats with type 2 diabetes mellitus(T2DM).Methods: Elderly Sprague-Dawley(SD) rats were randomly selected and fed with a high-fat diet combined with an intraperitoneal injection of streptozotocin to establish T2DM model. The model rats were stratified and randomly divided into the model group,metformin group, TDS high-dose group, TDS medium-dose group, and TDS low-dose group according to blood glucose combined with body weight, and the same batch of old SD rats was set as the normal control group. The effects of TDS in an elderly T2DM sarcopenia rat model were evaluated by observing the body positions of the rats, analyzing blood biochemistry, testing exercise capacity, and pathologically staining sectioned gastrocnemius muscle tissues. The molecular mechanisms of the effects were analyzed using quantitative real-time polymerase chain reaction and western blotting.Results: TDS has no statistically significant effect on blood glucose, insulin and glycosylated serum protein in aged rats with T2DM, but it can reduce levels of glycosylated serum protein, total cholesterol, triglycerides, and low-density lipoprotein;it improves pathological changes in rat gastrocnemius muscle tissues, and increases muscle cell activity in elderly rats with T2DM and sarcopenia. TDS also promoted the upregulation of the expression of mammalian target of rapamycin(mTOR)/protein kinase B(PKB/AKT)/phosphatidylinositol 3-kinase(PI3K)/ribosomal protein S6 kinase/eukaryotic initiation factor 4 E binding rotein1 mRNA in rats and triggered an increase in corresponding protein levels.Conclusions: TDS alleviated muscle decline in elderly rats with T2DM by activating the PI3 K/AKT/mTOR signaling pathway and regulating the synthesis of corresponding proteins.展开更多
Based on the collected multiwavelength data, namely in the radio(NVSS, FIRST, RATAN-600), IR(WISE),optical(Pan-STARRS), UV(GALEX), and X-ray(ROSAT, Swift-XRT) ranges, we have performed a cluster analysis for the blaza...Based on the collected multiwavelength data, namely in the radio(NVSS, FIRST, RATAN-600), IR(WISE),optical(Pan-STARRS), UV(GALEX), and X-ray(ROSAT, Swift-XRT) ranges, we have performed a cluster analysis for the blazars of the Roma-BZCAT catalog. Using two machine learning methods, namely a combination of PCA with k-means clustering and Kohonen's self-organizing maps(SOMs), we have constructed an independent classification of the blazars(five classes) and compared the classes with the known Roma-BZCAT classification(FSRQs, BL Lacs, galaxy-dominated BL Lacs, and blazars of an uncertain type) as well as with the high synchrotron peaked(HSP) blazars from the 3HSP catalog and blazars from the TeVCat catalog. The obtained groups demonstrate concordance with the BL Lac/FSRQ classification along with a continuous character of the change in the properties. The group of HSP blazars stands out against the overall distribution. We examine the characteristics of the five groups and demonstrate distinctions in their spectral energy distribution shapes. The effectiveness of the clustering technique for objective analysis of multiparametric arrays of experimental data is demonstrated.展开更多
We analyze the optical light curve data,obtained with the Zwicky Transient Facility(ZTF)survey,for 47 γ-ray blazars monitored by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope(Fermi).These 47sou...We analyze the optical light curve data,obtained with the Zwicky Transient Facility(ZTF)survey,for 47 γ-ray blazars monitored by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope(Fermi).These 47sources are selected because they are among the Fermi blazars with the largest optical variations in the ZTF data.Two color-magnitude variation patterns are seen in them,with one being redder-to-stable-when-brighter(RSWB;in 31 sources)and the other being stable when brighter(in 16 sources).The patterns fit with the results recently reported in several similar studies with different data.Moreover,we find that the colors in the stable state of the sources share similar values,for which(after being corrected for the Galactic extinction)most sources are in a range of 0.4–0.55.This feature could be intrinsic and may be applied in,for example,study of the intragalactic medium.We also determine the turning points for the sources showing the RSWB pattern,after which the color changes saturate and become stable.We find a correlation between optical fluxes and γ-ray fluxes at the turning points.The physical implications of the correlation remain to be investigated,probably better with a sample of high-qualityγ-ray flux measurements.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.:82074394)。
文摘Objective: Sarcopenia causes loss of skeletal muscle and function, thus seriously affecting the physical function and quality of life in the elderly. This article discusses the specific molecular mechanism and ameliorating effects of Tudangshen(TDS) on sarcopenia in elderly rats with type 2 diabetes mellitus(T2DM).Methods: Elderly Sprague-Dawley(SD) rats were randomly selected and fed with a high-fat diet combined with an intraperitoneal injection of streptozotocin to establish T2DM model. The model rats were stratified and randomly divided into the model group,metformin group, TDS high-dose group, TDS medium-dose group, and TDS low-dose group according to blood glucose combined with body weight, and the same batch of old SD rats was set as the normal control group. The effects of TDS in an elderly T2DM sarcopenia rat model were evaluated by observing the body positions of the rats, analyzing blood biochemistry, testing exercise capacity, and pathologically staining sectioned gastrocnemius muscle tissues. The molecular mechanisms of the effects were analyzed using quantitative real-time polymerase chain reaction and western blotting.Results: TDS has no statistically significant effect on blood glucose, insulin and glycosylated serum protein in aged rats with T2DM, but it can reduce levels of glycosylated serum protein, total cholesterol, triglycerides, and low-density lipoprotein;it improves pathological changes in rat gastrocnemius muscle tissues, and increases muscle cell activity in elderly rats with T2DM and sarcopenia. TDS also promoted the upregulation of the expression of mammalian target of rapamycin(mTOR)/protein kinase B(PKB/AKT)/phosphatidylinositol 3-kinase(PI3K)/ribosomal protein S6 kinase/eukaryotic initiation factor 4 E binding rotein1 mRNA in rats and triggered an increase in corresponding protein levels.Conclusions: TDS alleviated muscle decline in elderly rats with T2DM by activating the PI3 K/AKT/mTOR signaling pathway and regulating the synthesis of corresponding proteins.
文摘Based on the collected multiwavelength data, namely in the radio(NVSS, FIRST, RATAN-600), IR(WISE),optical(Pan-STARRS), UV(GALEX), and X-ray(ROSAT, Swift-XRT) ranges, we have performed a cluster analysis for the blazars of the Roma-BZCAT catalog. Using two machine learning methods, namely a combination of PCA with k-means clustering and Kohonen's self-organizing maps(SOMs), we have constructed an independent classification of the blazars(five classes) and compared the classes with the known Roma-BZCAT classification(FSRQs, BL Lacs, galaxy-dominated BL Lacs, and blazars of an uncertain type) as well as with the high synchrotron peaked(HSP) blazars from the 3HSP catalog and blazars from the TeVCat catalog. The obtained groups demonstrate concordance with the BL Lac/FSRQ classification along with a continuous character of the change in the properties. The group of HSP blazars stands out against the overall distribution. We examine the characteristics of the five groups and demonstrate distinctions in their spectral energy distribution shapes. The effectiveness of the clustering technique for objective analysis of multiparametric arrays of experimental data is demonstrated.
基金supported by the National Science Foundation under Grant No.AST-2034437 and a collaboration including Caltech,IPACsupported by the Basic Research Program of Yunnan Province(No.202201AS070005)+2 种基金the National Natural Science Foundation of China(NSFC,grant No.12273033)the Original Innovation Program of the Chinese Academy of Sciences(E085021002)the support of the science research program for graduate students of Yunnan University(KC-23234629)。
文摘We analyze the optical light curve data,obtained with the Zwicky Transient Facility(ZTF)survey,for 47 γ-ray blazars monitored by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope(Fermi).These 47sources are selected because they are among the Fermi blazars with the largest optical variations in the ZTF data.Two color-magnitude variation patterns are seen in them,with one being redder-to-stable-when-brighter(RSWB;in 31 sources)and the other being stable when brighter(in 16 sources).The patterns fit with the results recently reported in several similar studies with different data.Moreover,we find that the colors in the stable state of the sources share similar values,for which(after being corrected for the Galactic extinction)most sources are in a range of 0.4–0.55.This feature could be intrinsic and may be applied in,for example,study of the intragalactic medium.We also determine the turning points for the sources showing the RSWB pattern,after which the color changes saturate and become stable.We find a correlation between optical fluxes and γ-ray fluxes at the turning points.The physical implications of the correlation remain to be investigated,probably better with a sample of high-qualityγ-ray flux measurements.
