Paleozoic rocks in the Wadi El Sahu area are affected by many major faults in different directions.A reverse fault trending NE-SW is exposed for about 300 m of its length as it cuts through the Abu Hamata and Adedia f...Paleozoic rocks in the Wadi El Sahu area are affected by many major faults in different directions.A reverse fault trending NE-SW is exposed for about 300 m of its length as it cuts through the Abu Hamata and Adedia formations on the south side of Wadi El Sahu.A secondary ascending hydrothermal solution carrying heavy metals and radioactive minerals passed through the fault plain and the surrounding fractures,forming mineralized and radioactive zone.The mineralized zone thickness ranges from 60 cm to 200 cm along the fault plain.These rocks were analyzed radiometrically using a portable gamma-ray spectrometer,chemically by employing ICP-ES and ICP-MS,as well as mineralogically by both binocular and Environmental Scanning Electron microscope.Gold content was also determined by fire assay.REE and U contents reached up to 2682 and 1216 ppm,respectively.Mineralogical investigations indicated the presence of uraninite,torbernite,autunite,sklodowskite,kasolite as uranium minerals,thorite as a thorium mineral,monazite,allanite and xenotime as REE-bearing minerals,zircon and columbite as accessory minerals,gold and nickel as precious and base metals,in addition to cassiterite,chalcopyrite,chalcocite and chrysocolla.High REE and U contents are attributed to the circulation of epigenetic U and REE-bearing hydrothermal solutions along the fault plain and its surrounding fractures.Hydrothermal alteration processes could then be confirmed by the presence of the M-type tetrad effect in the REE-patterns of the ferruginous sandstone.The non-chondritic ratio of Nb/Ta,Zr/Hf and Y/Ho in the studied sandstone may be attributed to the tetrad effect.The Ce and Eu anomaly with unusual REE-patterns was represented by the presence of conjugated M-W tetrad effects,indicating either the dual effect of hydrothermal solutions or groundwater with seawater.The results clarify that the tetrad-effects could be used as evidence for the environment of deposition and as an indication for gold mineralization.展开更多
The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluorescence indicator di...The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluorescence indicator displacement assays have been used to identify ligands that can inhibit the ReveRRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient ReveRRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive ReveRRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)propylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the ReveRRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The ReveRRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.展开更多
In this article,we improve the order of precision of the two-dimensional Poisson equation by combining extrapolation techniques with high order schemes.The high order solutions obtained traditionally generate non-spar...In this article,we improve the order of precision of the two-dimensional Poisson equation by combining extrapolation techniques with high order schemes.The high order solutions obtained traditionally generate non-sparse matrices and the calculation time is very high.We can obtain sparse matrices by applying compact schemes.In this article,we compare compact and exponential finite difference schemes of fourth order.The numerical solutions are calculated in quadruple precision(Real*16 or extended precision)in FORTRAN language,and iteratively obtained until reaching the round-off error magnitude around 1.0E−32.This procedure is performed to ensure that there is no iteration error.The Repeated Richardson Extrapolation(RRE)method combines numerical solutions in different grids,determining higher orders of accuracy.The main contribution of this work is based on a process that initializes with fourth order solutions combining with RRE in order to find solutions of sixth,eighth,and tenth order of precision.The multigrid Full Approximation Scheme(FAS)is also applied to accelerate the convergence and obtain the numerical solutions on the fine grids.展开更多
文摘Paleozoic rocks in the Wadi El Sahu area are affected by many major faults in different directions.A reverse fault trending NE-SW is exposed for about 300 m of its length as it cuts through the Abu Hamata and Adedia formations on the south side of Wadi El Sahu.A secondary ascending hydrothermal solution carrying heavy metals and radioactive minerals passed through the fault plain and the surrounding fractures,forming mineralized and radioactive zone.The mineralized zone thickness ranges from 60 cm to 200 cm along the fault plain.These rocks were analyzed radiometrically using a portable gamma-ray spectrometer,chemically by employing ICP-ES and ICP-MS,as well as mineralogically by both binocular and Environmental Scanning Electron microscope.Gold content was also determined by fire assay.REE and U contents reached up to 2682 and 1216 ppm,respectively.Mineralogical investigations indicated the presence of uraninite,torbernite,autunite,sklodowskite,kasolite as uranium minerals,thorite as a thorium mineral,monazite,allanite and xenotime as REE-bearing minerals,zircon and columbite as accessory minerals,gold and nickel as precious and base metals,in addition to cassiterite,chalcopyrite,chalcocite and chrysocolla.High REE and U contents are attributed to the circulation of epigenetic U and REE-bearing hydrothermal solutions along the fault plain and its surrounding fractures.Hydrothermal alteration processes could then be confirmed by the presence of the M-type tetrad effect in the REE-patterns of the ferruginous sandstone.The non-chondritic ratio of Nb/Ta,Zr/Hf and Y/Ho in the studied sandstone may be attributed to the tetrad effect.The Ce and Eu anomaly with unusual REE-patterns was represented by the presence of conjugated M-W tetrad effects,indicating either the dual effect of hydrothermal solutions or groundwater with seawater.The results clarify that the tetrad-effects could be used as evidence for the environment of deposition and as an indication for gold mineralization.
基金supported by the Natural Science Foundation of Shaanxi Province of China(Grant No.:202012119)the Start-up Funding of Shaanxi University of Science and Technology(Grant No.:2019BJ-48)the Innovation Capability Support Program of Shaanxi Province of China(Grant No.:2021PT-044).
文摘The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluorescence indicator displacement assays have been used to identify ligands that can inhibit the ReveRRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient ReveRRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive ReveRRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)propylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the ReveRRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The ReveRRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.
文摘In this article,we improve the order of precision of the two-dimensional Poisson equation by combining extrapolation techniques with high order schemes.The high order solutions obtained traditionally generate non-sparse matrices and the calculation time is very high.We can obtain sparse matrices by applying compact schemes.In this article,we compare compact and exponential finite difference schemes of fourth order.The numerical solutions are calculated in quadruple precision(Real*16 or extended precision)in FORTRAN language,and iteratively obtained until reaching the round-off error magnitude around 1.0E−32.This procedure is performed to ensure that there is no iteration error.The Repeated Richardson Extrapolation(RRE)method combines numerical solutions in different grids,determining higher orders of accuracy.The main contribution of this work is based on a process that initializes with fourth order solutions combining with RRE in order to find solutions of sixth,eighth,and tenth order of precision.The multigrid Full Approximation Scheme(FAS)is also applied to accelerate the convergence and obtain the numerical solutions on the fine grids.
