Behind the prevalence of multimedia technology,digital copyright disputes are becoming increasingly serious.The digital watermarking prevention technique against the copyright infringement needs to be improved urgentl...Behind the prevalence of multimedia technology,digital copyright disputes are becoming increasingly serious.The digital watermarking prevention technique against the copyright infringement needs to be improved urgently.Among the proposed technologies,zero-watermarking has been favored recently.In order to improve the robustness of the zero-watermarking,a novel robust audio zerowatermarking method based on sparse representation is proposed.The proposed scheme is mainly based on the K-singular value decomposition(K-SVD)algorithm to construct an optimal over complete dictionary from the background audio signal.After that,the orthogonal matching pursuit(OMP)algorithm is used to calculate the sparse coefficient of the segmented test audio and generate the corresponding sparse coefficient matrix.Then,the mean value of absolute sparse coefficients in the sparse matrix of segmented speech is calculated and selected,and then comparing the mean absolute coefficient of segmented speech with the average value of the selected coefficients to realize the embedding of zero-watermarking.Experimental results show that the proposed audio zerowatermarking algorithm based on sparse representation performs effectively in resisting various common attacks.Compared with the baseline works,the proposed method has better robustness.展开更多
Cancer cells remodel their metabolic network to adapt to variable nutrient availability. Pentose phosphate pathway(PPP) plays protective and biosynthetic roles by oxidizing glucose to generate reducing power and ribos...Cancer cells remodel their metabolic network to adapt to variable nutrient availability. Pentose phosphate pathway(PPP) plays protective and biosynthetic roles by oxidizing glucose to generate reducing power and ribose. How cancer cells modulate PPP activity in response to glucose supply remains unclear. Here we show that ribose-5-phosphate isomerase A(RPIA), an enzyme in PPP, directly interacts with co-activator associated arginine methyltransferase 1(CARM1) and is methylated at arginine 42(R42). R42 methylation up-regulates the catalytic activity of RPIA. Furthermore, glucose deprivation strengthens the binding of CARM1 with RPIA to induce R42 hypermethylation. Insufficient glucose supply links to RPIA hypermethylation at R42, which increases oxidative PPP flux. RPIA methylation supports ROS clearance by enhancing NADPH production and fuels nucleic acid synthesis by increasing ribose supply. Importantly, RPIA methylation at R42 significantly potentiates colorectal cancer cell survival under glucose starvation. Collectively, RPIA methylation connects glucose availability to nucleotide synthesis and redox homeostasis.展开更多
As an emerging nanomaterial,nanofibrous aerogel possesses advantages such as low density,large specific surface area,low thermal conductivity,and high mechanical stability.Preparing nanofiber aerogels through electros...As an emerging nanomaterial,nanofibrous aerogel possesses advantages such as low density,large specific surface area,low thermal conductivity,and high mechanical stability.Preparing nanofiber aerogels through electrospinning is an emerging research topic.This review focuses on the key fabrication techniques for electrospun nanofibrous aerogels,including freezedrying,direct electrospinning,layer-by-layer stacking,and thermally induced self-agglomeration.In addition,by combining nanofibers’distinctive properties and aerogels’physical characteristics,nanofibrous aerogels demonstrate various potential academic and industrial applications,including thermal insulation,sound absorption,solar desalination,air filtration,oil-water separation,and biomedical engineering.This paper provides an overview of the fundamentals and recent advancements in electrospinning,summarizes the fabrication methods and applications of the most representative nanofibrous aerogels in recent years,and offers insights into nanofibrous aerogels’challenges and prospects.展开更多
The objective of this study is to evaluate the potential of various grids to satisfactorily simulate the development of a cooling film, using a coupled computation that takes into account the full geometry. Detailed c...The objective of this study is to evaluate the potential of various grids to satisfactorily simulate the development of a cooling film, using a coupled computation that takes into account the full geometry. Detailed computations of a single row of 30 degrees round holes on a flat plate are presented for blowing ratios of 0.764, 1.01 and 1.54. The simulation results are compared well with experimental data. The two-layer model gave more accurate results but consumed much more computational time than the standard wall functions. The k-ε turbulence model with wall functions with appropriate values of y^＋ is suitable for practical use. The results show the importance of the conjugate calculation for accurately describing the influence of the heat transfer within the cooling film.展开更多
基金the National Natural Science Foundation of China(No.62001100)the Fundamental Research Funds for the Central Universities(No.2232019D3-52)Shanghai Sailing Program.(No.19YF1402000).
文摘Behind the prevalence of multimedia technology,digital copyright disputes are becoming increasingly serious.The digital watermarking prevention technique against the copyright infringement needs to be improved urgently.Among the proposed technologies,zero-watermarking has been favored recently.In order to improve the robustness of the zero-watermarking,a novel robust audio zerowatermarking method based on sparse representation is proposed.The proposed scheme is mainly based on the K-singular value decomposition(K-SVD)algorithm to construct an optimal over complete dictionary from the background audio signal.After that,the orthogonal matching pursuit(OMP)algorithm is used to calculate the sparse coefficient of the segmented test audio and generate the corresponding sparse coefficient matrix.Then,the mean value of absolute sparse coefficients in the sparse matrix of segmented speech is calculated and selected,and then comparing the mean absolute coefficient of segmented speech with the average value of the selected coefficients to realize the embedding of zero-watermarking.Experimental results show that the proposed audio zerowatermarking algorithm based on sparse representation performs effectively in resisting various common attacks.Compared with the baseline works,the proposed method has better robustness.
基金supported by the Ministry of Science and Technology(2019YFA0801703)the National Natural Science Foundation of China(81790250,81790253 and 91959202)the Innovation Program of Shanghai Municipal Education Commission(N173606)。
文摘Cancer cells remodel their metabolic network to adapt to variable nutrient availability. Pentose phosphate pathway(PPP) plays protective and biosynthetic roles by oxidizing glucose to generate reducing power and ribose. How cancer cells modulate PPP activity in response to glucose supply remains unclear. Here we show that ribose-5-phosphate isomerase A(RPIA), an enzyme in PPP, directly interacts with co-activator associated arginine methyltransferase 1(CARM1) and is methylated at arginine 42(R42). R42 methylation up-regulates the catalytic activity of RPIA. Furthermore, glucose deprivation strengthens the binding of CARM1 with RPIA to induce R42 hypermethylation. Insufficient glucose supply links to RPIA hypermethylation at R42, which increases oxidative PPP flux. RPIA methylation supports ROS clearance by enhancing NADPH production and fuels nucleic acid synthesis by increasing ribose supply. Importantly, RPIA methylation at R42 significantly potentiates colorectal cancer cell survival under glucose starvation. Collectively, RPIA methylation connects glucose availability to nucleotide synthesis and redox homeostasis.
基金Shaanxi Province High-level Talent Programme(Project Nos.2023SYJ29)Research Grants Council of the Hong Kong,China,through(Project Nos.RFS2223-1S04,11218122,11209421)+1 种基金Science and Technology Plan Project of Sichuan Province(Project Nos.2023YFSY0030).Hong Kong University of Science and Technology.
文摘As an emerging nanomaterial,nanofibrous aerogel possesses advantages such as low density,large specific surface area,low thermal conductivity,and high mechanical stability.Preparing nanofiber aerogels through electrospinning is an emerging research topic.This review focuses on the key fabrication techniques for electrospun nanofibrous aerogels,including freezedrying,direct electrospinning,layer-by-layer stacking,and thermally induced self-agglomeration.In addition,by combining nanofibers’distinctive properties and aerogels’physical characteristics,nanofibrous aerogels demonstrate various potential academic and industrial applications,including thermal insulation,sound absorption,solar desalination,air filtration,oil-water separation,and biomedical engineering.This paper provides an overview of the fundamentals and recent advancements in electrospinning,summarizes the fabrication methods and applications of the most representative nanofibrous aerogels in recent years,and offers insights into nanofibrous aerogels’challenges and prospects.
文摘The objective of this study is to evaluate the potential of various grids to satisfactorily simulate the development of a cooling film, using a coupled computation that takes into account the full geometry. Detailed computations of a single row of 30 degrees round holes on a flat plate are presented for blowing ratios of 0.764, 1.01 and 1.54. The simulation results are compared well with experimental data. The two-layer model gave more accurate results but consumed much more computational time than the standard wall functions. The k-ε turbulence model with wall functions with appropriate values of y^＋ is suitable for practical use. The results show the importance of the conjugate calculation for accurately describing the influence of the heat transfer within the cooling film.
