Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the spe...Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the special case where p and n are comparable,we consider a much more general case in which log n=o(p^(1/3)).We prove that the maximum interpoint distance Mn=max{|X_(i)-X_(j)|;1≤i<j≤n}converges to an extreme-value distribution,where X_(i)and X_(j)denote the i-th and j-th row of M_(n,p),respectively.The proofs are completed by using the Chen-Stein Poisson approximation method and the moderation deviation principle.展开更多
FCC dry gas contains a large amount of ethylene. It is used by most of the refineries in China as fuel or simply burned in atmosphere. Few refineries make good use of the dry gas, so the precious ethylene resource in ...FCC dry gas contains a large amount of ethylene. It is used by most of the refineries in China as fuel or simply burned in atmosphere. Few refineries make good use of the dry gas, so the precious ethylene resource in the dry gas is wasted. In this article, the possibility of catalytic conversion of ethylene to C3, C4, and some high molecular weight hydrocarbons in a fixed bed micro-reactor using LTB-1 catalyst, with pure ethylene as feedstock was studied. Effects of reaction temperature, reaction pressure, and feedstock flow rate, on the conversion of ethylene and the distribution of products were investigated to determine the proper reaction parameters to be used in practice. Good results indicate that this study may provide a new way of using the ethylene resource in the FCC dry gas.展开更多
The oligomerization of ethylene in FCC dry gas over HZSM-5 catalyst with different Si/A12 ratios was studied. The effect of acid density of catalyst on the oligomerization of ethylene was discussed. By increasing the ...The oligomerization of ethylene in FCC dry gas over HZSM-5 catalyst with different Si/A12 ratios was studied. The effect of acid density of catalyst on the oligomerization of ethylene was discussed. By increasing the acid density of catalyst, ethylene conversion showed a linear increase, while the yields of olefins decreased when the acid density of catalyst exceeded 0.14mmolNH3/g owing to a promotion of hydrogen transfer reaction. Through comparing the average distance between acid sites on catalyst with kinetic diameters of olefins, it was found that the dimerization of ethylene was not restrained by the sparse distribution of acid sites, while the hydrogen transfer reaction of C3 and C4 olefins was limited. On these bases, a conclusion is proposed that the dimerization of ethylene proceeded via Eley-Rideal mechanism, while the hydrogen transfer reaction of C3 and C4 olefins followed the Langmuir-Hinshelwood mechanism.展开更多
Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair ce...Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.展开更多
AIM:To evaluate the potential efficacy and mechanisms of nintedanib in corneal neovascularization(NV)in rabbit models.METHODS:Corneal NV was induced using 1 mol/L Na OH.Rabbits(n=21)were randomized to 3 groups:Group 1...AIM:To evaluate the potential efficacy and mechanisms of nintedanib in corneal neovascularization(NV)in rabbit models.METHODS:Corneal NV was induced using 1 mol/L Na OH.Rabbits(n=21)were randomized to 3 groups:Group 1 were treated with 0.9%NaCl,Group 2 with Avastin(5 mg/mL),and Group 3 with nintedanib(1 mg/mL).All treatments star ted 1 d af ter alkaline burns and were topically performed 3 times a day for 2 wk.Photographs were taken on a slit lamp microscope on day 7 and 14.The NV area,the length of the vascularization and angiogenesis index(AI)were used to evaluate the corneal NV.On day 14,the immunohistochemical(IHC)studies of the cornea were examined.Western blot was performed to test the expression levels of vascular endothelial growth factor(VEGF),Akt,p-Akt,P38,p-P38,MMP-2 and MMP-9.RESULTS:The corneal NV area,vessel length and AI in Group 3 were significantly lower than Group 2,with both being lower than Group 1.IHC staining showed that VEGF was significantly overexpressed in the epithelium and stroma of cornea following alkaline burns.In contrast,the level of VEGF was significantly suppressed in both Group 2 and Group 3.Western blot results further confirmed that,compared with Group 1,Group 3 had significantly reduced expressions of VEGF,Akt,p-Akt,p-P38,MMP-2,and MMP-9 in corneal tissues.Trends of lower levels of MMP-2,AKT,and p-AKT in Group 3 than Group 2 were identified.CONCLUSION:Nintedanib and Avastin can effectively inhibit corneal NV,with P38 MAPK and AKT signaling pathways being possibly involved.Nintedanib seems more effective than Avastin and has the potential to be a novel therapy for preventing corneal NV.展开更多
Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured...Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured in marine sand deposits from Liaodong Bay (LDB), North Yellow Sea (NYS), Zhoushan area (ZS), Taiwan Shoal (TS) and Pearl River Mouth (PR), offshore China, which are potential marine sand mining areas. The radiation activity equivalent (Raeq), indoor gamma absorbed dose rate (DR), annual effective dose (HR), alpha index (Ia), gamma index (Ig), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the marine sands offshore China. From the analysis, it is found that these marine sands are safe for the constructions. The Pearson correlation coefficient reveals that the 226Ra distribution in the marine sands offshore China is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the entire data from the marine sands, wherein 98.22% of the total variance is explained. Our results provide good baseline data to expand the database of radioactivity of building materials in China and all over the world.展开更多
Drought is one of the major meteorological disasters affecting the climate in China.In this paper,the interannual variation and seasonal distribution changes of drought at different time scales were analyzed with the ...Drought is one of the major meteorological disasters affecting the climate in China.In this paper,the interannual variation and seasonal distribution changes of drought at different time scales were analyzed with the standardized precipitation index( SPI) as the drought evaluation criterion to the precipitation data of the 5 meteorological stations of Jinan,Tai'an,Yiyuan,Shen County and Yanzhou from 1960 to 2013.The results showed that:(1) the frequency of drought was low in spring and summer in inland areas of Shandong Province,while autumn had frequent occurrences of moderate drought,and winter had frequent occurrences of heavy and severe droughts.(2) In the 1960 s,1980 s and early 21^(st) century,the number of droughts increased significantly,and the SPI values showed a significant decrease.(3) The 3-month time scale range was wide,during which the frequency of occurrence was high.The trend of SPI changes at the 12-month time scale was affected by the accumulation of antecedent precipitation,and the change was slow.The research results can provide a scientific reference for arid climate analysis and water resources management in agriculture and production in inland areas of Shandong Province.展开更多
Air pollution has become the most concerned regional environmental problem in China at present.According to the data of typical cities in Shandong Province from January,2014 to December,2015,the air quality status,pol...Air pollution has become the most concerned regional environmental problem in China at present.According to the data of typical cities in Shandong Province from January,2014 to December,2015,the air quality status,pollution status and spatial variation characteristics of air pollutants were classified and analyzed,thereby providing a scientific basis for air pollution control.The conclusions of this study are as follows:(1) PM_(2.5) was the most important atmospheric pollutant in Shandong Province;(2) Qingdao had the best air quality with a good air quality rate of 73.7%,while Jinan had the worst air quality with a good air quality rate only of 31.3%; and(3) the days with heavy pollution were mainly concentrated in winter,mainly due to coal-fired heating in winter.展开更多
Introduction:Female breast nodules represent the most frequently detected lesions during breast ultrasound screening.Notably,nodules classified as BIRADS 4 or 5 indicate an elevated risk of breast cancer.Nevertheless,...Introduction:Female breast nodules represent the most frequently detected lesions during breast ultrasound screening.Notably,nodules classified as BIRADS 4 or 5 indicate an elevated risk of breast cancer.Nevertheless,the detection rate and BI-RADS classification of female breast nodules across China remain largely undocumented.Methods:This study analyzed health examination data from 6,412,893 urban women across 31 provincial-level administrative divisions(PLADs).We calculated detection rates of breast nodules and their various BI-RADS classifications.Chi-square(χ2)tests were performed to compare differences between groups.Multivariable logistic regression models were constructed to explore associations between breast nodules and BI-RADS 4-5 with demographic,socioeconomic,and metabolic indicators.Results:The overall detection rate of breast nodules in Chinese urban women was 27.9%,with provincial rates ranging from 11.6%to 37.0%.Among women with breast nodules marked with BI-RADS classification information,95.9%were categorized as BI-RADS 2-3,while 4.0%were classified as BI-RADS 4-5.Further analyses revealed that age,geographic region,per capita gross domestic product(GDP),body mass index(BMI),high triglyceride(TG),high lowdensity lipoprotein cholesterol(LDL-C),and diabetes were significant risk factors for BI-RADS 4-5 classification.Conclusions:This study highlights the importance of managing high-risk women with breast nodules through BI-RADS classification,underscoring the need for targeted health interventions while considering regional and socioeconomic disparities.展开更多
The metabolic state of an organism reflects both external environmental factors and internal genetic influences, providing insights into physiological conditions and potential disease mechanisms. Historically, our und...The metabolic state of an organism reflects both external environmental factors and internal genetic influences, providing insights into physiological conditions and potential disease mechanisms. Historically, our understanding of organismal metabolism was relatively limited by technological constraints. With the rapid advancement of mass spectrometrybased methods and strategies for studying endogenous small molecules.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.1177117812171198)+2 种基金the Science and Technology Development Program of Jilin Province(Grant No.20210101467JC)the Technology Program of Jilin Educational Department During the“14th Five-Year”Plan Period(Grant No.JJKH20241239KJ)the Fundamental Research Funds for the Central Universities.
文摘Let M_(n,p)=(X_(i,k))_(n×p)be an n×p random matrix whose p columns X^((1)),...,X^((p))are an n-dimensional i.i.d.random sample of size p from 1-dependent Gaussian populations.Instead of investigating the special case where p and n are comparable,we consider a much more general case in which log n=o(p^(1/3)).We prove that the maximum interpoint distance Mn=max{|X_(i)-X_(j)|;1≤i<j≤n}converges to an extreme-value distribution,where X_(i)and X_(j)denote the i-th and j-th row of M_(n,p),respectively.The proofs are completed by using the Chen-Stein Poisson approximation method and the moderation deviation principle.
文摘FCC dry gas contains a large amount of ethylene. It is used by most of the refineries in China as fuel or simply burned in atmosphere. Few refineries make good use of the dry gas, so the precious ethylene resource in the dry gas is wasted. In this article, the possibility of catalytic conversion of ethylene to C3, C4, and some high molecular weight hydrocarbons in a fixed bed micro-reactor using LTB-1 catalyst, with pure ethylene as feedstock was studied. Effects of reaction temperature, reaction pressure, and feedstock flow rate, on the conversion of ethylene and the distribution of products were investigated to determine the proper reaction parameters to be used in practice. Good results indicate that this study may provide a new way of using the ethylene resource in the FCC dry gas.
文摘The oligomerization of ethylene in FCC dry gas over HZSM-5 catalyst with different Si/A12 ratios was studied. The effect of acid density of catalyst on the oligomerization of ethylene was discussed. By increasing the acid density of catalyst, ethylene conversion showed a linear increase, while the yields of olefins decreased when the acid density of catalyst exceeded 0.14mmolNH3/g owing to a promotion of hydrogen transfer reaction. Through comparing the average distance between acid sites on catalyst with kinetic diameters of olefins, it was found that the dimerization of ethylene was not restrained by the sparse distribution of acid sites, while the hydrogen transfer reaction of C3 and C4 olefins was limited. On these bases, a conclusion is proposed that the dimerization of ethylene proceeded via Eley-Rideal mechanism, while the hydrogen transfer reaction of C3 and C4 olefins followed the Langmuir-Hinshelwood mechanism.
基金the National Natural Science Foundation of China(Nos.32070584,81830028,31771398,82222016,and 8207040100)the Zhejiang Provincial Natural Science Foundation of China(No.LZ19C060001)the Fundamental Research Funds for the Central Universities(No.2019QNA6001)。
文摘Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.
基金Supported by the Natural Science Foundation of Tianjin City(No.2150000045)。
文摘AIM:To evaluate the potential efficacy and mechanisms of nintedanib in corneal neovascularization(NV)in rabbit models.METHODS:Corneal NV was induced using 1 mol/L Na OH.Rabbits(n=21)were randomized to 3 groups:Group 1 were treated with 0.9%NaCl,Group 2 with Avastin(5 mg/mL),and Group 3 with nintedanib(1 mg/mL).All treatments star ted 1 d af ter alkaline burns and were topically performed 3 times a day for 2 wk.Photographs were taken on a slit lamp microscope on day 7 and 14.The NV area,the length of the vascularization and angiogenesis index(AI)were used to evaluate the corneal NV.On day 14,the immunohistochemical(IHC)studies of the cornea were examined.Western blot was performed to test the expression levels of vascular endothelial growth factor(VEGF),Akt,p-Akt,P38,p-P38,MMP-2 and MMP-9.RESULTS:The corneal NV area,vessel length and AI in Group 3 were significantly lower than Group 2,with both being lower than Group 1.IHC staining showed that VEGF was significantly overexpressed in the epithelium and stroma of cornea following alkaline burns.In contrast,the level of VEGF was significantly suppressed in both Group 2 and Group 3.Western blot results further confirmed that,compared with Group 1,Group 3 had significantly reduced expressions of VEGF,Akt,p-Akt,p-P38,MMP-2,and MMP-9 in corneal tissues.Trends of lower levels of MMP-2,AKT,and p-AKT in Group 3 than Group 2 were identified.CONCLUSION:Nintedanib and Avastin can effectively inhibit corneal NV,with P38 MAPK and AKT signaling pathways being possibly involved.Nintedanib seems more effective than Avastin and has the potential to be a novel therapy for preventing corneal NV.
文摘Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured in marine sand deposits from Liaodong Bay (LDB), North Yellow Sea (NYS), Zhoushan area (ZS), Taiwan Shoal (TS) and Pearl River Mouth (PR), offshore China, which are potential marine sand mining areas. The radiation activity equivalent (Raeq), indoor gamma absorbed dose rate (DR), annual effective dose (HR), alpha index (Ia), gamma index (Ig), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the marine sands offshore China. From the analysis, it is found that these marine sands are safe for the constructions. The Pearson correlation coefficient reveals that the 226Ra distribution in the marine sands offshore China is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the entire data from the marine sands, wherein 98.22% of the total variance is explained. Our results provide good baseline data to expand the database of radioactivity of building materials in China and all over the world.
基金Supported by Colleges and universities scientific research project of Shandong(J18KA197)
文摘Drought is one of the major meteorological disasters affecting the climate in China.In this paper,the interannual variation and seasonal distribution changes of drought at different time scales were analyzed with the standardized precipitation index( SPI) as the drought evaluation criterion to the precipitation data of the 5 meteorological stations of Jinan,Tai'an,Yiyuan,Shen County and Yanzhou from 1960 to 2013.The results showed that:(1) the frequency of drought was low in spring and summer in inland areas of Shandong Province,while autumn had frequent occurrences of moderate drought,and winter had frequent occurrences of heavy and severe droughts.(2) In the 1960 s,1980 s and early 21^(st) century,the number of droughts increased significantly,and the SPI values showed a significant decrease.(3) The 3-month time scale range was wide,during which the frequency of occurrence was high.The trend of SPI changes at the 12-month time scale was affected by the accumulation of antecedent precipitation,and the change was slow.The research results can provide a scientific reference for arid climate analysis and water resources management in agriculture and production in inland areas of Shandong Province.
基金Supported by Colleges and universities scientific research project of Shandong(J18KA197)
文摘Air pollution has become the most concerned regional environmental problem in China at present.According to the data of typical cities in Shandong Province from January,2014 to December,2015,the air quality status,pollution status and spatial variation characteristics of air pollutants were classified and analyzed,thereby providing a scientific basis for air pollution control.The conclusions of this study are as follows:(1) PM_(2.5) was the most important atmospheric pollutant in Shandong Province;(2) Qingdao had the best air quality with a good air quality rate of 73.7%,while Jinan had the worst air quality with a good air quality rate only of 31.3%; and(3) the days with heavy pollution were mainly concentrated in winter,mainly due to coal-fired heating in winter.
基金Strategic Research and Consultancy Project of the Chinese Academy of Engineering(2023-JB-11).
文摘Introduction:Female breast nodules represent the most frequently detected lesions during breast ultrasound screening.Notably,nodules classified as BIRADS 4 or 5 indicate an elevated risk of breast cancer.Nevertheless,the detection rate and BI-RADS classification of female breast nodules across China remain largely undocumented.Methods:This study analyzed health examination data from 6,412,893 urban women across 31 provincial-level administrative divisions(PLADs).We calculated detection rates of breast nodules and their various BI-RADS classifications.Chi-square(χ2)tests were performed to compare differences between groups.Multivariable logistic regression models were constructed to explore associations between breast nodules and BI-RADS 4-5 with demographic,socioeconomic,and metabolic indicators.Results:The overall detection rate of breast nodules in Chinese urban women was 27.9%,with provincial rates ranging from 11.6%to 37.0%.Among women with breast nodules marked with BI-RADS classification information,95.9%were categorized as BI-RADS 2-3,while 4.0%were classified as BI-RADS 4-5.Further analyses revealed that age,geographic region,per capita gross domestic product(GDP),body mass index(BMI),high triglyceride(TG),high lowdensity lipoprotein cholesterol(LDL-C),and diabetes were significant risk factors for BI-RADS 4-5 classification.Conclusions:This study highlights the importance of managing high-risk women with breast nodules through BI-RADS classification,underscoring the need for targeted health interventions while considering regional and socioeconomic disparities.
基金supported by the National Natural Science Foundation of China (T2341004,82274403,82321004, 82174054)the National Key Research and Development Program of China (2024YFC3507200,2024YFA0919800)+7 种基金Guangdong Basic and Applied Basic Research Foundation (2023B1515020020,2023B1515040016, 2021B1515120023)Guangdong Major Project of Basic and Applied Basic Research (2023B0303000013)Guangzhou Basic and Applied Basic Research Foundation (2024A04J6406)China Association of Chinese Medicine (CACM-2022-QNRC2-B08)K.C.Wong Education FoundationInnovation Team Project of Guangdong Provincial Department of Education (2020KCXTD003)Guangzhou Key Laboratory of Traditional Chinese Medicine & Disease Susceptibility (2024A03J090)Guangdong-Hong Kong-Macao Universities Joint Laboratory for the Internationalization of Traditional Chinese Medicine (2023LSYS002)。
文摘The metabolic state of an organism reflects both external environmental factors and internal genetic influences, providing insights into physiological conditions and potential disease mechanisms. Historically, our understanding of organismal metabolism was relatively limited by technological constraints. With the rapid advancement of mass spectrometrybased methods and strategies for studying endogenous small molecules.
