We experimentally demonstrate the recognition of positional isomers of propyl alcohol vapor through nonlinear fluorescence induced by high-intensity femtosecond laser filaments in air. By measuring characteristic fluo...We experimentally demonstrate the recognition of positional isomers of propyl alcohol vapor through nonlinear fluorescence induced by high-intensity femtosecond laser filaments in air. By measuring characteristic fluorescence of n-propyl and isopropyl alcohol vapors produced by femtosecond filament excitation, it is found that they show identical spectra, that is, those from molecular bands of CH, C2, Nit, OH and CN, while the relative intensities are different. By comparing the ratios of the CH and C2 signals, the two propyl alcohol isomers are differentiated. The different signal intensities are ascribed to different ionization potentials of the two isomer molecules, leading to different production efficiencies of fluorescing fragments.展开更多
In this paper, we study the existence of multiple positive periodic solutions for the second order differential equation x′′(t) + p(t)x′(t) + q(t)x(t) = f(t, x(t)).By using Krasnoselskii fixed point...In this paper, we study the existence of multiple positive periodic solutions for the second order differential equation x′′(t) + p(t)x′(t) + q(t)x(t) = f(t, x(t)).By using Krasnoselskii fixed point theorem, we establish some criteria for the existence and multiple positive periodic solutions for this differential equation.展开更多
In this paper, we prove the existence and uniqueness of positive solutions for a system of multi-order fractional differential equations. The system is used to represent constitutive relation for viscoelastic model of...In this paper, we prove the existence and uniqueness of positive solutions for a system of multi-order fractional differential equations. The system is used to represent constitutive relation for viscoelastic model of fractional differential equations. Our results are based on the fixed point theorems of increasing operator and the cone theory, some illustrative examples are also presented.展开更多
Background:Epigenetics,and especially DNA methylation,contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis(SALS).This study aimed to investigate the role of DNA methylation in SALS using whole blo...Background:Epigenetics,and especially DNA methylation,contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis(SALS).This study aimed to investigate the role of DNA methylation in SALS using whole blood of SALS patients.Methods::In total,32 SALS patients and 32 healthy controls were enrolled in this study.DNA was isolated from whole blood collected from the participants.DNA methylation profiles were generated using Infinium MethylationEPIC BeadChip.Results:We identified 34 significant differentially methylated positions(DMPs)in whole blood from SALS patients,compared with the healthy controls.Of these DMPs,five were hypermethylated and 29 were hypomethylated;they corresponded to 13 genes.For the DMPs,ATAD3B and BLK were hypermethylated,whereas DDO,IQCE,ABCB1,DNAH9,FIGN,NRP1,TMEM87B,CCSAP,ST6GALNAC5,MYOM2,and RUSC1-AS1 were hypomethylated.We also identified 12 differentially methylated regions(DMRs),related to 12 genes(NWD1,LDHD,CIS,IQCE,TNF,PDE1C,LGALS1,CSNK1E,LRRC23,ENO2,ELOVL2,and ELOVL2-AS1).According to data from the Kyoto Encyclopedia of Genes and Genomes database,DNAH9 and TNF are involved in the amyotrophic lateral sclerosis(ALS)pathway.Correlation analysis between clinical features and DNA methylation profiling indicated that the methylation level of ELOVL2 and ARID1B was positively associated with the age of onset(r=0.86,adjust P=0.001)and disease duration(r=0.83,adjust P=0.01),respectively.Conclusions:We found aberrant methylation in DMP-and DMR-related genes,implying that many epigenetic alterations,such as the hypomethylation of DNAH9 and TNF,play important roles in ALS etiology.These findings can be helpful for developing new therapeutic interventions.展开更多
In this paper,it is shown that for stable,steady state operation of devices typical of microwave and millimeter wave electronics,no negative differential capacitance is possible with conventional thinking.However,it m...In this paper,it is shown that for stable,steady state operation of devices typical of microwave and millimeter wave electronics,no negative differential capacitance is possible with conventional thinking.However,it may be possible,with strain engineering of materials,to obtain some if not all elements of the differential capacitance tensor which are negative.Rigorous derivations are provided based upon analyzing the physics using thermodynamic phenomenological free energy.It should be emphasized that,even with strain engineering,and possible discovery of some negative capacitive elements,stable operation will not be obtained because the thermodynamics precludes it.展开更多
By using the coding properties and statistic properties of the plaintext,the differential properties of the key stream sequences generated by a nonlinear combined generator were analyzed.Then a differential attack alg...By using the coding properties and statistic properties of the plaintext,the differential properties of the key stream sequences generated by a nonlinear combined generator were analyzed.Then a differential attack algorithm on the nonlinear combined sequences was proposed.At last,an attack example adopting the differential attack algorithm was presented.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 61427816 and 61235003the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20130061110047the Open Fund of the State Key Laboratory of High Field Laser Physics
文摘We experimentally demonstrate the recognition of positional isomers of propyl alcohol vapor through nonlinear fluorescence induced by high-intensity femtosecond laser filaments in air. By measuring characteristic fluorescence of n-propyl and isopropyl alcohol vapors produced by femtosecond filament excitation, it is found that they show identical spectra, that is, those from molecular bands of CH, C2, Nit, OH and CN, while the relative intensities are different. By comparing the ratios of the CH and C2 signals, the two propyl alcohol isomers are differentiated. The different signal intensities are ascribed to different ionization potentials of the two isomer molecules, leading to different production efficiencies of fluorescing fragments.
基金The Science Research Plan(Jijiaokehezi[2016]166)of Jilin Province Education Department During the 13th Five-Year Periodthe Science Research Starting Foundation(2015023)of Jilin Agricultural University
文摘In this paper, we study the existence of multiple positive periodic solutions for the second order differential equation x′′(t) + p(t)x′(t) + q(t)x(t) = f(t, x(t)).By using Krasnoselskii fixed point theorem, we establish some criteria for the existence and multiple positive periodic solutions for this differential equation.
基金Foundation item:The NSF(11071097,11101217)of Chinathe NSF(BK20141476)of Jiangsu Province of China
文摘In this paper, we prove the existence and uniqueness of positive solutions for a system of multi-order fractional differential equations. The system is used to represent constitutive relation for viscoelastic model of fractional differential equations. Our results are based on the fixed point theorems of increasing operator and the cone theory, some illustrative examples are also presented.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFC0905103)the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)(No.2016-I2M-1-004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB39000000,XDB39040100).
文摘Background:Epigenetics,and especially DNA methylation,contributes to the pathogenesis of sporadic amyotrophic lateral sclerosis(SALS).This study aimed to investigate the role of DNA methylation in SALS using whole blood of SALS patients.Methods::In total,32 SALS patients and 32 healthy controls were enrolled in this study.DNA was isolated from whole blood collected from the participants.DNA methylation profiles were generated using Infinium MethylationEPIC BeadChip.Results:We identified 34 significant differentially methylated positions(DMPs)in whole blood from SALS patients,compared with the healthy controls.Of these DMPs,five were hypermethylated and 29 were hypomethylated;they corresponded to 13 genes.For the DMPs,ATAD3B and BLK were hypermethylated,whereas DDO,IQCE,ABCB1,DNAH9,FIGN,NRP1,TMEM87B,CCSAP,ST6GALNAC5,MYOM2,and RUSC1-AS1 were hypomethylated.We also identified 12 differentially methylated regions(DMRs),related to 12 genes(NWD1,LDHD,CIS,IQCE,TNF,PDE1C,LGALS1,CSNK1E,LRRC23,ENO2,ELOVL2,and ELOVL2-AS1).According to data from the Kyoto Encyclopedia of Genes and Genomes database,DNAH9 and TNF are involved in the amyotrophic lateral sclerosis(ALS)pathway.Correlation analysis between clinical features and DNA methylation profiling indicated that the methylation level of ELOVL2 and ARID1B was positively associated with the age of onset(r=0.86,adjust P=0.001)and disease duration(r=0.83,adjust P=0.01),respectively.Conclusions:We found aberrant methylation in DMP-and DMR-related genes,implying that many epigenetic alterations,such as the hypomethylation of DNAH9 and TNF,play important roles in ALS etiology.These findings can be helpful for developing new therapeutic interventions.
文摘In this paper,it is shown that for stable,steady state operation of devices typical of microwave and millimeter wave electronics,no negative differential capacitance is possible with conventional thinking.However,it may be possible,with strain engineering of materials,to obtain some if not all elements of the differential capacitance tensor which are negative.Rigorous derivations are provided based upon analyzing the physics using thermodynamic phenomenological free energy.It should be emphasized that,even with strain engineering,and possible discovery of some negative capacitive elements,stable operation will not be obtained because the thermodynamics precludes it.
基金supported by the National Natural Science Foundation of China(No.60573028)Research Foundation of National University of Defense Technology(No.JC-02-02).
文摘By using the coding properties and statistic properties of the plaintext,the differential properties of the key stream sequences generated by a nonlinear combined generator were analyzed.Then a differential attack algorithm on the nonlinear combined sequences was proposed.At last,an attack example adopting the differential attack algorithm was presented.