Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between pr...Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.展开更多
This paper proposes a quasi-zero stiffness(QZS)isolator composed of a curved beam(as spider foot)and a linear spring(as spider muscle)inspired by the precise capturing ability of spiders in vibrating environments.The ...This paper proposes a quasi-zero stiffness(QZS)isolator composed of a curved beam(as spider foot)and a linear spring(as spider muscle)inspired by the precise capturing ability of spiders in vibrating environments.The curved beam is simplified as an inclined horizontal spring,and a static analysis is carried out to explore the effects of different structural parameters on the stiffness performance of the QZS isolator.The finite element simulation analysis verifies that the QZS isolator can significantly reduce the first-order natural frequency under the load in the QZS region.The harmonic balance method(HBM)is used to explore the effects of the excitation amplitude,damping ratio,and stiffness coefficient on the system’s amplitude-frequency response and transmissibility performance,and the accuracy of the analytical results is verified by the fourth-order Runge-Kutta integral method(RK-4).The experimental data of the QZS isolator prototype are fitted to a ninth-degree polynomial,and the RK-4 can theoretically predict the experimental results.The experimental results show that the QZS isolator has a lower initial isolation frequency and a wider isolation frequency bandwidth than the equivalent linear isolator.The frequency sweep test of prototypes with different harmonic excitation amplitudes shows that the initial isolation frequency of the QZS isolator is 3 Hz,and it can isolate 90%of the excitation signal at 7 Hz.The proposed biomimetic spider-like QZS isolator has high application prospects and can provide a reference for optimizing low-frequency or ultra-low-frequency isolators.展开更多
With the advent of the information age,augmented reality technology can enhance the sense of reality in the virtual world and immerse people in the real and virtual world.People have always been interested in virtual ...With the advent of the information age,augmented reality technology can enhance the sense of reality in the virtual world and immerse people in the real and virtual world.People have always been interested in virtual space or augmented reality technology,especially in the face of historical development trends.Museums have always been open to the public,they are not just a collection,but also an exhibition for the public.Through analyzing different museums,it is found that museums with augmented reality technology exhibitions are non-profit museums for the purpose of emotional experience.In order to find out the immersion factors of virtual reality in museums,on the basis of previous research,this paper divides immersion in augmented reality into story immersion,five-sense experience immersion,and spatial interaction immersion.Through the analysis of different museums,it is found that immersion through five-sense experience is the most commonly used method when all display media are included.This method provides educational content for museum visitors and projects virtual presentations through monitors and portable IT devices,thereby increasing visitors’viewing pleasure.展开更多
Extreme ultraviolet(EUV)observations are widely used in solar activity research and space weather forecasting since they can observe both the solar eruptions and the source regions of the solar wind.Flat field process...Extreme ultraviolet(EUV)observations are widely used in solar activity research and space weather forecasting since they can observe both the solar eruptions and the source regions of the solar wind.Flat field processing is indispensable to remove the instrumental non-uniformity of a solar EUV imager in producing high-quality scientific data from original observed data.FengYun-3E(FY-3E)is a meteorological satellite operated in a Sunsynchronous orbit,and the routine EUV imaging data from the Solar X-ray and Extreme Ultraviolet Imager(X-EUVI)onboard FY-3E has the characteristic of concentric rotation.Taking advantage of the concentric rotation,we propose a post-hoc flat field measurement method for its EUV 195A channel in this paper.This method removes the small-scale and time-varying component of coronal activities by taking the median value for each pixel along the time axis of a concentric rotation data cube,and then derives the large-scale and invariable component of the quiet coronal radiation,and finally generates a flat field image.The flat field can be generated with cadences from hundreds of minutes(one orbit)to several days.Higher flat field accuracy can be achieved by employing more data.Further analysis shows that our method is able to measure the instrumental spot-like nonuniformity possibly caused by contamination on the detector,which mostly disappears after the in-orbit selfcleaning process.It can also measure the quasi-periodic grid-like non-uniformity,possibly from the obscuration of the support mesh on the rear filter.After flat field correction,these instrumental non-uniformities from the original data are effectively removed.Moreover,the X-EUVI 195A data after dark and flat field corrections are consistent with the 193A imaging data from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory,verifying the suitability of the method.The post-hoc method does not occupy observation time,which is advantageous for space weather operations.Our method is not only suitable for FY-3E/X-EUVI but also a candidate method for the flat field measurement of future solar EUV telescopes.展开更多
BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in prom...BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in promoting functional recovery of the brain after traumatic injury. EGb is also effective in improving central nervous system plasticity and learning and memory functions of the elderly. OBJECTIVE： To study the effects of EGb on learning and memory, as well as hippocampal APP mRNA expression in the brains of diabetic rats, using Morris water maze behavioral testing and reverse transcription polymerase chain reaction （RT-PCR）, respectively. DESIGN： Complete random design, controlled experimental study. SETTING： Department of Pharmacology, Pharmaceutical School, Guangxi Medical University. MATERIALS： A total of 70 male Wistar rats （180-220 g）, 8 weeks old and specific pathogen free, were used for this study. GbE （containing 24.8% flavone glycosides and 6.2% diterpene lactone） was purchased from Guilin Sitejia Natural Plants Pharmaceutical Factory （Guangxi Province, Lot NO. 200405）. Streptozotocin was purchased from Sigma （USA）. Protamine zinc insulin injection was purchased from WANBANG Biochemical Pharmaceutical Co., Ltd. （Xuzhou Jiangsu, China）. METHODS： The experiment was performed in the Experimental Center of Guangxi Medical University from March to October 2005.（1） Experimental intervention： 70 rats were divided randomly into normal control group, diabetic model group （DM group）, diabetic model ＋10 μ g/kg insulin group （DM ＋ Ins group）, diabetic model ＋ 100 mg/kg ginkgo leaf extract group （DM ＋ EGb high-dose group）, and diabetic model ＋ 50 mg/kg ginkgo leaf extract group （DM ＋ EGb low-dose group）; there were 14 rats in each group. Rats with an intraperitoneal （i.p.） injection of citrate buffer solution （pH 4.4） served as the control group. To establish the diabetes model, rats were treated with i.p. injection of 55 mg/kg streptozotocin. Insulin （10 U/kg） was injected subcutaneously （s.c.） every day for 6 months in the DM group. EGb （100 mg/kg） and EGb （50 mg/kg） was administered intragastrically every day for 6 months in the DM ＋ EGb high-dose group and DM ＋ EGb low-dose group, respectively. The DM group and control group were administered distilled water intragastrically every day for 6 months. Drugs were administered once every morning. （2） Experimental evaluation： Six month after intervention, learning and memory of diabetic rats was tested by Morris water maze. Rats were allowed to train for 4 days, and the escape latency and platform-searching score were measured at days 5 and 8. Changes in hippocampal APP mRNA expression were measured with RT-PCR. MAIN OUTCOME MEASURES： Morris water maze performances and hippocampal APP mRNA expression in rats. RESULTS： A total of 70 Wistar rats were included in the final analysis, without any loss. （1） Learning and memory dysfunction of diabetic rats： After 4 days of Morris water maze training, escape latency was longer in the DM group on days 5 and 8, and the platform-searching score was lower in the DM group compared to the control group. In the DM ＋ EGb group, the escape latency score was shorter and platform-searching score was significantly increased compared to the DM group. （2） APP mRNA expression： in the hippocampus of diabetic rats, a 340 bp mRNA product was amplified, which is comparable to the APP mRNA amplification length of design. The expression of APP mRNA from the hippocampus of diabetic rats with learning and memory dysfunctions was significantly increased. EGb extract significantly inhibited the APP mRNA expression in these rats. CONCLUSION： EGb not only ameliorated the learning and memory dysfunctions in diabetic rats, but also significantly inhibited APP mRNA expression. Results from this study led to the hypothesis that diabetes could be one of the risk factors for AD.展开更多
We theoretically investigate the yield enhancement of elliptical high harmonics in the interaction of molecules with bicircular laser pulses by solving the time-dependent Schrodinger equation.It is shown that by adjus...We theoretically investigate the yield enhancement of elliptical high harmonics in the interaction of molecules with bicircular laser pulses by solving the time-dependent Schrodinger equation.It is shown that by adjusting the relative intensity ratio of the two bicircular field components in specific ranges the yield of the molecular high harmonics for the plateau and cutoff regions can be respectively enhanced.To analyze this enhancement phenomenon,we calculate the weights of the electron classical trajectories.Additionally,we also study the ellipticity distribution of harmonics for different intensity ratios.We find that these enhanced harmonics are elliptically polarized,which we mainly attribute to the recombination dipole moment of the major weighted trajectories.These enhanced elliptical extreme ultraviolet and soft x-ray radiations may serve as essential tools for exploring the ultrafast dynamics in magnetic materials and chiral media.展开更多
To explore the representation of users and uses of Englishes in the textbooks,a series of English textbooks for junior high school in China were examined in this study.Findings from analysis of representations of user...To explore the representation of users and uses of Englishes in the textbooks,a series of English textbooks for junior high school in China were examined in this study.Findings from analysis of representations of users and uses of Englishes were presented.The results show that China,the UK and the US are dominant in the representations of users.Outer circle countries and expanding countries(other than China)have no clear representations.展开更多
Grain weight and quality are always determined by grain filling.Plant microRNAs have drawn attention as key targets for regulation of grain size and yield.However,the mechanisms that underlie grain size regulation rem...Grain weight and quality are always determined by grain filling.Plant microRNAs have drawn attention as key targets for regulation of grain size and yield.However,the mechanisms that underlie grain size regulation remain largely unclear because of the complex networks that control this trait.Our earlier studies demonstrated that suppressed expression of miR167(STTM/MIM167)substantially increased grain weight.In a field test,the yield increased up to 12.90%-21.94% because of a significantly enhanced grain filling rate.Here,biochemical and genetic analyses revealed the regulatory effects of miR159 on miR167 expression.Further analysis indicated that OsARF12 is the major mediator by which miR167 regulates rice grain filling.Overexpression of OsARF12 produced grain weight and grain filling phenotypes resembling those of STTM/MIM167 plants.Upon in-depth analysis,we found that OsARF12 activates OsCDKF;2 expression by directly binding to the TGTCGG motif in its promoter region.Flow cytometry analysis of young panicles from OsARF12-overexpressing plants and examination of cell number in cdkf;2 mutants verified that OsARF12 positively regulates grain filling and grain size by targeting OsCDKF;2.Moreover,RNA sequencing results suggested that the miR167-OsARF12 module is involved in the cell development process and hormone pathways.OsARF12-overexpressing plants and cdkf;2 mutants exhibited enhanced and reduced sensitivity to exogenous auxin and brassinosteroid(BR)treatment,confirming that targeting of OsCDKF;2 by OsARF12 mediates auxin and BR signaling.Our results reveal that the miR167-OsARF12 module works downstream of miR159 to regulate rice grain filling and grain size via OsCDKF;2 by controlling cell division and mediating auxin and BR signals.展开更多
Dear Editor To date,tens of millions of people have been infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),causing the outbreak of the respiratory disease named the coronavirus disease 2019(COV...Dear Editor To date,tens of millions of people have been infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),causing the outbreak of the respiratory disease named the coronavirus disease 2019(COVID-19).As a newly emerged member of the coronavirus family,SARS-CoV-2 is an enveloped positive-strand RNA virus,which has probably the largest genome(approximately 30 kb)among all RNA viruses.The nucleocapsid(N)protein of SARS-CoV-2 is mainly responsible for recognizing and wrapping viral RNA into helically symmetric structures(Malik,2020).展开更多
Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box...Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box p3(Foxp3)is a key regulatory gene for the development and function of Treg cells.In zebrafish,Treg cells have been identified by using foxp3a as a reliable marker.However,little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation.Here,we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development.We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis,while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis.More than 80%of foxp3a^(-/-)mutants developed as subfertile males,and the rest of the mutants developed as fertile females with decreased ovulation.Further study revealed that foxp3a^(-/-)mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females,which led to a dominance of later male development.Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^(-/-)mutants,abundant T cells and macrophages expand to disrupt an immunosuppressive milieu,resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males.Therefore,our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.展开更多
We employ the Riemann-Hilbert(RH)method to study the Hirota equation with arbitrary order zero poles under zero boundary conditions.Through the spectral analysis,the asymptoticity,symmetry,and analysis of the Jost fun...We employ the Riemann-Hilbert(RH)method to study the Hirota equation with arbitrary order zero poles under zero boundary conditions.Through the spectral analysis,the asymptoticity,symmetry,and analysis of the Jost functions are obtained,which play a key role in constructing the RH problem.Then we successfully established the exact solution of the equation without reflection potential by solving the RH problem.Choosing some appropriate parameters of the resulting solutions,we further derive the soliton solutions with different order poles,including four cases of a fourthorder pole,two second-order poles,a third-order pole and a first-order pole,and four first-order points.Finally,the dynamical behavior of these solutions are analyzed via graphic analysis.展开更多
Flexible transparent conductive films are gaining attention day by day over the last few years due to it is a key component of next generation flexible electronics and optoelectronic devices.Indium tin oxide(ITO)as on...Flexible transparent conductive films are gaining attention day by day over the last few years due to it is a key component of next generation flexible electronics and optoelectronic devices.Indium tin oxide(ITO)as one of the most widely used transparent conductive material is limited by the traditional deposition approach cannot be achieve ultra-thin,which results in its brittle nature.Herein,a novel strategy for fabricating highly transparent conductive films by liquid metal interface phase separation technique based on low-melting liquid metal of InxSn100-x alloy is reported,during the solid-to-liquid phase transition of alloy,the monolayer of surface oxide film segregated with the bulk phase and was printed on the flexible polyethylene-naphthalate(PEN)substrate under the van der Waals.This novel strategy can directly print the ultra-thin self-oxide with the structure of ITO on PEN substrate,with the resulting of transparency over 97.5%and resistivity as low as 0.21 kU cm,providing a new way of lowcost raw ITO material as well as the personalized preparation strategy.The desirable highly transparent conductive films are comparable to recently reported ITO film,together with advantages of pretty steady,make them attractive as various flexible transparent conductive electrodes,for example,an ultra-thin ITO film is developed for luminescent devices.展开更多
Sugar and protein are the major macronutrients＇ sources, and their balanced intake is important for animal＇s health. It has been observed that animals are able to change food preference in an imbalanced nutritional ...Sugar and protein are the major macronutrients＇ sources, and their balanced intake is important for animal＇s health. It has been observed that animals are able to change food preference in an imbalanced nutritional condition to selectively consume nutrients that are deficient in the body （Dethier, 1976）. Early studies in both Drosophila and mouse have demonstrated that animals exhibit food rejection to imbalanced diets lacking essential amino acids （Hao et al., 2005; Bjordal et al., 2014）. Furthermore, the food preference change upon protein depri- vation has been characterized using a two choice assay in Drosophila （Ribeiro and Dickson, 2010; Vargas et al., 2010）. Different from protein food, sugar is the main energy source, and sugar deficiency severely affects animal survival （Lee et al., 2008）. However, whether animals adopt a strategy of fast food preference switch upon sugar deprivation had not been investigated, and the neural mechanisms underlying this behavior regulation remain poorly understood.展开更多
Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying ...Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.展开更多
基金supported by Central Public-Interest Scientific Institution Basal Research Fund,CAFS(2023TD74,2023TD78)the Earmarked Fund for CARS-47(CARS-47)+2 种基金Guangdong Provincial Science and Technology Plan Project(2023B0202010015)Central Public-Interest Scientific Institution Basal Research Fund,CAFS(Sanya Yazhou Bay Science and Technology City(SKJC-2020-02-013))Special Funds for Promoting Economic Development in Guangdong Province(For Modern Fishery)(YueNong 2019B14).
文摘Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.
基金supported by Yangtze River Delta HIT Robot Technology Research Institute(No.HIT-CXY-CMP2-VSEA-21-01)the Open Project Program(No.WDZL-202103)。
文摘This paper proposes a quasi-zero stiffness(QZS)isolator composed of a curved beam(as spider foot)and a linear spring(as spider muscle)inspired by the precise capturing ability of spiders in vibrating environments.The curved beam is simplified as an inclined horizontal spring,and a static analysis is carried out to explore the effects of different structural parameters on the stiffness performance of the QZS isolator.The finite element simulation analysis verifies that the QZS isolator can significantly reduce the first-order natural frequency under the load in the QZS region.The harmonic balance method(HBM)is used to explore the effects of the excitation amplitude,damping ratio,and stiffness coefficient on the system’s amplitude-frequency response and transmissibility performance,and the accuracy of the analytical results is verified by the fourth-order Runge-Kutta integral method(RK-4).The experimental data of the QZS isolator prototype are fitted to a ninth-degree polynomial,and the RK-4 can theoretically predict the experimental results.The experimental results show that the QZS isolator has a lower initial isolation frequency and a wider isolation frequency bandwidth than the equivalent linear isolator.The frequency sweep test of prototypes with different harmonic excitation amplitudes shows that the initial isolation frequency of the QZS isolator is 3 Hz,and it can isolate 90%of the excitation signal at 7 Hz.The proposed biomimetic spider-like QZS isolator has high application prospects and can provide a reference for optimizing low-frequency or ultra-low-frequency isolators.
文摘With the advent of the information age,augmented reality technology can enhance the sense of reality in the virtual world and immerse people in the real and virtual world.People have always been interested in virtual space or augmented reality technology,especially in the face of historical development trends.Museums have always been open to the public,they are not just a collection,but also an exhibition for the public.Through analyzing different museums,it is found that museums with augmented reality technology exhibitions are non-profit museums for the purpose of emotional experience.In order to find out the immersion factors of virtual reality in museums,on the basis of previous research,this paper divides immersion in augmented reality into story immersion,five-sense experience immersion,and spatial interaction immersion.Through the analysis of different museums,it is found that immersion through five-sense experience is the most commonly used method when all display media are included.This method provides educational content for museum visitors and projects virtual presentations through monitors and portable IT devices,thereby increasing visitors’viewing pleasure.
基金supported by the National Key R&D Program of China(2021YFA0718600)the National Natural Science Foundations of China(NSFC,Grant Nos.41931073,41774195)+2 种基金Ten-thousand Talents Program of JingSong Wang,and the Specialized Research Fund for State Key Laboratoriessupported by the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA 15018400supported by the China Postdoctoral Science Foundation(2021M700246)。
文摘Extreme ultraviolet(EUV)observations are widely used in solar activity research and space weather forecasting since they can observe both the solar eruptions and the source regions of the solar wind.Flat field processing is indispensable to remove the instrumental non-uniformity of a solar EUV imager in producing high-quality scientific data from original observed data.FengYun-3E(FY-3E)is a meteorological satellite operated in a Sunsynchronous orbit,and the routine EUV imaging data from the Solar X-ray and Extreme Ultraviolet Imager(X-EUVI)onboard FY-3E has the characteristic of concentric rotation.Taking advantage of the concentric rotation,we propose a post-hoc flat field measurement method for its EUV 195A channel in this paper.This method removes the small-scale and time-varying component of coronal activities by taking the median value for each pixel along the time axis of a concentric rotation data cube,and then derives the large-scale and invariable component of the quiet coronal radiation,and finally generates a flat field image.The flat field can be generated with cadences from hundreds of minutes(one orbit)to several days.Higher flat field accuracy can be achieved by employing more data.Further analysis shows that our method is able to measure the instrumental spot-like nonuniformity possibly caused by contamination on the detector,which mostly disappears after the in-orbit selfcleaning process.It can also measure the quasi-periodic grid-like non-uniformity,possibly from the obscuration of the support mesh on the rear filter.After flat field correction,these instrumental non-uniformities from the original data are effectively removed.Moreover,the X-EUVI 195A data after dark and flat field corrections are consistent with the 193A imaging data from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory,verifying the suitability of the method.The post-hoc method does not occupy observation time,which is advantageous for space weather operations.Our method is not only suitable for FY-3E/X-EUVI but also a candidate method for the flat field measurement of future solar EUV telescopes.
基金the Natural Science Foundation of Guangxi Science and Technology Bureau, No.0542073
文摘BACKGROUND： The mechanisms of brain injury Following diabetes could be related to amyloid precursor protein （APP） mRNA overexpression. Studies have shown that Gingko biloba leaf extract （EGb） is effective in promoting functional recovery of the brain after traumatic injury. EGb is also effective in improving central nervous system plasticity and learning and memory functions of the elderly. OBJECTIVE： To study the effects of EGb on learning and memory, as well as hippocampal APP mRNA expression in the brains of diabetic rats, using Morris water maze behavioral testing and reverse transcription polymerase chain reaction （RT-PCR）, respectively. DESIGN： Complete random design, controlled experimental study. SETTING： Department of Pharmacology, Pharmaceutical School, Guangxi Medical University. MATERIALS： A total of 70 male Wistar rats （180-220 g）, 8 weeks old and specific pathogen free, were used for this study. GbE （containing 24.8% flavone glycosides and 6.2% diterpene lactone） was purchased from Guilin Sitejia Natural Plants Pharmaceutical Factory （Guangxi Province, Lot NO. 200405）. Streptozotocin was purchased from Sigma （USA）. Protamine zinc insulin injection was purchased from WANBANG Biochemical Pharmaceutical Co., Ltd. （Xuzhou Jiangsu, China）. METHODS： The experiment was performed in the Experimental Center of Guangxi Medical University from March to October 2005.（1） Experimental intervention： 70 rats were divided randomly into normal control group, diabetic model group （DM group）, diabetic model ＋10 μ g/kg insulin group （DM ＋ Ins group）, diabetic model ＋ 100 mg/kg ginkgo leaf extract group （DM ＋ EGb high-dose group）, and diabetic model ＋ 50 mg/kg ginkgo leaf extract group （DM ＋ EGb low-dose group）; there were 14 rats in each group. Rats with an intraperitoneal （i.p.） injection of citrate buffer solution （pH 4.4） served as the control group. To establish the diabetes model, rats were treated with i.p. injection of 55 mg/kg streptozotocin. Insulin （10 U/kg） was injected subcutaneously （s.c.） every day for 6 months in the DM group. EGb （100 mg/kg） and EGb （50 mg/kg） was administered intragastrically every day for 6 months in the DM ＋ EGb high-dose group and DM ＋ EGb low-dose group, respectively. The DM group and control group were administered distilled water intragastrically every day for 6 months. Drugs were administered once every morning. （2） Experimental evaluation： Six month after intervention, learning and memory of diabetic rats was tested by Morris water maze. Rats were allowed to train for 4 days, and the escape latency and platform-searching score were measured at days 5 and 8. Changes in hippocampal APP mRNA expression were measured with RT-PCR. MAIN OUTCOME MEASURES： Morris water maze performances and hippocampal APP mRNA expression in rats. RESULTS： A total of 70 Wistar rats were included in the final analysis, without any loss. （1） Learning and memory dysfunction of diabetic rats： After 4 days of Morris water maze training, escape latency was longer in the DM group on days 5 and 8, and the platform-searching score was lower in the DM group compared to the control group. In the DM ＋ EGb group, the escape latency score was shorter and platform-searching score was significantly increased compared to the DM group. （2） APP mRNA expression： in the hippocampus of diabetic rats, a 340 bp mRNA product was amplified, which is comparable to the APP mRNA amplification length of design. The expression of APP mRNA from the hippocampus of diabetic rats with learning and memory dysfunctions was significantly increased. EGb extract significantly inhibited the APP mRNA expression in these rats. CONCLUSION： EGb not only ameliorated the learning and memory dysfunctions in diabetic rats, but also significantly inhibited APP mRNA expression. Results from this study led to the hypothesis that diabetes could be one of the risk factors for AD.
基金Project supported by the National Natural Science Foundation of China(Grant No.11904269)the Natural Science Foundation of Hubei Province,China(Grant Nos.2021CFB300 and 2020CFB362)Scientific Research Program of Hubei Provincial Department of Education(Grant No.B2020176)。
文摘We theoretically investigate the yield enhancement of elliptical high harmonics in the interaction of molecules with bicircular laser pulses by solving the time-dependent Schrodinger equation.It is shown that by adjusting the relative intensity ratio of the two bicircular field components in specific ranges the yield of the molecular high harmonics for the plateau and cutoff regions can be respectively enhanced.To analyze this enhancement phenomenon,we calculate the weights of the electron classical trajectories.Additionally,we also study the ellipticity distribution of harmonics for different intensity ratios.We find that these enhanced harmonics are elliptically polarized,which we mainly attribute to the recombination dipole moment of the major weighted trajectories.These enhanced elliptical extreme ultraviolet and soft x-ray radiations may serve as essential tools for exploring the ultrafast dynamics in magnetic materials and chiral media.
文摘To explore the representation of users and uses of Englishes in the textbooks,a series of English textbooks for junior high school in China were examined in this study.Findings from analysis of representations of users and uses of Englishes were presented.The results show that China,the UK and the US are dominant in the representations of users.Outer circle countries and expanding countries(other than China)have no clear representations.
基金funded by the National Natural Science Foundation of China(NSFC,32272014,32001440,31971846,and 31871554)the Natural Science Foundation of Henan Province-Excellent Youth Fund(222300420049)+2 种基金the Central Plains Talents Program of Henan Province(Talent Training Series)-Top Young Talents in Central Plains(ZYY-CYU202012170)the Support Plan for Scientific and Technological Innovation Talents in Colleges and Universities of Henan Province(21HAS-TIT037)the China Postdoctoral Science Foundation(2020M682294).
文摘Grain weight and quality are always determined by grain filling.Plant microRNAs have drawn attention as key targets for regulation of grain size and yield.However,the mechanisms that underlie grain size regulation remain largely unclear because of the complex networks that control this trait.Our earlier studies demonstrated that suppressed expression of miR167(STTM/MIM167)substantially increased grain weight.In a field test,the yield increased up to 12.90%-21.94% because of a significantly enhanced grain filling rate.Here,biochemical and genetic analyses revealed the regulatory effects of miR159 on miR167 expression.Further analysis indicated that OsARF12 is the major mediator by which miR167 regulates rice grain filling.Overexpression of OsARF12 produced grain weight and grain filling phenotypes resembling those of STTM/MIM167 plants.Upon in-depth analysis,we found that OsARF12 activates OsCDKF;2 expression by directly binding to the TGTCGG motif in its promoter region.Flow cytometry analysis of young panicles from OsARF12-overexpressing plants and examination of cell number in cdkf;2 mutants verified that OsARF12 positively regulates grain filling and grain size by targeting OsCDKF;2.Moreover,RNA sequencing results suggested that the miR167-OsARF12 module is involved in the cell development process and hormone pathways.OsARF12-overexpressing plants and cdkf;2 mutants exhibited enhanced and reduced sensitivity to exogenous auxin and brassinosteroid(BR)treatment,confirming that targeting of OsCDKF;2 by OsARF12 mediates auxin and BR signaling.Our results reveal that the miR167-OsARF12 module works downstream of miR159 to regulate rice grain filling and grain size via OsCDKF;2 by controlling cell division and mediating auxin and BR signals.
基金This work was supported in part by the National Natural Science Foundation of China(61872216 and 81630103 to JZ,31900862 to DZ,31871443 to PL)the National Key R&D Program(2019YFA0508403 to PL,2020YFA0803300 to HL)the Turing Al Institute of Nanjing and the Zhongguancun Haihua Institute for Frontier Information Technology.
文摘Dear Editor To date,tens of millions of people have been infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),causing the outbreak of the respiratory disease named the coronavirus disease 2019(COVID-19).As a newly emerged member of the coronavirus family,SARS-CoV-2 is an enveloped positive-strand RNA virus,which has probably the largest genome(approximately 30 kb)among all RNA viruses.The nucleocapsid(N)protein of SARS-CoV-2 is mainly responsible for recognizing and wrapping viral RNA into helically symmetric structures(Malik,2020).
基金supported by the National Key Research and Development Program of China(2018YFD0900505 to Y.-A.Z.and 2018YFA0801000 to Y.S.)the National Natural Science Foundation of China(32025037 and 31721005 to Y.S.)。
文摘Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box p3(Foxp3)is a key regulatory gene for the development and function of Treg cells.In zebrafish,Treg cells have been identified by using foxp3a as a reliable marker.However,little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation.Here,we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development.We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis,while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis.More than 80%of foxp3a^(-/-)mutants developed as subfertile males,and the rest of the mutants developed as fertile females with decreased ovulation.Further study revealed that foxp3a^(-/-)mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females,which led to a dominance of later male development.Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^(-/-)mutants,abundant T cells and macrophages expand to disrupt an immunosuppressive milieu,resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males.Therefore,our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.
基金supported by the National Natural Science Foundation of China under Grant No.11975306the Natural Science Foundation of Jiangsu Province under Grant No.BK20181351+2 种基金the Six Talent Peaks Project in Jiangsu Province under Grant No.JY-059the Fundamental Research Fund for the Central Universities under the Grant Nos.2019ZDPY07 and 2019QNA35the Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant No.KYCX212152.
文摘We employ the Riemann-Hilbert(RH)method to study the Hirota equation with arbitrary order zero poles under zero boundary conditions.Through the spectral analysis,the asymptoticity,symmetry,and analysis of the Jost functions are obtained,which play a key role in constructing the RH problem.Then we successfully established the exact solution of the equation without reflection potential by solving the RH problem.Choosing some appropriate parameters of the resulting solutions,we further derive the soliton solutions with different order poles,including four cases of a fourthorder pole,two second-order poles,a third-order pole and a first-order pole,and four first-order points.Finally,the dynamical behavior of these solutions are analyzed via graphic analysis.
基金financially supported by the National Nature Science Foundation of China(52103255,52103137)the Guangdong Basic and Applied Basic Research Foundation(2019A1515110343,2019A1515110135,2019A1515110422)+2 种基金Research Start-up Funds of DGUT(211135130)the Special Project for Key Areas of Guangdong Higher Education Institutions(2020ZDZX2024)the Training Program of Innovation and Entrepreneurship for Undergraduates,DGUT(202011819132,202111819341).
文摘Flexible transparent conductive films are gaining attention day by day over the last few years due to it is a key component of next generation flexible electronics and optoelectronic devices.Indium tin oxide(ITO)as one of the most widely used transparent conductive material is limited by the traditional deposition approach cannot be achieve ultra-thin,which results in its brittle nature.Herein,a novel strategy for fabricating highly transparent conductive films by liquid metal interface phase separation technique based on low-melting liquid metal of InxSn100-x alloy is reported,during the solid-to-liquid phase transition of alloy,the monolayer of surface oxide film segregated with the bulk phase and was printed on the flexible polyethylene-naphthalate(PEN)substrate under the van der Waals.This novel strategy can directly print the ultra-thin self-oxide with the structure of ITO on PEN substrate,with the resulting of transparency over 97.5%and resistivity as low as 0.21 kU cm,providing a new way of lowcost raw ITO material as well as the personalized preparation strategy.The desirable highly transparent conductive films are comparable to recently reported ITO film,together with advantages of pretty steady,make them attractive as various flexible transparent conductive electrodes,for example,an ultra-thin ITO film is developed for luminescent devices.
基金supported by the grants from the National Science Foundation of China(Nos. 91132709 and 31130027)
文摘Sugar and protein are the major macronutrients＇ sources, and their balanced intake is important for animal＇s health. It has been observed that animals are able to change food preference in an imbalanced nutritional condition to selectively consume nutrients that are deficient in the body （Dethier, 1976）. Early studies in both Drosophila and mouse have demonstrated that animals exhibit food rejection to imbalanced diets lacking essential amino acids （Hao et al., 2005; Bjordal et al., 2014）. Furthermore, the food preference change upon protein depri- vation has been characterized using a two choice assay in Drosophila （Ribeiro and Dickson, 2010; Vargas et al., 2010）. Different from protein food, sugar is the main energy source, and sugar deficiency severely affects animal survival （Lee et al., 2008）. However, whether animals adopt a strategy of fast food preference switch upon sugar deprivation had not been investigated, and the neural mechanisms underlying this behavior regulation remain poorly understood.
基金financially supported by the National Natural Science Foundation of China (No. 51871240)。
文摘Alloying with Se is proved to be feasible to suppress the lattice thermal conductivity(κL)of tellurium by introducing multidimensional lattice defects.However,extra ionization impurity centers induced by Se alloying are harmful to the electric transport properties of the matrix.In this paper,we propose that the incorporation of Ag could successfully compensate the lost carrier mobility(μH)due to Se alloying through the regulation of microstructure,resulting in the higher power factor(PF)than that of samples without Ag.After composition optimization,theκLdecreased from 1.29 W m^(-1)K^(-1) of Te_(0.99)Sb_(0.01) to 1.05 W m^(-1)K^(-1) of Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01) at 350 K,while the PF remained unchanged or even slightly increased.Benefit from the synergistic effect of carrier mobility compensation and phonon scattering,a maximum z T of 0.91 at 573 K and an average z T of 0.57(between 298 and 573 K)are achieved in Te_(0.94)Ag_(0.02)Se_(0.03)Sb_(0.01).This work presents a new strategy for decoupling the thermal and electric parameters of Te-based thermoelectric materials.
基金National Natural Science Foundation of China (Grant No. 51202117)Natural Science Foundation of Beijing (Grant No. 2162037)+5 种基金Beijing Nova Program (Z171100001117077)Beijing Outstanding Talent Program (No. 2015000020124G121) Fundamental Research Funds for the Central Universities (No. 2014QJ02)State Key Laboratory of Coal Resources and Safe Mining (No. SKLCRSM16KFB04)Key Laboratory of Advanced Materials of Ministry of Education (No. 2018AML03)Yue Qi Young Scholar Project of China University of Mining & Technology (Beijing) (No. 2017QN17).
基金the National Natural Science Foundation of China (Grant No.51602120)Natural Science Foundation of Education Department of Henan Province (No.17A430023)and the opening project of Henan Provincial Key Laboratory of Nanocomposites and Applications (No.hkd20170106).
