The gut is home to a large number of intestinal microbiota that play an important role in the metabolism and immune system of the host.A growing body of evidence suggests that a high-fat diet is closely associated wit...The gut is home to a large number of intestinal microbiota that play an important role in the metabolism and immune system of the host.A growing body of evidence suggests that a high-fat diet is closely associated with many metabolic disorders,including fatty liver and type 2 diabetes.According to reports,Tartary buckwheat extract has a positive effect on intestinal microbiota in animals.The effects of Tartary buckwheat on biochemical indexes and intestinal microflora in mice were studied.Tartary buckwheat protein(FGP),Tartary buckwheat resistant starch(FGS)and Tartary buckwheat flour(FGF)alleviated organ damage in mice and lowered the atherosclerotic index(AI)in plasma.Otherwise,principal coordinate analysis(PCoA)showed that intestinal bacterial structure of FGF were separated apparently from other groups.The Firmicutes/Bacteroidetes(F/B)value of the high-fat(HF)-FGF group was significantly lower than that of the HF-FGP and HF-FGS groups.FGF significantly increases the abundance of beneficial bacteria such as Bifidobacterium,while decreasing the abundance of lipopolysaccharide(LPS)-producing bacteria.Observation of blood lipid metabolism parameters and analysis of the intestinal microbiota suggested that FGF can be more effective than FGP and FGS to reduce the effects of a high-fat diet in mice,restoring the blood parameters to values similar of those in mice fed a low-fat diet.FGF may be used to prevent or treat blood lipid metabolism disorders and intestinal microbiota disorders in mice fed a high-fat diet.展开更多
A three-dimensional four species multi-fluid magnetohydrodynamic (MHD) model was constructed to simulate the solar wind global interaction with Mars. The model was augmented to consider production and loss of the sign...A three-dimensional four species multi-fluid magnetohydrodynamic (MHD) model was constructed to simulate the solar wind global interaction with Mars. The model was augmented to consider production and loss of the significant ion species in the Martian ionosphere, i.e., H^+, O2^+, O^+, CO^+2, associated with chemical reactions among all species. An ideal dipole-like local crustal field model was used to simplify the empirically measured Martian crustal field. Results of this simulation suggest that the magnetic pile-up region (MPR) and the velocity profile in the meridian plane are asymmetric, which is due to the nature of the multi-fluid model to decouple individual ion velocity resulting in occurrence of plume flow in the northern Martian magnetotail. In the presence of dipole magnetic field model, boundary layers, such as bow shock (BS) and magnetic pile-up boundary (MPB), become protuberant. Moreover, the crustal field has an inhibiting effect on the flux of ions escaping from Mars, an effect that occurs primarily in the region between the terminator (SZA 90°) and the Sun Mars line of the magnetotail (SZA 180°), partially around the terminator region. In contrast, near the tailward central line the crustal field has no significant impact on the escaping flux.展开更多
Idiopathic pulmonary fibrosis(IPF)is a progressive pulmonary disease that leads to interstitial inflammation,lung damage,and eventually life-threatening complications.Among various pathologic factors,Smad4 is a pivota...Idiopathic pulmonary fibrosis(IPF)is a progressive pulmonary disease that leads to interstitial inflammation,lung damage,and eventually life-threatening complications.Among various pathologic factors,Smad4 is a pivotal molecule involved in the progression and exacerbation of IPF.It mediates nuclear transfer of Smad2/Smad3 complexes and initiates the transcription of fibrosis-promoting genes.Thus,the inhibition of Smad4 expression in pulmonary fibroblasts by small interfering RNAs(siRNAs)might be a promising therapeutic strategy for IPF.Herein,we engineered exosome membranes(EM)by cationic lipid(i.e.,DOTAP)to load siRNAs against Smad4(DOTAP/siSmad4@EM),and investigated their specific delivery to pulmonary fibroblasts for treating IPF in a mouse model via pulmonary administration.As reference nanoscaffolds,undecorated DOTAP/siSmad4 complexes(lipoplexes,consisting of cationic lipid DOTAP and siRNAs)and siSmad4-loaded lipid nanoparticles(DOTAP/siSmad4@lipo,consisting of lipoplexes fused with DPPC–Chol liposomes)were also prepared.The results showed that DOTAP/siSmad4@EM exhibited a higher cellular uptake and gene silencing efficacies in mouse pulmonary fibroblasts(viz.,MLg2908)as compared to the two reference nanoscaffolds.Furthermore,the outcomes of the in vivo experiments illustrated that DOTAP/siSmad4@EM could significantly down-regulate the Smad4 expression with augmented anti-fibrosis efficiency.Additionally,the DOTAP/siSmad4@EM conferred excellent biocompatibility with low cytokine levels in bronchoalveolar lavage fluid and proinflammatory responses in the pulmonary area.Taken together,the outcomes of our investigation imply that specific inhibition of Smad4 expression in pulmonary fibroblasts by pulmonary administrated DOTAP/siSmad4@EM is a promising therapeutic strategy for IPF,which could safely and effectively deliver siRNA drugs to the targeted site of action.展开更多
To detect and recover random tampering areas,a combined-decision-based self-embedding watermarking scheme is proposed herein.In this scheme,the image is first partitioned into 2×2 size blocks.Next,the high 5 bits...To detect and recover random tampering areas,a combined-decision-based self-embedding watermarking scheme is proposed herein.In this scheme,the image is first partitioned into 2×2 size blocks.Next,the high 5 bits of a block’s average value is embedded into its offset block.The tampering type of block is detected by comparing the watermarks of its pre-offset and post-offset blocks.The theoretical analysis and experiments demonstrate that the proposed scheme not only has a lower ratio of false detection but also better performance with regard to avoiding random tampering.展开更多
Wavelike perturbations in the ionosphere of Titan,the largest satellite of Saturn,are explored based on the Cassini Ion Neutral Mass Spectrometer(INMS)measurements.Strong wavelike perturbations are identified for more...Wavelike perturbations in the ionosphere of Titan,the largest satellite of Saturn,are explored based on the Cassini Ion Neutral Mass Spectrometer(INMS)measurements.Strong wavelike perturbations are identified for more than twenty ion species,from simple ones such as N^(+)and CH_(4)^(+)to complex ones such as C_(2)H_(3)CNH^(+)and C_(4)H_(7)^(+).Simultaneous wavelike perturbations in background N_(2),indicative of atmospheric gravity waves,are also observed,motivating us to speculate that the INMS-derived ion perturbations are wave-driven.The amplitudes of the ion perturbations are found to be larger than that of the N_(2)perturbations.Clear compositional variation is revealed by the data:heavier ion species exhibit greater amplitudes.Such observations might be understood based on considerations either of force balance or chemical loss in Titan’s ionosphere.展开更多
Suprathermal electrons are an important population of the Martian ionosphere, either produced by photoionization of atmospheric neutrals or supplied from the Solar Wind (SW). This study is dedicated to an in-depth inv...Suprathermal electrons are an important population of the Martian ionosphere, either produced by photoionization of atmospheric neutrals or supplied from the Solar Wind (SW). This study is dedicated to an in-depth investigation of the pitch angle distribution of suprathermal electrons at two representative energies, 19−55 eV and 124−356 eV, using the extensive measurements made by the Solar Wind Electron Analyzer on board the Mars Atmosphere and Volatile Evolution. Throughout the study, we focus on the overall degree of anisotropy, defined as the standard deviation of suprathermal electron intensity among different directions which is normalized by the mean omni-directional intensity. The available data reveal the following characteristics: (1) In general, low energy electrons are more isotropic than high energy electrons, and dayside electrons are more isotropic than nightside electrons;(2) On the dayside, the anisotropy increases with increasing altitude at low energies but remains roughly constant at high energies, whereas on the nightside, the anisotropy decreases with increasing altitude at all energies;(3) Electrons tend to be more isotropic in strongly magnetized regions than in weakly magnetized regions, especially on the nightside. These observations indicate that the anisotropy is a useful diagnostic of suprathermal electron transport, for which the conversion between the parallel and perpendicular momenta as required by the conservation of the first adiabatic invariant, along with the atmospheric absorption at low altitudes, are two crucial factors modulating the observed variation of the anisotropy. Our analysis also highlights the different roles on the observed anisotropy exerted by suprathermal electrons of different origins.展开更多
Theoretical calculations serve as an effective method for determining plasma temperatures within planetary atmospheres.To simulate plasma temperature,a comprehensive implementation of the energy equation is used,which...Theoretical calculations serve as an effective method for determining plasma temperatures within planetary atmospheres.To simulate plasma temperature,a comprehensive implementation of the energy equation is used,which is governed by five terms:conductivity,heating,cooling,adiabatic expansion,and advection.The derivations mentioned are strongly dependent on the collision cross section between electrons and other particles(e.g.,neutrals,ions).It is notable that the momentum transfer cross sections between electrons and neutrals have been updated in recent decades.However,the widely used momentum average collision cross sections between electrons and neutrals,derived from the momentum transfer cross sections,are collected in studies dating back nearly half a century.Therefore,it becomes imperative to revise the momentum average collision cross sections relevant to astrophysical contexts,based on the latest studies.In this study,we summarize the momentum average collision cross sections of 13 species common in planetary atmospheres:H,H_(2),He,O,CH_(4),H_(2)O,CO,N_(2),O_(2),Ar,CO_(2),N_(2)O,and NO_(2).All results are derived from the latest studies concerning the electron-neutral collision cross section and are compared with previous studies.Furthermore,we present a comparison of the derived total electron-neutral collision frequency at Mars between this study and previous studies.Prominent differences in the total electron-neutral collision frequency between this and prior studies support the significance of updating the momentum average collision cross section between electrons and neutrals in studying the planetary atmospheres.展开更多
Cross-modal image-text retrieval is a fundamental task in bridging vision and language. It faces two main challenges that are typically not well addressed in previous works. 1) Generalizability: Existing methods often...Cross-modal image-text retrieval is a fundamental task in bridging vision and language. It faces two main challenges that are typically not well addressed in previous works. 1) Generalizability: Existing methods often assume a strong semantic correlation between each text-image pair, which are thus difficult to generalize to real-world scenarios where the weak correlation dominates. 2) Efficiency: Many latest works adopt the single-tower architecture with heavy detectors, which are inefficient during the inference stage because the costly computation needs to be repeated for each text-image pair. In this work, to overcome these two challenges, we propose a two-tower cross-modal contrastive learning (CMCL) framework. Specifically, we first devise a two-tower architecture, which enables a unified feature space for the text and image modalities to be directly compared with each other, alleviating the heavy computation during inference. We further introduce a simple yet effective module named multi-grid split (MGS) to learn fine-grained image features without using detectors. Last but not the least, we deploy a cross-modal contrastive loss on the global image/text features to learn their weak correlation and thus achieve high generalizability. To validate that our CMCL can be readily generalized to real-world scenarios, we construct a large multi-source image-text dataset called weak semantic correlation dataset (WSCD). Extensive experiments show that our CMCL outperforms the state-of-the-arts while being much more efficient.展开更多
基金Shanghai Natural Science Foundation(20ZR1455800)the National Science Foundation of China(31871805)Shanghai Municipal Education Commission(Plateau Discipline Construction Program)and China Agriculture Research System(CARS-08-D2)。
文摘The gut is home to a large number of intestinal microbiota that play an important role in the metabolism and immune system of the host.A growing body of evidence suggests that a high-fat diet is closely associated with many metabolic disorders,including fatty liver and type 2 diabetes.According to reports,Tartary buckwheat extract has a positive effect on intestinal microbiota in animals.The effects of Tartary buckwheat on biochemical indexes and intestinal microflora in mice were studied.Tartary buckwheat protein(FGP),Tartary buckwheat resistant starch(FGS)and Tartary buckwheat flour(FGF)alleviated organ damage in mice and lowered the atherosclerotic index(AI)in plasma.Otherwise,principal coordinate analysis(PCoA)showed that intestinal bacterial structure of FGF were separated apparently from other groups.The Firmicutes/Bacteroidetes(F/B)value of the high-fat(HF)-FGF group was significantly lower than that of the HF-FGP and HF-FGS groups.FGF significantly increases the abundance of beneficial bacteria such as Bifidobacterium,while decreasing the abundance of lipopolysaccharide(LPS)-producing bacteria.Observation of blood lipid metabolism parameters and analysis of the intestinal microbiota suggested that FGF can be more effective than FGP and FGS to reduce the effects of a high-fat diet in mice,restoring the blood parameters to values similar of those in mice fed a low-fat diet.FGF may be used to prevent or treat blood lipid metabolism disorders and intestinal microbiota disorders in mice fed a high-fat diet.
基金supported by the pre-research projects on Civil Aerospace Technologies No.D020103 and D020105 funded by China’s National Space Administration (CNSA)support from the National Natural Science Foundation of China (NSFC) under grants 41674176, 41525015, 41774186, 41574156, and 41941001
文摘A three-dimensional four species multi-fluid magnetohydrodynamic (MHD) model was constructed to simulate the solar wind global interaction with Mars. The model was augmented to consider production and loss of the significant ion species in the Martian ionosphere, i.e., H^+, O2^+, O^+, CO^+2, associated with chemical reactions among all species. An ideal dipole-like local crustal field model was used to simplify the empirically measured Martian crustal field. Results of this simulation suggest that the magnetic pile-up region (MPR) and the velocity profile in the meridian plane are asymmetric, which is due to the nature of the multi-fluid model to decouple individual ion velocity resulting in occurrence of plume flow in the northern Martian magnetotail. In the presence of dipole magnetic field model, boundary layers, such as bow shock (BS) and magnetic pile-up boundary (MPB), become protuberant. Moreover, the crustal field has an inhibiting effect on the flux of ions escaping from Mars, an effect that occurs primarily in the region between the terminator (SZA 90°) and the Sun Mars line of the magnetotail (SZA 180°), partially around the terminator region. In contrast, near the tailward central line the crustal field has no significant impact on the escaping flux.
基金supported by the Liaoning Pan Deng Xue Zhe Scholar(grant No.XLYC2002061)the National Natural Science Foundation of China(grant No.82173768)+7 种基金the Overseas Expertise Introduction Project for Discipline Innovation(“111 Project”)(grant No.D20029)M.Y.thanks Independent Research Fund Denmark for the financial support(Grant ID:10.46540/3105-00249B)L.W.acknowledges the financial supports of National Natural Science Foundation of China(grant No.82204316)China Postdoctoral Science Foundation(grant Nos.2021TQ0219 and 2022MD713776)H.B.thanks the financial support from National Natural Science Foundation of China,Govt.of China(grant No.82050410448)Fellowship of China Postdoctoral Science Foundation,Govt.of China(grant No.2021MD703857)D.C.acknowledges financial support from Nature Science Foundation of Liaoning Province(grant No.2022-MS-241)Ministry of Education Chunhui Program(2020).
文摘Idiopathic pulmonary fibrosis(IPF)is a progressive pulmonary disease that leads to interstitial inflammation,lung damage,and eventually life-threatening complications.Among various pathologic factors,Smad4 is a pivotal molecule involved in the progression and exacerbation of IPF.It mediates nuclear transfer of Smad2/Smad3 complexes and initiates the transcription of fibrosis-promoting genes.Thus,the inhibition of Smad4 expression in pulmonary fibroblasts by small interfering RNAs(siRNAs)might be a promising therapeutic strategy for IPF.Herein,we engineered exosome membranes(EM)by cationic lipid(i.e.,DOTAP)to load siRNAs against Smad4(DOTAP/siSmad4@EM),and investigated their specific delivery to pulmonary fibroblasts for treating IPF in a mouse model via pulmonary administration.As reference nanoscaffolds,undecorated DOTAP/siSmad4 complexes(lipoplexes,consisting of cationic lipid DOTAP and siRNAs)and siSmad4-loaded lipid nanoparticles(DOTAP/siSmad4@lipo,consisting of lipoplexes fused with DPPC–Chol liposomes)were also prepared.The results showed that DOTAP/siSmad4@EM exhibited a higher cellular uptake and gene silencing efficacies in mouse pulmonary fibroblasts(viz.,MLg2908)as compared to the two reference nanoscaffolds.Furthermore,the outcomes of the in vivo experiments illustrated that DOTAP/siSmad4@EM could significantly down-regulate the Smad4 expression with augmented anti-fibrosis efficiency.Additionally,the DOTAP/siSmad4@EM conferred excellent biocompatibility with low cytokine levels in bronchoalveolar lavage fluid and proinflammatory responses in the pulmonary area.Taken together,the outcomes of our investigation imply that specific inhibition of Smad4 expression in pulmonary fibroblasts by pulmonary administrated DOTAP/siSmad4@EM is a promising therapeutic strategy for IPF,which could safely and effectively deliver siRNA drugs to the targeted site of action.
基金This work was supported in part by the National Natural Science Foundation of China(No.61401512,61602508,61772549,6141512 and U1636219)the National Key R&D Program of China(No.2016YFB0801303 and 2016QY01W0105)+1 种基金the Key Technologies R&D Program of Henan Province(No.162102210032)the Key Science and Technology Research Project of Henan Province(No.152102210005).
文摘To detect and recover random tampering areas,a combined-decision-based self-embedding watermarking scheme is proposed herein.In this scheme,the image is first partitioned into 2×2 size blocks.Next,the high 5 bits of a block’s average value is embedded into its offset block.The tampering type of block is detected by comparing the watermarks of its pre-offset and post-offset blocks.The theoretical analysis and experiments demonstrate that the proposed scheme not only has a lower ratio of false detection but also better performance with regard to avoiding random tampering.
基金supported by the B-type Strategic Priority Program No. XDB41000000funded by the Chinese Academy of Sciences and the pre-research projects on Civil Aerospace Technologies No.s D020105 and D020103+1 种基金funded by China’s National Space Administrationsupport from the National Science Foundation of China through grants 42030201, 41904154 and 42104170
文摘Wavelike perturbations in the ionosphere of Titan,the largest satellite of Saturn,are explored based on the Cassini Ion Neutral Mass Spectrometer(INMS)measurements.Strong wavelike perturbations are identified for more than twenty ion species,from simple ones such as N^(+)and CH_(4)^(+)to complex ones such as C_(2)H_(3)CNH^(+)and C_(4)H_(7)^(+).Simultaneous wavelike perturbations in background N_(2),indicative of atmospheric gravity waves,are also observed,motivating us to speculate that the INMS-derived ion perturbations are wave-driven.The amplitudes of the ion perturbations are found to be larger than that of the N_(2)perturbations.Clear compositional variation is revealed by the data:heavier ion species exhibit greater amplitudes.Such observations might be understood based on considerations either of force balance or chemical loss in Titan’s ionosphere.
基金the National Natural Science Foundation of China through grants 42241114,42274218 and 42304166the B-type Strategic Priority Program No.XDB41000000 funded by the Chinese Academy of Sciences+1 种基金the pre-research project on Civil Aerospace Technologies No.D020105 funded by China’s National Space Administration,the Guangdong Basic and Applied Research Foundation Project 2021A1515110271the Key Laboratory of Geospace Environment,Chinese Academy of Sciences,University of Science&Technology of China.
文摘Suprathermal electrons are an important population of the Martian ionosphere, either produced by photoionization of atmospheric neutrals or supplied from the Solar Wind (SW). This study is dedicated to an in-depth investigation of the pitch angle distribution of suprathermal electrons at two representative energies, 19−55 eV and 124−356 eV, using the extensive measurements made by the Solar Wind Electron Analyzer on board the Mars Atmosphere and Volatile Evolution. Throughout the study, we focus on the overall degree of anisotropy, defined as the standard deviation of suprathermal electron intensity among different directions which is normalized by the mean omni-directional intensity. The available data reveal the following characteristics: (1) In general, low energy electrons are more isotropic than high energy electrons, and dayside electrons are more isotropic than nightside electrons;(2) On the dayside, the anisotropy increases with increasing altitude at low energies but remains roughly constant at high energies, whereas on the nightside, the anisotropy decreases with increasing altitude at all energies;(3) Electrons tend to be more isotropic in strongly magnetized regions than in weakly magnetized regions, especially on the nightside. These observations indicate that the anisotropy is a useful diagnostic of suprathermal electron transport, for which the conversion between the parallel and perpendicular momenta as required by the conservation of the first adiabatic invariant, along with the atmospheric absorption at low altitudes, are two crucial factors modulating the observed variation of the anisotropy. Our analysis also highlights the different roles on the observed anisotropy exerted by suprathermal electrons of different origins.
基金the National Natural Science Foundation of China through Grants 42261160643,42441806,42241114,and 42304166supported by the open project funded by the Key Laboratory of Geospace Environment,Chinese Academy of Sciences,University of Science and Technology of China.
文摘Theoretical calculations serve as an effective method for determining plasma temperatures within planetary atmospheres.To simulate plasma temperature,a comprehensive implementation of the energy equation is used,which is governed by five terms:conductivity,heating,cooling,adiabatic expansion,and advection.The derivations mentioned are strongly dependent on the collision cross section between electrons and other particles(e.g.,neutrals,ions).It is notable that the momentum transfer cross sections between electrons and neutrals have been updated in recent decades.However,the widely used momentum average collision cross sections between electrons and neutrals,derived from the momentum transfer cross sections,are collected in studies dating back nearly half a century.Therefore,it becomes imperative to revise the momentum average collision cross sections relevant to astrophysical contexts,based on the latest studies.In this study,we summarize the momentum average collision cross sections of 13 species common in planetary atmospheres:H,H_(2),He,O,CH_(4),H_(2)O,CO,N_(2),O_(2),Ar,CO_(2),N_(2)O,and NO_(2).All results are derived from the latest studies concerning the electron-neutral collision cross section and are compared with previous studies.Furthermore,we present a comparison of the derived total electron-neutral collision frequency at Mars between this study and previous studies.Prominent differences in the total electron-neutral collision frequency between this and prior studies support the significance of updating the momentum average collision cross section between electrons and neutrals in studying the planetary atmospheres.
文摘Cross-modal image-text retrieval is a fundamental task in bridging vision and language. It faces two main challenges that are typically not well addressed in previous works. 1) Generalizability: Existing methods often assume a strong semantic correlation between each text-image pair, which are thus difficult to generalize to real-world scenarios where the weak correlation dominates. 2) Efficiency: Many latest works adopt the single-tower architecture with heavy detectors, which are inefficient during the inference stage because the costly computation needs to be repeated for each text-image pair. In this work, to overcome these two challenges, we propose a two-tower cross-modal contrastive learning (CMCL) framework. Specifically, we first devise a two-tower architecture, which enables a unified feature space for the text and image modalities to be directly compared with each other, alleviating the heavy computation during inference. We further introduce a simple yet effective module named multi-grid split (MGS) to learn fine-grained image features without using detectors. Last but not the least, we deploy a cross-modal contrastive loss on the global image/text features to learn their weak correlation and thus achieve high generalizability. To validate that our CMCL can be readily generalized to real-world scenarios, we construct a large multi-source image-text dataset called weak semantic correlation dataset (WSCD). Extensive experiments show that our CMCL outperforms the state-of-the-arts while being much more efficient.
