Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these iss...Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these issues by in-situ forming a well-defined 2D perovskite(PMA)_(2)PbCl_(4)(phenmethylammonium is referred to as PMA)passivation layer on top of the WBG active layer.The 2D layer with highly pure dimensionality and halide components is realized by intentionally tailoring the side-chain substituent at the aryl ring of the post-treatment reagent.First-principle calculation and single-crystal X-ray diffraction results reveal that weak intermolecular interactions between bulky PMA cations and relatively low cation-halide hydrogen bonding strength are crucial in forming the well-defined 2D phase.The(PMA)_(2)PbCl_(4)forms improved type-I energy level alignment with the WBG perovskite,reducing the electron recombination at the perovskite/hole-transport-layer interface.Applying this strategy in fabricating semi-transparent WBG perovskite solar cells(indium tin oxide as the back electrode),the V_(OC)deficits can be reduced to 0.49 V,comparable with the reported state-of-the-art WBG perovskite solar cells using metal electrodes.Consequently,we obtain hysteresis-free 18.60%-efficient WBG perovskite solar cells with a high V_(OC)of 1.23 V.展开更多
The valence change of samarium from trivalent to divalent state in strontium borates (SrB6O10)prepared in air was observed. The high resolution spectra of Sm2+ in matrix were studied between 10 K and 300 K. The result...The valence change of samarium from trivalent to divalent state in strontium borates (SrB6O10)prepared in air was observed. The high resolution spectra of Sm2+ in matrix were studied between 10 K and 300 K. The results showed that three crystallographic sites for Sm2+ were available in the host. Energy transfer among these sites was possible. The vibronic transition of 5D0-7F0 of Sm2+ was studied at room temperature and the Huang-Rhys factor S was calculated. Due to the thermal population, 5D1 -7F0 transition at room temperature was展开更多
Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway....Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway.However,whether and how MAD1 might be directly involved in the DDR is largely unknown.Methods:We ectopically expressed the wild type,or a phosphorylation-site--mutated form of MAD1 in MAD1 knockdown cells to look for complementation effects.We used the comet assay,colony formation assay,immunofluorescence staining,and flow cytometry to assess the DDR,radiosensitivity,and the G2/M checkpoint.We employed co-immunoprecipitation followed by mass spectrometry to identify MAD1 interacting proteins.Data were analyzed using the unpaired Student'st-test.Results:We showed that MAD1 was required for an optimal DDR,as knocking down MAD1 resulted in impaired DNA repair and hypersensitivity to ionizing radiation(IR).We found that IR-induced serine 214 phosphorylation was ataxia-telangiectasia mutated(ATM)kinase-dependent.Mutation of serine 214 to alanine failed to rescue the phenotypes of MAD1 knockdown cells in response to IR.Using mass spectrometry,we identified a protein complex mediated by MAD1 serine 214 phosphorylation in response to IR.Among them,we showed that KU80 was a key protein that displayed enhanced interaction with MAD1 after DNA damage.Finally,we showed that MAD1 interaction with KU80 required serine 214 phosphorylation,and it was essential for activation of DNA protein kinases catalytic subunit(DNA-PKcs).Conclusions:MAD1 serine 214 phosphorylation mediated by ATM kinase in response to IR was required for the interaction with KU80 and activation of DNA-PKCs.展开更多
The gut microbiota consistently shows strong correlations with lipid metabolism in humans and animals,and whether the gut microbiota contributes to muscle fatty acid(FA)deposition and meat traits in farm animals has n...The gut microbiota consistently shows strong correlations with lipid metabolism in humans and animals,and whether the gut microbiota contributes to muscle fatty acid(FA)deposition and meat traits in farm animals has not been fully resolved.In this study,we aimed to unveil the microbial mechanisms underlying muscle FA deposition in pigs.First,we systematically revealed the correlation between the gut microbiome and muscle FA levels in 43 obese Ningxiang pigs and 50 lean Duroc Landrace Yorkshire(DLY)pigs.Mutual fecal microbial transplantation showed that the obese Ningxiang pig-derived microbiota increased the muscle FA content and improved meat quality by reshaping the gut microbial composition in lean DLY pigs.Lactobacillus reuteri has been identified as a potential microbial biomarker in obese Ningxiang pig-derived microbiota-challenged DLY pigs.A gavage experiment using lean DLY pigs confirmed that L.reuteri XL0930 isolated from obese Ningxiang pigs was the causal species that increased the muscle FA content.Mechanistically,SLC22A5,a carnitine transporter,was downregulated in L.reuteri XL0930-fed DLY pigs,resulting in reduced muscle carnitine levels.Muscle and intestinal L-carnitine levels,which correlated with the muscle FA content,impeded fat synthesis and FA accumulation in in vitro and in vivo models.In conclusion,we uncovered an unexpected and important role of the obese Ningxiang pig-derived microbiota in regulating muscle FA metabolism via the SLC22A5-mediated carnitine system.展开更多
Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted const...Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted constellations is a practical problem that needs to be faced and researched further. It is a shortcut that improves the availability in position domain whose key idea is to replace the conventional least squares process with a non-least-squares estimator to lower the integrity risk in exchange for a slight increase in nominal position error. The contributions given in this paper include two parts: First, the impacts of one satellite outage on different constellations are analyzed and compared. The conclusion is that GPS is more sensitive and vulnerable to one satellite outage. Second, a constellation weighted ARAIM(CW-ARAIM)position estimator is proposed. The position solution is replaced by a constellation weighted average solution to eliminate the constellation difference. The new solution will move close to the constellation solutions with respect to the accuracy requirement. The simulation results under baseline GPS and Galileo dual-constellation show that the one GPS satellite outage will knock the availability from 91% to only 50%. The performance remains stable with one Galileo satellite outage. With the assistance of the CW-ARAIM method, the availability can increase from 50% to more than80% under depleted GPS configurations. Even without any satellite outage, the proposed method can effectively improve the availability from 91.29% to 98.75%. The test results under optimistic constellations further verify that a balanced constellation is more important than more satellites on orbit and the superiority of CW-ARAIM method is still effective.展开更多
Molecular dynamics simulation was adopted to study the interaction between sulfosalicylic acid and aluminum,lanthanum and yttrium,and adsorption on kaolinite surfaces.A complexation reaction occurs between sulfosalicy...Molecular dynamics simulation was adopted to study the interaction between sulfosalicylic acid and aluminum,lanthanum and yttrium,and adsorption on kaolinite surfaces.A complexation reaction occurs between sulfosalicylic acid and aluminum,with an interaction energy of-10472.05 kJ/mol.O—Al covalent bonds are formed with a peak value of 7.93,while there is only weak adsorption between sulfosalicylic acid and rare earth ions.A hydrogen bonding reaction with 13605.82 kJ/mol energy occurs between sulfosalicylic acid and the surface of kaolinite(100).Thus,sulfosalicylic acid can form a complex with free aluminum ions,and can also be adsorbed on kaolinite by hydrogen bonding with aluminum in kaolinite(100)surfaces.Leaching of ion-adsorbed type rare earth ore was performed with aluminum inhibited,results show that when sulfosalicylic acid dosage increases from 0 to 0.15 wt%,aluminum ion concentration in the leaching solution decreases from 273.23 to 47.19 mg/L.And the effect of leaching pH value on the effect of sulfosalicylic acid on aluminum inhibition was studied,the result shows that,when the leaching pH value is 4.0—5.0,the rare earth leaching rate and the aluminum ion concentration basically remain unchanged.The molecular dynamics simulation results were verified by detection and analysis of XPS and SEM.展开更多
High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adapt...High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adaptability for high dynamics require either complicated structures or prior statistical information of noises.This paper proposes a high dynamics algorithm based on steepest ascent method that can circumvent the deficiencies of existing methods.First,the relationship between the error of carrier tracking and the maximum of Fast Fourier Transform(FFT)outputs is established,and a performance function based on the steepest ascent method is designed.It can keep stable in high dynamics.Second,a new carrier-tracking loop is constructed by deploying the performance function.When the variation of GPS receiver acceleration ranges from 10 g to 100 g,compared with the PLL that either loses lock or keeps tracking accuracy less than 33.89 Hz,the experimental results show that the proposed method can not only keep tracking,but also achieve tracking accuracy more than 2.77 Hz.展开更多
The Unmanned Aerial Helicopter(UAH)has attracted increasing attention in the military and civil areas with the unique flight performance.The significant impact on the attitude measurement performance of UAHs by the st...The Unmanned Aerial Helicopter(UAH)has attracted increasing attention in the military and civil areas with the unique flight performance.The significant impact on the attitude measurement performance of UAHs by the strong airflow disturbance is an essential factor threatening flight safety.To improve the attitude measurement performance of UAHs under atmospheric disturbance,an attitude fusion method over the factor graph is applied and provides the plug-and-play capability.Based on the relationship between position,velocity and attitude,a new attitude correction algorithm for the Modified Attitude Factor Graph Fusion(MAFGF)navigation method is designed and constructed through the fused position and velocity information.Finally,results of simulation and experiment are given to show the effectiveness of the proposed method.展开更多
Alterations in glucose metabolism occur in the brain in the early stage of Alzheimer's disease(AD),and menopausal women have more severe metabolic dysfunction and are more prone to dementia than men.Although estro...Alterations in glucose metabolism occur in the brain in the early stage of Alzheimer's disease(AD),and menopausal women have more severe metabolic dysfunction and are more prone to dementia than men.Although estrogen deficiency-induced changes in glucose metabolism have been previously studied in animal models,their molecular mechanisms in AD remain elusive.To investigate this issue,double transgenic(APP/PS1)female mice were subjected to bilateral ovariectomy at 3 months of age and were sacrificed 1 week,1 month and 3 months after surgery to simulate early,middle and late postmenopause,respectively.Our analysis demonstrated that estrogen deficiency exacerbates learning and memory deficits in this mouse model of postmenopause.Estrogen deficiency impairs the function of mitochondria in glucose metabolism.It is possible that the occurrence of AD is associated with the aberrant mitochondrial ERβ-mediated IGF-1/IGF-1R/GSK-3βsignaling pathway.In this study,we established a potential mechanism for the increased risk of AD in postmenopausal women and proposed a therapeutic target for AD due to postmenopause.展开更多
This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemi...This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)are utilized to study this synergism.The removal effect is not only reflected in ammonia chemical reaction with CO_(2).CO_(2) can also be absorbed by ammonium bicarbonate(NH_(4)HCO_(3)) crystal,which is the main component of the product,or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil.CO_(2) can be permanently deposited as carbonated minerals in the subsoil earth layers.展开更多
Dear Editor,Accumulating evidence supports that,as a critical genome guardian mechanism,the DNA damage response(DDR)is a barrier to early tumorigenesis.As a crucial DDR pathway,Ataxia Telangiectasia Mutated(ATM)-media...Dear Editor,Accumulating evidence supports that,as a critical genome guardian mechanism,the DNA damage response(DDR)is a barrier to early tumorigenesis.As a crucial DDR pathway,Ataxia Telangiectasia Mutated(ATM)-mediated phosphorylation of downstream targets is essential for activation of cell cycle checkpoints,DNA repair,and programed cell death in the presence of DNA damage.Despite extensive biochemical and cellular studies on ATM phosphorylation,these phosphorylation sites are rarely mutated in cancers,challenging the pathophysio-logical relevance of ATM-mediated phosphorylation in the disease setting.展开更多
Multipath interference seriously degrades the performance of Global Navigation Satellite System(GNSS)positioning in an urban canyon.Most current multipath mitigation algorithms suffer from heavy computational load or ...Multipath interference seriously degrades the performance of Global Navigation Satellite System(GNSS)positioning in an urban canyon.Most current multipath mitigation algorithms suffer from heavy computational load or need external assistance.We propose a multipath mitigation algorithm based on the steepest descent approach,which has the merits of less computational load and no need for external aid.A new ranging code tracking loop is designed based on the steepest descent method,which can save an early branch or a late branch compared with the narrow-spacing correlation method.The power of the Non-Line-of-Sight(NLOS)signal is weaker than that of the Line-of-Sight(LOS)signal when the LOS signal is not obstructed and with a relatively high Carrier Noise Ratio(CNR).The peak position in the X-axis of the ranging code autocorrelation function does not move with the NLOS interference.Meanwhile,the cost function is designed according to this phenomenon.The results demonstrate that the proposed algorithm outperforms the narrow-spacing correlation and the Multipath Estimated Delay Locked Loop(MEDLL)in terms of the code multipath mitigation and computation time.The Standard Deviation(STD)of the tracking error with the proposed algorithm is less than 0.016 chips.Moreover,the computation time of the proposed algorithm in a software defined receiver is shortened by 24.21%compared with the narrow-spacing correlation.展开更多
基金supported by the National Natural Science Foundation of China(22179042,U21A2078,and 51902110)the Natural Science Foundation of Fujian Province(2020J06021 and 2020J01064).
文摘Wide-bandgap(WBG)perovskite solar cells suffer from severe non-radiative recombination and exhibit relatively large opencircuit voltage(V_(OC))deficits,limiting their photovoltaic performance.Here,we address these issues by in-situ forming a well-defined 2D perovskite(PMA)_(2)PbCl_(4)(phenmethylammonium is referred to as PMA)passivation layer on top of the WBG active layer.The 2D layer with highly pure dimensionality and halide components is realized by intentionally tailoring the side-chain substituent at the aryl ring of the post-treatment reagent.First-principle calculation and single-crystal X-ray diffraction results reveal that weak intermolecular interactions between bulky PMA cations and relatively low cation-halide hydrogen bonding strength are crucial in forming the well-defined 2D phase.The(PMA)_(2)PbCl_(4)forms improved type-I energy level alignment with the WBG perovskite,reducing the electron recombination at the perovskite/hole-transport-layer interface.Applying this strategy in fabricating semi-transparent WBG perovskite solar cells(indium tin oxide as the back electrode),the V_(OC)deficits can be reduced to 0.49 V,comparable with the reported state-of-the-art WBG perovskite solar cells using metal electrodes.Consequently,we obtain hysteresis-free 18.60%-efficient WBG perovskite solar cells with a high V_(OC)of 1.23 V.
文摘The valence change of samarium from trivalent to divalent state in strontium borates (SrB6O10)prepared in air was observed. The high resolution spectra of Sm2+ in matrix were studied between 10 K and 300 K. The results showed that three crystallographic sites for Sm2+ were available in the host. Energy transfer among these sites was possible. The vibronic transition of 5D0-7F0 of Sm2+ was studied at room temperature and the Huang-Rhys factor S was calculated. Due to the thermal population, 5D1 -7F0 transition at room temperature was
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.81672743 and 81974464)Beijing Tianjin Hebei Basic Research Cooperation Project(Grant No.19JCZDJC64500(Z))+4 种基金Shenzhen Basic Research Project(Grant No.JCYJ20160331114230843)Tianjin Municipal Health Commission(Grant Nos.2015KR11 and 2013KG134)Tianjin Municipal Science and Technology Bureau(Grant No.18JCYBJC27800)US NIH grant RO 1 CAI33093,the Alabama Innovation Fund of the United Statesthe Tianjin Medical University Cancer Institute and Hospital Innovation Fund(Grant No.1803)。
文摘Objective:Mitotic arrest-deficient protein 1(MAD1)is a kinetochore protein essential for the mitotic spindle checkpoint.Proteomic studies have indicated that MAD1 is a component of the DNA damage response(DDR)pathway.However,whether and how MAD1 might be directly involved in the DDR is largely unknown.Methods:We ectopically expressed the wild type,or a phosphorylation-site--mutated form of MAD1 in MAD1 knockdown cells to look for complementation effects.We used the comet assay,colony formation assay,immunofluorescence staining,and flow cytometry to assess the DDR,radiosensitivity,and the G2/M checkpoint.We employed co-immunoprecipitation followed by mass spectrometry to identify MAD1 interacting proteins.Data were analyzed using the unpaired Student'st-test.Results:We showed that MAD1 was required for an optimal DDR,as knocking down MAD1 resulted in impaired DNA repair and hypersensitivity to ionizing radiation(IR).We found that IR-induced serine 214 phosphorylation was ataxia-telangiectasia mutated(ATM)kinase-dependent.Mutation of serine 214 to alanine failed to rescue the phenotypes of MAD1 knockdown cells in response to IR.Using mass spectrometry,we identified a protein complex mediated by MAD1 serine 214 phosphorylation in response to IR.Among them,we showed that KU80 was a key protein that displayed enhanced interaction with MAD1 after DNA damage.Finally,we showed that MAD1 interaction with KU80 required serine 214 phosphorylation,and it was essential for activation of DNA protein kinases catalytic subunit(DNA-PKcs).Conclusions:MAD1 serine 214 phosphorylation mediated by ATM kinase in response to IR was required for the interaction with KU80 and activation of DNA-PKCs.
基金National Natural Science Foundation of China(U20A2055 and 32172761)National Key Research and Development Program of China(2022YFD1301500)Hunan Youth Science and Technology Talent Project(2022RC1157).
文摘The gut microbiota consistently shows strong correlations with lipid metabolism in humans and animals,and whether the gut microbiota contributes to muscle fatty acid(FA)deposition and meat traits in farm animals has not been fully resolved.In this study,we aimed to unveil the microbial mechanisms underlying muscle FA deposition in pigs.First,we systematically revealed the correlation between the gut microbiome and muscle FA levels in 43 obese Ningxiang pigs and 50 lean Duroc Landrace Yorkshire(DLY)pigs.Mutual fecal microbial transplantation showed that the obese Ningxiang pig-derived microbiota increased the muscle FA content and improved meat quality by reshaping the gut microbial composition in lean DLY pigs.Lactobacillus reuteri has been identified as a potential microbial biomarker in obese Ningxiang pig-derived microbiota-challenged DLY pigs.A gavage experiment using lean DLY pigs confirmed that L.reuteri XL0930 isolated from obese Ningxiang pigs was the causal species that increased the muscle FA content.Mechanistically,SLC22A5,a carnitine transporter,was downregulated in L.reuteri XL0930-fed DLY pigs,resulting in reduced muscle carnitine levels.Muscle and intestinal L-carnitine levels,which correlated with the muscle FA content,impeded fat synthesis and FA accumulation in in vitro and in vivo models.In conclusion,we uncovered an unexpected and important role of the obese Ningxiang pig-derived microbiota in regulating muscle FA metabolism via the SLC22A5-mediated carnitine system.
基金funded by the National Natural Science Foundation of China (Nos. 61533008, 61374115, 61328301 and 61603181)the Funding of Jiangsu Innovation Program for Graduate Education of China (No. KYLX16_0379)the Open Fund of State Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University of China (No.17P02)
文摘Advanced Receiver Autonomous Integrity Monitoring(ARAIM) is a new technology that will provide worldwide coverage of vertical guidance in aviation navigation. The ARAIM performance and improvement under depleted constellations is a practical problem that needs to be faced and researched further. It is a shortcut that improves the availability in position domain whose key idea is to replace the conventional least squares process with a non-least-squares estimator to lower the integrity risk in exchange for a slight increase in nominal position error. The contributions given in this paper include two parts: First, the impacts of one satellite outage on different constellations are analyzed and compared. The conclusion is that GPS is more sensitive and vulnerable to one satellite outage. Second, a constellation weighted ARAIM(CW-ARAIM)position estimator is proposed. The position solution is replaced by a constellation weighted average solution to eliminate the constellation difference. The new solution will move close to the constellation solutions with respect to the accuracy requirement. The simulation results under baseline GPS and Galileo dual-constellation show that the one GPS satellite outage will knock the availability from 91% to only 50%. The performance remains stable with one Galileo satellite outage. With the assistance of the CW-ARAIM method, the availability can increase from 50% to more than80% under depleted GPS configurations. Even without any satellite outage, the proposed method can effectively improve the availability from 91.29% to 98.75%. The test results under optimistic constellations further verify that a balanced constellation is more important than more satellites on orbit and the superiority of CW-ARAIM method is still effective.
基金Project supported by the National Natural Science Foundation of China,(51674125,51604128)Outstanding Doctoral Dissertation Project Fund of JXUST(YB2016001)
文摘Molecular dynamics simulation was adopted to study the interaction between sulfosalicylic acid and aluminum,lanthanum and yttrium,and adsorption on kaolinite surfaces.A complexation reaction occurs between sulfosalicylic acid and aluminum,with an interaction energy of-10472.05 kJ/mol.O—Al covalent bonds are formed with a peak value of 7.93,while there is only weak adsorption between sulfosalicylic acid and rare earth ions.A hydrogen bonding reaction with 13605.82 kJ/mol energy occurs between sulfosalicylic acid and the surface of kaolinite(100).Thus,sulfosalicylic acid can form a complex with free aluminum ions,and can also be adsorbed on kaolinite by hydrogen bonding with aluminum in kaolinite(100)surfaces.Leaching of ion-adsorbed type rare earth ore was performed with aluminum inhibited,results show that when sulfosalicylic acid dosage increases from 0 to 0.15 wt%,aluminum ion concentration in the leaching solution decreases from 273.23 to 47.19 mg/L.And the effect of leaching pH value on the effect of sulfosalicylic acid on aluminum inhibition was studied,the result shows that,when the leaching pH value is 4.0—5.0,the rare earth leaching rate and the aluminum ion concentration basically remain unchanged.The molecular dynamics simulation results were verified by detection and analysis of XPS and SEM.
基金funded by National Natural Science Foundation of China(Nos.61533008,61603181,61673208,61873125)。
文摘High dynamic conditions impose critical challenges on Global Navigation Satellite System(GNSS)receivers,leading to large tracking errors or even loss of tracking.Current methods that intend to improve receivers’adaptability for high dynamics require either complicated structures or prior statistical information of noises.This paper proposes a high dynamics algorithm based on steepest ascent method that can circumvent the deficiencies of existing methods.First,the relationship between the error of carrier tracking and the maximum of Fast Fourier Transform(FFT)outputs is established,and a performance function based on the steepest ascent method is designed.It can keep stable in high dynamics.Second,a new carrier-tracking loop is constructed by deploying the performance function.When the variation of GPS receiver acceleration ranges from 10 g to 100 g,compared with the PLL that either loses lock or keeps tracking accuracy less than 33.89 Hz,the experimental results show that the proposed method can not only keep tracking,but also achieve tracking accuracy more than 2.77 Hz.
基金co-supported by the National Natural Science Foundation of China (Nos. 61533008, 61603181)the Fundamental Research Funds for the Central Universities of China (No. NS2018021)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘The Unmanned Aerial Helicopter(UAH)has attracted increasing attention in the military and civil areas with the unique flight performance.The significant impact on the attitude measurement performance of UAHs by the strong airflow disturbance is an essential factor threatening flight safety.To improve the attitude measurement performance of UAHs under atmospheric disturbance,an attitude fusion method over the factor graph is applied and provides the plug-and-play capability.Based on the relationship between position,velocity and attitude,a new attitude correction algorithm for the Modified Attitude Factor Graph Fusion(MAFGF)navigation method is designed and constructed through the fused position and velocity information.Finally,results of simulation and experiment are given to show the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(No.81671257,81371221,and 31600825)the Innovation Research Group at Institutions of Higher Education in Chongqing(No.CXQTP19019019034).
文摘Alterations in glucose metabolism occur in the brain in the early stage of Alzheimer's disease(AD),and menopausal women have more severe metabolic dysfunction and are more prone to dementia than men.Although estrogen deficiency-induced changes in glucose metabolism have been previously studied in animal models,their molecular mechanisms in AD remain elusive.To investigate this issue,double transgenic(APP/PS1)female mice were subjected to bilateral ovariectomy at 3 months of age and were sacrificed 1 week,1 month and 3 months after surgery to simulate early,middle and late postmenopause,respectively.Our analysis demonstrated that estrogen deficiency exacerbates learning and memory deficits in this mouse model of postmenopause.Estrogen deficiency impairs the function of mitochondria in glucose metabolism.It is possible that the occurrence of AD is associated with the aberrant mitochondrial ERβ-mediated IGF-1/IGF-1R/GSK-3βsignaling pathway.In this study,we established a potential mechanism for the increased risk of AD in postmenopausal women and proposed a therapeutic target for AD due to postmenopause.
基金the support by the National Development Programming of Key Fundamental Researches of China(2004CB217700)Program for Changjiang Scholars and Innovative Research Team of Ministry of Education(PCSIRT-IRT0620)Subsidy Scheme of Outstanding Academic Leaders in Shanghai(08XD1401300).
文摘This paper presents our study on removal of carbon dioxide(CO_(2)) greenhouse gas emissions by using the mixture of ammonia and soil.CO_(2) capture capacity using this method is 15%higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity.Scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR)are utilized to study this synergism.The removal effect is not only reflected in ammonia chemical reaction with CO_(2).CO_(2) can also be absorbed by ammonium bicarbonate(NH_(4)HCO_(3)) crystal,which is the main component of the product,or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil.CO_(2) can be permanently deposited as carbonated minerals in the subsoil earth layers.
基金This work was supported by grants from the National Natural Science Foundation of China[81672743,81974464 and 81972861]Bejing-Tanjin-Hebei Basic Research Cooperation Project[19JCZDJC64500(Z)]+2 种基金the Alabama Innovation Fund,from the Ministry of Science and Technology[2016YFC0904601]Shenzhen Basic Research Project(JCYJ20160331114230843)Tianjin Medical University Cancer Institute and Hospital Innovation Fund[1803].
文摘Dear Editor,Accumulating evidence supports that,as a critical genome guardian mechanism,the DNA damage response(DDR)is a barrier to early tumorigenesis.As a crucial DDR pathway,Ataxia Telangiectasia Mutated(ATM)-mediated phosphorylation of downstream targets is essential for activation of cell cycle checkpoints,DNA repair,and programed cell death in the presence of DNA damage.Despite extensive biochemical and cellular studies on ATM phosphorylation,these phosphorylation sites are rarely mutated in cancers,challenging the pathophysio-logical relevance of ATM-mediated phosphorylation in the disease setting.
基金National Natural Science Foundation of China(NO.61533008,61603181,61673208,61873125).
文摘Multipath interference seriously degrades the performance of Global Navigation Satellite System(GNSS)positioning in an urban canyon.Most current multipath mitigation algorithms suffer from heavy computational load or need external assistance.We propose a multipath mitigation algorithm based on the steepest descent approach,which has the merits of less computational load and no need for external aid.A new ranging code tracking loop is designed based on the steepest descent method,which can save an early branch or a late branch compared with the narrow-spacing correlation method.The power of the Non-Line-of-Sight(NLOS)signal is weaker than that of the Line-of-Sight(LOS)signal when the LOS signal is not obstructed and with a relatively high Carrier Noise Ratio(CNR).The peak position in the X-axis of the ranging code autocorrelation function does not move with the NLOS interference.Meanwhile,the cost function is designed according to this phenomenon.The results demonstrate that the proposed algorithm outperforms the narrow-spacing correlation and the Multipath Estimated Delay Locked Loop(MEDLL)in terms of the code multipath mitigation and computation time.The Standard Deviation(STD)of the tracking error with the proposed algorithm is less than 0.016 chips.Moreover,the computation time of the proposed algorithm in a software defined receiver is shortened by 24.21%compared with the narrow-spacing correlation.
