This paper presents an energy-efficient control strategy for electric vehicles(EVs)driven by in-wheel-motors(IWMs)based on discrete adaptive sliding mode control(DASMC).The nonlinear vehicle model,tire model and IWM m...This paper presents an energy-efficient control strategy for electric vehicles(EVs)driven by in-wheel-motors(IWMs)based on discrete adaptive sliding mode control(DASMC).The nonlinear vehicle model,tire model and IWM model are established at first to represent the operation mechanism of the whole system.Based on the modeling,two virtual control variables are used to represent the longitudinal and yaw control efforts to coordinate the vehicle motion control.Then DASMC method is applied to calculate the required total driving torque and yaw moment,which can improve the tracking performance as well as the system robustness.According to the vehicle nonlinear model,the additional yaw moment can be expressed as a function of longitudinal and lateral tire forces.For further control scheme development,a tire force estimator using an unscented Kalman filter is designed to estimate real-time tire forces.On these bases,energy efficient torque allocation method is developed to distribute the total driving torque and differential torque to each IWM,considering the motor energy consumption,the tire slip energy consumption,and the brake energy~?recovery.Simulation results of the proposed control strategy using the co-platform of Matlab/Simulink and CarSim way.展开更多
Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst ...Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst of Ir/MoS_(2) nanoflowers(Ir/MoS_(2) NFs) catalyst was reported for acidic water electrolysis which can be constructed by coupling three-dimensionally interconnected MoS_(2) NFs with ultrafine Ir nanoparticles.A more suitable adsorption ability for the H* and *OOH intermediates was revealed,where the Ir sites were proposed as the main active center and MoS_(2) promoted the charge relocation to electronically modify the interfacial structure.The significant interfacial charge redistribution between the MoS_(2) NFs and the Ir active sites synergistically induced excellent catalytic activity and stability for the water electrolysis reaction.Specifically,the catalyst required overpotentials of 270 and 35 mV to reach a kinetic current density of 10 mA cm^(-2)for OER and HER,respectively,loading on the glass carbon electrode,with high catalytic kinetics,stability,and catalytic efficiency.A two-electrode system constructed by Ir/MoS_(2) NFs drove 10 mA cm^(-2)at a cell voltage of 1.55 V,about 70 mV lower than that of the commercial Pt/C||IrO_(2) system.In addition,partial surface oxidation of Ir nanoparticles to generate high-valent Ir species was also found significant to accelerate OER.The enhanced catalytic performance was attributed to the strong metal-support interaction in the Ir/MoS_(2) NFs catalyst system that changed the electronic structure of Ir metal and promoted the synergistic catalytic effect between Ir and MoS_(2) NFs.The work presented a novel platform of Ir-catalyst for proton exchange membrane water electrolysis.展开更多
Buyang Huanwu Decoction fraction extracted from Buyang Huanwu Decoction contains saponins of Astragalus, total paeony glycoside and safflower flavones. The aim of this study was to demonstrate the neuroprotective effe...Buyang Huanwu Decoction fraction extracted from Buyang Huanwu Decoction contains saponins of Astragalus, total paeony glycoside and safflower flavones. The aim of this study was to demonstrate the neuroprotective effect and mechanism of Buyang Huanwu Decoction fraction on ischemic injury both in vivo and in vitro. In vivo experiments showed that 50-200 mg/kg Buyang Huanwu Decoction fraction reduced infarct volume and pathological injury in ischemia/reperfusion rats, markedly inhibited expression of nuclear factor-κB and tumor necrosis factor-α and promoted nestin protein expression in brain tissue. Buyang Huanwu Decoction fraction (200 mg/kg) exhibited significant effects, which were similar to those of 100 mg/kg Ginkgo biloba extract. In vitro experimental results demonstrated that 10-100 mg/L Buyang Huanwu Decoction fraction significantly improved cell viability, decreased the release of lactate dehydrogenase and malondialdehyde levels, and inhibited the rate of apoptosis in HT22 cells following oxygen-glucose deprivation. Buyang Huanwu Decoction fraction (100 mg/L) exhibited significant effects, which were similar to those of 100 mg/L Ginkgo biloba extract. These findings suggest that Buyang Huanwu Decoction fraction may represent a novel, protective strategy against cerebral ischemia/reperfusion injury in rats and oxygen-glucose deprivation-induced damage in HT22 cells in vitro by attenuating the inflammatory response and cellular apoptosis.展开更多
Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investig...Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study.展开更多
Although organellar genomes(including chloroplast and mitochondrial genomes)are smaller than nuclear genomes in size and gene number,organellar genomes are very important for the investigation of plant evolution and m...Although organellar genomes(including chloroplast and mitochondrial genomes)are smaller than nuclear genomes in size and gene number,organellar genomes are very important for the investigation of plant evolution and molecular ecology mechanisms.Few studies have focused on the organellar genomes of horticultural plants.Approximately 1193 chloroplast genomes and 199 mitochondrial genomes of land plants are available in the National Center for Biotechnology Information(NCBI),of which only 39 are from horticultural plants.In this paper,we report an innovative and efficient method for high-quality horticultural organellar genome assembly from next-generation sequencing(NGS)data.Sequencing reads were first assembled by Newbler,Amos,and Minimus software with default parameters.The remaining gaps were then filled through BLASTN search and PCR.The complete DNA sequence was corrected based on Illumina sequencing data using BWA(Burrows–Wheeler Alignment tool)software.The advantage of this approach is that there is no need to isolate organellar DNA from total DNA during sample preparation.Using this procedure,the complete mitochondrial and chloroplast genomes of an ornamental plant,Salix suchowensis,and a fruit tree,Ziziphus jujuba,were identified.This study shows that horticultural plants have similar mitochondrial and chloroplast sequence organization to other seed plants.Most horticultural plants demonstrate a slight bias toward A+T rich features in the mitochondrial genome.In addition,a phylogenetic analysis of 39 horticultural plants based on 15 protein-coding genes showed that some mitochondrial genes are horizontally transferred from chloroplast DNA.Our study will provide an important reference for organellar genome assembly in other horticultural plants.Furthermore,phylogenetic analysis of the organellar genomes of horticultural plants could accurately clarify the unanticipated relationships among these plants.展开更多
The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellin...The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellinus sp. 150802#, which were collected in Foshan city, Guangdong province, were investigated preliminarily by pre-test tube method and by comparison with the known natural compounds from Phellinus pini, and their antioxidant activities were evaluated by the biochemical assay of hydroxyl and 2,2-diphenyl-1-pricylhydrazyl (DPPH) radicals scavenging activity in vitro. The results show that both the two Phellinus mushrooms contain phenolics, alkaloids, lactones, steroids and terpenoids, and have potent antioxidant activities. The IC50 values of DPPH radicals and hydroxyl radicals for Phellinus pini 141016# were 74.37 μg/mL and 59.69 μg/mL, respectively, and the IC50 values of DPPH radicals and hydroxyl radicals for Phellinus sp. 150802# were 98.95 μg/mL and 165.47 μg/mL, respectively. They are comparable to the antioxidant activity of the standard antioxidant ascorbic acid.展开更多
The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses...The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses under test are millions of kilometers apart. The inter-spacecraft laser interferometry telescope deliver laser efficiently from one spacecraft to another. It is an important component of the gravitational wave detection observatory. It needs to meet the requirements of large compression ratio, high image quality and extraordinary stray light suppression ability. Based on the primary aberration theory, the method of the large compression ratio off-axis four-mirror optical system design is explored. After optimization, the system has an entrance pupil of 200 mm, compression ratio of 40 times, scientific field of view (FOV) of ±8 μrad. To facilitate suppressing the stray light and delivering the laser beam to the back-end scientific interferometers, the intermediate images and the real exit pupils are spatially available. Over the full FOV, the maximum root mean square (RMS) wavefront error is less than 0.007λ, PV value is less than 0.03λ (λ = 1064 nm). The image quality is approached to the diffraction-limit. The TTL noise caused by the wavefront error of the telescope is analyzed. The TTL noise in the image space of 300 μrad range is less than 1 × 10-10 m whose slope is lower than 0.6 μm/rad, which is under the noise budget of the laser interferometer space antenna (LISA), satisfying the requirements of space gravitational wave detection.展开更多
Thermal expansion control is always an obstructive factor and challenging in high precision engineering field.Here,the negative thermal expansion of NbF_(3)and NbOF_(2)was predicted by first-principles calculation wit...Thermal expansion control is always an obstructive factor and challenging in high precision engineering field.Here,the negative thermal expansion of NbF_(3)and NbOF_(2)was predicted by first-principles calculation with density functional theory and the quasi-harmonic approximation(QHA).We studied the total charge density,thermal vibration,and lattice dynamic to investigate the thermal expansion mechanism.We found that the presence of O induced the relatively strong covalent bond in NbOF_(2),thus weakening the transverse vibration of F and O in NbOF_(2),compared with the case of NbF_(3).In this study,we proposed a way to tailor negative thermal expansion of metal fluorides by introducing the oxygen atoms.The present work not only predicts two NTE compounds,but also provides an insight on thermal expansion control by designing chemical bond type.展开更多
To explore the structure-activity connections of amphiphilic permeation enhancers containing the length of the hydrophobic chains as well as the properties of the polar head,O-acylgeraniol and O-acylnerol derivatives ...To explore the structure-activity connections of amphiphilic permeation enhancers containing the length of the hydrophobic chains as well as the properties of the polar head,O-acylgeraniol and O-acylnerol derivatives were synthesized from geraniol/nerol(cis-isomer of geraniol) and pharmaceutical excipient acids in this research. Their promotion of the percutaneous absorption of three drugs as the model, flurbiprofen(FP), isosorbide dinitrate(ISDN) and donepezil(DNP), which were selected based on their physicochemical properties,was tested by in vitro skin penetration and in vivo. Molecular simulation, ATR-FTIR, CLSM and histological observation were implement to evaluate the mode of action of the enhancers.The results indicated that(E)-3,7-dimethyl-2,6-octadien-1-yl tetradecanoate(GER-C14, trans-)achieved the highest enhancement ability for the three drugs;additionally, the in vivo results obtained were in good correlation with the in vitro data. Molecular docking results suggested that enhancers loosen the hydrogen bonds between ceramides, and the results of molecular simulation indicated that GER-C14, NER-C14 could insert into the middle of the lipid bilayer to form an independent phase. According to ATR-FTIR and histological evaluation, the enhancers extracted lipids and influenced the protein region, thereby disturbing the skin array. In addition, CLSM described the dynamic effects of enhancers on lipids between stratum corneum(SC) cells. In conclusion, GER-C14 had a better penetration promotion effect, which broadened our understanding of stereoisomeric penetration enhancers.展开更多
The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materia...The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materials,although rare,are fundamental for this purpose.This work focuses on studying tetracyanidoborate salt CuB(CN)_(4),an interesting cubicstructure material that displays large isotropic NTE.A joint study of synchrotron x-ray diffraction,temperature-dependent Raman spectroscopy,and lattice dynamics calculations was conducted,showing that not only low-frequency optical modes(transverse thermal vibrations of N and C atoms)but also the acoustic modes(the vibrations of Cu atoms as a collective torsion of the neighboring atoms),contribute to NTE.As a result,new insights were gained into the NTE mechanism of CuB(CN)_(4) and related framework materials.展开更多
By the complete discrimination system for polynomials, we classify exact traveling wave solutions to the Zhiber-Shabat equation, and compute some new traveling wave solutions.
In order to explore the main progress and current status of domestic research on smart learning environment, this paper takes 260 core and CSSCI journal papers included in the CNKI database as the research objects, an...In order to explore the main progress and current status of domestic research on smart learning environment, this paper takes 260 core and CSSCI journal papers included in the CNKI database as the research objects, and uses CiteSpace visual analysis software and uses bibliometrics and knowledge graph analysis as the main research methods, summarizes and analyzes the time distribution of the literature, the distribution of institutions and authors, co-occurrence and clustering of keywords, and research hotspots,etc.展开更多
The discipline of lipidomics, as coined in 2003, has made profound advances and been rapidly expanded. Direct infusion-based shotgun lipidomics contributes a major part of the research in this discipline. However, des...The discipline of lipidomics, as coined in 2003, has made profound advances and been rapidly expanded. Direct infusion-based shotgun lipidomics contributes a major part of the research in this discipline. However, despite of its numerous advantages over other lipidomics platforms, the classical shotgun lipidomics approach suffers ion suppression and has the difficulties to assess low abundance lipid classes, particularly those less ionizable or that do not yield sensitive and specific fragments. To overcome this obstacle and broaden coverage, strategies have been developed based on unique chemistry and/or physics of lipid classes of interest to enhance shotgun lipidomics. This article overviews the recent enhancements of shotgun lipidomics, including prefractionation, acid/base hydrolysis, derivatization, charge feature utilization. We believe that, by this versatile platform, comprehensive coverage of cellular lipidomes would be achieved in more accurate and effective manner. Therefore, application of the enhanced shotgun lipidomics would greatly accelerate lipidomics research to substantiate the aberrant lipid metabolism, signaling, trafficking, and homeostasis under pathological conditions and their underpinning biochemical mechanisms. It would also facilitate precision medicine studies.展开更多
Phytohormone abscisic acid(ABA)plays vital roles in stress tolerance,while long-term overactivation of ABA signaling suppresses plant growth and development.However,the braking mechanism of ABA responses is not clear....Phytohormone abscisic acid(ABA)plays vital roles in stress tolerance,while long-term overactivation of ABA signaling suppresses plant growth and development.However,the braking mechanism of ABA responses is not clear.Protein tyrosine sulfation catalyzed by tyrosylprotein sulfotransferase(TPST)is a critical post-translational modification.Through genetic screening,we identified a tpst mutant in Arabidopsis that was hypersensitive to ABA.In-depth analysis revealed that TPST could interact with and sulfate SnRK2.2/2.3/2.6,which accelerated their degradation and weakened the ABA signaling.Taken together,these findings uncovered a novel mechanism of desensitizing ABA responses via protein sulfation.展开更多
基金Supported by Jiangsu Provincial Key R&D Plan (Grant No.BE2022053)Youth Fund of Jiangsu Provincial Natural Science Foundation (Grant No.BK20200423)National Natural Science Foundation of China (Grant No.5210120245)。
文摘This paper presents an energy-efficient control strategy for electric vehicles(EVs)driven by in-wheel-motors(IWMs)based on discrete adaptive sliding mode control(DASMC).The nonlinear vehicle model,tire model and IWM model are established at first to represent the operation mechanism of the whole system.Based on the modeling,two virtual control variables are used to represent the longitudinal and yaw control efforts to coordinate the vehicle motion control.Then DASMC method is applied to calculate the required total driving torque and yaw moment,which can improve the tracking performance as well as the system robustness.According to the vehicle nonlinear model,the additional yaw moment can be expressed as a function of longitudinal and lateral tire forces.For further control scheme development,a tire force estimator using an unscented Kalman filter is designed to estimate real-time tire forces.On these bases,energy efficient torque allocation method is developed to distribute the total driving torque and differential torque to each IWM,considering the motor energy consumption,the tire slip energy consumption,and the brake energy~?recovery.Simulation results of the proposed control strategy using the co-platform of Matlab/Simulink and CarSim way.
基金supported by the National Natural Science Foundation of China (21972124, 22272148)the Priority Academic Program Development of Jiangsu Higher Education Institution。
文摘Bi-functional electrocatalysts for acid overall water splitting reactions are crucial but still challenging to the development of proton exchange membrane water electrolysis.Herein,an efficient bi-functional catalyst of Ir/MoS_(2) nanoflowers(Ir/MoS_(2) NFs) catalyst was reported for acidic water electrolysis which can be constructed by coupling three-dimensionally interconnected MoS_(2) NFs with ultrafine Ir nanoparticles.A more suitable adsorption ability for the H* and *OOH intermediates was revealed,where the Ir sites were proposed as the main active center and MoS_(2) promoted the charge relocation to electronically modify the interfacial structure.The significant interfacial charge redistribution between the MoS_(2) NFs and the Ir active sites synergistically induced excellent catalytic activity and stability for the water electrolysis reaction.Specifically,the catalyst required overpotentials of 270 and 35 mV to reach a kinetic current density of 10 mA cm^(-2)for OER and HER,respectively,loading on the glass carbon electrode,with high catalytic kinetics,stability,and catalytic efficiency.A two-electrode system constructed by Ir/MoS_(2) NFs drove 10 mA cm^(-2)at a cell voltage of 1.55 V,about 70 mV lower than that of the commercial Pt/C||IrO_(2) system.In addition,partial surface oxidation of Ir nanoparticles to generate high-valent Ir species was also found significant to accelerate OER.The enhanced catalytic performance was attributed to the strong metal-support interaction in the Ir/MoS_(2) NFs catalyst system that changed the electronic structure of Ir metal and promoted the synergistic catalytic effect between Ir and MoS_(2) NFs.The work presented a novel platform of Ir-catalyst for proton exchange membrane water electrolysis.
基金supported by a grant from the Major Programs of Anhui Science and Technology Special Funds,No.08010302099the Doctor Funds of Anhui Medical University,No.XJ200813
文摘Buyang Huanwu Decoction fraction extracted from Buyang Huanwu Decoction contains saponins of Astragalus, total paeony glycoside and safflower flavones. The aim of this study was to demonstrate the neuroprotective effect and mechanism of Buyang Huanwu Decoction fraction on ischemic injury both in vivo and in vitro. In vivo experiments showed that 50-200 mg/kg Buyang Huanwu Decoction fraction reduced infarct volume and pathological injury in ischemia/reperfusion rats, markedly inhibited expression of nuclear factor-κB and tumor necrosis factor-α and promoted nestin protein expression in brain tissue. Buyang Huanwu Decoction fraction (200 mg/kg) exhibited significant effects, which were similar to those of 100 mg/kg Ginkgo biloba extract. In vitro experimental results demonstrated that 10-100 mg/L Buyang Huanwu Decoction fraction significantly improved cell viability, decreased the release of lactate dehydrogenase and malondialdehyde levels, and inhibited the rate of apoptosis in HT22 cells following oxygen-glucose deprivation. Buyang Huanwu Decoction fraction (100 mg/L) exhibited significant effects, which were similar to those of 100 mg/L Ginkgo biloba extract. These findings suggest that Buyang Huanwu Decoction fraction may represent a novel, protective strategy against cerebral ischemia/reperfusion injury in rats and oxygen-glucose deprivation-induced damage in HT22 cells in vitro by attenuating the inflammatory response and cellular apoptosis.
基金supported by the National Key Research and Development Plan of China(2016YFD0600101)the Fundamental Research Funds for the Central Non-Profit Research Institution of CAF(CAFYBB2014QB015)+3 种基金the National Natural Science Foundation of China(31570662,31500533,and 61401214)Jiangsu Provincial Department of Housing and Urban–Rural Development(2016ZD44)2017 Graduate Research and Innovation Program Projects in Jiangsu Province(KYCY17_0827)the PAPD(Priority Academic Program Development)program at Nanjing Forestry University
文摘Members of the WUSCHEL-related homeobox(WOX)transcription factor family are essential for determining cell fate and regulating diverse developmental processes in plants.Many WOX genes have been systematically investigated in woody plants such as Populus trichocarpa,but not in Salix suchowensis.Whole-genome sequence data for S.suchowensis is now available for comprehensive study of WOX genes in S.suchowensis.We thus surveyed the genome of S.suchowensis and demonstrated active expression of 15 WOX genes.In a phylogenetic analysis of WOX genes,the 15 SsWOX genes clustered among the modern/WUS,intermediate and ancient clades similar to the WOX genes of Arabidopsis thaliana.Based on the conserved intron/exon structure,SsWOX genes in the same subgroup had similar conserved exon–intron structures and motif domains.Furthermore,among several SsWOX subgroups,WUS(Wuschel)-box and EAR(the ERF-associated amphiphilic repression)-like motifs were conserved.Expression profiles of WOX genes in roots,stems and leaves indicate that SsWOX genes have various conserved roles in the tissues.Comparative analysis of the expression patterns in Salix suchowensis with that of Arabidopsis suggests that different shoot regeneration abilities are controlled by different WOX genes in plants.The analysis provide an overview of differentially expressed SsWOX genes during shoot regeneration,but also contribute to understanding the evolution of WOX genes in Salicaceae and the interrelations of WOX genes and other transcription factors,providing targets for further study.
基金This study was supported by the National Key Research and Development Plan of China(2016YFD0600101)2017 Graduate Research and Innovation Program Projects in Jiangsu Province(KYCY17_0827)+3 种基金the Fundamental Research Funds for the Central Non-Profit Research Institution of CAF(CAFYBB2014QB015)the National Natural Science Foundation of China(31570662,31500533,and 61401214)the Jiangsu Provincial Department of Housing and Urban-Rural Development(2016ZD44)the PAPD(Priority Academic Program Development)program at Nanjing Forestry University.
文摘Although organellar genomes(including chloroplast and mitochondrial genomes)are smaller than nuclear genomes in size and gene number,organellar genomes are very important for the investigation of plant evolution and molecular ecology mechanisms.Few studies have focused on the organellar genomes of horticultural plants.Approximately 1193 chloroplast genomes and 199 mitochondrial genomes of land plants are available in the National Center for Biotechnology Information(NCBI),of which only 39 are from horticultural plants.In this paper,we report an innovative and efficient method for high-quality horticultural organellar genome assembly from next-generation sequencing(NGS)data.Sequencing reads were first assembled by Newbler,Amos,and Minimus software with default parameters.The remaining gaps were then filled through BLASTN search and PCR.The complete DNA sequence was corrected based on Illumina sequencing data using BWA(Burrows–Wheeler Alignment tool)software.The advantage of this approach is that there is no need to isolate organellar DNA from total DNA during sample preparation.Using this procedure,the complete mitochondrial and chloroplast genomes of an ornamental plant,Salix suchowensis,and a fruit tree,Ziziphus jujuba,were identified.This study shows that horticultural plants have similar mitochondrial and chloroplast sequence organization to other seed plants.Most horticultural plants demonstrate a slight bias toward A+T rich features in the mitochondrial genome.In addition,a phylogenetic analysis of 39 horticultural plants based on 15 protein-coding genes showed that some mitochondrial genes are horizontally transferred from chloroplast DNA.Our study will provide an important reference for organellar genome assembly in other horticultural plants.Furthermore,phylogenetic analysis of the organellar genomes of horticultural plants could accurately clarify the unanticipated relationships among these plants.
文摘The Phellinus mushrooms have been known for its immunomodulatory, hypolipidemic, and anticancer activities. In the current work, the chemical constituents of two Phellinus mushrooms, Phellinus pini 141016# and Phellinus sp. 150802#, which were collected in Foshan city, Guangdong province, were investigated preliminarily by pre-test tube method and by comparison with the known natural compounds from Phellinus pini, and their antioxidant activities were evaluated by the biochemical assay of hydroxyl and 2,2-diphenyl-1-pricylhydrazyl (DPPH) radicals scavenging activity in vitro. The results show that both the two Phellinus mushrooms contain phenolics, alkaloids, lactones, steroids and terpenoids, and have potent antioxidant activities. The IC50 values of DPPH radicals and hydroxyl radicals for Phellinus pini 141016# were 74.37 μg/mL and 59.69 μg/mL, respectively, and the IC50 values of DPPH radicals and hydroxyl radicals for Phellinus sp. 150802# were 98.95 μg/mL and 165.47 μg/mL, respectively. They are comparable to the antioxidant activity of the standard antioxidant ascorbic acid.
文摘The fundamental measurement of space gravitational wave detection is to monitor the relative motion between pairs of freely falling test masses using heterodyne laser interferometry to a precision of 10 pm. The masses under test are millions of kilometers apart. The inter-spacecraft laser interferometry telescope deliver laser efficiently from one spacecraft to another. It is an important component of the gravitational wave detection observatory. It needs to meet the requirements of large compression ratio, high image quality and extraordinary stray light suppression ability. Based on the primary aberration theory, the method of the large compression ratio off-axis four-mirror optical system design is explored. After optimization, the system has an entrance pupil of 200 mm, compression ratio of 40 times, scientific field of view (FOV) of ±8 μrad. To facilitate suppressing the stray light and delivering the laser beam to the back-end scientific interferometers, the intermediate images and the real exit pupils are spatially available. Over the full FOV, the maximum root mean square (RMS) wavefront error is less than 0.007λ, PV value is less than 0.03λ (λ = 1064 nm). The image quality is approached to the diffraction-limit. The TTL noise caused by the wavefront error of the telescope is analyzed. The TTL noise in the image space of 300 μrad range is less than 1 × 10-10 m whose slope is lower than 0.6 μm/rad, which is under the noise budget of the laser interferometer space antenna (LISA), satisfying the requirements of space gravitational wave detection.
基金the National Natural Science Foundation of China(Grant Nos.11774078 and 21905252)China Postdoctoral Science Foundation(Grant No.2019M652558)Innovation Scientists and Technicians Troop Construction Projects of Henan Province,China(Grant No.10094100510025).
文摘Thermal expansion control is always an obstructive factor and challenging in high precision engineering field.Here,the negative thermal expansion of NbF_(3)and NbOF_(2)was predicted by first-principles calculation with density functional theory and the quasi-harmonic approximation(QHA).We studied the total charge density,thermal vibration,and lattice dynamic to investigate the thermal expansion mechanism.We found that the presence of O induced the relatively strong covalent bond in NbOF_(2),thus weakening the transverse vibration of F and O in NbOF_(2),compared with the case of NbF_(3).In this study,we proposed a way to tailor negative thermal expansion of metal fluorides by introducing the oxygen atoms.The present work not only predicts two NTE compounds,but also provides an insight on thermal expansion control by designing chemical bond type.
基金The Natural Science Foundation of Hebei Province [grant numbers H2019209254]North China University of Science and Technology Foundation for Distinguished Young Scholars[grant numbers JQ201713]Distinguished Young Scholars of Hebei Province。
文摘To explore the structure-activity connections of amphiphilic permeation enhancers containing the length of the hydrophobic chains as well as the properties of the polar head,O-acylgeraniol and O-acylnerol derivatives were synthesized from geraniol/nerol(cis-isomer of geraniol) and pharmaceutical excipient acids in this research. Their promotion of the percutaneous absorption of three drugs as the model, flurbiprofen(FP), isosorbide dinitrate(ISDN) and donepezil(DNP), which were selected based on their physicochemical properties,was tested by in vitro skin penetration and in vivo. Molecular simulation, ATR-FTIR, CLSM and histological observation were implement to evaluate the mode of action of the enhancers.The results indicated that(E)-3,7-dimethyl-2,6-octadien-1-yl tetradecanoate(GER-C14, trans-)achieved the highest enhancement ability for the three drugs;additionally, the in vivo results obtained were in good correlation with the in vitro data. Molecular docking results suggested that enhancers loosen the hydrogen bonds between ceramides, and the results of molecular simulation indicated that GER-C14, NER-C14 could insert into the middle of the lipid bilayer to form an independent phase. According to ATR-FTIR and histological evaluation, the enhancers extracted lipids and influenced the protein region, thereby disturbing the skin array. In addition, CLSM described the dynamic effects of enhancers on lipids between stratum corneum(SC) cells. In conclusion, GER-C14 had a better penetration promotion effect, which broadened our understanding of stereoisomeric penetration enhancers.
基金supported by the National Natural Science Foundation of China (Grant Nos. 22071221, 21905252, and 11774078)Natural Science Foundation of Henan Province, China (Grant No. 212300410086)+1 种基金Innovation Scientists and Technicians Troop Construction Projects of Henan Province, China (No. 10094100510025)supported by National Supercomputing Center in Zhengzhou
文摘The control of thermal expansion is essential in applications where thermal stability is required from fiber optics coatings,high performance fuel cell cathodes to tooth fillings.Negative thermal expansion(NTE)materials,although rare,are fundamental for this purpose.This work focuses on studying tetracyanidoborate salt CuB(CN)_(4),an interesting cubicstructure material that displays large isotropic NTE.A joint study of synchrotron x-ray diffraction,temperature-dependent Raman spectroscopy,and lattice dynamics calculations was conducted,showing that not only low-frequency optical modes(transverse thermal vibrations of N and C atoms)but also the acoustic modes(the vibrations of Cu atoms as a collective torsion of the neighboring atoms),contribute to NTE.As a result,new insights were gained into the NTE mechanism of CuB(CN)_(4) and related framework materials.
文摘By the complete discrimination system for polynomials, we classify exact traveling wave solutions to the Zhiber-Shabat equation, and compute some new traveling wave solutions.
文摘In order to explore the main progress and current status of domestic research on smart learning environment, this paper takes 260 core and CSSCI journal papers included in the CNKI database as the research objects, and uses CiteSpace visual analysis software and uses bibliometrics and knowledge graph analysis as the main research methods, summarizes and analyzes the time distribution of the literature, the distribution of institutions and authors, co-occurrence and clustering of keywords, and research hotspots,etc.
文摘The discipline of lipidomics, as coined in 2003, has made profound advances and been rapidly expanded. Direct infusion-based shotgun lipidomics contributes a major part of the research in this discipline. However, despite of its numerous advantages over other lipidomics platforms, the classical shotgun lipidomics approach suffers ion suppression and has the difficulties to assess low abundance lipid classes, particularly those less ionizable or that do not yield sensitive and specific fragments. To overcome this obstacle and broaden coverage, strategies have been developed based on unique chemistry and/or physics of lipid classes of interest to enhance shotgun lipidomics. This article overviews the recent enhancements of shotgun lipidomics, including prefractionation, acid/base hydrolysis, derivatization, charge feature utilization. We believe that, by this versatile platform, comprehensive coverage of cellular lipidomes would be achieved in more accurate and effective manner. Therefore, application of the enhanced shotgun lipidomics would greatly accelerate lipidomics research to substantiate the aberrant lipid metabolism, signaling, trafficking, and homeostasis under pathological conditions and their underpinning biochemical mechanisms. It would also facilitate precision medicine studies.
基金supported by the National Key R&D Program of China(2022YFA1503003)the National Natural Science Foundation of China(U20A20250,21801069 and 91961111)+2 种基金the Natural Science Foundation of Heilongjiang Province(YQ2021B008)the Basic Research Fund of Heilongjiang University in Heilongjiang Province(2022-KYYWF-1036 and 2021-KYYWF-0039)Heilongjiang University Excellent Youth Foundation.
基金supported by the National Natural Science Foundation of China(31771878 and 32071931)。
文摘Phytohormone abscisic acid(ABA)plays vital roles in stress tolerance,while long-term overactivation of ABA signaling suppresses plant growth and development.However,the braking mechanism of ABA responses is not clear.Protein tyrosine sulfation catalyzed by tyrosylprotein sulfotransferase(TPST)is a critical post-translational modification.Through genetic screening,we identified a tpst mutant in Arabidopsis that was hypersensitive to ABA.In-depth analysis revealed that TPST could interact with and sulfate SnRK2.2/2.3/2.6,which accelerated their degradation and weakened the ABA signaling.Taken together,these findings uncovered a novel mechanism of desensitizing ABA responses via protein sulfation.
