Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidi...Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate(AP)in solid propellants,but also a good performance explosive in itself.However,due to the strong hygroscopicity of ADN,its application in solid propellants and explosives is greatly limited.Solving the hygroscopicity of ADN is the key to realize the wide application of ADN.In this paper,we systematically review the research progress of anti-hygroscopic strategies of ADN coating.The surface coating methods are focusing on solvent volatilization,solvent-non-solvent,melt crystallization and atomic layer deposition technology.The characteristics of the different methods are compared and analyzed,and the basis for the classification and selection of the coating materials are introduced in detail.In addition,the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods.It is highly expected that the liquid phase method(solvent volatilization method,solvent-non-solvent method)would be the promising method for future ADN coating because of its effective,safety and facile operation.Furthermore,polymer materials,are the preferred coating materials due to their high viscosity,easy adhesion,good anti-hygroscopic effect,and heat resistance,which make ADN weak hygroscopicity,less sensitive,easier to preserve and good compatibility.展开更多
The number of people with eye diseases has increased with the use of electronics.However,the bioavailability of eye drops remains low owing to the presence of the ocular barrier and other reasons.Although many drug de...The number of people with eye diseases has increased with the use of electronics.However,the bioavailability of eye drops remains low owing to the presence of the ocular barrier and other reasons.Although many drug delivery systems have been developed to overcome these problems,they have certain limitations.In recent years,the development of contact lenses that can deliver drugs for long periods with high bioavailability and without affecting vision has increased the interest in using contact lenses for drug delivery.Hence,a review of the current state of research on drug delivery contact lenses has become crucial.This article reviews the key physical and chemical properties of drug-laden contact lenses,development and classification of contact lenses,and features of the commonly used materials.A review of the methods commonly used in current research to create contact lenses has also been presented.An overview on how drug-laden contact lenses can overcome the problems of high burst and short release duration has been discussed.Overall,the review focuses on drug delivery methods using smart contact lenses,and predicts the future direction of research on contact lenses.展开更多
Oral squamous cell carcinoma(OSCC)is a malignant tumor triggered by the accumulation of multiple gene mutations in oral epithelial cells.Different OSCC-related biomarkers have been reported in circulation in the perip...Oral squamous cell carcinoma(OSCC)is a malignant tumor triggered by the accumulation of multiple gene mutations in oral epithelial cells.Different OSCC-related biomarkers have been reported in circulation in the peripheral blood that support the occurrence and development of OSCC.Recent advances in high-throughput and highly sensitive detection methods have overcome the limitation of the low concentration of most peripheral blood biomarkers.Hence,blood biomarker detection has become an efficient screening tool for the early diagnosis of OSCC.The growing data available in public cancer and gene databases have provided new foundations for OSCC research.In particular,the identification of OSCC biomarkers using bioinformatic tools has shed new light on the underlying mechanisms as well as on the genetic landscape of OSCC.More recently,mRNA targeting therapies have emerged as valuable anticancer treatment strategies,as they allow for the regulation of the expression of certain functional proteins to reverse genetic abnormalities or induce tissue repair.Thus,mRNA-targeting therapies can be used to regulate the expression of antigens,antibodies,or cellular receptors by immune cells.Particularly,anti-cancer cellular immunotherapy carrying specific mRNAs has attracted significant attention in OSCC treatment.Here,we review the present knowledge on the role of peripheral blood mRNAs in the diagnosis,treatment,development,and prognosis of OSCC.Moreover,we address future research prospects of mRNAs in the peripheral blood in OSCC and the opportunities and challenges that may arise in future clinical therapeutic applications.展开更多
Objective:To construct the recombinant adenovirus vector carrying rat vascular endothelial growth factor(VEGF),as preparation for genetic transfection that follows.Methods:Rat VEGF was obtained by using RT-PCR amplifi...Objective:To construct the recombinant adenovirus vector carrying rat vascular endothelial growth factor(VEGF),as preparation for genetic transfection that follows.Methods:Rat VEGF was obtained by using RT-PCR amplification and then cloned into the shutter plasmid pDC316.Subsequently,this newly constructed plasmid pDC316-VEGF,after identification by nuclease digestion analysis and sequencing analysis,was transfected into human embryonic kidney cells HEK293 by Lipofectamine 2000 mediation,together with adenovirus-packaging plasmid pBHGE3.Based on the homologous recombination of the two plasmids within HEK293 cells,the recombinant adenovirus vector carrying VEGF and VDC316-VEGF was created.VDC316-VEGF was subsequently identified using PCR,purified using repeated plaque passages,proliferated using freezing and melting within HEK293 cells,and titrated using 50% Tissue Culture Infective Dose(TCID50)assay.Results:The newly constructed recombinant adenovirus was confirmed to carry rat VEGF based on PCR results,and its titration value determined based on TCID50 assay was 3 × 109 pfu/ml.Conclusion:The recombinant adenovirus carrying rat VEGF was successfully constructed.The newly constructed adenovirus can produce a sufficiently high titration value within HEK293 cells,providing a reliable tool for genetic transfection in further gene therapy researches.展开更多
Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botry...Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botrytis cinerea infection development. Additionally, in this study the dosage levels of SNP applied to the leaves had no direct, toxic impact on the development of the pathogen. The relationship between NO and reactive oxidant species (ROS) was studied by using both spectrophotometrical methods and staining leaf material with fluorescent dyes, nitro blue tetrazolium (NBT), and with 3,3-diaminobenzidine (DAB). The results showed that exogenous NO restrained the generation of ROS, especially H2O2, as the pathogen interacted with the Arabidopsis plant. And this inhibition of reactive oxidant burst coincided with delay infection development in NO-supplied leaves. The influence of elevated level of NO on antioxidant enzymes was investigated in this study. The activities of catalase (CAT) and guaiacol peroxidase (POD) were increased to different degrees in both: 1) SNP treated only leaves, and 2) SNP pretreated leaves that were subsequently inoculateted with pathogens. However, the activity of superoxide dismutase (SOD) was unchanged in the leaves studied. The decrease in H2O2 content probably resulted from the increase in activities of POD and CAT. Our study suggests that NO might trigger some metabolic reactions, i.e. enhanced enzyme activity that restrains H2O2 which ultimately results in resistance to B. cinerea infection.展开更多
This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an a...This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.展开更多
As a house keeping protein with stable expressions, β-actin is used as a loading control in normalization of western blotting. However, the actual numbers of β-actins at the single-cell level remain elusive. Based o...As a house keeping protein with stable expressions, β-actin is used as a loading control in normalization of western blotting. However, the actual numbers of β-actins at the single-cell level remain elusive. Based on a homedeveloped flow cytometry, single-cell numbers of β-actin from 8 cell types(subtypes) and 2 tumour patient samples were quantified as 9.62 ± 4.29 × 105(A549, Ncell= 14,242), 6.46 ± 3.34 × 105(Hep G2, Ncell= 35,932),1.58 ± 0.90 × 106(MCF 10 A, N6 cell= 16,650), 1.08 ± 0.48 × 10(HeLa, Ncell= 26,151), 7.60 ± 4.34 × 105(PC3, Ncell= 11,922), 1.10 ± 0.72 × 106(SACC-83, Ncell= 13,616), 8.58 ± 4.54 × 105(CAL 27, Ncell= 7271),9.00 ± 4.69 × 105(CAL 27-LN2, Ncell= 6222), 8.26 ± 4.48 × 105(Oral Tumour Patient I, Ncell= 359), and8.19 ± 5.12 × 105(Oral Tumour Patient II, Ncell= 175), and were analyzed by statistical approaches including one-way analysis of variance, neural network based pattern recognition and Bayesian estimation, with varied expressions of β-actins among different cell types located. The dataset reported in this study may serve as a reference in future studies of quantitative protein analysis.展开更多
In this work,a bio-based flame retardant(Cy-HEDP)was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression perfo...In this work,a bio-based flame retardant(Cy-HEDP)was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression performance.The product Cy-HEDP was well characterized by FTIR,^(1)H and^(31)P NMR and SEM tests.On the basis of the results,by adding 15 wt%Cy-HEDP,the EP15 can pass UL-94 V-0 rating,and the total smoke production(TSP)as well as total heat release(THR)can be decreased by 61.05%(from 22.61 to 8.7 m^(2)/m^(2))and 39.44%(from 103.19 to 62.50 MJ/m^(2))in comparison to the unfilled EP,reflecting the attenuated smoke toxicity and impeded heat generation.According to the analysis results of residual char,it can be concluded that Cy-HEDP possessed the ability to promote the formation of continuous and dense char layers,which would be a physical barrier to insulate oxygen and prevent heat feedback during the combustion of EP.This work provide inspiration towards developing bio-based flame retardant,probably extending the prospects to other polymeric material system.展开更多
In this study,with Saccharomyces cerevisiae as the experimental material,microwave-assisted technology,phenol-sulfuric acid method and UV spectrophotometry were employed to investigate the extraction rate of polysacch...In this study,with Saccharomyces cerevisiae as the experimental material,microwave-assisted technology,phenol-sulfuric acid method and UV spectrophotometry were employed to investigate the extraction rate of polysaccharides. Solid-liquid ratio,microwave power and microwave processing time were adopted as single factors to optimize the extraction conditions. Subsequently,orthogonal experiment was performed to investigate the optimal extraction process of polysaccharides from S. cerevisiae. The optimal extraction conditions were: solid-liquid ratio 1∶ 20,microwave power 250 W,microwave processing time 3 min,under which the extraction rate of polysaccharides reached 4. 98%. Compared with conventional hot water extraction method,microwave-assisted extraction technology exhibited shorter extraction time,higher efficiency,and could save more energy.展开更多
N6-methyladenosine(m6A)modification is the most widespread and conserved internal mRNA modification in mammalian cells.It greatly affects genetic regulation by enhancing the involvement of diverse cellular enzymes and...N6-methyladenosine(m6A)modification is the most widespread and conserved internal mRNA modification in mammalian cells.It greatly affects genetic regulation by enhancing the involvement of diverse cellular enzymes and thus,plays a significant role in basic life processes.Numerous studies on m6A modification identified FTO as a crucial demethylase that participates in various biological processes.Not only does FTO play a pivotal role in obesity-related conditions,but it also influences the occurrence,development,and prognosis of several cancers,such as acute myeloid leukemia,breast cancer,liver cancer,and lung cancer.Moreover,FTO also shows a close association with immunity and viral infections.This article summarized the molecular mechanism of FTO in tumorigenesis and tumor progression.展开更多
The development of modern air combat requires aircraft to have certain intelligent decision-making ability.In some of the existing solutions,the automatic control of aircraft is mostly composed of the upper mission de...The development of modern air combat requires aircraft to have certain intelligent decision-making ability.In some of the existing solutions,the automatic control of aircraft is mostly composed of the upper mission decision and the lower control system.Although the underlying PID(Proportional Integral Derivative)based controller has a good performance in stable conditions,it lacks stability in complex environments.So,we need to design a new system for the problem of aircraft decision making.Studies have shown that the behavior of an aircraft can be viewed as a combination of several basic maneuvers.The establishment of aircraft basic motion library will effectively reduce the difficulty of upper aircraft control.Given the good performance of reinforcement learning to solve the problem with continuous action space,in this paper,reinforcement learning is used to control the aircraft’s rod and rudder to generate a basic maneuver action library,and the flight of the aircraft under the 6 degrees of freedom(6-DOF)simulation engine is effectively controlled.The simulation results verify the feasibility of the method on a visual simulation platform.展开更多
In this study,tri-rutile type Mg_(0.5)Ti_(0.5)TaO_(4) ceramics were synthesized,where the structure–property relationship,especially the structural configuration and intrinsic dielectric origin of Mg_(0.5)Ti_(0.5)TaO...In this study,tri-rutile type Mg_(0.5)Ti_(0.5)TaO_(4) ceramics were synthesized,where the structure–property relationship,especially the structural configuration and intrinsic dielectric origin of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,and the low-firing characteristics were studied.It is found that the tri-rutile structural type is unambiguously identified through the Rietveld refinement analysis,the selected area electron diffraction(SAED),and the high-resolution transmission electron microscopy(HRTEM)along the[110]zone axis.With the increase in sintering temperature,the densification and uniformity of crystal growth play important roles in regulating the microwave dielectric properties of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics.Intrinsically,theoretical dielectric properties calculated by the far-infrared reflective spectra approached the experimental values,indicating the importance of structural features to dielectric properties.Furthermore,a glass additive with high matching relevance with ceramics has been developed to decrease the high sintering temperature of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,where 2–4 wt%Li_(2)O–MgO–ZnO–B_(2)O_(3)–SiO_(2)(LMZBS)glass frit was adopted to reduce the suitable temperature from 1275 to 1050℃ without significantly deteriorating the microwave dielectric characteristics.Specifically,Mg_(0.5)Ti_(0.5)TaO_(4) ceramics containing 2 wt% glass addition sintered at 1050℃for 4 h possess excellent microwave dielectric properties:dielectric constant(ε_(r))=44.3,quality factor multiplied by resonant frequency(Q×f)=23,820 GHz(f=6.2 GHz),and the temperature coefficient of resonant frequency(τ_(f))=123.2 ppm/℃.展开更多
The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter It is a pressing need to advance the development of dielectric ceramics utilization of emerg...The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization mechanism.This review provides the summary of the study of microwave dielectric ceramics(MWDCs)sintered higher than 1000℃ from 2010 up to now,with the purpose of taking a broad and historical view of these ceramics and illustrating research directions.To date,researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric properties.There are variety of factors that impact the permittivity,dielectric loss,and temperature stability of dielectric materials,covering intrinsic and extrinsic factors.Many of these factors are often intertwined,which can complicate new dielectric material discovery and the mechanism investigation.Because of the various ceramics systems,pseudo phase diagram was used to classify the dielectric materials based on the composition.In this review,the ceramics were firstly divided into ternary systems,and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was mentioned.Finally,some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method,characterization techniques,and significant theory developments.展开更多
Over a hundred sizable lakes,some even larger than^1 km2,are distributed across the lowlands between megadunes in the southeastern Badain Jaran Desert(BJD),northwest China.With rather limited precipitation and hardly ...Over a hundred sizable lakes,some even larger than^1 km2,are distributed across the lowlands between megadunes in the southeastern Badain Jaran Desert(BJD),northwest China.With rather limited precipitation and hardly any surface runoff,these lakes are fed mainly by groundwater.However,the source of the groundwater and the groundwater discharge rates to these lakes are poorly understood.Water level and temperature of four representative lakes in the southeastern BJD were monitored continuously between 2013 and 2017.Water surface evaporation and rainfall in this area were also measured.Combining these acquired data,groundwater discharge rates were estimated using water balance models.The results show that the four lakes have similar recharge and discharge patterns,but at different average net groundwater discharge rates ranging from 1.79 to 3.09 mm d?1.The lake level variation mainly depends on groundwater discharge and lake surface evaporation.We found that diurnal lake level variation may be controlled by earth tide and atmospheric pressure change,and is five times greater than the evaporation.The desert precipitation and deep confined groundwater with high temperature were found also recharging the desert lakes.An Empirical Mode Decomposition(EMD)method was used to identify the lake level trend.All lake levels increased over the last four years,except one decreased in 2015 and 2016.The lake levels’increasing trend is synchronously similar with the precipitation in north China.This study analyzes annual and seasonal lake level variations,and also finds the diurnal water cycle between the groundwater and lake water for the first time.展开更多
This article presents low-firing,low-loss and temperature stable ZnO-TiO_(2)-Nb_(2)O_(5) microwave dielectric composite ceramics with the assistance of lithium borosilicate(LBS)and zinc borosilicate(ZBS)glass frits.Th...This article presents low-firing,low-loss and temperature stable ZnO-TiO_(2)-Nb_(2)O_(5) microwave dielectric composite ceramics with the assistance of lithium borosilicate(LBS)and zinc borosilicate(ZBS)glass frits.There is a liquid phase(eutectic mixture)generated by LBS(ZBS)glass,and solid particles could be wetted and dissolved.Therefore,the migrations and rearrangements of particles could be performed.Besides,compared with ceramics undoped with glass frits,lower activation energies(E_(a))of ceramics doped with LBS and ZBS glass suggest that the low-temperature sintering behavior is easier to carry out.The results indicated that LBS and ZBS glass both are effective sintering aids to accelerate the sintering process and improve the microwave dielectric properties of composite ceramics by controlling the phase compositions under low temperature.Combination great properties of ZnO-TiO_(2)-Nb_(2)O_(5) ceramics were obtained when sintered at 900℃ for 4 h:ε_(r)=36.7,Q×f=20,000 GHz,τ_(f)=7 ppm/℃.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21805139,12102194 and 22005144)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2141202)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.30921011203)the Young Elite Scientists Sponsorship Program by CAST(YESS Program,2021QNRC001)。
文摘Ammonium dinitramide(ADN),which has the advantages of high energy density,no halogen and low characteristic signal,is not only considered as a new high-energy oxidizer that is expected to replace the traditional oxidizer ammonium perchlorate(AP)in solid propellants,but also a good performance explosive in itself.However,due to the strong hygroscopicity of ADN,its application in solid propellants and explosives is greatly limited.Solving the hygroscopicity of ADN is the key to realize the wide application of ADN.In this paper,we systematically review the research progress of anti-hygroscopic strategies of ADN coating.The surface coating methods are focusing on solvent volatilization,solvent-non-solvent,melt crystallization and atomic layer deposition technology.The characteristics of the different methods are compared and analyzed,and the basis for the classification and selection of the coating materials are introduced in detail.In addition,the feasibility of material for surface coating of ADN is evaluated by several compatibility analysis methods.It is highly expected that the liquid phase method(solvent volatilization method,solvent-non-solvent method)would be the promising method for future ADN coating because of its effective,safety and facile operation.Furthermore,polymer materials,are the preferred coating materials due to their high viscosity,easy adhesion,good anti-hygroscopic effect,and heat resistance,which make ADN weak hygroscopicity,less sensitive,easier to preserve and good compatibility.
基金supported by the Scientific Research Project of Liaoning Province Education Department(2020LJC16)
文摘The number of people with eye diseases has increased with the use of electronics.However,the bioavailability of eye drops remains low owing to the presence of the ocular barrier and other reasons.Although many drug delivery systems have been developed to overcome these problems,they have certain limitations.In recent years,the development of contact lenses that can deliver drugs for long periods with high bioavailability and without affecting vision has increased the interest in using contact lenses for drug delivery.Hence,a review of the current state of research on drug delivery contact lenses has become crucial.This article reviews the key physical and chemical properties of drug-laden contact lenses,development and classification of contact lenses,and features of the commonly used materials.A review of the methods commonly used in current research to create contact lenses has also been presented.An overview on how drug-laden contact lenses can overcome the problems of high burst and short release duration has been discussed.Overall,the review focuses on drug delivery methods using smart contact lenses,and predicts the future direction of research on contact lenses.
基金funded by the Key Project of Basic Research of Shenzhen Science and Technology Innovation Commission(Grant Number JCYJ20200109140208058)the Guangdong Provincial High Level Clinical Key Specialty(Grant Number SZGSP008).
文摘Oral squamous cell carcinoma(OSCC)is a malignant tumor triggered by the accumulation of multiple gene mutations in oral epithelial cells.Different OSCC-related biomarkers have been reported in circulation in the peripheral blood that support the occurrence and development of OSCC.Recent advances in high-throughput and highly sensitive detection methods have overcome the limitation of the low concentration of most peripheral blood biomarkers.Hence,blood biomarker detection has become an efficient screening tool for the early diagnosis of OSCC.The growing data available in public cancer and gene databases have provided new foundations for OSCC research.In particular,the identification of OSCC biomarkers using bioinformatic tools has shed new light on the underlying mechanisms as well as on the genetic landscape of OSCC.More recently,mRNA targeting therapies have emerged as valuable anticancer treatment strategies,as they allow for the regulation of the expression of certain functional proteins to reverse genetic abnormalities or induce tissue repair.Thus,mRNA-targeting therapies can be used to regulate the expression of antigens,antibodies,or cellular receptors by immune cells.Particularly,anti-cancer cellular immunotherapy carrying specific mRNAs has attracted significant attention in OSCC treatment.Here,we review the present knowledge on the role of peripheral blood mRNAs in the diagnosis,treatment,development,and prognosis of OSCC.Moreover,we address future research prospects of mRNAs in the peripheral blood in OSCC and the opportunities and challenges that may arise in future clinical therapeutic applications.
基金Natural Science Foundation of Jiangsu Province(BK2005158)
文摘Objective:To construct the recombinant adenovirus vector carrying rat vascular endothelial growth factor(VEGF),as preparation for genetic transfection that follows.Methods:Rat VEGF was obtained by using RT-PCR amplification and then cloned into the shutter plasmid pDC316.Subsequently,this newly constructed plasmid pDC316-VEGF,after identification by nuclease digestion analysis and sequencing analysis,was transfected into human embryonic kidney cells HEK293 by Lipofectamine 2000 mediation,together with adenovirus-packaging plasmid pBHGE3.Based on the homologous recombination of the two plasmids within HEK293 cells,the recombinant adenovirus vector carrying VEGF and VDC316-VEGF was created.VDC316-VEGF was subsequently identified using PCR,purified using repeated plaque passages,proliferated using freezing and melting within HEK293 cells,and titrated using 50% Tissue Culture Infective Dose(TCID50)assay.Results:The newly constructed recombinant adenovirus was confirmed to carry rat VEGF based on PCR results,and its titration value determined based on TCID50 assay was 3 × 109 pfu/ml.Conclusion:The recombinant adenovirus carrying rat VEGF was successfully constructed.The newly constructed adenovirus can produce a sufficiently high titration value within HEK293 cells,providing a reliable tool for genetic transfection in further gene therapy researches.
文摘Botrytis cinerea is a necrotrophic fungal pathogen that impacts a wide range of hosts, including Arabidopsis. Pretreatment with nitric oxide (NO) donor sodium nitroprusside (SNP) on Arabidopsis leaves suppressed Botrytis cinerea infection development. Additionally, in this study the dosage levels of SNP applied to the leaves had no direct, toxic impact on the development of the pathogen. The relationship between NO and reactive oxidant species (ROS) was studied by using both spectrophotometrical methods and staining leaf material with fluorescent dyes, nitro blue tetrazolium (NBT), and with 3,3-diaminobenzidine (DAB). The results showed that exogenous NO restrained the generation of ROS, especially H2O2, as the pathogen interacted with the Arabidopsis plant. And this inhibition of reactive oxidant burst coincided with delay infection development in NO-supplied leaves. The influence of elevated level of NO on antioxidant enzymes was investigated in this study. The activities of catalase (CAT) and guaiacol peroxidase (POD) were increased to different degrees in both: 1) SNP treated only leaves, and 2) SNP pretreated leaves that were subsequently inoculateted with pathogens. However, the activity of superoxide dismutase (SOD) was unchanged in the leaves studied. The decrease in H2O2 content probably resulted from the increase in activities of POD and CAT. Our study suggests that NO might trigger some metabolic reactions, i.e. enhanced enzyme activity that restrains H2O2 which ultimately results in resistance to B. cinerea infection.
基金supported by National Natural Science Foundation of China (No.90716025)
文摘This paper presents a composite magneto hydrodynamics(MHD) method to control the lowtemperature micro-ionized plasma flow generated by injecting alkali salt into the combustion gas to realize the thrust vector of an aeroengine.The principle of plasma flow with MHD control is analyzed.The feasibility of plasma jet deflection is investigated using numerical simulation with MHD control by loading the User-Defined Function model.A test rig with plasma flow controlled by MHD is established.An alkali salt compound with a low ionization energy is injected into combustion gas to obtain the low-temperature plasma flow.Finally,plasma plume deflection is obtained in different working conditions.The results demonstrate that plasma plume deflection with MHD control can be realized via numerical simulation.A low-temperature plasma flow can be obtained by injecting an alkali metal salt compound with low ionization energy into a combustion gas at 1800–2500 K.The vector angle of plasma plume deflection increases with the increase of gas temperature and the magnetic field intensity.It is feasible to realize the aim of the thrust vector of aeroengine by using MHD to control plasma flow deflection.
文摘As a house keeping protein with stable expressions, β-actin is used as a loading control in normalization of western blotting. However, the actual numbers of β-actins at the single-cell level remain elusive. Based on a homedeveloped flow cytometry, single-cell numbers of β-actin from 8 cell types(subtypes) and 2 tumour patient samples were quantified as 9.62 ± 4.29 × 105(A549, Ncell= 14,242), 6.46 ± 3.34 × 105(Hep G2, Ncell= 35,932),1.58 ± 0.90 × 106(MCF 10 A, N6 cell= 16,650), 1.08 ± 0.48 × 10(HeLa, Ncell= 26,151), 7.60 ± 4.34 × 105(PC3, Ncell= 11,922), 1.10 ± 0.72 × 106(SACC-83, Ncell= 13,616), 8.58 ± 4.54 × 105(CAL 27, Ncell= 7271),9.00 ± 4.69 × 105(CAL 27-LN2, Ncell= 6222), 8.26 ± 4.48 × 105(Oral Tumour Patient I, Ncell= 359), and8.19 ± 5.12 × 105(Oral Tumour Patient II, Ncell= 175), and were analyzed by statistical approaches including one-way analysis of variance, neural network based pattern recognition and Bayesian estimation, with varied expressions of β-actins among different cell types located. The dataset reported in this study may serve as a reference in future studies of quantitative protein analysis.
基金the financial supports from Fundamental Research Funds for the Central Universities(2020CDJQY-A006)the National Natural Science Foundation of China(No.51603025)The Opening Fund of State Key Laboratory of Fire Science(HZ2019-KF11).
文摘In this work,a bio-based flame retardant(Cy-HEDP)was synthesized from cytosine and HEDP through a facile salt-forming reaction and embedded into epoxy matrix to improve the flame retardancy and smoke suppression performance.The product Cy-HEDP was well characterized by FTIR,^(1)H and^(31)P NMR and SEM tests.On the basis of the results,by adding 15 wt%Cy-HEDP,the EP15 can pass UL-94 V-0 rating,and the total smoke production(TSP)as well as total heat release(THR)can be decreased by 61.05%(from 22.61 to 8.7 m^(2)/m^(2))and 39.44%(from 103.19 to 62.50 MJ/m^(2))in comparison to the unfilled EP,reflecting the attenuated smoke toxicity and impeded heat generation.According to the analysis results of residual char,it can be concluded that Cy-HEDP possessed the ability to promote the formation of continuous and dense char layers,which would be a physical barrier to insulate oxygen and prevent heat feedback during the combustion of EP.This work provide inspiration towards developing bio-based flame retardant,probably extending the prospects to other polymeric material system.
基金Supported by Science and Technology Project of Shandong Province(2011GS2114)Science and Technology Project of Heze City(2010S002)
文摘In this study,with Saccharomyces cerevisiae as the experimental material,microwave-assisted technology,phenol-sulfuric acid method and UV spectrophotometry were employed to investigate the extraction rate of polysaccharides. Solid-liquid ratio,microwave power and microwave processing time were adopted as single factors to optimize the extraction conditions. Subsequently,orthogonal experiment was performed to investigate the optimal extraction process of polysaccharides from S. cerevisiae. The optimal extraction conditions were: solid-liquid ratio 1∶ 20,microwave power 250 W,microwave processing time 3 min,under which the extraction rate of polysaccharides reached 4. 98%. Compared with conventional hot water extraction method,microwave-assisted extraction technology exhibited shorter extraction time,higher efficiency,and could save more energy.
基金This study was supported by the Natural Science Foundation of Guangdong Provincial(2019A1515011911)the Research Program of Shenzhen Innovation Council(JCYJ20200109140208058)+1 种基金the Sanming Project of Medicine in Shenzhen(SZSM202111012)the Oral and Maxillofacial Surgery Team,Professor Yu Guangyan,Stomatological Hospital Peking University,Guangdong Provincial High-Level Clinical Key Specialty(Shenzhen Matching Construction Fund)(Grant No.SZGSP008).
文摘N6-methyladenosine(m6A)modification is the most widespread and conserved internal mRNA modification in mammalian cells.It greatly affects genetic regulation by enhancing the involvement of diverse cellular enzymes and thus,plays a significant role in basic life processes.Numerous studies on m6A modification identified FTO as a crucial demethylase that participates in various biological processes.Not only does FTO play a pivotal role in obesity-related conditions,but it also influences the occurrence,development,and prognosis of several cancers,such as acute myeloid leukemia,breast cancer,liver cancer,and lung cancer.Moreover,FTO also shows a close association with immunity and viral infections.This article summarized the molecular mechanism of FTO in tumorigenesis and tumor progression.
基金supported by grant of No.U20A20161 from the State Key Program of National Natural Science Foundation of China.
文摘The development of modern air combat requires aircraft to have certain intelligent decision-making ability.In some of the existing solutions,the automatic control of aircraft is mostly composed of the upper mission decision and the lower control system.Although the underlying PID(Proportional Integral Derivative)based controller has a good performance in stable conditions,it lacks stability in complex environments.So,we need to design a new system for the problem of aircraft decision making.Studies have shown that the behavior of an aircraft can be viewed as a combination of several basic maneuvers.The establishment of aircraft basic motion library will effectively reduce the difficulty of upper aircraft control.Given the good performance of reinforcement learning to solve the problem with continuous action space,in this paper,reinforcement learning is used to control the aircraft’s rod and rudder to generate a basic maneuver action library,and the flight of the aircraft under the 6 degrees of freedom(6-DOF)simulation engine is effectively controlled.The simulation results verify the feasibility of the method on a visual simulation platform.
基金support from the open research fund of Songshan Lake Materials Laboratory (No.2022SLABFN20)the Qinchuangyuan Citing Highlevel Innovation and Entrepreneurship Talent Projects (No.QCYRCXM-2022-40)+3 种基金the Natural Science Basic Research Program of Shaanxi (No.2022JQ-390)the National Natural Science Foundation of China (No.52102123)the National Key R&D Program of China (No.2022YFB2807405)the Natural Science Foundation of Sichuan Province (Nos.22NSFSC1973 and 2022NSFSC1959).
文摘In this study,tri-rutile type Mg_(0.5)Ti_(0.5)TaO_(4) ceramics were synthesized,where the structure–property relationship,especially the structural configuration and intrinsic dielectric origin of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,and the low-firing characteristics were studied.It is found that the tri-rutile structural type is unambiguously identified through the Rietveld refinement analysis,the selected area electron diffraction(SAED),and the high-resolution transmission electron microscopy(HRTEM)along the[110]zone axis.With the increase in sintering temperature,the densification and uniformity of crystal growth play important roles in regulating the microwave dielectric properties of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics.Intrinsically,theoretical dielectric properties calculated by the far-infrared reflective spectra approached the experimental values,indicating the importance of structural features to dielectric properties.Furthermore,a glass additive with high matching relevance with ceramics has been developed to decrease the high sintering temperature of Mg_(0.5)Ti_(0.5)TaO_(4) ceramics,where 2–4 wt%Li_(2)O–MgO–ZnO–B_(2)O_(3)–SiO_(2)(LMZBS)glass frit was adopted to reduce the suitable temperature from 1275 to 1050℃ without significantly deteriorating the microwave dielectric characteristics.Specifically,Mg_(0.5)Ti_(0.5)TaO_(4) ceramics containing 2 wt% glass addition sintered at 1050℃for 4 h possess excellent microwave dielectric properties:dielectric constant(ε_(r))=44.3,quality factor multiplied by resonant frequency(Q×f)=23,820 GHz(f=6.2 GHz),and the temperature coefficient of resonant frequency(τ_(f))=123.2 ppm/℃.
基金supported by the National Natural Science Foundation of China(Grant No.51872037).
文摘The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization mechanism.This review provides the summary of the study of microwave dielectric ceramics(MWDCs)sintered higher than 1000℃ from 2010 up to now,with the purpose of taking a broad and historical view of these ceramics and illustrating research directions.To date,researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric properties.There are variety of factors that impact the permittivity,dielectric loss,and temperature stability of dielectric materials,covering intrinsic and extrinsic factors.Many of these factors are often intertwined,which can complicate new dielectric material discovery and the mechanism investigation.Because of the various ceramics systems,pseudo phase diagram was used to classify the dielectric materials based on the composition.In this review,the ceramics were firstly divided into ternary systems,and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was mentioned.Finally,some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method,characterization techniques,and significant theory developments.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(Grand No.XDA20090000)the National Natural Science Foundation of China(Grand No.41771016)NASA’s Surface Water and Ocean Topography(SWOT)Program(Grand No.NNX16A85G).
文摘Over a hundred sizable lakes,some even larger than^1 km2,are distributed across the lowlands between megadunes in the southeastern Badain Jaran Desert(BJD),northwest China.With rather limited precipitation and hardly any surface runoff,these lakes are fed mainly by groundwater.However,the source of the groundwater and the groundwater discharge rates to these lakes are poorly understood.Water level and temperature of four representative lakes in the southeastern BJD were monitored continuously between 2013 and 2017.Water surface evaporation and rainfall in this area were also measured.Combining these acquired data,groundwater discharge rates were estimated using water balance models.The results show that the four lakes have similar recharge and discharge patterns,but at different average net groundwater discharge rates ranging from 1.79 to 3.09 mm d?1.The lake level variation mainly depends on groundwater discharge and lake surface evaporation.We found that diurnal lake level variation may be controlled by earth tide and atmospheric pressure change,and is five times greater than the evaporation.The desert precipitation and deep confined groundwater with high temperature were found also recharging the desert lakes.An Empirical Mode Decomposition(EMD)method was used to identify the lake level trend.All lake levels increased over the last four years,except one decreased in 2015 and 2016.The lake levels’increasing trend is synchronously similar with the precipitation in north China.This study analyzes annual and seasonal lake level variations,and also finds the diurnal water cycle between the groundwater and lake water for the first time.
基金financial supports from the National Natural Science Foundation of China(No.51872037).
文摘This article presents low-firing,low-loss and temperature stable ZnO-TiO_(2)-Nb_(2)O_(5) microwave dielectric composite ceramics with the assistance of lithium borosilicate(LBS)and zinc borosilicate(ZBS)glass frits.There is a liquid phase(eutectic mixture)generated by LBS(ZBS)glass,and solid particles could be wetted and dissolved.Therefore,the migrations and rearrangements of particles could be performed.Besides,compared with ceramics undoped with glass frits,lower activation energies(E_(a))of ceramics doped with LBS and ZBS glass suggest that the low-temperature sintering behavior is easier to carry out.The results indicated that LBS and ZBS glass both are effective sintering aids to accelerate the sintering process and improve the microwave dielectric properties of composite ceramics by controlling the phase compositions under low temperature.Combination great properties of ZnO-TiO_(2)-Nb_(2)O_(5) ceramics were obtained when sintered at 900℃ for 4 h:ε_(r)=36.7,Q×f=20,000 GHz,τ_(f)=7 ppm/℃.
