A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat.Inter-plant and inter-row distances were used to define ratefixed pattern(...A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat.Inter-plant and inter-row distances were used to define ratefixed pattern(RR)and row-fixed pattern(RS)density treatments.Meanwhile,four nitrogen(N)rates(0,144,192,and 240 kg N ha-1,termed N0,N144,N192,and N240)were applied with three densities(225,292.5,and 360×10^(4)plants ha^(-1),termed D225,D292.5,and D360).The wheat canopy was clipped into three equal vertical layers(top,middle,and bottom layers),and their chlorophyll density(Ch D)and photosynthetically active radiation interception(FIPAR)were measured.Results showed that the response of Ch D and FIPAR to N rate,density,and pattern varied with different layers.N rate,density,and pattern had significant interaction effects on Ch D.The maximum values of whole-canopy Ch D in the two seasons appeared in N240 combined with D292.5 and D360 under RR,respectively.Across two growing seasons,FIPAR values of RR were higher than those of RS by 29.37%for the top layer and 5.68%for the middle layer,while lower than those of RS by 20.62%for the bottom layer on average.With a low N supply(N0),grain yield was not significantly affected by density for both patterns.At N240,increasing density significantly increased yield under RR,but D360 of RS significantly decreased yield by 3.72%and 9.00%versus D225 in two seasons,respectively.With an appropriate and sufficient N application,RR increased the yield of densely planted wheat more than RS.Additionally,the maximum yield in two seasons appeared in the combination of D360 with N144 or N192 rather than of D225 with N240 under both patterns,suggesting that dense planting combined with an appropriate N-reduction application is feasible to increase photosynthesis capacity and yield.展开更多
The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular sy...The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular systems, we introduce a modular reconfigurable flight array(MRFA) to pursue a multifunction aircraft fitting for diverse tasks and requirements,and investigate the attitude control and the control allocation problem by using the modular reconfigurable flight array as a platform. First, considering the variable and irregular topological configuration of the modular array, a center-of-mass-independent flight array dynamics model is proposed to allow control allocation under over-actuated situations. Secondly, in order to meet the stable, fast and accurate attitude tracking performance of the MRFA, a fixed-time convergent sliding mode controller with state-dependent variable exponent coefficients is proposed to ensure fast convergence rate both away from and near the system equilibrium point without encountering the singularity. It is shown that the controller also has fixed-time convergent characteristics even in the presence of external disturbances. Finally,simulation results are provided to demonstrate the effectiveness of the proposed modeling and control strategies.展开更多
Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,whic...Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,which makes it difficult to meet the requirements of ground control under complex conditions. As a new support form with high strength and rigidity, the confined concrete arch plays an important role in controlling the rock deformation under complex conditions. The section shape of the tunnel has an important impact on the mechanical properties and design of the support system. However, studies on the mechanical properties and influence mechanism of the new confined concrete arch are rarely reported. To this end, the mechanical properties of traditional U-shaped steel and new confined concrete arches are compared and comparative tests on arches of circular and straight-leg semicircular shapes in deep tunnels are conducted. A large mechanical testing system for underground engineering support structure is developed. The mechanical properties and influence mechanism of confined concrete arches with different section shapes under different loading modes and cross-section parameters are systematically studied. Test results show that the bearing capacity of the confined concrete arch is 2.10 times that of the U-shaped steel arch, and the bearing capacity of the circular confined concrete arch is 2.27 times that of the straight-leg semicircular arch. Among the various influencing factors and their engineering parameters,the lateral stress coefficient has the greatest impact on the bearing capacity of the confined concrete arch,followed by the steel pipe wall thickness, steel strength, and core concrete strength. Subsequently, the economic index of bearing capacity and cost is established, and the optimization design method for the confined concrete arch is proposed. Finally, this design method is applied to a high-stress tunnel under complex conditions, and the deformation of the surrounding rock is effectively controlled.展开更多
Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is t...Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is the evolution of rock failure with diferent master crack types as investigated using Brazilian splitting tests(BSTs),direct shear tests(DSTs),and uniaxial compression tests(UCTs).The AE parameters and typical modes of each fracture type were obtained,and the energy release characteristics of each fracture mechanism were discussed.From the observed changes in the AE parameters,the rock fracture process exhibits characteristics of staged intensifcation.The scale and energy level of crack activity in the BSTs were signifcantly lower than those in the DSTs and UCTs.The proportion of tensile cracks in the BSTs was 65%–75%,while the proportions of shear cracks in the DSTs and UCTs were 75%–85%and 70%–75%,respectively.During the rock loading process under diferent conditions,failure was accompanied by an increased number of shear cracks.The amplitude,duration,and rise time of the AE signal from rock failure were larger when the failure was dominated by shear cracks rather than tensile ones,and most of the medium-and high-energy signals had medium to low frequencies.After calculating the proposed energy amplitude ratio,the energy release of shear cracks was found to exceed that of tensile cracks at the same fracture scale.展开更多
Efcient and accurate monitoring and early warning of coal dynamic disaster and other disasters can provide guarantee for the efcient operation of mine transportation system.However,the traditional threshold early warn...Efcient and accurate monitoring and early warning of coal dynamic disaster and other disasters can provide guarantee for the efcient operation of mine transportation system.However,the traditional threshold early warning method often fails to warning some accidents.To address above issues,a new early warning method was proposed based on"quiet period"phenomenon of AE and EMR during fracture.It is found that,a"quiet period"of AE and EMR was present before the load reaches the peak stress,which could be used as one of the precursors to warn the imminent failure of coal and rock specimens.MS and AE signals increased abnormally followed by the phenomenon of"quiet period"before the occurrence of coal dynamic disaster on site,and the decrease of MS events in the"quiet period"is about 57%–88%compared with that in previous abnormal increase stage.During the damage evolution of coal and rock,"quiet period"phenomenon usually occurred at 85%–90%of the peak stress,where the slope of damage parameter curve is almost zero.The"quiet period"of the AE-EMR signals and the low change rate of damage parameter before failure provide a theoretical foundation for the coal dynamic disaster warning based on the"quiet period"precursor found in MS-AE-EMR monitoring system.These fndings will help reduce the number of under-reported events and improve early warning accuracy.展开更多
An experiment was conducted to investigate the response of periphyton biomass to addition of phosphorus (P) in an aquatic ecosystem dominated by submersed plants. Aquatic ecosystems dominated by Hydrilla verticillata ...An experiment was conducted to investigate the response of periphyton biomass to addition of phosphorus (P) in an aquatic ecosystem dominated by submersed plants. Aquatic ecosystems dominated by Hydrilla verticillata (L.f.) Royle and Vallisneria natans (Lour.) Hara were constructed in mesocosm aquaria. Mesocosms were dosed weekly with different P loads (0 μg/L/Week and 100 μg/L/Week) for 17 weeks. Total P (TP), total soluble P (TSP), and soluble reactive P (SRP) concentrations in the waters of mesocosms added with P were significantly higher as opposed to the unenriched control mesocosms. The biomass of the attached periphyton and the cover of floating periphyton remained abundant in P-unenriched control mesocosms throughout the test period with a TP, TSP, and SRP concentration ranging of 0.021 - 0.049 mg/L, 0.004 - 0.024 mg/L, and 0.003 - 0.018 mg/L, respectively. P addition caused the decline of attached periphyton biomass to a low level and loss of floating periphyton. Results indicate that P enrichment in an aquatic ecosystem dominated by submersed plants could reduce attached periphyton biomass and eliminate floating periphyton. The research would be useful to maintain periphyton by reducing excessive P in aquatic ecosystem dominated by submersed plants.展开更多
The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes. The ability of different species to take up and store nutrients from...The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes. The ability of different species to take up and store nutrients from the surrounding ambience varies, and hence plant community structure might be expected to affect the cycling of nutrients in lake ecosystems. In this study, the uptake of phosphorus by Hydrilla verticillata and Vallisneria natans was studied and compared in monoculture and competitive mixed-culture plantings. Results showed that for both studied species the phosphorus concentrations of different tissues and of whole plants was unaffected by competition. However, the quantity of phosphorus accumulated by whole plants of 1-1. verticillata was significantly higher in mixture culture than in monoculture, while that of V. natans was lower in the mixed culture. The results indicated that 11. verticillata has a competitive advantage over V. natans, when the two species are grown in competition, and is able to accumulate a greater quantity of phosphorus.展开更多
Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,w...Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,we described a VB1 auxotrophic mutant,chlorotic lethal seedling(cles)from the mutation of OsTH1,which displayed collapsed chloroplast membrane system and decreased pigment content.OsTH1 encoded a phosphomethylpyrimidine kinase/thiamin-phosphate pyrophosphorylase,and was expressed in various tissues,especially in seedlings,leaves,and young panicles.The VB1 content in cles was markedly reduced,despite an increase in the expression of VB1 synthesis genes.The decreased TPP content affected the tricarboxylic acid cycle,pentose phosphate pathway,and de novo fatty acid synthesis,leading to a reduction in fatty acids(C16:0 and C18:0)and sugars(sucrose and glucose)of cles.Additionally,irregular expression of chloroplast membrane synthesis genes led to membrane collapse.We also found that alternative splicing and translation allowed OsTH1 to be localized to both chloroplast and cytosol.Our study revealed that OsTH1 was an essential enzyme in VB1 biosynthesis and played crucial roles in seedling growth and development by participating in fatty acid and sugar metabolism,providing new perspectives on VB1 function in rice.展开更多
X chromosomal short tandem repeats(X-STRs)have the characteristics of both autosomal and uniparental genetic markers and have been shown to be particularly useful in forensic casework.However,relevant research or repo...X chromosomal short tandem repeats(X-STRs)have the characteristics of both autosomal and uniparental genetic markers and have been shown to be particularly useful in forensic casework.However,relevant research or reports have not focused on X-STRs in the Hani population.To investigate the genetic variation and forensic efficiency of 16 X-STR loci in the Hani ethnic minority,we calculated the allele frequencies and forensic parameters of 451(116 males and 335 females)unrelated healthy Hani individuals from Yunnan Province,Southwest China.All these loci are highly polymorphic in Hani individuals in Yunnan Province except DXS6800.The combined power of discrimination in males(PDM)and power of discrimination in females(PDF)were found to be 0.999999998433993 and 0.999999999999998,respectively.Furthermore,a population genetic structure investigation between the Yunnan Hani population and another 18 populations was performed using a principal component analysis,multidimensional scaling plot and neighbouring-joining phylogenetic tree and the findings illustrated that neighbouring populations and different nationalities in the same area appeared to have a closer evolutionary relationship.This study provides the first batch of X chromosome genetic polymorphism data of the Hani population in Yunnan Province,Southwest China and enriches the reference database of the Chinese minority population.展开更多
Objective:to evaluate the therapeutic effect of targeted endostatin-loaded microbubbles,combined with improved,focused,directional ultrasound radiation for inhibition of subcutaneous translocation in situ colon tumor ...Objective:to evaluate the therapeutic effect of targeted endostatin-loaded microbubbles,combined with improved,focused,directional ultrasound radiation for inhibition of subcutaneous translocation in situ colon tumor angiogenesis in colon cancer.Methods:65 BALB/c nude mice with subcutaneous translocation in situ colon tumors were randomly divided into five groups.Group A was the control group,without any treatments.In Group B,the mouse was treated with ultrasonic radiation.In Group C,the mouse was treated with ultrasonic radiation combined with empty SonoVue microbubbles.In Group D,the mouse was treated with ultrasonic radiation combined with empty Targestar-SA microbubbles.In Group E,the mouse was treated with ultrasonic radiation combined with endostatin microbubbles.The tumor size was measured before and 1,14,and 28 days after irradiation.The peak intensity(PI),regional blood volume(RBV)and regional blood flow(RBF)were recorded using contrast-enhanced ultrasound.The tumor tissue was removed for pathological examination;the tumor necrosis area and microvascular density(MVD)were evaluated by immunohistochemistry.Results:Tumors in Groups C,D and E were significantly smaller than in Groups A and B at 28 days after irradiation,with Group E the smallest.PI,RBF and RBV of Groups C,D,and E were significantly decreased 28 days after radiation with Group E the lowest,and significantly lower than Groups A and B(all P<0.05).The tumor tissue necrosis area of Group E was clearly greater while MVD was obviously lower than the other groups(all P<0.01)at 28 days after treatment.Conclusion:The targeted endostatin microbubbles,combined with focused,directional ultrasound radiation can damage tumor microvasculature of subcutaneous colon translocation in situ colon cancer,as well as inhibit the tumor angiogenesis.展开更多
基金supported by the National Key Research and Development Program of China(2022YFD2301402)the National Natural Science Foundation of China(32071903)+2 种基金the Jiangsu Provincial Key Technologies R&D Program of China(BE2019386)the Guidance Foundation of the Sanya Institute of Nanjing Agricultural University,China(NAUSY2D01)the Earmarked Fund for Jiangsu Agricultural Industry Technology System(JATS(2022)468,JATS(2022)168)。
文摘A two-year field experiment was conducted to measure the effects of densification methods on photosynthesis and yield of densely planted wheat.Inter-plant and inter-row distances were used to define ratefixed pattern(RR)and row-fixed pattern(RS)density treatments.Meanwhile,four nitrogen(N)rates(0,144,192,and 240 kg N ha-1,termed N0,N144,N192,and N240)were applied with three densities(225,292.5,and 360×10^(4)plants ha^(-1),termed D225,D292.5,and D360).The wheat canopy was clipped into three equal vertical layers(top,middle,and bottom layers),and their chlorophyll density(Ch D)and photosynthetically active radiation interception(FIPAR)were measured.Results showed that the response of Ch D and FIPAR to N rate,density,and pattern varied with different layers.N rate,density,and pattern had significant interaction effects on Ch D.The maximum values of whole-canopy Ch D in the two seasons appeared in N240 combined with D292.5 and D360 under RR,respectively.Across two growing seasons,FIPAR values of RR were higher than those of RS by 29.37%for the top layer and 5.68%for the middle layer,while lower than those of RS by 20.62%for the bottom layer on average.With a low N supply(N0),grain yield was not significantly affected by density for both patterns.At N240,increasing density significantly increased yield under RR,but D360 of RS significantly decreased yield by 3.72%and 9.00%versus D225 in two seasons,respectively.With an appropriate and sufficient N application,RR increased the yield of densely planted wheat more than RS.Additionally,the maximum yield in two seasons appeared in the combination of D360 with N144 or N192 rather than of D225 with N240 under both patterns,suggesting that dense planting combined with an appropriate N-reduction application is feasible to increase photosynthesis capacity and yield.
基金supported by the National Nature Science Foundation of China (62063011,62273169, 61922037, 61873115)Yunnan Fundamental Research Projects(202001AV070001)+1 种基金Yunnan Major Scientific and Technological Projects(202202AG050002)partially supported by the Open Foundation of Key Laboratory in Software Engineering of Yunnan Province (2020SE502)。
文摘The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular systems, we introduce a modular reconfigurable flight array(MRFA) to pursue a multifunction aircraft fitting for diverse tasks and requirements,and investigate the attitude control and the control allocation problem by using the modular reconfigurable flight array as a platform. First, considering the variable and irregular topological configuration of the modular array, a center-of-mass-independent flight array dynamics model is proposed to allow control allocation under over-actuated situations. Secondly, in order to meet the stable, fast and accurate attitude tracking performance of the MRFA, a fixed-time convergent sliding mode controller with state-dependent variable exponent coefficients is proposed to ensure fast convergence rate both away from and near the system equilibrium point without encountering the singularity. It is shown that the controller also has fixed-time convergent characteristics even in the presence of external disturbances. Finally,simulation results are provided to demonstrate the effectiveness of the proposed modeling and control strategies.
基金supported by the National Natural Science Foundation of China (Nos. 42277174, 42077267, and 52074164)the Natural Science Foundation of Shandong Province, China (No. ZR2020JQ23)+2 种基金Major Scientific and Technological Innovation Project of Shandong Province, China (No. 2019SDZY04)the Project of Shandong Province Higher Educational Youth Innovation Science and Technology Program, China (No. 2019KJG013)the opening project of State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology (No. KFJJ21-02Z)。
文摘Deep underground projects(e.g., coal mines), are often faced with complex conditions such as high stress and extremely soft rock. The strength and rigidity of the traditional support system are often insufficient,which makes it difficult to meet the requirements of ground control under complex conditions. As a new support form with high strength and rigidity, the confined concrete arch plays an important role in controlling the rock deformation under complex conditions. The section shape of the tunnel has an important impact on the mechanical properties and design of the support system. However, studies on the mechanical properties and influence mechanism of the new confined concrete arch are rarely reported. To this end, the mechanical properties of traditional U-shaped steel and new confined concrete arches are compared and comparative tests on arches of circular and straight-leg semicircular shapes in deep tunnels are conducted. A large mechanical testing system for underground engineering support structure is developed. The mechanical properties and influence mechanism of confined concrete arches with different section shapes under different loading modes and cross-section parameters are systematically studied. Test results show that the bearing capacity of the confined concrete arch is 2.10 times that of the U-shaped steel arch, and the bearing capacity of the circular confined concrete arch is 2.27 times that of the straight-leg semicircular arch. Among the various influencing factors and their engineering parameters,the lateral stress coefficient has the greatest impact on the bearing capacity of the confined concrete arch,followed by the steel pipe wall thickness, steel strength, and core concrete strength. Subsequently, the economic index of bearing capacity and cost is established, and the optimization design method for the confined concrete arch is proposed. Finally, this design method is applied to a high-stress tunnel under complex conditions, and the deformation of the surrounding rock is effectively controlled.
基金Major Program of Shandong Provincial Natural Science Foundation(No.ZR2019ZD13)Major Scientifc and Technological Innovation Project of Shandong Provincial Key Research Development Program(No.2019SDZY02)Project of Taishan Scholar in Shandong Province.
文摘Acoustic emission(AE)signals contain substantial information about the internal fracture characteristics of rocks and are useful for revealing the laws governing the release of energy stored therein.Reported here is the evolution of rock failure with diferent master crack types as investigated using Brazilian splitting tests(BSTs),direct shear tests(DSTs),and uniaxial compression tests(UCTs).The AE parameters and typical modes of each fracture type were obtained,and the energy release characteristics of each fracture mechanism were discussed.From the observed changes in the AE parameters,the rock fracture process exhibits characteristics of staged intensifcation.The scale and energy level of crack activity in the BSTs were signifcantly lower than those in the DSTs and UCTs.The proportion of tensile cracks in the BSTs was 65%–75%,while the proportions of shear cracks in the DSTs and UCTs were 75%–85%and 70%–75%,respectively.During the rock loading process under diferent conditions,failure was accompanied by an increased number of shear cracks.The amplitude,duration,and rise time of the AE signal from rock failure were larger when the failure was dominated by shear cracks rather than tensile ones,and most of the medium-and high-energy signals had medium to low frequencies.After calculating the proposed energy amplitude ratio,the energy release of shear cracks was found to exceed that of tensile cracks at the same fracture scale.
基金supported by Grants from the National Natural Science Foundation of China(No.52004016)the Postdoctoral Research Foundation of China(No.2021M700371)+3 种基金the Major Science and Technology Innovation Project of Shandong Province(No.2019SDZY02)the Open Fund Project of Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard(No.2021SKMS05)Science and Technology Support Plan Project of Guizhou Province(No.[2021]515)The authors are grateful to the anonymous referees for their precious comments and suggestions.
文摘Efcient and accurate monitoring and early warning of coal dynamic disaster and other disasters can provide guarantee for the efcient operation of mine transportation system.However,the traditional threshold early warning method often fails to warning some accidents.To address above issues,a new early warning method was proposed based on"quiet period"phenomenon of AE and EMR during fracture.It is found that,a"quiet period"of AE and EMR was present before the load reaches the peak stress,which could be used as one of the precursors to warn the imminent failure of coal and rock specimens.MS and AE signals increased abnormally followed by the phenomenon of"quiet period"before the occurrence of coal dynamic disaster on site,and the decrease of MS events in the"quiet period"is about 57%–88%compared with that in previous abnormal increase stage.During the damage evolution of coal and rock,"quiet period"phenomenon usually occurred at 85%–90%of the peak stress,where the slope of damage parameter curve is almost zero.The"quiet period"of the AE-EMR signals and the low change rate of damage parameter before failure provide a theoretical foundation for the coal dynamic disaster warning based on the"quiet period"precursor found in MS-AE-EMR monitoring system.These fndings will help reduce the number of under-reported events and improve early warning accuracy.
文摘An experiment was conducted to investigate the response of periphyton biomass to addition of phosphorus (P) in an aquatic ecosystem dominated by submersed plants. Aquatic ecosystems dominated by Hydrilla verticillata (L.f.) Royle and Vallisneria natans (Lour.) Hara were constructed in mesocosm aquaria. Mesocosms were dosed weekly with different P loads (0 μg/L/Week and 100 μg/L/Week) for 17 weeks. Total P (TP), total soluble P (TSP), and soluble reactive P (SRP) concentrations in the waters of mesocosms added with P were significantly higher as opposed to the unenriched control mesocosms. The biomass of the attached periphyton and the cover of floating periphyton remained abundant in P-unenriched control mesocosms throughout the test period with a TP, TSP, and SRP concentration ranging of 0.021 - 0.049 mg/L, 0.004 - 0.024 mg/L, and 0.003 - 0.018 mg/L, respectively. P addition caused the decline of attached periphyton biomass to a low level and loss of floating periphyton. Results indicate that P enrichment in an aquatic ecosystem dominated by submersed plants could reduce attached periphyton biomass and eliminate floating periphyton. The research would be useful to maintain periphyton by reducing excessive P in aquatic ecosystem dominated by submersed plants.
基金supported by the State Key Development Program of Basic Research of China (No. 2008CB418104)the National Major Science and Technology Program for Water Pollution Control and Management (No. 2008ZX07211-003)+1 种基金the China Post-doctoral Science Foundation (No. 20090461149)the Fundamental Research Funds for Central Universities
文摘The competition between submersed plants has been recognized as an important factor influencing the structure of plant communities in shallow lakes. The ability of different species to take up and store nutrients from the surrounding ambience varies, and hence plant community structure might be expected to affect the cycling of nutrients in lake ecosystems. In this study, the uptake of phosphorus by Hydrilla verticillata and Vallisneria natans was studied and compared in monoculture and competitive mixed-culture plantings. Results showed that for both studied species the phosphorus concentrations of different tissues and of whole plants was unaffected by competition. However, the quantity of phosphorus accumulated by whole plants of 1-1. verticillata was significantly higher in mixture culture than in monoculture, while that of V. natans was lower in the mixed culture. The results indicated that 11. verticillata has a competitive advantage over V. natans, when the two species are grown in competition, and is able to accumulate a greater quantity of phosphorus.
基金supported by the National Natural Science Foundation of China(32170337,31870303)。
文摘Vitamin B(VB1),including thiamin,thiamin monophosphate(TMP),and thiamin pyrophosphate(TPP),is an essential micronutrient for all living organisms.Nevertheless,the precise function of VB1 in rice remains unclear.Here,we described a VB1 auxotrophic mutant,chlorotic lethal seedling(cles)from the mutation of OsTH1,which displayed collapsed chloroplast membrane system and decreased pigment content.OsTH1 encoded a phosphomethylpyrimidine kinase/thiamin-phosphate pyrophosphorylase,and was expressed in various tissues,especially in seedlings,leaves,and young panicles.The VB1 content in cles was markedly reduced,despite an increase in the expression of VB1 synthesis genes.The decreased TPP content affected the tricarboxylic acid cycle,pentose phosphate pathway,and de novo fatty acid synthesis,leading to a reduction in fatty acids(C16:0 and C18:0)and sugars(sucrose and glucose)of cles.Additionally,irregular expression of chloroplast membrane synthesis genes led to membrane collapse.We also found that alternative splicing and translation allowed OsTH1 to be localized to both chloroplast and cytosol.Our study revealed that OsTH1 was an essential enzyme in VB1 biosynthesis and played crucial roles in seedling growth and development by participating in fatty acid and sugar metabolism,providing new perspectives on VB1 function in rice.
基金This work was supported by the National Natural Science Foundation of China[grant numbers 81860258 and 31860300]Joint Special Funds for the Department of Science and Technology of Yunnan Province-Kunming Medical University[grant numbers 2017FE467(-022),2018FE001(-131)and 2019FE001(-011)]+3 种基金Yunnan Educational Science Foundation program[grant numbers 2018JS170 and 2018JS171]Yunnan Provincial Young Academic and Technical Leader Reserve Talent Project[grant number 2018HB104]Hundred-Talent Program of Kunming Medical University[grant number 60117190447]Science and Technology Innovation Group of Kunming Medical University[grant number CXTD201803].
文摘X chromosomal short tandem repeats(X-STRs)have the characteristics of both autosomal and uniparental genetic markers and have been shown to be particularly useful in forensic casework.However,relevant research or reports have not focused on X-STRs in the Hani population.To investigate the genetic variation and forensic efficiency of 16 X-STR loci in the Hani ethnic minority,we calculated the allele frequencies and forensic parameters of 451(116 males and 335 females)unrelated healthy Hani individuals from Yunnan Province,Southwest China.All these loci are highly polymorphic in Hani individuals in Yunnan Province except DXS6800.The combined power of discrimination in males(PDM)and power of discrimination in females(PDF)were found to be 0.999999998433993 and 0.999999999999998,respectively.Furthermore,a population genetic structure investigation between the Yunnan Hani population and another 18 populations was performed using a principal component analysis,multidimensional scaling plot and neighbouring-joining phylogenetic tree and the findings illustrated that neighbouring populations and different nationalities in the same area appeared to have a closer evolutionary relationship.This study provides the first batch of X chromosome genetic polymorphism data of the Hani population in Yunnan Province,Southwest China and enriches the reference database of the Chinese minority population.
基金This work was supported by the following grants:National Natural Science Foundation of China(No.81071164,No.81271584)Zhejiang Provincial Natural Science Foundation of China(No.Y2110782)+2 种基金Public Technology for Applied Research Program Foundation from the Science and Technology Bureau of Zhejiang Province(No.2013C31002)Key Program Foundation from the Health Bureau of Zhejiang Province(No.2013ZDA020)the General Program Foundation from the Hangzhou City Health Bureau(No.2013A27).
文摘Objective:to evaluate the therapeutic effect of targeted endostatin-loaded microbubbles,combined with improved,focused,directional ultrasound radiation for inhibition of subcutaneous translocation in situ colon tumor angiogenesis in colon cancer.Methods:65 BALB/c nude mice with subcutaneous translocation in situ colon tumors were randomly divided into five groups.Group A was the control group,without any treatments.In Group B,the mouse was treated with ultrasonic radiation.In Group C,the mouse was treated with ultrasonic radiation combined with empty SonoVue microbubbles.In Group D,the mouse was treated with ultrasonic radiation combined with empty Targestar-SA microbubbles.In Group E,the mouse was treated with ultrasonic radiation combined with endostatin microbubbles.The tumor size was measured before and 1,14,and 28 days after irradiation.The peak intensity(PI),regional blood volume(RBV)and regional blood flow(RBF)were recorded using contrast-enhanced ultrasound.The tumor tissue was removed for pathological examination;the tumor necrosis area and microvascular density(MVD)were evaluated by immunohistochemistry.Results:Tumors in Groups C,D and E were significantly smaller than in Groups A and B at 28 days after irradiation,with Group E the smallest.PI,RBF and RBV of Groups C,D,and E were significantly decreased 28 days after radiation with Group E the lowest,and significantly lower than Groups A and B(all P<0.05).The tumor tissue necrosis area of Group E was clearly greater while MVD was obviously lower than the other groups(all P<0.01)at 28 days after treatment.Conclusion:The targeted endostatin microbubbles,combined with focused,directional ultrasound radiation can damage tumor microvasculature of subcutaneous colon translocation in situ colon cancer,as well as inhibit the tumor angiogenesis.
