Feature modeler of welded structure provides both 3D-geographical and non-geographical features for the off-line programming of arc welded robot. Welded structure is regarded as an assembly, the design of welded stru...Feature modeler of welded structure provides both 3D-geographical and non-geographical features for the off-line programming of arc welded robot. Welded structure is regarded as an assembly, the design of welded structure consists of three aspects f plane, joint, and groove design. Each aspect corresponds to a category of features. The plane features are defined by interactive feature definition. A method analogous to the 'mating feature' is introduced to represent the joint features. Based on AutoCAD 2000, a B-rep solid modeler, a prototype system is implemented.展开更多
The algebraic collapsing acceleration(ACA)technique maximizes the use of geometric flexibility of the method of characteristics(MOC).The spatial grids for loworder ACA are the same as the high-order transport,which ma...The algebraic collapsing acceleration(ACA)technique maximizes the use of geometric flexibility of the method of characteristics(MOC).The spatial grids for loworder ACA are the same as the high-order transport,which makes the numerical solution of ACA equations costly,especially for large-size problems.To speed-up the MOC transport iterations effectively for general geometry,a coarse-mesh ACA method that involves selectively merging fine-mesh cells with identical materials,called material-mesh ACA(MMACA),is presented.The energy group batching(EGB)strategy in the tracing process is proposed to increase the parallel efficiency for microscopic crosssection problems.Microscopic and macroscopic crosssection benchmark problems are used to validate and analyse the accuracy and efficiency of the MMACA method.The maximum errors in the multiplication factor and pin power distributions are from the VERA-4 B-2 D case with silver-indium-cadmium(AIC)control rods inserted and are 104 pcm and 1.97%,respectively.Compared with the single-thread ACA solution,the maximum speed-up ratio reached 25 on 12 CPU cores for microscopic cross-section VERA-4-2 D problem.For the C5 G7-2 D and LRA-2 D benchmarks,the MMACA method can reduce the computation time by approximately one half.The present work proposes the MMACA method and demonstrates its ability to effectively accelerate MOC transport iterations.展开更多
We study the plane deformation of an elastic composite system made up of an anisotropic elliptical inclusion and an anisotropic foreign matrix surrounding the inclusion.In order to capture the influence of interface e...We study the plane deformation of an elastic composite system made up of an anisotropic elliptical inclusion and an anisotropic foreign matrix surrounding the inclusion.In order to capture the influence of interface energy on the local elastic field as the size of the inclusion approaches the nanoscale,we refer to the Gurtin-Murdoch model of interface elasticity to describe the inclusion-matrix interface as an imaginary and extremely stiff but zero-thickness layer of a finite stretching modulus.As opposed to isotropic cases in which the effects of interface elasticity are usually assumed to be uniform(described by a constant interface stretching modulus for the entire interface),the anisotropic case considered here necessitates non-uniform effects of interface elasticity(described by a non-constant interface stretching modulus),because the bulk surrounding the interface is anisotropic.To this end,we treat the interface stretching modulus of the anisotropic composite system as a variable on the interface curve depending on the specific tangential direction of the interface.We then devise a unified analytic procedure to determine the full stress field in the inclusion and matrix,which is applicable to the arbitrary orientation and aspect ratio of the inclusion,an arbitrarily variable interface modulus,and an arbitrary uniform external loading applied remotely.The non-uniform interface effects on the external loading-induced stress distribution near the interface are explored via a group of numerical examples.It is demonstrated that whether the nonuniformity of the interface effects has a significant effect on the stress field around the inclusion mainly depends on the direction of the external loading and the aspect ratio of the inclusion.展开更多
The classical Green’s functions used in the literature for a heat source in a homogeneous elastic medium cannot lead to ?nite remote thermal stresses in the medium,so that they may not work well in practical thermal ...The classical Green’s functions used in the literature for a heat source in a homogeneous elastic medium cannot lead to ?nite remote thermal stresses in the medium,so that they may not work well in practical thermal stress analyses. In this paper, we develop a practical Green’s function for a heat source disposed eccentrically into an elastic disk/cylinder subject to plane deformation. The edge of the disk/cylinder is assumed to be thermally permeable and traction-free. The full thermal stress ?eld induced by the heat source in the disk/cylinder is determined exactly and explicitly via the Cauchy integral techniques. In particular, a very simple formula is obtained to describe the hoop thermal stress on the edge of the disk/cylinder, which may be conveniently useful for analyzing the thermal stresses in microelectronic components.展开更多
Due to the frequency of occlusion, cluttering and lowcontrast edges, gray intensity based active contour models oftenfail to segment meaningful objects. Prior shape information is usuallyutilized to segment desirable ...Due to the frequency of occlusion, cluttering and lowcontrast edges, gray intensity based active contour models oftenfail to segment meaningful objects. Prior shape information is usuallyutilized to segment desirable objects. A parametric shape priormodel is proposed. Firstly, principal component analysis is employedto train object shape and transformation is added to shaperepresentation. Then the energy function is constructed througha combination of shape prior energy, gray intensity energy andshape constraint energy of the kernel density function. The objectboundary extraction process is converted into the parameters solvingprocess of object shape. Besides, two new shape prior energyfunctions are defined when desirable objects are occluded by otherobjects or some parts of them are missing. Finally, an alternatingdecent iteration solving scheme is proposed for numerical implementation.Experiments on synthetic and real images demonstratethe robustness and accuracy of the proposed method.展开更多
Nanopaper has attracted considerable interest in the fields of films and paper research.However,the challenge of integrating the many advantages of nanopaper still remains.Herein,we developed a facile strategy to fabr...Nanopaper has attracted considerable interest in the fields of films and paper research.However,the challenge of integrating the many advantages of nanopaper still remains.Herein,we developed a facile strategy to fabricate multifunctional nanocomposite paper(NGCP)composed of wood-derived nanofibrillated cellulose(NFC)and graphene as building blocks.NFC suspension was consisted of long and entangled NFCs(10–30 nm in width)and their aggregates.Before NGCP formation,NFC was chemically modified with a silane coupling agent to ensure that it could interact strongly with graphene in NGCP.The resulting NGCP samples were flexible and could be bent repeatedly without any structural damage.Within the NGCP samples,the high aspect ratio of NFC made a major contribution to its high mechanical strength,whereas the sheet-like graphene endowed the NGCP with electrical resistance and electrochemical activity.The mechanical strength of the NGCP samples decreased as their graphene content increased.However,the electrical resistance and electrochemical activity of the NGCP samples both rose with increasing content of graphene.The NGCPs still kept advantageous mechanical properties even at high temperatures around 300℃ because of the high thermal stability of NFCs and their strong entangled web-like structures.In view of its sustainable building blocks and multifunctional characteristics,the NGCP developed in this work is promising as low-cost and high-performance nanopaper.展开更多
The identification of multiple interacting inclusions with uniform internal stresses in an infinite elastic matrix subjected to a uniform remote loading is of fundamental importance in the mechanics and design of part...The identification of multiple interacting inclusions with uniform internal stresses in an infinite elastic matrix subjected to a uniform remote loading is of fundamental importance in the mechanics and design of particulate composite materials.In anti-plane shear and plane deformations,certain sufficient conditions have been established in the literature which guarantee uniform internal stresses inside multiple interacting inclusions displaying various symmetries when the matrix is subjected to specific uniform remote loading.Correspondingly,sufficient conditions which allow for the design of multiple interacting inclusions independent of any specific form of(uniform)remote loading have also been established.In this paper,we demonstrate rigorously that,in all cases,these sufficient conditions are also necessary conditions and indeed allow for the identification of all possible collections of such inclusions.展开更多
[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was u...[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was used to study the effects of adding different concentrations of humic acid,DMPP and their compound on the growth of maize. [Results] Both humic acid and DMPP could increase plant height,stem diameter,SPAD and biomass of maize. The effect of adding 10 kg of humic acid per t was better than that adding 5 kg,and biomass increased by 5. 4% and 3. 3% compared with CK. The effect of adding 1 kg of DMPP was better than that adding 0. 5 kg,and biomass increased by 5. 7% and 2. 7% compared with CK. The compound application of the 2 improved the fertilizer efficiency. The best treatment was 5‰ humic acid ＋ 1 ‰ DMPP,which could increase plant height,stem diameter,SPAD,and dry weight by 8. 1%,12. 3%,10. 6%,and 10. 7%,respectively,and it also had lower economic costs compared with the compounding application of 10‰ humic acid ＋ 1‰ DMPP.[Conclusions]The 5‰ humic acid ＋ 1 ‰ DMPP compound fertilizer formula was more suitable for application in maize production.展开更多
We report on two strategies to design and implement the galvanometer-based laser-scanning mechanisms for the realization of reflectance confocal microscopy(RCM) and stimulated Raman scattering(SRS) microscopy systems....We report on two strategies to design and implement the galvanometer-based laser-scanning mechanisms for the realization of reflectance confocal microscopy(RCM) and stimulated Raman scattering(SRS) microscopy systems. The RCM system uses a resonant galvanometer scanner driven by a home-built field-programmable gate array circuit with a novel dual-trigger mode and a home-built high-speed data acquisition card. The SRS system uses linear galvanometers with commercially available modules. We demonstrate video-rate high-resolution imaging at 11 frames per second of in vivo human skin with the RCM system and label-free biomolecular imaging of cancer cells with the SRS system. A comparison of the two strategies for controlling galvanometer scanners provides scientific and technical reference for future design and commercialization of various laser-scanning microscopes using galvanometers.展开更多
Objective:To investigate the radioactivity levels of seawater,sediments,and biota in the Daya Bay sea area,China,in order to establish the radioactivity baseline values,and provide basic data for the assessment of pot...Objective:To investigate the radioactivity levels of seawater,sediments,and biota in the Daya Bay sea area,China,in order to establish the radioactivity baseline values,and provide basic data for the assessment of potential radiological risks that might result from the application of nuclear technology or human activities.Methods:Samples of seawater,sediments,and biota were collected from the Daya Bay sea area and analyzed.Their radioactivity baseline data were then compared with information from other regions in China and around the world reported in related literature.Results:For the seawater samples,the activity concentrations of natural radionuclide ^(40)K were 9.9-10.4 Bq/L,while ^(238)U,226Ra,^(210)Pb,^(137)Cs,and ^(110)Ag^(m) were below the minimum detectable activity(MDA).Regarding the sediment samples,the activity concentrations of ^(238)U,^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 38.1-40.4,49.1-53.7,32.6-38.6,59-95,590-650,and 0.48-0.88 Bq/(kg dry weight),respectively,while ^(110)Agm was below the MDA.For the marine shrimps in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(40)K,and ^(137)Cs were 1.14-2.75,0.17-0.43,63-76,and 0.038-0.045 Bq/(kg wet weight),respectively,while ^(238)U,^(210)Pb,and ^(110)Agm were all below the MDA.Furthermore,for the marine fishes in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 2.1-19.7,0.32-3.78,<2.2-2.8,59-70,and<0.007-0.026 Bq/(kg wet weight),respectively,while ^(238)U and ^(110)Ag^(m) were all below the MDA.^(228)Ra was found to be concentrated in Osteomugil ophuyseni with 19.7 Bq/(kg wet weight).Conclusions:The radioactivity levels of seawater and marine sediments in the Daya Bay sea area are within the range of the normal background values.Osteomugil ophuyseni exhibited higher concentrations of ^(228)Ra than other species in this study,while the other species in the biota show no significant difference in the radioactivity levels from data in relevant literature.展开更多
Background:Tuberculosis is a leading cause of morbidity and mortality in humans worldwide.There is an urgent need for new and effective drugs to treat tuberculosis and shorten the duration of tuberculosis therapy.1,25...Background:Tuberculosis is a leading cause of morbidity and mortality in humans worldwide.There is an urgent need for new and effective drugs to treat tuberculosis and shorten the duration of tuberculosis therapy.1,25-dihydroxy vitamin D3(1,25(OH)2D3)has been reported to have a synergistic effect with pyrazinamide(PZA)in killing tubercle bacilli in vitro.The addition of 1,25(OH)2D3 to standard tuberculosis treatment should benefit patients if the adjunctive drug has a synergistic effect in vivo.Thus,in this study,calcitriol(bioactive 1,25(OH)2D3)was administered to mice undergoing treatment for Mycobacterium tuberculosis(M.tb)infection with PZA,a first-line anti-tuberculosis drug,to determine whether vitamin D3 enhances the therapeutic effect.Methods:C57BL/6 female mice were infected with the M.tb H37Rv strain through aerosol exposure.Calcitriol and PZA,either alone or in combination,were orally administered to the M.tb infected mice.The effect of calcitriol on PZA activity was determined by evaluating the bacterial burden and analyzing the histopathological lesions in the lungs and spleen.To investigate the expression of inflammatory cytokines and anti-microbial peptide genes,we determined the transcriptional levels of interferon-γ(IFN-γ),interleukin-4(IL-4),mouseβ-defensin-2(mBD2),and cathelicidin LL-37 through real-time quantitative polymerase chain reaction.The protein levels of IFN-γwere detected by enzyme-linked immunosorbent assay.Differences between groups were analyzed with independent samples t-test or one-way analysis of variance.Results:Calcitriol alone had little effect on tuberculosis infection,whereas PZA,compared with saline control treatment,decreased the bacterial burden(spleens:PZA vs.saline,4.82±0.22 vs.5.22±0.40 Log10 colony-forming units[CFU]/gram,t=2.13,P<0.05;lungs:PZA vs.saline,5.55±0.15 vs.6.83±0.46 Log10 CFU/gram,t=6.56,P<0.01)and pathological lesions in the lungs.Simultaneous administration of calcitriol with PZA,compared with PZA alone,decreased the bacterial load(spleen:calcitriol+PZA vs.PZA,4.37±0.13 vs.4.82±0.22 Log10 CFU/gram,t=4.36,P<0.01;lung:calcitriol+PZA vs.PZA,5.03±0.32 vs.5.55±0.15 Log10 CFU/gram,t=3.58,P<0.01)and attenuated the lung lesions(gross pathological score:calcitriol+PZA vs.PZA,3.25±0.50 vs.2.50±0.58,t=1.96,P<0.05;affected area of total lung area:calcitriol+PZA vs.PZA,30.75%±6.50%vs.21.55%±2.99%,t=2.66,P<0.05).Further studies demonstrated calcitriol significantly increased the expression of anti-inflammatory cytokine IL-4 but suppressed production of the pro-inflammatory cytokine IFN-γ(IL-4:calcitriol vs.saline,5.69±0.50 vs.2.80±0.56 fold of control,t=6.74,P<0.01;IFN-γ:calcitriol vs.saline,1.36±0.11 vs.4.13±0.83 fold of control,t=5.77,P<0.01).In addition,calcitriol alone or in combination with PZA significantly enhanced the transcriptional level of anti-microbial peptides(cathelicidin LL-37:calcitriol vs.saline,10.59±1.03 vs.2.80±0.90 fold of control,t=9.85,P<0.01;mBD2:calcitriol vs.saline,7.92±0.62 vs.1.79±0.45 fold of control,t=13.82,P<0.01),whereas PZA exerted a negative effect on anti-microbial peptide gene expression.Conclusions:Calcitriol as adjunctive treatment can result in beneficial treatment outcomes in M.tb infection by suppressing the inflammatory response and up-regulating the expression of anti-microbial peptides.These results indicate the feasibility of using calcitriol adjunctively with standard chemotherapy for the treatment of M.tb infection.展开更多
Dear Editor,Microtubule cytoskeleton is consisted ofα/β-tubulin dimers,which assemble end-to-end for protofilaments to form the polar and hollow tube that is 25 nm in diameter(Gudimchuk and McIntosh,2021).Microtubul...Dear Editor,Microtubule cytoskeleton is consisted ofα/β-tubulin dimers,which assemble end-to-end for protofilaments to form the polar and hollow tube that is 25 nm in diameter(Gudimchuk and McIntosh,2021).Microtubule dynamics normally present at the plus end,driven byβ-tubulin-bound guanosine triphosphate(GTP)hydrolysis and the end-associated proteins,such as end-binding protein 1(EB1).In eukaryotes,EB1 tracks the growing microtubule plus end,which is dependent on the presence of theβ-tubulin-bound GTP nucleotide,to promote the microtubule growth and catastrophe frequency(Zhang et al.,2015).EB1 consists of a calponin homology(CH)domain for microtubule binding,a linker region(intrinsic disorder region),and an end-binding homolog(EBH)domain for dimerization.The dimerized EBH domains form a hydrophobic cavity to recruit the SxIP-containing microtubule plus-end tracking proteins(+TIPs),and the flexible C-terminal tail of EB1 contains an evolutionarily conserved glutamic acid-glutamic acid-tyrosine motif that is responsible for interactions with the CAP-GLY domain-containing binding partners(Gudimchuk and McIntosh,2021).展开更多
基金supported by the National Natural Science Foundation of China(No.59635160)Advanced University Doctoral Subject Foundation(No.98021311)
文摘Feature modeler of welded structure provides both 3D-geographical and non-geographical features for the off-line programming of arc welded robot. Welded structure is regarded as an assembly, the design of welded structure consists of three aspects f plane, joint, and groove design. Each aspect corresponds to a category of features. The plane features are defined by interactive feature definition. A method analogous to the 'mating feature' is introduced to represent the joint features. Based on AutoCAD 2000, a B-rep solid modeler, a prototype system is implemented.
基金supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000)the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016)。
文摘The algebraic collapsing acceleration(ACA)technique maximizes the use of geometric flexibility of the method of characteristics(MOC).The spatial grids for loworder ACA are the same as the high-order transport,which makes the numerical solution of ACA equations costly,especially for large-size problems.To speed-up the MOC transport iterations effectively for general geometry,a coarse-mesh ACA method that involves selectively merging fine-mesh cells with identical materials,called material-mesh ACA(MMACA),is presented.The energy group batching(EGB)strategy in the tracing process is proposed to increase the parallel efficiency for microscopic crosssection problems.Microscopic and macroscopic crosssection benchmark problems are used to validate and analyse the accuracy and efficiency of the MMACA method.The maximum errors in the multiplication factor and pin power distributions are from the VERA-4 B-2 D case with silver-indium-cadmium(AIC)control rods inserted and are 104 pcm and 1.97%,respectively.Compared with the single-thread ACA solution,the maximum speed-up ratio reached 25 on 12 CPU cores for microscopic cross-section VERA-4-2 D problem.For the C5 G7-2 D and LRA-2 D benchmarks,the MMACA method can reduce the computation time by approximately one half.The present work proposes the MMACA method and demonstrates its ability to effectively accelerate MOC transport iterations.
基金Project supported by the National Natural Science Foundation of China(No.11902147)the Natural Science Foundation of Jiangsu Province of China(No.BK20190393)。
文摘We study the plane deformation of an elastic composite system made up of an anisotropic elliptical inclusion and an anisotropic foreign matrix surrounding the inclusion.In order to capture the influence of interface energy on the local elastic field as the size of the inclusion approaches the nanoscale,we refer to the Gurtin-Murdoch model of interface elasticity to describe the inclusion-matrix interface as an imaginary and extremely stiff but zero-thickness layer of a finite stretching modulus.As opposed to isotropic cases in which the effects of interface elasticity are usually assumed to be uniform(described by a constant interface stretching modulus for the entire interface),the anisotropic case considered here necessitates non-uniform effects of interface elasticity(described by a non-constant interface stretching modulus),because the bulk surrounding the interface is anisotropic.To this end,we treat the interface stretching modulus of the anisotropic composite system as a variable on the interface curve depending on the specific tangential direction of the interface.We then devise a unified analytic procedure to determine the full stress field in the inclusion and matrix,which is applicable to the arbitrary orientation and aspect ratio of the inclusion,an arbitrarily variable interface modulus,and an arbitrary uniform external loading applied remotely.The non-uniform interface effects on the external loading-induced stress distribution near the interface are explored via a group of numerical examples.It is demonstrated that whether the nonuniformity of the interface effects has a significant effect on the stress field around the inclusion mainly depends on the direction of the external loading and the aspect ratio of the inclusion.
基金the National Natural Science Foundation of China(No.11902147)the Natural Science Foundation of Jiangsu Province of China(No.BK20190393)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘The classical Green’s functions used in the literature for a heat source in a homogeneous elastic medium cannot lead to ?nite remote thermal stresses in the medium,so that they may not work well in practical thermal stress analyses. In this paper, we develop a practical Green’s function for a heat source disposed eccentrically into an elastic disk/cylinder subject to plane deformation. The edge of the disk/cylinder is assumed to be thermally permeable and traction-free. The full thermal stress ?eld induced by the heat source in the disk/cylinder is determined exactly and explicitly via the Cauchy integral techniques. In particular, a very simple formula is obtained to describe the hoop thermal stress on the edge of the disk/cylinder, which may be conveniently useful for analyzing the thermal stresses in microelectronic components.
基金supported by the National Natural Science Foundation of China(6137214261571005U1401252)
文摘Due to the frequency of occlusion, cluttering and lowcontrast edges, gray intensity based active contour models oftenfail to segment meaningful objects. Prior shape information is usuallyutilized to segment desirable objects. A parametric shape priormodel is proposed. Firstly, principal component analysis is employedto train object shape and transformation is added to shaperepresentation. Then the energy function is constructed througha combination of shape prior energy, gray intensity energy andshape constraint energy of the kernel density function. The objectboundary extraction process is converted into the parameters solvingprocess of object shape. Besides, two new shape prior energyfunctions are defined when desirable objects are occluded by otherobjects or some parts of them are missing. Finally, an alternatingdecent iteration solving scheme is proposed for numerical implementation.Experiments on synthetic and real images demonstratethe robustness and accuracy of the proposed method.
基金This research was funded by the National Natural Science Foundation of China(Grant No.31800487)the Natural Science Foundation of Heilongjiang Province of China(Grant No.QC2018018)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.2572019BB03)the Foundation of Key Laboratory of Pulp and Paper Science and Technology of Ministry of Education/Shandong Province of China(Grant No.KF201721)Any research results expressed in this paper are those of the writer(s)and do not necessarily reflect the views of the foundations.
文摘Nanopaper has attracted considerable interest in the fields of films and paper research.However,the challenge of integrating the many advantages of nanopaper still remains.Herein,we developed a facile strategy to fabricate multifunctional nanocomposite paper(NGCP)composed of wood-derived nanofibrillated cellulose(NFC)and graphene as building blocks.NFC suspension was consisted of long and entangled NFCs(10–30 nm in width)and their aggregates.Before NGCP formation,NFC was chemically modified with a silane coupling agent to ensure that it could interact strongly with graphene in NGCP.The resulting NGCP samples were flexible and could be bent repeatedly without any structural damage.Within the NGCP samples,the high aspect ratio of NFC made a major contribution to its high mechanical strength,whereas the sheet-like graphene endowed the NGCP with electrical resistance and electrochemical activity.The mechanical strength of the NGCP samples decreased as their graphene content increased.However,the electrical resistance and electrochemical activity of the NGCP samples both rose with increasing content of graphene.The NGCPs still kept advantageous mechanical properties even at high temperatures around 300℃ because of the high thermal stability of NFCs and their strong entangled web-like structures.In view of its sustainable building blocks and multifunctional characteristics,the NGCP developed in this work is promising as low-cost and high-performance nanopaper.
基金Project supported by the National Natural Science Foundation of China(Nos.11902147,11872203,and 51921003)the Natural Science Foundation of Jiangsu Province of China(No.BK20190393)and the Natural Sciences and Engineering Research Council of Canada(No.RGPIN–2017-03716115112)。
文摘The identification of multiple interacting inclusions with uniform internal stresses in an infinite elastic matrix subjected to a uniform remote loading is of fundamental importance in the mechanics and design of particulate composite materials.In anti-plane shear and plane deformations,certain sufficient conditions have been established in the literature which guarantee uniform internal stresses inside multiple interacting inclusions displaying various symmetries when the matrix is subjected to specific uniform remote loading.Correspondingly,sufficient conditions which allow for the design of multiple interacting inclusions independent of any specific form of(uniform)remote loading have also been established.In this paper,we demonstrate rigorously that,in all cases,these sufficient conditions are also necessary conditions and indeed allow for the identification of all possible collections of such inclusions.
基金Supported by the Research and Demonstration of Key Technologies for Crop Cost-Effective and High-Yield Production of the Project for Industry Leading Talents of Taishan(Lukezi[2016]NO.16)
文摘[Objectives] The aim was to study the effects of humic acid and DMPP on the growth of maize and explore the appropriate added concentration to provide basis for industrial production. [Methods]The pot experiment was used to study the effects of adding different concentrations of humic acid,DMPP and their compound on the growth of maize. [Results] Both humic acid and DMPP could increase plant height,stem diameter,SPAD and biomass of maize. The effect of adding 10 kg of humic acid per t was better than that adding 5 kg,and biomass increased by 5. 4% and 3. 3% compared with CK. The effect of adding 1 kg of DMPP was better than that adding 0. 5 kg,and biomass increased by 5. 7% and 2. 7% compared with CK. The compound application of the 2 improved the fertilizer efficiency. The best treatment was 5‰ humic acid ＋ 1 ‰ DMPP,which could increase plant height,stem diameter,SPAD,and dry weight by 8. 1%,12. 3%,10. 6%,and 10. 7%,respectively,and it also had lower economic costs compared with the compounding application of 10‰ humic acid ＋ 1‰ DMPP.[Conclusions]The 5‰ humic acid ＋ 1 ‰ DMPP compound fertilizer formula was more suitable for application in maize production.
基金the China Scholar・ship Council(No.201904910117)Jilin Province Talent Development Fund[2018]853 awarded to F.Wang。
文摘We report on two strategies to design and implement the galvanometer-based laser-scanning mechanisms for the realization of reflectance confocal microscopy(RCM) and stimulated Raman scattering(SRS) microscopy systems. The RCM system uses a resonant galvanometer scanner driven by a home-built field-programmable gate array circuit with a novel dual-trigger mode and a home-built high-speed data acquisition card. The SRS system uses linear galvanometers with commercially available modules. We demonstrate video-rate high-resolution imaging at 11 frames per second of in vivo human skin with the RCM system and label-free biomolecular imaging of cancer cells with the SRS system. A comparison of the two strategies for controlling galvanometer scanners provides scientific and technical reference for future design and commercialization of various laser-scanning microscopes using galvanometers.
基金supported by the Medical Scientific Research Foundation of Guangdong province(B2020012,C2019062,C2023023,C2023022,C2021023,and B2023283),China.
文摘Objective:To investigate the radioactivity levels of seawater,sediments,and biota in the Daya Bay sea area,China,in order to establish the radioactivity baseline values,and provide basic data for the assessment of potential radiological risks that might result from the application of nuclear technology or human activities.Methods:Samples of seawater,sediments,and biota were collected from the Daya Bay sea area and analyzed.Their radioactivity baseline data were then compared with information from other regions in China and around the world reported in related literature.Results:For the seawater samples,the activity concentrations of natural radionuclide ^(40)K were 9.9-10.4 Bq/L,while ^(238)U,226Ra,^(210)Pb,^(137)Cs,and ^(110)Ag^(m) were below the minimum detectable activity(MDA).Regarding the sediment samples,the activity concentrations of ^(238)U,^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 38.1-40.4,49.1-53.7,32.6-38.6,59-95,590-650,and 0.48-0.88 Bq/(kg dry weight),respectively,while ^(110)Agm was below the MDA.For the marine shrimps in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(40)K,and ^(137)Cs were 1.14-2.75,0.17-0.43,63-76,and 0.038-0.045 Bq/(kg wet weight),respectively,while ^(238)U,^(210)Pb,and ^(110)Agm were all below the MDA.Furthermore,for the marine fishes in the biota samples,the activity concentrations of ^(228)Ra,^(226)Ra,^(210)Pb,^(40)K,and ^(137)Cs were 2.1-19.7,0.32-3.78,<2.2-2.8,59-70,and<0.007-0.026 Bq/(kg wet weight),respectively,while ^(238)U and ^(110)Ag^(m) were all below the MDA.^(228)Ra was found to be concentrated in Osteomugil ophuyseni with 19.7 Bq/(kg wet weight).Conclusions:The radioactivity levels of seawater and marine sediments in the Daya Bay sea area are within the range of the normal background values.Osteomugil ophuyseni exhibited higher concentrations of ^(228)Ra than other species in this study,while the other species in the biota show no significant difference in the radioactivity levels from data in relevant literature.
基金supported by a grant from the National Natural Sciences Foundation of China(No.81201261).
文摘Background:Tuberculosis is a leading cause of morbidity and mortality in humans worldwide.There is an urgent need for new and effective drugs to treat tuberculosis and shorten the duration of tuberculosis therapy.1,25-dihydroxy vitamin D3(1,25(OH)2D3)has been reported to have a synergistic effect with pyrazinamide(PZA)in killing tubercle bacilli in vitro.The addition of 1,25(OH)2D3 to standard tuberculosis treatment should benefit patients if the adjunctive drug has a synergistic effect in vivo.Thus,in this study,calcitriol(bioactive 1,25(OH)2D3)was administered to mice undergoing treatment for Mycobacterium tuberculosis(M.tb)infection with PZA,a first-line anti-tuberculosis drug,to determine whether vitamin D3 enhances the therapeutic effect.Methods:C57BL/6 female mice were infected with the M.tb H37Rv strain through aerosol exposure.Calcitriol and PZA,either alone or in combination,were orally administered to the M.tb infected mice.The effect of calcitriol on PZA activity was determined by evaluating the bacterial burden and analyzing the histopathological lesions in the lungs and spleen.To investigate the expression of inflammatory cytokines and anti-microbial peptide genes,we determined the transcriptional levels of interferon-γ(IFN-γ),interleukin-4(IL-4),mouseβ-defensin-2(mBD2),and cathelicidin LL-37 through real-time quantitative polymerase chain reaction.The protein levels of IFN-γwere detected by enzyme-linked immunosorbent assay.Differences between groups were analyzed with independent samples t-test or one-way analysis of variance.Results:Calcitriol alone had little effect on tuberculosis infection,whereas PZA,compared with saline control treatment,decreased the bacterial burden(spleens:PZA vs.saline,4.82±0.22 vs.5.22±0.40 Log10 colony-forming units[CFU]/gram,t=2.13,P<0.05;lungs:PZA vs.saline,5.55±0.15 vs.6.83±0.46 Log10 CFU/gram,t=6.56,P<0.01)and pathological lesions in the lungs.Simultaneous administration of calcitriol with PZA,compared with PZA alone,decreased the bacterial load(spleen:calcitriol+PZA vs.PZA,4.37±0.13 vs.4.82±0.22 Log10 CFU/gram,t=4.36,P<0.01;lung:calcitriol+PZA vs.PZA,5.03±0.32 vs.5.55±0.15 Log10 CFU/gram,t=3.58,P<0.01)and attenuated the lung lesions(gross pathological score:calcitriol+PZA vs.PZA,3.25±0.50 vs.2.50±0.58,t=1.96,P<0.05;affected area of total lung area:calcitriol+PZA vs.PZA,30.75%±6.50%vs.21.55%±2.99%,t=2.66,P<0.05).Further studies demonstrated calcitriol significantly increased the expression of anti-inflammatory cytokine IL-4 but suppressed production of the pro-inflammatory cytokine IFN-γ(IL-4:calcitriol vs.saline,5.69±0.50 vs.2.80±0.56 fold of control,t=6.74,P<0.01;IFN-γ:calcitriol vs.saline,1.36±0.11 vs.4.13±0.83 fold of control,t=5.77,P<0.01).In addition,calcitriol alone or in combination with PZA significantly enhanced the transcriptional level of anti-microbial peptides(cathelicidin LL-37:calcitriol vs.saline,10.59±1.03 vs.2.80±0.90 fold of control,t=9.85,P<0.01;mBD2:calcitriol vs.saline,7.92±0.62 vs.1.79±0.45 fold of control,t=13.82,P<0.01),whereas PZA exerted a negative effect on anti-microbial peptide gene expression.Conclusions:Calcitriol as adjunctive treatment can result in beneficial treatment outcomes in M.tb infection by suppressing the inflammatory response and up-regulating the expression of anti-microbial peptides.These results indicate the feasibility of using calcitriol adjunctively with standard chemotherapy for the treatment of M.tb infection.
基金supported by grants from the Ministry of Science and Tech-nology and the National Natural Science Foundation of China(2022YFA1303100-32090040,32370772,92253305,32090043)Anhui Provincial Natural Science Foundation Grant(2408085J014,202303a07020002,202303a07020003)+3 种基金the Ministry of Edu-cation(IRT_17R102,20113402130010YD2070006001)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB19040000)the Fundamental Research Funds for the Central Universities(WK2070000194)。
文摘Dear Editor,Microtubule cytoskeleton is consisted ofα/β-tubulin dimers,which assemble end-to-end for protofilaments to form the polar and hollow tube that is 25 nm in diameter(Gudimchuk and McIntosh,2021).Microtubule dynamics normally present at the plus end,driven byβ-tubulin-bound guanosine triphosphate(GTP)hydrolysis and the end-associated proteins,such as end-binding protein 1(EB1).In eukaryotes,EB1 tracks the growing microtubule plus end,which is dependent on the presence of theβ-tubulin-bound GTP nucleotide,to promote the microtubule growth and catastrophe frequency(Zhang et al.,2015).EB1 consists of a calponin homology(CH)domain for microtubule binding,a linker region(intrinsic disorder region),and an end-binding homolog(EBH)domain for dimerization.The dimerized EBH domains form a hydrophobic cavity to recruit the SxIP-containing microtubule plus-end tracking proteins(+TIPs),and the flexible C-terminal tail of EB1 contains an evolutionarily conserved glutamic acid-glutamic acid-tyrosine motif that is responsible for interactions with the CAP-GLY domain-containing binding partners(Gudimchuk and McIntosh,2021).
