Background： Early pregnancy failure has a profound impact on both human reproductive health and animal production. 2/3 pregnancy failures occur during the peri-implantation period; however, the underlying mechanism（...Background： Early pregnancy failure has a profound impact on both human reproductive health and animal production. 2/3 pregnancy failures occur during the peri-implantation period; however, the underlying mechanism（s） remains unclear. Well-organized modification of the endometrium to a receptive state is critical to establish pregnancy Aberrant endometrial modification during implantation is thought to be largely responsible for early pregnancy loss. Result： In this study, using well-managed recipient ewes that received embryo transfer as model, we compared the endometrial proteome between pregnant and non-pregnant ewes during implantation period. After embryo transfer, recipients were assigned as pregnant or non-pregnant ewes according to the presence or absence of an elongated conceptus at Day 17 of pregnancy. By comparing the endometrial proteomic profiles between pregnant and non-pregnant ewes, we identified 94 and 257 differentially expressed proteins （DEPs） in the endometrial caruncular and intercaruncular areas, respectively. Functional analysis showed that the DEPs were mainly associated with immune response, nutrient transport and utilization, as well as proteasome-mediated proteolysis. Conclusion： These analysis imply that dysfunction of these biological processes or pathways of DEP in the endometrium is highly associated with early pregnancy loss. In addition, many proteins that are essential for the establishment of pregnancy showed dysregulation in the endometrium of non-pregnant ewes. These proteins, as potential candidates, may contribute to early pregnancy loss.展开更多
Background:Implantation failure limits the success of in vitro fertilization and embryo transfer(IVF-ET).Wellorganized embryo-maternal crosstalk is essential for successful implantation.Previous studies mainly focused...Background:Implantation failure limits the success of in vitro fertilization and embryo transfer(IVF-ET).Wellorganized embryo-maternal crosstalk is essential for successful implantation.Previous studies mainly focused on the aberrant development of in vitro fertilized(IVF)embryos.In contrast,the mechanism of IVF-induced aberrant embryo-maternal crosstalk is not well defined.Results:In the present study,using ewes as the model,we profiled the proteome that features aberrant IVF embryo-maternal crosstalk following IVF-ET.By comparing in vivo(IVO)and IVF conceptuses,as well as matched endometrial caruncular(C)and intercaruncular(IC)areas,we filtered out 207,295,and 403 differentially expressed proteins(DEPs)in each comparison.Proteome functional analysis showed that the IVF conceptuses were characterized by the increased abundance of energy metabolism and proliferation-related proteins,and the decreased abundance of methyl metabolism-related proteins.In addition,IVF endometrial C areas showed the decreased abundance of endometrial remodeling and redox homeostasis-related proteins;while IC areas displayed the aberrant abundance of protein homeostasis and extracellular matrix(ECM)interaction-related proteins.Based on these observations,we propose a model depicting the disrupted embryo-maternal crosstalk following IVF-ET:Aberrant energy metabolism and redox homeostasis of IVF embryos,might lead to an aberrant endometrial response to conceptus-derived pregnancy signals,thus impairing maternal receptivity.In turn,the suboptimal uterine environment might stimulate a compensation effect of the IVF conceptuses,which was revealed as enhanced energy metabolism and over-proliferation.Conclusion:Systematic proteomic profiling provides insights to understand the mechanisms that underlie the aberrant IVF embryo-maternal crosstalk.This might be helpful to develop practical strategies to prevent implantation failure following IVF-ET.展开更多
The endometrium of sheep consists of plenty of raised intercaruncular areas （IC）. In order to better understand aglandular areas called caruncular （C）, and intensely glandular the endometrium involved mechanisms o...The endometrium of sheep consists of plenty of raised intercaruncular areas （IC）. In order to better understand aglandular areas called caruncular （C）, and intensely glandular the endometrium involved mechanisms of implantation, we used LC-MS/MS technique to profile the proteome of ovine endometrial C areas and IC areas separately during the peri-implantation period, and then compared the proteomic profiles between these two areas. We successfully detected 1740 and 1813 proteins in C areas and IC areas respectively. By comparing the proteome of these two areas, we found 170 differentially expressed proteins （DEPs） （P 〈 0.05）, functional bioinformatics analysis showed these DEPs were mainly involved in growth and remodeling of endometrial tissue, cell adhesion and protein transport, and so on Our study, for the first time, provided a proteomic reference for elucidating the differences between C and IC areas, as an integrated function unit respectively, during the peri-implantation period. The results could help us to better understand the implantation in the ewes. In addition, we established a relatively detailed protein database of ovine endometrium, which provide a unique reference for further studies.展开更多
Stray grains,the most serious casting defect,mainly occur in the platform because of the abrupt transition of the cross-section in the directional solidification of superalloy single-crystal blades.A new mould baffle ...Stray grains,the most serious casting defect,mainly occur in the platform because of the abrupt transition of the cross-section in the directional solidification of superalloy single-crystal blades.A new mould baffle technology based on 3D printing and gelcasting is proposed herein to reduce the formation of stray grains in the platform.The influence of the proposed mould baffle technology on the temperature field in the platform during solidification was investigated by simulation and experiment.The numerical simulation results indicate that the proposed mould baffle technology can effectively hinder the radiation and heat dissipation at the platform extremities,and therefore,reduce undercooling in the platform and the formation of stray grains during directional solidification.Casting trials of a hollow turbine blade were conducted using CMSX-4 superalloy.The trial results demonstrate the potential of the proposed approach for manufacturing single-crystal superalloy blades.展开更多
Porous oxide ceramics are widely used in extreme working conditions owing to their excellent resistance to high temperatures and corrosion.However,sintering is an inevitable process applied to ceramics,from the green ...Porous oxide ceramics are widely used in extreme working conditions owing to their excellent resistance to high temperatures and corrosion.However,sintering is an inevitable process applied to ceramics,from the green body to the final product.The highly complex structures exacerbate the shrinkage-induced ir-regular deformation and crack formation in the sintering process.A pioneering approach is developed in this study to achieve zero shrinkage for porous alumina ceramics during multistep sintering,using a combination of active fillers-ZrAl 3 and Al 75 Si 25.The response surface method is used to optimize the material compositions and sintering process,to achieve shrinkages of less than 0.05%for the entire pro-cess.The sintering expansion mechanism is investigated by analyzing the pyrolysis and microstructures of samples at different temperatures.The combination of ZrAl 3 and Al 75 Si 25 can attain the continuous expansion of the matrix in a wide temperature range of 600-1400°C.Furthermore,typical alumina com-ponents are fabricated and used to verify the effectiveness of the proposed approach.Owing to shrinkage suppression,the profile deviation of the samples is less than 0.1 mm,and the proportion of microcracks is reduced by 97.8%.The suggested approach shows potential applications in near-net,low-defect fabrica-tion of complex fine ceramic components.展开更多
The precision casting method based on aluminabased ceramic cores is one of the main techniques used to manufacture hollow turbine blades.Additive manufacturing(AM)technology provides an alternate solution to fabricati...The precision casting method based on aluminabased ceramic cores is one of the main techniques used to manufacture hollow turbine blades.Additive manufacturing(AM)technology provides an alternate solution to fabricating ceramic cores quickly and precisely.As the complexity of the structure increases and the strength of the material improves,the leaching process of the cores becomes more complicated.This study proposes a compound pore-forming method to increase the porosity of ceramic cores by adding a preformed-pore agent and materials that convert to easy-to-corrode phases.The preformed-pore agents(e.g.,carbon fibers)can be burned off during sintering to form pores before the leaching,and the easy-to-corrode phases(e.g.,CaCO3,SiO2,^-A12O3)can be leached firstly to form pores during the leaching process.The pores formed in the aforementioned two stages increase the contact area of the cores and leaching solution,thus improving the leaching rate.In the current study,the additive amount of the preformed-pore agent was optimized,and the effect of the easy-to-corrode phases on the comprehensive properties of the cores was then compared.Based on this,the corresponding model was established.展开更多
Investment casting based on stereolithography(SL)has the characteristics of short production cycle and low cost,which is especially suitable for fabricating complex aeronautical parts without metal dies.But there are ...Investment casting based on stereolithography(SL)has the characteristics of short production cycle and low cost,which is especially suitable for fabricating complex aeronautical parts without metal dies.But there are some problems during the fabrication process,such as low surface accuracy caused by the staircases of resin prototype,shell cracking caused by higher thermal stress during the sintering process and so on.Taking an engine turbine stator as a fabrication example,the surface accuracy of resin prototype under the effect of coating method was investigated using the laser confocal microscopy;what’s more,both theoretical analysis and finite element analysis(FEA)were combined and compared to reveal the thermal stress field of ceramic shell during pyrolyzing and sintering process under different situation.It was founded that the surface staircases of the resin prototype was eliminated and the surface quality was improved after coating process,the thermal stress was decreased and shell cracking was avoided by sintering the ceramic shell with the inner hollow resin prototype under the heating rate of 51C/min.The result showed that,the metal turbine stator had high dimensional accuracy of CT4-CT6 and had a good surface finish within Ra 3.2.展开更多
基金supported by grants from the National High-Tech R&D Program (Nos.2011AA100303,2013AA102506)the National Key Technology R&D Program(Nos.2011BAD19B01,2011BAD19B03,2011BAD19B04)
文摘Background： Early pregnancy failure has a profound impact on both human reproductive health and animal production. 2/3 pregnancy failures occur during the peri-implantation period; however, the underlying mechanism（s） remains unclear. Well-organized modification of the endometrium to a receptive state is critical to establish pregnancy Aberrant endometrial modification during implantation is thought to be largely responsible for early pregnancy loss. Result： In this study, using well-managed recipient ewes that received embryo transfer as model, we compared the endometrial proteome between pregnant and non-pregnant ewes during implantation period. After embryo transfer, recipients were assigned as pregnant or non-pregnant ewes according to the presence or absence of an elongated conceptus at Day 17 of pregnancy. By comparing the endometrial proteomic profiles between pregnant and non-pregnant ewes, we identified 94 and 257 differentially expressed proteins （DEPs） in the endometrial caruncular and intercaruncular areas, respectively. Functional analysis showed that the DEPs were mainly associated with immune response, nutrient transport and utilization, as well as proteasome-mediated proteolysis. Conclusion： These analysis imply that dysfunction of these biological processes or pathways of DEP in the endometrium is highly associated with early pregnancy loss. In addition, many proteins that are essential for the establishment of pregnancy showed dysregulation in the endometrium of non-pregnant ewes. These proteins, as potential candidates, may contribute to early pregnancy loss.
基金supported by the grants from National Key R&D Program(2017YFD0501901 and 2017YFD0501905)National Natural Science Foundation of China(No.3167246 and 31972573)+1 种基金National Support Program for Youth Top-notch Talentsthe Earmarked Fund for the Innovative Teams of Beijing Swine Industrialization Research Program.
文摘Background:Implantation failure limits the success of in vitro fertilization and embryo transfer(IVF-ET).Wellorganized embryo-maternal crosstalk is essential for successful implantation.Previous studies mainly focused on the aberrant development of in vitro fertilized(IVF)embryos.In contrast,the mechanism of IVF-induced aberrant embryo-maternal crosstalk is not well defined.Results:In the present study,using ewes as the model,we profiled the proteome that features aberrant IVF embryo-maternal crosstalk following IVF-ET.By comparing in vivo(IVO)and IVF conceptuses,as well as matched endometrial caruncular(C)and intercaruncular(IC)areas,we filtered out 207,295,and 403 differentially expressed proteins(DEPs)in each comparison.Proteome functional analysis showed that the IVF conceptuses were characterized by the increased abundance of energy metabolism and proliferation-related proteins,and the decreased abundance of methyl metabolism-related proteins.In addition,IVF endometrial C areas showed the decreased abundance of endometrial remodeling and redox homeostasis-related proteins;while IC areas displayed the aberrant abundance of protein homeostasis and extracellular matrix(ECM)interaction-related proteins.Based on these observations,we propose a model depicting the disrupted embryo-maternal crosstalk following IVF-ET:Aberrant energy metabolism and redox homeostasis of IVF embryos,might lead to an aberrant endometrial response to conceptus-derived pregnancy signals,thus impairing maternal receptivity.In turn,the suboptimal uterine environment might stimulate a compensation effect of the IVF conceptuses,which was revealed as enhanced energy metabolism and over-proliferation.Conclusion:Systematic proteomic profiling provides insights to understand the mechanisms that underlie the aberrant IVF embryo-maternal crosstalk.This might be helpful to develop practical strategies to prevent implantation failure following IVF-ET.
基金supported by grants from the National Key Technology R&D Program(Nos.2011BAD19B01,2011BAD19B03,2011BAD19B04)the National High-Tech R&D Program(No.2011AA100303,2013AA102506)
文摘The endometrium of sheep consists of plenty of raised intercaruncular areas （IC）. In order to better understand aglandular areas called caruncular （C）, and intensely glandular the endometrium involved mechanisms of implantation, we used LC-MS/MS technique to profile the proteome of ovine endometrial C areas and IC areas separately during the peri-implantation period, and then compared the proteomic profiles between these two areas. We successfully detected 1740 and 1813 proteins in C areas and IC areas respectively. By comparing the proteome of these two areas, we found 170 differentially expressed proteins （DEPs） （P 〈 0.05）, functional bioinformatics analysis showed these DEPs were mainly involved in growth and remodeling of endometrial tissue, cell adhesion and protein transport, and so on Our study, for the first time, provided a proteomic reference for elucidating the differences between C and IC areas, as an integrated function unit respectively, during the peri-implantation period. The results could help us to better understand the implantation in the ewes. In addition, we established a relatively detailed protein database of ovine endometrium, which provide a unique reference for further studies.
基金the Industry-University Research Cooperation Project of Aero Engine Corporation of China(Grant No.HFZL2019CXY023)the National Science and Technology Major Project(Grant No.2017-Ⅶ-0008-0101)。
文摘Stray grains,the most serious casting defect,mainly occur in the platform because of the abrupt transition of the cross-section in the directional solidification of superalloy single-crystal blades.A new mould baffle technology based on 3D printing and gelcasting is proposed herein to reduce the formation of stray grains in the platform.The influence of the proposed mould baffle technology on the temperature field in the platform during solidification was investigated by simulation and experiment.The numerical simulation results indicate that the proposed mould baffle technology can effectively hinder the radiation and heat dissipation at the platform extremities,and therefore,reduce undercooling in the platform and the formation of stray grains during directional solidification.Casting trials of a hollow turbine blade were conducted using CMSX-4 superalloy.The trial results demonstrate the potential of the proposed approach for manufacturing single-crystal superalloy blades.
基金the National Natural Science Foun-dation of China(No.52005392)the National Science and Tech-nology Major Project(No.J2019-Ⅶ−0013-0153)the Fundamental Research Funds for the Central Universities,and the Youth Innova-tion Team of Shaanxi Universities.
文摘Porous oxide ceramics are widely used in extreme working conditions owing to their excellent resistance to high temperatures and corrosion.However,sintering is an inevitable process applied to ceramics,from the green body to the final product.The highly complex structures exacerbate the shrinkage-induced ir-regular deformation and crack formation in the sintering process.A pioneering approach is developed in this study to achieve zero shrinkage for porous alumina ceramics during multistep sintering,using a combination of active fillers-ZrAl 3 and Al 75 Si 25.The response surface method is used to optimize the material compositions and sintering process,to achieve shrinkages of less than 0.05%for the entire pro-cess.The sintering expansion mechanism is investigated by analyzing the pyrolysis and microstructures of samples at different temperatures.The combination of ZrAl 3 and Al 75 Si 25 can attain the continuous expansion of the matrix in a wide temperature range of 600-1400°C.Furthermore,typical alumina com-ponents are fabricated and used to verify the effectiveness of the proposed approach.Owing to shrinkage suppression,the profile deviation of the samples is less than 0.1 mm,and the proportion of microcracks is reduced by 97.8%.The suggested approach shows potential applications in near-net,low-defect fabrica-tion of complex fine ceramic components.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51505457)the National Science and Technology Major Project(Grant No.2017-VII-0008-0101)+2 种基金the Key Research and Development Program of Shaanxi Province(Grant No.2018ZDXM-GY-059)the Open Fund of State Key Laboratory of Manufacturing Systems Engineering(Grant No.SKLMS2016013)the Fundamental Research Funds for the Central Universities,and the Youth Innovation Team of Shaanxi Universities.
文摘The precision casting method based on aluminabased ceramic cores is one of the main techniques used to manufacture hollow turbine blades.Additive manufacturing(AM)technology provides an alternate solution to fabricating ceramic cores quickly and precisely.As the complexity of the structure increases and the strength of the material improves,the leaching process of the cores becomes more complicated.This study proposes a compound pore-forming method to increase the porosity of ceramic cores by adding a preformed-pore agent and materials that convert to easy-to-corrode phases.The preformed-pore agents(e.g.,carbon fibers)can be burned off during sintering to form pores before the leaching,and the easy-to-corrode phases(e.g.,CaCO3,SiO2,^-A12O3)can be leached firstly to form pores during the leaching process.The pores formed in the aforementioned two stages increase the contact area of the cores and leaching solution,thus improving the leaching rate.In the current study,the additive amount of the preformed-pore agent was optimized,and the effect of the easy-to-corrode phases on the comprehensive properties of the cores was then compared.Based on this,the corresponding model was established.
基金National Science and Technology Major Project(No.2012ZX04007021).
文摘Investment casting based on stereolithography(SL)has the characteristics of short production cycle and low cost,which is especially suitable for fabricating complex aeronautical parts without metal dies.But there are some problems during the fabrication process,such as low surface accuracy caused by the staircases of resin prototype,shell cracking caused by higher thermal stress during the sintering process and so on.Taking an engine turbine stator as a fabrication example,the surface accuracy of resin prototype under the effect of coating method was investigated using the laser confocal microscopy;what’s more,both theoretical analysis and finite element analysis(FEA)were combined and compared to reveal the thermal stress field of ceramic shell during pyrolyzing and sintering process under different situation.It was founded that the surface staircases of the resin prototype was eliminated and the surface quality was improved after coating process,the thermal stress was decreased and shell cracking was avoided by sintering the ceramic shell with the inner hollow resin prototype under the heating rate of 51C/min.The result showed that,the metal turbine stator had high dimensional accuracy of CT4-CT6 and had a good surface finish within Ra 3.2.
