Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells en...Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.展开更多
Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects ...Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.展开更多
We report on the discovery of a new genus of microhylid subfamily Asterophryinae from northern and eastern Indochina, containing three new species. Vietnamophryne （3en. nov. are secretive miniaturized frogs （SVL〈21...We report on the discovery of a new genus of microhylid subfamily Asterophryinae from northern and eastern Indochina, containing three new species. Vietnamophryne （3en. nov. are secretive miniaturized frogs （SVL〈21 mm） with a mostly semi-fossorial lifestyle. To assess phylogenetic relationships, we studied 12S rRNA - 16S rRNA mtDNA fragments with a final alignment of 2 591 bp for 53 microhylid species. Morphological and osteological characters were analyzed using micro-CT scanning and used to describe the new genus. Results of phylogenetic analyses assigned the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Siamophryne from southern Indochina. The three specimens collected from Gia Lai Province in central Vietnam, Cao Bang Province in northern Vietnam, and Chiang Rai Province in northern Thailand proved to be separate species, different both in morphology and genetics （genetic divergence 3.1%〈P〈5.1%）. Our work provides further evidence for the ＂out of Indo-Eurasia＂ scenario for Asterophryinae, indicating that the initial cladogenesis and differentiation of this group of frogs occurred in the Indochina Peninsula. To date, eachof the three new species of Vietnamophryne Gen. nov. is known only from a single specimen; thus, their distribution, life history, and conservation status require further study.展开更多
Shale oil is one of the most promising alternative unconventional energies in the world,and Lucaogou Formation shows significant exploration potential,becoming the primary target in northwestern China.This paper compa...Shale oil is one of the most promising alternative unconventional energies in the world,and Lucaogou Formation shows significant exploration potential,becoming the primary target in northwestern China.This paper compared the mechanical properties of shale layered samples from oil layer and interlayer of Lucaogou Formation,using uniaxial compressive tests with real-time micro-CT scanning.After that,the mineral analysis was conducted on one cross-section of the fractured sample to analyze the influence of mineral composition and distribution on micro-crack propagation.Such research has rarely been reported before.The results showed the surface porosity and elastic modulus of oil-bearing samples is larger than that of the interlayer samples,while the uniaxial compressive strength is lower.Besides,when there is only one dominant mineral with a content greater than 60%,a main crack tends to form at this area;When there are 2~3 major minerals with a content of 10%-60%,a fractured zone with many fine micro-cracks is more likely to form here.Finally,the higher the Moh's hardness of the mineral,the more difficult it is for micro-cracks to develop through it.展开更多
Background With aging, the human fracture risk gradually increase. This is mainly due to the corresponding changes of the biomechanical parameters of human bone presents with aging. We measured the microstructural par...Background With aging, the human fracture risk gradually increase. This is mainly due to the corresponding changes of the biomechanical parameters of human bone presents with aging. We measured the microstructural parameters of lumbar bone from women in several age groups by micro-computed tomography and scanning electron microscopy. We observed changes in lumbar cancellous bone mineral density and in biomechanical parameters with aging to elucidate the relationship between age and risk of fracture. We provide theoretical support for human pathology, fracture risk increased with age and the individualized of each age group.展开更多
The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water floo...The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water flooding development effects of Mobei reservoir,the mercury intrusion porosimetry,water flooding CT scanning and micro-CT scanning experiments are used in this study.The result shows that the reservoir has the strong heterogeneity which is weaken gradually from A1 reservoir to A2 reservoir.Reservoir pore radius is mainly distributed in the 100e200 microns,the throat radius is mainly distributed in the 1e3 micron.The water flooding core experiment in each reservoir shows a short water-free oil production period and rapid water cut after breakthrough.The A2 reservoir core flooding process is similar to piston displacement,the A1 reservoir core flooding process refers to the phenomenon(The fingering phenomenon in the process of core flooding in the A1 reservoir is obvious).The calculated water drive efficiency of the A2 reservoir is 61.2%,which is higher than 49.1%of the A1 reservoir.According to the CT scanning process,the Mobei oilfield has low micro displacement efficiency and the A1 reservoir has a smaller spread(sweep area)and higher residual oil saturation.展开更多
基金supported by the National Natural Science Foundation of China,No.32171356(to YW)Self-Support Research Projects of Shihezi University,No.ZZZC2021105(to WJ)+1 种基金Capital Medical University Natural Science Cultivation Fund,No.PYZ23044(to FQM)Beijing Municipal Natural Science Foundation,No.7244410(to JHD)。
文摘Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.
基金supported by grants from the Human Resources Development program(Grant No.20204010600250)the Training Program of CCUS for the Green Growth(Grant No.20214000000500)by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)funded by the Ministry of Trade,Industry,and Energy of the Korean Government(MOTIE).
文摘Three-dimensional printing(3DP)offers valuable insight into the characterization of natural rocks and the verification of theoretical models due to its high reproducibility and accurate replication of complex defects such as cracks and pores.In this study,3DP gypsum samples with different printing directions were subjected to a series of uniaxial compression tests with in situ micro-computed tomography(micro-CT)scanning to quantitatively investigate their mechanical anisotropic properties and damage evolution characteristics.Based on the two-dimensional(2D)CT images obtained at different scanning steps,a novel void ratio variable was derived using the mean value and variance of CT intensity.Additionally,a constitutive model was formulated incorporating the proposed damage variable,utilizing the void ratio variable.The crack evolution and crack morphology of 3DP gypsum samples were obtained and analyzed using the 3D models reconstructed from the CT images.The results indicate that 3DP gypsum samples exhibit mechanical anisotropic characteristics similar to those found in naturally sedimentary rocks.The mechanical anisotropy is attributed to the bedding planes formed between adjacent layers and pillar-like structures along the printing direction formed by CaSO_(4)·2H_(2)O crystals of needle-like morphology.The mean gray intensity of the voids has a positive linear relationship with the threshold value,while the CT variance and void ratio have concave and convex relationships,respectively.The constitutive model can effectively match the stress–strain curves obtained from uniaxial compression experiments.This study provides comprehensive explanations of the failure modes and anisotropic mechanisms of 3DP gypsum samples,which is important for characterizing and understanding the failure mechanism and microstructural evolution of 3DP rocks when modeling natural rock behavior.
基金supported by the programs of the National Natural Science Foundation of China(31501843,31622052)Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(CAS)(Y4ZK111B01:2017CASSEABRIQG002)+2 种基金Animal Branch of the Germplasm Bank of Wild Species,CAS(Large Research Infrastructure Funding)Thailand Research Fund(TRF)(DBG6180001)Molecular experiments,phylogenetic analyses,specimen storage,examination and micro CT-analysis were carried out with the financial support of the Russian Science Foundation(RSF14-50-00029)
文摘We report on the discovery of a new genus of microhylid subfamily Asterophryinae from northern and eastern Indochina, containing three new species. Vietnamophryne （3en. nov. are secretive miniaturized frogs （SVL〈21 mm） with a mostly semi-fossorial lifestyle. To assess phylogenetic relationships, we studied 12S rRNA - 16S rRNA mtDNA fragments with a final alignment of 2 591 bp for 53 microhylid species. Morphological and osteological characters were analyzed using micro-CT scanning and used to describe the new genus. Results of phylogenetic analyses assigned the new genus into the mainly Australasian subfamily Asterophryinae as a sister taxon to the genus Siamophryne from southern Indochina. The three specimens collected from Gia Lai Province in central Vietnam, Cao Bang Province in northern Vietnam, and Chiang Rai Province in northern Thailand proved to be separate species, different both in morphology and genetics （genetic divergence 3.1%〈P〈5.1%）. Our work provides further evidence for the ＂out of Indo-Eurasia＂ scenario for Asterophryinae, indicating that the initial cladogenesis and differentiation of this group of frogs occurred in the Indochina Peninsula. To date, eachof the three new species of Vietnamophryne Gen. nov. is known only from a single specimen; thus, their distribution, life history, and conservation status require further study.
基金supported by the National Natural Science Foundation of China(No.42090023,42102323,51734009,42102322)the Scientific Research and Technology Development Project of China National Petroleum Corporation(2022DJ5503)the Joint Geological Funds of the National Natural Science Foundation of China(U2244223)。
文摘Shale oil is one of the most promising alternative unconventional energies in the world,and Lucaogou Formation shows significant exploration potential,becoming the primary target in northwestern China.This paper compared the mechanical properties of shale layered samples from oil layer and interlayer of Lucaogou Formation,using uniaxial compressive tests with real-time micro-CT scanning.After that,the mineral analysis was conducted on one cross-section of the fractured sample to analyze the influence of mineral composition and distribution on micro-crack propagation.Such research has rarely been reported before.The results showed the surface porosity and elastic modulus of oil-bearing samples is larger than that of the interlayer samples,while the uniaxial compressive strength is lower.Besides,when there is only one dominant mineral with a content greater than 60%,a main crack tends to form at this area;When there are 2~3 major minerals with a content of 10%-60%,a fractured zone with many fine micro-cracks is more likely to form here.Finally,the higher the Moh's hardness of the mineral,the more difficult it is for micro-cracks to develop through it.
文摘Background With aging, the human fracture risk gradually increase. This is mainly due to the corresponding changes of the biomechanical parameters of human bone presents with aging. We measured the microstructural parameters of lumbar bone from women in several age groups by micro-computed tomography and scanning electron microscopy. We observed changes in lumbar cancellous bone mineral density and in biomechanical parameters with aging to elucidate the relationship between age and risk of fracture. We provide theoretical support for human pathology, fracture risk increased with age and the individualized of each age group.
基金We gratefully acknowledge financial support from This work was supported by the National Science and Technology Major Project of China(2017ZX05070002,2017ZX05013003-001).
文摘The Mobei reservoir is a low-permeability-sandstone reservoir,due to differences in pore geometry,it can be divided into two independent reservoirs:A1 reservoir and A2 reservoir.For better understanding the water flooding development effects of Mobei reservoir,the mercury intrusion porosimetry,water flooding CT scanning and micro-CT scanning experiments are used in this study.The result shows that the reservoir has the strong heterogeneity which is weaken gradually from A1 reservoir to A2 reservoir.Reservoir pore radius is mainly distributed in the 100e200 microns,the throat radius is mainly distributed in the 1e3 micron.The water flooding core experiment in each reservoir shows a short water-free oil production period and rapid water cut after breakthrough.The A2 reservoir core flooding process is similar to piston displacement,the A1 reservoir core flooding process refers to the phenomenon(The fingering phenomenon in the process of core flooding in the A1 reservoir is obvious).The calculated water drive efficiency of the A2 reservoir is 61.2%,which is higher than 49.1%of the A1 reservoir.According to the CT scanning process,the Mobei oilfield has low micro displacement efficiency and the A1 reservoir has a smaller spread(sweep area)and higher residual oil saturation.
