CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-nu...CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-null mice showed decreased callus bone formation as assessed by microcomputed tomography 10 days post-fracture and increased fibrous volume as determined by histology.To understand the cellular basis for this phenotype,mesenchymal progenitors(MSC)were harvested from bone marrow.CD47-null MSC showed decreased large fibroblast colony formation(CFU-F),significantly less proliferation,and fewer cells in Sphase,although osteoblast differentiation was unaffected.However,consistent with prior research,CD47-null endothelial cells showed increased proliferation relative to WT cells.Similarly,in a murine ischemic fracture model,CD47-null mice showed reduced fracture callus size due to a reduction in bone relative to WT 15 days-post fracture.Consistent with our in vitro results,in vivo EdU labeling showed decreased cell proliferation in the callus of CD47-null mice,while staining for CD31 and endomucin demonstrated increased endothelial cell density.Finally,WT mice with ischemic fracture that were administered a CD47 morpholino,which blocks CD47 protein production,showed a callus phenotype similar to that of ischemic fractures in CD47-null mice,suggesting the phenotype was not due to developmental changes in the knockout mice.Thus,inhibition of CD47 during bone healing reduces both non-ischemic and ischemic fracture healing,in part,by decreasing MSC proliferation.Furthermore,the increase in endothelial cell proliferation and early blood vessel density caused by CD47 disruption is not sufficient to overcome MSC dysfunction.展开更多
Oral and maxillofacial diagnostic imaging is of paramount importance in dental clinical diagnosis,treatment planning,and follow-up procedures.Periapical ra-diographic examination and numerous panoramic systems are use...Oral and maxillofacial diagnostic imaging is of paramount importance in dental clinical diagnosis,treatment planning,and follow-up procedures.Periapical ra-diographic examination and numerous panoramic systems are used in routine clinical dental practice.Cone beam CT is widely used and currently the method of choice in oral and maxillofacial implantology,endodontics,maxillofacial surgery,periodontics,degenerative temporomandibular joint disease,orthodontics,airway studies,sleep disorders,and forensic dentistry.Another innovative laboratory re-search tool that offers three-dimensional(3D)detailed high-resolution images of in vitro teeth and neighboring structures with submicrometric accuracy is micro-computed tomography.Ultra-high radiation doses,long scanning times,and high costs preclude its routine clinical use.In response to the high demand for a te-chnique that could provide real-time images using a cost-effective,rapid,user-friendly,and portable technique without ionizing radiation,some authors pro-posed ultrasound imaging methods as an alternative to X-ray imaging techniques.Ultrasonography can be used in the dentomaxillofacial region for various diagno-stic purposes such as salivary gland and superficial tissue examination.Recently,dedicated dental magnetic resonance imaging with appropriate software,hard-ware,sequences,and field of view tailored to fit dentomaxillofacial anatomy was introduced.Lately,3D printing technologies and their application in dentistry has attracted attention.During 3D printing a given material is added in successive layers to create a 3D object.The application of this technology has the potential to decrease operation time and minimize operator bias and the possibility of proce-dural errors.Another hot topic regarding dentomaxillofacial radiology is artificial intelligence,which is a field related to computer science dedicated to developing systems or machines that can perform tasks traditionally associated with human intelligence.It is obvious that further investigation and research in the field of dentomaxillofacial radiology will make great contributions to diagnostic imaging for various dental specialties.展开更多
Deep geological sequestration is widely recognized as a reliable method for nuclear waste management,with expanded applications in thermal energy storage and adiabatic compressed air energy storage systems.This study ...Deep geological sequestration is widely recognized as a reliable method for nuclear waste management,with expanded applications in thermal energy storage and adiabatic compressed air energy storage systems.This study evaluated the suitability of granite,basalt,and marble as reservoir rocks capable of withstanding extreme high-temperature and high-pressure conditions.Using a custom-designed triaxial testing apparatus for thermal-hydro-mechanical(THM)coupling,we subjected rock samples to temperatures ranging from 20℃to 800℃,triaxial stresses up to 25 MPa,and seepage pressures of 0.6 MPa.After THM treatment,the specimens were analyzed using a Real-Time Load-Synchronized Micro-Computed Tomography(MCT)Scanner under a triaxial stress of 25 MPa,allowing for high-resolution insights into pore and fissure responses.Our findings revealed distinct thermal stability profiles and microscopic parameter changes across three phasesdslow growth,slow decline,and rapid growthdwith critical temperature thresholds observed at 500℃for granite,600℃for basalt,and 300℃for marble.Basalt showed minimal porosity changes,increasing gradually from 3.83%at 20℃to 12.45%at 800℃,indicating high structural integrity and resilience under extreme THM conditions.Granite shows significant increases in porosity due to thermally induced microcracking,while marble rapidly deteriorated beyond 300℃due to carbonate decomposition.Consequently,basalt,with its minimal porosity variability,high thermal stability,and robust mechanical properties,emerges as an optimal candidate for nuclear waste repositories and other high-temperature geological engineering applications,offering enhanced reliability,structural stability,and long-term safety in such settings.展开更多
Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SE...Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.展开更多
The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at appar...The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.展开更多
Background:Soil structure is a key indicator of the functioning of soil processes in grasslands,which is influenced by site conditions and management.Methods:In this study,we investigated soil structure and its relati...Background:Soil structure is a key indicator of the functioning of soil processes in grasslands,which is influenced by site conditions and management.Methods:In this study,we investigated soil structure and its relationship with root growth in 31 Leptosols under different grassland management intensities using X-ray microcomputed tomography.A close relationship between land use intensity,soil structure,and root growth was observed.Results:Our results show that land use type affects root development and soil structure.Pastures had more developed roots and more structured soils than meadows and mown pastures.However,all pastures were unfertilized,while meadows and mown pastures had both fertilized and unfertilized plots.Although no significant differences were found in the unfertilized plots,sample size was limited.In particular,fertilization negatively affected root growth and soil structure,resulting in significant differences between fertilized and unfertilized grasslands.Mowing frequency also had an effect on soil physics,but to a much lesser extent than fertilization.Conclusions:Increased land use intensity,characterized by increased fertilization and more frequent mowing,reduces root growth and adversely affects soil structure.Therefore,X-ray microcomputed tomography is a suitable method to investigate the relationship between soil structure and roots in the soil.展开更多
基金supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases(NIAMS)of the National Institutes of Health(NIH)under award numbers F30AR071201(R.L.Z.)and R01 AR066028(K.D.H.)Additional research support is provided by the NIH under a training award T32TR004371(C.A.C.).
文摘CD47 is a ubiquitous and pleiotropic cell-surface receptor.Disrupting CD47 enhances injury repair in various tissues but the role of CD47 has not been studied in bone injuries.In a murine closed-fracture model,CD47-null mice showed decreased callus bone formation as assessed by microcomputed tomography 10 days post-fracture and increased fibrous volume as determined by histology.To understand the cellular basis for this phenotype,mesenchymal progenitors(MSC)were harvested from bone marrow.CD47-null MSC showed decreased large fibroblast colony formation(CFU-F),significantly less proliferation,and fewer cells in Sphase,although osteoblast differentiation was unaffected.However,consistent with prior research,CD47-null endothelial cells showed increased proliferation relative to WT cells.Similarly,in a murine ischemic fracture model,CD47-null mice showed reduced fracture callus size due to a reduction in bone relative to WT 15 days-post fracture.Consistent with our in vitro results,in vivo EdU labeling showed decreased cell proliferation in the callus of CD47-null mice,while staining for CD31 and endomucin demonstrated increased endothelial cell density.Finally,WT mice with ischemic fracture that were administered a CD47 morpholino,which blocks CD47 protein production,showed a callus phenotype similar to that of ischemic fractures in CD47-null mice,suggesting the phenotype was not due to developmental changes in the knockout mice.Thus,inhibition of CD47 during bone healing reduces both non-ischemic and ischemic fracture healing,in part,by decreasing MSC proliferation.Furthermore,the increase in endothelial cell proliferation and early blood vessel density caused by CD47 disruption is not sufficient to overcome MSC dysfunction.
文摘Oral and maxillofacial diagnostic imaging is of paramount importance in dental clinical diagnosis,treatment planning,and follow-up procedures.Periapical ra-diographic examination and numerous panoramic systems are used in routine clinical dental practice.Cone beam CT is widely used and currently the method of choice in oral and maxillofacial implantology,endodontics,maxillofacial surgery,periodontics,degenerative temporomandibular joint disease,orthodontics,airway studies,sleep disorders,and forensic dentistry.Another innovative laboratory re-search tool that offers three-dimensional(3D)detailed high-resolution images of in vitro teeth and neighboring structures with submicrometric accuracy is micro-computed tomography.Ultra-high radiation doses,long scanning times,and high costs preclude its routine clinical use.In response to the high demand for a te-chnique that could provide real-time images using a cost-effective,rapid,user-friendly,and portable technique without ionizing radiation,some authors pro-posed ultrasound imaging methods as an alternative to X-ray imaging techniques.Ultrasonography can be used in the dentomaxillofacial region for various diagno-stic purposes such as salivary gland and superficial tissue examination.Recently,dedicated dental magnetic resonance imaging with appropriate software,hard-ware,sequences,and field of view tailored to fit dentomaxillofacial anatomy was introduced.Lately,3D printing technologies and their application in dentistry has attracted attention.During 3D printing a given material is added in successive layers to create a 3D object.The application of this technology has the potential to decrease operation time and minimize operator bias and the possibility of proce-dural errors.Another hot topic regarding dentomaxillofacial radiology is artificial intelligence,which is a field related to computer science dedicated to developing systems or machines that can perform tasks traditionally associated with human intelligence.It is obvious that further investigation and research in the field of dentomaxillofacial radiology will make great contributions to diagnostic imaging for various dental specialties.
基金financial supported by Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines(Grant No.DM2022B03)Youth Program of National Natural Science Foundation of China(Grant No.51904195)Scientific and Technological Innovation Programs of Higher Educations Institutions in Shanxi Province(Grant No.2022L608).
文摘Deep geological sequestration is widely recognized as a reliable method for nuclear waste management,with expanded applications in thermal energy storage and adiabatic compressed air energy storage systems.This study evaluated the suitability of granite,basalt,and marble as reservoir rocks capable of withstanding extreme high-temperature and high-pressure conditions.Using a custom-designed triaxial testing apparatus for thermal-hydro-mechanical(THM)coupling,we subjected rock samples to temperatures ranging from 20℃to 800℃,triaxial stresses up to 25 MPa,and seepage pressures of 0.6 MPa.After THM treatment,the specimens were analyzed using a Real-Time Load-Synchronized Micro-Computed Tomography(MCT)Scanner under a triaxial stress of 25 MPa,allowing for high-resolution insights into pore and fissure responses.Our findings revealed distinct thermal stability profiles and microscopic parameter changes across three phasesdslow growth,slow decline,and rapid growthdwith critical temperature thresholds observed at 500℃for granite,600℃for basalt,and 300℃for marble.Basalt showed minimal porosity changes,increasing gradually from 3.83%at 20℃to 12.45%at 800℃,indicating high structural integrity and resilience under extreme THM conditions.Granite shows significant increases in porosity due to thermally induced microcracking,while marble rapidly deteriorated beyond 300℃due to carbonate decomposition.Consequently,basalt,with its minimal porosity variability,high thermal stability,and robust mechanical properties,emerges as an optimal candidate for nuclear waste repositories and other high-temperature geological engineering applications,offering enhanced reliability,structural stability,and long-term safety in such settings.
基金Project(2017XKQY012)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.
基金the National High Technology Research and Development Program (863) of China(No. 2006AA02A137the Postgraduate Creativity Foundation of Shanghai Jiaotong University (No. BXJ0730)
文摘The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.
文摘Background:Soil structure is a key indicator of the functioning of soil processes in grasslands,which is influenced by site conditions and management.Methods:In this study,we investigated soil structure and its relationship with root growth in 31 Leptosols under different grassland management intensities using X-ray microcomputed tomography.A close relationship between land use intensity,soil structure,and root growth was observed.Results:Our results show that land use type affects root development and soil structure.Pastures had more developed roots and more structured soils than meadows and mown pastures.However,all pastures were unfertilized,while meadows and mown pastures had both fertilized and unfertilized plots.Although no significant differences were found in the unfertilized plots,sample size was limited.In particular,fertilization negatively affected root growth and soil structure,resulting in significant differences between fertilized and unfertilized grasslands.Mowing frequency also had an effect on soil physics,but to a much lesser extent than fertilization.Conclusions:Increased land use intensity,characterized by increased fertilization and more frequent mowing,reduces root growth and adversely affects soil structure.Therefore,X-ray microcomputed tomography is a suitable method to investigate the relationship between soil structure and roots in the soil.
