Recent research has demonstrated the impact of physical activity on the prognosis of glioma patients,with evidence suggesting exercise may reduce mortality risks and aid neural regeneration.The role of the small ubiqu...Recent research has demonstrated the impact of physical activity on the prognosis of glioma patients,with evidence suggesting exercise may reduce mortality risks and aid neural regeneration.The role of the small ubiquitin-like modifier(SUMO)protein,especially post-exercise,in cancer progression,is gaining attention,as are the potential anti-cancer effects of SUMOylation.We used machine learning to create the exercise and SUMO-related gene signature(ESLRS).This signature shows how physical activity might help improve the outlook for low-grade glioma and other cancers.We demonstrated the prognostic and immunotherapeutic significance of ESLRS markers,specifically highlighting how murine double minute 2(MDM2),a component of the ESLRS,can be targeted by nutlin-3.This underscores the intricate relationship between natural compounds such as nutlin-3 and immune regulation.Using comprehensive CRISPR screening,we validated the effects of specific ESLRS genes on low-grade glioma progression.We also revealed insights into the effectiveness of Nutlin-3a as a potent MDM2 inhibitor through molecular docking and dynamic simulation.Nutlin-3a inhibited glioma cell proliferation and activated the p53 pathway.Its efficacy decreased with MDM2 overexpression,and this was reversed by Nutlin-3a or exercise.Experiments using a low-grade glioma mouse model highlighted the effect of physical activity on oxidative stress and molecular pathway regulation.Notably,both physical exercise and Nutlin-3a administration improved physical function in mice bearing tumors derived from MDM2-overexpressing cells.These results suggest the potential for Nutlin-3a,an MDM2 inhibitor,with physical exercise as a therapeutic approach for glioma management.Our research also supports the use of natural products for therapy and sheds light on the interaction of exercise,natural products,and immune regulation in cancer treatment.展开更多
The ambient air quality has improved significantly under strict emission controls in Beijing,China over the last decade.Black carbon(BC),as a short-lived climate forcer in ambient aerosols,profoundly impacts the air q...The ambient air quality has improved significantly under strict emission controls in Beijing,China over the last decade.Black carbon(BC),as a short-lived climate forcer in ambient aerosols,profoundly impacts the air quality and climate.Previous studies have demonstrated a decline in the mass concentration of BC.In this study,we characterized the chemical compositions and size distributions of BC-containing particles during the cold season of 2022 in Beijing using state-of-the-art instruments capable of exclusively measuring BCcontaining particles.The optical properties of BC-containing particles were further calculated based on the Mie theory.Moreover,we compared the properties of BC-containing particles in 2022 with the results of previous studies.The results showed that the diameters of BC cores became larger while the coating thickness of BC-containing particles became thinner in 2022.For the coating materials,the mass fraction of nitrate increased obviously,and even replaced organic matter as the dominant component during the peak of the pollution period.Variations in chemical compositions and size distributions resulted in lower mass absorption cross-sections(MAC)of BC-containing particles from 10.5±1.1 m^(2)/g in 2016 to 7.3±0.8 m^(2)/g in 2022,reduced by 30.5%.Our results demonstrate the synergistic benefits of air pollution control in improving air quality and mitigating climate change.Therefore,the MAC of BC adopted in climate models should vary with the changing air pollution levels.This study emphasizes that it is imperative to conduct long-term observations of BC-containing particles to better estimate BC’s climate effects.展开更多
The thermal effects,spontaneity and proceeding degree of 32 chemical reactions during coal reductive decomposition phosphogypsum(PG)to prepare CaO and SO_(2)are analyzed utilizing thermodynamic theory and method.The i...The thermal effects,spontaneity and proceeding degree of 32 chemical reactions during coal reductive decomposition phosphogypsum(PG)to prepare CaO and SO_(2)are analyzed utilizing thermodynamic theory and method.The ideal reaction temperature for PG decomposition and desulfurization is 1173-1273 K.The 10 key chemical reactions controlling coal reductive decomposition PG have been selected.The heat release of critical exothermic reactions can satisfy the autothermal operation of PG decomposition and desulfurization process.Meanwhile,the spontaneity of oxidation reactions has thermodynamically priority over reduction reactions.But the reaction mechanism shows that the oxidation of CaS by O_(2)is in parallel competition with the reduction of CaSO_(4)by CO and C.Furthermore,clarifying the regulatory mechanisms of PG decomposition temperature and reaction atmosphere(reducibility and oxidation)is beneficial for maximizing the production of CaO and SO_(2).展开更多
Background Chinese indigenous pigs are popular with consumers for their juiciness,flavour and meat quality,but they have lower meat production.Insulin-like growth factor 2(IGF2) is a maternally imprinted growth factor...Background Chinese indigenous pigs are popular with consumers for their juiciness,flavour and meat quality,but they have lower meat production.Insulin-like growth factor 2(IGF2) is a maternally imprinted growth factor that promotes skeletal muscle growth by regulating cell proliferation and differentiation.A single nucleotide polymorphism(SNP) within intron 3 of porcine IGF2 disrupts a binding site for the repressor,zinc finger BED-type containing 6(ZBED6),leading to up-regulation of IGF2 and causing major effects on muscle growth,heart size,and backfat thickness.This favorable mutation is common in Western commercial pig populations,but absent in most Chinese indigenous pig breeds.To improve meat production of Chinese indigenous pigs,we used cytosine base editor 3(CBE3)to introduce IGF2 intron3-C3071T mutation into porcine embryonic fibroblasts(PEFs) isolated from a male Liang Guang Small Spotted pig(LGSS),and single-cell clones harboring the desired mutation were selected for somatic cell nuclear transfer(SCNT) to generate the founder line of IGF2^(T/T) pigs.Results We found the heterozygous progeny IGF2^(C/T) pigs exhibited enhanced expression of IGF2,increased lean meat by 18%-36%,enlarged loin muscle area by 3%-17%,improved intramuscular fat(IMF) content by 18%-39%,marbling score by 0.75-1,meat color score by 0.53-1.25,and reduced backfat thickness by 5%-16%.The enhanced accumulation of intramuscular fat in IGF2^(C/T) pigs was identified to be regulated by the PI3K-AKT/AMPK pathway,which activated SREBP1 to promote adipogenesis.Conclusions We demonstrated the introduction of IGF2-intron3-C3071T in Chinese LGSS can improve both meat production and quality,and first identified the regulation of IMF deposition by IGF2 through SREBP1 via the PI3KAKT/AMPK signaling pathways.Our study provides a further understanding of the biological functions of IGF2and an example for improving porcine economic traits through precise base editing.展开更多
The subgrid-scale(SGS)stress and SGS heat flux are modeled by using an artificial neural network(ANN)for large eddy simulation(LES)of compressible turbulence.The input features of ANN model are based on the first-orde...The subgrid-scale(SGS)stress and SGS heat flux are modeled by using an artificial neural network(ANN)for large eddy simulation(LES)of compressible turbulence.The input features of ANN model are based on the first-order and second-order derivatives of filtered velocity and temperature at different spatial locations.The proposed spatial artificial neural network(SANN)model gives much larger correlation coefficients and much smaller relative errors than the gradient model in an a priori analysis.In an a posteriori analysis,the SANN model performs better than the dynamic mixed model(DMM)in the prediction of spectra and statistical properties of velocity and temperature,and the instantaneous flow structures.展开更多
In this work we extend the method of the constrained large-eddy simulation(CLES)to simulate the tur-bulent flow over inhomogeneous rough walls.In the original concept of CLES,the subgrid-scale(SGS)stress is constraine...In this work we extend the method of the constrained large-eddy simulation(CLES)to simulate the tur-bulent flow over inhomogeneous rough walls.In the original concept of CLES,the subgrid-scale(SGS)stress is constrained so that the mean part and the fluctuation part of the SGS stress can be modelled separately to improve the accuracy of the simulation result.Here in the simulation of the rough-wall flows,we propose to interpret the extra stress terms in the CLES formulation as the roughness-induced stress so that the roughness inhomogeneity can be incorporated by modifying the formulation of the constrained SGS stress.This is examined with the simulations of the channel flow with the spanwise alternating high/low roughness strips.Then the CLES method is employed to investigate the temporal response of the turbulence to the change of the wall condition from rough to smooth.We demonstrate that the temporal development of the internal boundary layer is just similar to that in a spatial rough-to-smooth transition process,and the spanwise roughness inhomogeneity has little impact on the transition process.展开更多
Objective Pertussis cases have increased markedly since 2018 in Guangxi.The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population.Method A total of 10,215 s...Objective Pertussis cases have increased markedly since 2018 in Guangxi.The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population.Method A total of 10,215 serum samples from residents were collected from August-November 2018 and tested for anti-pertussis IgG and toxin IgG using the enzyme-linked immunosorbent assay(ELISA).Results Of the collected samples,1,833(17.94%)tested positive for anti-pertussis IgG,with the median concentration of 16.06 IU/mL.Antibody level<10 IU/mL accounted for more than 60%in children under 4 years of age,but declined with age,whereas the percentages of the other three levels(10-40,40-50,and≥50 IU/mL)increased almost with age(P<0.001).Moreover,7,924 samples were selected for anti-pertussis toxin IgG,of which 653(8.24%)tested positive(≥40 IU/mL)with the median concentration of 5.89 IU/mL,and 204 participants(2.56%)had recent pertussis infection(≥100 IU/mL).Among the different age groups,the highest rates of positivity and recent infection were observed at 11-20 years of age,the lowest positivity rate at 5 years of age,and the lowest recent infection rate at 4 years of age(P<0.001,P=0.005,respectively).Conclusion The survey results showed that all age groups in Guangxi lacked immunity against pertussis,which was one of the main factors contributing to the resurgence of pertussis in 2018.In addition,the prevalence of pertussis is relatively high in Guangxi,and its incidence is seriously underestimated,especially in adolescents and adults.展开更多
Skeletal muscle has a robust regeneration ability that is impaired by severe injury,disease,and aging.resulting in a decline in skeletal muscle function.Therefore,improving skeletal muscle regeneration is a key challe...Skeletal muscle has a robust regeneration ability that is impaired by severe injury,disease,and aging.resulting in a decline in skeletal muscle function.Therefore,improving skeletal muscle regeneration is a key challenge in treating skeletal muscle-related disorders.Owing to their significant role in tissue regeneration,implantation of M2 macrophages(M2MФ)has great potential for improving skeletal muscle regeneration.Here,we present a short-wave infrared(SWIR)fluorescence imaging technique to obtain more in vivo information for an in-depth evaluation of the skeletal muscle regeneration effect after M2MФtransplantation.SWIR fluorescence imaging was employed to track implanted M2MФin the injured skeletal muscle of mouse models.It is found that the implanted M2MФaccumulated at the injury site for two weeks.Then,SWIR fluorescence imaging of blood vessels showed that M2MФimplantation could improve the relative perfusion ratio on day 5(1.09±0.09 vs 0.85±0.05;p=0.01)and day 9(1.38±0.16 vs 0.95±0.03;p=0.01)post-injury,as well as augment the degree of skeletal muscle regencration on day 13 post-injury.Finally,multiple linear regression analyses determined that post-injury time and relative perfusion ratio could be used as predictive indicators to evaluate skeletal muscle regeneration.These results provide more in vivo details about M2MФin skeletal muscle regeneration and confirm that M2MФcould promote angiogenesis and improve the degree of skeletal muscle repair,which will guide the research and development of M2MФimplantation to improve skeletal muscle regeneration.展开更多
Inspired by the iterative procedure of computing mean fields with known Reynolds stresses(Guo et al.,Theor Appl Mech Lett,2021),we proposed a way to achieve data augmentation by utilizing the intermediate mean fields ...Inspired by the iterative procedure of computing mean fields with known Reynolds stresses(Guo et al.,Theor Appl Mech Lett,2021),we proposed a way to achieve data augmentation by utilizing the intermediate mean fields after proper selections.We also proposed modifications to the Tensor Basis Neural Network(Ling et al.,J Fluid Mech,2016)model.With the modification of the learning targets and the inclusions of wall distance and logarithm of normalized eddy viscosity in the model inputs,the modified version of the model with augmented training datasets shows better performance on Reynolds stress predictions for two dimensional incompressible flow over periodic hills under different geometries.Furthermore,better propagated mean velocity fields can be achieved,showing better agreements with the direct numerical simulations(DNS)results.展开更多
In this paper, we review some recent studies on compressible turbulence conducted by the authors＇ group, which include fundamental studies on compressible isotropic turbulence （CIT） and applied studies on developin...In this paper, we review some recent studies on compressible turbulence conducted by the authors＇ group, which include fundamental studies on compressible isotropic turbulence （CIT） and applied studies on developing a con- strained large eddy simulation （CLES） for wall-bounded turbulence. In the first part, we begin with a newly pro- posed hybrid compact-weighted essentially nonoscillatory （WENO） scheme for a CIT simulation that has been used to construct a systematic database of CIT. Using this database various fundamental properties of compressible turbulence have been examined, including the statistics and scaling of compressible modes, the shocklet-turbulence interac- tion, the effect of local compressibility on small scales, the kinetic energy cascade, and some preliminary results from a Lagrangian point of view. In the second part, the idea and for- mulas of the CLES are reviewed, followed by the validations of CLES and some applications in compressible engineering problems.展开更多
Tendon regeneration is still a great challenge due to its avascular structure and low self-renewal capability.The nitric oxide(NO)therapy emerges as a promising treatment for inducing the regeneration of injured tendo...Tendon regeneration is still a great challenge due to its avascular structure and low self-renewal capability.The nitric oxide(NO)therapy emerges as a promising treatment for inducing the regeneration of injured tendon by angiogenesis.Here,in this study,a system that NO-loaded metal–organic frameworks(MOFs)encapsulated in polycaprolactone(PCL)/gelatin(Gel)aligned coaxial scaffolds(NMPGA)is designed and prepared for tendon repair.In this system,NO is able to be released in vitro at a slow and stable average speed of 1.67 nM h^−1 as long as 15 d without a burst release stage in the initial 48 h.Furthermore,NMPGA can not only improve the tubular formation capability of endothelial cells in vitro but also obviously increase the blood perfusion near the injured tendon in vivo,leading to accelerating the maturity of collagen and recovery of biomechanical strength of the regenerated tendon tissue.As a NO-loaded MOFs therapeutic system,NMPGA can promote tendon regeneration in a shorter healing period with better biomechanical properties in comparison with control group by angiogenesis.Therefore,this study not only provides a promising scaffold for tendon regeneration,but also paves a new way to develop a NO-based therapy for biomedical application in the future.展开更多
A program incorporating the parallel code of large eddy simulation （LES） and particle transportation model is developed to simulate the motion of particles in an atmospheric turbulent boundary layer （ATBL）. A mode...A program incorporating the parallel code of large eddy simulation （LES） and particle transportation model is developed to simulate the motion of particles in an atmospheric turbulent boundary layer （ATBL）. A model of particles of 100-micrometer order coupling with large scale ATBL is proposed. Two typical cases are studied, one focuses on the evolution of particle profile in the ATBL and the landing displacement of particles, whereas the other on the motion of particle stream.展开更多
We investigate flow structures,nonlinear inertial waves and energy transfer in a rotating fluid sphere,using a Galerkin spectral method based on helical-wave decomposition(HWD).Numerical simulations of flows in a sphe...We investigate flow structures,nonlinear inertial waves and energy transfer in a rotating fluid sphere,using a Galerkin spectral method based on helical-wave decomposition(HWD).Numerical simulations of flows in a sphere are performed with different system rotation rates,where a large-scale forcing is employed.For the case without system rotation,the intense vortex structures are tube-like.When a weak rotation is introduced,small-scale structures are reduced and vortex tubes tend to align with the rotation axis.As the rotation rate increases,a large-scale anticyclonic vortex structure is formed near the rotation axis.The structure is shown to be led by certain geostrophic modes.When the rotation rate further increases,a cyclone and an anticyclone emerge from the top and bottom of the boundary,respectively,where two quasi-geostrophic equatorially symmetric inertial waves dominate the flow.Based on HWD,effects of spherical confinement on rotating turbulence are systematically studied.It is found that the forward cascade becomes weaker as the rotation increases.When the rotation rate becomes larger than some critical value,dual energy cascades emerge,with an inverse cascade at large scales and a forward cascade at small scales.Finally,the flow behavior near the boundary is studied,where the average boundary layer thickness gets smaller when system rotation increases.The flow behavior in the boundary layer is closely related to the interior flow structures,which create significant mass flux between the boundary layer and the interior fluid through Ekman pumping.展开更多
With the rising of modern data science,data-driven turbulence modeling with the aid of machine learning algorithms is becoming a new promising field.Many approaches are able to achieve better Reynolds stress predictio...With the rising of modern data science,data-driven turbulence modeling with the aid of machine learning algorithms is becoming a new promising field.Many approaches are able to achieve better Reynolds stress prediction,with much lower modeling error(∈_(M)),than traditional Reynolds-averaged Navier-Stokes(RANS)models,but they still suffer from numerical error and stability issues when the mean velocity fields are estimated by solving RANS equations with the predicted Reynolds stresses.This fact illustrates that the error of solving the RANS equations(∈_(P))is also very important for a RANS simulation.In the present work,the error∈_(P)is studied separately by using the Reynolds stresses obtained from direct numerical simulation(DNS)/highly resolved large-eddy simulation to minimize the modeling error∈_(M),and the sources of∈_(P)are derived mathematically.For the implementations with known Reynolds stresses solely,we suggest to run an auxiliary RANS simulation to make a first guess onν_(t)^(*)and S_(ij)^(0).With around 10 iterations,the error of the streamwise velocity component could be reduced by about one-order of magnitude in flow over periodic hills.The present work is not to develop a new RANS model,but to clarify the facts that obtaining mean field with known Reynolds stresses is nontrivial and that the nonlinear part of the Reynolds stresses is very important in flow problems with separations.The proposed approach to reduce∈_(P)may be very useful for the a posteriori applications of the data-driven turbulence models.展开更多
Experimental and numerical studies have shown similarities between localized turbulence in channel and pipe flows.By scaling analysis of a disturbed-flow model,this paper proposes a local Reynolds number Re M to chara...Experimental and numerical studies have shown similarities between localized turbulence in channel and pipe flows.By scaling analysis of a disturbed-flow model,this paper proposes a local Reynolds number Re M to characterize the threshold of transition triggered by finite-amplitude disturbances.The Re M represents the maximum contribution of the basic flow to the momentum ratio between the nonlinear convection and the viscous diffusion.The lower critical Re M observed in experiments of plane Poiseuille flow,pipe Poiseuille flow and plane Couette flow are all close to 323,indicating the uniformity of mechanism governing the transition to localized turbulence.展开更多
基金supported by Project of the Health Shanghai Initiative Special Fund(Medical-Sports Integration,Creating a New Model of Exercise for Health),No.JKSHZX-2022-02(to SC).
文摘Recent research has demonstrated the impact of physical activity on the prognosis of glioma patients,with evidence suggesting exercise may reduce mortality risks and aid neural regeneration.The role of the small ubiquitin-like modifier(SUMO)protein,especially post-exercise,in cancer progression,is gaining attention,as are the potential anti-cancer effects of SUMOylation.We used machine learning to create the exercise and SUMO-related gene signature(ESLRS).This signature shows how physical activity might help improve the outlook for low-grade glioma and other cancers.We demonstrated the prognostic and immunotherapeutic significance of ESLRS markers,specifically highlighting how murine double minute 2(MDM2),a component of the ESLRS,can be targeted by nutlin-3.This underscores the intricate relationship between natural compounds such as nutlin-3 and immune regulation.Using comprehensive CRISPR screening,we validated the effects of specific ESLRS genes on low-grade glioma progression.We also revealed insights into the effectiveness of Nutlin-3a as a potent MDM2 inhibitor through molecular docking and dynamic simulation.Nutlin-3a inhibited glioma cell proliferation and activated the p53 pathway.Its efficacy decreased with MDM2 overexpression,and this was reversed by Nutlin-3a or exercise.Experiments using a low-grade glioma mouse model highlighted the effect of physical activity on oxidative stress and molecular pathway regulation.Notably,both physical exercise and Nutlin-3a administration improved physical function in mice bearing tumors derived from MDM2-overexpressing cells.These results suggest the potential for Nutlin-3a,an MDM2 inhibitor,with physical exercise as a therapeutic approach for glioma management.Our research also supports the use of natural products for therapy and sheds light on the interaction of exercise,natural products,and immune regulation in cancer treatment.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701000,task 1&4)the National Natural Science Foundation of China(Nos.22221004 and 41977179).
文摘The ambient air quality has improved significantly under strict emission controls in Beijing,China over the last decade.Black carbon(BC),as a short-lived climate forcer in ambient aerosols,profoundly impacts the air quality and climate.Previous studies have demonstrated a decline in the mass concentration of BC.In this study,we characterized the chemical compositions and size distributions of BC-containing particles during the cold season of 2022 in Beijing using state-of-the-art instruments capable of exclusively measuring BCcontaining particles.The optical properties of BC-containing particles were further calculated based on the Mie theory.Moreover,we compared the properties of BC-containing particles in 2022 with the results of previous studies.The results showed that the diameters of BC cores became larger while the coating thickness of BC-containing particles became thinner in 2022.For the coating materials,the mass fraction of nitrate increased obviously,and even replaced organic matter as the dominant component during the peak of the pollution period.Variations in chemical compositions and size distributions resulted in lower mass absorption cross-sections(MAC)of BC-containing particles from 10.5±1.1 m^(2)/g in 2016 to 7.3±0.8 m^(2)/g in 2022,reduced by 30.5%.Our results demonstrate the synergistic benefits of air pollution control in improving air quality and mitigating climate change.Therefore,the MAC of BC adopted in climate models should vary with the changing air pollution levels.This study emphasizes that it is imperative to conduct long-term observations of BC-containing particles to better estimate BC’s climate effects.
基金financial support by the Phosphogypsum Low-Temperature Decomposition to Produce Calcium-Based Materials and Sulfuric Acid Raw Gas Technology(Horizontal Project)(8503009049)National Natural Science Foundation of China(52376101).
文摘The thermal effects,spontaneity and proceeding degree of 32 chemical reactions during coal reductive decomposition phosphogypsum(PG)to prepare CaO and SO_(2)are analyzed utilizing thermodynamic theory and method.The ideal reaction temperature for PG decomposition and desulfurization is 1173-1273 K.The 10 key chemical reactions controlling coal reductive decomposition PG have been selected.The heat release of critical exothermic reactions can satisfy the autothermal operation of PG decomposition and desulfurization process.Meanwhile,the spontaneity of oxidation reactions has thermodynamically priority over reduction reactions.But the reaction mechanism shows that the oxidation of CaS by O_(2)is in parallel competition with the reduction of CaSO_(4)by CO and C.Furthermore,clarifying the regulatory mechanisms of PG decomposition temperature and reaction atmosphere(reducibility and oxidation)is beneficial for maximizing the production of CaO and SO_(2).
基金supported by the National Natural Science Foundation of China (3207269732030102)+2 种基金CARS-PIG-35R&D Programmes of Guangdong Province (2018B020203003)Laboratory of Lingnan Modern Agriculture Project (NZ2021006)。
文摘Background Chinese indigenous pigs are popular with consumers for their juiciness,flavour and meat quality,but they have lower meat production.Insulin-like growth factor 2(IGF2) is a maternally imprinted growth factor that promotes skeletal muscle growth by regulating cell proliferation and differentiation.A single nucleotide polymorphism(SNP) within intron 3 of porcine IGF2 disrupts a binding site for the repressor,zinc finger BED-type containing 6(ZBED6),leading to up-regulation of IGF2 and causing major effects on muscle growth,heart size,and backfat thickness.This favorable mutation is common in Western commercial pig populations,but absent in most Chinese indigenous pig breeds.To improve meat production of Chinese indigenous pigs,we used cytosine base editor 3(CBE3)to introduce IGF2 intron3-C3071T mutation into porcine embryonic fibroblasts(PEFs) isolated from a male Liang Guang Small Spotted pig(LGSS),and single-cell clones harboring the desired mutation were selected for somatic cell nuclear transfer(SCNT) to generate the founder line of IGF2^(T/T) pigs.Results We found the heterozygous progeny IGF2^(C/T) pigs exhibited enhanced expression of IGF2,increased lean meat by 18%-36%,enlarged loin muscle area by 3%-17%,improved intramuscular fat(IMF) content by 18%-39%,marbling score by 0.75-1,meat color score by 0.53-1.25,and reduced backfat thickness by 5%-16%.The enhanced accumulation of intramuscular fat in IGF2^(C/T) pigs was identified to be regulated by the PI3K-AKT/AMPK pathway,which activated SREBP1 to promote adipogenesis.Conclusions We demonstrated the introduction of IGF2-intron3-C3071T in Chinese LGSS can improve both meat production and quality,and first identified the regulation of IMF deposition by IGF2 through SREBP1 via the PI3KAKT/AMPK signaling pathways.Our study provides a further understanding of the biological functions of IGF2and an example for improving porcine economic traits through precise base editing.
基金This work was supported by the National Natural Science Foundation of China(Grants 91952104,11702127,and 91752201)the Technology and Innovation Commission of Shenzhen Municipality(Grants KQTD20180411143441009,JCYJ20170412151759222,and ZDSYS201802081843517).This work was also supported by Center for Computational Science and Engineering of Southern University of Science and Technology.J.Wang acknowledges the support from Young Elite Scientist Sponsorship Program by CAST(Grant 2016QNRC001).
文摘The subgrid-scale(SGS)stress and SGS heat flux are modeled by using an artificial neural network(ANN)for large eddy simulation(LES)of compressible turbulence.The input features of ANN model are based on the first-order and second-order derivatives of filtered velocity and temperature at different spatial locations.The proposed spatial artificial neural network(SANN)model gives much larger correlation coefficients and much smaller relative errors than the gradient model in an a priori analysis.In an a posteriori analysis,the SANN model performs better than the dynamic mixed model(DMM)in the prediction of spectra and statistical properties of velocity and temperature,and the instantaneous flow structures.
基金supported by the National Natural Science Foundation of China (Grants 11988102, 91752201, and 11822208)the Department of Science and Technology of Guangdong Province (Grant 2019B21203001)+3 种基金Key Special Project for Introduced Tal ents Team of Southern Marine Science and Engineering Guang dong Laboratory (Guangzhou) (Grant GML2019ZD0103)Shenzhen Science & Technology Program (Grant KQTD2018 0411143441009)supported by Center for Computational Science and Engineering of Southern University of Science and Technologythe support from Centers for Mechanical Engineering Research and Education at MIT and SUSTech
文摘In this work we extend the method of the constrained large-eddy simulation(CLES)to simulate the tur-bulent flow over inhomogeneous rough walls.In the original concept of CLES,the subgrid-scale(SGS)stress is constrained so that the mean part and the fluctuation part of the SGS stress can be modelled separately to improve the accuracy of the simulation result.Here in the simulation of the rough-wall flows,we propose to interpret the extra stress terms in the CLES formulation as the roughness-induced stress so that the roughness inhomogeneity can be incorporated by modifying the formulation of the constrained SGS stress.This is examined with the simulations of the channel flow with the spanwise alternating high/low roughness strips.Then the CLES method is employed to investigate the temporal response of the turbulence to the change of the wall condition from rough to smooth.We demonstrate that the temporal development of the internal boundary layer is just similar to that in a spatial rough-to-smooth transition process,and the spanwise roughness inhomogeneity has little impact on the transition process.
基金approved by the Ethics Committee of the Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention(GXIRB 2018-0005),and the participants signed informed consent forms.
文摘Objective Pertussis cases have increased markedly since 2018 in Guangxi.The aim of this study was to evaluate antibody levels and the infection status of pertussis in the resident population.Method A total of 10,215 serum samples from residents were collected from August-November 2018 and tested for anti-pertussis IgG and toxin IgG using the enzyme-linked immunosorbent assay(ELISA).Results Of the collected samples,1,833(17.94%)tested positive for anti-pertussis IgG,with the median concentration of 16.06 IU/mL.Antibody level<10 IU/mL accounted for more than 60%in children under 4 years of age,but declined with age,whereas the percentages of the other three levels(10-40,40-50,and≥50 IU/mL)increased almost with age(P<0.001).Moreover,7,924 samples were selected for anti-pertussis toxin IgG,of which 653(8.24%)tested positive(≥40 IU/mL)with the median concentration of 5.89 IU/mL,and 204 participants(2.56%)had recent pertussis infection(≥100 IU/mL).Among the different age groups,the highest rates of positivity and recent infection were observed at 11-20 years of age,the lowest positivity rate at 5 years of age,and the lowest recent infection rate at 4 years of age(P<0.001,P=0.005,respectively).Conclusion The survey results showed that all age groups in Guangxi lacked immunity against pertussis,which was one of the main factors contributing to the resurgence of pertussis in 2018.In addition,the prevalence of pertussis is relatively high in Guangxi,and its incidence is seriously underestimated,especially in adolescents and adults.
基金supported by Shanghai Sailing Program(22YF1438700)National Key Research and Development Program of China(2021YFA1201303)+5 种基金National Natural Science Foundation of China(82172511,81972121,81972129,82072521,82011530023,and 82111530200)Sanming Project of Medicine in Shenzhen(SZSM201612078)the Introduction Project of Clinical Medicine Expert Team for Suzhou(SZYJTD201714)Shanghai Talent Development Funding Scheme 2020080Shanghai Sailing Program(21YF1404100 and 22YF1405200)Research Project of Shanghai Science and Technology Commission(22DZ2204900)。
文摘Skeletal muscle has a robust regeneration ability that is impaired by severe injury,disease,and aging.resulting in a decline in skeletal muscle function.Therefore,improving skeletal muscle regeneration is a key challenge in treating skeletal muscle-related disorders.Owing to their significant role in tissue regeneration,implantation of M2 macrophages(M2MФ)has great potential for improving skeletal muscle regeneration.Here,we present a short-wave infrared(SWIR)fluorescence imaging technique to obtain more in vivo information for an in-depth evaluation of the skeletal muscle regeneration effect after M2MФtransplantation.SWIR fluorescence imaging was employed to track implanted M2MФin the injured skeletal muscle of mouse models.It is found that the implanted M2MФaccumulated at the injury site for two weeks.Then,SWIR fluorescence imaging of blood vessels showed that M2MФimplantation could improve the relative perfusion ratio on day 5(1.09±0.09 vs 0.85±0.05;p=0.01)and day 9(1.38±0.16 vs 0.95±0.03;p=0.01)post-injury,as well as augment the degree of skeletal muscle regencration on day 13 post-injury.Finally,multiple linear regression analyses determined that post-injury time and relative perfusion ratio could be used as predictive indicators to evaluate skeletal muscle regeneration.These results provide more in vivo details about M2MФin skeletal muscle regeneration and confirm that M2MФcould promote angiogenesis and improve the degree of skeletal muscle repair,which will guide the research and development of M2MФimplantation to improve skeletal muscle regeneration.
基金This work was supported by the National Nat-420 ural Science Foundation of China(Grant Nos.11822208,11988102,42111772297,91852205)the Fundamental Research Funds for the 422 central Universities.
文摘Inspired by the iterative procedure of computing mean fields with known Reynolds stresses(Guo et al.,Theor Appl Mech Lett,2021),we proposed a way to achieve data augmentation by utilizing the intermediate mean fields after proper selections.We also proposed modifications to the Tensor Basis Neural Network(Ling et al.,J Fluid Mech,2016)model.With the modification of the learning targets and the inclusions of wall distance and logarithm of normalized eddy viscosity in the model inputs,the modified version of the model with augmented training datasets shows better performance on Reynolds stress predictions for two dimensional incompressible flow over periodic hills under different geometries.Furthermore,better propagated mean velocity fields can be achieved,showing better agreements with the direct numerical simulations(DNS)results.
基金supported by the National Natural Science Foundation of China (Grants 11221061, 91130001, and 11302006)the National Science Foundation for Postdoctoral Scientists of China (Grants 2011M500194 and 2012M520109)
文摘In this paper, we review some recent studies on compressible turbulence conducted by the authors＇ group, which include fundamental studies on compressible isotropic turbulence （CIT） and applied studies on developing a con- strained large eddy simulation （CLES） for wall-bounded turbulence. In the first part, we begin with a newly pro- posed hybrid compact-weighted essentially nonoscillatory （WENO） scheme for a CIT simulation that has been used to construct a systematic database of CIT. Using this database various fundamental properties of compressible turbulence have been examined, including the statistics and scaling of compressible modes, the shocklet-turbulence interac- tion, the effect of local compressibility on small scales, the kinetic energy cascade, and some preliminary results from a Lagrangian point of view. In the second part, the idea and for- mulas of the CLES are reviewed, followed by the validations of CLES and some applications in compressible engineering problems.
基金supported by National Key R&D Program of China(2016YFC1100300)National Natural Science Foundation of China(Nos.81772339,8181101445 and 81972129)+6 种基金The Key Clinical Medicine Center of Shanghai(2017ZZ01006)Sanming Project of Medicine in Shenzhen(SZSM201612078)Shanghai Rising-Star Project(18QB1400500)the Natural Science Foundation of Shanghai(No.19ZR1437800)The Introduction Project of Clinical Medicine Expert Team for Suzhou(SZYJTD201714)Development Project of Shanghai Peak Disciplines-Integrative Medicine(20180101)Shanghai Committee of Science and Technology(19441901600 and 19441902000).
文摘Tendon regeneration is still a great challenge due to its avascular structure and low self-renewal capability.The nitric oxide(NO)therapy emerges as a promising treatment for inducing the regeneration of injured tendon by angiogenesis.Here,in this study,a system that NO-loaded metal–organic frameworks(MOFs)encapsulated in polycaprolactone(PCL)/gelatin(Gel)aligned coaxial scaffolds(NMPGA)is designed and prepared for tendon repair.In this system,NO is able to be released in vitro at a slow and stable average speed of 1.67 nM h^−1 as long as 15 d without a burst release stage in the initial 48 h.Furthermore,NMPGA can not only improve the tubular formation capability of endothelial cells in vitro but also obviously increase the blood perfusion near the injured tendon in vivo,leading to accelerating the maturity of collagen and recovery of biomechanical strength of the regenerated tendon tissue.As a NO-loaded MOFs therapeutic system,NMPGA can promote tendon regeneration in a shorter healing period with better biomechanical properties in comparison with control group by angiogenesis.Therefore,this study not only provides a promising scaffold for tendon regeneration,but also paves a new way to develop a NO-based therapy for biomedical application in the future.
文摘A program incorporating the parallel code of large eddy simulation （LES） and particle transportation model is developed to simulate the motion of particles in an atmospheric turbulent boundary layer （ATBL）. A model of particles of 100-micrometer order coupling with large scale ATBL is proposed. Two typical cases are studied, one focuses on the evolution of particle profile in the ATBL and the landing displacement of particles, whereas the other on the motion of particle stream.
基金This work has been supported by the National Natural Science Foundation of China(NSFC)Basic Sci-ence Sci-ence Center Program(No.11988102)and NSFC(No.91752201)Department of Science and Technology of Guangdong Province(No.2019B21203001)+1 种基金Shenzhen Science and Technology Innovation Commission(No.KQTD20180411143441009)Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0103).
文摘We investigate flow structures,nonlinear inertial waves and energy transfer in a rotating fluid sphere,using a Galerkin spectral method based on helical-wave decomposition(HWD).Numerical simulations of flows in a sphere are performed with different system rotation rates,where a large-scale forcing is employed.For the case without system rotation,the intense vortex structures are tube-like.When a weak rotation is introduced,small-scale structures are reduced and vortex tubes tend to align with the rotation axis.As the rotation rate increases,a large-scale anticyclonic vortex structure is formed near the rotation axis.The structure is shown to be led by certain geostrophic modes.When the rotation rate further increases,a cyclone and an anticyclone emerge from the top and bottom of the boundary,respectively,where two quasi-geostrophic equatorially symmetric inertial waves dominate the flow.Based on HWD,effects of spherical confinement on rotating turbulence are systematically studied.It is found that the forward cascade becomes weaker as the rotation increases.When the rotation rate becomes larger than some critical value,dual energy cascades emerge,with an inverse cascade at large scales and a forward cascade at small scales.Finally,the flow behavior near the boundary is studied,where the average boundary layer thickness gets smaller when system rotation increases.The flow behavior in the boundary layer is closely related to the interior flow structures,which create significant mass flux between the boundary layer and the interior fluid through Ekman pumping.
基金This work was supported by the National Natural Science Foundation of China(Grants 11822208,11988102,11772297,91852205 and 91752202)Shenzhen Science and Technology Program(Grant KQTD20180411143441009)Xia was also supported from the Fun-damental Research Funds for the Central Universities.
文摘With the rising of modern data science,data-driven turbulence modeling with the aid of machine learning algorithms is becoming a new promising field.Many approaches are able to achieve better Reynolds stress prediction,with much lower modeling error(∈_(M)),than traditional Reynolds-averaged Navier-Stokes(RANS)models,but they still suffer from numerical error and stability issues when the mean velocity fields are estimated by solving RANS equations with the predicted Reynolds stresses.This fact illustrates that the error of solving the RANS equations(∈_(P))is also very important for a RANS simulation.In the present work,the error∈_(P)is studied separately by using the Reynolds stresses obtained from direct numerical simulation(DNS)/highly resolved large-eddy simulation to minimize the modeling error∈_(M),and the sources of∈_(P)are derived mathematically.For the implementations with known Reynolds stresses solely,we suggest to run an auxiliary RANS simulation to make a first guess onν_(t)^(*)and S_(ij)^(0).With around 10 iterations,the error of the streamwise velocity component could be reduced by about one-order of magnitude in flow over periodic hills.The present work is not to develop a new RANS model,but to clarify the facts that obtaining mean field with known Reynolds stresses is nontrivial and that the nonlinear part of the Reynolds stresses is very important in flow problems with separations.The proposed approach to reduce∈_(P)may be very useful for the a posteriori applications of the data-driven turbulence models.
基金supported by the NSFC(10972007,10921202 and 2009CB724100)
文摘Experimental and numerical studies have shown similarities between localized turbulence in channel and pipe flows.By scaling analysis of a disturbed-flow model,this paper proposes a local Reynolds number Re M to characterize the threshold of transition triggered by finite-amplitude disturbances.The Re M represents the maximum contribution of the basic flow to the momentum ratio between the nonlinear convection and the viscous diffusion.The lower critical Re M observed in experiments of plane Poiseuille flow,pipe Poiseuille flow and plane Couette flow are all close to 323,indicating the uniformity of mechanism governing the transition to localized turbulence.
