The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is ...The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is a promising plastic chemical recycling technology that offers benefits such as simple processes,convenient operation,and recyclable solvents.However,selecting suitable solvents remains a challenge.This study establishes a virtual solvent database containing 530 common inorganic and organic solvents.By calculating theσ-profile of polyvinyl chloride(PVC)and polyethylene(PE)models using quantum mechanical calculations and employing the conductor-like screening model for real solvents(COSMO-RS)method,the solubility performance of these solvents for PVC and PE at different temperatures was predicted.The results demonstrate the high accuracy of the COSMO-RS method in predicting solubility.By comparing the solubility differences between PVC and PE in different solvents,a series of solvents suitable for selectively removing PVC from mixed plastics were identified,for example,N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),tetrahydrofuran(THF),and N,Ndimethylacetamide(DMAc).This method provides a novel solution to the solvent selection challenge in plastic chemical recycling,potentially shortening the research and development period,reducing experimental costs,and promoting the development of green and refined waste plastic recycling processes.展开更多
The Mongolian gerbil has been widely used in many research fields and has been reported to be a diurnal laboratory animal. The circadian rhythmicity of these gerbils was investigated in the present study by measuring ...The Mongolian gerbil has been widely used in many research fields and has been reported to be a diurnal laboratory animal. The circadian rhythmicity of these gerbils was investigated in the present study by measuring two hormones that show daily oscillations, cortisol and ACTH, in serum using ELISA kits. The levels of the two hormones were highest at 8:00 am and their rhythmic changes were similar to those in humans. In addition, the influence of stress of handling and blood collection on the physiological parameters of the gerbils was examined. After adaptation to handling for 1 week, some serum parameters in the animals changed. Handling and blood collection did not impact significantly on the following parameters: creatine kinase (CK), lactate dehydrogenase (LD), alanine aminotransferase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN), and albumin (ALB). However, blood glucose (GLU), total protein (TP) and globulin (GLB) significantly increased while creatinine (CRE) and albumin/globulin (A/G) significantly decreased after adaptation. This work further confirms that the Mongolian gerbil is a diurnal animal and also indicates that a suitable adaptation procedure is necessary for getting reliable results when performing experiments using these animals.展开更多
Scavenger receptor class B,member 2(SCARB2)is linked to Gaucher disease and Parkinson’s disease.Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy(PME),a rare group of inherited neurodegenerative dis...Scavenger receptor class B,member 2(SCARB2)is linked to Gaucher disease and Parkinson’s disease.Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy(PME),a rare group of inherited neurodegenerative diseases characterized by myoclonus.We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption,accompanied with vitamin E deficiency.Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool,leading to hyperactivation of FXR in intestine.Hyperactivation of FXR impairs epithelium renewal and lipid absorption.Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E.Finally,inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice.These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration,and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.展开更多
Solid surfaces usually reach thermodynamic equilibrium through particle exchange with their environment under reactive conditions.A prerequisite for understanding their functionalities is detailed knowledge of the sur...Solid surfaces usually reach thermodynamic equilibrium through particle exchange with their environment under reactive conditions.A prerequisite for understanding their functionalities is detailed knowledge of the surface composition and atomistic geometry under working conditions.Owing to the large number of possible Miller indices and terminations involved in multielement solids,extensive sampling of the compositional and conformational space needed for reliable surface energy estimation is beyond the scope of ab initio calculations.Here,we demonstrate,using the case of iron carbides in environments with varied carbon chemical potentials,that the stable surface composition and geometry of multielement solids under reactive conditions,which involve large compositional and conformational spaces,can be predicted at ab initio accuracy using an approach that combines the bond valence model,Gaussian process regression,and ab initio thermodynamics.Determining the atomistic structure of surfaces under working conditions paves the way toward identifying the true active sites of multielement catalysts in heterogeneous catalysis.展开更多
With the discovery of the pivotal role of macrophages in tissue regeneration through shaping the tissue immune microenvironment, various immunomodulatory strategies have been proposed to modify traditional biomaterial...With the discovery of the pivotal role of macrophages in tissue regeneration through shaping the tissue immune microenvironment, various immunomodulatory strategies have been proposed to modify traditional biomaterials. Decellularized extracellular matrix (dECM) has been extensively used in the clinical treatment of tissue injury due to its favorable biocompatibility and similarity to the native tissue environment. However, most reported decellularization protocols may cause damage to the native structure of dECM, which undermines its inherent advantages and potential clinical applications. Here, we introduce a mechanically tunable dECM prepared by optimizing the freeze-thaw cycles. We demonstrated that the alteration in micromechanical properties of dECM resulting from the cyclic freeze-thaw process contributes to distinct macrophage-mediated host immune responses to the materials, which are recently recognized to play a pivotal role in determining the outcome of tissue regeneration. Our sequencing data further revealed that the immunomodulatory effect of dECM was induced via the mechnotrasduction pathways in macrophages. Next, we tested the dECM in a rat skin injury model and found an enhanced micromechanical property of dECM achieved with three freeze-thaw cycles significantly promoted the M2 polarization of macrophages, leading to superior wound healing. These findings suggest that the immunomodulatory property of dECM can be efficiently manipulated by tailoring its inherent micromechanical properties during the decellularization process. Therefore, our mechanics-immunomodulation-based strategy provides new insights into the development of advanced biomaterials for wound healing.展开更多
The goaf formed by coal seam mining would dramatically reduce the strength and stiffness of the ground in and around the goaf,which is not conducive to tunnel excavation near the mined-out area.By establishing the Fin...The goaf formed by coal seam mining would dramatically reduce the strength and stiffness of the ground in and around the goaf,which is not conducive to tunnel excavation near the mined-out area.By establishing the Finite differential method and Discrete element method coupling numerical analysis method and conducting similar model test,the influence of dip angle,thickness and distance of coal seam goaf on the stability of unsupported tunnel excavation is studied.The results show that when the tunnel under the goaf is exca-vated,the circumferential stress increment increases first and then decreases along the radial direction of the tunnel,the radial stress increment gradually decreases to zero along the radial direction of the tunnel,the displacement is approximately distributed in a trough shape,and the maximum displacement is at the top of the tunnel.The area of the stress loosening zone(SLZ)is negatively correlated with the dip angle and the distance of the goaf,and positively correlated with the thickness.The SLZ near the goaf is larger,and the peak value of the asymmetry is about 1.35.When the thickness of the mined-out area is 1.8–2.1 m,the SLZ and displacement around the tunnel increase sharply and then become stable.When the dip angle of the mined-out area is greater than 30°or the distance exceeds 1.3 times tunnel diameter(D),the asymmetry converges.The research results of this paper are of great importance to the design and construction of tunnel support and the formulation of excavation schemes.展开更多
Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the int...Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the interfacial localized states with potential fluctuations at the GaN/AlGaN heterointerface leads to photoluminescence peaks showing blue and S-shaped shifts owing to the excitation power and temperature,respectively.Photoexcited electrons in the localized states show a spin relaxation time longer than 1 ns because of the suppression of the D’yakonov-Perel’(DP)scattering,while the spin relaxation time of free electrons was approximately only 10 ps because of the giant Rashba spin-orbit coupling induced by the interfacial polarization field under the framework of the DP scattering mechanism.Furthermore,it is found that the high electron mobility at the heterointerface results in a long spin diffusion length of 300 nm at high temperatures,which is promising for the development of GaN-based spintronic devices.展开更多
基金financially supported by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.the National Natural Science Foundation of China(22302220)+2 种基金the Shanxi Province Science Foundation for Youth(202203021222403)Funding support was also received from the Synfuels China Co.,Ltd.the Institute of Coal Chemistry,Chinese Academy of Sciences。
文摘The widespread use of plastic waste has caused significant environmental pollution,becoming a focal point of global concern,particularly the challenge of dechlorination in mixed plastic waste.Selective dissolution is a promising plastic chemical recycling technology that offers benefits such as simple processes,convenient operation,and recyclable solvents.However,selecting suitable solvents remains a challenge.This study establishes a virtual solvent database containing 530 common inorganic and organic solvents.By calculating theσ-profile of polyvinyl chloride(PVC)and polyethylene(PE)models using quantum mechanical calculations and employing the conductor-like screening model for real solvents(COSMO-RS)method,the solubility performance of these solvents for PVC and PE at different temperatures was predicted.The results demonstrate the high accuracy of the COSMO-RS method in predicting solubility.By comparing the solubility differences between PVC and PE in different solvents,a series of solvents suitable for selectively removing PVC from mixed plastics were identified,for example,N-methyl-2-pyrrolidone(NMP),dimethyl sulfoxide(DMSO),tetrahydrofuran(THF),and N,Ndimethylacetamide(DMAc).This method provides a novel solution to the solvent selection challenge in plastic chemical recycling,potentially shortening the research and development period,reducing experimental costs,and promoting the development of green and refined waste plastic recycling processes.
基金National Natural Science Foundation of China,Grant/Award Number:No.31572341
文摘The Mongolian gerbil has been widely used in many research fields and has been reported to be a diurnal laboratory animal. The circadian rhythmicity of these gerbils was investigated in the present study by measuring two hormones that show daily oscillations, cortisol and ACTH, in serum using ELISA kits. The levels of the two hormones were highest at 8:00 am and their rhythmic changes were similar to those in humans. In addition, the influence of stress of handling and blood collection on the physiological parameters of the gerbils was examined. After adaptation to handling for 1 week, some serum parameters in the animals changed. Handling and blood collection did not impact significantly on the following parameters: creatine kinase (CK), lactate dehydrogenase (LD), alanine aminotransferase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN), and albumin (ALB). However, blood glucose (GLU), total protein (TP) and globulin (GLB) significantly increased while creatinine (CRE) and albumin/globulin (A/G) significantly decreased after adaptation. This work further confirms that the Mongolian gerbil is a diurnal animal and also indicates that a suitable adaptation procedure is necessary for getting reliable results when performing experiments using these animals.
基金supported by Tsinghua-Peking Center for Life Sciences,the National Key Research and Development Program of China(2018YFE0207300,2017YFA0503403)the National Natural Science Foundation of China(Grant Nos.31730028,82001681,81870889,82071258)+1 种基金Training Program of the Big Science Strategy Plan(2020YFE0202200)the Research Fund from Vanke School of Public Health of Tsinghua University.
文摘Scavenger receptor class B,member 2(SCARB2)is linked to Gaucher disease and Parkinson’s disease.Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy(PME),a rare group of inherited neurodegenerative diseases characterized by myoclonus.We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption,accompanied with vitamin E deficiency.Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool,leading to hyperactivation of FXR in intestine.Hyperactivation of FXR impairs epithelium renewal and lipid absorption.Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E.Finally,inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice.These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration,and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.
基金This work was financially supported by the National Science Fund for Distinguished Young Scholars of China(grant no.22225206)the National Key R&D Program of China(no.2022YFA1604103)+6 种基金the National Natural Science Foundation of China(nos.21972157 and 21972160)the CAS Project for Young Scientists in Basic Research(YSBR-005)the Key Research Program of Frontier Sciences CAS(ZDBS-LY-7007)the Major Research Plan of the National Natural Science Foundation of China(92045303)the Informatization Plan of the Chinese Academy of Sciences(grant no.CAS-WX2021SF0110)the Youth Innovation Promotion Association CAS(2020179)Funding support was also received from the Beijing Advanced Innovation Center for Materials Genome Engineering,Synfuels China Co.,Ltd.,and the Institute of Coal Chemistry,Chinese Academy of Sciences.
文摘Solid surfaces usually reach thermodynamic equilibrium through particle exchange with their environment under reactive conditions.A prerequisite for understanding their functionalities is detailed knowledge of the surface composition and atomistic geometry under working conditions.Owing to the large number of possible Miller indices and terminations involved in multielement solids,extensive sampling of the compositional and conformational space needed for reliable surface energy estimation is beyond the scope of ab initio calculations.Here,we demonstrate,using the case of iron carbides in environments with varied carbon chemical potentials,that the stable surface composition and geometry of multielement solids under reactive conditions,which involve large compositional and conformational spaces,can be predicted at ab initio accuracy using an approach that combines the bond valence model,Gaussian process regression,and ab initio thermodynamics.Determining the atomistic structure of surfaces under working conditions paves the way toward identifying the true active sites of multielement catalysts in heterogeneous catalysis.
基金supported by National Natural Science Foundation of China(82071167,82001095,81970975,81901055,82201124,82201119)China Postdoctoral Science Foundation(2021TQ0379,2022M713575)+2 种基金Guangdong Basic and Applied Basic Research Foundation(2021A1515110380,2023A1515011963)Health and Medical Research Fund(No.09201466)the Food and Health Bureau,the Government of the HKSAR,China.
文摘With the discovery of the pivotal role of macrophages in tissue regeneration through shaping the tissue immune microenvironment, various immunomodulatory strategies have been proposed to modify traditional biomaterials. Decellularized extracellular matrix (dECM) has been extensively used in the clinical treatment of tissue injury due to its favorable biocompatibility and similarity to the native tissue environment. However, most reported decellularization protocols may cause damage to the native structure of dECM, which undermines its inherent advantages and potential clinical applications. Here, we introduce a mechanically tunable dECM prepared by optimizing the freeze-thaw cycles. We demonstrated that the alteration in micromechanical properties of dECM resulting from the cyclic freeze-thaw process contributes to distinct macrophage-mediated host immune responses to the materials, which are recently recognized to play a pivotal role in determining the outcome of tissue regeneration. Our sequencing data further revealed that the immunomodulatory effect of dECM was induced via the mechnotrasduction pathways in macrophages. Next, we tested the dECM in a rat skin injury model and found an enhanced micromechanical property of dECM achieved with three freeze-thaw cycles significantly promoted the M2 polarization of macrophages, leading to superior wound healing. These findings suggest that the immunomodulatory property of dECM can be efficiently manipulated by tailoring its inherent micromechanical properties during the decellularization process. Therefore, our mechanics-immunomodulation-based strategy provides new insights into the development of advanced biomaterials for wound healing.
基金supported by the National Natural Science Fund of China(Grant No.52078090)the general program of Chongqing Natural Science Foundation(Grant No.cstc2020jcyj-msxmX0679)the Fund of State Key Laboratory of Mountain Bridge and Tunnel Engineering(Grant Nos.SKLBT-19-006,SKLBT-YF2106).
文摘The goaf formed by coal seam mining would dramatically reduce the strength and stiffness of the ground in and around the goaf,which is not conducive to tunnel excavation near the mined-out area.By establishing the Finite differential method and Discrete element method coupling numerical analysis method and conducting similar model test,the influence of dip angle,thickness and distance of coal seam goaf on the stability of unsupported tunnel excavation is studied.The results show that when the tunnel under the goaf is exca-vated,the circumferential stress increment increases first and then decreases along the radial direction of the tunnel,the radial stress increment gradually decreases to zero along the radial direction of the tunnel,the displacement is approximately distributed in a trough shape,and the maximum displacement is at the top of the tunnel.The area of the stress loosening zone(SLZ)is negatively correlated with the dip angle and the distance of the goaf,and positively correlated with the thickness.The SLZ near the goaf is larger,and the peak value of the asymmetry is about 1.35.When the thickness of the mined-out area is 1.8–2.1 m,the SLZ and displacement around the tunnel increase sharply and then become stable.When the dip angle of the mined-out area is greater than 30°or the distance exceeds 1.3 times tunnel diameter(D),the asymmetry converges.The research results of this paper are of great importance to the design and construction of tunnel support and the formulation of excavation schemes.
基金supported by the National Key Research and Development Program of China(Grants No.2018YFB0406603 and 2018YFE0125700)the National Natural Science Foundation of China(Grants No.61574006,61522401,61927806,61521004,and 11634002).
文摘Spin relaxation induced by the interfacial effects in GaN/Al_(0.25) Ga_(0.75) N heterostructures was carefully investigated using a photon-energy-dependent time-resolved Kerr rotation spectrum.The existence of the interfacial localized states with potential fluctuations at the GaN/AlGaN heterointerface leads to photoluminescence peaks showing blue and S-shaped shifts owing to the excitation power and temperature,respectively.Photoexcited electrons in the localized states show a spin relaxation time longer than 1 ns because of the suppression of the D’yakonov-Perel’(DP)scattering,while the spin relaxation time of free electrons was approximately only 10 ps because of the giant Rashba spin-orbit coupling induced by the interfacial polarization field under the framework of the DP scattering mechanism.Furthermore,it is found that the high electron mobility at the heterointerface results in a long spin diffusion length of 300 nm at high temperatures,which is promising for the development of GaN-based spintronic devices.
