Objective: To investigate the association between the T cell inhibitory receptor programmed death 1(PD-1)and T cell exhaustion status in T cells from patients with de novo acute myeloid leukemia(AML) and AML in c...Objective: To investigate the association between the T cell inhibitory receptor programmed death 1(PD-1)and T cell exhaustion status in T cells from patients with de novo acute myeloid leukemia(AML) and AML in complete remission(CR).Methods:Surface expression of PD-1 and the exhaustion and immunosenescence markers CD244 and CD57 on CD3+,CD4+ and CD8+ T cells from peripheral blood samples from 20 newly diagnosed,untreated AML patients and 10 cases with AML in CR was analyzed by flow cytometry.Twenty-three healthy individuals served as control.Results:A significantly higher percentage of PD-1+ cells were found for CD3+ T cells in the de novo AML group compared with healthy controls.In addition,an increased level of PD-1+ CD8+ T cells,but not PD-1+ CD4+,was found for CD3+ T cells in the de novo AML and AML-CR samples.A higher percentage of CD244+ CD4+,CD244+ CD8+,CD57+ CD4+ and CD57+ CD8+ T cells was found in CD3+ T cells in samples from those with de novo AML compared with those from healthy controls.Strong increased PD-1+ CD244+ and PD-1+ CD57+ coexpression was found for CD4+ and CD8+ T cells in the de novo AML group compared with healthy controls.Conclusions:We characterized the major T cell defects,including co-expression of PD-1 and CD244,CD57-exhausted T cells in patients with de novo AML,and found a particular influence on CD8+ T cells,suggesting a poor anti-leukemia immune response in these patients.展开更多
Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have be...Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have been identified in various potato species and most of these R genes have been used in potato breeding. The aim of this study was to develop and validate PCR-based assays for the R genes Rpi-blb1, Rpi-blb2, Rpi-blb3 and Rpi-bt1, to distinguish between late blight resistant and late blight susceptible potato progeny in the given breeding background. A total of 100 breeding progeny were screened for the presence of these R genes and tested for resistance against P. infestans mating type A2, genotype US-8 strain, using detached leaf and tuber rot assays. PCR products for the Rpi-blb1 and Rpi-bt1 resistance genes were identified in the resistant progeny but were absent in the susceptible ones;therefore these PCR assays could differentiate between late blight resistant and susceptible plants. Genotypic data from the DNA markers derived from the Rpi-blb1 and Rpi-bt1 genes was found to correlate with the phenotypic data for foliar late blight but not with data for tuber rot. Our results demonstrate that markers derived from these two R genes could be useful for marker-assisted selection (MAS) for foliar late blight resistance in potato breeding programs.展开更多
To improve the thermoelectric converting performance in applications such as power generation,reutilization of heat energy,refrigeration,and ultrasensitive sensors in scramjet engines,a thermoelectric film/substrate s...To improve the thermoelectric converting performance in applications such as power generation,reutilization of heat energy,refrigeration,and ultrasensitive sensors in scramjet engines,a thermoelectric film/substrate system is widely designed and applied,whose interfacial behavior dominates the strength and service life of thermoelectric devices.Herein,a theoretical model of a thermoelectric film bonded to a graded substrate is proposed.The interfacial shear stress,the normal stress in the thermoelectric film,and the stress intensity factors affected by various material and geometric parameters are comprehensively studied.It is found that adjusting the inhomogeneity parameter of the graded substrate,thermal conductivity,and current density of the thermoelectric film can reduce the risk of interfacial failure of the thermoelectric film/graded substrate system.Selecting a stiffer and thicker thermoelectric film is advantageous to the reliability of the thermoelectric film/graded substrate system.The results should be of great guiding significance for the present and upcoming applications of thermoelectric materials in various fields.展开更多
Zeolite-supported metal catalysts containing hydrogenation centers and acid sites are promising in the chemoselective hydrogenation of biomass platform molecules into value-added chemicals and fuels.The primary challe...Zeolite-supported metal catalysts containing hydrogenation centers and acid sites are promising in the chemoselective hydrogenation of biomass platform molecules into value-added chemicals and fuels.The primary challenge of employing such bifunctional catalysts for biomass conversion lies in catalyst stability in the liquid phase under harsh conditions. Herein, we have prepared a Ni/La-Y nanocatalyst via an improved wet impregnation method. Compared with Ni nanoparticles on H-Y, La addition shows a significantly enhanced stability and performance in the continuous liquid-phase hydrogenation of γ-valerolactone(GVL) into ethyl pentanoate(EP) at 200 ℃ for 1000 h. Complementary characterization studies reveal that La addition in the metal/zeolite catalyst not only efficiently modulates the acid property of the zeolite to alleviate coke formation, but also suppresses zeolite dealumination and metal agglomeration and leaching upon catalysis over a 1000 h period. These findings provide an efficient approach for improving the stability of zeolite-supported bifunctional catalysts, leading to potential application in hydrogen-assisted biomass valorization under the liquid-phase conditions.展开更多
The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical industry.Chemoselective hydrogenation pose...The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical industry.Chemoselective hydrogenation poses a significant challenge,which requires the rational design of the catalysts with proper hydrogenation ability for nitro group and simultaneously preventing dehalogenation of halogen group.Herein,a highly effective Rh@Al_(2)O_(3)@C single-atom catalyst(SAC)was developed for the hydrogenation of m-chloronitrobenzene(m-CNB)to m-chloroaniline(m-CAN),through an in-situ grafting of metal during the assembly of MIL-53(Al),followed by confined pyrolysis.Extensive characterizations reveal an exquisite structure of the Rh@Al_(2)O_(3)@C,containing atomically dispersed Rh sites onto Al_(2)O_(3) confined by the amorphous carbon.The five-coordinated aluminum(Al^(Ⅴ))species are essential for achieving the atomic dispersion of Rh atoms,providing the unsaturated coordinative sites for metal.Compared to the benchmark Rh/γ-Al_(2)O_(3) and Rh/C nanocatalysts,the Rh@Al_(2)O_(3)@C SAC affords an excellent turnover frequency of 2317 molm-CNB·molRh^(–1)·h^(–1),the highest value to date in heterogeneous catalyst systems for the hydrogenation of m-CNB at 313 K and 20 bar H2,together with a sustained selectivity to m-CAN(~98%)during five consecutive runs.The superior catalytic performance of the Rh@Al_(2)O_(3)@C is attributed to a proper modulation of electronic structure of hydrogenation metal by forming SAC,together with an enhanced accessibility of acid function sites.展开更多
Objective: The aim of the study was to investigate the expression pattern of hematopoietic transcription factor GATA-1, -2 and -3 genes in leukemic bone marrow (BM) micreenvironment [including bone marrow stremal c...Objective: The aim of the study was to investigate the expression pattern of hematopoietic transcription factor GATA-1, -2 and -3 genes in leukemic bone marrow (BM) micreenvironment [including bone marrow stremal cells (BMSCs) and BM hematopoietic cells]. Methods: Mononuclear cells were isolated from BM of patients with acute myeloid leukemia (AML), chronic myelogenous leukemia (CML), or acute lymphoblasUc leukemia (ALL). Adherent cells (BMSCs) and nonadherent ceils (BM hematopoietic cells) were collected after long-term culture in vitro. The semi-quantitative expression levels of GATA genes in the BMSCs or BM hematopoietic cells from patients with leukemia were analyzed by using RT-PCR-ELISA and com- pared with normal controls. Results: The expression level of GATA-1 gene in the BMSCs from CML group was significantly lower than that of the normal controls. The expression level of GATA-3 gene in the BMSCs from ALL was higher than that of the normal controls, but that from CML was lower than the normal controls. Dominant expression of GATA-3 gene was found in the normal BM hematopoietic cells. The dominant expression of GATA-2 gene was found in the normal BMSCs and the BMSCs from CML, whereas the dominant expression of GATA-3 gene was detected in the BMSCs from AML. Conclusion: GATA-1, -2 and -3 genes might play a role in hematopoiesis regulation in leukemia, and the changes of expression pattern of GATA genes might influence the hematopoiesis in BM microenvironment and relate to the pathogenesis and development of leukemia.展开更多
Objective: To investigate the effects of staphyococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARa peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy d...Objective: To investigate the effects of staphyococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARa peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy donor were obtained by density gradient centrifugation on Ficoll-Hypaque, MNC were cultured with PML-RARa peptide and SEA for 20 days. After induction, the cytotoxicity of T cells induced against NB4 and K562 cell lines were examined by Cell Counting Kit-8 (CCK-8). The CD4 and CD8 surface markers on the harvested CD3^+ T cells were detected by flow cytometry (FCM). Results: The cytotoxicity of T cells induced by PML-RARa peptide with SEA was higher than that of T cells induced only by PML-RARa peptide against NB4 cells. The FCM assay showed that the ratio of CD4^+/CD8^+ T cells were gradually decreased in both groups of PML-RARα peptide whether with SEA or not at the intervals of day 5,10 and 20 day after induction, but the most significantly decreased by PML-RARe peptide with SEA. Conclusion: The specific cytotoxicity of T cells induced by PML-RARa peptide against NB4 cells could be enhanced with superantigen SEA.展开更多
Tissue-resident memory T(TRM)cells infiltrating solid tumors could influence tumor progression and the response to immune therapies.However,the proportion and prognostic value of TRM cells in the bone marrow(BM)of pat...Tissue-resident memory T(TRM)cells infiltrating solid tumors could influence tumor progression and the response to immune therapies.However,the proportion and prognostic value of TRM cells in the bone marrow(BM)of patients with acute myeloid leukemia(AML)are unclear.In this study,we used flow cytometry to assay the phenotype of 49 BM samples from patients newly diagnosed with AML(ND-AML).We found that the BM CD8^(+)effector memory(TEM)cells highly expressed CD69(CD8^(+)TRM-like T cells),and their percentage was significantly increased in patients with ND-AML compared with that in healthy individuals(HI).The high percentage of CD8^(+)TRM-like subset was associated with poor overall survival in our ND-AML cohort.The Kaplan–Meier Plotter database verified a significantly reduced survival rate among patients with high expression of CD8^(+)TRM-like T cell characteristic genes(CD8A,CD69,and TOX),especially the M4 and M5 subtypes.Phenotypic analysis revealed that the BM CD8^(+)TRM-like subpopulation exhibited exhausted T cell characteristics,but its high expression of CD27 and CD28 and low expression of CD57 suggested its high proliferative potential.The single-cell proteogenomic dataset confirmed the existence of TRM-like CD8^(+)T cells in the BM of patients with AML and verified the high expression of immune checkpoints and costimulatory molecules.In conclusion,we found that the accumulation of BM CD8^(+)TRM-like cells could be an immune-related survival prediction marker for patients with AML.展开更多
Struvite crystallization is a promising method to remove and recover phosphorus from wastewater to ease both the scarcity of phosphorus rock resources and water eutrophication worldwide. To date, although various kind...Struvite crystallization is a promising method to remove and recover phosphorus from wastewater to ease both the scarcity of phosphorus rock resources and water eutrophication worldwide. To date, although various kinds of reactor systems have been developed, supporting methods are required to control the stmvite fines flushing out of the reactors. As an intrinsic property, aggregation is normally disregarded in the struvite crystallization process, although it is the key factor in final particle size and therefore guarantees phosphorus recovery efficiency. The present study developed a method to analyze the characteristics of struvite aggregates using fractal geometry, and the influence of operational parameters on struvite aggregation was evaluated. Due to its typical orthorhombic molecular structure, struvite particles are prone to crystallize into needle or rod shapes, and aggregate at the comers or edges of crystals. The determined fractal dimension (Dpf) of struvite aggregates was 1.52-1.31, with the corresponding range of equivalent diameter (d0.5) at 295.9-85.4 Ixm. Aggregates formed in relatively low phosphorus concentrations (3.0-5.0 mmol/L) and mildly alkaline conditions (pH 9.0-9.5) displayed relatively compact structures, large aggregate sizes and high aggregation strength. Increasing pH values led to continuous decrease of aggregate sizes, while the variation of Dpf was insignificant. As to the aggregate evolution, fast growth in a short time followed by a long steady stage was observed.展开更多
Struvite crystallization has been considered a promising approach to recover phosphorus from wastewater. However, its practical application is limited, probably because of the high cost of magnesium(Mg). In this stu...Struvite crystallization has been considered a promising approach to recover phosphorus from wastewater. However, its practical application is limited, probably because of the high cost of magnesium(Mg). In this study, a comprehensive economic analysis was conducted using five Mg sources(MgCl2, MgSO4, MgO, Mg(OH)2, and bittern) during the operation of a pilot-scale fluidized bed reactor(FBR), using swine wastewater as the case matrix. First, the economic operating conditions were investigated, and subsequently, the performance and the costs of the five Mg sources were compared. The results indicated that the FBR could be operated most economically at pH of 8.5 and Mg to phosphorus(Mg/P) molar ratio of 1.5. Under these conditions, no significant differences in phosphorus removal and product quality could be found between the five Mg sources. Selecting the most economical Mg source was thus highly dependent on the prices of the reagents and Mg sources. Low-solubility Mg sources were preferable when NaOH was priced higher, while high-solubility Mg sources proved more economical when HNO3 was expensive. The bittern was the most economical choice only when the distances for total inorganic orthophosphate removal and struvite recovery were shorter than 40 and 270 km, respectively. The current study provides an overview of the economic selection of an Mg source, which can help reduce the cost of struvite crystallization.展开更多
The granulation process, physic-chemical properties, pollution removal ability and bacterial com- munities of aerobic granules with different feed-waste- water (synthetic wastewater, R1; swine wastewater, R2), and t...The granulation process, physic-chemical properties, pollution removal ability and bacterial com- munities of aerobic granules with different feed-waste- water (synthetic wastewater, R1; swine wastewater, R2), and the change trend of some parameters of two types of granules in long-term operated reactors treating swine wastewater were investigated in this experiment. The result indicated that aerobic granulation with the synthetic wastewater had a faster rate compared with swine waste- water and that full granulation in R 1 and R2 was reached on the 30th day and 39th day, respectively. However, although the feed wastewater also had an obvious effect on the biomass fraction and extracellular polymeric sub- stances of the aerobic granules during the granulation process, these properties remained at a similar level after long-term operation. Moreover, a similar increasing trend could also be observed in terms of the nitrogen removal efficiencies of the aerobic granules in both reactors, and the average specific removal rates of the organics and ammonia nitrogen at the steady-state stage were 35.33mg.g^-1 VSS and 51.46mg.g^-1 VSS for R1, and 35.47mg.g^-1 VSS and 51.72mg.g^-1 VSS for R2, respectively. In addition, a shift in the bacterial diversity occurred in the granulation process, whereas bacterial communities in the aerobic granular reactor were not affected by the seed granules after long-term operation.展开更多
Tetracyclines(TCs) discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic m...Tetracyclines(TCs) discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters(SOMs) play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process.展开更多
When the wavelength of Rayleigh wave is comparable with nanometers,Rayleigh wave will become dispersive.Such an interesting phenomenon cannot be predicted by the classical theory of elastodynamics.In order to reveal t...When the wavelength of Rayleigh wave is comparable with nanometers,Rayleigh wave will become dispersive.Such an interesting phenomenon cannot be predicted by the classical theory of elastodynamics.In order to reveal the internal mechanism and influencing factors of the dispersion,a model of Rayleigh wave propagating on an elastic half space is established and analyzed by a new theory of surface elastodynamics,in which the surface effect characterized by both the surface energy density and surface inertia is introduced.Two intrinsic nano-length scales,including the ratio of bulk surface energy density to bulk shear modulus and the ratio of surface mass density to bulk mass density,are achieved.It is found that when the wavelength of Rayleigh wave is comparable with the two intrinsic nano-lengths,the surface effect becomes significant.As a result,dispersion of Rayleigh wave happens and even two Rayleigh waves with different wave speeds may appear.Furthermore,it is found that the effect of surface energy density would enhance the wave speed,while that of surface inertia would reduce it.With the increase of wavelength,both effects gradually disappear and the Rayleigh wave speed degenerates to the classical one.The results of this paper are not only helpful to understand the dispersive mechanism of elastic waves,but also helpful for the fine design and measurement of nanowave devices.展开更多
Phosphorus recovery in the form of struvite has been aroused in recent decades for its dual advantages in eutrophication control and resource protection.The usage of the struvite products is normally determined by the...Phosphorus recovery in the form of struvite has been aroused in recent decades for its dual advantages in eutrophication control and resource protection.The usage of the struvite products is normally determined by the size which is largely depended on the hydrodynamics.In this study,flow behavior of struvite pellets was simulated by means of Eulerian–Eulerian two-fluid model combining with kinetic theory of granular flow in a liquid–solid fluidized bed reactor(FBR).A parametric study including the mesh size,time step,discretization strategy,turbulent model and drag model was first developed,followed by the evaluations of crucial operational conditions,particle characteristics and reactor shapes.The results showed that a cold model with the mesh resolution of 16 × 240,default time step of 0.001 sec and first order discretization scheme was accurate enough to describe the fluidization.The struvite holdup profile using Syamlal–O'Brien drag model was best fitted to the experimental data as compared with other drag models and the empirical Richardson–Zaki equation.Regarding the model evaluation,it showed that liquid velocity and particle size played important roles on both solid holdups and velocities.The reactor diameter only influenced the solid velocity while the static bed height almost took no effect.These results are direct and can be applied to guide the operation and process control of the struvite fluidization.Moreover,the model parameters can also be used as the basic settings in further crystallization simulations.展开更多
Studies on pattern formation in coculture cell systems can provide insights into many physiological and pathological processes.Here,we investigate how the extracellular matrix(ECM)may influence the patterning in cocul...Studies on pattern formation in coculture cell systems can provide insights into many physiological and pathological processes.Here,we investigate how the extracellular matrix(ECM)may influence the patterning in coculture systems.The model coculture system we use is composed of highly motile invasive breast cancer cells,initially mixed with inert nonmetastatic cells on a 2D substrate and covered with a Matrigel layer introduced to mimic ECM.We observe that the invasive cells exhibit persistent centripetal motion and yield abnormal aggregation,rather than random spreading,due to a“collective pulling”effect resulting from ECM-mediated transmission of active contractile forces generated by the polarized migration of the invasive cells along the vertical direction.The mechanism we report may open a new window for the understanding of biological processes that involve multiple types of cells.展开更多
Hierarchically porous zeolites are promising candidates in catalytic conversion of relatively bulky molecules,and their syntheses have attracted significant attention.From both industrial and scientific perspectives,d...Hierarchically porous zeolites are promising candidates in catalytic conversion of relatively bulky molecules,and their syntheses have attracted significant attention.From both industrial and scientific perspectives,different carbon materials have been widely employed as hard templates for the preparation of hierarchically porous zeolites during the past two decades.In this review,the progress in synthetic strategies using carbon materials as templates is comprehensively summarized.Depending on the affinity between the carbon templates and zeolite precursors,the substantial strategies for synthesizing hierarchical zeolites are introduced in direct templates and indirect templates.Direct templates methods,by which the carbon materials are directly mixed with precursors gel as hard templates,are first reviewed.Then,we discuss the indirect templates method(crystallization of carbon-silica composites),by which the carbon is produced by in situ pyrolysis of organic-inorganic precursors.In addition,the technique of encapsulating metal species into zeolites crystals with the assistance of carbon templates is also discussed.In the conclusion part,the factors affecting the synthesis of carbon-templated hierarchically porous zeolites are remarked.This review is expected to attract interest in the synthesis strategies of hierarchically porous zeolites,especially cost-effective and large-scale production methodologies,which are essential to the industrial application of hierarchical zeolites.展开更多
基金supported by grants from the National Natural Science Foundation of China (No. 81570143 and 91642111)the Guangdong Provincial Basic Research Program (No. 2015B020227003)+3 种基金the Guangdong Provincial Applied Science and Technology Research & Development Program (No. 2016B020237006)the Guangzhou Science and Technology Project (No. 201510010211)the Fundamental Research Funds for the Central Universities (No. 21616108)the Medical Scientific Research Foundation of Guangdong Province, China (No. A2016045)
文摘Objective: To investigate the association between the T cell inhibitory receptor programmed death 1(PD-1)and T cell exhaustion status in T cells from patients with de novo acute myeloid leukemia(AML) and AML in complete remission(CR).Methods:Surface expression of PD-1 and the exhaustion and immunosenescence markers CD244 and CD57 on CD3+,CD4+ and CD8+ T cells from peripheral blood samples from 20 newly diagnosed,untreated AML patients and 10 cases with AML in CR was analyzed by flow cytometry.Twenty-three healthy individuals served as control.Results:A significantly higher percentage of PD-1+ cells were found for CD3+ T cells in the de novo AML group compared with healthy controls.In addition,an increased level of PD-1+ CD8+ T cells,but not PD-1+ CD4+,was found for CD3+ T cells in the de novo AML and AML-CR samples.A higher percentage of CD244+ CD4+,CD244+ CD8+,CD57+ CD4+ and CD57+ CD8+ T cells was found in CD3+ T cells in samples from those with de novo AML compared with those from healthy controls.Strong increased PD-1+ CD244+ and PD-1+ CD57+ coexpression was found for CD4+ and CD8+ T cells in the de novo AML group compared with healthy controls.Conclusions:We characterized the major T cell defects,including co-expression of PD-1 and CD244,CD57-exhausted T cells in patients with de novo AML,and found a particular influence on CD8+ T cells,suggesting a poor anti-leukemia immune response in these patients.
文摘Potato late blight, caused by the oomycete Phytophthora infestans, is one of the most devastating diseases in the agricultural sector around the world. Many genes (R genes) conferring resistance to late blight have been identified in various potato species and most of these R genes have been used in potato breeding. The aim of this study was to develop and validate PCR-based assays for the R genes Rpi-blb1, Rpi-blb2, Rpi-blb3 and Rpi-bt1, to distinguish between late blight resistant and late blight susceptible potato progeny in the given breeding background. A total of 100 breeding progeny were screened for the presence of these R genes and tested for resistance against P. infestans mating type A2, genotype US-8 strain, using detached leaf and tuber rot assays. PCR products for the Rpi-blb1 and Rpi-bt1 resistance genes were identified in the resistant progeny but were absent in the susceptible ones;therefore these PCR assays could differentiate between late blight resistant and susceptible plants. Genotypic data from the DNA markers derived from the Rpi-blb1 and Rpi-bt1 genes was found to correlate with the phenotypic data for foliar late blight but not with data for tuber rot. Our results demonstrate that markers derived from these two R genes could be useful for marker-assisted selection (MAS) for foliar late blight resistance in potato breeding programs.
基金Project supported by the National Natural Science Foundation of China(Nos.11972363 and12272401)the Opening Project of State Key Laboratory of Solid Lubrication(Lanzhou Institute of Chemical Physics)(No.LSL-20012001)the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures(Nanjing University of Aeronautics and Astronautics)(No.MCMS-E-0221G01)。
文摘To improve the thermoelectric converting performance in applications such as power generation,reutilization of heat energy,refrigeration,and ultrasensitive sensors in scramjet engines,a thermoelectric film/substrate system is widely designed and applied,whose interfacial behavior dominates the strength and service life of thermoelectric devices.Herein,a theoretical model of a thermoelectric film bonded to a graded substrate is proposed.The interfacial shear stress,the normal stress in the thermoelectric film,and the stress intensity factors affected by various material and geometric parameters are comprehensively studied.It is found that adjusting the inhomogeneity parameter of the graded substrate,thermal conductivity,and current density of the thermoelectric film can reduce the risk of interfacial failure of the thermoelectric film/graded substrate system.Selecting a stiffer and thicker thermoelectric film is advantageous to the reliability of the thermoelectric film/graded substrate system.The results should be of great guiding significance for the present and upcoming applications of thermoelectric materials in various fields.
基金The National Key R&D Program of China(2018YFB1501602)the National Natural Science Foundation of China(21721004 and 22078316)are acknowledged for financial support。
文摘Zeolite-supported metal catalysts containing hydrogenation centers and acid sites are promising in the chemoselective hydrogenation of biomass platform molecules into value-added chemicals and fuels.The primary challenge of employing such bifunctional catalysts for biomass conversion lies in catalyst stability in the liquid phase under harsh conditions. Herein, we have prepared a Ni/La-Y nanocatalyst via an improved wet impregnation method. Compared with Ni nanoparticles on H-Y, La addition shows a significantly enhanced stability and performance in the continuous liquid-phase hydrogenation of γ-valerolactone(GVL) into ethyl pentanoate(EP) at 200 ℃ for 1000 h. Complementary characterization studies reveal that La addition in the metal/zeolite catalyst not only efficiently modulates the acid property of the zeolite to alleviate coke formation, but also suppresses zeolite dealumination and metal agglomeration and leaching upon catalysis over a 1000 h period. These findings provide an efficient approach for improving the stability of zeolite-supported bifunctional catalysts, leading to potential application in hydrogen-assisted biomass valorization under the liquid-phase conditions.
文摘The catalytic hydrogenation of halonitroarenes to haloanilines is a green and sustainable process for the production of key nitrogen-containing intermediates in fine chemical industry.Chemoselective hydrogenation poses a significant challenge,which requires the rational design of the catalysts with proper hydrogenation ability for nitro group and simultaneously preventing dehalogenation of halogen group.Herein,a highly effective Rh@Al_(2)O_(3)@C single-atom catalyst(SAC)was developed for the hydrogenation of m-chloronitrobenzene(m-CNB)to m-chloroaniline(m-CAN),through an in-situ grafting of metal during the assembly of MIL-53(Al),followed by confined pyrolysis.Extensive characterizations reveal an exquisite structure of the Rh@Al_(2)O_(3)@C,containing atomically dispersed Rh sites onto Al_(2)O_(3) confined by the amorphous carbon.The five-coordinated aluminum(Al^(Ⅴ))species are essential for achieving the atomic dispersion of Rh atoms,providing the unsaturated coordinative sites for metal.Compared to the benchmark Rh/γ-Al_(2)O_(3) and Rh/C nanocatalysts,the Rh@Al_(2)O_(3)@C SAC affords an excellent turnover frequency of 2317 molm-CNB·molRh^(–1)·h^(–1),the highest value to date in heterogeneous catalyst systems for the hydrogenation of m-CNB at 313 K and 20 bar H2,together with a sustained selectivity to m-CAN(~98%)during five consecutive runs.The superior catalytic performance of the Rh@Al_(2)O_(3)@C is attributed to a proper modulation of electronic structure of hydrogenation metal by forming SAC,together with an enhanced accessibility of acid function sites.
基金Supported by a grant from National Scaling Height Program, China (No. 95-zhuan-10)
文摘Objective: The aim of the study was to investigate the expression pattern of hematopoietic transcription factor GATA-1, -2 and -3 genes in leukemic bone marrow (BM) micreenvironment [including bone marrow stremal cells (BMSCs) and BM hematopoietic cells]. Methods: Mononuclear cells were isolated from BM of patients with acute myeloid leukemia (AML), chronic myelogenous leukemia (CML), or acute lymphoblasUc leukemia (ALL). Adherent cells (BMSCs) and nonadherent ceils (BM hematopoietic cells) were collected after long-term culture in vitro. The semi-quantitative expression levels of GATA genes in the BMSCs or BM hematopoietic cells from patients with leukemia were analyzed by using RT-PCR-ELISA and com- pared with normal controls. Results: The expression level of GATA-1 gene in the BMSCs from CML group was significantly lower than that of the normal controls. The expression level of GATA-3 gene in the BMSCs from ALL was higher than that of the normal controls, but that from CML was lower than the normal controls. Dominant expression of GATA-3 gene was found in the normal BM hematopoietic cells. The dominant expression of GATA-2 gene was found in the normal BMSCs and the BMSCs from CML, whereas the dominant expression of GATA-3 gene was detected in the BMSCs from AML. Conclusion: GATA-1, -2 and -3 genes might play a role in hematopoiesis regulation in leukemia, and the changes of expression pattern of GATA genes might influence the hematopoiesis in BM microenvironment and relate to the pathogenesis and development of leukemia.
基金Supported by grants from the Science and Technology Commission of Guangdong Province (No.06025169,No.2005B50301016)the Key Laboratory of Pathophysiology of Jinan University
文摘Objective: To investigate the effects of staphyococcal enterotoxin A (SEA) on the cytotoxicity of T cells stimulated by PML-RARa peptide in vitro. Methods: Peripheral blood mononuclear cells (MNC) from healthy donor were obtained by density gradient centrifugation on Ficoll-Hypaque, MNC were cultured with PML-RARa peptide and SEA for 20 days. After induction, the cytotoxicity of T cells induced against NB4 and K562 cell lines were examined by Cell Counting Kit-8 (CCK-8). The CD4 and CD8 surface markers on the harvested CD3^+ T cells were detected by flow cytometry (FCM). Results: The cytotoxicity of T cells induced by PML-RARa peptide with SEA was higher than that of T cells induced only by PML-RARa peptide against NB4 cells. The FCM assay showed that the ratio of CD4^+/CD8^+ T cells were gradually decreased in both groups of PML-RARα peptide whether with SEA or not at the intervals of day 5,10 and 20 day after induction, but the most significantly decreased by PML-RARe peptide with SEA. Conclusion: The specific cytotoxicity of T cells induced by PML-RARa peptide against NB4 cells could be enhanced with superantigen SEA.
基金supported by grants from the National Natural Science Foundation of China(No.82000108)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515110310)+4 种基金the Guangdong Natural Science Foundation of China(No.2023A1515010170)NSFC Incubation Project of Guangdong Provincial People’s Hospital(No.KY0120220026)Guangdong Provincial Outstanding Young Medical Talents Supporting Research Foundation(No.KJ012019459)Key Laboratory for Regenerative Medicine of Ministry of Education Project(No.ZSYXM202001)the National Innovation and Entrepreneurship Training Program for Undergraduate(No.CX23386).
文摘Tissue-resident memory T(TRM)cells infiltrating solid tumors could influence tumor progression and the response to immune therapies.However,the proportion and prognostic value of TRM cells in the bone marrow(BM)of patients with acute myeloid leukemia(AML)are unclear.In this study,we used flow cytometry to assay the phenotype of 49 BM samples from patients newly diagnosed with AML(ND-AML).We found that the BM CD8^(+)effector memory(TEM)cells highly expressed CD69(CD8^(+)TRM-like T cells),and their percentage was significantly increased in patients with ND-AML compared with that in healthy individuals(HI).The high percentage of CD8^(+)TRM-like subset was associated with poor overall survival in our ND-AML cohort.The Kaplan–Meier Plotter database verified a significantly reduced survival rate among patients with high expression of CD8^(+)TRM-like T cell characteristic genes(CD8A,CD69,and TOX),especially the M4 and M5 subtypes.Phenotypic analysis revealed that the BM CD8^(+)TRM-like subpopulation exhibited exhausted T cell characteristics,but its high expression of CD27 and CD28 and low expression of CD57 suggested its high proliferative potential.The single-cell proteogenomic dataset confirmed the existence of TRM-like CD8^(+)T cells in the BM of patients with AML and verified the high expression of immune checkpoints and costimulatory molecules.In conclusion,we found that the accumulation of BM CD8^(+)TRM-like cells could be an immune-related survival prediction marker for patients with AML.
基金supported by the Hi-Tech Research and Development Program(863)of China(No.2011AA060902)the Xiamen Science and Technology Planning Project(No.3502Z20132016)
文摘Struvite crystallization is a promising method to remove and recover phosphorus from wastewater to ease both the scarcity of phosphorus rock resources and water eutrophication worldwide. To date, although various kinds of reactor systems have been developed, supporting methods are required to control the stmvite fines flushing out of the reactors. As an intrinsic property, aggregation is normally disregarded in the struvite crystallization process, although it is the key factor in final particle size and therefore guarantees phosphorus recovery efficiency. The present study developed a method to analyze the characteristics of struvite aggregates using fractal geometry, and the influence of operational parameters on struvite aggregation was evaluated. Due to its typical orthorhombic molecular structure, struvite particles are prone to crystallize into needle or rod shapes, and aggregate at the comers or edges of crystals. The determined fractal dimension (Dpf) of struvite aggregates was 1.52-1.31, with the corresponding range of equivalent diameter (d0.5) at 295.9-85.4 Ixm. Aggregates formed in relatively low phosphorus concentrations (3.0-5.0 mmol/L) and mildly alkaline conditions (pH 9.0-9.5) displayed relatively compact structures, large aggregate sizes and high aggregation strength. Increasing pH values led to continuous decrease of aggregate sizes, while the variation of Dpf was insignificant. As to the aggregate evolution, fast growth in a short time followed by a long steady stage was observed.
基金supported by the National Natural Science Foundation of China(No.51608503)the Natural Science Foundation of Fujian(No.2017J05091)the Cooperation Project between China and Japan(No.2016YFE0118000)
文摘Struvite crystallization has been considered a promising approach to recover phosphorus from wastewater. However, its practical application is limited, probably because of the high cost of magnesium(Mg). In this study, a comprehensive economic analysis was conducted using five Mg sources(MgCl2, MgSO4, MgO, Mg(OH)2, and bittern) during the operation of a pilot-scale fluidized bed reactor(FBR), using swine wastewater as the case matrix. First, the economic operating conditions were investigated, and subsequently, the performance and the costs of the five Mg sources were compared. The results indicated that the FBR could be operated most economically at pH of 8.5 and Mg to phosphorus(Mg/P) molar ratio of 1.5. Under these conditions, no significant differences in phosphorus removal and product quality could be found between the five Mg sources. Selecting the most economical Mg source was thus highly dependent on the prices of the reagents and Mg sources. Low-solubility Mg sources were preferable when NaOH was priced higher, while high-solubility Mg sources proved more economical when HNO3 was expensive. The bittern was the most economical choice only when the distances for total inorganic orthophosphate removal and struvite recovery were shorter than 40 and 270 km, respectively. The current study provides an overview of the economic selection of an Mg source, which can help reduce the cost of struvite crystallization.
文摘The granulation process, physic-chemical properties, pollution removal ability and bacterial com- munities of aerobic granules with different feed-waste- water (synthetic wastewater, R1; swine wastewater, R2), and the change trend of some parameters of two types of granules in long-term operated reactors treating swine wastewater were investigated in this experiment. The result indicated that aerobic granulation with the synthetic wastewater had a faster rate compared with swine waste- water and that full granulation in R 1 and R2 was reached on the 30th day and 39th day, respectively. However, although the feed wastewater also had an obvious effect on the biomass fraction and extracellular polymeric sub- stances of the aerobic granules during the granulation process, these properties remained at a similar level after long-term operation. Moreover, a similar increasing trend could also be observed in terms of the nitrogen removal efficiencies of the aerobic granules in both reactors, and the average specific removal rates of the organics and ammonia nitrogen at the steady-state stage were 35.33mg.g^-1 VSS and 51.46mg.g^-1 VSS for R1, and 35.47mg.g^-1 VSS and 51.72mg.g^-1 VSS for R2, respectively. In addition, a shift in the bacterial diversity occurred in the granulation process, whereas bacterial communities in the aerobic granular reactor were not affected by the seed granules after long-term operation.
基金supported by the Xiamen Science and Technology Planning Project (No. 3502Z20162002)
文摘Tetracyclines(TCs) discharged from livestock wastewater have aroused public concerns due to their pharmacological threats to ecosystems and human health. As an important medium in the wastewater, suspended organic matters(SOMs) play vital roles in antibiotics transport and degradation. However, limited information has been reported in the relevant literature. This study investigated TCs sorption behavior on SOM, withdrawn from swine wastewater. High TCs sorption capacities were detected, with the maximum values ranging from 0.337 to 0.679 mg/g. Increasing p H and temperature led to the decline of sorption capacity. Results from three-dimensional excitation–emission matrix fluorescence spectroscopy and Fourier transform infrared spectrometry revealed that amide and carboxyl groups were the main functional groups for TCs adsorption. The interactions between SOM and TCs were clarified as predominated by hydrogen-bonding and cation-exchange in acid conditions, and electrostatic repulsion in neutral or alkaline conditions. Adsorption kinetics modeling was conducted, and a satisfactory fitting was achieved with the Freundlich equation. These results indicated that the adsorption process was a rather complex process, involving a combination of cation-exchange and hydrogen-bonding. The results will provide a better understanding of the capability of SOM for TCs transport and abatement in the wastewater treatment process.
基金This work was supported by the National Natural Science Foundation of China(Grants 11532013,11872114,11772333,and 12002033)the Project of State Key Laboratory of Explosion Science and Technology(Grant ZDKT17-02).
文摘When the wavelength of Rayleigh wave is comparable with nanometers,Rayleigh wave will become dispersive.Such an interesting phenomenon cannot be predicted by the classical theory of elastodynamics.In order to reveal the internal mechanism and influencing factors of the dispersion,a model of Rayleigh wave propagating on an elastic half space is established and analyzed by a new theory of surface elastodynamics,in which the surface effect characterized by both the surface energy density and surface inertia is introduced.Two intrinsic nano-length scales,including the ratio of bulk surface energy density to bulk shear modulus and the ratio of surface mass density to bulk mass density,are achieved.It is found that when the wavelength of Rayleigh wave is comparable with the two intrinsic nano-lengths,the surface effect becomes significant.As a result,dispersion of Rayleigh wave happens and even two Rayleigh waves with different wave speeds may appear.Furthermore,it is found that the effect of surface energy density would enhance the wave speed,while that of surface inertia would reduce it.With the increase of wavelength,both effects gradually disappear and the Rayleigh wave speed degenerates to the classical one.The results of this paper are not only helpful to understand the dispersive mechanism of elastic waves,but also helpful for the fine design and measurement of nanowave devices.
基金supported by the Young Scientists Frontier Foundation of Institute of Urban Environment,Chinese Academy of Sciences(No.IUEQN201501)the National Natural Science Foundation of China(No.51608503)
文摘Phosphorus recovery in the form of struvite has been aroused in recent decades for its dual advantages in eutrophication control and resource protection.The usage of the struvite products is normally determined by the size which is largely depended on the hydrodynamics.In this study,flow behavior of struvite pellets was simulated by means of Eulerian–Eulerian two-fluid model combining with kinetic theory of granular flow in a liquid–solid fluidized bed reactor(FBR).A parametric study including the mesh size,time step,discretization strategy,turbulent model and drag model was first developed,followed by the evaluations of crucial operational conditions,particle characteristics and reactor shapes.The results showed that a cold model with the mesh resolution of 16 × 240,default time step of 0.001 sec and first order discretization scheme was accurate enough to describe the fluidization.The struvite holdup profile using Syamlal–O'Brien drag model was best fitted to the experimental data as compared with other drag models and the empirical Richardson–Zaki equation.Regarding the model evaluation,it showed that liquid velocity and particle size played important roles on both solid holdups and velocities.The reactor diameter only influenced the solid velocity while the static bed height almost took no effect.These results are direct and can be applied to guide the operation and process control of the struvite fluidization.Moreover,the model parameters can also be used as the basic settings in further crystallization simulations.
基金supported by the National Natural Science Foundation of China(Grant Nos.11774394,11974066,12074407,and 12090054)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000)+2 种基金the Start-Up Fund and University Graduate Fellowship of Arizona State University,the Natural Science Foundation of Chongqing Municipal Science and Technology Commission(Grant No.cstc2019jcyj-msxmX0477)the Fundamental Research Funds for the Central Universities(Grant No.2019CDYGYB007)the Capital Health Development Research Project,China(Grant No.2020-2-2072).
文摘Studies on pattern formation in coculture cell systems can provide insights into many physiological and pathological processes.Here,we investigate how the extracellular matrix(ECM)may influence the patterning in coculture systems.The model coculture system we use is composed of highly motile invasive breast cancer cells,initially mixed with inert nonmetastatic cells on a 2D substrate and covered with a Matrigel layer introduced to mimic ECM.We observe that the invasive cells exhibit persistent centripetal motion and yield abnormal aggregation,rather than random spreading,due to a“collective pulling”effect resulting from ECM-mediated transmission of active contractile forces generated by the polarized migration of the invasive cells along the vertical direction.The mechanism we report may open a new window for the understanding of biological processes that involve multiple types of cells.
基金supported by the National Natural Science Foundation of China(Grant No.21773128).
文摘Hierarchically porous zeolites are promising candidates in catalytic conversion of relatively bulky molecules,and their syntheses have attracted significant attention.From both industrial and scientific perspectives,different carbon materials have been widely employed as hard templates for the preparation of hierarchically porous zeolites during the past two decades.In this review,the progress in synthetic strategies using carbon materials as templates is comprehensively summarized.Depending on the affinity between the carbon templates and zeolite precursors,the substantial strategies for synthesizing hierarchical zeolites are introduced in direct templates and indirect templates.Direct templates methods,by which the carbon materials are directly mixed with precursors gel as hard templates,are first reviewed.Then,we discuss the indirect templates method(crystallization of carbon-silica composites),by which the carbon is produced by in situ pyrolysis of organic-inorganic precursors.In addition,the technique of encapsulating metal species into zeolites crystals with the assistance of carbon templates is also discussed.In the conclusion part,the factors affecting the synthesis of carbon-templated hierarchically porous zeolites are remarked.This review is expected to attract interest in the synthesis strategies of hierarchically porous zeolites,especially cost-effective and large-scale production methodologies,which are essential to the industrial application of hierarchical zeolites.