Caffeine intake during pregnancy is common,while its effect on gut microbiota composition of offspring and the relationship with susceptibility to adult diseases remains unclear.This study aimed to confirm the effects...Caffeine intake during pregnancy is common,while its effect on gut microbiota composition of offspring and the relationship with susceptibility to adult diseases remains unclear.This study aimed to confirm the effects of prenatal caffeine exposure(PCE)on the gut microbiota composition and its metabolites in female offspring rats,and to further elucidate its underlying mechanism and intervention targets in adult non-alcoholic fatty disease(NAFLD).The results showed that the gut microbiota of PCE female offspring at multiple time points from infancy to adolescence were significantly changed with depletion of butyric acid-producing bacteria,leading to a decrease in butyric acid in adulthood.It was also found that PCE female offspring rats were sensitive to NAFLD induced by a postnatal high-fat diet(HFD),which is mainly related to the enhancement of hepatic triglyceride synthesis function.Through mechanism exploration,we found that HFD further reduced the fecal and serum butyric acid levels in the PCE female offspring,which was significantly negatively correlated with hepatic SREBP-1c/FASN mRNA expression and triglyceride level.In vivo and in vitro experiments confirmed that sodium butyrate(NaB)supplementation could reduce hepatic lipid accumulation through MCT1/GPR109A-AMPK,thereby effectively decreasing the susceptibility to NAFLD in the PCE female offspring rats.展开更多
Glutamine is one of the most abundant non-essential amino acids in human plasma and plays a crucial role in many biological processes of the human body.Tumor cells take up a large amount of glutamine to meet their rap...Glutamine is one of the most abundant non-essential amino acids in human plasma and plays a crucial role in many biological processes of the human body.Tumor cells take up a large amount of glutamine to meet their rapid proliferation requirements,which is supported by the upregulation of glutamine transporters.Targeted inhibition of glutamine transporters effectively inhibits cell growth and proliferation in tumors.Among all cancers,digestive system malignant tumors(DSMTs)have the highest incidence and mortality rates,and the current therapeutic strategies for DSMTs are mainly surgical resection and chemotherapy.Due to the relatively low survival rate and severe side effects associated with DSMTs treatment,new treatment strategies are urgently required.This article summarizes the glutamine transporters involved in DSMTs and describes their role in DSMTs.Additionally,glutamine transportertarget drugs are discussed,providing theoretical guidance for the further development of drugs DSMTs treatment.展开更多
Corrosion can be very harmful to the service life and several properties of reinforced concrete structures.The metal magnetic memory(MMM)method,as a newly developed spontaneous magnetic flux leakage(SMFL)non-destructi...Corrosion can be very harmful to the service life and several properties of reinforced concrete structures.The metal magnetic memory(MMM)method,as a newly developed spontaneous magnetic flux leakage(SMFL)non-destructive testing(NDT)technique,is considered a potentially viable method for detecting corrosion damage in reinforced concrete members.To this end,in this paper,the indoor electrochemical method was employed to accelerate the corrosion of outsourced concrete specimens with different steel bar diameters,and the normal components Bz and its gradient of the SMFL fields on the specimen surfaces were investigated based on the metal magnetic memory(MMM)method.The experimental results showed that the SMFL experimental Bz curves are consistent with the analytical results of the theoretical model.Furthermore,the crest-to-trough behavior on the Bz signal curve and its zero-point gradient spacing can more accurately indicate the corroded area’s extent.Then,a magnetic characteristic parameter W based on a large amount of experimental data was established to characterize the degree of corrosion of the steel bars.The magnetic characteristic parameter W is linearly related to the maximum cross-sectional area loss rateof the corroded reinforcement.This paper will lay the foundation for future research on corrosion detection of reinforced concrete structures based on the MMM method and provide a feasible way for non-destructive detection of corrosion independent of the influence of reinforcement diameter and magnetization history.展开更多
Due to the high elevation, complex terrain, severe weather, and inaccessibility, direct meteorological observations do not exist over large portions of the Tibetan Plateau, especially the western part of it. Satellite...Due to the high elevation, complex terrain, severe weather, and inaccessibility, direct meteorological observations do not exist over large portions of the Tibetan Plateau, especially the western part of it. Satellite rainfall estimates have been very important sources for precipitation information, particularly in rain gauge-sparse regions. In this study, Tropical Rainfall Measuring Mission （TRMM） Multi-satellite Precipitation Analysis （TMPA） products 3B42, RTV5V6, and RTV7 were evaluated for their applicability to the upper Yellow and Yangtze River basins on the Tibetan Plateau. Moreover, the capability of the TMPA products to simulate streamflow was also investigated using the Variable Infiltration Capacity （VIC） semi-distributed hydrological model. Results show that 3B42 performs better than RTVSV6 and RTV7, based on verification of the China Meteorological Administration （CMA） observational precipitation data. RTVSV6 can roughly capture the spatial precipitation pattern but overestimation exists throughout the entire study region. The anticipated improvements of RTV7 relative to RTVSV6 have not been realized in this study. Our results suggest that RTV7 significantly overestimates the precipitation over the two river basins, though it can capture the seasonal cycle features of precipitation. 3B42 shows the best performance in streamflow simulation of the abovementioned satellite products. Although involved in gauge adjustment at a monthly scale, 3B42 is capable of daily streamflow simulation. RTV5V6 and RTV7 have no capability to simulate streamflow in the upper Yellow and Yangtze River basins.展开更多
BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish diffe...BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish different finite element models for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.METHODS The three-dimensional models of the normal and fractured pelvis and the five internal fixations were established using the computed tomography data of the pelvis of a living volunteer.After the vertebral body model was inserted in the way of origin matching and all cancellous bones were copied using the duplicated cancellous bone model as the subtractive entity,the Boolean operation was performed on the pelvis model to obtain the model of the complete pelvis cortical and cancellous bones.RESULTS In the standing position,the maximum stress was 46.21 MPa.In the sitting position,the sacrum bore the simulated gravity load at the upper end.When comparing the five fixations,there were no significant differences in the stress mean values among groups(sitting:P=0.9794;standing:P=0.9741).In terms of displacement,the average displacement of the internal iliac plate group was smaller than that of the spring plate group(P=0.002),and no differences were observed between the other pairs of groups(all P>0.05).In the standing position,there were no significant differences in the mean value of displacement among the groups(P=0.2985).It can be seen from the stress nephogram of the internal fixations in different positions that the stress of the internal fixation was mainly concentrated in the fracture segment.CONCLUSION There were no significant differences among the fixations for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.展开更多
CJC-ZrB2-ZrC-SiC composites were fabricated by polymer infiltration and pyrolysis （PIP） with a preform of G/ZrB2. The carbon fibers and the resin carbon were coated with ceramic layer after PIP in the com- posites. ...CJC-ZrB2-ZrC-SiC composites were fabricated by polymer infiltration and pyrolysis （PIP） with a preform of G/ZrB2. The carbon fibers and the resin carbon were coated with ceramic layer after PIP in the com- posites. The composite presents a pseudo-plastic fracture due to deflection of cracks and pullout of fibers. The composite has a higher bending strength by this method in comparison with the conventional PIP process due to fewer heat treatment cycles. The static oxidation test shows that the mass loss of the composites is no more than 1% after 20 rain oxidation at 1100 ~C. The ＂core-shell＂ structure between ZrC-SiC ceramic and other phases plays a positive role in preventing the inward diffusion of oxygen. The ablation resistance of the C/C-ZrB2-ZrC-SiC composite samples was tested using a plasma generator. After ablation for 120 s, the mass and linear ablation rates of the composites are 4.65 mg cm-2 s-1 and 2.46 μm s-1, respectively. The short carbon layer shows a better ablation resistance than the nonwoven carbon fabric layer after the ceramic coating is peeled off because of its higher ceramic content.展开更多
Nanodiamonds(NDs)were prepared under ambient pressure by sublimation decomposition of silicon carbide in an intermediate frequency furnace for only 8 min.The synthesis proceeded in the temperature range of 2600-2800℃...Nanodiamonds(NDs)were prepared under ambient pressure by sublimation decomposition of silicon carbide in an intermediate frequency furnace for only 8 min.The synthesis proceeded in the temperature range of 2600-2800℃ without any catalyst or highly active gas components(such as H2,alkane,and halogen).The conversion began at 2600℃ and produced NDs with particle sizes in the range of 1-5 nm with a uniform particle shape and excellent dispersion.The linear reaction kinetics allowed for rapid transformation to any depth with reasonable control of the temperature.The linear rate constant(K_(l))for the reaction at 2800℃ was 37.5 mm/h,which is 31.2 times that of the reaction at 2600℃.The Si C sublimation decomposition produced carbon atoms that filled the Si C lattice vacancies or were combined with the suspended carbon chain bonds to form sp3 carbon,while the diffusion of amorphous carbon atoms promoted nucleation and growth of diamond.High-resolution transmission electron microscopy analysis indicated that the NDs were separated from the Si C matrix by break-off due to propagation of the reaction front.This Si C sublimation decomposition method is considered simple,fast,environmentally friendly and promising for industrial-scale production.展开更多
基金funded by the National Natural Science Foundation of China(82030111,U23A20407)the National Key Research and Development Program of China(2020YFA0803900)+1 种基金the Major Technological Innovation Projects of Hubei Province(2019ACA140)Hubei Province’s Outstanding Medical Academic Leader program,and the Basic and Clinical Medical Research Joint Fund of Zhongnan Hospital,Wuhan University(ZNLH202208).
文摘Caffeine intake during pregnancy is common,while its effect on gut microbiota composition of offspring and the relationship with susceptibility to adult diseases remains unclear.This study aimed to confirm the effects of prenatal caffeine exposure(PCE)on the gut microbiota composition and its metabolites in female offspring rats,and to further elucidate its underlying mechanism and intervention targets in adult non-alcoholic fatty disease(NAFLD).The results showed that the gut microbiota of PCE female offspring at multiple time points from infancy to adolescence were significantly changed with depletion of butyric acid-producing bacteria,leading to a decrease in butyric acid in adulthood.It was also found that PCE female offspring rats were sensitive to NAFLD induced by a postnatal high-fat diet(HFD),which is mainly related to the enhancement of hepatic triglyceride synthesis function.Through mechanism exploration,we found that HFD further reduced the fecal and serum butyric acid levels in the PCE female offspring,which was significantly negatively correlated with hepatic SREBP-1c/FASN mRNA expression and triglyceride level.In vivo and in vitro experiments confirmed that sodium butyrate(NaB)supplementation could reduce hepatic lipid accumulation through MCT1/GPR109A-AMPK,thereby effectively decreasing the susceptibility to NAFLD in the PCE female offspring rats.
基金the National Natural Science Foundation of China(No.82003846)the Administration of Traditional Chinese Medicine of Guangdong Province,China(No.20212124).
文摘Glutamine is one of the most abundant non-essential amino acids in human plasma and plays a crucial role in many biological processes of the human body.Tumor cells take up a large amount of glutamine to meet their rapid proliferation requirements,which is supported by the upregulation of glutamine transporters.Targeted inhibition of glutamine transporters effectively inhibits cell growth and proliferation in tumors.Among all cancers,digestive system malignant tumors(DSMTs)have the highest incidence and mortality rates,and the current therapeutic strategies for DSMTs are mainly surgical resection and chemotherapy.Due to the relatively low survival rate and severe side effects associated with DSMTs treatment,new treatment strategies are urgently required.This article summarizes the glutamine transporters involved in DSMTs and describes their role in DSMTs.Additionally,glutamine transportertarget drugs are discussed,providing theoretical guidance for the further development of drugs DSMTs treatment.
文摘Corrosion can be very harmful to the service life and several properties of reinforced concrete structures.The metal magnetic memory(MMM)method,as a newly developed spontaneous magnetic flux leakage(SMFL)non-destructive testing(NDT)technique,is considered a potentially viable method for detecting corrosion damage in reinforced concrete members.To this end,in this paper,the indoor electrochemical method was employed to accelerate the corrosion of outsourced concrete specimens with different steel bar diameters,and the normal components Bz and its gradient of the SMFL fields on the specimen surfaces were investigated based on the metal magnetic memory(MMM)method.The experimental results showed that the SMFL experimental Bz curves are consistent with the analytical results of the theoretical model.Furthermore,the crest-to-trough behavior on the Bz signal curve and its zero-point gradient spacing can more accurately indicate the corroded area’s extent.Then,a magnetic characteristic parameter W based on a large amount of experimental data was established to characterize the degree of corrosion of the steel bars.The magnetic characteristic parameter W is linearly related to the maximum cross-sectional area loss rateof the corroded reinforcement.This paper will lay the foundation for future research on corrosion detection of reinforced concrete structures based on the MMM method and provide a feasible way for non-destructive detection of corrosion independent of the influence of reinforcement diameter and magnetization history.
基金supported by the National Basic Research Program of China(the 973 Program,Grant No.2010CB951101)the Special Fund of the State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering of Hohai University(Grant No.1069-50985512)the"Strategic Priority Research Program"of the Chinese Academy of Sciences(Grant No.XDA05110102)
文摘Due to the high elevation, complex terrain, severe weather, and inaccessibility, direct meteorological observations do not exist over large portions of the Tibetan Plateau, especially the western part of it. Satellite rainfall estimates have been very important sources for precipitation information, particularly in rain gauge-sparse regions. In this study, Tropical Rainfall Measuring Mission （TRMM） Multi-satellite Precipitation Analysis （TMPA） products 3B42, RTV5V6, and RTV7 were evaluated for their applicability to the upper Yellow and Yangtze River basins on the Tibetan Plateau. Moreover, the capability of the TMPA products to simulate streamflow was also investigated using the Variable Infiltration Capacity （VIC） semi-distributed hydrological model. Results show that 3B42 performs better than RTVSV6 and RTV7, based on verification of the China Meteorological Administration （CMA） observational precipitation data. RTVSV6 can roughly capture the spatial precipitation pattern but overestimation exists throughout the entire study region. The anticipated improvements of RTV7 relative to RTVSV6 have not been realized in this study. Our results suggest that RTV7 significantly overestimates the precipitation over the two river basins, though it can capture the seasonal cycle features of precipitation. 3B42 shows the best performance in streamflow simulation of the abovementioned satellite products. Although involved in gauge adjustment at a monthly scale, 3B42 is capable of daily streamflow simulation. RTV5V6 and RTV7 have no capability to simulate streamflow in the upper Yellow and Yangtze River basins.
基金National Natural Science Foundation of China,No.81272008.
文摘BACKGROUND With the modernization of society and transportation in the last decades in China,the incidence of high-energy trauma increased sharply in China,including that of acetabular fractures.AIM To establish different finite element models for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.METHODS The three-dimensional models of the normal and fractured pelvis and the five internal fixations were established using the computed tomography data of the pelvis of a living volunteer.After the vertebral body model was inserted in the way of origin matching and all cancellous bones were copied using the duplicated cancellous bone model as the subtractive entity,the Boolean operation was performed on the pelvis model to obtain the model of the complete pelvis cortical and cancellous bones.RESULTS In the standing position,the maximum stress was 46.21 MPa.In the sitting position,the sacrum bore the simulated gravity load at the upper end.When comparing the five fixations,there were no significant differences in the stress mean values among groups(sitting:P=0.9794;standing:P=0.9741).In terms of displacement,the average displacement of the internal iliac plate group was smaller than that of the spring plate group(P=0.002),and no differences were observed between the other pairs of groups(all P>0.05).In the standing position,there were no significant differences in the mean value of displacement among the groups(P=0.2985).It can be seen from the stress nephogram of the internal fixations in different positions that the stress of the internal fixation was mainly concentrated in the fracture segment.CONCLUSION There were no significant differences among the fixations for acetabular posterior column fractures involving the quadrilateral area of the acetabulum.
基金financially supported by the National Natural Science Foundation of China (No. 51404041)the Natural Science Foundation of Hunan Province (No. 2015JJ3016)
文摘CJC-ZrB2-ZrC-SiC composites were fabricated by polymer infiltration and pyrolysis （PIP） with a preform of G/ZrB2. The carbon fibers and the resin carbon were coated with ceramic layer after PIP in the com- posites. The composite presents a pseudo-plastic fracture due to deflection of cracks and pullout of fibers. The composite has a higher bending strength by this method in comparison with the conventional PIP process due to fewer heat treatment cycles. The static oxidation test shows that the mass loss of the composites is no more than 1% after 20 rain oxidation at 1100 ~C. The ＂core-shell＂ structure between ZrC-SiC ceramic and other phases plays a positive role in preventing the inward diffusion of oxygen. The ablation resistance of the C/C-ZrB2-ZrC-SiC composite samples was tested using a plasma generator. After ablation for 120 s, the mass and linear ablation rates of the composites are 4.65 mg cm-2 s-1 and 2.46 μm s-1, respectively. The short carbon layer shows a better ablation resistance than the nonwoven carbon fabric layer after the ceramic coating is peeled off because of its higher ceramic content.
基金financially supported by the National Natural Science Foundation of China(No.U19A2088)the Special Fund for Innovative Construction of Hunan Province(No.2019RS2058)。
文摘Nanodiamonds(NDs)were prepared under ambient pressure by sublimation decomposition of silicon carbide in an intermediate frequency furnace for only 8 min.The synthesis proceeded in the temperature range of 2600-2800℃ without any catalyst or highly active gas components(such as H2,alkane,and halogen).The conversion began at 2600℃ and produced NDs with particle sizes in the range of 1-5 nm with a uniform particle shape and excellent dispersion.The linear reaction kinetics allowed for rapid transformation to any depth with reasonable control of the temperature.The linear rate constant(K_(l))for the reaction at 2800℃ was 37.5 mm/h,which is 31.2 times that of the reaction at 2600℃.The Si C sublimation decomposition produced carbon atoms that filled the Si C lattice vacancies or were combined with the suspended carbon chain bonds to form sp3 carbon,while the diffusion of amorphous carbon atoms promoted nucleation and growth of diamond.High-resolution transmission electron microscopy analysis indicated that the NDs were separated from the Si C matrix by break-off due to propagation of the reaction front.This Si C sublimation decomposition method is considered simple,fast,environmentally friendly and promising for industrial-scale production.
