Histamine in food has attracted widespread attention due to the potential toxicity and associated health risk.However,its influences on immunological components,especially the function of key immune cells,are still po...Histamine in food has attracted widespread attention due to the potential toxicity and associated health risk.However,its influences on immunological components,especially the function of key immune cells,are still poorly known.In this work,we explored the effects of exogenous histamine on the function of key immune cells such as intestinal epithelial cells,dendritic cells,and T cells.The results showed that histamine could affect the expression of allergy-related genes in CMT93 cells at a high dose of histamine.Moreover,it’s found that histamine could cause an imbalance in the levels of relevant immune factors secreted by dendritic cells and T cells,especially those related to allergy.At the same time,the proportion of MHC class IIpositive dendritic cells and the proportion of T helper 2(Th2)cells in CD4^(+)T cells increased after histamine stimulation.We concluded that the presence of a certain level of histamine in food may affect the expression of allergy-related cytokines,disrupt the balance of the immune homeostasis,and potentially lead to adverse immune reactions.This work demonstrated the importance of including the estimation of histamine’s immune safety in aquatic products rather than merely considering the potential risk of food poisoning.展开更多
From June 2008 to August 2013,approximately 67 kt of CO_(2) was injected into a deep saline formation at the Ketzin pilot CO_(2) storage site.During injection,3D seismic surveys have been performed to monitor the migr...From June 2008 to August 2013,approximately 67 kt of CO_(2) was injected into a deep saline formation at the Ketzin pilot CO_(2) storage site.During injection,3D seismic surveys have been performed to monitor the migration of sequestered CO_(2).Seismic monitoring results are limited by the acquisition and signal-to-noise ratio of the acquired data.The multiphysical reservoir simulation provides information regarding the CO_(2) fluid behavior,and the approximated model should be calibrated with the monitoring results.In this work,property models are delivered from the multiphysical model during 3D repeated seismic surveys.The simulated seismic data based on the models are compared with the real data,and the results validate the effectiveness of the multiphysical inversion method.Time-lapse analysis shows the trend of CO_(2) migration during and after injection.展开更多
Mars is the terrestrial planet in the solar system that is closest to the Earth.Studying the atmospheric parameters of Mars and studying the evolutionary history of the Martian environment on this basis is helpful for...Mars is the terrestrial planet in the solar system that is closest to the Earth.Studying the atmospheric parameters of Mars and studying the evolutionary history of the Martian environment on this basis is helpful for people to discover signs of extraterrestrial life and to study the trend of climate change on Earth.Mie–Rayleigh scattering lidar is an important technology for detecting parameters from the surface to the middle and upper atmosphere.Because of the different aerosol distributions,Mie scattering and Rayleigh scattering have their own optimal detection ranges.Given the long period and high cost of any deep space exploration program,it is important to conduct sufficient feasibility studies and parameter simulations before the payload is launched.In this study,a parameterized lidar mathematical model and Earth’s atmospheric mode are used to compare with the measured signals of ground-based Mie–Rayleigh scattering lidar,and the correctness of the lidar mathematical model is verified.Using the model,we select the landing area of Tianwen-1 and substitute it into the Martian atmospheric mode,and then the Mie–Rayleigh lidar backscattering signal and the key parameters of the lidar system are systematically analyzed under the conditions of a clean Martian atmosphere and a global sandstorm.In addition,the optimal detection altitude ranges of Mie scattering and Rayleigh scattering on Mars under different atmospheric conditions are obtained,which provides a reference for the practical design and development of the subsequent lidar system for the Martian atmospheric environment.展开更多
Bacillus coagulans has been extensively studied so far,but there has been a lack of research on its usage in allergy.In this study,we designed to assess the effect of different concentrations of B.coagulans on food al...Bacillus coagulans has been extensively studied so far,but there has been a lack of research on its usage in allergy.In this study,we designed to assess the effect of different concentrations of B.coagulans on food allergy in a BALB/c mouse model of ovalbumin(OVA)-induced food allergy and its effect on gut microbes.The assessment of symptoms,specific immunoglobulin E(IgE),T-cell differentiation,and related gene expression levels in sensitized mice by assay indicated that high doses of oral B.coagulans could alleviate allergic symptoms.Treatment with B.coagulans,in the high-dose group,significantly reduced IgE and IgG1 levels and modulated the balance of T helper type 1 cell(Th1)and Th2 and the expression of relevant genes in the spleen.16S rRNA analysis showed that probiotics improved the structure of the microbiota,in particular by boosting the percentage of Clostridia,Bacteroides vulgatus and Enterococcus faecium,and by increasing the abundance of microbial species,thereby modulating the immune system.Therefore,this study can provide insights into the practical application of B.coagulans doses to alleviate OVA allergy.展开更多
The associations of individual amino acid with non-alcoholic fatty liver disease(NAFLD)risk remained unclear.The present study aimed to investigate the associations between the two in the Chinese elderly.Methods:A com...The associations of individual amino acid with non-alcoholic fatty liver disease(NAFLD)risk remained unclear.The present study aimed to investigate the associations between the two in the Chinese elderly.Methods:A community-based health check-up program was conducted in Qingdao,China.NAFLD was diagnosed by ultrasonography accompanied by epidemiological investigation.The dietary intakes of amino acids were investigated with 3-day,24-h dietary records and calculated by Nutrition Calculator software.Restricted cubic spline model was used to evaluate a nonlinear relationship between amino acid intake and NAFLD risk.Results:400 NAFLD subjects were identified,and 400 participants were randomly selected as controls and matched by gender and age(±3 years)Dose-response analysis showed that 1000 mg increment of aromatic amino acids(AAAs)was associated with reduced 16%risk of NAFLD.Dietary increments of 750 mg/d threonine,950 mg/d valine,or 1700 mg/d lysine were associated with a 20%reduction in the NAFLD risk(all P for linearity<0.05).Conclusion:The present study demonstrated that the dietary increases in milk,eggs and deep-sea fish,which are rich in the amino acids,might contribute to protecting against NAFLD in the elderly.展开更多
Mepiquat chloride(1,1-dimethyl piperidinium chloride,DPC)is a representative plant growth regulator which can regulate the source-sink relationship for yield increase and shape ideal plant type for mechanical cultivat...Mepiquat chloride(1,1-dimethyl piperidinium chloride,DPC)is a representative plant growth regulator which can regulate the source-sink relationship for yield increase and shape ideal plant type for mechanical cultivation.Here we show a DPC adsorbed layered double hydroxide(DPC-LDH)architecture with enhanced controlled release property and soil distribution.By drip irrigation on cotton,it makes total dosage of DPC reduced from 270 to 90 g/ha,while the frequency decreased from 5 to 2 times.The unique supramolecular interaction is confirmed as the basis of controlled release behavior.Moreover,except for the physical resistance to the sedimentation brought by the lamellar LDH,the enhanced electrostatic interaction makes DPC-LDH the dominant distribution in soil.It improves the efficiency of DPC molecules absorbed by cotton plants and greatly saves the inputs in labor and chemicals.This method is expected to achieve the yield increase and agricultural sustainability by energy saving and emission reduction.展开更多
Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article revi...Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.展开更多
One of the greatest challenges in the design of a gun is to balance muzzle velocity and recoil,especially for guns on aircrafts and deployable vehicles.To resolve the conflict between gun power and recoil force,a conc...One of the greatest challenges in the design of a gun is to balance muzzle velocity and recoil,especially for guns on aircrafts and deployable vehicles.To resolve the conflict between gun power and recoil force,a concept of rarefaction wave gun(RAVEN)was proposed to significantly reduce the weapon recoil and the heat in barrel,while minimally reducing the muzzle velocity.The main principle of RAVEN is that the rarefaction wave will not reach the projectile base until the muzzle by delaying the venting time of an expansion nozzle at the breech.Developed on the RAVEN principle,the purpose of this paper is to provide an engineering method for predicting the performance of a low-recoil gun with front nozzle.First,a two-dimensional two-phase flow model of interior ballistic during the RAVEN firing cycle was established.Numerical simulation results were compared with the published data to validate the reliability and accuracy.Next,the effects of the vent opening times and locations were investigated to determine the influence rules on the performance of the RAVEN with front nozzle.Then according to the results above,simple nonlinear fitting formulas were provided to explain how the muzzle velocity and the recoil force change with the vent opening time and location.Finally,a better vent venting opening time corresponding to the vent location was proposed.The findings should make an important contribution to the field of engineering applications of the RAVEN.展开更多
Background:Hemorrhage is one of the most serious complications of endoscopic sphincterotomy(EST).The risk factors for delayed hemorrhage are not clear.This study aimed to explore the risk factors for post-EST delayed ...Background:Hemorrhage is one of the most serious complications of endoscopic sphincterotomy(EST).The risk factors for delayed hemorrhage are not clear.This study aimed to explore the risk factors for post-EST delayed hemorrhage and suggest some precautionary measures.Methods:This study analyzed 8477 patients who successfully underwent endoscopic retrograde cholangiopancreatography(ERCP)and EST between January 2007 and June 2015 in the First Affiliated Hospital of Nanchang University.Univariate and multivariate analyses were performed to find the risk factors for delayed hemorrhage after EST.Results:Of the 8477 patients screened,137(1.62%)experienced delayed hemorrhage.Univariate analysis showed that male,the severity of jaundice,duodenal papillary adenoma and carcinoma,diabetes,intraoperative bleeding,moderate and large incisions,and directional deviation of incision were risk factors for post-EST delayed hemorrhage(P<0.05).Multivariate analysis showed that intraoperative bleeding[odds ratio(OR)=3.326;95%CI:1.785–6.196;P<0.001]and directional deviation of incision(OR=2.184;95%CI:1.266–3.767;P=0.005)were independent risk factors for post-EST delayed hemorrhage.Conclusions:Delayed hemorrhage is the most common and dangerous complication of EST.Intraoperative bleeding and directional deviation of incision are independent risk factors for post-EST delayed hemorrhage.展开更多
Food allergy is one of the most important food safety problems that has attracted increasing attention.The food allergy experimental models provide not only the accurate allergen detection and evaluation methods but a...Food allergy is one of the most important food safety problems that has attracted increasing attention.The food allergy experimental models provide not only the accurate allergen detection and evaluation methods but also the powerful approaches for mechanism investigations.In this paper,we reviewed the common food allergy cell models including mast cell,basophil granulocyte and basophil,as well as the animal models of BALB/c mouse,C3H/HeJ mouse,and BN rat.We also introduced zebrafish,a promising model organism for investigating immunity though lacking direct applications in food allergy to date,and focused on traumatic inflammation,bacterial infection and viral infection models.In addition,we also summarized the clinical diagnostic research methods for food allergy.The elucidation of these topics will help researchers to understand the characteristics and mechanisms of various models and thus select the proper models for particular study,so as to support further investigations of food allergy.展开更多
A new numerical technique named as fuzzy finite difference method is proposed to solve the heat conduction problems with fuzzy uncertainties in both the phys- ical parameters and initial/boundary conditions. In virtue...A new numerical technique named as fuzzy finite difference method is proposed to solve the heat conduction problems with fuzzy uncertainties in both the phys- ical parameters and initial/boundary conditions. In virtue of the level-cut method, the difference discrete equations with fuzzy parameters are equivalently transformed into groups of interval equations. New stability analysis theory suited to fuzzy difference schemes is developed. Based on the parameter perturbation method, the interval ranges of the uncertain temperature field can be approximately predicted. Subsequently, fuzzy solutions to the original difference equations are obtained by the fuzzy resolution theorem. Two numerical examples are given to demonstrate the feasibility and efficiency of the presented method for solving both steady-state and transient heat conduction problems.展开更多
Multiple metallogenic types(skarn-type and vein-type)related to hypabyssal granites are found at the Huangshaping polymetallic deposit in the Nanling Range,South China.To constrain the crystallization and mineralizati...Multiple metallogenic types(skarn-type and vein-type)related to hypabyssal granites are found at the Huangshaping polymetallic deposit in the Nanling Range,South China.To constrain the crystallization and mineralization processes of skarn formation,three generations of magnetite and pyrrhotite from the hydrous silicate stage,oxide stage,early quartz–sulfide stage,and late quartz–sulfide stage were distinguished.The geochemical compositions of magnetite and pyrrhotite were obtained by electron probe microanalyzer(EPMA)and in-situ ablation-inductively coupled plasma-mass spectrometry(LA‒ICP‒MS).The results show that there may be silicate inclusions in magnetite and interaction of wall rock occurred in the mineralization process.The geochemical trends recorded in pyrrhotite show the influence of limestone during the crystallization of pyrrhotite.The re-equilibration temperatures of Po I,Po II,and Po III are 420.46,380.45,and 341.81°C,respectively,which suggests a continuous evolution following the high-temperature W–Sn mineralized system.The content change of Ni and V reflects a gradual decrease of oxygen fugacity from Mag I to Mag III,while the sulfur fugacity calculated from pyrrhotite gradually decreases.This continuous skarn mineralization evolution process helps us to better understand the change of metallogenic environment in the retrograde stage of the Huangshaping deposit.展开更多
A current problem in diet recommendation systems is the matching of food preferences with nutritional requirements,taking into account individual characteristics,such as body weight with individual health conditions,s...A current problem in diet recommendation systems is the matching of food preferences with nutritional requirements,taking into account individual characteristics,such as body weight with individual health conditions,such as diabetes.Current dietary recommendations employ association rules,content-based collaborative filtering,and constraint-based methods,which have several limitations.These limitations are due to the existence of a special user group and an imbalance of non-simple attributes.Making use of traditional dietary recommendation algorithm researches,we combine the Adaboost classifier with probabilistic matrix factorization.We present a personalized diet recommendation algorithm by taking advantage of probabilistic matrix factorization via Adaboost.A probabilistic matrix factorization method extracts the implicit factors between individual food preferences and nutritional characteristics.From this,we can make use of those features with strong influence while discarding those with little influence.After incorporating these changes into our approach,we evaluated our algorithm’s performance.Our results show that our method performed better than others at matching preferred foods with dietary requirements,benefiting user health as a result.The algorithm fully considers the constraint relationship between users’attributes and nutritional characteristics of foods.Considering many complex factors in our algorithm,the recommended food result set meets both health standards and users’dietary preferences.A comparison of our algorithm with others demonstrated that our method offers high accuracy and interpretability.展开更多
Ultrasonic fatigue tests are performed on a magnesium alloy with and without ultrasonic peening treatment(UPT).Surface enhancement layer leads to the complete change of crack initiation sites.However,crack initiation ...Ultrasonic fatigue tests are performed on a magnesium alloy with and without ultrasonic peening treatment(UPT).Surface enhancement layer leads to the complete change of crack initiation sites.However,crack initiation mechanism keeps the same and results in a single-faceted morphology at crack initiation site.Microcracks initiate as Mode Ⅱ crack within the original grain,but deflect to Mode I crack outside of the original cracked grain.A threshold SIF value is proposed to evaluate the retarding effect of grain boundary on microcrack propagation.Outside of the original cracked grain,Mode I crack propagation below the threshold ΔK_(σ-th) is responsible for the formation of fine granular area(FGA,a nano-grain layer).Based on the Numerous Cyclic Pressing(NCP) model,it is proposed that crack type should be another necessary condition for the formation of FGA.展开更多
The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than ...The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than 9 years of mesopause temperatures and relative densities estimated by using ambipolar diffusion coefficient measurements observed by the Mengcheng meteor radar(33.4°N,116.5°E).The intercomparison between the meteor radar and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere by Broadband Emission Radiometry(TIMED/SABER)and Earth Observing System(EOS)Aura/Microwave Limb Sounder(MLS)observations indicates that the meteor radar temperatures and densities agree well with the simultaneous satellite measurements.Annual variations dominate the mesopause temperatures,with the maximum during winter and the minimum during summer.The mesopause relative densities also show annual variations,with strong maxima near the spring equinox and weak maxima before the winter solstice,and with a minimum during summer.In addition,the mesopause density exhibits a structure similar to that of the zonal wind:as the zonal wind flows eastward(westward),the mesopause density decreases(increases).At the same time,the meridional wind shows a structure similar to that of the mesopause temperature:as the meridional wind shows northward(southward)enhancements,the mesopause temperature increases(decreases).Simultaneous horizontal wind,temperature,and density observations provide multiple mesospheric parameters for investigating mesospheric dynamics and thermodynamic processes and have the potential to improve widely used empirical atmospheric models.展开更多
As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phen...As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phenomenon in the gas generator.The pyrotechnic gas generator is modelling by a simplified filter structure with fiber arrays.A finite-volume model of the heat and fluid flow is proposed to simulate the detailed multi-dimensional flow and energy conversion behaviors.Several verification results are in good agreement with data in different references.Simulation results demonstrate that the filter can not only absorb heat from the gas but also cause the high intensity enhancement of the heat transfer.The performance difference between inline and staggered arrays is also discussed.The findings of the study put a further prediction tool for the understanding and design of the filter system with fibers.展开更多
基金financially supported by the Key Project of Zhejiang Provincial Natural Science Foundation of China(LZ22C200003)the National Natural Science Foundation of China(32072290)。
文摘Histamine in food has attracted widespread attention due to the potential toxicity and associated health risk.However,its influences on immunological components,especially the function of key immune cells,are still poorly known.In this work,we explored the effects of exogenous histamine on the function of key immune cells such as intestinal epithelial cells,dendritic cells,and T cells.The results showed that histamine could affect the expression of allergy-related genes in CMT93 cells at a high dose of histamine.Moreover,it’s found that histamine could cause an imbalance in the levels of relevant immune factors secreted by dendritic cells and T cells,especially those related to allergy.At the same time,the proportion of MHC class IIpositive dendritic cells and the proportion of T helper 2(Th2)cells in CD4^(+)T cells increased after histamine stimulation.We concluded that the presence of a certain level of histamine in food may affect the expression of allergy-related cytokines,disrupt the balance of the immune homeostasis,and potentially lead to adverse immune reactions.This work demonstrated the importance of including the estimation of histamine’s immune safety in aquatic products rather than merely considering the potential risk of food poisoning.
基金supported by the National Natural Science Foundation of China(Grant No.42025403)the Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2023074).
文摘From June 2008 to August 2013,approximately 67 kt of CO_(2) was injected into a deep saline formation at the Ketzin pilot CO_(2) storage site.During injection,3D seismic surveys have been performed to monitor the migration of sequestered CO_(2).Seismic monitoring results are limited by the acquisition and signal-to-noise ratio of the acquired data.The multiphysical reservoir simulation provides information regarding the CO_(2) fluid behavior,and the approximated model should be calibrated with the monitoring results.In this work,property models are delivered from the multiphysical model during 3D repeated seismic surveys.The simulated seismic data based on the models are compared with the real data,and the results validate the effectiveness of the multiphysical inversion method.Time-lapse analysis shows the trend of CO_(2) migration during and after injection.
基金financial support from the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No. XDB41030000)the National Natural Science Foundation of China (Grant Nos. 42125402, 42188101, 42304165, and 42374182)+2 种基金the Key-Area Research and Development Program of Guangdong Province (Grant No. 2020B0303020001)the Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01)the Innovation Program for Quantum Science and Technology (Grant No. 2021ZD0300302)
文摘Mars is the terrestrial planet in the solar system that is closest to the Earth.Studying the atmospheric parameters of Mars and studying the evolutionary history of the Martian environment on this basis is helpful for people to discover signs of extraterrestrial life and to study the trend of climate change on Earth.Mie–Rayleigh scattering lidar is an important technology for detecting parameters from the surface to the middle and upper atmosphere.Because of the different aerosol distributions,Mie scattering and Rayleigh scattering have their own optimal detection ranges.Given the long period and high cost of any deep space exploration program,it is important to conduct sufficient feasibility studies and parameter simulations before the payload is launched.In this study,a parameterized lidar mathematical model and Earth’s atmospheric mode are used to compare with the measured signals of ground-based Mie–Rayleigh scattering lidar,and the correctness of the lidar mathematical model is verified.Using the model,we select the landing area of Tianwen-1 and substitute it into the Martian atmospheric mode,and then the Mie–Rayleigh lidar backscattering signal and the key parameters of the lidar system are systematically analyzed under the conditions of a clean Martian atmosphere and a global sandstorm.In addition,the optimal detection altitude ranges of Mie scattering and Rayleigh scattering on Mars under different atmospheric conditions are obtained,which provides a reference for the practical design and development of the subsequent lidar system for the Martian atmospheric environment.
基金financially supported by the National Key R&D Program of China (2019YFC1605003)the Zhejiang Provincial Natural Science Foundation of China (LGN21C200013)。
文摘Bacillus coagulans has been extensively studied so far,but there has been a lack of research on its usage in allergy.In this study,we designed to assess the effect of different concentrations of B.coagulans on food allergy in a BALB/c mouse model of ovalbumin(OVA)-induced food allergy and its effect on gut microbes.The assessment of symptoms,specific immunoglobulin E(IgE),T-cell differentiation,and related gene expression levels in sensitized mice by assay indicated that high doses of oral B.coagulans could alleviate allergic symptoms.Treatment with B.coagulans,in the high-dose group,significantly reduced IgE and IgG1 levels and modulated the balance of T helper type 1 cell(Th1)and Th2 and the expression of relevant genes in the spleen.16S rRNA analysis showed that probiotics improved the structure of the microbiota,in particular by boosting the percentage of Clostridia,Bacteroides vulgatus and Enterococcus faecium,and by increasing the abundance of microbial species,thereby modulating the immune system.Therefore,this study can provide insights into the practical application of B.coagulans doses to alleviate OVA allergy.
基金supported by National Natural Science Foundation of China(NSFC:82073538 and 81773433)by the 2018 Chinese Nutrition Society(CNS)Nutrition Research Foundation-DSM Research Fund(CNS-DSM2018A30)。
文摘The associations of individual amino acid with non-alcoholic fatty liver disease(NAFLD)risk remained unclear.The present study aimed to investigate the associations between the two in the Chinese elderly.Methods:A community-based health check-up program was conducted in Qingdao,China.NAFLD was diagnosed by ultrasonography accompanied by epidemiological investigation.The dietary intakes of amino acids were investigated with 3-day,24-h dietary records and calculated by Nutrition Calculator software.Restricted cubic spline model was used to evaluate a nonlinear relationship between amino acid intake and NAFLD risk.Results:400 NAFLD subjects were identified,and 400 participants were randomly selected as controls and matched by gender and age(±3 years)Dose-response analysis showed that 1000 mg increment of aromatic amino acids(AAAs)was associated with reduced 16%risk of NAFLD.Dietary increments of 750 mg/d threonine,950 mg/d valine,or 1700 mg/d lysine were associated with a 20%reduction in the NAFLD risk(all P for linearity<0.05).Conclusion:The present study demonstrated that the dietary increases in milk,eggs and deep-sea fish,which are rich in the amino acids,might contribute to protecting against NAFLD in the elderly.
基金supported by the National Key R&D Program of China(2021YFA0716704)the Young Scientists Fund of the National Natural Science Foundation of China(No.22208372).
文摘Mepiquat chloride(1,1-dimethyl piperidinium chloride,DPC)is a representative plant growth regulator which can regulate the source-sink relationship for yield increase and shape ideal plant type for mechanical cultivation.Here we show a DPC adsorbed layered double hydroxide(DPC-LDH)architecture with enhanced controlled release property and soil distribution.By drip irrigation on cotton,it makes total dosage of DPC reduced from 270 to 90 g/ha,while the frequency decreased from 5 to 2 times.The unique supramolecular interaction is confirmed as the basis of controlled release behavior.Moreover,except for the physical resistance to the sedimentation brought by the lamellar LDH,the enhanced electrostatic interaction makes DPC-LDH the dominant distribution in soil.It improves the efficiency of DPC molecules absorbed by cotton plants and greatly saves the inputs in labor and chemicals.This method is expected to achieve the yield increase and agricultural sustainability by energy saving and emission reduction.
基金supported by the Major State Basic Research and Development Program of China(973 Program),No.2014CB542201the National Key Research and Development Program of China,No.2016YFC1101601,2017YFA0104702+2 种基金the Natural Science Foundation of Beijing of China,No.7172202a grant from the 13th Five-Year Plan Period of People’s Liberation Army of China,No.BWS13C029-5a grant from the Science and Technology Project of Beijing of China,No.Z161100005016059
文摘Currently, researchers are using neural stem cell transplantation to promote regeneration after peripheral nerve injury, as neural stem cells play an important role in peripheral nerve injury repair. This article reviews recent research progress of the role of neural stem cells in the repair of peripheral nerve injury. Neural stem cells can not only differentiate into neurons, astrocytes and oligodendrocytes, but can also differentiate into Schwann-like cells, which promote neurite outgrowth around the injury. Transplanted neural stem cells can differentiate into motor neurons that innervate muscles and promote the recovery of neurological function. To promote the repair of peripheral nerve injury, neural stem cells secrete various neurotrophic factors, including brain-derived neurotrophic factor, fibroblast growth factor, nerve growth factor, insulin-like growth factor and hepatocyte growth factor. In addition, neural stem cells also promote regeneration of the axonal myelin sheath, angiogenesis, and immune regulation. It can be concluded that neural stem cells promote the repair of peripheral nerve injury through a variety of ways.
基金supported by the National Natural Science Foundation of China(Grant No.11502114)the Fundamental Research Funds for the Central Universities(Grant No.30918011323)
文摘One of the greatest challenges in the design of a gun is to balance muzzle velocity and recoil,especially for guns on aircrafts and deployable vehicles.To resolve the conflict between gun power and recoil force,a concept of rarefaction wave gun(RAVEN)was proposed to significantly reduce the weapon recoil and the heat in barrel,while minimally reducing the muzzle velocity.The main principle of RAVEN is that the rarefaction wave will not reach the projectile base until the muzzle by delaying the venting time of an expansion nozzle at the breech.Developed on the RAVEN principle,the purpose of this paper is to provide an engineering method for predicting the performance of a low-recoil gun with front nozzle.First,a two-dimensional two-phase flow model of interior ballistic during the RAVEN firing cycle was established.Numerical simulation results were compared with the published data to validate the reliability and accuracy.Next,the effects of the vent opening times and locations were investigated to determine the influence rules on the performance of the RAVEN with front nozzle.Then according to the results above,simple nonlinear fitting formulas were provided to explain how the muzzle velocity and the recoil force change with the vent opening time and location.Finally,a better vent venting opening time corresponding to the vent location was proposed.The findings should make an important contribution to the field of engineering applications of the RAVEN.
文摘Background:Hemorrhage is one of the most serious complications of endoscopic sphincterotomy(EST).The risk factors for delayed hemorrhage are not clear.This study aimed to explore the risk factors for post-EST delayed hemorrhage and suggest some precautionary measures.Methods:This study analyzed 8477 patients who successfully underwent endoscopic retrograde cholangiopancreatography(ERCP)and EST between January 2007 and June 2015 in the First Affiliated Hospital of Nanchang University.Univariate and multivariate analyses were performed to find the risk factors for delayed hemorrhage after EST.Results:Of the 8477 patients screened,137(1.62%)experienced delayed hemorrhage.Univariate analysis showed that male,the severity of jaundice,duodenal papillary adenoma and carcinoma,diabetes,intraoperative bleeding,moderate and large incisions,and directional deviation of incision were risk factors for post-EST delayed hemorrhage(P<0.05).Multivariate analysis showed that intraoperative bleeding[odds ratio(OR)=3.326;95%CI:1.785–6.196;P<0.001]and directional deviation of incision(OR=2.184;95%CI:1.266–3.767;P=0.005)were independent risk factors for post-EST delayed hemorrhage.Conclusions:Delayed hemorrhage is the most common and dangerous complication of EST.Intraoperative bleeding and directional deviation of incision are independent risk factors for post-EST delayed hemorrhage.
基金the State key research and development plan(2017YFD0400203).
文摘Food allergy is one of the most important food safety problems that has attracted increasing attention.The food allergy experimental models provide not only the accurate allergen detection and evaluation methods but also the powerful approaches for mechanism investigations.In this paper,we reviewed the common food allergy cell models including mast cell,basophil granulocyte and basophil,as well as the animal models of BALB/c mouse,C3H/HeJ mouse,and BN rat.We also introduced zebrafish,a promising model organism for investigating immunity though lacking direct applications in food allergy to date,and focused on traumatic inflammation,bacterial infection and viral infection models.In addition,we also summarized the clinical diagnostic research methods for food allergy.The elucidation of these topics will help researchers to understand the characteristics and mechanisms of various models and thus select the proper models for particular study,so as to support further investigations of food allergy.
基金supported by the National Special Fund for Major Research Instrument Development(2011YQ140145)111 Project(B07009)+1 种基金the National Natural Science Foundation of China(11002013)Defense Industrial Technology Development Program(A2120110001 and B2120110011)
文摘A new numerical technique named as fuzzy finite difference method is proposed to solve the heat conduction problems with fuzzy uncertainties in both the phys- ical parameters and initial/boundary conditions. In virtue of the level-cut method, the difference discrete equations with fuzzy parameters are equivalently transformed into groups of interval equations. New stability analysis theory suited to fuzzy difference schemes is developed. Based on the parameter perturbation method, the interval ranges of the uncertain temperature field can be approximately predicted. Subsequently, fuzzy solutions to the original difference equations are obtained by the fuzzy resolution theorem. Two numerical examples are given to demonstrate the feasibility and efficiency of the presented method for solving both steady-state and transient heat conduction problems.
基金supported by the National Key Research and Development Plan, China (No. 2018YFC0603901)the National Natural Science Foundation of China (No. 41502067)supported by the Fundamental Research Funds for the Central South University, China (No. 2021zzts0823)
文摘Multiple metallogenic types(skarn-type and vein-type)related to hypabyssal granites are found at the Huangshaping polymetallic deposit in the Nanling Range,South China.To constrain the crystallization and mineralization processes of skarn formation,three generations of magnetite and pyrrhotite from the hydrous silicate stage,oxide stage,early quartz–sulfide stage,and late quartz–sulfide stage were distinguished.The geochemical compositions of magnetite and pyrrhotite were obtained by electron probe microanalyzer(EPMA)and in-situ ablation-inductively coupled plasma-mass spectrometry(LA‒ICP‒MS).The results show that there may be silicate inclusions in magnetite and interaction of wall rock occurred in the mineralization process.The geochemical trends recorded in pyrrhotite show the influence of limestone during the crystallization of pyrrhotite.The re-equilibration temperatures of Po I,Po II,and Po III are 420.46,380.45,and 341.81°C,respectively,which suggests a continuous evolution following the high-temperature W–Sn mineralized system.The content change of Ni and V reflects a gradual decrease of oxygen fugacity from Mag I to Mag III,while the sulfur fugacity calculated from pyrrhotite gradually decreases.This continuous skarn mineralization evolution process helps us to better understand the change of metallogenic environment in the retrograde stage of the Huangshaping deposit.
基金This work was supported in part by the National Natural Science Foundation of China(51679105,51809112,51939003,61872160)“Thirteenth Five Plan”Science and Technology Project of Education Department,Jilin Province(JJKH20200990KJ).
文摘A current problem in diet recommendation systems is the matching of food preferences with nutritional requirements,taking into account individual characteristics,such as body weight with individual health conditions,such as diabetes.Current dietary recommendations employ association rules,content-based collaborative filtering,and constraint-based methods,which have several limitations.These limitations are due to the existence of a special user group and an imbalance of non-simple attributes.Making use of traditional dietary recommendation algorithm researches,we combine the Adaboost classifier with probabilistic matrix factorization.We present a personalized diet recommendation algorithm by taking advantage of probabilistic matrix factorization via Adaboost.A probabilistic matrix factorization method extracts the implicit factors between individual food preferences and nutritional characteristics.From this,we can make use of those features with strong influence while discarding those with little influence.After incorporating these changes into our approach,we evaluated our algorithm’s performance.Our results show that our method performed better than others at matching preferred foods with dietary requirements,benefiting user health as a result.The algorithm fully considers the constraint relationship between users’attributes and nutritional characteristics of foods.Considering many complex factors in our algorithm,the recommended food result set meets both health standards and users’dietary preferences.A comparison of our algorithm with others demonstrated that our method offers high accuracy and interpretability.
基金supported by the National Natural Science Foundation of China (Nos. 12102280, 12172238, 11832007, 12022208, 12072212, and 52003181)the Science & Technology Support Program of Sichuan Province (Nos. 2020YJ0230, and 2021YJ0555)the Fundamental Research Funds for the Central Universities of China (No.2021SCU12129)
文摘Ultrasonic fatigue tests are performed on a magnesium alloy with and without ultrasonic peening treatment(UPT).Surface enhancement layer leads to the complete change of crack initiation sites.However,crack initiation mechanism keeps the same and results in a single-faceted morphology at crack initiation site.Microcracks initiate as Mode Ⅱ crack within the original grain,but deflect to Mode I crack outside of the original cracked grain.A threshold SIF value is proposed to evaluate the retarding effect of grain boundary on microcrack propagation.Outside of the original cracked grain,Mode I crack propagation below the threshold ΔK_(σ-th) is responsible for the formation of fine granular area(FGA,a nano-grain layer).Based on the Numerous Cyclic Pressing(NCP) model,it is proposed that crack type should be another necessary condition for the formation of FGA.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42125402 and 42174183)the National Key Technologies R&D Program of China (Grant No. 2022YFF0503703)+5 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No. XDB41000000)the foundation of the National Key Laboratory of Electromagnetic Environmentthe Fundamental Research Funds for the Central Universitiesthe Chinese Meridian Projectfunded by the Anhui Provincial Natural Science Foundation (Grant No. 2008085MD113)the Joint Open Fund of Mengcheng National Geophysical Observatory (No. MENGO-202209)
文摘The atmospheric temperatures and densities in the mesosphere and lower thermosphere(MLT)region are essential for studying the dynamics and climate of the middle and upper atmosphere.In this study,we present more than 9 years of mesopause temperatures and relative densities estimated by using ambipolar diffusion coefficient measurements observed by the Mengcheng meteor radar(33.4°N,116.5°E).The intercomparison between the meteor radar and Thermosphere Ionosphere Mesosphere Energetics and Dynamics/Sounding of the Atmosphere by Broadband Emission Radiometry(TIMED/SABER)and Earth Observing System(EOS)Aura/Microwave Limb Sounder(MLS)observations indicates that the meteor radar temperatures and densities agree well with the simultaneous satellite measurements.Annual variations dominate the mesopause temperatures,with the maximum during winter and the minimum during summer.The mesopause relative densities also show annual variations,with strong maxima near the spring equinox and weak maxima before the winter solstice,and with a minimum during summer.In addition,the mesopause density exhibits a structure similar to that of the zonal wind:as the zonal wind flows eastward(westward),the mesopause density decreases(increases).At the same time,the meridional wind shows a structure similar to that of the mesopause temperature:as the meridional wind shows northward(southward)enhancements,the mesopause temperature increases(decreases).Simultaneous horizontal wind,temperature,and density observations provide multiple mesospheric parameters for investigating mesospheric dynamics and thermodynamic processes and have the potential to improve widely used empirical atmospheric models.
基金This work is supported by the National Natural Science Foundation of China(Grant No.11972194)the Fundamental Research Funds for the Central Universities,No.30918011323China Postdoctoral Science Foundation funded project(Grant No.2015M581797).
文摘As a key part of the pyrotechnic gas generator,the filter not only removes the particulate matter but also cools the hot gas to a safe level.This paper aims to improve the understanding of the basic heat and flow phenomenon in the gas generator.The pyrotechnic gas generator is modelling by a simplified filter structure with fiber arrays.A finite-volume model of the heat and fluid flow is proposed to simulate the detailed multi-dimensional flow and energy conversion behaviors.Several verification results are in good agreement with data in different references.Simulation results demonstrate that the filter can not only absorb heat from the gas but also cause the high intensity enhancement of the heat transfer.The performance difference between inline and staggered arrays is also discussed.The findings of the study put a further prediction tool for the understanding and design of the filter system with fibers.