Fructose and glucose are often widely used in food processing and may contribute to many metabolic diseases.To observe the effects of different doses of glucose and fructose on human metabolism and cellular communicat...Fructose and glucose are often widely used in food processing and may contribute to many metabolic diseases.To observe the effects of different doses of glucose and fructose on human metabolism and cellular communication,volunteers were given low,medium,and high doses of glucose and fructose.Serum cytokines,glucose,lactate,nicotinamide adenine dinucleotide(NADH)and metabolic enzymes were assayed,and central carbon metabolic pathway networks and cytokine communication networks were constructed.The results showed that the glucose and fructose groups basically maintained the trend of decreasing catabolism and increasing anabolism with increasing dose.Compared with glucose,low-dose fructose decreased catabolism and increased anabolism,significantly enhanced the expression of the inflammatory cytokine interferon-γ(IFN-γ),macrophage-derived chemokine(MDC),induced protein-10(IP-10),and eotaxin,and significantly reduced the activity of isocitrate dehydrogenase(ICDH)and pyruvate dehydrogenase complexes(PDHC).Both medium and high doses of fructose increase catabolism and anabolism,and there are more cytokines and enzymes with significant changes.Furthermore,multiple cytokines and enzymes show strong relevance to metabolic regulation by altering the transcription and expression of enzymes in central carbon metabolic pathways.Therefore,excessive intake of fructose should be reduced to avoid excessive inflammatory responses,allergic reactions and autoimmune diseases.展开更多
The current study focuses on spray cooling applied to the heat exchange components of a cooling tower.An optimization of such processes is attempted by assessing different spray flow rates and droplet sizes.For simpli...The current study focuses on spray cooling applied to the heat exchange components of a cooling tower.An optimization of such processes is attempted by assessing different spray flow rates and droplet sizes.For simplicity,the heat exchanger of the cooling tower is modeled as a horizontal round tube and a cooling tower spray cooling model is developed accordingly using a computational fluid dynamics(CFD)software.The study examines the influence of varying spray flow rates and droplet sizes on the heat flow intensity between the liquid layer on the surface of the cylindrical tube and the surrounding air,taking into account the number of nozzles.It is observed that on increasing the spray flow strength,the heat flow intensity and extent of the liquid film in the system are enhanced accordingly.Moreover,the magnitude of droplet size significantly impacts heat transfer.A larger droplet size decreases evaporation in the air and enhances the deposition of droplets on the round tube.This facilitates the creation of the liquid film and enhances the passage of heat between the liquid film and air.Increasing the number of nozzles,while maintaining a constant spray flow rate,results in a decrease in the flow rate of each individual nozzle.This decrease is not favorable in terms of heat transfer.展开更多
This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave(BSW) enhanced Goos–Hanchen(GH) shift in one-dimensional photonic crystal(1DPC). The BSW phe...This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave(BSW) enhanced Goos–Hanchen(GH) shift in one-dimensional photonic crystal(1DPC). The BSW phenomenon appearing in 1DPC enhances the GH shift generated in the attenuated total internal reflection structure. The GH shift is closely related to the thickness of the film which is composed of layer-structure of 1DPC. The GH shifts under multiple different incident light conditions will be obtained by varying the wavelength and angle of the measured light, and the thickness distribution of the entire structure of 1DPC is calculated by the particle swarm optimization(PSO) algorithm.The relationship between the structure of a 1DPC film composed of TiO_(2) and SiO_(2) layers and the GH shift, is investigated.Under the specific photonic crystal structure and incident conditions, a giant GH shift, 5.1 × 10^(3) times the wavelength of incidence, can be obtained theoretically. Simulation and calculation results show that the thickness of termination layer and periodic structure bilayer of 1DPC film with 0.1-nm resolution can be obtained by measuring the GH shifts. The exact structure of a 1DPC film is innovatively measured by the BSW-enhanced GH shift.展开更多
Ginseng(Panax ginseng C.A.Meyer)as a common dietary adjunct is widely applied in Traditional Chinese Medicine due to its health-promoting properties,but the differences between white ginseng and red ginseng was rarely...Ginseng(Panax ginseng C.A.Meyer)as a common dietary adjunct is widely applied in Traditional Chinese Medicine due to its health-promoting properties,but the differences between white ginseng and red ginseng was rarely studied.In the present study,color parameters and scanning electron microscope(SEM)were determined to evaluate the differences of ginseng color and microstructure induced by processing procedure.Quantitative analysis of multi-components by a single-marker(QAMS)method and anti-α-amylase activity test were used to assess variations of chemical ingredients and pharmacological activity between white and red ginseng.Finally,molecular docking studies were carried out to screen out the most effective compound againstα-amylase.Results indicated that processing had a significant impact on the physicochemical properties and pharmacological activity of white and red ginseng.After processing,the color value of L*declined significantly.Red ginseng sample displayed a compact structure and presented of a gel layer on the surface compared to white ginseng.Additionally,the content of ginsenosides and the activity of anti-α-amylase decreased.The contents of total ginsenosides were positively correlated with the anti-α-amylase activities of ginseng,and ginsenoside Rb1 might be the most effective compound to inhibit the activity ofα-amylase.展开更多
Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage admini...Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.展开更多
The distribution pattern of metals as active centers on a substrate can influence the peroxymonosulfate(PMS)activation and contaminants degradation.Herein,atomic layer deposition is applied to prepare Cu single atom(S...The distribution pattern of metals as active centers on a substrate can influence the peroxymonosulfate(PMS)activation and contaminants degradation.Herein,atomic layer deposition is applied to prepare Cu single atom(SA-Cu),cluster(C-Cu),and film(F-Cu)decorated MXene catalysts by regulating the number of deposition cycles.In comparison with SA-Cu-MXene(adsorption energy(E_(ads))=-4.236 eV)and F-Cu-MXene(E_(ads)=-3.548 eV),PMS is shown to adsorb preferably on the C-Cu-MXene surface for activation(E_(ads)=-5.435 eV),realizing higher utilization efficiency.More SO_(4)^(·-)are generated in C-Cu-MXene/PMS system with steady-state concentration and 1–3 orders of magnitude higher than those in the SA-Cu-MXene and F-Cu-MXene activated PMS systems.Particularly,the contribution of SO_(4)^(·-)oxidation to sulfamethoxazole(SMX)degradation followed the order,C-Cu-MXene(97.3%)>SA-Cu-MXene(90.4%)>FCu-MXene(71.9%),realizing the larger SMX degradation rate in the C-Cu-MXene/PMS system with the degradation rate constants(k)at 0.0485 min^(-1).Additionally,SMX degradation routes in C-Cu-MXene/PMS system are found with fewer toxic intermediates.Through this work,we highlighted the importance of guided design of heterogeneous catalysts in the PMS system.Appropriate metal distribution patterns need to be selected according to the actual water treatment demand.Metal sites could be then fully utilized to produce specific active species to improve the utilization efficiency of the oxidants.展开更多
In recent years,a great deal of attention has been focused on the environmental impact of plastics,includ-ing the carbon emissions related to plastics,which has promoted the application of biodegradable plas-tics.Coun...In recent years,a great deal of attention has been focused on the environmental impact of plastics,includ-ing the carbon emissions related to plastics,which has promoted the application of biodegradable plas-tics.Countries worldwide have shown high interest in replacing traditional plastics with biodegradable plastics.However,no systematic comparison has been conducted on the carbon emissions of biodegrad-able versus traditional plastic products.This study evaluates the carbon emissions of traditional and biodegradable plastic products(BPPs)over four stages and briefly discusses environmental and economic perspectives.Four scenarios-namely,the traditional method,chemical recycling,industrial composting,and anaerobic digestion-are considered for the disposal of waste BPPs(WBPPs).The analysis takes China as a case study.The results show that the carbon emissions of 1000traditional plastic products(plastic bags,lunch boxes,cups,etc.)were52.09-150.36 carbon emissions equivalent of per kilogram(kg CO_(2)eq),with the stage of plastic production contributing 50.71%-50.77%.In comparison,1000 similar BPPs topped out at 21.06-56.86 kg CO_(2)eq,approximately 13.53%-62.19%lower than traditional plastic prod-ucts.The difference was mainly at the stages of plastic production and waste disposal,and the BPPs showed significant carbon reduction potential at the raw material acquisition stage.Waste disposal plays an important role in environmental impact,and composting and anaerobic digestion are considered to be preferable disposal methods for WBPPs.However,the high cost of biodegradable plastics is a challenge for their widespread use.This study has important reference significance for the sustainable development of the biodegradableplastics industry.展开更多
This paper comprehensively analyzes the origins,current situation,and prospects of the sharing economy.The primary purpose is to present the issues and challenges confronting the sharing economy at its current,awkward...This paper comprehensively analyzes the origins,current situation,and prospects of the sharing economy.The primary purpose is to present the issues and challenges confronting the sharing economy at its current,awkward stage of development and to make reasonable speculations about its future.The research is based on academic literature on the sharing economy from both domestic and international sources.The findings indicate that despite current shortcomings in the regulatory system,industry structure,and user behavior,the scope of the sharing economy’s applications could still expand,and its technology could continue to advance.Overall,the prospects for the sharing economy are likely to be promising.展开更多
The study of the hydrate formation process in porous media is of great significance for hydrate application.In this work,the formation process of methane hydrate in porous media was monitored in situ by a low-field ma...The study of the hydrate formation process in porous media is of great significance for hydrate application.In this work,the formation process of methane hydrate in porous media was monitored in situ by a low-field magnetic resonance imaging(MRI)system.The formation characteristics of methane hydrate in porous media and the change of fractal dimension of pore space were studied through the change of residual water saturation and T2 relaxation time distribution.The experimental results show that the hydrate formation process is divided into two stages:fast and slow.During the formation process,the water in the pores is continuously consumed and transformed into hydrate,and the overall T2 distribution gradually shifts to the left.In the formation process of hydrate,the pore space becomes more complex,the change of fractal dimension from top to bottom of the reactor gradually increases,and the hydrate formation rate also gradually increases.展开更多
A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite (molar ratio of SiO2 to Al2O3 being 25) was 2:1. The CuO-ZnO-Al2O3-ZrO2 ...A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite (molar ratio of SiO2 to Al2O3 being 25) was 2:1. The CuO-ZnO-Al2O3-ZrO2 (CuO/ZnO/Al2O3=3/6/1 by weight) component was prepared by a modified 'two-step' co-precipitation method. The effects of ZrO2 on the performance of CuO-ZnO-Al2O3/HZSMo5 catalyst for dimethyl ether synthesis from CO2 hydrogenation were investigated. It was found that ZrO2 improved the properties of CuO-ZnO-Al2O3/HZSM-5 as a structural promoter.展开更多
Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facili- tates the formation of final tempered martensite under serving conditions. In this ...Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facili- tates the formation of final tempered martensite under serving conditions. In this study, we have gained deeper insights on the mechanism underlying the microstructural evolution during tempering treatment, including the precipitation of carbides and the coarsening of martensite laths, as systematically analyzed by optical microscopy, transmission electron microscopy, and high-resolution transmission electron mi- croscopy. The chemical composition of the precipitates was analyzed using energy dispersive X-ray spectroscopy. Results indicate the for- mation of M3C (cementite) precipitates under normalized conditions. However, they tend to dissolve within a short time of tempering, owing to their low thermal stability. This phenomenon was substantiated by X-ray diffraction analysis. Besides, we could observe the precipitation of fine carbonitrides (MX) along the dislocations. The mechanism of carbon diffusion controlled growth of M23C6 can be expressed by the Zener's equation. The movement of Y-junctions was determined to be the fundamental mechanism underlying the martensite lath coarsening process. Vickers hardness was estimated to determine their mechanical properties. Based on the comprehensive analysis of both the micro- structural evolution and hardness variation, the process of tempering can be separated into three steps.展开更多
The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model o...The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed. The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materi- als in different temperatures and under different stresses. The coupling effects of axial stress, magnetic field, and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested. Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress. Therefore, the proposed model possesses an important significance for the design of magnetostrictive devices.展开更多
In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated arou...In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.展开更多
Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coa...Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coagulant,anti-obesity and immunomodulatory effect.The biological effectiveness of TPSs has direct relation with their structures such as monosaccharide composition,molecular weight,glycosidic linkages,conformation and others,which can be influenced by tea materials,processing methods,extraction and purification procedures among others.Comparing to the study of tea polyphenols,the exploration of TPSs in structural elucidation and biofunctionality is very preliminary.Yet several factors affecting the structural change of TPSs have been studied and identified.Consequently,the variation of some TPS biological activity brought by the change of TPS structures has been evaluated and preliminary correlation of structure activity relationship of TPSs has been performed.Therefore,this review aims to serve as a summary research report regarding the influencing factors on TPSs structures and consequential effects on the biological activities of TPSs.We hope to provide updated information and systematic references for future study and functional food development of TPSs.展开更多
Reducing oxidative stress and hepatoprotective effect of Pu-erh tea water extracts on rats fed with high-fat diet were researched for explaining health care of Pu-erh tea.Fifty SD rats were divided into five groups.Th...Reducing oxidative stress and hepatoprotective effect of Pu-erh tea water extracts on rats fed with high-fat diet were researched for explaining health care of Pu-erh tea.Fifty SD rats were divided into five groups.The body weight was measured once a day.The malondialdehyde(MDA)and glucose(Glu)levels and the activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST),nitric oxide synthase(NOS),and pyruvate kinase(PK)in serum were determined.Furthermore,the hepatic glycogen level(HGL)and the activities of hepatic total superoxide dismutase(T-SOD),catalase(CAT),and glutathione peroxidase(GSH-Px)were also measured after continuous administration for 12 weeks.The result demonstrated that Pu-erh extract caused the decreases in body weight,fat index,MDA and NOS levels,and the increases in hepatic T-SOD,CAT and GSH-Px activities,indicating that the extract may be due to inhibiting the increases of body weight and fat index,reducing oxidant stress state and inhibiting lipid peroxidation,thus decreasing the activities of ALT and AST,and protecting the liver in rat.Meanwhile,the extracts could increase the production of hepatic glycogen and the activity of PK,and reduce glucose level,protecting the liver from the diseases associated with type II diabetes.展开更多
The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows tha...The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Nilr-type structure at high temperatures (above 1243℃), and the rhombohedral Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.展开更多
Objective:The effect of casein glycomacropeptide(CGMP)on the expression of NF-B subunit p65 in human colorectal cancer HT-29 cells induced by lipopolysaccharide(LPS)was investigated to explore the therapeutic efficacy...Objective:The effect of casein glycomacropeptide(CGMP)on the expression of NF-B subunit p65 in human colorectal cancer HT-29 cells induced by lipopolysaccharide(LPS)was investigated to explore the therapeutic efficacy of CGMP for human colorectal cancer.Methods:HT-29 cells cultured in 96-well plates were stimulated with LPS for 30 min at the concentrations of 0,0.001,0.01,0.1,1 and 10g/mL.After stimulation,the expression of p65 in HT-29 cells was evaluated by immunofluorescence method.Similarly,HT-29 cells were incubated with 0,0.001,0.01,0.1,1,10 and 100g/mL CGMP for 24 h at the optimal LPS concentration.After treatment with CGMP under the incubation with optimal LPS concentration for 30 min,the protein expression of p65 was analyzed by Western blotting.The optimum culture time was evaluated by incubating HT-29 cells with the optimal CGMP concentration for 6,12,24,48 and 72 h.Results:NF-B-p65 revealed that the highest protein expression was achieved with 1g/mL LPS treatment.Meanwhile,CGMP could inhibit the protein expression of NF-B-p65 in LPS-stimulated HT-29 cells,and the optimal inhibitory effect was observed at a CGMP concentration of 0.01g/mL with 48 h incubation.Conclusion:CGMP can regulate NF-B signaling pathway through inhibiting the expression of its subunit p65,which is beneficial for the further improvement of human colorectal cancer treatment.展开更多
The thermal stress of the quartz oscillator module packaging isinvestigated using digital-im- age correlation method (DICM), and theexperimental results are given. Under the quartz oscillator modulepackaging, the quar...The thermal stress of the quartz oscillator module packaging isinvestigated using digital-im- age correlation method (DICM), and theexperimental results are given. Under the quartz oscillator modulepackaging, the quartz oscillator and the Fe-Sn-Cu alloy frame arejoined together with the electroconductive adhesive (PI), and theelectroconductive adhesive needs to be cured twice at 150 deg. C and275 deg. C respective- ly.展开更多
Tea represents an abundant source of naturally occurring polyphenols.Tea polyphenols(TPs)have received growing attentions for its wide consumption in the world,and more importantly its pleiotropic bioeffects for human...Tea represents an abundant source of naturally occurring polyphenols.Tea polyphenols(TPs)have received growing attentions for its wide consumption in the world,and more importantly its pleiotropic bioeffects for human health.After ingestion,TPs may undergo absorption and phase II reaction in the small intestine,and most undigested proportion would be submitted to the colon to interact with gut microbiota.Interactions between gut microbiota and TPs are bidirectional,including not only bacteria-mediated TPs metabolism,e.g.,removal of gallic acid moiety and ring fission to release phenolic acid catabolites,but also TPs-based modification of bacterial profiles.Crosstalk between TPs and gut microbes may benefit for gut barrier function,for example,improvement of the intestinal permeability to alleviate inflammation.Moreover,by reshaping microbial composition and associated metabolites,TPs may exert a systemic protection on host metabolism,which contributes to improve certain chronic metabolic disorders.Given that,further understanding of the metabolic fate of TPs and interplay with gut microbiota as well as potential health-promoting effects are of great significance to development and application of tea and their polyphenolic components in the future as dietary supplements and/or functional ingredients in medical foods.展开更多
The aim of this paper is to apply the relatively new Adomian decomposition method to solving the system of linear fractional, in the sense of Riemann-Liouville and Caputo respectively, differential equations. The solu...The aim of this paper is to apply the relatively new Adomian decomposition method to solving the system of linear fractional, in the sense of Riemann-Liouville and Caputo respectively, differential equations. The solutions are expressed in terms of Mittag-Leffier functions of matric argument. The Adomian decomposition method is straightforward, applicable for broader problems and avoids the difficulties in applying integral transforms. As the order is 1, the result here is simplified to that of first order differential equation.展开更多
基金financially supported by National Natural Science Foundation of China(31901782)。
文摘Fructose and glucose are often widely used in food processing and may contribute to many metabolic diseases.To observe the effects of different doses of glucose and fructose on human metabolism and cellular communication,volunteers were given low,medium,and high doses of glucose and fructose.Serum cytokines,glucose,lactate,nicotinamide adenine dinucleotide(NADH)and metabolic enzymes were assayed,and central carbon metabolic pathway networks and cytokine communication networks were constructed.The results showed that the glucose and fructose groups basically maintained the trend of decreasing catabolism and increasing anabolism with increasing dose.Compared with glucose,low-dose fructose decreased catabolism and increased anabolism,significantly enhanced the expression of the inflammatory cytokine interferon-γ(IFN-γ),macrophage-derived chemokine(MDC),induced protein-10(IP-10),and eotaxin,and significantly reduced the activity of isocitrate dehydrogenase(ICDH)and pyruvate dehydrogenase complexes(PDHC).Both medium and high doses of fructose increase catabolism and anabolism,and there are more cytokines and enzymes with significant changes.Furthermore,multiple cytokines and enzymes show strong relevance to metabolic regulation by altering the transcription and expression of enzymes in central carbon metabolic pathways.Therefore,excessive intake of fructose should be reduced to avoid excessive inflammatory responses,allergic reactions and autoimmune diseases.
基金supported by the National Natural Science Foundation of China(Grant No.52376069)Shandong Province Science and Technology Small and Medium sized Enterprise Innovation Ability Enhancement Project(Grant No.2022TSGC2596).
文摘The current study focuses on spray cooling applied to the heat exchange components of a cooling tower.An optimization of such processes is attempted by assessing different spray flow rates and droplet sizes.For simplicity,the heat exchanger of the cooling tower is modeled as a horizontal round tube and a cooling tower spray cooling model is developed accordingly using a computational fluid dynamics(CFD)software.The study examines the influence of varying spray flow rates and droplet sizes on the heat flow intensity between the liquid layer on the surface of the cylindrical tube and the surrounding air,taking into account the number of nozzles.It is observed that on increasing the spray flow strength,the heat flow intensity and extent of the liquid film in the system are enhanced accordingly.Moreover,the magnitude of droplet size significantly impacts heat transfer.A larger droplet size decreases evaporation in the air and enhances the deposition of droplets on the round tube.This facilitates the creation of the liquid film and enhances the passage of heat between the liquid film and air.Increasing the number of nozzles,while maintaining a constant spray flow rate,results in a decrease in the flow rate of each individual nozzle.This decrease is not favorable in terms of heat transfer.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.51575387 and 51827812)。
文摘This paper puts forward a novel method of measuring the thin period-structure-film thickness based on the Bloch surface wave(BSW) enhanced Goos–Hanchen(GH) shift in one-dimensional photonic crystal(1DPC). The BSW phenomenon appearing in 1DPC enhances the GH shift generated in the attenuated total internal reflection structure. The GH shift is closely related to the thickness of the film which is composed of layer-structure of 1DPC. The GH shifts under multiple different incident light conditions will be obtained by varying the wavelength and angle of the measured light, and the thickness distribution of the entire structure of 1DPC is calculated by the particle swarm optimization(PSO) algorithm.The relationship between the structure of a 1DPC film composed of TiO_(2) and SiO_(2) layers and the GH shift, is investigated.Under the specific photonic crystal structure and incident conditions, a giant GH shift, 5.1 × 10^(3) times the wavelength of incidence, can be obtained theoretically. Simulation and calculation results show that the thickness of termination layer and periodic structure bilayer of 1DPC film with 0.1-nm resolution can be obtained by measuring the GH shifts. The exact structure of a 1DPC film is innovatively measured by the BSW-enhanced GH shift.
基金supported by Tianjin Key R&D Plan-Key Projects Supported by Science and Technology (19YFZCSN00010)
文摘Ginseng(Panax ginseng C.A.Meyer)as a common dietary adjunct is widely applied in Traditional Chinese Medicine due to its health-promoting properties,but the differences between white ginseng and red ginseng was rarely studied.In the present study,color parameters and scanning electron microscope(SEM)were determined to evaluate the differences of ginseng color and microstructure induced by processing procedure.Quantitative analysis of multi-components by a single-marker(QAMS)method and anti-α-amylase activity test were used to assess variations of chemical ingredients and pharmacological activity between white and red ginseng.Finally,molecular docking studies were carried out to screen out the most effective compound againstα-amylase.Results indicated that processing had a significant impact on the physicochemical properties and pharmacological activity of white and red ginseng.After processing,the color value of L*declined significantly.Red ginseng sample displayed a compact structure and presented of a gel layer on the surface compared to white ginseng.Additionally,the content of ginsenosides and the activity of anti-α-amylase decreased.The contents of total ginsenosides were positively correlated with the anti-α-amylase activities of ginseng,and ginsenoside Rb1 might be the most effective compound to inhibit the activity ofα-amylase.
基金supported by the National Key Research and Development Program of China under Grant(2022YFF1102800)the Graduate Scientific Research Innovation Project of Tianji(2022SKY109)+1 种基金the Project of Tianjin Science and Technology Program(22JCYBJC00360)the Project of Tianjin Science and Technology Program(21ZYJDJC00060)。
文摘Epicatechin(EC)was used in this study to antagonize the cognitive dysfunction caused by lead(Pb)exposure in mice.Eight-week-old male Kunming mice were treated with PbCl_(2)(20 mg/kg)and/or EC(50 mg/kg)by gavage administration for 4 weeks.Morris water maze test showed that EC could improve memory dysfunction induced by Pb.EC antagonized Ca^(2+)overload,activated Nrf2 signaling pathway and reduced the accumulation of Pb in the brain and serum,which suggested that EC might alter Pb distribution in mice.In vitro,spectroscopic analysis,potentiometric titration and docking studies were applied to inquiry into the interaction between bovine serum albumin(BSA)and Pb^(2+)in presence or absence of EC.EC was proved to chelate Pb^(2+)and reduced the interaction between BSA and Pb^(2+).In summary,EC might protect Pb-induced cognitive impairment by activating Nrf2 signaling pathway,and suppressing Pb accumulation via interference on the binding of Pb to albumin.
基金the National Natural Science Foundation of China(52100156)the Natural Science Foundation of Tianjin(21JCQNJC00400)the Shenzhen Science and Technology Program(GJHZ20200731095801005 and JCYJ20200109150210400)for financial support to this research.
文摘The distribution pattern of metals as active centers on a substrate can influence the peroxymonosulfate(PMS)activation and contaminants degradation.Herein,atomic layer deposition is applied to prepare Cu single atom(SA-Cu),cluster(C-Cu),and film(F-Cu)decorated MXene catalysts by regulating the number of deposition cycles.In comparison with SA-Cu-MXene(adsorption energy(E_(ads))=-4.236 eV)and F-Cu-MXene(E_(ads)=-3.548 eV),PMS is shown to adsorb preferably on the C-Cu-MXene surface for activation(E_(ads)=-5.435 eV),realizing higher utilization efficiency.More SO_(4)^(·-)are generated in C-Cu-MXene/PMS system with steady-state concentration and 1–3 orders of magnitude higher than those in the SA-Cu-MXene and F-Cu-MXene activated PMS systems.Particularly,the contribution of SO_(4)^(·-)oxidation to sulfamethoxazole(SMX)degradation followed the order,C-Cu-MXene(97.3%)>SA-Cu-MXene(90.4%)>FCu-MXene(71.9%),realizing the larger SMX degradation rate in the C-Cu-MXene/PMS system with the degradation rate constants(k)at 0.0485 min^(-1).Additionally,SMX degradation routes in C-Cu-MXene/PMS system are found with fewer toxic intermediates.Through this work,we highlighted the importance of guided design of heterogeneous catalysts in the PMS system.Appropriate metal distribution patterns need to be selected according to the actual water treatment demand.Metal sites could be then fully utilized to produce specific active species to improve the utilization efficiency of the oxidants.
基金the National Natural Science Foundation of China(52100157,52176197,and 52100156)the National Key Research and Development Program of China(2022YFD1601100).
文摘In recent years,a great deal of attention has been focused on the environmental impact of plastics,includ-ing the carbon emissions related to plastics,which has promoted the application of biodegradable plas-tics.Countries worldwide have shown high interest in replacing traditional plastics with biodegradable plastics.However,no systematic comparison has been conducted on the carbon emissions of biodegrad-able versus traditional plastic products.This study evaluates the carbon emissions of traditional and biodegradable plastic products(BPPs)over four stages and briefly discusses environmental and economic perspectives.Four scenarios-namely,the traditional method,chemical recycling,industrial composting,and anaerobic digestion-are considered for the disposal of waste BPPs(WBPPs).The analysis takes China as a case study.The results show that the carbon emissions of 1000traditional plastic products(plastic bags,lunch boxes,cups,etc.)were52.09-150.36 carbon emissions equivalent of per kilogram(kg CO_(2)eq),with the stage of plastic production contributing 50.71%-50.77%.In comparison,1000 similar BPPs topped out at 21.06-56.86 kg CO_(2)eq,approximately 13.53%-62.19%lower than traditional plastic prod-ucts.The difference was mainly at the stages of plastic production and waste disposal,and the BPPs showed significant carbon reduction potential at the raw material acquisition stage.Waste disposal plays an important role in environmental impact,and composting and anaerobic digestion are considered to be preferable disposal methods for WBPPs.However,the high cost of biodegradable plastics is a challenge for their widespread use.This study has important reference significance for the sustainable development of the biodegradableplastics industry.
文摘This paper comprehensively analyzes the origins,current situation,and prospects of the sharing economy.The primary purpose is to present the issues and challenges confronting the sharing economy at its current,awkward stage of development and to make reasonable speculations about its future.The research is based on academic literature on the sharing economy from both domestic and international sources.The findings indicate that despite current shortcomings in the regulatory system,industry structure,and user behavior,the scope of the sharing economy’s applications could still expand,and its technology could continue to advance.Overall,the prospects for the sharing economy are likely to be promising.
文摘The study of the hydrate formation process in porous media is of great significance for hydrate application.In this work,the formation process of methane hydrate in porous media was monitored in situ by a low-field magnetic resonance imaging(MRI)system.The formation characteristics of methane hydrate in porous media and the change of fractal dimension of pore space were studied through the change of residual water saturation and T2 relaxation time distribution.The experimental results show that the hydrate formation process is divided into two stages:fast and slow.During the formation process,the water in the pores is continuously consumed and transformed into hydrate,and the overall T2 distribution gradually shifts to the left.In the formation process of hydrate,the pore space becomes more complex,the change of fractal dimension from top to bottom of the reactor gradually increases,and the hydrate formation rate also gradually increases.
文摘A series of composite catalysts were prepared by the wet mixing method, and the mass ratio of CuO-ZnO-Al2O3-ZrO2 component to HZSM-5 zeolite (molar ratio of SiO2 to Al2O3 being 25) was 2:1. The CuO-ZnO-Al2O3-ZrO2 (CuO/ZnO/Al2O3=3/6/1 by weight) component was prepared by a modified 'two-step' co-precipitation method. The effects of ZrO2 on the performance of CuO-ZnO-Al2O3/HZSMo5 catalyst for dimethyl ether synthesis from CO2 hydrogenation were investigated. It was found that ZrO2 improved the properties of CuO-ZnO-Al2O3/HZSM-5 as a structural promoter.
基金financially supported by the China National Funds for Distinguished Young Scientists(No.51325401)the International Thermonuclear Experimental Reactor(ITER)Program Special Project(No.2014GB125006)+1 种基金the National Natural Science Foundation of China(No.51104107)the Major State Basic Research Development Program(No.2014CB046805)
文摘Tempering is an important process for T/P92 ferritic heat-resistant steel from the viewpoint of microstructure control, as it facili- tates the formation of final tempered martensite under serving conditions. In this study, we have gained deeper insights on the mechanism underlying the microstructural evolution during tempering treatment, including the precipitation of carbides and the coarsening of martensite laths, as systematically analyzed by optical microscopy, transmission electron microscopy, and high-resolution transmission electron mi- croscopy. The chemical composition of the precipitates was analyzed using energy dispersive X-ray spectroscopy. Results indicate the for- mation of M3C (cementite) precipitates under normalized conditions. However, they tend to dissolve within a short time of tempering, owing to their low thermal stability. This phenomenon was substantiated by X-ray diffraction analysis. Besides, we could observe the precipitation of fine carbonitrides (MX) along the dislocations. The mechanism of carbon diffusion controlled growth of M23C6 can be expressed by the Zener's equation. The movement of Y-junctions was determined to be the fundamental mechanism underlying the martensite lath coarsening process. Vickers hardness was estimated to determine their mechanical properties. Based on the comprehensive analysis of both the micro- structural evolution and hardness variation, the process of tempering can be separated into three steps.
基金supported by the National Natural Science Foundation of China (Nos. 50971056 and 51171057)the Youth Natural Science Foundation of Hebei Province (No. E2011202002)
文摘The variations of magnetization and magneto- striction with temperature and stress were investigated through the analysis of the effective field, induced by temperature and stress. A nonlinear magnetostrictive model of giant magnetostrictive materials was proposed. The proposed model can be used to calculate the magnetostrictive characterization of giant magnetostrictive materi- als in different temperatures and under different stresses. The coupling effects of axial stress, magnetic field, and temperature on the magnetostriction of a Terfenol-D rod were numerically simulated as well as experimentally tested. Comparison between the calculating and experimental results shows that the proposed model can better describe the magneto-thermo-mechanical characteristics of Terfenol-D rod under different temperatures and compressive stress. Therefore, the proposed model possesses an important significance for the design of magnetostrictive devices.
基金supported by Medical Scientific Research Program of Hebei Province in 2010, Hebei Provincial Health Department, No. 20100131
文摘In the present study, human umbilical cord blood mesenchymal stem cells were injected into a rat model of traumatic brain injury via the tail vein. Results showed that 5-bromodeoxyuridine-labeled cells aggregated around the injury site, surviving up to 4 weeks post-transplantation. In addition, transplantation-related death did not occur, and neurological functions significantly improved. Histological detection revealed attenuated pathological injury in rat brain tissues following human umbilical cord blood mesenchymal stem cell transplantation. In addition, the number of apoptotic cells decreased. Immunohistochemistry and in situ hybridization showed increased expression of brain-derived neurotrophic factor, nerve growth factor, basic fibroblast growth factor, and vascular endothelial growth factor, along with increased microvessel density in surrounding areas of brain injury. Results demonstrated migration of transplanted human umbilical cord blood mesenchymal stem cells into the lesioned boundary zone of rats, as well as increased angiogenesis and expression of related neurotrophic factors in the lesioned boundary zone.
基金supported by Hubei Science and Technology Plan Key Project(G2019ABA100)Assessment and Comprehensive Utilization of Characteristic Biological Resources in Dabie Mountains(4022019006)Natural Science Fund of Hubei Province(2019CFB395)。
文摘Tea polysaccharides(TPSs),one of the major bioactive ingredients in tea,have been widely studied due to their variety of biological activities,including antioxidant,cancer prevention,hypoglycemia,anti-fatigue,anti-coagulant,anti-obesity and immunomodulatory effect.The biological effectiveness of TPSs has direct relation with their structures such as monosaccharide composition,molecular weight,glycosidic linkages,conformation and others,which can be influenced by tea materials,processing methods,extraction and purification procedures among others.Comparing to the study of tea polyphenols,the exploration of TPSs in structural elucidation and biofunctionality is very preliminary.Yet several factors affecting the structural change of TPSs have been studied and identified.Consequently,the variation of some TPS biological activity brought by the change of TPS structures has been evaluated and preliminary correlation of structure activity relationship of TPSs has been performed.Therefore,this review aims to serve as a summary research report regarding the influencing factors on TPSs structures and consequential effects on the biological activities of TPSs.We hope to provide updated information and systematic references for future study and functional food development of TPSs.
文摘Reducing oxidative stress and hepatoprotective effect of Pu-erh tea water extracts on rats fed with high-fat diet were researched for explaining health care of Pu-erh tea.Fifty SD rats were divided into five groups.The body weight was measured once a day.The malondialdehyde(MDA)and glucose(Glu)levels and the activities of alanine aminotransferase(ALT),aspartate aminotransferase(AST),nitric oxide synthase(NOS),and pyruvate kinase(PK)in serum were determined.Furthermore,the hepatic glycogen level(HGL)and the activities of hepatic total superoxide dismutase(T-SOD),catalase(CAT),and glutathione peroxidase(GSH-Px)were also measured after continuous administration for 12 weeks.The result demonstrated that Pu-erh extract caused the decreases in body weight,fat index,MDA and NOS levels,and the increases in hepatic T-SOD,CAT and GSH-Px activities,indicating that the extract may be due to inhibiting the increases of body weight and fat index,reducing oxidant stress state and inhibiting lipid peroxidation,thus decreasing the activities of ALT and AST,and protecting the liver in rat.Meanwhile,the extracts could increase the production of hepatic glycogen and the activity of PK,and reduce glucose level,protecting the liver from the diseases associated with type II diabetes.
基金Supported by the National Natural Science Foundation of China under Grant No 50871074, and Tianjin University of Science and Technology under Grant No 0200153.
文摘The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Nilr-type structure at high temperatures (above 1243℃), and the rhombohedral Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.
文摘Objective:The effect of casein glycomacropeptide(CGMP)on the expression of NF-B subunit p65 in human colorectal cancer HT-29 cells induced by lipopolysaccharide(LPS)was investigated to explore the therapeutic efficacy of CGMP for human colorectal cancer.Methods:HT-29 cells cultured in 96-well plates were stimulated with LPS for 30 min at the concentrations of 0,0.001,0.01,0.1,1 and 10g/mL.After stimulation,the expression of p65 in HT-29 cells was evaluated by immunofluorescence method.Similarly,HT-29 cells were incubated with 0,0.001,0.01,0.1,1,10 and 100g/mL CGMP for 24 h at the optimal LPS concentration.After treatment with CGMP under the incubation with optimal LPS concentration for 30 min,the protein expression of p65 was analyzed by Western blotting.The optimum culture time was evaluated by incubating HT-29 cells with the optimal CGMP concentration for 6,12,24,48 and 72 h.Results:NF-B-p65 revealed that the highest protein expression was achieved with 1g/mL LPS treatment.Meanwhile,CGMP could inhibit the protein expression of NF-B-p65 in LPS-stimulated HT-29 cells,and the optimal inhibitory effect was observed at a CGMP concentration of 0.01g/mL with 48 h incubation.Conclusion:CGMP can regulate NF-B signaling pathway through inhibiting the expression of its subunit p65,which is beneficial for the further improvement of human colorectal cancer treatment.
基金the Natural Science Foundation of Tianjin (013605211)
文摘The thermal stress of the quartz oscillator module packaging isinvestigated using digital-im- age correlation method (DICM), and theexperimental results are given. Under the quartz oscillator modulepackaging, the quartz oscillator and the Fe-Sn-Cu alloy frame arejoined together with the electroconductive adhesive (PI), and theelectroconductive adhesive needs to be cured twice at 150 deg. C and275 deg. C respective- ly.
基金financial projects of the National Natural Science Foundation of China(No.81803548)Natural Science Foundation of Tianjin(No.19JCQNJC12400)+1 种基金Hubei Province Technical Innovation Special Project(No.2019ABA100)Tianjin Science and Technology Support Special Project(No.19YFZCSN00010)。
文摘Tea represents an abundant source of naturally occurring polyphenols.Tea polyphenols(TPs)have received growing attentions for its wide consumption in the world,and more importantly its pleiotropic bioeffects for human health.After ingestion,TPs may undergo absorption and phase II reaction in the small intestine,and most undigested proportion would be submitted to the colon to interact with gut microbiota.Interactions between gut microbiota and TPs are bidirectional,including not only bacteria-mediated TPs metabolism,e.g.,removal of gallic acid moiety and ring fission to release phenolic acid catabolites,but also TPs-based modification of bacterial profiles.Crosstalk between TPs and gut microbes may benefit for gut barrier function,for example,improvement of the intestinal permeability to alleviate inflammation.Moreover,by reshaping microbial composition and associated metabolites,TPs may exert a systemic protection on host metabolism,which contributes to improve certain chronic metabolic disorders.Given that,further understanding of the metabolic fate of TPs and interplay with gut microbiota as well as potential health-promoting effects are of great significance to development and application of tea and their polyphenolic components in the future as dietary supplements and/or functional ingredients in medical foods.
基金Supported by the NNSF of China(1027206710461005) the Scientific Research Foundation of Tianjin Education Committee(20050404).
文摘The aim of this paper is to apply the relatively new Adomian decomposition method to solving the system of linear fractional, in the sense of Riemann-Liouville and Caputo respectively, differential equations. The solutions are expressed in terms of Mittag-Leffier functions of matric argument. The Adomian decomposition method is straightforward, applicable for broader problems and avoids the difficulties in applying integral transforms. As the order is 1, the result here is simplified to that of first order differential equation.