Honorable Minister Lamola,Dear colleagues,Our meeting today is about G20 cooperation.I am convinced that under South Africa's Presidency,G20 cooperation will make new headway and deliver new results.At last year&#...Honorable Minister Lamola,Dear colleagues,Our meeting today is about G20 cooperation.I am convinced that under South Africa's Presidency,G20 cooperation will make new headway and deliver new results.At last year's summit in Rio de Janeiro,President Xi Jinping called on the G20 to be a force to improve global governance and move history forward.展开更多
Dear colleagues,Let me begin by congratulating South Africa on assuming the G20 presidency.I also thank the South African government for the thoughtful arrangements accorded to the Chinese delegation.The current inter...Dear colleagues,Let me begin by congratulating South Africa on assuming the G20 presidency.I also thank the South African government for the thoughtful arrangements accorded to the Chinese delegation.The current international landscape is marked by transformation and turbulence.Regional conflicts and turmoil break out from time to time.The global security deficit keeps growing.At the Rio de Janeiro Summit last November,G20 leaders pledged to build a just world and a sustainable planet,highlighted the importance of diplomacy and dialogue and the peaceful resolution of conflicts,and undertook to support all efforts conducive to addressing crises.展开更多
To the Third World Integrative Medicine Congress, I am pleased to learn the opening of the Third World Integrative Medicine Congress in Guangzhou. I would like to congratulate all the experts and congress participant...To the Third World Integrative Medicine Congress, I am pleased to learn the opening of the Third World Integrative Medicine Congress in Guangzhou. I would like to congratulate all the experts and congress participants from abroad and at home for the success of organizing this conference.展开更多
BACKGROUND Acute respiratory distress syndrome(ARDS)is a critical condition characterized by acute hypoxemia,non-cardiogenic pulmonary edema,and decreased lung compliance.The Berlin definition,updated in 2012,classifi...BACKGROUND Acute respiratory distress syndrome(ARDS)is a critical condition characterized by acute hypoxemia,non-cardiogenic pulmonary edema,and decreased lung compliance.The Berlin definition,updated in 2012,classifies ARDS severity based on the partial pressure of arterial oxygen/fractional inspired oxygen fraction ratio.Despite various treatment strategies,ARDS remains a significant public health concern with high mortality rates.AIM To evaluate the implications of driving pressure(DP)in ARDS management and its potential as a protective lung strategy.METHODS We conducted a systematic review using databases including EbscoHost,MEDLINE,CINAHL,PubMed,and Google Scholar.The search was limited to articles published between January 2015 and September 2024.Twenty-three peer-reviewed articles were selected based on inclusion criteria focusing on adult ARDS patients undergoing mechanical ventilation and DP strategies.The literature review was conducted and reported according to PRISMA 2020 guidelines.RESULTS DP,the difference between plateau pressure and positive end-expiratory pressure,is crucial in ARDS management.Studies indicate that lower DP levels are significantly associated with improved survival rates in ARDS patients.DP is a better predictor of mortality than tidal volume or positive end-expiratory pressure alone.Adjusting DP by optimizing lung compliance and minimizing overdistension and collapse can reduce ventilator-induced lung injury.CONCLUSION DP is a valuable parameter in ARDS management,offering a more precise measure of lung stress and strain than traditional metrics.Implementing DP as a threshold for safety can enhance protective ventilation strategies,po-tentially reducing mortality in ARDS patients.Further research is needed to refine DP measurement techniques and validate its clinical application in diverse patient populations.展开更多
To fulfill the new requirements of geological work in the modern era and explore the latest advancements,the cutting-edge directions and trends of hydrogeology science,as well as the key scientific issues and major de...To fulfill the new requirements of geological work in the modern era and explore the latest advancements,the cutting-edge directions and trends of hydrogeology science,as well as the key scientific issues and major demands in hydrogeology,those contribute to the development of an ecological civilization and effective natural resource management,the national hydrogeological academic symposium took place from October 25th to 27th,2024.Organized by the China Geological Society and collaboratively hosted by the Hydrogeology Professional Committee,the event featured an insightful speech by Mr.Wang Min,former Deputy Minister of the Ministry of Natural Resources.His perspectives offer valuable insights for current geological endeavours,and we have compiled the content of this speech into this article.展开更多
Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO...Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.展开更多
In this comprehensive review,the evolution and progress of bioplastics are examined,with an emphasis on their types,production methods,environmental impact,and biodegradability.In light of the increasing global effort...In this comprehensive review,the evolution and progress of bioplastics are examined,with an emphasis on their types,production methods,environmental impact,and biodegradability.In light of the increasing global efforts to address environmental degradation,bioplastics have emerged as a highly potential substitute for conventional petroleum-based plastics.This review classifies various categories of bioplastics,encompassing both biodegradable and bio-based variations,and assesses their environmental consequences using life cycle evaluations and biodegradability calculations.This paper analyzes the technological advancements that have enhanced the mechanical and thermal characteristics of bioplastics,hence increasing their feasibility for extensive commercial applications in diverse sectors.This review critically examines the possible uses of bioplastics in important industries including packaging,aerospace,and healthcare,emphasizing both achievements and current obstacles.In addition,the assessment addresses the economic and technical obstacles to expanding bioplastic manufacturing,namely concerns about cost,material efficiency,and waste disposal.Moreover,the article forecasts the future potential of bioplastics in furthering a sustainable circular economy and suggests methods to address existing constraints,such as improvements in recycling technology and the establishment of more economically efficient manufacturing methods.The findings are intended to educate policymakers,industry stakeholders,and researchers on the crucial contribution of bioplastics in attaining sustainability objectives and promoting innovation in the field of material science.展开更多
Through thermodynamic calculations and microstructural characterization,the effect of niobium(Nb)content on the solidifica-tion characteristics of Alloy 625 Plus was systematically investigated.Subsequently,the effect...Through thermodynamic calculations and microstructural characterization,the effect of niobium(Nb)content on the solidifica-tion characteristics of Alloy 625 Plus was systematically investigated.Subsequently,the effect of Nb content on hot deformation behaviorwas examined through hot compression experiments.The results indicated that increasing the Nb content lowers the liquidus temperatureof the alloy by 51℃,producing a denser solidification microstructure.The secondary dendrite arm spacing(SDAS)of the alloy decreasesfrom 39.09 to 22.61μm.Increasing the Nb content alleviates element segregation but increases interdendritic precipitates,increasing theirarea fraction from 0.15% to 5.82%.These precipitates are primarily composed of large Laves,δ,η,and γ″phases,and trace amounts of Nb C.The shapes of these precipitates change from small chunks to large elongated forms.No significant change in the type or amount ofinclusions within the alloy is detected.The inclusions are predominantly individual Al_(2)O_(3) and TiN,as well as Al_(2)O_(3)/Ti N composite inclu-sions.Samples with varying Nb contents underwent hot compression deformation at a true strain of 0.69,a strain rate of 0.5 s^(-1),and a de-formation temperature of 1150℃.Increasing the Nb content also elevates the peak stress observed in the flow curves.However,alloyswith higher Nb content exhibit more pronounced recrystallization softening effects.The Laves phase precipitates do not completely redis-solve during hot deformation and are stretched to elongated shapes.The high-strain energy storage increases the recrystallization fractionfrom 32.4% to 95.5%,significantly enhancing the degree of recrystallization and producing a more uniform deformation microstructure.This effect is primarily attributed to the addition of Nb,which refines the initial grains of the alloy,enhances the solid solution strengthen-ing of the matrix,and improves the induction of particle-stimulated nucleation.展开更多
Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-it...Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-ities.A metro system must be resilient to resist,adapt to,and recover its performance when such disruptions occur.Current studies on metro system resilience often lack a comprehensive view from a complex system perspective,leading to a plethora of choices for methods of analysis and indicators applied to different metro systems and external disturbances.Therefore,the present paper aims to provide a comprehensive review of the topics and works revolving around the resilience of metro systems.It first clarifies the concept of metro system resilience based on classical definitions from a technical perspective.Metro resilience encompasses both the structural and operational aspects of metro systems,including their damage mechanisms,analysis methods and indicators of resilience.Methods for enhancing metro system resilience across structural,operational and monitoring dimensions are explored.Finally,future research directions are discussed,emphasizing the impor-tance of considering the"system of systems"formed by interdependent infrastructure,refining uncertainty analysis,and investigating the opportunities arising from the application of artificial intelligence for improving metro system resilience against external disturbances.展开更多
Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were e...Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were enriched with a mixture of PAHs(naphthalene,phenanthrene,fluorene,pyrene,and fluoranthene).Isolation of culturable bacteria,high-throughput sequencing,and functional prediction were combined to systematically analyze bacterial structural and predicted functional responses to PAH exposure.High-throughput sequencing results showed that the relative abundance of Proteobacteria was significantly increased after enrichment,and Pseudomonas and Acinetobacter were identified as dominant genera under PAH exposure.These findings were consistent with the 19 potential PAH-degrading strains(mainly Pseudomonas)that were successfully isolated from enrichment cultures.Distinct bacterial taxa between enriched marine and intertidal sediments indicated the existence of distinct PAH-degrading groups.PICRUSt2-based functional predictions suggested higher predicted abundances of PAH-degradation pathways in polar sediments,likely through the preferential degradation of parent PAH compounds in response to elevated concentrations.This study provides valuable data on microbial responses to PAH pollution in polar regions and offers new insights for evaluating ecological hazards induced by PAHs.展开更多
Structural gradient changes are common in nature and play an important role in improving the carrying capacity of organisms.Graded lattice structures designed on this basis have received considerable attention due to ...Structural gradient changes are common in nature and play an important role in improving the carrying capacity of organisms.Graded lattice structures designed on this basis have received considerable attention due to their great design potential.In this study,two different layered gradient design strategies were proposed,and three lattice structures were designed.Samples with PA2200 nylon as the matrix material were prepared using additive manufacturing technology,and finite element models of the relevant lattice structures were established.The mechanical properties and energy absorption ability of the structures under different gradient spans and design strategies were investigated using quasi-static compression tests and numerical simulations.The results indicate that the layered design can improve the elastic modulus of the lattice structure by up to 40.05% and the energy absorption per unit volume by up to 13.04% compared to the conventional body-centered cubic(BCC)structure.However,it is worth noting that an excessively large interlayer gradient span can adversely affect the mechanical properties of the structure.In addition,all layered gradient lattice structures show significant anisotropy,and the energy absorption per unit volume can differ by up to 36.59%under different compression directions.The layered gradient structure design strategies proposed in this work can provide an effective reference for the design of gradient lattice structures.展开更多
Background and Objective Inflammation plays a pivotal role in the progression of coronary artery disease(CAD).High-sensitivity C-reactive protein(hsCRP)serves as a well-established biomarker for assessing cardiovascul...Background and Objective Inflammation plays a pivotal role in the progression of coronary artery disease(CAD).High-sensitivity C-reactive protein(hsCRP)serves as a well-established biomarker for assessing cardiovascular inflammation risk.However,the specific intestinal microbiota alteration contributing to increased inflammation remains unclear.Therefore,the present study investigated the correlation between the intestinal microbiota and inflammation in patients with unstable angina(UA).Methods A cohort of 92 patients with UA was recruited for this study.The plasma hsCRP level was measured via a CardioPhase hsCRP assay,fecal samples were collected after admission,and 16S rRNA sequencing was conducted to identify the fecal microbial profile.The participants were classified into two groups according to the median hsCRP level(1.11 mg/L).The composition of the fecal microbiota was compared between patients with hsCRP≥1.11 mg/L and those with hsCRP<1.11 mg/L.Additionally,the correlations between the fecal microbiota and clinical characteristics were analyzed.Results A notable reduction in the relative abundance of Akkermansia was observed in patients with hsCRP≥1.11 mg/L,whereas the diversity of the fecal microbiota was not significantly different between patients with hsCRP≥1.11 mg/L and those with hsCRP<1.11 mg/L.Furthermore,the abundance of Akkermansia was negatively correlated with hsCRP levels.Conclusion This study suggested a significant association between decreased levels of Akkermansia and inflammatory risk in patients with UA.These findings underscore the potential role of the intestinal microbiota in contributing to inflammation in UA patients.Further work is needed on the mechanism by which the microbiota contributes to inflammatory risk.展开更多
OBJECTIVE:To investigate the effect of icariin on proliferation of bone marrow mesenchymal stem cells(BMSCs)in Sprague-Dawley(SD)rats.METHODS:BMSCs were obtained from SD rat bone marrow with differential time adherent...OBJECTIVE:To investigate the effect of icariin on proliferation of bone marrow mesenchymal stem cells(BMSCs)in Sprague-Dawley(SD)rats.METHODS:BMSCs were obtained from SD rat bone marrow with differential time adherent method.Its characteristic was identified through differentiation cell surface antigens and the multi-lineage(osteo/adipo/chondo)differentiation potential.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)method and 5-Bromo-2-Deoxyuridine(Brd U)incorporation were applied to detect the effect of icariin on BMSCs proliferation.Flow cytometry was used to detect proliferation in-dex of BMSCs.The m RNA level and the distribution ofβ-catenin were evaluated by Real-time Polymerase Chain Reaction(PCR)and Immunofluorescent staining respectively.Western blot was used to detect protein expression levels ofβ-catenin,glycogen synthase kinase-3 beta(GSK-3β),phospho-glycogen synthase kinase-3 beta(p GSK-3β)and cyclin D1.RESULTS:Icariin promoted BMSCs proliferation at the concentration of 0.05-2.0 mg/L.The percentage of Brd U positive cells of BMSCs was increased from40.98%to 70.42%,and the proliferation index value was increased from 8.9%to 17.5%with the treatment of 0.05 mg/L icariin,which significance values were both less than 0.05.Compared with the control group,total and nuclearβ-catenin proteins,as well asβ-catenin m RNA expression,were all increased with icariin treatment.Meanwhile,the phosphorylation level of GSK-3βand cyclin D1 protein expressions were also increased in BMSCs with icariin treatment.CONCLUSION:The findings of the present study demonstrated that low dosage of icariin could promote BMSCs proliferation.The activation of Wnt/β-catenin pathways was involved in this process.展开更多
The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil...The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil of the pear （cv. Dangshansu on P.betulifolia Bunge. rootstock） orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil organic matter （SOM）, total nitrogen （STN）, total phosphorus （STP）, total potassium （STK）, available nitrogen （SAN）, and available potassium （SAK） in and between rows at different soil depths （0-60 cm）. The SOM, STN, STP, STK, SAN and SAK of the different soil layers under the two tillage models were different in the vertical direction. The SOM, STN, STP and SAN in the 0-20 cm soil layer were higher than those in the 20-40 and 40- 60 cm soil layers. The STK of 40-60 cm soil layer was higher than that in the 0-20 and 20-40 cm soil layers. The STK increased with the depth of soil in the vertical direction in the clean cultivated pear orchard. Variability of the SOM, STN, STP, STK, SAN and SAK of sample sites in between rows of the same soil layer was found in the pear orchard soil in the horizontal direction under clean and sod cultivation management systems, except that STK of all sites did not show the difference in identical soil layers in the pear orchard under clean cultivation. The sod cultivation model improved the SOM, STN, and STK in the 0-20 cm soil layer in the pear orchard, and the three components increased by 12.8, 12.7 and 7.3% compared to clean cultivation, respectively. The results can be applicable to plan collection of orchard soil samples, assess orchard soil quality, and improve orchard soil management practices.展开更多
The automated interpretation of rock structure can improve the efficiency,accuracy,and consistency of the geological risk assessment of tunnel face.Because of the high uncertainties in the geological images as a resul...The automated interpretation of rock structure can improve the efficiency,accuracy,and consistency of the geological risk assessment of tunnel face.Because of the high uncertainties in the geological images as a result of different regional rock types,as well as in-situ conditions(e.g.,temperature,humidity,and construction procedure),previous automated methods have limited performance in classification of rock structure of tunnel face during construction.This paper presents a framework for classifying multiple rock structures based on the geological images of tunnel face using convolutional neural networks(CNN),namely Inception-ResNet-V2(IRV2).A prototype recognition system is implemented to classify 5 types of rock structures including mosaic,granular,layered,block,and fragmentation structures.The proposed IRV2 network is trained by over 35,000 out of 42,400 images extracted from over 150 sections of tunnel faces and tested by the remaining 7400 images.Furthermore,different hyperparameters of the CNN model are introduced to optimize the most efficient algorithm parameter.Among all the discussed models,i.e.,ResNet-50,ResNet-101,and Inception-v4,Inception-ResNet-V2 exhibits the best performance in terms of various indicators,such as precision,recall,F-score,and testing time per image.Meanwhile,the model trained by a large database can obtain the object features more comprehensively,leading to higher accuracy.Compared with the original image classification method,the sub-image method is closer to the reality considering both the accuracy and the perspective of error divergence.The experimental results reveal that the proposed method is optimal and efficient for automated classification of rock structure using the geological images of the tunnel face.展开更多
文摘Honorable Minister Lamola,Dear colleagues,Our meeting today is about G20 cooperation.I am convinced that under South Africa's Presidency,G20 cooperation will make new headway and deliver new results.At last year's summit in Rio de Janeiro,President Xi Jinping called on the G20 to be a force to improve global governance and move history forward.
基金Wang Yi,Member of the Political Bureau of the CPC Central Committee and Minister of Foreign Affairs。
文摘Dear colleagues,Let me begin by congratulating South Africa on assuming the G20 presidency.I also thank the South African government for the thoughtful arrangements accorded to the Chinese delegation.The current international landscape is marked by transformation and turbulence.Regional conflicts and turmoil break out from time to time.The global security deficit keeps growing.At the Rio de Janeiro Summit last November,G20 leaders pledged to build a just world and a sustainable planet,highlighted the importance of diplomacy and dialogue and the peaceful resolution of conflicts,and undertook to support all efforts conducive to addressing crises.
文摘To the Third World Integrative Medicine Congress, I am pleased to learn the opening of the Third World Integrative Medicine Congress in Guangzhou. I would like to congratulate all the experts and congress participants from abroad and at home for the success of organizing this conference.
文摘BACKGROUND Acute respiratory distress syndrome(ARDS)is a critical condition characterized by acute hypoxemia,non-cardiogenic pulmonary edema,and decreased lung compliance.The Berlin definition,updated in 2012,classifies ARDS severity based on the partial pressure of arterial oxygen/fractional inspired oxygen fraction ratio.Despite various treatment strategies,ARDS remains a significant public health concern with high mortality rates.AIM To evaluate the implications of driving pressure(DP)in ARDS management and its potential as a protective lung strategy.METHODS We conducted a systematic review using databases including EbscoHost,MEDLINE,CINAHL,PubMed,and Google Scholar.The search was limited to articles published between January 2015 and September 2024.Twenty-three peer-reviewed articles were selected based on inclusion criteria focusing on adult ARDS patients undergoing mechanical ventilation and DP strategies.The literature review was conducted and reported according to PRISMA 2020 guidelines.RESULTS DP,the difference between plateau pressure and positive end-expiratory pressure,is crucial in ARDS management.Studies indicate that lower DP levels are significantly associated with improved survival rates in ARDS patients.DP is a better predictor of mortality than tidal volume or positive end-expiratory pressure alone.Adjusting DP by optimizing lung compliance and minimizing overdistension and collapse can reduce ventilator-induced lung injury.CONCLUSION DP is a valuable parameter in ARDS management,offering a more precise measure of lung stress and strain than traditional metrics.Implementing DP as a threshold for safety can enhance protective ventilation strategies,po-tentially reducing mortality in ARDS patients.Further research is needed to refine DP measurement techniques and validate its clinical application in diverse patient populations.
文摘To fulfill the new requirements of geological work in the modern era and explore the latest advancements,the cutting-edge directions and trends of hydrogeology science,as well as the key scientific issues and major demands in hydrogeology,those contribute to the development of an ecological civilization and effective natural resource management,the national hydrogeological academic symposium took place from October 25th to 27th,2024.Organized by the China Geological Society and collaboratively hosted by the Hydrogeology Professional Committee,the event featured an insightful speech by Mr.Wang Min,former Deputy Minister of the Ministry of Natural Resources.His perspectives offer valuable insights for current geological endeavours,and we have compiled the content of this speech into this article.
基金supported by the following funds:The National Natural Science Foundation of China(Nos.52275393,51935014,and 82072084)Jiangxi Provincial Natural Science Foundation of China(No.20224ACB204013)+2 种基金The Project of State Key Laboratory of Precision Manufacturing for Extreme Service Performancethe National Key Research and Development Program of China(No.2023YFB4605800)the Independent Exploration and Innovation Project of Central South University(No.1053320221707).
文摘Fast electron-hole recombination issues during titanium dioxide(TiO_(2))photocatalysis limit its application in preventing bacterial infection during bone defect repair.In this study,TiO_(2)@reduced graphene oxide(rGO)composites were synthesized using a hydrothermal method in which rGO,which possesses very high electrical conductivity,promotes the separation of photoelectron-hole pairs of TiO_(2),thus improving the efficiency of photocatalytic production of reactive oxygen species(ROS).Subsequently,TiO_(2)@rGO composites were introduced into poly-L-lactic acid(PLLA)to prepare bone scaffolds with photocatalytic antibacterial function via selective laser sintering.The results showed that TiO_(2)grew on the surface of rGO and formed a covalent bond connection(Ti-O-C)with rGO.A decreased electrochemical impedance of TiO_(2)@rGO composites was observed,and the transient photocurrent intensity increased from 0.05 to 0.5μA/cm^(2).Analysis of electron spin resonance found that the photocatalytic products of TiO_(2)were·OH and·O^(2-),two kinds of ROS capable of killing bacteria via disrupting the structure of the bacterial membrane in vitro.Antibacterial experiments showed that the PLLA/TiO_(2)@rGO scaffolds had good antibacterial properties against Escherichia coli and Staphylococcus aureus.Finally,we report that these scaffolds exhibited both enhanced mechanical properties due to the addition of TiO_(2)@rGO as a reinforcement material and good biocompatibility during cell proliferation.
基金the financial support given by the Ministry of Higher Education Malaysia(MOHE)under the Higher Institution Centre of Excellence(HICOE2.0/5210004)at the Institute of Tropical Forestry and Forest Products.
文摘In this comprehensive review,the evolution and progress of bioplastics are examined,with an emphasis on their types,production methods,environmental impact,and biodegradability.In light of the increasing global efforts to address environmental degradation,bioplastics have emerged as a highly potential substitute for conventional petroleum-based plastics.This review classifies various categories of bioplastics,encompassing both biodegradable and bio-based variations,and assesses their environmental consequences using life cycle evaluations and biodegradability calculations.This paper analyzes the technological advancements that have enhanced the mechanical and thermal characteristics of bioplastics,hence increasing their feasibility for extensive commercial applications in diverse sectors.This review critically examines the possible uses of bioplastics in important industries including packaging,aerospace,and healthcare,emphasizing both achievements and current obstacles.In addition,the assessment addresses the economic and technical obstacles to expanding bioplastic manufacturing,namely concerns about cost,material efficiency,and waste disposal.Moreover,the article forecasts the future potential of bioplastics in furthering a sustainable circular economy and suggests methods to address existing constraints,such as improvements in recycling technology and the establishment of more economically efficient manufacturing methods.The findings are intended to educate policymakers,industry stakeholders,and researchers on the crucial contribution of bioplastics in attaining sustainability objectives and promoting innovation in the field of material science.
基金the financial support from the National Natural Science Foundation of China(No.52174303)the Program of Introducing Talents of Disciplineto Universities,China(No.B21001)the Joint Program of Science and Technology Plans in Liaoning Province,China(No.2023JH2/101700302t)。
文摘Through thermodynamic calculations and microstructural characterization,the effect of niobium(Nb)content on the solidifica-tion characteristics of Alloy 625 Plus was systematically investigated.Subsequently,the effect of Nb content on hot deformation behaviorwas examined through hot compression experiments.The results indicated that increasing the Nb content lowers the liquidus temperatureof the alloy by 51℃,producing a denser solidification microstructure.The secondary dendrite arm spacing(SDAS)of the alloy decreasesfrom 39.09 to 22.61μm.Increasing the Nb content alleviates element segregation but increases interdendritic precipitates,increasing theirarea fraction from 0.15% to 5.82%.These precipitates are primarily composed of large Laves,δ,η,and γ″phases,and trace amounts of Nb C.The shapes of these precipitates change from small chunks to large elongated forms.No significant change in the type or amount ofinclusions within the alloy is detected.The inclusions are predominantly individual Al_(2)O_(3) and TiN,as well as Al_(2)O_(3)/Ti N composite inclu-sions.Samples with varying Nb contents underwent hot compression deformation at a true strain of 0.69,a strain rate of 0.5 s^(-1),and a de-formation temperature of 1150℃.Increasing the Nb content also elevates the peak stress observed in the flow curves.However,alloyswith higher Nb content exhibit more pronounced recrystallization softening effects.The Laves phase precipitates do not completely redis-solve during hot deformation and are stretched to elongated shapes.The high-strain energy storage increases the recrystallization fractionfrom 32.4% to 95.5%,significantly enhancing the degree of recrystallization and producing a more uniform deformation microstructure.This effect is primarily attributed to the addition of Nb,which refines the initial grains of the alloy,enhances the solid solution strengthen-ing of the matrix,and improves the induction of particle-stimulated nucleation.
基金supported by National Key R&D Program of China 2024YFC3808804National Natural Science Foundation of China NO.52478411+1 种基金China Scholarship Council No.202506260003Jinan Rail Transit Group Co.,Ltd(ggjn-sd-gd2022008fw).
文摘Metro systems are important transport infrastructures in megacities,and their long-term operational safety is challenged by frequent external disturbances,such as environmental extremes and human construction activ-ities.A metro system must be resilient to resist,adapt to,and recover its performance when such disruptions occur.Current studies on metro system resilience often lack a comprehensive view from a complex system perspective,leading to a plethora of choices for methods of analysis and indicators applied to different metro systems and external disturbances.Therefore,the present paper aims to provide a comprehensive review of the topics and works revolving around the resilience of metro systems.It first clarifies the concept of metro system resilience based on classical definitions from a technical perspective.Metro resilience encompasses both the structural and operational aspects of metro systems,including their damage mechanisms,analysis methods and indicators of resilience.Methods for enhancing metro system resilience across structural,operational and monitoring dimensions are explored.Finally,future research directions are discussed,emphasizing the impor-tance of considering the"system of systems"formed by interdependent infrastructure,refining uncertainty analysis,and investigating the opportunities arising from the application of artificial intelligence for improving metro system resilience against external disturbances.
基金supported by the project from the National Natural Science Foundation of China(Grant no.42230411)the Science&Technology Innovation Project of Laoshan Laboratory(Grant no.LSKJ202203206)。
文摘Understanding microbial responses to polycyclic aromatic hydrocarbon(PAH)pollution is crucial for assessing the current status of PAH contamination in polar regions.In this study,intertidal and marine sediments were enriched with a mixture of PAHs(naphthalene,phenanthrene,fluorene,pyrene,and fluoranthene).Isolation of culturable bacteria,high-throughput sequencing,and functional prediction were combined to systematically analyze bacterial structural and predicted functional responses to PAH exposure.High-throughput sequencing results showed that the relative abundance of Proteobacteria was significantly increased after enrichment,and Pseudomonas and Acinetobacter were identified as dominant genera under PAH exposure.These findings were consistent with the 19 potential PAH-degrading strains(mainly Pseudomonas)that were successfully isolated from enrichment cultures.Distinct bacterial taxa between enriched marine and intertidal sediments indicated the existence of distinct PAH-degrading groups.PICRUSt2-based functional predictions suggested higher predicted abundances of PAH-degradation pathways in polar sediments,likely through the preferential degradation of parent PAH compounds in response to elevated concentrations.This study provides valuable data on microbial responses to PAH pollution in polar regions and offers new insights for evaluating ecological hazards induced by PAHs.
基金supported by National Natural Science Foundation of China(Grant Nos.12172067,12072052,12372128,12072005,U23A2067)Fundamental Research Funds for the Central Universities(Grant Nos.2024CDJXY009,2022CDJQY-004)+3 种基金Aeronautical Science Foundation of China(Grant No.2022Z0570Q9002)Chongqing Talent Plan(Grant No.cstc2022ycjh-bgzxm0144)Young Elite Scientists Sponsorship Program by CAST(Grant No.2020QNRC001)Xiaomi Young Talents Program.
文摘Structural gradient changes are common in nature and play an important role in improving the carrying capacity of organisms.Graded lattice structures designed on this basis have received considerable attention due to their great design potential.In this study,two different layered gradient design strategies were proposed,and three lattice structures were designed.Samples with PA2200 nylon as the matrix material were prepared using additive manufacturing technology,and finite element models of the relevant lattice structures were established.The mechanical properties and energy absorption ability of the structures under different gradient spans and design strategies were investigated using quasi-static compression tests and numerical simulations.The results indicate that the layered design can improve the elastic modulus of the lattice structure by up to 40.05% and the energy absorption per unit volume by up to 13.04% compared to the conventional body-centered cubic(BCC)structure.However,it is worth noting that an excessively large interlayer gradient span can adversely affect the mechanical properties of the structure.In addition,all layered gradient lattice structures show significant anisotropy,and the energy absorption per unit volume can differ by up to 36.59%under different compression directions.The layered gradient structure design strategies proposed in this work can provide an effective reference for the design of gradient lattice structures.
基金the Yunnan Engineering Research Center Innovation Ability Construction and Enhancement Projects[2023-XMDJ-00617107]Natural Science Foundation of Yunnan Province[202401AS070646]Natural Science Foundation of Jiangxi Provincial[20232BAB214038].
文摘Despite progress in suppressing polysulfide shuttling,this challenge persists in lithium-sulfur battery commercialization.While existing strategies emphasize polysulfide adsorption and catalytic conversion,the critical role of diffusion kinetics in conversion–deposition processes remains underexplored.We design an MXene-based array architecture integrating 2D structural advantages and strong polysulfide affinity to regulate diffusion pathways.Combined experimental and multiscale computational studies reveal diffusion-mediated conversion-deposition dynamics.The sodium alginate-constructed MXene array enables three synergistic mechanisms:(1)Enhanced ion/electron delocalization reduces diffusion barriers,(2)Continuous ion transport channels facilitate charge transfer,and(3)Exposed polar surfaces promote polysulfide aggregation/conversion.Synchrotron X-ray tomography coupled with comprehensive electrochemical analyses reveals distinct mechanistic differences between conversion and deposition processes arising from diffusion heterogeneity.In situ characterization techniques combined with DFT simulation calculations demonstrate that diffusion kinetics exerts differential regulatory effects on these coupled electrochemical processes,exhibiting particular sensitivity toward the deposition mechanism.This work provides fundamental insights that reshape our understanding of diffusion-mediated phase transformation in complex multi-step electrochemical systems,offering new perspectives for advanced electrode architecture design in next-generation energy storage technologies.
基金supported by the National Natural Science Foundation of China(No.82030016,No 82230011 and No.82200533).
文摘Background and Objective Inflammation plays a pivotal role in the progression of coronary artery disease(CAD).High-sensitivity C-reactive protein(hsCRP)serves as a well-established biomarker for assessing cardiovascular inflammation risk.However,the specific intestinal microbiota alteration contributing to increased inflammation remains unclear.Therefore,the present study investigated the correlation between the intestinal microbiota and inflammation in patients with unstable angina(UA).Methods A cohort of 92 patients with UA was recruited for this study.The plasma hsCRP level was measured via a CardioPhase hsCRP assay,fecal samples were collected after admission,and 16S rRNA sequencing was conducted to identify the fecal microbial profile.The participants were classified into two groups according to the median hsCRP level(1.11 mg/L).The composition of the fecal microbiota was compared between patients with hsCRP≥1.11 mg/L and those with hsCRP<1.11 mg/L.Additionally,the correlations between the fecal microbiota and clinical characteristics were analyzed.Results A notable reduction in the relative abundance of Akkermansia was observed in patients with hsCRP≥1.11 mg/L,whereas the diversity of the fecal microbiota was not significantly different between patients with hsCRP≥1.11 mg/L and those with hsCRP<1.11 mg/L.Furthermore,the abundance of Akkermansia was negatively correlated with hsCRP levels.Conclusion This study suggested a significant association between decreased levels of Akkermansia and inflammatory risk in patients with UA.These findings underscore the potential role of the intestinal microbiota in contributing to inflammation in UA patients.Further work is needed on the mechanism by which the microbiota contributes to inflammatory risk.
基金the the National Natural Science Foundation of China(Study on the Bushen Chinese Medicine on the BMSCs Differentiation,No.81173619,81403479)Natural Science Foundation of the Jiangsu Province of China(Study of Acupuncture on Ischemic Stroke,No.BK20130956)Specialized Research Fund for the Doctoral Program of Higher Education of China(Epigenetic Mechanism of Acupuncture on Brain Injury,No.20133237120002)
文摘OBJECTIVE:To investigate the effect of icariin on proliferation of bone marrow mesenchymal stem cells(BMSCs)in Sprague-Dawley(SD)rats.METHODS:BMSCs were obtained from SD rat bone marrow with differential time adherent method.Its characteristic was identified through differentiation cell surface antigens and the multi-lineage(osteo/adipo/chondo)differentiation potential.3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)method and 5-Bromo-2-Deoxyuridine(Brd U)incorporation were applied to detect the effect of icariin on BMSCs proliferation.Flow cytometry was used to detect proliferation in-dex of BMSCs.The m RNA level and the distribution ofβ-catenin were evaluated by Real-time Polymerase Chain Reaction(PCR)and Immunofluorescent staining respectively.Western blot was used to detect protein expression levels ofβ-catenin,glycogen synthase kinase-3 beta(GSK-3β),phospho-glycogen synthase kinase-3 beta(p GSK-3β)and cyclin D1.RESULTS:Icariin promoted BMSCs proliferation at the concentration of 0.05-2.0 mg/L.The percentage of Brd U positive cells of BMSCs was increased from40.98%to 70.42%,and the proliferation index value was increased from 8.9%to 17.5%with the treatment of 0.05 mg/L icariin,which significance values were both less than 0.05.Compared with the control group,total and nuclearβ-catenin proteins,as well asβ-catenin m RNA expression,were all increased with icariin treatment.Meanwhile,the phosphorylation level of GSK-3βand cyclin D1 protein expressions were also increased in BMSCs with icariin treatment.CONCLUSION:The findings of the present study demonstrated that low dosage of icariin could promote BMSCs proliferation.The activation of Wnt/β-catenin pathways was involved in this process.
基金supported by the China Agriculture Research System(CARS-29-40)
文摘The soil organic matter and nutrients are fundamental for the sustainability of pear production, but little is known about the spatial distribution of soil organic matter and nutrients in a pear orchard. With the soil of the pear （cv. Dangshansu on P.betulifolia Bunge. rootstock） orchard under clean and sod cultivation models as test materials, the experiment was conducted to evaluate spatial variability of soil organic matter （SOM）, total nitrogen （STN）, total phosphorus （STP）, total potassium （STK）, available nitrogen （SAN）, and available potassium （SAK） in and between rows at different soil depths （0-60 cm）. The SOM, STN, STP, STK, SAN and SAK of the different soil layers under the two tillage models were different in the vertical direction. The SOM, STN, STP and SAN in the 0-20 cm soil layer were higher than those in the 20-40 and 40- 60 cm soil layers. The STK of 40-60 cm soil layer was higher than that in the 0-20 and 20-40 cm soil layers. The STK increased with the depth of soil in the vertical direction in the clean cultivated pear orchard. Variability of the SOM, STN, STP, STK, SAN and SAK of sample sites in between rows of the same soil layer was found in the pear orchard soil in the horizontal direction under clean and sod cultivation management systems, except that STK of all sites did not show the difference in identical soil layers in the pear orchard under clean cultivation. The sod cultivation model improved the SOM, STN, and STK in the 0-20 cm soil layer in the pear orchard, and the three components increased by 12.8, 12.7 and 7.3% compared to clean cultivation, respectively. The results can be applicable to plan collection of orchard soil samples, assess orchard soil quality, and improve orchard soil management practices.
基金supported by the Natural Science Foundation Committee Program of China(Grant Nos.1538009 and 51778474)Science and Technology Project of Yunnan Provincial Transportation Department(Grant No.25 of 2018)+1 种基金the Fundamental Research Funds for the Central Universities in China(Grant No.0200219129)Key innovation team program of innovation talents promotion plan by MOST of China(Grant No.2016RA4059)。
文摘The automated interpretation of rock structure can improve the efficiency,accuracy,and consistency of the geological risk assessment of tunnel face.Because of the high uncertainties in the geological images as a result of different regional rock types,as well as in-situ conditions(e.g.,temperature,humidity,and construction procedure),previous automated methods have limited performance in classification of rock structure of tunnel face during construction.This paper presents a framework for classifying multiple rock structures based on the geological images of tunnel face using convolutional neural networks(CNN),namely Inception-ResNet-V2(IRV2).A prototype recognition system is implemented to classify 5 types of rock structures including mosaic,granular,layered,block,and fragmentation structures.The proposed IRV2 network is trained by over 35,000 out of 42,400 images extracted from over 150 sections of tunnel faces and tested by the remaining 7400 images.Furthermore,different hyperparameters of the CNN model are introduced to optimize the most efficient algorithm parameter.Among all the discussed models,i.e.,ResNet-50,ResNet-101,and Inception-v4,Inception-ResNet-V2 exhibits the best performance in terms of various indicators,such as precision,recall,F-score,and testing time per image.Meanwhile,the model trained by a large database can obtain the object features more comprehensively,leading to higher accuracy.Compared with the original image classification method,the sub-image method is closer to the reality considering both the accuracy and the perspective of error divergence.The experimental results reveal that the proposed method is optimal and efficient for automated classification of rock structure using the geological images of the tunnel face.
