Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising techniqu...Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.展开更多
Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producin...Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producing in vitro nervous tissue models.However,the complexity of nervous tissues poses great challenges to 3D-printed bioengineered analogues,which should possess diverse architectural/chemical/electrical functionalities to resemble the native growth microenvironments for functional neural regeneration.In this work,we provide a state-of-the-art review of the latest development of 3D printing for bioengineered neural constructs.Various 3D printing techniques for neural tissue-engineered scaffolds or living cell-laden constructs are summarized and compared in terms of their unique advantages.We highlight the advanced strategies by integrating topographical,biochemical and electroactive cues inside 3D-printed neural constructs to replicate in vivo-like microenvironment for functional neural regeneration.The typical applications of 3D-printed bioengineered constructs for in vivo repair of injured nervous tissues,bio-electronics interfacing with native nervous system,neural-on-chips as well as brain-like tissue models are demonstrated.The challenges and future outlook associated with 3D printing for functional neural constructs in various categories are discussed.展开更多
The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity mate...The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.展开更多
Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong poten...Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong potential to enhance bioprinting's engineering versatility.Coaxial bioprinting assists in the fabrication of complex tissue constructs,by enabling concentric deposition of biomaterials.The fabricated tissue constructs started with simple,tubular vasculature but have been substantially developed to integrate complex cell composition and self-assembly,ECM patterning,controlled release,and multi-material gradient profiles.This review article begins with a brief overview of coaxial printing history,followed by an introduction of crucial engineering components.Afterward,we review the recent progress and untapped potential in each specific organ or biological system,and demonstrate how coaxial bioprinting facilitates the creation of tissue constructs.Ultimately,we conclude that this growing technology will contribute significantly to capabilities in the fields of in vitro modeling,pharmaceutical development,and clinical regenerative medicine.展开更多
The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhil...The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhile,ink with high permeability might facilitate uniform cell growth in biological constructs,which is beneficial to homogeneous tissue repair.Unfortunately,current bioinks are hard to meet these requirements simultaneously in a simple way.Here,based on the fast dynamic crosslinking of aldehyde hyaluronic acid(AHA)/N-carboxymethyl chitosan(CMC)and the slow stable crosslinking of gelatin(GEL)/4-arm poly(ethylene glycol)succinimidyl glutarate(PEG-SG),we present a time-sharing structure-supporting(TSHSP)hydrogel bioink with high permeability,containing 1%AHA,0.75%CMC,1%GEL and 0.5%PEG-SG.The TSHSP hydrogel can facilitate printing with proper viscoelastic property and self-healing behavior.By crosslinking with 4%PEG-SG for only 3 min,the integrity of the cell-laden construct can last for 21 days due to the stable internal and external GEL/PEG-SG networks,and cells manifested long-term viability and spreading morphology.Nerve-like,muscle-like,and cartilage-like in vitro constructs exhibited homogeneous cell growth and remarkable biological specificities.This work provides not only a convenient and practical bioink for tissue engineering,targeted cell therapy,but also a new direction for hydrogel bioink development.展开更多
Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a s...Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a serious problem. A potential solution to this problem is to fabricate skin constructs using biomaterial scaffolds with or without cells. Bioprinting is being applied to address the need for skin tissues suitable for transplantation, and can lead to the development of skin equivalents for wound healing therapy. Here, we summarize strategies of bioprinting and review current advances of bioprinting of skin constructs. There will be challenges on the way of 3D bioprinting for skin regeneration, but we still believe bioprinting will be potential skills for wounds healing in the foreseeable future.展开更多
In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy top...In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy topological spaces is investigated. Properties of a particular such subconstruct of CFTS, the constructof weak fuzzy neighborhood spaces, are discussed in detail. And it is proved that there exists exactly c suchsubconstructs between the subconstruct of weakly induced spaces and CFTS.展开更多
Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation...Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation features(SMFs) for transdisciplinary modeling of these systems. The main challenges of implementation of the toolbox are functional design- and language-independent computational realization of the warehouses, and systematic development and management of the various evolving implements of SMFs(genotypes, phenotypes, and instances). Therefore, an information schema construct(ISC) based approach is proposed to create the schemata of the associated warehouse databases and the above-mentioned SMF implements. ISCs logically arrange the data contents of SMFs in a set of relational tables of varying semantics. In this article we present the ISCs necessary for creation of genotypes and phenotypes. They increase the efficiency of the database development process and make the data relationships transparent. Our follow-up research focuses on the elaboration of the SMF instances based system modeling methodology.展开更多
Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management ...Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management and composing system models. First, we briefly present （1） the general process of pre-embodiment design with SMFs, （2） the procedures of creating genotypes and phenotypes of SMFs, （3） the specific procedure of instantiation of phenotypes of SMFs, and （4） the procedure of system model management and processing. Then, the chunks of information needed for instantiation of phenotypes of SMFs are discussed, and the ISCs designed for instantiation presented. Afterwards, the information management aspects of system modeling are addressed. Methodologically, system modeling involves （1） placement of phenotypes of SMF in the modeling space, （2） combining them towards the desired architecture and operation, （3） assigning values to the parameters and checking the satisfac- tion of constraints, and （4） storing the system model in the SMFs-based warehouse database. The final objective of the reported research is to develop an SMFs-based toolbox to support modeling of cyber-physical systems （CPSs）.展开更多
Neural tissue-like constructs have important application potential in both neural tissue regeneration and individual medical treatment due to the ideal bioenvironment they provide for the growth of primary and stem ce...Neural tissue-like constructs have important application potential in both neural tissue regeneration and individual medical treatment due to the ideal bioenvironment they provide for the growth of primary and stem cells.The biomaterials used in threedimensional(3D)biomanufacturing techniques play a critical role in bioenvironment fabrication.They help optimize the manufacturing techniques and the long-term environment that supports cell structure and nutrient transmission.This paper reviews the current progress being made in the biomaterials utilized in neural cell cultures for in vitro bioenvironment construction.The following four requirements for biomaterials are evaluated:biocompatibility,porosity,supportability,and permeability.This study also summarizes the recent culture models based on primary neural cells.Furthermore,the biomaterials used for neural stem cell constructs are discussed.This study’s results indicate that compared with traditional twodimensional(2D)cultures(with minimal biomaterial requirements),modulus 3D cultures greatly benefit from optimized biomaterials for long-term culturing.展开更多
Berun Holdings Group’s Xilingol Sunite Soda Industry Companystarted constructing a 200 000 t/a coal to mono-ethylene glycol(MEG) project at Xilingol,Inner Mongolia on October 18th. It isthe third coal to MEG project ...Berun Holdings Group’s Xilingol Sunite Soda Industry Companystarted constructing a 200 000 t/a coal to mono-ethylene glycol(MEG) project at Xilingol,Inner Mongolia on October 18th. It isthe third coal to MEG project in Inner Mongolia. The RMB2.3billion project will be constructed in two phases. Phase one is sched-展开更多
To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development...To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.展开更多
Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.T...Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.To contribute to a better understanding of the state of the art of smart techniques for engineering projects,this paper provides a comprehensive review of multi-criteria decision-making(MCDM)techniques,intelligent techniques,and their applications in CEM.First,a comprehensive framework detailing smart technologies for construction projects is developed.Next,the characteristics of CEM are summarized.A bibliometric review is then conducted to investigate the keywords,journals,and clusters related to the application of smart techniques in CEM during 2000-2022.Recent advancements in intelligent techniques are also discussed under the following six topics:①big data technology;②computer vision;③speech recognition;④natural language processing;⑤machine learning;and⑥knowledge representation,understanding,and reasoning.The applications of smart techniques are then illustrated via underground space exploitation.Finally,future research directions for the sustainable development of smart construction are highlighted.展开更多
Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review cover...Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review covers in-situ testing,intelligent monitoring,and geophysical testing methods,highlighting fundamental principles,testing apparatuses,data processing techniques,and engineering applications.The state-of-the-art summary emphasizes not only cutting-edge innovations for complex and harsh environments but also the transformative role of artificial intelligence and machine learning in data interpretations.The integration of big data and advanced algorithms is particularly impactful,enabling the identification,prediction,and mitigation of potential risks in underground projects.Key aspects of the discussion include detection capabilities,method integration,and data convergence of intelligent technologies to drive enhanced safety,operational efficiency,and predictive reliability.The review also examines future trends in intelligent technologies,emphasizing unified platforms that combine multiple methods,real-time data,and predictive analytics.These advancements are shaping the evolution of underground construction and maintenance,aiming for risk-free,high-efficiency underground engineering.展开更多
To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission leve...To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.展开更多
A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This pape...A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.展开更多
The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination ...The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination of microbial technology and a rotary kiln process was employed to expedite the carbonation of steel slag for fixation from cement kiln flue gas.This approach resulted in a significant increase in the CO_(2)-fixation rate,with a CO_(2)-fixation ratio of approximately 10%achieved within 1 h and consistent performance across different seasons throughout the year.Investigation revealed that both the CO_(2)-fixation ratio and the particle fineness are pivotal for increasing the soundness and reactivity of steel slag.When the CO_(2)-fixation ratio exceeds 8%and the specific surface area is at least 300 m2∙kg−1,the soundness issue of steel slag can be effectively addressed,facilitating the safe utilization of steel slag.Residual microbes present in the carbonated steel slag powder act as nucleating sites,increasing the hydration rate of the silicate phases in Portland cement to form more hydration products.Microbial regulation results in the biogenic calcium carbonate having smaller crystal sizes,which facilitates the formation of monocarboaluminate to increase the strength of hardened cement paste.At the same CO_(2)-fixation ratio,microbial mineralized steel slag powder exhibits greater hydration activity than carbonated steel slag powder.With a CO_(2)-fixation ratio of 10%and a specific surface area of 600 m^(2)∙kg^(−1),replacing 30%of cement clinker with microbial mineralized steel slag powder yields an activity index of 87.7%.This study provides a sustainable solution for reducing carbon emissions and safely and efficiently utilizing steel slag in the construction materials sector,while expanding the application scope of microbial technology.展开更多
Network pharmacology has gained widespread application in drug discovery,particularly in traditional Chinese medicine(TCM)research,which is characterized by its“multi-component,multi-target,and multi-pathway”nature....Network pharmacology has gained widespread application in drug discovery,particularly in traditional Chinese medicine(TCM)research,which is characterized by its“multi-component,multi-target,and multi-pathway”nature.Through the integration of network biology,TCM network pharmacology enables systematic evaluation of therapeutic efficacy and detailed elucidation of action mechanisms,establishing a novel research paradigm for TCM modernization.The rapid advancement of machine learning,particularly revolutionary deep learning methods,has substantially enhanced artificial intelligence(AI)technology,offering significant potential to advance TCM network pharmacology research.This paper describes the methodology of TCM network pharmacology,encompassing ingredient identification,network construction,network analysis,and experimental validation.Furthermore,it summarizes key strategies for constructing various networks and analyzing constructed networks using AI methods.Finally,it addresses challenges and future directions regarding cell-cell communication(CCC)-based network construction,analysis,and validation,providing valuable insights for TCM network pharmacology.展开更多
Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable developm...Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable development.This study analyzed the spatiotemporal evolution and landscape pattern change of construction land in the Yangtze River Delta(YRD)region from 1990 to 2018 by integrating Geographical Information System(GIS)spatial analysis and landscape pattern indices,and revealed its driving mechanism by XGBoost and SHapley Additive ex Planations(SHAP).Moreover,we compared the disparities in the core driving factors for construction land evolution in cities with diverse development orientations within the YRD region.Results show that:1)development intensity of construction land continued to increase from 7.54%in 1990 to 13.44%in 2018,primarily by occupying farmland.The landscape fragmentation of construction land in the YRD region decreased,and landscape dominance increased.Spatially,the eastern part of the YRD exhibits a high degree of spatial agglomeration of construction land,whereas the western part shows a high degree of fragmentation,revealing distinct spatial gradient differentiation characteristics.The landscape dominance of the construction land in the eastern region of the YRD is higher than that in the western and northern regions.2)Transportation and infrastructure exert the highest contribution rate on development intensity changes of construction land in the YRD.The industrial structure significantly influences the conversion of farmland to construction land.Additionally,infrastructure plays a crucial role in shaping the spatial agglomeration patterns of construction land.Population distribution is the dominant factor determining the regularity of the landscape shape of construction land.3)The core driving factors for the development intensity of construction land in central cities primarily lies in transportation,whereas for non-central cities,besides transportation,the year-end balance of per capita savings deposits of urban and rural residents also play a significant role.The area change of construction land occupying farmland in central and non-central cities is mainly driven by industrial structure and economic level,respectively.This study informs refined spatial optimization and regional high-quality integrated development.展开更多
文摘Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.
基金financially supported by the National Natural Science Foundation of China (52125501)OPEN Project (BHJ17C019)+4 种基金the Key Research Project of Shaanxi Province (2021LLRH-08)the Program for Innovation Team of Shaanxi Province (2023-CX-TD-17)the Natural Science Basic Research Program of Shaanxi Province (2023-JCQN-0543)the China Postdoctoral Science Foundation (2021M702597)the Fundamental Research Funds for the Central Universities
文摘Three-dimensional(3D)printing technology has opened a new paradigm to controllably and reproducibly fabricate bioengineered neural constructs for potential applications in repairing injured nervous tissues or producing in vitro nervous tissue models.However,the complexity of nervous tissues poses great challenges to 3D-printed bioengineered analogues,which should possess diverse architectural/chemical/electrical functionalities to resemble the native growth microenvironments for functional neural regeneration.In this work,we provide a state-of-the-art review of the latest development of 3D printing for bioengineered neural constructs.Various 3D printing techniques for neural tissue-engineered scaffolds or living cell-laden constructs are summarized and compared in terms of their unique advantages.We highlight the advanced strategies by integrating topographical,biochemical and electroactive cues inside 3D-printed neural constructs to replicate in vivo-like microenvironment for functional neural regeneration.The typical applications of 3D-printed bioengineered constructs for in vivo repair of injured nervous tissues,bio-electronics interfacing with native nervous system,neural-on-chips as well as brain-like tissue models are demonstrated.The challenges and future outlook associated with 3D printing for functional neural constructs in various categories are discussed.
基金This work was supported by the National Key Fundamental R&D Program of China (Grant No. G20000263).
文摘The optimization approach based on the biological evolution principle is used to con-struct the heat transport paths for volume-to-point problem. The transport paths are constructed by inserting high conductivity materials in the heat conduction domain where uniform or nonuniform heat sources exist. In the bionic optimization process, the optimal constructs of the high conductiv-ity material are obtained by numerically simulating the evolution and degeneration process ac-cording to the uniformity principle of the temperature gradient. Finally, preserving the features of the optimal constructs, the constructs are regularized for the convenience of engineering manu-facture. The results show that the construct obtained by bionic optimization is approximate to that obtained by the tree-network constructal theory when the heat conduction is enhanced for the do-main with a uniform heat source and high conductivity ratio of the inserting material to the sub-strate, the high conductivity materials are mainly concentrated on the heat outlet for the case with a uniform heat source and low thermal conductivity ratio, and for the case with nonuniform heat sources, the high conductivity material is concentrated in the heat source regions and construacts several highly effective heat transport paths to connect the regions to the outlet.
基金We thank Utah State University's College of Engineering Undergraduate Research Program(EURP)for supporting Andrew Kjar and Bailey McFarland.
文摘Bioprinting is a rapidly developing technology for the precise design and manufacture of tissues in various biological systems or organs.Coaxial extrusion bioprinting,an emergent branch,has demonstrated a strong potential to enhance bioprinting's engineering versatility.Coaxial bioprinting assists in the fabrication of complex tissue constructs,by enabling concentric deposition of biomaterials.The fabricated tissue constructs started with simple,tubular vasculature but have been substantially developed to integrate complex cell composition and self-assembly,ECM patterning,controlled release,and multi-material gradient profiles.This review article begins with a brief overview of coaxial printing history,followed by an introduction of crucial engineering components.Afterward,we review the recent progress and untapped potential in each specific organ or biological system,and demonstrate how coaxial bioprinting facilitates the creation of tissue constructs.Ultimately,we conclude that this growing technology will contribute significantly to capabilities in the fields of in vitro modeling,pharmaceutical development,and clinical regenerative medicine.
基金This work was supported by the National Natural Science Foundation of China[grant number 52075285]the Science and Technology Program of Guangzhou,China[grant number 201604040002]+1 种基金the Key-Area Research and Development Program of Guangdong Province,China[grant number 2020B090923003]the Key Research and Development Projects of People’s Liberation Army,China[grant number.BWS17J036].
文摘The ready-to-use,structure-supporting hydrogel bioink can shorten the time for ink preparation,ensure cell dispersion,and maintain the preset shape/microstructure without additional assistance during printing.Meanwhile,ink with high permeability might facilitate uniform cell growth in biological constructs,which is beneficial to homogeneous tissue repair.Unfortunately,current bioinks are hard to meet these requirements simultaneously in a simple way.Here,based on the fast dynamic crosslinking of aldehyde hyaluronic acid(AHA)/N-carboxymethyl chitosan(CMC)and the slow stable crosslinking of gelatin(GEL)/4-arm poly(ethylene glycol)succinimidyl glutarate(PEG-SG),we present a time-sharing structure-supporting(TSHSP)hydrogel bioink with high permeability,containing 1%AHA,0.75%CMC,1%GEL and 0.5%PEG-SG.The TSHSP hydrogel can facilitate printing with proper viscoelastic property and self-healing behavior.By crosslinking with 4%PEG-SG for only 3 min,the integrity of the cell-laden construct can last for 21 days due to the stable internal and external GEL/PEG-SG networks,and cells manifested long-term viability and spreading morphology.Nerve-like,muscle-like,and cartilage-like in vitro constructs exhibited homogeneous cell growth and remarkable biological specificities.This work provides not only a convenient and practical bioink for tissue engineering,targeted cell therapy,but also a new direction for hydrogel bioink development.
基金grants from Administration of Traditional Chinese Medicine of Sichuan(A2016N48)National Natural Science Foundation of China(81171780)+4 种基金Foundation for Distinguished Young Scientists of Sichuan Province(2016JQ0020)Project sub topics of the National 863 Project(2015AA020303)Scientific research fund for outstanding young scholars of Sichuan University(2014SCU04A12)Sichuan province science and technology support plan(2015SZ0049)Science and technology support program of Sichuan Province(2015FZ0040).
文摘Extensive burns and full-thickness skin wounds are difficult to repair. Autologous split-thickness skin graft (ASSG) is still used as the gold standard in the clinic. However, the shortage of donor skin tissues is a serious problem. A potential solution to this problem is to fabricate skin constructs using biomaterial scaffolds with or without cells. Bioprinting is being applied to address the need for skin tissues suitable for transplantation, and can lead to the development of skin equivalents for wound healing therapy. Here, we summarize strategies of bioprinting and review current advances of bioprinting of skin constructs. There will be challenges on the way of 3D bioprinting for skin regeneration, but we still believe bioprinting will be potential skills for wounds healing in the foreseeable future.
基金This work was supported by the National Natural Science Foundation of China,Fok Ying Tung Education foundation and the ScienceTechnology Foundation of Sichuan Province for Young Scholars.
文摘In this paper, the concretely both reflective and coreflective subconstructs of the construct CFTSof Chang fuzzy topological spaces are characterized and their relationship to such subconstructs of stratifiedfuzzy topological spaces is investigated. Properties of a particular such subconstruct of CFTS, the constructof weak fuzzy neighborhood spaces, are discussed in detail. And it is proved that there exists exactly c suchsubconstructs between the subconstruct of weakly induced spaces and CFTS.
文摘Our long-term objective is to develop a software toolbox for pre-embodiment design of complex and heterogeneous systems, such as cyber-physical systems. The novelty of this toolbox is that it uses system manifestation features(SMFs) for transdisciplinary modeling of these systems. The main challenges of implementation of the toolbox are functional design- and language-independent computational realization of the warehouses, and systematic development and management of the various evolving implements of SMFs(genotypes, phenotypes, and instances). Therefore, an information schema construct(ISC) based approach is proposed to create the schemata of the associated warehouse databases and the above-mentioned SMF implements. ISCs logically arrange the data contents of SMFs in a set of relational tables of varying semantics. In this article we present the ISCs necessary for creation of genotypes and phenotypes. They increase the efficiency of the database development process and make the data relationships transparent. Our follow-up research focuses on the elaboration of the SMF instances based system modeling methodology.
文摘Complementing our previous publications, this paper presents the information schema constructs （ISCs） that underpin the programming of specific system manifestation feature （SMF） orientated information management and composing system models. First, we briefly present （1） the general process of pre-embodiment design with SMFs, （2） the procedures of creating genotypes and phenotypes of SMFs, （3） the specific procedure of instantiation of phenotypes of SMFs, and （4） the procedure of system model management and processing. Then, the chunks of information needed for instantiation of phenotypes of SMFs are discussed, and the ISCs designed for instantiation presented. Afterwards, the information management aspects of system modeling are addressed. Methodologically, system modeling involves （1） placement of phenotypes of SMF in the modeling space, （2） combining them towards the desired architecture and operation, （3） assigning values to the parameters and checking the satisfac- tion of constraints, and （4） storing the system model in the SMFs-based warehouse database. The final objective of the reported research is to develop an SMFs-based toolbox to support modeling of cyber-physical systems （CPSs）.
基金supported by 111 Project(Grant No.B17026)the National Nature Science Foundation of China(Grant No.31700928)the Chinese Postdoctoral Science Foundation(Grant No.2017M610881)
文摘Neural tissue-like constructs have important application potential in both neural tissue regeneration and individual medical treatment due to the ideal bioenvironment they provide for the growth of primary and stem cells.The biomaterials used in threedimensional(3D)biomanufacturing techniques play a critical role in bioenvironment fabrication.They help optimize the manufacturing techniques and the long-term environment that supports cell structure and nutrient transmission.This paper reviews the current progress being made in the biomaterials utilized in neural cell cultures for in vitro bioenvironment construction.The following four requirements for biomaterials are evaluated:biocompatibility,porosity,supportability,and permeability.This study also summarizes the recent culture models based on primary neural cells.Furthermore,the biomaterials used for neural stem cell constructs are discussed.This study’s results indicate that compared with traditional twodimensional(2D)cultures(with minimal biomaterial requirements),modulus 3D cultures greatly benefit from optimized biomaterials for long-term culturing.
文摘Berun Holdings Group’s Xilingol Sunite Soda Industry Companystarted constructing a 200 000 t/a coal to mono-ethylene glycol(MEG) project at Xilingol,Inner Mongolia on October 18th. It isthe third coal to MEG project in Inner Mongolia. The RMB2.3billion project will be constructed in two phases. Phase one is sched-
文摘To fully leverage the advantages of mechanization and informatization in tunnel boring machine(TBM)operations,the authors aim to promote the advancement of tunnel construction technology toward intelligent development.This involved exploring the deep integration of next-generation artificial intelligence technologies,such as sensing technology,automatic control technology,big data technology,deep learning,and machine vision,with key operational processes,including TBM excavation,direction adjustment,step changes,inverted arch block assembly,material transportation,and operation status assurance.The results of this integration are summarized as follows.(1)TBM key excavation parameter prediction algorithm was developed with an accuracy rate exceeding 90%.The TBM intelligent step-change control algorithm,based on machine vision,achieved an image segmentation accuracy rate of 95%and gripper shoe positioning error of±5 mm.(2)An automatic positioning system for inverted arch blocks was developed,enabling real-time perception of the spatial position and deviation during the assembly process.The system maintains an elevation positioning deviation within±3 mm and a horizontal positioning deviation within±10 mm,reducing the number of surveyors in each work team.(3)A TBM intelligent rail transportation system that achieves real-time human-machine positioning,automatic switch opening and closing,automatic obstacle avoidance,intelligent transportation planning,and integrated scheduling and command was designed.Each locomotive formation reduces one shunter and improves comprehensive transportation efficiency by more than 20%.(4)Intelligent analysis and prediction algorithms were developed to monitor and predict the trends of the hydraulic and gear oil parameters in real time,enhancing the proactive maintenance and system reliability.
基金funded by the project of Guangdong Provincial Basic and Applied Basic Research Fund Committee(2022A1515240073)the Pearl River Talent Recruitment Program(2019CX01G338),Guangdong Province.
文摘Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.To contribute to a better understanding of the state of the art of smart techniques for engineering projects,this paper provides a comprehensive review of multi-criteria decision-making(MCDM)techniques,intelligent techniques,and their applications in CEM.First,a comprehensive framework detailing smart technologies for construction projects is developed.Next,the characteristics of CEM are summarized.A bibliometric review is then conducted to investigate the keywords,journals,and clusters related to the application of smart techniques in CEM during 2000-2022.Recent advancements in intelligent techniques are also discussed under the following six topics:①big data technology;②computer vision;③speech recognition;④natural language processing;⑤machine learning;and⑥knowledge representation,understanding,and reasoning.The applications of smart techniques are then illustrated via underground space exploitation.Finally,future research directions for the sustainable development of smart construction are highlighted.
基金supported by Ministry of Education of Singapore,under Academic Research Fund Tier 1(Grant Number RG143/23).
文摘Scientific and technological advancements are rapidly transforming underground engineering,shifting from labor-intensive,time-consuming methods to automated,real-time systems.This timely and comprehensive review covers in-situ testing,intelligent monitoring,and geophysical testing methods,highlighting fundamental principles,testing apparatuses,data processing techniques,and engineering applications.The state-of-the-art summary emphasizes not only cutting-edge innovations for complex and harsh environments but also the transformative role of artificial intelligence and machine learning in data interpretations.The integration of big data and advanced algorithms is particularly impactful,enabling the identification,prediction,and mitigation of potential risks in underground projects.Key aspects of the discussion include detection capabilities,method integration,and data convergence of intelligent technologies to drive enhanced safety,operational efficiency,and predictive reliability.The review also examines future trends in intelligent technologies,emphasizing unified platforms that combine multiple methods,real-time data,and predictive analytics.These advancements are shaping the evolution of underground construction and maintenance,aiming for risk-free,high-efficiency underground engineering.
基金supported by the Energy Foundation(No.G-2203-33693).
文摘To understand the smoke level and NO_(x)emission characteristics of in-use construction machinery in Beijing,we selected 905 construction machines in Beijing from August 2022 to April 2023 to monitor the emission level of smoke and NO_(x).The exhaust smoke level and excessive emission situation of different machinery types were identified,and their NO_(x)emission levels were monitored according to the free acceleration method.We investigated the correlation of NO_(x)and smoke emission,and proposed suggestions for controlling pollution discharge from construction machinery in the future.The results show that the exhaust smoke level was 0–2.62 m^(−1),followed a log-normal distribution(μ=-1.73,δ=1.09,R^(2)=0.99),with a 5.64%exceedance rate.Differenceswere observed amongmachinery types,with low-power engine forklifts showing higher smoke levels.The NO_(x)emission range was 71–1516 ppm,followed a normal distribution(μ=565.54,δ=309.51,R^(2)=0.83).Differences among machinery types were relatively small.Engine rated net power had the most significant impact on NO_(x)emissions.Thus,NO_(x)emissions from construction machinery need further attention.Furthermore,we found a weak negative correlation(p<0.05)between the emission level of smoke and NO_(x),that is the synergic emission reduction effect is poor,emphasizing the need for NO_(x)emission limits.In the future,the oversight in Beijing should prioritize phasing out ChinaⅠand ChinaⅡmachinery,and monitor emissions from highpower engine ChinaⅢmachinery.
文摘A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.
基金sponsored by the National Key Research and Development Program of China(2021YFB3802000 and 2021YFB3802004)the National Natural Science Foundation of China(52172016).
文摘The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination of microbial technology and a rotary kiln process was employed to expedite the carbonation of steel slag for fixation from cement kiln flue gas.This approach resulted in a significant increase in the CO_(2)-fixation rate,with a CO_(2)-fixation ratio of approximately 10%achieved within 1 h and consistent performance across different seasons throughout the year.Investigation revealed that both the CO_(2)-fixation ratio and the particle fineness are pivotal for increasing the soundness and reactivity of steel slag.When the CO_(2)-fixation ratio exceeds 8%and the specific surface area is at least 300 m2∙kg−1,the soundness issue of steel slag can be effectively addressed,facilitating the safe utilization of steel slag.Residual microbes present in the carbonated steel slag powder act as nucleating sites,increasing the hydration rate of the silicate phases in Portland cement to form more hydration products.Microbial regulation results in the biogenic calcium carbonate having smaller crystal sizes,which facilitates the formation of monocarboaluminate to increase the strength of hardened cement paste.At the same CO_(2)-fixation ratio,microbial mineralized steel slag powder exhibits greater hydration activity than carbonated steel slag powder.With a CO_(2)-fixation ratio of 10%and a specific surface area of 600 m^(2)∙kg^(−1),replacing 30%of cement clinker with microbial mineralized steel slag powder yields an activity index of 87.7%.This study provides a sustainable solution for reducing carbon emissions and safely and efficiently utilizing steel slag in the construction materials sector,while expanding the application scope of microbial technology.
基金supported by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang(No.2024C03106,X.F.)the National Natural Science Foundation of China(No.82474160,X.S.)+2 种基金the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(No.LBZ24H270001,X.P.)the Major Joint Projects Supported by the National Administration of TCM and Zhejiang Province(No.GZY-ZI-KJ-23037,X.P.)the Ningbo Top Medical and Health Research Program(No.2022030309,X.P.)。
文摘Network pharmacology has gained widespread application in drug discovery,particularly in traditional Chinese medicine(TCM)research,which is characterized by its“multi-component,multi-target,and multi-pathway”nature.Through the integration of network biology,TCM network pharmacology enables systematic evaluation of therapeutic efficacy and detailed elucidation of action mechanisms,establishing a novel research paradigm for TCM modernization.The rapid advancement of machine learning,particularly revolutionary deep learning methods,has substantially enhanced artificial intelligence(AI)technology,offering significant potential to advance TCM network pharmacology research.This paper describes the methodology of TCM network pharmacology,encompassing ingredient identification,network construction,network analysis,and experimental validation.Furthermore,it summarizes key strategies for constructing various networks and analyzing constructed networks using AI methods.Finally,it addresses challenges and future directions regarding cell-cell communication(CCC)-based network construction,analysis,and validation,providing valuable insights for TCM network pharmacology.
基金Under the auspices of the National Natural Science Foundation of China(No.42301470,42171389)。
文摘Scientifically understanding the evolution of urbanization and analysing the coupling mechanism of human-land systems are important foundations for solving spatial conflicts and promoting regional sustainable development.This study analyzed the spatiotemporal evolution and landscape pattern change of construction land in the Yangtze River Delta(YRD)region from 1990 to 2018 by integrating Geographical Information System(GIS)spatial analysis and landscape pattern indices,and revealed its driving mechanism by XGBoost and SHapley Additive ex Planations(SHAP).Moreover,we compared the disparities in the core driving factors for construction land evolution in cities with diverse development orientations within the YRD region.Results show that:1)development intensity of construction land continued to increase from 7.54%in 1990 to 13.44%in 2018,primarily by occupying farmland.The landscape fragmentation of construction land in the YRD region decreased,and landscape dominance increased.Spatially,the eastern part of the YRD exhibits a high degree of spatial agglomeration of construction land,whereas the western part shows a high degree of fragmentation,revealing distinct spatial gradient differentiation characteristics.The landscape dominance of the construction land in the eastern region of the YRD is higher than that in the western and northern regions.2)Transportation and infrastructure exert the highest contribution rate on development intensity changes of construction land in the YRD.The industrial structure significantly influences the conversion of farmland to construction land.Additionally,infrastructure plays a crucial role in shaping the spatial agglomeration patterns of construction land.Population distribution is the dominant factor determining the regularity of the landscape shape of construction land.3)The core driving factors for the development intensity of construction land in central cities primarily lies in transportation,whereas for non-central cities,besides transportation,the year-end balance of per capita savings deposits of urban and rural residents also play a significant role.The area change of construction land occupying farmland in central and non-central cities is mainly driven by industrial structure and economic level,respectively.This study informs refined spatial optimization and regional high-quality integrated development.
