检索结果-南通市图书馆

Journal of Animal Science and Biotechnology 2024年第3期15卷 1119-1130页

作者： Tae Hong Kang sang In lee Department of Animal Science and Biotechnology Kyungpook National UniversitySangjuGyeong‑Sangbuk‑Do 37224Republic of Korea Research Institute for Innovative Animal Science Kyungpook National University37224SangjuGyeong‑Sangbuk‑DoRepublic of Korea

Background Deoxynivalenol(DON)is a mycotoxin that has received recognition worldwide because of its ability to cause growth delay,nutrient malabsorption,weight loss,emesis,and a reduction of feed intake in livestock.Since DON-contaminated feedstuff is absorbed in the gastrointestinal tract,we used chicken organoids to assess the DON-induced dysfunction of the small intestine.Results We established a culture system using chicken organoids and characterized the organoids at passages 1 and 10.We confirmed the mRNA expression levels of various cell markers in the organoids,such as KI67,leucine-rich repeat containing G protein-coupled receptor 5(Lgr5),mucin 2(MUC2),chromogranin A(CHGA),cytokeratin 19(CK19),lysozyme(LYZ),and microtubule-associated doublecortin-like kinase 1(DCLK1),and compared the results to those of the small intestine.Our results showed that the organoids displayed functional similarities in permeability compared to the small intestine.DON damaged the tight junctions of the organoids,which resulted in increased permeability.Conclusions Our organoid culture displayed topological,genetic,and functional similarities with the small intes-tine cells.Based on these similarities,we confirmed that DON causes small intestine dysfunction.Chicken organoids offer a practical model for the research of harmful substances.

关键词： Barrier function Deoxynivalenol Organoids

Weighted Forwarding in Graph Convolution Networks for Recommendation Information Systems

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 1897-1914页

作者： sang-min lee Namgi Kim Department of Computer Science Kyonggi UniversitySuwonKorea

Recommendation Information Systems(RIS)are pivotal in helping users in swiftly locating desired content from the vast amount of information available on the Internet.Graph Convolution Network(GCN)algorithms have been employed to implement the RIS efficiently.However,the GCN algorithm faces limitations in terms of performance enhancement owing to the due to the embedding value-vanishing problem that occurs during the learning process.To address this issue,we propose a Weighted Forwarding method using the GCN(WF-GCN)algorithm.The proposed method involves multiplying the embedding results with different weights for each hop layer during graph learning.By applying the WF-GCN algorithm,which adjusts weights for each hop layer before forwarding to the next,nodes with many neighbors achieve higher embedding values.This approach facilitates the learning of more hop layers within the GCN framework.The efficacy of the WF-GCN was demonstrated through its application to various datasets.In the MovieLens dataset,the implementation of WF-GCN in LightGCN resulted in significant performance improvements,with recall and NDCG increasing by up to+163.64%and+132.04%,respectively.Similarly,in the Last.FM dataset,LightGCN using WF-GCN enhanced with WF-GCN showed substantial improvements,with the recall and NDCG metrics rising by up to+174.40%and+169.95%,respectively.Furthermore,the application of WF-GCN to Self-supervised Graph Learning(SGL)and Simple Graph Contrastive Learning(SimGCL)also demonstrated notable enhancements in both recall and NDCG across these datasets.

关键词： Deep learning graph neural network graph convolution network graph convolution network model learning method recommender information systems

Health risks of pest control and disinfection workers after the COVID-19 outbreak in South Korea

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 350-363页

作者： Yun-Hee Choi Da-An Huh Lita Kim sang ji lee Kyong Whan Moon Department of Health and Safety Convergence Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea BK21 FOUR R&E Center for Learning Health System Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Institute of Sciences Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea Department of Health and Environmental Science Korea UniversityAnam-ro 145Seongbuk-guSeoul 02841South Korea

The exposure patterns of pest control and disinfection workers have changed after the coronavirus disease 2019(COVID-19)outbreak,but the health risks of chemical exposure have not been assessed.We identified these workers’chemical exposure patterns and risks before and after the COVID-19 outbreak.We used data conducted between 2018(pre-pandemic)and 2021(post-pandemic)from three-year cross-sectional surveys on pest control and disinfection workers.Inhalation and dermal exposure concentrations were estimated using equations based on a biocidal product risk assessment model from the Korean National Institute of Environmental Research.The non-carcinogenic and carcinogenic risks of chemicals were calculated using the United States Environmental Protection Agency risk assessment model.We found that the annual work frequency(50^(th)percentile)of foggers using disinfectants increased the most among all the work types,from 140 uses/year to 176 uses/year after the COVID-19 outbreak.Moreover,all chemicals’non-carcinogenic and carcinogenic risks increased regardless of exposure routes.In the worst scenario(95^(th)percentile),the margin of exposure for citric acid,benzethonium chloride,benzyl-C12-16-alkyldimethyl chlorides,and sodium chlorite of inhalation exposure,and isopropyl alcohol and benzyl-C12-16-alkyldimethyl chlorides of dermal exposure were acceptable(>100)before the COVID-19outbreak but became unacceptable(10^(-6))before and after the COVID-19 outbreak but comparatively high after the COVID-19 outbreak.Additionally,significantly more workers experienced health symptoms after the COVID-19outbreak(p<0.05),with the most common being muscle lethargy(31%),skin/face stinging(28.7%),and breath shortness/neck pain(24.1%).

关键词： Biocide Disinfection Health risk assessment Occupational exposure Pest control

Effect of characteristics and distribution of Mg_(17)Al_(12)precipitates on tensile and bending properties of high-Al-containing Mg alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第2期12卷 779-793页

作者： Sumi Jo Gyo Myeong lee Jong Un lee Young Min Kim sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Department of Magnesium Korea Institute of Materials ScienceChangwon 51508Republic of Korea

This study investigates the effect of characteristics and distribution of Mg_(17)Al_(12)precipitates on the uniaxial tensile and three-point bending properties of extruded Mg alloys containing high Al contents.The extruded Mg–9Al–1Zn–0.3Mn(AZ91)alloy contains lamellar-structured Mg_(17)Al_(12)discontinuous precipitates along the grain boundaries,which are formed via static precipitation during natural air cooling.The extruded Mg–11Al–1Zn–0.3Mn(AZ111)alloy contains spherical Mg_(17)Al_(12)precipitates at the grain boundaries and inside the grains,which are formed via dynamic precipitation during extrusion.Due to inhomogeneous distribution of precipitates,the AZ111 alloy consists of two different precipitate regions:precipitate-rich region with numerous precipitates and finer grains and precipitate-scarce region with a few precipitates and coarser grains.The AZ111 alloy exhibits a higher tensile strength than the AZ91 alloy because its smaller grain size and more abundant precipitates result in stronger grain-boundary hardening and precipitation hardening effects,respectively.However,the tensile elongation of the AZ111 alloy is lower than that of the AZ91 alloy because the weak cohesion between the dynamic precipitates and the matrix facilitates the crack initiation and propagation.During bending,a macrocrack initiates on the outer surface of bending specimen in both alloys.The AZ111 alloy exhibits higher bending yield strength and lower failure bending strain than the AZ91 alloy.The bending specimens of the AZ91 alloy have similar bending formability,whereas those of the AZ111 alloy exhibit considerable differences in bending formability and crack propagation behavior,depending on the distribution and number density of precipitates in the specimen.In bending specimens of the AZ111 alloy,it is found that the failure bending strain(ε_(f,bending))is inversely proportional to the area fraction of precipitates in the outer zone of bending specimen(A_(ppt)),with a relationship ofε_(f,bending)=–0.1A_(ppt)+5.86.

关键词： Mg–Al alloy Extrusion Bending Precipitation Microstructure

Enhanced prediction of anisotropic deformation behavior using machine learning with data augmentation

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第1期12卷 186-196页

作者： Sujeong Byun Jinyeong Yu Seho Cheon Seong Ho lee sung Hyuk Park Taekyung lee School of Mechanical Engineering Pusan National UniversityBusan 46241South Korea School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566South Korea

Mg alloys possess an inherent plastic anisotropy owing to the selective activation of deformation mechanisms depending on the loading condition.This characteristic results in a diverse range of flow curves that vary with a deformation condition.This study proposes a novel approach for accurately predicting an anisotropic deformation behavior of wrought Mg alloys using machine learning(ML)with data augmentation.The developed model combines four key strategies from data science:learning the entire flow curves,generative adversarial networks(GAN),algorithm-driven hyperparameter tuning,and gated recurrent unit(GRU)architecture.The proposed model,namely GAN-aided GRU,was extensively evaluated for various predictive scenarios,such as interpolation,extrapolation,and a limited dataset size.The model exhibited significant predictability and improved generalizability for estimating the anisotropic compressive behavior of ZK60 Mg alloys under 11 annealing conditions and for three loading directions.The GAN-aided GRU results were superior to those of previous ML models and constitutive equations.The superior performance was attributed to hyperparameter optimization,GAN-based data augmentation,and the inherent predictivity of the GRU for extrapolation.As a first attempt to employ ML techniques other than artificial neural networks,this study proposes a novel perspective on predicting the anisotropic deformation behaviors of wrought Mg alloys.

关键词： Plastic anisotropy Compression Annealing Machine learning Data augmentation

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第3期12卷 841-872页

作者： Jong Un lee Hyun Ji Kim sang-Cheol Jin Ye Jin Kim Young Min Kim Bong Sun You Jun Ho Bae sung Hyuk Park Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Missile Research Institute Agency for Defense DevelopmentDaejeon 34060Republic of Korea

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials Science.SEN alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical properties.Their main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening effects.These enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in extrudability.Consequently,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

关键词： SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties Extrudability.

Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1584-1592页

作者： Jong Mi Park Masoud Rahmati sang Chul lee Jae Il Shin Yong Wook Kim Department and Research Institute of Rehabilitation Medicine Yonsei University College of MedicineSeoulSouth Korea Department of Physical Education and Sport Sciences Faculty of Literature and Human SciencesLorestan UniversityKhoramabadIran Department of Pediatrics Yonsei University College of MedicineSeoulSouth Korea

Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgro

关键词： animal animal experimentation mesenchymal stem cells models Parkinson’s disease stem cell transplantation

Cell architecture designs towards high-energy-density microscale energy storage devices

在线全文

学校读者我要写书评

暂无评论

Nano Research Energy 2024年第2期3卷 69-82页

作者： Kwon-Hyung lee sang-Young lee Ulsan Advanced Energy Technology R&D Center Korea Institute of Energy Research(KIER)Ulsan44776Republic of Korea Department of Chemical and Biomolecular Engineering Yonsei UniversitySeoul03722Republic of Korea

The rapid growth of miniaturized electronics has led to an urgent demand for microscale energy storage devices(MESDs)to sustainably power the micro electronic devices.However,most MESDs reported to date have suffered from the limited energy densities and shape versatility compared to conventional large-scale counterparts because of the architectural constraints inherent in microfabrication-based cell manufacturing and cell dimension/structure.This review addresses the cell architecture design for MESDs that can achieve both miniaturization and high energy density.We provide a comprehensive overview of five types of cell architectures of MESDs and their fabrication techniques.In addition,to enable practical applications of MESDs,several cell design approaches are presented with the aim of minimizing the inactive parts of the cell and maximizing the performance metrics of MESDs.Finally,we discuss development direction and outlook of MESDs with a focus on materials chemistry,energy-dense electrochemical systems,and cell performance normalization,which will help to expand their applications and manufacturing scalability.

关键词： microscale energy storage device cell architecture microfabrication miniaturization high-energy-density

Effect of organic mineral supplementation in reducing oxidative stress in Holstein calves during short‑term heat stress and recovery conditions

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2024年第2期15卷 812-825页

作者： A-Rang Son Seon-Ho Kim Mahfuzul Islam Michelle Miguel Ye Pyae Naing sang-Suk lee Ruminant Nutrition and Anaerobe Laboratory Department of Animal Science and TechnologySunchon National UniversitySuncheon 57922Korea Department of Microbiology and Parasitology Sher-e-Bangla Agricultural UniversityDhaka 1207Bangladesh

Background This study investigated the effects of inorganic and organic minerals on physiological responses,oxidative stress reduction,and rumen microbiota in Holstein bull calves(123.81±9.76 kg;5 months old)during short-term heat stress(HS)and recovery periods.Eight Holstein calves were randomly assigned to four treatment groups:no mineral supplementation(Con),inorganic minerals(IM),organic minerals(OM),and high-concentration organic minerals(HOM)and two thermal environments(HS and recovery)using 4×2 factorial arrangement in a crossover design of four periods of 35 d.Calves were maintained in a temperature-controlled barn.The experimental period consisted of 14 d of HS,14 d of recovery condititon,and a 7-d washing period.Results Body temperature and respiration rate were higher in HS than in the recovery conditions(P0.05).The principal coordinate analysis represented that the overall rumen microbiota was not influenced by mineral supplementation;however,temperature-induced microbial structure shifts were indicated(PERMANOVA:P<0.05).At the phylum level,Firmicutes and Actinobacteria decreased,whereas Fibrobacteres,Spirochaetes,and Tenericutes increased(P<0.05),under HS conditions.The genus Treponema increased under HS conditions,while Christensenella was higher in recovery conditions(P<0.05).Conclusion HOM supplementation during HS reduced cor

关键词： Antioxidant status Heat stress Holstein bull calves Organic mineral supplementation Oxidative stress

Vertical plane depth-resolved surface potential and carrier separation characteristics in flexible CZTSSe solar cells with over 12% efficiency

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第3期6卷 36-52页

作者： Dae-Ho Son Ha Kyung Park Dae-Hwan Kim Jin-Kyu Kang Shi-Joon sung Dae-Kue Hwang Jaebaek lee Dong-Hwan Jeon Yunae Cho William Jo Taeseon lee JunHo Kim sang-Hoon Nam Kee-Jeong Yang Division of Energy Technology DGISTDaeguRepublic of Korea Research Center for Thin Film Solar Cells DGISTDaeguRepublic of Korea Department of Physics Ewha Womans UniversitySeoulRepublic of Korea Department of Physics Incheon National UniversityIncheonRepublic of Korea Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

Cu2ZnSn(S,Se)4(CZTSSe)solar cells have resource distribution and economic advantages.The main cause of their low efficiency is carrier loss resulting from recombination of photo-generated electron and hole.To overcome this,it is important to understand their electron-hole behavior characteristics.To determine the carrier separation characteristics,we measured the surface potential and the local current in terms of the absorber depth.The elemental variation in the intragrains(IGs)and at the grain boundaries(GBs)caused a band edge shift and bandgap(Eg)change.At the absorber surface and subsurface,an upward Ec and Ev band bending structure was observed at the GBs,and the carrier separation was improved.At the absorber center,both upward Ec and Ev and downward Ec-upward Ev band bending structures were observed at the GBs,and the carrier separation was degraded.To improve the carrier separation and suppress carrier recombination,an upward Ec and Ev band bending structure at the GBs is desirable.

关键词： carrier separation CZTSSe flexible solar cell local current surface potential