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Effect of Powder Particle Shape on the Properties of In Situ Ti–TiB Composite Materials Produced by Selective Laser Melting

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Journal of Materials Science & Technology 2015年第10期31卷 1001-1005页

作者： Hooyar Attar Konda G.Prashanth Lai-Chang Zhang mariana calin Ilya V.Okulov Sergio Scudino Chao Yang Jürgen Eckert School of Engineering Edith Cowan University IFW Dresden Institute for Complex Materials TU Dresden Institute of Materials Science National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of Technology

This work studied the preparation of starting powder mixture influenced by milling time and its effect on the particle morphology （especially the shape） and, consequently, density and compression properties of in situ Ti-TiB composite materials produced by selective laser melting （SLM） technology. Starting powder composite system was prepared by mixing 95 wt% commercially pure titanium （CP-Ti） and 5 wt% titanium diboride （TiB2） powders and subsequently milled for two different times （i.e. 2 h and 4 h）. The milled powder mixtures after 2 h and 4 h show nearly spherical and irregular shape, respectively. Subsequently, the resultant Ti-5 wt% TiB2 powder mixtures were used for SLM processing. Scanning electron microscopy image of the SLM-processed Ti-TiB composite samples show needle-shape TiB phase distributed across the Ti matrix, which is the product of an in-situ chemical reaction between Ti and TiB2 during SLM. The Ti-TiB composite samples prepared from 2 h and 4 h milled Ti-TiB2 powders show different relative densities of 99.5% and 95.1%, respectively. Also, the compression properties such as ultimate strength and compression strain for the 99.5% dense composite samples is 1421 MPa and 17.8%, respectively, which are superior to those （883 MPa and 5.5%, respectively） for the 95.1% dense sample. The results indicate that once Ti and TiB2 powders are connected firmly to each other and powder mixture of nearly spherical shape is obtained, there is no additional benefit in increasing the milling time and, instead, it has a negative effect on the density （i.e. increasing porosity level） of the Ti-TiB composite materials and their mechanical properties.

关键词： Selective laser melting In situ Ti-TiB composite Powder shape Density Mechanical properties

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From prediction to prevention:Machine learning revolutionizes hepatocellular carcinoma recurrence monitoring

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World Journal of Gastroenterology 2024年第7期30卷 631-635页

作者： mariana Michelle Ramírez-Mejía Nahum Méndez-Sánchez Plan of Combined Studies in Medicine Faculty of MedicineNational Autonomous University of MexicoDistrito Federal 04510Mexico Liver Research Unit Medica Sur Clinic&FoundationDistrito Federal 14050Mexico Faculty of Medicine National Autonomous University of MexicoDistrito Federal 04510Mexico

In this editorial,we comment on the article by Zhang et al entitled Development of a machine learning-based model for predicting the risk of early postoperative recurrence of hepatocellular carcinoma.Hepatocellular carcinoma(HCC),which is characterized by high incidence and mortality rates,remains a major global health challenge primarily due to the critical issue of postoperative recurrence.Early recurrence,defined as recurrence that occurs within 2 years posttreatment,is linked to the hidden spread of the primary tumor and significantly impacts patient survival.Traditional predictive factors,including both patient-and treatment-related factors,have limited predictive ability with respect to HCC recurrence.The integration of machine learning algorithms is fueled by the exponential growth of computational power and has revolutionized HCC research.The study by Zhang et al demonstrated the use of a groundbreaking preoperative prediction model for early postoperative HCC recurrence.Challenges persist,including sample size constraints,issues with handling data,and the need for further validation and interpretability.This study emphasizes the need for collaborative efforts,multicenter studies and comparative analyses to validate and refine the model.Overcoming these challenges and exploring innovative approaches,such as multi-omics integration,will enhance personalized oncology care.This study marks a significant stride toward precise,efficient,and personalized oncology practices,thus offering hope for improved patient outcomes in the field of HCC treatment.

关键词： Hepatocellular carcinoma Early recurrence Machine learning XGBoost model Predictive precision medicine Clinical utility Personalized interventions

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Representation of three-dimensional mass distribution of the Earth's interior by biorthogonal series and its use for studying internal structure of the planet

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Geodesy and Geodynamics 2024年第3期15卷 264-275页

作者： Mykhailo Fys mariana Yurkiv Andrii Brydun Andrii Sohor Department of Cartography and Geospatial Modelling Lviv Polytechnic National UniversityLviv 79013Ukraine

This paper utilizes the mathematical concept of approximation within an ellipsoid from a single viewpoint to present the spatial mass distribution function of the Earth's interior and its internal potential.The primary focus lies in constructing the volume distribution of masses in the planet's interior, with the expansion coefficients being linear combinations of the Stokes constants. Several possible approaches are suggested for determining accurately these coefficients employing three-dimensional(biorthogonal)polynomials. By expressing the mass distribution function of the Earth's interior and its internal potential as a series, an algorithm is introduced for the calculation of gravitational energy. It allows us to estimate fluctuations in gravitational energy. The implementation of this algorithm offers the means of establishing the extent to which the Earth deviates from a state of hydrostatic equilibrium as a celestial body.Due to the aforementioned method, calculations have been conducted to validate its effectiveness and reliability. This example is given as an illustration of a given method for studying the internal structure of planets.

关键词： Mass distribution function Potential Stokes constants Biorthogonal polynomials

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Annual variation of adult survival of a south-temperate House Wren population in Argentina

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Avian Research 2024年第2期15卷 229-237页

作者： Gustavo J.Fernandez mariana E.Carro Paulo E.Llambías Grupo de Investigacion en Ecofisiología de Fauna Silvestre INIBIOMA-CONICETAsentamiento Universitario San Martín de los Andes(AUSMA)Universidad Nacional Del ComahuePasaje de la Paz 235(8370)San Martín de los AndesNeuquenArgentina Grupo de Investigacion de Biología de Aves IADIZA CCT-MendozaUniversidad Nacional de CuyoAvenida RuizLeal s/n Parque General San Martin5500MendozaArgentina

Identifying factors affecting the survival of individuals is essential for understanding the evolution of life-history traits and population dynamics.Despite numerous studies on this subject in north-temperate environments,there is a lack of equivalent studies at similar latitudes in the south.Here,we used a 14-year dataset of capture,banding,and resighting to estimate the annual variation in the apparent adult survival probability of a south-temperate population of House Wrens(Troglodytes aedon bonariae).We evaluated temporal variation in sur-vival and the effect of environmental(climatic)and demographic variables(adult abundance,total number of fledglings produced during each breeding season)on survival estimators.We found that the probability of adult survival decreased as the abundance of breeding adults increased.This density-dependent effect could be related to the resident lifestyle of southern House Wrens,which could determine an intense competition for territories and resources that ultimately would affect their survival.

关键词： Annual variation CJS Density-dependence Survival Troglodytes aedon bonariae

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Grazing Pressure and Plant Functional Types in Puna Highlands,Northwestern Argentina

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 1067-1080页

作者： Quiroga Mendiola mariana Tálamo Andrés IPAF NOA—INTA(National Institute for Agricultural Technology) Posta de HornillosJujuy4622Argentina Facultad de Ciencias Naturales Universidad Nacional de SaltaSalta4400Argentina Instituto de Bio y Geociencias del NOA(IBIGEO) UNSa-CONICET.Laboratorio de Ecología Aplicada a la Conservación(LEAC)Facultad de Ciencias NaturalesUniversidad Nacional de SaltaSalta4400Argentina Maestría en Gestión Ambiental Escuela de NegociosUniversidad Católica de Salta(UCASAL)Salta4400Argentina

The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(Lama glama)and sheep.However,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna grasslands.We analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral management.At two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near stockyards.Furthermore,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of GPI.The only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near stockyards.In summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations vary.Finally,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.

关键词： Natural grasslands Puna herbivory ecological perturbation

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Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

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Advances in Polar Science 2024年第1期35卷 132-140页

作者： mariana A.JUÁRES AnahíM.SILVESTRO Brenda C.ALFONSO M.Mercedes SANTOS Departamento Biología de Predadores Tope Instituto Antártico Argentino(IAA)Buenos Aires B1650CSPArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Buenos Aires C1425FQBArgentina Laboratorios Anexos Facultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa Plata B1904AMAArgentina INEDES(CONICET-UNLu) Buenos Aires C1425FQBArgentina Facultad de Ciencias Naturales y Museo Universidad Nacional de La PlataLa Plata B1900FWAArgentina Instituto Antártico Argentino(IAA) Buenos Aires B1650CSPArgentina

In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

关键词： long-term monitoring Adélie penguin breeding pairs chicks crèched breeding success population trends

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EZH2 inhibitors promote β-like cell regeneration in young and adult type 1 diabetes donors

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Signal Transduction and Targeted Therapy 2024年第2期9卷 679-692页

作者： Keith Al-Hasani Safiya Naina Marikar Harikrishnan Kaipananickal Scott Maxwell Jun Okabe Ishant Khurana Thomas Karagiannis Julia J.Liang Lina mariana Thomas Loudovaris Thomas Kay Assam El-Osta Epigenetics in Human Health and Disease Program Baker Heart and Diabetes Institute75 Commercial RoadMelbourne 3004 VICAustralia Department of Diabetes Central Clinical SchoolMonash UniversityMelbourne 3004 VICAustralia Epigenetics in Human Health and Disease Laboratory Central Clinical SchoolMonash UniversityMelbourne 3004 VICAustralia School of Science STEM CollegeRMIT UniversityMelbourne 3001 VICAustralia Immunology and Diabetes Unit St Vincent’s Institute of Medical ResearchFitzroy 3065 VICAustralia Department of Medicine and Therapeutics The Chinese University of Hong KongSha TinHong Kong SAR Hong Kong Institute of Diabetes and Obesity Prince of Wales HospitalThe Chinese University of Hong Kong3/F Lui Che Woo Clinical Sciences Building30-32-Ngan Shing StreetSha TinHong Kong SAR Li Ka Shing Institute of Health Sciences The Chinese University of Hong KongSha TinHong Kong SAR Biomedical Laboratory Science Department of TechnologyFaculty of HealthUniversity College CopenhagenCopenhagenDenmark

β-cells are a type of endocrine cell found in pancreatic islets that synthesize,store and release insulin.In type 1 diabetes(T1D),T-cells of the immune system selectively destroy the insulin-producingβ-cells.Destruction of these cells leads to a lifelong dependence on exogenous insulin administration for survival.Consequently,there is an urgent need to identify novel therapies that stimulateβ-cell growth and induceβ-cell function.We and others have shown that pancreatic ductal progenitor cells are a promising source for regeneratingβ-cells for T1D owing to their inherent differentiation capacity.Default transcriptional suppression is refractory to exocrine reaction and tightly controls the regenerative potential by the EZH2 methyltransferase.In the present study,we show that transient stimulation of exocrine cells,derived from juvenile and adult T1D donors to the FDAapproved EZH2 inhibitors GSK126 and Tazemetostat(Taz)influence a phenotypic shift towards aβ-like cell identity.The transition from repressed to permissive chromatin states are dependent on bivalent H3K27me3 and H3K4me3 chromatin modification.Targeting EZH2 is fundamental toβ-cell regenerative potential.Reprogrammed pancreatic ductal cells exhibit insulin production and secretion in response to a physiological glucose challenge ex vivo.These pre-clinical studies underscore the potential of small molecule inhibitors as novel modulators of ductal progenitor differentiation and a promising new approach for the restoration ofβ-like cell function.

关键词： EZH2 struction inhibitors

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New avenues for the treatment of immunotherapy-resistant pancreatic cancer

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1134-1153页

作者： Luis Guilherme de Oliveira Silva Fabian Fellipe Bueno Lemos Marcel Silva Luz Samuel Luca Rocha Pinheiro mariana dos Santos Calmon Gabriel Lima Correa Santos Gabriel Reis Rocha Fabrício Freire de Melo Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil

Pancreatic cancer(PC)is characterized by its extremely aggressive nature and ranks 14th in the number of new cancer cases worldwide.However,due to its complexity,it ranks 7th in the list of the most lethal cancers worldwide.The pathogenesis of PC involves several complex processes,including familial genetic factors associated with risk factors such as obesity,diabetes mellitus,chronic pancreatitis,and smoking.Mutations in genes such as KRAS,TP53,and SMAD4 are linked to the appearance of malignant cells that generate pancreatic lesions and,consequently,cancer.In this context,some therapies are used for PC,one of which is immunotherapy,which is extremely promising in various other types of cancer but has shown little response in the treatment of PC due to various resistance mechanisms that contribute to a drop in immunotherapy efficiency.It is therefore clear that the tumor microenvironment(TME)has a huge impact on the resistance process,since cellular and non-cellular elements create an immunosuppressive environment,characterized by a dense desmoplastic stroma with cancerassociated fibroblasts,pancreatic stellate cells,extracellular matrix,and immunosuppressive cells.Linked to this are genetic mutations in TP53 and immunosuppressive factors that act on T cells,resulting in a shortage of CD8+T cells and limited expression of activation markers such as interferon-gamma.In this way,finding new strategies that make it possible to manipulate resistance mechanisms is necessary.Thus,techniques such as the use of TME modulators that block receptors and stromal molecules that generate resistance,the use of genetic manipulation in specific regions,such as microRNAs,the modulation of extrinsic and intrinsic factors associated with T cells,and,above all,therapeutic models that combine these modulation techniques constitute the promising future of PC therapy.Thus,this study aims to elucidate the main mechanisms of resistance to immunotherapy in PC and new ways of manipulating this process,resulting in a more efficient therapy

关键词： Pancreatic cancer Immunotherapy Resistance Tumor microenvironment manipulation Combined immunotherapy

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Update on the use of 45S5 bioactive glass in the treatment of bone defects in regenerative medicine

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World Journal of Orthopedics 2024年第3期15卷 204-214页

作者： Dayane Maria Braz Nogueira Marcelie Priscila de Oliveira Rosso Daniela Vieira Buchaim mariana Schutzer Ragghianti Zangrando Rogério Leone Buchaim Department of Prosthodontics and Periodontics Bauru School of DentistryUniversity of São PauloBauru 17012-901Brazil Department of Biological Sciences Bauru School of DentistryUniversity of São PauloBauru 17012-901Brazil Medical School University Center of AdamantinaAdamantina 17800-000Brazil Postgraduate Program in Structural and Functional Interactions in Rehabilitation Postgraduate DepartmentUniversity of MaríliaMarília 17525-902Brazil

Bone regeneration is a critical area in regenerative medicine,particularly in orthopedics,demanding effective biomedical materials for treating bone defects.45S5 bioactive glass(45S5 BG)is a promising material because of its osteoconductive and bioactive properties.As research in this field continues to advance,keeping up-to-date on the latest and most successful applications of this material is imperative.To achieve this,we conducted a comprehensive search on Pub-Med/MEDLINE,focusing on English articles published in the last decade.Our search used the keywords“bioglass 45S5 AND bone defect”in combination.We found 27 articles,and after applying the inclusion criteria,we selected 15 studies for detailed examination.Most of these studies compared 45S5 BG with other cement or scaffold materials.These comparisons demonstrate that the addition of various composites enhances cellular biocompatibility,as evidenced by the cells and their osteogenic potential.Moreover,the use of 45S5 BG is enhanced by its antimicrobial properties,opening avenues for additional investigations and applications of this biomaterial.

关键词： Biocompatible materials Bioglass Bone regeneration

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Effect of biochar on the metabolome of soybean seedlings

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Oil Crop Science 2024年第1期9卷 60-68页

作者： Nathalia E.Silva mariana G.Aguilar Osania E.Ferreira Gleicia M.Paulino Jaqueline C.L.Carvalho Lúcia P.S.Pimenta Alan R.T.Machado Programa de Pos-graduaçao em Ciencias Ambientais Universidade do Estado de Minas GeraisFrutalMinas Gerais38202-436Brazil Departamento de Química Universidade Federal de Minas GeraisMinas GeraisBelo Horizonte31270-901Brazil Departamento de Engenharia Aplicada e Tecnologias Ambientais Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil Departamento de Ciencias Exatas Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil

The use of biochar can have several effects on plant germination,depending on raw material,preparation method and application dose.However,the molecular mechanisms that lead to those results have yet to be elucidated.The aim of this research was to improve the understanding of these mechanisms by characterizing the metabolic effects of sugarcane bagasse biochar on soybean germination.Three types of biochars were prepared by pyrolysis at 300℃(SCB300),400℃(SCB400)and 600℃(SCB600).Then,each one was mixed into sand at 1%,3%,5%(w/w)dose,respectively.The experiment was performed in 8 days of incubation,when the number of germinated seeds and the average radicle length were determined.To evaluate the metabolome,the dry biomass(DB)was subjected to extraction with a mixture of methanol-d4 and D2O(1:1 v/v).The extracts were submitted to metabolomics analysis by Proton Nuclear Magnetic Resonance.The Relative Germination,Relative Average Radicle Growth and Germination Index increased in all treatments compared to control.On the other hand,the DB increased in all treatments,except for SCB300,at doses of 1%and 3%w/w.Seven metabolites(alanine,asparagine,acetic acid,citric acid,glycerol,fatty acids and sucrose)were identified and quantified in DB extracts as the most influential finding for the separation of treatments.Taken together,these results strongly suggested that biochars accelerated the catabolism of triacylglycerols to sucrose and induced a slight osmotic stress.

关键词： Germination Metabolomics 1H NMR Pyrolysis Sugarcane bagasse

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