47 research outputs found
Interfacial adhesion of compositional gradient ternary FCC alloy films
Combinatorial materials design of thin films allows for the investigation of fundamental mechanic relationships and optimization of thin films for engineering applications. By depositing a wide range of compositions on a single sample, a systematic study of the full alloy composition of particular material system can be investigated for a number of different properties in a relatively short amount of time. Using an integrated shutter controller, specifically designed and manufactured to allow for precise control over coating design, ternary alloys with the full compositional range can be deposited on a single wafer. By specifically programming the shutters it was possible to create multilayered thickness gradients of three elements, which were then annealed to create thin films with a large compositional gradient across the wafer. The adhesion strength of an Al2O3Â ALD coating on two such compositional gradient FCC alloy adhesion layers, AlCuAu and AuAgPd, was investigated as a function of the changing composition. The AlCuAu alloy sample consists of multiple phases and intermetallics across the wafer which are dependent on composition; whereas the AuAgPd alloy is a solid-solution across the compositional gradient. For this investigation, instrumented indentation with a conical diamond tip was used to locally measure the adhesion of the ALD coating with different adhesion layer compositions. By performing small arrays of indents over the surface of the coating, it was possible to test the adhesion-promoting properties of a broad spectrum of interface compositions in a single sample.
Please click Additional Files below to see the full abstract
Fundamental nanomechanic investigations using combinatorial deposition techniques
Combinatorial materials design of thin films allows for the investigation of broad ranges of both thickness and composition within a single sample; this can be utilized both for fundamental nanomechanics investigations and for the optimization of thin films for engineering applications. Using a unique self-constructed deposition chamber that combines magnetron sputtering, e-beam evaporation, nanoparticle deposition and atomic layer deposition (ALD), the architectural design of thin films can be tailored to study multiple physical and chemical properties.
Recent investigations have focused on using this chamberâs unique ability to create a gradient composition film of up to three different materials with a range of approximately 20 vol% for each material, allowing for a broad range of compositions to be tested in a single sample. This is highly beneficial in the optimization of thin film performance. Specifically, two different alloys with varying composition have been studied recently: a CuZrTi bulk metallic glass and a NbWTa solid-solution alloy. Si wafers were sputtered by PVD, resulting in composition gradients, to investigate mechanical properties and glass formation as a function of composition in the CuZr, CuZrTi, and NbWTa systems. Composition was measured using XRF and correlated with mechanical properties, such as elastic modulus and hardness, measured using nanoindentation. Structural properties of the NbWTa three-component solid-solution alloy was also investigated as a function of the changing composition: tracking the change in the lattice parameter using XRD and the solid-solution strengthening using nanoindentation. The NbWTa sample was also used in an adhesion study to survey the effect of composition on the interfacial adhesion, measured via the Marshall and Evans (1984) method, between the film and a 500 nm thick layer of Al2O3 deposited using ALD.
The same method can be used to create multilayers with different layer thicknesses across a single wafer. In this way, the fundamental deformation and strengthening mechanisms of multilayers can be probed at a range of layer thicknesses. An additional chamber mounted to the system allows for in-line ALD of a variety of different oxides. This adds the capability for interface engineering using ceramic layers with sub-nanometer thickness control. Initial studies of this capability have focused on proof-of-concept trilayer systems consisting of Al2O3 and TiO2 ALD layers sandwiched between thicker Cu layers deposited by PVD. Physical and mechanical characterisation of these trilayers, including micropillar compression, has demonstrated that the interfacial adhesion is good and that nanometer thick ALD layers can provide significant hardening to Cu thin films.
A newly integrated shutter controller has been specifically designed and manufactured to allow for even more control over coating design. By specifically programming the shutters it is possible to create thickness gradients of two or three different materials, which can then be annealed to create a film with compositional gradients over almost the complete spectrum. Furthermore, the shutter system can be used to deposit a grid of samples with different deposition conditions, compositions, or layer thicknesses on the same wafer, cutting down sample manufacturing time and eliminating uncontrollable errors due to day-to-day differences in deposition chamber conditions.
The newest addition to the PVD chamber is the NanoGen50 nanoparticle generator manufactured by Mantis Depositions Ltd., which uses an adaptation of traditional magnetron sputtering to force agglomeration of the sputtered ions into small particles. Recently, the first known nanoparticle reinforced metal films using PVD were produced using Cu nanoparticles in a Zr matrix. The microstructure, particle size and density were characterized using STEM and initial nanoindentation investigations were conducted to determine how nanoparticle inclusion effects the hardness and modulus of these new films
Marine seagrass extract of Thalassia testudinum suppresses colorectal tumor growth, motility and angiogenesis by autophagic stress and immunogenic cell death pathways
Marine plants have become an inexhaustible reservoir of new phytopharmaceuticals for cancer treatment. We demonstrate in vitro/in vivo antitumor efficacy of a standardized polyphenol extract from the marine angiosperm Thalassia testudinum (TTE) in colon tumor cell lines (RKO, SW480, and CT26) and a syngeneic allograft murine colorectal cancer model. MTT assays revealed a dose-dependent decrease of cell viability of RKO, CT26, and SW480 cells upon TTE treatment with IC50 values of, respectively, 175, 115, and 60 mu g/mL. Furthermore, TTE significantly prevented basal and bFGF-induced angiogenesis in the chicken chorioallantoic membrane angiogenesis assay. In addition, TTE suppressed bFGF-induced migration of endothelial cells in a wound closure assay. Finally, TTE treatment abrogated CT26 colorectal cancer growth and increased overall organism survival in a syngeneic murine allograft model. Corresponding transcriptome profiling and pathway analysis allowed for the identification of the mechanism of action for the antitumor effects of TTE. In line with our in vitro/in vivo results, TTE treatment triggers ATF4-P53-NF kappa B specific gene expression and autophagy stress pathways. This results in suppression of colon cancer cell growth, cell motility, and angiogenesis pathways in vitro and in addition promotes antitumor immunogenic cell death in vivo
Entomopathogenic nematology in Latin America: A brief history, current research and future prospects
Since the 1980s, research into entomopathogenic nematodes (EPNs) in Latin America has produced many remarkable discoveries. In fact, 16 out of the 117 recognized species of EPNs have been recovered and described in the subcontinent, with many more endemic species and/or strains remaining to be discovered and identified. In addition, from an applied perspective, numerous technological innovations have been accomplished in relation to their implementation in biocontrol. EPNs have been evaluated against over 170 species of agricultural and urban insects, mites, and plant-parasitic nematodes under laboratory and field conditions. While much success has been recorded, many accomplishments remain obscure, due to their publication in non-English journals, thesis dissertations, conference proceedings, and other non-readily available sources. The present review provides a brief history of EPNs in Latin America, including current findings and future perspectives.Fil: San Blas, Ernesto. Instituto Venezolano de Investigaciones CientĂficas; VenezuelaFil: Campos Herrera, Raquel. Consejo Superior de Investigaciones CientĂficas; EspañaFil: Dolinski, Claudia. Universidade Estadual Do Norte Fluminense Darcy Ribeiro; BrasilFil: Monteiro, Caio. Universidade Federal de GoiĂĄs; BrasilFil: AndalĂł, Vanessa. Universidade Federal de Uberlandia; BrasilFil: Leite, Luis GarrigĂłs. Universidade Estadual de Campinas; BrasilFil: RodrĂguez, Mayra G.. Centro Nacional de Sanidad Agropecuaria; CubaFil: Morales Montero, Patricia. Instituto Venezolano de Investigaciones CientĂficas; VenezuelaFil: SĂĄenz Aponte, Adriana. Pontificia Universidad Javeriana; ColombiaFil: Cedano, Carolina. Universidad Nacional de Trujillo; PerĂșFil: LĂłpez Nuñez, Juan Carlos. Centro Nacional de Investigaciones del CafĂ©; ColombiaFil: del Valle, Eleodoro Eduardo. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Doucet, Marcelo Edmundo. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Centro de ZoologĂa Aplicada; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Diversidad y EcologĂa Animal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto de Diversidad y EcologĂa Animal; ArgentinaFil: Lax, Paola. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Centro de ZoologĂa Aplicada; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de Diversidad y EcologĂa Animal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂsicas y Naturales. Instituto de Diversidad y EcologĂa Animal; ArgentinaFil: Navarro, Patricia D.. Instituto de Investigaciones Agropecuarias; ChileFil: BĂĄez, Francisco. Instituto Nacional Autonomo de Investigaciones Agropecuarias; EcuadorFil: Llumiquinga, Pablo. Instituto Nacional Autonomo de Investigaciones Agropecuarias; EcuadorFil: Ruiz Vega, Jaime. Instituto PolitĂ©cnico Nacional ; MĂ©xicoFil: Guerra Moreno, Abby. Laboratorio de BiotecnologĂa; PanamĂĄFil: Stock, S. Patricia. University of Arizona; Estados Unido
The global burden of adolescent and young adult cancer in 2019 : a systematic analysis for the Global Burden of Disease Study 2019
Background In estimating the global burden of cancer, adolescents and young adults with cancer are often overlooked, despite being a distinct subgroup with unique epidemiology, clinical care needs, and societal impact. Comprehensive estimates of the global cancer burden in adolescents and young adults (aged 15-39 years) are lacking. To address this gap, we analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, with a focus on the outcome of disability-adjusted life-years (DALYs), to inform global cancer control measures in adolescents and young adults. Methods Using the GBD 2019 methodology, international mortality data were collected from vital registration systems, verbal autopsies, and population-based cancer registry inputs modelled with mortality-to-incidence ratios (MIRs). Incidence was computed with mortality estimates and corresponding MIRs. Prevalence estimates were calculated using modelled survival and multiplied by disability weights to obtain years lived with disability (YLDs). Years of life lost (YLLs) were calculated as age-specific cancer deaths multiplied by the standard life expectancy at the age of death. The main outcome was DALYs (the sum of YLLs and YLDs). Estimates were presented globally and by Socio-demographic Index (SDI) quintiles (countries ranked and divided into five equal SDI groups), and all estimates were presented with corresponding 95% uncertainty intervals (UIs). For this analysis, we used the age range of 15-39 years to define adolescents and young adults. Findings There were 1.19 million (95% UI 1.11-1.28) incident cancer cases and 396 000 (370 000-425 000) deaths due to cancer among people aged 15-39 years worldwide in 2019. The highest age-standardised incidence rates occurred in high SDI (59.6 [54.5-65.7] per 100 000 person-years) and high-middle SDI countries (53.2 [48.8-57.9] per 100 000 person-years), while the highest age-standardised mortality rates were in low-middle SDI (14.2 [12.9-15.6] per 100 000 person-years) and middle SDI (13.6 [12.6-14.8] per 100 000 person-years) countries. In 2019, adolescent and young adult cancers contributed 23.5 million (21.9-25.2) DALYs to the global burden of disease, of which 2.7% (1.9-3.6) came from YLDs and 97.3% (96.4-98.1) from YLLs. Cancer was the fourth leading cause of death and tenth leading cause of DALYs in adolescents and young adults globally. Interpretation Adolescent and young adult cancers contributed substantially to the overall adolescent and young adult disease burden globally in 2019. These results provide new insights into the distribution and magnitude of the adolescent and young adult cancer burden around the world. With notable differences observed across SDI settings, these estimates can inform global and country-level cancer control efforts. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe
XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"
Este tĂtulo, sugestivo por los impactos durante la situaciĂłn de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy crĂticos, permiten asumir la obligada superaciĂłn de tensiones sociales, polĂticas, y econĂłmicas; pero sobre todo cientĂficas y tecnolĂłgicas.
Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial despuĂ©s de que haya cesado la perturbaciĂłn a la que fue sometida por la catastrĂłfica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aĂșn se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrĂĄ que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemĂĄn y catedrĂĄtico de economĂa de la Universidad de Princeton- en su libro The Resilient SocietyâŠLa cuestiĂłn no es preveerlo todo sino poder reaccionarâŠaprender a recuperarse rĂĄpido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological.
Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Recommended from our members
Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study
Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9â27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6â16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2â1.8), stage II (OR 1.6; 95% CI 1.4â1.9), and stage III or worse (OR 2.8; 95% CI 2.3â3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat