413 research outputs found
Cycling Empirical Antibiotic Therapy in Hospitals: Meta-Analysis and Models
The rise of resistance together with the shortage of new broad-spectrum antibiotics underlines the urgency of optimizing the use of available drugs to minimize disease burden. Theoretical studies suggest that coordinating empirical usage of antibiotics in a hospital ward can contain the spread of resistance. However, theoretical and clinical studies came to different conclusions regarding the usefulness of rotating first-line therapy (cycling). Here, we performed a quantitative pathogen-specific meta-analysis of clinical studies comparing cycling to standard practice. We searched PubMed and Google Scholar and identified 46 clinical studies addressing the effect of cycling on nosocomial infections, of which 11 met our selection criteria. We employed a method for multivariate meta-analysis using incidence rates as endpoints and find that cycling reduced the incidence rate/1000 patient days of both total infections by 4.95 [9.43–0.48] and resistant infections by 7.2 [14.00–0.44]. This positive effect was observed in most pathogens despite a large variance between individual species. Our findings remain robust in uni- and multivariate metaregressions. We used theoretical models that reflect various infections and hospital settings to compare cycling to random assignment to different drugs (mixing). We make the realistic assumption that therapy is changed when first line treatment is ineffective, which we call “adjustable cycling/mixing”. In concordance with earlier theoretical studies, we find that in strict regimens, cycling is detrimental. However, in adjustable regimens single resistance is suppressed and cycling is successful in most settings. Both a meta-regression and our theoretical model indicate that “adjustable cycling” is especially useful to suppress emergence of multiple resistance. While our model predicts that cycling periods of one month perform well, we expect that too long cycling periods are detrimental. Our results suggest that “adjustable cycling” suppresses multiple resistance and warrants further investigations that allow comparing various diseases and hospital settings
Auf dem Weg zu einem klimaneutralen Luftverkehr – nachhaltige Kraftstoffe und neue Antriebskonzepte
Die Notwendigkeit und Dringlichkeit, gangbare Wege für eine Transformation des Luftverkehrs hin zur Kli-maneutralität zu entwickeln, steigen. Nicht nur trägt der globale Luftverkehr signifikant zur Klimaerwär-mung bei, auch hat die Anzahl an Flügen in den letzten 20 Jahren weltweit deutlich zugenommen und Prognosen sagen einen noch stärkeren Anstieg bis zum Jahr 2050 voraus. Neue Kraftstoffe und Antriebskonzepte sind daher essenziell, um den Luftverkehr in Zukunft möglichst klimaneutral zu gestalten.
Die globale Luftfahrt ist bei Weitem die energieintensivste Form der Fortbewegung und ein starker Treiber der anthropogenen Klimaerwärmung. Ihr Anteil liegt derzeit bei 3,5 %, was mengenmäßig in etwa dem kompletten CO2-Ausstoß Japans entspricht. Neben dem ausgestoßenen CO2 tragen vor allem Kondensstreifen und Kondensstreifenzirren sowie Emissionen wie Stickoxide (NOX), Wasserdampf, Ruß, Sulfat- und andere Aerosolpartikel zur Klimawirkung der Luftfahrt bei.
2019 gab es global ca. 47 Mio. Flüge, was einen Anstieg von 26 % im Vergleich zu 2014 bedeutet. Wenn vor Ausbruch der Coronapandemie erstellte Prognosen herangezogen werden, steht dabei der eigentlich entscheidende Anstieg der Flugzahlen noch bevor, mit sehr starken Wachstumsraten bis hin zu einer Verdreifachung zwischen 2020 und 2050.
Vor diesem Hintergrund kommt technischen Innovationen zur klimaneutralen Gestaltung des Luftverkehrs eine sehr wichtige Rolle zu. Hierzu zählen insbesondere nachhaltige Kraftstoffe und Antriebskonzepte, etwa auf Basis von grünem Wasserstoff wie sogenannte E-Fuels. Ihr technischer Entwicklungsstand, ihr Klimaschutzpotenzial sowie zusammenhängende Fragen und Herausforderungen werden hier dargestellt
Use of spherical salt for reducing sodium content with no change in salty perception in the development of a lamb meat burger with high-rated technological and sensory properties
Se utilizó sal esférica como estrategia para la reducción del contenido de sodio en una hamburguesa de carne de cordero con respecto a una hamburguesa control —elaborada con sal de mesa al 1,5%— con el objeto de conservar la misma percepción de gusto salado en el producto nal. La formulación de este último fue de nida mediante una serie de pruebas desarrolladas con un panel de evaluadores entrenados en percepción de gusto salado. Se determinó el contenido de sodio, la composición centesimal y el contenido graso del producto crudo y se estimaron el rendimiento y la humedad expresible. Mediante un ensayo hedónico con 112 consumidores se determinó la aceptabilidad del producto nal. Se logró desarrollar una hamburguesa con 14,75% menos de sodio y sin diferencias perceptibles en el gusto salado con respecto a la muestra control, valorada positivamente por más del 85% de los consumidores. Adicionalmente, las características tecnológicas del nuevo producto se hallaron dentro de los parámetros esperados.A spherical salt was the strategy used to reduce the sodium content in a lamb meat burger in relation to a control sample —formulated with 1.5% sodium content— in order to maintain the same salty taste perception. e nal product was de ned by a series of tests developed with a sensory panel trained for salty taste detection. Sodium content, centesimal composition and fat composition were analyzed on raw burgers. Cooking yield and expressible moisture were estimated. A hedonic test was performed with the nal product to assess overall acceptability. e developed burger contained 14.75% (w/w) less sodium than the control sample but no di erence in its salty taste and presented adequate technological features. Furthermore, the burger obtained 87.5% of positive reviews in the acceptance test.Fil: Soteras, T.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Cunzolo, Sebastian Abel. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Carduza, F.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Mass Loss and Displacement Modeling for Multi-Axis Milling
During the cutting process, material of the workpiece is continuously being
removed by the cutting tool, which results in a reduction of mass as well as a
displacement in the center of the workpiece mass. When using workpiece sided
force sensors, such as table dynamometers, the total mass and the displacement
of the center of mass affects the force measurement due to gravitational and
inertial effects. The high flexibility of the milling process leads to a
complex change of volume and mass and necessitates the consideration of the
engagement conditions between tool and workpiece along the tool path in order
to estimate changes in mass and center of mass. This paper proposes a method
for estimating the mass loss and the displacement of the center of mass during
multi-axis milling processes. In this method the tool gets numerically sliced
along the tool axis and the workpiece removal for each slice along an arbitrary
tool path gets calculated. To validate the mass loss model, experiments in both
three-axis milling as well as multi-axis milling processes have been conducted.
Since it is difficult to measure the center of mass, validation for the
displacement of the center of mass was done by comparison with data extracted
from CAD. The results show good agreement between the simulated and measured
mass loss using the proposed approach
A Contribution of Beef to Human Health: A Review of the Role of the Animal Production Systems
Meat and meat products constitute important source of protein, fat, and several functional compounds. Although beef consumption may implicate possible negative impacts on human health, its consumption can also contribute to human health. Quality traits of beef, as well as its nutritional properties, depend on animal genetics, feeding, livestock practices, and post mortem procedures. Available data show that emerging beef production systems are able to improve both, quality and nutritional traits of beef in a sustainable way. In this context, Argentina’s actions are aimed at maximising beef beneficial effects and minimising its negative impact on human health, in a way of contributing to global food security.Fil: Pighín, Darío Gabriel. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Universidad de Morón; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pazos, Adriana Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Universidad de Morón; ArgentinaFil: Chamorro, Monica Viviana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Paschetta, María Fernanda. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Cunzolo, Sebastian Abel. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Universidad de Morón; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Godoy, Maria Fernanda. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; ArgentinaFil: Messina, Valeria Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Pordomingo, Anibal Javier. Instituto Nacional de Tecnología Agropecuaria. Centro Regional La Pampa-San Luis. Estación Experimental Agropecuaria Anguil; ArgentinaFil: Grigioni, Gabriela Maria. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Agroindustria. Instituto de Tecnología de Alimentos; Argentina. Universidad de Morón; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Thermally stable mesoporous tetragonal zirconia through surfactant-controlled synthesis and Si-stabilization
Thermally stable, highly mesoporous Si-stabilized ZrO₂ was prepared by sol–gel-synthesis. By utilizing the surfactant dodecylamine (DDA), large mesopores with a pore width of ∼9.4 nm are formed. Combined with an NH₃-treatment on the hydrogel, a high specific surface area of up to 225 m² g⁻¹ and pore volume up to 0.46 cm³ g⁻¹ are obtained after calcination at 973 K. The individual contributions of Si-addition, DDA surfactant and the NH₃-treatment on the resulting pore system were studied by inductively coupled plasma with optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), N₂ sorption, and transmission electron microscopy (TEM). Electron tomography was applied to visualize and investigate the mesopore network in 3D space. While Si prevents the growth of ZrO₂ crystallites and stabilizes the t-ZrO₂ phase, DDA generates a homogeneous mesopore network within the zirconia. The NH₃-treatment unblocks inaccessible pores, thereby increasing specific surface area and pore volume while retaining the pore width distribution
Hard X‐ray Nanotomography for 3D Analysis of Coking in Nickel‐based Catalysts
Understanding catalyst deactivation by coking is crucial for knowledge-based catalyst and process design in reactions with carbonaceous species. Post-mortem analysis of catalyst coking is often performed by bulk characterization methods. Here, hard X-ray ptychographic computed tomography (PXCT) was used to study Ni/AlO catalysts for CO methanation and CH dry reforming after artificial coking treatment. PXCT generated quantitative 3D maps of local electron density at ca. 80 nm resolution, allowing to visualize and evaluate the severity of coking in entire catalyst particles of ca. 40 μm diameter. Coking was primarily revealed in the nanoporous solid, which was not detectable in resolved macropores. Coke formation was independently confirmed by operando Raman spectroscopy. PXCT is highlighted as an emerging characterization tool for nanoscale identification, co-localization, and potentially quantification of deactivation phenomena in 3D space within entire catalyst particles
Harte Röntgen‐Nanotomographie zur 3D‐Analyse der Verkokung in Nickel‐basierten Katalysatoren
Das Verständnis der Katalysatordesaktivierung durch Verkokung ist entscheidend für ein wissensbasiertes Katalysator- und Prozessdesign bei Reaktionen mit Kohlenstoffverbindungen. Die Katalysatorverkokung wird dabei typischerweise durch Post-Mortem-Analyse untersucht. In der vorliegenden Arbeit wird ptychographische Röntgentomographie (PXCT) zur Analyse von künstlich verkokten Ni/Al2O3-Katalysatoren für die CO2-Methansierung und CH4-Trockenreformierung verwendet. PXCT liefert dabei 3D-Informationen der lokalen Elektronendichte mit ca. 80 nm Auflösung und ermöglicht somit die Visualisierung und Untersuchung der Ausprägung der Verkokung in Katalysatorpartikeln mit einem Durchmesser von ca. 40 μm. Die Verkokung wurde hauptsächlich im nanoporösen Festkörper identifiziert und konnte nicht in den aufgelösten Makroporen gefunden werden. Die Kohlenstoffbildung wurde unabhängig dazu mittels operando Raman-Spektroskopie bestätigt. PXCT wird als aufkommende Charakterisierungstechnik hervorgehoben, die eine nanoskalige Identifizierung, Lokalisierung und möglicherweise Quantifizierung von verschiedenen Desaktivierungsphänomenen mit 3D-Auflösung in kompletten Katalysatorpartikeln ermöglicht
Hard X-Ray Nanotomography for 3D Analysis of Coking in Nickel-Based Catalysts
Understanding catalyst deactivation by coking is crucial for knowledge-based catalyst and process design in reactions with carbonaceous species. Post-mortem analysis of catalyst coking is often performed by bulk characterization methods. Here, hard X-ray ptychographic computed tomography (PXCT) was used to study Ni/Al2O3 catalysts for CO2 methanation and CH4 dry reforming after artificial coking treatment. PXCT generated quantitative 3D maps of local electron density at ca. 80 nm resolution, allowing to visualize and evaluate the severity of coking in entire catalyst particles of ca. 40 μm diameter. Coking was primarily revealed in the nanoporous solid, which was not detectable in resolved macropores. Coke formation was independently confirmed by operando Raman spectroscopy. PXCT is highlighted as an emerging characterization tool for nanoscale identification, co-localization, and potentially quantification of deactivation phenomena in 3D space within entire catalyst particles
Characterization and dermal bioaccessibility of residual- and listed PFAS ingredients in cosmetic products
As a large group of chemicals with diverse properties, per- and polyfluoroalkyl substances (PFAS) have found extensive application throughout consumer products, including cosmetics. Little is known about the importance of dermal uptake as a human exposure pathway for PFAS. Here we investigate a suite of listed-ingredient and residual PFAS in cosmetic products, along with their dermal bioaccessibility using in vitro incubations with artificial sweat. Concentrations of volatile listed ingredients (including cyclic perfluorinated alkanes, perfluorinated ethers, and polyfluorinated silanes) in three products ranged from 876-1323 μg g -1, while polar listed ingredients ( i.e., polyfluoroalkyl phosphate esters [PAPs]) in a single product occurred at up to 2427 μg g -1 (6 : 2/6 : 2 diPAP)). Residual perfluoroalkyl carboxylic acids (PFCAs) were also measured at concentrations ranging from 0.02-29 μg g -1. When listed ingredients were included, our targeted analysis accounted for up to 103% of the total fluorine, while highlighting ambiguous and/or incorrect International Nomenclature of Cosmetic Ingredient (INCI) names used in several products. Bioaccessibility experiments revealed that residual PFCAs readily partitioned to artificial sweat (bioaccessible fractions ranging from 43-76% for detectable substances) while listed ingredients ( i.e., PAPs and neutral/volatile PFAS) displayed negligible partitioning. This work provides new insight into the occurrence of PFAS in cosmetic products, while furthering our understanding on their mechanisms of dermal uptake. </p
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