Stability of Pyruvic Acid Adsorbed Onto Clays and Exposed to Ionizing Radiation: Relevance in Chemical Evolution

Chemical evolution studies focus on the synthesis and stability of organic molecules during various transformative physicochemical processes. Gaining insight into the possible mechanisms behind these processes requires the use of various energy sources and catalysts that can produce such transformations. In this work, ionizing radiation (60Co) was used as a source of energy, and two clays with different exchangeable cations-sodium and iron (III)-were combined with pyruvic acid, a key alpha keto acid in metabolism. The samples of pyruvic acid were prepared at a concentration of 0.01 M; then, adsorption experiments were carried out by combining sodium or iron montmorillonite at different times. The amount that adsorbed onto iron montmorillonite was greater than the amount that adsorbed onto sodium montmorillonite. Samples of alpha keto acid at the same concentration were irradiated-in the absence of clay-at 0 to 146.1 kGy and at two pHs (6.7 and 2.0). The suspended samples with sodium and iron clay were then irradiated at the same doses. The results show that keto acid decomposes more quickly at more acidic pHs. The main reaction to irradiation without clay involves the dimerization of pyruvic acid, and 2,3-dimethyltartaric acid is the majority product. When irradiated in the presence of clay, the main reaction is decarboxylation, and acetic acid is the majority product. The exchangeable cation type modifies the interactions between the organic molecule and the solid phase. The percentage of recovered pyruvic acid is higher for iron montmorillonite than for sodium montmorillonite

Three-dimensional shear in granular flow

The evolution of granular shear flow is investigated as a function of height in a split-bottom Couette cell. Using particle tracking, magnetic-resonance imaging, and large-scale simulations we find a transition in the nature of the shear as a characteristic height $H^*$ is exceeded. Below $H^*$ there is a central stationary core; above $H^*$ we observe the onset of additional axial shear associated with torsional failure. Radial and axial shear profiles are qualitatively different: the radial extent is wide and increases with height while the axial width remains narrow and fixed.Comment: 4 pages, 5 figure

Datasets on technological GHG emissions mitigation options for the agriculture sector

The 2030 EU policy framework for climate and energy confirms that all sectors, including agriculture, should contribute to climate stabilisation and greenhouse gas (GHG) emission reduction in the most cost-effective way. Since 2009, the European Commission's Joint Research Centre (JRC) analyses the economic impact of GHG mitigation policy options for EU agriculture. However, the lack of precise, integrated and harmonised data on the current and potential uptake, cost-effectiveness and GHG emissions reduction potential of technological (i.e. technical and management based) mitigation options hampers the analysis of the economic impacts of GHG mitigation in agriculture. Against this background, the JRC organised a workshop in Seville on 14th June 2016 which gathered European Commission staff and experts from diverse international institutions aiming to: i) identify current activities conducted by research institutes on the building of datasets for GHG mitigation technologies and their state and development, ii) establish synergies and working mechanisms among the different institutions working on the topic, iii) identify which are the current gaps and limitations of existing datasets and models and, iv) conceive a roadmap to build possible new datasets per mitigation technology. The present report is based on the workshop results and concludes on how to move forward.JRC.D.4-Economics of Agricultur

Impact of an excise tax on the consumption of sugar-sweetened beverages in young people living in poorer neighbourhoods of Catalonia, Spain: a difference in differences study

BACKGROUND: Sugar-sweetened beverage consumption is contributing to the obesity epidemic. On 28 March 2017, Catalonia enacted a law levying an excise tax on sugar-sweetened beverages for public health reasons. The purpose of this study is to assess the impact of the tax on the consumption of sugar-sweetened beverages in Catalonia (Spain). METHODS: Before-and-after study to assess changes in the prevalence of consumption of sugar-sweetened beverages among 1929 persons aged 12 to 40 years residing in low-income neighbourhoods of Barcelona (intervention) and Madrid (control). Beverage consumption frequency was ascertained via a validated questionnaire administered during the month prior to the tax's introduction (May 2017) and again at 1 year after it had come into force. The effect of the tax was obtained using Poisson regression models with robust variance weighted using propensity scores. RESULTS: While the prevalence of regular consumers of taxed beverages fell by 39% in Barcelona as compared to Madrid, the prevalence of consumers of untaxed beverages remained stable. The main reason cited by more than two-thirds of those surveyed for reducing their consumption of sugar-sweetened beverages was the increase in price, followed by a heightened awareness of their health effects. CONCLUSIONS: The introduction of the Catalonian excise tax on sugar-sweetened beverages was followed by a reduction in the prevalence of regular consumers of taxed beverages.This study was supported by the Spanish Health Research Fund (Fondo deInvestigación Sanitaria - FIS) of the Carlos III Institute of Health (Project ENPY120/18) and the Spanish Consumers’Organisation (Organización deConsumidores y Usuarios - OCU). The funders had no role in the design of thestudy, in collection, analysis, and interpretation of data, or in writing themanuscriptS

Using Plasma Etching to Access the Polymer Density Distribution and Diffusivity of Gel Particles

In this paper we examine the polymer density distribution of gel particles and its effect on solvent diffusivity through the polymer network. In order to access the inner particle regions, external polymer layers were removed by plasma etching, thus reducing them from the outside. Higher polymer densities after erosion showed internal heterogeneity, with the density increasing towards the center of the particles. An exponential decay polymer density model is proposed, and the spatial relaxation length measured. The diffusion of solvent through the particles, before and after the plasma oxidation, revealed a correlation between the diffusion coefficient and the internal density

Structural Properties of Thermoresponsive Poly(N-isopropylacrylamide)-poly(ethyleneglycol) Microgels

The application of RNA interference to treat disease is an important yet challenging concept in modern medicine. In particular, small interfering RNA (siRNA) have shown tremendous promise in the treatment of cancer. However, siRNA show poor pharmacological properties, which presents a major hurdle for effective disease treatment especially through intravenous delivery routes. In response to these shortcomings, a variety of nanoparticle carriers have emerged, which are designed to encapsulate, protect, and transport siRNA into diseased cells. To be effective as carrier vehicles, nanoparticles must overcome a series of biological hurdles throughout the course of delivery. As a result, one promising approach to siRNA carriers is dynamic versatile nanoparticles that can perform several in vivo functions. Over the last several years, our research group has investigated hydrogel nanoparticles (nanogels) as candidate delivery vehicles for therapeutics, including siRNA. Throughout the course of our research, we have developed higher order architectures composed entirely of hydrogel components, where several different hydrogel chemistries may be isolated in unique compartments of a single construct. In this Account, we summarize a subset of our experiences in the design and application of nanogels in the context of drug delivery, summarizing the relevant characteristics for these materials as delivery vehicles for siRNA. Through the layering of multiple, orthogonal chemistries in a nanogel structure, we can impart multiple functions to the materials. We consider nanogels as a platform technology, where each functional element of the particle may be independently tuned to optimize the particle for the desired application. For instance, we can modify the shell compartment of a vehicle for cell-specific targeting or evasion of the innate immune system, whereas other compartments may incorporate fluorescent probes or regulate the encapsulation and release of macromolecular therapeutics. Proof-of-principle experiments have demonstrated the utility of multifunctional nanogels. For example, using a simple core/shell nanogel architecture, we have recently reported the delivery of siRNA to chemosensitize drug resistant ovarian cancer cells. Ongoing efforts have resulted in several advanced hydrogel structures, including biodegradable nanogels and multicompartment spheres. In parallel, our research group has studied other properties of the nanogels, including their behavior in confined environments and their ability to translocate through small pores

New chromium steel grade for creep applications

In this study, a novel Chromium steel grade (COIN2) is produced as a result of a new steel composition and an innovative heat treatment. This new steel grade COIN2 evolves from the P92 steel grade and other novel steel grade recently created by the authors (COIN), and represents an enhancement of hardness, tensile properties, and creep behaviour with respect to them, which validates the metallurgical strategy used for further research in order to increase the efficiency of power plants and thus reduce the CO2 emissions. The characterization reveals a significant property improvement with the innovative thermal treatment, contributing to the production of a novel and more competitive steel grade for creep applications.This research was funded by the Basque Government under the ELKARTEK programme [KK-2019/00074]

First 3-D Ru-Ru-Au organometallic polymer with layered structure

A new water soluble heterometallic polymeric complex [{(PTA)2 CpRu-l-CN-1jC:2j2N-RuCp(PTA)2}-l-{Au(CN)4}4]n 2H2O (1) is synthesized and characterized by single crystal X-ray diffraction. This complex self-assembles forming 3D polymeric structures with large scale hexagonal conformation. They also organize as 3D stacks of polymer sandwiches that can be exfoliated providing mono heterometallic-3D layers, as shown by electron microscopy. Regarding the polymer dynamics, quasi-elastic neutron scattering shows a transition from vibrational Debye–Waller behaviour to a more dynamically active state as a result of the loss of structural water molecules