Search results for "chemistry [Carbon]"

The Metalloprotease Meprin β Is an Alternative β-Secretase of APP

2017

The membrane bound metalloprotease meprin β is important for collagen fibril assembly in connective tissue formation and for the detachment of the intestinal mucus layer for proper barrier function. Recent proteomic studies revealed dozens of putative new substrates of meprin β, including the amyloid precursor protein (APP). It was shown that APP is cleaved by meprin β in distinct ways, either at the β-secretase site resulting in increased levels of Aβ peptides, or at the N-terminus releasing 11 kDa, and 20 kDa peptide fragments. The latter event was discussed to be rather neuroprotective, whereas the ectodomain shedding of APP by meprin β reminiscent to BACE-1 is in line with the amyloid h…

Microwear and isotopic analyses on cave bear remains from Toll Cave reveal both short-term and long-term dietary habits

2019

Dietary habits of the extinct Ursus spelaeus have always been a controversial topic in paleontological studies. In this work, we investigate carbon and nitrogen values in the bone collagen and dental microwear of U. spelaeus specimens recovered in Level 4 from Toll Cave (Moia, Catalonia, NE Iberian Peninsula). These remains have been dated to > 49,000 C-14 BP. The ability of both proxies to provide data on the diet of U. spelaeus at different times in the life-history (isotopes: average diet of life; microwear: last days/weeks before death), allows us to generate high-resolution and complementary data. Our results show lower values (delta C-13 & delta N-15) in cave bears than in strict herb…

2021

The hydrophobic tails of aliphatic primary alcohols do insert into the hydrophobic core of a lipid bilayer. Thereby, they disrupt hydrophobic interactions between the lipid molecules, resulting in a decreased lipid order, i.e., an increased membrane fluidity. While aromatic alcohols, such as 2-phenylethanol, also insert into lipid bilayers and disturb the membrane organization, the impact of aromatic alcohols on the structure of biological membranes, as well as the potential physiological implication of membrane incorporation has only been studied to a limited extent. Although diverse targets are discussed to be causing the bacteriostatic and bactericidal activity of 2-phenylethanol, it is …

The long journey towards standards for engineering biosystems: Are the Molecular Biology and the Biotech communities ready to standardise?

2020

Standards are the basis of technology: they allow rigorous description and exact measurement of properties, reliable reproducibility and a common “language” that enables different communities to work together. Molecular biology was in part created by physicists; yet, the field did not inherit the focus on the quantitation, the definition of system boundaries and the robust, unequivocal language that is characteristic of the other natural sciences. However, synthetic biology (SynBio) increasingly requires scientific, technical, operational and semantic standards for the field to become a full‐fledged engineering discipline with a high level of accuracy in the design, manufacturing and perfor…

Monod-based ‘single-data’ strategy for biodegradation screening tests

2020

Environmental contextObtaining biodegradation data over time can be difficult, especially when dealing with environmental compartments of increasing complexity. We evaluated the possibility of obtaining a full biodegradation depletion curve from a single biodegradation-time experimental measurement, and found that environmental information related to potential chemical persistence can be derived. The applicability of this ‘single-data’ strategy is illustrated using simulated and experimental data for several compounds. AbstractInformation obtained from biodegradability tests, e.g. half-life (t50) or kinetics parameters, is relevant in environmental risk assessment of new chemicals. In thes…

Performance Study of Twisted Darrieus Hydrokinetic Turbine With Novel Blade Design

2021

Abstract Twisted Darrieus water turbine is receiving growing attention for small-scale hydropower generation. Accordingly, the need for raised water energy conversion incentivizes researchers to focus on the blade shape optimization of twisted Darrieus turbine. In view of this, experimental analysis has been performed to appraise the efficiency of a spiral Darrieus water rotor in the present work. To better the performance parameters of the studied water rotor with twisted blades, three novel blade shapes, namely U-shaped blade, V-shaped blade, and W-shaped blade, have been numerically tested using a computational fluid dynamics three-dimensional numerical model. The maximum power coefficie…

Force Field for Water over Pt(111): Development, Assessment, and Comparison

2018

Metal/water interfaces are key in many natural and industrial processes, such as corrosion, atmospheric, or environmental chemistry. Even today, the only practical approach to simulate large interfaces between a metal and water is to perform force-field simulations. In this work, we propose a novel force field, GAL17, to describe the interaction of water and a Pt(111) surface. GAL17 builds on three terms: (i) a standard Lennard-Jones potential for the bonding interaction between the surface and water, (ii) a Gaussian term to improve the surface corrugation, and (iii) two terms describing the angular dependence of the interaction energy. The 12 parameters of this force field are fitted again…

Nitrogen isotopes in tooth enamel record diet and trophic level enrichment: results from a controlled feeding experiment

2021

Nitrogen isotope ratios (δ15N) are a well-established tool for investigating the dietary and trophic behavior of animals in terrestrial and marine food webs. To date, δ15N values in fossils have primarily been measured in collagen extracted from bone or dentin, which is susceptible to degradation and rarely preserved in deep time (>100,000 years). In contrast, tooth enamel organic matter is protected from diagenetic alteration by the mineral structure of hydroxyapatite and thus is often preserved over geological time. However, due to the low nitrogen content (<0.01 %) of enamel, the measurement of its nitrogen isotopic composition has been prevented by the analytical limit…

Preface: Environmental benefits of biochar

2014

J. Paz-Ferreiro1, A. Mendez6, A. M. Tarquis3,4, A. Cerda5, and G. Gasco2 1School of Civil, Environmental and Chemical Engineering, RMIT University, GPO Box 2476, Melbourne 3001, VIC, Melbourne, Australia 2Departamento de Produccion Agraria, E.T.S.I. Agronomos, Universidad Politecnica de Madrid, Ciudad Universitaria, 28004 Madrid, Spain 3CEIGRAM, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain 4Departamento de Matematica Aplicada, Universidad Politecnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain 5Soil Erosion and Degradation Research Group, Department of Geography, University of Valencia, C/Blasco Ibanez 10, 46010 Valencia, Spain 6Departamento de Ingen…

Non-invasive Geophysical Surveys in Search of the Roman Temple of Augustus Under the Cathedral of Tarragona (Catalonia, Spain): A Case Study

2018

An integrated geophysical survey has been conducted at the Tarragona’s Cathedral (Catalonia, NE Spain) with the aim to confirm the potential occurrence of archaeological remains of the Roman Temple dedicated to the Emperor Augustus. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most renowned temples of Spain (twelfth century) evolving from Romanesque to Gothic styles. A geophysical project including electrical resistivity tomography (ERT) and ground probing radar (GPR) was planned over 1 year considering the administrative and logistic difficulties of such a project inside a cathedral of religious…