3,135 research outputs found
On Hopf's Lemma and the Strong Maximum Principle
In this paper we consider Hopf's Lemma and the Strong Maximum Principle for
supersolutions to a class of non elliptic equations. In particular we prove a
sufficient condition for the validity of Hopf's Lemma and of the Strong Maximum
Principle and we give a condition which is at once necessary for the validity
of Hopf's Lemma and sufficient for the validity of the Strong Maximum
Principle.Comment: 27 pages,4 figure
Promoting Sustainable Food Consumption: An Agent-Based Model About Outcomes of Small Shop Openings
A useful way of promoting sustainable food consumption is to consider the spread of food retail operations focused on food diversification, food specialization, and fresh and local products. These food shops are generally small, which is a great problem for survival against ruthless competition from supermarkets. Our research objective was to construct a simulation with an agent-based model, reproducing the local food consumption market and to investigate how a new, small food retailing shop interacts with this market. As a case study, the model simulates the opening of a small farmers' market. The intent of the model is to reproduce the current status of consumption for food products within a certain territorial context and given time period, and to investigate how consumers' behaviour changes with the opening of the new shop. As a result, we could predict changes in consumers' habits, the economic positioning of new, small shops and its best location. This information is of considerable interest for farmers' markets and also for policymakers
Ectopic mineralization in heart valves: New insights from in vivo and in vitro procalcific models and promising perspectives on noncalcifiable bioengineered valves
Ectopic calcification of native and bioprosthetic heart valves represents a major public health
problem causing severe morbidity and mortality worldwide. Valve procalcific degeneration is known to be
caused mainly by calcium salt precipitation onto membranes of suffering non-scavenged cells and dead-cellderived
products acting as major hydroxyapatite nucleators. Although etiopathogenesis of calcification in
native valves is still far from being exhaustively elucidated, it is well known that bioprosthesis mineralization
may be primed by glutaraldehyde-mediated toxicity for xenografts, cryopreservation-related damage for
allografts and graft immune rejection for both. Instead, mechanical valves, which are free from calcification,
are extremely thrombogenic, requiring chronic anticoagulation therapies for transplanted patients. Since
surgical substitution of failed valves is still the leading therapeutic option, progressive improvements in tissue
engineering techniques are crucial to attain readily available valve implants with good biocompatibility,
proper functionality and long-term durability in order to meet the considerable clinical demand for valve
substitutes. Bioengineered valves obtained from acellular non-valvular scaffolds or decellularized native
valves are proving to be a compelling alternative to mechanical and bioprosthetic valve implants, as they
appear to permit repopulation by the host\u2019s own cells with associated tissue remodelling, growth and repair,
besides showing less propensity to calcification and adequate hemodynamic performances. In this review,
insights into valve calcification onset as revealed by in vivo and in vitro procalcific models are updated as well
as advances in the field of valve bioengineering
Biochar impact on the estimation of the colorimetric-based enzymatic assays of soil
This study was carried out in order to assess the influence of biochar applications on
the estimation of colorimetric-based
enzymatic assays and to verify the effectiveness
of the most common methods. Since most methods used to determine enzymatic
activities in the soil are based on colorimetry, biochar may absorb substrates and/
or coloured products thereby distorting the analytical result. Biochar was added to
two soils, with different textures and cation exchangeable capacities, at a rate of
2% (w/w), and seven enzyme activities were determined following standard methods.
The biochar amendment lowered the spectrophotometer reading of the activity
of FDAase and dehydrogenase in the sandy soil. In the three enzymatic activities
based on p-nitrophenol
production (β-glucosidase,
phosphatase and arylsulphatase),
the addition of biochar did not change the enzyme assays. The biochar led to an
overestimation in terms of the protease and urease activities in the sandy soil. In the
clay loamy soil, biochar did not change the response of any of the enzyme activities
tested. A biochar dose of up to 2% only guarantees the effectiveness of the most common
spectrophotometric methods for not excessively sandy soils
The Transformative Potential of Lipid Nanoparticle-Protein Corona for Next-Generation Vaccines and Therapeutics
The integration of the lipid nanoparticle (LNP)-protein corona as a pioneering approach for the development of vaccines against the present and future SARS-CoV-2 variants of concern marks a significant shift in the field. This concept holds great promise, offering a universal platform that can be adaptable to combat future pandemics caused by unknown viruses. Understanding the complex interactions among the protein corona, LNPs, and receptors is crucial for harnessing its potential. This knowledge will allow optimal vaccine formulations and improve their effectiveness. Safety assessments are essential to ensure suitability for human use, compliance with regulatory standards, and rigorous quality control in manufacturing. This transformative workflow requires collaborative efforts, expanding our foundational knowledge and translating advancements from the laboratory to clinical reality. The LNP-protein corona approach represents a paradigmatic shift with far-reaching implications. Its principles and insights can be leveraged beyond specific applications against SARS-CoV-2, enabling a universal platform for addressing viral threats, cancer, and genetic diseases
The non-indigenous Paranthura japonica Richardson, 1909 in the Mediterranean Sea: travelling with shellfish?
An anthurid isopod new to the Mediterranean Sea has recently been observed in samples from three localities of the Italian coast: the Lagoon of Venice (North Adriatic Sea), La Spezia (Ligurian Sea) and Olbia (Sardinia, Tyrrhenian Sea). The specimens collected showed strong affinity to a species originally described from the NW Pacific Ocean: Paranthura japonica Richardson, 1909. The comparison with specimens collected from the Bay of Arcachon (Atlantic coast of France), where P. japonica had been recently reported as non-indigenous, confirmed the identity of the species. This paper reports the most relevant morphological details of the Italian specimens, data on the current distribution of the species and a discussion on the pathways responsible for its introduction. The available data suggest that the presence of this Pacific isopod in several regions of coastal Europe might be due to a series of aquaculture-mediated introduction events that occurred during the last decades of the 1900s. Since then, established populations of P. japonica, probably misidentified, remained unnoticed for a long time
Biomimetic Electrospun Self-Assembling Peptide Scaffolds for Neural Stem Cell Transplantation in Neural Tissue Engineering
Spinal cord regeneration using stem cell transplantation is a promising strategy for regenerative therapy. Stem cells transplanted onto scaffolds that can mimic natural extracellular matrix (ECM) have the potential to significantly improve outcomes. In this study, we strived to develop a cell carrier by culturing neural stem cells (NSCs) onto electrospun 2D and 3D constructs made up of specific crosslinked functionalized self-assembling peptides (SAPs) featuring enhanced biomimetic and biomechanical properties. Morphology, architecture, and secondary structures of electrospun scaffolds in the solid-state and electrospinning solution were studied step by step. Morphological studies showed the benefit of mixed peptides and surfactants as additives to form thinner, uniform, and defect-free fibers. It has been observed that β-sheet conformation as evidence of self-assembling has been predominant throughout the process except for the electrospinning solution. In vitro NSCs seeded on electrospun SAP scaffolds in 2D and 3D conditions displayed desirable proliferation, viability, and differentiation in comparison to the gold standard. In vivo biocompatibility assay confirmed the permissibility of implanted fibrous channels by foreign body reaction. The results of this study demonstrated that fibrous 2D/3D electrospun SAP scaffolds, when shaped as micro-channels, can be suitable to support NSC transplantation for regeneration following spinal cord injury
Cholesterol dependent macropinocytosis and endosomal escape control the transfection efficiency of lipoplexes in CHO Living Cells
Here we investigate the cellular uptake mechanism and final intracellular fate of two cationic liposome formulations characterized by similar physicochemical properties but very different lipid composition and efficiency for intracellular delivery of DNA. The first formulation is made of cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and the zwitterionic helper dioleoylphosphocholine (DOPC), while the second one is made of the cationic 3 beta-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic lipid dioleoylphosphatidylethanolamine (DOPE). Combining pharmacological and imaging approaches we show that both DOTAP-DOPC/DNA and DC-Chol-DOPE/DNA lipoplexes are taken up in Chinese hamster ovary (CHO) living cells mainly through fluid-phase macropinocytosis. Our results also indicate that lipoplex macropinocytosis is a cholesterol-sensitive uptake mechanism. On the other side, both clathrin-mediated and caveolae-mediated endocytosis play a minor role, if any, in the cell uptake. Colocalization of fluorescently tagged lipoplexes and Lysosensor, a primary lysosome marker, reveals that poorly efficient DOTAP-DOPC/DNA lipoplexes are largely degraded in the lysosomes, while efficient DC-Chol-DOPE/DNA systems can efficiently escape from endosomal compartments
Análisis y ejecución de estrategias en la industria de sensores mediante la simulación CAPSIM
Documento en el que se muestra el trabajo realizado en la dirección de una empresa de la industria de sensores dentro del simulador de negocios Capsim. Se presenta un análisis de la industria de los sensores, se describe la empresa en la que se trabajó, las estrategias de negocio y el proceso de su implementación, así como los resultados finales
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