Fluorite mineralization related to the dolomitization: an equilibrium study of the Proterozoic stratabound carbonate Macaia-Ijaci Basin, Lavras, Minas Gerais, Brazil

Stratabound fluorite occurring as thin films in the concomitantly derived dolomitic portions of the calcitic limestone of the Proterozoic Carandaí Formation in the Macaia-Ijaci Basin was supposedly formed by metasomatic reactions between the carbonate and HF- and Mg2+- rich brines, during metamorphism. Thirteen electron microprobe analyses from the carbonate in a single petrographic thin section, allowed the determination of the temperature of the carbonate formation in the range 180º-230ºC, using the Mg-calcite solvus geothermometer. Five key mineral reactions in the system Mg-Ca-C-H-O-F plotted in diagrams in terms of either, CO2- and HF-fugacities or chemical potentials of CO2 and HF yielding fluorite + dolomite from calcite + Mg2+, are proposed. Apparently the fluorite formation is related with dolomitization. Additional reaction involving fluorite was calculated and inserted in the phase diagram, according to the existence of calcite-fluorite veinlets bordered by dolomite selvages, at the Casa de Pedra quarry.Fluorita estratiforme ocorrendo como delgados filmes nas concomitantemente derivadas porções dolomíticas do calcário calcítico da Formação Carandaí do Proterozóico, na Bacia Macaia-Ijaci foi su-postamente formada por reações metassomáticas entre o carbonato e salmouras ricas em HF e Mg2+, durante o metamorfismo. Treze análises de micro-sonda eletrônica dos carbonatos em uma única lâmina petrográfica delgada , permitiram a determinação da temperatura de formação dos carbonatos na faixa 180º-230ºC, utilizando o geotermômetro Mg-calcita/solvus. Cinco reações-chave no sistema Mg-Ca-C-H-O-F lançadas em diagramas em termos de fugacidades ou potenciais químicos de CO2 e HF produzindo fluorita+dolomita a partir de calcita+Mg2+ são propostas. Aparentemente a formação de fluorita é relacionada à dolomitização. Reação adicional envolvendo fluorita foi calculada e inserida no diagrama de fases, de acordo com a existência de venulações de fluorita-calcita bordejados por dolomita na pedreira de Casa de Pedra

Signals from the Niche: Insights into the Role of IGF-1 and IL-6 in Modulating Skeletal Muscle Fibrosis

Abstract Muscle regeneration, characterized by the activation and proliferation of satellite cells and other precursors, is accompanied by an inflammatory response and the remodeling of the extracellular matrix (ECM), necessary to remove cellular debris and to mechanically support newly generated myofibers and activated satellite cells. Muscle repair can be considered concluded when the tissue architecture, vascularization, and innervation have been restored. Alterations in these connected mechanisms can impair muscle regeneration, leading to the replacement of functional muscle tissue with a fibrotic scar. In the present review, we will discuss the cellular mediators of fibrosis and how the altered expression and secretion of soluble mediators, such as IL-6 and IGF-1, can modulate regulatory networks involved in the altered regeneration and fibrosis during aging and diseases

Cardiotoxicity of Anticancer Drugs: Molecular Mechanisms and Strategies for Cardioprotection

Chemotherapy and targeted therapies have significantly improved the prognosis of oncology patients. However, these antineoplastic treatments may also induce adverse cardiovascular effects, which may lead to acute or delayed onset of cardiac dysfunction. These common cardiovascular complications, commonly referred to as cardiotoxicity, not only may require the modification, suspension, or withdrawal of life-saving antineoplastic therapies, with the risk of reducing their efficacy, but can also strongly impact the quality of life and overall survival, regardless of the oncological prognosis. The onset of cardiotoxicity may depend on the class, dose, route, and duration of administration of anticancer drugs, as well as on individual risk factors. Importantly, the cardiotoxic side effects may be reversible, if cardiac function is restored upon discontinuation of the therapy, or irreversible, characterized by injury and loss of cardiac muscle cells. Subclinical myocardial dysfunction induced by anticancer therapies may also subsequently evolve in symptomatic congestive heart failure. Hence, there is an urgent need for cardioprotective therapies to reduce the clinical and subclinical cardiotoxicity onset and progression and to limit the acute or chronic manifestation of cardiac damages. In this review, we summarize the knowledge regarding the cellular and molecular mechanisms contributing to the onset of cardiotoxicity associated with common classes of chemotherapy and targeted therapy drugs. Furthermore, we describe and discuss current and potential strategies to cope with the cardiotoxic side effects as well as cardioprotective preventive approaches that may be useful to flank anticancer therapies

Reawakening the Intrinsic Cardiac Regenerative Potential: Molecular Strategies to Boost Dedifferentiation and Proliferation of Endogenous Cardiomyocytes

Despite considerable efforts carried out to develop stem/progenitor cell-based technologies aiming at replacing and restoring the cardiac tissue following severe damages, thus far no strategies based on adult stem cell transplantation have been demonstrated to efficiently generate new cardiac muscle cells. Intriguingly, dedifferentiation, and proliferation of pre-existing cardiomyocytes and not stem cell differentiation represent the preponderant cellular mechanism by which lower vertebrates spontaneously regenerate the injured heart. Mammals can also regenerate their heart up to the early neonatal period, even in this case by activating the proliferation of endogenous cardiomyocytes. However, the mammalian cardiac regenerative potential is dramatically reduced soon after birth, when most cardiomyocytes exit from the cell cycle, undergo further maturation, and continue to grow in size. Although a slow rate of cardiomyocyte turnover has also been documented in adult mammals, both in mice and humans, this is not enough to sustain a robust regenerative process. Nevertheless, these remarkable findings opened the door to a branch of novel regenerative approaches aiming at reactivating the endogenous cardiac regenerative potential by triggering a partial dedifferentiation process and cell cycle re-entry in endogenous cardiomyocytes. Several adaptations from intrauterine to extrauterine life starting at birth and continuing in the immediate neonatal period concur to the loss of the mammalian cardiac regenerative ability. A wide range of systemic and microenvironmental factors or cell-intrinsic molecular players proved to regulate cardiomyocyte proliferation and their manipulation has been explored as a therapeutic strategy to boost cardiac function after injuries. We here review the scientific knowledge gained thus far in this novel and flourishing field of research, elucidating the key biological and molecular mechanisms whose modulation may represent a viable approach for regenerating the human damaged myocardium

Unraveling the selective antibacterial activity and chemical composition of citrus essential oils

ABSTRACT Post-weaning diarrhea (PWD) is an often disease affecting piglets. It is caused mainly by enterotoxigenic Escherichia coli (ETEC) colonization in pig gut. Antibiotics has been used to prevent, combat and control PWD and its negative impact on the productivity of pig breeding sector. Nonetheless, antibiotics due to their wide antibacterial spectrum also can reach beneficial gut bacteria, such as Lactobacillus. Lately, essential oils (EOs) have emerged as a potential alternative to using antibiotics in animal breeding because of their effect on bacterial growth. Commonly, citrus EOs are by-products of food industry and the availability of these EOs in the worldwide market is huge. Thus, six commercials citrus EOs were evaluated on ETEC strains, as model of pathogenic bacteria, and on Lactobacillus species, as models of beneficial bacteria. In overall, citrus EOs exhibited a selective antibacterial activity with higher effect on pathogenic bacteria (ETECs) than beneficial bacteria (Lactobacillus). Brazilian orange terpenes (BOT) oil presented the highest selective performance and caused higher disturbances on the normal growth kinetic of ETEC than on Lactobacillus rhamnosus. The action was dose-dependent on the maximal culture density (A) and the lag phase duration (λ) of the ETEC. The highest sub-inhibitory concentration (0.925 mg/mL) extended the λ duration to ETEC eight times (14.6 h) and reduced A in 55.9%. For L. rhamnosus, the λ duration was only extended 1.6 times. Despite the fact that limonene was detected as the major compound, the selective antibacterial activity of the citrus EOs could not be exclusively attributed to limonene since the presence of minor compounds could be implicated in conferring this feature

Estimación de la vida útil de corazones de alcachofa (Cynara scolymus L.) marinados en conserva y el contenido de omega 3 y omega 6

In this study we estimated shelf life of canned marinated hearts of artichoke (Cynara scolymus L.) which had the major sensory preference in color and flavor evaluated by a semi trained panel conformed by 15 judges. Also omega 3 and omega 6 content was determined (28.69 g/100g y 43.26 g/100g of fat respectively) which are within the limit approved by the World Health Organization. It was done the estimation of the shelf life by accelerated testing, the samples were incubated at 37oC, 49oC and 55oC, evaluating the kinetic of deterioration of the fat in function of the peroxide index that followed a reaction of order zero. The temperature effect was evaluated with the equation of Arrhenius, and the activation energy was 96115.6 J/mol. At a storage temperature of 20 oC, the estimation of shelf life was 892 days.Se estimó el tiempo de vida útil de cuartos de corazones de alcachofa (Cynara scolymus L.) marinados en conserva que presentaron mayor preferencia sensorial en color y sabor evaluados por un panel semientrenado conformado por 15 jueces. A esta conserva se le determinó el contenido de ácidos grasos omega 3 y omega 6 (28.69 g/100g y 43.26 g/100g de grasa respectivamente), los cuales están dentro del límite aprobado por la Organización Mundial de la Salud. El tiempo de vida útil se determinó mediante pruebas aceleradas, incubando las muestras a las temperaturas de 37oC, 49oC y 55oC, evaluando la cinética de deterioro de la grasa en función al índice de peróxido, que siguió una reacción de orden cero. El efecto de la temperatura se evaluó con la ecuación de Arrhenius, encontrándose un valor de Energía de activación de 96115.6 J/mol. El tiempo de vida útil estimado fue de 892 días a la temperatura de almacenamiento de 20°C

Spheroid three-dimensional culture enhances Notch signaling in cardiac progenitor cells

Cardiac progenitor cells (CPCs) are a promising candidate for cardiac regeneration, and the interaction between CPCs and their microenvironment can influence their regenerative response. Notch signaling plays a key role in cell fate decisions in the developing and adult heart. Here, we investigated the effect of three-dimensional (3D) spheroid culture, as a model of the 3D microenvironment, on Notch in fetal and adult human CPCs, under room air (20%) and physiological (5%) oxygen tension. Notch signaling is enhanced in 3D spheroids; spheroid culture under 5% O2 further increases Notch signaling enhancement, and might ultimately improve the regenerative potential of CPCs

The autocrine loop of ALK receptor and ALKAL2 ligand is an actionable target in consensus molecular subtype 1 colon cancer

In the last years, several efforts have been made to classify colorectal cancer (CRC) into well-defined molecular subgroups, representing the intrinsic inter-patient heterogeneity, known as Consensus Molecular Subtypes (CMSs)

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements