Biodegradation of diethylketone by Penicillium sp. and Alternaria sp.: a comparative study biodegradation of diethylketone by fungi

Two contaminating fungi were isolated from a bioreactor containing diethylketone and Streptococcus equisimilis, subsequently characterized at molecular level and identified as belonging to the Alternaria and Penicillium genera. The ability of these fungi to biodegrade DEK is evaluated. The kinetic parameters are estimated using four growth kinetic models for biodegradation of organic compounds available in literature. The experimental data for Alternaria sp. and Penicillium sp. was found to be better fitted by the Haldane and the Luong respectively. Biodegradation rate kinetics was evaluated using zero-order, pseudo-first order, pseudo-second order and three-half order models. The pseudo-second-order model was found suitable for all the concentrations of DEK tested for the biodegradation assays using Penicillium sp. whereas for the Alternaria sp. this model just describes properly the assays with initial concentrations of DEK higher than 0.5 g/L. The percentage of biodegraded DEK were approximately 100%, for all the initial concentrations tested

Antimicrobial activity of phenolic extracts of Eucalyptus globulus and Juglans regia against dairy industry pathogens

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Bovine mastitis (BM) is the most expensive pathology for dairy industry and Staphylococcus aureus is amongst the most prevalent causative agents of this disease. Nowadays, it is known that S. aureus contaminated milk can enter the dairy production chain and be the origin of food contamination. Due to the poor efficacy of antibiotics and to the ability to form biofilms evidenced by this pathogen, BM has become increasingly difficult to control and to eradicate. Phenolic plant extracts are nowadays being evaluated since they are a rich source of bioactive molecules. Thus, in this work the antimicrobial activity of E. globulus and J. regia alone and in combination against S. aureus BM isolates was evaluated and compared with penicillin G (Pen G), an antibiotic commonly used in the treatment of this pathology. The evaluation of the cytotoxic potential of both extracts was also performed. [...]info:eu-repo/semantics/publishedVersio

Introduction: new trends on dynamical systems and differential equations

The main contributions of [Int. J. Dyn. Syst. Differ. Equ., Vol. 8, Nos. 1/2 (2018)], consisting of 11 papers selected and revised from the international conference IMAME’2016, are highlighted.publishe

Necessary Optimality Conditions for Higher-Order Infinite Horizon Variational Problems on Time Scales

We obtain Euler-Lagrange and transversality optimality conditions for higher-order infinite horizon variational problems on a time scale. The new necessary optimality conditions improve the classical results both in the continuous and discrete settings: our results seem new and interesting even in the particular cases when the time scale is the set of real numbers or the set of integers.Comment: This is a preprint of a paper whose final and definite form will appear in Journal of Optimization Theory and Applications (JOTA). Paper submitted 17-Nov-2011; revised 24-March-2012 and 10-April-2012; accepted for publication 15-April-201

COVID-19 in relation to hyperglycemia and diabetes mellitus

Coronavirus disease 2019 (COVID-19), triggered by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), may lead to extrapulmonary manifestations like diabetes mellitus (DM) and hyperglycemia, both predicting a poor prognosis and an increased risk of death. SARS-CoV-2 infects the pancreas through angiotensin-converting enzyme 2 (ACE2), where it is highly expressed compared to other organs, leading to pancreatic damage with subsequent impairment of insulin secretion and development of hyperglycemia even in non-DM patients. Thus, this review aims to provide an overview of the potential link between COVID-19 and hyperglycemia as a risk factor for DM development in relation to DM pharmacotherapy. For that, a systematic search was done in the database of MEDLINE through Scopus, Web of Science, PubMed, Embase, China National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), and Wanfang Data. Data obtained underline that SARS-CoV-2 infection in DM patients is more severe and associated with poor clinical outcomes due to preexistence of comorbidities and inflammation disorders. SARS-CoV-2 infection impairs glucose homeostasis and metabolism in DM and non-DM patients due to cytokine storm (CS) development, downregulation of ACE2, and direct injury of pancreatic beta-cells. Therefore, the potent anti-inflammatory effect of diabetic pharmacotherapies such as metformin, pioglitazone, sodium-glucose co-transporter-2 inhibitors (SGLT2Is), and dipeptidyl peptidase-4 (DPP4) inhibitors may mitigate COVID-19 severity. In addition, some antidiabetic agents and also insulin may reduce SARS-CoV-2 infectivity and severity through the modulation of the ACE2 receptor expression. The findings presented here illustrate that insulin therapy might seem as more appropriate than other anti-DM pharmacotherapies in the management of COVID-19 patients with DM due to low risk of uncontrolled hyperglycemia and diabetic ketoacidosis (DKA). From these findings, we could not give the final conclusion about the efficacy of diabetic pharmacotherapy in COVID-19; thus, clinical trial and prospective studies are warranted to confirm this finding and concern

Targeting the Oxidative Stress Response System of Fungi with Redox-Potent Chemosensitizing Agents

The cellular antioxidant system is a target in the antifungal action of amphotericin B (AMB) and itraconazole (ITZ), in filamentous fungi. The sakAΔ mutant of Aspergillus fumigatus, a mitogen-activated protein kinase (MAPK) gene deletion mutant in the antioxidant system, was found to be more sensitive to AMB or ITZ than other A. fumigatus strains, a wild type and a mpkCΔ mutant (a MAPK gene deletion mutant in the polyalcohol sugar utilization system). Complete fungal kill (≥99.9%) by ITZ or AMB was also achieved by much lower dosages for the sakAΔ mutant than for the other strains. It appears msnA, an Aspergillus ortholog to Saccharomyces cerevisiae MSN2 (encoding a stress-responsive C2H2-type zinc-finger regulator) and sakA and/or mpkC (upstream MAPKs) are in the same stress response network under tert-butyl hydroperoxide (t-BuOOH)-, hydrogen peroxide (H2O2)- or AMB-triggered toxicity. Of note is that ITZ-sensitive yeast pathogens were also sensitive to t-BuOOH, showing a connection between ITZ sensitivity and antioxidant capacity of fungi. Enhanced antifungal activity of AMB or ITZ was achieved when these drugs were co-applied with redox-potent natural compounds, 2,3-dihydroxybenzaldehyde, thymol or salicylaldehyde, as chemosensitizing agents. We concluded that redox-potent compounds, which target the antioxidant system in fungi, possess a chemosensitizing capacity to enhance efficacy of conventional drugs

Transversality Conditions for Infinite Horizon Variational Problems on Time Scales

We consider problems of the calculus of variations on unbounded time scales. We prove the validity of the Euler-Lagrange equation on time scales for infinite horizon problems, and a new transversality condition.Comment: Submitted 6-October-2009; Accepted 19-March-2010 in revised form; for publication in "Optimization Letters"

Electromechanical Modulations in Transition Metal Dichalcogenide Nanosheets: Implications for Environmental Sensors

Transition metal dichalcogenides (TMDs) are key players in the two-dimensional materials nanoarena due to their exquisite optoelectronic properties under a standard environment (room temperature and atmospheric pressure). Nevertheless, as reported in the literature, they may also portray interesting physical properties under different environments. Here, we show two distinct and significant electromechanical modulations in TMD nanosheets which are tuned by the environmental conditions (applied pressure and adsorbents). Using scanning probe microscopy techniques, we modify the environmental conditions and observe steplike rises in the electrical response of all studied TMDs (MoS2, WS2, MoSe2, and WSe2—monolayers and few layers). Ab initio calculations enable full understanding of specific mechanisms behind these electromechanical modulations, which may find important applications in the design of TMD-based environmental sensors

Phenolic bioactives as antiplatelet aggregation factors: the pivotal ingredients in maintaining cardiovascular health

Cardiovascular diseases (CVD) are one of the main causes of mortality in the world. The development of these diseases has a specific factor—alteration in blood platelet activation. It has been shown that phenolic compounds have antiplatelet aggregation abilities and a positive impact in the management of CVD, exerting prominent antioxidant, anti-inflammatory, antitumor, cardioprotective, antihyperglycemic, and antimicrobial effects. Thus, this review is intended to address the antiplatelet activity of phenolic compounds with special emphasis in preventing CVD, along with the mechanisms of action through which they are able to prevent and treat CVD. In vitro and in vivo studies have shown beneficial effects of phenolic compound-rich plant extracts and isolated compounds against CVD, despite that the scientific literature available on the antiplatelet aggregation ability of phenolic compounds in vivo is scarce. Thus, despite the current advances, further studies are needed to confirm the cardioprotective potential of phenolic compounds towards their use alone or in combination with conventional drugs for effective therapeutic interventions.N.C.-M. acknowledges the Portuguese Foundation for Science and Technology under the Horizon 2020 Program (PTDC/PSI-GER/28076/2017).info:eu-repo/semantics/publishedVersio

Curcumin encapsulation in nanostructures for cancer therapy: a 10-year overview

Journal pre-proofsCurcumin (CUR) is a phenolic compound present in some herbs, including Curcuma longa Linn. (turmeric rhizome), with a high bioactive capacity and characteristic yellow color. It is mainly used as a spice, although it has been found that CUR has interesting pharmaceutical properties, acting as a natural antioxidant, anti-inflammatory, antimicrobial, and antitumoral agent. Nonetheless, CUR is a hydrophobic compound with low water solubility, poor chemical stability, and fast metabolism, limiting its use as a pharmacological compound. Smart drug delivery systems (DDS) have been used to overcome its low bioavailability and improve its stability. The current work overviews the literature from the past 10 years on the encapsulation of CUR in nanostructured systems, such as micelles, liposomes, niosomes, nanoemulsions, hydrogels, and nanocomplexes, emphasizing its use and ability in cancer therapy. The studies highlighted in this review have shown that these nanoformulations achieved higher solubility, improved tumor cytotoxicity, prolonged CUR release, and reduced side effects, among other interesting advantages.This study was funded by the Coordination for Higher Level Graduate Improvements (CAPES/Brazil, finance code 001), National Council for Scientific and Technological Development (CNPq/Brazil, PIBIC process #123483/2020-4), State of São Paulo Research Foundation (FAPESP/Brazil, processes #2017/10789-1, #2018/10799-0, #2018/06475-4, #2018/07707-6, #2019/08549-8, and #2020/03727-2). This work was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project AgriFood XXI (NORTE-01-0145-FEDER-000041) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Our Figures were created with BioRenderinfo:eu-repo/semantics/publishedVersio