COVID-19 and Lung Mast Cells: The Kallikrein–Kinin Activation Pathway

Mast cells (MCs) have relevant participation in inflammatory and vascular hyperpermeability events, responsible for the action of the kallikrein–kinin system (KKS), that affect patients inflicted by the severe form of COVID-19. Given a higher number of activated MCs present in COVID-19 patients and their association with vascular hyperpermeability events, we investigated the factors that lead to the activation and degranulation of these cells and their harmful effects on the alveolar septum environment provided by the action of its mediators. Therefore, the pyroptotic processes throughout caspase-1 (CASP-1) and alarmin interleukin-33 (IL-33) secretion were investigated, along with the immunoexpression of angiotensin-converting enzyme 2 (ACE2), bradykinin receptor B1 (B1R) and bradykinin receptor B2 (B2R) on post-mortem lung samples from 24 patients affected by COVID-19. The results were compared to 10 patients affected by H1N1pdm09 and 11 control patients. As a result of the inflammatory processes induced by SARS-CoV-2, the activation by immunoglobulin E (IgE) and degranulation of tryptase, as well as Toluidine Blue metachromatic (TB)-stained MCs of the interstitial and perivascular regions of the same groups were also counted. An increased immunoexpression of the tissue biomarkers CASP-1, IL-33, ACE2, B1R and B2R was observed in the alveolar septum of the COVID-19 patients, associated with a higher density of IgE⁺ MCs, tryptase⁺ MCs and TB-stained MCs, in addition to the presence of intra-alveolar edema. These findings suggest the direct correlation of MCs with vascular hyperpermeability, edema and diffuse alveolar damage (DAD) events that affect patients with a severe form of this disease. The role of KKS activation in events involving the exacerbated increase in vascular permeability and its direct link with the conditions that precede intra-alveolar edema, and the consequent DAD, is evidenced. Therapy with drugs that inhibit the activation/degranulation of MCs can prevent the worsening of the prognosis and provide a better outcome for the patient.     

Photoinduced birefringence in blends of a polyurethane bearing azobenzene moieties and a poly(amide–imide)

A polyurethane (MDI‐DR19Cl) bearing azobenzene moieties was prepared by condensation of 4,4′‐diphenylmethylenediisocyanate and an azobenzene compound, 2‐chloro‐4‐nitro‐4′‐[bis‐(2‐hydroxyethyl)]amine‐azobenzene (DR19Cl). Blends of MDI‐DR19Cl and a poly(amide‐imide) were prepared and characterized by UV‐visible and Fourier transform infrared spectroscopy and by DSC. The purpose of using the blends was to overcome the lack of stability of cast films of pure MDI‐DR19Cl, which tend to crack on storage under ambient conditions. This was successfully achieved and, depending on blend proportions, flexible self‐standing films could be prepared after thermal treatment. Optical storage experiments performed with the blends and pure MDI‐DR19Cl cast films showed a decrease in the remnant values of photoinduced birefringence in the blends (60 % for the blend with 5 wt% MDI‐DR19Cl) compared to pure MDI‐DR19Cl (75%), but, taking into account the low content of MDI‐DR19Cl used, the results obtained are probably sufficient to show the viability of these blends in optical storage applications. Copyright © 2006 Society of Chemical Industry     

Aerobic Training in Young Men Increases the Transfer of Cholesterol to High Density Lipoprotein In Vitro: Impact of High Density Lipoprotein Size

Exercise training not only improves the plasma lipid profile but also reduces risk of developing coronary heart disease. We investigate whether plasma lipids and high density lipoprotein (HDL) metabolism are affected by aerobic training and whether the high-density lipoprotein cholesterol (HDL-C) levels at baseline influence exercise-induced changes in HDL. Seventy-one male sedentary volunteers were evaluated and allocated in two subgroups, according to the HLD-C levels (< or >40 mg/dL). Participants underwent an 18-week aerobic training period. Blood was sampled before and after training for biochemical analysis. Plasma lipids, apolipoproteins, HDL diameter, and VO₂ peak were determined. Lipid transfers to HDL were determined in vitro by incubating plasma samples with a donor lipid artificial nanoemulsion. After the 18-week period of aerobic training, the VO₂ peak increased, while the mean body mass index (BMI) decreased. HDL-C concentration was higher after the training period, but low-density lipoprotein cholesterol (LDL-C) and non-HDL-C did not change. The transfer of esterified cholesterol and phospholipids was greater after exercise training, but the triacylglycerol and unesterified cholesterol transfers were unchanged. The HDL particle diameter increased after aerobic training in all participants. When the participants were separated in low-HDL and normal-HDL groups, the postaerobic exercise increment in HDL-C was higher in the low-HDL group, while the transfer of esterified cholesterol was lower. In conclusion, aerobic exercise training increases the lipid transfers to HDL, as measured by an in vitro method, which possibly contributes to the classical elevation of the HDL-C associated with training.     

Femtosecond-laser selective printing of graphene oxide and PPV on polymeric microstructures

Direct laser writing techniques are suitable for the high precision-patterning of 2D and 3D micro/nanostructures, featuring a variety of geometries and materials. Here, we demonstrated the use of laser-induced forward transfer with fs-pulses (fs-LIFT) to selectively transfer graphene oxide and poly(p-phenylene vinylene) patterns onto polymeric microstructures, fabricated by two-photon polymerization. The influence of different fs-LIFT experimental parameters on the width and height of the printed patterns was investigated. Upon optimum fs-LIFT parameters, we achieved homogeneous printed areas of both materials onto specific regions of the microstructures. Raman spectroscopy confirmed that fs-LIFT does not change the donor material upon transfer. Overall, this work demonstrates a promising strategy with precise printing capabilities, thus opening new opportunities for the development of photonic and optoelectronic devices.

     

Rue and Brazilian peppertree essential oils inhibit the germination and initial development of the invasive plant lovegrass

ABSTRACT

Lovegrass (Eragrostis plana) is the most important invasive plant in pastures of southern Brazil. The research evaluated the potential of Ruta graveolens (rue) and Schinus terebinthifolius (Brazilian peppertree) essential oils (EOs) to inhibit germination and initial development of lovegrass. The in vitro treatments tested were control (distilled water), alcohol control, 0.001, 0.005, 0.01, 0.05 and 0.1% (v/v) of both EOs. Higher concentrations of these EOs were applied to germinated plants under greenhouse conditions. The EOs of both species were effective in reducing lovegrass germination, with emphasis on rue. Height and shoot dry mass, at greenhouse conditions, were significantly reduced by both EOs, especially when applied at a concentration of 1%. The results point to the potential of rue and Brazilian peppertree EOs for the formulation of natural herbicides.     

Polyvinylpyrrolidone electrospun nanofibers doped with Eu3+: Fabrication,characterization, and application in gas sensors

Polymer nanofibers (NFs)-based optical sensors hold great potential to fabricate low-cost devices capable to monitor different volatile organic compounds (VOCs) related to healthcare and environmental conditions. For instance, ammonia detection is a subject of paramount importance, owing to the serious health problems associated to the exposition to this volatile. In this context, here, we report on the development of optical electrospun NFs composed of polyvinylpyrrolidone (PVP) doped with Europium (Eu³⁺) aiming at the detection of ammonia. The fabricated NFs were characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, fluorescence microscopy, photoluminescence, and excited state lifetime spectroscopies. The luminescence properties changes were evaluated by exposing the PVP_Eu³⁺ NFs to ammonia and other distinct interfering VOCs including toluene, tetrahydrofuran, acetone, triethylamine, acetic acid, and chloroform. The sensor exhibited a linear response to ammonia exposition in the concentration range from 0 to 50 ppm, yielding a detection limit of 4.7 ppm. Our results indicate the potential application of PVP_Eu³⁺ electrospun NFs in optical sensors for ammonia detection at room temperature based on luminescence quenching. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47775.     

Hybrid composite material based on polythiophene derivative nanofibers modified with gold nanoparticles for optoelectronics applications

Conjugated polymers have been extensively applied as active materials in nanostructured platforms for optical and electrical devices. The incorporation of metal nanoparticles (NPs) into the polymer-based platform arises as a strategy to develop novel hybrid functional nanocomposites with enhanced electrical and optical properties. However, efficient and simple processing routes to produce such nanocomposites are still on demand. In this work, we present an effective route to obtain functional nanocomposites based on electrospun nanofibers coated with gold nanoparticles, displaying interesting optical and electrical properties. Polymethyl methacrylate (PMMA) electrospun nanofibers doped with poly(3-hexyl thiophene-2,5-diyl) (P3HT) were obtained by the electrospinning technique, and displayed a strong red emission centered at 650 nm assigned to P3HT. Such nanofibers were deposited on to fluorine-doped tin oxide electrodes and with modified with gold nanoparticles (AuNPs) in order to produce hybrid composite materials. The performance of electrodes modified with PMMA/P3HT-AuNPs composite material was evaluated by impedance spectroscopy and revealed an enhancement of electron transfer kinetics, which indicates it as a potential platform for optical and electrochemical (bio)sensors.     

Obtaining the threat model for e-mail phishing

Phishing is a kind of embezzlement that uses social engineering in order to obtain personal information from its victims, aiming to cause losses. In the technical literature only the hit rate of the classifiers is mentioned to justify the effectiveness of the phishing detecting techniques. Aspects such as the accuracy of the classifier results (false positive rate), computational effort and the number of features used for phishing detection are rarely taken into account. In this work we propose a technique that yields the minimum set of relevant features providing reliability, good performance and flexibility to the phishing detection engine. The experimental results reported in this work show that the proposed technique could be used to optimize the detection engine of the anti-phishing scheme.     

Exercise–Linked Irisin: Consequences on Mental and Cardiovascular Health in Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) is a metabolic disorder associated with insulin resistance and hyperglycemia. Chronic exposure to a T2DM microenvironment with hyperglycemia, hyperinsulinemia, oxidative stress and increased levels of proinflammatory mediators, has negative consequences to the cardiovascular system and mental health. Therefore, atherosclerotic cardiovascular diseases (CVD) and mental health issues have been strongly associated with T2DM. Lifestyle modifications, including physical exercise training, are necessary to prevent T2DM development and its associated complications. It is widely known that the regular practice of exercise provides several physiological benefits to subjects with T2DM, such as managing glycemic and blood pressure levels. Different types of exercise, from aerobic to resistance training, are effective to improve mental health and cognitive function in T2DM. Irisin is a myokine produced in response to exercise, which has been pointed as a relevant mechanism of action to explain the benefits of exercise on cardiovascular and mental health in T2DM patients. Here, we review emerging clinical and experimental evidence about exercise-linked irisin consequences to cardiovascular and mental health in T2DM.