Numerical simulation of atom-transfer radical polymerization of tert-butyl methacrylate

Block copolymers based on tert-butyl methacrylate (tBMA) have many uses, such as thermoresponsive polymers, amphiphilic copolymers, and many applications in the medical field. Atom-transfer radical polymerization (ATRP) is the main technique to produce these controlled macromolecular architectures. This paper provides a simplified kinetic modeling and computational study of tBMA ATRP. The main objective is to understand the behavior of chemical species in the reaction and its influence on polymer properties (molecular weight and dispersity). The proposed model presented good reproducibility of the experimental data, with average errors less than 10%. The simulations indicated a strong initiator and catalyst concentration dependence on the monomer conversion. Although the highest initiator proportion induced a dispersity increase in conversions less than 20%, in general, for tBMA ATRP, the range of operational condition cannot affect dispersity directly. In addition, our finds about the effect of Keq on polymer properties indicated that to conduct the reaction using catalyst systems with Keq around 10-5 - 10-6 would provide very low dispersity polymers in a fast reaction time224COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão tem2018/02508-

Effects of exercise training on atrophy gene expression in skeletal muscle of mice with chronic allergic lung inflammation

We evaluated the effects of chronic allergic airway inflammation and of treadmill training (12 weeks) of low and moderate intensity on muscle fiber cross-sectional area and mRNA levels of atrogin-1 and MuRF1 in the mouse tibialis anterior muscle. Six 4-month-old male BALB/c mice (28.5 ± 0.8 g) per group were examined: 1) control, non-sensitized and non-trained (C); 2) ovalbumin sensitized (OA, 20 µg per mouse); 3) non-sensitized and trained at 50% maximum speed _ low intensity (PT50%); 4) non-sensitized and trained at 75% maximum speed _ moderate intensity (PT75%); 5) OA-sensitized and trained at 50% (OA+PT50%), 6) OA-sensitized and trained at 75% (OA+PT75%). There was no difference in muscle fiber cross-sectional area among groups and no difference in atrogin-1 and MuRF1 expression between C and OA groups. All exercised groups showed significantly decreased expression of atrogin-1 compared to C (1.01 ± 0.2-fold): PT50% = 0.71 ± 0.12-fold; OA+PT50% = 0.74 ± 0.03-fold; PT75% = 0.71 ± 0.09-fold; OA+PT75% = 0.74 ± 0.09-fold. Similarly significant results were obtained regarding MuRF1 gene expression compared to C (1.01 ± 0.23-fold): PT50% = 0.53 ± 0.20-fold; OA+PT50% = 0.55 ± 0.11-fold; PT75% = 0.35 ± 0.15-fold; OA+PT75% = 0.37 ± 0.08-fold. A short period of OA did not induce skeletal muscle atrophy in the mouse tibialis anterior muscle and aerobic training at low and moderate intensity negatively regulates the atrophy pathway in skeletal muscle of healthy mice or mice with allergic lung inflammation.FAPESPCNP

Effect of methylprednisolone on perivascular pulmonary edema, inflammatory infiltrate, VEGF and TGF-beta immunoexpression in the remaining lungs of rats after left pneumonectomy

Pneumonectomy is associated with high rates of morbimortality, with postpneumonectomy pulmonary edema being one of the leading causes. An intrinsic inflammatory process following the operation has been considered in its physiopathology. The use of corticosteroids is related to prevention of this edema, but no experimental data are available to support this hypothesis. We evaluated the effect of methylprednisolone on the remaining lungs of rats submitted to left pneumonectomy concerning edema and inflammatory markers. Forty male Wistar rats weighing 300 g underwent left pneumonectomy and were randomized to receive corticosteroids or not. Methylprednisolone at a dose of 10 mg/kg was given before the surgery. After recovery, the animals were sacrificed at 48 and 72 h, when the pO2/FiO2 ratio was determined. Right lung perivascular edema was measured by the index between perivascular and vascular area and neutrophil density by manual count. Tissue expression of vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) were evaluated by immunohistochemistry light microscopy. There was perivascular edema formation after 72 h in both groups (P = 0.0031). No difference was observed between operated animals that received corticosteroids and those that did not concerning the pO2/FiO2 ratio, neutrophil density or TGF-β expression. The tissue expression of VEGF was elevated in the animals that received methylprednisolone both 48 and 72 h after surgery (P = 0.0243). Methylprednisolone was unable to enhance gas exchange and avoid an inflammatory infiltrate and TGF-β expression also showed that the inflammatory process was not correlated with pulmonary edema formation. However, the overexpression of VEGF in this group showed that methylprednisolone is related to this elevation

Spectra of weighted algebras of holomorphic functions

We consider weighted algebras of holomorphic functions on a Banach space. We determine conditions on a family of weights that assure that the corresponding weighted space is an algebra or has polynomial Schauder decompositions. We study the spectra of weighted algebras and endow them with an analytic structure. We also deal with composition operators and algebra homomorphisms, in particular to investigate how their induced mappings act on the analytic structure of the spectrum. Moreover, a Banach-Stone type question is addressed.Comment: 25 pages Corrected typo

Propriedades nutricionais, químicas e bioativas de duas espécies de cogumelos silvestres do género Leccinum, provenientes do Nordeste Transmontano

Os cogumelos são muito apreciados, não apenas pelas suas propriedades organoléticas e nutricionais, mas também pelo seu potencial medicinal e capacidade de produção e acumulação de compostos bioativos. As suas propriedades antioxidantes e antitumorais têm sido amplamente documentadas, nomeadamente, pelo nosso grupo de investigação [1,2]. No entanto, das numerosas espécies que caracterizam a micoflora transmontana, existem ainda espécies pouco estudadas como é o caso de Leccinum molle (Bon) Bon e Leccinum vulpinum Watling. Assim sendo, o objetivo do presente trabalho foi caracterizar nutricional e quimicamente amostras silvestres das espécies referidas, em exemplares provenientes do nordeste transmontano (novembro, 2012). As propriedades antioxidantes e antitumorais dos seus extratos metanólicos foram também estudadas em condições in vitro. As contribuições energéticas obtidas após determinação dos macronutrientes foram 391 e 360 kcal/100 g massa seca para L. molle e L. vulpinum, respetivamente. O açúcar presente em maior quantidade em L. molle foi o manitol (11 g/100 g), enquanto que para L. vulpinum foi a trealose (8 g/100 g). A percentagem de ácidos gordos encontrada em L. molle e L. vulpinum foi, respectivamente: ácidos gordos saturados- 17% (maioritariamente ácido palmítico), monoinsaturados- 39 e 29% (maioritariamente ácido oleico), polinsaturados- 44 e 54% (maioritariamente ácido linoleico). Relativamente à vitamina E, a isoforma β-tocoferol foi a maioritária em L. molle (13 μg/100 g) e γ-tocoferol em L. vulpinum (296 μg/100 g). A composição em ácidos fenólicos foi 0.19 mg/100 g (ácidos p-hidroxibenzóico e cinâmico) e 0.69 mg/100 g (também os ácidos gálico e protocatéquico), respetivamente, e em ácidos orgânicos 4 mg/100 g (ácidos oxálico, cítrico e fumárico) e 0.5 mg/100 g (ácido quínico em vez de cítrico). L. vulpinum apresentou maior atividade antioxidante em todos os ensaios (atividade captadora de radicais livres, poder redutor e inibição da peroxidação lipídica): valores de EC50 < 1.2 mg/mL. No que concerne a atividade antitumoral, esta espécie foi a única que inibiu a proliferação de linhas celulares tumorais humanas (mama, pulmão, cólon, cervical e hepatocelular), sendo a linha celular HCT-15 a mais susceptível (carcinoma de cólon; GI50 = 78 μg/mL). Até 400 μg/mL, os extratos não revelaram toxicidade para células não tumorais (culturas primárias de células de fígado). Este estudo contribui para a valorização das espécies de cogumelos anteriormente mencionadas, fornecendo mais informação relativamente à sua composição química e bioatividade

Fluctuations and Dissipation of Coherent Magnetization

A quantum mechanical model is used to derive a generalized Landau-Lifshitz equation for a magnetic moment, including fluctuations and dissipation. The model reproduces the Gilbert-Brown form of the equation in the classical limit. The magnetic moment is linearly coupled to a reservoir of bosonic degrees of freedom. Use of generalized coherent states makes the semiclassical limit more transparent within a path-integral formulation. A general fluctuation-dissipation theorem is derived. The magnitude of the magnetic moment also fluctuates beyond the Gaussian approximation. We discuss how the approximate stochastic description of the thermal field follows from our result. As an example, we go beyond the linear-response method and show how the thermal fluctuations become anisotropy-dependent even in the uniaxial case.Comment: 22 page

The Combined Deficiency of Immunoproteasome Subunits Affects Both the Magnitude and Quality of Pathogen- and Genetic Vaccination-Induced CD8+ T Cell Responses to the Human Protozoan Parasite Trypanosoma cruzi

The beta1i, beta2i and beta5i immunoproteasome subunits have an important role in defining the repertoire of MHC class I-restricted epitopes. However, the impact of combined deficiency of the three immunoproteasome subunits in the development of protective immunity to intracellular pathogens has not been investigated. Here, we demonstrate that immunoproteasomes play a key role in host resistance and genetic vaccination-induced protection against the human pathogen Trypanosoma cruzi (the causative agent of Chagas disease), immunity to which is dependent on CD8+ T cells and IFN-gamma (the classical immunoproteasome inducer). We observed that infection with T. cruzi triggers the transcription of immunoproteasome genes, both in mice and humans. Importantly, genetically vaccinated or T. cruzi-infected beta1i, beta2i and beta5i triple knockout (TKO) mice presented significantly lower frequencies and numbers of splenic CD8+ effector T cells (CD8+CD44highCD62Llow) specific for the previously characterized immunodominant (VNHRFTLV) H-2Kb-restricted T. cruzi epitope. Not only the quantity, but also the quality of parasite-specific CD8+ T cell responses was altered in TKO mice. Hence, the frequency of double-positive (IFN-gamma+/TNF+) or single-positive (IFN-gamma+) cells specific for the H-2Kb-restricted immunodominant as well as subdominant T. cruzi epitopes were higher in WT mice, whereas TNF single-positive cells prevailed among CD8+ T cells from TKO mice. Contrasting with their WT counterparts, TKO animals were also lethally susceptible to T. cruzi challenge, even after an otherwise protective vaccination with DNA and adenoviral vectors. We conclude that the immunoproteasome subunits are key determinants in host resistance to T. cruzi infection by influencing both the magnitude and quality of CD8+ T cell responses

Metabolic and nutritional triggers associated with increased risk of liver complications in SARS-CoV-2

Obesity, diabetes, cardiovascular and respiratory diseases, cancer and smoking are risk factors for negative outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can quickly induce severe respiratory failure in 5% of cases. Coronavirus disease-associated liver injury may occur during progression of SARS-CoV-2 in patients with or without pre-existing liver disease, and damage to the liver parenchyma can be caused by infection of hepatocytes. Cirrhosis patients may be particularly vulnerable to SARS-CoV-2 if suffering with cirrhosis-associated immune dysfunction. Furthermore, pharmacotherapies including macrolide or quinolone antibiotics and steroids can also induce liver damage. In this review we addressed nutritional status and nutritional interventions in severe SARS-CoV-2 liver patients. As guidelines for SARS-CoV-2 in intensive care (IC) specifically are not yet available, strategies for management of sepsis and SARS are suggested in SARS-CoV-2. Early enteral nutrition (EN) should be started soon after IC admission, preferably employing iso-osmolar polymeric formula with initial protein content at 0.8 g/kg per day progressively increasing up to 1.3 g/kg per day and enriched with fish oil at 0.1 g/kg per day to 0.2 g/kg per day. Monitoring is necessary to identify signs of intolerance, hemodynamic instability and metabolic disorders, and transition to parenteral nutrition should not be delayed when energy and protein targets cannot be met via EN. Nutrients including vitamins A, C, D, E, B6, B12, folic acid, zinc, selenium and ω-3 fatty acids have in isolation or in combination shown beneficial effects upon immune function and inflammation modulation. Cautious and monitored supplementation up to upper limits may be beneficial in management strategies for SARS-CoV-2 liver patients