902 resultados para acid and alkali-tolerant
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O buriti e o patauá são duas palmeiras endêmicas da região Amazônica. As polpas destes frutos são tradicionalmente consumidas pela população local, mas ainda não ganharam os mercados nacional e internacional. A composição nutricional em ácidos graxos e tocoferol foi determinada com metodologias analíticas modernas de cromatografia gasosa (CG) e cromatografia líquida de alta eficiência (CLAE) baseadas nos padrões da AOCS (AMERICAN..., 2002) e AOAC (ASSOCIATION..., 1997), respectivamente. As duas polpas se mostraram bastante energéticas, com uma alta concentração em ácidos graxos, respectivamente 38,4% e 29,1% em massa seca (MS), em proteínas, 7,8% e 7,4% MS e em fibras dietéticas, 46% e 44,7%. A polpa de buriti pode ser considerada uma ótima fonte de vitamina E devido ao seu alto teor de tocoferol (1169 µg.g-1 MS). O perfil de ácidos graxos encontrados para a polpa de patauá foi muito semelhante ao de azeite de oliva.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Objective: To investigate the influence of a regular oral use of acetylsalicylic acid in the prevalence of actinic keratosis.Methods: A case-control study with dermatologic outpatients above 50 years of age assessed between 2009 and 2011. Cases were defined as those who had been under regular use of oral acetylsalicylic acid for more than six consecutive months. The assessment focused on: age, sex, skin-type, tobacco smoking, use of medication, occurrence of individual or family skin cancer, and sunscreen and sun exposure habits. Actinic keratoses were counted in the medial region of the face and upper limbs. Counts were adjusted by co-variables based on a generalized linear model.Results: A total of 74 cases and 216 controls were assessed. The median time of acetylsalicylic acid use was 36 months. Cases differed from controls as to the highest age, highest prevalence of use of angiotensin-converting enzyme inhibitors and fewer keratosis on the face and on the upper limbs (p < 0.05). The multivariate model showed that the use of acetylsalicylic acid was associated to lower counts of face actinic keratosis and upper-limb erythematous actinic keratosis (p < 0.05), regardless of other risk factors.Conclusion: The regular use of oral acetylsalicylic acid for more than six months was associated to a lower prevalence of actinic keratosis, especially facial and erythematous ones.
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Objective: This study aims to compare the clot stabilization on root surfaces conditioned with citric acid and ethylenediaminetetraacetic acid (EDTA). Materials and methods: Scaled root samples (n = 100) were set in five groups: group I?control group (saline solution); group II (24% EDTA); group III (25% citric acid); group IV (EDTA + citric acid); group V (citric acid + EDTA). Fifty samples were assessed using the root surface modification index (RSMI). The other 50 received a blood drop after conditioning. Clot formation was assessed using blood elements adhesion index (BEAI). A blind examiner evaluated photomicrographs. Statistical analysis considered p < 0.05. Results: Groups-III and G-V attained the best results for RSMI and BEAI in comparison to control. The worst results for clot stabilization were seen in group-II. EDTA employment before citric acid (group-IV) reduced clot formation in comparison to citric acid use alone (group-III). Conclusion: Root conditioning with citric acid alone and before EDTA had the best results for smear layer removal and clot stabilization. EDTA inhibited clot stabilization on root surface and must have a residual activity once it has diminished clot adhesion to root even after citric acid conditioning. Thus, EDTA can be used to neutralize citric acid effects on periodontal cells without affecting clot stabilization. Clinical significance: To demonstrate that citric acid use on root surfaces previously affected by periodontal disease may favor clot stabilization and may have a beneficial effect on surgical outcomes. Also, EDTA can be used to neutralize citric acid effects on periodontal cells.
Surface roughness analysis of dental ceramics treated with hydrofl uoric acid and aluminum oxide jet
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The aim of this study was to evaluate the surface roughness of 5 indirect restorative materials treated with hydrofluoric acid to 10%, with aluminum oxide jet and a combination of both. The specimens was prepared with 10 mm in diameter and 2 mm thickness, divided into fi ve groups: (1) Ceromer (CeseadII-Kuraray), (2) Leucite crystals ceramics (IPS EmpressIIIvoclarforcasket), (3) glass ceramic with fluorapatite (IPS D. Sign-Ivoclar), (4) lithium disilicate ceramic (IPS Empress II-Ivoclar restorations), (5) ceramics (Cergogold-Degussa). For all groups were performed the controls, and the surfaces with the 3 types of treatment. For testing roughness used the rugosimeter Taylor/Hobson-Precision, model form tracerSV-C525 high sensitivity. After confi rmation of variance analysis with a signifi cance level of 1% (p < 0.01), there was equality between the average roughness of materials from groups 1, 3 and 5, and the group 2 was different from the others. It was also found that the ceramics of the group 5 behaved similar to group 4. However the lowest average roughness was observed in group 2 ceramic. In the evaluation between the types of treatment, the aluminum oxide jet and associations and blasting with hydrofl uoric acid were similar, and different isolated hydrofl uoric acid, and 3 types of treatment signifi cantly higher than the control group. All treatments promoted superfi cial alterations in all tested materials.
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Purpose: To analyze whether immersion in sodium fluoride (NaF) solutions and/or common acidic beverages (test solutions) would affect the surface roughness or topography of lithium disilicate ceramic. Methods: 220 ceramic discs were divided into four groups, each of which was subdivided into five subgroups (n = 11). Control group discs were immersed in one of four test beverages for 4 hours daily or in artificial saliva for 21 days. Discs in the experimental groups were continuously immersed in 0.05% NaF, 0.2% NaF, or 1.23% acidulated phosphate fluoride (APF) gel for 12, 73, and 48 hours, respectively, followed by immersion in one of the four test beverages or artificial saliva. Vickers microhardness, surface roughness, scanning electron microscopy (SEM) associated with energy dispersive spectroscopy, and atomic force microscopy (AFM) assessments were made. Data were analyzed by nested analysis of variance (ANOVA) and Tukey's test (alpha = 0.05). Results: Immersion in the test solutions diminished the microhardness and increased the surface roughness of the discs. The test beverages promoted a significant reduction in the Vickers microhardness in the 0.05% and 0.2% NaF groups. The highest surface roughness results were observed in the 0.2% NaF and 1.23% APF groups, with similar findings by SEM and AFM. Acidic beverages affected the surface topography of lithium disilicate ceramic. Fluoride treatments may render the ceramic surface more susceptible to the chelating effect of acidic solutions.
A critical review of the properties of fusidic acid and the analytical methods for its determination
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Fusidic acid, an antibiotic produced from the Fusidium coccineum fungus, belongs to the class of steroids, but has no corticosteroid effects. It is indicated for the treatment of infections caused by methicillin-resistant Staphylococcus aureus strains. The aim of this study was to search for the properties of fusidic acid published so far in the literature, as well as the methods developed for its determination in biological samples and pharmaceutical formulations. From the findings, we can conclude that fusidic acid has been used for decades and is indicated for the treatment of serious infections caused by Gram-positive microorganisms to this day. Furthermore, it is a hypoallergenic agent, has low toxicity, shows low resistance, and has no cross-resistance with other clinically used antibiotics. The analytical method of high-performance liquid chromatography has been widely used, since it can reduce the cost and time of analysis, making it more viable for routine quality control in the pharmaceutical industry.
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The protective effect of gallic acid and its esters, methyl, propyl, and lauryl gallate, against 2,2'-azobis(2-amidinopropane)hydrochloride (AAPH)-induced hemolysis and depletion of intracellular glutathione (GSH) in erythrocytes was studied. The inhibition of hemolysis was dose-dependent, and the esters were significantly more effective than gallic acid. Gallic acid and its esters were compared with regard to their reactivity to free radicals, using the DPPH and AAPH/pyranine free-cell assays, and no significant difference was obtained. Gallic acid and its esters not only failed to inhibit the depletion of intracellular GSH in erythrocytes induced by AAPH but exacerbated it. Similarly, the oxidation of GSH by AAPH or horseradish peroxidase/H(2)O(2) in cell-free systems was exacerbated by gallic acid or gallates. This property could be involved in the recent findings on pro-apoptotic and pro-oxidant activities of gallates in tumor cells. We provide evidence that lipophilicity and not only radical scavenger potency is an important factor regarding the efficiency of antihemolytic substances.
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The acetic acid and phenyl-p-benzoquinone are easy and fast screening models to access the activity of novel candidates as analgesic drugs and their mechanisms. These models induce a characteristic and quantifiable overt pain-like behavior described as writhing response or abdominal contortions. The knowledge of the mechanisms involved in the chosen model is a crucial step forward demonstrating the mechanisms that the candidate drug would inhibit because the mechanisms triggered in that model will be addressed. Herein, it was investigated the role of spinal mitogen-activated protein (MAP) kinases ERK (extracellular signal-regulated kinase), JNK (Jun N-terminal Kinase) and p38, PI3K (phosphatidylinositol 3-kinase) and microglia in the writhing response induced by acetic acid and phenyl-p-benzoquinone, and flinch induced by formalin in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing response over 20 min. The nociceptive response in these models were significantly and in a dose-dependent manner reduced by intrathecal pre-treatment with ERK (PD98059), JNK (SB600125), p38 (SB202190) or PI3K (wortmannin) inhibitors. Furthermore, the co-treatment with MAP kinase and PI3K inhibitors, at doses that were ineffective as single treatment, significantly inhibited acetic acid- and phenyl-p-benzoquinone-induced nociception. The treatment with microglia inhibitors minocycline and fluorocitrate also diminished the nociceptive response. Similar results were obtained in the formalin test. Concluding. MAP kinases and PI3K are important spinal signaling kinases in acetic acid and phenyl-p-benzoquinone models of overt pain-like behavior and there is also activation of spinal microglia indicating that it is also important to determine whether drugs tested in these models also modulate such spinal mechanisms. (C) 2012 Elsevier Inc. All rights reserved.
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More than 40% of the World population is at risk of contracting malaria, which affects primarily poor populations in tropical and subtropical areas. Antimalarial pharmacotherapy has utilised plant-derived products such as quinine and artemisinin as well as their derivatives. However, worldwide use of these antimalarials has caused the spread of resistant parasites, resulting in increased malaria morbidity and mortality. Considering that the literature has demonstrated the antimalarial potential of triterpenes, specially betulinic acid (1) and ursolic acid (2), this study investigated the antimalarial activity against P. falciparum chloroquine-sensitive 3D7 strain of some new derivatives of 1 and 2 with modifications at C-3 and C-28. The antiplasmodial study employed flow cytometry and spectrofluorimetric analyses using YOYO-1, dihydroethidium and Fluo4/AM for staining. Among the six analogues obtained, compounds 1c and 2c showed excellent activity (IC50 = 220 and 175 nM, respectively) while 1a and b demonstrated good activity ( IC50 = 4 and 5 mu M, respectively). After cytotoxicity evaluation against HEK293T cells, 1a was not toxic, while 1c and 2c showed IC50 of 4 mu M and a selectivity index (SI) value of 18 and 23, respectively. Moreover, compound 2c, which presents the best antiplasmodial activity, is involved in the calcium-regulated pathway(s).