986 resultados para maple coordinate reaction morse potential
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Phosphatases have long been regarded as tumor suppressors, however there is emerging evidence for a tumor initiating role for some phosphatases in several forms of cancer. Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP; acid phosphatase 1 [ACP1]) is an 18 kDa enzyme that influences the phosphorylation of signaling pathway mediators involved in cancer and is thus postulated to be a tumor-promoting enzyme, but neither unequivocal clinical evidence nor convincing mechanistic actions for a role of LMWPTP have been identified. In the present study, we show that LMWPTP expression is not only significantly increased in colorectal cancer (CRC), but also follows a step-wise increase in different levels of dysplasia. Chemical inhibition of LMWPTP significantly reduces CRC growth. Furthermore, downregulation of LMWPTP in CRC leads to a reduced migration ability in both 2D- and 3D-migration assays, and sensitizes tumor cells to the chemotherapeutic agent 5-FU. In conclusion, this study shows that LMWPTP is not only overexpressed in colorectal cancer, but it is correlated with the malignant potential of this cancer, suggesting that this phosphatase may act as a predictive biomaker of CRC stage and represents a rational novel target in the treatment of this disease.
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Ofloxacin is an antimicrobial agent frequently found in significant concentrations in wastewater and surface water. Its continuous introduction into the environment is a potential risk to non-target organisms or to human health. In this study, ofloxacin degradation by UV/TiO2 and UV/TiO2/H2O2, antimicrobial activity (E. coli) of samples subjected to these processes, and by-products formed were evaluated. For UV/TiO2, the degradation efficiency was 89.3% in 60 min of reaction when 128 mg L(-1) TiO2 were used. The addition of 1.68 mmol L(-1) hydrogen peroxide increased degradation to 97.8%. For UV/TiO2, increasing the catalyst concentration from 4 to 128 mg L(-1) led to an increase in degradation efficiency. For both processes, the antimicrobial activity was considerably reduced throughout the reaction time. The structures of two by-products are presented: m/z 291 (9-fluoro-3-methyl-10-(methyleneamino)-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid) and m/z 157 ((Z)-2-formyl-3-((2-oxoethyl)imino)propanoic acid).
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Cocoa is rich in flavonoids, which are potent antioxidants with established benefits for cardiovascular health but unproven effects on neurodegeneration. Sirtuins (SIRTs), which make up a family of deacetylases, are thought to be sensitive to oxidation. In this study, the possible protective effects of cocoa in the diabetic retina were assessed. Rat Müller cells (rMCs) exposed to normal or high glucose (HG) or H2O2 were submitted to cocoa treatment in the presence or absence of SIRT-1 inhibitor and small interfering RNA The experimental animal study was conducted in streptozotocin-induced diabetic rats randomized to receive low-, intermediate-, or high-polyphenol cocoa treatments via daily gavage for 16 weeks (i.e., 0.12, 2.9 or 22.9 mg/kg/day of polyphenols). The rMCs exposed to HG or H2O2 exhibited increased glial fibrillary acidic protein (GFAP) and acetyl-RelA/p65 and decreased SIRT1 activity/expression. These effects were cancelled out by cocoa, which decreased reactive oxygen species production and PARP-1 activity, augmented the intracellular pool of NAD(+), and improved SIRT1 activity. The rat diabetic retinas displayed the early markers of retinopathy accompanied by markedly impaired electroretinogram. The presence of diabetes activated PARP-1 and lowered NAD(+) levels, resulting in SIRT1 impairment. This augmented acetyl RelA/p65 had the effect of up-regulated GFAP. Oral administration of polyphenol cocoa restored the above alterations in a dose-dependent manner. This study reveals that cocoa enriched with polyphenol improves the retinal SIRT-1 pathway, thereby protecting the retina from diabetic milieu insult.
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To evaluate p16(INK) (4a) immunoexpression in CIN1 lesions looking for differences between cases that progress to CIN2/3 maintain CIN1 diagnosis, or spontaneously regress. Seventy-four CIN1 biopsies were studied. In the follow-up, a second biopsy was performed and 28.7% showed no lesion (regression), 37.9% maintained CIN1, and 33.4% progressed to CIN2/3. Immunostaining for p16(INK) (4a) was performed in the first biopsy and it was considered positive when there was strong and diffuse staining of the basal and parabasal layers. Pearson's chi-square was used to compare the groups (p ≤ 0.05). The age of the patients was similar. There was no significant difference in p16(INK) (4a) immunoexpression in the groups, however, statistical analyses showed a significant association when only the progression and regression groups were compared (p = 0.042). Considering p16(INK) (4a) positivity and the progression to CIN2/3, the sensitivity, specificity, positive, and negative predictive values in our cohort were 45%, 75%, 47%, and 94%, respectively. We emphasize that CIN1 with p16(INK) (4a) staining was associated with lesion progression, but the sensitivity was not high. However, the negative predictive value was more reliable (94%) and p16(INK) (4a) may represent a useful biomarker that can identify CIN1 lesions that need particular attention, complementing morphology.
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Cutinases (EC 3.1.1.74) are also known as cutin hidrolases. These enzymes share catalytic properties of lipases and esterases, presenting a unique feature of being active regardless the presence of an oil-water interface, making them interesting as biocatalysts in several industrial processes involving hydrolysis, esterification and trans-esterification reactions. They are also active in different reaction media, allowing their applications in different areas such as food industry, cosmetics, fine chemicals, pesticide and insecticide degradation, treatment and laundry of fiber textiles and polymer chemistry. The present review describes the characteristics, potential applications and new perspectives for these enzymes.
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Cuphea carthagenensis (Jacq.) J.F. Macbr. is an herb, which occurs preferably in wet places. Amongst other species of the genus, C. carthagenensis is distinguished for its great chemical potential and frequent use in popular medicine. In this study the morphological and anatomical structures were identified, as well as the histochemical characterization was done. Samples of root, stem and leaves were collected from adult plants. This material was processed for anatomical and histochemical analysis in light microscopy and for morphological analysis, in scanning electron microscopy. Important morphological and anatomical considerations were added for C. carthagenensis, such as: the occurrence of aerenchymatous phellem with suberized layers; the types of trichomes present in the vegetative organs, the characterization of secretory trichomes, as well as the secreted substances. The groups of secondary metabolites presents in the root, stem and leaf of C. carthagenensis with more intense histochemical reaction were: proanthocyanidins, phenolic compounds, acids polysaccharides (mucilage especially) and lipids.
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This work investigated the cytotoxic and genotoxic potential of water from the River Paraíba do Sul (Brazil) using Allium cepa roots. An anatomo-morphological parameter (root length), mitotic indices, and frequency of micronuclei were analysed. Eight bulbs were chosen at random for treatment for 24 to 120 hours with the River water collected in the years of 2005 and 2006 from sites in the cities of Tremembé and Aparecida (São Paulo state, Brazil). Daily measurements of the length of the roots grown from each bulb were carried out throughout the experiment. Mitotic index (MI) and frequency of micronuclei (MN) were determined for 2000 cells per root, using 3-5 root tips from other bulbs (7-10). Only in the roots treated with samples of the River water collected in 2005 in Tremembé city was there a decrease in the root length growth compared to the respective control. However, a reduction in MI values was verified for both sites analysed for that year. Considering the data involving root length growth and especially MI values, a cytotoxic potential is suggested for the water of the River Paraíba do Sul at Tremembé and Aparecida, in the year of 2005. On the other hand, since in this year the MN frequency was not affected with the river water treatments, genotoxicity is not assumed for the river water sampled at the aforementioned places.
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The aim of this study was to evaluate the tissue compatibility of a silorane-based resin system (FiltekTM Silorane) and a methacrylate-based nanoparticle resin (FiltekTM Supreme XT) after implantation in the subcutaneous connective tissue of isogenic mice. One hundred and thirty five male isogenic BALB/c mice were randomly assigned to 12 experimental and 3 control groups, according to the implanted material and the experimental period of 7, 21 and 63 days. At the end of each period, the animals were killed and the tubes with the surrounding tissues were removed and processed for microscopic analysis. Samples were subjected to a descriptive and a semi-quantitative analyses using a 4-point scoring system (0-3) to evaluate the collagen fiber formation and inflammatory infiltrate. Data were statistically analyzed using the Kruskal Wallis test (?=0.05). The results showed that there was no significant difference between the experimental and control groups considering the three evaluation periods (p>0.05). The silorane-based and the methacrylate-based nanoparticle resins presented similar tissue response to that of the empty tube (control group) after subcutaneous implantation in isogenic mice.
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This study analyzed the reaction layer and measured the marginal crown fit of cast titanium applied to different phosphate-bonded investments, prepared under the following conditions (liquid concentration/casting temperature): Rema Exakt (RE) - 100%/237°C, 75%/287°C, Castorit Super C (CS)-100%/70°C, 75%/141°C and Rematitan Plus (RP)- 100%/430°C (special to titanium cast, as the control group). The reaction layer was studied using the Vickers hardness test, and analyzed by two way ANOVA and Tukey's HSD tests (α = 0.05). Digital photographs were taken of the crowns seated on the die, the misfit was measured using an image analysis system and One-way ANOVA, and Tukey's test was applied (α = 0.05). The hardness decreased from the surface (601.17 VHN) to 150 μm (204.03 VHN). The group CS 75%/141°C presented higher hardness than the other groups, revealing higher surface contamination, but there were no differences among the groups at measurements deeper than 150 μm. The castings made with CS - 100%/70°C presented the lowest levels of marginal misfit, followed by RE -100%/237°C. The conventional investments CS (100%) and RE (100%) showed better marginal fit than RP, but the CS (75%) had higher surface contamination.
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INTRODUCTION: This study evaluated whether leprosy reactions could be associated with oral infection. METHODS: Leprosy patients (n = 38) with (Group I) and without (Group II) oral infections were selected. Reactions were identified from the clinical and histopathological features associated with serum C-reactive protein (CRP) and10kDa interferon-gamma-induced protein (IP-10) levels, determined before and after elimination of the foci of infection. RESULTS: Group I presented more reactions than group II did, and improvement of the reactions after dental treatment. Serum CRP and IP-10 did not differ before and after the dental treatment, but differed between the groups. CONCLUSIONS: Oral infection could be an exacerbating factor in leprosy reactions.
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Nitric oxide (NO) has been considered a key molecule in infammation. OBJECTIVE: The aim of this study was to evaluate the effect of treatment with L-NAME and sodium nitroprussiate, substances that inhibit and release NO, respectively, on tissue tolerance to endodontic irrigants. MATERIAL AND METHODS: The vital dye exudation method was used in a rat subcutaneous tissue model. Injections of 2% Evans blue were administered intravenously into the dorsal penial vein of 14 male rats (200-300 g). The NO inhibitor and donor substances were injected into the subcutaneous tissue in the dorsal region, forming two groups of animals: G1 was inoculated with L-NAME and G2 with sodium nitroprussiate. Both groups received injections of the test endodontic irrigants: acetic acid, 15% citric acid, 17% EDTA-T and saline (control). After 30 min, analysis of the extravasated dye was performed by light absorption spectrophotometry (620 nm). RESULTS: There was statistically signifcant difference (p<0.05) between groups 1 and 2 for all irrigants. L-NAME produced a less intense infammatory reaction and nitroprussiate intensifed this process. CONCLUSIONS: Independently of the administration of NO inhibitors and donors, EDTA-T produced the highest irritating potential in vital tissue among the tested irrigating solutions.
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Contents of proteins, carbohydrates and oil of seeds of 57 individuals of Vochysiaceae, involving one species of Callisthene, six of Qualea, one of Salvertia and eight of Vochysia were determined. The main nutritional reserves of Vochysiaceae seeds are proteins (20% in average) and oils (21. 6%). Mean of carbohydrate contents was 5. 8%. Callisthene showed the lowest protein content (16. 9%), while Q. cordata was the species with the highest content (30% in average). The contents of ethanol soluble carbohydrates were much higher than those of water soluble carbohydrates. Oil contents lay above 20% for most species (30. 4% in V. pygmaea and V. pyramidalis seeds). The predominant fatty acids are lauric (Q. grandiflora), oleic (Qualea and Salvertia) or acids with longer carbon chains (Salvertia and a group of Vochysia species). The distribution of Vochysiaceae fatty acids suggests for seeds of some species an exploitation as food sources (predominance of oleic acid), for other species an alternative to cocoa butter (high contents or predominance of stearic acid) or the production of lubricants, surfactants, detergents, cosmetics and plastic (predominance of acids with C20 or C22 chains) or biodiesel (predominance of monounsaturated acids). The possibility of exploitation of Vochysiaceae products in a cultivation regimen and in extractive reserves is discussed.
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The aim of this study was to look for evidence of allelochemicals in B. decumbens, in parts of the plant from where they could easily be released to the environment. The germination inhibition of Phalaris canariensis, Lactuca sativa (standard species) and Melinis minutiflora, another invasive African grass, was tested using B. decumbens germinating seeds and aqueous leachates of the roots, green and senescent leaves, at 5, 10 and 20% w/v. Both the germinating seeds and the aqueous leachates of B. decumbens reduced the germination of the species tested; the effectiveness of the aqueous leachates increased according to concentration. Apparently, the competitive advantage of B. decumbens in the cerrados could be amplified via allelopathy.
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Attention deficit, impulsivity and hyperactivity are the cardinal features of attention deficit hyperactivity disorder (ADHD) but executive function (EF) disorders, as problems with inhibitory control, working memory and reaction time, besides others EFs, may underlie many of the disturbs associated with the disorder. OBJECTIVE: To examine the reaction time in a computerized test in children with ADHD and normal controls. METHOD: Twenty-three boys (aged 9 to 12) with ADHD diagnosis according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, 2000 (DSM-IV) criteria clinical, without comorbidities, Intelligence Quotient (IQ) >89, never treated with stimulant and fifteen normal controls, age matched were investigated during performance on a voluntary attention psychophysical test. RESULTS: Children with ADHD showed reaction time higher than normal controls. CONCLUSION: A slower reaction time occurred in our patients with ADHD. This findings may be related to problems with the attentional system, that could not maintain an adequate capacity of perceptual input processes and/or in motor output processes, to respond consistently during continuous or repetitive activity.
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Testing contexts have been shown to critically influence experimental results in psychophysical studies. One of these contexts that show important modulation of the behavioral effects of different stimulatory conditions is the separate (blocked) or mixed presentation of these stimulatory conditions. The study presents evidence that the apparent discriminabilities of two target stimuli can change according to which of these two testing contexts is used. A cross inside a ring and a vertical line inside a ring were presented as go stimuli in a go/no-go reaction time task. In one experiment, each of these stimuli was presented to a different group of volunteers and in another experiment they were presented to the same group of volunteers, randomly mixed in the blocks of trials. Similar reaction times were obtained for the two stimuli in the first experiment, and different reaction times (faster for the cross) in the second experiment. The latter result indicates that the two stimuli have different discriminabilities from the no-go stimulus; the cross having greater discriminability. This difference is however masked, presumably by the adoption of specific compensatory attentional sets, in a separate testing context.