78 results on '"Figueiredo Neto AM"'
Search Results
2. Optical- and x-ray-scattering studies of ionic ferrofluids ofMnFe2O4, γ-Fe2O3, andCoFe2O4
- Author
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da Silva Mf and Figueiredo Neto Am
- Subjects
Ferrofluid ,Optics ,Birefringence ,Materials science ,Condensed matter physics ,Liquid crystal ,Scattering ,business.industry ,X-ray ,Ionic bonding ,business ,Magnetic liquids - Published
- 1993
3. Coupling between tilt and polar orders in liquid crystal phases formed from achiral bent shaped molecules
- Author
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P. Tolédano, Figueiredo Neto Am, and O. G. Martins
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Coupling ,Materials science ,Condensed matter physics ,business.industry ,Bent molecular geometry ,Condensed Matter::Soft Condensed Matter ,Dipole ,Tilt (optics) ,Optics ,Liquid crystal ,Electric field ,Antiferroelectricity ,Polar ,business - Abstract
A phenomenological description is given of the mesophases which may arise below a liquid formed from achiral molecules possessing a transverse dipole, as the result of a coupling between their tilt and polar orders. Six stable mesophases are found. Two of them have a cholesteric biaxial structure. The others display antiferroelectric or ferrielectric, incommensurately modulated, structures with in-plane or out-of-plane spontaneous polarization. The in-plane polarized structures become unstable under application of a longitudinal electric field. Other field-induced effects are discussed.
- Published
- 1999
4. Dynamics of lyotropic ferronematic liquid crystals submitted to magnetic fields
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Bacri Jc and Figueiredo Neto Am
- Subjects
Paramagnetism ,Materials science ,Condensed matter physics ,Liquid crystal ,Lyotropic ,Dynamics (mechanics) ,Magnetic liquids ,Magnetic field - Published
- 1994
5. Anchoring properties of lyotropic liquid crystals near the nematic-isotropic transition
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E. A. Oliveira and Figueiredo Neto Am
- Subjects
Nuclear magnetic resonance ,Materials science ,Condensed matter physics ,Liquid crystal ,Lyotropic liquid crystal ,Isotropy ,Anchoring - Published
- 1994
6. Optical- and x-ray-scattering studies of ionic ferrofluids of MnFe2O4, gamma -Fe2O3, and CoFe2O4
- Author
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da Silva MF and Figueiredo Neto AM
- Published
- 1993
7. Orientational order parameter and shape anisotropy of the micelles in a lyotropic nematic phase
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Y. Galerne, L. Liebert, and Figueiredo Neto Am
- Subjects
Physics ,Diffraction ,Optics ,business.industry ,Liquid crystal ,Phase (matter) ,Lyotropic ,Order (ring theory) ,Thermodynamics ,POTASSIUM LAURATE ,Anisotropy ,business ,Micelle - Abstract
The average distances between micelles are measured by x-ray diffraction as a function of temperature in the discotic nematic phase of the lyotropic system comprised of potassium laurate 1-decanol, and ${\mathrm{D}}_{2}$O. The variations with temperature of the orientational order parameter are found to follow the variations of the shape anisotropy of the micelles, in good agreement with the microscopic models of the Onsager or Flory types.
- Published
- 1985
8. Structural characterization of cholesterol-rich nanoemulsion (LDE).
- Author
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Perez AS, Morikawa AT, Maranhão RC, and Figueiredo Neto AM
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- Humans, Animals, Particle Size, Paclitaxel chemistry, Paclitaxel pharmacology, Scattering, Small Angle, Etoposide chemistry, Antineoplastic Agents chemistry, Antineoplastic Agents pharmacology, X-Ray Diffraction, Molecular Structure, Emulsions chemistry, Cholesterol chemistry, Nanoparticles chemistry, Methotrexate chemistry
- Abstract
Cholesterol-rich nanoemulsion (LDE) can carry chemotherapeutic agents in the circulation and can concentrate those agents in the neoplastic and inflammatory tissues. This method improves the biodistribution of the drug and reduces toxicity. However, the structural stability of LDE particles, without or with associated drugs, has not been extensively investigated. The aim of the present study is to investigate the structural stability of LDE and LDE associated to paclitaxel, etoposide or methotrexate in aqueous solution over time by small-angle X-ray scattering (SAXS and Ultra SAXS) and dynamic light scattering (DLS). The results show that LDE and LDE associated with those chemotherapeutic agents had reproducible and stable particle diameter, physical structure, and aggregation behavior over 3-month observation period. As estimated from both DLS and Ultra-SAXS methods, performed at pre-established intervals, the average particle diameter of LDE alone was approx. 32 nm, of LDE-paclitaxel was 31 nm, of LDE-methotrexate was 35 nm and of LDE-etoposide was 36 nm. Ultra-SAXS analysis showed that LDE nanoparticles were quasi-spherical, and SAXS showed that drug molecules inside the particles showed a layered-like organization. Formulations of LDE with associated PTX, ETO or MTX were successfully tested in animal experiments and in patients with cancer or with cardiovascular disease, showing markedly low toxicity, good tolerability and possible superior pharmacological action. Our results may be useful for ensuing clinical trials of this novel Nanomedicine tool, by strengthening the knowledge of the structural aspects of those LDE formulations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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9. Effect of adjuvant probiotic therapy (Lactobacillus reuteri) in the treatment of periodontitis associated with diabetes mellitus: clinical, controlled, and randomized study.
- Author
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Jardini MAN, Pedroso JF, Ferreira CL, Nunes CMM, Reichert CO, Aldin MN, Figueiredo Neto AM, Levy D, and Damasceno NRT
- Subjects
- Humans, Combined Modality Therapy, Adjuvants, Immunologic, Cytokines, Lipoproteins, Limosilactobacillus reuteri, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 therapy, Periodontitis therapy
- Abstract
Objectives: Subgingival instrumentation (SI) with probiotics may be a proposal for the treatment of periodontitis (P), for patients with type 2 diabetes mellitus (T2DM). The Lactobacillus reuteri probiotic as an adjunctive therapy in the treatment of P associated with T2DM was evaluated., Materials and Methods: Forty diabetic participants diagnosed with P (stage III and IV, grade B) were randomized into SI + Placebo (n = 20): subgingival instrumentation plus placebo lozenges and SI + Probi (n = 20): subgingival instrumentation plus probiotics. Probing depth (PD), gingival recession (GR), clinical attachment level (CAL), plaque index (PI), bleeding on probing (BoP), and PISA index were performed at baseline and 30, 90, and 180 days. Cytokine concentration in the gingival crevicular fluid, subgingival biofilm sample, and LDL and HDL subfractions were evaluated., Results: In the deep pockets, PD in SI + Probi showed increased values (p = 0.02) compared to SI + Placebo at 90 days. For CAL, SI + Probi showed increased values compared to SI + Placebo, with a significant difference at 30 days (p = 0.03), 90 days (p = 0.02), and 180 days (p = 0.04). At #PD ≥ 7 mm, SI + Probi had a more frequent number of sites (p = 0.03) compared to SI + Placebo only at baseline. For the PISA, SI + Probi showed a significant difference (p = 0.04) compared to SI + Placebo at 90 days. For cytokines, SI + Probi showed higher quantification than SI + Placebo for IL-10 (p < 0.001) at 90 days, IL-12 (p = 0.010) at 90 days, IL-1β (p = 0.035) at 90 days, and IL-8 (p = 0.003) at baseline. SI + Placebo showed higher quantification of IL-1β (p = 0.041) compared to SI + Probi only at 30 days. There was a reduction in all microbial complexes. SI + Probi improved LDL size (246.7 nm vs 260.4 nm; p < 0.001), while large HDL subfractions were reduced aft 180 days of treatment (24.0% vs 20.3%; p = 0.022) when compared with SI + Placebo; this response was dependent of probiotics (1.0 mg/dL vs - 6.2 mg/dL; p = 0.002)., Conclusion: Subgingival instrumentation improved the clinical periodontal parameters in patients with T2DM. The use of L. reuteri probiotics had no additional effects compared with the placebo; however, there was a positive effect on the lipoprotein subfraction., Clinical Relevance: Scientific rationale for study: subgingival instrumentation with probiotics may be a proposal for the treatment of periodontitis (P), especially for patients with type 2 diabetes mellitus (T2DM)., Principal Findings: the use of L. reuteri probiotics had no additional effects compared with the placebo; however, there was a positive effect on the lipoprotein subfraction. Practical implications: L. reuteri as an adjunct to subgingival instrumentation may have significant therapeutic implications in dyslipidemia., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2024
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10. The Soret coefficient of human low-density lipoprotein in solution: a thermophilic behavior.
- Author
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Machado LO, Reis D, and Figueiredo Neto AM
- Subjects
- Humans, Temperature, Lipoproteins, LDL
- Abstract
Thermodiffusion, or Soret effect, is the physical phenomenon of matter gradients originated by the migration of chemical species induced by thermal gradients. Thermodiffusion has been widely applied in the study of colloidal suspensions. In this study, we investigate the termodiffusion behavior of low-density lipoprotein (LDL) particles, by the Soret coefficient measurement. It is a new approach to studies of plasma lipoproteins. The experimental work was based on thermal- and Soret-lens effects. These effects were induced by laser irradiation of the samples, at two different time scales, in a Z-scan setup. LDL samples were analyzed under physiological conditions, notedly, ionic strength and pH, and at different temperatures. Temperature dependence of Soret coefficient showed a slight decrease in the absolute value of this coefficient, as a function of temperature increasing. However, its sign does not change at the temperatures investigated (15, 22.5 and 37.5 °C). The results show that LDL particles exhibit thermophilic behavior. The origin of this thermophilic behavior is not yet completely understood. We discuss some aspects that can be related with the Soret effect in LDL samples., (© 2023. The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2023
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11. Regular Practice of Physical Activity Improves Cholesterol Transfers to High-Density Lipoprotein (HDL) and Other HDL Metabolic Parameters in Older Adults.
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Braga PGS, Freitas FR, Bachi ALL, Amirato GR, Baroni RV, Alves MJNN, Vieira RP, Vaisberg MW, Aldin MN, Kalil Filho R, Figueiredo Neto AM, Damasceno NRT, Tavoni TM, and Maranhão RC
- Subjects
- Humans, Aged, Aryldialkylphosphatase, Cholesterol, Cholesterol Esters, Exercise, Cholesterol, HDL, Lipoproteins, HDL, Antioxidants
- Abstract
The effects of regular physical activity on two important anti-atherosclerosis functions of high-density lipoprotein (HDL), namely its capacity to receive both forms of cholesterol and its anti-oxidant function, were investigated in this study comparing older adults with young individuals. One-hundred and eight healthy adult individuals were enrolled and separated into the following groups: active older (60-80 yrs, n = 24); inactive older (60-79 yrs, n = 21); active young (20-34 yrs, n = 39); and inactive young (20-35 yrs, n = 24). All performed cardiopulmonary tests. Blood samples were collected in order to assess the following measures: lipid profile, HDL anti-oxidant capacity, paraoxonase-1 activity, HDL subfractions, and lipid transfer to HDL. Comparing active older and active young groups with inactive older and inactive young groups, respectively, the active groups presented higher HDL-C levels ( p < 0.01 for both comparisons), unesterified cholesterol transfer ( p < 0.01, p < 0.05), and intermediate and larger HDL subfractions ( p < 0.001, p < 0.01) than the respective inactive groups. In addition, the active young group showed higher esterified cholesterol transfer than the inactive young group ( p < 0.05). As expected, the two active groups had higher VO
2 peak than the inactive groups; VO2 peak was higher in the two younger than in the two older groups ( p < 0.05). No differences in unesterified and esterified cholesterol transfers and HDL subfractions were found between active young and active older groups. HDL anti-oxidant capacity and paraoxonase-1 activity were equal in all four study groups. Our data highlight and strengthen the benefits of regular practice of physical activity on an important HDL function, the capacity of HDL to receive cholesterol, despite the age-dependent decrease in VO2 peak.- Published
- 2023
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12. New Lyotropic Complex Fluid Structured in Sheets of Ellipsoidal Micelles Solubilizing Fragrance Oils.
- Author
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Tchakalova V, Oliveira CLP, and Figueiredo Neto AM
- Abstract
New lyotropic, fragranced, viscoelastic fluid with a complex structure is obtained from fragranced microemulsions by the addition of a fatty acid. Nonhomogeneous mixing of an appropriate nonionic surfactant, a fatty acid, and a fragrance oil led to the formation of anisotropically shaped and highly oriented micelles in aqueous solution. The nano- and microstructures, and consequently the viscosity, are controlled by the balance of fatty acids used as a cosurfactant and fragrance molecules, which partly behave as a cosurfactant and partly segregate in the micelles of the hydrophilic nonionic surfactant. The transition from isotropic microemulsion to a more structured viscoelastic solution is characterized by X-ray scattering and rheological methods. Considering our X-ray scattering results, we propose a structure composed of planar sheets of ellipsoidal micelles arranged in a lamellar type of stacking. The complex structured, low viscous, transparent fluid is capable of solubilizing a fragrance inside the ellipsoidal micelles, as well as retaining microparticles containing fragrance, without the addition of a polymeric thickener or another gelator. These features allow the creation of a 2-in-1 fragrance-solubilizing liquid product compatible with all types of home and body care consumer products., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)
- Published
- 2023
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13. Molecular Dynamics Approach to Calculate the Thermodiffusion (Soret and Seebeck) Coefficients of Salts in Aqueous Solutions.
- Author
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Rezende Franco L, Sehnem AL, Figueiredo Neto AM, and Coutinho K
- Abstract
An approach to investigate the physical parameters related to ion thermodiffusion in aqueous solutions is proposed herein by calculating the equilibrium hydration free energy and the self-diffusion coefficient as a function of temperature, ranging from 293 to 353 K, using molecular dynamics simulations of infinitely diluted ions in aqueous solutions. Several ion force field parameters are used in the simulations, and new parameters are proposed for some ions to better describe their hydration free energy. Such a theoretical framework enables the calculation of some single-ion properties, such as heat of transport, Soret coefficient, and mass current density, as well as properties of salts, such as effective mass and thermal diffusion, Soret and Seebeck, coefficients. These calculated properties are compared with experimental data available from optical measurements and showed good agreement revealing an excellent theoretical predictability of salt thermodiffusion properties. Differences in single-ion Soret and self-diffusion coefficients of anions and cations give rise to a thermoelectric field, which affects the system response that is quantified by the Seebeck coefficient. The fast and slow Seebeck coefficients are calculated and discussed, resulting in values with mV/K order of magnitude, as observed in experiments involving several salts, such as K
+ Cl- , Na+ Cl- , H+ Cl- , Na+ OH- , TMA+ OH- , and TBA+ OH- . The present approach can be adopted for any ion or charged particle dispersed in water with the aim of predicting the thermoelectric field induced through the fluid. It has potential applications in designing electrolytes for ionic thermoelectric devices in order to harvest energy and thermoelectricity in biological nanofluids.- Published
- 2021
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14. Free ions in kerosene-based ferrofluid detected by impedance spectroscopy.
- Author
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Batalioto F, Barbero G, Campos AFC, and Figueiredo Neto AM
- Abstract
The influence of the free ions on the electric response of cells filled with kerosene-based ferrofluids in the low-frequency region is explored. The experimental investigations have been performed on cells limited by different types of electrodes, with the same kind of ferrofluid, by means of the impedance spectroscopy technique. The electrodes considered in our study are made of titanium, platinum, gold, brass and surgical steel. The analysis of the spectra of the real and imaginary parts of the electric impedance of the cell data has been done by means of a simplified version of the Poisson-Nernst-Planck model, in which only the carriers of a given sign are mobile. The agreement between the theoretical predictions and the experimental data is rather good on the whole frequency range. From the analysis of the data in the low-frequency range, dominated by the properties of the electrodes, we discovered that only gold electrodes behave in a manner different from the other electrodes. From the best fit of the experimental data the free-ions density is determined as well as their diffusion coefficient in kerosene. The estimated dielectric constant of the kerosene is in good agreement with the values reported in the literature. In the framework of our model, the surface conductivity of the electrodes has been also determined.
- Published
- 2021
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15. Microcurrent electrotherapy improves palatal wound healing: Randomized clinical trial.
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Miguel MMV, Mathias-Santamaria IF, Rossato A, Ferraz LFF, Figueiredo-Neto AM, de Marco AC, Casarin RCV, Wallet SM, Tatakis DN, Mathias MA, and Santamaria MP
- Subjects
- Humans, Pain, Re-Epithelialization, Wound Healing, Electric Stimulation Therapy, Palate surgery
- Abstract
Background: This study was conducted to assess the clinical, immunological, and patient-centered outcomes of microcurrent electrotherapy on palatal wound healing., Methods: This was a parallel, double-masked randomized clinical trial, in which 53 patients with ridge preservation indications were selected and randomly assigned to one of two groups. In the control (sham) group (n = 27), palatal wounds, after free gingival grafts (FGG) harvest, received sham application of electrotherapy. In the test (electrotherapy treatment [EE]) group (n = 26), palatal wounds, after FGG harvest, received application of microcurrent electrotherapy protocol. Clinical parameters, patient-centered outcomes, and inflammatory markers were evaluated, up to 90 days postoperatively., Results: The EE group achieved earlier wound closure (P <0.001) and epithelialization (P <0.05; P = 0.03) at 7 and 14 days after harvest when compared with the sham group. Painful symptomatology was reported less frequently in the EE group than in the sham group at 3-day follow-up (P = 0.008). Likewise, an improvement in Oral Health Impact Profile was reported 2 days after the procedure by the EE group (P = 0.04). In addition, favorable modulation of inflammatory wound healing markers occurred when electrotherapy was applied., Conclusion: Within the limits of the present study, it can be concluded that the use of a low-intensity electrotherapy protocol may accelerate palatal wound healing and decrease patient discomfort after FGG harvest., (© 2020 American Academy of Periodontology.)
- Published
- 2021
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16. Magnetic, structural and cation distribution studies on [Formula: see text] (x = 0.00, 0.02, 0.04, 0.06 and 0.1) nanoparticles.
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Araujo WWR, Araujo JFDF, Oliveira CLP, Brito GES, and Figueiredo Neto AM
- Abstract
We synthesized and characterized the colloidal suspensions of [Formula: see text] nanoparticles with x = 0.00, 0.02, 0.04, 0.06 and 0.1. The effect of the Fe
3+ ion replacement by Nd3+ on the crystal structure is in-depth studied. The samples were characterized by the following techniques: X-ray diffraction (XRD), UV-Vis spectrophotometry, transmission electronic microscopy (TEM), small-angle X-ray scattering (SAXS), magnetization as a function of applied magnetic field (M-H loops) and magnetization as a function of temperature in zero-field-cooled and field-cooled regimes (ZFC-FC). From XRD cation distribution, structural parameters were extracted. The increasing in the bandgap is interpreted as a result of the higher interatomic separation with the doping. TEM micrographs reveal a polydisperse size and shape distribution of particles. The results for the volume-weighted average diameter measured by SAXS are consistent with those determined by XRD. From the M-H loops we found that the superparamagnetic (SPM) regime contributes with 95-97% for all samples, while only 3-5% contribution comes from the paramagnetic (PM) regime. The saturation magnetization increases in a steady manner upon increasing the Nd3+ ion molar ratio from 0.00 up to 0.06, reaching the maximum value of 105.8±0.4 Am2 /kg at x = 0.06. It is worth to mention that the result for the saturation magnetization value are higher than that of the bulk material.- Published
- 2019
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17. Circulating microparticles and central blood pressure according to antihypertensive strategy.
- Author
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Massunaga ND, França CN, Bianco HT, Ferreira CES, Kato JT, Póvoa RMS, Figueiredo Neto AM, Izar MCO, and Fonseca FAH
- Subjects
- Adult, Aged, Drug Therapy, Combination, Female, Flow Cytometry, Humans, Male, Middle Aged, Prospective Studies, Amlodipine administration & dosage, Antihypertensive Agents administration & dosage, Cell-Derived Microparticles drug effects, Hydrochlorothiazide administration & dosage, Hypertension drug therapy, Rosuvastatin Calcium administration & dosage, Valsartan administration & dosage
- Abstract
Objectives: This prospective, randomized, open-label study aimed to compare the effects of antihypertensive treatment based on amlodipine or hydrochlorothiazide on the circulating microparticles and central blood pressure values of hypertensive patients., Methods: The effects of treatments on circulating microparticles were assessed during monotherapy and after the consecutive addition of valsartan and rosuvastatin followed by the withdrawal of rosuvastatin. Each treatment period lasted for 30 days. Central blood pressure and pulse wave velocity were measured at the end of each period. Endothelial, monocyte, and platelet circulating microparticles were determined by flow cytometry. Central blood pressure values and pulse wave velocity were recorded at the end of each treatment period., Results: No differences in brachial blood pressure were observed between the treatment groups throughout the study. Although similar central blood pressure values were observed during monotherapy, lower systolic and diastolic central blood pressure values and early and late blood pressure peaks were observed in the amlodipine arm after the addition of valsartan alone or combined with rosuvastatin. Hydrochlorothiazide-based therapy was associated with a lower number of endothelial microparticles throughout the study, whereas a higher number of platelet microparticles was observed after rosuvastatin withdrawal in the amlodipine arm., Conclusions: Despite similar brachial blood pressure values between groups throughout the study, exposure to amlodipine was associated with lower central blood pressure values after combination with valsartan, indicating a beneficial interaction. Differences between circulating microparticles were modest and were mainly influenced by rosuvastatin withdrawal in the amlodipine arm.
- Published
- 2019
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18. Influence of Periodontal Disease on cardiovascular markers in Diabetes Mellitus patients.
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Pedroso JF, Lotfollahi Z, Albattarni G, Arrruda Schulz M, Monteiro A, Sehnem AL, Gidlund MA, Figueiredo Neto AM, and Jardini MAN
- Subjects
- Biomarkers blood, Cardiovascular Diseases prevention & control, Dental Plaque Index, Dental Scaling, Diabetes Mellitus, Type 2 blood, Gingivitis blood, Gingivitis surgery, Gingivitis therapy, Humans, Inflammation, Lipoproteins, LDL blood, Oxidative Stress, Periodontal Attachment Loss blood, Periodontal Attachment Loss complications, Periodontal Debridement, Periodontal Index, Periodontitis blood, Periodontitis therapy, Blood Glucose analysis, Cardiovascular Diseases blood, Cholesterol blood, Diabetes Mellitus, Type 2 complications, Gingivitis complications, Glycated Hemoglobin analysis, Lipoproteins blood, Periodontitis complications, Triglycerides blood
- Abstract
The objective of the present study was to establish if individuals with Diabetes Mellitus (DM2) and periodontal diseases (gingivitis or periodontitis) presented an increase in the concentration of modified LDL (moLDL) and what is the influence of periodontal treatment on the decrease of moLDL particles with consequent improvement in the parameters of DM2. Twenty-four diabetic patients with periodontitis (Group 1) and twenty-four diabetic patients with gingivitis (Group 2) were followed up for a period of 12 months. Group 1 was treated with periodontal debridement, and Group 2 received supra-gingival scaling and prophylaxis. In both groups, periodontal clinical parameters: probing depth (PD), clinical attachment level (CAL), gingival resection (GR), bleeding on probing index (BOP) and plaque index; inflammatory serum markers (glycemia, A1c, total cholesterol, HDL-cholesterol (HDL-c), LDL-cholesterol (LDL-c), triglycerides and hs-CRP) and oxidized LDL (oxLDL) were measured at baseline, t = 6 and t = 12 months after treatment. Solutions of LDL were analyzed using the nonlinear optical Z-Scan and optical absorption techniques. The periodontal clinical parameters showed significant improvement (p < 0.05) in both Group after 12 months. For both groups, total cholesterol, HDL-c, LDL-c, triglycerides and A1c levels did not show significant reductions after periodontal therapy. hs-CRP levels in Group 1 presented a significant reduction after 12 months. The glycemic rate and the oxLDL concentrations did not show significant differences as a function of time. The optical measurements of LDL solutions revealed an improvement of the LDL-c quality in both groups. Periodontal debridement was able to improve periodontal parameters and the quality of LDL-c in diabetic patients but without changes in the oxLDL concentration in both groups. Considering the clinical relevance, the reduction of infectious and inflammatory sites present in the oral cavity through periodontal therapy may help with the control and prevention of hyperglycemia and precursors of cardiovascular diseases.
- Published
- 2019
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19. Beneficial effects of green banana biomass consumption in patients with pre-diabetes and type 2 diabetes: a randomised controlled trial.
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Costa ES, França CN, Fonseca FAH, Kato JT, Bianco HT, Freitas TT, Fonseca HAR, Figueiredo Neto AM, and Izar MC
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- Biomass, Blood Glucose metabolism, Body Composition drug effects, Fasting blood, Female, Glycated Hemoglobin metabolism, Humans, Insulin blood, Insulin Resistance, Male, Middle Aged, Diabetes Mellitus, Type 2 blood, Diet methods, Musa, Prediabetic State blood, Starch administration & dosage
- Abstract
Diabetes mellitus is a global epidemic, characterised as a heterogeneous group of metabolic disorders associated with high risk of CVD. Green banana biomass, which is composed of resistant starches (RS) and cannot be hydrolysed by amylases, delays gastric emptying and modulates insulin sensitivity, thus contributing to improve metabolic disorders. The aim of the present study was to investigate the effects of consumption of RS from green banana biomass on body composition, fasting plasma glucose, glycated Hb (HbA1c) and homeostasis model assessment of insulin resistance in subjects with pre-diabetes or type 2 diabetes on top of treatment. Middle-aged subjects (n 113) of both sexes with pre-diabetes (HbA1c: 5·7-6·4 %) or diabetes (HbA1c ≥ 6·5 %) were randomised to receive nutritional support plus green banana biomass (40 g) (RS: approximately 4·5 g, G1, n 62) or diet alone (G2, n 51) for 24 weeks. Body composition, biochemical analyses and dietary intake were evaluated at the beginning and end of the study. In the experimental group (G1), consumption of RS was associated with reduction in HbA1c (P = 0·0001), fasting glucose (P = 0·021), diastolic blood pressure (P = 0·010), body weight (P = 0·002), BMI (P = 0·006), waist and hip circumferences (P < 0·01), fat mass percentage (P = 0·001) and increase in lean mass percentage (P = 0·011). In controls (G2), reductions were observed in waist and hip circumferences (P < 0·01), HbA1c (P = 0·002) and high-density lipoprotein-cholesterol (P = 0·020). In pre-diabetes or diabetes, non-significant differences were observed in the percentage reduction in HbA1c and fasting glucose in exploratory analyses. Our results indicate that the consumption of bioactive starches is a good dietary strategy to improve metabolic control and body composition.
- Published
- 2019
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20. Thermodiffusion of Monovalent Organic Salts in Water.
- Author
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Sehnem AL, Niether D, Wiegand S, and Figueiredo Neto AM
- Abstract
The ionic Soret effect induced by temperature gradients is investigated in organic electrolytes (tetramethylammonium and tetrabutylammonium hydroxides) dispersed in water using a holographic grating experiment. We report the influences of temperature and salt concentrations on the Soret, diffusion, and thermal diffusion coefficients. Experimental results to the thermal diffusion coefficient are compared with a theoretical description for thermodiffusion of Brownian particles in liquids based in the thermal expansion of the liquid solution. It is observed that the obtained thermal diffusion coefficients for the organic electrolytes present a similar temperature dependence as the theoretical prediction. Comparing the experimental results for the organic and common inorganic salts it is proposed an additional physical mechanism as the cause to the different thermal diffusion coefficients in both types of salt. We propose that the temperature dependence of hydration free energy gives rise to a force term that also leads to ion migration in a temperature gradient. We describe the thermal diffusion results as a competition between thermal expansion and hydration effects. The specific structure each type of ion cause in water molecules is considered in the heat of transport theory to describe thermal diffusion of electrolytes. A qualitative agreement is seen between our results and the classical heat of transport theory.
- Published
- 2018
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21. Is Lipid Accumulation Product Associated with an Atherogenic Lipoprotein Profile in Brazilian Subjects?
- Author
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Cartolano FC, Pappiani C, Freitas MCP, Figueiredo Neto AM, Carioca AAF, and Damasceno NRT
- Subjects
- Adult, Aged, Anthropometry, Apolipoprotein A-I blood, Apolipoproteins B blood, Atherosclerosis ethnology, Biomarkers blood, Blood Glucose analysis, Brazil, Cardiovascular Diseases blood, Cardiovascular Diseases etiology, Epidemiologic Methods, Fatty Acids, Nonesterified blood, Female, Humans, Insulin blood, Insulin Resistance, Lipid Accumulation Product ethnology, Male, Middle Aged, Reference Values, Sex Factors, Atherosclerosis blood, Cholesterol, HDL blood, Cholesterol, LDL blood, Lipid Accumulation Product physiology, Risk Assessment methods
- Abstract
Background: Lipid accumulation product (LAP), a simple and low-cost tool, is a novel biomarker of central lipid accumulation and represents a potential surrogate marker for atherogenic lipoprotein profile. However, its association with lipoprotein subfractions has not been described in the literature., Objective: To determine whether LAP index could be used as a marker of low- and high-density lipoprotein (LDL and HDL) size in Brazilian individuals., Methods: This cross-sectional study included patients (n = 351) of both sexes and age between 30-74 years. Clinical and sociodemographic data and family history of diseases were evaluated. Lipoprotein size, and levels of total cholesterol (TC), lipoproteins, apolipoprotein AI and B (APO AI/APO B), glucose, insulin, insulin resistance index (HOMA-IR) and non-esterified fatty acids (NEFA) were assessed in blood samples. LAP was calculated by the formulas [(waist circumference[cm]-58) × (triglycerides[mmol/L]) for women and (waist circumference [cm]-65) × (triglycerides [mmol/L]) for men]. The association between LAP and metabolic parameters were tested by linear trend (general linear model, GLM test) before and after multiple adjustments for potential confounders (sex, age, smoking, statin, fibrate, and hypoglycemic drugs) at significant level p < 0.05., Results: LAP was positively associated with TC, APO B, NEFA, glucose, insulin and HOMA-IR values, and negatively associated with HDL-C. Higher central lipid accumulation was corelated with higher percentage of intermediate HDL and of small LDL and HDL and less amount of large HDL. LDL size was also reduced in greater LAP index values. The negative impact of LAP was maintained after adjustment for multiple variables., Conclusion: LAP was robustly associated with atherogenic profile of lipoprotein subfractions, independently of multiple confounders.
- Published
- 2018
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22. Optical Properties of Europium Tetracycline Complexes in the Presence of High-Density Lipoproteins (HDL) Subfractions.
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Sicchieri LB, Monteiro AM, Figueiredo Neto AM, Gomes L, and Courrol LC
- Subjects
- Humans, Lipoproteins, HDL classification, Europium chemistry, Lipoproteins, HDL blood, Lipoproteins, HDL chemistry, Spectrometry, Fluorescence methods, Tetracyclines chemistry
- Abstract
Standard lipoprotein measurements of triglycerides, total cholesterol, low-density lipoproteins (LDL), and high-density lipoproteins (HDL) fail to identify many lipoprotein abnormalities that contribute to cardiovascular heart diseases (CHD). Studies suggested that the presence of CHD is more strongly associated with the HDL subspecies than with total HDL cholesterol levels. The HDL particles can be collected in at least three subfractions, the HDL2b, HDL2a, and HDL3. More specifically, atherosclerosis is associated with low levels of HDL2. In this work, the optical spectroscopic properties of europium tetracycline (EuTc) complex in the presence of different HDL subspecies was studied. The results show that the europium spectroscopic properties in the EuTc complex are influenced by sizes and concentrations of subclasses. Eu
3+ emission intensity and lifetime can discriminate the subfractions HDL3 and HDL2b.- Published
- 2017
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23. Insulin Resistance Predicts Atherogenic Lipoprotein Profile in Nondiabetic Subjects.
- Author
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Cartolano FC, Dias GD, de Freitas MCP, Figueiredo Neto AM, and Damasceno NRT
- Subjects
- Adult, Aged, Cholesterol, HDL blood, Cholesterol, LDL blood, Female, Glucose Tolerance Test, Humans, Male, Middle Aged, Risk Factors, Atherosclerosis metabolism, Blood Glucose metabolism, Insulin Resistance physiology, Lipoproteins blood
- Abstract
Background: Atherogenic diabetes is associated with an increased cardiovascular risk and mortality in diabetic individuals; however, the impact of insulin resistance (IR) in lipid metabolism in preclinical stages is generally underreported. For that, we evaluated the capacity of IR to predict an atherogenic lipid subfraction profile., Methods: Complete clinical evaluation and biochemical analysis (lipid, glucose profile, LDL, and HDL subfractions and LDL phenotype and size) were performed in 181 patients. The impact of IR as a predictor of atherogenic lipoproteins was tested by logistic regression analysis in raw and adjusted models., Results: HDL-C and Apo AI were significantly lower in individuals with IR. Individuals with IR had a higher percentage of small HDL particles, lower percentage in the larger ones, and reduced frequency of phenotype A (IR = 62%; non-IR = 83%). IR individuals had reduced probability to have large HDL (OR = 0.213; CI = 0.999-0.457) and had twice more chances to show increased small HDL (OR = 2.486; CI = 1.341-7.051). IR was a significant predictor of small LDL (OR = 3.075; CI = 1.341-7.051) and atherogenic phenotype (OR = 3.176; CI = 1.469-6.867)., Conclusion: IR, previously DM2 diagnosis, is a strong predictor of quantitative and qualitative features of lipoproteins directly associated with an increased atherogenic risk.
- Published
- 2017
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24. Effect of classic ketogenic diet treatment on lipoprotein subfractions in children and adolescents with refractory epilepsy.
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Azevedo de Lima P, Baldini Prudêncio M, Murakami DK, Pereira de Brito Sampaio L, Figueiredo Neto AM, and Teixeira Damasceno NR
- Subjects
- Adolescent, Atherosclerosis epidemiology, Atherosclerosis etiology, Atherosclerosis prevention & control, Biomarkers blood, Brazil epidemiology, Child, Diet, Atherogenic adverse effects, Disease Progression, Drug Resistant Epilepsy blood, Drug Resistant Epilepsy physiopathology, Dyslipidemias physiopathology, Female, Follow-Up Studies, Humans, Lipoproteins, HDL blood, Lipoproteins, LDL blood, Male, Prospective Studies, Risk, Adolescent Nutritional Physiological Phenomena, Child Nutritional Physiological Phenomena, Diet, Ketogenic adverse effects, Drug Resistant Epilepsy diet therapy, Dyslipidemias etiology
- Abstract
Objective: The aim of this study was to evaluate the effects of the classic ketogenic diet (KD) on low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subfractions in children and adolescents with refractory epilepsy., Methods: This prospective study recruited children and adolescents of either sex, whose epilepsy was refractory to treatment with multiple drugs. To be included, the patient had to have an indication for treatment with the KD and be treated as an outpatient. At baseline and after 3 and 6 mo of the KD, lipid profile (total cholesterol [TC], triacylglycerols [TG], LDL cholesterol [LDL-C], and HDL cholesterol [HDL-C]), apolipoproteins (apoA-I and apoB), 10 subfractions of HDL, 7 subfractions of LDL, LDL phenotype, and LDL size were analyzed using the Lipoprint system., Results: The lipid profile components (TC, TG, LDL-C, HDL-C, apoA-I, and apoB) increased during the 3-mo follow-up, and remained consistent after 6 mo of treatment. Similarly, non-HDL-C, TC/HDL-C, LDL-C/HDL-C, and apoB/apoA-I ratios, representing atherogenic particles, significantly increased. In contrast, qualitative lipoprotein characteristics progressively changed during the follow-up period. Small LDL subfractions increased, and this profile was related with reduced LDL size (27.3 nm to 26.7 nm). The LDL phenotype became worse; 52.1% of the patients had a non-A phenotype after 6 mo of the KD. Small HDL subfractions decreased only after 6 mo of the KD., Conclusions: KD treatment promotes negative changes in lipoprotein size and phenotype, contributing to atherogenic risk in these patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2017
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25. Non-linear Optical Responses of Low-Density Lipoprotein are Associated with Intima-Media Thickness of Carotid Artery in Athletes.
- Author
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Fonseca HA, Bittencourt CR, Fonseca FA, Monteiro AM, Santos PR, Camargo L, Costa LA, Murad A, Gidlund M, Figueiredo-Neto AM, and Izar MC
- Subjects
- Adult, Carotid Arteries pathology, Carotid Arteries physiology, Female, Humans, Male, Oxidation-Reduction, Oxygen Consumption, Young Adult, Athletes, Carotid Arteries diagnostic imaging, Carotid Intima-Media Thickness, Lipoproteins, LDL metabolism, Nonlinear Dynamics, Optical Phenomena
- Abstract
We investigated the association between the degree of oxidative modification of LDL particles by non-linear optical response of LDL (Z-scan technique) and the presence of subclinical atherosclerosis in different segments of the carotid artery. We recruited high-intensity athlete runners (n = 44) and controls (n = 51) to participate in the study. The carotid intima-media thickness (cIMT), interleukin 10 (IL-10), TNF-alpha, and the non-linear optical responses of LDL particle (Z-scan) were assessed. In athletes, the mean cIMT differed between genders, with higher values observed in female athletes compared to male athletes (P < 0.05). Higher mean values for cIMT were seen in the right carotid arteries of female athletes as compared to female controls (P < 0.05). Higher levels of TNF-alpha and IL-10 were found in athletes (P < 0.05). Yet, ΔΓpv (transmittance curve) of Z-scan in athletes was higher than in the non-athletes, indicating less oxidation in LDL particles of athletes (P < 0.05). There was an inverse association between the ΔΓpv and cIMT in the right internal carotid segments (β = -0.163, P < 0.05) in all subjects, and between the VO2max and the mean cIMT (β = -0.003, P < 0.05) in male subjects. The present study shows that the Z-scan technique enabled to detect less oxidative modifications in LDL particles from athletes. This effect was associated with cIMT in a gender-dependent mode.
- Published
- 2016
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26. Antihypertensive therapy increases natural immunity response in hypertensive patients.
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Fonseca HA, Fonseca FA, Lins LC, Monteiro AM, Bianco HT, Brandão SA, Povoa RM, Juliano L, Figueiredo-Neto AM, Boschcov P, Gidlund M, and Izar MC
- Subjects
- Angiotensin-Converting Enzyme Inhibitors pharmacology, Angiotensin-Converting Enzyme Inhibitors therapeutic use, Antihypertensive Agents pharmacology, Female, Humans, Hydrochlorothiazide pharmacology, Hypertension immunology, Immunity, Innate immunology, Indapamide pharmacology, Male, Middle Aged, Perindopril pharmacology, Single-Blind Method, Antihypertensive Agents therapeutic use, Hydrochlorothiazide therapeutic use, Hypertension drug therapy, Immunity, Innate drug effects, Indapamide therapeutic use, Perindopril therapeutic use
- Abstract
Aims: The aim of this work was to evaluate the effects of treatment of hypertension on the autoantibodies to apolipoprotein B-derived peptides (anti-ApoB-D peptide Abs) response, inflammation markers and vascular function., Main Methods: Eighty-eight patients with hypertension (stage 1 or 2) were recruited and advised to receive perindopril (4mg), hydrochlorothiazide (25mg), or indapamide (1.5mg) for 12weeks in a blinded fashion. Office and 24-h ambulatory blood pressure monitoring (24h ABPM), flow-mediated dilatation (FMD), nitrate-induced dilatation (NID), titers of IgG and IgM anti-ApoB-D peptide Abs, hsCRP, and interleukins (IL-8 and IL-10) were evaluated at baseline and 12weeks after therapies., Key Findings: All treatments reduced office BP, and improved FMD (P<0.05 vs. baseline). The NID was improved only in the perindopril arm (P<0.05 vs. baseline). The 24h-ABPM was reduced with perindopril and hydrochlorothiazide therapies (P<0.05 vs. baseline), but not with indapamide, and this effect was followed by increase in titers of IgM Anti-ApoB-D peptide Abs (P<0.05 vs. baseline), without modifications in titers IgG Anti-ApoB-D peptide Abs and interleukins. Multivariable regression analysis has shown that change in the titers of IgM anti-ApoB-D peptide was associated with the changes in FMD (β -0.347; P<0.05)., Significance: These findings shed light to a possible modulator effect of the antihypertensive therapy on the natural immunity responses and vascular function., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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27. Temperature dependence of the Soret coefficient of ionic colloids.
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Sehnem AL, Figueiredo Neto AM, Aquino R, Campos AF, Tourinho FA, and Depeyrot J
- Abstract
The temperature dependence of the Soret coefficient S(T)(T) in electrostatically charged magnetic colloids is investigated. Two different ferrofluids, with different particles' mean dimensions, are studied. In both cases we obtain a thermophilic behavior of the Soret effect. The temperature dependence of the Soret coefficient is described assuming that the nanoparticles migrate along the ionic thermoelectric field created by the thermal gradient. A model based on the contributions from the thermoelectrophoresis and variation of the double-layer energy, without fitting parameters, is used to describe the experimental results of the colloid with the bigger particles. To do so, independent measurements of the ζ potential, mass diffusion coefficient, and Seebeck coefficient are performed. The agreement of the theory and the experimental results is rather good. In the case of the ferrofluid with smaller particles, it is not possible to get experimentally reliable values of the ζ potential and the model described is used to evaluate this parameter and its temperature dependence.
- Published
- 2015
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28. Magnetic and structural study of electric double-layered ferrofluid with MnFe(2)O(4)@γ-Fe(2)O(3) nanoparticles of different mean diameters: Determination of the magnetic correlation distance.
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Gonçalves ES, Cornejo DR, Oliveira CL, Figueiredo Neto AM, Depeyrot J, Tourinho FA, and Aquino R
- Abstract
Magnetic fluids based on manganese ferrite nanoparticles were studied from the structural point of view through small angle x-rays scattering (SAXS) and from the magnetic point of view through zero-field cooling and field cooling (ZFC-FC) and ac susceptibility measurements (MS). Three different colloids with particles mean diameters of 2.78,3.42, and 6.15 nm were investigated. The size distribution obtained from SAXS measurements follows a log-normal behavior. The ZFC-FC and MS results revealed the presence of an important magnetic interaction between the nanoparticles, characterized by a magnetic correlation distance Λ. The colloidal medium can be pictures as composed by magnetic cluster constituted by N interacting particles. These magnetic clusters are not characterized by a physical aggregation of particles. The energy barrier energy obtained is consistent with the existence of this magnetic clusters. Besides the magnetic interaction between particles, confinement effects must be included to account for the experimental values of the magnetic energy barrier encountered.
- Published
- 2015
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29. Effect of oxidation on the structure of human low- and high-density lipoproteins.
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Oliveira CL, Santos PR, Monteiro AM, and Figueiredo Neto AM
- Subjects
- Fourier Analysis, Humans, Light, Oxidation-Reduction, Scattering, Radiation, Scattering, Small Angle, Static Electricity, X-Ray Diffraction, Lipoproteins, HDL chemistry, Lipoproteins, HDL metabolism, Lipoproteins, LDL chemistry, Lipoproteins, LDL metabolism
- Abstract
This work presents a controlled study of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) structural changes due to in vitro oxidation with copper ions. The changes were studied by small-angle x-ray scattering (SAXS) and dynamic light scattering (DLS) techniques in the case of LDL and by SAXS, DLS, and Z-scan (ZS) techniques in the case of HDL. SAXS data were analyzed with a to our knowledge new deconvolution method. This method provides the electron density profile of the samples directly from the intensity scattering of the monomers. Results show that LDL particles oxidized for 18 h show significant structural changes when compared to nonoxidized particles. Changes were observed in the electrical density profile, in size polydispersity, and in the degree of flexibility of the APO-B protein on the particle. HDL optical results obtained with the ZS technique showed a decrease of the amplitude of the nonlinear optical signal as a function of oxidation time. In contrast to LDL results reported in the literature, the HDL ZS signal does not lead to a complete loss of nonlinear optical signal after 18 h of copper oxidation. Also, the SAXS results did not indicate significant structural changes due to oxidation of HDL particles, and DLS results showed that a small number of oligomers formed in the sample oxidized for 18 h. All experimental results for the HDL samples indicate that this lipoprotein is more resistant to the oxidation process than are LDL particles., (Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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30. Anomalous behavior in the crossover between the negative and positive biaxial nematic mesophases in a lyotropic liquid crystal.
- Author
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Akpinar E, Reis D, and Figueiredo Neto AM
- Abstract
A novel quaternary lyotropic liquid-crystalline mixture of dodecyltrimethylammonium bromide (DDTMABr)/sodium bromide/1-dodecanol/water, presenting the biaxial nematic phase (NB ) in addition to two uniaxial discotic (ND) and calamitic (NC) nematic ones, was synthesized. The partial phase diagram of this new mixture was constructed as a function of the DDTMABr molar-fraction concentration. The phase transitions from uniaxial to biaxial nematic phases were studied by means of the temperature dependence of the optical birefringence. In a particular region of the phase diagram, anomalous behavior was observed in the crossover from N-B to N+b: the contrast of the conoscopic fringes, which allows the birefringence measurements, almost vanishes, and the sample loses its alignment. This behavior, which was not observed before in lyotropics, was interpreted as a decrease in the mean diamagnetic susceptibility anisotropy (Δχ) of the sample, which was related to the shape anisotropy of the micelles. Small-angle X-ray scattering measurements were performed to evaluate the micellar shape anisotropy; these revealed that this mixture presented a smaller shape anisotropy than those of other lyotropic micellar systems presenting the NB phase., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
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31. Thermodiffusion in positively charged magnetic colloids: influence of the particle diameter.
- Author
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Sehnem AL, Aquino R, Campos AF, Tourinho FA, Depeyrot J, and Figueiredo Neto AM
- Abstract
The Soret coefficient (ST) of positively charged magnetic colloids was measured as a function of the nanoparticles' diameter. The Z-scan technique and the generalization of the thermal lens model proved to be a reliable technique to measure ST. We show that ST is negative and increases with the particle's diameter, being best described by a functional dependence of the type ST∝d0. Potentiometric and conductometric experiments show that the particle's surface charge decreases as the temperature increases, changing the electrostatic interaction between the nanoparticles. The temperature gradient imposed in the ferrofluid by the Gaussian laser beam leads to the formation of the particle's concentration gradient. The origin of this phenomenon is discussed in terms of the decrease of the particle's surface charge in the hottest region of the sample and the thermoelectric field due to the inhomogeneous distribution of hydrogenous ions present in the colloidal suspension.
- Published
- 2014
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32. Dynamic light scattering and viscosity measurements in a ternary and quaternary discotic lyotropic nematic liquid crystal: tuning the backflow with salt.
- Author
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Risi CL, Figueiredo Neto AM, Akpinar E, and Santos MB
- Abstract
Using a dynamic light scattering technique, we measure the damping rate of thermal fluctuations of the nematic director for the so-called disklike nematic N(D) phase of both the ternary lyotropic K-laurate-1-decanol-H(2)O system and the quaternary one of similar composition except for the addition of salt (K(2)SO(4)). By varying the scattering angle in suitable geometries and polarizations, we are able to measure the orientational diffusivities associated with the pure deformations of splay and twist. A previous study made in the N(D) phase of the same ternary system yielded a large deviation between the splay and twist diffusivities. The effect was then interpreted in terms of the anisotropy between their associated viscosities due to induced flows, or backflow. In the present work we observe a strong increase of the backflow as an effect of the added salt. In addition, we make auxiliary measurements of shear viscosity and magnetic instabilities, which help to characterize the effect of the salt in the orientational diffusivities as they are mixed quantities involving elastic constants and viscosity coefficients.
- Published
- 2013
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33. Common sources and composition of phytosterols and their estimated intake by the population in the city of São Paulo, Brazil.
- Author
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Martins CM, Fonseca FA, Ballus CA, Figueiredo-Neto AM, Meinhart AD, de Godoy HT, and Izar MC
- Subjects
- Adult, Aged, Brazil, Cholesterol administration & dosage, Cholesterol analysis, Cholesterol blood, Chromatography, Gas, Cross-Sectional Studies, Edible Grain chemistry, Fabaceae chemistry, Female, Fruit chemistry, Humans, Male, Middle Aged, Nutrition Assessment, Phytosterols analysis, Plant Oils chemistry, Plants, Edible chemistry, Seeds chemistry, Sitosterols analysis, Stigmasterol analysis, Surveys and Questionnaires, Vegetables chemistry, Young Adult, Cholesterol analogs & derivatives, Feeding Behavior, Phytosterols administration & dosage, Sitosterols administration & dosage, Stigmasterol administration & dosage
- Abstract
Objective: Phytosterols have been used alone, or combined with lipid-altering drugs, to reduce cholesterol levels and the burden of cardiovascular disease. Considerable variation in the composition of phytosterols exists and its consumption, in a regular diet, by the Brazilian population is still unknown. Thus, the aim of the present study was to determine the phytosterols content of the most consumed plant foods and to estimate the phytosterols intake by this population., Methods: Intake of plant foods of a representative population of the city of São Paulo (n = 1609), randomly selected on the basis of the Brazilian Institute for Geography and Statistics census data (2010), was obtained by a food frequency questionnaire (FFQ). Foods were chosen on the basis of the Consume Expenditure Survey (2002-2003) and from answers to the FFQ. Phytosterols composition of most consumed greens, legumes, cereals, and seeds, fruits, and vegetable oils was determined by gas chromatography (flame ionization detection). Daily phytosterols intake was estimated in terms of mg per 100 g (mg/100 g(-1)) of edible portion. Underreporters and overreporters were excluded., Results: Mean (SE) daily phytosterols intake in the diet of the study population was 100.6 (1.2) mg, with β-sitosterol as the largest sterol component (65.4%), followed by campesterol (23.2%), and stigmasterol (10%). No significant changes in daily phytosterols intake were observed after exclusion of underreporters and overreporters. Considerable variation was observed in phytosterols content among the most consumed plant foods., Conclusions: Analysis of phytosterols composition in most consumed plant foods has shown that phytosterols content varied among food groups. Dietary intake of phytosterols in a large population of the city of São Paulo is in the same range of some countries., (Copyright © 2013 Elsevier Inc. All rights reserved.)
- Published
- 2013
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34. Effect of alkyl chain length of alcohols on cholesteric uniaxial to cholesteric biaxial phase transitions in a potassium laurate/alcohol/potassium sulfate/water/brucine lyotropic mixture: evidence of a first-order phase transition.
- Author
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Reis D, Akpinar E, and Figueiredo Neto AM
- Abstract
Lyotropic cholesteric liquid crystalline phases were prepared by doping the quaternary mixture of potassium laurate (KL)/potassium sulfate (K(2)SO(4))/alcohol (n-OH)/water with the chiral agent brucine. Different long-chain alcohols whose alkyl chains (n) vary from 8 (1-octanol) to 16 (1-hexadecanol) were used. The cholesteric uniaxial to cholesteric biaxial phase transitions were investigated by measuring the birefringences via polarizing optical microscopy, and the phase diagram was constructed as a function of the alkyl chain length of the alcohols. Alcohols with 9 ≤ n ≤ 12 presented the three cholesteric phases (cholesteric discotic-Ch(D), cholesteric biaxial-Ch(B), and cholesteric calamitic-Ch(C)). The Ch(D)-to-Ch(B) transition was shown to be continuous, with a bare correlation length bigger than the typical micellar dimensions. Mixtures with n = 8 and n = 13 showed a first-order phase transition between the Ch(D) and the Ch(C) phases, without the presence of the Ch(B) phase in between. These results are interpreted in terms of the nanosegregation of the alcohol molecules in the micelles with respect to the main amphiphiles molecules.
- Published
- 2013
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35. Adaptive immunity is related to coronary artery disease severity after acute coronary syndrome in subjects with metabolic syndrome.
- Author
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Izar MC, Fonseca HA, Pinheiro LF, Monteiro CM, Póvoa RM, Monteiro AM, Figueiredo-Neto AM, Gidlund MA, and Fonseca FA
- Subjects
- Acute Coronary Syndrome complications, Adult, Age Factors, Aged, Angina, Unstable complications, Angina, Unstable immunology, Autoantibodies blood, Coronary Angiography, Coronary Artery Disease complications, Enzyme-Linked Immunosorbent Assay, Female, Humans, Male, Metabolic Syndrome complications, Middle Aged, Myocardial Infarction complications, Myocardial Infarction immunology, Prospective Studies, Severity of Illness Index, Sex Factors, Acute Coronary Syndrome immunology, Adaptive Immunity, Autoantibodies immunology, Coronary Artery Disease immunology, Lipoproteins, LDL immunology, Metabolic Syndrome immunology
- Abstract
Metabolic syndrome (MetS) is an inflammatory state associated with high coronary disease risk. Inflammation and adaptive immunity modulate atherosclerosis and plaque instability. We examined early changes in anti-oxidized low-density lipoprotein (LDL) (anti-oxLDL) autoantibodies (Abs) in patients with MetS after an acute coronary syndrome (ACS). Patients of both genders (n=116) with MetS were prospectively included after an acute myocardial infarction (MI) or hospitalization due to unstable angina. Anti-oxLDL Abs (IgG class) were assayed at baseline, three and six weeks after ACS. The severity of coronary disease was evaluated by the Gensini score. We observed a decrease in anti-oxLDL Abs titers (p<0.002 vs. baseline), mainly in males (p=0.01), in those under 65 y (p=0.03), and in subjects with Gensini score above median (p=0.04). In conclusion, early decrease in circulating anti-oxLDL Abs is associated with coronary disease severity among subjects with MetS.
- Published
- 2013
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36. Measurement of the nonlinear optical response of low-density lipoprotein solutions from patients with periodontitis before and after periodontal treatment: evaluation of cardiovascular risk markers.
- Author
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Monteiro AM, Jardini MA, Giampaoli V, Alves S, Figueiredo Neto AM, and Gidlund M
- Subjects
- Adult, Biomarkers blood, Cardiovascular Diseases blood, Cardiovascular Diseases etiology, Chronic Periodontitis complications, Chronic Periodontitis therapy, Female, Humans, Inflammation Mediators blood, Lipoproteins, LDL chemistry, Male, Middle Aged, Nonlinear Dynamics, Optical Phenomena, Oxidation-Reduction, Prospective Studies, Risk Factors, Solutions, Chronic Periodontitis blood, Lipoproteins, LDL blood
- Abstract
The Z-Scan (ZS) technique in the thermal regime has been used to measure the nonlinear optical response of low-density lipoprotein (LDL). The ZS technique is carried out in LDL from 40 patients with chronic periodontitis before and after three, six, and 12 months of periodontal treatment. Clinical parameters such as probing depths, bleeding on probing, total and differential white blood cells counts, lipid profiles, cytokine levels, and antibodies against oxidized LDL are also determined and compared over time. Before the treatment, the ZS experimental results reveal that the LDL particles of these patients are heavily modified. Only after 12 months of the periodontal treatment, the ZS results obtained reveal behavioral characteristics of healthy particles. This conclusion is also supported by complementary laboratorial analysis showing that the periodontal treatment induces systemic changes in several inflammatory markers.
- Published
- 2012
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37. Differences in synthesis and absorption of cholesterol of two effective lipid-lowering therapies.
- Author
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Kasmas SH, Izar MC, França CN, Ramos SC, Moreira FT, Helfenstein T, Moreno RA, Borges NC, Figueiredo-Neto AM, and Fonseca FA
- Subjects
- Adult, Aged, Biomarkers blood, Cholesterol, LDL blood, Drug Therapy, Combination, Ezetimibe, Female, Humans, Male, Middle Aged, Prospective Studies, Rosuvastatin Calcium, Anticholesteremic Agents administration & dosage, Azetidines administration & dosage, Cholesterol, LDL drug effects, Fluorobenzenes administration & dosage, Hydroxymethylglutaryl-CoA Reductase Inhibitors administration & dosage, Hypercholesterolemia drug therapy, Pyrimidines administration & dosage, Simvastatin administration & dosage, Sulfonamides administration & dosage
- Abstract
Effective statin therapy is associated with a marked reduction of cardiovascular events. However, the explanation for full benefits obtained for LDL cholesterol targets by combined lipid-lowering therapy is controversial. Our study compared the effects of two equally effective lipid-lowering strategies on markers of cholesterol synthesis and absorption. A prospective, open label, randomized, parallel design study, with blinded endpoints, included 116 subjects. We compared the effects of a 12-week treatment with 40 mg rosuvastatin or the combination of 40 mg simvastatin/10 mg ezetimibe on markers of cholesterol absorption (campesterol and β-sitosterol), synthesis (desmosterol), and their ratios to cholesterol. Both therapies similarly decreased total and LDL cholesterol, triglycerides and apolipoprotein B, and increased apolipoprotein A1 (P < 0.05 vs baseline for all). Simvastatin/ezetimibe increased plasma desmosterol (P = 0.012 vs baseline), and decreased campesterol and β-sitosterol (P < 0.0001 vs baseline for both), with higher desmosterol (P = 0.007) and lower campesterol and β-sitosterol compared to rosuvastatin, (P < 0.0001, for both). In addition, rosuvastatin increased the ratios of these markers to cholesterol (P < 0.002 vs baseline for all), whereas simvastatin/ezetimibe significantly decreased the campesterol/cholesterol ratio (P = 0.008 vs baseline) and tripled the desmosterol/cholesterol ratio (P < 0.0001 vs baseline). The campesterol/cholesterol and β-sitosterol/cholesterol ratios were lower, whereas the desmosterol/cholesterol ratio was higher in patients receiving simvastatin/ezetimibe (P < 0.0001 vs rosuvastatin, for all). Pronounced differences in markers of cholesterol absorption and synthesis were observed between two equally effective lipid-lowering strategies.
- Published
- 2012
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38. Behavior of the thermal diffusivity of native and oxidized human low-density lipoprotein solutions studied by the Z-scan technique.
- Author
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Santos PR, Genaro-Mattos TC, Monteiro AM, Miyamoto S, and Figueiredo Neto AM
- Subjects
- Chromatography, High Pressure Liquid methods, Humans, Nonlinear Dynamics, Oxidation-Reduction, Phospholipids chemistry, Solutions chemistry, Spectrometry, Fluorescence methods, Spectrophotometry, Ultraviolet methods, Thermodynamics, Lipoproteins, LDL chemistry
- Abstract
Modifications in low-density lipoprotein (LDL) have emerged as a major pathogenic factor of atherosclerosis, which is the main cause of morbidity and mortality in the western world. Measurements of the heat diffusivity of human LDL solutions in their native and in vitro oxidized states are presented by using the Z-Scan (ZS) technique. Other complementary techniques were used to obtain the physical parameters necessary to interpret the optical results, e.g., pycnometry, refractometry, calorimetry, and spectrophotometry, and to understand the oxidation phase of LDL particles. To determine the sample's thermal diffusivity using the thermal lens model, an iterative one-parameter fitting method is proposed which takes into account several characteristic ZS time-dependent and the position-dependent transmittance measurements. Results show that the thermal diffusivity increases as a function of the LDL oxidation degree, which can be explained by the increase of the hydroperoxides production due to the oxidation process. The oxidation products go from one LDL to another, disseminating the oxidation process and caring the heat across the sample. This phenomenon leads to a quick thermal homogenization of the sample, avoiding the formation of the thermal lens in highly oxidized LDL solutions.
- Published
- 2012
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39. Lyotropic mixture made of potassium laurate/1-undecanol/K2SO4/water presenting high birefringences and large biaxial nematic phase domain: a laser conoscopy study.
- Author
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Akpinar E, Reis D, and Figueiredo Neto AM
- Abstract
The lyotropic liquid crystalline quaternary mixture made of potassium laurate (KL), potassium sulphate, 1-undecanol and water was investigated by experimental optical methods (optical microscopy and laser conoscopy). In a particular temperature and relative concentrations range, the three nematic phases (two uniaxial and one biaxial) were identified. The biaxial domain in the temperature/KL concentration surface is larger when compared to other lyotropic mixtures. Moreover, this new mixture gives nematic phases with higher birefringence than similar systems. The behavior of the symmetric tensor order parameter invariants σ (3) and σ (2) calculated from the measured optical birefringences supports that the uniaxial-to-biaxial transitions are of second order, described by a mean-field theory.
- Published
- 2012
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40. Tricritical-like behavior of the nonlinear optical refraction at the nematic-isotropic transition in the E7 thermotropic liquid crystal.
- Author
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Lenart VM, Gómez SL, Bechtold IH, Figueiredo Neto AM, and Salinas SR
- Subjects
- Birefringence, Phase Transition, Liquid Crystals chemistry, Models, Chemical
- Abstract
We use Z-scan technique to investigate the nonlinear optical response of the thermotropic liquid crystal E7 in the neighborhood of the nematic-isotropic phase transition. The analysis of the data for the nonlinear optical birefringence is compatible with an effective critical exponent of the order parameter, β = 0.28 ± 0.03, which is close to the classical value, β = 0.25 , for a tricritical point. The nonlinear optical absorption in the nematic range depends on the geometrical configuration of the nematic director with respect to the polarization beam, and vanishes in the isotropic phase.
- Published
- 2012
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41. Oxidative stress and modification of renal vascular permeability are associated with acute kidney injury during P. berghei ANKA infection.
- Author
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Elias RM, Correa-Costa M, Barreto CR, Silva RC, Hayashida CY, Castoldi A, Gonçalves GM, Braga TT, Barboza R, Rios FJ, Keller AC, Cenedeze MA, Hyane MI, D'Império-Lima MR, Figueiredo-Neto AM, Reis MA, Marinho CR, Pacheco-Silva A, and Câmara NO
- Subjects
- Acute Kidney Injury pathology, Animals, Apoptosis, Cell Adhesion, Cell Hypoxia, Endothelial Cells parasitology, Endothelial Cells pathology, Erythrocytes parasitology, Erythrocytes pathology, Heme metabolism, Inflammation complications, Kidney blood supply, Kidney parasitology, Kidney pathology, Mice, Mice, Inbred BALB C, Reactive Oxygen Species metabolism, Acute Kidney Injury complications, Acute Kidney Injury metabolism, Capillary Permeability, Kidney metabolism, Malaria complications, Oxidative Stress, Plasmodium berghei pathogenicity
- Abstract
Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.
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- 2012
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42. Antioxidant status and biomarkers of oxidative stress in bovine leukemia virus-infected dairy cows.
- Author
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Souza FN, Monteiro AM, dos Santos PR, Sanchez EM, Blagitz MG, Latorre AO, Figueiredo Neto AM, Gidlund M, and Della Libera AM
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- Animals, Biomarkers blood, Cattle, Female, Glutathione Peroxidase blood, Lipids blood, Lipoproteins, LDL blood, Antioxidants metabolism, Enzootic Bovine Leukosis blood, Oxidative Stress
- Abstract
Bovine leukemia virus (BLV) is among the most widespread livestock pathogens in many countries. Despite advances in understanding the pathogenesis of this disease, little is known about the involvement of oxidative stress. Therefore, this study examined the antioxidant status and the markers of oxidative stress in BLV-infected dairy cows. BLV infection was associated with an increase in triacylglycerol levels, a decrease in glutathione peroxidase (GSH-Px) activity and a tendency toward lower superoxide dismutase activity in the infected animals. No significant difference was observed in other markers of oxidative stress (i.e., conjugated dienes, hydroperoxides and malondialdehyde) in the infected animals compared to controls. A novel method for the analysis of oxidative stress, Z-scan based on the measurement of the mean-value of θ in low density lipoprotein indicated that the infected animals had low-density lipoprotein particles that were slightly less modified than those from the healthy group. Thus, we conclude that BLV infection is associated with a selective decrease in GSH-Px activity without any alteration in the common plasma markers of oxidative stress., (Copyright © 2011 Elsevier B.V. All rights reserved.)
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- 2011
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43. The influence of adsorption phenomena on the impedance spectroscopy of an electrolytic cell.
- Author
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Batalioto F, Martins OG, Duarte AR, and Figueiredo Neto AM
- Subjects
- Adsorption, Electrodes, Models, Theoretical, Potassium Chloride chemistry, Surface Properties, Dielectric Spectroscopy methods, Electrolysis methods
- Abstract
In this work we investigate the influence of the adsorption of ions on the impedance spectroscopy of an electrolytic cell. We consider that the positive and negative ions present in a dielectric liquid are adsorbed in the electrode surfaces with different adsorption energies. This difference in adsorption energies causes an additional plateaux in the limit of the low-frequency range of the real part of the impedance Z. In the same frequency range, a second minimum in the imaginary part of Z is predicted. The theory is illustrated with measurements of the impedance of an electrolytic solution in the frequency range from 10(-2) Hz to 1 KHz. A comparison between the present model and others from the literature to describe the experimental results is also made.
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- 2011
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44. Characterization of the biocompatible magnetic colloid on the basis of Fe3O4 nanoparticles coated with dextran, used as contrast agent in magnetic resonance imaging.
- Author
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Gamarra LF, Amaro E Jr, Alves S, Soga D, Pontuschka WM, Mamani JB, Carneiro SM, Brito GE, and Figueiredo Neto AM
- Subjects
- Spectroscopy, Mossbauer, Biocompatible Materials, Colloids, Contrast Media, Ferrous Compounds chemistry, Magnetic Resonance Imaging, Magnetics, Metal Nanoparticles
- Abstract
The magnetic resonance imaging contrast agent, the so-called Endorem colloidal suspension on the basis of superparamagnetic iron oxide nanoparticles (mean diameter of 5.5 nm) coated with dextran, were characterized on the basis of several measurement techniques to determine the parameters of their most important physical and chemical properties. It is assumed that each nanoparticle is consisted of Fe3O4 monodomain and it was observed that its oxidation to gamma-Fe2O3 occurs at 253.1 degrees C. The Mössbauer spectroscopy have shown a superparamagnetic behavior of the magnetic nanoparticles. The Magnetic Resonance results show an increase of the relaxation times T1, T2, and T2* with decreasing concentration of iron oxide nanoparticles. The relaxation effects of SPIONs contrast agents are influenced by their local concentration as well as the applied field strength and the environment in which these agents interact with surrounding protons. The proton relaxation rates presented a linear behavior with concentration. The measured values of thermo-optic coefficient dn/dT, thermal conductivity kappa, optical birefringence delta n0, nonlinear refractive index n2, nonlinear absorption beta' and third-order nonlinear susceptibility |chi(3)| are also reported.
- Published
- 2010
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45. Early increase in autoantibodies against human oxidized low-density lipoprotein in hypertensive patients after blood pressure control.
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Brandão SA, Izar MC, Fischer SM, Santos AO, Monteiro CM, Póvoa RM, Helfenstein T, Carvalho AC, Monteiro AM, Ramos E, Gidlund M, Figueiredo Neto AM, and Fonseca FA
- Subjects
- Aged, Apolipoproteins blood, Biomarkers, Blood Chemical Analysis, Blood Pressure drug effects, Coronary Disease blood, Coronary Disease complications, Endothelium, Vascular physiology, Female, Humans, Inflammation blood, Lipids blood, Male, Middle Aged, Muscle Relaxation physiology, Muscle, Smooth, Vascular physiology, Vasodilation physiology, Antihypertensive Agents therapeutic use, Autoantibodies metabolism, Blood Pressure physiology, Hypertension drug therapy, Hypertension immunology, Lipoproteins, LDL immunology
- Abstract
Background: Oxidized lipoproteins and antioxidized low-density lipoprotein (anti-oxLDL) antibodies (Abs) have been detected in plasma in response to blood pressure (BP) elevation, suggesting the participation of the adaptive immune system. Therefore, treatment of hypertension may act on the immune response by decreasing oxidation stimuli. However, this issue has not been addressed. Thus, we have here analyzed anti-oxLDL Abs in untreated (naive) hypertensive patients shortly after initiation of antihypertensive therapeutic regimens., Methods: Titers of anti-oxLDL Abs were measured in subjects with recently diagnosed hypertension on stage 1 (n = 94), in primary prevention of coronary disease, with no other risk factors, and naive of antihypertensive medication at entry. Subjects were randomly assigned to receive perindopril, hydrochlorothiazide (HCTZ), or indapamide (INDA) for 12 weeks, with additional perindopril if necessary to achieve BP control. Abs against copper-oxidized LDL were measured by enzyme-linked immunosorbent assay., Results: Twelve-week antihypertensive treatment reduced both office-based and 24-h ambulatory BP measurements (P < 0.0005). The decrease in BP was accompanied by reduction in thiobarbituric acid-reactive substances (TBARS) (P < 0.05), increase in anti-oxLDL Ab titers (P < 0.005), and improvement in flow-mediated dilation (FMD) (P < 0.0005), independently of treatment. Although BP was reduced, we observed favorable changes in anti-oxLDL titers and FMD., Conclusions: We observed that anti-oxLDL Ab titers increase after antihypertensive therapy in primary prevention when achieving BP targets. Our results are in agreement with the concept that propensity to oxidation is increased by essential hypertension and anti-oxLDL Abs may be protective and potential biomarkers for the follow-up of hypertension treatment.
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- 2010
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46. High circulating autoantibodies against human oxidized low-density lipoprotein are related to stable and lower titers to unstable clinical situation.
- Author
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Santos AO, Fonseca FA, Fischer SM, Monteiro CM, Brandão SA, Póvoa RM, Bombig MT, Carvalho AC, Monteiro AM, Ramos E, Gidlund M, Figueiredo Neto AM, and Izar MC
- Subjects
- Acute Coronary Syndrome blood, Acute Coronary Syndrome complications, Acute Coronary Syndrome immunology, Adult, Aged, Analysis of Variance, Biomarkers blood, C-Reactive Protein metabolism, Female, Humans, Hypertension blood, Hypertension complications, Hypertension immunology, Linear Models, Male, Middle Aged, Risk Factors, Autoantibodies blood, Autoantibodies immunology, Lipoproteins, LDL immunology
- Abstract
Background: Oxidized lipoproteins and antibodies anti-oxidized low-density lipoprotein (anti-oxLDL) have been detected in human plasma and in atherosclerotic lesions. However, the role of these autoantibodies in the maintenance of vascular health or in the pathogenesis of acute vascular insults remains unclear. We examined the relationship of human immunoglobulin G (IgG) anti-oxLDL antibodies with cardiovascular disease risk markers in stable subjects and in patients after an acute coronary syndrome (ACS)., Methods: Titers of human anti-oxLDL antibodies were measured in hypertensive subjects in primary prevention (n=94), without other risk factors, and in individuals after a recent ACS event who also had metabolic syndrome (n=116). Autoantibodies against copper ion oxidized LDL were measured by enzyme-linked-immunosorbent assay., Results: Anti-oxLDL titers were higher in hypertensive patients and these subjects presented lower high sensitivity C-reactive protein (hs-CRP) than those with ACS (p<0.0001). We found significant correlations between anti-oxLDL and hs-CRP (r=-0.284), body mass index (r=-0.256), waist circumference (r=-0.368), apolipoprotein B (r=-0.191), glucose (r=-0.303), systolic blood pressure (r=0.319), diastolic blood pressure (r=0.167), high-density lipoprotein cholesterol (r=0.224) and apolipoprotein A1 (r=0.257) (p<0.02 for all). After multiple linear regression hs-CRP, fasting glucose and waist circumference remained independently and inversely associated with anti-oxLDL., Conclusions: Acute inflammatory and metabolic conditions decrease titers of human antibodies of IgG class against oxidized LDL, and that circulating anti-oxLDL antibodies could be associated with a protective role in atherosclerosis.
- Published
- 2009
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47. Cardiovascular disease parameters in periodontitis.
- Author
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Monteiro AM, Jardini MA, Alves S, Giampaoli V, Aubin EC, Figueiredo Neto AM, and Gidlund M
- Subjects
- Adult, Age Factors, Antibodies blood, Body Mass Index, Case-Control Studies, Cholesterol blood, Cholesterol, HDL blood, Cholesterol, LDL blood, Cholesterol, LDL immunology, Female, Humans, Hypercholesterolemia complications, Hypertriglyceridemia complications, Interleukin-6 blood, Interleukin-8 blood, Leukocyte Count, Lipid Peroxides blood, Lipoproteins, LDL blood, Male, Middle Aged, Neutrophils pathology, Oxidation-Reduction, Refractometry, Risk Factors, Sex Factors, Thiobarbituric Acid Reactive Substances analysis, Chronic Periodontitis complications, Coronary Artery Disease complications
- Abstract
Background: Recently, there has been an increasing in the impact of oral health on atherosclerosis and subsequent cardiovascular disease. The aim of this study is to investigate the association between chronic periodontitis and cardiovascular risk markers., Methods: Forty patients with periodontitis and 40 healthy gender-, body mass index-, and age-matched individuals were compared by measuring total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, levels of cytokines, antibodies against oxidized low-density lipoprotein, thiobarbituric acid reactive substances, total and differential white blood cell counts, and the non-linear index of refraction., Results: The levels of triglycerides and high-density lipoprotein in periodontitis patients were significantly higher and lower, respectively (P = 0.002 and P = 0.0126), compared to controls. Total cholesterol, low-density lipoprotein, and lipid peroxide levels were the same in both groups (P = 0.2943, P = 0.1284, and P = 0.067, respectively). Interleukin (IL)-6 and -8, antibodies against oxidized low-density lipoprotein, and leukocyte and neutrophil counts were significantly higher in periodontitis patients (P <0.05). The value of the non-linear index of refraction of low-density lipoprotein solutions was higher in the controls (P = 0.015) compared to individuals with periodontitis., Conclusion: Our results confirmed and further strengthened the suggested association between coronary artery disease and periodontitis.
- Published
- 2009
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48. Thermodiffusion in a multicomponent lyotropic mixture in the vicinity of the critical micellar concentration by using the Z -scan technique.
- Author
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Santos MP, Gómez SL, Bringuier E, and Figueiredo Neto AM
- Abstract
Thermodiffusion in a lyotropic mixture of water and potassium laurate is investigated by means of an optical technique (Z scan) distinguishing the index variations due to the temperature gradient and the mass gradients. A phenomenological framework allowing for coupled diffusion is developed in order to analyze thermodiffusion in multicomponent systems. An observable parameter relating to the mass gradients is found to exhibit a sharp change around the critical micellar concentration, and thus may be used to detect it. The change in the slope is due to the markedly different values of the Soret coefficients of the surfactant and the micelles. The difference in the Soret coefficients is due to the fact that the micellization process reduces the energy of interaction of the ball of amphiphilic molecules with the solvent.
- Published
- 2008
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49. Novel fluorescent probe for low density lipoprotein, based on the enhancement of Europium emission band.
- Author
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Courrol LC, Monteiro AM, O Silva FR, Gomes L, Vieira ND Jr, Gidlund MA, and Figueiredo Neto AM
- Abstract
We report here the observation of the enhancement of Europium-tetracycline complex emission in Low Density Lipoprotein (LDL) solutions. Europium emission band of tetracycline solution containing Europium (III) chloride hexahydrate was tested to obtain effective enhancement in the presence of native LDL and oxidized LDL. Europium emission lifetime in the presence of lipoproteins was measured, resulting in a simple method to measure the lipoproteins quantity in an aqueous solution at physiological pH. This method shows that the complex can be used as a sensor to determine the different states of native and oxidized LDL in biological fluids.
- Published
- 2007
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50. Relaxation time for the ionic current in a nematic cell under a large electric field.
- Author
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Barbero G, Figueiredo Neto AM, Freire FC, and Le Digabel J
- Abstract
We evaluate the ionic relaxation time of a nematic cell subjected to a potential difference, V0 , very large with respect to VT=KBT/q=0.025 V, where KBT is the thermal energy, and q the electrical charge of the ions, assumed monovalent. The analysis is performed by assuming that the mobilities of the positive and negative ions are the same, and that the ions can be considered pointlike. We show that, for V0>>VT, the relaxation time tends to the time of flight of the ions. In our analysis the ionic charges are assumed to form two surface layers responsible for a partial screening of the external field. In this framework, the evolution of the surface-charge density is determined by a simple differential equation related to the conservation of the ions number. According to our calculations, the relaxation time of the surface density of ionic origin, and of the electrical potential close to the electrodes, depends on the applied voltage, in agreement with the experimental observations.
- Published
- 2006
- Full Text
- View/download PDF
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