967 resultados para 18-CROWN-6


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The [Ru3O(Ac)6(py)2(CH3OH)]+ cluster provides an effective electrocatalytic species for the oxidation of methanol under mild conditions. This complex exhibits characteristic electrochemical waves at -1.02, 0.15 and 1.18 V, associated with the Ru3III,II,II/Ru3III,III,II/Ru 3III,III,III /Ru3IV,III,III successive redox couples, respectively. Above 1.7 V, formation of two RuIV centers enhances the 2-electron oxidation of the methanol ligand yielding formaldehyde, in agreement with the theoretical evolution of the HOMO levels as a function of the oxidation states. This work illustrates an important strategy to improve the efficiency of the oxidation catalysis, by using a multicentered redox catalyst and accessing its multiple higher oxidation states.

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Examinou-se a prevalência e fatores associados à anemia em estudo transversal com 429 crianças de 6 a 59 meses do Município de Jordão, Estado do Acre, Brasil. Modelos múltiplos de regressão de Poisson foram utilizados com seleção hierárquica das variáveis independentes. A anemia foi altamente prevalente (57,3%; IC95%: 52,5%-62,1%). Ter idade entre 6 e 23,9 meses [razão de prevalência - RP (IC95%): 1,40 (1,09-1,74)], morar na área rural [RP: 1,23 (1,04-1,44)], morar em domicílio com 5 a 14 crianças [RP: 1,23 (1,04-1,44)], ter mãe que fumou na gravidez [RP: 1,29 (1,09-1,53)], mãe anêmica [RP: 1,18 (1,00-1,39)] e apresentar déficit de altura para idade [RP: 1,19 (1,01-1,39)] foram fatores associados ao risco de anemia, e ter mãe que trabalha fora [RP: 0,78 (0,64-0,94)] foi fator de proteção. A anemia é um grave problema de saúde pública nesse município. Estratégias multissetoriais de combate à pobreza, aumento da cobertura e qualidade de serviços de assistência à saúde materno-infantil devem ser implementados.

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O tempo de irrompimento dentário é essencial para o planejamento de medidas de prevenção da cárie oclusal. Com a ampliação do ensino fundamental de oito para nove anos de duração, um número maior de crianças entre cinco e seis anos de idade é incluído na primeira série do ensino fundamental. OBJETIVO: O objetivo foi estimar as tendências do irrompimento dos primeiros molares permanentes em meninos e meninas de 5 e 6 anos de idade. MÉTODOS: Em estudo longitudinal, espaços dentários de 497 crianças de 60 meses e mais de idade foram examinados quatro vezes por um dentista calibrado (kappa > 0,97) durante 18 meses. O primeiro molar permanente foi considerado irrompido quando qualquer parte de sua superfície podia ser tocada por uma sonda de ponta esférica. A idade dos participantes foi medida em meses. Intervalos para 95% de confiança dos valores de prevalência e incidência foram apurados conforme o sexo para três coortes etárias: 60,0 a 65,9; 66,0 a 71,9; 72,0 a 77,9 meses. A razão entre as taxas de incidência foi estimada por meio de análise de regressão de Poisson. RESULTADOS: A maioria das crianças entre 66,0 e 71,9 meses e entre 72,0 e 77,9 meses tem pelo menos um molar permanente irrompido. No grupo de 66,0 a 71,9 meses, de cada três crianças pelo menos uma apresentou os quatro primeiros molares permanentes irrompidos. CONCLUSÃO. As tendências de irrompimento observadas justificam a necessidade da adoção de medidas de vigilância e de proteção específica em relação à lesão de cárie oclusal.

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The objective of the present study was to estimate (co)variance components for length of productive life (LPL) and some alternative reproductive traits of 6-year-old Nellore cattle. The data set contained 57,410 records for age at first calving from Nellore females and was edited to remove animal records with uncertain paternity and cows with just one piece of calving information. Only animals with age at first calving ranging from 23 to 48 months and calving intervals between 11 and 24 months were kept for analysis. LPL and life production ( LP) were used to describe productive life. LPL was defined as the number of months a cow was kept in the herd until she was 6 years old, given that she was alive at first calving and LP was defined as total number of calves in that time. Four traits were used to describe reproductive traits: two breeding efficiencies on original scale were estimated using Wilcox and Tomar functions (BEW and BET, respectively), and two breeding efficiencies transformed (ASBEW and ASBET, respectively), using the function [arcsine (square root (BEi/100))]. Estimates of heritability for measures of LPL and LP were low and ranged from 0.04 to 0.05. Estimates of heritability for breeding efficiencies on original and transformed scales oscillated from 0.18 to 0.32. Estimates of genetic correlations ranged from -0.57 to 0.79 for LPL and other traits and from 0.28 to 0.63 for LP and other traits.

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High-precision data of backward-angle elastic and quasielastic scattering for the weakly bound (6)Li projectile on (144)Sm target at deep-sub-barrier, near-, and above-barrier energies were measured. From the deep-sub-barrier data, the surface diffuseness of the nuclear interacting potential was studied. Barrier distributions were extracted from the first derivatives of the elastic and quasielastic excitation functions. It is shown that sequential breakup through the first resonant state of the (6)Li is an important channel to be included in coupled-channels calculations, even at deep-sub-barrier energies.

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Angular distributions for the elastic scattering of (8)B, (7)Be, and (6)Li on a (12)C target have been measured at E(lab) = 25.8, 18.8, and 12.3 MeV, respectively. The analyses of these angular distributions have been performed in terms of the optical model using Woods-Saxon and double-folding type potentials. The effect of breakup in the elastic scattering of (8)B + (12)C is investigated by performing coupled-channels calculations with the continuum discretized coupled-channel method and cluster-model folding potentials. Total reaction cross sections were deduced from the elastic-scattering analysis and compared with published data on elastic scattering of other weakly and tightly bound projectiles on (12)C, as a function of energy. With the exception of (4)He and (16)O, the data can be described using a universal function for the reduced cross sections.

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Multipulse rectifier topologies based on autoconnections are increasingly applied as interface stages between mains and power electronics converters. These topologies are attractive and cost-effective solutions for meeting the requirements of low total harmonic distortion of line current and high power factor. Furthermore, as only a small fraction of the total power required by the load is processed in the magnetic core, the overall resulting volume and weight are reduced. This paper proposes a mathematical analysis based on phasor diagrams that results in a single and general expression capable of unifying all delta and wye step-up or step-down autotransformer connections for 12-and 18-pulse ac-dc converters. The expression obtained allows the choice of a wide range of input/output voltage ratio for step-up or step-down autotransformer, and this general expression is also presented in a graphical form for each converter. Moreover, it simplifies the procedure for determining turn ratios and polarities for all windings of the autotransformer. A routine for easy and fast calculations is developed and validated by a design example. Finally, experimental results are presented along with comments on a 6-kW 220-V line voltage, 400-V rectified voltage, and 18-pulse delta-autoconnected prototype.

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Sclerotinia sclerotiorum is a highly aggressive pathogen that causes great economic losses, especially in temperate climates. Several biological control agents are available, but actinobacteria have seldom been used to control this fungus. Our objective was to evaluate the efficiency and ultrastructural effects of the secondary metabolites produced by the ant-associated actinobacterium Propionicimonas sp. ENT-18 in controlling the sclerotia of S. sclerotiorum. We demonstrated total inhibition of sclerotia treated with 62.5 mu g/10 mu l of an ethyl acetate extract of compounds produced by ENT-18, and calculated an LC(50) of 1.69 mu g/sclerotia. Histological and ultrastructural analysis indicated that the cells of the treated sclerotia were severely damaged, suggesting direct action of the biomolecule(s) produced by the actinobacterium ENT-18 on the cell structure of the medullae and rind cell wall. This is the first report demonstrating a novel property of Propionicimonas sp.-antifungal activity against S. sclerotiorum.

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Background: A combination of antihypertensive agents of different drug classes in a fixed-dose combination (FDC) may offer advantages in terms of efficacy, tolerability, and treatment compliance. Combination of a calcium channel blocker with an angiotensin-converting enzyme inhibitor may act synergistically to reduce blood pressure (BP). Objective: The aim of this study was to compare the efficacy and tolerability of an amlodipine/ramipril FDC with those of amlodipine monotherapy. Methods: This 18-week, prospective, randomized, double-blind study was conducted at 8 centers across Brazil. Patients with stage 1 or 2 essential hypertension were enrolled. After a 2-week placebo run-in phase, patients received amlodipine/ramipril 2.5/2.5 mg or amlodipine 2.5 mg, after which the doses were titrated, based on BP, to 515 then 10/10 mg (amlodipme/ramipril) and 5 then 10 mg (amiodipine). The primary end point was BP measured in the intent-to-treat (ITT) population. Hematology and serum biochemistry were assessed at baseline and study end. Tolerability was assessed using patient interview, laboratory analysis, and physical examination, including measurement of ankle circumference to assess peripheral edema. Results: A total of 222 patients completed the study (age range, 40-79 years; FDC group, 117 patients [mean dose, 7.60/7.60 mg]; monotherapy, 105 patients [mean dose, 7.97 mg]). The mean (SD) changes in systolic BP (SBP) and diastolic BP (DBP), as measured using 24-hour ambulatory blood pressure monitoring (ABPM) and in the physician`s office, were significantly greater with combination therapy than monotherapy, with the exception of office DBP (ABPM, -20.76 [1.25] vs -15.80 [1.18] mm Hg and -11.71 [0.78] vs -8.61 [0.74] mm Hg, respectively [both, P = 0.004]; office, -27.51 [1.40] vs -22.84 [1.33] min Hg [P = 0.012] and -16.41 [0.79] vs -14.64 [0.75] mm Hg [P = NS], respectively). In the ITT analysis, the mean changes in ambulatory, but not office-based, BP were statistically significant (ABPM: SBP, -20.21 [1.14] vs -15.31 [1.12] mm Hg and DBP, -11.61 [0.72] vs -8.42 [0.70] mm Hg, respectively [both, P = 0.002]; office: SBP, -26.60 [1.34] vs -22.97 [1.30] mm Hg and DBP, -16.48 [0.78] vs -14.48 [0.75] mm Hg [both, P = NS]). Twenty-nine patients (22.1%) treated with combination therapy and 41 patients (30.6%) treated with monotherapy experienced >= 1 adverse event considered possibly related to study drug. The combmation-therapy group had lower prevalence of edema (7.6% vs 18.7%; P = 0.011) and a similar prevalence of dry cough (3.8% vs 0.8%; P = NS). No clinically significant changes in laboratory values were found in either group. Conclusions: In this population of patients with essential hypertension, the amlodipine/ramipril FDC was associated with significantly reduced ambulatory and office-measured BP compared with amlodipine monotherapy, with the exception of office DBP. Both treatments were well tolerated. (Clin Ther. 2008;30: 1618-1628) (C) 2008 Excerpta Medica Inc.

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Despite modern reanimation surgical techniques, facial paralysis presents with functional and aesthetic deficits. We evaluated facial symmetry after treating with botulinum toxin the healthy side of the face of 25 patients with long-standing facial paralysis who had previously been treated by surgical methods, with 6 months follow-up. Evaluation consisted of a clinical score, the two subscales of the Facial Disability Index, and surface electromyography. The mean botulinum toxin dose was 38 +/- A 5 U (range = 15-69 U). The clinical score showed significant reduction of asymmetry of 48.4% at 1 month and 16.8% after 6 months. The initial result was a consequence of reduced motion on the treated side combined with better motion on the paralyzed side. At 6 months, the treated side returned to basal scores. The residual effect seen in symmetry was due to an increase (18%) of motion in the paralyzed side. There was a significant decrease in the action potential of muscles on the nonparalyzed side 1 month post injection but completely reverted after 6 months. The Physical Function Index increased, but not significantly. The Social/Well-Being Function Index showed a significant increase at 6 months compared to pretreatment. The proposed treatment improved facial symmetry for up to 6 months. Even after the end of the clinical effect of the drug, the paralyzed side`s clinical score was 18% higher than pretreatment, with an increased quality of life.

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Introduction. Few population-based studies in erectile dysfunction (ED) included subjects less than 40 years old and analyzed the several factors and consequences potentially associated with this condition. Aim. Evaluation of the prevalence of erectile dysfunction (ED) and associated factors in a sample of Brazilian men aged 18 to 40 years old. Methods. Cross-sectional study in which subjects were contacted in public places of 18 major Brazilian cities and interviewed using an anonymous questionnaire. Survey data were submitted to chi-squared, student`s t-test and logistic regression analyses. Main Outcome Measures. The data were collected by means of a self-administered questionnaire with 87 questions about sociodemographic variables, general health, habits and lifestyle-related factors, sexual behavior and sexual difficulties, including ED which was assessed by a single question. Results. Prevalence of ED in 1,947 men was 35.0% (73.7% mild, 26.3% moderate/complete). Greater frequency of ED was seen in subjects that never had information about sex, experienced difficulties in the beginning of sexual life and have never masturbated. ED was associated to lower level of education, but not to race, sexual orientation, employment or marital status. Also, no association was found between ED and smoking, alcoholism, obesity, sedentary life, diabetes, hypertension, cardiovascular disease, hyperlipidemia, depression or anxiety. ED caused negative impact in men`s self-esteem, interpersonal relationships, work and leisure activities, and in sexual life satisfaction. Less than 10% of men with ED had received medical treatment for this problem. Conclusions. Prevalence of ED in this young population was high, mostly of mild severity. Low education and psychosocial problems were associated to ED and, due probably to the sample subjects` young age, no association was found with organic problems. Measures in the fields of education and psychosocial difficulties prevention would have a positive impact in the control of erectile dysfunction in the young population. Martins FG, and Abdo CHN. Erectile dysfunction and correlated factors in Brazilian men aged 18-40 years. J Sex Med 2010;7:2166-2173.

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Nocturnal melatonin pineal output is triggered by sympathetic outflow. Antidepressants that block norepinephrine neuronal uptake should increase pineal function. This can be monitored by measuring 6-sulfatoximelatonin (aMT6s), the main melatonin metabolite, in the urine. In this study, we compared the excretion of aMT6s before (baseline), one, and 21 days after administration of clomipramine to healthy subjects (n = 32). At the end of treatment, subjects were divided into responders (n = 12) and non-responders (n = 20) according to the improvement in their emotional state in three out of four domains (interpersonal tolerance, efficiency, well-being and feeling different from the usual self). There was no difference in aMT6s before clomipramine between responders and non-responders in any of the time intervals analysed (06:00-12:00, 12:00-18:00, 18:00-24:00 and 24:00-06:00 hours). At day one, but not at day 21, the fraction of aMT6s excreted during the time interval 24:00-06:00, relative to the total amount excreted by each subject per day, was significantly higher (P = 0.0287) than baseline (0.57 +/- 0.04) in responders. No significant difference was observed in non-responders. The increase in pineal function induced by clomipramine was restricted to day one, indicating that long-lasting adaptation restores pineal function. In addition, the day one increase in aMT6s was significantly increased only in the responders group, raising the possibility that the blocking of neuronal uptake is predictive of emotional improvement.

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Our objective was to assess the prognostic value of (18)F-FDG PET after 2 cycles of chemotherapy using doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in Hodgkin lymphoma (HL) patients overall and in subgroups of patients with early and advanced stages and with low and high risks according to the International Prognostic Score (IPS). Methods: One hundred fifteen patients with newly diagnosed HL were prospectively included in the study. All underwent standard ABVD therapy followed by consolidation radiotherapy in cases of bulky disease. After 2 cycles of ABVD, the patients were evaluated with PET (PET2). Prognostic analysis compared the 3-y event-free survival (EFS) rate to the PET2 results, clinical data, and IPS. Results: Of the 104 evaluated patients, 93 achieved complete remission after first-line therapy. During a median follow-up of 36 mo, relapse or disease progression was seen in 22 patients. Treatment failure was seen in 16 of the 30 PET2-positive patients and in only 6 of the 74 PET2-negative patients. PET2 was the only significant prognostic factor. The 3-y EFS was 53.4% for PET2-positive patients and 90.5% for PET2-negative ones (P < 0.001). When patients were categorized according to low or high IPS risk and according to early or advanced stage of disease, PET2 was also significantly associated with treatment outcome. Conclusion: PET2 is an accurate and independent predictor of EFS in HL. A negative interim (18)F-FDG PET result is highly predictive of treatment success in overall HL patients, as well as in subgroups with early or advanced-stage disease and with low or high IPS risk.

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Objective To determine normal blood flow velocities across the fetal tricuspid valve (TV) at 11-13 weeks and 6 days of gestation and to examine the reproducibility of these measurements. Methods A prospective study involving 166 normal singleton pregnancies examined at 11-13 weeks and 6 days was carried out. Descriptive analysis of E- and A-waves` maximum velocities, E/A ratio, duration of the cardiac cycle (C) and diastole (D) and D/C ratio were calculated. Intraobserver and interobserver agreement analysis was performed in a subgroup of 12 cases. Results Average (+/- SD) flow velocities were: E-wave, 25.0 (+/- 4.6) cm/s; A-wave. 42.9 (+/- 5.9) cm/s; E/A, 0.58 (+/- 0.07); cardiac cycle, 390 (+/- 21.1) ms; diastole, 147 (+/- 18) ms and D/C, 0.38 (+/- 0.04). Significant correlation was observed between all parameters (except A-wave) and gestational age but not with nuchal translucency (NT). Intraclass correlation coefficients (interobserver, intraobsever examiner I and intraobserver examiner 2) were: E-wave, 0.53, 0.53 and 0.64; A-wave, 0.45, 0.46 and 0.49; cardiac cycle, 0.70, 0.79 and 0.84 and diastole, 0.63, 0.85 and 0.82, respectively. Conclusions The present study establishes normal Doppler parameters for blood flow across the TV at 11 - 13 weeks and 6 days and demonstrates that these parameters do not correlate with NT measurement and have good/moderate reproducibility. Copyright (C) 2010 John Wiley & Sons, Ltd.

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There are evidences that targeting IL-18 might be beneficial to inhibit inflammatory symptoms, including hypernociception (decrease in nociceptive threshold). The mechanism of IL-18 mechanical hypernociception depends on endothelin in rats and mice. However, the role of IL-18 in overt pain-like behaviour remains undetermined. Therefore, we addressed the role of IL-18 in writhing response induced by intraperitoneal (i.p.) injection of phenyl-p-benzoquinone (PBQ) and acetic acid in mice. Firstly, it was detected that PBQ and acetic acid i.p. injection induced a dose-dependent number of writhes in Balb/c mice. Subsequently, it was observed that the PBQ- but not the acetic acid-induced writhes were diminished in IL-18 deficient ((-/-)) mice. Therefore, considering that IFN-gamma, endothelin and prostanoids mediate IL-18-induced mechanical hypernociception, we also investigated the role of these mediators in the same model of writhing response in which IL-18 participates. It was noticed that PBQ-induced writhes were diminished in IFN-gamma(-/-) mice and by the treatment with bosentan (mixed enclothelin ETA/ETB receptor antagonist), BQ 123 (cyclo[DTrp-DAsp-Pro-DVal-Leu], selective enclothelin ETA receptor antagonist), BQ 788 (N-cys-2,6-dimethylpiperidinocarbonyl-L-methylleucyl-D-1 -methoxycarboyl-D-norleucine, selective endothelin ETB receptor antagonist) or indomethacin (cycloxigenase inhibitor). Thus, IL-18, IFN-gamma, endothelin acting on endothelin ETA and ETB receptors, and prostanoids mediate PBQ-induced writhing response in mice. To conclude, these results further advance the understanding of the physiopathology of overt pain-like behaviour, and suggest for the first time a role for IL-18 in writhing response in mice. (C) 2008 Elsevier B.V. All rights reserved.