998 resultados para Reactive parameters
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Membrane reactor, reactive membrane separation, arrheotrope, azeotrope, dusty gas model, esterification, residue curve map, distillation, kinetics, singular point, bifurcation
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Background: Ischemic postconditioning (IPost) is a method of protecting the heart against ischemia-reperfusion (IR) injury. However, the effectiveness of IPost in cases of ischemic heart disease accompanied by co-morbidities such as hypothyroidism remains unclear. Objective: The aim of this study was to determine the effect of IPost on myocardial IR injury in hypothyroid male rats. Methods: Propylthiouracil in drinking water (500 mg/L) was administered to male rats for 21 days to induce hypothyroidism. The hearts from control and hypothyroid rats were perfused in a Langendorff apparatus and exposed to 30 min of global ischemia, followed by 120 min of reperfusion. IPost was induced immediately following ischemia. Results: Hypothyroidism and IPost significantly improved the left ventricular developed pressure (LVDP) and peak rates of positive and negative changes in left ventricular pressure (±dp/dt) during reperfusion in control rats (p < 0.05). However, IPost had no add-on effect on the recovery of LVDP and ±dp/dt in hypothyroid rats. Furthermore, hypothyroidism significantly decreased the basal NO metabolite (NOx) levels of the serum (72.5 ± 4.2 vs. 102.8 ± 3.7 μmol/L; p < 0.05) and heart (7.9 ± 1.6 vs. 18.8 ± 3.2 μmol/L; p < 0.05). Heart NOx concentration in the hypothyroid groups did not change after IR and IPost, whereas these were significantly (p < 0.05) higher and lower after IR and IPost, respectively, in the control groups. Conclusion: Hypothyroidism protects the heart from IR injury, which may be due to a decrease in basal nitric oxide (NO) levels in the serum and heart and a decrease in NO after IR. IPost did not decrease the NO level and did not provide further cardioprotection in the hypothyroid group.
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Background: High sensitivity C-reactive protein (hs-CRP) is commonly used in clinical practice to assess cardiovascular risk. However, a correlation has not yet been established between the absolute levels of peripheral and central hs-CRP. Objective: To assess the correlation between serum hs-CRP levels (mg/L) in a peripheral vein in the left forearm (LFPV) with those in the coronary sinus (CS) of patients with coronary artery disease (CAD) and a diagnosis of stable angina (SA) or unstable angina (UA). Methods: This observational, descriptive, and cross-sectional study was conducted at the Instituto do Coração, Hospital das Clinicas, Faculdade de Medicina, Universidade de São Paulo, and at the Hospital Beneficência Portuguesa de Sao Paulo, where CAD patients referred to the hospital for coronary angiography were evaluated. Results: Forty patients with CAD (20 with SA and 20 with UA) were included in the study. Blood samples from LFPV and CS were collected before coronary angiography. Furthermore, analysis of the correlation between serum levels of hs-CRP in LFPV versus CS showed a strong linear correlation for both SA (r = 0.993, p < 0.001) and UA (r = 0.976, p < 0.001) and for the entire sample (r = 0.985, p < 0.001). Conclusion: Our data suggest a strong linear correlation between hs-CRP levels in LFPV versus CS in patients with SA and UA.
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Moving grate, LEPOL, Particle, Limestone, Decomposition, Clinker, Fluidisation
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Heavy duty Diesel engine, alternative fuels, EGR, exhaust emissions, HC, NOx, FSN
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Abstract Background: Hemorheological and glycemic parameters and high density lipoprotein (HDL) cholesterol are used as biomarkers of atherosclerosis and thrombosis. Objective: To investigate the association and clinical relevance of erythrocyte sedimentation rate (ESR), fibrinogen, fasting glucose, glycated hemoglobin (HbA1c), and HDL cholesterol in the prediction of major adverse cardiovascular events (MACE) and coronary heart disease (CHD) in an outpatient population. Methods: 708 stable patients who visited the outpatient department were enrolled and followed for a mean period of 28.5 months. Patients were divided into two groups, patients without MACE and patients with MACE, which included cardiac death, acute myocardial infarction, newly diagnosed CHD, and cerebral vascular accident. We compared hemorheological and glycemic parameters and lipid profiles between the groups. Results: Patients with MACE had significantly higher ESR, fibrinogen, fasting glucose, and HbA1c, while lower HDL cholesterol compared with patients without MACE. High ESR and fibrinogen and low HDL cholesterol significantly increased the risk of MACE in multivariate regression analysis. In patients with MACE, high fibrinogen and HbA1c levels increased the risk of multivessel CHD. Furthermore, ESR and fibrinogen were significantly positively correlated with HbA1c and negatively correlated with HDL cholesterol, however not correlated with fasting glucose. Conclusion: Hemorheological abnormalities, poor glycemic control, and low HDL cholesterol are correlated with each other and could serve as simple and useful surrogate markers and predictors for MACE and CHD in outpatients.
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Abstract Background: Metabolic syndrome (MetS) is associated with a higher risk of all-cause mortality. High-sensitivity C-reactive protein (hsCRP) is a prototypic marker of inflammation usually increased in MetS. Women with MetS-related diseases present higher hsCRP levels than men with MetS-related diseases, suggesting sex differences in inflammatory markers. However, it is unclear whether serum hsCRP levels are already increased in men and/or women with MetS risk factors and without overt diseases or under pharmacological treatment. Objective: To determine the impact of the number of MetS risk factors on serum hsCRP levels in women and men. Methods One hundred and eighteen subjects (70 men and 48 women; 36 ± 1 years) were divided into four groups according to the number of MetS risk factors: healthy group (CT; no risk factors), MetS ≤ 2, MetS = 3, and MetS ≥ 4. Blood was drawn after 12 hours of fasting for measurement of biochemical variables and hsCRP levels, which were determined by immunoturbidimetric assay. Results: The groups with MetS risk factors presented higher serum hsCRP levels when compared with the CT group (p < 0.02). There were no differences in hsCRP levels among groups with MetS risk factors (p > 0.05). The best linear regression model to explain the association between MetS risk factors and hsCRP levels included waist circumference and HDL cholesterol (r = 0.40, p < 0.01). Women with MetS risk factors presented higher hsCRP levels when compared with men (psex < 0.01). Conclusions: Despite the absence of overt diseases and pharmacological treatment, subjects with MetS risk factors already presented increased hsCRP levels, which were significantly higher in women than men at similar conditions.
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Magdeburg, Univ., Fak. für Maschinenbau, Diss., 2010
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Abstract Background: More than 50% of the patients with heart failure have normal ejection fraction (HFNEF). Iodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy and cardiopulmonary exercise test (CPET) are prognostic markers in HFNEF. Nebivolol is a beta-blocker with vasodilating properties. Objectives: To evaluate the impact of nebivolol therapy on CPET and123I-MIBG scintigraphic parameters in patients with HFNEF. Methods: Twenty-five patients underwent 123I-MIBG scintigraphy to determine the washout rate and early and late heart-to-mediastinum ratios. During the CPET, we analyzed the systolic blood pressure (SBP) response, heart rate (HR) during effort and recovery (HRR), and oxygen uptake (VO2). After the initial evaluation, we divided our cohort into control and intervention groups. We then started nebivolol and repeated the tests after 3 months. Results: After treatment, the intervention group showed improvement in rest SBP (149 mmHg [143.5-171 mmHg] versus 135 mmHg [125-151 mmHg, p = 0.016]), rest HR (78 bpm [65.5-84 bpm] versus 64.5 bpm [57.5-75.5 bpm, p = 0.028]), peak SBP (235 mmHg [216.5-249 mmHg] versus 198 mmHg [191-220.5 mmHg], p = 0.001), peak HR (124.5 bpm [115-142 bpm] versus 115 bpm [103.7-124 bpm], p= 0.043), HRR on the 1st minute (6.5 bpm [4.75-12.75 bpm] versus 14.5 bpm [6.7-22 bpm], p = 0.025) and HRR on the 2nd minute (15.5 bpm [13-21.75 bpm] versus 23.5 bpm [16-31.7 bpm], p = 0.005), but no change in peak VO2 and 123I-MIBG scintigraphic parameters. Conclusion: Despite a better control in SBP, HR during rest and exercise, and improvement in HRR, nebivolol failed to show a positive effect on peak VO2 and 123I-MIBG scintigraphic parameters. The lack of effect on adrenergic activity may be the cause of the lack of effect on functional capacity.
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Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2010
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Otto-von-Guericke-Universität, Fakultät für Naturwissenschaften, Dissertation, 2016
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We investigated the following aspects of the biology of a population of Cnemidophorus vacariensis Feltrim & Lema, 2000 during the four seasons: thermal biology, relationship with the thermal environment, daily and seasonal activity, population structure and growth rate. Cnemidophorus vacariensis is restricted to rocky outcrops of the "campos de cima da serra" grasslands on the Araucaria Plateau, southern Brazil, and is currently listed as regionally and nationally threatened with extinction. Data were collected from October 2004 through September 2007 in the state of Rio Grande do Sul. Sampling was conducted randomly from 08:00 a.m. to 6:00 p.m. The capture-mark-recapture method was employed. The lizards were captured by hand, and their cloacal temperature, sex, snout-ventral length (SVL), mass, and the temperature of their microhabitat (substrate temperature and air temperature) were recorded. Individuals were then marked by toe-clipping and released at the site of capture. Body temperatures were obtained for 175 individuals, activity data for 96 individuals, and data on population structure and growth for 59 individuals. All data were obtained monthly, at different times of the day. Cnemidophorus vacariensis average body temperature was 23.84ºC, ranging between 9.6 and 38.2ºC. Temperatures ranged between 21 and 29ºC. The correlation between external heat sources, substrate and air were positive and significant and there was a greater correlation between lizard's temperature and the temperature of the substrate (tigmothermic species). The relatively low body temperatures of individuals are associated with the climate of their environment (altitude up to 1,400 m), with large variations in temperature throughout the day and the year, and low temperatures in winter. The average body temperature observed for C. vacariensis was low when compared with that of phylogenetically related species, suggesting that the thermal biology of this species reflects adaptations to the temperate region where it lives. The monthly rates of activity of lizards were related to monthly variations in the ambient temperatures. Our data suggest that the daily and seasonal activity of C. vacariensis result from the interaction between two factors: changes in the environment temperature and the relationship between individuals and their thermal environment. The population structure of C. vacariensis varied throughout the study period, with maximum biomass in January and maximum density in February (recruitment period). The sex ratio diverged from the expected 1:1. The growth analysis showed a negative relationship between the growth rate of individuals and the SVL, revealing that young individuals grow faster than adults, a typical pattern for short-lived species. The population studied showed a seasonal and cyclical variation associated with the reproductive cycle. The life strategy of C. vacariensis seems to include adaptations to the seasonal variations in temperature, typical of its environment.
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Age and growth parameters of cachara Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae) (males and females) were estimated through the analysis of growth rings in spines of pectoral fins. Fish were collected from January to December 2007, in the area directly influenced by the Aproveitamento Múltiplo de Manso (APM Manso) and in the Cuiabá River (upper parts of the Pantanal). The maximum number of growth rings was seven for males, and eight, for females. The analysis of temporal variations in mean marginal increment showed that rings found in the spines were formed annually, in December. Growth rings were associated to spawning (in the study region from November to March) of the species. The growth curve in length was obtained by the von Bertalanffy model adjusted by the Ford-Walford transformation. The equations are: Ls = 72.7*[1-e-0.44(t+1.5974)] for males, and Ls = 84.5*[1-e-0.33(t+2.0943)] for females. The equations that describe the growth curve in weight are: Wt = 4991.61*[1-e-0.44 (t+1.5974] 2.70 for males and Wt = 7503.17*[1-e-0.33 (t+2.0943] 2.99 for females.
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Nymphs and adults of Tingis americana Drake, 1922 were found feeding on leaves of Handroanthus heptaphyllus (Vell.) Mattos and Handroanthus chrysotrichus (Mart. ex A. DC.) Mattos in the Botanic Garden, Porto Alegre, state of Rio Grande do Sul, Brazil. This is the first record of T. americana on these host plants and in the southern Brazil. We aimed to compare the nymphal development on both hosts and to analyze the reproductive parameters on H. heptaphyllus (25 ± 1ºC; 60 ± 10% RH; 16 h photophase). The mean nymphal period (days) was shorter in individuals reared on H. heptaphyllus (12.69 ± 0.076) than on H. chrysotrichus (19.11 ± 0.208) (P < 0.0001), however, nymph viability was similar. On H. heptaphyllus, the mean embryonic period lasted 12.32 ± 0.274 days and the egg viability was 92%. The mean total and daily fecundity were 310.0 ± 19.40 eggs/female and 7.46 ± 0.302 eggs/female/day, respectively. Paired males and females showed similar longevity (P = 0.0691), while unpaired females lived longer than unpaired males (P = 0.0460).
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The in vitro growth and multiplication of the erythrocytic stages of Plasmodium falciparum within Saimiri sciureus (squirrel monkey) red blood cells have been studied. Various parameters, such as the origin of the red blood cells and serum supplement, nature of the buffer, influence of the final pH of the medium, role of proteose peptone and glucose addition, were investigated. The selection of the best culture conditions led to the obtention of a reproducible in vitro growth of two parasite cycles in Saimiri erythrocytes, which is an useful achievement for in vitro studies. Our failure to establish a continuous culture line for longer than 19 days, could be explained by a dramatic increasing of osmotic fragility of the Saimiri red blood cells related to their small size.