924 resultados para Carbon and low-alloy steels
Resumo:
The Cretaceous Banhado alkaline complex in southeastern Brazil presents two potassic SiO2-undersaturated series. The high-Ca magmatic series consist of initially fractionated olivine (Fo(92-91)) + diopside (Wo(48-43)En(49-35)Ae(0-7)), as evidenced by the presence of xenocrysts and xenoliths. In that sequence, diopside (Wo(47-38)En(46-37)Ae(0-8)) + phlogopite + apatite + perovskite (Prv(> 92)) crystallized to form the phlogopite melteigite and led to the Ca enrichment of the magma. Diopside (Wo(47-41)En(32-24) Ae(3-14)) continued to crystallize as an early mafic mineral, followed by nepheline (Ne(74.8-70.1)Ks(26.3-21.2)Qz(7.6-0.9)) and leucite (Lc(65-56)) and subsequently by melanite and potassic feldspar (Or(85-99)Ab(1-7)) to form melanite ijolites, wollastonite-melanite urtites and melanite-nepheline syenites. Melanite-pseudoleucite-nepheline syenites are interpreted to be a leucite accumulation. Melanite nephelinite dykes are believed to represent some of the magmatic differentiation steps. The low-Ca magmatic series is representative of a typical fractionation of aegirine-augite (Wo(36-29)En(25-4)Ae(39-18)) + alkali feldspar (Or(57-96)Ab(3-43)) + nepheline (Ne(76.5-69.0)Ks(19.9-14.4)Qz(15.1-7.7)) + titanite from phonolite magma. The evolution of this series from potassic nepheline syenites to sodic sodalite syenites and sodalitolites is attributed to an extensive fractionation of potassic feldspar, which led to an increase of the NaCl activity in the melt during the final stages forming sodalite-rich rocks. Phonolite dykes followed a similar evolutionary process and also registered some crustal assimilation. The mesocratic nepheline syenites showed interactions with phlogopite melteigites, such as compatible trace element enrichments and the presence of diopside xenocrysts, which were interpreted to be due to a mixing/mingling process of phonolite and nephelinite magmas. The geochemical data show higher TiO2 and P2O5 contents and lower SiO2 contents for the high-Ca series and different LILE evolution trends and REE chondrite-normalized patterns as compared to the low-Ca series. The Sr-87/Sr-86, Nd-143/Nd-144, Pb-206/Pb-204 and Pb-208/Pb-204 initial ratios for the high-Ca series (0.70407-0.70526, 0.51242-0.51251, 17.782-19.266 and 38.051-39.521, respectively) were slightly different from those of the low-Ca series (0.70542-0.70583, 0.51232-0.51240, 17.758-17.772 and 38.021-38.061, respectively). For both series, a CO2-rich potassic metasomatized lithospheric mantle enriched the source with rutile-bearing phlogopite clinopyroxenite veins. Kamafugite-like parental magma is attributed to the high-Ca series with major contributions from the melting of the veins. Potassic nephelinite-like parental magma is assigned to the low-Ca series, where the metasomatized wall-rock played a more significant role in the melting process.
Resumo:
Background: Myocardium damage during Chagas' disease results from the immunological imbalance between pro-and production of anti-inflammatory cytokines and has been explained based on the Th1-Th2 dichotomy and regulatory T cell activity. Recently, we demonstrated that IL-17 produced during experimental T. cruzi infection regulates Th1 cells differentiation and parasite induced myocarditis. Here, we investigated the role of IL-17 and regulatory T cell during human Chagas' disease. Methodology/Principal Findings: First, we observed CD4(+)IL-17(+) T cells in culture of peripheral blood mononuclear cells (PBMC) from Chagas' disease patients and we evaluated Th1, Th2, Th17 cytokine profile production in the PBMC cells from Chagas' disease patients (cardiomyopathy-free, and with mild, moderate or severe cardiomyopathy) cultured with T. cruzi antigen. Cultures of PBMC from patients with moderate and severe cardiomyopathy produced high levels of TNF-alpha, IFN-gamma and low levels of IL-10, when compared to mild cardiomyopathy or cardiomyopathy-free patients. Flow cytometry analysis showed higher CD4(+)IL-17(+) cells in PBMC cultured from patients without or with mild cardiomyopathy, in comparison to patients with moderate or severe cardiomyopathy. We then analyzed the presence and function of regulatory T cells in all patients. All groups of Chagas' disease patients presented the same frequency of CD4(+)CD25(+) regulatory T cells. However, CD4(+)CD25(+) T cells from patients with mild cardiomyopathy or cardiomyopathy-free showed higher suppressive activity than those with moderate and severe cardiomyopathy. IFN-gamma levels during chronic Chagas' disease are inversely correlated to the LVEF (P = 0.007, r = -0.614), while regulatory T cell activity is directly correlated with LVEF (P = 0.022, r = 0.500). Conclusion/Significance: These results indicate that reduced production of the cytokines IL-10 and IL-17 in association with high levels of IFN-gamma and TNF-alpha is correlated with the severity of the Chagas' disease cardiomyopathy, and the immunological imbalance observed may be causally related with deficient suppressor activity of regulatory T cells that controls myocardial inflammation.
Resumo:
Abstract Background The purpose of the present study was to compare dynamic muscle strength, functional performance, fatigue, and quality of life in premenopausal systemic lupus erythematosus (SLE) patients with low disease activity versus matched-healthy controls and to determine the association of dynamic muscle strength with fatigue, functional performance, and quality of life in SLE patients. Methods We evaluated premenopausal (18–45 years) SLE patients with low disease activity (Systemic lupus erythematosus disease activity index [SLEDAI]: mean 1.5 ± 1.2). The control (n = 25) and patient (n = 25) groups were matched by age, physical characteristics, and the level of physical activities in daily life (International Physical Activity Questionnaire IPAQ). Both groups had not participated in regular exercise programs for at least six months prior to the study. Dynamic muscle strength was assessed by one-repetition maximum (1-RM) tests. Functional performance was assessed by the Timed Up and Go (TUG), in 30-s test a chair stand and arm curl using a 2-kg dumbbell and balance test, handgrip strength and a sit-and-reach flexibility test. Quality of life (SF-36) and fatigue were also measured. Results The SLE patients showed significantly lower dynamic muscle strength in all exercises (leg press 25.63%, leg extension 11.19%, leg curl 15.71%, chest press 18.33%, lat pulldown 13.56%, 1-RM total load 18.12%, P < 0.001-0.02) compared to the controls. The SLE patients also had lower functional performance, greater fatigue and poorer quality of life. In addition, fatigue, SF-36 and functional performance accounted for 52% of the variance in dynamic muscle strength in the SLE patients. Conclusions Premenopausal SLE patients with low disease activity showed lower dynamic muscle strength, along with increased fatigue, reduced functional performance, and poorer quality of life when compared to matched controls.
Resumo:
OBJECTIVE: To compare low and high MELD scores and investigate whether existing renal dysfunction has an effect on transplant outcome. METHODS: Data was prospectively collected among 237 liver transplants (216 patients) between March 2003 and March 2009. Patients with cirrhotic disease submitted to transplantation were divided into three groups: MELD > 30, MELD < 30, and hepatocellular carcinoma. Renal failure was defined as a ± 25% decline in estimated glomerular filtration rate as observed 1 week after the transplant. Median MELD scores were 35, 21, and 13 for groups MELD > 30, MELD < 30, and hepatocellular carcinoma, respectively. RESULTS: Recipients with MELD > 30 had more days in Intensive Care Unit, longer hospital stay, and received more blood product transfusions. Moreover, their renal function improved after liver transplant. All other groups presented with impairment of renal function. Mortality was similar in all groups, but renal function was the most important variable associated with morbidity and length of hospital stay. CONCLUSION: High MELD score recipients had an improvement in the glomerular filtration rate after 1 week of liver transplantation.
Resumo:
Objective: to discuss the current PAHO recommendation that does not support the substitution of traditional cellular DTP vaccine by acellular DTP, and the role of mutations, in humans, as the main cause of rare adverse events, such as epileptic-like convulsions, triggered by pertussis vaccine. Data review: the main components related to toxic effects of cellular pertussis vaccines are the lipopolysaccharide of bacterial cell wall and pertussis toxin. The removal of part of lipopolysaccharide layer has allowed the creation of a safer cellular pertussis vaccine, with costs comparable to the traditional cellular vaccine, and which may be a substitute for the acellular vaccine. Conclusion: The new methodology introduced by Instituto Butantan allows for the development of a new safer pertussis vaccine with low LPS content (Plow), and the use of the lipopolysaccharide obtained in the process in the production of monophosphoryl lipid A. This component has shown potent adjuvant effect when administered together with influenza inactivated vaccine, making possible to reduce the antigen dose, enhancing the production capacity and lowering costs.
Resumo:
[EN] It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean's food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes; i.e., production plus respiration, PCD) of deep-water communities has been consistently reported for the dark realm of the global ocean. While the amount of sinking POC flux declines exponentially with depth, the concentration of suspended, buoyant non-sinking POC (nsPOC; obtained with oceanographic bottles) exhibits only small variations with depth in the (sub)tropical Northeast Atlantic. Based on available data for the North Atlantic we show here that the sinking POC flux would contribute only 4–12% of the PCD in the mesopelagic realm (depending on the primary production rate in surface waters). The amount of nsPOC potentially available to heterotrophic prokaryotes in the mesopelagic realm can be partly replenished by dark dissolved inorganic carbon fixation contributing between 12% to 72% to the PCD daily. Taken together, there is evidence that the mesopelagic microheterotrophic biota is more dependent on the nsPOC pool than on the sinking POC supply. Hence, the enigmatic major mismatch between the organic carbon demand of the deep-water heterotrophic microbiota and the POC supply rates might be substantially smaller by including the potentially available nsPOC and its autochthonous production in oceanic carbon cycling models.
Resumo:
Recently, the increasing interest in organic food products and environmental friendly practices has emphasized the importance of selecting crop varieties suitable for the low-input systems. Additionally, in recent years the relationship between diet and human health has gained much attention among consumers, favoring the investigations on food nutraceutical properties. Among cereals, wheat plays an important role in human nutrition around the world and contributes to the daily intake of essential nutrients such as starch and protein. Moreover, whole grain contains several bioactive compounds that confer to wheat-derived products unique nutraceutical properties (dietary fibre, antioxidants). The present research provided interesting insights for the selection of wheat genotypes suitable for low-input systems and the development of specific breeding programs dedicated to organic farming. The investigation involved 5 old not dwarf genotypes (Andriolo, Frassineto, Gentil rosso, Inallettabile, Verna) and 1 modern dwarf variety (Palesio), grown under biodynamic management, over two consecutive growing seasons (2009/2010, 2010/2011). Results evidenced that under low-input farming some investigated old wheat genotypes (Frassineto, Inallettabile) were comparable to the modern cultivar in terms of whole agronomic performance. As regards the nutritional and nutraceutical properties, some old genotypes (Andriolo, Gentil rosso, Verna) emerged for their relevant content of several investigated phytochemicals (such as insoluble dietary fibre, polyphenols, flavonoids, in vitro antioxidant activity) and nutrients (protein, lipid, minerals). Despite of the low technological features, the six wheat varieties grown under low-input management may efficiently provide raw material for the preparation of traditionally processed bread with valuable sensory and nutritional properties. Results highlighted that old wheat varieties have peculiar phytochemical composition and may be a valuable source of nutraceutical compounds. Some of the genetic material involved in the present study may be used in breeding programs aimed at selecting varieties suitable for low-input farming and rich in health-promoting compounds.
Resumo:
The effect of soil incorporation of 7 Meliaceae derivatives (6 commercial neem cakes and leaves of Melia azedarach L.) on C and N dynamics and on nutrient availability to micropropagated GF677 rootstock was investigated. In a first laboratory incubation experiment the derivatives showed different N mineralization dynamics, generally well predicted by their C:N ratio and only partly by their initial N concentration. All derivatives increased microbial biomass C, thus representing a source of C for the soil microbial population. Soil addition of all neem cakes (8 g kg-1) and melia leaves (16 g kg-1) had a positive effect on plant growth and increased root N uptake and leaf green colour of micropropagated plants of GF677. In addition, the neem cakes characterized by higher nutrient concentration increased P and K concentration in shoot and leaves 68 days after the amendment. In another experiment, soil incorporation of 15N labeled melia leaves (16 g kg-1) had no effect on the total amount of plant N, however the percentage of melia derived-N of treated plants ranged between 0.8% and 34% during the experiment. At the end of the growing season, about 7% of N added as melia leaves was recovered in plant, while 70% of it was still present in soil. Real C mineralization and the priming effect induced by the addition of the derivatives were quantified by a natural 13C abundance method. The real C mineralization of the derivatives ranged between 22% and 40% of added-C. All the derivatives studied induced a positive priming effect and, 144 days after the amendment, the amount of C primed corresponded to 26% of added-C, for all the derivatives. Despite this substantial priming effect, the C balance of the soil, 144 days after the amendment, always resulted positive.
Resumo:
In this thesis the potential risks associated to the application of biochar in soil as well the stability of biochar were investigated. The study was focused on the potential risks arising from the occurrence of polycyclic aromatic hydrocarbons (PAHs) in biochar. An analytical method was developed for the determination of the 16 USEPA-PAHs in the original biochar and soil containing biochar. The method was successfully validated with a certified reference material for the soil matrix and compared with methods in use in other laboratories during a laboratory exercise within the EU-COST TD1107. The concentration of 16 USEPA-PAHs along with the 15 EU-PAHs, priority hazardous substances in food, was determined in a suite of currently available biochars for agricultural field applications derived from a variety of parent materials and pyrolysis conditions. Biochars analyzed contained the USEPA and some of the EU-PAHs at detectable levels ranging from 1.2 to 19 µg g-1. This method allowed investigating changes in PAH content and distribution in a four years study following biochar addition in soils in a vineyard (CNR-IBIMET). The results showed that biochar addition determined an increase of the amount of PAHs. However, the levels of PAHs in the soil remained within the maximum acceptable concentration for European countries. The vineyard soil performed by CNR-IBIMET was exploited to study the environmental stability of biochar and its impact on soil organic carbon. The stability of biochar was investigated by analytical pyrolysis (Py-GC-MS) and pyrolysis in the presence of hydrogen (HyPy). The findings showed that biochar amendment significantly influence soil stable carbon fraction concentration during the incubation period. Moreover, HyPy and Py-GC-MS were applied to biochars deriving from three different feedstock at two different pyrolysis temperatures. The results evidenced the influence of feedstock type and pyrolysis conditions on the degree of carbonisation.
Resumo:
The study of inorganic carbon chemistry of the coastal ocean is conducted in the Gulf of Cádiz (GoC). Here we describe observations obtained during 4 sampling cruises in March, June, September and November 2015. The primary data set consists of state-of-the-art measurements of the keystone parameters of the marine CO2 system: Total Alkalinity (TA), pH, dissolved inorganic carbon (DIC). We have then calculated aragonite and calcite saturation state. The distribution of inorganic carbon system parameters in the north eastern shelf of the Gulf of Cádiz showed temporal and spatial variability. River input, mixing, primary production, respiration and remineralization were factors that controlled such distributions. Data related to carbonate saturation of calcite and aragonite reveal the occurrence of a supersaturated water; in any case, both species increased with distance and decreased with depth. The carbon system parameters present a different behaviour close to the coast to offshore ad at deeper water. In this area six water masses are clearly identified by their different chemical properties: Surface Atlantic Water, North Atlantic Central Water (NACW) and Mediterranean Water (MOW). Moreover, with this work the measurement of calcium in seawater is optimize, allowing a better quantification for future work of the saturation state of CaCO3.
Resumo:
Wear of attachments leads to a loss of retention and reduces the function of overdentures. This study evaluated the retention force changes of an attachment system for overdentures. The influence of the lubricant and the alloy on wear constancy was examined.
Resumo:
Malignant rhabdoid tumor (MRT) of the liver is a rare malignancy with grave prognosis. This entity should be considered in the differential diagnosis of any aggressive liver tumor with low levels of alpha fetoprotein. We report 2 cases of hepatic MRT presenting in infancy. In these 2 cases, we show that loss of INI1 facilitates making the correct diagnosis of primary hepatic MRT utilizing BAF 47 (INI1 gene product) immunostains. Difficulty encountered in making this rare diagnosis, including the need for repeated biopsies, can be avoided if MRT is considered in the differential diagnosis early on and BAF 47 immunohistochemistry is ordered.