1,516 research outputs found

    Synthesis of FeTi hydrogen storage material via ball milling: effect of milling energy and atmosphere.

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    Attempts were made earlier to synthesize and activate the FeTi intermetallic during ball milling (BM), for H2 storage using sodium boron tetra-hydride (NaBH4) additive as a process controlling agent. Simple reactive milling starting from Fe and Ti powders resulted in heavy agglomeration of powders, due to the self sustaining nature of the reaction following an incubation period. When NaBH4 was used as the process control agent to avoid agglomeration, this resulted in the production of titanium hydride besides FeTi, and as a consequence unfavorable irreversibility in the subsequent hydrogen charging/discharging cycles [1,2,12]. The present work reports on modifications introduced in the synthesis process by changing two processing parameters, namely the milling energy and atmosphere compositio

    Antibodies Against M-Type Phospholipase A2 Receptor (PLA2R) in Patients with Primary Membranous Nephropathy and Lupus Nephritis Class V: A Review

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    Membranous nephropathy (MN) is a very common disease of male adults with nephrotic syndrome. The disease can be primary, when the cause is not known, or secondary associated with infections, drugs, neoplasias and autoimmune systemic diseases, such as systemic lupus erythematosus (SLE). The primary form accounts for 70–80% of the cases. SLE is a common cause of secondary MN affecting young women. The differential diagnosis from primary and lupus MN by clinical and morphological findings can be difficult. The search for autoantibodies against podocyte antigen M-type phospholipase A2 receptor (PLA2R) has demonstrated high positivity in the serum and renal biopsies in the primary MN and negativity in lupus MN (WHO class V). There is a large literature on the role of anti-PLA2R antibody in the diagnosis and follow-up of patients with membranous nephropathy. The aim of this review is to summarize the literature data on the etiopathogenesis of MN and the value of anti-PLA2R antibody screening for the diagnosis and management of patients

    Distribuição das Diatomáceas Modernas nos Sedimentos da Baía de Guanabara e Áreas Oceânicas, Rio de Janeiro (Brasil)

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    One hundred and fifty three superficial sediments were collected in Guanabara Bay to physical-chemistry and diatom analyses in the ambit to Monitoring Project (CENPES/PETROBRAS). A total of 146 taxa of diatoms were identified where the most frequent taxa in Guanabara Bay were Amphora spp., Coscinodiscus spp. and Navicula yarrensis var. yarrensis. These species are potentially harmful that might harm fisheries and mariculture during blooms. The values of ecological indexes like richness and diversity followed the estuarine gradient were the higher values were found in the mouth and de low in the inner part. The multivariate analyzes permitted recognize seven diatom assemblages in the bay. The DCA analyze shows the most influence in the distribution of assemblages were the depth and pH. The diatom assemblages analyze proved to be an efficient tool in the environmental diagnosis of Guanabara Bay.Cento e ciquenta e três amostras de sedimento superficial da Baía de Guanabara foram coletadas durante o Projeto de Monitoramento Ambiental (CENPES/PETROBRAS). Foram identificados 146 táxons de diatomáceas onde as espécies mais abundantes foram Amphora spp., Coscinodiscus spp. e Navicula yarrensis var. yarrensis. Estas espécies identificadas são potencialmente tóxicas e podem prejudicar peixes e a maricultura durante períodos de florescência. Os índices ecológicos de riqueza e diversidade acompanharam o gradiente estuarino sendo maior na entrada da baía e baixos na região interna. As análises multivariadas permitiram reconhecer sete assembléias de diatomáceas na baía. As análises em DCA mostrou que os parâmetros ambientais mais influentes na distribuição das assembléias foram a profundidade e o pH. Os resultados obtidos mostraram que as assembléias de diatomáceas são uma importante ferramenta na caracterização ambiental da Baía de Guanabara

    Natural resources with sweetener power: phytochemistry and antioxidant characterisation of Stevia Rebaudiana (Bert.), sensorial and centesimal analyses of lemon cake recipes with S. Rebaudiana incorporation

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    Stevia rebaudiana leaf extracts are calorie-free sweeteners of natural origin, derived from the Stevia rebaudiana plant known as a natural sweetener, which contains steviol glycosides and others bioactive compounds recognized by their biological properties. The present study was designed to evaluate the total phenolics (26.0 mg gallic acid/g) and total flavonoids contents (9.7 mg catechin/g) of a hydroalcoholic extract of Stevia rebaudiana dried leaves. A similar hydroalcoholic extract of commercial powder steviol sweetener was also evaluated, showing lower contents of bioactive compounds (11.9 mg/g and 5.1 mg/g, for total phenolics and flavonoids, respectively). The hydroalcoholic extract of dried Stevia rebaudiana leaves also showed high in vitro antioxidant activity, besides a positive correlation between total phenolic compounds and the DPPH and FRAP assays. Moreover, Stevia rebaudiana leaves have sensory and functional properties superior to those of many other high-potency sweeteners and is likely to become a major source of natural sweetener for the growing food market. Thus, four different lemon cakes formulations were studied (a traditional cake control recipe with sugar, two cakes with incorporation of Stevia rebaudiana fresh leaf and a cake with commercial powder steviol), using a sensory analysis covering 100 untrained consumers. Centesimal composition analyses of the four lemon cakes showed significant differences in fat, ashes, proteins and carbohydrates contents (p<0.05). Also, the raised energy value observed for the cake control was superior to the cake with Stevia rebaudiana leaves incorporation (309.8 Kcal/100 g, 268.0 Kcal/100 g,142 respectively). Sensorial analysis results showed that Stevia rebaudiana leaves were accepted and, in the future, they can be a natural option to replace some or all the saccharose in cakes formulations.info:eu-repo/semantics/publishedVersio

    Depression and Oral FTC/TDF Pre-exposure Prophylaxis (PrEP) Among Men and Transgender Women Who Have Sex With Men (MSM/TGW).

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    We conducted a longitudinal and cross-sectional analysis of depressive symptomology in iPrEx, a randomized, placebo-controlled trial of daily, oral FTC/TDF HIV pre-exposure prophylaxis (PrEP) in men and transgender women who have sex with men. Depression-related adverse events (AEs) were the most frequently reported severe or life-threatening AEs and were not associated with being randomized to the FTC/TDF arm (152 vs. 144 respectively OR 0.66 95&nbsp;% CI 0.35-1.25). Center for Epidemiologic Studies Depression scale (CES-D) and a four questions suicidal ideation scale scores did not differ by arm. Participants reporting forced sex at anal sexual debut had higher CES-D scores (coeff: 3.23; 95&nbsp;% CI 1.24-5.23) and were more likely to have suicidal ideation (OR 2.2; 95&nbsp;% CI 1.09-4.26). CES-D scores were higher among people reporting non-condom receptive anal intercourse (ncRAI) (OR 1.46; 95&nbsp;% CI 1.09-1.94). We recommend continuing PrEP during periods of depression in conjunction with provision of mental health services

    The Action of Polyphenols in Diabetes Mellitus and Alzheimer's Disease: A Common Agent for Overlapping Pathologies

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    Diabetes Mellitus (DM) and Alzheimer's disease (AD) are two prevalent diseases in modern societies, which are caused mainly by current lifestyle, aging and genetic alterations. It has already been demonstrated that these two diseases are associated, since individuals suffering from DM are prone to develop AD. Conversely, it is also known that individuals with AD are more susceptible to DM, namely type 2 diabetes (T2DM). Therefore, these two pathologies, although completely different in terms of symptomatology, end up sharing several mechanisms at the molecular level, with the most obvious being the increase of oxidative stress and inflammation. Polyphenols are natural compounds widely spread in fruits and vegetables whose dietary intake has been considered inversely proportional to the incidence of DM and AD. So, it is believed that this group of phytochemicals may have preventive and therapeutic potential, not only by reducing the risk and delaying the development of these pathologies, but also by improving brain's metabolic profile and cognitive function. The aim of this review is to understand the extent to which DM and AD are related pathologies, the degree of similarity and the relationship between them, to detail the molecular mechanisms by which polyphenols may exert a protective effect, such as antioxidant and anti-inflammatory effects, and highlight possible advantages of their use as common preventive and therapeutic alternatives.info:eu-repo/semantics/publishedVersio

    Benthic Foraminifera and Bacterial Activity as a Proxy for Environmental Characterization in Potengi Estuary, Rio Grande do Norte, Brazil

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    The aim of this study was to identify possible zonation patterns and assess the environmental impact on the Potengi River Estuary, Rio Grande do Norte State, through the distribution of benthic foraminifera associated to bacterial activity and abiotic parameters. Six sediment samples were collected from locations that presented clear signs of pollution. The environment was predominantly anaerobic and fermentation occurred at all sites. Forty-two species of foraminifera were identified. The dominant species were Ammonia tepida and Arenoparrella mexicana, which are known to be opportunistic, and able to adapt to rapidly changing conditions. CCA analyses showed that salinity and organic matter, followed by bacterial carbon, were more strongly linked to organism distribution in the Potengi River Estuary. Dissolved oxygen concentration, temperature and total organic matter were higher at the estuary mouth than at the other sites, creating favorable conditions for foraminiferal growth and allowing the faunistic succession on the upper estuary. As foraminifera assemblages when associated to environmental parameters can be used as efficient proxies for environmental diagnosis, these results suggest that the Potengi Estuary is under great stress from the surrounding urban development

    High frequency of the EMRSA-15 clone (ST22-MRSA-IV) in hospital wastewater

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    Hospital wastewaters often carry multidrug-resistant bacteria and priority pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). Pathogens and antibiotic resistance genes present in wastewaters may reach the natural environment facilitating their spread. Thus, we aimed to isolate MRSA from wastewater of 3 hospitals located in the north of Portugal and to characterize the isolates regarding the antimicrobial resistance and genetic lineages. A total of 96 wastewater samples were collected over six months. The water was filtered, and the filtration membrane was immersed in BHI broth supplemented with 6.5% of NaCl and incubated. The inoculum was streaked in ORSAB agar plates for MRSA isolation. The isolates susceptibility testing was performed against 14 antimicrobial agents. The presence of resistance and virulence genes was accessed by PCR. Molecular typing was performed in all isolates. From the 96 samples, 28 (29.2%) were MRSA-positive. Most isolates had a multidrug-resistant profile and carried the mecA, blaZ, aac(6′)-Ie-aph(2′′)-Ia, aph(3′)-IIIa, ermA, ermB, ermC, tetL, tetM, dfrA dfrG and catpC221 genes. Most of the isolates were ascribed to the immune evasion cluster (IEC) type B. The isolates belonged to ST22-IV, ST8-IV and ST105-II and spa-types t747, t1302, t19963, t6966, t020, t008 and tOur study shows that MRSA can be found over time in hospital wastewater. The wastewater treatment processes can reduce the MRSA load. The great majority of the isolates belonged to ST22 and spa-type t747 which suggests the fitness of these genetic lineages in hospital effluents.info:eu-repo/semantics/publishedVersio
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