534 research outputs found

    Giant magnetoimpedance: new electrochemical option to monitor surface effects?

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    Magnetoimpedance, MI, change due to surface modification of the sensitive element caused by biofluids was studied with the aim of creating a robust sensor capable of separating the chemical surface modification from the sensing process. A MI sensor prototype with an as-quenched FeCoSiB amorphous ribbon sensitive element was designed and calibrated for a frequency range of 0.5 to 10 MHz at an intensity of the current of 60 mA. Measurements as a function of the exposure time were made, first, in a regime where chemical surface modification and sensing were separated and then, in a regime where they were not separated (in a bath for fluids). The MI variation was explained by the change of the surface magnetic anisotropy. It was shown that the magnetoimpedance effect can be successfully employed as a new electrochemical option to probe the electric features of surface-modified magnetic electrodes when the biofluid, the material of the sensitive element, and the detection conditions are properly selected and synergetically adjusted.Comment: 22 pages, 6 figure

    Crude glycerol in the diets of the juveniles ofAmazon catfish(female Pseudoplatystoma punctifer x male Leiarius marmoratus)

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    This research aimed to determine the best inclusion level of crude glycerol in the diet of the Amazon catfish (Pintado), through zootechnical performance, body composition, metabolic profile and histopathology. The experiment was conducted at the Laboratory of Morphophysiology and Biochemistry of Neotropical Fishes of the Federal University of Tocantins. There was used 150 juvenilles of pintado, these with initial weight of 6,83 ± 1,11 (g) and 10,06 ± 0,57 (cm) lenght in a completely randomised design, with 3 replications (10 animals in each one). They were fed with five diets containing increasing levels of glycerol (0 g kg-1, 50 g kg-1, 75 g kg-1, 100 g kg-1, and 125 g kg-1) during 90 days (30 days of adaption and 60 experimental days). The indexes were evaluated and they did not present statistical difference between each other, except for the specific growth rate, which showed a moderate linear behavior and muscular glycogen that at the level of 125 g kg-1 presented a lower concentration compared with the control diet (0 g kg-1). Regarding histology, the crude glycerin did not cause significant hepatic and renal changes in the referred specie, since the alterations found in the two tissues were considered lesions that did not compromise the functioning of the organ or that are reversible. Finally, it was indicated that the juveniles of Amazon Pintado are able to metabolize the crude glycerin up to 100 g kg-1level

    O impacto da poliquimioterapia no perfil epidemiológico da hanseníase em Juiz de Fora, Brasil

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    We investigated the impact of multidrug therapy (MDT) on the epidemiological pattern of leprosy in Juiz de Fora, Brazil, from 1978 to 1995. Evaluation of 1,283 medical charts was performed according to the treatment regimen used in two different periods. Following the introduction of MDT in 1987, prevalence of leprosy decreased from 22 patients/10,000 inhabitants to 5.2 patients/10,000 inhabitants in 1995. Incidence rate of leprosy was lower in period II (1987-1995) than in period I (1978-1986). Decreasing prevalence and incidence appear to be related to drug efficacy rather than decreased case identification, since both self-referred and professionally referred treatment increased markedly from period I to period II. For both periods, multibacillary leprosy was the most frequent clinical form of the disease (±68%), and the main infection risk factor identified was household contact. Leprosy is predominantly manifested in adults, but an increase in the number of very old and very young patients was observed in period II. The MDT program has been effective both in combating leprosy and in promoting awareness of the disease.Investigamos o impacto da poliquimioterapia (PQT) no perfil epidemiológico da hanseníase em Juiz de Fora, Brasil, de 1978 a 1995. Fizemos uma avaliação de 1.283 prontuários, de acordo com o esquema terapêutico adotado em dois diferentes períodos. Desde a introdução da PQT, em 1987, a prevalência da hanseníase caiu de 22 pacientes/dez mil habitantes para 5,2 pacientes/dez mil habitantes em 1995. A incidência da doença foi menor no período II (1987-1995) em comparação ao período I (1978-1986). A diminuição da prevalência e da incidência está mais relacionada à eficácia das drogas que a uma queda na identificação da infecção, já que tanto a procura espontânea quanto os encaminhamentos aumentaram significativamente do período I para o período II. Em ambos os períodos, a forma clínica mais freqüente foi a multibacilar (±68%), e o contato intradomicilicar foi o maior fator de risco conhecido associado à infecção. Um aumento de pacientes muito velhos ou muito novos foi observado no período II. Os resultados indicam que o esquema PQT tem sido eficaz no combate à hanseníase e tem aumentado a conscientização e o conhecimento da doença

    Evaluation of antifungal activity and potential application as fluorescent probes of indolenine and benzo[e]indole-based squarylium dyes

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    The antifungal performance and the possible use as fluorescent probes of a series of squarylium dyes derived from indolenine and benzo[e]indole previously synthesized was evaluated. Some photophysical properties were performed in ethanol and phosphate buffer, and the type of aggregates form in phosphate buffer was analyzed. Using the 1,3-diphenylisobenzofuran assay, a qualitative assessment of the capacity of dyes to produce singlet oxygen after irradiation was performed. Regarding the antifungal activity, this was studied through a broth microdilution assay using Saccharomyces cerevisiae PYCC 4072 as a biological model. The effect of irradiation of the dyes, with an appropriate light emitting diode system, on the antifungal activity was also evaluated, and it was verified that some of the dyes improve their activity after irradiation. Using fluorescence microscopy techniques, the colocalization of dyes in S. cerevisae cells was investigated and it was possible to verify that some of the squarylium dyes with a barbituric moiety in the four-membered central ring stained and accumulated preferentially in the mitochondrial web and perinuclear membrane of the cells. The possible use as a fluorescent probe for the detection of HSA was also evaluated for one of the dyes of the series, demonstrating a linear variation of the fluorescence intensity accompanied by the increase of the protein concentration.We thank to Fundação para a Ciência e Tecnologia (FCT), Comissão de Coordenação e Desenvolvimento Regional do Norte (CCDR-N) and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centers CQ/UM (UIDB/00686/2020), CBMA (UID/BIA/04050/2020), CQ/VR (UID/QUI/UI0616/2019) and CICSUBI (POCI-01-0145-FEDER-007491), as well as PhD grants to V.S.D.G. (UMINHO/BD/43/2016) and J.C.C.F. (SFRH/BD/133207/2017)

    Squaraine dyes derived from indolenine and benzo[e]indole as potential fluorescent probes for HSA detection and antifungal agents

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    Four squaraine dyes derived from 2,3,3-trimethylindolenine and 1,1,2-trimethyl-1H-benzo[e]indole with different combinations of barbituric groups attach to the central ring, having ester groups and alkyl chains in the nitrogen atoms of heterocyclic rings were synthesized. These dyes were fully characterized and their photophysical behavior was studied in ethanol and phosphate-buffered saline solution. Absorption and emission bands between 631 and 712 nm were detected, with the formation of aggregates in aqueous media, which is typical of this class of dyes. Tests carried out with 1,3-diphenylisobenzofuran allowed us to verify the ability of the dyes to produce singlet oxygen. The interaction of synthesized dyes with human serum albumin (HSA) was also evaluated, being demonstrated a linear correlation between fluorescence intensity and protein concentration. The antifungal potential of the dyes against the yeast Saccharomyces cerevisiae was evaluated using a broth microdilution assay. In order to test the photosensitizing capacity of the synthesized dyes, tests were carried out in the dark and with irradiation, using a custom-built light-emitting diode that emits close to the absorption wavelength of the studied dyes. The results showed that the interaction of dyes with HSA and the antifungal activity depends on the different structural modifications of the dyes.We thanks to Fundação para a Ciência e Tecnologia (FCT), Comissão de Coordenação e Desenvolvimento Regional do Norte (CCDR-N) and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centers CQ/UM (UIDB/00686/2020), CBMA (UID/BIA/04050/2020), CQ/VR (UID/QUI/UI0616/2019) and CICSUBI (POCI-01-0145-FEDER-007491), as well as PhD grants to V.S.D.G. (UMINHO/BD/43/2016) and J.C.C.F. (SFRH/BD/133207/2017)

    Conservation Biogeography of the Sahara‐Sahel: additional protected areas are needed to secure unique biodiversity

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    Aim Identification of priority conservation areas and evaluation of coverage of the current protected areas are urgently needed to halt the biodiversity loss. Identifying regions combining similar environmental traits (climate regions) and species assemblages (biogroups) is needed for conserving the biodiversity patterns and processes. We identify climate regions and biogroups and map species diversity across the Sahara-Sahel, a large geographical area that exhibits wide environmental heterogeneity and multiple species groups with distinct biogeographical affinities, and evaluate the coverage level of current network of protected areas for biodiversity conservation. Location Sahara-Sahel, Africa. Methods We use spatially explicit climate data with the principal component analysis and model-based clustering techniques to identify climate regions. We use distributions of 1147 terrestrial vertebrates (and of 125 Sahara-Sahel endemics) and apply distance clustering methods to identify biogroups for both species groups. We apply reserve selection algorithms targeting 17% of species distribution, climate regions and biogroups to identify priority areas and gap analysis to assess their representation within the current protected areas. Results Seven climate regions were identified, mostly arranged as latitudinal belts. Concentrations of high species richness were found in the Sahel, but the central Sahara gathers most endemic and threatened species. Ten biogroups (five for endemics) were identified. A wide range of biogroups tend to overlap in specific climate regions. Identified priority areas are inadequately represented in protected areas, and six new top conservation areas are needed to achieve conservation targets. Main conclusions Biodiversity distribution in Sahara-Sahel is spatially structured and apparently related to environmental variation. Although the majority of priority conservation areas are located outside the areas of intense human activities, many cross multiple political borders and require internationally coordinated efforts for implementation and management. Optimized biodiversity conservation solutions at regional scale are needed. Our work contradicts the general idea that deserts are uniform areas and provide options for the conservation of endangered species.info:eu-repo/semantics/publishedVersio

    Effects of a multidisciplinar cognitive rehabilitation program for patients with mild Alzheimer's disease

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    OBJECTIVE: To evaluate the effects of a multidisciplinary rehabilitation program on cognition, quality of life, and neuropsychiatry symptoms in patients with mild Alzheimer's disease. METHOD: The present study was a single-blind, controlled study that was conducted at a university-based day-hospital memory facility. The study included 25 Alzheimer's patients and their caregivers and involved a 12-week stimulation and psychoeducational program. The comparison group consisted of 16 Alzheimer's patients in waiting lists for future intervention. INTERVENTION: Group sessions were provided by a multiprofessional team and included memory training, computer-assisted cognitive stimulation, expressive activities (painting, verbal expression, writing), physiotherapy, and physical training. Treatment was administered twice a week during 6.5-h gatherings. MEASUREMENTS: The assessment battery comprised the following tests: Mini-Mental State Examination, Short Cognitive Test, Quality of Life in Alzheimer's disease, Neuropsychiatric Inventory, and Geriatric Depression Scale. Test scores were evaluated at baseline and the end of the study by raters who were blinded to the group assignments. RESULTS: Measurements of global cognitive function and performance on attention tasks indicated that patients in the experimental group remained stable, whereas controls displayed mild but significant worsening. The intervention was associated with reduced depression symptoms for patients and caregivers and decreased neuropsychiatric symptoms in Alzheimer's subjects. The treatment was also beneficial for the patients' quality of life. CONCLUSION: This multimodal rehabilitation program was associated with cognitive stability and significant improvements in the quality of life for Alzheimer's patients. We also observed a significant decrease in depressive symptoms and caregiver burden. These results support the notion that structured nonpharmacological interventions can yield adjunct and clinically relevant benefits in dementia treatment

    Receptor-Induced Dilatation in the Systemic and Intrarenal Adaptation to Pregnancy in Rats

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    Normal pregnancy is associated with systemic and intrarenal vasodilatation resulting in an increased glomerular filtration rate. This adaptive response occurs in spite of elevated circulating levels of angiotensin II (Ang II). In the present study, we evaluated the potential mechanisms responsible for this adaptation. The reactivity of the mesangial cells (MCs) cultured from 14-day-pregnant rats to Ang II was measured through changes in the intracellular calcium concentration ([Cai]). The expression levels of inducible nitric oxide synthase (iNOS), the Ang II-induced vasodilatation receptor AT2, and the relaxin (LGR7) receptor were evaluated in cultured MCs and in the aorta, renal artery and kidney cortex by real time-PCR. The intrarenal distribution of LGR7 was further analyzed by immunohistochemistry. The MCs displayed a relative insensitivity to Ang II, which was paralleled by an impressive increase in the expression level of iNOS, AT2 and LGR7. These results suggest that the MCs also adapt to the pregnancy, thereby contributing to the maintenance of the glomerular surface area even in the presence of high levels of Ang II. The mRNA expression levels of AT2 and LGR7 also increased in the aorta, renal artery and kidney of the pregnant animals, whereas the expression of the AT1 did not significantly change. This further suggests a role of these vasodilatation-induced receptors in the systemic and intrarenal adaptation during pregnancy. LGR7 was localized in the glomeruli and on the apical membrane of the tubular cells, with stronger labeling in the kidneys of pregnant rats. These results suggest a role of iNOS, AT2, and LGR7 in the systemic vasodilatation and intrarenal adaptation to pregnancy and also suggest a pivotal role for relaxin in the tubular function during gestation
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