527 research outputs found
Caffeine Dose-Response Relationship and Behavioral Screening in Zebrafish
It has been centuries since humans consume coffee and get the benefits of this bean. Many researches worldwide continue to show healthful properties of coffee, while others suggest a number of side effects. In fact, anything consumed in excess may cause disturbance of the body functioning, whereas caffeine is a central nervous system stimulant that increases focus and improves performance, its high concentration can cause insomnia, dizziness, and vomiting. Thus, the question is: which coffee dose promotes benefits and prevents risks? To answer it, we used the zebrafish, a popular animal model that is at the vanguard of psychopharmacological research due to its unique combination of complexity and simplicity, translational relevance and applicability to high throughput behavioral drug screens. In the current study, we examine time-course and dose-dependent changes in zebrafish following exposure to caffeine. Our data show an inverted U-shaped path for the locomotor parameters and crescent path for the anxiety-like parameters. High doses are harmful to the individual, because the stimulating effect disappears and anxiogenic effects take place. We conclude that temporal analysis of zebrafish behavior is a sensitive method for the study of acute caffeine exposure–induced functional changes in the vertebrate brain
Stability of casein micelles cross-linked with genipin: a physicochemical study as a function of pH
Chemical or enzymatic cross-linking of casein micelles (CMs) increases their
stability against dissociating agents. In this paper, a comparative study of
stability between native CMs and CMs cross-linked with genipin (CMs-GP) as a
function of pH is described. Stability to temperature and ethanol were
investigated in the pH range 2.0-7.0. The size and the charge
(-potential) of the particles were determined by dynamic light
scattering. Native CMs precipitated below pH 5.5, CMs-GP precipitated from pH
3.5 to 4.5, whereas no precipitation was observed at pH 2.0-3.0 or pH 4.5-7.0.
The isoelectric point of CMs-GP was determined to be pH 3.7. Highest stability
against heat and ethanol was observed for CMs-GP at pH 2, where visible
coagulation was determined only after 800 s at 140 C or 87.5% (v/v) of
ethanol. These results confirmed the hypothesis that cross-linking by GP
increased the stability of CMs.Comment: 5 pages, 2 figures, International Dairy Journal, 201
A Decade of Implantation of the Bachelor’s Degree in Electrical Engineering in the Western Amazon
This paper deals with the implementation of the Bachelor\u27s Degree in Electrical Engineering in Western Amazonia, as well as it presents an analysis of the academic performance of students in the Basic and Professional Core. The Federal University of Rondônia Foundation (UNIR), located in Porto Velho, Brazil, started the activities of the course in 2007 and continues to invest in the infrastructure and qualification of human resources in order to stimulate technological development in the region. Analyzing the performance data of the academics regarding the degree of difficulty established from the curricular offer, it is possible to infer some answers. In the course of the analysis, the databases emerged by taking note, such as students who only enroll and do not attend the course, among others. The disciplines diverged into two segments, Basic Core (NB) and Professional Core (NP). The data refers to the grades obtained by the students in all the disciplines studied and offered by the Academic Electrical Engineering Department (DAEE) in the period from 2007/1 to 2016/2. Along the analysis, two graphs demonstrated the evaluation. The analysis of the academic performance of students in the subjects during the NB and NP reinforces the result obtained in the Program for International Student Assessment (PISA), since Brazil has not obtained progress in science, reading, and mathematics averages. The results obtained indicate the necessity of effective measures in primary and secondary education since the deficit propagated to superior levels
Coagulation/flocculation/flotation/nanofiltration processes using Moringa Oleifera as coagulant of Eutrophized river
This study investigated the efficiency of Moringa oleifera (MO) seeds as natural coagulant in
coagulation/flocculation/dissolved air flotation (C/F/DAF), followed by nanofiltration (NF) for Microcystis
protocystis and microcystin-LR removal. The methodology adopted in this work was performed in two steps: 1)
coagulation/flocculation/dissolved air flotation (C/F/DAF) process using the MO extracted in saline solution of
potassium chloride (KCl-1M) and sodium chloride (NaCl-1M) in optimum dosage 50 mg·L-1; 2) nanofiltration
process using NF90 and NF270 membrane provided Dow Chemical Company®. A working pressure of 8 bar
was applied. In all samples were analyzed color, turbidity, pH, cyanobacterial cells count and microcystin
concentration. The use of MO seeds as natural coagulant, obtained satisfactory results in the M. protocystis,
color and turbidity removal. NF was able to completely remove cyanobacterial cells and microcystins (100 %)
from M. protocystis (always under the quantification limit). Therefore, C/F/DAF+NF sequence is a safe barrier against M. protocystis and microcystins in drinking water.CAPES (Coordination for the Improvement of Higher Education Personnel) National Council of Technological and Scientific Development (CNPq
Evaluation of the potential of fucoidan-based microparticles for diabetes treatment
Abstract
INTRODUCTION: Marine organisms have in their constitution materials with a wide range of properties and characteristics inspiring their application within the biomedical field. One important example is fucoidan (Fu), an underexploited sulfated polysaccharide extracted from the cell wall of the brown seaweeds, with high solubility in water1. Fucoidan is composed of L- fucose and glucuronic acid including sulfate groups and has important bioactive properties such as antioxidative, anticoagulant, anticancer and in the reduction of blood glucose1,2. In this work, the biomedical potential of fucoidan was assessed by processing modified fucoidan (MFu) into microparticles by photocrosslinking using superhydrophobic surfaces and visible light3,4. Biological performance on the developed constructs using human pancreatic beta cells is currently under investigation.
METHODS: To design the materials structures, fucoidan was modified by methacrylation reaction3. Briefly, Fu aqueous solution 4% w/v was mixed with methacrylated anhydride (MA) in volume of 12% v/v at 50oC to react for 6h. Further, MFu particles with and without insulin (0.5% w/v) were produced by pipetting a solution of 5% MFu v/v with triethanolamine and eosin-y (photoinitiators) onto superhydrophobic surfaces4 (Fig. 1A) and then photocrosslinking using visible light4. MFu and developed particles were characterized using 1HNMR, turbidimetry and SEM to assess their chemistry and morphology, respectively. Moreover, the insulin release was evaluated in phosphate buffered saline (PBS) solution at pH 7and simulated intestinal fluid (SIF) at pH 5. The ability of the developed materials to support adhesion and proliferation of cells was assessed by suspension culture of human pancreatic cells 1.1B4 (3.5x105 cells/ml) in contact with MFu microparticles during up to 7 days. RESULTS: The chemical modification performed on Fu was confirmed by the presence of vinyl and additional methyl peaks in the 1HNMR of modified fucoidan, not present in Fu spectrum. Methacrylated fucoidan was obtained with a methacrylation degree of 17%. The produced fucoidan particles have round shape and average diameter of 1.53 mm (Fig. 1B). The insulin release in PBS and SIF demonstrate that the particles can release insulin in a sustained manner under the studied period. It seems that the insulin release is slower for SIF (pH5, Fig. 1C), than for PBS. The biological tests regarding the culture of pancreatic beta cells demonstrate that cells show a round-like shape and tend to form pseudo-islets during the culture period studied (Fig. 1D).
DISCUSSION & CONCLUSIONS: This work demonstrates the successful production of fucoidan- based-microparticles through the methacrylation of fucoidan, using visible light and superhydrophobic surfaces. The covalent crosslinking methacrylated fucoidan through visible light represents a promising method to obtain biocompatible fucoidan particles with a uniform round shape. The obtained insulin release profiles are sensitive to different pH (pH7 and pH5), mimicking the normal physiological pathway for insulin release. Furthermore, the results suggest these systems could be used for treatment of type I diabetes mellitus as they sustain beta cells viability and proliferation. The response also suggested, that the MFu particles could be a good candidate as drug delivery vehicles for the diabetes mellitus treatment.
REFERENCES: 1 Silva TH et al (2012), Biomatter 2(4): 278:289. 2Sezer Alidemir et al (2011), Fucoidan: A versatile biopolymer for biomedical applicatons (Springer Ber.Heid).pp377-406. 3Mihaila S.et al (2013), Adv. Health. Mat. 2(6): 895-907. 4Rial Hermida et al, Acta Biomater.(2014) 10(10) 4314-4322.
ACKNOWLEDGEMENTS: This work was partially funded by projects 0687_NOVOMAR_1_P (POCTEP), CarbPol_u_Algae (EXPL/MAR- BIO/0165/2013), ComplexiTE (ERC-2012-ADG 20120216-321266). Portuguese Foundation for Science and Technology is also gratefully acknowledged for doctoral grants of L. Reys and N. Oliveira and post- doctoral grants of S.S. Silva and D. Soares da Costafunded by projects 0687_NOVOMAR_1_P (POCTEP), CarbPol_u_Algae (EXPL/MARBIO/0165/2013)
, ComplexiTE(ERC-2012-ADG 20120216-321266). Portuguese Foundation for Science and Technologyinfo:eu-repo/semantics/publishedVersio
Use of retinoids during oocyte maturation diminishes apoptosis in caprine embryos
Exposure of caprine oocytes and embryos to retinoids enhances embryonic development, but the mechanisms governing this phenomenon have not been characterised. The aim of the present study was to evaluate if the incidence of apoptosis is affected by the addition of retinyl acetate (RAc) and 9-cis-retinoic acid (RA) during in vitro maturation (IVM) of caprine oocytes. Embryonic development was recorded on days 3 and 8 post-fertilisation, and apoptosis was measured by caspase activity and DNA fragmentation (TUNEL assay). Control zygotes had lower capacity to cleave and reach the blastocyst stage (24.45 ± 2.32 and 5.32 ± 0.81, respectively) than those of RAc- (29.96 ± 1.62 and 7.94 ± 0.93, respectively) and RA-treated groups (30.12 ± 1.51 and 7.36 ± 1.02, respectively). Oocytes and blastocysts positive for TUNEL assay were more frequent, respectively, in the controls (8.20 ± 0.78, 8.70 ± 1.05) than in RAc (5.60 ± 0.52, 4.80 ± 0.51) and RA (6.40 ± 0.69, 5.40 ± 0.69). Caspase activity did not differ between control oocytes (7.20 ± 0.91), RAc (6.60 ± 0.68) and RA (7.30 ± 0.67), but it was reduced in RAc- (5.05 ± 0.62) and RA-treated blastocysts (5.75 ± 0.22) compared to controls (8.35 ± 0.71). These results indicate that the addition of retinoids during IVM increases the developmental potential of goat embryos with a concomitant reduction in apoptosis rates
Sexual dimorphism, female fertility, and diet of Physalaemus feioi (Anura: Leptodactylidae) from southeastern Brazil
Physalaemus feioi é uma rã da América do Sul, endêmica da Mata Atlântica, registrada nos estados de Minas Gerais e São Paulo. Avaliamos o dimorfismo sexual, a fertilidade nas fêmeas e dieta dessa espécie em duas localidades do estado de Minas Gerais, incluindo a localidade-tipo da espécie. Coletamos 73 indivÃduos (16 fêmeas adultas e 57 machos adultos) por meio de busca ativa. O número de oócitos encontrados para P. feioi (xÌ… = 1385 ± 498,13) foi alto quando comparado com outras espécies do gênero como P. maculiventris, P. signifer, P. cuvieri e P. ephippifer mas este semelha o número de oócitos de P. centralis, P. kroyeri e P. marmoratus. As presas com maior Ãndice de importância foram Coleoptera (IIR = 24,26) e Formicidae (IIR = 16,46). Não houve diferenças entre machos e fêmeas quanto ao número de presas ingeridas e nem o volume do conteúdo estomacal. Em resumo, Physalaemus feioi teve semelhanças com outras espécies do gênero em relação ao dimorfismo sexual, fecundidade e hábitos alimentares.Physalaemus feioi is a South American frog endemic to the Brazilian Atlantic Forest that occurs in the states of Minas Gerais and São Paulo. We evaluated sexual dimorphism, female fertility, and diet of P. feioi from two locations in the state of Minas Gerais, including the type locality of the species. We collected 73 individuals (16 adult females and 57 adult males). The number of oocytes of P. feioi (xÌ… = 1385 ±498.13) was higher than in other species of the genus, such as P. maculiventris, P. signifer, P. cuvieri, and P. ephippifer, but it resembles that of P. centralis, P. kroyeri, and P. marmoratus. The prey items with the highest index of importance were Coleoptera (IIR = 24.26) and Formicidae (IIR = 16.46). We found no sex differences regarding the number of ingested prey and the volume of the stomach contents. In summary, Physalaemus feioi was similar to other species of the genus regarding sexual dimorphism, fecundity, and feeding habits
The influence of aerobic fitness status on ventilatory efficiency in patients with coronary artery disease
OBJECTIVE: To test the hypotheses that 1) coronary artery disease patients with lower aerobic fitness exhibit a lower ventilatory efficiency and 2) coronary artery disease patients with lower initial aerobic fitness exhibit greater improvements in ventilatory efficiency with aerobic exercise training. METHOD: A total of 123 patients (61.0±0.7 years) with coronary artery disease were divided according to aerobic fitness status into 3 groups: group 1 (n = 34, peak VO2;17.5 and ;24.5 ml/kg/min). All patients performed a cardiorespiratory exercise test on a treadmill. Ventilatory efficiency was determined by the lowest VE/VCO2 ratio observed. The exercise training program comprised moderate-intensity aerobic exercise performed 3 times per week for 3 months. Clinicaltrials.gov: NCT02106533 RESULTS: Before intervention, group 1 exhibited both lower peak VO2 and lower ventilatory efficiency compared with the other 2 groups (
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