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1.
Epilepsia ; 65(6): 1531-1547, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38506635

RESUMO

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a widespread invasive procedure for treating drug-resistant epilepsy. Nonetheless, there is a persistent debate regarding the short-term and long-term efficacy and safety of ANT-DBS. Thus we conducted a systematic review and meta-analysis. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we searched PubMed, Cochrane, Embase, and Web of Science for studies treating refractory epilepsy with ANT-DBS. Short-term analysis was considered for studies with a mean follow-up of 3 years or less. The following outcomes were assessed for data extraction: procedure responders and nonresponders, increased seizure frequency, complications, and procedure-related mortality. Of 650 studies, 25 fit our inclusion criteria, involving 427 patients. Previous surgical treatments have been reported in 214 patients (50.1%) and a median average baseline seizure frequency of 64.9 monthly seizures. In the short-term analysis, we observed a proportion of 67% (95% confidence interval [CI] 54%-79%) of responders and 33% (95% CI 21%-46%) of nonresponders. In addition, 4% (95% CI 0%-9%) of the patients presented increased seizure frequency. In the long-term analysis, we observed 72% (95% CI 66%-78%) responders and 27% (95% CI 21%-34%) nonresponders. Moreover, there was a 2% (95% CI 0%-5%) increase in seizure frequency. No procedure-related mortality was reported at any follow-up. ANT-DBS effectively treats refractory epilepsy, with lasting short-term and long-term benefits. It remains safe and efficient despite complications, showing no procedure-linked fatalities, high patient responsiveness, and minimal increased seizures. Consistent results over time and low morbidity/mortality rates emphasize its worth. Further research is necessary to diminish the discrepancy among results.


Assuntos
Núcleos Anteriores do Tálamo , Estimulação Encefálica Profunda , Epilepsia Resistente a Medicamentos , Humanos , Estimulação Encefálica Profunda/métodos , Epilepsia Resistente a Medicamentos/terapia , Resultado do Tratamento
2.
Exp Physiol ; 108(7): 932-939, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37036125

RESUMO

NEW FINDINGS: What is the central question of this study? What is the effect of peripheral chemoreflex and muscle metaboreflex integration on ventilation regulation, and what is the effect of integration on breathing-related sensations and emotions? What is the main finding and its importance? Peripheral chemoreflex and muscle metaboreflex coactivation during isocapnic static handgrip exercise appeared to elicit a hyperadditive effect with regard to ventilation and an additive effect with regard to breathing-related sensations and emotions. These findings reveal the nature of the integration between two neural mechanisms that operate during small-muscle static exercise performed under hypoxia. ABSTRACT: Exercise augments the hypoxia-induced ventilatory response in an exercise intensity-dependent manner. A mutual influence of hypoxia-induced peripheral chemoreflex activation and exercise-induced muscle metaboreflex activation might mediate the augmentation phenomenon. However, the nature of these reflexes' integration (i.e., hyperadditive, additive or hypoadditive) remains unclear, and the coactivation effect on breathing-related sensations and emotions has not been explored. Accordingly, we investigated the effect of peripheral chemoreflex and muscle metaboreflex coactivation on ventilatory variables and breathing-related sensations and emotions during exercise. Fourteen healthy adults performed 2-min isocapnic static handgrip, first with the non-dominant hand and immediately after with the dominant hand. During the dominant hand exercise, we (a) did not manipulate either reflex (control); (b) activated the peripheral chemoreflex by hypoxia; (c) activated the muscle metaboreflex in the non-dominant arm by post-exercise circulatory occlusion (PECO); or (d) coactivated both reflexes by simultaneous hypoxia and PECO use. Ventilation response to coactivation of reflexes (mean ± SD, 13 ± 6 l/min) was greater than the sum of responses to separated activations of reflexes (mean ± SD, 8 ± 8 l/min, P = 0.005). Breathing-related sensory and emotional responses were similar between coactivation of reflexes and the sum of separate activations of reflexes. Thus, the peripheral chemoreflex and muscle metaboreflex integration during exercise appeared to be hyperadditive with regard to ventilation and additive with regard to breathing-related sensations and emotions in healthy adults.


Assuntos
Força da Mão , Músculos , Adulto , Humanos , Força da Mão/fisiologia , Reflexo/fisiologia , Respiração , Hipóxia , Músculo Esquelético/fisiologia
3.
Int J Obes (Lond) ; 46(11): 2006-2012, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35987956

RESUMO

BACKGROUND/OBJECTIVE: There is evidence that metabolic profile changes after Roux-Y gastric bypass (RYGB), especially due to modifications in the gastrointestinal tract. In addition, previous studies have suggested that probiotics can modify the microbiome and produce metabolites important for metabolic health maintenance. In this sense, the aim of this study was to verify the influence of probiotic supplementation on the plasma metabolite profile after RYGB. METHODS: This was a randomized, double-blind, placebo-controlled clinical trial conducted with 31 patients subjected to RYGB surgery, randomized in probiotic group that was supplemented with a probiotic supplement (FloraVantage®) for 3 months after surgery or a placebo group. Plasma metabonomics was performed using nuclear magnetic resonance (NMR) at the preoperative period (T0) and at 45-50 days (T1) and 90-95 days (T2) during the postoperative period/intervention. RESULTS: Reductions in trimethylamine-N-oxide (TMAO) and alanine were observed in both groups, however this reduction was greater in the probiotic group (TMAO 13.82%, p = 0.01 and alanine 14.03%, p = 0.03) at T2. Additionally, ß-hydroxybutyrate (BHB) levels increased 10.77% in the probiotic group (p = 0.03) compared to the placebo group at T2. CONCLUSION: Supplementation with Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 was able to associate with significant differences in relevant plasma metabolites associated with improved metabolic health.


Assuntos
Derivação Gástrica , Probióticos , Humanos , Ácido 3-Hidroxibutírico , Estudos Prospectivos , Glicemia/metabolismo , Probióticos/uso terapêutico , Suplementos Nutricionais , Método Duplo-Cego , Alanina , Óxidos
4.
J Phys Chem A ; 126(48): 8901-8909, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36441960

RESUMO

The linear and nonlinear properties of the stilbazolium derivative, 2-[2-(3-hydroxy-4-methoxy-phenyl)-vinyl]-1-methyl-pyridinium naphthalene-2-sulfonate dihydrate crystal (VSNS), were investigated using an iterative electrostatic embedding scheme and density functional theory (DFT). The dipole moment and second hyperpolarizability of the VSNS molecule are sharply influenced by its crystalline phase. Standard DFT global hybrids such as B3LYP and M06 are strongly benefited by the effects of crystalline polarization. The performance can be further improved by making small changes in the amount of Hartree-Fock exchange included in the hybrid, delivering good hyperpolarizability and spectroscopy.

5.
Parasitol Res ; 121(3): 839-849, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35118512

RESUMO

This study aimed to evaluate the effects of a commercial formulation containing fipronil and fluazuron on the reproductive biology and the morphology of ovaries from Rhipicephalus microplus engorged females. To carry out the study, three calves were artificially infested every 3 days with approximately 5000 larvae. On day 0, the animals were treated with a commercial formulation containing fipronil (1.25 mg/kg) + fluazuron (2.5 mg/kg). Before the application of the acaricide, engorged females of R. microplus were collected to constitute the control group (10 for biology analyses and 20 for histology analyses). After applying the commercial formulation, naturally detached engorged females were recovered on days + 5, + 10, and + 20 (10 engorged females/day) to evaluate their reproductive biology, and on days + 4, + 12, and + 20 (20 engorged females/day) for histological evaluation of the ovaries. Females from the treated groups produced smaller amounts of eggs, exhibiting lower viability when compared to eggs from the control group (p < 0.05). The ovaries of females from all treated groups (+ 4, + 12, and + 20) showed morphological changes, including: cytoplasmic disorganization, cytoplasmic degradation, irregular shape of the oocyte and germinal vesicle, reduction and vacuolization of yolk granules and oocyte disruption. Oocytes were observed in smaller numbers in all stages of development (I, II, III, IV, and V) and greater numbers of indeterminate oocytes were verified in the ovaries of the treated groups when compared to the control group. Therefore, results showed that the commercial formulation containing fipronil and fluazuron affected the reproductive biology, caused morphological changes in the ovaries, and reduced the number of oocytes in R. microplus engorged females.


Assuntos
Acaricidas , Doenças dos Bovinos , Rhipicephalus , Infestações por Carrapato , Acaricidas/farmacologia , Animais , Biologia , Bovinos , Feminino , Ovário , Compostos de Fenilureia , Pirazóis , Infestações por Carrapato/veterinária
6.
J Strength Cond Res ; 35(2): 458-464, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29351158

RESUMO

ABSTRACT: Lopes, TJA, Simic, M, Alves, DdS, Bunn, PdS, Rodrigues, AI, Terra, BdS, Lima, MdS, Ribeiro, FM, Vilão, P, and Pappas, E. Physical performance measures of flexibility, hip strength, lower limb power, and trunk endurance in healthy navy cadets: Normative data and differences between sex and limb dominance. J Strength Cond Res 35(2): 458-464, 2021-The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single-leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a 2-way mixed analysis of variance. A total of 545 Brazilian Navy cadets (394 men) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean ± SD, 95% confidence interval and percentiles. For tests of muscle strength, power, and endurance, men performed better than women (p < 0.001). For flexibility tests, women achieved greater distances than men for the sit and reach test (p < 0.001), but no difference for ankle dorsiflexion (p = 0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, men presented higher values for lower limb strength and power, as well as trunk endurance than women, whereas women demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective because the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.


Assuntos
Força Muscular , Desempenho Físico Funcional , Brasil , Feminino , Humanos , Extremidade Inferior , Masculino , Resistência Física , Tronco
7.
J Org Chem ; 85(16): 10561-10573, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32806092

RESUMO

In this work, we described the synthesis of 10 new fluorescent 2,1,3-benzoselenadiazole small-molecule derivatives and their chemical- and photocharacterizations. The new derivatives could, for the first time, be successfully applied as selective live cell imaging probes (at nanomolar concentrations) and stained lipid-based structures preferentially. Density functional theory (DFT) calculations were used to help in understanding the photophysical data and the intramolecular charge-transfer (ICT) processes of the synthesized dyes. Some derivatives showed impressive cellular responses, allowing them to be tested as probes in a complex multicellular model (i.e., Caenorhabditis elegans). When compared with the commercially available dye, the new fluorescent compounds showed far better results both at the cellular level and inside the live worm. Inside the multicellular complex model, the tested probes also showed selectivity, a feature not observed when the commercial dye was used to carry out the bioimaging experiments.


Assuntos
Corantes Fluorescentes , Gotículas Lipídicas , Coloração e Rotulagem
8.
Phys Chem Chem Phys ; 22(30): 17171-17180, 2020 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-32638754

RESUMO

Accurate ab initio calculations provide the reliable information needed to study the potential energy surfaces that control the non-covalent interactions (NCIs) responsible for the formation of weak van der Waals complexes. In this work, relying on the state of the art method for NCI computations, namely symmetry adapted perturbation theory (SAPT), we calculated the potential energy curves for the interaction of noble gases (Ng = He, Ne, Ar and Kr) with methanol in three different interaction sites to account for orientational anisotropy of the interaction potential. Different levels of the SAPT and basis set were employed to disclose the nature of the stabilizing forces acting upon formation of the Ng-CH3OH adducts. SAPT-derived NCIs indicate that dispersion forces are indeed the dominating component of the total energy, but also that induction and electrostatic effects are important to counterbalance the steric repulsions. By solving the Radial Nuclear Schrödinger Equation for the complexes, we also determined the rovibrational structure of the interaction wells to extract invaluable information about the thermodynamic stability of the adducts and how different temperature conditions affect the structure of the dimers. Although SAPT calculations reveal net attractive forces, these do not afford a spontaneous complexation process even at temperatures as low as 40 K.

9.
J Food Sci Technol ; 57(4): 1251-1257, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32180621

RESUMO

Most of the population is dependent on supplemental products to reach the recommended level of omega-3 polyunsaturated fatty acid (ω-3 PUFA) intake. Thus, knowledge about the quality of ω-3 supplements is important for their safe consumption. In this work, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy were applied to assess the quality of fourteen commercial ω-3 supplements. Using ATR-FTIR data, we could identify whether ω-3 PUFA was esterified as either triacylglyceride (71%) or ethyl (29%) esters in ω-3 supplements. The type of esterification is rarely included in the product labels, although the consumer should have the right to choose which form of the supplement to consume. On the other hand, 1H NMR spectra were useful to determine the relative concentration of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, and ω-3 PUFA in these commercial samples. Ethyl esters have higher concentrations of unsaturated fatty acids. The NMR results showed a good agreement between the obtained and declared DHA and EPA amounts on the product labels, except for one sample whose high level of ω-3 PUFA indicated it to be a vegetable oil-enriched supplement. Moreover, ω-3 supplements from Schizochytrium sp. microalgae oil revealed higher levels of DHA and ω-3 PUFA, but lower levels of EPA than fish oil. These findings indicate the need for a constant assessment of the quality of commercial products whose ATR-FTIR spectra could be routinely used for the evaluation of PUFA esterification, and NMR analysis could be used to provide advanced quantitative information on commercial ω-3 supplements.

10.
Eur J Appl Physiol ; 119(3): 621-632, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30542933

RESUMO

PURPOSE: High cardiac vagal control in endurance athletes has been generally associated with adequate recovery from training and readiness to cope high-intensity training. A method that improves cardiac vagal control in endurance athletes could therefore be advantageous. Accordingly, we sought to test whether ischemic preconditioning (IPC) could enhance cardiac vagal control in endurance runners. METHODS: Fifteen subjects underwent IPC, sham ultrasound (SHAM) or control (CT), in random order. Subjects were informed both IPC and SHAM would be beneficial vs. CT (i.e., similar placebo induction), and IPC would be harmless despite ischemia sensations (i.e., nocebo avoidance). Resting cardiac vagal control was assessed via respiratory sinus arrhythmia (RSA) and heart rate variability (HRV) indexes. Post-exercise cardiac vagal control was assessed via heart rate recovery [HR time constant decay (T30) and absolute HR decay (HRR30s)] during 30-s breaks of a discontinuous incremental test. Capillary blood samples were collected for lactate threshold identification. RESULTS: RSA and HRV were similar among interventions at pre- and post-intervention assessments. Lactate threshold occurred at 85 ± 4% of maximal effort. T30 was similar among interventions, but IPC increased HRR30s at 70% and 75% of maximal effort vs. SHAM and CT (70%: IPC = 31 ± 2 vs. SHAM = 26 ± 3 vs. CT = 26 ± 2 bpm, mean ± SEM, P < 0.01; 75%: IPC = 29 ± 2 vs. SHAM = 25 ± 2 vs. CT = 24 ± 2 bpm, P < 0.01). CONCLUSION: IPC did not change resting cardiac vagal control, but boosted fast post-exercise cardiac vagal reactivation at exercise intensities below lactate threshold in endurance runners.


Assuntos
Precondicionamento Isquêmico , Resistência Física/fisiologia , Corrida/fisiologia , Nervo Vago/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Descanso/fisiologia
11.
Sensors (Basel) ; 19(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547378

RESUMO

The interest of the scientific community for ultrasound techniques has increased in recent years due to its wide range of applications. A continuous effort of researchers and industries has been made in order to improve and increase the applicability of non-destructive evaluations (NDE). In this context, the monitoring of manufacturing processes, such as the grinding process, arises. This work proposes a novel technique of ultrasound monitoring (chirp-through-transmission) through low-cost piezoelectric diaphragms and digital signal processing. The proposed technique was applied to the monitoring of material removal during the grinding process. The technique is based on changes in ultrasonic waves when propagated through the material under study, with the difference that this technique does not use traditional parameters of ultrasonic techniques but digital signal processing (RMS and Counts). Furthermore, the novelty of the proposed technique is also the use of low-cost piezoelectric diaphragms in the emission and reception of ultrasonic waves, enabling the implementation of a low-cost monitoring system. The results show that the monitoring technique proposed in this work, when used in conjunction with the frequency band selection, is sensitive to the material removal in the grinding process and therefore presents an advance for monitoring the grinding processes.

12.
Magn Reson Chem ; 56(5): 311-320, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29315783

RESUMO

Ilex paraguariensis (mate) is a species native to South America and is widely consumed in countries such Argentina, Uruguay, Paraguay, and Brazil. Mate consumption is associated with several phytotherapeutic functions, in addition to its cultural and regional importance. However, the harvest period can affect the properties of the mate, due to variations in the constituent proportions, as a consequence of seasonal changes. In this work, we employed nuclear magnetic resonance and chemometrics to evaluate the chemical variations in leaf extracts of I. paraguariensis over the four seasons of the year. We found significant changes in the levels of glucose, myo-inositol, caffeine, theobromine, and fatty acids. These changes can be related to resource allocation for the flowering period, or to responses to environmental stresses, such as temperature.


Assuntos
Ilex paraguariensis/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Extratos Vegetais/análise , Folhas de Planta/metabolismo , Cafeína/análise , Ácidos Graxos/análise , Glucose/análise , Ilex paraguariensis/química , Inositol/análise , Folhas de Planta/química , Estações do Ano , Teobromina/análise
13.
Chem Pharm Bull (Tokyo) ; 66(1): 61-64, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29311513

RESUMO

Several applications have been proposed for tyrosinase inhibitors in the pharmaceutical, food bioprocessing, and environmental industries. However, only a few compounds are known to serve as effective tyrosinase inhibitors. This study evaluated the tyrosinase-related activity of resorcinol (1), orcinol (2) lecanoric acid (3), and derivatives of this acid (4-15). Subjected to alcoholysis, lecanoric acid (3), a depside isolated from the lichen Parmotrema tinctorum, produces orsellinic acid (2,4-dihydroxy-6-methylbenzoic acid) (4) and orsellinates (2,4-dihydroxy-6-methyl benzoates) (5-15). At 0.50 mM, methyl (5), ethyl (6), n-propyl (7), tert-butyl (11), and n-cetyl orsellinates (15) acted as tyrosinase activators, whereas n-butyl (8), iso-propyl (9), sec-butyl (10), n-pentyl (12), n-hexyl (13), and n-octyl orsellinates (14) behaved as inhibitors. Tyrosinase inhibition rose with chain elongation-n-butyl (8)

Assuntos
Agaricales/enzimologia , Inibidores Enzimáticos/farmacologia , Líquens/química , Monofenol Mono-Oxigenase/antagonistas & inibidores , Resorcinóis/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Cinética , Estrutura Molecular , Monofenol Mono-Oxigenase/metabolismo , Resorcinóis/química , Resorcinóis/isolamento & purificação , Relação Estrutura-Atividade
15.
Infection ; 45(2): 139-145, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27573387

RESUMO

BACKGROUND: Central venous catheters (CVC) are the only option when hemodialysis is needed for patients without definitive vascular access. However, CVC is associated with complications, such as infection, thrombosis, and dysfunction, leading to higher mortality and expenditures. The aim of this study was to compare the effectiveness of 30 % trisodium citrate (TSC30 %) with heparin as CVC lock solutions in preventing catheter-related bloodstream infections (CRBSI) and dysfunction in hemodialysis patients. METHODS: Randomized, double-blind controlled trial comparing the event-free survival of non-tunneled CVC locked with heparin or TSC30 % in adult hemodialysis patients. RESULTS: The study included 464 catheters, 233 in heparin group, and 231 in TSC30 % group. The CRBSI-free survival of TSC30 % group was significantly shorter than that of heparin group. When stratified by insertion site, heparin was better than TSC30 % only in subclavian CVC. The dysfunction-free survival was not different between groups in the main analysis, but there is also a shorter survival among subclavian CVC locked with TSC30 % in stratified analysis. CONCLUSION: There was no difference on CRBSI-free or dysfunction-free survival between jugular vein CVC locked with heparin or 30 % citrate. However, subclavian CVC locked with 30 % citrate presented shorter event-free survival. This difference may be related to anatomical and positional effects, CVC design, and hydraulic aspects of the lock solution. CLINICALTRIALS. GOV IDENTIFIER: NCT02563041.


Assuntos
Anticoagulantes/administração & dosagem , Coagulação Sanguínea/efeitos dos fármacos , Infecções Relacionadas a Cateter/prevenção & controle , Cateterismo Venoso Central/métodos , Citratos/administração & dosagem , Heparina/administração & dosagem , Diálise Renal/efeitos adversos , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
J Food Sci Technol ; 54(5): 1146-1157, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28416864

RESUMO

Low-calorie structured lipids (SLs) rich in behenic and oleic acids were produced by enzymatic (EI) and chemical interesterification (CI) of high oleic sunflower oil and fully hydrogenated Crambe abyssinica oil in proportions of 60:40, 50:50, 40:60 and 30:70 (w/w), respectively. The immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) was used for 3 h at 70 °C at a dosage of 7% (w/w) free of organic solvents. The original blend (BE) and the reaction products were evaluated for their fatty acid (FA) and triacylglycerols (TAG) compositions, solid fat contents, thermal analysis, regiospecific distribution of the FA, microstructure and polymorphism. The tendency was towards a reduction in the C52, C54, C60, C62 and C64 TAG contents and an increase in the C56, C58 e C66 TAG contents, therefore the solid fat content was reduced. There was lower acyl migration at the sn-2 position of the TAGs in EI as compared to CI in all the blends ratios. Needle-like crystals were predominant in the IE while large symmetrical spherulites were observed in the BE. Reduction in the mean crystal diameter was observed in all the blends, in addition to modifications of the crystal morphology. X-ray diffraction analysis showed a predominance of the ß' form crystals in both the IE and CI. The SLs were produced for application in the food industry as bakery/confectionery fats in the proportions of 60:40/50:50 and as additive in the crystallization of lipids in the proportions of 40:60/30:70.

17.
J Am Chem Soc ; 138(49): 16056-16068, 2016 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-27960317

RESUMO

Although major progress has recently been achieved through ex situ methods, there is still a lack of understanding of the behavior of the active center in non-precious metal Fe-N/C catalysts under operating conditions. Utilizing nitrite, nitric oxide, and hydroxylamine as molecular probes, we show that the active site for the oxygen reduction reaction (ORR) is different under acidic and alkaline conditions. An in-depth investigation of the ORR in acid reveals a behavior which is similar to that of iron macrocyclic complexes and suggests a contribution of the metal center in the catalytic cycle. We also show that this catalyst is highly active toward nitrite and nitric oxide electroreduction under various pH values with ammonia as a significant byproduct. This study offers fundamental insight into the chemical behavior of the active site and demonstrates a possible use of these materials for nitrite and nitric oxide sensing applications or environmental nitrite destruction.

18.
Environ Monit Assess ; 188(11): 644, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27796829

RESUMO

This quantitative and qualitative study aimed to identify fungi isolated from patient beds at a reference hospital in Teresina, Piauí, Brazil, and evaluate the efficacy of 70 % ethanol and 1 % hypochlorite for removing the contamination. Thirty-eight beds were chosen at random and the collection was carried out in three situations: before and after disinfection with 70 % alcohol or hypochlorite 1 %. Each sample was inoculated onto Sabouraud dextrose agar containing chloramphenicol and incubated at room temperature to allow fungal growth. We identified 13 species belonging to the genera Aspergillus, Cladosporium, Alternaria, Rhizopus, Penicillium, and Candida. All of these species are pathogenic and can worsen the clinical condition of patients. The 1 % hypochlorite solution proved to be an efficient disinfectant against the fungi, but the same was not observed using 70 % ethanol. Based on these findings, we recommended that the use of 1 % hypochlorite during bed disinfection be added to the hospital biosafety protocol to reduce cross contamination and contribute to patient recovery.


Assuntos
Desinfetantes/farmacologia , Fungos/efeitos dos fármacos , Hospitais , Aspergillus , Brasil , Infecção Hospitalar/prevenção & controle , Desinfecção/métodos , Humanos , Penicillium
19.
BMC Genet ; 15: 21, 2014 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-24517472

RESUMO

BACKGROUND: Feed intake plays an important economic role in beef cattle, and is related with feed efficiency, weight gain and carcass traits. However, the phenotypes collected for dry matter intake and feed efficiency are scarce when compared with other measures such as weight gain and carcass traits. The use of genomic information can improve the power of inference of studies on these measures, identifying genomic regions that affect these phenotypes. This work performed the genome-wide association study (GWAS) for dry matter intake (DMI) and residual feed intake (RFI) of 720 Nellore cattle (Bos taurus indicus). RESULTS: In general, no genomic region extremely associated with both phenotypic traits was observed, as expected for the variables that have their regulation controlled by many genes. Three SNPs surpassed the threshold for the Bonferroni multiple test for DMI and two SNPs for RFI. These markers are located on chromosomes 4, 8, 14 and 21 in regions near genes regulating appetite and ion transport and close to important QTL as previously reported to RFI and DMI, thus corroborating the literature that points these two processes as important in the physiological regulation of intake and feed efficiency. CONCLUSIONS: This study showed the first GWAS of DMI to identify genomic regions associated with feed intake and efficiency in Nellore cattle. Some genes and QTLs previously described for DMI and RFI, in other subspecies (Bos taurus taurus), that influences these phenotypes are confirmed in this study.


Assuntos
Ingestão de Alimentos/genética , Ração Animal , Animais , Apetite/genética , Peso Corporal , Bovinos , Ingestão de Alimentos/fisiologia , Estudos de Associação Genética , Genótipo , Transporte de Íons/genética , Masculino , Carne , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Aumento de Peso
20.
Amino Acids ; 46(11): 2573-86, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25106507

RESUMO

Although glycine-rich antimicrobial peptides (AMPs) are found in animals and plants, very little has been reported on their chemistry, structure activity-relationship, and properties. We investigated those topics for Shepherin I (Shep I), a glycine-rich AMP with the unique amino acid sequence G(1)YGGHGGHGGHGGHGGHGGHGHGGGGHG(28). Shep I and analogues were synthesized by the solid-phase method at 60 °C using conventional heating. Purification followed by chemical characterization confirmed the products' identities and high purity. Amino acid analysis provided their peptide contents. All peptides were active against the clinically important Candida species, but ineffective against bacteria and mycelia fungi. Truncation of the N- or C-terminal portion reduced Shep I antifungal activity, the latter being more pronounced. Carboxyamidation of Shep I did not affect the activity against C. albicans or C. tropicalis, but increased activity against S. cerevisiae. Carboxyamidated analogues Shep I (3-28)a and Shep I (6-28)a were equipotent to Shep I and Shep Ia against Candida species. As with most cationic AMPs, all peptides had their activity significantly reduced in high-salt concentrations, a disadvantage that is defeated if 10 µM ZnCl2 is present. At 100 µM, the peptides were practically not hemolytic. Shep Ia also killed C. albicans MDM8 and ATCC 90028 cells. Fluo-Shep Ia, an analogue labeled with 5(6)-carboxyfluorescein, was rapidly internalized by C. albicans MDM8 cells, a salt-sensitive process dependent on metabolic energy and temperature. Altogether, such results shed light on the chemistry, structural requirements for activity, and other properties of candidacidal glycine-rich peptides. Furthermore, they show that Shep Ia may have strong potential for use in topical application.


Assuntos
Peptídeos/química , Proteínas de Plantas/química , Motivos de Aminoácidos , Sequência de Aminoácidos , Aminoácidos/química , Anti-Infecciosos/química , Bactérias/metabolismo , Candida/metabolismo , Candida albicans , Membrana Celular/metabolismo , Separação Celular , Dicroísmo Circular , Citometria de Fluxo , Glicina/química , Histidina/química , Cinética , Testes de Sensibilidade Microbiana , Microscopia Confocal , Dados de Sequência Molecular , Peptídeos/farmacologia , Estrutura Terciária de Proteína , Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Relação Estrutura-Atividade , Temperatura
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