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1.
Front Chem ; 11: 1304063, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38025069

RESUMO

Electrocatalytic materials are pivotal for clean chemical production and energy conversion in devices like electrolyzers and fuel cells. These materials usually consist of metallic nanoparticles which serve as active reaction sites, and support materials which provide high surface area, conductivity and stability. When designing novel electrocatalytic composites, the focus is often on the metallic sites, however, the significance of the support should not be overlooked. Carbon materials, valued for their conductivity and large surface area, are commonly used as support in benchmark electrocatalysts. However, using alternative support materials instead of carbon can be beneficial in certain cases. In this minireview, we summarize recent advancements and key directions in developing novel supports for electrocatalysis, encompassing both carbon and non-carbon materials.

2.
In Vitro Cell Dev Biol Anim ; 51(6): 546-55, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25678460

RESUMO

Typical form of neurons is crucially important for their functions. This is maintained by microtubules and associated proteins like tau. Hyperphosphorylation of tau is a major concern in neurodegenerative diseases. Glycogen synthase kinase3ß (GSK3ß) and cyclin-dependent protein kinase 5 (Cdk5) are the enzymes that govern tau phosphorylation. Currently, efforts are being made to target GSK3ß and Cdk5 as possible therapeutic avenues to control tau phosphorylation and treat neurodegenerative diseases related to taupathies. In a number of studies, caloric restriction mimetic 2-deoxyglucose (C6H12O5) was found to be beneficial in improving the brain functions. However, no reports are available on the effect of 2-deoxyglucose 2-DG on tau phosphorylation. In the present study, hippocampal pyramidal neurons from E17 mouse embryos were isolated and cultured on poly-L-lysine-coated coverslips. Neurons from the experimental group were treated with 10 mM 2-deoxyglucose. The treatment of 2-DG resulted in healthier neuronal morphology in terms of significantly lower number of cytoplasmic vacuoles, little or no membrane blebbings, maintained axon hillock and intact neurites. There were decreased immunofluorescence signals for GSK3ß, pTau at Ser262, Cdk5 and pTau at Ser235 suggesting decreased tau phosphorylation, which was further confirmed by Western blotting. The results indicate the beneficial effects of 2-DG in controlling the tau phosphorylation and maintaining the healthy neuronal cytoarchitecture.


Assuntos
Restrição Calórica , Desoxiglucose/farmacologia , Hipocampo/citologia , Células Piramidais/citologia , Células Piramidais/metabolismo , Proteínas tau/metabolismo , Animais , Western Blotting , Células Cultivadas , Quinase 5 Dependente de Ciclina/metabolismo , Imunofluorescência , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Camundongos , Proteínas Associadas aos Microtúbulos/metabolismo , Fosforilação/efeitos dos fármacos , Células Piramidais/efeitos dos fármacos
3.
Chem Commun (Camb) ; 50(86): 13124-6, 2014 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-25223460

RESUMO

We present a novel, scaled-up sol-gel synthesis which enables one to produce 20 g batches of highly active and stable carbon supported PtCu3 nanoparticles as cathode materials for low temperature fuel cell application. We confirm the presence of an ordered intermetallic phase underneath a multilayered Pt-skin together with firm embedment of nanoparticles in the carbon matrix.

4.
Theriogenology ; 81(4): 520-5, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24360404

RESUMO

Flow cytometry sex-sorting technology was developed in 1989. However, it is only the bovine species in which offspring of the desired sex are obtained at a commercial level. The aim of the present work was to evaluate efficiency parameters when using fresh sexed semen in a large-scale equine commercial embryo transfer program. During the 2009, 2010 and 2011 breeding seasons, 938 synchronized cycles were artificially inseminated. One hundred (10.6%) mares failed to ovulate, and for the remaining 838 useable cycles, 887 doses of sexed semen were used, representing 1.06 doses per cycle. In general, 435 (51.9%) out of 838 flushing performed resulted in the recovery of at least one embryo and 496 (59.1%) embryos were recovered, including twins and triplets. Pregnancy rate at 25 days achieved 81.5% (one embryo transferred per recipient). Embryo recovery rate was not statistically different either between preovulatory and postovulatory artificially inseminated mares or when increased quantities of sexed sperm per dose were used (15-45 million) (P > 0.05). A broad variation in embryo recovery rate was observed between the different stallions used in this study. Sex accuracy of the sex sorting assessed by ultrasound fetal sex determination was 90.3%. Finally, overall efficiency (female embryo pregnancies per useable cycles) was 39% (325/838), meaning that to obtain a female pregnancy of at least 75 days it was necessary to perform 2.5 flushing.


Assuntos
Transferência Embrionária/veterinária , Cavalos/fisiologia , Inseminação Artificial/veterinária , Sêmen/fisiologia , Pré-Seleção do Sexo/veterinária , Animais , Distribuição de Qui-Quadrado , Transferência Embrionária/métodos , Feminino , Citometria de Fluxo/veterinária , Inseminação Artificial/métodos , Masculino , Gravidez , Pré-Seleção do Sexo/métodos
5.
Indian J Pharm Sci ; 72(1): 128-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20582205

RESUMO

The aim of present study is to investigate the effect of flow aids on the observed in vitro mucoadhesion of two representative polymers; polyoxyethylene and Carbopol((R)) 971P. More recently it has been shown that the addition of small amounts of certain excipients to a mucoadhesive formulation can lead to a substantial decrease in observed mucoadhesion in an in vitro test system, which suggests that formulation of these systems could be crucial in developing successful dosage forms. A series of experiments has been carried out which indicates that the presence of flow aids at high concentrations present in tablets can affect the observed ex-vivo mucoadhesive bond. Magnesium stearate (5%) exerts its negative effect on the mucoadhesion of Carbopol((R)) 971P and polyoxyethylene combination by hindering the hydration of the polymer. Adhesion time of formulation containing 5% magnesium stearate was found 4.7+/-0.34 h and percent hydration of same formulation was 70.12%.Talc and colloidal silicon dioxide (Aerosil), which do not possess the same hydrophobic properties or have available divalent cations were found to be viable alternatives to magnesium stearate.

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