Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Waste Manag ; 119: 111-121, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33065334

RESUMO

Sustainability and enhancement of recycling differing polymer waste has become a leading driver for industries associated with this type of waste. However, polymer waste streams that have not seen as 'typical' have existed in smaller but not insignificant amounts. This study has focused on the recycling of such a waste resource that is not classified as a typical one in developed countries but appears in other locations globally where opportunities for careful waste pretreatment are hindered, therefore creating a challenge for waste handling and the application of modern techniques. Compatibilizing is a strategy employed to recycle ground tire rubber (GTR) by blending with waste high density polyethylene (w-HDPE). Such processing methods and measurement techniques have been chosen to allow easy access without extra costs. For enhanced incorporation of the filler into the matrix olefin-maleic-anhydride copolymer based additives have been synthesized and have succeeded in creating a more homogenous blend with samples having a good surface appearance and mechanical properties. Outstanding Charpy impact strength at room temperature (10.1 kJ/m2) has been achieved in compatibilized 70/30 w-HDPE/GTR (containing 20% PE-contaminant), while elongation at break and tensile strength have been 10.3% and 14.9 MPa. Morphological structure of rubber resources and blends have been assessed by SEM while analytical properties and other features of experimental compatibilizing additives have been studied by e.g. FT-IR.


Assuntos
Pessoas com Deficiência , Borracha , Humanos , Resíduos Industriais , Reciclagem , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Physiol Int ; 106(2): 140-150, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31282761

RESUMO

INTRODUCTION: The quality and function of movements undergo deterioration due to weight gain. Aerobic training normalizes body weight, improves the health status, and in addition, it is expected to improve the dynamics of movements. The aims of this study were to prove the beneficial effects of recreational physical activities on the movements. METHODS: Participants were divided into five different age categories: second childhood, adolescence, mature age I, mature age II, and aging. Squatting and vertical jumping of the participants were measured at the beginning and at the end of a 5-month training program. These movements simulated ordinary daily movements. Changes in the body were determined by InBody230. APAS 3D system was used for movement analysis. RESULTS: The results showed significant improvements in body weight, fat mass, muscle mass, fat mass-body weight ratio, muscle mass-body weight ratio, body mass index, body fat percentage, and waist-hip ratio. During jumping, the lifting and sinking of the center of gravity's (CG) position and its velocity and acceleration were improved. In case of squatting, the results showed significant improvements in the velocity and acceleration of dynamical characteristics of the CG. Other correlations were observed between changes in body composition and the dynamics of movements. DISCUSSION: The research proved that recreational training optimized body composition and improved the characteristics of CG's dynamics. The study suggests considerable connection between body composition and the characteristics of the movements' dynamics. From this point of view, our training program was the most effective in the working age groups.


Assuntos
Exercício Físico/fisiologia , Aceleração , Adolescente , Adulto , Idoso , Composição Corporal/fisiologia , Índice de Massa Corporal , Peso Corporal/fisiologia , Criança , Feminino , Gravitação , Humanos , Masculino , Pessoa de Meia-Idade , Circunferência da Cintura/fisiologia , Adulto Jovem
3.
J Mol Neurosci ; 60(4): 525-530, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27752928

RESUMO

The effects of ghrelin on vasopressin and oxytocin secretion were studied in 13-14-day cell cultures of isolated rat neurohypophyseal tissue. The vasopressin and oxytocin contents of the supernatant were determined by radioimmunoassay after a 1- or 2-h incubation. Significantly increased levels of vasopressin and oxytocin production were detected in the cell culture media following ghrelin administration, depending on the ghrelin doses. The oxytocin level proved to be more elevated than that of vasopressin. The increase of vasopressin and oxytocin secretion could be totally blocked by previous administration of the ghrelin receptor antagonist ([D-Lys3]-growth hormone-releasing peptide-6). Application of the ghrelin receptor antagonist after ghrelin administration proved ineffective. The results indicate that vasopressin and oxytocin release is influenced directly by the ghrelin system, and the effects of ghrelin on vasopressin and oxytocin secretion from the neurohypophyseal tissue in rats can occur at the level of the posterior pituitary. Our observations lend support to the view that neurohypophysis contains ghrelin receptors.


Assuntos
Exocitose , Grelina/farmacologia , Hormônios/farmacologia , Células Neuroendócrinas/metabolismo , Ocitocina/metabolismo , Hipófise/citologia , Vasopressinas/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Masculino , Células Neuroendócrinas/efeitos dos fármacos , Oligopeptídeos/farmacologia , Hipófise/metabolismo , Ratos , Ratos Wistar , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/metabolismo
4.
Regul Pept ; 155(1-3): 76-80, 2009 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-19289145

RESUMO

The effects of dopamine (DA), serotonin (5-HT), histamine (HA), adrenaline (ADR), noradrenaline (NADR) and K(+) administration on vasopressin (VP) secretion were studied in 13-14-day cultures of rat neurohypophyseal (NH) cells, and it was examined whether galanin (GAL) can modify the VP release enhancement induced by these monoaminergic compounds. An enzymatic dissociation technique was used to make the rat NH cell cultures. The VP contents of the supernatants of 14-day cultures were determined by radioimmunoassay. Following the administration of 10(-6) M GAL, the VP secretion into the supernatant media decreased. DA, 5-HT, ADR or NADR treatment increased the VP level substantially, while the enhancing effect of HA was more moderate. GAL administration before DA, ADR and NADR treatment prevented the VP concentration increase induced by DA, ADR or NADR. Preincubation with GAL reduced the 5-HT- or HA-induced VP level increases; the VP concentrations of the supernatant media remained above the control level. The GAL blocking effect was prevented by previous treatment with the GAL receptor antagonist galantid (M15). GAL had no effect on the VP level increase induced by K(+), which causes a non-specific hormone secretion. The results indicate that the changes in VP secretion induced by the monoaminergic system can be directly influenced by the GAL-ergic system. The interactions between the monoaminergic and GAL-ergic systems regarding VP secretion occur at the level of the posterior pituitary.


Assuntos
Galanina/farmacologia , Neuro-Hipófise/efeitos dos fármacos , Neuro-Hipófise/metabolismo , Vasopressinas/metabolismo , Agonistas Adrenérgicos/farmacologia , Animais , Células Cultivadas , Dopamina/farmacologia , Dopaminérgicos/farmacologia , Interações Medicamentosas , Epinefrina/farmacologia , Histamina/farmacologia , Agonistas dos Receptores Histamínicos/farmacologia , Masculino , Norepinefrina/farmacologia , Neuro-Hipófise/citologia , Radioimunoensaio , Ratos , Ratos Wistar , Serotonina/farmacologia , Serotoninérgicos/farmacologia
5.
Regul Pept ; 148(1-3): 1-5, 2008 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-18462818

RESUMO

UNLABELLED: The effects of adrenaline (A) and noradrenaline (NA) on vasopressin (VP) secretion were studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP contents of the supernatant media were determined by radioimmunoassay after a 1 or 2-h incubation. Significantly increased VP levels were detected in the tissue culture media following the administration of A (an alpha+beta(2)-receptor agonist), depending on the dose of A. The VP secretion elevation was totally blocked by the previous administration of phentolamine (an alpha(1)+alpha(2)-receptor antagonist) or corynanthine (an alpha(1)-receptor antagonist). Yohimbine (an alpha(2)-receptor antagonist) did not influence the VP secretion increase induced by A. After the administration of NA (a beta+alpha(1)-receptor agonist), a VP secretion elevation was again detected, but the degree of enhancement proved smaller than that of the VP secretion increase induced by A. Propranolol (a beta(1)+beta(2)-receptor antagonist) before NA administration prevented the VP secretion increase. Atenolol (a beta(1)-receptor antagonist) did not block the VP secretion elevation induced by NA. Corynanthine (an alpha(1)-receptor antagonist) treatment before NA administration reduced the NA-induced VP enhancement, because NA has an alpha(1)-receptor agonist character in addition to its main character (a beta-receptor agonist). Surprisingly, the administration of pindolol (a beta(1)+beta(2)-receptor antagonist) enhanced VP secretion. This contradictory effect can be explained in that pindolol not only acts as a blocker, but also exerts "intrinsic sympathomimetic action" and a strong adrenergic agonist effect. Pindolol before NA administration significantly increased the NA-induced VP elevation. CONCLUSIONS: Mainly the alpha(1)- and beta(2)-adrenergic receptors are involved in the A- or NA-induced increase of VP secretion in isolated NH tissue cultures. The results indicate that VP release is influenced directly by the adrenergic system, and the adrenergic control of VP secretion from the NH tissue in rats can occur at the level of the posterior pituitary.


Assuntos
Norepinefrina/farmacologia , Neuro-Hipófise/metabolismo , Vasopressinas/metabolismo , Antagonistas de Receptores Adrenérgicos alfa 1 , Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas de Receptores Adrenérgicos beta 2 , Animais , Epinefrina/farmacologia , Masculino , Fentolamina/farmacologia , Pindolol/farmacologia , Neuro-Hipófise/efeitos dos fármacos , Propranolol/farmacologia , Radioimunoensaio , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa 1/fisiologia , Receptores Adrenérgicos beta 2/fisiologia , Técnicas de Cultura de Tecidos , Ioimbina/farmacologia
6.
Regul Pept ; 134(2-3): 82-8, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16530280

RESUMO

The effects of histamine (HA) on vasopressin (VP) and oxytocin (OT) secretion were studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP and OT contents of the supernatant were determined by radioimmunoassay (RIA) after a 1 or 2-h incubation. Significantly increased levels of VP and OT production were detected in the tissue culture media following HA administration, depending on the HA dose. The elevation of NH hormone secretion could be partially blocked by previous administration of the HA antagonist mepyramine (MEP, an H1 receptor antagonist) or cimetidine (CIM, an H2 receptor antagonist). Thioperamide (TPE, an H3-H4 receptor antagonist) did not influence the VP or OT secretion increase induced by HA. The application of MEP, CIM or TPE after HA administration proved ineffective. The H1 and H2 receptors are mainly involved in the HA-induced increase of both VP and OT secretion in isolated NH tissue cultures. The results indicate that NH hormone release is influenced directly by the histaminergic system, and the histaminergic control of VP and OT secretion from the NH tissue in rats can occur at the level of the posterior pituitary.


Assuntos
Histamina/farmacologia , Ocitocina/metabolismo , Neuro-Hipófise/metabolismo , Vasopressinas/metabolismo , Animais , Cimetidina/farmacologia , Relação Dose-Resposta a Droga , Antagonistas dos Receptores Histamínicos/farmacologia , Cinética , Masculino , Piperidinas/farmacologia , Neuro-Hipófise/efeitos dos fármacos , Pirilamina/farmacologia , Ratos , Técnicas de Cultura de Tecidos
7.
Regul Pept ; 116(1-3): 35-41, 2003 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-14599713

RESUMO

The regulation of oxytocin (OT) release by galanin (GAL) at the neurohypophyseal (NH) nerve terminal is not adequately understood. The effect of GAL on the secretion of OT was studied in 13- to 14-day cultures of isolated rat NH tissue. By this time, the hormone content of the medium had become constant. The OT content of the supernatant medium was determined by RIA after a 1- or 2-h incubation. A significantly decreased content of OT was found following incubation with 10(-6)-10(-8) M doses of GAL. Dopamine (DA) and the DA-active drugs apomorphine (APM) and Pro-Lys-Gly (PLG) (10(-6) M in each medium) increased the OT synthesis of NH tissue cultures. This elevation of OT secretion could be blocked by the administration of GAL together with DA, APM or PLG. The DA-blocking effect of GAL was prevented by previous treatment with the GAL receptor antagonist galantid (M15). The results indicate that OT release from the NH is directly influenced by the GAL-ergic system. The GAL-ergic control of OT secretion from NH tissue in rats can occur at the level of the posterior pituitary.


Assuntos
Dopamina/farmacologia , Galanina/farmacologia , Ocitocina/metabolismo , Neuro-Hipófise/efeitos dos fármacos , Neuro-Hipófise/metabolismo , Animais , Relação Dose-Resposta a Droga , Masculino , Neuro-Hipófise/citologia , Ratos , Ratos Wistar
8.
Regul Pept ; 110(1): 17-23, 2002 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-12468105

RESUMO

The effect of galanin (GAL) on vasopressin (VP) secretion was studied in 13-14-day cultures of isolated rat neurohypophyseal (NH) tissue. The VP content of the supernatant was determined by radioimmunoassay (RIA) after a 1- or 2-h incubation. A significantly decreased content of VP was detected following the administration of 10(-6)-10(-9) M doses of GAL. Dopamine (DA) and the DA-active drugs apomorphine (APM) and Pro-Lys-Gly (PLG) (10(-6) M in each medium) increased the VP level of NH tissue cultures. This VP concentration elevation could be blocked by the administration of GAL together with DA, APM or PLG. The DA-blocking effect of GAL was prevented by previous treatment with the GAL receptor antagonist galantid (M15). The results indicate that VP release is directly influenced by the GAL-ergic system. The GAL-ergic control of VP secretion from NH tissue in rats can occur independently of the hypothalamus, at the level of the posterior pituitary.


Assuntos
Antagonistas de Dopamina/farmacologia , Dopamina/farmacologia , Galanina/análogos & derivados , Galanina/farmacologia , Neuro-Hipófise/efeitos dos fármacos , Neuro-Hipófise/metabolismo , Substância P/análogos & derivados , Vasopressinas/metabolismo , Animais , Apomorfina/farmacologia , Técnicas de Cultura , Agonistas de Dopamina/farmacologia , Relação Dose-Resposta a Droga , Interações Medicamentosas , Galanina/antagonistas & inibidores , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Cinética , Masculino , Radioimunoensaio , Ratos , Ratos Wistar , Receptores de Neuropeptídeos/antagonistas & inibidores , Substância P/farmacologia
9.
Acta Biol Hung ; 53(1-2): 67-75, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12064780

RESUMO

The polysialylated, embryonic form of the neuronal cell adhesion molecule (PSA-NCAM) is known to participate in a whole series of synaptic rearrangements even in adult animals. The possible role of this molecule in neuroplastic changes of the adult rat somatosensory cortex induced by unilateral transection of the infraorbital branch of the trigeminal nerve was studied with PSA-NCAM immunostaining at light microscopic level. Two- and three-month-old CFY albino rats were sacrificied on days 1, 4, 6, 14 and 21 following operation and PSA-NCAM immunoreaction was examined at three levels of the vibrissa-cortex neuraxis, namely, in the principal nucleus of the trigeminal nerve, in the ventral posteromedial nucleus of the thalamus and in the somatosensory cortex. The lower levels of the neuraxis remained free of PSA-NCAM labeling, similarly to control, intact animals. However, a large number of scattered small neurons became PSA-NCAM immunoreactive in layers IV-VI on both ipsi- and contralateral sides of the somatosensory cortex from day 6 onwards, suggesting a possible transynaptic regulation of NCAM sialylation state.


Assuntos
Molécula L1 de Adesão de Célula Nervosa/metabolismo , Ácidos Siálicos/metabolismo , Córtex Somatossensorial/metabolismo , Traumatismos do Nervo Trigêmeo , Nervo Trigêmeo/metabolismo , Animais , Imuno-Histoquímica , Regeneração Nervosa , Plasticidade Neuronal , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA