Effects Of Hybridization On The Performance Of The Epoxy-Based Nanocomposites.

Epoxy composites were prepared by hybridization of glass fiber and precipitated nano-calcium carbonate (PNCC)

Water pH effects on survival, reproductive performances and ultrastructure of gonads, gills and skins of Javanese medaka (Oryzias javanicus)

The Javanese medaka (Oryzias javanicus) has the potential to be developed as a test organism. It also exhibited many characteristics that are similar to those of well-known laboratory fishes. This study determined the effects of water pH on the survival, reproductive performances, and ultrastructure of the gonads, gills, and skins of the Javanese medaka. This study confirmed that Javanese medakas treated with pH 6-7 displayed the lowest mortality, but increased in egg production and hatchability. This supposition is supported by strong evidence from the oocytes and testes stage analyses, including histological examinations. The ultrastructure of gills and skins of fish treated in that range was also less histologically affected, indicating its suitability range. The sensitivity of the Javanese medaka towards environmental changes, in terms of the selected physiological performances and cellular level, indicate its potential as a test organism in tropical regions

Evaluation of the neurotoxic effects of chronic embryonic exposure with inorganic mercury on motor and anxiety-like responses in zebrafish (Danio rerio) larvae

Chronic exposure to mercury (Hg) can lead to cumulative impairments in motor and cognitive functions including alteration in anxiety responses. Although several risk factors have been identified in recent year, little is known about the environmental factors that either due exposure toward low level of inorganic mercury that may led to the developmental disorders. The present study investigated the effects of embryonic exposure of mercury chloride on motor function and anxiety-like behavior. The embryo exposed to 6 different concentrations of HgCl2 (7.5, 15, 30, 100, 125, 250 nM) at 5 hpf until hatching (72 hpf) in a semi-static condition. The mortality rate increased in a dose dependent manner where the chronic embryonic exposure to 100 nM decreased the number of tail coiling, heartbeat, and swimming activity. Aversive stimulus was used to examine the effects of 100 nM interferes with the development of anxiety-related behavior. No elevation in both thigmotaxis and avoidance response of 6 dpf larvae exposed with 100 nM were found. Biochemical analysis showed HgCl2 exposure affects proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. These results showed that implication of HgCl2 on locomotor and biochemical defects affects motor performance and anxiety-like responses. Yet, the potential underlying mechanisms these responses need to be further investigated which is crucial to prevent potential hazards on the developing organism due to neurotoxicant exposure

Time dependent effect of chronic embryonic exposure to ethanol on zebrafish: morphology, biochemical and anxiety alterations

Exposure to ethanol during critical period of development can cause severe impairments in the central nervous system (CNS). This study was conducted to assess the neurotoxic effects of chronic embryonic exposure to ethanol in the zebrafish, taking into consideration the time dependent effect. Two types of exposure regimen were applied in this study. Withdrawal exposure group received daily exposure starting from gastrulation until hatching, while continuous exposure group received daily exposure from gastrulation until behavioural assessment at 6dpf (days post fertilization). Chronic embryonic exposure to ethanol decreased spontaneous tail coiling at 24hpf (hour post fertilization), heart rate at 48hpf and increased mortality rate at 72hpf. The number of apoptotic cells in the embryos treated with ethanol was significantly increased as compared to the control. We also measured the morphological abnormalities and the most prominent effects can be observed in the treated embryos exposed to 1.50% and 2.00%. The treated embryos showed shorter body length, larger egg yolk, smaller eye diameter and heart edema as compared to the control. Larvae received 0.75% continuous ethanol exposure exhibited decreased swimming activity and increased anxiety related behavior, while withdrawal ethanol exposure showed increased swimming activity and decreased anxiety related behavior as compared to the respective control. Biochemical analysis exhibited that ethanol exposure for both exposure regimens altered proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. Our results indicated that time dependent effect of ethanol exposure during development could target the biochemical processes thus leading to induction of apoptosis and neurobehavioral deficits in the zebrafish larvae. Thus it raised our concern about the safe limit of alcohol consumption for pregnant mother especially during critical periods of vulnerability for developing nervous system