Transient increase in IL-1ß, IL-6 and TNF-α gene expression in rat liver exposed to gold nanoparticles.

Most studies have used in vitro systems to test inflammatory responses of nanoparticles; these may not reflect the real biological response of body organs. In fact, certain nanoparticles have provoked opposite effects under in vitro and in vivo conditions. Current understanding of the biocompatibility of gold nanoparticles is controversial. We studied the acute (1 day) and sub-chronic (5 days) effects of gold nanoparticles (10 and 50 nm in diameter) on expression of interleukin-1 beta (IL-1ß), IL-6 and tumor necrosis factor alpha (TNF-α) in rat liver. Real-time PCR analysis showed that gold nanoparticles of both sizes significantly increased cytokine gene expression on day 1; this had subsided by day 5. The 50-nm gold nanoparticle produced more severe inflammation than the smaller gold nanoparticle. These findings indicate a possible biocompatibility of medium-sized gold nanoparticles, as they caused only a transient increase in proinflammatory cytokines, followed by normalization during sub-chronic repeated exposure.

Effect of intensity of eggshell pigment and illuminated incubation on hatchability of brown eggs.

The effects of intensity of brown eggshell pigment (light (LBP), medium (MBP) and dark (DBP)) and light intensity during incubation (low and high, 900 to 1380 and 1430 to 2080 lux, respectively) on eggshell characteristics, embryonic growth, hatchability traits, chick hatching weight and hatching time were investigated using eggs from a meat-type breeder (Hybro) flock at 32, 36 and 41 weeks of age in three trials. With eggs of similar weights the intensity of brown pigment was not associated with eggshell weight and thickness, and did not influence embryo weight and egg weight loss during incubation. The shade of brown pigment of eggs laid by young hens influenced the percentage hatchability (HP) of eggs incubated under light. Illuminated incubation improved HP of LBP eggs (compared with MBP and DBP eggs) from 32- and 36-week-old hens, but had no significant effect on HP of eggs from 41-week-old hens. Light intensity during incubation did not influence egg weight loss. High intensity of light during incubation reduced HP and increased early death percentage (EDP) in the LBP and MBP groups, and did not influence HP and EDP in the DBP group. Brown eggshell pigment and intensity of light during incubation did not influence hatching time. It is concluded that the shade of brown pigment, intensity of light during incubation and age of the breeder hens influenced the hatchability performance of embryos from brown eggs. Light during incubation improved the hatchability of embryos in light brown eggs laid by young hens and the shade of brown pigment of eggs laid by older hens did not influence hatchability under illuminated incubation. High intensity of light during incubation reduced hatchability of light and medium brown eggs, but not the dark brown eggs.

Long-term monitoring and analysis of hourly solar UV radiation in the 290-380 nm range in the middle region of Saudi Arabia.

The UV and global solar radiation on a horizontal surface at ground level in Riyadh City (latitude 24 degrees 34' N, longitude 46 degrees 43' E) have been measured and analyzed. Measurements of UV radiation (295-385 nm) were recorded every 10 min for five years (January 1983-December 1987). The maximum recorded hourly mean irradiance UV radiation was 28 W/m2 and occurred in July, while the minimum was 14 W/m2 in December. A steady monthly value of [formula: see text] was obtained and equaled 2.9%. A similar trend was found for the monthly variation of [formula: see text] and [formula: see text]. Maximum values of 90% and 2.6% were recorded in June for Kt and Kv, respectively, while minimum values of 35% and 1%, respectively, were obtained in December. A linear correlation was obtained between Kv and Kt. These findings were discussed and connected to the meteorological events. The results were compared with the regions of Kuwait, Bahrain, Dhahran, and Makkah.