Gold nanoelectrodes of varied size: transition to molecule-like charging

A transition from metal-like double-layer capacitive charging to redox-like charging was observed in electrochemical ensemble Coulomb staircase experiments on solutions of gold nanoparticles of varied core size. The monodisperse gold nanoparticles are stabilized by short-chain alkanethiolate monolayers and have 8 to 38 kilodaltons core mass (1.1 to 1.9 nanometers in diameter). Larger cores display Coulomb staircase responses consistent with double-layer charging of metal-electrolyte interfaces, whereas smaller core nanoparticles exhibit redox chemical character, including a large central gap. The change in behavior is consistent with new near-infrared spectroscopic data showing an emerging gap between the highest occupied and lowest unoccupied orbitals of 0.4 to 0.9 electron volt.     

Essential oil of Aloysia triphylla in Nile tilapia: anaesthesia,stress parameters and sensory evaluation of fillets

The optimum concentration of anaesthetic used to facilitate fish handling can be determined based on induction and recovery time, among other factors. This study aimed to evaluate the effectiveness of the essential oil of Aloysia triphylla (EOAT) as an anaesthetic in the handling of Nile tilapia juveniles. Nile tilapias exemplars were immersed at 0 (control group), 10, 20, 30, 40, 80, 150, 300 and 450 μL L^?1 EOAT to evaluate sedation, anaesthesia and recovery time. The stress response was evaluated by the determination of plasma glucose, cortisol, lactate and paraoxonase levels in anaesthetized (300 μL L^?1 EOAT) and non‐anaesthetized fish. Fillets from both groups were evaluated for organoleptic characteristics (taste and odour). Concentrations of 80–450 μL L^?1 EOAT were effective in inducing anaesthesia. There was a significant reduction in plasma cortisol levels one hour after handling in individuals anaesthetized with 300 μL L^?1 EOAT compared to the control group. Tasters did not detect differences in fillet taste and odour between fish exposed and not exposed to EOAT. A concentration of 300 μL L^?1 EOAT is recommended for handling Nile tilapia because it presents good anaesthetic induction and recovery times, causes a reduction in plasma cortisol levels one hour after handling and does not affect the taste or odour of the fillets.     

Oued Bouhlou: A new hope for the Moroccan pearl mussel

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Identification and genetic relationship based on ISSR analysis in a germplasm collection of sea buckthorn (Hippophae L.) from China and other countries

Sea buckthorn (Hippophae L.) is a woody, outcrossing dioecious pioneer plant, being widely planted as a new berry crop with rich nutritional and medicinal compounds, as well as a means of prevention of soil erosion. Inter simple sequence repeat (ISSR) markers were generated in 219 plants of 40 cultivars from China and other countries, representing two species of Hippophae salicifolia and Hippophae rhamnoides that includes two subspecies (ssp. mongolica and ssp. rhamnoides) and intraspecific hybrids between ssp. mongolica and ssp. sinensis. Fifteen selected ISSR primers generated 385 bands with an average of 25.6 bands per primer. Thirty hundred and eighty-five bands were used to generate a Dice's coefficient matrix of pairwise comparisons between individual ISSR profiles. Cluster analysis based on this matrix showed clustering of plants into groups which was in good agreement with their taxonomic classification. The results also revealed the presence of different cultivars with the same name, identical cultivars but with a different name and the genetic relationship of cultivars with unknown parentage to those with known parentage. Our data will be helpful in collection and conservation of sea buckthorn germplasm and potential hybrid strategy for breeding.