854 research outputs found
Take a stand on your decisions, or take a sit: posture does not affect risk preferences in an economic task
Physiological and emotional states can affect our decision-making processes, even when these states are seemingly insignificant to the decision at hand. We examined whether posture and postural threat affect decisions in a non-related economic domain. Healthy young adults made a series of choices between economic lotteries in various conditions, including changes in body posture (sitting vs. standing) and changes in elevation (ground level vs. atop a 0.8-meter-high platform). We compared three metrics between conditions to assess changes in risk-sensitivity: frequency of risky choices, and parameter fits of both utility and probability weighting parameters using cumulative prospect theory. We also measured skin conductance level to evaluate physiological response to the postural threat. Our results demonstrate that body posture does not significantly affect decision making. Secondly, despite increased skin conductance level, economic risk-sensitivity was unaffected by increased threat. Our findings indicate that economic choices are fairly robust to the physiological and emotional changes that result from posture or postural threat
Carum carvi mediated green synthesis of copper nanoparticles and its effect on Solanum lycopersicum seedlings
The present study aims to synthesis the copper nanoparticles (CuNPs) and their effect on the biochemical and physiological characteristics of Solanum lycopersicum. The results exhibited the color change in the Carum carvi aqueous extract from clear deep brown to a greenish color and this observation indicated the green-biosynthesis of CuNPs by reduction of Cu+ to Cu0. Also, the absorbance broadening band for the green-biosynthetic CuNPs appeared at the 340 nm wavelength using UV-Vis but the C. carvi aqueous extract not showed any peaks at this wavelength. SEM analysis exhibited the micrographic surface morphology and the shape of the green-biosynthetic CuNPs with a scan area of 50 ÎŒm and showed the spherical shape particles of CuNPs aggregation. The three-dimensional image and the surface morphology of green-biosynthesized CuNPs and C. carvi aqueous extract were examined using AFM analysis that showed the surface of C. carvi aqueous extract was 45.5 nm size with non-homologus and irregular form of distribution, but the green-biosynthesized CuNPs were 12.4 nm size in nanoscale with regular and homogenous distribution form. The results also showed that the effect of bio-synthesized copper nanoparticles was evident on the S. lycopersicum seedlings fresh and dry weight according to the different reading times after treatment with nanoparticles. Also, the concentration of 2.5 mg/mL (CuNPs) showed a significant increase in the chlorophyll content (58.51 ÎŒg/cmÂČ) on the 21st day after treatment and a significant increase in the activity of peroxidase enzyme (35.12 U min-1 mg-1 protein) was obtained at the concentration of 2.5 mg/mL (CuNPs) at 21st day after germination
Determination of caffeine in roasted and irradiated coffee beans with gamma rays by high performance liquid chromatography
The present study was carried out to investigate a simple, quick and organic solvent saving procedure for the high performance liquid chromatography determination of caffeine in two different coffee beans (Indonesian and Brazilian) which roasted at two different temperatures (150 & 220 ÂșC) and irradiated at 3, 6, and 9 kGy doses by gamma rays. A linear calibration curve was generated with caffeine concentration ranging from 0.005 to 0.25 mg/g with correlation coefficient (R2= 0.9995, n=4) and relative standard deviation ? 2.1 %. The developed procedure provided a 7.3 x 10-9 mg/g and 2.2 x 10-8 mg/g limit of detection and limit of quantification, respectively. The developed method was repeatable and could be applied to determine trace amounts of caffeine in popular irradiated coffee beans with three different irradiation doses. Moreover, irradiation treatments at doses up to 9 kGy showed no significant effect on the caffeine content. Keywords: Caffeine determination; High performance liquid chromatography;Â Coffee bean; Roasting; Gamma rays; Statistical analysi
PVA/Chitosan/Silver Nanoparticles Electrospun Nanocomposites: Molecular Relaxations Investigated by Modern Broadband Dielectric Spectroscopy
In this study, we used broadband dielectric spectroscopy to analyze polymer nanofibers of poly(vinyl alcohol)/chitosan/silver nanoparticles. We also studied the effect of incorporating silver nanoparticles in the polymeric mat, on the chain motion dynamics and their interactions with chitosan nanofibers, and we calculated the activation energies of the sub-Tg relaxation processes. Results revealed the existence of two sub-Tg relaxations, the first gets activated at very low temperature (â90 °C) and accounts for motions of the side groups within the repeating unit such as âNH2, âOH, and âCH2OH in chitosan and poly(vinyl alcohol). The second process gets activated around â10 °C and it is thought to be related to the local main chain segmentsâ motions that are facilitated by fluctuations within the glycosidic bonds of chitosan. The activation energy for the chitosan/PVA/AgNPs nanocomposite nanofibers is much higher than that of the chitosan control film due to the presence of strong interactions between the amine groups and the silver nanoparticles. KramersâKrönig integral transformation of the ΔâČâČ vs. f spectra in the region of the chitosan Tg helped resolve this relaxation and displayed the progress of its maxima with increasing temperature in the regular manner
Developing a Thermally Stable Ester-Based Drilling Fluid for Offshore Drilling Operations by Using Aluminum Oxide Nanorods
Funding: This work was supported by an Institutional Links grant, ID 352343681, under the NewtonâMosharafa Fund partnership. The grant is funded by the UK Department for Business, Energy and Industrial Strategy, and Science, Technology & Innovation Funding Authority (STDF) and delivered by the British Council. For further information, please visit www.newtonfund.ac.uk. Science, Technology & Innovation Funding Authority (STDF) support was under the grant No. (30894). Acknowledgments: The authors would like to acknowledge the School of Engineering at the University of Aberdeen for providing the required facilities to complete this research. In addition, the authors would like to thank the support from MI-SWACO in providing commercial emulsifiers and consumables used in this project.Peer reviewedPublisher PD
Histological and Morphometrical Studies on the Ampulla of the Deferent Duct of Donkey (Equus Asinus) in Different Seasons
The objective of this study is to describe the histological and histochemical structure of the ampulla ductus defrentis during different seasons of the year. The experiment was carried out on the ampulla of the deferent duct of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. Both the lamina epithelialis and the epithelium lining the ampullary glands of the donkey showed highly significant (P < 0.01) seasonal variations. The interstitial tissue/ glandular tissue ratio of the ampullary glands showed as seasonal variations. The glandular epithelium of the ampullary glands of donkey had strong PAS positive reaction. This reaction decreased gradually during summer and autumn to reach its minimal amount during winter. In conclusions, the ampullary glands of donkey appeared more active during spring and this activity decreased gradually during the summer and autumn to reach it lowest activity during winter
Histological and Histochemical Studies on the Ampulla of the Deferent Duct of Donkey (Equus asinus)
The present study was performed on the ampulla of the deferent duct of 24 sexually mature apparently healthy male donkeys (5 to 7 years) distributed over the four seasons of the year. The ampullary glands were branched tubulo-alveolar in type which they were opened in a central lumen. The luminal and the glandular epithelium were formed of principal and basal cells. Singly scattered rod- shaped cells were observed among the principal cells. PAS positive reactivity was observed in the surface and the glandular epithelium of the ampulla ductus deferentis. Only the luminal contents and the secretory materials attached to the apical border of the principal cells, showed positive reactivity for alcian blue. The present study presents the first description of the ampulla ductus deferentis of donkey. In addition to, it acts as a reservoir for sperms it had a secretory function for neutral and acid mucopolysaccharid
DEVELOPMENT AND IN VITRO EVALUATION OF MUCOADHESIVE BILAYER BUCCAL TABLETS OF CARVEDILOL
Objectives: Carvedilol (CVD) is a nonselective ĂÂČ-adrenergic blocker that suffers from low absolute bioavailability (25-35%) due to first-pass metabolism. CVD-loaded buccal tablets were developed as a promising approach to overcome this limitation.Methods: The bilayers tablets were prepared by the direct compression technique. CVD-containing layer was based on one of four high molecular weight polymers; hydroxy propyl methylcellulose K15M (HPMC), Polyethylene oxide WSR N-750 (PEO), chitosan (CH) and EudragitĂŸàRS-100 (EUD). An occlusive backing of ethylcellulose 20 (EthocelĂÂź) was adopted as a second layer. The tablets were characterized for weight variation, thickness, friability % and drug content. Further studies were conducted to evaluate their swelling indices, surface pH, in vitro adhesion retention periods and in vitro drug release profiles.Results: The prepared tablets followed the compendial requirements for thickness, friability %, drug content and weight variation. The surface pH of all tablets ranged from 6.43 to 7.44 while their adhesion retention periods varied from 3.12 to 4.24 h. The best achieved system (PEO-based matrix; F4) displayed a reasonable adhesion retention period and a promising sustained drug release profile, over at least 8 hours, following non-fickian diffusion kinetics. This could indicate the contribution of swelling and erosion mechanisms for drug release.Conclusions: The current work succeeded in developing and evaluation of promising mucoadhesive CVD matrices suitable for buccal administration. Further pharmacokinetic and clinical studies are suggested to confirm the ability of the best achieved system to avoid the first pass metabolism of CVD and improve patient compliance.Ă
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