5 research outputs found
Energy and system size dependence of \phi meson production in Cu+Cu and Au+Au collisions
We study the beam-energy and system-size dependence of \phi meson production
(using the hadronic decay mode \phi -- K+K-) by comparing the new results from
Cu+Cu collisions and previously reported Au+Au collisions at \sqrt{s_NN} = 62.4
and 200 GeV measured in the STAR experiment at RHIC. Data presented are from
mid-rapidity (|y|<0.5) for 0.4 < pT < 5 GeV/c. At a given beam energy, the
transverse momentum distributions for \phi mesons are observed to be similar in
yield and shape for Cu+Cu and Au+Au colliding systems with similar average
numbers of participating nucleons. The \phi meson yields in nucleus-nucleus
collisions, normalised by the average number of participating nucleons, are
found to be enhanced relative to those from p+p collisions with a different
trend compared to strange baryons. The enhancement for \phi mesons is observed
to be higher at \sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations
for the produced \phi(s\bar{s}) mesons clearly suggest that, at these collision
energies, the source of enhancement of strange hadrons is related to the
formation of a dense partonic medium in high energy nucleus-nucleus collisions
and cannot be alone due to canonical suppression of their production in smaller
systems.Comment: 20 pages and 5 figure
Phytochemical characterisation and bioactive properties of Solanum sodomaeum L. fruits at two stages of maturation
Introduction: Solanum sodomaeum L. has been observed to have several medicinal properties, in particular,
in the treatment of several types of human skin cancer.
Objective: The influence of the maturation stage of S. sodomaeum fruits on the total lipid contents, fatty
acid profiles, essential oil yields and compositions, as well as the antibacterial and antioxidant activities of
the essential oils, was investigated.
Methods: The fatty acid and essential oil constituents were identified using gas chromatography (GC) and
GC–mass spectrometry (GC–MS). The antioxidant properties of essential oil and vegetal oil were assessed
using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging and reducing power assays. The antibacterial ac-tivity of essential oil was tested using the disc diffusion assay for resistance in human pathogenic bacteria.
Results: Mature fruits showed higher total lipid content (17%) and were characterised by polyunsaturated
fatty acids (53.87%), represented mainly by linoleic acid (53.11%). Similar yields of essential oils were detected
for immature (0.43%) and mature (0.45%) fruits. Tetrahydronaphthalene (41.79%) was detected as
the major essential oil component at the immature stage versus dihydrocoumarin pentane (18.27%), hexadecanoic
acid (17.43%) and 2-undecanone (13.20%) in mature fruits. The DPPH test showed that essential
oils had better antioxidant properties; however, the vegetal oils showed better performance in the reducing
power assay. Moreover, the essential oil of S. sodomaeum mature fruits was active against bacterial strains.
Conclusions: S. sodomaeum fruits could be a valuable source of natural antioxidants and antibacterial
agents
Phytochemical characterisation and bioactive properties of Solanum sodomaeum
Introduction: Solanum sodomaeum L. has been observed to have several medicinal properties, in particular,
in the treatment of several types of human skin cancer.
Objective: The influence of the maturation stage of S. sodomaeum fruits on the total lipid contents, fatty
acid profiles, essential oil yields and compositions, as well as the antibacterial and antioxidant activities of
the essential oils, was investigated.
Methods: The fatty acid and essential oil constituents were identified using gas chromatography (GC) and
GC–mass spectrometry (GC–MS). The antioxidant properties of essential oil and vegetal oil were assessed
using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging and reducing power assays. The antibacterial ac-tivity of essential oil was tested using the disc diffusion assay for resistance in human pathogenic bacteria.
Results: Mature fruits showed higher total lipid content (17%) and were characterised by polyunsaturated
fatty acids (53.87%), represented mainly by linoleic acid (53.11%). Similar yields of essential oils were detected
for immature (0.43%) and mature (0.45%) fruits. Tetrahydronaphthalene (41.79%) was detected as
the major essential oil component at the immature stage versus dihydrocoumarin pentane (18.27%), hexadecanoic
acid (17.43%) and 2-undecanone (13.20%) in mature fruits. The DPPH test showed that essential
oils had better antioxidant properties; however, the vegetal oils showed better performance in the reducing
power assay. Moreover, the essential oil of S. sodomaeum mature fruits was active against bacterial strains.
Conclusions: S. sodomaeum fruits could be a valuable source of natural antioxidants and antibacterial
agents