1,720,992 research outputs found
Analisi citomorfologiche e chimiche di fronde di Pteris vittata cresciute in un sito contaminato da arsenico
No full textHydathode structure and localization in Pteris vittata fronds and evidence for their involvement in arsenic leaching
No full textRemediation of an As polluted site in the North of Italy, using the fern Pteris vittata: a pilot study
No full textEpoxy resins composites for X-ray shielding materials additivated by coated barium sulfate with improved dispersibility
No full textEpoxy resins additivated by barium sulfate proved to be promising low cost, easy workable and environmentally
friendly alternative to lead and steel as X-ray shielding materials, but the composites tends to be stratified, with
the additive accumulating in the bottom side of the sample. This sedimentation process has been, at first, studied
by in situ X-ray powder diffraction, thermogravimetric techniques and X-ray tomography and then inhibited by
exploiting finer barite sources, implementing a grinding procedure, combined to a surface modification of the
inorganic additives. Stearic acid and sodium dodecyl sulfate were used to coat barite surface, using a liquid
assisted grinding (LAG) approach. The functionalized additives resulted more compatible with the resin and their
dispersion within the polymer resulted much improved. The produced composite samples were then studied by
optical and electron microscopy, X-ray radiography, X-ray diffraction, thermogravimetric analysis and tensile
strength test. The use of a finer additive and the grinding procedure allowed to limit the sedimentation and
induced a marked hardening of the samples, with the drawback of a reduction of their plasticity. Stearic acid
coating was able to eliminate sedimentation maintaining good mechanical properties
Palladium uptake by Pisum sativum: partitioning and effects on growth and reproduction
No full textEnvironmental palladium levels are increasing because of anthropogenic activities. The considerable mobility of the metal, due to solubilisation phenomena, and its known bioavailability may indicate interactions with higher organisms. The aim of the study was to determine the Pd uptake and distribution in the various organs of the higher plant Pisum sativum and the metal-induced effects on its growth and reproduction. P. sativum was grown in vermiculite with a modified Hoagland's solution of nutrients in the presence of Pd at concentrations ranging 0.10-25 mg/L. After 8-10 weeks in a controlled environment room, plants were harvested and dissected to isolate the roots, stems, leaves, pods and peas. The samples were analysed for Pd content using AAS and SEM-EDX. P. sativum absorbed Pd, supplied as K2PdCl4, beginning at seed germination and continuing throughout its life. Minimal doses (0.10-1.0 mg Pd/L) severely inhibited pea reproductive processes while showing a peculiar hormetic effect on root development. Pd concentrations ≥1 mg/L induced developmental delay, with late growth resumption, increased leaf biomass (up to 25 %) and a 15-20 % reduction of root mass. Unsuccessful repeated blossoming efforts led to misshapen pods and no seed production. Photosynthesis was also disrupted. The absorbed Pd (ca. 0.5 % of the supplied metal) was primarily fixed in the root, specifically in the cortex, reaching concentrations up to 200 μg/g. The metal moved through the stem (up to 1 μg/g) to the leaves (2 μg/g) and pods (0.3 μg/g). The presence of Pd in the pea fruits, together with established evidence of environmental Pd accumulation and bioavailability, suggests possible contamination of food plants and propagation in the food chain and must be the cause for concern
Use of arbuscular mycorrhizal fungi to improve the performance of the fern Pteris vittata in the phytoremediation of highly arsenic polluted sites: from the molecular level to the in field experiments.
No full textSensitivity of Candida albicans to essential oils: are they an alternative to antifungal agents?
No full textAims: Candida albicans is an important opportunistic pathogen, responsible for the majority of yeast infections in humans. Essential oils, extracted from aromatic plants, are well-known antimicrobial agents, characterized by a broad spectrum of activities, including antifungal properties. The aim of this work was to assess the sensitivity of 30 different vaginal isolated strains of C. albicans to 12 essential oils, compared to the three main used drugs (clotrimazole, fluconazole and itraconazole).
Methods and results: Thirty strains of C. albicans were isolated from vaginal swab on CHROMagarTM Candida. The agar disc diffusion method was employed to determine the sensitivity to the essential oils. The antifungal activity of the essential oils and antifungal drugs (clotrimazole, itraconazole and fluconazole) were investigated using a microdilution method. Transmission and scanning electron microscopy analyses were performed to get a deep inside on cellular damages. Mint, basil, lavender, tea tree oil, winter savory and oregano essential oils inhibited both the growth and the activity of C. albicans more efficiently than clotrimazole. Damages induced by essential oils at the cellular level were stronger than those caused by clotrimazole.
Conclusions: Candida albicans is more sensitive to different essential oils compared to the main used drugs. Moreover, the essential oil affected mainly the cell wall and the membranes of the yeast.
Significance and impact of the study: The results of this work support the research for new alternatives or complementary therapies against vaginal candidiasis
Caratterizzazione molecolare di due arsenato reduttasi in Pteris vittata, una felce che iperaccumula arsenico
No full textIn vitro activity of twelve essential oils against clinical skin isolates Staphylococcus aureus
No full text- …
