Morphological Research on Indigenous Sambucus Species Pollen

The pollen grains have a definite shape, size, colour, structure for each species, genus and family and these characters are useful for systematical botany. The pollen has nutritive properties due to its content: proteins, lipids, carbohydrates, vitamins, hormones and minerals. In the Romanian flora vegetate three species of Sambucus, but only S. nigra L. (elder or black elder) supplies a vegetal medical product, Sambuci flos or elder flowers, whereas the others species S. ebulus L. (dwarf elder) and S. racemosa L. (mountain elder or red elder) are considered adulterations. The pollen of Sambucus species were already studied using optical microscopy (Tarnavschi et al.), but the images are in one single layout, therefore the structure details cannot be easily notice. In this context the pollen grains of the three species already mentioned above were studied by SEM (Scanning Electron Microscopy). The results demonstrated that this pollen have a small-middle size, oblat-sphaeroidal-prolat shape, threecolpat and the exine adornments are of reticulate type, haemitectate with sticks in the meshs of polygonale net. The flavonoids content is lower than in others species (0.146-0.564 %). The SEM analyse of Sambucus pollen allow a reliable identification of the genus but less for the species

Porous chalcogenide based on zinc sulfide with enhanced adsorption properties

We report the preparation of porous zinc indium sulfide (ZIS) with high ability to adsorb organic dyes such as methyl orange (MO). The influence of reaction temperature and zinc concentration on the morpho-structural characteristics of ZIS were investigated

Ultrastructure and Development of Anthracoidea Elynae Ustilospores

The aim of the study was to examine the ultrastructure of Anthracoidea elynae ustilospores isolated from Kobresia myosuroides (Vill.) Fiori plant ovaries, harvested in the Bucegi Mountains, Romania. Samples examination was performed using scanning (SEM) and transmission (TEM) electron microscopy. The results showed that A. elynae ustilospores had a dynamic ultrastructure, because their three-layered cell wall, nucleus shape, lipid and glycogen accumulations in the cytoplasm changed at each developmental stage. In conclusion, according to the ultrastructural changes, A. elynae ustilospores development may be divided into three stages

Roman Republican coarse ware from Norba, Southern Lazio (Italy):a multi‑analytical study of production technology and trade

The first objective of this paper is to reconstruct the production technology of fourth–first centuries BCE coarse ware from surveys near the ancient town of Norba in the Lepini Mountains of Southern Lazio, Italy, adopting a multi-analytical method, combining macroscopic observation with polarised light optical microscopy (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The second objective of this study is to gain insight into Norba’s integration in broader production and distribution networks in Southern Lazio between the fourth–first centuries BCE, by comparing the results with previous data for coarse ware prevalent in the region at that time. The results indicate that the coarse ware from Norba was produced with Fe-rich, Ca-poor, and illite-muscovite clays and fired in an oxidising atmosphere between 750 and 900 °C. Differences among the coarse ware exist in the paste recipes, e.g. intentionally added temper. Most coarse ware from Norba bears compositional similarities to that from the Alban Hills and the Tiber Valley, north of Rome, suggesting that Norba was integrated into the marketing of pottery that was common in Southern Lazio during the fourth–first centuries BCE. In comparison, only a few coarse wares seem to have been produced in the surrounding area (e.g. Satricum and Forum Appii), or even locally in Norba. The results further indicate changes in these regional/local distribution networks; some coarse ware seems to have been imported from Satricum, where a workshop was active during the fourth century BCE. When ceramic production at Satricum ceased, potters settled in the towns of Forum Appii and Norba, where they produced ceramic building material and fine ware in the second–first centuries BCE, respectively. The results of this study tentatively suggest that potters in these locations may have also manufactured coarse ware during this period

Influence of heavy metal ions on the luminescence of zinc oxide-based compounds

Luminescent zinc hydroxide (ZH) and zinc carbonate (ZHC) compounds were prepared by precipitation with different precipitating agents. The effect of various heavy metal ions on the optical properties of samples was discussed

Dynamics of semi-flexible polymer solutions in the highly entangled regime

We present experimental evidence that the effective medium approximation (EMA), developed by D.C. Morse [Phys. Rev. E {\bf 63}, 031502, (2001)], provides the correct scaling law of the macroscopic plateau modulus $G^{0}\propto\rho^{4/3}L^{-1/3}_{p}$ (where $\rho$ is the contour length per unit volume and $L_{p}$ is the persistence length) of semi-flexible polymer solutions, in the highly entangled concentration regime. Competing theories, including a self-consistent binary collision approximation (BCA), have instead predicted $G^{0}\propto\rho^{7/5}L^{-1/5}_{p}$. We have tested both the EMA and BCA scaling predictions using actin filament (F-actin) solutions which permit experimental control of $L_p$ independently of other parameters. A combination of passive video particle tracking microrheology and dynamic light scattering yields independent measurements of the elastic modulus $G$ and $L_{p}$ respectively. Thus we can distinguish between the two proposed laws, in contrast to previous experimental studies, which focus on the (less discriminating) concentration functionality of $G$.Comment: 4 pages, 6 figures, Phys. Rev. Lett. (accepted

Tracking soil particle deposition using bio-indication evidence and nondestructive FESEM and EDS analyses: A preliminary (pilot) study

The present study present chemometric bioindication methodology for fast and effective monitoring in long distant distribution of top soil pollution and evidence for element soil dust deposition. Both varieties of Briophytes, Hypnum cupressiforme (Hedw.) and Homalothecium lutescens (Hedw.) has been used for improving the effective nondestructive bio-indication. Although mosses do not have a root system, influence from soil dusting cannot be disregarded, in praticular in areas with windblown mineral dust from local soil. As far as the surface bound fraction is concerned, little is known about the binding mechanisms, but the fact that different metals show rather large differences in their retention capacities, indicates that both simple cation exchange on negative surface charges and complex formation with ligands on the moss surface are involved. Laboratory analysis, using field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectrometer (EDS) has been involved for determination of the dry deposition occurred within moss biomonitors. The bioindication chemometric model was improved for nondestuctive evidence effectively for biogenic elements carbon and oxygen, macroelements Mg, Al, Si, K, Ca, and microelements Fe, Cu and Zn. Both moss species can be used interchangeable for dust deposition investigation

A characterization of four B16 murine melanoma cell sublines molecular fingerprint and proliferation behavior

Background: One of the most popular and versatile model of murine melanoma is by inoculating B16 cells in the syngeneic C57BL6J mouse strain. A characterization of different B16 modified cell sub-lines will be of real practical interest. For this aim, modern analytical tools like surface enhanced Raman spectroscopy/scattering (SERS) and MTT were employed to characterize both chemical composition and proliferation behavior of the selected cells. Methods: High quality SERS signal was recorded from each of the four types of B16 cell sub-lines: B164A5, B16GMCSF, B16FLT3, B16F10, in order to observe the differences between a parent cell line (B164A5) and other derived B16 cell sub-lines. Cells were incubated with silver nanoparticles of 50–100 nm diameter and the nanoparticles uptake inside the cells cytoplasm was proved by transmission electron microscopy (TEM) investigations. In order to characterize proliferation, growth curves of the four B16 cell lines, using different cell numbers and FCS concentration were obtained employing the MTT proliferation assay. For correlations doubling time were calculated. Results: SERS bands allowed the identification inside the cells of the main bio-molecular components such as: proteins, nucleic acids, and lipids. An "on and off" SERS effect was constantly present, which may be explained in terms of the employed laser power, as well as the possible different orientations of the adsorbed species in the cells in respect to the Ag nanoparticles. MTT results showed that among the four tested cell sub-lines B16 F10 is the most proliferative and B164A5 has the lower growth capacity. Regarding B16FLT3 cells and B16GMCSF cells, they present proliferation ability in between with slight slower potency for B16GMCSF cells. Conclusion: Molecular fingerprint and proliferation behavior of four B16 melanoma cell sub-lines were elucidated by associating SERS investigations with MTT proliferation assay

Copper-releasing, borate-based glasses with antibacterial properties: synthesis and in vitro characterization

In this study, glasses within the system (60-x) B2O3⋅x ZnO⋅34CaO⋅1CuO, with x=5, 10, 15, 20, 25 mol% and with B2O3/ZnO ratios 11; 5; 3; 2; 1.4 have been synthesized and characterized in vitro. After being immersed in simulated body fluid (SBF) and saline solution, weight loss reduction and pH measurments, followed by inductively coupled plasma optical emission spectometry (ICP-OES), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed, in order to evaluate the changes in glass morphology. In vitro biodegradation and surface reaction were observed in all of the glasses, especially in the x=10, 15, 20 samples. SEM and XRD results revealed the presence of a hydrotalcite-like structure (double layered hydroxid) at the aqueous solution-glass surface interface, while Cu, Zn, Ca and B ions, with proangiogenic properties, were detected in the immersion fluid

Percolation Behavior of Electrically Conductive Graphene Nanoplatelets/Polymer Nanocomposites: Theory and Experiment

<div><p>Percolation behavior of graphene nanoplatelet (GNP) filled electrically conductive nanocomposites of polymers was studied theoretically and experimentally. A modified power law based percolation theory was formulated to include particulate geometry and temperature dependence. Pristine and vinyl acetate/butyl acrylate functionalized GNPs were synthesized for further usage in preparation of poly(methyl methacrylate) (PMMA) nanocomposites via in situ polymerization. Structural characterization of the samples showed their unique quality. Best values of percolation threshold and maximum conductivity were found to be 0.3 vol.% and 10⁻¹ S/cm, respectively. Modified power law allowing one to predict the percolation by knowing only aspect ratio of GNPs was successfully described our graphene-polymer model system as well as wide range of literature collected data. Our results could serve as a design tool in graphite nanofiller based conductive composites.</p> </div