Morphological and Ultrastructural Characteristics of Dumontinia tuberosa (Bull.) L.M. Kohn from Ranunculus ficaria L.

Dumontinia tuberosa fungus was observed in different stages of development growing on the roots of Ranunculus ficaria in Cluj-Napoca (Romania), over the course of several years. It is not frequently encountered, therefore, we decided that will be interesting to cultivate it on nutritive medium, and to use the morphological data and the colony’s characteristics to identify the fungus. The identity of the fungus was reaffirmed through a molecular analysis of sclerotium DNA sequences. A new favourable nutritive medium for the growth and development of the fungus is proposed. The morphology and ultrastructure of the fungus were examined by light and electron microscopy, and micrographs of the relevant details are provided. Differences between the ultrastructural characteristics of sclerotium, apothecium stipe, ascospores, asci and paraphyses are presented and discussed. Intercellular spaces were identified in sclerotium and apothecium stipe and the paraphyses. Asci and ascospores were found to be covered by a sticky mucilage. The ultrastructural characteristics of the aforementioned tissues are presented for different developmental stages. Additionally, the main food stores of the fungus, represented by glycogen, lipids and proteins, are located and described along with other characteristic compounds, such as melanin pigment and a glucan extracellular matrix. The present study complements prior information on the worldwide distribution of this rare species in nature and contributes new findings regarding its morphological and ultrastructural characteristics

Allometric relationships between diaspore morphology and diaspore covering anatomy of herbaceous species from central-eastern Europe

AbstractAnatomical and morphological seed traits are of great ecological importance and are a main subject of, for example, seed bank or endozoochory studies. However, we observed a lack of information about the relationship between seed anatomy and seed morphology and its ecological implications. To fill this gap, we linked the anatomical features of diaspore coverings to morphological characteristics of free seeds and one-seeded fruits. We predicted that: (1) the thickness and anatomical complexity of seed coat and pericarp are related to diaspore size and shape; and (2) the presence or absence of the pericarp may influence seed-coat thickness and anatomy. In our study we investigated diaspores of 39 central-eastern European herbaceous species and recorded the thickness and anatomical complexity of their seed coverings, and we determined diaspore mass and shape. Our results indicate that diaspore mass is positively related to covering thickness, lignification degree and anatomical complexity. This might be the case because bigger diaspores tend to remain on the soil surface and are more exposed to predation risk and environmental threat than smaller diaspores. Furthermore, more round-shaped diaspores had disproportionately thicker and more lignified coverings than long or flat ones, probably because round-shaped diaspores much more frequently form seed banks and therefore persist for a long time in the soil. We also found that free seeds as diaspores have a thicker and more lignified seed coat than seeds enclosed in fruits. In one-seeded fruits, the pericarp ‘takes the protective role’, it is thick, and the seed coat is poorly developed.</jats:p

THE EFFECT OF RADIONUCLIDES AND HEAVY METALS ON THE ULTRASTRUCTURAL FEATURES OF LEAVES IN HELIANTHUS ANNUUS

The ultrastructural features of the leaf in mature plants of Helianthus annuus (during flowering), cultivated in three different areas: in normal culture (Floresti village, Cluj district) and in cultures on sites polluted with heavy metals and radionuclides: (a) near the power station Turceni and (b) on sterile waste dump in the Pedological Research Station of Rovinari (Gorj district), were analyzed. The soil analysis in the three sites showed a higher content in radionuclides and heavy metals, especially on the soil from Turceni, as compared to Control. The ultrastructural analysis pointed out the effect of the presence of high amounts of radionuclides and heavy metals, as well as the plant reaction: the parietal disposition of the heterochromatin in the nucleus in the shape of bodyguard, synthesis and accumulation of some substances (probably with antioxidant or chelating role) in vacuoles, which interacted with exogenous particles, a/

Serological, clinical and epidemiological aspects of Lyme borreliosis in Mures County, Romania

Borrelioza Lyme (BL) este cea mai frecventă infecţie transmisă de căpuşe din genul Ixodes, atât în Statele Unite ale Americii (SUA), cât şi în Europa. Obiectivele studiului au constat în monitorizarea incidenţei şi a manifestărilor clinice ale bolii în judeţul Mureș. Material şi metodă. Studiul s-a efectuat pe o perioadă de 2 ani, 1 ianuarie 2010 - 31 decembrie 2011, pe un număr de 120 pacienţi. Diagnosticul cert sau probabil al BL s-a stabilit pe baza criteriilorCenters for Diseases Control and Prevention (CDC, Atlanta, SUA) şi European Union Concerted Action on Lyme Borreliosis (EUCALB) şi anume epidemiologice, clinice şi serologice. Pentru identificarea anticorpilor antiBb IgM, IgG din ser şi LCR s-au utilizat tehnicile ELISA şi Western-Blot. Rezultate. În anul 2010 s-au înregistrat 44 cazuri, iar în anul 2011, 76 cazuri. Conform definiţiei de caz, 106 cazuri au fost confirmate, 14 probabile. BL a fost evidenţiată cu o frecvenţă mai ridicată la copii, adulţi tineri şi adulţi, comparativ cu grupa de vârstă peste 60 ani. Incidenţa afecţiunii a fost mai ridicată la sexul feminin, 68 pacienţi (56,66%) faţă de sexul masculin 52 pacienţi (43,33%), cu o pondere, mai crescută la persoanele din mediul urban, 78 pacienţi (65,0%), comparativ cu cele din mediul rural 42 pacienţi (35,0%). Manifestările clinice au fost acute de tipul eritemului migrator (EM) la 64,16 din pacienţi, neurologice la 22,50% pacienţi, articulare la 1,66% pacienţi şi cardiace la 0,83% din cazuri. Concluzii. În judetul Mureș s-a constatat o incidenţă în creştere a bolii în anul 2011 comparativ cu anul 2010. Manifestările clinice predominante au fost cele acute dermatologice, neurologice

SPION size dependent effects on normal and cancer cells

Iron oxide nanoparticles have become widely used today in medical applications. In this study, we report a hyperthermia treatment with 10 and 100 nm naked and polyethylene glycol(PEG)-coated Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) to normal and tumor cells in culture. Cells’ responses to nanoparticles were analyzed by cell viability assays (MTT and LDH) and transmission electron microscopy. Results indicate that even if 10 nm SPIONs have good magnetization saturation, the hyperthermia treatment is not effective due to the fact that cells do not endocytose them. 100 nm SPIONs are better engulfed by cells, and their hyperthermia effect is slightly increased. Macavei et al (PDF

Scanning Electron Microscopy and Raman Spectroscopy Characterization of Structural Changes Induced by Thermal Treatment in Innovative Bio-Based Polyamide Nanocomposites

A comprehensive Raman scattering-based characterization of a full bio-based polyamide loaded with graphene nanoplatelets or layered double hydroxides (LDH) was assessed. The potential of the Raman spectroscopy was used to reveal several particularities of the nanocomposite structures induced by thermal treatment. Thus, a complete morpho-structural picture was obtained in combination with scanning electron microscopy (SEM) analysis of the neat polyamide and polyamide nanocomposites exposed at different thermal conditions (room temperature, 80 °C, and 145 °C). The analysis of G, D and 2D Raman peaks and their relative intensity ratio ID/IG, revealed the fact that the presence of graphene in polyamide is suitable for improving the essential physical properties and is also responsible for the decrease in the defects’ occurrence in the graphene layers. The surface of nanocomposites based on full bio-based polyamide, with different 2D fillers (graphenic and non-graphenic structures), was carefully evaluated before and after the thermal treatment by employing SEM and Raman analyses. The two thermal treatments allowed different chain mobility of the polymer (first temperature being over the polymer Tg and second one close to the melting phase in the viscoelastic stage). The spectroscopic and microscopic investigation was used to determine the conformational changes in filler aggregates and polymer surface, respectively

Characterization of defect structures in nanoscaled W-doped TiO2 tested as supercapacitor electrode materials

In this work, Tungsten(W)-doped TiO 2 nanoparticles were synthesized using the sol–gel method and were used as electrode materials in supercapacitor applications. The structural and morphological properties of the prepared samples were analyzed by means of XRD, STEM, TEM, and XPS. The analysis of the defect centers was carried out using EPR spectroscopy. The electrochemical analysis of the assembled supercapacitor was done using cyclic voltammetry, galvanostatic cycling with potential limitation technique, potentiostatic electrochemical impedance spectroscopy, and voltage-holding experiments. All the presented samples showed paramagnetic defects in the EPR analysis, while 0.5% W-doped TiO 2 showed a maximum signal intensity. The supercapacitor performance from the synthesized electrode material showed highly encouraging results. The equivalent series resistance (Rs) value for all the designs showed values under “1 Ω ,” which reflects high conductivity. As the maximum EPR intensity comes from TiO 2 doped with 0.5% W, the supercapacitor performance of this sample was tested with a newly designed five-electrode system. This design showed superior performance compared to any other used designs with a specific capacitance of 25.5 F g- 1, with an energy density of 14.16 Wh kg- 1 at 302 kW kg- 1

Study of the Influence of the Dielectrophoretic Force on the Preferential Growth of Bacterial Biofilms in 3D Printed Microfluidic Devices

Understanding the effect of different electric potentials upon the preferential formation of biofilms inside microfluidic devices could represent a step forward in comprehending the mechanisms that govern biofilm formation and growth. 3D printed microfluidic devices were used to investigate the influence of the dielectrophoretic forces on the formation and growth of Staphylococcus aureus ATCC 25923 biofilms. Bacterial suspensions of 2.5 McF were pushed through microfluidic channels while simultaneously applying various potential differences between 10 and 60 V. The overall electric field distribution within the channel was simulated using the COMOSL software. The effect of the electric potential variation on the preferential biofilm formation was determined using an adjusted microtiter plate technique, as well as a qualitative method, Scanning Electron Microscopy (SEM). SEM images were used to describe the morphology of the biofilm surface. The conclusions show that the dielectrophoretic forces, resulting due to inhomogeneity of the electric field, have more visible effects upon the cells up to 40 V. Above this magnitude, due to a more homogenous distribution of the electric field, the formation and growth of the biofilm become more uniform. At around 60 V, the distance between the high electric gradient regions decreases, leading to an almost uniform distribution of the electric field and, therefore, to a shift from dielectrophoretic to electrophoretic forces acting upon the bacterial cells

In Vivo Distribution of Poly(ethylene glycol) Functionalized Iron Oxide Nanoclusters: An Ultrastructural Study

The in vivo distribution of 50 nm clusters of polyethylene glycol-conjugated superparamagnetic iron oxide nanoparticles (SPIONs-PEG) was conducted in this study. SPIONs-PEG were synthesized de novo, and their structure and paramagnetic behaviors were analyzed by specific methods (TEM, DLS, XRD, VSM). Wistar rats were treated with 10 mg Fe/kg body weight SPIONs-PEG and their organs and blood were examined at two intervals for short-term (15, 30, 60, 180 min) and long-term (6, 12, 24 h) exposure evaluation. Most exposed organs were investigated through light and transmission electron microscopy, and blood and urine samples were examined through fluorescence spectrophotometry. SPIONs-PEG clusters entered the bloodstream after intraperitoneal and intravenous administrations and ended up in the urine, with the highest clearance at 12 h. The skin and spleen were within normal histological parameters, while the liver, kidney, brain, and lungs showed signs of transient local anoxia or other transient pathological affections. This study shows that once internalized, the synthesized SPIONs-PEG disperse well through the bloodstream with minor to nil induced tissue damage, are biocompatible, have good clearance, and are suited for biomedical applications