88 research outputs found
Structure and thermal behaviour of dichlorobis(thiourea)cadmium(ii), a single-source precursor for CdS thin films
The title compound (1) crystallites in the space group Pmn2(1) with a =
13.110 (3), b = 5.813(1) and c = 6.482(1) Angstrom. Its crystal
structure was redetermined from three-dimensional single-crystal data
to a final R-value of 0.0221. The Cd2+ ion is tetrahedrally coordinated
to two sulfur atoms from the tiourea ligand (Cd-S = 2.509 Angstrom) and
to two chloride ions at distances 2.545 and 2.518 Angstrom. When heated
in air or in an inert atmosphere 1 undergoes a complex degradation
process which was studied in situ by simultaneous TG/DTA as well as by
EGA-FTIR. The gaseous species evolved include NH3, HCl, H2NCN, HNCS and
CS2, which upon oxidation yield also HCN, SO2, COS and CO2. In the
solid residue, NH4CdCl3 and CdS were detected by X-ray diffraction,
Elemental and XPS analyses also indicated the presence of Cl and N as
well as some carbon residue. The results of the thermoanalytical study
are not directly applicable to the spray pyrolysis process because of
the different experimental conditions, but they nevertheless indicate
that it is extremely difficult to prepare impurity-free CdS. The
formation of HCN, not detected earlier, should also be taken into
account when designing the process parameters and safety measures
Neural Cell Response to Nanostructured Biosensor Surfaces
AbstractIn our work we investigate the interaction of cells and nanotextured surfaces as a model of implanted device surface and living tissue interaction. We developed a maskless nanostructuring method, which can be integrated into our neural biosensor fabrication process. Morphology of the fabricated nanograss was characterised using SEM. The nanorods are 520-800nm in height and their density is 18-70/ÎŒm2. Electrochemical impedance spectroscopy and contact angles of different surfaces were measured. The specific surface area is 30 times larger than the reference. The contact-angle can be tuned. The samples will be tested in viability and adhesion assays using neural cell cultures
Isolation of Radial Glia-Like Neural Stem Cells from Fetal and Adult Mouse Forebrain via Selective Adhesion to a Novel Adhesive Peptide-Conjugate
Preferential adhesion of neural stem cells to surfaces covered with a novel synthetic adhesive polypeptide (AK-cyclo[RGDfC]) provided a unique, rapid procedure for isolating radial glia-like cells from both fetal and adult rodent brain. Radial glia-like (RGl) neural stem/progenitor cells grew readily on the peptide-covered surfaces under serum-free culture conditions in the presence of EGF as the only growth factor supplement. Proliferating cells derived either from fetal (E 14.5) forebrain or from different regions of the adult brain maintained several radial glia-specific features including nestin, RC2 immunoreactivity and Pax6, Sox2, Blbp, Glast gene expression. Proliferating RGl cells were obtained also from non-neurogenic zones including the parenchyma of the adult cerebral cortex and dorsal midbrain. Continuous proliferation allowed isolating one-cell derived clones of radial glia-like cells. All clones generated neurons, astrocytes and oligodendrocytes under appropriate inducing conditions. Electrophysiological characterization indicated that passive conductance with large delayed rectifying potassium current might be a uniform feature of non-induced radial glia-like cells. Upon induction, all clones gave rise to GABAergic neurons. Significant differences were found, however, among the clones in the generation of glutamatergic an
Environmental and Toxicological Impacts of Glyphosate with Its Formulating Adjuvant
Environmental and toxicological characteristics of formulated pesticides may substantially differ from those of their active ingredients or other components alone. This phenomenon is demonstrated in the case of the herbicide active ingredient glyphosate. Due to its extensive application, this active ingredient was found in surface and ground water samples collected in BĂ©kĂ©s Country, Hungary, in the concentration range of 0.54â0.98 ng/ml. The occurrence of glyphosate appeared to be somewhat higher at areas under intensive agriculture, industrial activities and public road services, but the compound was detected at areas under organic (ecological) farming or natural grasslands, indicating environmental mobility. Increased toxicity of the formulated herbicide product Roundup compared to that of glyphosate was observed on the indicator aquatic organism Daphnia magna Straus. Acute LC50 values of Roundup and its formulating adjuvant polyethoxylated tallowamine (POEA) exceeded 20 and 3.1 mg/ml, respectively, while that of glyphosate (as isopropyl salt) was found to be substantially lower (690-900 mg/ml) showing good agreement with literature data. Cytotoxicity of Roundup, POEA and glyphosate has been determined on the neuroectodermal cell line, NE-4C measured both by cell viability test and holographic microscopy. Acute toxicity (LC50) of Roundup, POEA and glyphosate on NE-4C cells was found to be 0.013±0.002%, 0.017±0.009% and 6.46±2.25%, respectively (in equivalents of diluted Roundup solution), corresponding to 0.022±0.003 and 53.1±18.5 mg/ml for POEA and glyphosate, respectively, indicating no statistical difference between Roundup and POEA and 2.5 orders of magnitude difference between these and glyphosate. The same order of cellular toxicity seen in average cell area has been indicated under quantitative cell visualization. The results indicate that toxicity of the formulated herbicide is caused by the formulating agent, but in some parameters toxicological synergy occurs between POEA and glyphosate
Exponential Distribution of Locomotion Activity in Cell Cultures
In vitro velocities of several cell types have been measured using computer
controlled video microscopy, which allowed to record the cells' trajectories
over several days. On the basis of our large data sets we show that the
locomotion activity displays a universal exponential distribution. Thus, motion
resulting from complex cellular processes can be well described by an
unexpected, but very simple distribution function. A simple phenomenological
model based on the interaction of various cellular processes and finite ATP
production rate is proposed to explain these experimental results.Comment: 4 pages, 3 figure
No faster-than-light observers (GenRel)
We have previously verified, in the first order theory SpecRel of Special Relativity, that inertial observers cannot travel faster than light. We now prove the corresponding result for GenRel, the first-order theory of General Relativity. Specifically, we prove that whenever an observer m encounters another observer k (so that m and k are both present at some spacetime location x), k will necessarily be observed by m to be traveling at less than light speed
Atomic Force Microscopy of height fluctuations of fibroblast cells
We investigated the nanometer scale height fluctuations of 3T3 fibroblast
cells with the atomic force microscope (AFM) under physiological conditions.
Correlation between these fluctuations and lateral cellular motility can be
observed. Fluctuations measured on leading edges appear to be predominantly
related to actin polymerization-depolymerization processes. We found fast (5
Hz) pulsatory behavior with 1--2 nm amplitude on a cell with low motility
showing emphasized structure of stress fibres. Myosin driven contractions of
stress fibres are thought to induce this pulsation.Comment: 6 pages, 5 figures, 1 tabl
Correction to: How will a drier climate change carbon sequestration in soils of the deciduous forests of Central Europe?
The initial online publication contained a typesetting mistake in the author information. The original article has been corrected
Deviations in Circulating TNF α
Objectives. Tumor necrosis factor alpha (TNFα) plays a pivotal role in the inflammatory host response. The serum-level of TNFα and the production of TNFα by lympho/monocytes, however, seem to show high individual variations. The goal of the present study was to investigate the variations and inducibility of TNFα-activity in two age-groups of healthy volunteers. Methods. Sixty elderly, healthy volunteers were studied. These persons were free of malignant diseases, and within three months, they did not have any trauma or inflammatory disease and were not taking any steroids or nonsteroid anti-inflammatory drugs. Thirty young volunteers were also included. Blood samples were taken; lympho/monocytes were separated and cultured with or without endotoxin (LPS) stimulation. Serum and culture supernatant TNFα levels were determined by bioassay using WEHI 164 cells. Results. The results indicated significant individual variations in TNFα levels of healthy volunteers irrespective of age. Subgroups with low, middle, and high serum TNF-levels were distinguished. In about 50% of volunteers with low serum-TNFα activity, LPS stimulation failed to increase the TNFα production by isolated lympho/monocytes. Conclusion. Our data suggest a chance to select individuals with enhanced sensitivity for septic complications
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