Analysis of heavy metal pollution in soil using transversely excited atmospheric CO2 laser-induced plasma by trapping the soil in microstructured holes on metal subtargets

A unique technique for direct analysis of soil samples utilizing a special advantage of a transversely excited atmospheric (TEA) CO(2) laser-induced plasma generated at atmospheric pressure on a metal target has been developed. In this technique, a metal subtarget, such as nickel plate, structured with intentional microholes on its surface, each with dimensions of around 100 microm in diameter and depth, was used to selectively trap small sized soil particles by immersing the metal plate subtarget into the polluted soil sample. The trapped small soil particles on the metal subtarget were irradiated by a TEA CO(2) laser (10.6 microm, 1.5 J, 200 ns) at atmospheric pressure under defocused condition with a spot size of 3 mm x 3 mm. This trapping and confining scheme substantially suppresses the blowing off effect; thus, the trapped soil particles can effectively be dissociated and atomized in the microstructured holes. Using this method of a microstructured metal plate subtarget, quantitative analysis was carried out on loam soil samples polluted by Pb. A linear calibration curve was obtained with a detection limit of approximately 50 mg/kg. Preliminary quantitative studies were carried out for a quartz sand sample containing Cr and Hg, resulting in linear calibration curves with detection limits of approximately 25 mg/kg and 10 mg/kg, respectively, at this stage. This technique is promising as a potential field screening tool for soil analysis.     

Low-frequency electrophoretic actuation of nanoscale optoentropic transduction mechanisms

Inherent bistabilities within DNA-assembled fluorescent resonant energy transfer systems demonstrated time-varying optical signals in response to an electrophoretic driving force. Frequency responses of electrophoretically driven FRET systems were shown to be sequence specific. Integration of these signals over time gave near single-molecule sensitivity within a high background of autofluorescence. This research suggests that externally driven nanoscale mechanical systems may help improve information flow within morphologically intact specimens.     

Molecular Basis of Endometriosis and Endometrial Cancer: Current Knowledge and Future Perspectives

The human endometrium is a unique tissue undergoing important changes through the menstrual cycle. Under the exposure of different risk factors in a woman’s lifetime, normal endometrial tissue can give rise to multiple pathologic conditions, including endometriosis and endometrial cancer. Etiology and pathophysiologic changes behind such conditions remain largely unclear. This review summarizes the current knowledge of the pathophysiology of endometriosis and its potential role in the development of endometrial cancer from a molecular perspective. A better understanding of the molecular basis of endometriosis and its role in the development of endometrial pathology will improve the approach to clinical management.     

Investment appraisal of a small, grid-connected photovoltaic plant under the Serbian feed-in tariff framework

Serbian government has recently introduced the system of feed-in tariffs for electricity generated from renewable sources. The proposed feed-in tariff for photovoltaic electricity is set to 0.23 €/kWh paid for 12 years, with the PV electricity produced after the first 12 years being sold at the grid electricity market price for the rest of the plant lifetime. Although such FIT could have been justified by the small, average retail grid electricity price of just 0.054 €/kWh for Serbian households, the investment appraisal of a real case of 2.82 kWp PV power plant in two Serbian cities of Zlatibor and Negotin, clearly illustrates that the proposed FIT framework is not sufficient to attract investments into PV in Serbia. In the second part of the paper, we have analyzed alternative, more reasonable feed-in tarrif frameworks, with the goal of selecting those able to sustain the PV adoption and diffusion in Serbia.     

Hydro energy potential of cooling water at the thermal power plant

The hydro energy of the gravity water flow from the coal-fired thermal power plant units to the river in an open cooling system of turbine condensers is determined. On the basis of statistical data for a long time period, the water net head duration curve due to the river annual level change, as well as the reduction of the hydro energy potential due to the thermal power plant overhauls periods, are evaluated in the case study of the Thermal Power Plant “Nikola Tesla B” in Serbia. A small hydro power plant is designed for the utilization of this hydro energy, and the economic benefits of the project are calculated. The internal rate of returns and pay back periods are calculated in dependence of the electricity price and total investment costs. The increase of profitability is assessed, bearing in mind that the plant might be realized as the Clean Development Mechanism project according to the Kyoto protocol. The obtained results show that the project is economically attractive, and it can be carried out with standard matured solutions of hydro turbines available at the market. Even for the relatively low electricity price from small hydro power plants in Serbia of 0.08 €/kW h the internal rate of return and the pay back period are 17.5% and 5.5 years.     

CSBD Healing in Rats after Application of Bovine Xenogeneic Biomaterial Enriched with Magnesium Alloy

Xenogeneic biomaterials Cerbone^® and OsteoBiol^® are widely used in oral implantology. In dental practice, xenogeneic biomaterial is usually combined with autologous bone to provide bone volume stability needed for long-term dental implants. Magnesium alloy implants dissolve and form mineral corrosion layer that is directly in contact with bone tissue, allowing deposition of the newly formed bone. CSBD heals by intramembranous ossification and therefore is a convenient model for analyses of ostoconductive and osteoinductive properties of different type of biomaterials. Magnesium alloy-enriched biomaterials have not yet been applied in oral implantology. Therefore, the aim of the current study was to investigate biological properties of potentially new bovine xenogeneic biomaterial enriched with magnesium alloy in a 5 mm CSBD model. Osteoconductive properties of Cerabone^®, Cerabone^® + Al. bone, and OsteoBiol^® were also analyzed. Dynamics of bone healing was followed up on the days 3, 7, 15, 21, and 30. Calvary bone samples were analyzed by micro-CT, and values of the bone morphometric parameters were assessed. Bone samples were further processed for histological and immunohistochemical analyses. Histological observation revealed CSBD closure at day 30 of the given xenogeneic biomaterial groups, with the exception of the control group. TNF-α showed high intensity of expression at the sites of MSC clusters that underwent ossification. Osx was expressed in pre-osteoblasts, which were differentiated into mature osteoblasts and osteocytes. Results of the micro-CT analyses showed linear increase in bone volume of all xenogeneic biomaterial groups and also in the control. The highest average values of bone volume were found for the Cerabone^® + Mg group. In addition, less residual biomaterial was estimated in the Cerabone^® + Mg group than in the Cerabone^® group, indicating its better biodegradation during CSBD healing. Overall, the magnesium alloy xenogeneic biomaterial demonstrated key properties of osteoinduction and biodegradidibility during CSBD healing, which is the reason why it should be recommended for application in clinical practice of oral implantology.     

The effect of lignin on the structure and characteristics of composite coatings electrodeposited on titanium

Composite coatings based on lignin, obtained by electrophoretic deposition (EPD) on titanium, were investigated. The aim of this work was to produce hydroxyapatite/lignin (HAP/Lig) coatings on titanium and to investigate the effect of the lignin concentration on microstructure, morphology, phase composition, thermal behavior and cytotoxicity of the HAP/Lig coatings. An organosolv lignin was used for the production of the composite coatings studied in this research. The properties of HAP/Lig coatings were characterized using X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FT-IR) and X-ray photoelectron spectroscopy (XPS), as well as the MTT test of cytotoxicity. The results showed that higher lignin concentrations protected the HAP lattice during sintering, thereby improving the stability of the HAP/Lig coatings. The cell survival of peripheral blood mononuclear cells (PBMC) after proliferation indicates that the HAP/Lig coating with 1 wt% Lig electrodeposited on titanium was non-toxic with significant promise as a potential bone-repair material.