Reversible lymphomagenesis in conditionally c-MYC expressing mice

It is well documented that deregulation of MYC leads to tumor development, yet many aspects of this process are only partially understood. We have established a transgenic mouse model in which c-MYC is conditionally expressed in lymphoid cells using the tetracycline-regulated system of gene regulation. Mice with continuously expressed transgenic c-MYC died of invasive T- or B-cell lymphomas within 4 months. Lymphomas developing in transgenic mice were c-MYC dependent since doxycycline treatment led to tumor regression. Using transplantation of established tumor cell lines labeled with GFP, we followed the fate of neoplastic cells in recipients upon MYC inactivation. This approach allowed us to elucidate both apoptosis and differentiation as mechanisms of tumor elimination. Comparative genomic hybridization (CGH) and FISH analyses were performed in order to analyze possible chromosomal aberrations induced by c-MYC. We observed that overexpression of c-MYC is sufficient to induce recurrent patterns of genomic instability. The main observation was a gain of genomic material that corresponded to chromosome 15 in several T-cell tumors, which could be identified as trisomy

Mechanochemical synthesis of bismuth ferrite

A powder mixture of Bi2O3 and Fe2O3 was mechanically treated in a planetary ball mill in an air from 30 to 720 minutes. It was shown that the mechanochemical formation of BiFeO3 (BFO) phase was initiated after 60 min and its amount increased gradually with increasing milling time. A detailed XRPD structural analysis is realized by Rietveld’s structure refinement method. The resulting lattice parameters, relative phase abundances, crystallite sizes and crystal lattice microstrains were determined as a function of milling time. Microstructural analysis showed a little difference in morphology of obtained powders. The primary particles, irregular in shape and smaller than 400 nm are observed clearly, although they have assembled together to form agglomerates with varying size and morphology. Dense BFO ceramics were prepared by conventional solid-state reaction at the temperature of 810ºC for 1h followed immediately by quenching process. [Projekat Ministarstva nauke Republike Srbije, br. III45007: Zero- to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processin

Kinetics of nanocrystalline phase transformations in spray pyrolysed ZnO particles

The thermal behavior of ZnO powder obtained by ultrasonic spray pyrolysis of nitrate solution (c=0.8mol/dm3, D0=2.695µm, Tmax=6000C, FG=1.2dm3/min) was investigated using non-isothermal differential scanning calorimetry (DSC, heating rates 5, 10, 15, 20O/min). The exothermic heat effects at the temperature range from 350 to 5000C were linked to particles structural data obtained by XRD, SEM and TEM analysis. Produced particles are characterized by uniform submicronic size (D=800nm, BET=4.94m2/g), high phase purity and granular or circular “open” surface due to the presence of primary crystallites (d= 20nm). Observed structural changes during heating of this powder were attributed to simultaneous processes of nucleation and growth of primary crystallites inside the produced particles

Novel amino modified GMA-EGDMA-m-PMMA monolith for efficient cationic pollutant removal

Novel macro/micro-porous monolith material containing surface amino functional groups was developed for efficient cationic pollutant removal. The monolith was prepared by copolymerization process of monomers glycidyl methacrylate (GMA), ethylene glycol dimethacrylate (EGDMA) and modified low molar mass poly(methyl methacrylate) (PMMA). In order to improve mechanical stability of GMA-EGDMA monolith, surface of PMMA was modified with ethanol amine in first step, and introduction of methacryloyl chloride in a second step produced m-PMMA. Synthesized GMA-EGDMA-m-PMMA monolith was modified with poly(ethylene imine) (PEI). The effectiveness of copolymerization, as well as introduction of amino groups via PEI modification were confirmed by FTIR and Raman analyses. The morphological appearance of the synthesized monolith, examined by scanning electron microscopy (SEM), clearly indicates porous structure. The results of textural parameters, i.e. monolith porosity, determined by using liquid saturating method, indicate high degree of porosity. Cationic pollutant removal capacity, cadmium and lead, of 32.0 and 42.5 mg g−1 at 25 °C indicates that this monolith is high efficient. This macro/micro-porous monolith could be a promising adsorbent because of its low-cost synthesis process and excellent performance

The synthesis: Structure relationship in the ZnO-Cr2O3 system

In this work the development of the spinel phase in the ZnO-Cr2O3 system was discussed from the viewpoint of the synthesis-structure relationship. The nanostructure evolution in particles obtained either via solution-based (spray pyrolysis) or solid-state (mechanical activation) synthesis procedures were investigated by XRD analysis. A detailed structural analysis of the spinel phase lattice parameters, average primary crystallite sizes and micro strains were performed in accordance with a procedure based on the Koalariet-Xfit program. Due to the importance of spinel-phase cat ion distribution for chemical and physical properties, a study of the site occupation factors, i.e. changes in the stoichiometric, of ZnCr2O4 spinals was undertaken. The calculation based on atomistic methods for the description of both perfect and defect spinel ZnCr2O4 crystal lattices has been applied and the presence of individual structural defects was determined

Nest-site preference of griffon vulture (gyps fulvus) in Herzegovina

Although formerly an abundant species, the Eurasian Griffon (Gyps fulvus Hablizl, 1783) has undergone a dramatic decline in Herzegovina. Such an unfavorable trend may be associated with frequent poisoning incidents (consumption of poisoned baits), shortage of food and hunting. This species disappeared from its breeding habitats in Herzegovina during the last decade of the 20th century. The extinction was probably caused by military activities during the civil war. Using data that were collected over a period of long-term (1980-1991) monitoring of the breeding population, we discovered optimal environmental conditions for the nesting of the Eurasian Griffon Vulture in Herzegovina. Information on nest-site preference is valuable for conservation programs and the possible reintroduction of the Eurasian Griffon, not only in Herzegovina, but also to a much wider region. During the study period, we observed 61 nests and 252 nesting cases in four colonies of Eurasian Griffon Vulture. Most nests were located on limestone and dolomite rocks. The average altitude of nests was 378 m a.s.l.; most of nests (85%) were located below 500 m a.s.l. Also, the majority of nests were located on west-exposed sites

Adsorption capacity of wollastonite based adsorbents with porous structure controlled with different progeny agents

Porous wollastonite (WL) based adsorbents were fabricated by a pressureless sintering process by using low molecular weight poly(methyl methacrylate) (PMMA), nanocellulose (NC) and yeast as the pore forming agents. WL based adsorbents were synthesized in two step process. In the first step, calcium carbonate and methylhidrogen cyclosiloxane were mixed with isopropyl alcohol, dried and calcined at 250 °C. Second step included WL mixing with porogen, followed by controlled calcination and on that way the sintered materials with randomly distributed pores were obtained. The effectiveness of the synthesis steps as well as material properties, i.e., the pore morphology were determined by FTIR analysis and scanning electron microscopy (SEM), respectively. The pore morphology and adsorption capacity was changed dramatically by changing the pore forming agent. The highest adsorption capacity was obtained when NC was used as the pore forming agent. Obtained materials showed moderate adsorption capacities of 10.56, 8.42 and 11.33 mg/g with respect to As5+, Cr6+ and phosphate, respectively. The con centrations of heavy metal ions were determined by using Ion chromatography coupled with mass spectrometry (ICP-MS)

Urea-Assisted Self-Combustion Aerosol Synthesis of Y3Al5O12:Ce3+

Poster presented at the 10th Conference of the Materials Research Society of Serbia - YUCOMAT 2008, Herceg Novi, Crna Gora, 8-12. septembar 200

Postural stability – a comparison between rowers and field sport athletes

Postural stability (PS) is an important function for maintaining equilibrium during periods of standing still, locomotion, and any motor activities that require high degree of balance. High PS is essential in different sports for the regulation of voluntary movement and for improving athletic physical condition and performance. Purpose: The purpose of this study was to compare the static PS of elite rowing athletes and field sport athletes. Methods: A total of 90 elite athletes (age: 23.9 ± 1.97 years; body height: 174.9 ± 8.9 cm; body weight: 67.7 ± 12.03 kg) were divided into Rowing (N = 47) and Field sport (N = 43) athlete groups. Static PS parameters were assessed with a static double-leg and single-leg standing stability test on a force plate platform. Results: The multivariate analysis of variance showed a general stability difference between the groups (F = 13.255; P ≤ 0.0001), in double leg stability (F = 16.735; P ≤ 0.0001), and left leg (F = 15.097; P ≤ 0.0001) stability parameters. When analyzing variables separately, significant statistical differences were observed in favor of the Rowing group in double leg sway area (p = 0.017; ES = −0.07), double leg center of force (COF) traveled way (p ≤ 0.0001; ES = −27.42), length function of surface (p ≤ 0.0001; ES = −26.86), right leg ML displacement (p = 0.030; ES = −0.46), left leg sway area (p = 0.030; ES = −0.44), left leg COF traveled way (p ≤ 0.0001; ES = −60.63), left leg AP displacement (p = 0.043; ES = −0.44). Conclusion: These results underline the differences in rowing and field sport athletes in terms of static PS. The characteristics of sport and competition may affect PS, and it is important to adjust training modalities for the required level of PS in every sport, especially in rowing

Repair of a damaged turbocharger

The turbocharger is among the highest quality assemblies for modern internal combustion engines. Its contribution to engine operation is immeasurable – it increases the power output of the engine while indirectly reducing fuel consumption. Like all devices, turbochargers require quality maintenance as they are susceptible to failure. Faulty turbochargers are either repaired or replaced with new ones. Repair ensures substantial financial savings. The paper presents the consequences of damage to the turbocharger and the process of its repair