Gamma-radiation-induced damage of proteins in the thick fraction of egg white

The 60Co gamma-ray irradiation of ovomucin based protein network of the thick fraction of egg white in the absence of oxygen causes both protein cross linking and protein fragmentation. Protein fragmentation in the absence of oxygen is interpreted as a consequence of decreased diffusion of protein radicals within the protein network. Both protein cross linking and fragmentation, are dose dependent processes, with fragmentation prevailing below 10-15 kGy, and cross linking prevailing at the radiation doses >15 kGy. The radiolytic behaviour of the thick fraction of egg white, suggests that gamma irradiation of similar mucine containing structures might also result in accumulation of structurally altered and conceivably non-functional proteins in vivo.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200

Effect of different types of stress on adrenal gland parameters and adrenal hormones in the blood serum of male Wistar rats

In the present study, we examined gross changes in the mass of whole adrenal glands and that of the adrenal cortex and medulla in mature male Wistar rats subjected to three different stress types: acute, chronic, and combined, i.e., chronic followed by acute stress. These parameters were correlated with adrenal activity as judged from serum levels of corticosterone and catecholamine, respectively, as well as with serum levels of ACTH and glucose. Under all three conditions, we observed bilaterally asymmetric and stress-type-independent hypertrophy of whole adrenals, as well as adrenal cortices and medullas. Under acute and combined stress, adrenal hypertrophy was followed by increase of adrenal hormones in the blood serum. However, under chronic stress, both cortical and medullar activities as judged from low or unaltered levels of the respective hormones and glucose were compromised and disconnected from the input signal of ACTH. Since all of the studied adrenal activities could be restored by subsequent acute stress, it is concluded that chronic isolation can be viewed as partly maladaptive stress with characteristics resembling stress resistance rather than the stress exhaustion stage of the general adaptation syndrome

A case of excessive lateral vibrations of patrol boat shafting: Failures, analysis and solution

During the endurance trials of three identical patrol boats with "Vee" type main shafting system (3x900 kW each), three (of nine) shaft lines broke. The excessive lateral vibrations of the main shafting (excited by, cardan joints) were recognized as the main cause of the failures, and some corrective measures were proposed. The authors of this paper were engaged a while later to make a thorough vibration measurement of the repaired boats. As the record showed that the improvement was not satisfactory, some additional more effective measures had to be accomplished. The paper discusses the possible additional measures, and identifies the installation of an additional bearing (at the proper location along the shaft line) as the most promising. Such a bearing shifts the first natural frequency out of the working range, and releases the vibrating system of the existing critical. The paper gives the vibration data chronologically (from the first identification of the excessive vibrations to the last measurements, after the installation of the additional bearings), so that the successive steps of the healing action could be followed. Finally, the paper shows that the applied measure did reduce the horizontal (most dangerous) vibrations sufficiently, but also had some negative (unpredictable) effects on the vertical component of the vibrations

Neuroendocrine and Oxidoreductive Mechanisms of Stress-Induced Cardiovascular Diseases

Summary The review concerns a number of basic molecular pathways that play a crucial role in perception, transmission, and modulation of the stress signals, and mediate the adaptation of the vital processes in the cardiovascular system (CVS). These highl

Optimization and Application of NTC Thick Film Segmented Thermistors

NTC thermistor paste for printing thermal sensors on alumina was formed of very fine Ni0.5Cu0.2Zn1.0Mn1.3O4 thermistor powder obtained by a combined mechanical activation/thermal treatment process, organic vehicle and glass frit. Sheet resistivity was measured using an R-test matrix and it was much lower than the value determined for pure nickel manganite thermistors. The thermistor exponential coefficient was calculated from the R[ diagram measured in the temperature range-30 to +120°C in a climatic chamber. Thick film segmented thermistors with reduced dimensions (optimized construction) were printed sequentially layer by layer, dried and fired at 850°C/10 min in air. Electrodes were printed of PdAg conductive and solderable paste. The samples obtained were characterized by electrical and thermal measurements. The obtained NTC segmented thermistors with reduced dimensions were applied in a thermal sensor for water flow in the water mains. It contained a cold thermistor for measuring input water temperature and a self-heating thermistor for measuring the dependence of water current on water flow rate at a set input voltage power. Initial measurements show that the thermal sensor system requires a low input voltage power making it much easier and safer for operation

Stress-induced phosphorylation of c-Jun-N-terminal kinases and nuclear translocation of Hsp70 in the Wistar rat hippocampus

Abstract — Glucocorticoids are key regulators of the neuroendocrine stress response in the hippocampus. Their action is partly mediated through the subfamily of MAPKs termed c-Jun-N-terminal kinases (JNKs)� � whose activation correlates with neurodegeneration. The stress response also involves activation of cell protective mechanisms through various heat shock proteins (HSPs) that mediate neuroprotection. We followed both JNKs and Hsp70 signals in the cytoplasmic and nuclear compartments of the hippocampus of Wistar male rats exposed to acute� � chronic� � and combined stress. The activ� ity of JNK1 was decreased in both compartments by all three types of stress� � while the activity of cytoplasmic JNK2/3 was elevated in acute and unaltered or lowered in chronic and combined stress. Under all stress conditions� � Hsp70 trans� location to the nucleus was markedly increased. The results suggest that neurodegenerative signaling of JNKs may be counteracted by increase of nuclear Hsp70� � especially under chronic stress. Key words: Wistar rat� � neuroendocrine stress� � hippocampus� � JN�� � Hsp70 Udc 577.25:612.819:59:591.481.

Novel uniaxial anemometer containing NTC thick film segmented thermistors

A novel uniaxial anemometer was created using a NTC thick film segmented thermistor to measure wind speed and direction. The anemometer operated on the principle of heat loss caused by the air volume flow and air speed. A NTC segmented thermistor served as a wind sensor in the anemometer. It was self-heated by a DC constant voltage. The self-heated DC current through the thermistor was changed by heat loss due to resistivity changes. The wind speed was varied from 1 to 15 m/s for different input air temperatures in the range of -20 to +40°C. The wind direction was determined by measuring voltage differences on the inner electrodes of the NTC segmented thermistor. The air temperature was measure by a cold NTC thick film segmented thermistor calibrated in the claim chamber. Anemometar inertia was measured at room temperature (at 25°C) and normal room humidity (at 50%). The results obtained enable fast optimization and implementation of a uniaxial anemometer in a 3D anemometer. © 2008 IEEE

Analysis of Bessel procedures in solving the main geodetic tasks on an ellipsoid

This paper deals with the problem of Bessel procedures and processes in solving the main geodetic problems on an ellipsoid. There are a number of methods for solving the main geodetic tasks on the Earth's ellipsoid. They can be grouped into three categories, ie models for: short distances (up to 200 km), medium distances (200 to 1000 km) and long distances (over 1000 km). The aim of this paper is the application of the methodology for solving the main geodetic tasks for all distances on the eelipsoid, ie the application of one universal method. Since this method is iterative, the modern way of its implementation is a significant relief compared to its application in the past when there were no software designs and automated procedures. From the obtained results and length values, numerous analysis and conclusions can be derived, ie, process monitoring and error growth trend with increasing distance

Izrada i analiza 3d modela na osnovu uav snimaka

Glavni fokus rada je izrada, vizualizacija i analiza kvaliteta 3D modela dobijenih iz snimaka bespilotnih letelica - UAV (Unmanned Aerial Vehicle). Analiza prikaza i kvaliteta 3D modela ukljueuje stepen odstupanja geometrijskih karakteristika objekata u različitim modelima i formatima, odnosno u softverskim okruženjima. Proces prikupljanja i obrade podataka je opisan pa fazama, kao i njihova naknadna vizualizacija u dva različita softverska okruženja - Agisoft Metashape i Pix4Dmapper. Kao rezultat obrade u datim softverima, dobijeni su digitalni model visina (DMV) i digitalni model povdi (DMP). Analiza i poređenje kvaliteta obavljeni su kreiranjem aplikacije GUI (graphical user interface) kroz interakciju grafičkih i tekstualnih podataka u programskom paketu MatLAB.The main focus of the paper is the creating, visualization and analysis of the quality of 3D models obtained from images of Unmanned Aerial Vehicles (UAV). The analysis of the display and quality of 3D models includes the degree of deviation of the geometric characteristics of objects in different models and formats, ie in software environments. The process of data collection and processing is described in stages, as well as their subsequent visualization in two different software solutions - Agisoft Metashape and Pix4Dmapper. As a result of processing in the given software, digital elevation models (DEM) and digital surface model (DSM) were obtained. Quality analysis and comparison were performed by creating a GUI application (graphical user interface) through the interaction of graphic and textual data in the MatLAB software package