Authors:E. Tabar, F. Lambrecht, C. Gunduz, and M. Yucebas
Radiolabeled molecules have an important role to evaluate tumor characteristics such as aggressiveness, and to identify the
effectiveness of cancer treatments such as chemotherapy and radiotherapy. Various radionuclide (18F, 99mTc, 124I) labeled molecules can be used apoptosis detection by estimating decrescendos cell viability after therapy. 99mTc-tetrofosmin which is used as a myocardial perfusion imaging agent in routine and at the same time is known to accumulate
in various tumors including breast tumor. The aim of this study was to assess the utility of 99mTc-tetrofosmin for monitoring the early response of MCF-7 breast cancer to chemotherapy. To evaluate the role of 99mTc-tetrofosmin in vitro chemotherapy, the uptake ratio was determined using MCF-7 breast cancer line after the cells had been
treated with cisplatin. When we examined the apoptotic ratios which induced with different dose of cisplatin in MCF-7 breast
cancer cells by using Annexin V and TUNEL methods, it was observed that the rate of apoptosis increased with soaring dose.
The uptake rates of 99mTc-tetrofosmin in MCF-7 cell line in the chemotherapeutic groups were lower than it is in the control group (p < 0.01). The negative correlation between uptake ratios and apoptotic rates shows that 99mTc-tetrofosmin may be used a radiopharmaceutical for evaluating chemotherapy response. 99mTc-tetrofosmin might be probably useful as an imaging agent for estimation of early chemotherapy response in breast cancer.
The first results are presented from some experiments aimed to determine the porosity and different capacity to absorb humidity from soil of several pre-hispanic building materials covered with mural painting which are under restoration at present. The main destructive agents are not coming from external weather conditions, but from humidity originated in the soil with a great variety of dissolved salts. In the laboratory small prism shaped samples of the same raw materials utilized in ancient times have been tested and put in contact with a 1& Na2SO4 solution labeled with 22Na during fixed time periods. In this way, counts obtained divided by weight of each sample gives a figure approximately proportional to its porosity or capacity to absorb humidity from soil, making possible to compare the difference of this condition for several materials, and to test the efficiency of the proposed methods to control this problem. One suitable way to achieve it, seems to be the use of one solution of BaAc, plus thio-urea and methyl-methacrylate, in order to form a solid polymer. This method works reasonably well at laboratory level, and even when it has not been tested in the real scale, seems to be cheap and easy enough to slow down the increasing deterioration due to humidity and salts deposits coming from soil. However, even when this polymer is completely insoluble in water, the start of the reaction to form it requires the final addition of hydrogen peroxide, and temperature increase till the boiling point of the reagents, which may be too aggressive for ancient dyes and raw materials. Thus, the use of the so called French gelatin is proposed, and results at laboratory level are considered to chose the material better suitable at real scale with a minimum risk for the material.
Authors:László Kátai, Péter Szendrő, and Péter Gárdonyi
The V-belt drive is a rather popular, widely used form of power transmission in agricultural and food industry engineering. At the same time, its stability, the lifetime of V-belt is influenced by several environmental factors, namely in the food industry by the contamination affecting the belt sides, the ambient temperature, humidity and the occasionally aggressive (acidic, alkaline air, air saturated with gases, etc.) medium. In the case of agricultural machinery, the vibration caused by uncertainly oriented pulleys with bearing in different plate structures (often being shaken in the fields) as well as alignment adjustment inaccuracies jeopardize the reliability of the parameters of the drive. Furthermore, the efficiency is determined by several factors together: the slippage occurring during drive transmission, the hysteresis loss resulting from the external and internal friction occurring with the belt entering and exiting the pulley. Experimental equipment and calculation methods were developed to determine the dynamics of temperature increase generated by the belt and pulley relationship. The temperature generated in the V-belt was measured as a function of pretension, pulley diameter and bending frequency. The so-called damping factor characterizing the contact with the pulley (the external friction when entering and exiting the groove) and the hysteresis loss (inner friction) are also determined. On the basis of the damping factor (ζ ≈ 400 Ns/m2) of the V-belt involved in the experiments the other losses (Poth) occurring from the pulley—V-belt contact and internal friction may be estimated. The drive parameters may be optimized with the mathematical model describing the effect of the pulley diameter and belt frequency on the increase in temperature.
A standardized calculation method as well as design factors valid for the properly adjusted drive and normal operating conditions determined through empirical and laboratory experiments are used for the sizing of V-belt drives. The lifetime of V-belt drives designed in this way, used in extreme conditions typical of agricultural machinery will not be appropriate and will not provide clear, predictable information for maintenance planning. In such cases the results of our own many lifetime tests conducted in the given circumstances can be safely relied on.
The agricultural harvesting machines are large plate-body self-propelled structures on which most of the power supply of the (threshing, cleaning, moving, etc.) machine units handling the crop is realized via belt drives. The distance and angular displacement of the axes involved in the drive can vary within wide limits. The misalignment and angular displacement of the pulleys can be the result of installation instability — due to the plate structure — and the deformation of the plate structure occurring during the operation as well. V-belt drives operate satisfactorily under such conditions as well, however these faults are unfavourable in terms of belt lifetime and result in the reduction of drive efficiency.
A further aim of our research is to examine through experiments the lifetime and efficiency of V-belts used in agricultural machines as a function of drive adjustment errors. According to the results of the measurements of the geometrical adjustment errors of V-belt drives performed in the field, the pulleys of agricultural equipment are not always positioned in the medium plane of the drive. In our experiments these data served as independent variables. Figure 1 shows the arrangement of a V-belt drive in a grain harvester with the laser pulley alignment measuring instrument installed as an accessory. In the case of many machine types in 80% of the tested drives three times the permissible error was measured, and because of off-road use, due to dynamic load these errors further increased as a result of the frame deformation.
The results of both the belt bending testing and the geometrical adjustment testing of the drive offer great help in the design of belt drives. At the same time they can be the source of lifetime and efficiency forecasts.
Authors:D. Chaliampalias, G. Vourlias, E. Pavlidou, and K. Chrissafis
similar aggressive environments.
The specimens, which were used, were cut from a Cr–Mo–V steel sheet. In particular, the experimental coupons were machined in rectangular specimens with dimensions 5 × 3 × 2 mm
Authors:Adriana Samide, Bogdan Tutunaru, Aurelian Dobritescu, and Catalin Negrila
performed with carbon steel, type C38, in the form of plates with the following composition: C = 0.1%, Mn = 0.5%, P = 0.025%, S = 0.025%, and Fe remainder. The aggressive solutions used were made of HCl AR grade. Appropriate concentrations of acid were
Authors:Iulian Rusu, Daniel Sutiman, Gabriela Lisa, Daniel Mareci, and Nicoleta Melniciuc Puică
the alloy from the aggressive environment. These aspects results in absolute values of the impedance around 10 4 Ω cm 2 .
The analysis of SEM analyses ( Fig. 4 ) indicates the appearance of corrosion points at the surface of sample 2, and the
Authors:Tongsheng Zhang, Qijun Yu, Jiangxiong Wei, and Jianxin Li
Mortar prisms of selected blended cements after 28 days of curing in lime-saturated water were placed in 5% Na 2 SO 4 solutions and lime-saturated water, respectively. After 90 and 180 days of exposing in aggressive medium, the
Authors:M. Kuliffayová, L’. Krajči, I. Janotka, and V. Šmatko
refinement [ 24 , 27 ]. SEM microstructures indicate a good improvement for the matrix structure of the composites where a more dense structure is observed [ 28 ]. Since cement-based materials are often subjected to action of aggressive environment [ 29
Authors:Dora Melucci, Giuseppe Chiavari, Simona Montalbani, and Silvia Prati
less aggressive than TMAH leads to an increased yield of tris-TMS-phosphate, which is clearly visible in the total ion chromatogram: the peak 2 ( Fig. 9 ) has a molecular peak corresponding at 314 m / z , which is the molecular weight of tris
Authors:Gisele Cristiane Becher Ribas, Gledison Rogério de Souza, and Fernando Luis Fertonani
not uniformly distributed on the surface of the substrate, exposing regions of the substrate, apparently not attacked or subjected to a less aggressive action by the Hg. The results of the mapping of the elements for Pt, Rh, and Hg ( Fig. 2 b–d) show a