The changes of surface potential and built-in charge in alumina films after the anodization process

We have shown that the surface potential of anodic alumina films changes in time: immediately after the anodization process it was positively followed by the substantial decrease to negative values. Such variations of the surface potential can be associated with the negative built-in electric charge in alumina. The highest negative charge density occurs in the films formed in citric and phosphoric electrolytes

Effects of alpha fetoprotein on escape of Bel 7402 cells from attack of lymphocytes

BACKGROUND: Involvement of AFP against apoptosis of tumor cell has been implicated in its evasion of immune surveillance. However, the molecular events of immune escape mechanisms are still unknown. The major observations reported here relate to a possible mechanism by which heptoloma Bel 7402 cells escape immune surveillance in vitro. METHODS: Western blotting and a well-characterized cofocal scanning image were performed to analyze the expression of Fas/FasL and caspase-3 in co-cultured Bel 7402 and Jurkat cells. RESULTS: After co-culture with Jurkat cells, up-regulated Fas and reduced FasL expression could be observed. Treatment with AFP could remarkably inhibit the elevated Fas and, whereas, induce the FasL expression in co-cultured Bel 7402 cells. Cells co-culture could induce the expression of caspase-3 in both cells line. The elevated caspase-3 in Bel 7402 cells was abolished following the treatment of AFP. The expression of caspase-3 was elevated in co-cultured Jurkat cells treated with AFP. No detectable change on the expression of survivin was examined in both cells line. Monoclonal antibody against AFP treatment alone did not obviously influence the growth of cells, as well as the expression of Fas/FasL and caspase-3. However, the effect of AFP could be blocked by antibody. CONCLUSIONS: our results provide evidence that AFP could promote the escape of liver cancer cells from immune surveillance through blocking the caspase signal pathway of tumor cells and triggering the Fas/FasL interaction between tumor cells and lymphocytes

Deep Learning in Processing Medical Images and Calculating the Orbit Volume

A software tool for calculating the volume of a soft-tissue eye orbit using the deep learning of neural network Mask R-CNN has been developed and tested. The result of the development will be in demand when evaluating the results of surgical intervention for the reconstruction of the thin bones of the orbit. It was established that the inaccuracy in constructing the contour of a soft-tissue orbit is 4–8%

Formation of alumina nanotubes and jet effect during high voltage local anodization of aluminum

Using an improved heat sink from the barrier layer, the voltage of anodic electrochemical oxidation of aluminum in sulfuric electrolytes is successfully increased from the conventional limit of about 40 to 200 V. This is done by localization of the anodized regions within the windows in the niobium thin film masks with the diameters of 0.3 μm to 2.5 mm. High-voltage anodization in water solutions of sulfuric acid is observed to be accompanied by a reproducible formation of densely packed alumina nanotubes and intense gas propulsion from the pores of the forming alumina. The latter is proposed and experimentally confirmed for use as an efficient driving agent in micro- and nanoengines. Test samples are accelerated to the velocities up to 1 cm s−1, demonstrating a thrust-to-weight ratio of about 1000

Влияние поверхностного потенциала анодных алюмооксидных пленок на их зарядовые свойства

The surface potential of anodic alumina films and their charge properties have been studied. The surface potential of anodic alumina films after anodic process has positive values, but then this potential is decreased to zero level with subsequent transition to negative values. The negative displacement of the surface potential is associated with a negative built-in electric charge of aluminum anodic oxide. The mechanism of transition from the positive built-in electric charge to the negative one inside the anodic oxides is proposed. The highest density of the negative charge is observed in the films formed in electrolytes based on the aqueous solutions of the citric and phosphoric acids.Представлены результаты исследования поверхностного потенциала анодных алюмооксидных пленок и их зарядовых свойств. Показано, что поверхностный потенциал анодных алюмооксидных пленок сразу после окончания анодного процесса имеет положительное значение, но с течением времени этот потенциал уменьшается до нулевого уровня с последующим переходом в область отрицательных значений. Установлено, что отрицательное смещение поверхностного потенциала связано с отрицательным встроенным электрическим зарядом анодного оксида алюминия. Предложен механизм перехода от положительного встроенного электрического заряда к отрицательному внутри анодных оксидов. Установлено, что наибольшая плотность отрицательного заряда наблюдается в пленках, сформированных в электролитах на основе водных растворов лимонной и ортофосфорной кислот

ИССЛЕДОВАНИЕ ДЖОУЛЕВА РАЗОГРЕВА ОКСИДА АЛЮМИНИЯ В ПРОЦЕССЕ ЭЛЕКТРОХИМИЧЕСКОГО АНОДИРОВАНИЯ

The temperature distribution within the anodic alumina during the anodic process has been studied. The temperature increase can reach 300 °C at high lever of Joule heat. The parameters of the heat process such as the heat temperature coefficient, the specific temperature change and the number of thermal process similarity criteria have been determined. The simulation of the temperature distribution within the test system for the given parameters of anodizing has been performed.Проведено исследование распределения температуры внутри оксида алюминия вследствие выделения джоулева тепла во время электрохимического анодирования. Обнаружено, что температура растущего оксида может достигать 300 °С в зависимости от мощности выделяемого джоулева тепла. Определен ряд параметров (коэффициент теплопередачи, удельное изменение температуры) и значения критериев подобия процесса теплопередачи. Проведено численное моделирование распределения температуры внутри исследуемых систем при заданной потребляемой мощности электрохимического анодирования

Ciprofloxacin induces apoptosis and inhibits proliferation of human colorectal carcinoma cells

Efficacy of chemotherapy in advanced stages of colorectal tumours is limited. The quinolone antibiotic ciprofloxacin was recently shown to inhibit growth and to induce apoptosis in human bladder carcinomas cells. We investigated the effect of ciprofloxacin on colon carcinoma lines in vitro. CC-531, SW-403 and HT-29 colon carcinoma and HepG2 hepatoma cells (control cells) were exposed to ciprofloxacin. Proliferation was assessed by bromodeoxyuridine-incorporation into DNA and apoptosis was measured by flow cytometry after propidium iodide or JC-1 staining. Expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax was analyzed by semiquantitative Western blot analysis and activity of caspases 3, 8 and 9 by substrate-cleavage assays. Ciprofloxacin suppressed DNA synthesis of all colon carcinoma cells time- and dose-dependently, whereas the hepatoma cells remained unaffected. Apoptosis reached its maximum between 200 and 500 μg ml−1. This was accompanied by an upregulation of Bax and of the activity of caspases 3, 8 and 9, and paralleled by a decrease of the mitochondrial membrane potential. Ciprofloxacin decreases proliferation and induces apoptosis of colon carcinoma cells, possibly in part by blocking mitochondrial DNA synthesis. Therefore, qualification of ciprofloxacin as adjunctive agent for colorectal cancer should be evaluated

The Apoptosome: Emerging Insights and New Potential Targets for Drug Design

Apoptosis plays a crucial role in tissue homeostasis, development and many diseases. The relevance of Apaf1, the molecular core of apoptosome, has been underlined in mitochondria-dependent apoptosis, which according to a growing body of evidence, is involved in various pathologies where the equilibrium of life-and-death is dysregulated, such as heart attack, stroke, liver failure, cancer and autoimmune diseases. Consequently, great interest has emerged in devising therapeutic strategies for regulating the key molecules involved in the life-and-death decision. Here we review recent progress in apoptosis-based pharmacological therapies and, in particular, we point out a possible role of the apoptosome as an emerging and promising pharmacological target