Numerical Simulation of Nano Scanning in Intermittent-Contact Mode AFM under Q control

We investigate nano scanning in tapping mode atomic force microscopy (AFM) under quality (Q) control via numerical simulations performed in SIMULINK. We focus on the simulation of whole scan process rather than the simulation of cantilever dynamics and the force interactions between the probe tip and the surface alone, as in most of the earlier numerical studies. This enables us to quantify the scan performance under Q control for different scan settings. Using the numerical simulations, we first investigate the effect of elastic modulus of sample (relative to the substrate surface) and probe stiffness on the scan results. Our numerical simulations show that scanning in attractive regime using soft cantilevers with high Qeff results in a better image quality. We, then demonstrate the trade-off in setting the effective Q factor (Qeff) of the probe in Q control: low values of Qeff cause an increase in tapping forces while higher ones limit the maximum achievable scan speed due to the slow response of the cantilever to the rapid changes in surface profile. Finally, we show that it is possible to achieve higher scan speeds without causing an increase in the tapping forces using adaptive Q control (AQC), in which the Q factor of the probe is changed instantaneously depending on the magnitude of the error signal in oscillation amplitude. The scan performance of AQC is quantitatively compared to that of standard Q control using iso-error curves obtained from numerical simulations first and then the results are validated through scan experiments performed using a physical set-up

The effects of propolis on gill, liver, muscle tissues of rainbow trout (Oncorhynchus mykiss) exposed to various concentrations of cypermethrin

WOS: 000353484100015The aim of this study was to investigate the therapeutic effects of propolis for the toxicity of cypermethrin (CYP) on histopathological changes in tissues of rainbow trout (Oncorhynchus mykiss). CYP is one of the most toxic pyrethroids highly for the aquatic organisms. The fish were exposed to three sublethal concentrations of CYP (0.0041, 0.0082 and 0.0123 ppm). In addition, different concentrations of propolis (10, 20 and 30 ppm) were used in the investigation for the period of 96 h. Propolis was collected by honeybees from different plants to prevent oxidative damages as an antioxidant. The therapeutic concentration of propolis was determined at 10 ppm. 10 ppm propolis was added to three cypermethrin concentrations. Shorting the secondary lamellae, fusion of secondary lamellae, oedema, necrosis, vacuolization and cartilage damage in gill tissue of fish exposed to CYP were observed by histopatological analyses. Hepatic lesions in liver tissue of fish exposed to CYP were characterized as hydropic degeneration, necrosis, mononuclear cell infiltration and narrowing of sinusoids. The most common changes in muscle tissues at all concentrations of CYP were nuclear proliferation and congestion. Besides, 10 ppm propolis on gill, liver, muscle tissues of rainbow trouts showed significant therapeutic effects. Histological analysis revealed that propolis may serve as an antitoxic agent against pesticide toxicity.Nigde University Research FundNigde University Research Fund (FEB 2007/13) is gratefully acknowledged for support of this work

The effects of selenium on rainbow trout liver treated with heavy metals

31st Congress of the Federation-of-European-Biochemical-Societies (FEBS) -- JUN 24-29, 2006 -- Istanbul, TURKEYWOS: 000238914001109…Federat European Biochem So

The defensive effects of synthetic organoselenium compounds on the antioxidative system of DMBA induced rat brain

31st Congress of the Federation-of-European-Biochemical-Societies (FEBS) -- JUN 24-29, 2006 -- Istanbul, TURKEYWOS: 000238914001108Federat European Biochem So

Effects of propolis on some blood parameters and enzymes in carp exposed to arsenic

WOS: 000306752300015The purpose of this study was to investigate the therapeutic effects of natural products like propolis on biochemical and hematologic parameters in carp (Cyprinus carpio, Linnaeus 1758) exposed to arsenic. In this study fish were exposed to 0.01 mg/L arsenic and 10 mg/L propolis for seven days. Our results indicated that triglyceride, urea, total cholesterol, cobalt, ALT (alanine amino transferase), AST (aspartate amino transferase), LDH (lactate dehydrogenase) values increased when exposed to arsenic (P<0.05) but reduced by combination of arsenic and propolis (P<0.05). Granulocyte, erythrocyte, hemoglobin, hematocrit values were decreased by use of arsenic in comparison to control group. These parameters increased in arsenic+propolis group (P<0.05). In addition levels of leucocyte, agranulocyte, MCV (mean corpuscular volume), MCH (mean corpuscular hemoglobin) and MCHC (mean corpuscular hemoglobin concentration) increased in the arsenic group (P<0.05) and decreased in arsenic+propolis group (P<0.05). We can say that propolis can improve biochemical and hematologic functions of common carp blood, after being exposed to arsenic