Background: Recent studies have shown that microRNAs (miRNAs) are involved in the process of cardiomyocyte apoptosis. We have previously reported that granulocyte-colony stimulating factor (G-CSF) ameliorated diastolic dysfunction and attenuated cardiomyocyte apoptosis in a rat model of diabetic cardiomyopathy. In this study, we hypothesized a regulatory role of cardiac miRNAs in the mechanism of the anti-apoptotic effect of G-CSF in a diabetic cardiomyopathy rat model. Methods: Rats were given a high-fat diet and low-dose streptozotocin injection and then randomly allocated to receive treatment with either G-CSF or saline. H9c2 rat cardiomyocytes were cultured under a high glucose (HG) condition to induce diabetic cardiomyopathy in vitro. We examined the extent of apoptosis, miRNA expression, and miRNA target genes in the myocardium and H9c2 cells. Results: G-CSF treatment significantly decreased apoptosis and reduced miR-34a expression in diabetic myocardium and H9c2 cells under the HG condition. G-CSF treatment also significantly increased B-cell lymphoma 2 (Bcl-2) protein expression as a target for miR-34a. In addition, transfection with an miR-34a mimic significantly increased apoptosis and decreased Bcl-2 luciferase activity in H9c2 cells. Conclusion:Our results indicate that G-CSF might have an anti-apoptotic effect through down-regulation of miR-34a in a diabetic cardiomyopathy rat model.

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We performed an offshore experiment with a new marine small loop electromagnetic (EM) survey system, which was developed primarily for exploration of seafloor hydrothermal deposits. The system is a multi-frequency loop EM system designed to endure high pressure in deep sea up to 2000 m. In order to maintain altitude of the system from the seafloor in rough seafloor topography condition, the system was connected rigidly to ROV (Remotely Operated Vehicle) which tows the system. We performed a test with the new loop EM system by keeping altitude of ROV 2 m above from the seafloor at a depth of 300 m near Tonga offshore. The ROV position and attitude while moving (pitch, roll, yaw) and CTD (Conductivity, Temperature, Depth) data are also recorded simultaneously with electromagnetic responses. Experimental results showed that electromagnetic anomaly was clearly identified at the location of metallic object, and the pattern of the EM responses matches well with the theoretical responses from a 3-D integral equation EM modeling code. With the test in Tonga offshore, we confirmed that the method of operation of the EM survey system by ROV was readily feasible, and the system could detect actual seafloor hydrothermal deposits in the highly conductive seafloor environment.

<p>Among many parameters needed to characterize subsurface rock mass related to underground storage and disposal projects, an important one is the heat production rate of the bedrock itself.</p> <p>The rock produces heat from the decay of radioactive isotopes consisting of minerals and its gamma-ray emissions, of which the magnitude is dominated by contents of major radioactive isotopes, e.g., uranium, thorium, and potassium. The heat production rate is generally calculated from the rock density and the radiogenic isotope contents, which can be measured from the spectrometry of drilled cores or rock fragments. However, such approaches are rarely available in deep boreholes because recovering rock samples from several hundred meters to a few kilometers is quite difficult.</p> <p>A recent geophysical logging technique for deep boreholes is available where the uranium, thorium, and potassium contents are measured from the gamma-ray spectrum. However, this technique requires the density to be measured separately, and the measurement depth of the equipment is still limited. As an alternative method, a natural gamma-ray logging tool was adopted to estimate briefly the heat production from the total gamma activity, which is relatively easy to measure. This study introduces the development of the proposed method for evaluating the heat production of a granitic rock mass with domestic commercial borehole logging tools, as well as its application and verifications in deep boreholes.</p>