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The concentrations of a,M, and in particular its stability at low pH suggest that this protein may be useful in screening for tubular abnormalities and detecting chronic asymptomatic renal tubular dysfunction.Urinary a,M >15 mg/g creatinine is strongly suspicious of a proximal tubular dysfunction. The distinction between pure tubular proteinuria and mixed glomerular and tubular proteinuria requires further analysis.

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SummaryTwo-photon excitation laser scanning fluorescence microscopy (2p-LSM) was compared with UV-excitation confocal laser scanning fluorescence microscopy (UV-CLSM) in terms of three-dimensional (3-D) calcium imaging of living cells in culture. Indo-1 was used as a calcium indicator. Since the excitation volume is more limited and excitation wavelengths are longer in 2p-LSM than in UV-CLSM, 2p-LSM exhibited several advantages over UV-CLSM: (1) a lower level of background signal by a factor of 6-17, which enhances the contrast by a factor of 6-21; (2) a lower rate of photobleaching by a factor of 2-4; (3) slightly lower phototoxicity. When 3-D images were repeatedly acquired, the calcium concentration determined by UV-CLSM depended strongly on the number of data acquisitions and the nuclear regions falsely exhibited low calcium concentrations, probably due to an interplay of different levels of photobleaching of Indo-1 and autofluorescence, while the calcium concentration evaluated by 2p-LSM was stable and homogeneous throughout the cytoplasm. The spatial resolution of 2p-LSM was worse by 10% in the focal plane and by 30% along the optical axis due to the longer excitation wavelength. This disadvantage can be overcome by the addition of a confocal pinhole (two-photon excitation confocal laser scanning fluorescence microscopy), which made the resolution similar to that in UV-CLSM. These results indicate that 2p-LSM is preferable for repeated 3-D reconstruction of calcium concentration in living cells. In UV-CLSM, 0 . 18-mW laser power with a 2 . 6-f pinhole (in normalized optical coordinate) gives better signal-to-noise ratio, contrast and resolution than 0 . 09-mW laser power with a 4 . 9-f pinhole. However, since the damage to cells and the rate of photobleaching is substantially greater under the former condition, it is not suitable for repeated acquisition of 3-D images.

We propose a new sequestration process for anthropogenic carbon dioxide (CO 2 ) that uses waste cement. The proposed process consists of two main reactions. The first is the extraction of calcium ions (Ca 2+ ) from waste cement particles by pressurized carbon dioxide (several megapascals of pressure). The second is the precipitation of calcium carbonate (CaCO 3 ). Ca 2+ extracted from waste cement is deposited as CaCO 3 when the pressure is reduced. CaCO 3 is disposed of directly, or recycled as a raw material for cement production. In the latter case, the same amount of CO 2 is considered to be sequestered because the net amount of virgin limestone mined can be reduced. The power consumption and cost of the proposed sequestration process for CO 2 emitted from a 100 MW thermal power plant were evaluated, on the basis of laboratory-scale experimental results. The power consumption for the operating process strongly depended on the operating conditions such as the cement/water ratio, the CO 2 pressure, and the average cement diameter. The minimum power consumption was 25.9 MW/100 MW of power generation when optimized within the operating conditions studied experimentally, and the sequestration cost associated with the power consumption (excluding capital and maintenance) would be about $22.6/t of carbon dioxide. This result indicates that the present process is highly competitive with previously reported CO 2 sequestration scenarios such as ocean sequestration. Sensitivity analysis of the operating parameters was carried out on the operating power consumption, and it was found that a smaller ratio of waste cement to water and a lower CO 2 pressure will decrease the operating power consumption.

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