The X-ray phase tomography of biological samples is reported, which is based on X-ray Talbot interferometry. Its imaging principle is described in detail, and imaging results obtained for a cancerous rabbit liver and a mouse tail with synchrotron radiation are presented. Because an amplitude grating is needed to construct an X-ray Talbot interferometer, a high-aspectratio grating pattern was fabricated by X-ray lithography and gold electroplating. X-ray Talbot interferometry has an advantage that it functions with polychromatic cone-beam X-rays. Finally, the compatibility with a compact X-ray source is discussed.

We fabricated dye-adsorbed NiO solar cells (pDSCs) with six different metal-free organic dyes having various ground-state oxidation potentials. Under monochromatic light irradiation, all dyes showed cathodic current at wavelengths where the dyes absorb, suggesting hole injection occurred from the adsorbed dyes to the valence band of NiO. Absorbed photon-to-current conversion efficiency (APCE) tends to increase with the increase of energy difference (∆E) between the valence band edge of NiO and the ground state of the dyes. The maximum APCE of 30% was obtained with 0.6 eV of the ∆E. The apparent hole diffusion coefficient in the NiO electrode was nearly independent from light intensity, and the values were estimated to be 4 × 10 -8 cm 2 /s. On the other hand, hole lifetime depends on light intensity, ranging from 3 × 10 -2 to 1 × 10 0 s. Investigation of the anchoring site of the dyes and the results of molecular orbital calculations suggested that electron injection from the dye to the valence band of NiO, occurring just after the hole injection, is the major factor of the relatively low efficiency even with the case of large ∆E.

Colloidal gold nanoparticles with a broad size distribution were prepared by laser ablation of a gold metal plate in an aqueous solution of sodium dodecyl sulfate (SDS) and were fragmented under irradiation of a 532 nm laser at different SDS concentrations and laser fluences. Gold nanoparticles with a desired average size (1.7-5.5 nm in diameter) were prepared by tuning properly the surfactant concentration and the laser fluence. The concentration of SDS was found to be higher than a critical micelle concentration so as to gain a significant size reduction and to obtain stable final products. Laser ablation in combination with the laser-induced size control provides a versatile full physical preparation method of size-selected gold nanoparticles.

Platinum nanoparticles were produced by laser ablation of a platinum metal plate in an aqueous solution of sodium dodecyl sulfate (SDS). The absorption spectrum of the platinum nanoparticles was essentially the same as that of platinum nanoparticles chemically prepared in a solution. The size distribution of the nanoparticles thus produced was measured to be in the range of 1-7 nm in diameter by an electron microscope. The abundance of the nanoparticles changes with the concentration of SDS in the solution. Stable platinum nanoparticles were found to be produced by this method even in pure water.

oronary artery disease (CAD) and its thrombotic complications are the leading cause of morbidity and mortality in the industrialized countries. Over the past 30 years, invasive coronary angiography (ICAG) has been the gold standard method for the visualization and detection of coronary stenosis. Recently, efforts have been made to develop reliable noninvasive diagnostic methods that would allow a broader use, as well as decreasing the risks linked to an invasive examination.Multislice computed tomography (MSCT), which started with a 4-slice scanner in 1998, was the beginning of visualizing the coronary arteries noninvasively, 1-9 and with the development of 16-slice MSCT, this desire has been realized to some extent. To date, many investigators have evaluated the accuracy of MSCT for detecting significant coronary stenosis and in most of the published studies the sensitivity is approximately 80% and the specificity approximately 90%. [10][11][12][13][14][15][16][17][18][19] The results appear promising, but those studies did not consist of consecutive patients, including those with unsatisfactory images for interpretation. Besides, cases with severe calcification, high heart rates (>70 beats/min), or previous revascularization, were excluded from most of the studies.In daily practice, however, we often encounter patients with advanced CAD, having severely calcified arteries, or patients who are post percutaneous coronary intervention (PCI) using different treatment modalities such as stenting, plain old balloon dilatation, or debulking.The new 64-slice MSCT (64-MSCT), which provides a 0.4 mm isotropic resolution and less than 165 ms temporal resolution, has the potential to overcome image-degrading artifacts related to motion, pixel noise, calcification or coronary stents to some extent. 20,21 The aim of our study was to evaluate the diagnostic accuracy of 64-MSCT in various types of patients, including those with severely calcified arteries or post-PCI, as Background Multislice computed tomography (MSCT) is a promising noninvasive method of detecting coronary artery disease (CAD). However, most data have been obtained in selected series of patients. The purpose of the present study was to investigate the accuracy of 64-slice MSCT (64 MSCT) in daily practice, without any patient selection. Methods and ResultsUsing 64-slice MSCT coronary angiography (CTA), 69 consecutive patients, 39 (57%) of whom had previously undergone stent implantation, were evaluated. The mean heart rate during scan was 72 beats/min, scan time 13.6 s and the amount of contrast media 72 mL. The mean time span between invasive coronary angiography (ICAG) and CTA was 6 days. Significant stenosis was defined as a diameter reduction of >50%. Of 966 segments, 884 (92%) were assessable. Compared with ICAG, the sensitivity of CTA to diagnose significant stenosis was 90%, specificity 94%, positive predictive value (PPV) 89% and negative predictive value (NPV) 95%. With regard to 58 stented lesions, the sensitivity, specificity, PPV and NPV were 93...

Correlation of in vivo IVUS RF data analysis with histopathology shows a high accuracy. In vivo IVUS RF data analysis is a useful modality for the classification of different types of coronary components, and may play an important role in the detection of vulnerable plaque.

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X-ray Talbot interferometry, which uses two transmission gratings, has the advantage that broad energy bandwidth x-rays can be used. We demonstrate the use of white synchrotron radiation for high-speed X-ray phase imaging and tomography in combination with an X-ray Talbot interferometer. The moiré fringe visibility over 20% was attained, enabling quantitative phase measurement. X-ray phase images with a frame rate of 500 f/s and an X-ray phase tomogram with a scan time of 0.5 s were obtained successfully. This result suggests a breakthrough for time-resolved three-dimensional observation of objects that weakly absorb X-rays, such as soft material and biological objects.