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Photothermal imaging is useful for detecting individual nanoparticles and obtaining the absorption spectra. This study presents a wide-field photothermal reflectance spectroscopy technique achieved by incorporating a pump beam, a probe beam, and a charge-coupled device (CCD) camera into a commercial microscopic setup. The presented design does not require precise alignment between the pump and the probe beams and enables the observation of numerous individual nanoparticles during image acquisition. Despite the use of a simple imaging processing method, i.e., a four-bucket method using a CCD camera, sufficient sensitivity for the spectral imaging of a single gold nanorod (20 nm diameter and 84 nm length) is demonstrated. Numerous individual nanoparticles within a wide field of view (240 μm × 180 μm) are detected in an image captures at an imaging measurement speed of 0.02 mm2 min−1. Furthermore, the proposed photothermal reflectance spectroscopy technique can detect the variation in the absorption peak of the measured spectra depending on the aspect ratio of individual nanoparticles within a spectral resolution of 1 nm.

We report parallel spectral-domain optical coherence tomography (OCT) at 500 000 A-scan/s. This is the highest-speed spectral-domain (SD) OCT system using a single line camera. Spectrally encoded line-field scanning is proposed to increase the imaging speed in SD-OCT effectively, and the tradeoff between speed, depth range, and sensitivity is demonstrated. We show that three imaging modes of 125k, 250k, and 500k A-scan/s can be simply switched according to the sample to be imaged considering the depth range and sensitivity. To demonstrate the biological imaging performance of the high-speed imaging modes of the spectrally encoded line-field OCT system, human skin and a whole leaf were imaged at the speed of 250k and 500k A-scan/s, respectively. In addition, there is no sensitivity dependence in the B-scan direction, which is implicit in line-field parallel OCT using line focusing of a Gaussian beam with a cylindrical lens. [ABSTRACT FROM AUTHOR]

Hematein, a natural compound, is a known anti-inflammatory and antiatherogenic agent in the rabbit model. The authors investigated the effects of this compound on atherogenesis and possible mechanisms of the actions in the hyperlipidemic mice. Low-density lipoprotein receptor-deficient (Ldlr-/-) mice fed a high-cholesterol diet alone for 8 weeks developed the fatty streak lesion in the aortic sinus, whereas this lesion was significantly reduced by hematein treatment without a change in plasma lipid levels compared with control mice. Hematein treatment reduced plasma levels of lipid peroxide and superoxide generation in LPS-stimulated peritoneal macrophage. Hematein treatment inhibited NF-kappaB-DNA binding activity in peritoneal macrophages from Ldlr-/- mice and the activation of NF-kappaB in RAW264.7 macrophages. This compound suppressed plasma nitrite/nitrate levels in Ldlr-/- mice and NO production and iNOS expression in LPS+IFNgamma-stimulated peritoneal macrophages. Hematein treatment also suppressed the activity of iNOS promoters in RAW264.7 macrophages, and reduced the plasma levels of TNF-alpha and IL-1beta and the production of these cytokines in LPS+IFNgamma-stimulated peritoneal macrophages. These results suggest that hematein inhibits atherosclerotic lesion formation, possibly by reducing proinflammatory mediators through a decrease in reactive oxygen species generation and NF-kappaB activation.