Application of Scan-less Two-Dimensional Confocal Microscopy Based on a Combination of Confocal Slit With Wavelength/Space Conversion

Confocal laser microscope (CLM) has been widely used in the fields of the non-contact surface topography, biomedical imaging, and other applications, because the confocality gives two-dimensional (2D) optical-sectioning or three-dimensional (3D) imaging capability with the depth selectivity. Combination of line-focused CLM with one-dimensional (1D) spectral encoding CLM enables us to obtain the 2D confocal image without the need for the mechanical scanning. So-called scan-less 2D CLM is a unique imaging modality, however, there are no attempts to apply for practical application. In this paper, we constructed scan-less 2D CLM with the image acquisition time of 0.23 ms, the lateral resolution of 1.2 µm, the depth resolution of 2.4 µm, and apply it for different kinds of application to evaluate its practical potential

The effect of leg hyperthermia using far infrared rays in bedridden subjects with type 2 diabetes mellitus

We examined the effect of leg hyperthermia on oxidative stress in bedridden subjects with type 2 diabetes mellitus using 15-min sessions of far infrared rays over a two-week period. Four subjects (male 1, female 3) incapacitated by a stroke were recruited for this study. All patients were admitted to Takahashi Central Hospital and ate the same hospital meals. Fasting plasma glucose, HbA1c, tumor necrosis factor (TNF)alpha, free fatty acid, leptin, adiponectin and plasma 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha) levels as a marker of oxidative stress were measured on admission, just before and 2 weeks after local heating of the leg. Results showed that plasma total 8-epi-PGF2alpha levels were decreased significantly while TNFalpha levels were increased significantly. On the other hand, glucose, HbA1c, free fatty acid, leptin and adiponectin levels were not changed during the study period. These results suggest that repeated leg hyperthermia may protect against oxidative stress.</p

Scan-Less, Kilo-Pixel, Line-Field Confocal Phase Imaging with Spectrally Encoded Dual-Comb Microscopy

Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection, and its image acquisition rate is boosted by scan-less imaging techniques. However, the optical-intensity-based image contrast in CLM makes it difficult to visualize transparent non-fluorescent objects or reflective objects with nanometer unevenness. In this paper, we introduce an optical frequency comb (OFC) to scan-less CLM to give the optical-phase-based image contrast. One-dimensional (1D) image pixels of a sample are separately encoded onto OFC modes via 1D spectral encoding by using OFC as an optical carrier of amplitude and phase with a vast number of discrete frequency channels. Then, line-field confocal information of amplitude and phase are decoded from a mode-resolved OFC amplitude and phase spectra obtained by dual-comb spectroscopy. The proposed confocal phase imaging will further expand the application fields of CLM

Scan-Less, Kilo-Pixel, Line-Field Confocal Phase Imaging with Spectrally Encoded Dual-Comb Microscopy

Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection, and its image acquisition rate is boosted by scan-less imaging techniques. However, the optical-intensity-based image contrast in CLM makes it difficult to visualize transparent non-fluorescent objects or reflective objects with nanometer unevenness. In this paper, we introduce an optical frequency comb (OFC) to scan-less CLM to give the optical-phase-based image contrast. One-dimensional (1D) image pixels of a sample are separately encoded onto OFC modes via 1D spectral encoding by using OFC as an optical carrier of amplitude and phase with a vast number of discrete frequency channels. Then, line-field confocal information of amplitude and phase are decoded from a mode-resolved OFC amplitude and phase spectra obtained by dual-comb spectroscopy. The proposed confocal phase imaging will further expand the application fields of CLM

Inhibitory Effect of 1α-Hydroxyvitamin D3 on N-nitrosobis (2-oxopropyl)Amine-induced Cholangiocarcinogenesis in Syrian Hamsters

Sixty-three male 5-week-old Syrian hamsters received the carcinogen N-nitrosobis(2-oxopropyl)amine (BOP) s.c. in 5 weekly injections (the first, 70mg/kg body, and the remaining, 20mg/kg each). The hamsters that received BOP were given intragastric administration of 0.2ml of medium chain triglyceride (MCT) with or without 0.04μg of 1α-hydroxyvitamin D3 [1α(OH)D3] through a feeding tube for 12 weeks. Thus, 3 groups were assigned:Group 1;BOP alone (n＝20), Group 2;BOP＋MCT (n＝18) and Group 3;BOP＋1α(OH)D3 (n＝25). The mean body weight of Group 3 was lower than those of Groups 1 and 2 at the end of the experiment (p＜0.001,Tukey-Kramer HSD test). At the end of week 12, all surviving hamsters were put to sleep. The incidences of liver tumors were 80%, 72% and 32% in Groups 1, 2 and 3, respectively. The incidence of tumors in Group 3 was significantly lower than in Group 1 and Group 2 (p＜0.05, χ2-test). All tumors were cholangiocarcinoma. These results indicated that BOP-induced cholangiocarcinogenesis was suppressed by the supplemental administration of 1α(OH)D3

Dual-optical-comb spectroscopic ellipsometry

Spectroscopic ellipsometry is a means to investigate optical and dielectric material responses. Conventional spectroscopic ellipsometry has trade-offs between spectral accuracy, resolution, and measurement time. Polarization modulation has afforded poor performance due to its sensitivity to mechanical vibrational noise, thermal instability, and polarization wavelength dependency. We equip a spectroscopic ellipsometer with dual-optical-comb spectroscopy, viz. dual-optical-comb spectroscopic ellipsometry (DCSE). The DCSE directly and simultaneously obtains amplitude and phase information with ultra-high spectral precision that is beyond the conventional limit. This precision is due to the automatic time-sweeping acquisition of the interferogram using Fourier transform spectroscopy and optical combs with well-defined frequency. Ellipsometric evaluation without polarization modulation also enhances the stability and robustness of the system. In this study, we evaluate the DCSE of birefringent materials and thin films, which showed improved spectral accuracy and a resolution of up to 1.2x10-5 nm across a 5-10 THz spectral bandwidth without any mechanical movement.Comment: 30 pages, 4 figure

Farber's disease (disseminated lipogranulomatosis): the first case reported in Japan.

We report the first case in Japan, i.e., the first case among oriental subject of Farber's disease. This is a rare disorder of lipid metabolism in infancy subsequent to a genetically-determined defect in ceramide degradation. Main features are characterized clinically by hoarseness, joint swelling, subcutaneous nodules and retarded psychomotor development. Lipid analysis and pathological investigation on the material obtained from a subcutaneous nodule confirmed clearly the presence of ceramide and intracytoplasmic inclusion bodies characteristic for Farber's disease. In this case, we experienced also corneal opacity and striking abnormalities in electroencephalogram, which have apparently not been noticed in the 17 cases hitherto reported.</p

Dual-comb spectroscopic ellipsometry

Spectroscopic ellipsometry is a means of investigating optical and dielectric material responses. Conventional spectroscopic ellipsometry is subject to trade-offs between spectral accuracy, resolution, and measurement time. Polarization modulation has afforded poor performance because of its sensitivity to mechanical vibrational noise, thermal instability, and polarization-wavelength dependency. We combine spectroscopic ellipsometry with dual-comb spectroscopy, namely, dual-comb spectroscopic ellipsometry. Dual-comb spectroscopic ellipsometry (DCSE). DCSE directly and simultaneously obtains the ellipsometric parameters of the amplitude ratio and phase difference between s-polarized and p-polarized light signals with ultra-high spectral resolution and no polarization modulation, beyond the conventional limit. Ellipsometric evaluation without polarization modulation also enhances the stability and robustness of the system. In this study, we construct a polarization-modulation-free DCSE system with a spectral resolution of up to 1.2 × 10−5 nm throughout the spectral range of 1514–1595 nm and achieved an accuracy of 38.4 nm and a precision of 3.3 nm in the measurement of thin-film samples

Scan-less confocal phase imaging based on dual-comb microscopy

Confocal laser microscopy (CLM) is a powerful tool in life science research and industrial inspection because it offers two-dimensional optical sectioning or three-dimensional imaging capability with micrometer depth selectivity. Furthermore, scan-less imaging modality enables rapid image acquisition and high robustness against surrounding external disturbances in CLM. However, the objects to be measured must be reflective, absorptive, scattering, or fluorescent because the image contrast is given by the optical intensity. If a new image contrast can be provided by the optical phase, scan-less CLMcan be further applied for transparent non-fluorescent objects or reflective objects with nanometer unevenness by providing information on refractive index, optical thickness, or geometrical shape. Here, we report scan-less confocal dual-comb microscopy offering a phase image in addition to an amplitude image with depth selectivity by using an optical frequency comb as an optical carrier of amplitude and phase with discrete ultra-multichannels. Our technique encodes confocal amplitude and phase images of a sample onto a series of discrete modes in the optical frequency comb with well-defined amplitude and phase to establish a one-to-one correspondence between image pixels and comb modes. The technique then decodes these images from comb modes with amplitude and phase. We demonstrate confocal phase imaging with milliradian phase resolution under micrometer depth selectivity on the millisecond timescale. As a proof of concept, we demonstrate the quantitative phase imaging of standing culture fixed cells and the surface topography of nanometer-scale step structures. Our technique for confocal phase imaging will find applications in three-dimensional visualization of stacked living cells in culture and nanometer surface topography of semiconductor objects