• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제32권3호
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• pp.99-103
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• 2021

The purpose of this review is to examine the clinical use of functional near-infrared spectroscopy (fNIRS) in children and adolescents with psychiatric disorders. Many studies have been conducted using objective evaluation tools for psychiatric evaluation, such as predicting psychiatric symptoms and treatment responses. Compared to other tools, fNIRS has the advantage of being a noninvasive, inexpensive, and portable method and can be used with patients in the awake state. This study mainly focused on its use in patients with attention-deficit/hyperactivity disorder and autism spectrum disorder. We hope that research involving fNIRS will be actively conducted in various diseases in the future.

• Journal of Chest Surgery
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• 제54권6호
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• pp.517-520
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• 2021

Innominate artery aneurysms are challenging for surgeons to treat because of the requirement for brain protection during surgery. In innominate artery aneurysms, the endovascular approach does not require cardiopulmonary bypass, but patients who can be treated using this approach are limited in number, and the long-term results of endovascular treatment are unclear. Here, we report our experience of successfully treating a patient with an innominate artery aneurysm using near-infrared spectroscopy without cardiopulmonary bypass support or hypothermic circulatory arrest.

• Journal of the Optical Society of Korea
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• 제20권2호
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• pp.269-275
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• 2016

This study has investigated the feasibility of 980-nm low-energy pulsed near-infrared laser stimulation to evoke auditory responses, as well as the effects of radiant exposure and pulse duration on auditory responses. In the experiments, a hole was drilled in the basal turn of the cochlea in guinea pigs. An optical fiber with a 980-nm pulsed infrared laser was inserted into the hole, orientating the spiral ganglion cells in the cochlea. To model deafness, the tympanic membrane was mechanically damaged. Acoustically evoked compound action potentials (ACAPs) were recorded before and after deafness, and optically evoked compound action potentials (OCAPs) were recorded after deafness. Similar spatial selectivity between optical and acoustical stimulation was found. In addition, OCAP amplitudes increased with radiant exposure, indicating a photothermal mechanism induced by optical stimulation. Furthermore, at a fixed radiant exposure, OCAP amplitudes decreased as pulse duration increased, suggesting that optical stimulation might be governed by the time duration over which the energy is delivered. Thus, the current experiments have demonstrated that a 980-nm pulsed near-infrared laser with low energy can evoke auditory neural responses similar to those evoked by acoustical stimulation. This approach could be used to develop optical cochlear implants.

• 공업화학
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• 제33권1호
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• pp.17-27
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• 2022

형광 이미징은 시간 분해능과 공간 해상도가 높기 때문에 기초연구에서 세포나 소동물 이미징에 널리 활용된다. 기존의 형광 이미징은 가시광선 영역의 광원을 활용하기 때문에 조직 내 광투과도가 낮고, 광원에 의한 광독성이 생길 수 있으며, 자가형광에 의한 간섭으로 검출 민감도가 떨어지는 한계가 있다. 이러한 점을 개선하기 위해 에너지가 낮은 장파장의 광원을 활용하고자 하며, 700~900 nm 영역을 활용하는 근적외선-I 형광 이미징이 개발되었고, 이미징 성능을 대폭 향상시키기 위해서 1000~1700 nm 영역의 장파장을 이용하는 근적외선-II 이미징이 연구자들의 관심을 받고 있다. 근적외선-II 영역은 광산란이 최소화되어 생체조직 내 투과도를 약 10 mm까지 향상시킬 수 있고, 생체조직의 자가형광도 최소화되어 고민감도와 고해상도의 형광 이미징이 가능하다. 본 총설에서는 다양한 근적외선-II 형광 이미징 탐침 중에서 광안정성이 뛰어나고 발광 파장 조절이 용이한 무기 나노입자 기반 탐침에 대해 살펴보았고, 그 중에서 단층 탄소 나노튜브와 양자점 및 란탄족 나노입자에 대해 중점적으로 기술하였다.

• 천문학회보
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• 제46권1호
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• pp.45.1-45.1
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• 2021

The polarization degree as a function of phase angle (the Sun-target-observer's angle), so-called the polarimetric phase curves (PPC), have provided priceless information on asteroids' albedos since B. Lyot (1929). Succeeding experimental works in 1970s have confirmed the Umow law: There is a universal and strong correlation between the albedo and the PPC slope (slope of the tangential line at the zero of the PPC at phase angle ~ 20 degrees). Experiments in 1990s (ref [1]), on the other hand, have demonstrated that the negative branch of PPC is dependent on the size parameter (X ~ π * particle-size / wavelength), especially when X <~5. The change in particle size changed the minimum polarization degree, location of the minimum, and the width of the negative branch (called the inversion angle). From polarimetry[2] and spectroscopy[3], large asteroids are expected to be covered with fine (<~ 10 ㎛ size) particles due to the gravity. The size parameters are X ~ 30 at the optical wavelength (λ ~ 0.5 ㎛) and X ~ 10 in near-infrared (J, H, Ks bands; λ ~ 1.2-2.2 ㎛), if the representative particle size of 5 ㎛ is considered. Accordingly, the near-infrared polarimetry has a great potential to validate the idea in ref[1]. We conducted near-infrared photopolarimetry of the large asteroid (4) Vesta using the Nishiharima Infrared Camera (NIC) at Nishi-Harima Astronomical Observatory (NHAO). NIC allows simultaneous polarimetric measurements in J, H, and Ks bands, and thus the change of PPC is obtained for three different size parameters. As a result, we found a signature of the change in the negative branch in the PPC of asteroid (4) Vesta. We will introduce our observation and the results and give an interpretation of the regolith on Vesta.

• 천문학회보
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• 제44권2호
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• pp.50.2-50.2
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• 2019

We present the results of high-resolution (R ≥ 30,000) optical and near-infrared spectroscopic monitoring observations of a FU Orionis-type object, 2MASS J06593158-0405277. We have monitored 2MASS J06593158-0405277 with the Bohyunsan Optical Echelle Spectrograph (BOES) and the Immersion GRating INfrared Spectrograph (IGRINS) since December 2014. Various features produced by wind, disk, and outflow/jet were detected. The wind features varied over time and disappeared about a year after the outburst occurred. The double-peaked line profiles were detected in the optical and near-infrared, and the line widths decrease with increasing wavelength. The disk features in the optical spectra are fit well with G2-type or G5-type stellar spectra convolved with a disk rotational profile of about 45 km s^-1, which corresponds to a disk radius of about 71 R_⊙for a central mass of 0.75 M_⊙. Disk features in near-infrared spectra are fit well with a K1-type stellar spectrum convolved with a disk rotational profile of about 35 km s^-1, which corresponds to a disk radius of about 117 R_⊙ for a central mass of 0.75 M_⊙. We also detected [S II] and H2 emission lines, which are rarely found in FUors but are usually found in the earlier stage of young stellar objects. Therefore, we suggest that 2MASS J06593158-0405277 is in the relatively earlier part of Class II stage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.391-392
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• 2012

• 천문학논총
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• 제32권1호
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• pp.327-329
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• 2017

We report a spatial fluctuation analysis of the sky brightness in the near-infrared from observations towards the north ecliptic pole (NEP) by AKARI at 2.4 and $3.2{\mu}m$. As a follow up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000". After pre-processing, additional correction procedures were done to correct time varying components and instrumental effects such as MUXbleed. To remove resolved objects, we applied $2{\sigma}$ clipping and point spread function (PSF) subtraction. We finally obtained mosaicked images which can be used for the study of various diffuse emissions in the near-infrared sky and found that there are spatial structures in the mosaicked images using a power spectrum analysis.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.4106-4106
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• 2001

A method to discriminate human gallstones by nea. infrared(NIR) spectrometry using a soft independent modeling of class analogy (SIMCA) has been studied. The fifty NIR spectra of gallstones in the wavenumber range from 4500 to 10,000 cm$\^$-1/ were measured. The forty samples were classified to three classes, cholesterol stone, calcium bilirubinate stone and calcium carbonate stone according to the contents of major components in each gallstone. The training set which contained objects of the different known class was constructed using forty NIR spectra and the test set was made with ten different gallstone spectra. The number of important principal components(PCs) to describe the class was determined by cross validation in order to improve the decision criterion of the SIMCA for the training set. The score plots of the class training set whose objects belong to the other classes were inspected. The critical distance of each class was computed using both the Euclidean distance and the Mahalanobis distance at a proper level of significance(${\alpha}$). Two methods were compared with respect to classification and their robustness towards the number of PCs selected to describe different classes.

• 천문학회보
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• 제41권2호
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• pp.57.2-57.2
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• 2016

Polarimetry is an important tool for studying the physical processes in the interstellar medium, including star-forming regions. Polarimetry of young stellar objects and their circumstellar structures provides invaluable information about distributions of matter and configurations of magnetic fields in their environments. However, only a few near-infrared circular polarization (CP) observations were reported so far (before our survey). A systematic near-infrared CP survey has been firstly conducted in various star-forming regions, covering high-mass, intermediate-mass, and low-mass young stellar objects. All the observations were made using the SIRPOL imaging polarimeter on the Infrared Survey Facility (IRSF) 1.4 m telescope at the South African Astronomical Observatory (SAAO). In this presentation, we present the first CP survey results. The polarization patterns, extents, and maximum degrees of circular and linear polarizations are used to determine the prevalence and origin of CP in the star-forming regions. Our results are explained with a combination of circumstellar scattering and dichroic extinction mechanism generating the high degrees of CP in star-forming regions. The universality of the large and extended CPs in star-formaing regions can also be linked with the origin of homochirality of life.