• KIPS Transactions on Computer and Communication Systems
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• v.3 no.1
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• pp.1-6
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• 2014

Most of the previous algorithms focus on computing the convex hull for a set of points. In this paper, we present a method for approximating the convex hull for a set of spheres with various radii in discrete space. Computing the convex hull for a set of spheres is a base technology for many applications that study structural properties of molecules. We present a voxel map data structures, where the molecule is represented as a set of spheres, and corresponding algorithms. Based on CUDA programming for using the parallel architecture of GPU, our algorithm takes less than 40ms for computing the convex hull of 6,400 spheres in average.

• BMB Reports
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• v.40 no.6
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• pp.1009-1015
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• 2007

In this communication, we report the efficacy of $\beta$-carotene towards differentiation and apoptosis of leukemia cells. Dose ($20{\mu}M$) and time dependence (12 h) tests of $\beta$-carotene showed a higher magnitude of decrease (significance p < 0.05) in cell numbers and cell viability in HL-60 cells than U937 cells but not normal cell like Peripheral blood mononuclear cell (PBMC). Microscopical observation of $\beta$-carotene treated cells showed a distinct pattern of morphological abnormalities with inclusion of apoptotic bodies in both leukemia cell lines. When cells were treated with $20{\mu}M$ of $\beta$-carotene, total genomic DNA showed a fragmentation pattern and this pattern was clear in HL-60 than U937 cells. Both the cell lines, on treatment with $\beta$-carotene, showed a clear shift in $G_1$ phase of the cell cycle. In addition the study also revealed anti-oxidant properties of $\beta$-carotene since there was reduction in relative fluorescent when treated than the control at lower concentration. Collectively this study shows the dual phenomenon of apoptosis and differentiation of leukemia cells on treatment with $\beta$-carotene.

• Rapid Communication in Photoscience
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• v.4 no.2
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• pp.31-33
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• 2015

Fluorescence (FL) properties of a novel donor-acceptor dyad, comprised of mesitylene and 1,4-dicyano-2-methylnaphthalene (DCMN) subunits connected by an ether linkage, were elucidated. The dyad in cyclohexane exhibits FL arising from an intramolecular exciplex. In the crystalline state, the dyad does not emit light from intra- and inter-molecular exciplexes but rather displays FL that is nearly equivalent to that of 2-methoxymethyl-substituted DCMN. However, the emission spectrum of the crystalline dyad contains a shoulder in the long wavelength region, suggesting that weak intercolumnar charge-transfer interactions take place between columns consisting of the mesitylene and DCMN subunits.

• Rapid Communication in Photoscience
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• v.2 no.2
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• pp.56-59
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• 2013

Plant phytochromes, molecular light switches that regulate various aspects of plant growth and development, are known as autophosphorylating serine/threonine kinases. Although recent studies reveal that phytochrome autophosphorylation plays an important role in the regulation of phytochrome signaling through the control of phyA protein stability, the in vivo functional roles of phytochrome kinase activity in plant light signaling are largely unknown. Thus, it is necessary to investigate the detailed function of phytochrome as a protein kinase, which might include mapping of kinase domain on the phytochrome molecule, searching for substrates that could be phosphorylated by phyA, and in vivo functional analysis of the kinase activity with phytochrome mutants displaying reduced kinase activity. Our recent studies reveal that the kinase activity of phytochrome plays a positive role in plant light signaling. Therefore, we highlight the current knowledge about the functional roles of phytochrome kinase activity in the light signal transduction of plants, based on our recent results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.7
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• pp.29-35
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• 2000

The relationship between calculated hydrogen molecular concentration in fiber core and measured index change during the grating growth is analyzed. The index change increases by ${\sim}2{\times}10^{-5}$ per 100ppm of $H_2$ concentration in standard telecommunication optical fiber and the defects related photosensitivity generate ${\sim}3.8{\times}10^{17}$ per 100ppm of $H_2$.

• BMB Reports
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• v.42 no.5
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• pp.281-285
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• 2009

Peroxisomes play an important role in cellular defense systems and generate secondary messengers for cellular communication. Saccharomyces cerevisiae containing oleate-induced peroxisomes were subjected to buffer-soluble extraction and two chromatographic procedures, and a protein with antifungal activity was isolated. The results of MALDI-TOF analysis identified the isolated protein as peroxisomal 3-ketoacyl-CoA thiolase (ScFox3). Purified yeast ScFox3 exhibited thiolase activity that catalyzed the thiolytic cleavage of 3-ketoacyl-CoA to acetyl-CoA and acyl-CoA. ScFox3 protein inhibited various pathogenic fungal strains, with the exception of Aspergillus flavus. Using ScFox3-GFP and PTS2 signal-truncated ScFox3M-GFP, we showed that only ScFox3-GFP, with an intact PTS2 peroxisome signal sequence, was able to translocate into peroxisomes. Yeast ScFox3 is a natural antifungal agent found in peroxisomes.

• Journal of Animal Science and Technology
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• v.55 no.6
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• pp.521-530
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• 2013

Direct cell-cell communication via the transfer of small molecules between neighboring cells in tissue is accomplished by gap junctions composed of various connexins (Cxs). Proper postnatal development of the epididymis is important for acquisition of male reproduction. The epididymal epithelium is composed of several cell types, and some of these cells are connected by gap junctions. The present study was conducted to determine the presence of Cx transcripts in the corpus and cauda epididymis. In addition, transcriptional changes of Cxs expressed during different postnatal stages were examined by real-time PCR analysis. In both epididymal regions, the same nine Cx transcripts of thirteen Cxs tested were detected. In the corpus epididymis, the highest levels of Cxs31.1 and 37 transcripts were observed at 45 days of age, and amounts of Cxs26, 30.3, and 32 transcripts increased with age and subsequently decreased in the elderly. Expression of Cx31 was greatly increased in the adult and elder stages, while Cxs40, 43, and 45 were abundant in the early postnatal stages. In the cauda epididymis, expression of Cxs26, 30.3, 31.1, 37, and 40 reached the highest levels at 5 months of age. The levels of Cxs31 and 32 mRNAs fluctuated throughout the postnatal period. The amounts of Cxs43 and 45 transcripts were more abundant during the late neonatal and prepubertal ages than later ages. These findings suggest that regional specification of the epididymis is partly regulated by differential expression of Cx genes during the postnatal developmental period.

• Rapid Communication in Photoscience
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• v.4 no.1
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• pp.1-8
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• 2015

For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

• Rapid Communication in Photoscience
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• v.4 no.3
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• pp.54-58
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• 2015

Under the condition of femtosecond impulsive nonlinear optical irradiation, the bright and narrowed blue emission of silicon nanocrystal was observed. This synthetic method produced very small (~ 4 nm) oxide-capped silicon nanocrystal having probably ultra small emitting core (~ 1 nm) inferred from luminescence. By controlling the stirring condition, very high efficiencies of luminescence ( 4 fold higher) were obtained compared with the other conventional femtosecond laser fragmentation methods, which was attributed to the differences in hydration shell structure during the femtosecond laser induced irreversible phase transition reaction. When we properly adjusted the irradiation times of the white light continuum and stirring condition, very homogeneous luminescent silicon nanocrystal bands having relatively sharp lineshape were obtained, which can be attributable to the luminescent core site isolated and free from the surface defects.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.4
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• pp.335-336
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• 2007

Meniscus-like presentation of ulcerating gastric carcinoma on upper gastrointestinal series radiograph was first described in 1921 by Carman and has since been known as a useful differential diagnostic sign in radiology. In 1982 using then newly introduced computed tomography (CT) Widder and Mueller revisited the meniscus sign. Their study was primarily focused on a dynamic assessment of the demonstrability of the meniscus sign that largely depends on the judgment and technical skill of examiner, especially graded compression and patient positioning. One year earlier Balfe et al. assessed the diagnostic reliability of gastric wall thickening as observed on CT scan in adenocarcinoma, lymphoma and leiomyosarcoma and concluded that it is not a reliable finding. In contrast, however, Lee et al. recently emphasized that the wall thickness measurement on CT of exophytic carcinoma, myoma and ulcers was a useful diagnostic means. Thus, it appears that gastric wall thickening or mucosal heave-up is by itself not as reliable as the meniscus sign. The electronic search of world literature failed to disclose earlier report of this sign demonstrated by $^{18}F-FDG$ positron emission tomography and computed tomography (PET/CT). The present communication documents $^{18}F-FDG$ PET/CT finding of the meniscus sign as encountered in a case of ulcerating gastric carcinoma, the histological diagnosis of which was moderately differentiated tubular adenocarcinoma. Unlike most gastric tumors without ulceration that tend to unimpressively accumulate $^{18}F-FDG$ the present case of Borrmann type III gastric carcinoma demonstrated markedly increased $^{18}F-FDG$ uptake.