• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1818-1825
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• 2007

S-Adenosylmethionine (SAM) was previously documented to activate secondary metabolism in a variety of Streptomyces spp. and to promote actinorhodin (ACT) and undecylprodigiosin (RED) in Streptomyces coelicolor. The SAM-induced proteins in S. coelicolor include several ABC transporter components (SCO5260 and SCO5477) including BldKB, the component of a well-known regulatory factor for differentiations. In order to assess the role of these ABC transporter complexes in differentiation of Streptomyces, SCO5260 and SCO5476, the first genes from the cognate complex clusters, were individually inactivated by gene replacement. Inactivation of either SCO5260 or SCO5476 led to impaired sporulation on agar medium, with the more drastic defect in the SCO5260 null mutant (${\Delta}SCO5260$). ${\Delta}SCO5260$ displayed growth retardation and reduced yields of ACT and RED in liquid cultures. In addition, SAM supplementation failed in promoting the production of ACT and RED in ${\Delta}SCO5260$. Inactivation of SCO5476 gave no significant change in growth and production of ACT and RED, but impaired the promoting effect of SAM on ACT production without interfering with the effect on RED production. The present study suggests that SAM induces several ABC transporters to modulate secondary metabolism and morphological development in S. coelicolor.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.136-146
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• 1996

Studies on normal human embryos and on malformed human hearts have been two main sources of the information on the developmental cardiology, Recent advances in the biological technology has opened a new era and descriptive embryology is being shifted into dynamic developmental biology. In this review, we discuss the current understanding on the cardiac embryology relevant to clinical practices of pediatric cardiology. Classical cardiac embryology starts with understanding on five segments of a straight heart tube : the sinus venosus, the primitive atria, the embryonic left ventricle, the embryonic right ventricle and the truncus arteriosus. Key steps in the normal morphogenetic process are the complex spiral septation of ventriculoarterial junction and two jumping connections : between the embryonic right atrium and embryonic right ventricle, and between the embryonic left ventricle and the aorta. Only after these two steps are successfully completed, the third fetal stage tak s place, when myocardial growth and remodeling take place There are two outstanding progresses on the cardiac embryology during recent five-year period. One is immunohistochemical mapping of the conduction system in the developing heart and the other is the understanding on the neural crest cell migration followed by molecular detection of the microdeletion of chromosome 22. A balanced progress of classical morphological studies, modern biological technics and advanced clinical medicine is an urgent task for doctors and scientists dealing with children with sick hearts.

• Korean Journal of Materials Research
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• v.20 no.8
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• pp.412-417
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• 2010

Mo thin films were used for the back electrode because of the low resistivity in the Mo/$CuInGaSe_2$ contact in chalcopyrite solar cells. $1\;{\mu}m$ thick Mo thin films were deposited on soda lime glass by varying the Ar pressure with the dc-magnetron sputtering process. The effects of the Ar pressure on the morphology of the Mo back electrode were studied and the relationships between the morphology and electro-optical properties, namely, the resistivity as well as the reflectance of the Mo thin films, were investigated. The resitivity increased from $24\;{\mu}{\Omega}{\cdot}cm$ to $11833\;{\mu}{\Omega}{\cdot}cm$; this was caused by the increased surface defect and low crystallinity as the Ar pressure increased from $3{\times}10^{-3}$ to $3{\times}10^{-2}\;Torr$. The surface morphologies of the Mo thin films changed from somewhat coarse fibrous structures to irregular and fine celled structures with increased surface cracks along the cell boundaries, as the Ar pressure increased from $3{\times}10^{-3}$ to $3{\times}10^{-2}\;Torr$. The changes of reflectances in the visible light range with Ar pressures were mainly attributed to the surface morphological changes of the Mo thin films. The reflectance in the visible light range showed the highest value of 45% at $3{\times}10^{-3}\;Torr$ and decreased to 18.5% at $3{\times}10^{-2}\;Torr$.

• Archives of Plastic Surgery
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• v.45 no.1
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• pp.62-68
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• 2018

Background Amputation is commonly performed for toe necrosis secondary to peripheral vascular diseases, such as diabetes mellitus. When amputating a necrotic toe, preservation of the bony structure is important for preventing the collapse of adjacent digits into the amputated space. However, in the popular terminal Syme's amputation technique, partial amputation of the distal phalanx could cause increased tension on the wound margin. Herein, we introduce a new way to resect sufficient bony structure while maintaining the normal length, based on a morphological analysis of the toes. Methods Unlike the pulp of the finger in the distal phalanx, the toe has abundant teardrop-shaped pulp tissue. The ratio of the vertical length to the longitudinal length in the distal phalanx was compared between the toes and fingers. Amputation was performed at the proximal interphalangeal joint level. Then, a mobilizable pulp flap was rotated $90^{\circ}$ cephalad to replace the distal soft tissue defect. This modified toe fillet flap was performed in 5 patients. Results The toe pulp was found to have a vertically oriented morphology compared to that of the fingers, enabling length preservation through cephalad rotation. All defects were successfully covered without marginal ischemia. Conclusions While conventional toe fillet flap coverage focuses on the principle of length preservation as the first priority, our modified method takes both wound healing and length into account. The fattiest part of the pulp is advanced to the toe tip, providing a cushioning effect and enough length to substitute for phalangeal bone loss. Our modified method led to satisfactory functional and aesthetic outcomes.

• Journal of Chest Surgery
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• v.55 no.2
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• pp.151-157
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• 2022

Background: We investigated surgical outcomes after the surgical repair of cor triatriatum sinister (CTS). Methods: Thirty-two consecutive patients who underwent surgical repair of CTS from 1993 through 2020 were included in this study. The morphological characteristics, clinical features, and surgical outcomes were described and analyzed. Results: The median age and body weight at operation were 9 months (interquartile range [IQR], 3-238 months) and 7.5 kg (IQR, 5.8-49.6 kg), respectively. There were 16 males (50%). According to the modified Lucas classification, type IA (classical CTS) was most common (n=20, 62.5%). Atrial septal defect was associated in 22 patients (68.8%) and anomalous pulmonary venous return in 8 patients (25%). Pulmonary hypertension was preoperatively suspected with a high probability in 18 patients (56.3%). There was 1 early death (3.1%) after emergent membrane excision and hybrid palliation in a high-risk hypoplastic left heart syndrome patient. There were no late deaths. The overall survival rate was 96.9% at 15 years post-repair. No early survivors required reoperation during follow-up. Most survivors (31 of 32 patients, 96.9%) were in New York Heart Association functional class I at a median follow-up of 74 months (IQR, 39-195 months). At the latest echocardiography performed at a median of 42 months (IQR, 6-112 months) after repair, no residual lesion was observed except in 1 patient who had moderate pulmonary hypertension (mean pulmonary arterial pressure of 36 mm Hg). Conclusion: Surgical repair of cor triatriatum could be performed safely and effectively with an extremely low risk of recurrence.

• Advances in materials Research
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• v.12 no.3
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• pp.179-192
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• 2023

We have studied the structural and optical properties of the non-doped and Co 0.08 at.%, Co 0.02 at.%, and Co 0.11 at.% doped ZnO nanorods (NRs) synthesized using the simple low-temperature chemical bath deposition (CBD) method at 95℃ for 2 hours. The scanning electron microscope (SEM) images confirmed the morphology of the ZnO NRs are affected by Co incorporation. As observed, the Co 0.08 at.% doped ZnO NRs have a larger dimension with an average diameter of 153.4 nm. According to the International Centre for Diffraction Data (ICDD) number #00-036-1451, the x-ray diffraction (XRD) pattern of non-doped and Co-doped ZnO NRs with the preferred orientation of ZnO NRs in the (002) plane possess polycrystalline hexagonal wurtzite structure with the space group P63mc. Optical absorbance indicates the Co 0.08 at.% doped ZnO NRs have stronger and blueshift bandgap energy (3.104 ev). The room temperature photoluminescence (PL) spectra of ZnO NRs exhibited excitonicrelates ultraviolet (UV) and defect-related green band (GB) emissions. By calculating the UV/GB intensity, the Co 0.08 at.% is the proper atomic percentage to have fewer intrinsic defects. We predict that Co-doped ZnO NRs induce a blueshift of near band edge (NBE) emission due to the Burstein-Moss effect. Meanwhile, the redshift of NBE emission is attributed to the modification of the lattice dimensions and exchange energy.

• Korean Journal of Medicinal Crop Science
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• v.5 no.4
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• pp.307-313
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• 1997

Seed germination test done in laboratory does not coincide with field emergence in general. The experiments were carried out to examine the effect of priming and $GA_3$, treatment to seeds of Platycodon grandiflorum; Codonopsis lanceolata and C. pilosula on lapsed time to first seedling emergence, seedling emergence, morphological characters and growth and the cause of poor emergence of C. pilosula. No-treatment as Control (water), priming or $GA_3$ treatment was done with only distilled water for 2 days, $CA(NO_3)_2$ 150 mM for 2 days or $GA_3$ 0.1 mM for 3 days, respectively. Seedling emergence rate was counted every 2 days but morphological characters and dry weight of shoot and root were measured on 38 days after sowing. Their internal seed structures were examined with Scanning Electron Microscope. C. pilosula had poorer seedling emergence rate than P grandiflorum and C. lanceolata showing nearly same rate: Compared to the other treatment (s) P. grandiflorum displayed higher rate in priming and $GA_3$, treatments but C. lanceolata or C. pilosula did the greatest rate in only $GA_3$ or priming treatment, respectively. $GA_3$ treatment to seeds of P. grandiflorum and C. lanceolata shortened the lapsed time to seedling emergence in comparison with Control, 2-days water imbibition before sowing. In all the species plant height and number of leaves per seedling became shorter and less in priming treatment than the other treatments except plant height of C. Pilosula while their hypocotyl length was nearly same in all treatments. Although priming treatment had nearly similar effect to morphological characters, $GA_3$ treatment forced greater shoot, root and aftermath total dry weight per seedling. Poor seedling emergence of C. pilosula was caused by its seed defect like cleavage or lack of embryo, poor development of embryo and endosperm or their separation.

• Journal of Biomedical Engineering Research
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• v.28 no.4
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• pp.512-519
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• 2007

The purpose of this study is to investigate the potential of a novel tissue engineering approach to regenerate intervertebral disc. In this study, thermosensitive scaffold (chitosan-Pluronic hydrogel) and nanofiber were used to replace the nucleus pulposus (NP) and annulus fibrosus of a degenerated intervertebral disc, leading to an eventual regeneration of the disc using the minimally invasive surgical procedure and organ culture. In preliminary study, disc cells were seeded into the scaffolds and cellular responses were assessed by MTT assay and scanning electron microscopy (SEM). Based on these results, we could know that tissue engineered scaffolds might provide favorable environments for the regeneration of tissues. Organ culture was performed in fresh porcine spinal motion segments with endplates on both sides. These spinal motion segments were classified into three groups: control (Intact), injured NP (Defect), and inserting tissue engineered scaffolds (Insert). The specimens were cultivated for 7 days, subsequently structural stability, cell proliferation and morphological changes were evaluated by the relaxation time, quantity of DNA, GAG and histological examination. In these results, inserting group showed higher relaxation time, reduced decrement of DNA contents, and accumulated GAG amount. Consequently, the tissue engineered scaffolds used in this study seen to be a promising base scaffolds for regenerative intervertebral disc due to its capacity to absorb external dynamic loading and the possible ideal environment provided for disc cell growing.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.1
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• pp.71-76
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• 2008

Purpose: A simple and efficient method to prepare nanocrystalline ZnO thin film with pure strong UV emission on soda-lime-silica glass substrates by low-temperature annealing was improved. Methods: Crystal structural, surface morphological, and optical characteristics of nanocrystalline ZnO thin films deposited on soda-lime-silica glass substrates by prefiring final annealing process at 300$^{\circ}C$ were investigated by using X-ray diffraction analysis, field emission-scanning electron microscope, scanning probe microscope, ultraviolet-visible-near infrared spectrophotometer, and photoluminescence. Results: Highly c-axis-oriented ZnO films were obtained by prefiring at 300$^{\circ}C$. A high transmittance in the visible spectra range and clear absorption edge in the ultra violet range of the film was observed. The PL spectrum of ZnO thin film with a deep near band edge emission was observed while the defect-related broad green emission was nearly quenched. Conclusions: Our work will be possibly adopted to cheaply and easily fabricate ZnO-based optoelectronic devices at low temperature, below 300$^{\circ}C$, in the future.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.839-848
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• 2007

Purpose: Various kinds of biodegradable membranes are currently used in dental clinics. And the frequency and the necessity of their usage are increasing due to their numerous advantages. Therefore it is important to understand the difference of various membranes and histological reaction against implanted membranes. Materials and Methods: Biodegradable membranes of $Biogide^{(R)}$, $Resolute^{(R)}$, and $Tutodent^{(R)}$ were cut into small pieces by $1.0{\times}0.5cm$. The membranes were implanted 1.5cm apart from each other under the epithelium on the skull of 18 Sprague Dawley rats. The animals were sacrificed at 3, 7, and 14 days after surgical procedure. The specimens were examined by histological analysis. Results: 1. Early period after implantation of the membranes showed connective tissues surrounding membranes and there were a few inflammatory cells present. 2. In $Biogide^{(R)}$ and $Tutodent^{(R)}$ specimens, inflammatory cells and surrounding tissues were shown to infiltrate from outside with slight density difference inside. In $Resolute^{(R)}$ specimens, membranes were fragmented. Inflammatory cells and connective tissues were also observed inside. 3. In $Resolute^{(R)}$ specimen, giant cells were present which implicates that foreign body reaction has occurred. 4. $Biogide^{(R)}$ had lower integrity than other membranes and is not enough to be used alone in defect area. However, $Resolute^{(R)}$ had superior firmness than others. $Tutodent^{(R)}$ had middle level of integrity. Conclusion: This experimental model enabled to observe early inflammatory reactions and morphological changes of materials and can be used to develop and evaluate the efficacy of biodegradable membranes. Duplication of standardized human oral environment will be required in future experiments.