• Mycobiology
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• v.34 no.3
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• pp.148-150
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• 2006

Karoowia saxeti was recorded during the lichen field expedition in southern part of Korea in 2006. The lichen was found on the rock surface along coastal line. This species was easily recognized by chemistry (K+ yellow) and the presence of isidia. Thallus was saxicolous, subcrustose, more or less lobate at the center with clearly lobed margins, $2{\sim}6\;cm$ broad and pale yellowish green. Thalli lobes were irregular, variable, up to 1.0mm wide, not branched, flat to more or less convex and contiguous to subimbricate. Upper surface of the thalli was continuous, emaculate, moderately isidiate. The isidia was subglobose to cynlindrical, darkening at the tips and unbranched. Low surface of the thalii was black with a spongy rhizoidal and lamellar layer. HPLC analysis proved the presence of stictic acid (K+ yellow), norstictic acid and usnic acid. This is the first record of the species in South Korea.

• Korean Journal of Plant Taxonomy
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• v.46 no.1
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• pp.33-54
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• 2016

Many of the historic plant specimens collected from the Korean Peninsula in the early 20th century deposited in herbaria in Korea were destroyed during the Korean War. However, duplicates of the specimens deposited in the Herbarium of the University of Tokyo (TI) remained unharmed. We examined historic plant specimens, identified undetermined specimens, and made a list to provide fundamental information on the early taxonomic history of Korea. One set of duplicate specimens was donated by TI and deposited into the Chonnam National University herbarium (CNU) and into the herbarium of the National Institute of Biological Resources in Korea (KB).

• Journal of Preventive Medicine and Public Health
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• v.40 no.2
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• pp.95-101
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• 2007

Focusing on complex diseases of public health significance, strategic issues regarding the on-going Korean Genome Cohort were reviewed: target size and diseases, measurements, study design issues, and follow-up strategy of the cohort. Considering the epidemiologic characteristics of Korean population as well as strengths and drawbacks of current research environment, we tried to tailor the experience of other existing cohorts into proposals for this Korean study. Currently 100,000 individuals have been participating the new Genome Cohort in Korea. Target size of de novo collection is recommended to be set as between 300,000 to 500,000. This target size would allow acceptable power to detect genetic and environmental factors of moderate effect size and possible interactions between them. Family units and/or special subgroups are recommended to parallel main body of adult individuals to increase the overall efficiency of the study. Given that response rate to the conventional re-contact method may not be satisfactory, successful follow-up is the main key to the achievement of the Korean Genome Cohort. Access to the central database such as National Health Insurance data can provide enormous potential for near-complete case detection. Efforts to build consensus amongst scientists from broad fields and stakeholders are crucial to unleash the centralized database as well as to refine the commitment of this national project.

• Korean Journal of Ichthyology
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• v.33 no.3
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• pp.196-201
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• 2021

The Indo-West Pacific pipefish, Hippichthys penicillus was newly recorded from Korean waters based on a single specimen (124.5 mm SL) collected from a lower reach of creek of the Namhaedo Island flowing into Dongdae Bay. It is separable from congeners in having a longer snout and unique configuration of principle body ridges including discontinuous superior trunk and tail ridges and straight lateral trunk ridge ending near anus. A new Korean name, "Huin-jeom-sil-go-gi", is proposed for the species.

• Korean Journal of Ichthyology
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• v.35 no.3
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• pp.194-200
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• 2023

The Yellowfin surgeonfish, Acanthurus xanthopterus was reported as the first confirmed record from Korea based on a single specimen (332.6 mm SL) collected from the coast from Geomundo Island. It is characterized by having a longitudinal yellowish band in front of eye, dorsal and anal fins with 4 bluish stripes, and broad yellowish bar distally on pectoral fin. The new Korean name, "No-rang-munui-yang-jwi-dom", is proposed for the species.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.193-198
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• 1972

Twenty seven specimens of deteriolated storage rice were collected all over Korea. Types of deteriolation were classified according to color outlooks, and for 48 grains of each specimen the causative storage microorganisms were isolated and identified. The following results were observed; 1. 27 specimens of deteriolated rice were classified according to color outlooks into 7 types: reddish yellow 1, light reddish yellow 3, light grayish yellow 4, light red 6, dark gray 7, light gray 3, and rice weevil type 3. 2. The most common storage microorganisms group which infected deteriolated Korean rice were Aspergillus glaucus group, especially species of A. amstelodami, A. chevalieri, A. montevidensis, and A. ruber, which were frequently associated with Penicillium, Brevibactereum, and Bacillus. 3. As a specific case sometimes a specimen of deteriolated rice was infected chiefly by one deminant species of microorganism. Five cases were observed: that is, by P. islandicum, P. lanosum, B. lentus, Pseudomonas cohaerans, Brev. lipolyticum. 4. No definite relationship was observed between color outlook types and the deteriolation causing microorganisms. Only the heavily infected rice by Penicillium islandicum expressed discernible reddish yellow color indicative of the infection by this mold. 5. Mycotoxin problem could be noted in one specimen of deteriolated imported rice heavily infected by P. islandicum. Other mycotoxin producing fungi, A. flavus, A. ochraceus, A. fumigatus were also detected, but their growth frequencies were so low that it might not be serious problem.

• Korean Journal of Plant Taxonomy
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• v.44 no.3
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• pp.165-170
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• 2014

Most evergreen Quercus species are typical, dominant members of Korean evergreen forests. However, little is known about the distribution status of Q. myrsinifolia Blume there. To enhance our knowledge about their natural range in Korea, we conducted field surveys based on specimen records and an extensive literature search. We also determined their exact number as a first step in planning their conservation. The results indicated that these trees are strictly limited to Jin Island, and 169 mature individuals were the maximum number and occurred in only three subpopulations on that island. Previous misidentifications and perhaps mislabeled locations for plant specimens were the main reasons for earlier confusion about distribution. We believe that these results can provide guidance when making specific recommendations for management interventions. These discoveries also demonstrate the value in having reliable information about plant specimens in general. We also speculated about what makes this species particularly vulnerable to local extinction.

• The Journal of Korean Academy of Prosthodontics
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• v.43 no.6
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• pp.751-763
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• 2005

Statement of problem. To improve a direct implant fixation to the bone, various strategies have been developed focusing on the surface of materials. The surface quality of the implant depends on the chemical, physical, mechanical and topographical properties of the surface. The different properties will interact with each other and a change in thickness of the oxide layer may also result in a change in surface energy, the surface topography and surface, chemical composition. However, there is limited the comprehensive study with regard to changed surface and biologic behavior of osteoblast by anodization. Purpose of study. The aim of this study was to analyze the characteristics of an oxide layer formed and to evaluate the cellular biologic behaviors on titanium by anodic oxidation (anodization) by cellular proliferation, differentiation, ECM formation and gene expression. And the phospholipase activity was measured on the anodized surface as preliminary study to understand how surface properties of Ti implant are transduced into downstream cellular events. Methods and Materials. The surface of a commercially pure titanium(Grade 2) was modified by anodic oxidation. The group 1 samples had a machined surface and other three experimental specimens were anodized under a constant voltage of 270 V(Group 2), 350 V(Group 3), and 450 V(Group 4). The specimen characteristics were inspected using the following five categories; the surface morphology, the surface roughness, the thickness of oxide layer, the crystallinity, and the chemical composition of the oxide layer. Cell numbers were taken as a marker for cell proliferation. While the expression of alkaline phosphatase and Runx2 (Cbfa1) was used as early differentiation marker for osteoblast. The type I collagen production was determined, which constitutes the main structural protein of the extracellular matrix. Phospholipase $A_2$ and D activity were detected. Results. (1) The anodized titanium had a porous oxide layer, and there was increase in both the size and number of pores with increasing anodizing voltage. (2) With increasing voltage, the surface roughness and thickness of the oxide film increased significantly (p<0.01), the $TiO_2$phase changed from anatase to rutile. During the anodic oxidization, Ca and P ions were more incorporated into the oxide layer. (3) The in vitro cell responses of the specimen were also dependant on the oxidation conditions. With increasing voltage, the ALP activity, type I collagen production, and Cbfa 1 gene expression increased significantly (p<0.01), while the cell proliferation decreased. (4) In preliminary study on the relation of surface property and phospholipase, PLD activity was increased but $PLA_2$ activity did not changed according to applied voltage. Conclusion. The anodized titanium shows improved surface characteristics than the machined titanium. The surface properties acquired by anodization appear to give rise more mature osteoblast characteristics and might result in increased bone growth, and contribute to the achievement of a tight fixation. The precise mechanism of surface property signaling is not known, may be related to phospholipase D.

• Journal of Technologic Dentistry
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• v.31 no.1
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• pp.55-61
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• 2009

Passive fitting of meso-structure and super-structures is a predominant requirement for the longevity and clinical success of osseointegrated dental implants. However, precision and passive fitting has been unpredictable with conventional methods of casting as well as for corrective techniques. Alternative to conventional techniques, electro discharge machining(EDM) is an advanced method introduced to dental technology to improve the passive fitting of implant prosthesis. In this technique material is removed by melting and vaporization in electric sparks. Regarding the efficacy of EDM, the application of this technique induces severe surface morphological and elemental alterations due to the high temperatures developed during machining, which vary between $10,000{\sim}20,000^{\circ}C$. The aim of this study was to investigate the morphological and elemental alterations induced by EDM process of casting dental gold alloy and non-precious alloy used for the production of implant-supported prosthesis. A conventional clinical dental casting alloys were used for experimental specimens patterns, which were divided in three groups, high fineness gold alloy(Au 75%, HG group), low fineness gold alloy(Au 55%, LG group) and nonprecious metal alloy(Ni-Cr, NP group). The UCLA type plastic abutment patterns were invested with conventional investment material and were cast in a centrifugal casting machine. Castings were sandblasted with $50{\mu}m\;Al_2O_3$. One casting specimen of each group was polished by conventional finishing(HGCON, LGCON, NPCON) and one specimen of each group was subjected to EDM in a system using Cu electrodes, kerosene as dielectric fluid in 10 min for gold alloy and 20 min for Ni-Cr alloy(HGEDM. LGEDM, NOEDM). The surface morphology of all specimens was studied under an energy dispersive X-ray spectrometer (EDS). The quantitative results from EDS analysis are presented on the HGEDM and LGEDM specimens a significant increase in C and Cu concentrations was found after EDM finishing. The different result was documented for C on the NPEDM with a significant uptake of O after EDM finishing, whereas Al, Si showed a significant decrease in their concentrations. EDS analysis showed a serious uptake of C and Cu after the EDM procedure in the alloys studied. The C uptake after the EDM process is a common finding and it is attributed to the decomposition of the dielectric fluid in the plasma column, probably due to the development of extremely high temperatures. The Cu uptake is readily explained from the decomposition of Cu electrodes, something which is also a common finding after the EDM procedure. However, all the aforementioned mechanisms require further research. The clinical implication of these findings is related with the biological and corrosion resistance of surfaces prepared by the EDM process.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.21-29
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• 2020

Morphology of a strain of unspecified Skeletonema species established from Korean coast was examined by light, fluorescence and scanning electron microscopy, and SSU(small subunit) and LSU(large subunit) rDNA of the strain were also sequenced. The specimen was characterized by solitary or short chains, and each cell contained 1-2 chloroplasts. The valve face was slightly convex, and the terminal fultoportula processes (TFPPs) were open and showed narrow distal ends that could be truncated or spiny with claw-like protrusions. The basal part of the TFPPs was tubular and oblique to the cell axis. The intercalary fultoportula processes (IFPPs) were also narrow, completely open, and joined in a 1 : 1 junction. Occasionally, one IFPP was connected with two opposing IFPPs. The morphological features of the specimen were identical to those of Skeletonema pseudocostatum. Molecular phylogeny based on SSU rDNA revealed that the Korean strain is nested within a clade comprising S. pseudocostatum and S. tropicum. However, based on D1-D2 LSU rDNA sequences, a clade including S. pseudocostatum and a Korean strain was separated from the S. tropicum clade. This indicates that the Korean strain can be identified as S. pseudocostatum. This species represents the first record from Korean coastal waters.