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Search Results: 1 - 10 of 8124 matches for " Choong-Hak Park "
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Retiform Sertoli-Leydig Cell Tumor of the Ovary  [PDF]
Gyu-Bong Yu, Seung-Kyu Choi, Yun-Dan Kang, Choong-Hak Park
International Journal of Clinical Medicine (IJCM) , 2016, DOI: 10.4236/ijcm.2016.79065
Abstract: Sertoli-Leydig cell tumor of the ovary is a kind of sex cord-stromal tumor, which occurs between teens and twenties with symptoms including abdominal pain and swelling. The incidence rate is infinitely rare comprising less than 0.5% of all ovarian tumor. The average age of “retiform Sertoli-Leydig cell tumor” is 17 years as compared to 25 years for Sertoli-Leydig cell tumors as a group. We have experienced this rare case of retiform Sertoli-Leydig cell tumor in a 25-year-old foreign patient with the complaint of palpable mass on the right lower quadrant and an irregular menstrual period. The patient underwent right salpingo-oophorectomy and tumor stage was FIGO stage 1A. We report with a brief review of literature.
Antibiotic Resistance of Bacteria Isolated from the Internal Organs of Edible Snow Crabs
Misoon Kim, Tae-Hyung Kwon, Su-Mi Jung, Seung-Hak Cho, Seon Yeong Jin, Nyun-Ho Park, Choong-Gon Kim, Jong-Shik Kim
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0070887
Abstract: Antibiotic resistance and microbiota within edible snow crabs are important for the Chionoecetes (snow crab) fishing industry. We investigated these parameters using culture methods and antibiotic susceptibility tests with six internal organs from three species of Chionoecetes. Each sample revealed many unexpected microbial species within Chionoecetes internal organs. On the basis of 16S rRNA sequence analysis of 381 isolates, the most abundant genera identified in Chionoecetes opilio were Acinetobacter spp. (24%), Bacillus spp. (4%), Pseudomonas spp. (34%), Stenotrophomonas spp. (28%), and Agreia spp. (11%). In Chionoecetes sp. crabs, Acinetobacter spp. (23%), Bacillus spp. (12%), and Psychrobacter spp. (20%) were most prevalent, while Agreia spp. (11%), Bacillus spp. (31%), Microbacterium spp. (10%), Rhodococcus spp. (12%), and Agrococcus spp. (6%) were most abundant in C. japonicus. Our antibiotic resistance test found resistance to all nine antibiotics tested in 19, 14, and two of the isolates from C. opilio, Chionoecetes sp., and, C. japonicus respectively. Our results are the first to show that microbes with antibiotic resistance are widely distributed throughout the internal organs of natural snow crabs.
Hamartomatous Polyp of Minor Salivary Gland Arising in the Tongue: A Report of the First Case  [PDF]
Yosep Chong, Young Hak Park, Tae-Jung Kim, Chang Suk Kang
Open Journal of Pathology (OJPathology) , 2014, DOI: 10.4236/ojpathology.2014.43013
Abstract:

Benign tumorous condition can be encountered at very unusual location in oral cavity and pharyngeal region, which leads diagnostic difficulty. Here we describe a very unusual presentation of polypoid hamartoma on the root of the tongue. A 59-year-old woman presented with a polypoid tumor mass on the dorsal root of the tongue. Microscopically, it was hamartoma showing normal salivary glands of mucinous and serous types, lymphoid hyperplasia, and skeletal muscle bundles. Major differential diagnoses include accessory tongue, adenomatoid hyperplasia, and idiopathic hyperplasia of sublingual glands. To our knowledge, this is the first report of hamartoma arising in the root of the tongue presenting as polypoid mass. Correct diagnosis based on pathologic examination is essential for proper treatment.

Determination of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) surfactant with liquid chromatography: Comparative study of evaporative light scattering detector, ultraviolet detector and conductivity detector
Ho Ryul Ryu,Hong Soon Park,Choong Kyun Rhee
Journal of Analytical Science & Technology , 2010,
Abstract: This work presents comparison of performance of ultraviolet (UV) detector, conductivity detector (CD) and evaporative light scattering detector (ELSD) in terms of quantitative analysis of AOT (sodium bis(2-ethylhexyl)sulfosuccinate) using liquid chromatography. The employed chromatographic condition, including an acetonitrile/water (45:55, v/v) isocratic eluent system, is suitable for the three different detectors, and the figures of merits obtained by building up calibration plots are compared. The sensitivities of the detectors are in the order of ELSD ≈ CD >> UV detector. The linear range for quantification of AOT depends on the type of detector: the lower limits are in the order of UV detector (207 mL-1) < CD (310 mL-1) << ELSD (930 mL-1), while the upper limits are 3720 mL-1 for all the detectors (the maximum concentration of injected standard solution). The detection limits are 155 mL-1 for ELSD, 78 mL-1 for UV detector and 13 mL-1 for CD, respectively. The figures of merit for each detector could be a guideline in choosing a detector in quantization of AOT. Furthermore, application of the chromatographic method to two commercial products is demonstrated.
Percutaneous coronary intervention for unprotected left main coronary artery stenosis
Seung-Jung Park,Young-Hak Kim
World Journal of Cardiology , 2010,
Abstract: Hemodynamically significant left main coronary artery stenosis (LMCA) is found in around 4% of diagnostic coronary angiograms and is known as unprotected LMCA stenosis if the left coronary artery and left circumflex artery has no previous patent grafts. Previous randomized studies have demonstrated a significant reduction in mortality when revascularization by coronary artery bypass graft (CABG) surgery was undertaken compared with medical treatment. Therefore, current practice guidelines do not recommend percutaneous coronary intervention (PCI) for such a lesion because of the proven benefit of surgery and high rates of restenosis with the use of bare metal stents. However, with the advent of drug-eluting stents (DES), the long term outcomes of PCI with DES to treat unprotected LMCA stenoses have been acceptable. Therefore, apart from the current guidelines, PCI for treatment of unprotected LMCA stenosis is often undertaken in individuals who are at a very high risk of CABG or refuse to undergo a sternotomy. Future randomized studies comparing CABG vs PCI using DES for treatment of unprotected LMCA stenosis would be a great advance in clinical knowledge for the adoption of appropriate treatment.
Environmental dependence of AGN activity. I.: the effects of host galaxy
Yun-Young Choi,Jong-Hak Woo,Changbum Park
Physics , 2009, DOI: 10.1088/0004-637X/699/2/1679
Abstract: Using a large sample of local galaxies (144,940) with -17.5< Mr <-22 and 0.025< z <0.107, selected from SDSS DR5, we compare AGN host galaxies with non-AGN galaxies at matched luminosity, velocity dispersion, color, color gradient, or concentration index, to investigate how AGN activity is related with galaxy properties. The AGN sample is composed of Type II AGNs identified with flux ratios of narrow-emission lines with S/N > 6. We find that the fraction of galaxies hosting an AGN (f_AGN) depends strongly on morphology together with color, and very weakly on luminosity or velocity dispersion of host galaxies. In particular, f_AGN of early-type galaxies is almost independent of luminosity nor velocity dispersion when color is fixed. The host galaxy color preferred by AGNs is u-r ~2.0 for early-type hosts and u-r=2.0-2.4 for late-type hosts. This trend suggests that AGNs are dominantly hosted by intermediate-mass late-type galaxies. We also investigate how the accretion power varies with galaxy properties. While the Eddington ratio ([OIII] line luminosity normalized by black hole mass) ranges over three orders of magnitude for both morphological types, late-type galaxies are the dominant hosts over all AGN power. Among late-type galaxies, bluer color galaxies host higher power AGNs. These results are consistent with a scenario that more massive and redder galaxies are harder to host AGNs since these galaxiesalready consumed gas at the center or do not have sufficient gas supply to feed the black hole. In contrast, intermediate-mass, intermediate-color, and more concentrated late-type galaxies are more likely to host AGNs, implying that perhaps some fraction of low-mass, blue, and less concentrated lat e-type galaxiesmay not host massive black holes or may host very low-power AGNs.
Calibrating CIV-based black hole mass estimators
Daeseong Park,Jong-Hak Woo,Kelly Denney,Jaejin Shin
Physics , 2013, DOI: 10.1088/0004-637X/770/2/87
Abstract: We present the single-epoch black hole mass estimators based on the CIV (1549 A) broad emission line, using the updated sample of the reverberation-mapped AGNs and high-quality UV spectra. By performing multi-component spectral fitting analysis, we measure the CIV line widths (FWHM_CIV) and line dispersion (sigma_CIV) and the continuum luminosity at 1350 A (L_1350) to calibrate the CIV-based mass estimators. By comparing with the Hbeta reverberation-based masses, we provide new mass estimators with the best-fit relationships, i.e., M_BH \propto L_1350 ^ (0.50+-0.07) sigma_CIV ^2 and M_BH \propto L_1350 ^ (0.52+-0.09) FWHM_CIV ^ (0.56+-0.48). The new CIV-based mass estimators show significant mass-dependent systematic difference compared to the estimators commonly used in the literature. Using the published Sloan Digital Sky Survey QSO catalog, we show that the black hole mass of high-redshift QSOs decreases on average by ~0.25 dex if our recipe is adopted.
The black hole mass - stellar velocity dispersion relation of narrow-line Seyfert 1 galaxies
Jong-Hak Woo,Yosep Yoon,Songyoun Park,Daeseong Park,Sang Chul Kim
Physics , 2014, DOI: 10.1088/0004-637X/801/1/38
Abstract: Narrow-line Seyfert 1 galaxies (NLS1s) are arguably one of the key AGN subclasses in investigating the origin of the black hole mass - stellar velocity dispersion (M-sigma) relation because of their high accretion rate and significantly low black hole mass. Currently, it is under discussion whether present-day NLS1s offset from the M-sigma relation. Using the directly measured stellar velocity dispersion of 93 NLS1s at z<0.1, and black hole mass estimates based on the updated mass estimators, we investigate the M-sigma relation of NLS1s in comparison with broad-line AGNs. We find no strong evidence that the NLS1s deviates from the M-sigma relation, which is defined by reverberation-mapped type 1 AGNs and quiescent galaxies. However, there is a clear trend of the offset with the host galaxy morphology, i.e., more inclined galaxies toward the line-of-sight have higher stellar velocity dispersion, suggesting that the rotational broadening plays a role in measuring stellar velocity dispersion based on the single-aperture spectra from the Sloan Digital Sky Survey. In addition, we provide the virial factor log f = $0.05 \pm 0.12$ (f = 1.12), for black hole mass estimators based on the FWHM of H$\beta$, by jointly fitting the M-sigma relation using quiescent galaxies and reverberation-mapped AGNs.
Alterations in cell surface area and deformability of individual human red blood cells in stored blood
HyunJoo Park,Misook Ji,SangYun Lee,Kyoohyun Kim,Yong-Hak Sohn,Seongsoo Jang,YongKeun Park
Quantitative Biology , 2015,
Abstract: The functionality and viability of stored human red blood cells (RBCs) is an important clinical issue in transfusion. To systematically investigate changes in stored whole blood, the hematological properties of individual RBCs were quantified in blood samples stored for various periods with and without a preservation solution called CPDA-1. With 3-D quantitative phase imaging techniques, the optical measurements of the 3-D refractive index (RI) distributions and membrane fluctuations were done at the individual cell level. From the optical measurements, the morphological (volume, surface area and sphericity), biochemical (hemoglobin content and concentration), and mechanical parameters (dynamic membrane fluctuation) were simultaneously quantified to investigate the functionalities and their progressive alterations in stored RBCs. Our results show that the stored RBCs without CPDA-1 had a dramatic morphological transformation from discocytes to spherocytes within 2 weeks which was accompanied with significant decreases in cell deformability and cell surface area, and increases in sphericity. However, the stored RBCs with CPDA-1 maintained their morphology and deformability for up to 6 weeks.
Management of chest keloids
Tae Hwan Park, Sang Won Seo, June Kyu Kim, Choong Hyun Chang
Journal of Cardiothoracic Surgery , 2011, DOI: 10.1186/1749-8090-6-49
Abstract: Keloids are relatively resistant to treatment, with high recurrence rates using a single treatment modality. Keloids have a tendency to recur after surgical excision as a single treatment, with rates approximately up to 80-100%. Keloids can arise from skin trauma and must be removed through skin truma. Therein lies the challenge of treatment, where recurrence would seem inevitable. Surgical excision is considered as a kind of skin trauma and it promotes additional collagen synthesis, resulting in regrowth and even larger keloids[1]. This is why we were focused on the article recently published in your esteemed journal by Patel et al.[2] that dealt with the challenging topic of chest keloids.58 patients were treated with surgical excision combined with intraoperative/postoperative intralesional steroid injection therapy over a period of six years from July 2003 to June 2009 at our hospital. In all patients, a follow-up period of 18 months was required. Treatment outcome was assessed with global aesthetic improvement score (GAIS). All statistical analyses were conducted using SPSS version 17.0 (SPSS, Inc., Chicago, IL, USA). Our data were not normally distributed; consequently non-parametric tests were used. Descriptive statistics are presented as medians with interquartile ranges or as numbers and percentages.41 (70.7%) were women and 17 (29.3%) were men. The average age was 32 (range 29-35). The average time interval between keloid formation (or prior complete treatment) and time of treatment was 6 (range 5-7) years. The average pretreatment total size of lesions was 3.5 (range 2.0-5.0). 45 patients (29.3%) were treated for a treatment-resistant keloid that failed to respond to previous interventions. These included surgical excision (2 patients, 3.4%), intralesional steroid injection (33 patients, 56.9%), laser therapy (5 patients, 8.6%), acupuncture (3 patients, 5.3%), and cryotherapy (2 patients, 3.4%). The etiologies of chest keloid, in order of decreasing frequ
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