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Kwon YS, Maruyama S, Morimoto K. Life events and posttraumatic stress in Hanshin-Awaji earthquake victims. Environ Health Prev Med 2012; 6:97-103. [PMID: 21432244 DOI: 10.1007/bf02897953] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2000] [Accepted: 02/08/2001] [Indexed: 11/26/2022] Open
Abstract
Stress induced by disaster is experienced to varying degrees by all respondents, and is known to evoke psychophysiological reactions. In this study, we investigated the relationships between earthquake-related life events and posttraumatic stress symptoms. A total of 380 adults were surveyed one year after the 1995 Hanshin-Awaji earthquake in Japan. The questionnaire included items concerning earthquake-related life events, emotional support and posttraumatic stress disorder (PTSD) symptoms.As a result, after controlling for demographic variables, earthquake-related life events were significantly related to the grade of posttraumatic stress and its three components: re-experience, avoidance and arousal, in both male and female subjects. Male subjects who currently had lower emotional support showed higher scores of posttraumatic stress and arousal. In conclusion, a higher experience of earthquake-related life events appears to be an important risk factor for development of poor mental health status following an earthquake disaster.
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Ha SY, Kwon YS, Kim BM, Kim DI, Kim DJ. Clinical and angiographic characteristics of multiple dural arteriovenous shunts. AJNR Am J Neuroradiol 2012; 33:1691-5. [PMID: 22538077 DOI: 10.3174/ajnr.a3054] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The pathogenesis and characteristics of multiple DAVSs are not well-known. The purpose of this study was to evaluate the angiographic and clinical characteristics of patients with multiple DAVSs with an emphasis on the pathomechanism. MATERIALS AND METHODS One hundred seventy-nine patients with DAVS were reviewed. Patients with ≥ 2 fistulas at anatomically separate sites were included. Multiple DAVSs were categorized into synchronous (simultaneous multiplicity) or metachronous (temporal sequential development of multiplicity) types. The angiographic and clinical characteristics of these lesions were analyzed. RESULTS Fourteen patients were diagnosed with multiple DAVSs (7.8%; synchronous, n = 7; metachronous, n = 7). Thirteen of the 14 patients showed CVR (93%, Borden type II/III). Multiple DAVSs were frequently associated with dural sinus thrombosis (71.4%, n = 10). Synchronous DAVSs developed in association with an occluded sinus (n = 5). De novo metachronous lesions developed in association with thrombosis of a previously patent dural sinus (n = 3) or reopening of an occluded sinus (n = 2). Multiplicity was associated with aggressive initial symptoms in 64.3% (n = 9). The newly developed lesions in the metachronous types were accompanied by hemorrhage (n = 1), neurologic deficit (n = 1), worsening of the initial benign symptoms (n = 2), and incidental detection (n = 3). The mean time interval between the initial diagnosis and de novo lesion detection was 31.3 ± 29.8 months (range, 12-92 months). CONCLUSIONS Multiplicity of DAVSs is associated with poor angiographic and clinical prognosis, requiring an aggressive treatment and management strategy. Sinus thrombosis has a prominent role in the pathomechanism of DAVSs.
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Yun GS, Bac LH, Kim JS, Kwon YS, Choi HS, Kim JC. Effect of synthetic temperature on the dispersion stability of gold nanocolloid produced via electrical explosion of wire. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2011; 11:6429-6432. [PMID: 22121729 DOI: 10.1166/jnn.2011.4394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this study, gold nanocolloid was produced via the electrical explosion of wire in water, for the purpose of medical treatment. Thus, the use of other additives was avoided to stabilize the gold nanocolloid. The temperature of the water that was to be used for explosion was changed, and its effect on the stability of the gold nanocolloid was investigated. The synthetic temperature was varied from ice temperature to 80 degrees C. The morphology and particle size were studied using a transmission electron microscope. The UV-Vis spectra confirmed the formation of gold nanoparticles in the water. The stability of the gold nanocolloid was estimated using the zeta-potential and Turbiscan methods. The results showed that the synthetic temperature affected the stability of the gold nanocolloid. The TEM images of the gold nanoparticles prepared at low temperatures (0 and 20 degrees C) have several big particles. But, when the synthetic temperature was increased to 80 degrees C, most of the nanoparticles formed a spherical shape, without neck connection. Better stability was obtained in the gold nanocolloid sample prepared at a higher temperature. The gold nanocolloid that was synthesized at 80 degrees C was stable for more than three months, with small sedimentation.
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Im HJ, Ito T, Kim HD, Kimura S, Lee KE, Hong JB, Kwon YS, Yasui A, Yamagami H. Direct observation of dispersive Kondo resonance peaks in a heavy-fermion system. PHYSICAL REVIEW LETTERS 2008; 100:176402. [PMID: 18518313 DOI: 10.1103/physrevlett.100.176402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2007] [Indexed: 05/26/2023]
Abstract
Ce 4d-4f resonant angle-resolved photoemission spectroscopy was carried out to study the electronic structure of strongly correlated Ce 4f electrons in a quasi-two-dimensional nonmagnetic heavy-fermion system CeCoGe1.2Si0.8. For the first time, dispersive coherent peaks of an f state crossing the Fermi level, the so-called Kondo resonance, are directly observed together with the hybridized conduction band. Moreover, the experimental band dispersion is quantitatively in good agreement with a simple hybridization-band picture based on the periodic Anderson model. The obtained physical quantities, i.e., coherent temperature, Kondo temperature, and mass enhancement, are comparable to the results of thermodynamic measurements. These results manifest an itinerant nature of Ce 4f electrons in heavy-fermion systems and clarify their microscopic hybridization mechanism.
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Garcia DR, Gweon GH, Zhou SY, Graf J, Jozwiak CM, Jung MH, Kwon YS, Lanzara A. Revealing charge density wave formation in the LaTe2 system by angle resolved photoemission spectroscopy. PHYSICAL REVIEW LETTERS 2007; 98:166403. [PMID: 17501439 DOI: 10.1103/physrevlett.98.166403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Indexed: 05/15/2023]
Abstract
We present the first direct study of charge density wave (CDW) formation in quasi-2D single layer LaTe2 using high-resolution angle resolved photoemission spectroscopy and low energy electron diffraction. CDW formation is driven by Fermi surface (FS) nesting, however, characterized by a surprisingly smaller gap ( approximately 50 meV) than seen in the double layer RTe2 compounds, extending over the entire FS. This establishes LaTe2 as the first reported semiconducting 2D CDW system where the CDW phase is FS nesting driven. In addition, the layer dependence of this phase in the tellurides and the possible transition from a stripe to a checkerboard phase is discussed.
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Ryu YJ, Kim H, Yu CM, Choi JC, Kwon YS, Kwon OJ. Use of silicone stents for the management of post-tuberculosis tracheobronchial stenosis. Eur Respir J 2006; 28:1029-35. [PMID: 16971412 DOI: 10.1183/09031936.00020906] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The role of bronchoscopic management in post-tuberculosis tracheobronchial stenosis is not well defined. To investigate the role of bronchoscopic intervention, including silicone stenting, in the management of post-tuberculosis tracheobronchial stenosis, the current retrospective study was conducted at a tertiary referral hospital. Under rigid bronchoscopy, 80 patients underwent ballooning, neodymium-yttrium aluminium garnet laser resection and/or bougienation as first-line methods of airway dilatation between January 2000 and December 2003 inclusive, and were followed for a median of 41 months. Silicone stents were required in 75 out of 80 (94%) patients to maintain airway patency. Bronchoscopic intervention provided immediate symptomatic relief and improved lung function in 88% of the patients. After airway stabilisation, stents were removed successfully in 49 out of 75 (65%) patients at a median of 14 months post-insertion. Three patients out of 75 (4%) eventually underwent surgical management. Acute complications included: excessive bleeding (n = 1); pneumothorax (n = 5); and pneumomediastinum without mortality (n = 2). Stent-related late complications, such as migration (51%), granuloma formation (49%), mucostasis (19%) and re-stenosis (40%), were controllable during a median follow-up of 41 months. In conclusion, bronchoscopic intervention, including silicone stenting, could be a useful and safe method for treating post-tuberculosis tracheobronchial stenosis.
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Wang J, Pillay A, Kwon YS, Wall AD, Loughran CG. An analysis of fishing vessel accidents. ACCIDENT; ANALYSIS AND PREVENTION 2005; 37:1019-24. [PMID: 15979552 DOI: 10.1016/j.aap.2005.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Accepted: 05/11/2005] [Indexed: 05/03/2023]
Abstract
In this paper, accident data collected from the Marine Accident Investigation Branch are presented and an analysis is carried out to determine the most common causes of accidents on fishing vessels. Discussions on fishing vessel-safety assessment and data problems are given.
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Kwon YS, Ann HS, Nabeshima T, Shin EJ, Kim WK, Jhoo JH, Jhoo WK, Wie MB, Kim YS, Jang KJ, Kim HC. Selegiline potentiates the effects of EGb 761 in response to ischemic brain injury. Neurochem Int 2004; 45:157-70. [PMID: 15082233 DOI: 10.1016/j.neuint.2003.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2003] [Accepted: 10/28/2003] [Indexed: 11/22/2022]
Abstract
We evaluated whether combined treatment with selegiline, a selective MAO-B inhibitor, and EGb 761, a standard extract of Ginkgo biloba, has synergistic effects against ischemic reperfusion injury (IRI) in gerbils. Interestingly, we observed that pretreatment with EGb 761 significantly attenuated selegiline-induced hyperactivity. This finding paralleled striatal fos-related antigen immunoreactivity (FRA-IR) in mice. Four minutes of bilateral carotid artery occlusion caused substantial cell loss in the CA1 of the hippocampus 5 days post-ischemic insult. Pretreatment with EGb 761, with or without selegiline, significantly attenuated this neuronal loss. Combined treatment with EGb 761 plus selegiline was more efficacious in preventing this loss. Synaptosomal formations of protein carbonyl, lipid peroxidation (malondialdehyde (MDA) + 4-hydroxyalkenal (4-HDA)), and reactive oxygen species (ROS) in the hippocampus remained elevated 5 days post-ischemic insult. The antioxidant effects appeared to be most significant in the group treated with EGb 761 plus selegiline. This combined treatment produced more significant attenuation of IRI-induced alterations in intramitochondrial calcium accumulation, the mitochondrial transmembrane potential, and mitochondrial Mn-superoxide dismutase-like immunoreactivity (Mn-SOD-IR) than either treatment alone. Our results suggest that co-administration of EGb 761 and selegiline produces significant neuroprotective effects via suppression of oxidative stress and mitochondrial dysfunction without affecting neurological function.
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Zheng CL, Nair TM, Gribskov M, Kwon YS, Li HR, Fu XD. A database designed to computationally aid an experimental approach to alternative splicing. PACIFIC SYMPOSIUM ON BIOCOMPUTING. PACIFIC SYMPOSIUM ON BIOCOMPUTING 2004:78-88. [PMID: 14992494 DOI: 10.1142/9789812704856_0008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A unique microarray approach has been developed to profile alternative splicing in the cell. To support the development of this approach, we have developed the Manually Annotated Alternatively Spliced Events (MAASE) database system, which is a unique alternative splicing information resource designed specifically with experimentalists in mind. MAASE is an online resource for the convenient access, identification, and annotation of alternative splicing events (ASEs). MAASE consists of two components: an annotation system and a curated database. The annotation system is a web-based workspace that combines manual and computational approaches to identifying and annotating ASEs, a combination that is vital if a comprehensive collection is to be obtained. The annotation system is publicly available and provides a scalable solution to acquiring as well as contributing to annotated ASEs. MAASE annotated ASEs are deposited into the database component, which can either be queried one entry at a time or multiple entries at a time with convenient access to alternatively spliced junctional and surrounding sequences to facilitate the design of microarray experiments.
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Kwon YS, Eun MY, Sohn JK. Marker-assisted selection for identification of plant regeneration ability of seed-derived calli in rice (Oryza sativa L.). Mol Cells 2001; 12:103-6. [PMID: 11561716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Quantitative trait loci (QTL), associated with the ability of plant regeneration from seed-derived callus of rice, were mapped using a recombinant inbred (RI) population from Milyang 23/Gihobyeo. Each flanking marker, RZ474 and RZ575, tightly linked to two QTLs (qSGR-3-1 and qSGR-3-2) that are located on chromosome 3 was used in marker-assisted selection (MAS). These markers were tested on IR 36/MG RI036 (F3), Milyang 23/MG RI036 (F3), and forty-one rice cultivars. A restriction fragment length polymorphism (RFLP) marker, RZ575, that is located on chromosome 3 could effectively differentiate lines with high and poor regeneration ability, based on marker genotypes. This marker might be applicable for screening rice germplasms with high regeneration ability. Its introgression into elite lines might also be valuable in breeding programs to develop highly responsive genotypes to tissue culture.
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Kim JW, Sohn MH, Kim DS, Sohn SM, Kwon YS. Production of granular activated carbon from waste walnut shell and its adsorption characteristics for Cu(2+) ion. JOURNAL OF HAZARDOUS MATERIALS 2001; 85:301-315. [PMID: 11489530 DOI: 10.1016/s0304-3894(01)00239-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Production of granular activated carbon by chemical activation has been attempted employing walnut shells as the raw material. The thermal characteristics of walnut shell were investigated by TG/DTA and the adsorption capacity of the produced activated carbon was evaluated using the titration method. As the activation temperature increased, the iodine value increased. However, a temperature higher than 400 degrees C resulted in a thermal degradation, which was substantiated by scanning electron microscopy (SEM) analysis, and the adsorption capacity decreased. Activation longer than 1h at 375 degrees C resulted in the destruction of the microporous structure of activated carbon. The iodine value increased with the increase in the concentration of ZnCl2 solution. However, excessive ZnCl2 in the solution decreased the iodine value. The extent of activation by ZnCl2 was compared with that by CaCl2 activation. Enhanced activation was achieved when walnut shell was activated by ZnCl2. Applicability of the activated carbon as adsorbent was examined for synthetic copper wastewater. Adsorption of copper ion followed the Freundlich model. Thermodynamic aspects of adsorption have been discussed based on experimental results. The adsorption capacity of the produced activated carbon met the conditions for commercialization and was found to be superior to that made from coconut shell.
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Choe YH, Kwon YS, Jung MK, Kang SK, Hwang TS, Hong YC. Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes. J Pediatr 2001; 139:100-4. [PMID: 11445801 DOI: 10.1067/mpd.2001.114700] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The objective was to investigate the role of Helicobacter pylori infection in iron-deficiency anemia (IDA) of pubescent athletes. STUDY DESIGN Blood sampling and a questionnaire survey were performed on 440 regular high school students and 220 athletes of a physical education high school. Hemoglobin, serum iron, total iron-binding capacity, ferritin, and immunoglobulin G antibody to H. pylori were measured to compare the prevalence of IDA and H. pylori infection in the groups. Nutritional analysis and a questionnaire survey for socioeconomic status were undertaken to compare and control for other risk factors that might influence IDA and H. pylori infection in the groups. In those with IDA coexistent with H. pylori infection, we also determined whether IDA can be managed by H pylori eradication. RESULTS The prevalence rates of IDA, H pylori infection, and H. pylori -associated IDA in female athletes were higher than in the control group. The relative risk of IDA was 2.9 (95% CI, 1.5 to 5.6) for those with H. pylori infection. Athletes who exhibited H. pylori -associated IDA showed significant increases in hemoglobin, iron, and ferritin levels after H. pylori eradication. The subjects in the control group who were treated orally with iron alone showed no significant changes. CONCLUSION Adolescent female athletes may have development of H. pylori -associated IDA, which can be managed by H. pylori eradication.
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Kwon YS, Kim KM, Eun MY, Sohn JK. Quantitative trait loci mapping associated with plant regeneration ability from seed derived calli in rice (Oryza sativa L.). Mol Cells 2001; 11:64-7. [PMID: 11266122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Quantitative trait loci (QTLs), which are associated with the ability of plant regeneration from seed derived calli, were detected using a recombinant inbred (RI) population from a cross between 'Milyang 23 (toingil)' and 'Gihobyeo (japonica)' in rice (Oryza sativa L.). A tongil type cultivar, 'Milyang 23', has a lower frequency of callus induction and plant regeneration than those of japonica 'Gihobyeo'. Transgressive segregations were observed for the callus induction rate and plant regeneration ability from seed derived calli of the RI population. An interval mapping analysis was used to identify the QTL controlling the plant regeneration ability. Two QTLs for the callus induction rate were detected on chromosomes 1 and 2, explaining the 10.9% total phenotypic variation. Four QTLs that are associated with the plant regeneration ability were located on chromosomes 2, 3, and 11, accounting for 25.7% of the total phenotypic variation.
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Kwon YS, Choe YH, Chin HS. Development of glaucoma in the course of interferon alpha therapy for chronic hepatitis B. Yonsei Med J 2001; 42:134-6. [PMID: 11293492 DOI: 10.3349/ymj.2001.42.1.134] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Previous reported ocular complications of interferon alfa administration are extremely rare. These include oculomotor palsy, corneal allograft rejection, retinal hemorrhage and cotton wool patches. A 15-year-old boy with chronic hepatitis B was treated with interferon alpha for six months, and then developed glaucoma. After the interferon therapy had been discontinued the glaucoma improved. Accordingly, we report a case of glaucoma development during the course of interferon alpha therapy for chronic hepatitis B.
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Kwon YS, Kang C. Bipartite modular structure of intrinsic, RNA hairpin-independent termination signal for phage RNA polymerases. J Biol Chem 1999; 274:29149-55. [PMID: 10506170 DOI: 10.1074/jbc.274.41.29149] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The phage SP6 RNA and T7 RNA polymerases, which are closely related to each other, intrinsically stop at two signals in the Escherichia coli rrnB terminator t1 through different mechanisms. The downstream signal functioned without an RNA secondary structure formation, in which the signal was still active when separated from the upstream, hairpin-forming signal, and IMP incorporation enhanced its efficiency. The sequence from -15 to -1 was essential for the downstream, hairpin-independent termination (at -1). The results of SP6 transcription with heteroduplex templates and ribonucleotide analogs suggested that the downstream signal consists of two functionally different modules. The effects of iodo-CMP or IMP incorporation into RNA on termination efficiency were not sensitive to incorporation at -9 and upstream, but they were reactive to incorporation at -6 and -2, as reflected by strong iodo-rC:dG and weak rI:dC base pairing. Thus, the downstream module (from -8 approximately -6 to -1) appears to facilitate the release of RNA. Mismatches in the templates at -6 to +1 allowed for efficient termination, unlike those upstream of the sequence. The upstream module (from -15 to -9 approximately -7) functions as a duplex. Pausing of the SP6 elongation complex at the termination site was detected when RNA release was suppressed by the incorporation of 5-bromo-UMP, and it was dependent on the upstream module. Results of single-round SP6 transcriptions using 3'-deoxynucleotides and immobilized templates indicated that RNA was not released from the elongation complexes halted at the termination site on the template variants carrying mutations in the upstream or downstream module, whereas such complexes on the wild type template were dissociated. Thus, halting or simple pausing was not sufficient for termination even when the downstream module was intact. The upstream module appears to mediate such conformation change necessary for termination.
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Kim KM, Park GH, Kim JH, Kwon YS, Sohn JK. Selection of RAPD marker for growth of seedlings at low temperature in rice. Mol Cells 1999; 9:265-9. [PMID: 10420984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023] Open
Abstract
We have developed a polymerase chain reaction (PCR)-based assay that could effectively reduce the time period required to screen and select the cold tolerance gene of rice seedlings under field conditions. The two specific random amplified polymorphic DNA (RAPD) fragments for the assay were identified on the basis of quantitative trait loci (QTL) analysis which were found to be tightly linked to cold sensitivity. The two RAPD fragments, OPT8(600) in the cold sensitivity rice cultivar 'Dular (indica)' and OPU20(1200) in the resistance rice cultivar 'Toyohatamochi (japonica)', were identified after screening 11 RAPD fragments using 2 random primers on the genomic DNAs of 'Dular' and 'Toyohatamochi'. These primers, when used in a multiplexed PCR, specifically amplified a 0.6 kb and a 1.2 kb fragment in the sensitive and resistant rice cultivars, respectively. When this assay was performed on the genomic DNAs of 16 japonica, 3 Tongil (indica/ japonica), and 2 indica rice cultivars, the primers amplified a 0.6 kb fragment in all of the cold sensitivity rice cultivars or 1.2 kb fragment in all of the resistance ones. These markers can be of potential use in the marker-assisted selection (MAS) for cold tolerance in rice seedling. As screening for resistance can now be conducted independent of the availability of low temperature, the breeding of cold tolerance cultivars can be hastened.
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Kwon YS, Kim J, Kang C. Viability of E. coli cells containing phage RNA polymerase and promoter: interference of plasmid replication by transcription. GENETIC ANALYSIS : BIOMOLECULAR ENGINEERING 1998; 14:133-9. [PMID: 9834856 DOI: 10.1016/s1050-3862(98)00007-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Strong transcription of phage promoters often renders the host E. coli cells containing the phage RNA polymerase inviable. When expression of the phage SP6 RNA polymerase gene in one plasmid was induced in the E. coli JM109 cells, cells that bear an active SP6 promoter were inviable. When it was not induced (the polymerase was still produced in low levels), viability of the host cells and stability of the promoter-bearing plasmids depended on the orientation of the promoter with respect to that of the replication origin and on the sequence of the origin. A group of SP6 promoter-bearing plasmids (group I plasmids) that had the promoter directed towards the ColE1 replication origin, rendered the polymerase-containing host cells inviable in selective media. When the sequence of the origin was different (group II plasmids), this adverse effect was not observed. When the promoter direction was same as the replication origin and the ampicillin-resistant gene (group III plasmids), many satellites formed around the colonies on ampicillin-containing agar plates. These effects were caused by strong transcription of the phage SP6 promoter by its RNA polymerase, since they were reduced or eliminated by inserting an active terminator just downstream of the promoter. The viability of host cells and copy number of the promoter/terminator-bearing plasmids appear to be quantitatively related with efficiency of initiation and termination of the phage transcription. These systems may be useful for in vivo screening for mutant variants of the phage promoter, polymerase and terminator that are affected in their efficiency.
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Lee YI, Park HJ, Kwon YS. In vitro stimulation of cumulus-cell expansion by human cord serum in mouse oocyte-cumulus complexes. J Assist Reprod Genet 1998; 15:145-53. [PMID: 9547691 PMCID: PMC3454982 DOI: 10.1023/a:1023060905457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
PURPOSE The aim of this study was to test whether human cord serum (HCS) containing gonadotropins has an effect on the expansion of oocyte-cumulus complexes (OCCs). METHODS The concentration of follicle stimulating hormone (FSH) and luteinizing hormone (LH) was measured in HCS by radioimmunoassay (RIA). After short-term culture (4 hr) with or without OCCs, medium containing 0.4% bovine serum albumin (BSA) as control or 10% HCS was collected and analyzed for its concentration of estradiol, progesterone, and testosterone. RESULTS The FSH concentration was at the basal level, but the LH level was as high as 142.4 mIU/ml in both natured and denatured serum. Undetectable levels of steroids were observed in control media with or without OCCs. In contrast, a moderate amount of steroid hormones was detected in culture medium containing HCS. OCCs secreted a minute amount of steroid hormones in response to HCS. Similar patterns of cumulus expansion were observable by treatment with HCS, human chorionic gonadotropin (hCG), or HCS plus hCG after 4, 8, or 22 hr of culture. However, no cumulus expansion was observed in controls. CONCLUSION These results suggest that LH in HCS induces cumulus expansion but does not affect the secretion of steroid hormones by OCCs during culture.
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So HS, Yoon HS, Choi DY, Kwon YS, Sung JH, Lee TG, Park ES, Cho HS, Lee BM, Cho JM, Ryu WS. Effect of a novel saponin adjuvant derived from Quillaja saponaria on the immune response to recombinant hepatitis B surface antigen. Mol Cells 1997; 7:178-86. [PMID: 9163729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Adjuvant activity of saponins extracted from the South American tree Quillaja saponaria has been demonstrated with many antigens. Recently, four saponin fractions (designated as QS-7, QS-17, QS-18, and QS-21) with adjuvant activity were purified by reverse phase chromatography. In particular, efficacy of the less toxic QS-21 fraction has been demonstrated with several recombinant viral antigens including HIV gp120. Here, we report a novel saponin fraction (designated as QS-L1) derived from Quillaja saponaria. Unlike previously identified saponins, QS-L1 had a different chemical structure and showed adjuvant activity only when administered in the presence of alum-precipitated antigen. Interestingly, the QS-L1 greatly increased not only a humoral immune response but also cellular immune response to recombinant hepatitis B virus surface antigen (HBsAg). Furthermore, QS-L1 showed lower toxicity in vivo and in vitro than the previously identified saponin fraction, QS-21. Finally, we examined the chemical structure of the QS-L1 using mass spectroscopic analysis, carbohydrate composition analysis and NMR spectroscopic analysis. Thus, our results indicated that this novel QS-L1 saponin fraction had several desirable properties required for an effective adjuvant.
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Kwon YS, Kobayashi A, Kajiyama S, Kawazu K, Kanzaki H, Kim CM. Antimicrobial constituents of Angelica dahurica roots. PHYTOCHEMISTRY 1997; 44:887-889. [PMID: 9115693 DOI: 10.1016/s0031-9422(96)00634-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
One novel coumarin from Angelica dahurica roots was elucidated to be 5,8-di(2,3-dihydroxy-3-methylbutoxy)-psoralen. It occurs together with six other known coumarins and ferulic acid. The antimicrobial activity of the coumarins and ferulic acid were compared.
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Li DX, Haga Y, Shida H, Suzuki T, Kwon YS. Electrical transport properties of semimetallic GdX single crystals (X=P, As, Sb, and Bi). PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:10483-10491. [PMID: 9984843 DOI: 10.1103/physrevb.54.10483] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ji JK, Kwon YS. Conical microlens arrays that flatten optical-irradiance profiles of nonuniform sources. APPLIED OPTICS 1995; 34:2841-2843. [PMID: 21052430 DOI: 10.1364/ao.34.002841] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
One can create conical microlens arrays on a glass plate by simply spin coating spin-on-glass film on the glass, patterning the photoresist, and then etching the glass in a HF solution. These arrays can be used to obtain more-uniform irradiance profiles from nonuniform incoherent sources.
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Wainapel SF, Kwon YS, Fazzari PJ. Severe visual impairment on a rehabilitation unit: incidence and implications. Arch Phys Med Rehabil 1989; 70:439-41. [PMID: 2730305 DOI: 10.1016/0003-9993(89)90002-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Eleven of the first 191 admissions (5.8%) to a rehabilitation inpatient unit met the criteria for legal blindness; two additional patients (1%) had severe visual impairment (visual acuity above 20/200 but less than 20/70 with corrective lenses). All but three of these patients were ambulatory with a walkerette or cane when discharged to their homes. The commonest causes of blindness were macular degeneration, cataract, glaucoma, and diabetic retinopathy. Despite being older (mean age 79.7 years compared to 70.4 years for all 191 admissions) and having visual impairment superimposed on their primary rehabilitation diagnosis, these patients' lengths of stay (LOS) were not prolonged (mean LOS = 33.1 days compared to 35.9 days for all 191 admissions). It is concluded that severe visual impairment is not uncommon among rehabilitation inpatients, particularly those aged 70 or older. Health care professionals working in rehabilitation should become more familiar with, and proficient in, the basic principles and treatment techniques used in the rehabilitation of visually impaired persons.
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Kwon KY, Kwon YS. Dependence of supermode discrimination and radiation angles on channel widths and spacings in laser arrays. APPLIED OPTICS 1987; 26:764-766. [PMID: 20454216 DOI: 10.1364/ao.26.000764] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Song JW, Shin SY, Kwon YS. Optical bistability, regenerative oscillation, and monostable pulse generation in a liquid crystal bistable optical device. APPLIED OPTICS 1984; 23:1521. [PMID: 18212861 DOI: 10.1364/ao.23.001521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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