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Kim SH, Park YJ, Cha AR, Kim GW, Bang JH, Lim CS, Choi SB. A feasibility work on the applications of MRE to automotive components. ACTA ACUST UNITED AC 2018. [DOI: 10.1088/1757-899x/333/1/012013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Gupta KK, Choi SB, Lung SF, Ibrahim A. Aerothermoelastic-Acoustics Simulation of Flight Vehicles. AIAA J 2016; Volume 55:49-56. [PMID: 31806909 PMCID: PMC6894403 DOI: 10.2514/1.j055088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/16/2016] [Accepted: 04/18/2016] [Indexed: 06/10/2023]
Abstract
This paper describes a novel computational-fluid-dynamics-based numerical solution procedure for effective simulation of aerothermoacoustics problems with application to aerospace vehicles. A finite element idealization is employed for both fluid and structure domains, which fully accounts for thermal effects. The accuracies of both the fluid and structure capabilities are verified with flight- and ground-test data. A time integration of the structural equations of motion, with the governing flow equations, is conducted for the computation of the unsteady aerodynamic forces, which uses a transpiration boundary condition at the surface nodal points in lieu of the updating of the fluid mesh. Two example problems are presented herein to that effect. The first one relates to a cantilever wing with a NACA 0012 airfoil. The solution results demonstrate the effect of temperature loading that causes a significant increase in acoustic response. A second example, the hypersonic X-43 vehicle, is also analyzed; and relevant results are presented. The common finite element-based aerothermoelastic-acoustics simulation process, its applicability to the efficient and routine solution of complex practical problems, the employment of the effective transpiration boundary condition in the computational fluid dynamics solution, and the development and public domain distribution of an associated code are unique features of this paper.
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Affiliation(s)
- K K Gupta
- NASA Armstrong Flight Research Center, Edwards, California 93523
| | - S B Choi
- California State University, Los Angeles, Los Angeles, California 90032
| | - S F Lung
- Jacobs Technology, Inc., Edwards, California 93523
| | - A Ibrahim
- Norfolk State University, Norfolk, Virginia 23504
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Park P, Kim WY, Lee JB, Choi SB, Kim WB, Choi SY. Incidental renal cell carcinoma originating from a native kidney after en-bloc resection for adrenal carcinoma in a kidney transplant recipient. Transplant Proc 2014; 46:637-9. [PMID: 24656033 DOI: 10.1016/j.transproceed.2013.11.078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Accepted: 11/22/2013] [Indexed: 10/25/2022]
Abstract
BACKGROUND Renal transplantation is the best treatment for patients with end-stage renal disease. Although there is significantly increased risk of malignancy after renal transplantation, carcinoma of the native kidney is very rare, and moreover, the risk of endocrinologic malignancy after renal transplantation is lower than in the general population and adrenal cortical carcinoma extremely rare. We report a case of incidental renal cell carcinoma originating from a native kidney after en-bloc resection for adrenal carcinoma in a kidney transplant recipient. CASE REPORT A 57 year-old male patient had undergone living-donor kidney transplantation for chronic renal failure from hypertension 15 years earlier and had a right adrenal tumor diagnosed on surveillance abdomen-pelvis computerized tomography. Based on 24-hour catecholamine laboratory findings, nonfunctioning tumor was suspected. The planned en-bloc resection of right adrenal gland and right native kidney combining the perirenal tissue and Gerota fascia was performed, because the tumor was suspicious for malignancy and could possibly invade the perirenal tissue or right kidney. On the final pathology, combined adrenal cortical carcinoma and incidental renal cell carcinoma was confirmed. Renal cell carcinoma was papillary, type I, and stage T1N0M0. Adrenal cortical carcinoma was 7.6 × 6.5 cm in size, had marked nuclear atypia, and was grade IV/IV. Mitotic counts were >10 per high-power field, but it had no capsular invasion or vascular invasion, and free resection margin was confirmed. In the preoperative period, he had taken immunosuppressants FK506 and mycophenolate sodium, but after combined carcinomas were confirmed, the regimen of combination of immunosuppressants was changed to sirolimus with low-dose FK506 and half-dose mycophenolate sodium.
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Khaw KY, Choi SB, Tan SC, Wahab HA, Chan KL, Murugaiyah V. Prenylated xanthones from mangosteen as promising cholinesterase inhibitors and their molecular docking studies. Phytomedicine 2014; 21:1303-1309. [PMID: 25172794 DOI: 10.1016/j.phymed.2014.06.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 04/30/2014] [Accepted: 06/16/2014] [Indexed: 06/03/2023]
Abstract
Garcinia mangostana is a well-known tropical plant found mostly in South East Asia. The present study investigated acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of G. mangostana extract and its chemical constituents using Ellman's colorimetric method. Cholinesterase inhibitory-guided approach led to identification of six bioactive prenylated xanthones showing moderate to potent cholinesterases inhibition with IC50 values of lower than 20.5 μM. The most potent inhibitor of AChE was garcinone C while γ-mangostin was the most potent inhibitor of BChE with IC50 values of 1.24 and 1.78 μM, respectively. Among the xanthones, mangostanol, 3-isomangostin, garcinone C and α-mangostin are AChE selective inhibitors, 8-deoxygartanin is a BChE selective inhibitor while γ-mangostin is a dual inhibitor. Preliminary structure-activity relationship suggests the importance of the C-8 prenyl and C-7 hydroxy groups for good AChE and BChE inhibitory activities. The enzyme kinetic studies indicate that both α-mangostin and garcinone C are mixed-mode inhibitors, while γ-mangostin is a non-competitive inhibitor of AChE. In contrast, both γ-mangostin and garcinone C are uncompetitive inhibitors, while α-mangostin is a mixed-mode inhibitor of BChE. Molecular docking studies revealed that α-mangostin, γ-mangostin and garcinone C interacts differently with the five important regions of AChE and BChE. The nature of protein-ligand interactions is mainly hydrophobic and hydrogen bonding. These bioactive prenylated xanthones are worthy for further investigations.
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Affiliation(s)
- K Y Khaw
- Discipline of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - S B Choi
- Bioprocess Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - S C Tan
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - H A Wahab
- Pharmaceutical Design and Simulation (PhDS) Laboratory, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - K L Chan
- Discipline of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - V Murugaiyah
- Discipline of Pharmacology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
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Jung SW, Kim DS, Yu YD, Ji WB, Park PJ, Choi SB, Park JW, Yoon SY, Han HJ, Song TJ, Choi SY, Suh SO. Does procurement technique affect posttransplant graft function in deceased donor liver transplantation? Transplant Proc 2014; 45:2880-5. [PMID: 24156997 DOI: 10.1016/j.transproceed.2013.08.084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Various techniques have been described deceased donor liver transplantation (DDLT) procurement. One is a technique whereby almost total dissection is done in the porta hepatis and perihepatic detachment is carried out before cross-clamping the donor aorta. In another approach, after the donor aorta is cross-clamped, rapid and minimal en bloc dissection is performed with minimal manipulation. We evaluated early posttransplant graft function among liver procurement techniques. METHOD Between January 2008 and August 2012, we performed 45 consecutive adult DDLTs. One patient was excluded from this analysis due to early death from sepsis after transplantation. The 44 included patients were divided into two cohorts according to the procurement technique: A warm dissection (n = 23; 52%) and a cold dissection group (n = 21; 48%). We compared early posttransplant graft function using the aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (T-bil), and prothrombin time (PT) values of the two groups from the first to seventh postoperative day. RESULT The AST values in the warm group were significantly greater than those in the cold group on postoperative days 3 and 5. In addition, the ALT values in the warm group were greater than those in the cold group on postoperative days 4, 5, and 6. Moreover, the T-bil values in the warm group were greater than those in the cold group on postoperative days 2, 3, 4, 5, 6, and 7. However, there were no differences in PT values. CONCLUSION During liver procurement for DDLT, rapid en bloc procurement with minimal manipulation after clamping the donor aorta achieved better early graft function posttransplantation.
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Affiliation(s)
- S W Jung
- Department of Surgery, Korea University College of Medicine, Seoul, Korea
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Kim H, Kim DH, Han JY, Choi SB, Ko YG, Do YJ, Seong HH. 63 THE EFFECT OF A MODIFIED CRYOPRESERVATION METHOD ON THE VIABILITY OF FROZEN–THAWED PRIMORDIAL GERM CELL ON THE KOREAN NATIVE CHICKEN (Ogye). Reprod Fertil Dev 2014. [DOI: 10.1071/rdv26n1ab63] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cryopreservation of poultry semen has been reported, but preservation of female genetic material has not been possible because of the unique anatomical and physiological characteristics of the avian egg. Thus, conservation of genetic material in chickens was attempted by preserving primordial germ cells (PGC) in LN2. This study established a method for preserving chicken PGC that enables long-term storage in LN2 for preservation of species. The purpose of this study was to clarify the effects of fetal bovine serum (FBS) or chicken serum (CS) treatment on the viability of cryopreserved PGC in the Korean native chicken (Ogye). Primordial germ cells were separated from a germinal gonad using a fine glass micropipette under a microscope and were suspended in a freezing medium containing freezing and protecting agents [e.g. dimethyl sulfoxide (DMSO) and ethylene glycol (EG)]. The PGC were then purified using the magnetic-activated cell sorting (MACS) method. The viability of the PGC in both groups was determined by the trypan blue exclusion method. The values of the 0, 5, 10, and 15% DMSO plus FBS treatment were 21.6, 30.36, 36.42, 50.39, and 48.36%, respectively. The viability of PGC after freeze-thawing was significantly higher for the 10% EG plus FBS treatment than for the 10% EG plus CS treatment (P < 0.05; 64.36 v. 50.66%). This study established a method for preserving chicken PGC that enables systematic storage and labelling of cryopreserved PGC in LN2 at a germplasm repository and ease of entry into a database. In the future, the importance of this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germ line chimeras.
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Oh JS, Shin WK, Uhm CH, Lee SR, Han YM, Choi SB. Control of haptic master – slave robot system for minimally invasive surgery (MIS). ACTA ACUST UNITED AC 2013. [DOI: 10.1088/1742-6596/412/1/012041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Abstract
BACKGROUND AND AIMS The prognosis for patients with ampulla of Vater cancer is better than other periampullary cancers. The aim of the present study is to determine the clinicopathologic factors predictive of survival and recurrence in patients with ampulla of Vater cancer. MATERIAL AND METHODS From 1991 to 2008, we identified and reviewed 78 patients with ampulla of Vater cancer retrospectively. Clinicopathologic factors possibly influencing survival and recurrence were statistically analyzed. RESULTS Pancreaticoduodenectomy was performed in 68 patients and 2 patients underwent transduodenal ampullectomy. Hospital mortality was 2.6%. The 5-year survival rates following resection were 59.9%. Univariate analysis for overall survival revealed that total bilirubin greater than 5 mg/dl, ulcerative tumors, differentiation, and pancreatic invasion were significant prognostic factors. Recurrence occurred in 31 patients. Univariate analysis for disease-free survival revealed that total bilirubin greater than 5mg/dl, preoperative biliary drainage, tumor differentiation, and stage were statistically significant. Multivariate analysis revealed that tumor differentiation was an independent prognostic factor for recurrence. The presence of lymph node metastasis did not affect overall survival significantly in this study. However, two or more metastatic lymph nodes significantly affect disease-free survival. CONCLUSIONS Pancreaticoduodenectomy is a safe surgical procedure with acceptable long-term survival for ampulla of Vater cancer. Pancreaticoduodenectomy with lymph node dissection might control lymph node spread and enhance survival outcome.
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Affiliation(s)
- S B Choi
- Department of Surgery, Korea University College of Medicine, Seoul, Korea
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Wahlstrand JK, Zhang H, Choi SB, Sipe JE, Cundiff ST. Electric field-induced coherent control in GaAs: polarization dependence and electrical measurement [Invited]. Opt Express 2011; 19:22563-22574. [PMID: 22109135 DOI: 10.1364/oe.19.022563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A static electric field enables coherent control of the photoexcited carrier density in a semiconductor through the interference of one- and two-photon absorption. An experiment using optical detection is described. The polarization dependence of the signal is consistent with a calculation using a 14-band k · p model for GaAs. We also describe an electrical measurement. A strong enhancement of the phase-dependent photocurrent through a metal-semiconductor-metal structure is observed when a bias of a few volts is applied. The dependence of the signal on bias and laser spot position is studied. The field-induced enhancement of the signal could increase the sensitivity of semiconductor-based carrier-envelope phase detectors, useful in stabilizing mode-locked lasers for use in frequency combs.
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Affiliation(s)
- J K Wahlstrand
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, CO 80309-0440, USA
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Wahlstrand JK, Zhang H, Choi SB, Kannan S, Dessau DS, Sipe JE, Cundiff ST. Optical coherent control induced by an electric field in a semiconductor: a new manifestation of the Franz-Keldysh effect. Phys Rev Lett 2011; 106:247404. [PMID: 21770599 DOI: 10.1103/physrevlett.106.247404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2010] [Revised: 04/05/2011] [Indexed: 05/31/2023]
Abstract
In (100)-oriented GaAs illuminated at normal incidence by a laser and its second harmonic, interference between one- and two-photon absorption results in ballistic current injection, but not modulation of the overall carrier injection rate. Results from a pump-probe experiment on a transversely biased sample show that a constant electric field enables coherent control of the carrier injection rate. We ascribe this to the nonlinear optical Franz-Keldysh effect and calculate it for a two-band parabolic model. The mechanism is relevant to centrosymmetric semiconductors as well.
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Affiliation(s)
- J K Wahlstrand
- JILA, National Institute of Standards and Technology, and the University of Colorado, Boulder, Colorado 80309, USA
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Abstract
We describe a pulsed terahertz (THz) emitter that uses a rapidly oscillating, high-voltage bias across electrodes insulated from a photoconductor. Because no carriers are injected from the electrodes, trap-enhanced electric fields do not form. The resulting uniform field allows excitation with a large laser spot, lowering the carrier density for a given pulse energy and increasing the efficiency of THz generation. Compared to a dc bias, less susceptibility to damage is observed.
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Affiliation(s)
- H Zhang
- JILA, National Institute of Standards and Technology and the University of Colorado, Boulder, Colorado 80309-0440, USA
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Furukawa H, Ko N, Go YB, Aratani N, Choi SB, Choi E, Yazaydin AO, Snurr RQ, O'Keeffe M, Kim J, Yaghi OM. Ultrahigh Porosity in Metal-Organic Frameworks. Science 2010; 329:424-8. [DOI: 10.1126/science.1192160] [Citation(s) in RCA: 2908] [Impact Index Per Article: 207.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Choi SB, Han YM, Sohn JW, Choi HJ. Bingham characteristics of polymer-based electrorheological fluids with different electrode gaps and materials. J Appl Polym Sci 2009. [DOI: 10.1002/app.31036] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Park DJ, Choi SB, Ahn YH, Rotermund F, Sohn IB, Kang C, Jeong MS, Kim DS. Terahertz near-field enhancement in narrow rectangular apertures on metal film. Opt Express 2009; 17:12493-12501. [PMID: 19654650 DOI: 10.1364/oe.17.012493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report huge field accumulations in rectangular aperture arrays on thin metal film by using shape resonance in THz frequency region. A huge far-field transmission enhancement is observed in samples of various widths ranging from 10 mum to 1.8 mum which correspond to only an order of lambda/100. Theoretical calculations based on vector diffraction theory indicates 230 times near-field enhancement in case of the 1.8 mum wide rectangular aperture. Transmission measurement through the single rectangular aperture shows that the shape resonance, not the periodicity, is mainly responsible for the transmission enhancement and the corresponding field enhancement.
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Affiliation(s)
- D J Park
- Center for Subwavelength Optics and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
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Park DP, Lim ST, Lim JY, Choi HJ, Choi SB. Electrorheological characteristics of solvent-cast polypyrrole/clay nanocomposite. J Appl Polym Sci 2009. [DOI: 10.1002/app.29636] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Choy YH, Lee CW, Kim HC, Choi SB, Choi JG, Hwang JM. Genetic Models for Carcass Traits with Different Slaughter Endpoints in Selected Hanwoo Herds I. Linear Covariance Models. Asian Australas J Anim Sci 2008. [DOI: 10.5713/ajas.2008.60001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
BACKGROUND Central bisectionectomy, which involves the removal of the central hepatic segments (IVA, IVB, V, VIII) for hepatocellular carcinoma (HCC), is performed to reduce the volume of resected liver and to overcome the problem of insufficient future residual volume. METHODS Twenty-seven patients with HCC underwent central bisectionectomy from January 1998 to April 2007 in one hospital. The surgical techniques, clinicopathological characteristics and outcomes were reviewed. RESULTS The median operating time was 330 min. Twelve patients developed postoperative complications and two died. The most common complication, occurring in five patients, was bile duct injury leading to biloma or bile leakage. Median follow-up was 19.1 (range 1.4-102.2) months and eight patients developed a recurrence. Twenty-four patients were alive at the time of writing. CONCLUSION Although biliary complications occur somewhat frequently, central bisectionectomy in centrally located HCC can be performed safely to preserve liver volume.
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Affiliation(s)
- J G Lee
- Department of Surgery, Ewha Womans University School of Medicine, Seoul, Korea
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Abstract
The effects of ultraviolet (UV) intensity and wavelength on triclosan (TCS) photodegradation kinetic, efficiency, mechanisms and pathway were studied. The TCS photodegradation followed the pseudo-first order kinetic model at all UV intensities examined at the wavelengths of 254 and 365 nm and the photodegradation rate increased with increasing UV intensity. TCS photodegradation efficiencies of 90 to 98% and 79 to 90% were obtained at the wavelengths of 254 and 365 nm, respectively. TCS was degraded mainly by photon induced hydroxyl radicals while the direct photon reaction with TCS played a subordinate role. Chlorophenol, dichlorophenol and phenol were the intermediates detected in all experiments conducted. Dibenzodichloro-p-dioxin and dibenzo-p-dioxin were observed as the intermediates only at lower UV intensities investigated at the wavelength of 365 nm. Based on these intermediates, a complete TCS photolysis pathway was proposed for the first time.
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Affiliation(s)
- H S Son
- Dept. of Environmental Health, School of Public Health, Seoul National University, Seoul 110-799, Korea
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Kim SR, Choi SB, Yuh YJ. A phase II study of combination chemotherapy with gemcitabine, 5-fluorouracil, and cisplatin (GFP) for advanced pancreatic cancer. J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.14066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
14066 Background: Gemcitabine has been the standard regimen for advanced pancreatic cancer, but the effect on the response rate and survival is still disappointing. 5-fluorouracil(5-FU) and cisplatin are synergistic with gemcitabine as well as with each other. This study is aimed to determine the efficacy and safety of combination chemotherapy with gemcitabine, 5-FU and cisplatin for advanced pancreatic cancer. Methods: Patients(pt) with recurred or advanced pancreatic cancer were entered into this study, who had histologically proven adenocarcinoma, no prior radiotherapy, measurable lesion (≥2cm), ECOG performance scale (PS) 0–2, age 18–70, adequate bone marrow, cardiac and renal function, ALT ≤ 3× normal, and total bilirubin ≤ 2mg/dL.The pt were treated every 3weeks with gemcitabine 800 mg/m2, at 10mg/m2/min on days 1 and 8, 5-FU 1g/m2/24 hour continuous infusion from day 1 through 3 for 72 hours (extended to 4 days later in 12 pt due to lack of toxicity), and cisplatin 60 mg/m2 on day 2, 24 hours after the start of gemcitabine. Concurrent chemo-radiotherapy with gemcitabine 250 mg/m2/week was given to the pt with response of stable disease or better after 4 cycles of chemotherapy, if PS ≤1 and age ≤ 65. Results: Characteristics of 25 eligible pt; 17 male/ 8 female, PS 0,1 in 20 pt, 2 in 4 pt, Stage III in 3 pt, IV in 22, age 40–69 (median 62). Five pt had prior 5-FU-based chemotherapy. A total of 109 cycles were given (median 4; 1–10 cycles/person). Response by WHO criteria: 3 PR (14.3%; 95% confidence interval: 0 - 29.6%), 11 SD (52.4%) and 7 PD in 21 assessable pt. The median time to progression was 230 days (48+-478+) and median survival was 322 days (70+-757+). WHO grade ≥3 toxicity: neutropenia 19.3% (/cycle), thrombocytopenia 28.4%, mucositis 1.8%, and nausea and vomiting 5.6%. The clinical benefit response and correlation of tumor response with CA-19–9 level will be detailed on presentation. Conclusions: The chemotherapy with gemcitabine, 5-FU and cisplatin for advanced pancreatic cancer is safe, active and may have better survival benefit than gemcitabine alone. Based on these results, a nationwide phase III trial comparing with gemcitabine alone has been started. No significant financial relationships to disclose.
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Affiliation(s)
- S. R. Kim
- Inje University, Seoul, Republic of Korea
| | - S. B. Choi
- Inje University, Seoul, Republic of Korea
| | - Y. J. Yuh
- Inje University, Seoul, Republic of Korea
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Choi SB, Lee JW, Choy YH, Na KJ, Kim NS. Estimates of Parameters for Genetic Relationship between Reproductive Performances and Body Condition Score of Hanwoo Cows. Asian Australas J Anim Sci 2005. [DOI: 10.5713/ajas.2005.909] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Choi SB, Choi HJ, Choi YT, Wereley NM. Preparation and mechanical characteristics of poly(methylaniline) based electrorheological fluid. J Appl Polym Sci 2005. [DOI: 10.1002/app.21633] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Won SW, Choi SB, Chung BW, Park D, Park JM, Yun YS. Biosorptive Decolorization of Reactive Orange 16 Using the Waste Biomass of Corynebacterium glutamicum. Ind Eng Chem Res 2004. [DOI: 10.1021/ie049559o] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. W. Won
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - S. B. Choi
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - B. W. Chung
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - D. Park
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - J. M. Park
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
| | - Y.-S. Yun
- Division of Environmental and Chemical Engineering and Research Center of Industrial Technology, Chonbuk National University, Chonbuk 561-756, Korea, and Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
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Abstract
Biomass waste, mainly Corynebacterium glutamicum, is generated from large-scale lysine fermentation process. In this study, protonated C. glutamicum biomass was evaluated as a biosorbent for the removal of lead from synthetic wastewater. As Pb2+ were bound to the biomass, the solution pH deceased, indicating that protons in the biomass were exchanged with lead ions. The Corynebacterium biomass bound Pb2+ at up to 2.74 mmol g(-1) at pH 5, where lead does not precipitate. Compared with other biosorbents and conventional sorbents, such as natural zeolite, activated carbon and synthetic ion exchange resin, the protonated C. glutamicum biomass was considered to be a useful biomaterial for lead biosorption.
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Affiliation(s)
- S B Choi
- Division of Environmental and Chemical Engineering and Research Institute of Industrial Technology, Chonbuk National University, Chonju, Chonbuk 561-756, Korea
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Okita TW, Sun J, Sakulringharoj C, Choi SB, Edwards GE, Kato C, Ito H, Matsui H. Increasing rice productivity and yield by manipulation of starch synthesis. Novartis Found Symp 2002; 236:135-46; discussion 147-52. [PMID: 11387976 DOI: 10.1002/9780470515778.ch10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Plant productivity and yield are dependent on source-sink relationships, i.e. the capacity of source leaves to fix CO2 and the capacity of developing sink tissues and organs to assimilate and convert this fixed carbon into dry matter. Studies from our laboratories as well as others have demonstrated that rice productivity and yield are mainly sink-limited during its development because of limited capacity to utilize the initial photosynthetic product (triose phosphate). This limitation in triose phosphate utilization, evident at both the vegetative and reproductive stages of rice development, may be associated with limited capacity for carbohydrate synthesis in rice leaves (which are poor accumulators of starch) or feedback due to limited sink strength of developing seeds. Strategies in improving triose phosphate utilization by enhancing starch production in leaves and developing seeds by the expression of engineered genes for ADP glucose pyrophosphorylase, a key regulatory enzyme of starch biosynthesis, are discussed.
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Affiliation(s)
- T W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164, USA
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Choi SB, Kim BK, Boudjouk P, Grier DG. Amine-promoted disproportionation and redistribution of trichlorosilane: formation of tetradecachlorocyclohexasilane dianion. J Am Chem Soc 2001; 123:8117-8. [PMID: 11506569 DOI: 10.1021/ja002831a] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S B Choi
- Center for Main Group Chemistry Department of Chemistry North Dakota State University Fargo, North Dakota 58105, USA
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Sami-Subbu R, Choi SB, Wu Y, Wang C, Okita TW. Identification of a cytoskeleton-associated 120 kDa RNA-binding protein in developing rice seeds. Plant Mol Biol 2001; 46:79-88. [PMID: 11437252 DOI: 10.1023/a:1010643209402] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
During rice seed development, prolamine RNAs are localized to the surface of the prolamine storage protein bodies (PBs), organelles bounded by the endoplasmic reticulum (ER). The exact mechanism by which prolamine RNAs are enriched on this ER subdomain is not known but recent evidence indicates the directed transport and targeting of prolamine RNAs to the prolamine PBs. As such a process involves RNA signal determinants and cytoskeleton-interacting proteins that recognize these signals, we obtained an enriched cytoskeleton-PB fraction and identified a prominent RNA-binding activity, Rp120, by RNA-binding UV-cross-linking assay. Recombinant cDNA clones of Rp120 revealed that the primary sequence shared considerable structural homology to the human transcriptional coactivator p100 and possessed a modular organization, four nucleic acid-binding SN domains, a tudor domain and a coil-coil domain. Consistent with the presence of SN domains, Rp120 binds a variety of RNAs including prolamine RNA. Interaction with the latter RNA, however, was specific as binding activity was evident only to the prolamine 3' UTR and not to the 5' UTR or coding sequences. Rp120 is also able to interact with other proteins as its sedimentation behavior in sucrose density gradient suggests an association with the cytoskeleton. The presence of a tudor domain, suggested to have a role in RNA processing or transport, together with the SN and coiled-coil domains are consistent with the view that Rp120 may be involved in RNA sorting in rice endosperm.
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Affiliation(s)
- R Sami-Subbu
- Institute of Biological Chemistry, Washington State University, Pullman 99164-6340, USA
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Abstract
ADP-glucose pyrophosphorylase (AGPase), a key regulatory enzyme in higher plant starch biosynthesis, is composed of a pair of large and small subunits (alpha(2)beta(2)). Current evidence suggests that the large subunit has primarily a regulatory function, while the small subunit has both regulatory and catalytic roles. To define the structure-function relationship of the large subunit (LS), the LS of potato AGPase was subjected to chemical mutagenesis and coexpressed with the wild-type (WT) small subunit (SS) cDNA in an AGPase defective Escherichia coli strain. An LS mutant (M143) was isolated, which accumulated very low levels of glycogen compared to the WT recombinant AGPase, but maintained normal catalytic activity when assayed under saturating conditions. Sequence analysis revealed that M143 has a single amino acid change, V463I, which lies adjacent to the C-terminus. This single mutation had no effect on the Km for ATP and Mg(2+), which were similar to the WT enzyme. The K(m) for glucose 1-P, however, was sixfold higher than the WT enzyme. These results suggest that the LS plays a role in binding glucose 1-P through its interaction with the SS.
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Affiliation(s)
- I H Kavakli
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, 99164, USA
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Choi SB, Kim KH, Kavakli IH, Lee SK, Okita TW. Transcriptional expression characteristics and subcellular localization of ADP-glucose pyrophosphorylase in the oil plant Perilla frutescens. Plant Cell Physiol 2001; 42:146-53. [PMID: 11230568 DOI: 10.1093/pcp/pce019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Three ADP-glucose pyrophosphorylase clones were isolated from the cotyledon cDNA library of the oil plant, Perilla frutescens, and their intracellular localization investigated. Two of three cDNAs (PfagpS1 and PfagpS2) were homologous to the catalytic small subunit of AGPases found in other plants, while the third clone (PfagpL) was highly similar to the large subunit type. Transcripts for PfagpS1 and PfagpS2 were observed in both photosynthetic and non-photosynthetic tissue, showing the highest expression in the stem, while PfagpL transcripts were abundantly expressed in stem and cotyledon. To evaluate the subcellular localization of PfagpS2 and PfagpL as well as the maize BT2, N-terminus-GFP DNA fusion were constructed and transformed into tobacco plants. Immunoblot analysis showed that the expressed PfagpS2- and PfagpL-GFP fusions were targeted to the plastid in the heterologous tobacco system whereas the BT2-GFP remained intact, suggesting a cytoplasmic location. These intracellular assignments were confirmed by direct confocal microscopic examination. GFP signals were localized to the cytoplasm as well as in the nucleus in BT2-GFP plants, and to the plastids in PfagpS2- and PfagpL-GFP plants. Our results indicate that Perilla cotyledons contain multiple AGPase subunits, of which at least two isoforms and very likely the third, are plastidial in nature.
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Affiliation(s)
- S B Choi
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
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Choi SB, Wang C, Muench DG, Ozawa K, Franceschi VR, Wu Y, Okita TW. Messenger RNA targeting of rice seed storage proteins to specific ER subdomains. Nature 2000; 407:765-7. [PMID: 11048726 DOI: 10.1038/35037633] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rice seeds, a rich reserve of starch and protein, are a major food source in many countries. Unlike the seeds of other plants, which typically accumulate one major type of storage protein, rice seeds use two major classes, prolamines and globulin-like glutelins. Both storage proteins are synthesized on the endoplasmic reticulum (ER) and translocated to the ER lumen, but are then sorted into separate intracellular compartments. Prolamines are retained in the ER lumen as protein bodies whereas glutelins are transported and stored in protein storage vacuoles. Mechanisms responsible for the retention of prolamines within the ER lumen and their assembly into intracisternal inclusion granules are unknown, but the involvement of RNA localization has been suggested. Here we show that the storage protein RNAs are localized to distinct ER membranes and that prolamine RNAs are targeted to the prolamine protein bodies by a mechanism based on RNA signal(s), a process that also requires a translation initiation codon. Our results indicate that the ER may be composed of subdomains that specialize in the synthesis of proteins directed to different compartments of the plant endomembrane system.
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Affiliation(s)
- S B Choi
- Institute of Biological Chemistry, Washington State University, Pullman 99164, USA
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Lee JW, Choi SB, Jung YH, Keown JF, Van Vleck LD. Parameter estimates for direct and maternal genetic effects on yearling, eighteen-month, and slaughter weights of Korean native cattle. J Anim Sci 2000; 78:1414-21. [PMID: 10875621 DOI: 10.2527/2000.7861414x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Data collected by the National Livestock Research Institute of the Rural Development Administration of Korea were used to estimate genetic parameters for yearling (YWT, n = 5,848), 18-mo (W18, n = 4,585), and slaughter (SWT, n = 2,279) weights for Korean Native cattle. Nine animal models were used to obtain REML estimates of genetic parameters: DP-2 included genetic, uncorrelated dam, and residual random effects; DQ-2 included genetic, sire x region x year-season interaction, and residual random effects; DPQ-2 was based on DQ-2 but included both interaction and dam effects; DMP-2 was based on DP-2 but with dam effect partitioned to include maternal genetic and permanent environmental effects; and DMPQ-2 was based on DMP-2 but also included sire interaction effects. Those five models included two fixed factors: region x year-season and age of dam x sex effects. Models DP-3, DQ-3, DPQ-3, and DMPQ-3 were based on DP-2, DQ-2, DPQ-2, and DMPQ-2 but included as a third fixed factor whether or not identification of the sire was known. Estimates of heritability with DMPQ-3 for YWT, with DPQ-3 for W18 and SWT when analyzed with single-trait analyses were .14, .11, and .17, respectively, and were nearly the same with bivariate analyses. Estimate of maternal heritability for YWT from single-trait analysis was .04, with estimates for other traits near zero. For bivariate analyses, the estimate for YWT was .01. With single trait analysis, estimate of the direct-maternal genetic correlation for YWT was negative (-.81). Estimates of direct genetic correlations between YWT and W18, YWT and SWT, and W18 and SWT were .99, 1.00, and .97, respectively. Estimates of environmental correlations varied from .60 to .81; the largest was between W18 and SWT. Including a fixed factor for whether sire identification was missing or not missing reduced the estimate of heritability for slaughter weight. The results suggest that the sire x region x year-season interaction is important for yearling weight and may be needed in a model for slaughter weight. Maternal effects may be of slight importance for yearling weight but of no importance for W18 and SWT. Models for national cattle evaluations for Korean Native cattle for YWT should be considered that include maternal genetic and permanent environmental as well as sire x region x year-season interaction effects, but those effects seem not to be needed for models for W18 and SWT. Not much reranking of sires occurred when ranked was based on the different models for W18 and SWT.
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Affiliation(s)
- J W Lee
- Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA
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Abstract
Data (n = 1,746) collected from 1985 through 1995 on Korean Native Cattle by the National Livestock Research Institute of Korea were used to estimate genetic parameters for marbling score, dressing percentage, and longissimus muscle area, with backfat thickness, slaughter age, or slaughter weight as covariates. Estimates were obtained with REML. Model 1 included animal genetic and residual random effects. Model 2 was extended to include an uncorrelated random effect of the dam. Model 3 was based on Model 1 but also included sire x region x year-season interaction effects. Model 4 combined Models 2 and 3. All models included fixed effects for region x year-season and age of dam x sex combinations. From single-trait analyses, estimates of heritability with covariates to adjust for backfat thickness, slaughter age, and slaughter weight from Model 4 were, respectively, .10, .08, and .01 for marbling score; .09, .12, and .16 for dressing percentage; and .18, .17, and .24 for longissimus muscle area. From three-trait analyses, estimates of genetic correlations between marbling score and dressing percentage, marbling score and longissimus muscle area, and dressing percentage and longissimus muscle area were, respectively, -.99, .20, and -.11 with backfat thickness as covariate; -.88, .47, and .01 with slaughter age as covariate; and -.03, .39, and .91 with slaughter weight as covariate. Results of this study suggest that choice of covariate (backfat thickness, slaughter age, or slaughter weight) for the model seems to be important for carcass traits for Korean Native Cattle. Including sire x region x year-season interaction effects in the model for marbling score and dressing percentage may be important because whether sire x region x year-season interaction effects were in the model affected estimates of other variance components for the three carcass traits. Whether the maternal effect was in the model had little effect on estimates of other parameters. With backfat thickness and slaughter age end points, selection for increasing marbling score would be expected to result in decreasing dressing percentage for Korean Native Cattle. With slaughter weight as a covariate for end point, increased longissimus muscle area would be associated with increased dressing percentage, and increased marbling score would be related to increased longissimus muscle area. The differences in estimates associated with choice of end point, however, need further study.
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Affiliation(s)
- J W Lee
- Department of Animal Science, University of Nebraska, Lincoln 68583-0908, USA
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Abstract
The reaction of N,N,N',N"-pentamethyldiethylenetriamine (pmdeta) with HSiCl3 and H2SiCl2 in dry CH2Cl2 affords the novel cationic intermolecular hexacoordinate silanes [pmdeta.HSiCl2]+Cl- (1) and [pmdeta.H2SiCl]+Cl(2), respectively. The addition of N,N,N',N',N"-pentaethyldiethylenetriamine (pedeta) to a solution of HSiCl3 in dry CH2Cl2 gives the redistribution product formulated as the salt [pedeta.H2SiCl]+Cl- (3) and SiC4. Treatment of H2SiCl2 with pedeta and N,N,N',N',N",N"'-hexamethyltriethylenetetramine (hmteta) produces [pedeta.H2SiCl]+Cl(3) and [hmteta.H2SiCl]+C1- (HCl) (4). In 4, the fourth amine is not bonded to silicon. Reactions of 2, 3, and 4 with NaBPh4 give the ion exchange products [pmdeta.H2SiC1]+BPh4- (5), [pedeta.H2SiCl]+BPh4- (6), and [hmteta.H2SiCl]+BPh4- (HCl) (7), respectively. The salts 1, 5, 6, and 7 were characterized by single-crystal X-ray diffraction analysis. Most notable is that the cations in 1, 5, 6, and 7 are slightly distorted octahedra in which two hydrogen atoms are at the trans positions. The reactions of 3 with tmeda and pmdeta afford the intermolecular ligand exchange products tmeda.H2SiCl2 and 2, respectively.
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Affiliation(s)
- B K Kim
- Center for Main Group Chemistry, Department of Chemistry, North Dakota State University, Fargo 58105, USA
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Choi SB, Lee JW, Kim NS, Na SH, Keown JF, Van Vleck LD. Estimation of Genetic Parameters for Direct, Maternal and Grandmaternal Genetic Effects for Birth, Weaning and Six Month Weights of Hanwoo (Korean Cattle). Asian Australas J Anim Sci 2000. [DOI: 10.5713/ajas.2000.149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Choi SB, Lee KW, Cho SH. Cloning of CTP:phosphocholine cytidylyltransferase cDNA from Arabidopsis thaliana. Mol Cells 1997; 7:58-63. [PMID: 9085266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
As one of the first steps to elucidate the relationship between the structure and function of CTP:phosphocholine cytidylytransferase (EC 2.7.7.15) in plants, the cytidylyltransferase cDNA of Arabidopsis thaliana was cloned and characterized. The A. thaliana cytidylyltransferase cDNA is 1447 bp long and contains an open reading frame of 993 bp coding for a protein of 331 amino acids. The deduced structure of the enzyme was composed of three main regions; the catalytic domain in the N-terminal half, the hydrophilic C-terminal region and the amphipathic domain in the middle. The catalytic domain region was relatively well conserved among different organisms, showing 76 and 72% homology with the rat and yeast protein sequences, respectively. The hydropathy profile revealed that the C-terminal non-catalytic portion of the protein was very hydrophilic, highly enriched in negatively charged aspartic acid and glutamic acid residues. In the region between the catalytic domain and the C-terminal region, there was an amphipathic alpha-helical domain, which was believed to bind the membrane surface in the active formation. Unlike animal counterparts, there was only one potential site of phosphorylation by protein kinase C and none by Ca2+/calmodulin protein kinase II in the C-terminal region. The identity of cytidylyltransferase cDNA was verified by successful transformation of a yeast mutant defective in the enzyme activity, using an expression vector inserted with the A. thaliana cytidylyltransferase cDNA. This was further confirmed by in vivo analysis of the enzyme reaction product after labeling the yeast transformants with radioactive phosphocholine. Southern analysis indicated the presence of a single copy of the citidylyltransferase gene in A. thaliana.
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Affiliation(s)
- S B Choi
- Department of Biology, Inha University, Inchon, Korea
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Kim MN, Park CG, Hwang ES, Lim DG, Park JW, Seoh JY, Kook YH, Lee HJ, Choi SB, Cha CY. Gene cloning of the human cytomegalovirus (HCMV) antigen reactive with the serum from a HCMV-infected patient. J Korean Med Sci 1994; 9:476-81. [PMID: 7786444 PMCID: PMC3054222 DOI: 10.3346/jkms.1994.9.6.476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The human cytomegalovirus(HCMV) gene encoding the protein reactive with the sera of HCMV-infected patient was cloned and characterized. A reactive phage clone was screened from a lambda gt11 expression library of cDNA of HCMV AD169 strain using HCMV-infected patient sera. The recombinant protein was expressed as 138 kDa-fusion protein with beta-galactosidase, which was reactive with IgM or IgG HCMV antibody-positive sera, but not with anti-HCMV antibody-negative sera. A homology search of the DNA sequence of the cloned gene with HCMV AD169 sequences revealed that it was composed of 709 base pairs spanning between 0.174 and 0.177 map units of the UL32 region of the HCMV AD169 strain genome. This position corresponded to a part of the gene encoding 150 kDa phosphoprotein-(pp150), a major tegument protein, which was reported as an immunogenic protein which evoked strong and longstanding antibody response and had no sequence homology with the proteins of other herpesviruses. These results suggested that pp150 was an immunogenic protein in natural HCMV infection and therefore this clone was regarded as a useful candidate for developing an antigen for the serodiagnosis of HCMV.
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Affiliation(s)
- M N Kim
- Department of Microbiology, Seoul National University College of Medicine, Korea
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Park CS, Kim IC, Lee JB, Choi MS, Choi SB, Chang WH, Kim I. Analysis of antigenic characteristics of Rickettsia tsutsugamushi Boryong strain and antigenic heterogeneity of Rickettsia tsutsugamushi using monoclonal antibodies. J Korean Med Sci 1993; 8:319-24. [PMID: 8305138 PMCID: PMC3053706 DOI: 10.3346/jkms.1993.8.5.319] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Twenty-four monoclonal antibodies were produced by immunizing BALB/c mice with Rickettsia tsutsugamushi Boryong strain and used for the analysis of antigenic characteristics of R.tsutsugamushi Boryong strain and antigenic heterogeneity of R.tsutsugamushi by indirect immunofluorescent(IF) test. R. tsutsugamushi Kato, Karp, Gilliam, TA686, TA716, TA763, TC586, TH1817, and Boryong were used for the analysis of antigenic heterogeneity of R.tsutsugamushi. Five monoclonal antibodies were reactive with 27-kDa protein, four monoclonal antibodies were reactive with 47-kDa protein, and eight monoclonal antibodies were reactive with 56-kDa protein of R.tsutsugamushi Boryong strain. The reactive protein of seven monoclonal antibodies could not be identified by immunoblotting method. All monoclonal antibodies to 27-kDa protein and three monoclonal antibodies to 47-kDa protein, and five monoclonal antibodies to 56-kDa protein were reactive with three to eight strains among nine strains of R. tsutsugamushi tested. One monoclonal antibody reactive to 47-kDa protein(KI18) and two monoclonal antibodies reactive to 56-kDa protein(KI36, and KI37) reacted with all the strains of R. tsutsugamushi tested. Strain-specific monoclonal antibody(KI58) could be found among antibodies which were reactive with 56-kDa protein. There was no strain which showed same reactivity pattern to these 24 monoclonal antibodies among nine strains. From this results, it could be concluded that Boryong strain is antigenically different from other strains of R.tsutsugamushi and antigenic heterogeneity of R.tsutsugamushi is due to the antigenic diversity of several proteins of R. tsutsugamushi including 56-kDa protein.
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Affiliation(s)
- C S Park
- Department of Microbiology, Seoul National University College of Medicine
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Rossetti L, Farrace S, Choi SB, Giaccari A, Sloan L, Frontoni S, Katz MS. Multiple metabolic effects of CGRP in conscious rats: role of glycogen synthase and phosphorylase. Am J Physiol 1993; 264:E1-10. [PMID: 8430777 DOI: 10.1152/ajpendo.1993.264.1.e1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Calcitonin gene-related peptide (CGRP) is a neuropeptide that is released at the neuromuscular junction in response to nerve excitation. To examine the relationship between plasma CGRP concentration and intracellular glucose metabolism in conscious rats, we performed insulin (22 pmol.kg-1.min-1) clamp studies combined with the infusion of 0, 20, 50, 100, 200, and 500 pmol.kg-1.min-1 CGRP (plasma concentrations ranging from 2 x 10(-11) to 5 x 10(-9) M). CGRP antagonized insulin's suppression of hepatic glucose production at plasma concentrations (approximately 10(-10) M) that are only two- to fivefold its basal portal concentration. Insulin-mediated glucose disposal was decreased by 20-32% when CGRP was infused at 50 pmol.kg-1.min-1 (plasma concentration 3 x 10(-10) M) or more. The impairment in insulin-stimulated glycogen synthesis in skeletal muscle accounted for all of the CGRP-induced decrease in glucose disposal, while whole body glycolysis was increased despite the reduction in total glucose uptake. The muscle glucose 6-phosphate concentration progressively increased during the CGRP infusions. CGRP inhibited insulin-stimulated glycogen synthase in skeletal muscle with a 50% effective dose of 1.9 +/- 0.36 x 10(-10) M. This effect on glycogen synthase was due to a reduction in enzyme affinity for UDP-glucose, with no changes in the maximal velocity. In vitro CGRP stimulated both hepatic and skeletal muscle adenylate cyclase in a dose-dependent manner. These data suggest that 1) CGRP is a potent antagonist of insulin at the level of muscle glycogen synthesis and hepatic glucose production; 2) inhibition of glycogen synthase is its major biochemical action in skeletal muscle; and 3) these effects are present at concentrations of the peptide that may be in the physiological range for portal vein and skeletal muscle. These data underscore the potential role of CGRP in the physiological modulation of intracellular glucose metabolism.
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Affiliation(s)
- L Rossetti
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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Frontoni S, Choi SB, Banduch D, Rossetti L. In vivo insulin resistance induced by amylin primarily through inhibition of insulin-stimulated glycogen synthesis in skeletal muscle. Diabetes 1991; 40:568-73. [PMID: 2022302 DOI: 10.2337/diab.40.5.568] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We examined the in vivo mechanisms of amylin-induced resistance in concious rats (n = 18). During 180-min euglycemic insulin-clamp (21.5 pmol.kg-1.min-1) studies, amylin (50, 200, or 500 pmol.kg-1.min-1; plasma concentration from 3 x 10(-10) to 9 x 10(-9) M) infusion determined a 19-27% reduction in glucose uptake (117.8 +/- 7.0 vs. 145.8 +/- 11.0, 107.1 +/- 9.2 vs. 145.1 +/- 6.7, and 105.0 +/- 7.2 vs. 144.4 +/- 7.0 mumol.kg-1.min-1 at 50, 200, or 500 pmol.kg-1.min-1, respectively, P less than 0.01) versus insulin alone, whereas 10-pmol.kg-1.min-1 amylin infusion (plasma concn 5 x 10(-11) M) failed to affect insulin-mediated glucose disposal. After amylin infusion, the contribution of whole-body glycolysis to overall glucose disposal increased from 43-48 to 62-79%, whereas muscle glycogen synthesis decreased significantly at all peptide concentrations greater than 3 x 10(-10) M, completely accounting for the decrease in glucose uptake. Skeletal muscle glucose-6-phosphate concentration rose from 0.219 +/- 0.038 mumol/g (insulin alone) to 0.350 +/- 0.018, 0.440 +/- 0.020, and 0.505 +/- 0.035 mumol/g (insulin plus amylin at 50, 200, or 500 pmol.kg-1.min-1, P less than 0.01). Suppression of hepatic glucose production by insulin was unaffected by a 50-pmol.kg-1.min-1 amylin infusion (18.5 +/- 4.3 vs. 21.7 +/- 2.9 mumol.kg-1.min-1), whereas it was slightly but significantly impaired by amylin infusion at 200 pmol.kg-1.min-1 (17.8 +/- 3.9 vs. 24.7 +/- 4.5 mumol.kg-1.min-1, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S Frontoni
- Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7886
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Abstract
Calcitonin gene-related peptide (CGRP) is a peptide with structural homology to amylin, which is present in nerve terminals of skeletal muscle and intestine. The effect of this peptide on in vivo insulin action was studied in conscious rats. All rats received 180 min euglycemic (5.6 mM) insulin (21.5 pmol.kg-1.min-1) clamp study in combination with [3-3H]- and [U-14C]glucose infusions. In the basal state, the plasma CGRP concentration was 36 +/- 5 pM, and the skeletal muscle CGRP concentration was 376 +/- 88 pmol/kg wet wt. CGRP was infused at 100 pmol.kg-1.min-1 during the last 90 min of the insulin clamp study and determined a rise in plasma concentration to 781 +/- 34 pM. Hepatic glucose production was stimulated by the infusion of CGRP (35.6 +/- 6.1 vs. 24.4 +/- 4.4 mumol.kg-1.min-1). During infusion in insulin alone, glucose uptake was 133.3 +/- 8.9 mumol.kg-1.min-1 and decreased to 105.5 +/- 12.2 mumol.kg-1.min-1 with CGRP. However, the whole body rates of glycolysis (3H2O generation) were higher during the infusion of CGRP (83.9 +/- 6.1 mumol.kg-1.min-1) compared with insulin alone (72.2 +/- 7.8 mumol.kg-1.min-1). By contrast, CGRP determined a severe impairment in muscle glycogen synthesis (11.7 +/- 3.9 vs. 47.8 +/- 5.0 mumol.kg-1.min-1). Skeletal muscle glucose 6-phosphate concentration was significantly increased after CGRP infusion compared with insulin alone (0.540 +/- 0.052 vs. 0.219 +/- 0.038 mumol/g wet wt; P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- S B Choi
- Department of Medicine, University of Texas Health Science Center, San Antonio 78284
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Abstract
The limitations of the current generation of robotic systems has triggered a new research thrust for predicting the elastodynamic response of assemblages of articulating flexible-bodied systems. This research thrust is extended herein by proposing the fabrication of robotic systems in either monolithic or ultra-advanced composite laminated high-strength, high-stiffness materials in which are incorporated electro-rheological fluids. These multiphase fluid systems, which change their rheological behavior instantaneously when subjected to an externally applied electrical field, provide a potential for tailoring the vibrational characteristics of these hybrid materials from which the structural members of the proposed robotic systems are fabricated. This paper is focused on developing the necessary design tools for predicting the vibrational response of flexible multibodied articulating systems fabricated with this new class of advanced materials. A variational theorem is developed herein as a basis for finite element formulations which can be employed to predict the elastodynamic response of these systems. A coherent combination of experimental and theoretical work on cantilevered beams is presented to demonstrate the viability of the proposed design methodology. In addition, computer simulation results are presented to demonstrate the potential payoffs in terms of superior performance characteristics of a new generation of robotic systems capitalizing on this innovative and revolutionary design philosophy.
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Affiliation(s)
- M. V. Gandhi
- Intelligent Materials and Structures Laboratory, and Machinery Elastodynamics Laboratory, Michigan State University, East Lansing, MI 48824-1226
| | - B. S. Thompson
- Intelligent Materials and Structures Laboratory, and Machinery Elastodynamics Laboratory, Michigan State University, East Lansing, MI 48824-1226
| | - S. B. Choi
- Intelligent Materials and Structures Laboratory, and Machinery Elastodynamics Laboratory, Michigan State University, East Lansing, MI 48824-1226
| | - S. Shakir
- Intelligent Materials and Structures Laboratory, and Machinery Elastodynamics Laboratory, Michigan State University, East Lansing, MI 48824-1226
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Yoon KW, Choi SB, Choi MG, Lee HK, Kim CY, Min HK. Analyses of RBC insulin receptor bindings in chronic liver disease. Korean J Intern Med 1986; 1:140-4. [PMID: 3154607 PMCID: PMC4536708 DOI: 10.3904/kjim.1986.1.2.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
125I-insulin binding to erythrocytes was measured to evaluate the role of insulin receptors in the mechanism of insulin resistance in partients with chronic liver disease (CLD). Patients with CLD were divided into two groups by the fasting plasma glucose level (FBS) and the glucose disappearance rate (k-glucose) during intravenous glucose tolerance tests: one with normal FBS and normal k-glucose (group I), and the other with higher FBS and lower k-glucose (group II). Insulin receptor bindings were reduced in group I patients compared with those of normal controls, but were not reduced in group II patients. Fasting insulin levels were significantly higher in group I patients than those in normal subjects, and down-regulation by hyperinsulinemia might be the cause of reduced insulin receptor bindings in these patients. However down-regulation of insulin receptors was not associated with glucose intolerance. So it is suggested that insulin resistance in CLD is not due to a primary defect of insulin receptors in peripheral tissues, and down-regulation of insulin receptors is an epiphenomenon of hyperinsulinemia.
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