• Applied Biological Chemistry
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• v.35 no.4
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• pp.227-231
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• 1992

The plasmids pSUPBT and pSUPBTR were constructed with a vector pSUP2021 and the BT toxin gene in the plasmid pES 1. The plasmids constructed were introduced into the antagonistic rhizobacteria P. fluorescens KR164 by conjugation and P. fluorescens having pSUPBT and pSUPBTR were named P. fluorescens KR164(pSUPBT)#2, KR164(pSUPBT)#3, KR164(pSUPBTR)#2 and KR164(pSUPBTR)#3, respectively. The BT toxin gene were identified in all transformants by Southern hybridization and the final product of BT toxin gene was identified only in P. fluorescens KR164(pSUPBTR)#3 by SDS-PAGE. This crystal toxin protein were also observed in electron microscopy.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.647-651
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• 2002

An LC/MS/MS method for the simultaneous determination of a neuroprotective agent for ischemia-reperfusion damage, KR-31378 and its N-acetyl metabolite KR-31612 in human plasma was developed. KR-31378, KR-31612 and the internal standard. KR-31543 were extracted from human plasma by liquid-liquid extraction. A reverse-phase HPLC separation was performed on Luna phenylhexyl column with the mixture of acetonitrile-5 mM ammonium formate (55:45, v/v) as mobile phase. The detection of analytes was performed using an electrospray ionization tandem mass spectrometry in the multiple reaction monitoring mode. The lower limits of quantification for KR-31378 and KR-31612 were 2.0 ng/ml. The method showed a satisfactory sensitivity, precision, accuracy, recovery and selectivity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3473-3479
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• 2009

The pharmacological profile of KR-31081, a newly synthesized AT1 receptor antagonist, was evaluated in pithed rats, conscious renal hypertensive rats (RHRs) and conscious furosemide-treated beagle dogs. In pithed rats, KR-31081 (i.v.) induced a non-parallel right shift in the dose-pressor response curve to angiotensin II (ID50: 0.05 mg/kg) with a dose-dependent reduction in the maximum responses; this antagonistic effect was about 40 times more potent than losartan (ID50: 1.74 mg/kg) which showed competitive antagonism. KR-31081 did not alter the responses induced by other agonists such as norepinephrine and vasopressin. In RHRs, orally given KR-31081 produced a dose-dependent and long-lasting (>24 h) antihypertensive effect with a higher potency to losartan (ED20: 0.30 and 3.36 mg/kg, respectively). In furosemide-treated dogs, orally given KR-31081 produced a dose-dependent and long-lasting (>8h) antihypertensive effect with a rapid onset of action (time to Emax: 1-1.5 h) and 20-fold greater potency than losartan (ED20: 0.41 and 8.13 mg/kg, respectively). These results suggest that KR-31081 is a potent, orally active AT1 receptor antagonist useful for the research and diagnostic tools as an added exploratory potential.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.113-120
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• 2012

Newcastle disease virus (NDV) Kr005/V strain was generated through 55 serial passages of NDV Kr005 strain in Vero cells. The Kr005/V virus yielded high infective titers of $10^{7.8}$ $TCID_{50}/mL$ in Vero cells and the infected cells showed cytopathic effects such as marked cell rounding, though less frequent syncytia. The Kr005/V virus was heat-stable and classified into the lentogenic type with a Mean Death Time (MDT) of 120h or greater while the Kr005 strain was heat-labile and velogenic (MDT of 49.6 h). Only the single amino acid substitution (T to S) was observed at position 433 of the HN protein of the Kr005/V strain, whereas no amino acid change was found in the F protein. The Kr005/V input virus correlated well (correlation coefficient $r^2$=0.97) with the Kr005 virus when ten field sera were tested by virus neutralization test. The biological properties and usefulness of Vero cell-adapted Kr005/V virus were discussed.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.3
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• pp.168-177
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• 2008

Trafficablility of a miner and potential environmental impacts due to mining activities should be considered in the selection of a commercial manganese nodule mining site. These two factors can be evaluated comparatively with physical properties and shear strength of sea-bed sediments. For the qualitative comparison of potential minig sites in terms of these two factors, physical properties such as water contents, void ratios, porosities, and grain densities, and shear strengths of surface sediments were determined for the three potential manganese nodule mining sites(KR1, KR2, and KR5) in the Korean manganese nodule contract area, northeast Pacific. For the study, sediment samples were collected from 107 stations from 2004 to 2006. The physical properties of surface sediments showed more significant differences between northern(KR1, KR2) and southern(KR5) blocks than between northern blocks(KR1 vs. KR2). Water content, void ratio, and porosity of sediments from KR5 were relatively higher than those from KR1 and KR2. Grain density of sediments from KR5 was relatively lower than those from KR1 and KR2. Shear strengths of the top 10cm sediments were higher in KR1 and KR2, whereas those of the deeper part were highest in KR5 block. Generally, sediments of high water contents are less suspendible than those of the low water contents by benthic disturbances, thus less disturbance is expected in the sediments of high water content by mining activities. In terms of trafficability, the shear strength of sediment below 10 cm deep is more important than shallower part because miner will disturb at least top 10 cm interval of the surface sediments. Base on these results, we conclude that KR5 area will be the best site for commercial mining among three investigated sites in this study.

• Ocean and Polar Research
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• v.36 no.4
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• pp.373-381
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• 2014

Korea contract Mn-nodule field in the NE equatorial Pacific is composed of seven sectors with average water depths of 4,513-5,025 m. Of the various factors controlling the properties of Mn-nodule, it seems that water depth is likely connected to the chemical composition and occurrence of nodules. To test whether such an assumption held in each sector, we reviewed previous research data accumulated since 1994 for one of the northern sectors (hereafter KR1) where there are stark contrasts in water depth. High-resolution seabed mapping clearly separates a northern part (KR1N) from a deeper southern part (KR1S), cutting across in the middle of the KR1. In addition, significant volcanic activities forming numerous seamounts are distinctive especially in KR1N. In terms of nodule occurrence, manganese nodules in KR1S are comparatively larger (2-4 cm) with a discoidal shape, while those in KR1N are generally small (<2 cm) with poly-lobate and irregular shapes. Nodules in KR1N also have lower Co, Cu, Mn and Ni, and higher Fe contents. The spatial separation in nodule characteristics might be caused by volcanic activities in KR1N rather than water depth contrast. During the formation of the seamounts in KR1N, rock fragments and volcanic ashes as new nuclei of the nodules would have been continuously generated. As a result, the nodules could not grow larger than 2 cm and display the shapes of a newbie (i.e., irregular and poly-lobate shapes). Moreover, significant Fe supply from volcanic activities probably decreases the Mn/Fe ratio, which may lead to the KR1 nodules being misinterpreted as a hydrogenic in origin compared to other sectors where a high Mn/Fe ratio is present.

• Physical Therapy Korea
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• v.4 no.1
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• pp.48-62
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• 1997

Several studies have evaluated the effects of types of relative frequency and delay interval of knowledge of results(KR) on motor skill learning independently. The purpose of this study was to determine more effective types of KR relative frequency and KR delay interval for motor learning. Forty-six healthy subjects (15 female, 31 male) with no previous experience with this experiment participated. The subjects ranged in age from 20 to 29 years (mean=23.9, SD=0.474). All subjects were assigned to one of four groups: a high-instant group, a high-delay group, a low-instant group, and a low-delay group. During the acquisition phase, subjects practiced movements to a target (400 mm) with either a high (83%) or low (33%) KR relative frequency, and with either an instantaneous or delayed (after 8s) KR. Four groups were evaluated on retention (after 3min and 24hr) and transfer (450 mm) tests. The major findings were as follows: (1) there were no between-group differences in acquisition and short-term retention (p>0.05, (2) a low (33%) KR relative frequency during practice was as effective for learning as measured by both long-tenn retention and transfer tests, compared with high (83%) KR practice conditions (p<0.05), (3) delayed (8s) KR enhanced learning as measured by both long-term retention and transfer tests, compared with instantaneous KR practice conditions (p<0.05), and (4) there were no interactions between KR relative frequency and KR delay interval during acquisition, retention, and transfer phases. The results suggest that relatively less frequent and delayed KR are more effective types for motor learning than more frequent and instantaneous KR.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.136-141
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• 1990

The vasorelaxant effects of KR-30075 in guinea-pig pulmonary, bovine coronary and renal arterial strips contracted by either$K^+$depolarization, phenylephrine, or prostaglandin $F_{2a}$($PGF_{2a}$) were evaluated. KR-30075 was more potent than imazodan as a vasorelaxant against $PGF_{2a}$-induced contractions in bovine coronary and renal arteries, whereas against$K^+$induced contractions KR-30075 was less potent than imazodan in guieapig pulmonary arteries and more potent in bovine coronary arteries. KR-30075 was more potent against contractions induced by phenylephrine or $PGF_{2a}$ than the contractions induced by $K^+$ This profile of activity for KR-30075 was similar to that of imazodan and dissimilar from the calcium entry blocking agent nifedipine. There was no vascular selectivity of KR-30075 between bovine coronary and renal arterial strip preparations. In conclusion, this study shows that KR-30075 represents the vasorelaxant effects on guinea-pig pulmonary, bovine coronary and renal arteries without specific vascular selectivity. The vasorelaxant profile of KR-30075, with different sources of vascular smooth muscle, is unlike that of calcium entry blocking agent and more similar to the profile of the agent that inhibit cyclic nucleotide phosphodiesterase.

• YAKHAK HOEJI
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• v.58 no.1
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• pp.16-20
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• 2014

KR-31064 was developed for the strong angiotensin II receptor antagonist among the one of pyridyl imidazol series compounds. To investigate the receptor-ligand binding characteristics of this nonpeptide antagonist, binding experiments were deployed in various conditions and ex vivo contractile responses were tested toward the standard compound, losartan. Receptor binding experiments with radiolabeled angiotensin II, the $IC_{50}$ value for KR-31064 resulted 0.67 nM without any activities toward type 2 angiotensin II receptor. The comparative potency against losartan was more than 18 fold and the specific activity in type 1 angiotensin II receptor was more than 10,000 fold comparing to the type 2 receptor. Scatchard analysis of saturation binding data showed KR-31064 acted on the receptor in a competitive mode. KR-31064 inhibited the contractile response derived by angiotensin II ($pK_B$: 9.86) similar to that of losartan with decreased maximum signals. As a potent and specific type 1 angiotensin II receptor antagonist, KR-31064 may have possibilities for the development of diagnostic ligands that can be used as tools for various biochemical research experiments and non-invasive diagnostics.

• Korean Journal of Psychosomatic Medicine
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• v.17 no.2
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• pp.75-81
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• 2009

Objectives : This study aimed to evaluate the clinical usefulness of Korean version of Strengths and Difficulties Questionnaire(SDQ-Kr) by comparing with Korean version of Childhood Behavior Checklist (K-CBCL). Methods : The parent version of SDQ-Kr and K-CBCL were administered to parents of 313 children in psychiatric clinic, 91 children referred for psychiatric consultation from pediatric clinic and 93 control children in pediatric clinic. All children aged 4-11 years old. Children in psychiatric clinic were diagnosed with one of followings;ADHD, emotional disorders and oppositional/conduct disorder. Mean scores were compared among three groups by gender. Coefficients were calculated for corresponding problem scales and total scores of both questionnaires. ROC analysis was performed for discriminant validity to distinguish psychiatry and pediatrics samples, and also to distinguish diagnostic groups of psychiatry sample. Results : The psychiatry sample showed highest means of problem scales and total scores, followed by consultation and control sample of pediatrics. SDQ-Kr and K-CBCL were significantly correlated, and equally able to distinguish those samples with SDQ-Kr showing better results. Within the psychiatry sample, SDQ-Kr had higher predictive power for all diagnostic groups. Conclusion : This study supports clinical usefulness of SDQ-Kr. We suggest that SDQ-Kr could be used not only as a diagnostic tool for children in psychiatric clinic but also as an effective and efficient screening instrument for children in need for psychiatric evaluation in pediatric clinic.