• Food Science of Animal Resources
• /
• v.41 no.4
• /
• pp.650-663
• /
• 2021

The objective of this study was to examine the relationship between meat quality attributes and the changes of sarcoplasmic protein acetylation and myofibrillar protein acetylation in lamb longissimus thoracis et lumborum muscles at different postmortem phases. Protein acetylation, color, pH, shear force, myofibril fragmentation index and cooking loss were measured. The total level of acetylated sarcoplasmic proteins showed a negative relation with pH, a positive relation with a^*, b^* and cooking loss at the pre-rigor phase. Sarcoplasmic proteins acetylation affected postmortem pH by regulating glycolysis, which in turn affects color and cooking loss. The total level of acetylated myofibrillar proteins showed a positive relation with shear force at the pre-rigor phase. Myofibrillar proteins acetylation affected meat tenderness by regulating muscle contraction. This study indicated that acetylation played a regulatory role of meat color, water-holding capacity, and tenderization process at early postmortem.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.3
• /
• pp.21-29
• /
• 2023

In this study, the stress characteristics of temporary fixed steel rods were analyzed in the "temporary fixing system using internal prestressing tension", which is mainly applied to the construction of superstructures by FCM. It was difficult to confirm the changes in initial tensile force in this system because the steel rod was internally connected to the pier and the PSC BOX. Therefore, measurement was performed before and after the completion of each segment using an FBG sensor to measure the change in the micro length of the steel rod. The results of the analysis showed that 75% to 90% of the maximum vertical contraction of the steel rod that occurred until the completion of the cantilever segment occurred in the fixing ~ 1segment, and the maximum loss of initial prestressing force was 39%. Such excessive loss of tension force to 1 segment means that tension is needed to improve the precision of construction during the fixation, and re-tension is needed to secure stability for conduction of cantilever segments after the completion of 1segment. In the 2 ~ last segment, the stress of the steel rod decreased gradually, and in the summer, the decrease in stress tended to partially recover due to the increase in the length of the steel rod corresponding to the increase in the vertical volume of PSC BOX. The dominant factor in the stress change in 2~ last segment in this phenomenon is judged to be the change in the length of the steel rod according to the temperature. Unlike the change in length, the relaxation was 1.2-2.7%, which was mostly offset by the opposite stress corresponding to the temperature stress. Therefore, a plan was proposed to improve the internal stress, such as adjusting the fixation time.

• Journal of the Korea Furniture Society
• /
• v.21 no.6
• /
• pp.459-468
• /
• 2010

Materials are such an important factor in designing furniture. Wood is the biggest part of furniture materials. While wood is soft, eco-friendly and natural material, it is variable because it is characterized by severe expansion and contraction. Thus, if the changeable characteristic of wood is not considered in furniture design, the good design of furniture cannot be produced. As one of the skills dealing with woods, bending is such a useful way for making various forms of furniture. While it has been used in furniture-making for a long time, wood processing techniques like steaming bending, bending with ammonia and high frequency bending has been advanced. As wood is a viscoelastic material and has some plasticity, beautiful curves can be created when force is applied. Therefore this paper studies the types of bending methods for furniture and each characteristic of them. Furthermore, this study classifies wood process according to suitability for mass production or small-scale production and researches the proper wood process by the forms and the way of furniture production. Also this study aims to help furniture designers and cabinet makers with wood bending.

• Applied Microscopy
• /
• v.27 no.2
• /
• pp.121-130
• /
• 1997

It has been demonstrated that majority of cells in the mammalian body such as myocytes and epithelial cells of skin and intestine respond to mechanical force or environmental factors and exhibit partial disruption of cell membrane, i. e., cell wounding, even in a physiological condition. Myocardial cells are rather apt to be wounded than other cells since they are definitely exposed to mechanical stress by contraction-relaxation and blood flow. However, the mechanism how myocardial cells protect themselves against cell wounding is not yet clarified. On this background, the present study was performed to elucidate whether albumin leakage is related to cell wounding and to assess whether diltiazem, a potent calcium channel blocker, is beneficial in isoproterenol-induced cell wounding in the heart. Hearts isolated from New Zealand White rabbits ($1.5\sim2.0kg$ body weight, n=20) were perfused with Tyrode solution by Langendorff technique. After stabilization of baseline hemodynamics, the hearts were subjected to bolus administration of isoproterenol and diltiazem as following order: $1.6{\mu}M$ isoproterenol at zero min (the beginning point): $16{\mu}M$ diltiazem at 20min; $1.6{\mu}M$ isoproterenol at 25min; $16{\mu}M$ isoproterenol at 45 min; $160{\mu}M$ diltiazem at 65 min; $16{\mu}M$ isoproterenol at 70 min. During all experiments, the left ventricular function was recorded, albumin leakage in the coronary effluents was analyzed by electrophoresis and Western blot, and myocardial cell membranes were examined by conventional transmission electron microscopy. Data were analyzed by t-test and linear regression test. Isoproterenol significantly increased the inotropic and chronotropic contractions, coronary flow, and frequency of arrhythmia, however, diltiazem did not influence on hemodynamics except decrease in the frequency of arrhythmia and a slight decrease in contractility. Isoproterenol also resulted partial disruption of myocardial cell membrane and inclose in albumin leakage, while diltiazem pretreatment showed number of electron-dense plaques in the cell membrane and a tendency of decrease in albumin leakage. These results indicate that albumin leakage may be an indirect index of cell wounding in the heart and diltiazem nay be beneficial to protect myocardial cells against isoproterenol-induced cell wounding. It is likely that diltiazem promotes resealing process of the cell membrane.

• Clinics in Shoulder and Elbow
• /
• v.2 no.2
• /
• pp.170-177
• /
• 1999

The electromyographic activity of four muscles(biceps, supraspinatus, infraspinatus and subscapularis) was mea­sured from non-dominant shoulders of 12 volunteers by six different provocative test for the biceps pathology. The provocative tests were Speed, Yergason, Ludington, Heuter, O'Brien and the abduction-extension test. Each test was performed in a force of 30% of maximal voluntary contraction. The levels of activity of the biceps were higher than those of the other rotator cuff muscles only in Speed's test: 28% in the biceps, 26% in the infraspinatus, 25% in the supraspinatus and 21 % in the subscapularis. The levels of activity of the biceps as a percent of MMT(maximal manual test) were higher in Speed's(42%) and O'Brien's test with the arm supinatecl(42%). Speed's test can isolate the activity of biceps better than the other tests but it is a nonspecific test by which the biceps tendon was also activated within other rotator cuff muscles.

• Journal of Ginseng Research
• /
• v.26 no.1
• /
• pp.1-5
• /
• 2002

It has been well known that Korea red ginseng has an antihypertensive effect. The antihypertensive effect may be due to its ability to change the peripheral resistance. Change of vascular tone in the resistance-sized artery contribute to the peripheral resistance, thereby regulate the blood pressure. Therefore, we investigated to clarify the vasorelaxing mechanism induced by crude saponin of Korea red ginseng in the resistance-sized mesenteric artery of rats. The resistance-sized mesenteric artery was isolated and cut into a ring. The ring segment was immersed in HEPES-buffered solution and its isometric tension was measured using myograph force-displacement transducer. Crude saponin of ginseng relaxed the mesenmetric arterial rings precontracted with norepinephrine (3$\mu$M) in dose-dependent manner (0.01 mg/㎖ -1 mg/㎖. The relaxation by crude saponin was smaller in endothelium-intact preparation than that in endothelium-denuded preparation. The contraction induced by A23187 or phorbol 12,13-dibutyrate was not affected by crude saponin of ginseng. The vasorelaxing effect of crude saponin of ginseng was significantly attenuated by the increase of the extracellular K$\^$+/ concentration. Crude saponin-induced vasorelaxation was not affected by tetraethylammonium (1 mM), glybenclamide (10$\mu$M), and 4-aminopyridine (0.1 mM) in these preparations. Ba$\^$2+/(10$\mu$M ∼100$\mu$M) markedly reduced the crude saponin-induced vasorelakation dose-dependently. From the above results, we suggest that crude saponin of ginseng may stimulate K$\^$+/ efflux and hyperpolarize the membrane, thereby cause the vasorelaxation in the resistance-sized mesenteric artery of rats.

• The Korean Journal of Pharmacology
• /
• v.22 no.2
• /
• pp.105-114
• /
• 1986

This study was undertaken to search for a new antiarrhythmic agent in natural plants. Extracts of Buxus microphylla var. koreana Nakai have been used as folk remedies of several diseases, including malaria and venereal disease, but any study on the pharmacological actions of this plant has not yet been carried out and its active ingredients have not been identified. In our laboratory, we isolated buxuletin (nonalkaloid) and cyclobuxine D (steroidal alkaloid) from Buxus microphylla var. koreana Nakai and reported their pharmacological actions: diuretic effects of buxuletin in rabbits and hypotensive effect of cyclobuxine D in rats. In the present study, we investigated the effect of cyclobuxine D on isolated frog heart and heart rate in urethane anesthetized rats. In order to clarify the mechanism of bradycardic effect of cyclobuxine D, we examined the changes of the ECG parameters (PR, QRS and R ${\alpha}$ T interval) produced by intravenous injection of cyclobuxine D in anesthetized rats. Cyclobuxine D depressed the contractile force in isolated frog heart and exerted a dose-dependent bradycardic effect in anesthetized rats. Intracerebroventricular injection of cyclobuxine D caused a fall in blood pressure and an increase in heart rate, but those effects were not significant. Cyclobuxine D prolonged the PR interval and RaT interval (${\alpha}$ Tindicates the apex of T), but was without significant effects on the duration of the QRS complex and PRc in urethane anesthetized rats.

• Journal of Industrial Convergence
• /
• v.20 no.10
• /
• pp.87-94
• /
• 2022

This paper seeks to raise inflection points of battery manufacturing bases in Korea in the V4 region through the reorganization of new industrial technologies in accordance with ESG. As a result, the global supply chain market is cut off. The Russian-Ukraine war and the U.S.-China hegemony are competing in the economic crisis caused by COVID-19. It is showing diversification of new suppliers in an environment where mineral, grain procurement, gas, and even wheat imports from China and Russia are not possible. As a protective glocal, this area is used as a buffer zone(Pro-Russia, Hungary). to an isolated zone(anti-Russia, Poland) by war. In this paper, economic growth is expected to slow further due to the EU tapering period and high inflation in world countries. Due to these changes, the conversion of new tech industry and the contraction of Germany's structure due to energy supply may lose the driving force for economic growth over the past 20 years. This is caused by market disconnection(chasm) in the nominal indicators in this area. On the other hand, Korea should actively develop into the V4 area as an energy generation export (nuclear and electric hydrogen generation) area as a bypass development supply area due to the imbalance in the supply chain of rare earth materials that combines AI. By linking this industry, the energy platform can be scaled up and reliable supply technology (next generation BT, recycling technology) in diversification can be formed in countries around the world. This paper proves that in order to overcome the market chasm caused by the industries connection, new energy development and platform size can be achieved and reliable supply technology (next-generation battery and recycling technology, Low-cost LFP) can be diversified in each country.

• Korean Journal of Food Science and Technology
• /
• v.26 no.1
• /
• pp.88-92
• /
• 1994

The influence of the storage temperature between $0^{\circ}C$ and $30^{\circ}C$ on the biochemical, physical changes and meat qualities in the red muscle(M. sternomandibularis and M. mastoideus) of Korean native cattle postmortem were studied. The results obtained were summarized as follows; The pH-value during the first hours post mortem was dropped faster in storage temperature $0^{\circ}C$ than in $10^{\circ}C$, but the final pH-value reached after about 30 hrs. post mortem. The muscle which was stored in $30^{\circ}C$ reached the final pH within 10 hrs. The muscle which was stored in $0^{\circ}C$ showed the increased R-value at fast speed from the beginning. It reached maximum R-value after 20 hrs as it gradually increase showing low R-value by 10 hrs. in $10^{\circ}C$. The muscle which was stored in $0^{\circ}C$ shortened to about 46% after 10 hrs. It was contracted about 17% after 15 hrs in $10{\sim}20^{\circ}C$. The sarcomere length of Korean native cattle had the least contraction in $10^{\circ}C$ and it was contracted $18{\sim}20%\;(1.60{\sim}1.63\;{\mu}m)$ after 5 hrs., $45{\sim}46%$after 24 hrs in $0^{\circ}C$ and $30^{\circ}C$ which was generated cold shortening and rigor shortening. The meat that was stored in $0^{\circ}C$ and $30^{\circ}C$ showed about 2-fold higher shear force than it that was stored in $10^{\circ}C$ at postmortem 24 hrs. The meat that was stored in $10^{\circ}C$ at postmortem 24 hrs. showed drip loss less than 3% during the 9 days ripening period. The meat with cold shortening and rigor shortening showed the high drip loss.

• Journal of the Korean Arthroscopy Society
• /
• v.8 no.2
• /
• pp.82-88
• /
• 2004

Purpose: In this study, we intended to ascertain the benefit of KT-2000 Knee arthrometer(KT-2000) in the diagnosis of ACL(Anterior cruciate ligament) injury by comparing the anterior displacement of normal knee with that of ACL deficient knee. Materials and Methods: We designated two examiners to measure the anterior displacement of the knee joint of 30 healthy individuals, using KT-2000, at 30$^{\circ}$ flexion setting of muscle full relaxation, contraction, 25$^{\circ}$ internal rotation and 25$^{\circ}$ external rotation and analyzed these results according to the variables and measured the preoperative anterior displacement of the ACL injured knee in the 30 patients who have gone through an arthroscopic ACL reconstruction later. Results: The results of examiner 1 are 6.5${\pm}$1.5 mm, 2.5${\pm}$0.9 mm, 4.8${\pm}$1.2 mm, 6.4${\pm}$1.3 mm in right knee and 5.6${\pm}$1.3 mm, 2.1${\pm}$0.8 mm, 4.5${\pm}$1.2 mm, 5.2${\pm}$1.3 mm in left knee, in order of muscle full relaxation, contraction, 25$^{\circ}$ internal rotation and 25$^{\circ}$ external rotation. The results of examiner 2 are 6.9${\pm}$1.2mm, 2.9${\pm}$1.1mm, 5.6${\pm}$1.6mm, 6.9${\pm}$1.5mm in right, 5.5${\pm}$1.7 mm,1.9${\pm}$0.9 mm, 5.1${\pm}$1.9 mm, 5.7${\pm}$1.6 mm in left knee, The side to side difference of examiner 1 in the setting of muscle relaxation is 0.9${\pm}$1.0 mm. The anterior displaement of ACL injured knee is average 11${\pm}$2.93 mm and difference of average 6.5${\pm}$2.31 mm form that of normal. In comparison between the right and left knees of healthy individuals, the both results of two examiners showed the statistical difference in the setting of muscle full relaxation but, the results showed the side to side difference below 2 mm in 25case(83%), 21case(70%) respectively and above 3 mm in just 1 case. In the comparison between the normal and ACL injured knees, the results show the statistical difference of the side to side difference in the setting of muscle relaxation(p<0.05). Conclusion: The KT-2000 result is affected by relaxation of muscles around knee, flexion angle of knee joint, rotation of tibia, the strength of displacing force, time of the test and physical factors as height and weight. However, the Accuracy of diagnosis of ACL injury by KT-2000 will increase if the examiner is skillful and the tests are made on the exact position of knee joint.