• Korean Journal of Applied Biomechanics
• /
• v.25 no.2
• /
• pp.183-190
• /
• 2015

Objective : Walking with a Material handling is an activity frequently undertaken by agricultural workers in Korea, due to the nature of their work. This study aimed to investigate differences in biomechanical variables according to the mechanical alignment of the lower limbs when walking with a heavy load, and to use this as basic data in the design of various working environments to reduce the skeletomuscular burden on the knee joint. Method : The study subjects comprised of 22 right-foot dominant adult men and women aged between 20 and 23 years. The subjects were divided into a varus or valgus group according to the mechanical alignment of the lower limb by using radiographic findings. The subjects walked without any load and with a load of 10%, 20%, or 30% of their body weight held in front of them. The Kwon3d XP program was used to calculate biomechanical variables. Results : The flexion/extension moment of the knee joint showed a decreasing trend with increased load, irrespective of the mechanical alignment of the lower limb, while the varus group did not show normal compensatory action when supported by one leg at the point of maximum vertical ground reaction force. In addition, in terms of the time taken, subjects showed no difficulties in one-foot support time up to 20%/BW, but at 30%/BW, despite individual differences, there was an increase in single limb. The increased load resulted in a decrease in the ratio of standing phase to ensure physical stability. The valgus group showed a trend of increasing the stability of their center of mass with increasing load, through higher braking power in the early standing phase. Conclusion : In conclusion, although there was no statistical difference in biomechanical variables according to the mechanical alignment of the lower limbs, the varus group showed a more irregular walking pattern with a Material handling than the valgus group, partially proving the association between lower limb alignment and walking with a Material handling.

• The Journal of the Korean dental association
• /
• v.47 no.10
• /
• pp.669-676
• /
• 2009

Purpose : Anterior region is crucial area for esthetic implant restoration. However, the alveolar process undergoes atrophy after removal of teeth and creates unfavorable situation for implant installation. The knowledge of the thickness of alveolar bone is required to estimate and expect the bone resorption after extraction. The aim of this study is to measure facial, palatal and faciopalatal bone thickness on maxillary anterior teeth. Methods : Facial, palatal, and faciopalatal bone thickness were measured on the computed tomography (CT) images from 57 patients, using an image analyzer program (Ondemand$3D^{(R)}$, Cybermed, Seoul, Korea). Results : The thickness of facial bone in incisors, lateral incisors and canines were less than 1 mm. The thickness of facial bone increased from anterior to posterior region and the thickness of palatal bone increased from posterior to anterior region. Conclusion : The measurement can be used for planning implant surgery before extraction. CT has are clinically useful in the evaluation of thickness of alveolar bone.

• Journal of Periodontal and Implant Science
• /
• v.33 no.3
• /
• pp.359-372
• /
• 2003

Among objectives of periodontal therapy. the principal one is the morphological and functional reconstruction of lost periodontal supporting tissues. This includes de novo formation of connective tissue attachment and the regrowth of alveolar bone. The use of enamel matrix derivative(EMD) may be a suitable means of regeneration new periodontal attachment in the infrabony defects. Implant used to replace lost tooth but, implantitis occurred after installation. The purpose of this study was to investigate the effects of EMD on differentiation and growth of osteoblast in titanium disc. Twentyfive millimeter diameter and 1mm thick Ti disc which was coated 25, 50, 100, 200${\mu}g$/ml of EMD(Emdogain(R)) used as experimental group, 25, 50, 100, 200ng/d of rhBMP-2 as positive control group, and no coat as negative control group. A human osteosarcoma cell line Saos-2 was cultured in Ti disc and cell proliferation and Alkaline phosphatase (ALP) activity were measured at 1 and 6 days. PCR was performed at 2 and 8 hours. Semi-quantitative RT-PCR for mRNA expressions of various osteoblastic differentiation markers -type I collagen, ALP, osteopontin, and bone sialoprotein - were performed at appropriate concentrations based upon the results of MTT and ALP assay. Cultured cell-disc complexes were prepared for scanning electron microscopy (SEM) at 2 hour. Data were analyzed using Mann-Whitney and repeated- measures 1-way analysis of variance(SPSS software version 10,SPSS. Chicago. IL). After culture, there was more osteoblast in EMD100${\mu}g$/ml than in EMD50, 200${\mu}g$/ml on day 6. There was significant difference in experimental and positive control group compared control group, as times go by(1 and 6 days). Alkaline phosphatase activity was different significantly in EMD100, 200${\mu}g$/ml and BMP100, 200${\mu}g$/ml on day 6. The results of reverse transcriptase-polymerase chain reaction (RT-PCR) showed that expression of mRNA for ALPase, collagen type I, osteopontin. hone sialoprotein and BMP-2 was detected at 2 hour and 8 hour in EMI 200${\mu}g$/ml subgroup and BMP100ng/ml subgroup. The results of this study suggest that application of enamel matrix derivative on osteoblast attached to titanium surface facilitate the expression of bone specific protein and the differentiation and growth of osteoblast.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.1
• /
• pp.87-94
• /
• 1996

For evaluating the suitability of human follicular fluid(HFF) as protein supplement in ART, this preliminary study was performed to examine the maturation promoting activity of HFF on mouse follicular oocytes in vitro. Mouse follicular oocytes were collected from ovaries of 21-28 day old ICR mice by puncturing the antral follicles with fine needle at 48 hours after PMSG injection. The oocytes were rinsed and cultured in modified Whittingham's $T_6$ medium containing purines or dbcAMP to maintain meiotic arrest, and different concentrations of HFF were added into the culture medium to examine the effect of HFF on releasing the oocytes from the suppressive influence of the meiotic inhibitors. As a control for HFF, the maturation promoting activity of human fetal cord serum(HFCS) was investigated and compared with the activity of HFF. While HFF was separated, by molecular weight(M.W), into high M.W. fraction(M.W>30,000) and low M.W. fraction(M.W<30,000) and the effects of the fractions on meiotic resumption were investigated in the presence of the meiotic inhibitors. Also hormone analysis was performed to compare the content of hormones in HFF with that in HFCS. Same concentrations of HFF and HFCS induced similar germinal vesicle break down(GVBD) rates of the oocytes meiotic arrested by purines(4mM hypoxanthine+0.75mM adenosine), but the extrusion rate of 1st polar body(PB) of the oocytes cultured in HFF(65.0%, P<0.05) was significantly higher than that(51.6%) in HFCS. While, in the presence of 200 M dbcAMP, the maturation promoting activity of HFF (GVBD: 70.5%, $p<10^{-6}$; 1st PB extrusion: 67.1%, $p<10^{-3}$) was significantly greater than that of HFCS(GVBD: 35.2%; 1st PB extrusion: 41.1%). The oocytes cultured in the fraction of HFF containing high M.W. components showed higher meiotic maturation rates than the oocytes cultured in the low M.W. fraction of HFF. Gonadotropins and $E_2$ were known to improve the completion of maturation changes, and the levels of these hormones were higher in HFF than in HFCS. Therefore, HFF was more effective than HFCS to use for promoting meiotic resumption of mouse oocytes in vitro.

• The Korean Journal of Pharmacology
• /
• v.16 no.2 s.27
• /
• pp.15-24
• /
• 1980

[${\alpha}$]-Amylase catalyses the hydrolysis of starch, glycogen, and related poly- and oligosac-charide by random cleavage of ${\alpha}$-D-(l-4) glucan linkage. In man large amounts of amylase are secreted into the digestive tract by the salivary and exocrine pancreatic gland, minimal amount being produced also in other tissues. It has been known that ${\alpha}$-amylase exists in multiple molecular forms, isoenzyme which can be separated from each other because of difference in their physicochemical properties. By using various methods, several groups of investigator have separated the many isoenzyme in serum, saliva and pancreatic juice. Furthermore, changes of the normal serum isoenzyme pattern is diagnostically useful even when the total serum enzyme activity is noninformative, such as the clinical use of isoenzyme of serum lactate dehydrogenase. Procarboxypeptidase-A which is one of the pancreatic enzymes is also present as isoenzymes. Four forms of procarboxypeptidase-A haye been found in the bovine enzyme and three forms of the porcine enzyme. In human pancreatic juice four forms of procarboxypeptidase-A isoenzyme were found by isoelectric focusing method. Recently, the so-called isoamylase analysis was developed for the diagnostic use of amylase in pancreatic diseases. In alcohotic patients, the serum concentration of pancreatic isoamylase is subnormal and this lowered activity provides strong evidence for pancreatic exocrine insufficiency. The purpose of this study was to elucidate the variations of the isoenzyme of amylase and procarboxypeptidase-A in serum, saliva and pancreatic juice of the experimental animals. The results are as follow. 1) Three main forms of isoenzyme of amylase by isoelectric focusing were found in pancreatic juice of normal rabbit. However, many new bands were appeared in the pancreatic juice of cholic acid administered animal intravenously while the infusion of cholic acid or elastase into pancreatic duct produced the decrease of number of the fractions on the isoelectric focusing. In the case of serum isoenzyme from normal animal, two major and a few minor isoamylases were observed. By injecting alcohol intravenousely the fractions of serum isoamylase were significantly decreased and in contrary to the pattern in the pancreatic juice the infusion of cholic acid or elastase into pancreatic duct exhitited a significant decrease of the isoenzyme of amylase fractions. In saliva from normal animal three main isoamylase were produced of the administration of alcohol. 2) In the case of procarboxypeptidase-A isoenzyme, two major fractions which have isoelectric point at 6.2 and 6.4 and other two minor bands were observed in the pancreatic juice of normal rabbit. By the treatment of the juice with trypsin, only one band was produced on the isoelectric focusing. No procarboxypeptidase was appeared on the electrofocusing by the infusion of cholic acid or phospholipase A into the pancreatic duct of rabbit. However, a single major fraction of procarboxypeptidase-A was appeared at 3 hr after simple ligation of the pancreatic duct. No significant changes were observed in the juice of the alcohol or cholic acid administered group.

• Proceedings of the KSPS conference
• /
• 1997.07a
• /
• pp.11-25
• /
• 1997

This presentation will focus on building basic English Prosodic Skills which are very useful and helpful for Japanese learners of English. The focus first will be on recognizing the seven basic nuclear tones, analysing intonation structures, distinguishing intonation patterns and then on the way of improving speaking ability using sufficient verbal contents of intonation (mini-dialogue). My presentation deals mainly with some difficulties which Japanese learners of English have in the field of RP intonation, It is chiefly concerned with identifying, describing and analysing tone-group sequences. It sometimes happens that Japanese learners of English can pronounce isolated bounds correctly and read phonetic symbols sufficiently, bet have difficult problems in carrying out accurate prosodic features. The use of wrong intonation is sometimes the cause of misunderstanding of speaker's attitude, connotation and shades of meaning, etc.. However accurately students can pronounce the nuclear tone or tone-group of English, they have to learn how to connect tone-groups properly for suitable sequences in respect to meaning or implication. We are faced with the complicated theory of RF intonation on the one hand and difficult realization of it on the other. Japanese learners of English have special difficulties in employing "rising tune" and "falling + rising tune". If students are taught pitch movements by indicating dots graphically between two horizontal lines, they can easily understand the whole shape of pitch movements. In this presentation, I illuminate several tone-group sequences which are very useful for Japanese learning English intonation. Among them, four similar Pitch Patterns, such as, (1) (equation omitted)- type, (2) (equation omitted) - type, (3) (equation omitted) - type and (4) (Rising Head) (equation omitted)- type are clarified and other important tone-group sequences aye also highlighted from the point of view of teaching English as a foreign language. The intonation theory, tone marks and technical terms are, in all essentials, those of Intonation of Colloquial English by O'Connor, J. D. and Arnold, G. F., Longman, 2nd ed., 1982. The changes of tone are shown graphically between two horizontal lines representing the ordinary high and low zones of the utterance. A.C.Gimson (1981:314) : The intonation of English has been studied in greater detail and for longer than that of any other language. No definitive analysis, classifying the features of RP intonation, has yet appeared (though that presented by O'Connor and Arnold (1973) provides the most comprehensive and useful account from the foreign learner's point of view).

• Journal of Advanced Marine Engineering and Technology
• /
• v.8 no.1
• /
• pp.17-36
• /
• 1984

Since 1973, the competition on the development of fuel saving type internal combustion engines has become severe by the two times oil shock, and new type engines are reported every several months. Whenever these new type engines are developed, new designs are required and they will be offered in the market after performing the endurance test for a long time. But the engine market is faced with a heavy burden of finance, as the developing of a new engine requires tremendous expenses. For this reason, the computer simulation method has been lately developed to cope with it. The computer simulation method can be available to perform the reasonable research works by the theoretical analysis before carrying out practical experiments. With these processes, the developing expenses are cut down and the period of development is curtailed. The object of this study is the development of simulation computer program for the small naturally aspirated four-stroke diesel engine which is intended to product by the original design of our country. The process of simulation is firstly investigated for the ideal engine cycle, and secondly for the real engine cycle. In the ideal engine cycle, each step of the cycle is simulated by the energy balance according to the first law of thermodynamics, and then the engine performance is calculated. In the real cycle imulation program, the injection rate, the preparation rate and the combustion rate of fuel and the heat transfer through the wall of combustion chamber are considered. In this case, the injection rate is supposed as constant through the crank angle interval of injection and the combustion rate is calculated by the Whitehouse-Way equation and the heat transfer is calculated by the Annand's equation. The simulated values are compared with measured values of the YANMAR NS90(C) engine and Mitsubishi 4D30 engine, and the following conclusions are drawn. 1. The heat loss by the exhaust gas is well agree with each other in the lower load, but the measured value is greater than the calculated value in the higher load. The maximum error rate is about 15% in the full load. 2. The calculated quantity of heat transfer to the cooling water is greater than the measured value. The maximum error rate is about 11.8%. 3. The mean effective pressure, the fuel consumption, the power and the torque are well agree with each other. The maximum error is occurred in the fuel consumption, and its error rate is about 7%. From the above remarks, it may be concluded that the prediction of the engine performance is possibly by using the developed program, although the program needs to reform by adding the simulation of intake and exhaust process and assumping more reliable mechanical efficiency, volumetric efficiency, preparation rate and combustion rate.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.3
• /
• pp.69-76
• /
• 2005

The young leaves of A. princeps have been a well known for a crude medicine and used in treatment of colic pain, vomiting and menstrual irregularity. Based on TLC and HPLC and used an artemisinin, an anti-malarial compounds which is believed to be detected only in A. annuaup so far can be biosynthesized in A. princeps. To investigate the production of secondary metabolites like artemisinin in cultured cells, the cell culture of A. princeps was established. Callus and suspension cultured cells of A. princeps were induced and grown highest in MS media containing $0.2\;mg/{\ell}$ 2,4-D, $0.1\;mg/{\ell}$ BAP and 2% sucrose. Different metabolites from in vitro cultured cells (callus and suspension cultured cell) and intact plants were analyzed by TLC analysis. As a result, we can confirm that in vitro culture has a potential for mass production of secondary metabolites from A. princeps.

• Applied Biological Chemistry
• /
• v.50 no.3
• /
• pp.204-209
• /
• 2007

The objective of this research was to evaluate the inhibitory activities of phenolic compounds isolated from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$. The content of total phenolic compounds of water extract from Crataegi Fructus was 22.5 mg/g. The inhibitory activity of the water extract (200 ${\mu}g/ml$) from Crataegi Fructus on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was determined to be 100% and 82.6%, respectively. Isolation of inhibitory compounds was carried out on Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient elution procedure of increasing MeOH in $H_2O$. The chemical structure of the inhibitory compound against ${\alpha}-amylase$ and ${\alpha}-glucosidase$ was confirmed as chlorogenic acid by spectroscopic analysis of FAB-MS, NMR and IR spectrum.

• Journal of Periodontal and Implant Science
• /
• v.46 no.2
• /
• pp.116-127
• /
• 2016

Purpose: The objective of this study was to investigate the relationships between primary implant stability as measured by impact response frequency and the structural parameters of trabecular bone using cone-beam computed tomography(CBCT), excluding the effect of cortical bone thickness. Methods: We measured the impact response of a dental implant placed into swine bone specimens composed of only trabecular bone without the cortical bone layer using an inductive sensor. The peak frequency of the impact response spectrum was determined as an implant stability criterion (SPF). The 3D microstructural parameters were calculated from CT images of the bone specimens obtained using both micro-CT and CBCT. Results: SPF had significant positive correlations with trabecular bone structural parameters (BV/TV, BV, BS, BSD, Tb.Th, Tb.N, FD, and BS/BV) (P<0.01) while SPF demonstrated significant negative correlations with other microstructural parameters (Tb.Sp, Tb.Pf, and SMI) using micro-CT and CBCT (P<0.01). Conclusions: There was an increase in implant stability prediction by combining BV/TV and SMI in the stepwise forward regression analysis. Bone with high volume density and low surface density shows high implant stability. Well-connected thick bone with small marrow spaces also shows high implant stability. The combination of bone density and architectural parameters measured using CBCT can predict the implant stability more accurately than the density alone in clinical diagnoses.