• Journal of radiological science and technology
• /
• v.31 no.2
• /
• pp.183-188
• /
• 2008

Aim of this study is to investigate the feasibility of 2D ion chamber array as a substitute of the water phantom system in a periodic Linac QA. For the feasibility study, a commercial ion chamber matrix was used as a substitute of the water phantom in the measurement for a routine QA beam properties. The device used in this study was the I'm RT MatriXX (Wellhofer Dosimetrie, Germany). The MatriXX consists of a 1,020 vented ion chamber array, arranged in $24{\times}24\;cm^2$ matrix. Each ion chamber has a volume of $0.08\;cm^3$, spacing of 0.762 cm. We investigated dosimetric parameters such as dose symmetry, energy ($TPR_{20,10}$), and absolute dose for comparing with the water phantom data with a Farmer-type ionization chamber (FC65G, Wellhofer Dosimetrie, Germany). For the MatriXX measurements, we used the white polystyrene phantom (${\rho}:\;1.18\;g/cm^3$) and also considered the intrinsic layer (${\rho}:\;1.06\;g/cm^3$, t: 0.36 cm) of MatriXX to be equivalent to water depth. In the preliminary study of geometrical QA using MatriXX, the rotation axis of collimator and half beam junction test were included and compared with film measurements. Regarding the dosimetrical QA, the MatriXX has shown good agreements within ${\pm}1%$ compared to the water phantom measurements. In the geometrical test, the data from MatriXX were comparable with those from the films. In conclusion, the MatriXX is a good substitute for water phantom system and film measurements. In addition, the results indicate that the MatriXX as a cost-effective novel QA tool to reduce time and personnel power.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1982.05a
• /
• pp.10.1-10
• /
• 1982

The use of phonosurgery in the recent development of laryngomicrosurgery has enabled the restoration of a normal voice in respect to functional laryngeal surgery which in Korea in the past limited to simple removal of benign laryngeal tumor such as laryngeal polyp or nodules and cordal injection of $Teflon^{{\circledR}}$ for the treatment of recurrent nerve paralysis under the vision of suspension laryngoscopy. Performance of phonosurgery for the treatment of cord paralysis, mutational dysphonia, vocal cord atrophy, hyperkinetic dysphonia and sulcus vocalis is a happy event in the view point of development of phonosurgery in Korea. In this aspect thyroplasty to change the position and physical characteristics of the cord outside the glottis instead of the direct handling of the vocal cord through direct endoscopy is popular. Among the 4 types of thyroplasty, classified by Insshiki(1974), type I thyroplasty(1ateral compression of vocal cord) and type IV thyroplasty(lengthening of vocal cord) were effective in the treatment of unilateral vocal cord paralysis. Advantages of this operation are the fine adjustment of the degree of lateral compression under local anesthesia according to the phonation of the patient during operation and avoidance of dyspnea and intralaryngeal hemorrhage due to the manipulation outside the internal perichondrium of the thyroid cartilage. We did 7 cases of thyroplasty for the treatment of unilateral vocal cord paralysis in the 7 months from September 1981 to March 1982. Before the operation aerodynamic study, psychoacoustical evaluation, stroboscopy and sound spectrographic analysis were done. Two months after the operation the above procedures were performed again. Results of preoperative and postoperative examination were compared and the following results were obtained. 1) In the aerodynamic study, maximum phonation time increased to 158% of the preoperative value and the phonation quotient and the mean flow rate decreased to 58% and 54% of preoperative values. 2) The degree of hoarseness improved in the psychoacoustical evaluation and the glottic chink during phonation was decreased in the stroboscopic examiantion. 3) In the sound spectrographic analysis, periodicity was much restored and noise distribution decreased especially in the high frequency area.

• The korean journal of orthodontics
• /
• v.24 no.2
• /
• pp.303-317
• /
• 1994

This study was designed to measure the changes in the titer of tooth root antibodies accompanying root resorption associated with orthodontic tooth movement in dogs to explore a role of the specific immune response in root resorption during orthodontic tooth movement. Five adult mongrel dogs, 2 years of age, were used in the study. Six lower incisors were extracted as sources of homologous antigen in the dogs. Tooth root antigen preparations were made from a 6M Guanidine-HCl-10% EDTA(pH5.0) extract of these root dentins. Root resorption was elicited by intrusion of six maxillary incisors with 200-250gm intrusive force. In 9th week, resorbing six maxillary anterior teeth were extracted. Serum samples were taken from each dog prior to intrusion and weekly for 11 consecutive weeks. Serum autoantibody titers were determined with an enzyme-linked immunosorbent assay. As controls for antibody specificity, sera which were previously incubated with tooth root antigen as well as sera to an unrelated bacterial antigen (Porphyromonas gingivalis 33277) for 3 hours at 25 were measured in all runs. Root resorption was monitored monthly using occlusal radiographs. And then root resorption patterns were observed with a zoom stereo microscope (Model SZH-121, Olympus optical Co. Ltd.). Incisors did not show clear radiographic evidence of significant and progressive root resorption, but periodontal ligament space had widened. But root resorption was observed on the apical regions of the maxillary incisors with a zoom stereo microscope. Teeth showed the shallow depression generally accompanying deep resorption. These demonstrate a slight tendency for an immediate decrease followed by rebound to levels above the pre-treatment baseline. A peak titer of autoantibody to dentin antigen occurred on day 28, then steadily decreased during the 9th week period as the roots resorbed and then rapidly spiked in animals when the resorbing teeth were extracted. When sera is incubated with tooth root antigen, serum activity in the ELISA was almost absent. This is because serum activity in the ELISA could be removed by absorption of the serum with dog dentin antigen. Serum ELISA activity to the unrelated bacterial antigen remained essentially unchanged in all animals throughout the experimental period. When the time course of changes in autoantibody to homologous tooth root antigen prepatration and unrelated bacterial antigen was compared, no significant differences were found(${\alpha}=0.05$). In general, the overall pattern of changes in autoantibody was similar to the two antigens. These findings suggest the possibility that these immunologic changes precede a significant development of root resorption lesions rather than merely reflecting their presence. Therefore, this suggests that the changes of antibody levels may have some predictive value for root resorption.

• Childhood Kidney Diseases
• /
• v.2 no.1
• /
• pp.34-40
• /
• 1998

Present study was conducted to determine the frequency, clinical characteristics and long-term outcome of children with idiopathic hypercalciuria. Study patients consisted of 150 children with isolated hematuria (recurrent gross or persistent microscopic), and hypercalciuria was defined as urinary calcium excretion over 4 mg/kg/day. During follow-up period up to $6{\sim}8$ years, serial check-up of renal sonogram for stone formation and Dipstick examination for hematuria were done. Forty-four (29%) out of 150 cases were diagnosed as idiopathic hypercalciuria, and in hypercalciuric children compared to normocalciuric children boys were more common than girls (9:35) and gross hematuria was more common than microscopic hematuria (37:7) (P<0.05). Oral calcium loading test showed renal type in 29 cases, absorptive type in 8 cases and in 7 cases type could not be definable. Among 3 types no differences could be found in 24 hour urinary calcium excretion and in clinical or laboratory data. Urolithiasis developed in 4 out of 44 cases (2 at the time of initial diagnosis and 2 within $1{\sim}2$ years of follow-up periods) and these children showed lower chronologic age ($3.7{\pm}2.7\;vs\;7.2{\pm}2.9\;yr$) and more girl than boys (3:1 vs 6:34) (P<0.05) compared to the rest of the hypercalciuric children. Follow-up urinalysis showed disappearance of hematuria in 56, 50, 66 and 75% of children at $1{\sim}2,\;2{\sim}4,\;4{\sim}6$ and $6{\sim}8$ years after initial diagnosis respectively. In conclusion, present study demonstrates that idiopathic hypercalciuria is a major cause of isolated hematuria in children so that in these children 24 hour urinary calcium excretion test seems to be an essential test to be performed. And serial renal sonography should be done to detect development of nephrolithiasis. However, clinical significance of dividing hypercalciuric children into two pathophysiologically distinct subtypes by oral calcium loading test seems to be in doubt and further study is needed to solve this problem.

• Journal of Embryo Transfer
• /
• v.17 no.1
• /
• pp.67-77
• /
• 2002

This study was carried out to assess the effect of superovulation response and quality of embryos recovered from donor cows after a single subcutaneous injection of FSH dissolved in polyethylene glycol (PEG). Cows were allocated into control and 3 experimental treatment groups. In control, cows were injected intramuscularly 50 mg FSH twice daily for 4 days. Group 1 were injected subcutaneously with a single dose of 400 mg FSH dissolved in 30% PEG solution. Group 2 were injected subcutaneously with a single dose of 200 mg FSH dissolved in 30% PEG solution. Finally in group 3, cows were injected twice 200 mg FSH dissolved in 30% PEG solution by subcutaneous. Superovulation was initiated by injection of FSH between Day 8 and 14 of the estrus cycle (Day 0, the day of estrus), and followed by injection of 25 mg PGF$_2$$\alpha$ at 48 h after first FSH injection. Cows were then artificially inseminated (AI) with semen twice at 48 and 60 h after PGF$_2$$\alpha$ injection. At 7 days after the second AI, embryos collected non-surgically by flushing the uterine horns and were counted and compared morphologically as being transferable and degenerated among different superovulation treatments. Furthermore, progesterone and estradiol -17 $\beta$ in plasma were measured by radioimmunoassay following different treatments at given days All cows of treated groups were observed heat. but control group was showed 77.8%. Superovulation response was observed as 77.8, 87.5, 88.9, and 100% in control, Groups 1, 2 and 3 The mean number of corpus lutea (CL) detected in Group 1 were 19.6, which was, respectively significantly (P<0.05) higher than those of other groups (11.1, 13.4 and 7.6, respectively). However, there did not differ on the mean number of total embryos recovered and of transferable embryos between control and treated groups.

• Ocean and Polar Research
• /
• v.28 no.4
• /
• pp.407-413
• /
• 2006

The effect of water temperature and photoperiod on the oxygen consumption of the fasted juvenile parrot fish, Oplegnathus fasciatus was investigated to provide empirical data for the early-stage culture management and bioenergetic growth model of the species. The mean body weight of the juvenile used for the experiment was $21.5{\pm}1.9g$, and the oxygen consumption rate was measured under four water temperatures (10, 15, 20 and $25^{\circ}C$) and three photoperiods (24L:0D, 12L:12D and OL:24D) with an interval of 5 minutes for 24 hours using a continuous flow-through respirometer. In each treatment three replicates were set up and 15 juveniles were totally involved. The oxygen consumption rates increased with increasing water temperature under all photoperiod treatments (P<0.001). Mean oxygen consumption rates at 10, 15, 20 and $25^{\circ}C$ ranged $202.1{\sim}403.4,\;306.7{\sim}502.2,\;536.7{\sim}791.0\;and\;879.9{\sim}1,077.4mg\;O_2\;kg^{-1}h^{-1}$, respectively. $Q_{10}$ values ranged $1.58{\sim}2.30$ between 10 and $15^{\circ}C,\;2.44{\sim}3.06$ between 15 and $20^{\circ}C\;and\;1.86{\sim}2.6y9$ between 20 and $25^{\circ}C$, respectively. Mean oxygen consumption rates of O. fasciatus were the highest in continuous light (24L:0D) followed by 12L:12D and 0L:24D (P<0.001). The oxygen consumption of fish exposed to the 12L:12D photoperiod was significantly higher during the light phase than during the dark phase under all temperature treatments (P<0.001). In summary, oxygen consumption rates of the juvenile parrot fish increase with increasing water temperature and lengthening daylight period; and, thereby, changes in water quality resulted from the depletion of oxygen under high temperature and long daylight photoperiod conditions should be monitored.

• Clinical and Experimental Pediatrics
• /
• v.46 no.8
• /
• pp.777-783
• /
• 2003

Purpose : The aim of this study was to evaluate the effect of inhaled nitric oxide(iNO) on gas exchange, hemodynamics and pulmonary inflammation in newborn piglets with E. coli induced septic lung. Methods : Twenty three instrumented and ventilated piglets were randomized into three groups : CON(n=6), PCON(n=9), and PNO(n=8). In the piglets of the PCON and PNO groups, E. coli septic lung was induced by endotracheal instillation of E. coli. Ten ppm iNO was given continuously in the PNO group after endotracheal instillation of E. coli. All animals were mechanically ventilated for six hour with a peak inspiratory pressure of 30 $cmH_2O$, frequency of 25 breaths/min, $FiO_2$ 1.0 and a positive end-expiratory pressure of 4 $cmH_2O$. All measurements were made at one hour intervals during the experiment. At the end of the experiment, lung tissue was harvested for the analysis of myeloperoxidase activity, indicative of lung inflammation. Results : All piglets with pulmonary instillation of E. coli developed E. coli sepsis. Piglets in the PCON group developed progresseve pulmonry hypertension, hypoxemia and hypercarbia compared to the CON group due to increased pulmonary vascular resistance, intrapulmonary shunt fraction and physiologic dead space fraction. iNO did not reverse pulmonary hypertension in the PNO group. However iNO significantly improved oxygenation, which was attributed to marked improvement of venous admixture and partial attenuation of increase in dead space fraction. Increased myeloperoxidase activity in PCON compared to CON was significantly attenuated in PNO. Conclusion : iNO improves oxygenation and lung inflammation in newborn piglets with E. coli induced septic lung.

• The Journal of Korean Society for Radiation Therapy
• /
• v.27 no.2
• /
• pp.167-174
• /
• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

• Economic and Environmental Geology
• /
• v.48 no.1
• /
• pp.51-63
• /
• 2015

I produced a secular variation model of geomagnetic field by using the magnetic component data from four geomagnetic observatories located in Northeast Asia during the years between 1997 and 2011. The Earth's magnetic field varies with time and location due to the dynamics of fluid outer core and the magnetic observatories on the surface measure in time series. To adequately represent the magnetic field or secular variations of the Earth, a spatio-temporal model is required. In making a global model, satellite observations as well as limited observatory data are necessary to cover the regions and time intervals. However, you need a considerable work and time to process a huge amount of the dataset with complicated signal separation procedures. When you update the model, the same amount of chores is demanded. Besides, the global model might be affected by the measurement errors of each observatory that are biased and the processing errors in satellite data so that the accuracy of the model would be degraded. In this study, as considered these problems, I introduced a localized method in modeling secular variation of the Earth's magnetic field over Northeast Asia region. Secular variation data from three Japanese observatories and one Chinese observatory that are all in the INTERMAGNET are implemented in the model valid between 1997 to 2011 with the interval of 6 months. With the resulting model, I compared with the global model called CHAOS-4, which includes the main, secular variation and secular acceleration models between 1997 to 2013 by using the three satellites' databases and INTERMAGNET observatory data. Also, the geomagnetic 'jerk' which is known as a sudden change in the time derivatives of the main field of the Earth, was discussed from the localized secular acceleration coefficients derived from spline models.

• Journal of Oral Medicine and Pain
• /
• v.32 no.4
• /
• pp.403-411
• /
• 2007

This investigation was carried out to evaluate the effect of Transcutaneous Electric Nerve Stimulation (TENS) to experimentally induced masticatory muscle pain and muscular fatigue. Twenty-nine healthy volunteers (18 men and 11 women, aged $26.1{\pm}4.7$ years) without past history or present symptoms of temporomandibular disorders were participated in this study. All of the subjects were randomly assigned to experimental group and control group, after at least 3 days interval, two groups were reassigned conversely. Subjects assigned to experimental group were received TENS and others assigned to control group were received sham-TENS therapy for 45 minutes, respectively. The changes of Visual Analogue Scale (VAS), Pressure Pain Threshold (PPT), and EMG power spectrum were measured on the masseter muscle both before and after sustained fatiguing contraction in each group. The major findings of this study are as follows : 1. PPTs and median frequencies of masseter muscles were significantly decreased after sustained isometric contraction resulting in muscular fatigue. 2. In experimental group received TENS therapy, PPTs measured both before and after occurrence of experimentally induced muscular fatigue were significantly increased. 3. In experimental group received TENS therapy, the changes of PPTs during sustained isometric contraction resulting in muscular fatigue were significantly decreased. 4. In experimental group received TENS therapy, VAS measured after occurrence of experimentally induced muscular fatigue was significantly decreased. 5. Although there were not statistical significances, endurance time was increased in experimental group received TENS therapy and decreased in control group received sham-TENS therapy. 6. In experimental group received TENS therapy, the changes of median frequencies were the less decreased and the slope of median frequency shift was the more increased during endurance time than in control group, however, there were not statistical significances.