• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.589-596
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• 2018

Purpose : We compared intraocular pressure (IOP) values measured by two types of tonometers in condition of normotensive and glaucomatous rat model. We tried to determine which of tonometer can more easily and accurately measure the IOP of animal model. Methods : Glaucomatous eyes were induced by intracameral injections of hyaluronic acid in right eyes of six-week-old male Spargue-Dawley (SD) rats. Normotensive contralateral eyes were left eyes of the SD rats. IOP was measured using a rebound tonometer (Tonolab) and a immersive tonometer ($Tonopen^{(R)}$ XL) about 3:00 pm. Results : The mean IOP values of normotensive control eyes were $10.80{\pm}1.03mmHg$ by Tonopen, and $15.10{\pm}0.73mmHg$ by Tonolab. They were statistically insignificant (p = .1). The mean IOP values of glaucomatous experimental eyes were $30.20{\pm}2.67mmHg$ by Tonopen, and $37.90{\pm}2.73mmHg$ by Tonolab. They were statistically insignificant (p = .95). High IOP values of glaucomatous eyes by two types of tonometers had strong positive correlation each other (r = .904, p < .01). Conclusion : This is the first study to compare IOP values using two types of tonometers between normotensive and glaucomatous model made by intracameral injection of hyaluronic acid. Tonopen should be used carefully when the IOP is within normal range, and both Tonopen and Tonolab can be used reliably when the IOP is high.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.392-395
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• 2003

For the purpose of digital x-ray imaging, many materials such as $PbI_2$, $HgI_2$, TlBr, CdTe and CdZnTe have been under development for servaral years as direct converter layer. $Hgl_2$ film detector have recently been shown as one of the most promising semiconductor materials to be used as direct converters in x-ray digital radiography. This paper, the $HgI_2$ films are deposited on conductive-coated glass by screen printing, in which $HgI_2$ powder is embedded in a binder and solvent, and the slurry is used to coat the conductive-coated glass. We investigated electrical characteristic of the fabricated $HgI_2$ films. The x-ray response to radiological x-ray generator of 70Kvp using the current integration mode will be reported for screen printing films. These results indicate that $HgI_2$ detectors have high potential as new digital x-ray imaging devices for radiography.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.25-29
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• 1984

To assess the effect of noise on the blood pressure of workers, 70 weaving and 70 refining female workers in 15 to 24 years of ages were tested for the changes of blood pressure before and after exposure to the noise. The noise levels at work place were 99 dB (A) for weavers and 80 dB(A) for refiners. The mean age of refiners was 17,7 years and that of weavers was 18.6 years, and the difference in mean ages was statistically significant (p<0.05). The means of heights, weights and working durations were not significantly different between two groups. The mean systolic blood pressure of the weavers was 112.5mmHg before exposure to the noise and it was increased to 115.7mmHg after exposure to 99 dB(A) of noise for 30 minutes, and the mean diastolic blood pressure from 71.6mmHg to 74.1mmHg. These increments of blood pressure were statististically significant (p<0.05). The mean systolic blood pressure of the refiners was decreased from 108.9mmHg to 106.7mmHg after exposure to 80 dB(A) of noise for 30 minutes, and the mean diastolic blood pressure from 67.3mmHg to 67.1mmHg. These changes of blood pressure were not statistically significant. The mean systolic and diastolic blood pressure of the weavers before exposure to the noise were significantly higher than that of refiners (p<0.05). The difference of blood pressure between refiners and weavers was significantly associated with noises (p<0.05), and not ages and their interactions. The study results support the hypothesis that exposure to excessive noise increases the blood pressure of workers.

• Journal of Preventive Medicine and Public Health
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• v.30 no.2 s.57
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• pp.308-326
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• 1997

Many studies have led to the notion that essential hypertension in adults is the result of a process that starts early in life: investigation of blood pressure(BP) in children and adolescents can therefore contribute to knowledge of the etiology of the condition. A unique longitudinal study on BP in Korea, known as Kangwha Children's Blood Pressure(KCBP) Study was initiated in 1986 to investigate changes in BP in children. This study is a part of the KCBP study. The purposes of this study are to show changes in BP and to determine factors affecting to BP level and change in Korean adolescents during age period 12 to 16 years. A total of 710 students(335 males, 375 females) who were in the first grade at junior high school(12 years old) in 1992 in Kangwha County, Korea have been followed to measure BP and related factors(anthropometric, serologic and dietary factors) annually up to 1996. A total of 562 students(242 males, 320 females) completed all five annual examinations. The main results are as follows: 1. For males, mean systolic and diastolic BP at age 12 and 16 years old were 108.7 mmHg and 118.1 mmHg(systolic), and 69.5 mmHg and 73.4 mmHg(diastolic), respectively. BP level was the highest when students were at 15 years old. For females, mean systolic and diastolic BP at age 12 and 16 years were 114.4 mmHg and 113.5 mmHg(systolic) and 75.2 mmHg and 72.1 mmHg(diastolic), respectively. BP level reached the highest point when they were 13-14 years old. 2. Anthropometric variables(height, weight and body mass index, etc) increased constantly during the study period for males. However, the rate of increase was decreased for females after age 15 years. Serum total cholesterol decreased and triglyceride increased according to age for males, but they did not show any significant trend fer females. Total fat intake increased at age 16 years compared with that at age 14 years. Compositions of carbohydrate, protein and fat among total energy intake were 66.2:12.0:19.4, 64.1:12.1:21.8 at age 14 and 16 years, respectively. 3. Most of anthropometric measures, especially, height, body mass index(BMI) and triceps skinfold thickness showed a significant correlation with BP level in both sexes. When BMI was adjusted, serum total cholesterol showed a significant negative correlation with systolic BP at age 12 years in males, but at age 14 years the direction of correlation changed to positive. In females serum total cholesterol was negatively correlated with diastolic BP at age 15 and 16 years. Triglyceride and creatinine showed positive correlation with systolic and diastolic BP in males, but they did not show any correlation in females. There was no consistent findings between nutrient intake and BP level. However, protein intake correlated positively with diastolic BP level in males. 4. Blood pressure change was positively associated with changes in BMI and serum total cholesterol in both sexes. Change in creatinine was associated with BP change positively in males and negatively in females. Students whose sodium intake was high showed higher systolic and diastolic BP in males, and students whose total fat intake was high maintained lower level of BP in females. The major determinants on BP change was BMI in both sexes.

• Journal of Chest Surgery
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• v.32 no.6
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• pp.495-503
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• 1999

Background: We tested the technical feasibility of fetal cardiac bypass and collected baseline data on the fetal hemodynamics and placental functions related to the cardiopulmonary bypass in the fetal lamb model. Material and Method: Eleven fetuses at 120 to 150 days of gestation were subjected to bypass via trans-sternal approach with a 12 G pulmonary arterial cannula and 14 to 18 F venous cannula for 30 minutes. All ewes received general anesthesia with ketamine. In all the fetuses, no anesthetic agents were used except muscle relaxant. Eight served as a group in which placenta was excluded from the extracorporeal circulation by clamping the umbilical cord during the bypass(the oxygenator group) and in the remaining three, the placenta worked as the only source of oxygen supply(the placenta group). Observations were made every 10 minute during a 30-minute bypass and 30-minute post bypass period. No prostaglandin inhibitors were used both in ewes and in fetuses. Result: Weights of the fetuses ranged from 1.9 to 5.2 kg. In the oxygenator group, means of arterial pressure, PaO2, atrial pressure, heart rate, and bypass flow rate ranged 69.8 to 82.6 mmHg, 201.7 to 220.9 mmHg, 4.1 to 4.3 mmHg, 169 to 182/min, and 140.3 to 164.0 ml/kg/min, respectively during bypass, but rapid deterioration of the fetal cardiac functions and the placental gas exchange was observed after the cessation of bypass. In the placenta group, means of arterial pressure decreased from 44.7 to 14.4 mmHg and means of PaCO2 increased from 61.9 to 129.6 mmHg during bypass. Flow rate was suboptimal(74.3 to 97.0 ml/kg/min) during bypass. All hearts fibrillated immediately after the discontinuation of bypass. Conclusion: In this study, the technical feasibility of fetal cardiopulmonary bypass was confirmed in the fetal lamb model. However, further studies with modifications of the bypass including an addition of prostaglandin inhibitor, an application of the total spinal anesthesia on the fetus, a creation of more concise bypass circuit, and a use of active pump are mandatory to improve the outcome.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.173-176
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• 2000

This study was carried out to investigate the filtration characteristics of membrane modules according to hollow fiber dispersion for direct solid-liquid separation of activated sludge. 2 bundle, 4 bundle, and 10 bundle, and 10 bundle module used in this experiment according to hollow fiber dispersion was manufactured at laboratory and permeate flux and transmembrane pressure(TMP) of each module were observed under a suction pressure of 0.5kgf/c$m^2$. As the hollow fibers were dispersed, permeate flux was increased and TMP was decreased. Permeate flux and TMP of each module was 15.0 $\ell$/$m^2$.h and 31.8 cmHg for 2 bundle, 16.0 $\ell$/$m^2$ .h and 17.4 cmHg for 4 bundle, and 20.4 $\ell$/m2 .h and 31.8 cmHg for 10 bundle. In conclusion, the membrane fouling is expected to be decrease by maintaining lower TMP with hollow fiber dispersion.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.687-691
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• 1993

Complexation of $Cd^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions with four cryptands were studied by potentiometry and solution calorimetry in various weight percent methanol-aqueous solvent at 25${\circ}$C under $CO_2$free nitrogen atmosphere. The stabilities of the complexes were dependent on the cavity size of macrocycles. The $Hg^{2+}$ ion stability constants are higher than those of $Cd^{2+}\;and\;Pb^{2+}$ ion. All the cryptands formed complexes having 1 : 1 (metal to ligand) mole-ratio except for $Hg^{2+}-L_1$ (cryptand 1,2b: 3,5-benzo-9,14,17-trioxa-1,7-diazabicyclo-(8,5,5) heptadecane) and $Cd^{2+}-L_2$ (cryptand 2,2b: 3,5-benzo-10,13,18,21-tetraoxa-1,7-diazabicyclo (8,5,5) eicosane) complexes. $Hg^{2+}-L_1$ complex was a sandwitch type, and the $Cd^{2+}-L_2$ complex showed two stepwise reactions. Thermodynamic parameters of the $Cd^{2+}-L_2$ complex were $6.08(log\;K_1)$, -7.28 Kcal/mol $({\Delta}H_1)$, and $4.78\;(log\;K_2)$, -4.62 Kcal/mol $({\Delta}H_2)$, respectively, for 1 : 1 and 2: 1 mole-ratio. The sequences of the selectivity were increased in the order of $Hg^{2+}\;>Pb^{2+}\;>Cd^{2+}$ ion for $L_3\;and\;L_4$ macrocycles, and the $L_2$-macrocycle has a selectivity for $Cd^{2+}$ ion relative to $Zn^{2+},\;Ni^{2+},\;Pb^{2+}\;and\;Hg^{2+}$ ions. Thus, it is expected that the $L_2$ can be used as carrier for seperation of the post transition metals by macrocycles-mediated liquid membrane because $L_2$ is not soluble in water, and the difference of stability constants of the metal complexes with $L_2$ are large as compared with the other transition metal complexes. The $^1H\;and\;^{13}C-NMR studies indicated that the nitrogen atoms of cryptands have greater affinity to the post transition metal ions than the oxygen atoms, and that the planarities of the macrocycles were lost by complexation with the metal ions because of the perturbation of ring current of benzene molecule attached to macrocycles and counter-anions.

• Journal of Chest Surgery
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• v.23 no.2
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• pp.222-230
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• 1990

Protamine, a polycationic peptide extracted from fish, has been widely used for the reversal of anticoagulant action of heparin. However it may cause untoward circulatory side effects including hypotension and bradyarrhythmia. Nowadays, histamine and prostacyclin are regarded as one of the causative agents in the underlying mechanism of hemodynamic changes. To certify the possible role of histamine and prostacyclin, we observed simultaneous changes of the hemodynamic status, plasma concentration of thromboxane B, and circulating platelet count before and after intravenous injection of protamine. Experimental dogs, weighing 12-14kg, were divided into 2 groups; group A animals [n=10], were pretreated with indomethacin[2.5mg/kg] and group B animals[n=10] were pretreated with chlorpheniramine[0.5mg/kg] Heparin[3mg/kg] and protamine [3mg/kg] were administered sequentially in both groups. The results were as follows ; 1. The mean systemic arterial pressure was maintained well in groups A, whereas in group B it decreased from 165\ulcorner18mmHg to 138\ulcorner30mmHg[p<0.01] and 151\ulcorner21 mmHg[p<0.05] at 1 minute and 2 minutes after protamine injection. The mean pulmonary arterial pressure was not changed significantly in group A, whereas in group B it increased from 852 mmHg to 11\ulcorner3 mmHg[p<0.05], 11\ulcorner3 mmHg[p<0.05] and 10\ulcorner3 mmHg[p<0.05] at 1 minute, 3 minutes and 5 minutes after protamine injection. 2 The thromboxane B2 was not changed significantly in group A, whereas in group B it increased from 399\ulcorner401 \ulcornerg/ml to 744\ulcorner615 \ulcornerg/ml[p<0.05] and 814\ulcorner1070 \ulcornerg/ml [p<0.0 5] at 1 minute and 3 minutes after protamine injection without concomitant changes of pulmonary vascular resistance and pulmonary capillary wedge pressure. 3. The number of circulating platelet was not changed in group A, whereas in group B it decreased from 207100\ulcorner103600/\ulcornerl to 159700\ulcorner90900/\ulcornerl [p<0.05] at 1 minute after protamine injection, Although thromboxane B2 and platelet count were changed significantly after protamine injection, they did not cause the remarkable hemodynamic changes. Considering the above results, hemodynamic changes may be caused mainly by prostacyclin rather than thromboxane or platelet. Therefore, the pretreatment with cyclooxygenase inhibitor would be beneficial to prevent circulatory adverse effects of protamine for the patients undergoing cardiac surgery.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.12
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• pp.189-194
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• 2014

In this study, from a new x-ray detector that combines a columnar CsI:Na scintillation layer with a photosensitive mercuric iodide layer was investigated. In this structure, X-rays are converted into visible light on a thick CsI:Na layer, which is then converted to electric charges in a thin $HgI_2$ bottom layer. The thin coplanar mercuric iodide films as a photosensitive converter requiring only a few tens of volts of bias, associated with a thick columnar coating of phosphor layer, were simulated and designed. The results of this research suggest that the new coplanar x-ray detector with a hybrid-type structure can resolve the following problems: high voltage from the a-Se, and low conversion efficiency from the indirect conversion method. The results of this research suggest that the new CsI:Na/$HgI_2$ x-ray detector with a double-layer type structure can resolve the following problems: high voltage from the direct conversion method, and low conversion efficiency from the indirect conversion method.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.330-330
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• 2007

Polycrystalline mercuric iodide $HgI_2$) films are being developed as a new detector technology for digital x-ray imaging. The $HgI_2$ is generally vacuum deposited by physical vapor deposition (PVD) process. But the PVD thick deposition has been caused any instability in the biasing due to any defects or cracks. In this work we present a new particle-in-binder (PIB) methodologies used for the $HgI_2$ thick films. These growth techniques can be easily extended to produce much larger film areas. This paper, for the first time, presents results and comparison of polycrystalline $HgI_2$ films derived by various PIB methods. We investigated the structural and morphological properties of the films using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The films were characterized with respect to their electrical properties and in response to x-ray photons. Physical and electrical results were also compared between conventional polycrystalline PVD and our detectors. Leakage current as low as $350\;pA/cm^2$ at the bias voltage of ~ 200 V has been observed. And high sensitivity and good linearity in the response to x-rays was obtained in the film derived by PIB sedimentation method. Our future efforts will concentrate on optimization of film growth techniques for uniform large area deposition on image readout arrays.