• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.23-29
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• 2006

A rapid, selective and sensitive reversed-phase HPLC method for the determination of promethazine in human serum was developed, validated, and applied to the pharmacokinetic study of promethazine. Promethazine and internal standard, chlorpromazine, were extracted from human serum by liquid-liquid extraction with n-hexane containing 0.8% isopropanol and analyzed on a Capcell Pak CN column with the mobile phase of acetonitrile-0.2 M potassium dihydrogen phosphate (42:58, v/v, adjusted to pH 6.0 with 1 M NaOH). Detection wavelength of 251 nm and flow rate of 0.9 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed promethazine concentration (10 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 1-40 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was 1 ng/mL, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 96.15 to 105.40% for promethazine with overall precision (% C.V.) being 6.70-11.22%. The relative mean recovery of promethazine for human serum was 63.54%. Stability (freeze-thaw and short-term) studies showed that promethazine was stable during storage, or during the assay procedure in human serum. However, the storage at $-80^{\circ}C$ for 4 weeks showed that promethazine was not stable. Extracted serum sample and stock solution were not allowed to stand at ambient temperature for 12 hr prior to injection. The peak area and retention time of promethazine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of promethazine in human serum samples for the pharmacokinetic studies of orally administered Himazin tablet (25 mg as promethazine hydrochloride) at three different laboratories, demonstrating the suitability of the method.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.912-919
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• 2020

Purpose This study aimed to compare the brain perfusion status of patients with chronic kidney disease to a normal control group to identify any significant differences. Materials and Methods The perfusion state of the brain was measured by MRI using the arterial spin labeling technique in 36 patients undergoing hemodialysis due to chronic kidney disease and 36 normal controls. Images were then analyzed in a voxel-wise manner to detect brain areas showing significant perfusion differences between the two groups. Results Patients with chronic kidney disease showed increased perfusion in the form of large clusters across the right fronto-parieto-temporal lobe and the left parieto-occipital lobe. In addition, perfusion increased in the bilateral thalami, midbrain, pons, and cerebellum (p < 0.01, familywise error corrected). Conclusion Brain perfusion appears to increase in patients with chronic kidney disease compared to normal controls. Uremic toxicity is thought to be the cause of this increase as it can cause damage to the microscopic blood vessels and their surrounding structures.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.43.1-43.14
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• 2021

Group 3 innate lymphoid cells (ILC3), which express IL-22 and IL-17A, has been introduced as one of pathologic cells in axial spondyloarthritis (axSpA). Dyslipidaemia should be managed in axSpA patients to reduce cardiovascular disease, and dyslipidaemia promotes inflammation. This study aimed to reveal the role of circulating ILC3 in axSpA and the impact of dyslipidaemia on axSpA pathogenesis. AxSpA patients with or without dyslipidaemia and healthy control were recruited. Peripheral blood samples were collected, and flow cytometry analysis of circulating ILC3 and CD4⁺ T cells was performed. The correlation between Ankylosing Spondylitis Disease Activity Score (ASDAS)-C-reactive protein (CRP) and circulating immune cells was evaluated. The effect of oxidized low-density lipoprotein cholesterol (oxLDL-C) on immune cell differentiation was confirmed. AxSpA human monocytes were cultured with with oxLDL-C, IL-22, or oxLDL-C plus IL-22 to evaluate osteoclastogenesis using tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative PCR of osteoclast-related gene expression. Total of 34 axSpA patients (13 with dyslipidaemia and 21 without) were included in the analysis. Circulating IL-22⁺ ILC3 and Th17 were significantly elevated in axSpA patients with dyslipidaemia (p=0.001 and p=0.034, respectively), and circulating IL-22⁺ ILC3 significantly correlated with ASDAS-CRP (Rho=0.4198 and p=0.0367). Stimulation with oxLDL-C significantly increased IL-22⁺ ILC3, NKp44^- ILC3, and Th17 cells, and these were reversed by CD36 blocking agent. IL-22 and oxLDL-C increased TRAP⁺ cells and osteoclast-related gene expression. This study suggested potential role of circulating IL-22⁺ ILC3 as biomarker in axSpA. Furthermore, dyslipidaemia augmented IL-22⁺ ILC3 differentiation, and oxLDL-C and IL-22 markedly increased osteoclastogenesis of axSpA.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.797-806
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• 2008

In a double-passage cascade apparatus, only two blades are installed in order to increase the accuracy of experimental result by applying bigger blade than the size of multi-blades on the same apparatus. However, this causes difficulties to make correct periodic condition. In this study, sidewalls are designed to meet periodic condition without removing the operating fluid or adjusting tail boards. Surface Mach number on the blade surface is applied to a responsible variable, and 12 design variables which are related with sidewall profile control are selected. A gradient-based optimization is adopted for wall design and CFX-11 is used for the internal flow computation. The computed result shows that it could obtain the same flow structure by modifying only the sidewalls of the double-passage cascade apparatus.

• The Korean Journal of Pain
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• v.26 no.4
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• pp.374-378
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• 2013

Background: Incisional pain is particularly troublesome after hysterectomy. A method called transversus abdominis plane block (TAPB) has shown promise in managing postoperative pain. In this study, we evaluated the analgesic efficacy of ultrasound-guided TAPB after hysterectomy at different time points and at each time point separately for 48 hours. Methods: Forty-two patients (ASA I, II) who were electively chosen to undergo total abdominal hysterectomy were divided into 2 groups, control (group C) and intervention (group I). Twenty-one patients underwent TAPB (group I) and 21 patients received only the standard treatment with a fentanyl pump (group C). Both groups received standard general anesthesia. For patients in group I, following the surgery and before emergence from anesthesia, 0.5 mg/kg of ropivacaine 0.2% (about 20 cc) was injected bilaterally between the internal oblique and transverse abdominis muscles using sonography. Pain scores using the Visual Analogue Scale (VAS) and drug consumption were measured at 2, 6, 12, 24, and 48 hours after TAPB. Results: There were no significant differences in demographics between the two groups. VAS scores appeared to be lower in group I, although there was no interaction with time when we compared mean VAS measurements at different time points between group I and group C (P > 0.05). The amount of fentanyl flow was consistently higher in group C, but when we compared the two groups at each time point separately, the observed difference was not statistically significant (P < 0.053). The incidence of vomiting was 10% in group I and 28% in group C. There were no complaints of itching, and sedation score was 0 to 3. There were no complications. Conclusions: This study showed that TAPB did not result in a statistically significant decrease in VAS scores at different time points. TAPB did lead to decreased fentanyl flow, but when we compared the two groups at each time point separately, the observed difference was not statistically significant.

• The KSFM Journal of Fluid Machinery
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• v.20 no.1
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• pp.53-58
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• 2017

This paper describes liquidity evaluation on the horizontal branch pipe connected to a food waste disposer and performance of five disposers marketed. Experimental apparatus for analyzing the five disposers has been introduced to measure vibration, sound level and power consumption of the disposers. Simulator for analyzing the required water velocity to avoid waste jam inside the pipe connected to a food waste disposer has been designed and constructed. The simulator can control some experimental parameters: pipe slope, disposer supply water quantity, food waste materials and operation time of a disposer. Throughout the experimental measurements of the disposers marketed, it is found that the time need to crash food waste is about 20 seconds on the average. At the same flow condition, increase rate of internal water velocity is accelerated as the pipe slope increases. The water velocity inside the pipe having 50 A and slope of 1/50 is 0.26 m/s when the water flowrate to supply the disposer is 16 l pm. Considering the specific gravity and adhesion property of food waste, water velocity of the horizontal branch pipe connected to a food waste disposer need to excess 0.26 m/s at least to avoid the waste blockage inside the pipe.

• International Journal of Fluid Machinery and Systems
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• v.9 no.4
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• pp.370-381
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• 2016

As a single-channel pump is used for wastewater treatment, this particular pump type can prevent performance reduction or damage caused by foreign substances. However, the design methods for single-channel pumps are different and more difficult than those for general pumps. In this study, a design optimization method to improve the hydrodynamic performance of a single-channel pump impeller is implemented. Numerical analysis was carried out by solving three-dimensional steady-state incompressible Reynolds-averaged Navier-Stokes equations using the shear stress transport turbulence model. As a state-of-the-art impeller design method, two design variables related to controlling the internal cross-sectional flow area of a single-channel pump impeller were selected for optimization. Efficiency was used as the objective function and was numerically assessed at twelve design points selected by Latin hypercube sampling in the design space. An optimization process based on a radial basis neural network model was conducted systematically, and the performance of the optimum model was finally evaluated through an experimental test. Consequently, the optimum model showed improved performance compared with the base model, and the unstable flow components previously observed in the base model were suppressed remarkably well.

• Journal of Drive and Control
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• v.18 no.1
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• pp.1-8
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• 2021

This paper presents research on methods for the reduction of forklifts' noise level for the increased comfort and safety of its operator. A cooling fan with a high air volume flow rate installed in the forklift acts as an important design parameter which efficiently cools the heat exchanger system, helping to transfer internal heat from the engine room to the outdoors with both transmitted and diffracted opening noises. The cooling fan contributes significantly to both the forklift's emitted sound power and the operator room's noise level, thereby necessitating research on the forklift's reduction of acoustic power level and transmission. A noise analysis for various fan models with a biomimetic design based on eagle-wing geometry was conducted. In addition to the acoustic power generation, the aerodynamic performance of the cooling blade is also strongly influenced by the design of airfoil distribution, thereby requiring optimization. The cooling fans were fabricated and installed in the forklift in order to check the efficacy of the forklift engine's cooling, and the final version of the fan was measured for its ability to lower acoustic power level and cool the engine room. This study explains the aerodynamic and acoustic features of the designed fans with the use of BEM analysis and forklift test results.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.136-145
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• 1997

Background : Tracheal Gas Insufflation (TGI) is one of the newer ancillary measures in mechanical ventilation employed to enhance carbon dioxide elimination. TGI exerts its effect through reduction of deadspace ventilation, but the factors determining its effect are not well studied yet. Method : The subjects were seven mechanically-ventilated patients ($58.8{\pm}10.6$ yrs) who showed increased physiologic deadspace greater than 60%. After 30 nun of stabilization with 100% oxygen on pressure control ventilation, continuous flow TGI was administered via the insufflation lumen of Hi-Lo Jet Tracheal Tube (Mallincrodt, USA) for 15 min at 3 L/min and 5 L/min each. Results : $PaCO_2$ was decreased ($51.4{\pm}17.6$ at baseline, $49.1{\pm}18.9$ at TGJ 3 L/min $45.0{\pm}14.9$ mm Hg at TGI 5 L/min, p=0.050), and pH was increased ($7.37{\pm}0.12$, $7.38{\pm}0.13$, $7.39{\pm}0.12$, respectively, p=0.037) while mixed expired $CO_2$ ($P_ECO_2$) was not changed significantly from baseline (p=0.336) by TGI. Physiologic deadspace(Vdphy) was decreased ($73.0{\pm}7.9$% at baseline, $69.8{\pm}10.0$% at TGI 3 L/min, and $67.1{\pm}10.1$% at TGI 5 L/min, p=0.015). $AaDO_2$(p=0.147), Vt(p=0.2140), Pmean(p=0.7788) and mean arterial pressure(p=0.4169) were not changed. The correlation between % maximal decrease of Vdphy were r=0.790 with the ratio of baseline Vdana/Vdphy(p=0.035) and r=-0.754 with baseline Vdalv(p=0.050). Conclusion: TGI was effective in reducing $PaCO_2$ and deadspace, and the deadspace-reducing effect was best correlated with baseline anatomic/physiologic deadspace ratio.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.388-397
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• 1999

Purpose: Propranolol is known to decrease portal pressure by reducing blood flow of portal vein. Perrectal portal scintigraphy with Tc-99m pertechnetate has been introduced to evaluate the portal circulation and early diagnosis of liver cirrhosis. We evaluated the effects of propranolol on portal circulation by using per-rectal portal scintigraphy. Materials and Methods: We analyzed the portal hemodynamics by per-rectal portal scintigraphy in 51 patients with liver cirrhosis, 10 chronic hepatitis and 10 normal subjects. 38 patients with cirrhosis underwent per-rectal portal scintigraphy before and after propranolol medication. Perrectal portal scintigraphy was performed after per-rectal administration of 370 MBq of Tc-99m pertechnetate. The shunt index was calculated as the ratio, expressed as a percentage of heart radioactivity to the sum of heart and liver radioactivity during the first 30 seconds. Results: The shunt index in 40 patients with cirrhosis ($59.8{\pm}27.2%$) was significantly higher than that of normal control ($5.0{\pm}1.2%$. p<0.01) and chronic hepatitis ($11.4{\pm}3.5%$, p<0.01). Shunt index was significantly different according to Child's classification and the degree of esophageal varix (p<0.01). After propranolol medication, shunt index was significantly decreased from $59.9{\pm}27.3%$ to $51.3{\pm}15.3%$ (p<0.01) in 38 patients with liver cirrhosis. There was no significant difference of the amount of shunt index reduction after propranolol according to Childs' classification and the degree of esophgageal varix. Conclusion : The effect of propranolol on portal circulation was demonstrated as decreasing shunt index on per-rectal portal scintigraphy in patients with liver cirrhosis. Per-rectal portal scintigraphy may be useful to evaluate the portal circulation and to predict the effect of propranolol in patients with liver cirrhosis.