• Korean Journal of Clinical Laboratory Science
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• v.53 no.2
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• pp.151-157
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• 2021

Charcot-Marie-Tooth disease (CMT) is a slowly progressive hereditary degenerative disease and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired immune-mediated disorder characterized by weakness and sensory deficits. The purpose of this study was to analyze and compare the electrophysiological characteristics observed in sensory nerve conduction studies (SNCS) of both diseases. A retrospective study of 65 patients with a diagnosis of CIDP (N=35) and CMT type I (N=30) was performed. This study analyzed No potentials ratio, distal compound nerve action potential (dCNAP) of various nerve types, and a correlation coefficient analysis of the sensory nerve conduction velocity (SNCV). As a result, I found that CMT 1 was more severe systemic demyelinating and axonal polyneuropathy better than CIDP (P<0.05). In a quantitative analysis of dCNAP and SNCV, especially sural nerve was the most severe nerve injury observed in both diseases. In correlation and scatter plot analysis, CMT 1 showed relatively high correlations compared to CIDP based on the correlation coefficient analysis (Fisher's Z test) of SNCV. The results of this study suggested that CMT 1 showed the slowness in SNCV, one of the characteristics of demyelinating polyneuropathy, and this slowing had a uniform pattern. In conclusion, electrophysiological characteristic of SNCS may be useful in the diagnosis and research between patients with CMT 1 and CIDP.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.381-393
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• 2021

Physical, mechanical, hydraulic, and geophysical tests were applied to validate methods of inspecting the effectiveness of grouting on an agricultural reservoir dam. Data obtained from series of in situ and laboratory tests considered four stages: before grouting; during grouting; immediately after grouting; and after aging the grouting for 28 days. The results of SPT and triaxial tests, including the unit weight, compressive strength, friction angle, cohesion, and N-value, indicated the extent of ground improvement with respect to grout injection. However, they sometimes contained errors caused by ground heterogeneity. Hydraulic conductivity obtained from in situ variable head permeability testing is most suitable for identifying the effectiveness of grouting because the impermeability of the ground increased immediately after grouting. Electric resistivity surveying is useful for finding a saturated zone and a seepage pathway, and multichannel analysis of surface waves (MASW) is suitable for analyzing the effectiveness of grouting, as elastic velocity increases distinctly after grouting injection. MASW also allows calculation from the P- and S- wave velocities of dynamic properties (e.g., dynamic elastic modulus and dynamic Poisson's ratio), which can be used in the seismic design of dam structures.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.3
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• pp.37-46
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• 2024

This study investigates the evolution of concrete damage due to chloride-induced steel corrosion through Impact-echo (IE) testing. Three reinforced concrete specimens, each measuring 1500 mm in length, 400 mm in width, and 200 mm in thickness, were fabricated using three concrete mixture proportions of blended cement types: ordinary Portland cement, ground granulated blast-furnace slag and fly ash. Steel corrosion in the concrete was accelerated by impressing a 0.5 A current following a 35-day cycle of wet-and-dry saturation in a 3% NaCl solution. Initial IE data collected during the saturation phase showed no significant changes, indicating that moisture had a minimal impact on IE signals and highlighting the slow progress of corrosion under natural conditions. Post-application of current, however, there was a noticeable decline in both IE peak frequency and the P-wave velocity in the concrete as the duration of the impressed current increased. Remarkably, progressive monitoring of IE proves highly effective in capturing the critical features of steel-corrosion induced concrete deterioration, such as the onset of internal damages and the rate of damage propagation. These results demonstrate the potential of progressive IE data monitoring to enhance the reliability of diagnosing and prognosticating the evolution of concrete damage in marine environment.

• Korean Journal of Environmental Biology
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• v.18 no.1
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• pp.77-93
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• 2000

Field survey on the spatio-temporal distribution of water quality and chlorophyll a concentration, and the environmental factors on the variation of phytoplankton biomass were carried out at the 23 stations for four seasons in the Shiahae, southwestern coast of Korean Peninsula from February to October in 1995. I made an analysis on biological factor as chlorophyll a concentration as well as environmental factors such as water temperature, salinity and nutrients; ammonia, nitrite, nitrate, dissolved inorganic nitrogen, phosphate, N/P ratio, silicate and Si/P ratio. The waters in the Shiahae were not stratified due to the tidal mixing and high velocity of tidal current. And the high productivity in photic layer were supported by high nutrients concentration from freshwater on lands and bottom waters The low depth of transparency in the Shiahae had a bad influence upon primary production and marine biology. In Shiahae had a sufficient nutrients for primary production during a year. Especially dissolved inorganic nitrogen and silicate were high, the other side, phosphate was low. The source of nutrients in summer and silicate supply depend on input of freshwater from lands, the other side, dissolved inorganic nitrogen and phosphate were depend on rather supplied from bottom layer by the mixing and input of seawater from outside than input of freshwater from lands. Phosphate seemed to become a limiting nutrient for the primary production at all area of Shiahae in winter and at the northern parts in other seasons. However, dissolved inorganic nitrogen seemed to do it at the southern parts in other seasons except winter. Silicate didn't become a limiting nutrient for diatoms in Shiahae. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, it was controlled by the combination of the several environmental factors, especially of nitrogen, phosphorus and the physical factors such as light intensity. [Spatio-temporal distribution, Seasonal fluctuation, Nnutrients, Chlorophyll a, Environmental factors, Nutrient source, Limiting Nutrient, Light, Shiahae] .

• Journal of Animal Science and Technology
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• v.48 no.4
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• pp.555-562
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• 2006

The objective of this study was to evaluate the effects of dietary cation-anion difference (DCAD) with or without ruminally protected fat and niacin on the thermoregulatory ability, milk yield and milk composition of lactating dairy cows during summer in Korea. Thirty mid-lactating Holstein cows (134±12.4 DIM and 23.4±2.3kg/d of milk yield) were divided into three groups (10 animals/group). Cows were housed in a free-stall barn and were provided with forced- air ventilation (wind velocity = 4 m/s) using 41 cm diameter fans. Diet one was formulated to contain low DCAD (+15 DCAD) while the remaining two diets were higher in DCAD (+30 DCAD). One higher DCAD diet was formulated to contain by-pass fat and the second higher DCAD diet contained the niacin along with by-pass fat. The maximum ambient temperature during July was 28.5℃ which could be seen as a period of mild heat stress. As summer progressed, August was characterized as a severe heat stress condition with maximum ambient temperature (32.4℃) and THI (74.0). Dry matter, crude protein and total digestible nutrients intake was not affected by the DCAD level and supplementation of ruminally protected fat or niacin. Milk production was higher in cows fed diets supplemented with fat and niacin than those fed un-supplemented diet. No difference in milk yield was observed in cows fed diets supplemented with fat or niacin plus fat. Milk fat and rectal temperature were not affected by the DCAD level and supplementation of ruminally protected fat or niacin. However, respiration rate was decreased in cows fed diets supplemented with either fat or fat and niacin compared to those fed. The results of the present study indicated that higher DCAD (+30) and supplementation of fat along with niacin can somehow mitigate the negative effects of heat stress on milk yield and physiology of lactating Holsteins during July and August in Korea. In present study reduced respiration rate and increased milk yield in lactating cows may be attributed to the cooling effect of supplemented fat along with vasodilatory functions of niacin. (Key Words: DCAD, Heat stress, THI, milk yield, Milk fat, Holstein)

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.769-777
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• 2020

The purpose of this study was to investigate the effects of 8 weeks Self-Myofascial Release exercise on body composition, vascular and metabolic functions in obese female college students. The subjects were 19 obese female college students (n = 9) who were randomly assigned to an exercise group(n=9) and control group(n=9), with an exception of except 1 abandonment. The Self-Myofascial Release exercise group performed exercises twice a week for 8 weeks and for 40 minutes at one time using a foam roller, and the control group maintained normal life pattern for the same period. Body composition was measured by body weight, body fat percentage, vascular function was measured by pulse wave velocity(PWV), augmentation index(AIx), brachial artery vascular flow-mediated dilation(FMD), and metabolic function was measured by fasting glucose and triglyceride levels. The Self-Myofascial Release exercise with foam roller showed no significant effect on body weight and body fat percentage. The Self-Myofascial Release exercise with foam roller showed no significant effect on heart rate, FMD, PWV but, SBP, CSBP and AIx were significant decreased. The Self-Myofascial Release exercise with foam roller showed no significant effect on fasting glucose and triglyceride levels. In conclusion, 8-week Self-Myofascial Release exercise for obese female college students showed no significant effect on body composition and metabolic function, but improved SBP, CSBP and AIx levels significantly. Therefore, Self-Myofascial Release exercise will be an effective way to improve the vascular function of obese female college students.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.295-302
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• 2014

This study demonstrates a double-path CDI as an alternative of advanced wastewater treatment process. While the CDI typically consists of many pairs of electrodes connected in parallel, the new double-path CDI is designed to have series flow path by dividing the module into two stages. The CFD model showed that the double-path had uniform flow distribution with higher velocity and less dead zone compared with the single-path. However, the double-path was predicted to have higher pressure drop(0.7 bar) compared the single-path (0.4 bar). From the unit cell test, the highest TDS removal efficiencies of single- and double-path were up to 88% and 91%, respectively. The rate of increase in pressure drop with an increase of flow rate was higher in double-path than single-path. At 70 mL/min of flow rate, the pressure drop of double-path was 1.67 bar, which was two times higher than single-path. When the electrode spacing was increased from 100 to $200{\mu}m$, the pressure drop of double-path decreased from 1.67 to 0.87 bar, while there was little difference in TDS removal. When proto type double-path CDI was operated using sewage water, TDS, $NH_4{^+}$-N, $NO_3{^-}$-N and $PO_4{^{3-}}$-P removal efficiencies were up to 78%, 50%, 93% and 50%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1278-1286
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• 2008

The effect of Tween 20 addition on changes in the stability of methylcellulose (MC) emulsions (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris buffer, pH 7) was investigated by creaming stability and orthokinetic stability measurements. In the case of MC emulsions containing varying amounts of oil (1$\sim$30 wt%) and no Tween 20 added, creaming stability, judged by mean migration velocity of fat globules ($V_m$), was found to depend on droplet size: the larger the droplet size, the worse the stability [$V_m$: 0.326 $\mu$m $min^{-1}$ ($d_{32}$: 0.32 $\mu$m) ${\rightarrow}V_m$: 0.551 $\mu$m $min^{-1}$ ($d_{32}$: 0.53 $\mu$m)]. With Tween 20, creaming stability was found to be worse than the one without Tween 20, except for MC emulsion containing 0.2 wt% Tween 20. In addition, cream stability was the lowest with the lowest concentration of Tween 20 and a tendency to recover with increasing Tween 20 concentration [$V_m$: 0.598 $\mu$m $min^{-1}$ (0.01 wt%)${\rightarrow}V_m$: 0.389 $\mu$m $min^{-1}$ (0.2 wt%)] was found. From viscosity measurement for aqueous bulk phase of MC emulsions, such a change in the creaming stability was found to coincide well with the results of viscosity measurement. Therefore, it was reasonable to say that creaming stability of MC emulsions containing Tween 20 depended on MC concentration in aqueous bulk phase, which was in turn varied by competitive adsorption between MC and Tween 20 at the oil droplet surface. In case of orthokinetic stability, judged by destabilization time ($t_d$), it was found that the addition of Tween 20 resulted in lowered stability with more pronounce tendency at higher concentrations [$t_d$: 160 min (0.03 wt%)${\rightarrow}t_d$: 100 min (0.2 wt%)]. Moreover, combined with previous results, the orthokinetic stability of MC emulsions containing Tween 20 was found to be exponentially proportional to MC load. In conclusion, competitive adsorption between MC and Tween 20 may affect the stability properties of MC emulsion to varying extents, depending on the concentration of Tween 20.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.292-297
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• 2006

Purpose : In medulloblastoma, craniospinal radiation therapy combined with chemotherapy improves the prognosis of tumors but results in significant endocrine morbidities. We studied the endocrine morbidity, especially growth pattern changes. Methods : The medical records of 37 patients with medulloblastoma were reviewed retrospectively for evaluation of endocrine function and growth. We performed the growth hormone stimulation test in 16 patients whose growth velocity was lower than 4 cm/yr. Results : The height loss was progressive in most patients. The height standard deviation score (SDS) decreased from $-0.1{\pm}1.3$ initially to $-0.6{\pm}1.0$ after 1 year(P<0.01). Growth hormone deficiency(GHD) developed in 14 patients. During the 2 years of growth hormone(GH) treatment, the improvements of height gain or progressions of height loss were not observed. Twelve patients(32.4 percent) revealed primary hypothyroidism. One of six patients diagnosed with compensated hypothyroidism progressed to primary hypothyroidism. Primary and hypergonadotropic hypogonadism were observed in two and one patients respectively. There was no proven case of central adrenal insufficiency. Conclusion : Growth impairment developed frequently, irrespective of the presence of GHD in childhood survivors of medulloblastoma. GH treatment may prevent further loss of height. The impairment of the hypothalamic-pituitary-gonadal and hypothalamic-pituitary-thyroidal axis is less common, while central adrenal insufficiency was not observed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.527-536
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• 1996

The patterns of diel horizontal migration (DHM) of 7 copepod species are compared as part of a general investigation of the zooplankton adaptations to the surf zone habitats. In a sandy shore surf zone of Yongil Bay, 3 sites such as the bottom and surface of 1 m water depth and water's edge are sampled with a sledge net(n=108). The surf zone copepod assemblage is dominated by 7 species; Acartia hudsonica, Fseudodiaptomus marinus, Paracalanus indicus, Calanus sinicus, Oithona similis, Sinocalanus tenellus and Labidocera bipinnata. Threefold variations in copepod abundance are observed within a diel cycle. Abundances of 7 dominant species and total copepods captured in the surface exhibit significant diel differences, but those taken in the bottom are not significantly affected by diel period. It is shown that about $90\%$ of the surf zone copepods performed DHM. The nocturnal high densities of copepods occurred for a neap tide when the offshore winds prevailed, suggesting the animals' ability for horizontal orientation and an active locomotion without invoking passive transportation by currents. Photoreactive behavior of copepods triggered by relative changes in light intensity may be a primary factor inducing DHM by aggregating in the surf zone during the night and spreading out at day; then copepods may reduce encounters with visual predators. In A. hudsonica, ontogenetic variations in timings of DHM are evident. Such variations are likely to minimize intraspecific competition for diets. Data on shoreward migration of copepods indicate that A. hudsonica, P. indicus, O. similis and S. tenellus can maintain swimming velocities of about $20m\;h^{-1}$ for durations of more than an hour. Our observations of strong diel difference in abundances point out the need for both day and night samplings in surf zone habitats, if the importance of these habitats to planktonic copepods are to be fully understood.