• Advances in nano research
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• v.11 no.6
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• pp.649-655
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• 2021

Nanotechnology is widely considered a major technology of the twenty-first century. Nanoparticles (NPs) has been shown to pass through reproductively significant biological barriers such as the blood-testicle and placental barriers. Thus, the purpose of this study was to determine the effect of silver Nanoparticles (Ag-NPs) on sperm-egg interaction and spermatozoa quality parameters in quail spermatozoa. Semen was suspended in Ringer solution containing Ag-NPs levels at 5.5 × 106 sperm/ml (0, 0.01, 0.1, 1 and 10 ppm). The results indicated that when sperm were counted at 0.1 ppm, the number of holes formed on the inner perivitelline layer was significantly increased compared to the control. The 10 ppm group had a significant reduction in sperm viability. At 0.1 and 1 ppm, the membrane integrity was significantly decreased (P < 0.05). All treatments (except 0.01 ppm Ag-NPs) had a significant (P < 0.05) effect on the percentage of spermatozoa with an intact acrosome when compared to the control group. At 0.1, 1, and 10 ppm Ag-NPs, morphological defects in the acrosome were observed. As a result, Ag-NPs is likely capable of destroying the acrosome membrane. This research indicates that Ag-NPs may be cytotoxic to spermatozoa by impairing sperm functionality and increasing sperm mortality.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.21-27
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• 2015

In this study, interfacial characteristics between SOFC and Ag paste as current collector was estimated in the high temperature environment. The Ag paste was used to connect the unit cell of SOFC strongly with interconnector and provide the electrical conductivity between them. To confirm electrical conductivity, Ag paste was treated in the furnace at $800^{\circ}C$ for 48 hours. The sheet resistance of Ag paste was measured to compare the resistance values before and after the heat treatment. Also, the four-point bending test was performed to measure the interfacial adhesion. The unit cell of SOFC and $SiO_2$ wafer were diced and then attached by Ag paste. The $SiO_2$ wafer had the center notch to initiate a crack from the tip of the notch. The modified stereomicroscope combined with the CCD camera and system for measuring the length was used to observe the fracture behavior. To compare the characteristics before heat treatment and after heat treatment, the specimen was exposed in the furnace at $800^{\circ}C$ for 48 hours and then the interfacial adhesion was evaluated. Finally, the interfacial adhesion energy quantitatively increases $1.78{\pm}0.07J/m^2$ to $4.9{\pm}0.87J/m^2$ between the cathode and Ag paste and also increase $2.9{\pm}0.47J/m^2$ to $5.12{\pm}1.01J/m^2$ between the anode and Ag paste through the high temperature. Therefore, it is expected that Ag paste as current collector was appropriate for improving the structural stability in the stacked SOFC system if the electrical conductivity was more increased.

• KSBB Journal
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• v.15 no.3
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• pp.243-246
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• 2000

One of recent topics in the case of hepatits B virus(HVB) is the value of hepatitis B surface antigen(HBsAg) concentration as a prognostic maker. We developed uantitative method of rapid immunochromatographic assay(ICA) kit for HBsAg using computer image analysis (CIA) for the purpose of home diagnosis. uantitative ICA using CIA demonstrated integrated optical density(IOD) values proportional to log of reference HBsAg concentrations in the range of 2-200 ng/mL and enzyme-linked immunosorbent assay(ELISA) demonstrated the same in the range of 0.1-100 ng/mL however the test results with sample sear showed the same concentration on both kits. Furthermore repeated tests with the same samples revealed that this quantitative ICA using CIA would be reproducible and coefficient of variation(CV) of the results was 1.38~6.30%.

• Applied Microscopy
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• v.32 no.1
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• pp.1-8
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• 2002

To confirm the effect of electroacupuncture on the regeneration of injured peripheral nerve, the change of evoked potential in the sciatic nerve, the change of enzyme activity in the spinal cord, and morphological change of injured sciatic nerve were examined comparatively in acupuncture group (AG) and control group (CG) after sciatic nerve of guinea pig was injured by purpose. The value of evoked potential after injury of the sciatic nerve was increased in both AG and CG, but the increase rate of that was higher in AG than CG. Acid phosphatase activity of the spinal cord was increased in 1CG and 2AG, but shown are tendency to return to the normal state as time went by. Ultrastructural recovering rate of the injured sciatic nerve was higher in AG than CG. Also, there was developed only adipose tissue in sciatic nerve of AG. As mentioned above, the effect of electroacupuncture on the regeneration of injured peripheral nerve was confirmed experimentally by change of evoked potential, acid phosphatase and ultrastructure. Especially, the effect of electroacupuncture was appeared clearly in an early stage than other treatment stages.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.5
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• pp.243-250
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• 2011

When alloys are vacuum-deposited on cooled substrates, super-rapidly cooled alloy films in the unequilibrium state can be obtained. As an application of this method, Ag-Cu, Ag-Ni and Ag-C alloys were successfully produced, and their mechanical properties with tempering temperature were investigated. The following results were obtained : (1) In case of Ag-Cu alloys, the solid solution was hardened by tempering at $150^{\circ}C$. The hardening is considered to occur when the solid solution begins to decompose into ${\alpha}$ and ${\beta}$ phases. The Knoop hardness number of a 40 at.%Ag-Cu alloy film deposited on a cooled glass substrate was 390 $kg/mm^2$. The as-deposited films were generally very hard but fractured under stresses below their elastic limits. (2) In case of Ag-Ni and Ag-C alloys, after the tempering of 4 at.%Ni-Ag alloy at $400^{\circ}C$ and of 1 and 2 at.%C-Ag alloys at $200^{\circ}C$, they were hardened by the precipitation of fine nickel and carbon particles. The linear relationship between proof stress vs. $(grain\;diameter)^{-l/2}$ for bulk silver polycrystals can be applied to vacuum-deposited films up to about 0.1 ${\mu}m$ grain diameter, but the proof stress of ultra-fine grained silver with grain diameters of less than 0.1 ${\mu}m$ was smaller than the value expected from the Petch's relation.

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.50-59
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• 1998

Purpose : Hepatitis B virus (HBV) infection has been involved in several forms of immune-related glomerulopathy but the pathogenic role of HBV infection is not clear. To evaluate the clinicopathological features of HBV-associated glomerulopathy, a clinicopathological analysis and immunohistochemical stain for HBs Ag and HBe Ag were done. Methods : Clinicopathological features of HBV-associated glomerulopathy were analyzed with renal biopsies in 28 HBsAg seropositive patients from April 1990 to February 1997 at Pusan Paik Hospital, and immunohistochemical evaluation for HBsAg and HBeAg was done in renal tissues. Light microscopic, immunofluorescent and electron microscopic examination and immunohistochemical staining for HBsAg (DAKO) and HBeAg (BIONIKE) of renal tissue were performed. Result ; 1. The age distribution was 6 to 73 years old, and eight were children and 20 were adults. Male : female ratio was 3:1. Nineteen (67.9%) and 21 (75.0%) of 28 cases showed hematuria and proteinuria, respectively at the time of biopsy. Sixteen (57.2%) of them had nephrotic syndrome. 2. Liver function test was performed in 11 patients and seven (63.6%) of them showed increased AST and ALT levels. Liver biopsy was done in three patients and revealed findings of chronic active hepatitis. 3. HBV-associated glomerulopathy was membranous glomerulonephritis (MGN) in 10 (35.7%), mesangiopathy in 8 (28.6%), membranoproliferative glomerulonephritis (MPGN) in 7 (25.0%) and minimal change disease in 3 (10.7%) out of 28 cases. 4. Ultrastructurally HBV-associated MGN showed conspicuous subepithelial deposits with intramembranous, mesangial and subendothelial deposits and proliferation of mesangial cells and matrix, which were suggestive of MPGN. In HBV-associated MPGN, intramembranous and subepithelial deposits were scattered. 5. Immunohistochemical staining revealed no expression for HBsAg, but positive reaction for HBeAg along capillary wall in 8 cases (28.6%), of which 3 cases were checked for serum HBeAg, all showed positivity. Conclusion : HBV-associated glomerulopathy showed a wide morphologic spectrum and overlapping ultrastructural features in MGN and MPGN, and the activity of hepatitis B virus may be related to the development of HBV-associated glomerulopathy but further studies are recommended to confirm this relationship.

• Journal of Life Science
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• v.22 no.4
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• pp.516-523
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• 2012

The purpose of this study was to investigate the effect of exercise and/or L-arginine on abdominal fat, IGF-1 on GH/IGF-1 axis, fibrinogen, and PAI-1 in aged and obese rats. Male Sprague-Dawley rats were treated with a D-galactose aging inducing agent (50 mg/kg) given intraperitoneally for 12 weeks. Thirty-two male Sprague-Dawley rats were treated and divided into four groups: aging-high fat diet group (AG+HF), AG+HF with L-arginine intake group (AG+LA), AG+HF with exercise group (AG+EX), and AG+EX with L-arginine intake group (AG+LA+EX). The experimental rats underwent treadmill training (60 min/day, 6 days/week at 0% gradient) for 12 weeks. L-arginine was given orally (150 mg/kg/day) for 12 weeks. After the experiment, blood was collected from the left ventricle and abdominal fat was extracted. The results showed that GH was significantly increased in AG+EX and AG+AL+EX. IGF-1 was significantly increased in both the AG+AL+EX and AG+EX group ($p$<0.05), while fibrinogen and PAI-1 were not significantly different among the groups. Abdominal fat was significantly decreased in the AG+LA, AG+EX, and AG+LA+EX groups ($p$<0.05) compared with the AG+HF group. In conclusion, this study suggests that exercise alone or L-arginine alone or a combination not only increases the GH and IGF-1 concentration, but also decreases the abdominal fat mass.

• Journal of Biomedical Engineering Research
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• v.32 no.1
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• pp.37-44
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• 2011

This paper describes the development and assessment of conductive fabric sensor for evaluating knee movement using bio-impedance measurement method. The proposed strip-typed conductive fabric sensor is compared with a dot-typed Ag/AgCl electrode for evaluating validity under knee movement condition. Subjects are composed of ten males($26.6{\pm}2.591$) who have not had problems on their knee. The strip-typed conductive fabric sensor is analyzed by correlation and reliability between a dot-typed Ag/AgCl electrode and the strip-typed conductive fabric sensor. The difference of bio-impedance between a dot-typed Ag/AgCl electrode and the strip-typed conductive fabric sensor averages $7.067{\pm}13.987\;{\Omega}$ As the p-value is under 0.0001 in 99% of t-distribution, the strip-typed conductive fabric sensor is correlated with a dot-typed Ag/AgCl electrode by SPSS software. The strip-typed conductive fabric sensor has reliability when it is compared with a dot-typed Ag/AgCl electrode because most of bio-impedance values are in ${\pm}1.96$ standard deviation by Bland-Altman Analysis. As a result, the strip-typed conductive fabric sensor can be used for assessing knee movement through bio-impedance measurement method as a dot-typed Ag/AgCl electrode. Futhermore, the strip-typed conductive fabric sensor is available for wearable circumstances, applications and industries in the near future.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.1
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• pp.19-24
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• 2000

To make stacked chip packages far high-density packaging of memory chips used in workstations or PC severs, several lead-frames are to be connected vertically. Fer this purpose. Sn or Sn/Ag were electrochemically deposited on Cu lead-frames and their microstructures were examined by XRD and SEM. Then, two specimens were annealed at $250^{\circ}C$ for 10 min. and pressed to be joined. The shear stresses of joined lead-frames were measured fur comparison. In the case of Sn only, $Cu_3Sn$ was formed by the reaction of Sn and Cu lead-frames. In the case of Sn/Ag, besides $Cu_3Sn$. $Ag_3Sn$ was formed by the reaction of Sn and Ag. Compared to joined specimens made from Sn only, those made from Sn/Ag showed 1.2 times higher shear stress. This was attributed to the $Ag_3Sn$ phase formed at the joined interface.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1759-1764
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• 2002

Two crystal structures of dehydrated $Ag^+-andTl^+$-exchanged zeolite X$Ag_{27}Tl_{65-}X\;and\;Ag_{23}Tl_{69-}X$have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21(1) $^{\circ}C(a=24.758(4)\AAa=24.947(4)$, ${\AA}respectively).$, Their structures were refined to the final error indices $R_1$=0.055 and $wR_2$=0.057 with 375 reflections, and $R_1$=0.057 and $wR_2$=0.057 with 235 reflections, respectively, for which I > $3\sigma(I).$ In the structure of $Ag_{27}Tl_{65-}X,\;27\;Ag^+$ ions were found at two crystallographic sites: 15$Ag^+$ ions at site I at the center of the hexagonal prism and the remaining 12$Ag^+$ ions at site II' in the sodalite cavity. Sixty-five $Tl^+$ ions were located at three crystallographic sites: 20$Tl^+$ ions at site II opposite single six-rings in the supercage, 18$Tl^+$ ions at site I' in the sodalite cavity opposite the D6Rs, and the remaining 27$Tl^+$ ions at site III' in the supercage. In the structure of $Ag_{23}Tl_{69-}X$, 23$Ag^+$ ions were found at two crystallographic sites: 15 at site I and 8 at site II'. Sixty-nine $Tl^+$ ions are found at four crystallographic sites: 24 at site II, 17 at stie I', and the remaining 28 at two III' sites with occupancies of 22 and 6.