• Journal of Oral Medicine and Pain
• /
• v.32 no.4
• /
• pp.347-355
• /
• 2007

The aim of this study was to evaluate the differences of salivary lead (Pb) and cadmium (Cd) concentrations, using ASV analysis, after various pre-treatment procedures. 10 unstimulated whole saliva samples of non-exposed subjects to Pb and Cd were collected. Each sample was divided into 6 aliquots and centrifugation was performed in only 3 aliquots. After centrifugation, 3 different types of pre-treatment procedures were carried out. Also, these pre-treatment procedures were carried out for another 3 aliquots, without centrifugation. Pre-treated aliquots were analyzed electrochemically, by ASV. The results are as follows: 1. Mean concentration of Pb in saliva after centrifugation was significantly higher than that of non-centrifugation. 2. In the detection sensitivity of Pb in saliva, those of simple dilution technique by HCl and acid digestion technique by nitric acid were significantly higher than that of simple dilution technique by electrolyte. 3. Mean concentration of Cd in saliva after centrifugation was significantly higher than that of non-centrifugation. 4. In the detection sensitivity of Cd in saliva, those of simple dilution technique by HCl and acid digestion technique by nitric acid were higher than that of simple dilution technique by electrolyte. But, there were no significant differences between them.

• Journal of the Korean Geotechnical Society
• /
• v.21 no.6
• /
• pp.117-126
• /
• 2005

The chemical property analysis on the deposited clay using scanning electron microscope and energy dispersive x-ray spectrometer were performed. Also, the triaxial compression tests and consolidation tests using NaCl aqueous solution and leachate as substitute pore (or saturated) water in samples were carried out to find out the behaviour characteristics of strength and deformation of contaminated deposited clay. from the chemical composition analysis results of clay samples, the magnitudes of composition ratio were revealed in the order of O, C, Si, Al, and Fe. Of these, why the ratio of carbon appeared to be large is estimated as due to the increase of the phyto-planktons after the construction of tide embankment. In the triaxial compression test and consolidation test results, the shear strength and compression properties have increased with the increase in concentration of contaminant (NaCl). This phenomenon is considered as to be caused by the changes of soil structure to flocculent structure owing to the decrease in the thickness of diffuse double layer in proportion to increase in the concentration of electrolyte.

• Resources Recycling
• /
• v.15 no.6 s.74
• /
• pp.41-47
• /
• 2006

A study for recovering of copper and lead from electronic scraps has been carried out using a combination of bioleaching and solvent extraction. It was found that the citric acid generated by Aspergillus niger could be an imporant leaching agent acting in the solubilization of copper, iron, lead and tin from the electronic scrap. Copper could be selectively extracted by 10% LIX84 from the leaching solution and it recoved 99.9% of metallic copper by electrowinning process. Tin and iron were extracted from the remaining solution by 10% Alamine336 and stripped by NaCl solution. Finally, tin could be recovered as a metallic precipitates from the mixed solution of tin and iron by cementation with iron powder.

• Journal of Soil and Groundwater Environment
• /
• v.13 no.1
• /
• pp.13-23
• /
• 2008

The triaxial compression tests and consolidation tests using NaCl solution and leachates as substitute pore (or saturated) water in samples were carried out to find out the behavior characteristics of strength, deformation and permeability coefficient of contaminated clay. Also, the chemical property analysis on the clay samples using scanning electron microscope and energy dispersive x-ray spectrometer were involved. The magnitudes of composition ratio were shown in the order of O, C, Si, Al, and Fe as a result of chemical composition analysis for clay samples. Besides, as the results of triaxial compression tests and consolidation tests, the shear strength, compression and permeability properties were increased with increasing in the concentration of contaminant (NaCl). It may be considered that these circumstances be caused by the changes of soil structure to flocculent structure due to the decrease in the thickness of diffuse double layer with increasing in the concentration of electrolyte. MT3D model was also using to grasp the procedures that the groundwater may be contaminated by the leachates permeated through the clay liner. The results of contaminant transport analysis showed a tendency that the predicted concentration of groundwater was higher with increasing in the initial concentration of $Cl^-$ ion and increased as a nonlinear curves with time. The transportation distance calculated by the use of regression equation between the distance from contaminant source and the concentration of $Cl^-$ ion was increased with increasing the initial concentration.

• Applied Chemistry for Engineering
• /
• v.10 no.5
• /
• pp.652-659
• /
• 1999

The trend of poisoning of reforming catalyst along with the position of anodic catalyst bed was studied. Keeping the conditions that steam to carbon ratio was 2.5, operating voltage was 0.75 V, current density was $140mA/cm^2$, the unit cell was operated during 24 hrs at a steady state. And then the cell was stopped, the catalysts packed in the position of inlet, middle and outlet were sampled individually and then the amount of carbon, Li and K poisoned were analysed. After 100 hrs operated, the catalysts at the same positions were analysed at the same manner. The result of this experiment was as followings. After 24 hrs operated, the poisoning amounts of Li and K in the catalyst were 0.27 wt% at inlet, 0.23 wt% at middle and the highest value 1.59 wt% at outlet. After 100 hrs, the amount of poisoning is the highest in the catalyst packed at the inlet of unit cell. The performance simulation of unit cell explained these trends of poisoning catalysts. The simulation told that the catalyst in the region of the inlet of unit cell treated the 90% of initial methane flow rate and the highest electrochemical reaction happened in this region. So the catalysts of this region were the most poisoned with carbon, Li and K and also the rate of poisoning is faster than that of the catalyst at other regions. The temperature at the region of outlet of unit cell was $30^{\circ}C$ higher than that of other regions, so more Li, and K vaporized than at other regions and little reforming reaction at this region made the catalysts poisoning rate low.

• Korean Journal of Clinical Laboratory Science
• /
• v.47 no.4
• /
• pp.267-272
• /
• 2015

'Tight junctions (TJ)' have recently been identified in the granular cell layer of the human epidermis, where they contribute to the normal adhesion between keratinocytes and to the physiologic barrier function of the epidermis. Among the TJ proteins in the epidermis, occludin is an important transmembrane protein, which is considered as a major component. The purpose of this study is to investigate whether regional variation exists in the expression of the tight junction protein occludin in normal human epidermis. Indirect immunofluorescence staining for occludin was performed with specimens taken from different areas of normal skin (4 from each of 7 different anatomical sites, including the scalp, face, posterior neck, upper arm, abdomen, lower back, and inner thigh). The degrees of the expression-intensity in each specimen were estimated with the reciprocals of positive end-point titer of occludin in an indirect immunofluorescence study. The highest degree expression-intensity of the TJ protein occludin among the different areas of normal epidermis was observed on the face and abdomen with a titer of 600 (p=0.001). The lowest intensity of expression of occludin was seen in the epidermis from the upper arm. Skin specimens from the scalp, neck, back, and leg demonstrated intermediate degrees of the expression in intensity. The expression of occludin in the skin samples obtained from different locations of the body showed a statistically significant variation. This suggests that there is a certain degree of regional variation in the expression-intensity of TJ protein 'occludin' in the human epidermis.

• Journal of the Mineralogical Society of Korea
• /
• v.27 no.4
• /
• pp.207-222
• /
• 2014

In order to recover the metallic copper powder from the mine-waste rock, heap bioleaching, Fe removal and electrowinning experiments were carried out. The results of heap leaching with the mine-waste rock sample containing 0.034% Cu showed that, the leaching rate of Cu were 61% and 62% in the bacteria leaching and sulfuric acid leaching solution, respectively. Sodium hydroxide (NaOH), hydrogen peroxide ($H_2O_2$) and calcium hydroxide ($Ca(OH)_2$) were applied to effectively remov Fe from the heap leaching solution, and then $H_2O_2$ was selected for the most effective removing Fe agent. In order to prepare the electrolytic solution, $H_2O_2$ were again treated in the heap leaching, and Fe removal rates were 99% and 60%, whereas Cu removal rates were 5% and 7% in the bacteria and sulfuric acid leaching solutions, respectively. After electrowinning was examined in these leaching solution, the recovery rates of Cu were obtained 98% in bacteria and obtained 76% in the sulfuric leaching solution. The dendritic form of metallic copper powder was recovered in both leaching solutions.

• Journal of Chest Surgery
• /
• v.39 no.5 s.262
• /
• pp.366-375
• /
• 2006

Background: Hypomagnesemia is a common complication after cardiac surgery with cardiopulmonary bypass. The purpose of this study was to assess the clinical beneficial effect of administration of magnesium sulfate in cardiac surgery. Material and Method: Thirty five patients scheduled for elective cardiac surgery were randomly assigned to magnesium group (n=20) which received magnesium sulfate in priming solution (1 g) and cardioplegic solution (1 g) or control group (n=15) which did not receive it. Arterial blood samples were drawn for measuring $Mg^{++}$ and electrolytes contents, blood gas analysis, CBC, total protein, albumin, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, tumor necrosis factor-${\alpha}$ $(TNF-{\alpha})$, interleukin-6 (IL-6), interleukin-10 (IL-10), creatine phosphokinase (CpK), creatine kinase-MB (CK-MB), lactate dehydrogenase(LDH), troponin-1 (TNI), prothrombin time (PT) and activated pratial thromboplastin time level (aPTT). Venous blood samples were drawn before and after the operation for measuring activated clotting time level (ACT). Result: $Mg^{++}$ levels in magensium group were higher than those of control group at intraoperative and post-operative periods (p<0.05). dysrhythmias were lower in magnesium group (8 cases out of 17 patients, 46.4%) than in control group (10 cases out of 10, 100%, p=0.050). Conclusion: These results showed that administration of low dose magnesium sulfate during cardiac surgery prevented hypomagnesemia and lowered incidence of dysrhythmia.