• Geomechanics and Engineering
• /
• 제33권1호
• /
• pp.29-40
• /
• 2023

Xanthan gum and starch compound biopolymer (XS), an environmentally friendly soil-binding material produced from natural resources, has been suggested as a slope protection material to enhance soil strength and erosion resistance. Insufficient wet strength and the consequent durability concerns remain, despite XS biopolymer-soil treatment showing high strength and erosion resistance in the dried state, even with a small dosage of soil mass. These concerns need to be solved to improve the field applicability and post-stability of this treatment. This study explored the utilization of an alkaline-based cation crosslinking method using calcium hydroxide and sodium hydroxide to induce non-thermal gelation, resulting in the enhancement of the wet strength and durability of biopolymer-treated soil. Laboratory experiments were conducted to assess the unconfined compressive strength and cyclic wetting-drying durability performance of the treated soil using a selected recipe based on a preliminary gel formation test. The results demonstrated that the uniformity of the gel structure and gelling time varied depending on the ratio of crosslinkers to biopolymer; consequently, the strength of the soil was affected. Subsequently, site soil treated with the recipe, which showed the best performance in indoor assessment, was implemented on the field slope at the bridge abutment via compaction and pressurized spraying methods to assess feasibility in field implementation. Moreover, the variation in surface soil hardness was monitored periodically for one year. Both slopes implemented by the two construction methods showed sufficient stability against detachment and scouring, with a higher soil hardness index than the natural slope for a year.

• 열처리공학회지
• /
• 제37권1호
• /
• pp.16-22
• /
• 2024

The conventional degreasing process involves removing oil and contaminants at temperatures above 80℃, resulting in excessive energy consumption, increased process costs, and environmental issues. In this study, we aimed to find the optimal degreasing conditions for the pre-treatment process of electro-galvanizing cold-rolled steel sheets, conducted efficiently at room temperature without the need for a separate heating device. To achieve this, we developed a room temperature degreasing solution and a brush-type degreasing tool, aiming to reduce energy consumption and normalize the decrease in degreasing efficiency caused by temperature reduction. Alkaline degreasing solution were prepared using KOH, SiO₂, NaOH, Na₂CO₃, and Sodium Lauryl Sulfate, with KOH and NaOH as the main components. To enhance the degreasing performance at room temperature, we manufactured additives including sodium oleate, sodium stearate, sodium palmitate, sodium lauryl sulfate, ammonium lauryl sulfate, silicone emulsion, and EDTA-Na. Room temperature additives were added to the alkaline degreasing solution in quantities ranging from 0.1 to 20 wt.%, and the uniformity of degreasing and the adhesion of the galvanized layer were evaluated through Dyne Test, T-bending Test, OM, SEM, and EDS analyses. The results indicated that the optimal degreasing solution composition consisted of NaOH (30 g/L), Na₂CO₃ (30 g/L), SLS (6 g/L), and room temperature additives (≤1 wt%).

• Journal of Periodontal and Implant Science
• /
• 제51권3호
• /
• pp.213-223
• /
• 2021

Purpose: The atmospheric pressure plasma jet (APPJ) has been introduced as an effective disinfection method for titanium surfaces due to their massive radical generation at low temperatures. Helium (He) has been widely applied as a discharge gas in APPJ due to its bactericidal effects and was proven to be effective in our previous study. This study aimed to evaluate the safety and effects of He-APPJ application at both the cell and tissue levels. Methods: Cellular-level responses were examined using human gingival fibroblasts and osteoblasts (MC3T3-E1 cells). He-APPJ was administered to the cells in the experimental group, while the control group received only He-gas treatment. Immediate cell responses and recovery after He-APPJ treatment were examined in both cell groups. The effect of He-APPJ on osteogenic differentiation was evaluated via an alkaline phosphatase activity assay. In vivo, He-APPJ treatment was administered to rat calvarial bone and the adjacent periosteum, and samples were harvested for histological examination. Results: He-APPJ treatment for 5 minutes induced irreversible effects in both human gingival fibroblasts and osteoblasts in vitro. Immediate cell detachment of human gingival fibroblasts and osteoblasts was shown regardless of treatment time. However, the detached areas in the groups treated for 1 or 3 minutes were completely repopulated within 7 days. Alkaline phosphatase activity was not influenced by 1 or 3 minutes of plasma treatment, but was significantly lower in the 5 minute-treated group (P=0.002). In vivo, He-APPJ treatment was administered to rat calvaria and periosteum for 1 or 3 minutes. No pathogenic changes occurred at 7 days after He-APPJ treatment in the He-APPJ-treated group compared to the control group (He gas only). Conclusions: Direct He-APPJ treatment for up to 3 minutes showed no harmful effects at either the cell or tissue level.

• 한국의류학회지
• /
• 제36권12호
• /
• pp.1310-1317
• /
• 2012

This study examines the possibilities to improve natural dyestuff's (Pinux$^{TM}$) dyeability and colorfastness for C/R (Cotton/Rayon (40/60)) and W/T (Wool/Tencel (10/90)) knitted fabrics in cationizing and smectiting for pre-treatment, simultaneous-treatment and post-treatment process sequences; as well as various other treatment methods. The sample dyeability showed the strongest K/S value in the order of smectite (S) < cationization + smectite (C+S) < cationization (C); however, the K/S value showed a low level in the simultaneoustreatment method of smectite. Colorfastness to washing improved in the order of C < C+S < S, and after the smectite post-treatment process, C/R improved from Grade 1 to Grade 4 and W/T improved from Grade 1-2 to Grade 4. Colorfastness to perspiration generally improved in the same order as the colorfastness to washing and after the smectite post-treatment process C/R, W/T sample's acidic and alkaline colorfastness to perspiration improved greatly. As for the colorfastness to rubbing, the addition of smectite in the simultaneous-treatment and post-treatment processes resulted in improved wet-colorfastness; however, smectite showed less effect on the colorfastness to light compared to other colorfastness ratings.

• Toxicological Research
• /
• 제19권3호
• /
• pp.217-225
• /
• 2003

Changes of plasma DNA contents and serum biochemical values were measured in rats administered with lead acetate to investigate the in vivo cytotoxic effects of lead and examine the usefulness of these in vivo cytotoxicity changes as indicators of lead exposure and diagnosis of lead poisoning. Rats were given once intraperitonealy with lead acetate (1.6, 8, 40 and 200 mg/kg b.w) and the changes of plasma DNA contents and serum biochemical values were measured at the time of 2, 4, 8, 24, 48 and 72 hours after the administration of lead acetate. Plasma DNA contents began to increase at 2 hours after the administration of lead acetate in the treatment groups of 8, 40 and 200 mg/kg b.w dose-dependently and significantly compared with control group. These DNA increases of each dosage group were continued until 24, 48 and 72 hours and the maximum levels of DNA (4.02, 10.67 and 14.10 times of control) were arrived at 8, 8 and 4 hours after the each treatment, respectively. Among 10 serum biochemical indicators, the activities of creatine kinase were increased to maximum level (6.55 times of control) at 2 hours after the administration and remained to be significantly higher than that of control by 8 hours in the treatment group of 200 mg, however, after 48 hours, the levels in the treatment groups of 40 mg above were lower than that of control. The values of aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase were higher than that of control from 2 to 24 hours in the treatment group of 200 mg. Maximum levels of these enzymes were 3.34, 3.00 and 3.19 times of control, respectively. Both of alkaline phosphatase and triglyceride values in the treatment groups were decreased compared with control. In the case of alka-line phosphatse, the values were significanly decreased from 24 hours and more severely decreased until 72 hours in the treatment groups of 40 mg above (p<0.01). The minimum value was 0.36 times of control in the 200 mg group. The values of triglyceride were significantly decreased in the tratment groups of 40 mg above (p<0.01), but the values were not different significantly among the treatment groups. This study demonstrates that plasma DNA content and serum biochemical values such as aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, alkaline phosphatase and triglyceride are valuable as biomarkers for exposure assessment and diagnosis of lead poisoning.

• 한국식품영양과학회지
• /
• 제45권5호
• /
• pp.664-670
• /
• 2016

Polyglutamic acid(PGA) 함유량이 증대된 청국장이 조골세포에 미치는 영향을 세포 수준에서 관찰하고자 하였다. 조골세포에 미치는 영향을 관찰하기 위하여 세포 생존율, 염기성 인산분해효소(alkaline phosphatase, ALP) 활성, 골 석회화 형성능, 조골세포 분화 관련 유전자 발현능을 측정하였다. 세포 독성이 없는 농도에서 염기성 인산분해효소 활성을 측정한 결과 농도에 의존적으로 ALP 활성이 증가하였으며, 일반 청국장 A보다 PGA 함유량이 증가한 청국장 B가 더 높은 ALP 활성 증가 효과를 나타내었다. 청국장의 골 석회화 형성능을 측정한 결과 역시 청국장 A보다 B가 더 높은 석회화 형성능을 나타내었다. 또한 분화 관련 유전자인 OCN, OPN, Col1, ALP 역시 청국장 B가 A보다 유전자 발현이 더 높게 나타났다. 이러한 실험 결과를 바탕으로 PGA가 증대된 청국장이 기존 청국장보다 조골세포의 활성에 효과적일 것으로 생각한다.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제33권1호
• /
• pp.10-18
• /
• 2011

Purpose: The purpose of this study is to find out the effects of bisphosphonates (BPs) on the proliferation and the alkaline phosphatase (ALP) activity of human bone marrow derived mesenchymal stem cells (hMSCs), and thus state its correlation with bisphosphonate related osteonecrosis of the jaw (BRONJ). Methods: hMSCs was obtained by collecting and culturing cancellous bone fragments from a patient undergoing iliac bone graft. Alendronate (Aln) and Pamidronate (Pam), Ibandronate (Ibn) were added to the culture media in the concentration from $10^{-3}$ M to $10^{-11}$ M and cell toxicity, viability were measured. For ALP activity evaluation, Aln and Pam were added to the culture media in the concentration from $5{\times}10^{-7}$ M to $1{\times}10^{-8}$ M and were cultured for 1 week, 2 weeks and 3 weeks. ALP activity data were standardized using protein assay. Control groups were prepared for each examination. Results: Aln, Pam and Ibn all failed to increase the proliferation of hMSCs. With 1 week, 2 weeks of $5{\times}10^{-8}$M of Aln treatment, the ALP activity increased. Pam treatment increased the ALP activity with 2 weeks of $5{\times}10^{-8}$ M and$1{\times}10^{-8}$M. Also Ibn treatment increased the ALP activity with 2 weeks of $5{\times}10^{-8}$ M and $1{\times}10^{-8}$ M. Conclusion: It is considered that BPs are not capable of improving the proliferation of hMSCs. Also, after a transient increase in the ALP activity with the lower concentration of BPs, the activity decreased again. Therefore, in patients on long-term medication of BPs, the proliferation and osteoblast differentiation of hMSCs are restrained, and thus delayed wound healing and increase in BRONJ complications may occur.

• Toxicological Research
• /
• 제22권2호
• /
• pp.75-85
• /
• 2006

This study was designed to evaluate the possible DNA damaging effects of T-2 toxin using an alkaline single cell gel electrophoresis (SCGE) comet assay and also to investigate toxic effects in chickens. A total of 20 chickens were used in these experiments. Graded concentrations of dietary T-2 toxin (0, 4, 8, and $16{\mu}g/g$ of diet) were given to groups of 5 broiler chickens. In comet assay, The DNA damage was analysed by the tail extent moment (TEM) and tail length (TL), which were used as markers of DNA strand breaks in SCGE. A significant dose-dependent increase in the extent of DNA migration as well as in the percentage of cells with tails was observed after treatment with T-2 toxin (P<0.05). Treatment with the low T-2 toxin ($4{\mu}/g$ of diet) induced a relatively low level of DNA damage in comparison with the high T-2 toxin ($16{\mu}/g$ of diet) group. The growth rate was significantly reduced by concentrations of 8, and $16{\mu}/g$ of diet (P < 0.05). The feed conversion ratio were significantly affected by any concentrations (P < 0.05). The relative weight of the spleen, and lung was decreased by the growth inhibitory concentrations. The bursa of Fabricius, thymus, and kid- ney were decreased in relative weight by concentrations of $16{\mu}/g$ of diet. The relative weight of the liver and heart were unaffected. The hemoglobin (Hb), hematocrit (HCT), and mean corpuscular hemoglobin (MCH) were decreased at concentration of $16{\mu}/g$ of diet. As compared with control chickens, there was no marked change in serum components except uric acid in T-2 treated chickens. All lymphoid tissues retained atrophic and lymphoid cell depletion throughout the three weeks trial.

• Toxicological Research
• /
• 제29권1호
• /
• pp.43-52
• /
• 2013

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium that are found in cereals and agricultural products. ZEN has been implicated in mycotoxicosis in farm animals and in humans. The toxic effects of ZEN are well known, but the ability of an alkaline Comet assay to assess ZEN-induced oxidative DNA damage in Chang liver cells has not been established. The first aim of this study was to evaluate the Comet assay for the determination of cytotoxicity and extent of DNA damage induced by ZEN toxin, and the second aim was to investigate the ability of N-acetylcysteine amide (NACA) to protect cells from ZEN-induced toxicity. In the Comet assay, DNA damage was assessed by quantifying the tail extent moment (TEM; arbitrary unit) and tail length (TL; arbitrary unit), which are used as indicators of DNA strand breaks in SCGE. The cytotoxic effects of ZEN in Chang liver cells were mediated by inhibition of cell proliferation and induction of oxidative DNA damage. Increasing the concentration of ZEN increased the extent of DNA damage. The extent of DNA migration, and percentage of cells with tails were significantly increased in a concentration-dependent manner following treatment with ZEN toxin (p < 0.05). Treatment with a low concentration of ZEN toxin (25 ${\mu}M$) induced a relatively low level of DNA damage, compared to treatment of cells with a high concentration of ZEN toxin (250 ${\mu}M$). Oxidative DNA damage appeared to be a key determinant of ZEN-induced toxicity in Chang liver cells. Significant reductions in cytolethality and oxidative DNA damage were observed when cells were pretreated with NACA prior to exposure to any concentration of ZEN. Our data suggest that ZEN induces DNA damage in Chang liver cells, and that the antioxidant activity of NACA may contribute to the reduction of ZEN-induced DNA damage and cytotoxicity via elimination of oxidative stress.

• Journal of the Korean Wood Science and Technology
• /
• 제9권2호
• /
• pp.1-30
• /
• 1981

알칼리 펄프화중(化中)에 생성(生成)되는 리그닌의 착색구조(着色構造)를 구명(究明)하기 위(爲)하여 바닐린알코올[${\alpha}-^{13}C$] 과이아실 글리세롤-${\beta}$-아릴에테르[${\alpha}-^{13}C$] 혹은 [${\gamma}-^{13}C$] 페닐쿠마란[${\alpha}-^{13}C$] 구조(構造)를 각각(各各) 165$^{\circ}C$에서 1.5~3시간(時間) 알칼리용액을 처리한 후(後) 반응생성물(反應生成物)을 단리(單離) 또는 반응혼합물(反應混合物)을 $^{13}C$-NMR로 조사(調査)한 결과(結果), 바닐린아코올의 알칼리 처리(處理)는 Ca-$C_1$ 및 Ca-$C_5$의 결합(結合)을 갖는 축합체(縮合體)(II-1~5)로 되며, 이들은 공기산화(空氣酸化)에 의(依)해 퀴노이드 공역형구조(共役型構造)(Fig 3-7)로 산화(酸化)되며, 과이아실글리세롤 -${\beta}$- 아릴에테르의 알칼리 처리(處理)는 ${\alpha}$-아릴-${\beta}$-아록시퀴논구조(構造)(IV-15, IV-16) 디과이아실-1, 4-펜탄디엔 ${\beta}$, ${\beta}$' -디아록시스티렌메탄(V-4) ${\beta}$-아록시스티렌메탄(V-6)이 생성(生成)되며 스티렌메탄 구조(構造)는 공기산화(空氣酸化)에 의(依)해 O-퀴논메티드구조(V-8, V-9)로 된다. 페닐쿠마란은 알칼리처리(處理)에 의(依)해 다량(多量)의 스틸벤유도체(誘導體)를 생성(生成)하지만 이스틸벤구조가 퀴논구조로 산화되기 보다는 2량체(量體)(IV-11)로 안정화(安定化)되는 경향(傾向)이 있다. 이상(以上)과 같은 착색구조(着色構造)는 반응기구의 견지에서 알칼리 펄프화중(化中)에 생산되는 중요한 착색구조(着色構造)라고 생각된다.