• Title/Summary/Keyword: surface washing

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Doxorubicin-loaded PEI-silica Nanoparticles for Cancer Therapy

  • Heekyung Park;Seungho Baek;Donghyun Lee
    • Korean Chemical Engineering Research
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    • v.61 no.4
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    • pp.570-575
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    • 2023
  • Targeted anticancer drug delivery systems are needed to enhance therapeutic efficacy by selectively delivering drugs to tumor cells while minimizing off-target effects, improving treatment outcomes and reducing toxicity. In this study, a silica-based nanocarrier capable of targeting drug delivery to cancer cells was developed. First, silica nanoparticles were synthesized by the Stöber method using the surfactant cetyltrimethylammonium bromide (CTAB). Increasing the ratio of EtOH in the solvent produced uniformly spherical silica nanoparticles. Washing the nanoparticles removed unreacted residues, resulting in a non-toxic carrier for drug delivery in cells. Upon surface modification, the pH-responsive polymer, polyethyleneimine (PEI) exhibited slow doxorubicin release at pH 7.4 and accelerated release at pH 5.5. By exploiting this feature, we developed a system capable of targeted drug release in the acidic tumor microenvironment.

Effect of proton concentration in TEOS to improve durability of hydrophilic and high light transmittance properties of nanosilica coating (친수 및 높은 광투과 기능을 함유한 나노실리카 코팅액의 내구성 향상을 위한 수소이온 농도에 따른 TEOS의 반응 연구)

  • Lee, Soo;Chan, Sung Il;Hwang, Heon
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.3
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    • pp.483-491
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    • 2016
  • Even though the antifogging property of nanosilica coated glass surface is highly increased due to the hydrophilic hydroxyl groups on nanosilica surface, the durability of this property on outdoor glass was diminished rapidly after rain washing. In addition the topology of nanosilica coated glass surface plays very important roles to control an light transmittance or antireflection property. To improve these coating durability and characteristics a hydrophilic nanosilica coating on glass was prepared by coating with 1.5 wt% of nanosilica (Ludox) suspension in the presence of hydrolyzed tetraethylorthosilicate (TEOS). The optimum hydrolysis condition of TEOS in acidic or basic aqueous solution was also examined by contact angle measurement. The final transparent hydrophilic coating layer coated with nanosilica-TEOS in acidic condition (pH=4) showed much improved durability of hydrophilic surface as well as higher visible light transmittance than original uncoated glass by 2 % point.

Localized Surface Plasmon Resonance (LSPR) Biosensors on Metal Nanoparticles with the Design of Bioreceptors

  • Kim, Min-Gon;Park, Jin-Ho;Byun, Ju-Young;Shin, Yong-Beom
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.126-126
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    • 2014
  • Label-free biomolecular assay based localized surface plasmon resonance (LSPR) of noble metal nanoparticles enables simple and rapid detection with the use of simple equipment. Nanosized metal nanoparticles exhibit a strong absorption band when the incident light frequency is resonant with the collective oscillation of the electrons, which is known as the LSPR. Here we demonstrate localized surface plasmon resonance (LSPR) substrates such as plasmonic Au nanodisks fabricated by a nanoimprinting process and gold nanorod-immobilized surfaces and their applications to highly sensitive and/or label-free biosensing. To increase detection sensitivity various bioreceptors weree designed. A single chain variable fragment (scFv) was used as a receptor to bind C-reactive protein (CRP). The results of this effort showed that CRP in human serum could be quantitatively detected lower than 1 ng/ml. Aptamers, which were immobilized on gold nanorods, were used to detect mycotoxins. The specific binding of ochratoxin A (OTA) to the aptamer was monitored by the longitudinal wavelength shift of LSPR peak in the UV-Vis spectra resulting from the changes of local refractive index near the GNR surface induced by accumulation of OTA and G-quadruplex structure formation of the aptamer. According to our results, OTA could be quantitatively detected lower than 1 nM level. Additionally, aptamer-functionalized GNR substrate was quite robust and can be regenerated many times by rinsing at 70 OC to remove bound target. During seven times of washing steps, the developed OTA sensing system could be reusable. Moreover, the proposed biosensor exhibited selectivity over other mycotoxins with an excellent recovery for detection in grinded corn samples, suggesting that the proposed LSPR based aptasensor plays an important role in label-free detection of mycotoxins.

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Effect of Chlorine Dioxide Gas Application to Egg Surface: Microbial Reduction Effect, Quality of Eggs, and Hatchability

  • Chung, Hansung;Kim, Hyobi;Myeong, Donghoon;Kim, Seongjoon;Choe, Nong-Hoon
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.487-497
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    • 2018
  • Controlling of microorganisms in the industrial process is important for production and distribution of hatching and table eggs. In the previous study, we reported that chlorine dioxide ($ClO_2$) gas of a proper concentration and humidity can significantly reduce the load of Salmonella spp. on eggshells. In this study, we compared microbial reduction efficacy on egg's surface using hatching eggs and table eggs, internal quality of table eggs, and hatchability after both the conventional method (washing and UV expose, fumigation with formalin) and $ClO_2$ gas disinfection. Application of 40 ppm $ClO_2$ gas to the table and hatching eggs, respectively, reduced the aerobic plate count (APC) with no statistical difference compared with the conventional methods. Additionally, we didn't observed that any significant difference in albumin height, Haugh unit (HU), and yolk color, this result confirms that 40 ppm $ClO_2$ had no effect on the internal quality of the table eggs, when comparing with the UV treatment method. The hatchability of hatching eggs was not statistical different between formaldehyde fumigation and 80 ppm $ClO_2$ gas treatment, though the value was decreased at high concentration of 160 ppm $ClO_2$ gas. From these results, we recommend that $ClO_2$ gas can be used as a safe disinfectant to effectively control egg surface microorganisms without affecting egg quality.

Development of New Surface Design Technique for Natural Dyeing of Silk Fabric by Salt-Shrinkage Finishing (염축가공에 의한 견직물 천연염색의 새로운 표면 디자인 구현기법 개발)

  • Kim, Chaeyeon;Yoo, Dong Il;Shin, Younsook
    • Textile Coloration and Finishing
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    • v.28 no.3
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    • pp.189-194
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    • 2016
  • The objectives of this research were to study the effect of salt-shrinkage finishing of silk on shrinkage degree and dyeing property of cochineal, and to investigate the efficacy of obtained results for imparting surface design effect on silk fabric. Ultimately it was aimed to suggest a technical process for developing natural dyed silk products with diverse design. Premordanted silk fabric was treated with $Ca(NO_3)_2$ solution(gravity: 1.45) at $90^{\circ}C$ for 1 min, washed, dried for further evaluation. The shrinkage of salt-treated fabric was calculated. The effects of salt treatment on the dye uptake of cochineal and colorfastness were investigated. The degrees of shrinkage were 10% and 3% for warp and weft, respectively. The salt treatment resulted in improving dye uptake of cochineal slightly. In addition, it improved colorfastness to washing and light. On the basis of the results, a technical process composed of premordanting, salt treatment and natural dyeing was suggested and using the process, two examples of textile design were presented. It can be concluded to impart various three dimensional surface design effect on silk fabric by applying salt-shrinkage finishing with combination of natural dyeing and mordanting.

Effect of fluoride application after dental prophylaxis by the type of dental floss (치실 종류에 따른 치면세마 시행에 대한 불소도포 효과)

  • Kim, Kyung-Hee;Ha, Myung-Ok;Hong, Nam-Hee;Cho, Min-Jung
    • Journal of Korean society of Dental Hygiene
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    • v.16 no.1
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    • pp.77-83
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    • 2016
  • Objectives: This study was carried out to investigate the effect of fluoride application after dental prophylaxis by the type of dental floss. Methods: Artificial caries lesion was made on the surface of cow's permanent teeth having sound enamel surface and vickers hardness number(VHN) was measured. Specimens were classified into APF gel group and artificial saliva group. Each group was divided into waxed floss group and unwaxed flossed group. All specimens were immersed into the artificial saliva for one minute and dental flossing was applied to waxed or unwaxed floss. After washing and drying, APF gel groups were applied with fluoride for four minutes and artificial saliva groups were immersed into the artificial saliva for four minutes. After treatment, specimens were measured by VHN and surface conditions of enamel were confirmed by scanning electron microscopy(SEM). Results: VHN of waxed flossing and fluoride application group increased to $6.78{\pm}2.75$. VHN of unwaxed flossing and fluoride application group increased to $7.36{\pm}2.51$. There was no significant difference between waxed and unwaxed groups(p>0.05). VHN of waxed flossing and artificial saliva group increased to $1.07{\pm}2.84$. VHN of waxed flossing and artificial saliva group increased to $1.05{\pm}3.13$. There was no significant difference between waxed and unwaxed groups(p>0.05). There was significant increase in VHN between waxed/unwaxed flossing and fluoride application. However, waxed/unwaxed flossing with artificial saliva showed no significant VHN increase. SEM demonstrated no residue on the enamel surface in the waxed flossing groups. Conclusions: No difference was found in the remineralization of enamel by waxed flossing or unwaxed flossing.

The Characterization of Metal Silicon and Compacts for the Nitridation (질화반응용 금속규소 및 그 Compacts의 Characterization(Densification of Silocon Nitride 1보))

  • 박금철;최상욱
    • Journal of the Korean Ceramic Society
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    • v.20 no.3
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    • pp.211-216
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    • 1983
  • This work aims at characterizing silicon grains and its compacts. In order to remove iron silicon grains were washed with 5N hydrochloride at 60-7$0^{\circ}C$ for 170 hrs, and then followed the chemical analysis by atomic absorption spectrophotometer X-ray diffraction analysis SEM observation and specific surface area determination by B. E. T. Mixtures of graded silicon particles with two or three different sizes were made into packings by mechanical vibration. The mixtures were used to make compacts with 10 mm in diameter and 70mm in length by isostatically pressing at 1, 208 kg/$cm^2$ (20 kpsi) and 4, 255kg/$cm^2$ (60 kpsi) respectively. Bulk densities of packings and compacts were measured. A slip made of magnesium nitrate solution and fine silicon particles was spray-dried and then decomposed at 30$0^{\circ}C$ for the purpose of coating the uniform layer of magnesium oxide on the surface of particles. The results obtained are as follows: (1) About two thirds of iron content could be removed from silicon by washing silicon powders with hydrochloride. (2) Uniform layer of magnesium oxide on the surface of silicon could be prepared by spray-drying suspension and by decomposing it. (3) B. E. T. specific surface area of fine silicon particles was 2, 826.753$m^3$/kg. (4) In the binary system with two sizes of 40-53$\mu\textrm{m}$ particles and <10$\mu\textrm{m}$ particles the maximum bulk density of packing was 55% of theoretical value and that of compacts made at the pressure of 4, 255 kg./$cm^2$ (60 kpsi) was 73% of theoretical value. (5) In the ternary system with three sizes the maximum bulk density of packing was 1.43 g/$cm^3$and that of compacts was 1.80g/$cm^3$which is equivalent to 77.6% of theoretical value. The composition of the closest compact was consisted of 50% of 40-53$\mu\textrm{m}$ particles 20% of 10-30$\mu\textrm{m}$ particles and 30% of <10$\mu\textrm{m}$ parti-cles.

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Preparation of Silica Monoliths with Macropores and Mesopores and of High Specific Surface Area with Low Shrinkage using a Template Induced Method

  • Guo, Jianyu;Lu, Yan;Whiting, Roger
    • Bulletin of the Korean Chemical Society
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    • v.34 no.2
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    • pp.447-452
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    • 2013
  • In this study we report a new method for the synthesis of a silica monolithic column bed with bimodal pores (throughpores and mesopores). The template induced synthesis method was used to direct bimodal pores simultaneously instead of the usual post base-treating method. Block polymer Pluronic F127 was chosen as a dual-function template to form hierarchically porous silica monolith with both macropores and mesopores. This is a simplification of the method of monolithic column preparation. Poly(ethylene glycol) was used as a partial substitute for F127 can effectively prevent shrinkage during the monolith aging process without losing much surface area (944 $m^2/g$ to 807 $m^2/g$). More importantly, the resultant material showed a much narrower mesopore size (centered at 6 nm) distribution than that made using only F127 as the template reagent, which helps the mass transfer process. The solvent washing method was used to remove the remaining organic template, and it was proved to be effective enough. The new synthesis method makes the fabrication of the silica monolithic column (especially capillary column) much easier. All the structure parameters indicate that monolith PFA05 prepared by the above method is a good material for separation, with the merits of much higher surface area than usual commercial HPLC silica particles, suitable mesopore volume, narrow mesopore size distribution, low shrinkage and it is easily prepared.

A Study on the Application of Physical Soil Washing Technology at Lead-contaminated Shooting Range in a Closed Military Shooting Range Area (폐 공용화기사격장 내 납오염 사격장 군부지의 물리적 토양세척정화기술 적용성 연구)

  • Jung, Jaeyun;Jang, Yunyoung
    • Journal of Environmental Impact Assessment
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    • v.28 no.5
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    • pp.492-506
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    • 2019
  • Heavy metal contaminants in the shooting range are mostly present in a warhead circle or a metal fragment present as a particle, these fine metal particles are weathered for a long period of time is very likely that the surface is present as an oxide or carbon oxide. In particular, lead which is a representative contaminant in the shooting range soil, is present as more fine particles because it increases the softness and is stretched well. Therefore, by physical washing experiment, we conducted a degree analysis, concentration of heavy metals by cubic diameter, composition analysis of metallic substances, and assessment of applicability of gravity, magnetism and floating selection. The experimental results FESEM analysis and the measurement results lead to the micro-balance was confirmed thatthe weight goes outless than the soil ofthe same size in a thinly sliced and side-shaped structure according to the dull characteristics it was confirmed that the high specific gravity applicability. In addition, the remediation efficiency evaluation results using a hydrocyclone applied to this showed a cumulative remediation efficiency of 71%,twice 80%, 3 times 91%. On the other hand, magnetic sifting showed a low efficiency of 17%,floating selection -35mesh (0.5mm)target soil showed a relatively high efficiency to 39% -10mesh (2mm) efficiency was only 16%. The target treatment diameter of soil washing should be 2mm to 0.075mm, which is applied to the actual equipment by adding an additional input classification, which would require management as additional installation costs and processes are constructed. As a result, it is found that the soilremediation of shooting range can be separately according to the size of the warhead. The size is larger than the gravel diameter to most 5.56mm, so it is possible to select a specific gravity using a high gravity. However, the contaminants present in the metal fragments were found to be processed by separating using a hydrocyclone of the soil washing according to the weight is less than the soil of the same particle size in a thinly fragmented structure.

Phenanthrene Uptake by Surfactant Sorbed on Activated Carbon (활성탄에 흡착된 계면활성제에 의한 Phenanthrene 흡착)

  • Ahn, Chi-Kyu;Woo, Seung-Han;Park, Jong-Moon
    • Journal of Soil and Groundwater Environment
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    • v.13 no.2
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    • pp.1-11
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    • 2008
  • Phenanthrene uptake by surfactant sorbed on activated carbon was investigated to recycle of surfactant in washed solution for contaminated soil. The partitioning of phenanthrene to the activated carbon coating with Triton X-100 as a surfactant was also evaluated by a mathematical model. Phenanthrene-contaminated soil (200 mg/kg) was washed in 10 g/L of surfactant solution. Washed phenanthrene in solution was separated by various particle loadings of granular activated carbon through a mode of selective adsorption. Removal of phenanthrene was 99.3%, and surfactant recovery was 88.9% by 2.5 g/L of granular activated carbon, respectively. Phenanthrene uptake by activated carbon was greater than that of phenanthrene calculated by a standard model for a system with one partitioning component. This is accounted for enhanced surface solubilization by hemi-micelles adsorbed onto granular activated carbon. The effectiveness factor is greater than 1 and molar ratio of solubilization to sorbed surfactant is higher than that of liquid surfactant. Results suggest that separation of contaminants and surfactants by activated carbon through washing process in soil is much effective than that of calculated in a theoretical model.