Controlled Crystal Growth of Two-Dimensional Layered Nanomaterials in Hydrogel via a Modified Electrical Double Migration Method

Gwak, Gyeong-Hyeon,Kwon, Na Kyung,Lee, Won-Jae,Paek, Seung-Min,Kim, So Youn,Oh, Jae-Min The American Chemical Society 2017 CRYSTAL GROWTH AND DESIGN Vol.17 No.12

<P>Layered double hydroxide (LDH) nanomaterials of uniform size and homogeneous distribution are successfully developed in agarose hydrogel through the electrical double migration method. To grow LDH crystals in agarose matrix, both cationic (Ni<SUP>2+</SUP>, Ga<SUP>3+</SUP>) and anionic precursors (OH<SUP>–</SUP> and CO<SUB>3</SUB><SUP>2–</SUP>) of LDH are simultaneously transported from solution to agarose hydrogel through electric potential, resulting in the in situ crystal growth of LDH. X-ray diffraction patterns, X-ray absorption spectra, and high-resolution transmission electron microscopic images confirm that the developed LDH is ∼15 nm in size and had a well-defined crystal structure. Scanning electron microscopy and small-angle X-ray scattering spectroscopy showed homogeneous arrays of LDH nanocrystals along agarose sheets with homogeneous distribution. On the basis of the characterization results, we suggest that crystal nuclei are first developed on the agarose chain, and then LDHs homogeneously grow along sheets of agarose matrix.</P><P>Layered double hydroxides (LDHs) of uniform size and homogeneous distribution are developed in agarose hydrogel through the electrical double migration method. Developed LDH had a well-defined crystal structure and homogeneous arrays along agarose sheets with homogeneous distribution. Thus, we suggest that crystal nuclei are first developed on the agarose chain, and then LDHs homogeneously grow along sheets of agarose matrix.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cgdefu/2017/cgdefu.2017.17.issue-12/acs.cgd.7b01252/production/images/medium/cg-2017-01252b_0009.gif'></P>

Identification and characterization of Dunaliella salina OH214 strain newly isolated from a saltpan in Korea

Minjae, Kim,Hyeon Jun, Oh,Khanh, Nguyen,EonSeon, Jin The Korean Society of Phycology 2022 ALGAE Vol.37 No.4

Carotenoids are effective antioxidants that are found in various photosynthetic organisms. Marine microalgae are an advantageous bioresource for carotenoid production because they do not compete with other crops for freshwater and arable land. This study reports a newly isolated Dunaliella strain from the Geumhong Saltpan on Yeongjong Island, West Sea, Korea. The new strain was isolated and classified as Dunaliella salina through phylogenetic analysis and was named the OH214 strain (Deposit ID: KCTC14434BP). The newly isolated strain can survive in a wide range of NaCl concentrations (0.3-5.0 M NaCl), but grows well in 0.6 to 1.5 M NaCl culture medium. Under high-light conditions (500 ± 10 μmol photons m^-2 s^-1), the cells accumulated three times more β-carotene than under low-light conditions (50 ± 5 μmol photons m^-2 s^-1). The cells accumulated 2.5-fold more β-carotene under nitrogen-deficient (1 mM KNO₃) conditions (3.24 ± 0.36 ㎍ 10⁶ cells^-1) than in nitrogen-sufficient conditions (>5 mM KNO₃). The lutein content under nitrogen-deficient conditions (1.73 ± 0.09 ㎍ 10⁶ cells^-1) was more than 24% higher than that under nitrogen-sufficient conditions. Under the optimized culture condition for carotenoid induction using natural seawater, D. salina OH214 strain produced 7.97 ± 0.09 mg g DCW^-1 of β-carotene and 4.65 ± 0.18 mg g DCW^-1 of lutein, respectively. We propose that this new microalga is a promising strain for the simultaneous production of β-carotene and lutein.

Electrophoretic Preparation of an Organic–Inorganic Hybrid of Layered Metal Hydroxide and Hydrogel for a Potential Drug‐Delivery System

Gwak, Gyeong‐,Hyeon,Paek, Seung‐,Min,Oh, Jae‐,Min Wiley-VCH 2012 European journal of inorganic chemistry Vol. No.

<P><B>Abstract</B></P><P>We have prepared organic–inorganic hybrid materials consisting of layered metal hydroxides and hydrogel polymers for potential use as a drug delivery system. The hybrid materials were synthesized by an electrophoretic method; anionic precursors, OH<SUP>–</SUP>/CO<SUB>3</SUB><SUP>2–</SUP>, and cationic metal Zn<SUP>2+</SUP> were migrated into hydrogel by applying an electrical potential of 25 V for 20 min to form inorganic nanocrystals inside the hydrogel matrix. Hydrozincite [Zn<SUB>5</SUB>(OH)<SUB>8</SUB>(CO<SUB>3</SUB>)] nanoparticles, a kind of layered metal hydroxide, were determined to develop inside the hydrogel according to powder X‐ray diffraction, FTIR, and X‐ray absorption spectroscopy. Scanning electron microscopic images showed that the prepared hybrid materials have well‐dispersed inorganic nanoparticles in the hydrogel matrix. In order to evaluate the potential of the thus prepared hybrid materials as a drug‐delivery system, the well‐known antioxidant ferulic acid was incorporated and their time‐dependent release profile was obtained by HPLC.</P>

수산화칼슘 처리된 Porphyromonas endodontalis Lipopolysaccharide가 다형핵백혈구의 IL-1과 TNF-α 생성에 미치는 영향에 관한 연구

박찬제,박동성,유현미,오태석,임성삼 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.5

Bacterial lipopolysaccharide (LPS) plays a major role in stimulating the synthesis and release of the principal osteoclast-activating cytokines , namely, interleukin 1 and tumor necrosis factor-α from immune cells, Although monocytes/macrophages are the main producers of these cytokines, recent evidence has indicated that polymorphonuclear leukocytes (PMN) have the ability to release IL-1 and TNF-α. Calcium hydroxide has been shown to be an effective medicament in root canal infectionsm, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of Ca(OH)_2 may also be the result of direct inactivation of LPS. The purpose of this study was to investigate whether treatment of Porphyromanas endodonatalis LPS with calcium hydroxide alters its biological action as neasured by human PMN secretion of IL-1 and TNF-α, and it was compared with Escherichia coli LPS. P.endodonatalis ATCC 35406 was cultured in anaerobic condition, and LPS was extracted using the hot-phenol water extraction method and purified. Purchased E. coli LPS was also purified . 100 ㎍/ml of each LPS in pyrogen free water were incubated with 25mg/ml Ca(OH)_2 at 37℃ for 7 days. The supernatants were subjected to ultrafiltration. And the isolates were lyophilized and weighed. PMNs were obtained from peripheral blood by centrifugation layered over Lymphoprep. The cells were resuspended (4 × 10^6 cells/ml) in RPMI 1640 followed by treatment with various concentrations of LPS (0, 0.1, 1, 10㎍/ml) for 24 hours at 37℃ in 5% CO_2 incubator. The supernatants of cells were collected and the levels of IL-1α, IL-1β and TNF-α were measured by enzyme-linked immunosorbent assay. The results were as follows; 1. The levels of IL-1α, IL-1β, TNF-α from PMN treated with each LPS were significantly higher than those released from unstimulated PMN of the control group (p<0.05). 2. The levels of all three cytokines released from PMN stimulated with each calcium hydroxide treated LPS were significantly lower than those released from PMN stimulated with each untreated LPS (p<0.05). while they were not significantly different from those released from unstimulated PMN of the control group (p>0.05). 3. The levels of secretion or all three cytokines were affected in a dose-dependent manner in PMN stimulated with each LPS (p<0.05), but not in PMN stimulated with each calcium hydroxide treated LPS (p>0.05). 4. The levels of all three cytokines released from PMN stimulated with P.endodontalis LPS were significantly lower than those released from PMN stimulated with E. coli LPS (p<0.05).

pH, 이온종류 및 농도, 퇴적물의 성분에 따른 하천 내 불소의 거동특성

이동민(Dong Min LEE),주광진(Kwang Jin Joo),최이송(ISong Choi),장광현(Kwang Hyeon Chang),오종민(Jong Min Oh) 응용생태공학회 2018 Ecology and resilient infrastructure Vol.5 No.1

하천에 유입된 오염물질은 다양한 환경 조건에 의하여 수체 및 퇴적물의 상호작용에 따라 수체의 수질에 영향을 미친다. 특히 최근 수체의 수리학적 체류시간이 상대적으로 긴 정체수역 내에서는 퇴적물의 축적량이 증가하고 있어 퇴적물과 수체 내에서의 물질적 거동특성 파악은 중요한 수질적 관점 요소이다. 본 연구에서는 하천 내 pH, 이온종류 및 농도, 퇴적물의 점토함량에 따라 불소의 거동이 어떻게 변화하는지 검토하기 위하여 경기도에 위치한 중소하천을 대상으로 조건별 실험을 실시하였다. pH에 따른 흡착 및 용출특성 실험결과, pH가 높을수록 불소의 흡착량이 감소하였고, 용출되는 불소량은 증가하는 경향을 나타냈다. 이온농도 및 종류에 따른 흡착 및 용출특성 실험결과, Cl<SUP>-</SUP>, SO₄<SUP>2-</SUP> 이온은 불소의 흡착능에 큰 영향을 주지 않는 것으로 나타났으나, 불소와의 활발한 이온경쟁효과를 지닌 OH<SUP>-</SUP>와의 반응에서는 흡착량이 줄고, 용출량이 늘었음을 알 수 있었다. 퇴적물의 성분에 따른 흡착 및 용출특성 실험 결과 상대적으로 입경이 작은 Silt와 Clay 성분이 많이 포함된 시료에서 불소의 흡착량이 많고 용출되는 불소량이 줄어드는 것을 알 수 있었다. 이는 수체의 환경조건이 퇴적물 내 불소의 흡착 및 용출에 크게 영향을 미치기 때문에, 퇴적물 내 불소를 적절하게 관리하기 위해서는 수체의 환경조건에 대한 이해가 선행되어야 한다는 것을 의미한다. Water quality is affected by the pollutants flowing into rivers since the interaction between water bodies and sediments in various environmental conditions. Especially, accumulation of sediments increases in the stagnant water areas due to a relative long hydrological retention time in the water bodies. Therefore, it is an important factor of water quality to understand characterization of the material behavior in water bodies and sediments. In this study, the objective of the conditional experiments was small and medium sized streams located in Gyeonggi-do. To estimate how the changes of fluoride behavior, depending on the pH, ion type, concentration, and clay contents. The pH results showed a trend that adsorption amount of fluorine decreased and the dissolution of fluorine increased following by pH increasing. The concentration and type of ions results showed that Cl<SUP>-</SUP> and SO₄<SUP>2-</SUP> ions had no significant effect on the adsorption ability of fluorine, the amount of dissolution was increased because OH<SUP>-</SUP> ion had active competition with fluorine in the reaction. The ingredient of sediment results showed that the amounts of fluoride adsorption and dissolution were reduced in samples, which contain relatively large amounts of Silt and Clay components. This means that the environmental conditions of water bodies greatly affect the adsorption and dissolution of fluoride in the sediments, so that proper management of fluoride in the sediments must precede an understanding of the environmental conditions of the water bodies.

올레산의 비율에 따른 아데노신의 경피 투과의 영향

남현빈,정세진,구민석,오예진,김용민,이훈희,윤수정,임정균 순천향대학교 부설 산업기술연구소 2021 순천향 산업기술연구소논문집 Vol.27 No.2

In addition to the development of functional cosmetics, technology to increase percutaneous absorption rate when applied to the skin is an important task. In this experiment, oleic acid was used as a skin absorption promoter, and its effect on transdermal permeability of adenosine was studied and analyzed using a skin-like membrane. As a result of the experiment, it was investigated that the permeability coefficient and concentration of adenosine are proportional to the content of oleic acid. This indicates that a high proportion of oleic acid is effective as a skin absorption promoter.

Xe放電管에 의하여 폄핑된 色素레이저 機構의 分光學的 檢討

吳喆漢,金賢壽 慶北大學校 1985 論文集 Vol.39 No.-

The oscillating mechanism of a dye laser pumped by the Xe discharge tube (flashlamp) has been studied by means of spectral analysis. The spectrum of Xe-pumping light covered fully the absorption spectrum of Rhodamine 6G lasant. The spectrum of the dye laser is appeared within the fluorescence band of the lasant and its peak wavelength is 5990A, which is coincident to the central wavelength of the mirror. Its spectral width is approximately 29A˚. The peak value of laser output pulse is about 38.6W when pumped by the Xe flashlamp with 12KV and 200Torr, and the risetime of the laser pulse is 7㎲ and its FWHM is 9㎲. The laser power is increased linearly as the input energy is increased and the critical input energy (calculated as energy per unit volume of dye cuvette) of the laser sytsem for lasing is about 31.6J/㎤.

作物의 氣象感應에 依한 生育 및 生産性 變動要因 解析(I) : Phenological Response of Two-rowed Barley to Temperature and Photo-period and their Varietal Difference 二條大麥 發育의 氣象反應과 그 品種間 差異

吳現道 제주대학교 1990 논문집 Vol.30 No.-

This study was conducted to investigate relationships between emergence, spikelet and flolet initiations and heading, and climatic factors in five two-rowed barley cultivars sown at the different seasons. The results obtained are summarized as follows; 1. There was a close relationship between the number of days from sowing to emergence and average air temperature. 2. Although differences among cultivars were observed for sensitivity to daylength at the developmental phase from emergence to spikelet initiation, little differences among cultivars was recongnized for the number of days from sowing to heading and sensitivity to daylength at this developmental phase. 3. there were significant differences among cultivars for the number of days from spikelet initiation to heading and much larger differences for the number of days from spikelet initiation to flolet initiation.

유지류의 생육지 기후와 종자중의 지방산, 옥소가와의 관계

오현도 濟州大學校 亞熱帶農業硏究所 1999 亞熱帶農業硏究 Vol.16 No.-

Abstract This study determined the relationship between climate and the fatty acid composition of seeds and the property of oils and fats in 35 oilseed crops grown in tropical, subtropical and temperate zones by analyzing data from published reports. Climate generally affected fatty acid composition of seeds and the property of oils and fats in these crops. Lauric, palmitic, and oleic acids were predominant fatty acids of the tropical oil seed crops and thus the tropical oil seed crops had higher saturated fatty acid content. Unsaturated fatty acid such as linoleic and linolenic acids were main fatty acids of the most temperate oilseed crops and thus the temperate oil seed crops had lower saturated fatty acid content. Because of fatty acid composition, seeds of most tropical oil seed crops were normally low in iodine value and had fat and non-drying/semi-drying oils while those of most temperate oilseed crops had drying oils. There were many woody oilseed crops in tropical zones and many herbaceous oilseed crops in temperate zones. Most woody oilseed crops had lower iodine value compared with herbaceous species.

법랑질에 대한 total etching과 self-etching 접착제의 산부식 효과와 미세인장결합강도

오선경,허복,김현철 大韓齒科保存學會 2004 Restorative Dentistry & Endodontics Vol.29 No.3

The purpose of this study was to evaluate the etching effects and bond strength of total etching and self-etching adhesive system on unground enamel using scanning electron microscopy and microtensile bond strength test. The buccal coronal unground enamel from human extracted molars were prepared using low-speed diamond saw. Scotchbond Multi-Purpose (group SM), Clearfil SE Bond (group SE), or Adper Prompt L-Pop (group LP) were applied to the prepared teeth, and the blocks of resin composite (Filtek Z250) were built up incrementally. Resin tag formation was evaluated by scanning electron microscopy, after removal of enamel surface by acid dissolution and dehydration. For microtensile bond strength test, resin-bonded teeth were sectioned to give a bonded surface area of 1㎟. Microtensile bond strength test was perfomed. The results of this study were as follows. 1. A definite etching pattern was observed in Scotchbond Multi-Purpose group. 2. Self-etching groups were characterized as shallow and irregular etching patterns. 3. The results (mean) of microtensile bond strength were SM; 26.55 MPa, SE; 18.15 MPa, LP; 15.57 MPa. SM had significantly higher microtensile bond strength than SE and PL (p〈0.05), but there was no significant difference between SE and PL.