Magnetically separable and reusable zinc ferrite/reduced graphene oxide ( ZnFe2O4/rGO) nanocomposite has been prepared by hydrothermal method. The results illustrate that the construction of ZnFe2O4 and rGO occur concurrently in a hydrothermal reaction that initiates the formation of rGO-wrapped ZnFe2O4 nanospheres. The morphological and structural features of the ZnFe2O4/ rGO nanocomposites reveal that the rGO nanosheets anchored to the ZnFe2O4 sphere act as a self-protective clamping layer to avoid the photo corrosion effect under photo irradiations. The nanocomposites express the soft magnetic behavior with high saturation magnetization under annealing temperature at 300 °C, which may attribute to the well-defined crystalline structure and surface defects. In addition, the GZF 300 nanocomposites exhibit the enhanced photocatalytic degradation over Rhodamine B dye which is 3.4, 1.15, and 1.32 times higher than that of ZF, GZF, and GZF 600 over under visible irradiation in 120 min. The GZF 300 nanocomposites demonstrate their ability to degrade RhB efficiently, even after several photocatalysis cycles with high catalyst recovery by its magnetically separable behavior. The high densities of oxygen defects improvise electron transfer from ZnFe2O4 to rGO and delay the recombination process of the nanocomposite, resulting in enhanced visible photocatalytic activity. The strong magnetic properties of rGO wrapped ZnFe2O4 nanocomposite catalysts the easy separation from the suspension system for multiple usages in water treatment.

단순 침전법으로 제조한 CdZnS/ZnO 광촉매를 이용하여 가시광선하에서 메틸렌블루의 광분해 반응에 대한 연구를 수행하였다. X선 회절분석법과 UV-vis 확산반사 분광법 등을 이용하여 제조된 촉매들의 물리화학적 특성을 분석하였다. 그리고 CdZnS/ZnO 광촉매의 활성을 조사하고 CdS 및 TiO2와 비교 검토하였다. CdZnS/ZnO 광촉매는 자외선뿐만 아니라 400nm에서 600nm 범위의 가시광선 영역에 있어서도 우수한 광흡수 특성을 나타내었다. 가시광선하에서 메틸렌 블루의 광분해 반응에 대해서 CdZnS/ZnO 광촉매는 CdS 와 TiO2 보다 우수한 광촉매 활성을 나타내는 것을 알 수 있었다. 그리고 가시광선하에서의 메틸렌블루의 광분해 반응에는 광촉매 반응뿐만 아니라 감광반응도 관여하고 있음을 확인할 수 있었다.

This study aimed to investigate growth rate and nutrient consumption of Chlorella vulgaris according to different light irradiation interval. Applied light irradiation intervals were 12 hr, 4 hr, 1 hr, and 1 min. The light source was flexible LED(Blue:Red=1:1), light intensity was 200 PPFD and Light/Dark cycle was 1:1. As a result, growth rate and nutrient removal efficiencies showed no significant differences depending on the light irradiation interval. Considering the reproduction characteristics of applied microalgae cultures of this study, this is thought to be one of the possible reasons of above results. Because Chlorella vulgaris performs an asexual reproduction and it is known that there is no significant relationship between light irradiation interval and growth rate, including nutrient consumption in case of asexual reproduction.

본 연구는 수출 과정에서 UVA + LED처리가 절화백합의 품 질과 수명에 미치는 영향을 알아보고자 저장·수송 과정별 시 뮬레이션 실험을 수행하였다. 실험재료는 오리엔탈 백합 ‘Siberia’를 사용하였으며, 이 때 절화는 습식조건으로 증류수와 상업용 절화보존제(Chrysal SVB, 1/3 tablet/L)를 처리하였다. 동시에 UVA가 혼합된 청색(448nm), 적색(634nm과 661nm) LED를 3일간 처리하였고, 봄철과 여름철 일본 수출 환경과 동 일한 조건으로 생장상의 환경을 설정하였다. 그 결과, 수송 과정 중 수확 후부터 경매단계까지는 봄철에 비해 여름철이 꽃의 크 기가 크고, 상대 생체중과 수분 흡수율은 높았다. 경매 후 상대 생체중, 수분 흡수율, 잎의 엽록소 함량 등은 봄철이 높았으며, 인공광원 처리 유무에 따른 절화 품질은 처리간 유의적 차이가 없었다. 봄철과 여름철의 절화수명은 증류수와 절화보존제 처 리구에 비해 UVA + LED를 조사한 처리구에서 연장되었다. 봄 철 절화수명은 증류수 처리 18일, 절화보존제 처리 22일, UVA + Red LED 처리 22.5일로 나타났으며 UVA + Blue LED처리가 25.3일로 다른 처리에 비해 2~7일 연장되었다. 여름철 절화수명 은 증류수와 절화보존제 처리 16일, 적색 LED 처리 18일, 청색 LED 처리가 20일로 나타났다. 결론적으로 절화수명은 청색 LED 처리에서 절화 수명 연장 효과가 확인되었다.

SnS-TiO2 nanocomposites are synthesized using simple, cheap, and less toxic SnCl2 as the tin (II) precursor. The prepared nanoparticles are characterized using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectra (DRS). The XRD and TEM results indicate that the prepared product has SnS nanoparticles and a grain diameter of 30 nm. The DRS demonstrate that SnS-TiO2 possesses the absorption profile across the entire visible light region. The generation of reactive oxygen species is detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). It is found that the photocurrent density and photocatalytic effect increase with the modified SnS. Excellent catalytic degradation of Texbrite BA-L (TBA) solution is observed using the SnS-TiO2 composites under visible light irradiation. It is proposed that both the strong visible light absorption and the multiple exciton excitations contribute to the high visible light photocatalytic activity.

식물공장 내 적색광, 청색광, 적청 혼합광, 자외선, 적외선, 형광등의 광원을 달리하여 어린잎 상추의 생육과 무기성분 흡수를 검토하였다. 잎의 형태는 Red 파장에서 초장 및 하배축의 길이신장이 촉진되어 도장하였고 Far red에서는 생장이 불가능하였으나 Red + Blue의 혼합광원에서는 초장이 짧고 엽수가 많고 생체중이 증가하여 상추의 형태 및 발달 차원에서 유의적으로 좋았다. 광질에 따른 어린잎 상추의 색차 및 상대 엽록소 함량을 조사한 결과, 적색도를 나타내는 Hunter a* 값은 Red + Blue 혼합광 및 형광등에서 높았고 적색광 및 자외선에서는 낮게 나타났는데 상대 엽록소 함량을 나타내는 SPAD도 같은 경향이었다. 특히 상대엽록소 함량은 형광등의 10.5에 비해 혼합광에서 1.8배 향상된 적색도를 나타내었다. 광원별 상추의 무기물 함량을 조사한 결과, pH 및 K 함량은 모든 처리에서 차이가 없었으나 N, Ca, Mg, Mn, Fe, Ascorbic acid 함량은 LED 처리구에서 많았고 P 및 Mn 함량은 형광등 처리구에서 많았다. 이상의 결과를 요약하면 단색광에 비하여 Red + Blue 혼합광에서 상추의 생육이 우수하고 무기물 함량이 증대되어 식물공장 내 생산성 향상을 위해서는 혼합광 조절로 상품성 있는 고품질의 상추 생산이 가능 할 것으로 생각되었다.

Peri-implantitis (PI) is bacteria-induced inflammatory condition which affects the alveolar bone and soft tissue around implants and may result in the loss of supporting bone. Attenuation of the P. gingivalis lipopolysaccharide (LPS)-induced inflammatory response can be a new therapeutic approach in the treatment of PI. This study was conducted to evaluate the anti-inflammatory effect of 635-nm light-emitting diode (LED) irradiation over MG63 osteoblast-like cell. Scratch was made on MG63 cells with or without LPS, then 635-nm irradiated. The expression of the cyclooxygenase-2 (COX-2) proteins was evaluated with western blot. The production of the prostaglandin E2 (PGE2) and expression of the receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG) was measured with enzyme-linked immunoassay, and the cytokine profile was evaluated with the human inflammation antibody array. Wound closure effect presented in the cells treated with LPS was observed more significantly in the cells with 635-nm irradiation than the cells without irradiation. The 635-nm irradiaiton reduced LPS-induced expression of the COX-2 and production of the PGE2. Also, 635-nm irradiation affect the expression of RANKL, OPG, and proinflammatory cytokines. These results indicate that 635-nm irradiation could reduce the alveolar bone resorption induced by LPS stimulation through the inhibition of COX-2 expression and PGE2 production, the suppression of proinflammatory cytokine, and the modulation of RANKL/OPG balance in MG63 cells.

AC and ZnS modified TiO2 composites (AC/ZnS/TiO2) were prepared using a sol-gel method. The composite obtained was characterized by Brunauer-Emmett-Teller (BET) surface area measurements, X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, scanning electron microscope (SEM) analysis, and according to the UV-vis absorption spectra (UV-vis). XRD patterns of the composites showed that the AC/ZnS/TiO2 composites contain a typical single and clear anatase phase. The surface properties as observed by SEM present the characterization of the texture of the AC/ZnS/TiO2 composites, showing a homogenous composition in the particles showing the micro-surface structures and morphology of the composites. The EDX spectra of the elemental identification showed the presence of C and Ti with Zn and S peaks for the AC/ZnS/TiO2 composite. UV-vis patterns of the composites showed that these composites had greater photocatalytic activity under visible light irradiation. A rhodamine B (Rh.B) solution under visible light irradiation was used to determine the photocatalytic activity. The degradation of Rh.B was determined using UV/Vis spectrophotometry. An increase in the photocatalytic activity was observed. From the photocatalytic results, the excellent activity of the Y-fullerene/TiO2 composites for the degradation of methylene blue under visible irradiation could be attributed to an increase in the photo-absorption effect caused by the ZnS and to the cooperative effect of the AC.

LED 보광이 파프리카의 착과와 생육에 미치는 영향을 구명하기 위해 파프리카 생육기간동안 일몰 후부터 5시간 동안 red(660nm), blue(460nm) red + blue(4 : 1)광을 작물의 50cm 상단에서 조사하였다. 광원별 광합성유효광량자속(PPF)은 red광 79μmol·m-2·s-1, blue광 75μmol·m-2·s-1, red + blue광 102μmol·m-2·s-1였다. 파프리카 엽온은 LED 보광한 것이 무보광에 비하여 높았는데 blue광에서 가장 높았다. 한편 과실 온도는 무보광한 것이 가장 높았으며 엽온보다는 낮은 경향이었다. 파프리카 초장은 무보광에서 가장 길었고 blue LED에서 가장 짧았다. 잎 크기는 무보광에 비해 LED 보광한 것이 컸다. 과실무게는 LED 보광한 것이 무거웠으나 주당 과실 수와 상품과 수량은 무보광에 비해 적었다.

분리막을 이용한 수처리 공정에서 유입 수에 함유된 부유물질이나 기타 오염물질이 막 표면 또는 내부에 축적 흡착 등의 막 오염현상으로 인해 막 성능 감소와 함께 막 분리 공정에 큰 영향을 미치게 된다. 본 연구에서는 막 표면에서의 막 오염현상을 실시간으로 모니터링 할 수 있는 기술을 연구하였다. 투명한 오염물질에 의한 분리막 표면 오염을 측정하기 위해 막 표면에 360 nm 파장의 가시광선을 조사하여 이미지를 R. G. B 값으로 추출하여 막의 오염현상을 실시간으로 모니터링 하였다. 추출된 이미지 중 400~499 nm 파장영역인 B 값이 가장 강도가 강하게 나타났다. 막 오염정도의 변화를 이미지의 강도 차이로 관찰함으로써 실시간 분석이 가능함을 확인하였다.

Intracellular reactive oxygen species(ROS) produced in a various pathologic state was known to intermediate many cellular response such as inflammation. Recently, low level light irradiation by HeNe laser used in many clinical field could improve inflammatory state by scavenging intracellular ROS through photo-detachment/dissociation process. The purpose of this study is to investigate the differential effects of blue and red light irradiation on ROS scavenging effects. Immortalized human oral keratinocyte HaCat cells were used. Phorbol 12-myristate 13-acetate(PMA) was treated for inflammation. Red(635nm) and blue(470nm) light irradiation was carried out. To asses the intracellular ROS by light irradiation, confocal microscopic and flow cytometric assay with DCF fluorescence for total ROS and ESR spectrometry of DMPO-O2 - for superoxide anion were caried out. And microarray was performed for mRNA expression level. Released intracellular total ROS in PMA treated HaCat cell lines was dissociated efficiently by red light irradiation, while blue light irradiation did not. Rather, blue light irradiation increased ROS formation. For superoxide anion generated the first synthetic form of ROS, red light irradiation reduced its amount but blue light irradiation did not. In the mRNA expression in line with cyclooxygenase(COX) pathway, prostagrandin endoperoxide synthase 1(PTGS 1), prostagrandin endoperoxide synthase 2(PTGS 2) and phospholipase A2(PLA2) were increased by both light irradiation and they were decreased as time flows. And genes associated with ROS releasing, mRNA expressions of tumor necrosis factor receptor (TNFR) and interleukin 1beta(IL1B) were increased by 1 hour red light irradiation but did not by blue light irradiation. As a result, red and blue light irradiation showed different response in affecting the level of ROS. These findings indicate that red light rather than blue light is more useful for anti-inflammation in clinical field

본 연구는 저광 조사 저온 저장 중 광합성유효방사(PAR)내의 각 파장이 토마토 묘의 형태와 엽색 변화에 미치는 영향을 조사하기 위하여 실시되었다. 10±0.5℃의 온도와 피크 파장이 각각 405, 450, 505, 545, 600, 645, 680, 700nm의 발광다이오드로부터 조사된 3μmol m-2s-1의 광합성유효광량 자속밀도 조건에서 토마토 접목묘를 28일간 저장하였다. 405, 450, 505nm의 파장에서 저장된 묘의 잎은 다른 파장에서 저장된 잎에 비해 직립하는 경향을 보였으며, 특히 450과 505nm 파장에서 저장된 묘의 경우 엽축 생장이 억제되면서 콤팩트한 형태를 보였다. 파장의 변화에 따른 엽색의 규칙적인 변화는 저장 전후를 비교하여 관찰되지 않았으나, 405와 700nm 파장에서 저장된 묘는 엷은 녹색을 나타내었다. 저광 조사 저온 저장 중, 450~545nm 영역의 광조사는 토마토 묘의 직립을 유도하여 외관상 건강한 묘로 인정 받는데 기여할 것으로 기대된다.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotion of wound healing have been well known, there are few reports about molecular mechanisms associated with wound healing by LED irradiation. The purpose of the present study was to investigate the expression pattern of various extracellular matrix(ECM) molecules in relation to wound healing after LED irradiation on primary human gingival fibroblasts(hGFs) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635 nm, and manufactured that energy density was 5 mW/cm2 on sample surfaces. The hGFs were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 24 and 48 hour after irradiation. To investigate the molecular mechanisms associated with wound healing, we examined the mRNA expression of 6 types of collagens, 7 types of matrix metalloproteinases(MMPs) and 4 types of tissue inhibition of metalloproteinases(TIMPs) after LED irradiation by RT-PCR. The mRNA expression of collagen 4, MMP-3, 9, and 16, and TIMP-3 was influenced by LED irradiation. Generally, the collagen expression of the irradiation group was slightly increased, particularly collagen 4 was significantly increased at 0 hour. The expression of MMP-3 was increased at 0 and 24 hours and MMP-16 was increased at 24 hours, respectively. The expression of MMP-9 was decreased at 0 hour and increased at 24 and 48 hours. The mRNA expression of TIMP-3 was significantly decreased at 24 and 48 hours after irradiation. These results suggest that the altered expression of ECM molecules after LED irradiation may contribute to the accelerated wound healing.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reports about molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examine the molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was 5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanisms associated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclin D1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstrated the percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiated by LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0 hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation, cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cells through transition from S to G2 phase.

LEDs have been shown to be a safe, efficient, light-weight, and less-expensive alternative to heal wound. LED irradiation at the same biostimulatory wavelength of previous laser studies have similar biochemical effects The purpose of present study is to evaluate the effects of wound healing by LED irradiation. Thirty 34-day-old sprague dawley were used for present study. 1.5mm diameter defected holes were formed in both ear lobes of rat by rubber dam punch. 635nm and 890nm irradiation was performed by LED for 2 weeks, followed by histologíc examination staíned with H&E and Masson trichrome. Also, RT-PCR was carried out to find out the mRNA expression level in gingival fjbroblast irradiated by 635nm for 1 hour. In gross exarnination, wound healing was observed in irradiated group comparing to control For microscopic exarnination, repair by connective tissues was filled in defects of irradiated group, while dense cellular bands consisting of fjbroblasts and capi llaries were found at the end of defect in control By staining of masson trichrome, amount of collagens were found in irradiated group. In a result of RT-PCR, mRNA expressions of TGF- ß , MMP-1,3 and Timp-3 were down-regulated in irradiated group comparing with their expression in control group. Taken together, LED irradiation increase the prolifeation and the activity of fibroblasts and down-regualted the TGF-ß , MMP- 1,3 and Timp- 3 mRNA, followed by activation of would healing.

We synthesized the p-nonyloxyazobenzene derivatives with functional structures and carried out this experiments to observe photoisomerization irradiated by alternate lights. We found that it was reversibly induced to cis-trans photoisomerization in several solvents. Spreading solutions for the LB films were prepared in chloroform(1.2×10-2 mmol). As a result, it is found that the absorption spectra of the LB monolayer films was induced to photoisomerization by alternative irradiation lights, temperatures and pH(HCL and NH3), respectively.

Graphene oxide (GO)-titania composites have emerged as an attractive heterogeneous photocatalyst that can enhance the photocatalytic activity of TiO2 nanoparticles owing to their potential interaction of electronic and adsorption natures. Accordingly, TiO2-GO mixtures were synthesized in this study using a simple chemical mixing process, and their heterogeneous photocatalytic activities were investigated to determine the degradation of airborne organic pollutants (benzene, ethyl benzene, and o-xylene (BEX)) under different operational conditions. The Fourier transform infrared spectroscopy results demonstrated the presence of GO for the TiO2-GO composites. The average efficiencies of the TiO2-GO mixtures for the decomposition of each component of BEX determined during the 3-h photocatalytic processes were 26%, 92%, and 96%, respectively, whereas the average efficiencies of the unmodified TiO2 powder were 3%, 8%, and 10%, respectively. Furthermore, the degradation efficiency of the unmodified TiO2 powder for all target compounds decreased during the 3-h photocatalytic processes, suggesting a potential deactivation even during such a short time period. Two operational conditions (air flow entering into the air-cleaning devices and the indoor pollution levels) were found to be important factors for the photocatalytic decomposition of BEX molecules. Taken together, these results show that a TiO2-GO mixture can be applied effectively for the purification of airborne organic pollutants when the operating conditions are optimized.

Agri-food garlic has been recognized as healthful because of its antibacterial, anticancer and antioxidant effects. As such, its consumption is steadily increasing. This study was conducted to amplify the healthful ingredient of garlic, allicin, using light irradiation. The following conclusions were drawn from the investigation of peeled garlic under various conditions like fluorescent lighting, color (green, yellow, blue and red) and ultraviolet light (UV-A, UV-B and UV-C). The allicin content increased most with the 15-second 0.129 W/m2 (40 W) UV-B treatment of the garlic at a 700 mm distance from the light source. At the treatment of the garlic with 126 lx (40W) red light for 24 hours at a 700 mm distance from the light source, its allicin content increased from 15.15±0.25 mg/g to 15.15±0.34 mg/g, for a 10-percent amplification effect. Therefore, it is believed that the healthfulness of garlic can be amplified through irradiation processing of its healthful ingredient, allicin, and the development of its processing unit.

To investigate the effect of culture conditions on growth and ginsenosides accumulation, we cultured the ginseng hairy root under three different media, white light or ultra-violet irradiation. The MS/B5 medium containning MS basal salt and B5 vitamin was good for the growth and ginsenoside accumulation. The light during the culture period of ginseng hairy root was irradiated. The growth was abundant in the ginseng hairy root cultured in dark. But the ginsenosides accumulation was higher than in the ginseng hairy root cultured in the light irradiation. When the ginseng hairy root was cultured in 20 L bioreactor, the ginsenosides accumulation was observed at 34% higher than the hairy root cultured in dark. UV irradiated the ginseng hairy root during the culture period. The long time irradiation of UV was caused decreasing the growth of ginseng hairy root, but the accumulation of ginsenosidess was increased as to the irradiated time.