• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.429-434
• /
• 2021

The feasibility of lecithin as a material for dissolving microneedles to improve skin permeability of drugs and the effect of the composition of lecithin on the mechanical strength, solubility, and skin permeability of rhodamine B (RhB) of the dissolving microneedles were investigated. Dissolving microneedles with needles of uniform shape and size were fabricated with the mold made using the laser-writing technique, simpler and more efficient method compared to the photolithography method, the conventional method to fabricate the microneedle mold. The composition of lecithin in the microneedle affected the mechanical strength and solubility of the needle thus, the mechanical strength of the needle increased as the composition of lecithin in the needle increased, resulting in improving the skin permeability of RhB contained in the microneedles. When comparing the microneedles containing same composition of amylopectin (AP), the skin permeability of RhB of the microneedles containing lecithin was higher. These results indicate that lecithin can be used as a material for dissolving microneedles and the skin permeability of the microneedle could be controlled by changing the composition of lecithin.

• Analytical Science and Technology
• /
• v.36 no.3
• /
• pp.121-127
• /
• 2023

The detection of blood at a crime scene is an important process for identification and case reconstruction. However, blood may be difficult to observe with the naked eye on dark or multi-colored surfaces. Acidic hydrogen peroxide (AHP) is a recently reported blood enhancement reagent that can enhance blood with high sensitivity by increasing the exposure time of the camera. However, it has never been compared to previously known techniques on dark or multi-colored surfaces. For this purpose, the method of observation/photographing (UV and IR photography), alginate casting, leuco rhodamine 6G (LR6G), and AHP were applied to bloody impression on dark or multi-colored surfaces and the results were compared. As a result, blood treated with AHP had a higher contrast to the surfaces than UV and IR photography, and it was applicable on all surfaces, opposed to alginate casting. In addition, AHP successfully enhanced blood on dark or multi-colored surfaces, similar to LR6G.

• Advances in nano research
• /
• v.16 no.1
• /
• pp.41-52
• /
• 2024

In this study, rare-earth orthoferrites LnFeO₃ were synthesized using a facile hydrothermal reaction and their visible-light-induced photo-Fenton degradation of organics was optimized through Ln variation (Ln = La, Pr, or Gd). The morphological, structural, and chemical characteristics of as-prepared samples were examined in detail by using different methods, including XRD, SEM, TEM, XPS, etc. On the other side, under visible light illumination, the photo-Fenton-like catalytic activities of LnFeO₃ were assessed in terms of the removal of selected organic models, i.e., pharmaceuticals (ketoprofen and tetracycline) and dyes (rhodamine B and methyl orange). As compared with PrFeO₃ or GdFeO₃, the sample of LaFeO₃ displayed more structural distortion, larger specific surface area, and narrower band gap, resulting in its higher photo-Fenton-like catalytic activity toward the degradation of organics. In organic-containing solution, in which the initial solution pH = 5, catalyst dosage = 1 g/L and H₂O₂ concentration = 10 mM, 98.2% of rhodamine B, 31.1% of methyl orange, 67.7% of ketoprofen, or 96.4% of tetracycline was removed after 90-min exposure to simulated visible light. Our findings revealed that variation of Ln site on rare-earth orthoferrites was an effective strategy for optimizing their organic removal via visible-light-induced photo-Fenton reaction.

• International Journal of Stem Cells
• /
• v.16 no.1
• /
• pp.93-107
• /
• 2023

Background and Objectives: Chronic periodontitis can lead to alveolar bone resorption and eventually tooth loss. Stem cells from exfoliated deciduous teeth (SHED) are appropriate bone regeneration seed cells. To track the survival, migration, and differentiation of the transplanted SHED, we used super paramagnetic iron oxide particles (SPIO) Molday ION Rhodamine-B (MIRB) to label and monitor the transplanted cells while repairing periodontal bone defects. Methods and Results: We determined an appropriate dose of MIRB for labeling SHED by examining the growth and osteogenic differentiation of labeled SHED. Finally, SHED was labeled with 25 ㎍ Fe/ml MIRB before being transplanted into rats. Magnetic resonance imaging was used to track SHED survival and migration in vivo due to a low-intensity signal artifact caused by MIRB. HE and immunohistochemical analyses revealed that both MIRB-labeled and unlabeled SHED could promote periodontal bone regeneration. The colocalization of hNUC and MIRB demonstrated that SHED transplanted into rats could survive in vivo. Furthermore, some MIRB-positive cells expressed the osteoblast and osteocyte markers OCN and DMP1, respectively. Enzyme-linked immunosorbent assay revealed that SHED could secrete protein factors, such as IGF-1, OCN, ALP, IL-4, VEGF, and bFGF, which promote bone regeneration. Immunofluorescence staining revealed that the transplanted SHED was surrounded by a large number of host-derived Runx2- and Col II-positive cells that played important roles in the bone healing process. Conclusions: SHED could promote periodontal bone regeneration in rats, and the survival of SHED could be tracked in vivo by labeling them with MIRB. SHED are likely to promote bone healing through both direct differentiation and paracrine mechanisms.

• Proceedings of the KSME Conference
• /
• 2007.05b
• /
• pp.2459-2464
• /
• 2007

In present study, a temperature field of specimens which was coated with fluorescence dye such as Rhodamine-B(Rh-B) has been measured, based on the fluorescence intensity. Silica(SiO2) nano porous structure with 1um thickness was constructed on a cover glass, and fluorescence dye was digested into these porous thin films. To optimize manufacturing coating process, various solvents, Rh-B concentration, and other chemical materials were applied to fabricate the specimen and all specimens were measured on the various temperature conditions. For the measurement, a 14 bit cooled CCD camera with 1600 by 1200 spatial resolution is equipped with epifluorescence microscope to obtain only fluorescence intensity from 1.2 mm by 0.9 mm field of view of the illuminated coated specimen.

• Advances in materials Research
• /
• v.2 no.1
• /
• pp.65-75
• /
• 2013

Heterogeneous photocatalysis is a rapidly developing field in environmental engineering. It has a great potential to cope with the increasing pollution in the air. The addition of a photocatalyst to ordinary building materials such as tiles, concrete, paints, creates environmental friendly materials by which air pollution or pollution of the surface itself can be controlled and diminished. This work reports the results of the laboratory research, especially carried out towards air purifying action and self-cleaning measurements. In particular the research was focused on the study of the photocatalytic behavior of industrially prepared tiles produced starting from commercial micro-sized $TiO_2$. Air purification action has been investigated through NOx degradation tests. On the contrary, the degradation of pollution at the surface, also called as self-cleaning action, is verified by the degradation of two different organic dyes: Rhodamine B (red color) and Metanil yellow (yellow).

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.28 no.3
• /
• pp.365-370
• /
• 2004

Simultaneous measurement with PLIF(Planar Laser-Induced Fluorescence) and Stereo-PIV(Stereo Particle Image Velocimetry) was performed to investigate the structural characteristics of flow field in Rushton Turbine Mixer. Instantaneous 3D velocity fields are measured by two 2K${\times}$2K CCD cameras focused on an object plane with the angular displacement methods while the concentration fields are obtained through the measurement of the fluorescence intensity of Rhodamine B tracer excited by the second pulse of Nd:Yag laser light. Image distortion due to the camera view-angle is compensated by a mapping function. Finally, the spatial structures of turbulent flow around Rushton turbine were identified by the calculation of synchronized data of the velocity field and concentration field.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2003.05a
• /
• pp.267-270
• /
• 2003

수용성 양이온 안료인 RhB를 대상으로 분말 $TiO_2$와 고정화 $TiO_2$를 이용하여 색도제거실험을 수행한 결과 다음과 같은 결론을 얻었다. 1) 분말 $TiO_2$의 최적 투입량은 0.2 g/L였으며, 대부분 광촉매 반응에 의하여 제거되었다. 고정화 $TiO_2$의 최적 투입량은 210.7 g/L이었고, 광촉매와 흡착에 의해 제거되었다. Langmuir - Hinshelwood 식으로 표현되지 못하였다. 2) 고정화 $TiO_2$를 이용하여 Rhodamine B를 제거할 경우 광촉매 분리 문제는 해결할 수 있으며, 광 투과율을 증가시킬 수 있으나 같은 제거율을 얻기 위해 투입량이 분말에 비해 매우 높은 것이 문제점으로 나타났다.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.218-218
• /
• 1996

Brazilin은 포도당 수송을 증가시키는 물질로 autooxidation에 의하여 산화되면서 hydrogen peroxide를 생성할 것으로 추정되었으며, hydrogen peroxide는 phosphatase를 억제하여 포도당 수송을 증가시키는 것으로 보고되었다. 따라서 본 실험에서 brazilin의 산화에 의한 hydrogen peroxide의 생성여부를 확인하고 phosphatase 활성에 미치는 braziline의 작용을 살펴보았다. 먼저 UV absorption spectra를 이용하여 brazilin이 반응액중에서 구조적인 변화를 일으키는지 확인하였다. Hydrogen peroxide의 생성은 rhodamine 123를 이용한 형광측정법으로 측정하였으며, phosphatase의 활성은 pH에 따른 phosphatase의 활성을 p-NPP의 탈인산화의 UV 흡광도 변화로 측정하였다. PP2A의 활성은 phosphorylase a를 기질로 하여 측정하였다.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.177-177
• /
• 2006

Copolymers containing oxime-urethane groups, which led to the formation of pendant amino groups photochemically, were applied to a fluorescent image-recording material through the reaction with fluorescamine, a prefluorescent dye for amino groups. This imaging method permits the fluorescent image to be erased or restored by treatment with base or acid. Copolymers containing phthalimide carbamate groups were applied to a bicolor fluorescent imaging material through the consecutive reaction with fluorescamine and rhodamine. A various colored fluorescent micropattern (green, red or red-yellow) was observed through the changes of excitation wavelength by using a conforcal microscope.