• Title/Summary/Keyword: Skin Target Layer

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Implications of using a 50-μm-thick skin target layer in skin dose coefficient calculation for photons, protons, and helium ions

  • Yeom, Yeon Soo;Nguyen, Thang Tat;Choi, Chansoo;Han, Min Cheol;Lee, Hanjin;Han, Haegin;Kim, Chan Hyeong
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1495-1504
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    • 2017
  • In a previous study, a set of polygon-mesh (PM)-based skin models including a $50-{\mu}m-thick$ radiosensitive target layer were constructed and used to calculate skin dose coefficients (DCs) for idealized external beams of electrons. The results showed that the calculated skin DCs were significantly different from the International Commission on Radiological Protection (ICRP) Publication 116 skin DCs calculated using voxel-type ICRP reference phantoms that do not include the thin target layer. The difference was as large as 7,700 times for electron energies less than 1 MeV, which raises a significant issue that should be addressed subsequently. In the present study, therefore, as an extension of the initial, previous study, skin DCs for three other particles (photons, protons, and helium ions) were calculated by using the PM-based skin models and the calculated values were compared with the ICRP-116 skin DCs. The analysis of our results showed that for the photon exposures, the calculated values were generally in good agreement with the ICRP-116 values. For the charged particles, by contrast, there was a significant difference between the PM-model-calculated skin DCs and the ICRP-116 values. Specifically, the ICRP-116 skin DCs were smaller than those calculated by the PM models-which is to say that they were under-estimated-by up to ~16 times for both protons and helium ions. These differences in skin dose also significantly affected the calculation of the effective dose (E) values, which is reasonable, considering that the skin dose is the major factor determining effective dose calculation for charged particles. The results of the current study generally show that the ICRP-116 DCs for skin dose and effective dose are not reliable for charged particles.

In Vitro and In Vivo Studies of Topical Delivery System of Gentisic Acid in Hairless Mice

  • Bian, Shengjie;Zheng, Junmin;Kim, Jung-Sun;Choi, Myeong-Jun;Chung, Ho-Kwon;Lee, Chi-Ho;Kim, Dae-Duk
    • Journal of Pharmaceutical Investigation
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    • v.32 no.3
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    • pp.161-164
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    • 2002
  • Gentisic acid is a skin-whitening agent which inhibits the tyrosinase activity, an essential enzyme in the process of biological synthesis of melanin. Since melanin is synthesized in melanocytes located between the viable epidermis and dermis layer, drug amount delivered into the epidermis/dermis layer can provide valuable information for the biological effect of skin-whitening agents. The purpose of this study was to prepare the gentisic acid patches with 2% dodecylamine as enhancer, and to observe the in vitro skin permeation and in vivo skin deposition of gentisic acid. Gentisic acid in DuroTak 87-2510 patch formulation permeated across hairless mouse skin at the rate of $40.79\;{\mu}g/cm^2/hr$. In vivo study showed that the gentisic acid amount in both the stratum corneum and the viable epidermis/dermis increased with the increase of application time. The amount of gentisic acid in the stratum corneum was higher than that in the epidermis/dermis layer, and was expected to provide a reservoir effect even after removing the patches. Thus, the patch formulation seems to be useful for the topical delivery of skin-whitening agent into the epidermis/dermis layer, the target site.

Region-based Face Makeup using two example face images (두 가지 예제 이미지를 이용한 얼굴 영역 별 메이크업)

  • Lee, Jae-Yoon;Kang, Hang-Bong
    • Journal of Korea Multimedia Society
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    • v.18 no.9
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    • pp.1019-1026
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    • 2015
  • In this paper, we propose a new method of eye, face, and lip makeup techniques on the target face image from several makeup examples without losing detail features such as eyelids, eyebrows, hair. After detection of the feature layer for the skin, we applied our makeup techniques to the target face by using a blending technique. We used a cartoon rendering using bilateral filter. In order to smoothly makeup the target face, we created two Gaussian Weight maps for natural skin makeup effects. Our method did not need to perform complex operations, so the makeup results are so natural. Our experimental results show good performances in various makeups.

MicroRNAs in Human Diseases: From Autoimmune Diseases to Skin, Psychiatric and Neurodegenerative Diseases

  • Ha, Tai-You
    • IMMUNE NETWORK
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    • v.11 no.5
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    • pp.227-244
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    • 2011
  • MicroRNAs (miRNAs) are small noncoding RNA molecules that negatively regulate gene expression via degradation or translational repression of their target messenger RNAs (mRNAs). Recent studies have clearly demonstrated that miRNAs play critical roles in several biologic processes, including cell cycle, differentiation, cell development, cell growth, and apoptosis and that miRNAs are highly expressed in regulatory T (Treg) cells and a wide range of miRNAs are involved in the regulation of immunity and in the prevention of autoimmunity. It has been increasingly reported that miRNAs are associated with various human diseases like autoimmune disease, skin disease, neurological disease and psychiatric disease. Recently, the identification of miRNAs in skin has added a new dimension in the regulatory network and attracted significant interest in this novel layer of gene regulation. Although miRNA research in the field of dermatology is still relatively new, miRNAs have been the subject of much dermatological interest in skin morphogenesis and in regulating angiogenesis. In addition, miRNAs are moving rapidly center stage as key regulators of neuronal development and function in addition to important contributions to neurodegenerative disorder. Moreover, there is now compelling evidence that dysregulation of miRNA networks is implicated in the development and onset of human neruodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Tourette's syndrome, Down syndrome, depression and schizophrenia. In this review, I briefly summarize the current studies about the roles of miRNAs in various autoimmune diseases, skin diseases, psychoneurological disorders and mental stress.

Primary Cilia, A Novel Bio-target to Regulate Skin Pigmentation (바이오 안테나인 일차 섬모 조절을 통한 피부 미백 기술)

  • Choi, Hyunjung;Park, Nokhyun;Kim, Jihyun;Cho, Dong-Hyung;Lee, Tae Ryong;Kim, Hyoung-June
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.1
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    • pp.73-79
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    • 2018
  • The primary cilium protrudes from the cell body like a bio-antenna that has many receptors, channels and signaling molecules to sense and response to external stimuli. The external environment such as ultraviolet irradiation, temperature, humidity, gravity and shear stress always influences skin. Skin responds to external stimuli and differentiates by making melanin, collagen and horny layer. Ciliogenesis participates in developmental processes of skin, such as keratinocyte differentiation and hair formation. And it was reported that skin pigmentation was inhibited when ciliogenesis was induced by sonic hedgehog-smoothened-GLI2 signaling. When skin is exposed to ultraviolet irradiation, alpha-melanocyte stimulating hormones (${\alpha}$-MSH) increase melanin synthesis through activation of the cAMP pathway in melanocytes. We observed that ${\alpha}$-MSH and cAMP production inducers inhibited ciliogenesis of melanocytes. Therefore, we thought that regulation of ciliogenesis is potential candidate target for the development of agents to treat undesirable hyperpigmentation of skin. As a result, we found out that an ethanol extract of Glycyrrhiza glabra (EGG) root and 3,4,5-trimethoxy cinnamate thymol ester (TCTE, Melasolv) significantly inhibit melanin synthesis of normal human melanocyte by inducing primary cilium formation. This study proposed new theory to regulate skin pigmentation and cosmetic components for skin whitening.

Optimization of drag reduction effect of air lubrication for a tanker model

  • Park, Seong Hyeon;Lee, Inwon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.10 no.4
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    • pp.427-438
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    • 2018
  • The reduction of $CO_2$ emissions has been a key target in the marine industry since the IMO's MEPC published its findings in 2009. Air lubrication method is one of the mature technologies for commercialization to reduce the frictional resistance and enhance fuel efficiency of ships. Air layer is formed by the coalescence of the injected air bubbles beyond a certain air flow rate. In this study, a model ship (${\lambda}=33.33$) of a 50,000 ton medium range tanker is equipped with an air lubrication system. The experiments were conducted in the 100 m long towing tank facility at the Pusan National University. By selecting optimal air injector configuration and distribution ratio between two injectors, the total resistance of model $R_{TM}$ was able to be reduced down to 18.1% in the model scale. Key issue was found to suppress the sideway leakage of injected air by appropriate injection parameters.

Average Glandular Dose In Mammography

  • Kim, K.H.;Ryu, Y.C.;Oh, C.H.
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.319-321
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    • 2004
  • The average glandular dose (AGD) is determined by the breast entrance skin exposure, x-ray tube target material, beam quality (half-value layer), breast thickness, and breast composition. Almost breast cancer always arises in glandular breast tissue. As a result, the average radiation absorbed dose to glandular tissue is the preferred measure of the radiation risk associated with mammography. If the normalized average glandular dose is known, the average glandular dose can be computed from the product of the normalized average glandular dose and breast entrance skin exposure. In this study, AGD was calculated by the breast thickness and various x-ray energy (HVL) in 50% glandular 50% adipose breast by Mo.-Rh. assembly. AGD is 84 mrad in compressed 5 cm breast. These results show that as increasing the breast thickness, dose also increases. But as increasing the x-ray tube voltage, dose decreases because of high penetrating ratio through the object. But high tube voltage is reducing the subject contrast. From this result, we have to consider the trade-off between subject contrast of image and dose to the patient and choose proper x-ray energy range.

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A Study on the Lubricating Air-layer Detection Techniques with Digital Image Analysis in Flat Plate Air Lubrication Test (공기윤활평판실험에서 디지털 영상분석을 통한 윤활공기막 검출기법)

  • Park, SeongHyeon;Lee, Inwon
    • Journal of the Korean Society of Visualization
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    • v.14 no.1
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    • pp.27-32
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    • 2016
  • The reduction of $CO_2$ emissions has been a key target in the Marine Industry since the IMO's Marine Environment Protection Committee published its findings in 2009. The representative emission index is termed as the EEDI (Energy Efficiency Design Index) for the new ships. Among various flow control techniques ever proposed, the air lubrication method is the one of most promising one in terms of practical applicability. The present study examines the basic characteristics of the flat plate test with intention of applying the air lubrication technology to the reduction of the resistance of a ship. Image analysis technique is proposed as a tool to quantify the effectiveness of the air lubrication method.

Efficiency on the Field Edge Block which was used at Junction Field of Head & Neck Cancer in the Radiotherapy (두경부 종양의 방사선치료 시 접합 조사야에 사용된 조사면 끝단 차폐물의 유용성)

  • Lee, Jae-Seung;Kim, Jung-Nam
    • The Journal of the Korea Contents Association
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    • v.8 no.11
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    • pp.235-241
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    • 2008
  • If the target volume cannot be included with one field at head and neck cancer, we commonly used two or more field. It is very important to irradiate uniform dose at junction area of the fields. However, according to body shape of patient or general condition of patient, skin junction area can be matched incorrect, So overdose area or underdose area can be appeared in the junction area. This study researched therapy technique which can give uniform dose at skin junction owing to applying the edge block of lateral field at head and neck cancer. We measured the changed distance and rotational angle between central line of anterior supraclavicle lymph node and low margin of right lateral field on simulation process using the shielding block of variable rotation. As a result, the changed distance between central line of anterior supraclavicle lymph node and low margin of right lateral field was below 2mm to ${\pm}$10cm distance at central line of Y axis, changed angle was average 1.28 degree. But by using it the shielding block of variable rotation, the incorrect match at junction can be minimized. We think that this technique is very efficient one to apply this technique at head and neck cancered by the movement of organs can be not included, Therefore we have to pay attention on the process to imput MLC layer

A Multicenter Noncomparative Clinical Study on Midface Rejuvenation Using a Nonabsorbable Polypropylene Mesh: Evaluation of Efficacy and Safety

  • Pak, Chang Sik;Chang, Lan Sook;Lee, Hobin;Jeong, Jae Hoon;Jeong, Jinwook;Yoon, Eul-Sik;Heo, Chan Yeong
    • Archives of Plastic Surgery
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    • v.42 no.5
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    • pp.572-579
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    • 2015
  • Background Facial rejuvenation can be achieved using a variety of techniques. Since minimally invasive procedures for face lifting have become popular because of their convenience and short operating time, numerous minimally invasive surgical procedures have been developed. In this study, a nonabsorbable polypropylene mesh is introduced as a new face lifting instrument, with the nasolabial fold as the main target area. In this paper, we report the efficacy and safety of a polypropylene mesh in midface rejuvenation. Methods Thirty-three subjects with moderate-to-severe nasolabial folds were enrolled from two medical institutions for a noncomparative single-sample study. A mesh was inserted above the superficial muscular aponeurotic system layer, reaching the nasolabial folds through a temporal scalp incision. After 3 weeks, the temporal end of the mesh was pulled to provide a lifting effect. Then, the mesh was fixed to the deep temporal fascia using nonabsorbable sutures. To evaluate efficacy, we compared the scores on the Wrinkle Severity Rating Scale and a visual analog scale for patient satisfaction between the baseline and 7 weeks postoperatively. In addition, we evaluated safety based on the incidence of adverse events. Results The treatment was deemed effective at improving wrinkles in 23 of 28 cases, and patient satisfaction improved significantly during the study period. There were seven cases of skin or subcutaneous tissue complications, including edema and erythema, but there were no suspected serious adverse events. Conclusions Face lifting using a nonabsorbable mesh can improve nasolabial folds without serious adverse effects. Thus, this technique is safe and effective for midface rejuvenation.