• Title/Summary/Keyword: radiation/induce

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Radiative Properties of Greenhouse Gases, Aerosols and Clouds in Korea

  • Moon, Yun-Seob;Bang, So-Young;Oh, Sung-Nam
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.51-54
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    • 2003
  • We analyzed radiative properties of aerosols, $CO^{2}$ and clouds using Optical Properties of Aerosols and Clouds(OPAC) and the Column Radiation Model (CRM). From OPAC, if the soot component is disregarded, dust-like components depict the highest extinction values in the solar spectral range and the lowest. single scattering albedoes, which are attributable to the presence of large particles. In the dust aerosol, the high absorptivity in the infrared may induce a warming of the lower atmospheric layer in the nighttime. The radiative properties of aerosols, clouds and double $CO^{2}$ using the CRM model at Seoul (37N, 127.4 E) on 3 April 2003 were calculated. The solar zenith angle is 65˚ and the surface albedo is 0.1836 during the clear day. The aerosol optical depth change 0.14 to 1.7, which is derived during Asian dust days in Korea. At this time, abedo by aerosols is considered as 0.3. In cloudy condition, the short wave cloud forcing on both the TOA and the surface is -193.89 $Wm^{-2}$ and -195.03 $Wm^{-2}$, respectively, and the long wave cloud forcing is 19.58 $Wm^{-2}$ and 62.08 $Wm^{-2}$, respectively. As a result, the net radiative cloud forcing is -174.31 $Wm^{-2}$ and -132.95 $Wm^{-2}$, respectively. We calculate also radiative heating rates by double $CO^{2}$ during the clear day. The $CO^{2}$ volumn mixing ratio is 3.55E-4.

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Pemetrexed Induces G1 Phase Arrest and Apoptosis through Inhibiting Akt Activation in Human Non Small Lung Cancer Cell Line A549

  • Wu, Dong-Ming;Zhang, Peng;Xu, Guang-Chao;Tong, Ai-Ping;Zhou, Cong;Lang, Jin-Yi;Wang, Chun-Ting
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1507-1513
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    • 2015
  • Pemetrexed is an antifolate agent which has been used for treating malignant pleural mesothelioma and non small lung cancer in the clinic as a chemotherapeutic agent. In this study, pemetrexed inhibited cell growth and induced G1 phase arrest in the A549 cell line. To explore the molecular mechanisms of pemetrexed involved in cell growth, we used a two-dimensional polyacrylamide gel electrophoresis (2-DE) proteomics approach to analyze proteins changed in A549 cells treated with pemetrexed. As a result, twenty differentially expressed proteins were identified by ESI-Q-TOF MS/MS analysis in A549 cells incubated with pemetrexed compared with non-treated A549 cells. Three key proteins (GAPDH, HSPB1 and EIF4E) changed in pemetrexed treated A549 cells were validated by Western blotting. Accumulation of GAPDH and decrease of HSPB1 and EIF4E which induce apoptosis through inhibiting phosphorylation of Akt were noted. Expression of p-Akt in A549 cells treated with pemetrexed was reduced. Thus, pemetrexed induced apoptosis in A549 cells through inhibiting the Akt pathway.

A Study on Calibration of Neutron Moisture Gauge Using MCNP4A (MCNP4A 전산코드를 이용한 중성자 수분함량 측정기의 교정식 및 교정상수 도출방법 연구)

  • Whang, Joo-Ho;Lim, Chun-Il;Song, Jung-Ho
    • Journal of Radiation Protection and Research
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    • v.22 no.4
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    • pp.289-298
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    • 1997
  • Time-consuming experiments have been required in the development of neutron moisture gauge to induce a relation between the water content in soil and the neutron counts. Applying a monte carlo computer code to simulate the experiments of neutron moisture gauging may contribute to reduce time and efforts for experiments and produce a calibration equation which is more applicable to soil in general. In this study MCNP4A, a monte carlo computer code, was employed to simulate soil experiments and the simulated results were compared with experimental ones. The comparative study showed that MCNP4A is applicable to simulate the experiments and calibration equation can be obtained through simulations. Effects of dry density changes were also studied.

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A Study on Optimization of Single-Channel Monopulse Tracking System using Phased Array Antenna (위상배열안테나를 이용한 단일 채널 모노펄스 추적 시스템의 최적화에 관한 연구)

  • Jung, Jin-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.4
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    • pp.705-712
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    • 2018
  • The radiation characteristics of a phased array antenna is changed according to the beam steering angle. The monopulse tracking system calculates the prediction angle using the radiation characteristics of antenna. Therefore, the monopulse ratio curve is changed according to the beam steering angle for the monopulse tracking system using a phase array antenna, and the tracking accuracy goes down. In the case of a single-channel monopulse system, the monopulse rate curve is controlled by the configuration variables of the system. In this paper, a simplified formula was presented for adaptive control of monopulse system configuration variables on beam steering angle. The presented formula can induce a uniform monopulse ratio curve for the beam steering angle as well as the phased array antenna design parameters.

Selection of Male-sterile and Dwarfism Genetically Modified Zoysia japonica through Gamma Irradiation (감마선 처리에 의한 웅성불임 및 왜성형질의 유전자변형 들잔디(Zoysia japonica Steud.) 선발)

  • Bae, Tae-Woong;Song, In-Ja;Kang, Hong-Gyu;Jeong, Ok-Cheol;Sun, Hyeon-Jin;Ko, Suk-Min;Lim, Pyung-Ok;Song, Pill-Soon;Song, Sung Jun;Lee, Hyo-Yeon
    • Journal of Radiation Industry
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    • v.4 no.3
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    • pp.239-246
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    • 2010
  • The aim of this study is selection of the male-sterile plant for inhibiting transgene flow through gamma-irradiation ($^{60}Co$) at the pollination and fertilization cycle of herbicide-tolerant genetically modified (GM) zoysiagrass (Zoysia japonica Steud.). High frequencies of plant mutations were obtained about 18% from $M_1$ generation at the doses (10 to 50 Gy). We also found that some $M_1$ plants showed male-sterile plants using de-husked seeds and comparison of stainable pollen using $KI-I_2$ solution. Besides the effects of irradiation on pollination and fertilization cycle, various other mutations like dwarf, cold tolerance, increasing grains and mass were observed. Four of dwarfism plants were selected through comparison of morphological characteristic between control and mutants during 4 years. These results demonstrated that the gamma-irradiation on pollination and fertilization cycle is very effective to induce the various mutations, and the male-sterile mutants are useful for controlling transgene flow and developing of high quality turfgasses.

The Effect of γ-Aminobutyric Acid Intake on UVB- Induced Skin Damage in Hairless Mice

  • Hairu Zhao;Bomi Park;Min-Jung Kim;Seok-Hyun Hwang;Tae-Jong Kim;Seung-Un Kim;Iksun Kwon;Jae Sung Hwang
    • Biomolecules & Therapeutics
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    • v.31 no.6
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    • pp.640-647
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    • 2023
  • The skin, the largest organ in the body, undergoes age-related changes influenced by both intrinsic and extrinsic factors. The primary external factor is photoaging which causes hyperpigmentation, uneven skin surface, deep wrinkles, and markedly enlarged capillaries. In the human dermis, it decreases fibroblast function, resulting in a lack of collagen structure and also decreases keratinocyte function, which compromises the strength of the protective barrier. In this study, we found that treatment with γ-aminobutyric acid (GABA) had no toxicity to skin fibroblasts and GABA enhanced their migration ability, which can accelerate skin wound healing. UVB radiation was found to significantly induce the production of matrix metalloproteinase 1 (MMP-1), but treatment with GABA resulted in the inhibition of MMP-1 production. We also investigated the enhancement of filaggrin and aquaporin 3 in keratinocytes after treatment with GABA, showing that GABA can effectively improve skin moisturization. In vivo experiments showed that oral administration of GABA significantly improved skin wrinkles and epidermal thickness. After the intake of GABA, there was a significant decrease observed in the increase of skin thickness measured by calipers and erythema. Additionally, the decrease in skin moisture and elasticity in hairless mice exposed to UVB radiation was also significantly restored. Overall, this study demonstrates the potential of GABA as functional food material for improving skin aging and moisturizing.

Variable Optical Attenuator using Optical Coupling between a Side Polished Fiber and Refractive Index Matching Liquid (측면 연마된 광섬유와 굴절률 정합액사이의 광결합을 이용한 가변 광 감쇠기)

  • Kim, Kwang-Taek;Song, Jae-Won
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.9
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    • pp.50-55
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    • 1999
  • In this paper we proposed a variable optical attenuator using the side polished fiber coupled with a refractive index matching liquid. Small variation of refractive index of matching liquid can induce very large change of optical loss due to the coupling between the fiber mode and radiation mode. The thermo-optic effect of matching liquid was used to ontrol the optical attenuation. The side polished fiber block was fabricated using the silicon V gloove. Experimental results showed that $5^{\circ}C$ temperature variation was enough to adjust full range attenuation. The polarization dependent loss and insertion loss of the fabricated devices were 0.5dB and 0.2dB respectively.

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Measurement of electro-physiological changes in the brain exposed to eletromagnetic wave radiation (전자파에 노출된 생체두부의 전기생리적 변화의 측정에 관한 연구)

  • 이준하;신현진;이상학;유동수;이무영;김성규
    • Progress in Medical Physics
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    • v.5 no.2
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    • pp.35-43
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    • 1994
  • Electromagnetic wave may induce effect and damage on the bio-body, either by electric fields of magnetic fields. We measure electrophysiological changs in rabbit's brain exposed to 2.45GHz micro wave(power density 40mW/cm$^2$) which distance 30cm from the source. In order to process the bio-electrical signal (EEG), used pre-amplifier module with self-made and Digtal analyzer computer system. Spectal analysis of the EEG showed variable power in the frequency range(1~30Hz) through each exposure time(10min, 20min, 30min) before and after. In effectively measured by the bio-electrical signal processing and can found threshold of minmal permissible exposure and lethal exposure.

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Multidimensional Rehabilitation in Patients with Aspiration Following Head and Neck Cancer Treatment (두경부암 치료에 따라 발생한 흡인 환자에 대한 다각적 재활운동 치료)

  • Jung, Young Ho;Jin, Young Ju
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.29 no.1
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    • pp.5-8
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    • 2018
  • Patients who have the head and neck cancer are usually treated by surgery, radiation therapy, chemotherapy, or combinations of them. These treatments can induce variable degree of aspiration with dysphagia. The type and severity of aspiration depends on the size and location of the original tumor, the structures involved, and the treatment modality used for treatment. The management of aspiration after the head and neck cancer's treatment begins with an accurate evaluation for the cause and mechanism of aspiration through modified barium swallow (MBS) and fiberoptic endoscopic examination of swallowing (FEES). Then, the clinician can use postures, maneuvers, and exercises to treat the swallow disorder and to help the patient achieve optimal function. To achieve optimal swallowing without aspiration, multidimensional rehabilitation by various medical personnel is definitely necessary.

Surgical Strategies for Prevention and Treatment of Airway Aspiration in Head and Neck Cancer Patients (두경부암 환자에서 기도 흡인의 예방과 치료를 위한 수술 전략)

  • Baek, Min Kwan;Kim, Dong Young
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.29 no.1
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    • pp.9-13
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    • 2018
  • Postoperative airway aspiration is not uncommon in patients with head and neck cancer. Airway aspiration has serious consequences, such as swallowing disorders, nutrition-related health problem, or reducing the quality of life due to maintenance of tracheal or nasogastric tubes. The postoperative oropharyngeal defect due to the surgery may interfere with normal swallowing reflex, or the laryngeal dysfunction caused by radiation therapy may cause severe airway aspiration, which may lead to complications such as dyspnea and pneumonia. Complete removal of the disease is also important in the treatment of head and neck cancer, but it is necessary to select a method to avoid and predict the occurrence of airway aspiration according to the treatment method. The most important factor to prevent airway aspiration after surgery is to preserve the proper volume of the oropharynx and to preserve at least one of the cricoarytenoid joint function. It is also the most effective way to reduce additional complications by seeking appropriate surgical treatment according to airway aspiration status. The purpose of this study is to review the operative methods that can induce airway aspiration and consider the prevention and treatment strategy through review of the literature.