• Title/Summary/Keyword: High Dose Rate

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Effects of Low Dose $\gamma$-Radiation on the Growth, Activities of Enzymes and Photosynthetic Activities of Gourd (Lagenaria siceraria) (저선량 $\gamma$선 조사가 참박의 초기 생육과 효소 활성 및 광합성 능에 미치는 영향)

  • 이혜연;김재성;백명화;이영근;임돈순
    • Korean Journal of Environmental Biology
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    • v.20 no.3
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    • pp.197-204
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    • 2002
  • Gourd seeds were irradiated with the doses of 0-20 Gy to investigate the effect of the low dose $\gamma$-radiation on the early growth and physiological activity. The stimulating effects of the low dose y- radiation on the early growth were not noticeably high, but were increased generally at 4-16 Gy irradiation group. The catalase and peroxidase activity of cotyledon from seeds irradiated with $\gamma$- radiation were increased at 8 Gy irradiation group. The photochemical activity of leaf was noticeably high at 4 Gy irradiation group. The photochemical yield of PSII, estimated as Fv/Fm, decreased with increasing illumination time by 50% after 4 hrs in the control and 8 Gy irradiation group, while Fo slightly increased. However, Fv/Em in the 4 Gy irradiation group decreased by 40% of inhibition, indicating that photoinhibition decreased by the low dose $\gamma$- radiation. Changes in the effective quantum yield of PSII, $\varphi_{PSII}$ and 1/Fo- l/Fm, a measure of the rate constant of excitation trapping by the PSII reaction center, showed similar pattern to Fv/Em. NPQ decreased by 70% after photoinhibitory treatment with showing similar pattern between the control and the irradiation group. These results showed the positive effect of low dose $\gamma$- radiation on the seedling growth and the reduction of photoinhibition in the 4 Gy irradiation group.

Comparisons between the KKU-Model and Conventional Rectal Tubes as Markers for Checking Rectal Doses during Intracavitary Brachytherapy of Cervical Cancer

  • Padoongcharoen, Prawat;Krusun, Srichai;Palusuk, Voranipit;Pesee, Montien;Supaadirek, Chunsri;Thamronganantasakul, Komsan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6115-6120
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    • 2014
  • Background: To compare the KKU-model rectal tube (KKU-tube) and the conventional rectal tube (CRT) for checking rectal doses during high-dose-rate intracavitary brachytherapy (HDR-ICBT) of cervical cancer. Materials and Methods: Between February 2010 and January 2011, thirty -two patients with cervical cancer were enrolled and treated with external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT). The KKU-tube and CRT were applied intrarectally in the same patients at alternate sessions as references for calculation of rectal doses during ICBT. The gold standard references of rectum anatomical markers which are most proximal to radiation sources were anterior rectal walls (ARW) adjacent to the uterine cervix demonstrated by barium sulfate suspension enema. The calculated rectal doses derived from actual anterior rectal walls, CRT and the anterior surfaces of the KKU-tubes were compared by using the paired t-test. The pain caused by insertion of each type of rectal tube was assessed by the visual analogue scale (VAS). Results: The mean dose of CRT was lower than the mean dose of ARW ($Dmean_0-Dmean_1$) by $80.55{\pm}47.33cGy$ (p-value <0.05). The mean dose of the KKU-tube was lower than the mean dose of ARW ($Dmean_0-Dmean_2$) by $30.82{\pm}24.20cGy$ (p-value <0.05). The mean dose difference [($Dmean_0-Dmean_1$)-($Dmean_0-Dmean_2$)] was $49.72{\pm}51.60cGy$, which was statistically significant between 42.32 cGy -57.13 cGy with the t-value of 13.24 (p-value <0.05). The maximum rectal dose by using CRT was higher than the KKU-tube as much as 75.26 cGy and statistically significant with the t-score of 7.55 (p-value <0.05). The mean doses at the anterior rectal wall while using the CRTs and the KKU-tubes were not significantly different (p-value=0.09). The mean pain score during insertion of the CRT was significantly higher than the KKU-tube by a t-score of 6.15 (p-value <0.05) Conclusions: The KKU-model rectal tube was found to be an easily producible, applicable and reliable instrument as a reference for evaluating the rectal dose during ICBT of cervical cancer without negative effects on the patients.

Early Growth Changes in Juvenile Abalone Haliotis discus discus Produced by Irradiation with Low-dose 60Co Gamma Rays (저선량 60Co감마선 조사 후 생산된 둥근전복(Haliotis discus discus)치패의 초기성장 변화에 관한 연구)

  • Jwa, Min Seok;Yeo, In-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.2
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    • pp.193-199
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    • 2015
  • We observed that the growth and physiological change in Haliotis discus discus by low-dose irradiation with gamma ray.Irradiation with gamma ray was undertaken by using the low-level irradiation facility ($^{60}CO$) in cooperation with the Institute of Nuclear Science and Technology at Jeju National University. The parent abalones were attached one by one and then fixed by using the rubber band to the front side of the fabricated case for irradiation with gamma ray. The experimental plots of irradiation with gamma ray were set as 10, 15, 20 and 25 Gy and the 25 female abalones and 10 male abalones were utilized for each experimental plot. The sperms and eggs were fertilized by setting an interval for each dose to prevent mixing with other experimental plots when fertilizing the sperms and eggs for each dose of irradiation with gamma ray. As for the fertility, it was confirmed to be 85% the control and 10 Gy groups, whereas it was found to be 80%, 65% and 50% in the 15 Gy, 20 Gy and 25 Gy groups, respectively. As a conclusion, the hatching rate and attachment rate were higher at 10 and 15 Gy than the other experimental plots, and the growth rate was higher at 20 Gy than the other experimental plots. Also the changes in lysozyme activity in accordance with the stress of water temperature were found to have a significant increase in the other experimental plots as compared with the control plot at the end of 0 h. The changes in lysozyme activity have remained constant in all the experimental plots at the end of 12 h. These results allowed us to confirm that lysozyme was undertaking the biodefense action by reacting sensitively to the stress of water temperature in the control experimental plot. As for the other experimental plots, they are believed to avoid the biodefense mechanism due to the high degree of anti-parasite mechanism and anti-viral mechanism. Thus, it is believed that it would be imperative to conduct development and research on breeds that were potent for environmental tolerance by applying the method of irradiation with gamma ray to other marine animals and plants.

A Study of volumetric modulated arc therapy for stereotactic body radiation therapy in case of multi-target liver cancer using flattening filter free beam (다중표적 간암의 정위적체부방사선치료에서 무편평화여과기선질 용적변조회전치료의 유용성 평가)

  • Yeom, Misuk;Yoon, Inha;Hong, Donggi;Back, Geummun
    • The Journal of Korean Society for Radiation Therapy
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    • v.27 no.1
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    • pp.31-43
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    • 2015
  • Purpose : Stereotactic body radiation therapy (SBRT) has proved its efficacy in several patient populations with primary and metastatic limited tumors. Because SBRT prescription is high dose level than Conventional radiation therapy. SBRT plan is necessary for effective Organ at risk (OAR) protection and sufficient Planning target volume (PTV) dose coverage. In particular, multi-target cases may result excessive doses to OAR and hot spot due to dose overlap. This study evaluate usefulness of Volumetric modulated arc therapy (VMAT) in dosimetric and technical considerations using Flattening filter free (FFF) beam. Materials and Methods : The treatment plans for five patients, being treated on TrueBeam STx(Varian$^{TM}$, USA) with VMAT using 10MV FFF beam and Standard conformal radiotherapy (CRT) using 15MV Flattening filter (FF) beam. PTV, liver, duodenum, bowel, spinal cord, esophagus, stomach dose were evaluated using the dose volume histogram(DVH). Conformity index(CI), homogeneity index(HI), Paddick's index(PCI) for the PTV was assessed. Total Monitor unit (MU) and beam on time was assessed. Results : Average value of CI, HI and PCI for PTV was $1.381{\pm}0.028$, $1.096{\pm}0.016$, $0.944{\pm}0.473$ in VMAT and $1.381{\pm}0.042$, $1.136{\pm}0.042$, $1.534{\pm}0.465$ in CRT respectively. OAR dose in CRT plans evaluated 1.8 times higher than VMAT. Total MU in VMAT evaluated 1.3 times increase than CRT. Average beam on time was 6.8 minute in VMAT and 21.3 minute in CRT. Conclusion : VMAT for SBRT in multi-target liver cancer using FFF beam is effective treatment techniqe in dosimetric and technical considerations. VMAT decrease intra-fraction error due to treatment time shortening using high dose rate of FFF beam.

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Efficacy of High Dose Radiotherapy in Post-operative Treatment of Glioblastoma Multiform - A Single Institution Report

  • Pashaki, Abdolazim Sedighi;Hamed, Ehsan Akbari;Mohamadian, Kamal;Abassi, Mohammad;Safaei, Afsane Maddah;Torkaman, Tayebe
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2793-2796
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    • 2014
  • Background: Glioblastoma multiform (GBM) is a highly aggressive tumor with median survival of approximately 14 months. Management consists of maximal surgical resection followed by post-operative chemoradiation with concurrent then adjuvant temozolamide. The standard radiotherapy dose is 60Gy in 2-Gy fractions recommended by the radiation therapy oncology group (RTOG). With the vast majority of tumor recurrences occurring within the previous irradiation field and the poor outcome associated with standard therapy, regimens designed to deliver higher radiation doses to improve local control and enhance survival are needed. In this study, we report a single institutional experience in treatment of 68 consecutive patients with GBM, treated with resection, and given post-operative radiotherapy followed by concurrent and/or adjuvant chemotherapy. Results: Of the 80 patients who entered this study, 68 completed the treatment course; 45 (66.2%) males and 23 (33.8%) females with a mean age at diagnosis of $49.0{\pm}12.9$ (21-75) years. At a median follow up of 19 months, 39 (57.3%) patients had evidence of tumor progression and 36 (52.9%) had died. The median over all survival for all patients was 16 months and progression free survival for all patients was 6.02 months. All potential prognostic factors were analyzed to evaluate their effects on overall survival. Age ${\leq}50$ year, concurrent and adjuvant chemotherapy and extent of surgery had significant p values. We found lower progression rate among patients who received higher doses of radiotherapy (>60Gy). Higher radiation doses improved progression free survival (p=0.03). Despite increasing overall survival, this elevation was not significant. Conclusions: This study emphasize that higher radiation doses of (>60Gy) can improve local control and potentially survival, so we strongly advise prospective multi centric studies to evaluate the role of higher doses of radiotherapy on GBM patient outcome.

The Removal of Algae by Pre-oxidation (전산화 공정을 이용한 조류제거)

  • Son, Hee-Jong;Jung, Chul-Woo;Bae, Sang-Dae;Choi, Young-Ik;Kang, Lim-Seok
    • Journal of Environmental Science International
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    • v.18 no.3
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    • pp.289-298
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    • 2009
  • The blue-green algae which caused odor problem in the tap water are difficult to precipitate in sedimentation basin and clogged the filter void rapidly. The studies of this paper were not only oxidation, coagulation and sedimentation processes for effectively removing blue-green algae but yellow clay and polyamine for verification as coagulants aids. The results of this research are summarized as follows: Higher ozone dose(C) and longer contact time(T) were needed for a high degree of removing blue-green algae efficiency. the removal rate of blue-green algae was proportional to the $C\times T$ value. The removal percent of chlorophyll-a by sedimentation and filter without pre-ozonation was about 75% but 1 mg/L pre-ozonation could increase the removal percent of chlorophyll-a to 99% and more pre-ozonation could remove completely. Though the removal efficiency of turbidity could increased by high dose of chlorination, the dissolved organic carbon was increased. More chlorine dose from 4 to 10 mg/L dissolved organic carbon was decreased. Using yellow clay as coagulant aids increased density of floc so the settling velocity of floc become rising but polyamine could not increase settling velocity of floc though it could formated large floc.

Protective Effect of Herbal Mixture Including Lycii Fructus on Hepatotoxicity Induced by Thioacetamide in Mice (구기자 복합물 약침액이 간기능 개선에 미치는 영향)

  • Kim, Yong-Min;Hwang, Dong-Suk;Kwak, Byeong-Mun;Kim, Ee-Hwa
    • Korean Journal of Acupuncture
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    • v.36 no.4
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    • pp.221-229
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    • 2019
  • Objectives : This study investigated the hepatoprotective effect of herbal mixture including Lycii fructus (HML) in thioacetamide (TAA)-induced hepatotoxicity in mice. Methods : To confirm the liver protective effect, induced by TAA for 3 days injection at 100 mg/kg mice, HML were treated for 8 weeks at 300 mg/kg/day, 1000 mg/kg/day. Positive control was treated silymarin 50 mg/kg/day after TAA injection. The changes of mortality rate, clinical signs, organ weight, relative liver, blood chemistry and histopathological findings were analyzed after experiment. Results : Body weight gain was observed in all groups, but TAA treated group at 4th week and all treated groups decreased weight compared to the untreated group. As a result of organ weight measurement, organ weight gain due to hepatic injury was observed statistically significantly in TAA-treated group and TAA+Silymarin treated group, and the herbal mixture-treated group showed a tendency to decrease compared to the TAA treated group. Blood biochemistry showed that total cholesterol and very low density lipoprotein cholesterol decreased statistically in TAA+low-dose and high dose herbal mixture treated group compared to the TAA-treated group. Histopathological examination showed that liver abnormalities were not observed in untreated group, liver fibrosis was observed in liver injury with TAA treated and herbal mixture treated group. And, TAA+high dose herbal mixture group showed relaxation tendency on liver calcification compared to the TAA treated group. Conclusions : According to the above results, HML provided hepatoprotective effects on the hepatic injury by reduction of inflammatory responses.

Preparation and Characterization of Alginate-Chitosan Microsphere for Controlled Delivery of Silver Sulfadiazine (설파디아진은의 방출제어를 위한 알지네이트-키토산 미립구의 제조 및 특성)

  • Cho, Ae-Ri
    • Journal of Pharmaceutical Investigation
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    • v.31 no.2
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    • pp.101-106
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    • 2001
  • Alginate-chitosan (anion-cationic polymeric complex) was prepared to control the release rate of silver sulfadiazine (AgSD). Na-alginate (2%) solution containing AgSD was gelled in $CaCl_2$ solution. The gel beads formed were immediately encapsulated with chitosan (CS). The gel matrix and membrane were then reinforced with chondroitin-6-sulfate (Ch6S). Release rate of AgSD from the gel matrix was investigated by placing alginate beads in the sac of cellulose membrane simmered in HEPES-buffer solution. The concentration of AgSD released was analyzed by UV at 264 nm. Incorporation capacity of AgSD in Ca-alginate gel was more than 90%. Alginate-Ch6S-CS could control the release rate of AgSD. The amount of AgSD release was dependent on the AgSD loading dose. Incorporation of tripolyphosphate (polyanionic crosslinker) onto the alginate-Ch6S-CS bead increased the release rate of AgSD. Collagen-coating had no influence on the AgSD release rate. Alginate-Ch6S-CS beads with a sufficiently high AgSD encapsulation were capable of controlling the release of the drug over 10 days. In summary, alginate-Ch6S-CS beads could be used as a sustained delivery for AgSD and provide local targeting with low silver toxicity and patient discomfort.

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Differentiation of tidal volume & mean airway pressure with different Bag-Valve-Mask compression depth and compression rate (Bag-Valve-Mask의 사용방법에 따른 일회호흡량과 평균기도압의 변화 연구)

  • Jo, Seung-Mook;Jung, Hyung-Keon
    • The Korean Journal of Emergency Medical Services
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    • v.16 no.2
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    • pp.67-74
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    • 2012
  • Purpose : The purpose of this study is to get basal user guidelines of safer bag-valve-mask application on patient with normal pulmonary patho-physiologic condition. Methods : This study was accomplished by pre-qualified 25 EMS junior grade students. Participants were instructed randomly compress bag to one-third, half and total and also with differesnt compression speed. Resultant tidal volumes and mean airway pressures obtained in RespiTrainer were analysed in relation to the each compression depth and rate. Results : Demographic difference does not affect tidal volume with any compression depth and rate change. Increasing compression depth is correlated with tidal volume increasement at any compression rate and also with mean airway pressure. If the compression depth is same, compression rate change did not affect significantly the resultant tidal volume or mean airway pressure. Conclusion : Hand size, Experience, BMI dose not affect tidal volume. Compress the 1600 ml bag half to total amount is safe way to offer sufficient tidal volume without risky high airway pressure delivery to patient airway who with normal lung patho-physiologic condition.

The Effects of High Dose Rate Brachytherapy in Recurrent Obstructive Bronchogenic Cancer after External Irradiation Therapy (외부 방사선 치료 조사후 재발한 기관지내 악성종양에서 고선량율 근접조사치료(High Dose Rate Brachytherapy)의 효과)

  • Cho, Jae-Youn;In, Kwang-Ho;Suh, Jung-Kyung;Kang, Sea-Yong;Shim, Jae-Jeong;Kang, Kyung-Ho;Kim, Kwang-Taak;Kim, Cheol-Yong;Yoo, Sa-Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.68-76
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    • 1998
  • Background: Patients with centrally recurred bronchogenic carcinoma make a complaint of many symptoms like hemoptysis, cough & dyspnea. At these conditions, the goal of treatment is only to relieve their symptoms. High dose rate brachytherapy(HDR-BT) is the palliative treatment modality of centrally located endobronchial tumor regardless of previous external irradiation(XRT) on the same site in symptomatic patients. Methods: We studied the effects of HDR-BT in 26 patients with symptomatic recurrent lung cancer. Patients(male: 24, mean age: 54yrs)were treated with HDR-BT underwent bronchoscopic placement of $^{192}Ir$ HDR after loading unit(Gammamed$^{(T)}$, Germany) to deliver 500cGY intraluminal irradiation at a depth of 1cm every lwk on 3 occasions. Evaluation at base line and 4wks after HDR brachytherapy included chest X-ray, bronchscopy, symptoms (Standadized Scale for dyspnea,cough,hemoptysis), and Karnofsky performance scale. Results: Endobronchial obstruction was improved in 11/26 patients(37%). Atelectasis in chest X-ray was improved in 5/15 patients(33%). Hemoptysis, dyspnea & cough were improved in 5/10 patients (50%), 5/8 patients (62%) & 10/18 patients (56%) respectively. Karnofsky performance status was changed from 76.4 scores in pretreatment to 77.6 scores after treatment. During HDR-BT, massive hemoptysis (2 patients) and pneumothorax(1 patient) were occurred as complications. Conclusion: We concluded that HDR-BT gave additional benefits for the control of symptoms and general performance and endobronchial obstruction & atelectasis. And HDR-BT will be an additional treatment for the recurrent and endobronchial obstructive lung cancer.

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