• Title/Summary/Keyword: dose-response model

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Risk Relationship of Cataract and Epilation on Radiation Dose and Smoking Habit

  • Tomita, Makoto;Otake, Masanori;Moon, Sung-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.4
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    • pp.1349-1364
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    • 2006
  • An analytic approach that provides explicit estimates of risk on cataract and epilation data is evaluated by reasonableness of conceivable relative risk models regarding a simple, odds, logistic or Gompertz regression method, assuming a binomial distribution. In these analyses, we apply relative risk models with two thresholds between epilators and nonepilators from a highly characteristic lesion of which radiation cataract does not occur around 2 gray for a single acute exposure. The risk models are fitted to the data assuming 10 as a constant relative biological effectiveness of neutron. The likelihood of observing the entire data set in these models fitted is evaluated by an individual binary-response array. Estimation of a threshold with or without severe epilation and the 100 ($1-\alpha$)% confidence limits are derived from the maximum likelihood approach. The relative risk model with two thresholds can be expressed as a formula with structure of Background $\times$ RR, where RR includes threshold models with or without epilation. The radiosensitivity of ionizing radiation to cataracts has been examined for the relationship between epilators and nonepilators.

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Characterization of Low-temperature SU-8 Negative Photoresist Processing for MEMS Applications

  • May Gary S.;Han, Seung-Soo;Hong, Sang-Jeen
    • Transactions on Electrical and Electronic Materials
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    • v.6 no.4
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    • pp.135-139
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    • 2005
  • In this paper, negative SU-8 photoresist processed at low temperature is characterized in terms of delamination. Based on a $3^3$ factorial designed experiment, 27 samples are fabricated, and the degree of delamination is measured for each. In addition, nine samples are fabricated for the purpose of verification. Employing the. neural network modeling technique, a process model is established, and response surfaces are generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. From the response surfaces generated, two significant parameters associated with delamination are identified, and their effects on delamination are analyzed. Higher PEB temperature at a fixed PEB time results in a greater degree of delamination. In addition, a higher dose of exposure energy lowers the temperature at which the delamination begins and also results in a larger degree of delamination. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.

Prostaglandin A2 triggers a strong oxidative burst in Laminaria: a novel defense inducer in brown algae?

  • Zambounis, Antonios;Gaquerel, Emmanuel;Strittmatter, Martina;Salaun, Jean-Pierre;Potin, Philippe;Kupper, Frithjof C.
    • ALGAE
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    • v.27 no.1
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    • pp.21-32
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    • 2012
  • We report an oxidative burst triggered by prostaglandin $A_2(PGA_2)$ in the brown algal kelp Laminaria digitata, constituting the first such discovery in an alga and the second finding of an oxidative burst triggered by a prostaglandin in a living organism. The response is more powerful than the oxidative burst triggered by most other chemical elicitors in Laminaria. Also, it is dose-dependent and cannot be inhibited by diphenylene iodonium, suggesting that another source than NAD(P)H oxidase is operational in the production of reactive oxygen species. Despite the very strong oxidative response, rather few effects at other levels of signal transduction pathways could be identified. $PGA_2$ does not increase lipolysis (free fatty acids) in Laminaria, and only one oxylipin (15-hydroxyeicosatetraenoic acid; 15-HETE) was found to be upregulated in Laminaria. In a subsequent set of experiments in the genome model Ectocarpus siliculosus, none of 5 selected candidate genes, all established participants in various stress responses, showed any significant differences in their expression profiles.

Investigation of physical characteristics for Al2O3:C dosimeter using LM-OSL

  • Kim, Myung-Jin;Lee, Young-Ju;Kim, Ki-Bum;Hong, Duk-Geun
    • Analytical Science and Technology
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    • v.32 no.4
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    • pp.131-138
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    • 2019
  • This paper reports results on the physical properties of a powder type of $Al_2O_3:C$ commonly used as a luminescence dosimeter using the LM-OSL technique. On the analysis with the general order kinetics model, the LM-OSL signal measured appeared to be composed of three components (fast, medium, slow) showing the largest area in the medium component. The photoionization cross sections of three components were distributed between $10^{-19}{\sim}10^{-21}cm^2$. The values of the thermal assistance energy were evaluated the largest in slow component and the smallest in fast component, which indicates the electrons trapped in defects attributed to slow component should be the most sensitive to thermal vibration among three components. In illumination to blue light, the fast component showed a rapid linear decay and completely disappeared after light exposure time of about 5 s. The medium component decayed with two exponential elements but the slow component did not observed any noticeable change until light exposure time of 40 s. In a dose response study, all components exhibited a linear behaviour up to approximately 10 Gy.

Experimental Study of Citri Reticulatae Viride Pericarpium extract on the Cerebral Hemodynamics in Rats (청피가 뇌혈류역학에 미치는 실험적 연구)

  • Lee Geum Soo;Jeong Hyun Woo;Lee Won Suk
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.1
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    • pp.104-110
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    • 2002
  • Citri Reticulatae Viride Pericarpium extract(CRVP) have been used in oriental medicine for many centuries as a therapeutic agent for Soothing the liver and regulating the circulation of qi(疏肝理氣), and promoting digestion and removing stagnated food(消積化滯). The effects of CRVP on the vascular system is not known. The purpose of this Study was to investigate the effects of CRVP on the pial arterial diameter and regional cerebral blood flow(rCBF) in normal rats and ischemic cerebrovascular pathologic model rats. The changes in rCBF was determinated by Laser-Doppler Flowmetry(LDF), and the changes in pial arterial diameter were determinated by video microscopy methods and video analyzer. The results were as follows ; 1. Pial arterial diameter was significantly increased by CRVP in a dose-dependent manner. 2. Pretreatment with L-NNA significantly inhibited CRVP induced increased rCBF and pial arterial diameter. 3. Both the methylene chloride fraction and the hexane fraction of CRVP dose-dependently improved the altered cerebral hemodynamics of cerebral ischemic animal by increasing rCBF. 4. Pretreatment with L-NNA and indomethacin significantly inhibited CRVP(MC) induced increased rCBF. 5. Pretreatment with L-NNA and indomethacin significantly inhibited CRVP(hexane) induced increased rCBF. 6. Pretreatment with CRVP maredly stabilized the changes rCBF and pial arterial diameter during the period of cerebral reperusion. In conclusion, CRVP causes a diverse response of rCBF and pial arterial diameter, and CRVP dose-dependently improved the altered cerebral hemodynamics of cerebral ischemic animal by increasing rCBF and pial arterial diameter. These results suggest that the improvement of cerebral hemodynamics is also mediated by nitric oxide synthase and cyclooxygenase.

Anti-inflammatory and anti-noceceptive action of the crude extracts of Costus specious on rodents

  • Alam, Ashraful;Subhan, Nusrat;Awal, Abdul;Alam, Shohidul;Akramudau, Kazi
    • Advances in Traditional Medicine
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    • v.8 no.3
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    • pp.243-251
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    • 2008
  • The effect of alcoholic extracts of Costus specious (Family: Zingiberaceae) was evaluated in experimental models of pain and inflammation. Oral administration of 100, 200 and 300 mg/kg of C. specious extracts were used for the above study. Crude extracts of C. specious (300 mg/kg dose) showed maximum time needed for the response against thermal stimuli ($7.242\;{\pm}\;0.532\;s$) which is comparable to diclofenac sodium ($8.471\;{\pm}\;0.25\;s$) in the hot plate test. The MPH (Maximum Possible Analgesia) has been found to be 14.285 for 300 mg/kg dose of the crude extract while the MPH for diclofenac was 15.857 after 60 min of administration in the hot tail-flick method. The crude extract at 300 and 200 mg/kg doses showed significant reduction in acetic acid induced writhings in mice with a maximum effect of 59.661% reduction at 300 mg/kg dose which is comparable to standard diclofenac sodium (73.4%). Alcoholic extract of C. specious showed significant inhibition in serotonin and egg albumin induced hind paw oedema in rats at 100, 200 and 300 mg/kg of the crude extracts respectively (Serotonin induced edema 44.22; 53.75; 58.51%; egg albumin induced edema - 41.317; 53.892; 59.880% inhibition after 4 h respectively). The antiinflammatory effects showed by the extract were comparable to that of standard indomethacin 5 mg/kg (Serotonin induced edema 77.56%; egg albumin induced edema 77.844% inhibition after 4 h). These results suggest that the extract possesses both the anti-inflammatory and analgesic activity on mice and rat model.

The Mechanical Antiallodynic Effect of Intrathecal Lamotrigine in Rats with Spinal Nerve Ligation (척추신경결찰 흰쥐에서 척수강내로 투여한 Lamotrigine의 기계적 항이질통 효과)

  • Song, Jun Gol;Jun, In Gu;Kwon, Mi Young;Park, Jong Yeon
    • The Korean Journal of Pain
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    • v.18 no.2
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    • pp.118-123
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    • 2005
  • Background: A nerve ligation injury may produce a tactile allodynia. The effects of intrathecally delivered lamotrigine on allodynia induced due to fifth and sixth lumbar spinal nerves ligation in rats, using lumbar intrathecal catheters were examined. Methods: Sprague-Dawley rats (body weight 160-180 g) were prepared by tightly ligating the fifth and sixth left lumbar spinal nerves, with the implantation of a chronic intrathecal catheter for drug administration. Mechanical allodynia and allodynic threshold were measured using von Frey filaments and the updown method, respectively. After the baseline hind paw withdrawal thresholds had been obtained, lamotrigine (10, 30, 100 and $300{\mu}g$) was administered intrathecally. Thereafter, the dose-response curves and 50% effective dose ($ED_{50}$) were obtained. Motor dysfunction was assessed by observing the righting/stepping reflex responses and abnormal weight bearing. Results: Intrathecal administration of lamotrigine produced a dose-dependent antiallodynic action ($ED_{50}=61.7{\mu}g$). Mild motor weakness was observed with $300{\mu}g$ lamotrigine, but no severe motor impairment was found. Conclusions: It is suggested that intrathecal lamotrigine could produce moderate antagonism of mechanical allodynia at the spinal level in a rat neuropathic pain model with minimal motor weakness.

The Comparative Study of Fructus Immaturus Ponciri and Fructus Ponciri Effect on Allergic Reaction (알레르기반응에 대한 지실과 지각의 효과 비교 연구)

  • 엄용대;김대한;정종길;신민교;송호준
    • The Journal of Korean Medicine
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    • v.22 no.4
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    • pp.10-21
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    • 2001
  • Objective : To investigate the effect between Fructus Immaturus Ponciri (FIP, the immature fruit of Poncirus trifoliata) and Fructus Ponciri (FP, the ripe fruit of Poncirus trifoliata) on mast cell-mediated immediate-type allergic reactions. Methods : We performed anaphylactic reaction, histamine release, cAMP, $TNF-{\alpha}$, IgE. Results : The aqueous extract of FIP dose-dependently inhibited systemic and local allergic reaction was induced by compound 48/80 or anti-dinitrophenyl (DNP) IgE in a murine model. FIP also significantly inhibited mast cell-dependent ear swelling response induced by topical application of compound 48/80. When mice were orally pretreated with FIP, the plasma histamine levels were reduced in a dose-dependent manner. FIP dose-dependently inhibited histamine release from the rat peritoneal mast cells (RPMCs) was activated by compound 48/80 or anti-DNP IgE. The level of cAMP in RPMCs, when FIP was added, increased compared with that of a normal or control. In addition, FIP had a significant inhibitory effect on anti-DNP IgE-induced tumor necrosis factor-a ($TNF-{\alpha}$) production from the RPMCs and IgE produced by lipopolysaccharide-stimulated murine whole spleen cells or U266B1 as human IgE-bearing B cells. However, FP showed the lower inhibition rate than those of FIP in above all allergic reactions. Conclusion : These data have important implications for our understanding of the clinical effects of FIP and FP on allergic diseases, and FIP is more effective than FP on the allergic reaction.

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Antibacterial Activity of Herbal Complex ABHC for Development of Novel Therapeutic Agent Against Sepsis (패혈증 치료제 개발을 위한 황백이 포함된 생약혼합제제 ABHC의 항균 효능)

  • Lee, Ki Man;Lee, Geum Seon;Kim, Yu Ri;Park, Jun Woo;Boo, Kyung-Jun;Yim, Dongsool;Kang, Tae Jin
    • Korean Journal of Pharmacognosy
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    • v.50 no.3
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    • pp.191-197
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    • 2019
  • Sepsis, an infectious disease, is a life-threatening condition that arises when the response to infection causes injury to tissues and organs. The purpose of this study was to demonstrate whether ABHC-1 and ABHC-2, two functional extracts from herbal complex, have an anti-bacterial effect against Escherchia coli in vivo, in vitro experimental model. ABHC-1 and ABHC-2 showed the antibacterial activity against the bacteria by paper disc method. The minimum inhibitory concentration (MIC) was measured using alamar blue reagent. The MIC was shown at $60{\mu}g/ml$ from ABHC-1 and $500{\mu}g/ml$ from ABHC-2 against E. coli. We next examined the effect of ABHCs on the production of inflammatory cytokine, such as tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$), which is related to the induction of inflammation, in RAW 264.7 cell. ABHC-1 and ABHC-2 increased $TNF-{\alpha}$ production of RAW 264.7 cell in a dose-dependent manner while two extract decreased $TNF-{\alpha}$ production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cell in a dose-dependent manner. At a dose of $1{\times}10^8$ E. coli. i.p., non-treated mice were succumbed, while most of mice treated with ABHC-1 were survived. Therefore, our results suggest that ABHC-1 has anti-bacterial activity and can be a novel therapeutic agent against infectious diseases.

Role of radiotherapy in local control of non-AIDS associated Kaposi's sarcoma patients in Korea: a single institution experience

  • Chang, Ji Hyun;Kim, Il Han
    • Radiation Oncology Journal
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    • v.30 no.4
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    • pp.153-157
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    • 2012
  • Purpose: There has been no definite consensus on standard treatment, either local or systemic, for the Kaposi's sarcoma (KS). Radiotherapy (RT) can be a good local therapeutic choice especially in non-AIDS associated KS (NAKS) for its indolent behavior. Materials and Methods: Medical records of 17 KS patients treated with RT at the Seoul National University Hospital from February 1998 to January 2012 were retrospectively reviewed. One human immunodeficiency virus (HIV)+ patient with 3 lesions was excluded. The total number of the lesion was 23 among the 16 patients. The median follow-up period was 27.9 months. Correlation between response and variables was analyzed using the logistic regression model. Median age of the patients was 75 years. All the 23 lesions were located at the extremities. Fourteen (61%) of those had pain or local swelling as the initial presentation. Ten patients had possible causes of immunodeficiency and were regarded as iatrogenic, and other 6 were classic KS. Median dose of RT was 36 Gy. Results: No KS-related death was observed. Excluding 2 with short-term follow-up only, complete response and partial response were obtained in 2 (9%) and 19 (73%) lesions, respectively. Of those, 3 lesions underwent local progression. Six had out-of-field recurrence after RT. Symptom improvement was achieved in 13 (93%) of 14 patients. Grade 2 skin toxicities were found in 9 lesions but all got improvement after treatment. When divided into responsive and progressive group, free from progression was not related to any of the possible variables. Conclusion: RT is effective in local control of NAKS resulting great response rate.