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Confidence limits for patient‐specific IMRT dose QA: a multi‐institutional study in Korea
Kim, Jung‐,in,Chung, Jin‐,Beom,Song, Ju‐,Young,Kim, Sung Kyu,Choi, Yunseok,Choi, Chang Heon,Choi, Won Hoon,Cho, Byungchul,Kim, Jin Sung,Kim, Sung Jin,Ye, Sung‐,Joon John Wiley and Sons Inc. 2016 Journal of applied clinical medical physics Vol.17 No.1
<P>This study aims to investigate tolerance levels for patient‐specific IMRT dose QA (DQA) using the confidence limits (CL) determined by a multi‐institutional study. Eleven institutions participated in the multi‐institutional study in Korea. A total of 155 DQA measurements, consisting of point‐dose differences (high‐ and low‐dose regions) and gamma passing rates (composite and per‐field) for IMRT patients with brain, head and neck (H&N), abdomen, and prostate cancers were examined. The Shapiro‐Wilk test was used to evaluate the normality of data grouped by the treatment sites and the DQA methods. The confidence limit coefficients in cases of the normal distribution, and the two‐sided Student's <I>t</I>‐distribution were applied to determine the confidence limits for the grouped data. The Spearman's test was applied to assess the sensitivity of DQA results within the limited groups. The differences in CLs between the two confidence coefficients based on the normal and <I>t</I>‐distributions were negligible for the point‐dose data and the gamma passing rates with 3%/3 criteria. However, with 2%/2 criteria, the difference in CLs were 1.6% and 2.2% for composite and per‐field measurements, respectively. This resulted from the large standard deviation and the more sensitive criteria of 2%/2. There was no noticeable correlation among the different QA methods. Our multi‐institutional study suggested that the CL was not a suitable metric for defining the tolerance level when the statistics of the sample group did not follow the normality and had a large standard deviation.</P><P>PACS number: 87.55.Qr</P>
Ha, ByungChul,Ko, HyunSuk,Kim, BongLee,Sohn, Eun Jung,Jung, Ji Hoon,Kim, Ji Sung,Yoon, Jung Jae,Won, Gunho,Kim, Ji-Hyun,Jung, Deok-beom,Yun, Miyong,Shim, BumSang,Kim, Sung-Hoon American Chemical Society and American Society of 2014 Journal of natural products Vol.77 No.1
<P>The underlying antimetastatic mechanism of anethole (<B>1</B>) still remains unclear in association with the molecules of the epithelial to mesenchymal transition (EMT). Herein, the role of the EMT molecules was elucidated in terms of the antimetastatic activity of <B>1</B> using DU145 cells. Anethole significantly inhibited the adhesion of DU145 cells to vitronectin-coated plates, as well as migration in a wound-healing assay and invasion using a Boyden chamber. Also, anethole suppressed the expression of MMP-9 in DU145 cells by zymography, ELISA, and RT-PCR. Consistently, the silencing of MMP-9 enhanced the activity of <B>1</B> to upregulate the expression of E-cadherin and to attenuate the expression of Vimentin in DU145 cells. Compound <B>1</B> enhanced E-cadherin, which is an epithelial marker and attenuated the expression of Vimentin, Twist, and Snail as mesenchymal molecules at the mRNA level. Consistently, anethole upregulated E-cadherin and downregulated the expression of Vimentin, Twist and PI3K, and AKT at the protein level in DU145 cells. Conversely, the antimetastatic effects of <B>1</B> to inhibit invasion and the expression of MMP-9 and upregulate E-cadherin were reversed by the EMT inducer TGF-β in DU145 cells. Overall, the present findings suggest that anethole exerts antimetastatic activity via regulation of crosstalk between EMT molecules and MMP-9 on the basis of the in vitro data obtained.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jnprdf/2014/jnprdf.2014.77.issue-1/np4006376/production/images/medium/np-2013-006376_0006.gif'></P>
National Follow-up Survey of Preventable Trauma Death Rate in Korea
Kwon Junsik,Lee Myeonggyun,Moon Jonghwan,Huh Yo,Song Seoyoung,Kim Sora,Lee Seung Joon,Lim Borami,Kim Hyo Jin,Kim Yoon,il Kim Hyung,Yun Jung-Ho,Yu Byungchul,Lee Gil Jae,Kim Jae Hun,Kim Oh Hyun,Choi Woo 대한의학회 2022 Journal of Korean medical science Vol.37 No.50
Background: The preventable trauma death rate survey is a basic tool for the quality management of trauma treatment because it is a method that can intuitively evaluate the level of national trauma treatment. We conducted this study as a national biennial follow-up survey project and report the results of the review of the 2019 trauma death data in Korea. Methods: From January 1, 2019 to December 31, 2019, of a total of 8,482 trauma deaths throughout the country, 1,692 were sampled from 279 emergency medical institutions in Korea. All cases were evaluated for preventability of death and opportunities for improvement using a multidisciplinary panel review approach. Results: The preventable trauma death rate was estimated to be 15.7%. Of these, 3.1% were judged definitive preventable deaths, and 12.7% were potentially preventable deaths. The odds ratio for preventable traumatic death was 2.56 times higher in transferred patients compared to that of patients who visited the final hospital directly. The group that died 1 hour after the accident had a statistically significantly higher probability of preventable death than that of the group that died within 1 hour after the accident. Conclusion: The preventable trauma death rate for trauma deaths in 2019 was 15.7%, which was 4.2%p lower than that in 2017. To improve the quality of trauma treatment, the transfer of severe trauma patients to trauma centers should be more focused.
Experimental Study on Freezing Phenomena of Water Saturated Square Cavity with Inclined Cold Surface
Kim, Jongjun,An, Sangsu,Kim, Byungchul CHOSUN UNIVERSITY 1997 Basic Science and Engineering Vol.1 No.1
It was studied the phenomena of transient freezing of an inclined water-saturated enclosure. One side of the test section was cooled and the other sides were insulated. The effects of the initial temperature, the inclination angle on the temperature field and the shape of the ice-water interface were observed. In the beginning f freezing, when inclination angle increased, the freezing rate was increased and when the water in test section formed the more stable density layer, freezing was faster because the convective fluid flow became small. When the initial temperature was above the 4℃, the frozen thickness in the upper part of inclined surface was thinner than that of the lower part, but with time the frozen thickness of upper part was thicker than that of lower part, below the 4℃, the frozen thickness in the upper part was thicker than that of lower part from the begining, and above the 8℃, upper part was thinner with concave in the beginning.
Reaction characteristics of dimethyl ether (DME) steam reforming catalysts for hydrogen production
Kim, Daesuk,Park, Gyeongho,Choi, Byungchul,Kim, Young-Bae Pergamon Press 2017 International journal of hydrogen energy Vol.42 No.49
<P><B>Abstract</B></P> <P>The purpose of this study was to develop new catalysts for dimethyl ether (DME) steam reforming (SR) in the absence of a carrier gas for hydrogen fuel cell vehicles and to find the optimal reaction conditions for said process. The steam reforming catalysts were prepared by impregnation of Cu, the active material, with Ce and Ni additives using mordenite (MOR) and alumina as supports. The prepared catalysts were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), and inductively coupled plasma – optical emission spectrometer (ICP-OES). The catalysts were prepared in honeycomb and pellet form. The hydrogen yield with the pellet Cu10MOR10/γ-Al<SUB>2</SUB>O<SUB>3</SUB> catalyst was 80% at 400 °C, higher than that obtained with the honeycomb catalyst under the same experimental conditions (50%). The ratio of H<SUB>2</SUB>O/DME, one of the most important parameters among the experimental conditions, afforded the best hydrogen yield at a value of 6, higher than the theoretical ratio of 3. Space velocity (SV) values in the range of 340–510 h<SUP>−1</SUP> afforded hydrogen yields of ∼80%. The hydrogen yield was similar at temperatures in the range of 300–550 °C although, at 400–450 °C, higher DME conversions and lower CH<SUB>4</SUB> production were observed. The addition of Ni to the catalyst resulted in the inhibition of the deposition of hydrocarbons, and the Ce additive was found to increase the DME conversion. Finally, it was found that the best catalyst for DME steam reforming was Cu10Ce4MOR10/γ-Al<SUB>2</SUB>O<SUB>3</SUB>. The optimum reaction conditions for H<SUB>2</SUB> production were determined as SV = 340 h<SUP>−1</SUP>, H<SUB>2</SUB>O/DME ratio = 6, the pellet-type catalyst, and a catalytic reaction temperature range of 400–450 °C.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Development of Dimethyl ether steam reforming (SR) catalyst for H<SUB>2</SUB> fuel cell vehicles. </LI> <LI> Best amounts of Ce and Ni for the DME SR catalyst was less than 14 wt%. </LI> <LI> Pellet type catalyst has advantageous for DME steam reforming reaction. </LI> <LI> Best H<SUB>2</SUB> yield reached 80% on the Cu10MOR10/γ-Al<SUB>2</SUB>O<SUB>3</SUB> catalyst at 400 °C. </LI> <LI> Additive Ni suppressed CH<SUB>4</SUB>, DME emission, and Ce suppressed carbon deposition. </LI> </UL> </P>
Kim, Byungchul,Jang, Jinsung,Kim, Tae Kyu,Ahn, Jung-Ho American Scientific Publishers 2012 Journal of Nanoscience and Nanotechnology Vol.12 No.7
<P>In the present work, the evolution of nanoparticles during annealing and hot-consolidation in mechanically alloyed Ni-22Cr-1.5Y, Ni-22Cr-1.5Y2O3 and Ni-3% Y2O3 was examined. The high-energy ball-milling of elemental powders resulted in the complete dissolution of the constituent Cr, Y, or Y2O3, forming a Ni-based solid solution. During the subsequent annealing, however, oxide particles precipitated from the solid solution. In the case of mechanically alloyed Ni-22Cr-1.5Y2O3, over-grown Cr2O3 precipitated at a temperature as low as above approximately 500 degrees C and ternary YCrO3 particles precipitated at 1100 degrees C. In the case of mechanically alloyed Ni-22Cr-1.5Y, on the other hand, the binary Y2O3 phase precipitated at 1100 degrees C during spark plasma sintering. The presence of Cr in the alloy composition facilitated the formation of Cr2O3 or YCrO3, and the precipitated oxides were highly prone to grain growth during hot-consolidation, sometimes reaching several micrometers. In Cr-exempt Ni-3%Y or Ni-3% Y2O3, however, the growth of nanodispersoids was restrained even at temperatures as high as 1000 degrees C and the resulting dispersoid was only nano-sized Y2O3.</P>
An Experimental Study on Two Stratified Fluids with A Lower Cooling Surface
Kim, byungchul,Jean, hyungdong,Lee, dongsuk,An, sangsu CHOSUN UNIVERSITY 1997 Basic Science and Engineering Vol.1 No.1
Two stratified fluids (water and spindle oil) in aspect ratio o 1 to 1 were studied experimently with the variation of an initial temperature and a cooling surface temperature in a square cavity with a lower cooling surface. As an initial temperature and a cooling surface temperature were varied, the supercooling phenomenon was observed. As soon as a supercooling phenomenon was fininshed, a latent heat was emitted. It was investigated the range of the temperature of spindle oil which was increased with the influence of the latent heat. when the initial tmperature was low, the temperature of spindle oil was increased up to the upper part of the test section. In other case, the temperature of spindle oil was increased up to the center of that oil.