Assessment of potential jaw‐tracking advantage using control point sequences of VMAT planning

Kim, Jung&#x2010,in,Park, Jong Min,Park, So&#x2010,Yeon,Choi, Chang Heon,Wu, Hong&#x2010,Gyun,Ye, Sung&#x2010,Joon unknown 2014 Journal of applied clinical medical physics Vol.15 No.2

<P>This study aims to evaluate the potential jaw‐tracking advantage using control point sequences of volume volumetric‐modulated arc therapy (VMAT) planning. VMAT plans for patients with prostate and head and neck (H&N) cancers were converted into new static arc (SA) plans. The SA plan consisted of a series of static fields at each control point of the VMAT plan. All other machine parameters of the SA plan were perfectly identical to those of the original VMAT plan. The jaw‐tracking static arc (JTSA) plans were generated with fields that closed the jaws of each SA field into the multileaf collimators (MLCs) aperture. The dosimetric advantages of JTSA over SA were evaluated in terms of a dose‐volume histogram (DVH) of organ at risk (OAR) after renormalizing both plans to make the same target coverage. Both plans were delivered to the MatriXX‐based COMPASS system for 3D volume dose verification. The average jaw size reduction of the JTSA along the X direction was 3.1±0.9 cm for prostate patients and 6.9±1.9 cm for H&N patients. For prostate patients, the organs far from the target showed larger sparing (3.7%—8.1% on aver‐age) in JTSA than the organs adjacent to the target (1.1%—1.5%). For the H&N plans, the mean dose reductions for all organs ranged from 4.3% to 11.9%. The dose reductions were more significant in the dose regions of <SUB>D80</SUB>,<SUB>D90</SUB>, and <SUB>D95</SUB> than the dose regions of <SUB>D5</SUB>,<SUB>D10</SUB>, and <SUB>D20</SUB> for all patients. Likewise, the deliverability and reproducibility of jaw‐tracking plan were validated. The measured dosimetric advantage of JTSA over SA coincided with the calculated one above.</P><P>PACS numbers: 87.55.D‐, 87.55.ne</P>

Combining In Situ Synchrotron X‐Ray Diffraction and Absorption Techniques with Transmission Electron Microscopy to Study the Origin of Thermal Instability in Overcharged Cathode Materials for Lithium‐Ion Batteries

Nam, Kyung&#x2010,Wan,Bak, Seong&#x2010,Min,Hu, Enyuan,Yu, Xiqian,Zhou, Youngning,Wang, Xiaojian,Wu, Lijun,Zhu, Yimei,Chung, Kyung&#x2010,Yoon,Yang, Xiao&#x2010,Qing WILEY‐VCH Verlag 2013 Advanced Functional Materials Vol.23 No.8

<P><B>Abstract</B></P><P>The thermal instability of the cathode materials in lithium‐ion batteries is an important safety issue, requiring the incorporation of several approaches to prevent thermal runaway and combustion. Systematic studies, using combined well‐defined in situ techniques, are crucial to obtaining in‐depth understanding of the structural origin of this thermal instability in overcharged cathode materials. Here time‐resolved X‐ray diffraction, X‐ray absorption, mass spectroscopy, and high‐resolution transmission electron microscopy during heating are combined to detail the structural changes in overcharged Li<SUB><I>x</I></SUB>Ni<SUB>0.8</SUB>Co<SUB>0.15</SUB>Al<SUB>0.05</SUB>O<SUB>2</SUB> and Li<SUB><I>x</I></SUB>Ni<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>O<SUB>2</SUB> cathode materials. By employing these several techniques in concert, various aspects of the structural changes are investigated in these two materials at an overcharged state; these include differences in phase‐distribution after overcharge, phase nucleation and propagation during heating, the preferred atomic sites and migration paths of Ni, Co, and Mn, and their individual contributions to thermal stability, together with measuring the oxygen release that accompanies these structural changes. These results provide valuable guidance for developing new cathode materials with improved safety characteristics.</P>

The effect of body contouring on the dose distribution delivered with volumetric‐modulated arc therapy technique

Lee, Jaegi,Park, Jong Min,Wu, Hong&#x2010,Gyun,Kim, Jin Ho,Ye, Sung&#x2010,Joon unknown 2015 Journal of applied clinical medical physics Vol.16 No.6

<P>The purpose of the study was to investigate the dosimetric effect defining the body structure with various Hounsfield unit (HU) threshold values on the dose distributions of volumetric‐modulated arc therapy (VMAT) plans. Twenty patients with prostate cancer and twenty patients with head and neck (H&N) cancer were retrospectively selected. For each patient, the body structure was redefined with HU threshold values of −180(<SUB>Body180</SUB>), −350(<SUB>Body350</SUB>), −700(<SUB>Body700</SUB>), and −980(<SUB>Body980</SUB>). For each patient, dose‐volumetric parameters with those body structures were calculated using identical VMAT plans. The differences in dose‐volumetric parameters due to the varied HU threshold values were calculated. For the prostate boost target volume, the maximum dose, mean dose, <SUB>D95%</SUB>, and <SUB>D5%</SUB> with <SUB>Body180</SUB> were higher than those with <SUB>Body980</SUB> by approximately 0.7% (p<0.001). For H&N target volumes, the changes in <SUB>D95%</SUB> of the targets receiving 67.5 Gy, 54 Gy, and 48 Gy between <SUB>Body180</SUB> and <SUB>Body980</SUB> were −1.2%, −0.9%, and −1.2%, respectively (p<0.001). The differences were larger for H&N VMAT plans than for prostate VMAT plans due to the inclusion of an immobilization device in the irradiated region in H&N cases. To apply all attenuating materials to dose calculation, the body structure would be defined with −980 HU. Otherwise, systematic error of about 1%, resulting in underdosage of the target volume, can occur.</P><P>PACS number: 87.55.ne</P>

6,6′‐Bieckol inhibits adipocyte differentiation through downregulation of adipogenesis and lipogenesis in 3T3‐L1 cells

Kwon, Tae&#x2010,Hyung,Wu, Yong&#x2010,Xiang,Kim, Jong&#x2010,Shik,Woo, Jung&#x2010,Hee,Park, Kyu Tae,Kwon, O Jun,Seo, Hyun&#x2010,Ju,Kim, Taewan,Park, Nyun&#x2010,Ho John Wiley Sons, Ltd 2015 Journal of the Science of Food and Agriculture Vol.95 No.9

<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>Brown algae have been used for their nutritional value as well as a source of bioactive compounds with antioxidant, anti‐inflammatory, antimicrobial and anti‐obesity effects. Obesity is an important condition implicated in various diseases, including diabetes, hypertension, dyslipidemia and coronary heart disease. However, anti‐obesity effects of <I>Eisenia bicyclis</I> remain unknown.</P><P><B>RESULTS</B></P><P>We investigated the anti‐obesity effects of 6,6′‐bieckol, 6,8′‐bieckol, 8,8′‐bieckol, dieckol and phlorofucofuroeckol A isolated from <I>E</I>. <I>bicyclis.</I> Anti‐obesity activity was evaluated by examining the inhibition of differentiation of 3T3‐L1 adipocytes and the expression of peroxisome proliferator‐activated receptor γ (PPARγ), CCATT/enhancer‐binding protein α (C/EBPα) and sterol regulatory element binding protein‐1c (SREBP‐1c) at the mRNA and protein level. Differentiated 3T3‐L1 cells were treated with the purified phlorotannins at concentrations of 10, 25 and 50 µg mL<SUP>−1</SUP> for 8 days. The results indicated that the purified phlorotannins suppressed the differentiation of 3T3‐L1 adipocytes in a dose–dependent manner, without toxic effects. Among the five compounds, 6,6′‐bieckol markedly decreased lipid accumulation and expression levels of PPARγ, C/EBPα, SREBP‐1c (mRNA and protein), and fatty acid synthase and acyl‐coA carboxylase (mRNA).</P><P><B>CONCLUSION</B></P><P>These findings suggest that <I>E</I>. <I>bicyclis</I> suppressed differentiation of 3T3‐L1 adipocyte through downregulation of adipogenesis and lipogenesis. © 2014 Society of Chemical Industry</P>

The multiple merger assembly of a hyperluminous obscured quasar at redshift 4.6

Di&#x301,az-Santos, T.,Assef, R. J.,Blain, A. W.,Aravena, M.,Stern, D.,Tsai, C.-W.,Eisenhardt, P.,Wu, J.,Jun, H. D.,Dibert, K.,Inami, H.,Lansbury, G.,Leclercq, F. American Association for the Advancement of Scienc 2018 Science Vol.362 No.6418

<P><B>Mergers drive a powerful dusty quasar</B></P><P>Massive galaxies in the early Universe host supermassive black holes at their centers. When material falls toward the black hole, it releases energy and is observed as a quasar. Astronomers found a population of powerful distant quasars that are obscured by dust, but it has been unclear how they are formed. Díaz-Santos <I>et al.</I> observed the dust-obscured quasar WISE J224607.56-052634.9 at submillimeter wavelengths, finding three small companion galaxies connected to the quasar by bridges of gas and dust. They inferred that galaxy mergers can provide both the raw material to power a quasar and large quantities of dust to obscure it.</P><P><I>Science</I>, this issue p. 1034</P><P>Galaxy mergers and gas accretion from the cosmic web drove the growth of galaxies and their central black holes at early epochs. We report spectroscopic imaging of a multiple merger event in the most luminous known galaxy, WISE J224607.56−052634.9 (W2246−0526), a dust-obscured quasar at redshift 4.6, 1.3 billion years after the Big Bang. Far-infrared dust continuum observations show three galaxy companions around W2246−0526 with disturbed morphologies, connected by streams of dust likely produced by the dynamical interaction. The detection of tidal dusty bridges shows that W2246−0526 is accreting its neighbors, suggesting that merger activity may be a dominant mechanism through which the most luminous galaxies simultaneously obscure and feed their central supermassive black holes.</P>

Sclerodermatous chronic graft‐versus‐host disease induced by host T‐cell‐mediated autoimmunity

Lee, You Jeong,Min, Hye Sook,Kang, Eun Ha,Park, Hyo Jin,Jeon, Yoon Kyung,Kim, Ju Hyun,Wu, Hong Gyun,Lee, Eun&#x2010,Bong,Park, Chung&#x2010,Gyu,Yoon, Sung&#x2010,Soo,Park, Seong Hoe,Jung, Kyeong Cheon Nature Publishing Group 2012 Immunology and cell biology Vol.90 No.3

<P>Despite a long‐standing hypothesis that chronic graft‐versus‐host disease (cGVHD) is an autoimmune disorder, most mouse models of cGVHD have been developed on the assumption that donor T cells are essential for its development. Here we show that cGVHD may be caused by autoreactive host T cells in mice that have been lethally irradiated and grafted with T‐cell‐depleted allogeneic bone marrow cells. In this chimera, host T cells derived from radioresistant intrathymic T‐cell precursors caused dermal fibrosis and periportal inflammation, without the requirement for donor T cells. The lack of host DCs within the thymus after high‐dose irradiation allowed autoreactive host T cells to escape thymic negative selection. Moreover, the homeostatic expansion of these T cells may augment their autoreactivity. These findings indicate that host T‐cell‐mediated cGVHD is an autoimmune process that occurs following the grafting of T‐cell‐depleted BM cells into hosts with functioning thymuses. We propose, based on the present data, that host T‐cell‐dependent autoimmunity is a potential mechanism by which cGVHD is induced.</P>

A new plan quality index for dose painting radiotherapy

Park, Yang&#x2010,Kyun,Park, Soyeon,Wu, Hong&#x2010,Gyun,Kim, Siyong unknown 2014 Journal of applied clinical medical physics Vol.15 No.4

<P>Dose painting radiotherapy is considered a promising radiotherapy technology that enables more targeted dose delivery to tumor rich regions while saving critical normal tissues. Obviously, dose painting planning would be more complicated and hard to be evaluated with current plan quality index systems that were developed under the paradigm of uniform dose prescription. In this study, we introduce a new plan quality index, named “index of achievement (IOA)” that assesses how close the planned dose distribution is to the prescribed one in a dose painting radiotherapy plan. By using voxel‐based comparison between planned and prescribed dose distributions in its formulation, the index allows for a single‐value evaluation regardless of the number of prescribed dose levels, which cannot be achieved with the conventional indices such as conventional homogeneity index. Benchmark calculations using patient data demonstrated feasibility of the index not only for contour‐based dose painting plans, but also for dose painting by numbers plans. Also, it was shown that there is strong correlation between the new index and conventional indices, which indicates a potential of the new index as an alternative to conventional ones in general radiotherapy plan evaluation.</P><P>PACS number: 87.55.D‐</P>

Oxidation of Cymantrene Analogues of Ferrocifen: Electrochemical, Spectroscopic, and Computational Studies of the Parent Complex 1,1′-Diphenyl-2-cymantrenylbutene

Wu, Kan,Park, Ji Young,Al-Saadon, Rachael,Nam, Hyerim,Lee, Yujin,Top, Siden,Jaouen, Ge&#x301,rard,Baik, Mu-Hyun,Geiger, William E. American Chemical Society 2018 Organometallics Vol.37 No.12

<P>The oxidative electrochemical behavior of 1,1′-diphenyl-2-cymantrenylbutene (<B>1</B>), a cymantrene analogue of the breast cancer drug ferrocifen, was shown to involve the sequential electron-transfer series <B>1</B>/<B>1</B><SUP>+</SUP>/<B>1</B><SUP>2+</SUP> in dichloromethane/0.05 M [NBu<SUB>4</SUB>][B(C<SUB>6</SUB>F<SUB>5</SUB>)<SUB>4</SUB>] (<I>E</I><SUB>1/2</SUB> values 0.78 and 1.18 V vs ferrocene). By a combination of spectroscopic and computational techniques, it was shown that the cymantrene functionality plays an important role in dissipating the positive charges in the oxidized compounds and is therefore an active participant in the redox events. The redox-active orbital goes from roughly equal degrees of organometallic and π-organic (diphenylolefin) makeup in <B>1</B> to increasingly organic based fractions in <B>1</B><SUP>+</SUP> and <B>1</B><SUP>2+</SUP>. Structural changes mimicking those of oxidized tetrakis(aryl)ethylenes accompany the one-electron oxidations. There is sufficient unpaired electron density on the manganese center in <B>1</B><SUP>+</SUP> to allow for oxidatively induced ligand exchange of one or more of the carbonyl ligands with donor ligands, including phosphites and pyridine. The complex Mn(CO)<SUB>2</SUB>P(OPh)<SUB>3</SUB>(η<SUP>5</SUP>-C<SUB>5</SUB>H<SUB>4</SUB>(Et)C═C(C<SUB>6</SUB>H<SUB>5</SUB>)<SUB>2</SUB>) was prepared by the “electrochemical switch” method, wherein [Mn(CO)<SUB>2</SUB>P(OPh)<SUB>3</SUB>(η<SUP>5</SUP>-C<SUB>5</SUB>H<SUB>4</SUB>(Et)C═C(C<SUB>6</SUB>H<SUB>5</SUB>)<SUB>2</SUB>)]<SUP>+</SUP>, produced by the oxidation of <B>1</B> in the presence of P(OPh)<SUB>3</SUB>, was reduced back to the neutral CO-substituted complex.</P> [FIG OMISSION]</BR>

ACA‐specific RNA sequence recognition is acquired via the loop 2 region of MazF mRNA interferase

Park, Jung&#x2010,Ho,Yoshizumi, Satoshi,Yamaguchi, Yoshihiro,Wu, Kuen&#x2010,Phon,Inouye, Masayori Wiley Subscription Services, Inc., A Wiley Company 2013 Proteins Vol.81 No.5

<P><B>Abstract</B></P><P>MazF is an mRNA interferase that cleaves mRNAs at a specific RNA sequence. MazF from <I>E</I>. <I>coli</I> (MazF‐ec) cleaves RNA at A and CA. To date, a large number of MazF homologs that cleave RNA at specific three‐ to seven‐base sequences have been identified from bacteria to archaea. MazF‐ec forms a dimer, in which the interface between the two subunits is known to be the RNA substrate‐binding site. Here, we investigated the role of the two loops in MazF‐ec, which are closely associated with the interface of the MazF‐ec dimer. We examined whether exchanging the loop regions of MazF‐ec with those from other MazF homologs, such as MazF from <I>Myxococcus xanthus</I> (MazF‐mx) and MazF from <I>Mycobacterium tuberculosis</I> (MazF‐mt3), affects RNA cleavage specificity. We found that exchanging loop 2 of MazF‐ec with loop 2 regions from either MazF‐mx or MazF‐mt3 created a new cleavage sequence at (A/U)(A/U)AA and C in addition to the original cleavage site, A and CA, whereas exchanging loop 1 did not alter cleavage specificity. Intriguingly, exchange of loop 2 with 8 or 12 consecutive Gly residues also resulted in a new RNA cleavage site at (A/U)(A/U)AA and C. The present study suggests a method for expanding the RNA cleavage repertoire of mRNA interferases, which is crucial for potential use in the regulation of specific gene expression and for biotechnological applications. Proteins 2013. © 2012 Wiley Periodicals, Inc.</P>

<i>Cis‐</i>control of <i>Six1</i> expression in neural crest cells during craniofacial development

Wu, Zhaoming,Rao, Yanxia,Zhang, Sushan,Kim, Eun&#x2010,Jung,Oki, Shinya,Harada, Hidemitsu,Cheung, Martin,Jung, Han&#x2010,Sung John WileySons, Inc. 2019 Developmental dynamics Vol.248 No.12

<P><B>Abstract</B></P><P><B>Background</B></P><P><I>Six1</I> is a transcriptional factor that plays an important role in embryonic development. Mouse and chick embryos deficient for <I>Six1</I> have multiple craniofacial anomalies in the facial bones and cartilages. Multiple <I>Six1</I> enhancers have been identified, but none of them has been reported to be active in the maxillary and mandibular process.</P><P><B>Results</B></P><P>We studied two <I>Six1</I> enhancers in the chick neural crest tissues during craniofacial development. We showed that two evolutionarily conserved enhancers, Six1E1 and Six1E2, act synergistically. Neither Six1E1 nor Six1E2 alone can drive enhancer reporter signal in the maxillary or mandibular processes. However, their combination, Six1E, showed robust enhancer activity in these tissues. Similar reporter signal can also be driven by the mouse homolog of Six1E. Mutations of multiple conserved transcriptional factor binding sites altered the enhancer activity of Six1E, especially mutation of the LIM homeobox binding site, dramatically reduced the enhancer activity, implying that the Lhx protein family be an important regulator of <I>Six1</I> expression.</P><P><B>Conclusion</B></P><P>This study, for the first time, described the synergistic activation of two <I>Six1</I> enhancers in the maxillary and mandibular processes and will facilitate more detailed studies of the regulation of <I>Six1</I> in craniofacial development.</P><P><B>Key Findings</B></P><P>Two evolutionarily conserved enhancers control <I>Six1</I> expression in the maxillary and mandibular process synergistically. The synergy is also evolutionarily conserved. Lhx binding site is important for the enhancer activity.</P>