Cation-Dependent Intrinsic Electrical Conductivity in Isostructural Tetrathiafulvalene-Based Microporous Metal–Organic Frameworks

Park, Sarah S.,Hontz, Eric R.,Sun, Lei,Hendon, Christopher H.,Walsh, Aron,Van Voorhis, Troy,Dincă,, Mircea American Chemical Society 2015 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.137 No.5

<P>Isostructural metal–organic frameworks (MOFs) M<SUB>2</SUB>(TTFTB) (M = Mn, Co, Zn, and Cd; H<SUB>4</SUB>TTFTB = tetrathiafulvalene tetrabenzoate) exhibit a striking correlation between their single-crystal conductivities and the shortest S···S interaction defined by neighboring TTF cores, which inversely correlates with the ionic radius of the metal ions. The larger cations cause a pinching of the S···S contact, which is responsible for better orbital overlap between p<SUB><I>z</I></SUB> orbitals on neighboring S and C atoms. Density functional theory calculations show that these orbitals are critically involved in the valence band of these materials, such that modulation of the S···S distance has an important effect on band dispersion and, implicitly, on the conductivity. The Cd analogue, with the largest cation and shortest S···S contact, shows the largest electrical conductivity, σ = 2.86 (±0.53) × 10<SUP>–4</SUP> S/cm, which is also among the highest in microporous MOFs. These results describe the first demonstration of tunable intrinsic electrical conductivity in this class of materials and serve as a blueprint for controlling charge transport in MOFs with π-stacked motifs.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2015/jacsat.2015.137.issue-5/ja512437u/production/images/medium/ja-2014-12437u_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja512437u'>ACS Electronic Supporting Info</A></P>

INFLUENCE OF ENDOGENOUS SOMATOSTATIN ON LACTATION IN RATS

Sun, S.S.,Myung, K.H.,Spencer, G.S.G. Asian Australasian Association of Animal Productio 1996 Animal Bioscience Vol.9 No.3

The role of endogenous somatostatin on lactation in rats was examined by passive immuno-neutralization of Wistar rats. In one study, the rats were given either immunoglobulin raised in sheep against somatostatin, or non-specific sheep immunoglobulins by daily s.c. injection from parturition through the first two weeks of lactation. The growth of the pups was recorded by weighting every second day, and the milk yield calculated from the pup weight and weight gain. Immunoneutralization of maternal somatostatin during pregnancy had a slight effect (p < 0.05) on the mean birth weight of the pups but no subsequent effect on postnatal growth rate of the pups or milk yield ($25.32{\pm}0.88g/day$) compared with young control rats given normal sheep serum ($25.55{\pm}1.04g/day$). Similarly, passive immunization against somatostatin during lactation ($21.96{\pm}1.57g/day$) also did not affect milk yields compared with controls ($24.85{\pm}1.03g/day$). These data do not support a significant role for endogenous somatostatin in regulating milk production in lactating rats.

Expression of cancer-associated fibroblast-related proteins in thyroid papillary carcinoma

Sun, W. Y.,Jung, W. H.,Koo, J. S. Springer Science + Business Media 2016 TUMOR BIOLOGY Vol.37 No.6

<P>The purpose of this study was to evaluate the association between expression of cancer-associated fibroblast (CAF)-related proteins in papillary thyroid carcinoma (PTC) and clinicopathologic factors. Using tissue microarray (TMA) constructed from 339 cases of PTC (303 classic type, 36 follicular variant), we performed immunohistochemical staining for podoplanin, prolyl 4-hydroxylase, FAP alpha, S100A4, PDGFR alpha, PDGFR beta, NG2, 5-meC, and BRAF V600E and evaluated the association with clinicopathologic parameters. We classified the stroma of PTC as desmoplastic type, sclerotic type, pauci type, or inflammatory type. The expression of prolyl 4-hydroxylase (p = 0.042), FAP alpha (p = 0.044), PDGFR alpha (p < 0.001), and 5-meC (p = 0.030) in cancer cells differed according to the histologic subtype, higher in classic type than follicular type. The expression of FAP alpha (p = 0.034) and 5-meC (p = 0.021) in stromal cells was higher in the classic type than follicular type. PTC with BRAF mutation showed higher expression of podoplanin (p < 0.001), prolyl 4-hydroxylase (p = 0.013), FAP alpha (p < 0.001), S100A4 (p < 0.001), PDGFR alpha (p < 0.001), and 5-meC (p < 0.001) in the tumor cell compartment and of FAP alpha (p = 0.004), S100A4 (p < 0.001), PDGFR alpha (p = 0.002), PDGFR beta (p < 0.001), and 5-meC (p < 0.001) in the stromal cell compartment. There was also a difference in the expression of CAF-related proteins according to stromal phenotype; the expression of FAP alpha, S100A4, and PDGFR alpha was higher in desmoplastic type than in other subtypes, whereas NG2 expression was higher in inflammatory type (p < 0.001). Tumoral podoplanin negativity (p = 0.043) was associated with shorter DFS, and tumoral S100A4 positivity (p = 0.044) and stromal PDGFR beta positivity (p = 0.035) were associated with shorter OS. In conclusion, the expression of CAF-related proteins in cancer cells and stromal cells of PTC was different according to histologic subtype, BRAF V600E mutation, and subtype of stroma, and was related to prognosis.</P>

Contribution of small phytoplankton to total primary production in the Chukchi Sea

Lee, S.H.,Sun Yun, M.,Kyung Kim, B.,Joo, H.,Kang, S.H.,Keun Kang, C.,Whitledge, T.E. Pergamon Press ; Elsevier Science Ltd 2013 Continental shelf research Vol.68 No.-

Given a projection of thriving small phytoplankton in the Arctic Ocean under climate-induced environmental changes, it is important to estimate the contribution of small phytoplankton (0.7-5μm) to the total primary production in the Chukchi Sea, which is an important conduit of organic matter from the North Pacific to the Arctic Ocean. Based on a <SUP>13</SUP>C-<SUP>15</SUP>N dual isotope tracer technique, small phytoplankton productivity measurements were taken during two consecutive cruises in the Chukchi Sea in 2004. The total phytoplankton carbon uptake rates ranged from 0 to 25.38mgCm<SUP>-3</SUP>h<SUP>-1</SUP>, whereas the uptake rates of small phytoplankton ranged from 0 to 2.87mgCm<SUP>-3</SUP>h<SUP>-1</SUP>. In comparison with the carbon uptake rates, total phytoplankton nitrate uptake rates ranged from 0 to 4.40mgNm<SUP>-3</SUP>h<SUP>-1</SUP> while small phytoplankton nitrate uptake rates ranged from 0 to 0.39mgNm<SUP>-3</SUP>h<SUP>-1</SUP>. Ammonium uptake rates ranged from 0 to 8.34mgNm<SUP>-3</SUP>h<SUP>-1</SUP> and from 0.01 to 2.18mgNm<SUP>-3</SUP>h<SUP>-1</SUP>, for total and small phytoplankton, respectively. Small phytoplankton contributed 24.80% (S.D.=+/-23.0%) to the total chlorophyll-a concentration, and 59.41% (S.D.=+/-52.12%) to the total carbon biomass due to its higher particulate organic carbon per chlorophyll-a unit during the two cruises in 2004. In the Chukchi Sea, the average contributions of small phytoplankton to carbon and total nitrogen (nitrate+ammonium) uptake rates were 31.72% (S.D.=+/-23.59%) and 37.31% (S.D.=+/-26.06%), respectively.

Ribosomal Protein S6, a Target of Rapamycin, Is Involved in the Regulation of rRNA Genes by Possible Epigenetic Changes in <i>Arabidopsis</i>

Kim, Yun-Kyoung,Kim, Sunghan,Shin, Yun-jeong,Hur, Yoon-Sun,Kim, Woo-Young,Lee, Myung-Sok,Cheon, Choong-Ill,Verma, Desh Pal S. American Society for Biochemistry and Molecular Bi 2014 The Journal of biological chemistry Vol.289 No.7

<P>The target of rapamycin (TOR) kinase pathway regulates various biological processes, including translation, synthesis of ribosomal proteins, and transcription of rRNA. The ribosomal protein S6 (RPS6) is one of the well known downstream components of the TOR pathway. Ribosomal proteins have been known to have diverse functions in regulating cellular metabolism as well as protein synthesis. So far, however, little is known about other possible role(s) of RPS6 in plants, besides being a component of the 40 S ribosomal subunit and acting as a target of TOR. Here, we report that RPS6 may have a novel function via interaction with histone deacetylase 2B (AtHD2B) that belongs to the plant-specific histone deacetylase HD2 family. RPS6 and AtHD2B were localized to the nucleolus. Co-expression of RPS6 and AtHD2B caused a change in the location of both RPS6 and AtHD2B to one or several nucleolar spots. ChIP analysis suggests that RPS6 directly interacts with the rRNA gene promoter. Protoplasts overexpressing both <I>AtHD2B</I> and <I>RPS6</I> exhibited down-regulation of pre-18 S rRNA synthesis with a concomitant decrease in transcription of some of the ribosomal proteins, suggesting their direct role in ribosome biogenesis and plant development. This is consistent with the mutation in <I>rps6b</I> that results in reduction in 18 S rRNA transcription and decreased root growth. We propose that the interaction between RPS6 and AtHD2B brings about a change in the chromatin structure of rDNA and thus plays an important role in linking TOR signaling to rDNA transcription and ribosome biogenesis in plants.</P>

Rational Design of Low Cost and High Energy Lithium Batteries through Tailored Fluorine-free Electrolyte and Nanostructured S/C Composite

Agostini, M.,Lim, D.-H.,Sadd, M.,Hwang, J.-Y.,Brutti, S.,Heo, J. W.,Ahn, J. H.,Sun, Y. K.,Matic, A. Wiley (John WileySons) 2018 ChemSusChem Vol.11 No.17

<P>We report a new Li-S cell concept based on an optimized F-free catholyte solution and a high loading nanostructured C/S composite cathode. The Li2S8 present in the electrolyte ensures both buffering against active material dissolution and Li+ conduction. The high S loading is obtained by confining elemental S (approximate to 80%) in the pores of a highly ordered mesopores carbon (CMK3). With this concept we demonstrate stabilization of a high energy density and excellent cycling performance over 500 cycles. This Li-S cell has a specific capacity that reaches over 1000 mA hg(-1), with an overall S loading of 3.6 mg cm(-2) and low electrolyte volume (i.e., 10 mu L cm(-2)), resulting in a practical energy density of 365 Wh kg(-1). The Li-S system proposed thus meets the requirements for large scale energy storage systems and is expected to be environmentally friendly and have lower cost compared with the commercial Li-ion battery thanks to the removal of both Co and F from the overall formulation.</P>

Clinical Significance of Chronic Kidney Disease and Atrial Fibrillation on Morbidity and Mortality in Patients with Acute Myocardial Infarction

Hwang, Hyeon Seok,Park, Mahn-Won,Yoon, Hye Eun,Chang, Yoon Kyung,Yang, Chul Woo,Kim, Suk Young,Cho, Jung Sun,Kim, Chan Joon,Park, Gyung-Min,Park, Chul-Soo,Choi, Yun-Seok,Koh, Yoon-Seok,Lee, Jong Min,S S. Karger AG 2014 American journal of nephrology Vol.40 No.4

<P>Abstract</P><P><B><I>Background/Aims:</I></B> Atrial fibrillation (AF) often coexists with acute myocardial infarction (AMI), and chronic kidney disease (CKD) is a major risk for AMI. However, the combined impact of CKD and AF on the mortality and morbidity in AMI population has not been determined. <B><I>Methods:</I></B> Between January 2004 and December 2009, a total of 4,738 AMI patients were enrolled prospectively. Patients were divided into four groups according to the combined status of CKD and AF. The primary endpoint was a combination of 5-year major adverse cardiac and cerebrovascular events (MACCE). <B><I>Results:</I></B> The prevalence of AF was significantly higher in CKD patients than in non-CKD patients (6.76 vs. 3.31%, p < 0.001). The highest cumulative event rate of MACCE and death was observed in patients with both CKD and AF (68.5 and 64.0%), respectively. In multivariable analyses, compared with patients with neither AF nor CKD, hazard ratios (HR) for composite of MACCE were 1.66 (95% CI, 1.14-2.41), 1.24 (95% CI, 1.06-1.46), and 2.10 (95% CI, 1.42-3.13) for patients with AF only, those with CKD only, and those with both CKD and AF, respectively (p for interaction = 0.935). Patients with both CKD and AF had a greatest risk for all-cause mortality (HR 2.54; 95% CI, 1.60-4.53), and the significant synergistic interaction was observed between CKD and AF (p for interaction = 0.015). <B><I>Conclusion:</I></B> The combined effect of AF and CKD on the risk of MACCE after an AMI is stronger than any separate condition, and it confers a synergistic effect on the all-cause mortality risk.</P><P>© 2014 S. Karger AG, Basel</P>

Is 15 mm Size Criterion for Lacunar Infarction Still Valid? A Study on Strictly Subcortical Middle Cerebral Artery Territory Infarction Using Diffusion-Weighted MRI

Cho, A-Hyun,Kang, Dong-Wha,Kwon, Sun U.,Kim, Jong S. S. Karger AG 2007 Cerebrovascular diseases Vol.23 No.1

<P><I>Background and Purpose:</I> The ‘lacunar hypothesis’ has been challenged, since small (diameter <15 mm) subcortical infarcts can be produced by middle cerebral artery disease (MCAD) or cardioembolism (CE), while a larger infarct can occur without evidence of MCAD or CE. We sought to assess whether the lacunar hypothesis based on size is still valid. <I>Methods:</I> We studied 118 patients who were admitted within 72 h after stroke onset and had acute deep subcortical MCA territory infarcts detected by diffusion-weighted MRI, and who had undergone angiography (mostly MR angiography). Stroke mechanisms were arbitrarily categorized regardless of lesion size: (1) MCAD when there was a corresponding MCA lesion; (2) internal carotid artery disease (ICAD) when there was a significant (>50%) ipsilateral ICAD; (3) CE when there was emboligenic heart disease without MCAD or ICAD, and (4) small vessel disease (SVD) when there was neither CE nor MCAD. SVD was further divided into definite SVD (dSVD, longest diameter <15 mm) or probable SVD (pSVD, longest diameter ≥15 mm). <I>Results:</I> Seventy-three patients (62%) had SVD, of which 38 (32%) had pSVD and 35 (30%) dSVD. Thirty-three patients (28%) had MCAD, five (4%) CE, and seven (6%) ICAD. The infarct diameter in MCAD was not larger than in SVD (p = 0.35), and there was no difference in clinical features or risk factors between MCAD and SVD, or between pSVD and dSVD. CE was distinguished from SVD by its larger size and cortical symptoms. <I>Conclusions:</I> There are no clinical and lesion-size differences between MCAD and SVD, suggesting that there seems to be no rationale for the 15 mm size criterion for lacunar or small-vessel infarction.</P><P>Copyright © 2007 S. Karger AG, Basel</P>

Lateral Thalamic Infarction and the Vascular Geometry of the Posterior Cerebral Artery

Kim, Bum Joon,Kim, Seung Min,Ahn, Sung-ho,Kang, Dong-Wha,Kwon, Sun U.,Kim, Jong S. S. Karger AG 2016 Cerebrovascular Diseases Vol.41 No.1

<P>Background: The geometric properties of the parental artery affect the development of local atherosclerosis and perforator infarction. In this study, we aimed at investigating the association between vascular geometry of the posterior cerebral artery (PCA) and the development of isolated lateral thalamic infarction (LTI), the most frequent type of thalamic infarction. Methods: The geometric properties of the corresponding PCA in LTI patients were assessed and they include the diameters of the distal basilar artery (BA) and proximal PCA, distal BA - PCA angle, first PCA angle (angle between P1 and P2), and the presence of the posterior communicating artery (Pcom). These parameters obtained from the ipsilesional PCA were compared with the contralesional PCA and the corresponding PCA in age-and sex-matched controls. Results: Forty-five LTI patients were enrolled. The ipsilesional PCA in LTI patients demonstrated a greater ipsilesional P1 - P2 angle (81.4 +/- 22.6 vs. 71.3 +/- 23.2 degrees, respectively; p = 0.04) and a higher prevalence of Pcom (42.2 vs. 13.3%; p = 0.002) when compared to control subjects. In comparison with the contralesional PCA, ipsilesional PCA demonstrated a smaller diameter, larger angle between P1 and P2 segment, and a higher prevalence of Pcom. The presence of hyperlipidemia (OR 3.548 (1.283-9.811); p = 0.02) and Pcom (OR 3.507 (1.104-11.135); p = 0.03) was a factor that was independently associated with LTI. Conclusions: Local hemodynamics in the PCA may be influenced by the P1 - P2 angle and the presence of Pcom, which are associated with the development of LTI. (C) 2015 S. Karger AG, Basel</P>

Effects of phosphorus on the δ-Ni₃Nb phase precipitation and the stress rupture properties in alloy 718

Sun,W.R.,Lee,J.H.,Guo,S.R.,Yoo,Y.S.,Choe,S.J.,Park,N.K.,Hu,Z.Q. 창원대학교 공작기계기술연구센터 1999 연구업적집 Vol.1 No.1

The effects of phosphorus on the phase transformation and stress rupture properties of alloy 718 were investigated. The nucleation of δ- phase, which does not contain phosphorus, was suppressed by the enrichment of phosphorus at grain boundaries. A low level of phosphorus resulted in the formation of faults-containing film-like δ- phase along the grain boundaries, while a higher level of phosphorus favored the long lath-like δ- phase precipitation. Phosphorus greatly prolonged the stress rupture life of the alloy in the range of 0.0008-0.013 wt.% while it reduced the stress rupture life in the range of 0.013-0.049 wt.% The effect of phosphorus in the stress rupture properties was closely related to its interaction with oxygen. Phosphorus atoms, in the range of 0.0008-0.013 wt.%, enhanced the resistance to oxygen intrusion along the grain boundaries, protected the grain boundaries from decohesion by oxygen atoms and oxidation, and subsequently prolonged the rupture life of the alloy. The protection effect of p is clearly demonstrated by the phenomenon that the crack initiation site was shifted from the surface to the center in the stress-ruptured samples with increasing addition of P. Over 0.013 wt.%, the protection effect of phosphorus is excessive and phosphorus began to display its inherent effect of damaging the grain boundary strength ; the stress rupture life of the alloy was reduced accordingly. Maximum stress rupture life was thus obtained at ∼0.013 wt.% P ⓒ 1998 Elsevier Science S.A. All rights reserved.