Structure and Stacking Faults in Sr₂Be₂B₂O7 Crystal

X. Y. Meng,X. H. Wen,G. L. Liu 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4

Inspired by the successful study on the structure instability of Na₂Al₂B₂O7 (NABO), we extend our interest to a theoretical study, by using density functional theory, on the crystal structures of Sr₂Be₂B₂O7 (SBBO), which possess pretty much the same [M₂B₂O7]∞ (M = Be, Al) double layers as those of the NABO crystal. The energy differences of the SBBO structural variants are found to be so slight that stacking faults could readily occur in the crystal. We propose that different phases may coexist in the same SBBO crystallite, forming domain structure similar to those of NABO which were found by using single-crystal X-ray diffraction. The structural stability of SBBO is closely related to the cohesion forces between [Be₂B₂O7 ∞ layers. A similar structure analysis can be extended to the SBBO isomorphism. Inspired by the successful study on the structure instability of Na₂Al₂B₂O7 (NABO), we extend our interest to a theoretical study, by using density functional theory, on the crystal structures of Sr₂Be₂B₂O7 (SBBO), which possess pretty much the same [M₂B₂O7]∞ (M = Be, Al) double layers as those of the NABO crystal. The energy differences of the SBBO structural variants are found to be so slight that stacking faults could readily occur in the crystal. We propose that different phases may coexist in the same SBBO crystallite, forming domain structure similar to those of NABO which were found by using single-crystal X-ray diffraction. The structural stability of SBBO is closely related to the cohesion forces between [Be₂B₂O7 ∞ layers. A similar structure analysis can be extended to the SBBO isomorphism.

OBSERVATIONAL AND DYNAMICAL CHARACTERIZATION OF MAIN-BELT COMET P/2010 R2 (La Sagra)

Hsieh, Henry H.,Yang, Bin,Haghighipour, Nader,Novakovi&#x107,, Bojan,Jedicke, Robert,Wainscoat, Richard J.,Denneau, Larry,Abe, Shinsuke,Chen, Wen-Ping,Fitzsimmons, Alan,Granvik, Mikael,Grav, Tommy,Ip, American Institute of Physics 2012 The Astronomical journal Vol.143 No.5

<P>We present observations of the recently discovered comet-like main-belt object P/2010 R2 (La Sagra) obtained by Pan-STARRS1 and the Faulkes Telescope-North on Haleakala in Hawaii, the University of Hawaii 2.2 m, Gemini-North, and Keck I telescopes on Mauna Kea, the Danish 1.54 m telescope (operated by the MiNDSTEp consortium) at La Silla, and the Isaac Newton Telescope on La Palma. An antisolar dust tail is observed to be present from 2010 August through 2011 February, while a dust trail aligned with the object's orbit plane is also observed from 2010 December through 2011 August. Assuming typical phase darkening behavior, P/La Sagra is seen to increase in brightness by >1 mag between 2010 August and December, suggesting that dust production is ongoing over this period. These results strongly suggest that the observed activity is cometary in nature (i.e., driven by the sublimation of volatile material), and that P/La Sagra is therefore the most recent main-belt comet to be discovered. We find an approximate absolute magnitude for the nucleus of H<SUB>R</SUB> = 17.9 ± 0.2 mag, corresponding to a nucleus radius of ~0.7 km, assuming an albedo of p = 0.05. Comparing the observed scattering surface areas of the dust coma to that of the nucleus when P/La Sagra was active, we find dust-to-nucleus area ratios of A<SUB>d</SUB>/A<SUB>N</SUB> = 30-60, comparable to those computed for fellow main-belt comets 238P/Read and P/2008 R1 (Garradd), and one to two orders of magnitude larger than for two other main-belt comets (133P/Elst-Pizarro and 176P/LINEAR). Using optical spectroscopy to search for CN emission, we do not detect any conclusive evidence of sublimation products (i.e., gas emission), finding an upper limit CN production rate of Q<SUB>CN</SUB> < 6 × 10<SUP>23</SUP> mol s<SUP>–1</SUP>, from which we infer an H<SUB>2</SUB>O production rate of <img SRC='http://ej.iop.org/images/1538-3881/143/5/104/aj423523ieqn1.gif' ALIGN='MIDDLE' ALT='$Q_{\rm H_2O}\,{<}\,10^{26}$'/> mol s<SUP>–1</SUP>. Numerical simulations indicate that P/La Sagra is dynamically stable for >100 Myr, suggesting that it is likely native to its current location and that its composition is likely representative of other objects in the same region of the main belt, though the relatively close proximity of the 13:6 mean-motion resonance with Jupiter and the (3,–2,–1) three-body mean-motion resonance with Jupiter and Saturn mean that dynamical instability on larger timescales cannot be ruled out.</P>

Nanosized Carbon Black Combined with Ni₂O₃ as “Universal” Catalysts for Synergistically Catalyzing Carbonization of Polyolefin Wastes to Synthesize Carbon Nanotubes and Application for Supercapacitors

Wen, Xin,Chen, Xuecheng,Tian, Nana,Gong, Jiang,Liu, Jie,Ru&#x308,mmeli, Mark H.,Chu, Paul K.,Mijiwska, Ewa,Tang, Tao American Chemical Society 2014 Environmental science & technology Vol.48 No.7

<P>The catalytic carbonization of polyolefin materials to synthesize carbon nanotubes (CNTs) is a promising strategy for the processing and recycling of plastic wastes, but this approach is generally limited due to the selectivity of catalysts and the difficulties in separating the polyolefin mixture. In this study, the influence of nanosized carbon black (CB) and Ni<SUB>2</SUB>O<SUB>3</SUB> as a novel combined catalyst system on catalyzing carbonization of polypropylene (PP), polyethylene (PE), polystyrene (PS) and their blends was investigated. We showed that this combination was efficient to promote the carbonization of these polymers to produce CNTs with high yields and of good quality. Catalytic pyrolysis and model carbonization experiments indicated that the carbonization mechanism was attributed to the synergistic effect of the combined catalysts rendered by CB and Ni<SUB>2</SUB>O<SUB>3</SUB>: CB catalyzed the degradation of PP, PE, and PS to selectively produce more aromatic compounds, which were subsequently dehydrogenated and reassembled into CNTs via the catalytic action of CB together with Ni particles. Moreover, the performance of the synthesized CNTs as the electrode of supercapacitor was investigated. The supercapacitor displayed a high specific capacitance as compared to supercapacitors using commercial CNTs and CB. This difference was attributed to the relatively larger specific surface areas of our synthetic CNTs and their more oxygen-containing groups.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2014/esthag.2014.48.issue-7/es404646e/production/images/medium/es-2013-04646e_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es404646e'>ACS Electronic Supporting Info</A></P>

R&D Status of High-current Accelerators at IFP

J. J. Deng,J. S. Shi,W. P. Xie,L. W. Zhang,K. Z. Zhang,S. P. Feng,J. Li,M. Wang,Y. He,L. S. Xia,Z. Y. Dai,H. T. Li,L. Wen,S. F. Chen,X. Li,Q. G. Lai,M. H. Xia,Y. C. Guan,S. Y. Song,L. Chen 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.61

High-current accelerators have many important applications in Z-pinches, high-power microwaves, and free electron lasers, imploding liners and radiography and so on. Research activities on Zpinches, imploding liners, radiography at the Institute of Fluid Physics (IFP) are introduced. Several main high-current accelerators developed and being developed at IFP are described, such as the Linear Induction Accelerator X-Ray Facility Upgrade (LIAXFU, 12 MeV, 2.5 kA, 90 ns), the Dragon-I linear induction accelerator (20 MeV, 2.5 kA, 60 ns), and the Primary Test Stand for Z-pinch (PTS, 10 MA, 120 ns). The design of Dragon-II linear induction accelerator (20 MeV, 2.5 kA, 3 × 60 ns) to be built will be presented briefly.

Growth Performance, Carcass Composition and Meat Quality of Jiulong-yak (Bos grunniens)

Zi, X.D.,Zhong, G.H.,Wen, Y.L.,Zhong, J.C.,Liu, C.L.,Ni, Y.A.,Yezi, Y.H.,Ashi, M.G. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.3

Estimated liveweights, carcass characteristics, the proximate composition and amino-acid composition of the whole rib cut of the 10th/12th thoracic vertebrae have been determined for Jiulong-yak. The animal grows rapidly up to puberty at 2-3 years of age. At those ages, females reached 143.0$\pm$34.7 kg and 184.0$\pm$30.8 kg (SD) respectively, which was 60 to 80% of their mature weight at 6 to 7 yr old, then the rate of growth significantly slowed down. Males continued to rapidly increase body weight until an older age possibly due to the selection procedures. Animals included 20 males aged from 2.5 to 6.5 yr, seven females aged of 4.5 yr and 11 steers aged of 4.5-5.5 yr were slaughtered for carcass determination and chemical analysis of meat samples. Dressing-out percentage and ribeye area ranged from 48.53-55.04% and 48.02-68.56 $cm^2$ respectively, both of which differed by age and sex. Yak meat is scarlet in color and intramuscular marbling is poor. The 10th/12th rib-cut contained 24.99-31.93% dry matter; 19.98-22.58% protein; 2.52-10.86% fat and 0.93-1.00% ash. Meat from females and steers contained a higher percentage of fat than those from bulls. The pH of M. Longissimus dorsi measured at 24 h post-mortem ranged from 5.84-6.11. Amino acid composition was similar to that for other red meat, except for a lower content of methionine (1.26 g/100 g meat). The results indicated that yak meat can make a valuable contribution to the diets for the highlanders.

Ursolic acid increases the secretion of atrial natriuretic peptide in isolated perfused beating rabbit atria

Cui, H.Z.,Wen, J.F.,Choi, H.R.,Li, X.,Cho, K.W.,Kang, D.G.,Lee, H.S. North-Holland ; Elsevier Science Ltd 2011 european journal of pharmacology Vol.653 No.1

Ursolic acid is reported to have beneficial effects on the regulation of cardiovascular homeostasis. However, the effects of ursolic acid on cardiac hormone secretion are yet to be defined. The present study was designed to test the effects of ursolic acid on the secretory and contractile functions of the atria. Experiments were conducted in isolated perfused beating rabbit atria. We measured the changes in atrial dynamics, pulse pressure, stroke volume, cAMP efflux, as well as the secretion of atrial natriuretic peptide (ANP). Ursolic acid increased ANP secretion and mechanical dynamics in a concentration-dependent manner. The inhibition of L-type Ca<SUP>2+</SUP> channels with nifedipine attenuated the ursolic acid-induced increase in ANP secretion but not mechanical dynamics. The inhibition of K<SUP>+</SUP><SUB>ATP</SUB> channels with glibenclamide attenuated the ursolic acid-induced increase in ANP secretion-but not atrial dynamics-in a concentration-dependent manner. The selective Na<SUP>+</SUP>-K<SUP>+</SUP>-ATPase inhibitor ouabain blocked the ursolic acid-induced increase in atrial dynamics but not ANP secretion. These findings show that ursolic acid increases ANP secretion via its activation of K<SUP>+</SUP><SUB>ATP</SUB> channels and subsequent inhibition of Ca<SUP>2+</SUP> entry through L-type Ca<SUP>2+</SUP> channels in rabbit atria. These data also suggest that ursolic acid increases atrial dynamics via its inhibition of Na<SUP>+</SUP>-K<SUP>+</SUP>-ATPase activity.

Cardiovascular effects of ethanol extract of Rubus chingii Hu (Rosaceae) in rats: an in vivo and in vitro approach.

Su, X H,Duan, R,Sun, Y Y,Wen, J F,Kang, D G,Lee, H S,Cho, K W,Jin, S N The Society 2014 Journal of physiology and pharmacology Vol.65 No.3

<P>Rubus chingii Hu (Rosaceae) is an important traditional Chinese medicine that has been used to improve function of the kidney and treat excessive polyuria. However, the effects of Rubus chingii on the cardiovascular system and its pharmacological mechanisms of action have not been studied. The aim of the present study was to evaluate the cardiovascular effects of ethanol extract of Rubus chingii (ERC) in rats. The changes in systolic blood pressure and heart rate of rats and vascular tone of aortic rings in in vitro were measured using pressure transducer and force transducer, respectively, connected to a multichannel recording system. ERC decreased systolic blood pressure and heart rate in a concentration-dependent manner. ERC induced vasorelaxation in a concentration-dependent manner. The ERC-induced vasorelaxation was not observed in the absence of the endothelium. The vasorelaxant effect of ERC was significantly attenuated by inhibition of endothelial NO synthase (eNOS), soluble guanylyl cyclase (sGC), or Ca(2+) entry from extracellular sources with L-NAME, ODQ, diltiazem, or extracellular Ca(2+) depletion, respectively. Similarly, an inhibition of Akt with wortmannin attenuated the ERC-induced vasorelaxation. Modulators of the store-operated Ca(2+) entry, thapsigargin, Gd(3+), and 2-aminoethyl diphenylborinate markedly attenuated the ERC-induced vasorelaxation. Furthermore, 4-aminopyridine an inhibitor of voltage-dependent K(+) (KV) channel, significantly attenuated the ERC-induced vasorelaxation. However, tetraethylammonium and glibenclamide, had no significant effect on the ERC-induced vasorelaxation. Indomethacin, atropine, and propranolol had no effects on the ERC-induced vasorelaxation. The present study demonstrates that ERC induces vasorelaxation via endothelium-dependent two-step signaling: an activation of the Ca(2+)-eNOS-NO signaling in the endothelial cells and then subsequent stimulation of the NO-sGC-cGMP-KV channel signaling in the vascular smooth muscle cells. The Akt-eNOS pathway is also suggested to be involved in this relaxation. Also, the findings suggest that the ERC-induced vasorelaxation is closely related to the hypotensive action of the agent.</P>

Prognostic significance of stromal GREM1 expression in colorectal cancer

Jang, B.G.,Kim, H.S.,Chang, W.Y.,Bae, J.M.,Oh, H.J.,Wen, X.,Jeong, S.,Cho, N.Y.,Kim, W.H.,Kang, G.H. W.B. Saunders Co 2017 Human pathology Vol.62 No.-

<P>Cancer-associated fibroblasts are the dominant cell population in the cancer stroma. Gremlin 1 (GREM1), an antagonist of the bone morphogenetic protein pathway, is expressed by cancer-associated fibroblasts in a variety of human cancers. However, its biological significance for cancer patients is largely unknown. We applied RNA in situ hybridization to evaluate the prognostic value of stromal GREM1 expression in a large cohort of 670 colorectal cancers (CRCs). Overall, GREM1 expression in CRCs was lower than that of the matched normal mucosa, and GREM1 expression had a strong positive correlation with BMI1 and inverse correlations with EPHB2 and OLFM4. RNA in situ hybridization localized the GREM expression to smooth muscle cells of the muscularis mucosa and fibroblasts around crypt bases and in the submucosal space of a normal colon. In various colon polyps, epithelial GREM1 expression was exclusively observed in traditional serrated adenomas. In total, 44% of CRCs were positive for stromal GREM1, which was associated with decreased lymphovascular invasion, a lower cancer stage, and nuclear beta-catenin staining. Stromal GREM1 was significantly associated with improved recurrence-free and overall survival, although it was not found to be an independent prognostic marker in multivariate analyses. In addition, for locally advanced stage II and III CRC, it was associated with better, stage-independent clinical outcomes. In summary, CRCs are frequently accompanied by GERM1-expressing fibroblasts, which are closely associated with low lymphovascular invasion and a better prognosis, suggesting stromal GREM1 as a potential biomarker and possible candidate for targeted therapy in the treatment of CRCs. (C) 2017 Elsevier Inc. All rights reserved.</P>

Are clinicopathological features of colorectal cancers with methylation in half of CpG island methylator phenotype panel markers different from those of CpG island methylator phenotype-high colorectal cancers?

Bae, J.M.,Rhee, Y.Y.,Kim, K.J.,Wen, X.,Song, Y.S.,Cho, N.Y.,Kim, J.H.,Kang, G.H. W. B. Saunders Co ; Centrum Philadelphia 2016 Human pathology Vol.47 No.1

<P>CpG island methylator phenotype (CIMP)-high (CIMP-H) colorectal cancer (CRC) is defined when a tumor shows methylation at greater than or equal to 60% of CIMP panel markers. Although CRCs with methylation at 50% of panel markers are classified as CIMP-low/CIMP-0 tumors, little is known regarding the clinicopathological and molecular features of CRCs with methylation at 4/8 panel markers (4/8 methylated markers) and whether they are akin to CIMP-H or CIMP-low/CIMP-0 CRCs in terms of their clinicopathological or molecular features. A total of 1164 cases of surgically resected CRC were analyzed for their methylation status in 8 CIMP panel markers, and the frequencies of various clinicopathological and molecular features were compared between CRCs with 0/8, 1/8 to 3/8,4/8, and 5/8 to 8/8 methylated markers. CRCs with 4/8 methylated markers were closer to CRCs with 5/8 to 8/8 methylated markers in terms of sex distribution, mucin production, serration, nodal metastasis, CK7 expression, CK20 loss, and CDX2 loss frequencies and overall survival rate. CRCs with methylation at 4/8 markers were closer to CRCs with 1/8 to 3/8 methylated markers in terms of less frequent right colon location and poor differentiation. CRCs with 4/8 methylated markers showed the shortest overall survival time compared with CRCs with 0/8, 1/8 to 3/8,4/8, or 5/8 to 8/8 methylated markers. In terms of clinicopathological and molecular features, CRCs with 4/8 methylated markers appeared to be closer to CIMP-H than to CIMP-low/CIMP-0 and would thus be better classified as CIMP-H if the CRCs require classification into either CIMP-H or CIMP-low/CIMP-0. (C) 2015 Elsevier Inc. All rights reserved.</P>

Performance Evaluation of Busbar Protection Schemes under Different Fault Scenarios

X. Xu,H. Li,H. Wen 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Busbar plays an important role in the transmission and distribution network of the electrical power system, and busbar protection is also an indispensable part of the relaying protection. This digest will focus on studying the property of the busbar protection. The basic analyzing approaches are explained and the performance of busbar protection is discussed by the simulation and calculation results. Three fault scenarios are analyzed through the software of PSCAD and MATLAB. The corresponding protective action of different zones in the double busbar system is derived. Simulation results show that the relay can make right decision for different fault scenarios.