http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Localizing virtual fundamental cycles for semi-perfect obstruction theories
World Scientific 2018 International Journal of Mathematics Vol.29 No.4
<P>Recently, Chang and Li generalized the theory of virtual fundamental class to the setting of semi-perfect obstruction theory. A semi-perfect obstruction theory requires only the local existence of a perfect obstruction theory with compatibility conditions. In this paper, we generalize the torus localization of Graber-Pandharipande [T. Graber and R. Pandharipande, Localization of virtual cycles, <I>Invent. Math.</I><B>135</B>(2) (1999) 487-518], the cosection localization [Y.-H. Kiem and J. Li, Localizing virtual cycles by cosections, <I>J. Amer. Math. Soc.</I><B>26</B>(4) (2013) 1025-1050] and their combination [H.-L. Chang, Y.-H. Kiem and J. Li, Torus localization and wall crossing for cosection localized virtual cycles, <I>Adv. Math.</I><B>308</B> (2017) 964-986], to the setting of semi-perfect obstruction theory. As an application, we show that the Jiang-Thomas theory [Y. Jiang and R. Thomas, Virtual signed Euler characteristics, preprint (2014), arXiv:1408.2541] of virtual signed Euler characteristic works without the technical quasi-smoothness assumption from derived algebraic geometry.</P>
Kiem, Phan Van,Anh, Hoang Le Tuan,Nhiem, Nguyen Xuan,Minh, Chau Van,Thuy, Nguyen Thi Kim,Yen, Pham Hai,Hang, Dan Thuy,Tai, Bui Huu,Mathema, Vivek Bhakta,Koh, Young-Sang,Kim, Young Ho The Pharmaceutical Society of Japan 2012 Chemical & pharmaceutical bulletin Vol.60 No.2
<P>The rhizomes of <I>Hedychium coronarium</I> have been used for the treatment of inflammation, skin diseases, headache, and sharp pain due to rheumatism in traditional medicine. From this plant, two new labdanes, 15-methoxylabda-8(17),11<I>E</I>,13-trien-16,15-olide (<B>1</B>) and 16-methoxylabda-8(17),11<I>E</I>,13-trien-15,16-olide (<B>3</B>), named hedycoronens A and B, as well as four known, labda-8(17),11,13-trien-16,15-olide (<B>2</B>), 16-hydroxylabda-8(17),11,13-trien-15,16-olide (<B>4</B>), coronarin A (<B>5</B>), and corronarin E (<B>6</B>) were isolated. Their chemical structures were elucidated by mass, 1D- and 2D-nuclear magnetic resonance (NMR) spectroscopy. They were evaluated for inhibitory effects on the lipopolysaccharide (LPS)-stimulated production of pro-inflammatory cytokines in bone marrow-derived dendritic cells. Among of them, compounds <B>1</B>—<B>3</B> were potent inhibitors of LPS-stimulated interleukin-6 (IL-6) and IL-12 p40, with IC<SUB>50</SUB> ranging from 4.1±0.2 to 9.1±0.3 μ<SMALL>M</SMALL>. Compounds <B>1</B> and <B>3</B> showed moderate inhibitory activity on the tumor necrosis factor-α (TNF-α) production with IC<SUB>50</SUB> values of 46.0±1.3 and 12.7±0.3 μ<SMALL>M</SMALL>. The remains of compounds showed inactivity. These results warrant further studies concerning the potential anti-inflammatory benefits of labdane-diterpenes from <I>H. coronarium</I>.</P>
CRITICAL VIRTUAL MANIFOLDS AND PERVERSE SHEAVES
Kiem, Young-Hoon,Li, Jun Korean Mathematical Society 2018 대한수학회지 Vol.55 No.3
In Donaldson-Thomas theory, moduli spaces are locally the critical locus of a holomorphic function defined on a complex manifold. In this paper, we develop a theory of critical virtual manifolds which are the gluing of critical loci of holomorphic functions. We show that a critical virtual manifold X admits a natural semi-perfect obstruction theory and a virtual fundamental class $[X]^{vir}$ whose degree $DT(X)=deg[X]^{vir}$ is the Euler characteristic ${\chi}_{\nu}$(X) weighted by the Behrend function ${\nu}$. We prove that when the critical virtual manifold is orientable, the local perverse sheaves of vanishing cycles glue to a perverse sheaf P whose hypercohomology has Euler characteristic equal to the Donaldson-Thomas type invariant DT(X). In the companion paper, we proved that a moduli space X of simple sheaves on a Calabi-Yau 3-fold Y is a critical virtual manifold whose perverse sheaf categorifies the Donaldson-Thomas invariant of Y and also gives us a mathematical theory of Gopakumar-Vafa invariants.
Phenolic Constituents with Inhibitory Activity against NFAT Transcription from Desmos chinensis
Kiem Phan Van,Minh Chau Van,Huang Hoang Thanh,Lee Jung Joon,Lee Im Seon,Kim Young Ho The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.12
Six phenolic constituents, 2-methoxybenzyl benzoate (1), negletein (2), 2',3'-dihydroxy-4',6'dimethoxydihydrochalcone (3), 5,6-dihydroxy-7-methoxy-dihydroflavone (4), astilbin (5), and quercitrin (6) were isolated from the methanol extract of the dried leaves of Desmos chinensis. Their structures were elucidated from spectral and chemical data. Of these constituents, compounds 2 ($IC_{50}$: 3.89 $\pm$ 0.39 $\mu$M) and 3 ($IC_{50}$: 9.77 $\pm$ 0.26 $\mu$M) exhibited potent inhibitory activity against nuclear factor of activated T cells (NFAT) transcription factor, and compound 1 ($IC_{50}$: 28.4 $\pm$ 2.62 $\mu$M) exhibited moderate inhibitory activity.
Pentacyclic Triterpenoids from Mallotus apelta
Kiem, Phan-Van,Minh, Chau-Van,Huong, Hoang-Thanh,Nam, Nguyen-Hoai,Lee, Jung-Joon,Kim, Young-Ho The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.11
A new triterpene (1) and six known pentacyclic terpenoids (2-7) were isolated from the methanol extract of the dried leaves from Mallotus apelta. Based on the spectral and chemical evidence, their structures were determined to be 3$\alpha$-hydroxyhop-22(29)-ene (1), hennadiol (2), friedelin (3), friedelanol (4), epifriedelanol (5), taraxerone (6), and epitaraxerol (7).
Two New Phenylpropanoid Glycosides from the Stem Bark of Acanthopanax trifoliatus
Kiem, Phan-Van,Minh, Chau-Van,Dat, Nguyen-Tien,Cai, Xing-Fu,Lee, Jung-Joon,Kim, Young-Ho The Pharmaceutical Society of Korea 2003 Archives of Pharmacal Research Vol.26 No.12
Two new phenylpropanoid glycosides, 1-$\beta$-D-glucopyranosyl-2,6-dimethoxy-4-propenylphenol (1) and 1-[$\beta$-D-glucopyranosyl-(1$\rightarrow6)-\beta$-D-glucopyranosyl]-2,6-dimethoxy-4-propenylphenol (2) were isolated from the stem bark of Acanthopanax trifoliatus along with four known compounds (3∼6). Their structures were established on the basis of spectral and chemical evidences.
A New 24-Nor-Lupane-Glycoside of Acanthopanax trifoliatus
Kiem, Phan-Van,Minh, Chau-Van,Cai, Xing-Fu,Lee, Jung-Joon,Kim, Young-Ho The Pharmaceutical Society of Korea 2003 Archives of Pharmacal Research Vol.26 No.9
A new 24-nor-lupaneglycoside was isolated from the leaves of Acanthopanax trifoliatus. Based on spectroscopic data its chemical structure was determined as 24-nor-11$\alpha$-hydroxy-3-oxo-lup-20(29)-en-28-oic acid 28-Ο-$\alpha$-L-rhamnopyranosyl-(1$\rightarrow4)-\beta-D-glucopyranosyl-(1\rightarrow6)-\beta$-D-glucopyranosyl ester.