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Liang Shen

Publications and source records attributed to Liang Shen.

28 records · Page 2Linked to original sources
PubMed2004

Catena-Poly[[[1,8-bis(2-hydroxyethyl)-1,3,6,8,10,13-hexaazacyclotetradecane]copper(II)]-micro-cyano-[tricyanonitrosoiron(III)]-micro-cyano].

The bimetallic title complex, [CuFe(CN)(5)(C(12)H(30)N(6)O(2))(NO)] or [Cu(L)Fe(CN)(5)(NO)] [where L is 1,8-bis(2-hydroxyethyl)-1,3,6,8,10,13-hexaazacyclotetradecane], has a one-dimensional zigzag polymeric -Cu(L)-NC-Fe(NO)(CN)(3)-CN-Cu(L)- chain, in which the Cu(II) and Fe(II) centres are linked by two CN groups. In the complex, the Cu(II) ion is coordinated by four N atoms from the L ligand [Cu-N(L) = 1.999 (2)-2.016 (2) A] and two cyanide N atoms [Cu-N = 2.383 (2) and 2.902 (3) A], and has an elongated octahedral geometry. The Fe(II) centre is in a distorted octahedral environment, with Fe-N(nitroso) = 1.656 (2) A and Fe-C(CN) = 1.938 (3)-1.948 (3) A. The one-dimensional zigzag chains are linked to form a three-dimensional network via N-H.N and O-H.N hydrogen bonds.

Journal Article↗
PubMed2004

Tandem mass spectrometric analysis of distinct fragmentation patterns to [M+Na]/z and [M+H]/z of dendritic Al(III) and Zn(II) quinolates.

The synthesis of two novel dendritic aluminum and zinc quinolates, which are soluble in common solvents, was monitored effectively by positive ion electrospray ionization mass spectrometry (ESI-MS). Through tandem mass spectrometric analysis of the complexes, distinct fragmentation pathways for sodium adduct molecular ion [M+Na]+ and protonated molecular ion [M+H]+ were observed.

Journal Article↗
PubMed2003

Tissue microarray study for classification of breast tumors.

Clinical and pathological heterogeneity of breast cancer hinders selection of appropriate treatment for individual cases. Molecular profiling at gene or protein levels may elucidate the biological variance of tumors and provide a new classification system that correlates better with biological, clinical and prognostic parameters. We studied the immunohistochemical profile of a panel of seven important biomarkers using tumor tissue arrays. The tumor samples were then classified with a monothetic (binary variables) clustering algorithm. Two distinct groups of tumors are characterized by the estrogen receptor (ER) status and tumor grade (p = 0.0026). Four biomarkers, c-erbB2, Cox-2, p53 and VEGF, were significantly overexpressed in tumors with the ER-negative (ER-) phenotype. Eight subsets of tumors were further identified according to the expression status of VEGF, c-erbB2 and p53. The malignant potential of the ER-/VEGF+ subgroup was associated with the strong correlations of Cox-2 and c-erbB2 with VEGF. Our results indicate that this molecular classification system, based on the statistical analysis of immunohistochemical profiling, is a useful approach for tumor grouping. Some of these subgroups have a relative genetic homogeneity that may allow further study of specific genetically-controlled metabolic pathways. This approach may hold great promise in rationalizing the application of different therapeutic strategies for different subgroups of breast tumors.

Algorithms↗
PubMed2003

Diaqua(2,2'-bipyridine)malonatomanganese(II).

In the crystal structure of the title compound, [Mn(C(3)H(2)O(4))(C(10)H(8)N(2))(H(2)O)(2)], the Mn(II) atom demonstrates a distorted octahedral geometry, being coordinated by two N atoms of a 2,2'-bipyridine ligand, two O atoms from the carboxylate groups of the chelating malonate dianion and two O atoms of two cis water molecules. The complex molecules are linked to form a three-dimensional supramolecular array by both hydrogen-bonding interactions between coordinated water and the carboxylate groups of neighboring molecules and aromatic pi-pi-stacking interactions of the bipyridine rings.

Journal Article↗
PubMed2003

Ribbons of hydrogen-bonded rings in the 1:2 complex of pyromellitic acid and dimethyl sulfoxide.

In the title complex, pyromellitic acid-dimethyl sulfoxide (1/2), C(10)H(6)O(8).2C(2)H(6)OS, molecules of pyromellitic acid (1,2,4,5-benzenetetracarboxylic acid) and dimethyl sulfoxide, the latter being well ordered, are linked to each other by O-H.O hydrogen bonds. The formula unit displays crystallographic inversion symmetry. The packing consists of ribbons of hydrogen-bonded rings that can be described by graph set C(2)(1)(10)R(4)(2)(18).

Journal Article↗
PubMed2002

catena-Poly[tris(ethylenediamine-kappa2N,N')nickel(II) [[trithiocyanato-kappa3N-sodium(I)]-mu-aqua-kappa2O:O]].

The title complex, ([Ni(C(2)H(8)N(2))(3)][Na(NCS)(3)(H(2)O)])(n), consists of discrete [Ni(en)(3)](2+) dications (en is ethylenediamine) and polymeric [(H(2)O)(0.5)Na(NCS)(3)(H(2)O)(0.5)](n)(2n-) anions. The compound crystallizes in space group P-3c1. The Ni(II) atom lies on a threefold axis and has a distorted octahedral coordination geometry. The Na(+) cation also lies on a site with imposed crystallographic threefold symmetry and is coordinated by the thiocyanate N atoms (the thiocyanates are in general positions), by one water molecule with crystallographically imposed 32 symmetry and by a second water molecule with crystallographically imposed -3 symmetry. The unique Na atom thus has trigonal-bipyramidal coordination. The O atoms of the water molecules bridge the Na(+) cations to form one-dimensional polymeric chains in the crystal structure. The [Ni(en)(3)](2+) dications are distributed around and between the chains and are linked to them via N-H.S hydrogen bonds.

Journal Article↗
PubMed2002

[2,2'-(1,3,5,8,10,12-Hexaazacyclotetradecane-3,10-diyl)diethanol-kappa4N1,N5,N8,N12]bis(thiocyanato-kappaS)copper(II).

In the crystal structure of the title compound, [Cu(NCS)(2)(C(12)H(30)N(6)O(2))], the Cu atom lies on an inversion centre and has an elongated octahedral coordination, with Cu-N distances of 2.004 (2) and 2.015 (2) A, and a Cu-S distance of 2.9696 (10) A. The 2,2'-ethanol chains are axially oriented. The molecules are linked to form a three-dimensional network via O-H.N, N-H.O and N-H.S hydrogen bonds.

Journal Article↗
PubMed2002

u-Cyano-1:2 kappa(2)C:N-tetracyano-1 kappa(4)C-(5-methyl-5-nitro-3,7-diazanonane-1,9-diamine-2 kappa(4)N(1,3,6,9))-nitrosyl-1 kappa N-copper(II)iron(II) dihydrate.

The title binuclear complex, [CuFe(CN)(5)(C(8)H(21)N(5)O(2))(NO)] x 2H(2)O or [CuFe(nelin)(CN)(5)(NO)] x 2H(2)O (nelin is 5-methyl-5-nitro-3,7-diazanonane-1,9-diamine) consists of discrete binuclear mixed-metal species, with a Cu centre linked to an Fe centre through a cyano bridge, and two water molecules of crystallization. In the complex, the Cu(II) ion is coordinated by five N atoms and has a distorted square-pyramidal geometry. The Fe(II) centre is in a distorted octahedral environment.

Journal Article↗
PubMedDate not supplied

A theoretical elucidation on the solvent-dependent photosensitive behaviors of C60.

In this paper, the solvent-dependent photosensitive behaviors of fullerene (C(60)) were investigated in polar and nonpolar solvents by time-dependent density functional theory (TD-DFT) calculation. Based on the calculated physicochemical parameters on triplet state, it is revealed that excited-state C(60) only generates (1)O(2) via energy transfer in benzene, but can give birth to O(2)(.-) and (1)O(2) in water via energy transfer and electron transfer, respectively. Considering the fact that electron transfer is more favorable compared with energy transfer in polar biological systems, especially with the presence of electron donors, the O(2)(.-)-generating process will get predominant in physiological systems. These results account well for the experimental observations that O(2)(.-) and (.)OH are primarily responsible for the photoinduced DNA cleavage by C(60) under physiological conditions, whereas (1)O(2) plays a critical role in nonpolar solvents.

DNA Damage↗