47 research outputs found
The -rainbow index of random graphs
A tree in an edge colored graph is said to be a rainbow tree if no two edges
on the tree share the same color. Given two positive integers , with
, the \emph{-rainbow index} of is the
minimum number of colors needed in an edge-coloring of such that for any
set of vertices of , there exist internally disjoint rainbow
trees connecting . This concept was introduced by Chartrand et. al., and
there have been very few related results about it. In this paper, We establish
a sharp threshold function for and
respectively, where and are
the usually defined random graphs.Comment: 7 pages. arXiv admin note: substantial text overlap with
arXiv:1212.6845, arXiv:1310.278
Design and synthesis of non-peptidic thiosemicarbazone derivatives as inhibitors of cathepsins L and K.
Cathepsin L, a member of the lysosome cysteine proteases, is ubiquitously expressed in tissue and is responsible for protein turnover. An overexpression of cathepsin L by certain tumor types is associated with enhanced tumor expansion through degradation of the extracellular matrix and the invasion and migration of cancer cells. Therefore, the inhibition of cathepsin L has emerged as a therapeutic strategy against metastatic cancer. Cathepsin K is involved in osteoclastic bone resorption because it is selectively expressed in osteoclasts and is capable of degrading bone matrix. In this project, a small library of thiosemicarbazone derivatives containing thiochromanone, 2,3-dihydroquinoline-4-one, and dibenzoylbenzene scaffolds has been successfully designed and synthesized as potential inhibitors of cathepsin L and other homologous cathepsins (B and K). Through a collaborative study, ten compounds from this library were found to be potent inhibitors (IC50 < 300 nM) of cathepsin L, and nine compounds were potent inhibitors of cathepsin K. None of these inhibitors showed activity against cathepsin B. For example, 6,7-difluorothiochromanone thiosemicarbazone 4 (IC50 = 46 nM) was the most potent inhibitor against cathepsin L from this group, while the 6-trifluoromethyl derivative 28 (IC50 = 21 nM) was the most potent inhibitor against cathepsin K. Structure activity relationship (SAR) studies centered on the thiochromanone thiosemicarbazone scaffold demonstrated that electron-withdrawing functionalities, incorporated primarily at the 6-position of the thiochromanone scaffold, showed good inhibition against cathepsin L in comparison to related analogues bearing electron-donating groups. Collectively, these results expand the known SAR regarding molecular structures and their inhibitory activity against cathepsins L and K.Ph.D
New skew Laplacian energy of simple digraphs
For a simple digraph of order with vertex set, let and denote theout-degree and in-degree of a vertex in , respectively. Let and. In this paper we introduce to be a new kind of skewLaplacian matrix of , where and is the skew-adjacency matrix of , and from which we definethe skew Laplacian energy of as the sum of the norms ofall the eigenvalues of . Some lower and upperbounds of the new skew Laplacian energy are derived and the digraphsattaining these bounds are also determined
Preparation of the Carbonized Zif−8@PAN Nanofiber Membrane for Cadmium Ion Adsorption
The zeolitic imidazolate framework (ZIF−8)@polyacrylonitrile (PAN) nanofiber membrane was prepared and carbonized for heavy metal cadmium ion (Cd2+) adsorption in aqueous medium. Zinc oxide (ZnO) was first sputtered onto the surface of the PAN electrospun nanofiber membrane to provide a metal ion source. Then, the ZIF−8@PAN nanofiber membrane was prepared via in situ solvothermal reaction and carbonized in a tube furnace at 900 °C under a N2 atmosphere to enhance adsorption performance. The synthesized ZIF−8 particles with polyhedral structure were uniformly immobilized on the surface of the PAN electrospun nanofiber membrane. After being heated at 900 °C, the polygonal ZIF−8 shrank, and the carbonized ZIF−8@PAN nanofiber membrane was obtained. Compared with the nanofiber membrane without being carbonized, the adsorption capacity of the carbonized ZIF−8@PAN nanofiber membrane reached 102 mg L−1, and its Cd2+ adsorption efficiency could be more than 90% under the adsorption temperature of 35 °C and solution of pH = 7.5 conditions. According to the adsorption thermodynamics analysis, the Cd2+ adsorption process of the carbonized ZIF−8@PAN nanofiber membrane was spontaneous. The whole Cd2+ adsorption process was more suitably described by the pseudo second-order adsorption kinetics model, indicating that there exists a chemical adsorption mechanism besides physical adsorption
Oral Administration of a Seed-based Bivalent Rotavirus Vaccine Containing VP6 and NSP4 Induces Specific Immune Responses in Mice
Rotavirus is the leading cause of severe diarrheal disease among newborns. Plant-based rotavirus vaccines have been developed in recent years and have been proven to be effective in animal models. In the present study, we report a bivalent vaccine candidate expressing rotavirus subunits VP6 and NSP4 fused with the adjuvant subunit B of E. coli heat-labile enterotoxin (LTB) in maize seeds. The RT-PCR and Western blot results showed that VP6 and LTB-NSP4 antigens were expressed and accumulated in maize seeds. The expression levels were as high as 0.35 and 0.20% of the total soluble protein for VP6 and LTB-NSP4, respectively. Oral administration of transgenic maize seeds successfully stimulated systemic and mucosal responses, with high titers of serum IgG and mucosal IgA antibodies, even after long-term storage. This study is the first to use maize seeds as efficient generators for the development of a bivalent vaccine against rotavirus