On the relations of graph parameters and its total parameters

In this paper we get some relations between α（G）, α＇（G）, β（G）, β＇（G） and αT（G）, βT（G）. And all bounds in these relations are best possible, where α（G）, α＇（G）,/3（G）, β（G）, αT（G） and βT（G） are the covering number, edge-covering number, independent number, edge-independent number （or matching number）, total covering number and total independent number, respectively.     

Search for new red phosphors using genetic algorithm-assisted combinatorial chemistry

A genetic algorithm was employed in association with high-throughput synthesis and characterization in an attempt to search for red phosphors with high photoluminescent intensity. A tetravalent manganese-doped alkali earth germanium oxide system, with an emission color close to a desirable deep red, was screened with the assistance of a genetic algorithm to pinpoint the phosphor exhibiting the highest photoluminescence. As the genetic algorithm was in progress, the PL intensity increased and maximized in the fourth generation. The highest and the average PL intensity of the fourth generation improved by 23 and 120%, respectively, compared with that of the first generation.     

Stereocalpin A, a bioactive cyclic depsipeptide from the Antarctic lichen Stereocaulon alpinum

A new cyclic depsipeptide stereocalpin A (1) has been isolated from the MeOH extract of the Antarctic lichen Stereocaulon alpinum by various chromatographic methods. The structure of stereocalpin A (1) was mainly determined by analysis of the NMR spectroscopic data and by chemical methods. Stereocalpin A (1) is a unique cyclic peptide incorporating an unprecedented 5-hydroxy-2,4-dimethyl-3-oxo-octanoic acid in the structure. Stereocalpin A (1) shows moderate cytotoxicity against three human solid tumor cell lines.     

SMART: A data reporting standard for mass spectrometry imaging By Ying Xi,Alexandria L. Sohn,Alena N. Joignant,Stephanie M. Cologna,Boone M. Prentice and David C. Muddiman

Mass spectrometry imaging (MSI) is an important analytical technique that simultaneously reports the spatial location and abundance of detected ions in biological, chemical, clinical, and pharmaceutical studies. As MSI grows in popularity, it has become evident that data reporting varies among different research groups and between techniques. The lack of consistency in data reporting inherently creates additional challenges in comparing intra- and inter-laboratory MSI data. In this tutorial, we propose a unified data reporting system, SMART, based on the common features shared between techniques. While there are limitations to any reporting system, SMART was decided upon after significant discussion to more easily understand and benchmark MSI data. SMART is not intended to be comprehensive but rather capture essential baseline information for a given MSI study; this could be within a study (e.g., effect of spot size on the measured ion signals) or between two studies (e.g., different MSI platform technologies applied to the same tissue type). This tutorial does not attempt to address the confidence with which annotations are made nor does it deny the importance of other parameters that are not included in the current SMART format. Ultimately, the goal of this tutorial is to discuss the necessity of establishing a uniform reporting system to communicate MSI data in publications and presentations in a simple format to readily interpret the parameters and baseline outcomes of the data.     

Change in the interfacial reaction of Hf-silicate film as a function of thickness and stoichiometry

Medium energy ion scattering and high-resolution transmission electron microscopy are used to investigate the depth of the interfacial reaction of Hf-silicate film. The interfacial reaction is critically affected by the film thickness and the mole fraction of HfO(2) in silicate film. The interfacial compressive strain generated at the surface of the Si substrate is dependent on the film thickness during the postannealing process in film with a thickness of approximately 4 nm. Finally, the phase separation phenomenon demonstrates critically different behaviors at different film thicknesses and stoichiometries because the diffusion of Si from interface to surface is dependent on these factors. Moreover, the oxidation by oxygen impurity in the inert ambient causes SiO(2) top formation.     

Metabolism and excretion of 5-ethyl-2-{5-[4-(2-hydroxyethyl)piperazine-1-sulfonyl]-2-propoxyphenyl}-7-propyl-3,5-dihydropyrrolo[3,2-d]-pyrimidin-4-one (SK3530) in rats

The in vitro and in vivo metabolism of a novel PDE 5 inhibitor, SK3530, was investigated in rats. Bile, plasma, feces, urine and liver samples were collected and analyzed using a high-performance liquid chromatography (HPLC) system equipped with ultraviolet (UV), mass spectrometric and radioactivity detectors. After a single oral administration, the mean radiocarbon recovery was 92.32+/-6.26%, with 91.25+/-6.25 and 1.07+/-0.21% in the feces and urine, respectively. The biliary excretion of radioactivity for the first 24 h period was approximately 38.82%, suggesting that SK3530 is cleared by hepatobiliary excretion. In vitro incubation of SK3530 with rat and human liver microsomes resulted in the formation of twelve and ten metabolites, respectively. SK3530 was extensively metabolized to twenty different metabolites, including three glucuronide and three sulfate conjugates in rats. The structures of these metabolites were elucidated based on MSn spectral analyses. Six major metabolic pathways were identified in the rat: N-dealkylation and oxidation of the hydroxyethyl moiety; N,N-deethylation and hydroxylation of the piperazine ring; hydroxylation of the propyl group and sulfate conjugation. An additional metabolite due to aromatic hydroxylation was also identified in hepatic microsomes.     

1-Phenyl-1-propyne on Cu(111): TOFMS TPD, XPS, UPS, and 2PPE Studies

The bonding properties of 1-phenyl-1-propyne (PP, C6H5CCCH3) on Cu(111) at 100 K have been studied using temperature-programmed desorption (TPD), and X-ray, ultraviolet, and two-photon photoemission spectroscopies (XPS, UPS, and 2PPE). In TPD, there is no evidence for dissociation. Multilayer desorption occurs at 187 K, and monolayer desorption occurs at 320 (83.5 kJ/mol) and 390 K (102.4 kJ/mol), with the latter dominating. Based on the calibrated C(1s) XPS, the saturation monolayer coverage is one PP per four surface Cu atoms. The broad and asymmetric C(1s) intensity profile of the monolayer can be resolved into three symmetric components, with peaks at 283.6, 284.5, and 285.2 eV and intensities of 2:6:1, respectively. These are attributed, respectively, to acetylenic carbons bound to Cu, phenyl, and methyl carbons. The monolayer valence band ultraviolet photoemission spectrum profile contains four resonances attributable to PP perturbed by interactions with the Cu(111) substrate. With the exception of the highest occupied molecular orbital (HOMO) that is shifted by 0.4 eV, these are uniformly shifted by 1 eV further from the Fermi level for the multilayer. Calculated electron density plots of the occupied orbitals coupled with UPS profiles suggest a spectator role for the phenyl group and bonding to Cu via the acetylenic carbons. The adsorption of 1.0 monolayer (ML) of PP on Cu(111) lowers the work function by 0.85 eV. Using 2PPE, two unoccupied orbitals were identified at 1.0 (U1*-LUMO) and 0.6 eV (U2*-image state) below the vacuum level. A chemisorption model consistent with these spectroscopic results and the major chemisorption peak in TPD involve di-sigma-bonding of the acetylenic carbons to a pair of second-nearest neighbor surface Cu atoms (cross-bridge).     

在不同温度下球墨鑄铁的冲击性能

本文描述高温冲击实验的技术,以及由-85℃至1070℃的铸态和锻造后的球墨铸铁的冲击性能。研究结果找到了基体主要为铁素体的球墨铸铁的两个变脆温度范围(-20℃以下和550℃至700℃之间)和一个比较具有韧性的温度范围(850℃与1050℃之间)。在这些温度范围内,曾考查试样的断口情况和断裂时的弯曲角度,并与其基体组织的变化相联系,进行讨论。最后,本文指出研究结果在球墨铸铁的应用上所起的作用,以及在球墨铸铁热加工时对于选择热加工温度的意义。     

Copper-catalyzed aerobic oxidative dehydrogenation for conversion of 2-(alkylthio)-1,4-dihydropyrimidines to 2-(alkylthio)pyrimidines

A simple and efficient aerobic oxidative dehydrogenation reaction method for the conversion of 2-(alkylthio)-1,4-dihydropyrimidines to 2-(alkylthio)pyrimidines using copper catalyst with no additives, such as an oxidant, acid, or base, has been developed. The reaction was successful with a wide range of 2-(alkylthio)-1,4-dihydropyrimidine substrates.