4-Benzyl-4-methyl­morpholinium hexa­fluoro­phosphate

In the title compound, C12H18NO+·PF6 −, the asymmetric unit consists of two cation–anion pairs. The six F atoms of one anion are disordered over two sets of sites in a 0.592 (6):0.408 (6) ratio. The morpholinium rings adopt chair conformations

Amide Activation by Tf2O: Reduction of Amides to Amines by NaBH4 under Mild Conditions

An expeditious and practical method for the reduction of amides to amines is reported. The method is consisted of activation of amides with Tf2O followed by reduction with sodium borohydride in THF at room temperature. Various amides/lactams gave the corresponding amines in good to excellent yields, even with hindered amides and secondary amides. This method also presents other advantages such as TBDPS-group tolerance, short reaction time, simple workup and purification procedure.NSF of China [20832005]; National Basic Research Program (973 Program) of China [2010CB833200

Isospin dependence of nucleon effective mass in Dirac Brueckner-Hartree-Fock approach

The isospin dependence of the nucleon effective mass is investigated in the framework of the Dirac Brueckner-Hartree-Fock (DBHF) approach. The definition of nucleon scalar and vector effective masses in the relativistic approach is clarified. Only the vector effective mass is the quantity related to the empirical value extracted from the analysis in the nonrelatiistic shell and optical potentials. In the relativistic mean field theory, where the nucleon scalar and vector potentials are both energy independent, the neutron vector potential is stronger than that of proton in the neutron rich nuclear matter, which produces a smaller neutron vector effective mass than that of proton. It is pointed out that the energy dependence of nucleon potentials has to be considered in the analysis of the isospin dependence of the nucleon effective mass. In the DBHF the neutron vector effective mass is larger than that of proton once the energy dependence of nucleon potentials is considered. The results are consistent with the analysis of phenomenological isospin dependent optical potentials.Comment: 4 pages, 3 Postscript figure

Decay Widths of Excited Heavy Mesons From QCD Sum Rules at the Leading Order of HQET

The widths for pionic decays of lowest two excited doublets (0^+,1^+) and (1^+,2^+) of heavy mesons are studied with QCD sum rules in the leading order of heavy quark effective theory. The ambiguity due to presence of two distinct 1^+ states are solved. The soft pion approximation is not used.Comment: RevTeX, 16 pages including 1 figure; minor changes, final version to appear in Physical Review

The value of restatement to fraud prediction

A financial report restatement reflects errors in the previous financial statement, and thus it increases investors’ doubt about the credibility of the financial statement. The primary objective of this paper is to examine whether restatement announcements imply increased fraud risks in Chinese firms in the context that up to one quarter of listed companies have restated their financial reports in China, and explore the implications of the content, severity and reasons for restatements with respect to fraud. In this paper, firms with financial restatements prove to be more likely to be labeled as fraudulent by regulators in China. Second, the following results also are revealed: (1) financial statements, except balance sheet restatements, provide insights into the revelation of fraudulent behaviors, (2) the severity of restatements is positively correlated with future fraud disclosures, and (3) restatements due to negligence are positively correlated with future fraud occurrences. These results imply that restatement announcements and their different characteristics provide important information for detecting financial statement fraud

On the Secrecy Performance of Random VLC Networks with Imperfect CSI and Protected Zone

This paper investigates the physical-layer security for a random indoor visible light communication (VLC) network with imperfect channel state information (CSI) and a protected zone. The VLC network consists of three nodes, i.e., a transmitter (Alice), a legitimate receiver (Bob), and an eavesdropper (Eve). Alice is fixed in the center of the ceiling, and the emitted signal at Alice satisfies the non-negativity and the dimmable average optical intensity constraint. Bob and Eve are randomly deployed on the receiver plane. By employing the protected zone and considering the imperfect CSI, the stochastic characteristics of the channel gains for both the main and the eavesdropping channels is first analyzed. After that, the closed-form expressions of the average secrecy capacity and the lower bound of secrecy outage probability are derived, respectively. Finally, Monte-Carlo simulations are provided to verify the accuracy of the derived theoretical expressions. Moreover, the impacts of the nominal optical intensity, the dimming target, the protected zone and the imperfect CSI on secrecy performance are discussed, respectively.Comment: Accepted by IEEE Systems Joutna

Identification of MACC1 as a novel prognostic marker in hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Metastasis-associated in colon cancer-1 (<it>MACC1</it>) is a newly identified gene that plays a role in colon cancer metastasis through upregulation of c-MET proto-oncogene (c-MET). However, the value of <it>MACC1 </it>as a potential biomarker for hepatocellular carcinoma (HCC) remains unknown.</p> <p>Methods</p> <p><it>MACC1 </it>mRNA expression in 128 HCC tissues was examined by quantitative polymerase chain reaction. To show the potential correlation of <it>MACC1 </it>and c-MET, c-MET was also analysed.</p> <p>Results</p> <p><it>MACC1 </it>was more highly expressed in HCC than in non-HCC tissues (<it>P </it>= 0.009). High <it>MACC1 </it>expression was significantly increased in cases with high alpha fetoprotein (AFP) (<it>P </it>= 0.025). A positive correlation was found between <it>MACC1 </it>and c-MET mRNAs (r = 0.235, <it>P </it>= 0.009). Both univariate and multivariate analyses revealed that <it>MACC1 </it>expression was associated with overall survival (OS) and disease-free survival (DFS). Moreover, stratified analysis showed that tumour-node-metastasis (TNM) stage I patients with high <it>MACC1 </it>levels had shorter OS and DFS than those with low <it>MACC1</it>.</p> <p>Conclusions</p> <p><it>MACC1 </it>may identify low- and high-risk individuals with HCC and be a valuable indicator for stratifying the prognosis of TNM stage I patients. <it>MACC1 </it>may serve as a novel biomarker for HCC.</p

Toll-like receptor 9 interaction with CpG ODN – An in silico analysis approach

BACKGROUND: Toll-like receptor 9 (TLR9) recognises unmethylated CpG DNA and activates a signalling cascade, leading to the production of inflammatory cytokines such as TNF-α, IL-1, IL-6 and IL-12 via the adaptor protein MyD88. However, the specific sequence and structural requirements of the CpG DNA for the recognition of and binding to TLR9 are unknown. Moreover, the 3D structures of TLR9 and the TLR9-ODN complex have not been determined. In this study, we propose a reliable model of the interaction of the TLR9 ECD with CpG ODN using bioinformatics tools. RESULTS: The three-dimensional structures of two TLR9 ECD-CpG ODN complexes were constructed using a homology modelling and docking strategy. Based on the models of these complexes, the TLR9 ECD-CpG ODN interaction patterns were calculated. The results showed that the interface between the human TLR9 and the CpG ODN molecule is geometrically complementary. The computed molecular interactions indicated that LRR11 is the main region of TLR9 that binds to CpG ODN and that five positively charged residues within LRR11 are involved in the binding of the TLR9 ECD to the CpG ODN. Observations in the close-up view of these interactions indicated that these five positively charged residues contribute differently to the binding region within the TLR9 ECD-CpG ODN complex. 337Arg and 338Lys reside in the binding sites of ODN, forming hydrogen bonds and direct contacts with the CpG ODN, whereas 347Lys, 348Arg, and 353His do not directly contact the CpG ODN. These results are in agreement with previously reported experimental data. CONCLUSION: In this study, we present two structural models for the human and mouse TLR9 ECD in a complex with CpG ODN. Some features predicted by this model are consistent with previously reported experimental data. This complex model may lead to a better understanding of the function of TLR9 and its interaction with CpG ODN and will improve our understanding of TLR9-ligand interaction in general