Hepatitis B Virus X Protein Upregulates Intracellular Calcium Signaling by Binding C-terminal of Orai1 Protein

Hepatitis B virus X(HBx)protein plays a pivotal role in the development of hepatitis B virus(HBV)-associated hepatocellular carcinoma.Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein,the mechanism of HBx protein regulating intracellular calcium level remains poorly understood.The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry(SOCE)components,Orai1 and stromal interaction molecule 1,and then identified the targets of HBx protein,with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis.By employing co-immunoprecipitation and GST-pull-down assay,we found that Orai1 protein interacted with HBx protein,and the C-terminus of Orai1 was implicated in the interaction.Confocal microscopy also revealed that HBx protein could co-localize with full-length Orai1 protein in HEK293 cells.Moreover,live cell calcium imaging exhibited that HBx protein elevated intracellular calcium,possibly by binding to SOCE components.Our results suggest that HBx protein binds to STIM1-Orai1 complexes to positively regulate the activity of plasma membrane store-operated calcium channels.

Synthesis and in vitro antitumor activity of novel diaryl urea derivatives

A series of novel diaryl ureas containing 4-[（2-amino-6-trifluromethyl）pyrimidine-4-yl]piperazine-l-yl group were synthesized and evaluated for their cytotoxic activities in a panel of human cancer cell lines. Compared with the reference drug Sorafenib,some compounds showed more potent and a broader spectrum of anti-cancer activities.Among them,compound 2p demonstrated significant inhibitory activities against MDA-MB-231,HT-29 and MCF-7 cell lines with IC_（50） values of 0.016,0.63,0.001μmol/L, respectively.

Effect of process parameters on steel tube roundness in straightening process

The inclined six-roll tube straightener is an important equipment for the finishing line.It can not only straighten the steel pipe,but also finish the ovality of the cross section.In the actual straightening process,the cross section of the tube is prone to deform,that is,the round ness is not good.The flatteni ng displacement is an import a nt parameter to control cross-section forming of tube.According to the established mechanical model,the analytical calculation equations of the flattening force and the flattening displacement were derived using the energy method.Based on the finite element simulation data,the ratios of the finite element results of the什attening force to the analytical ones were fitted.The correlation coefficient after fitting is greater than 99%,and the fitting effect is excelleni.The flattening experiment was carried out on tubes of different materials and different specifications,and the setting method of the optimal flattening displacement during straightening process was obtained.In the actual straightening process,using this flattening displacement,the ovality of straightened steel tube is less than 0.3%.Therefore,the proposed method can provide a reference for the flattening displacement in the actual straightening process.

Asymptotic Behaviour of Hessian Equation with Boundary Blow Up

We consider the boundary blow up problem for k-hessian equation with nonlinearities of power and of exponential type, and prove their existence, uniqueness and asymptotic behaviour. Moreover we also show that their perturbed problem has a unique positive solution, which satisfies some asymptotic behaviors to unperturbed problems under appropriate structure hypotheses for perturbed terms.