Critical behaviors near the (tri-)critical end point of QCD within the NJL model

We investigate the dynamical chiral symmetry breaking and its restoration at finite density and temperature within the two-flavor Nambu-Jona-Lasinio model, and mainly focus on the critical behaviors near the critical end point (CEP) and tricritical point (TCP) of quantum chromodynamics. The multi-solution region of the Nambu and Wigner ones is determined in the phase diagram for the massive and massless current quark, respectively. We use the various susceptibilities to locate the CEP/TCP and then extract the critical exponents near them. Our calculations reveal that the various susceptibilities share the same critical behaviors for the physical current quark mass, while they show different features in the chiral limit

Variational-based data assimilation to simulate sediment concentration in the Lower Yellow River, China

The heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available

Distinct Tumor Microenvironment at Tumor Edge as a Result of Astrocyte Activation Is Associated With Therapeutic Resistance for Brain Tumor

Tumor vasculatures and hypoxia are critical tumor micro-environmental factors associated with tumor response to the therapy and heterogeneous in both time- and location-dependent manner. Using a murine orthotopic anaplastic astrocytoma model, ALTS1C1, this study showed that brain tumor edge had a very unique microenvironment, having higher microvascular density (MVD) and better vessel function than the tumor core, but on the other hand was also positive for hypoxia markers, such as pimonidazole (PIMO), hypoxia inducible factor-1α (HIF-1α), and carbonic anhydrase IV (CAIX). The hypoxia at tumor edge was transient, named as peripheral hypoxia, and caused by different mechanisms from the chronic hypoxia in tumor core. The correlation of CAIX staining with astrocyte activation marker, glial fibrillary acid protein (GFAP), at the tumor edge indicated the involvement of astrocyte activation on the development of peripheral hypoxia. Peripheral hypoxia was a specific trait of orthotopic brain tumors at tumor edge, regardless of tumor origin. The hypoxic cells were resistant to the therapy, regardless of their location. Surviving cells, particularly those at the hypoxic region of tumor edge, are likely the cause of tumor recurrence after the therapy. New therapeutic platform that targets cells in tumor edge is likely to achieve better treatment outcomes

Stanniocalcin-1 promotes tumor angiogenesis through up-regulation of VEGF in gastric cancer cells

<p>Abstract</p> <p>Background</p> <p>Stanniocalcin-1(STC-1) is up-regulated in several cancers including gastric cancer. Evidences suggest that STC-1 is associated with carcinogenesis and angiogenic process. However, it is unclear on the exact role for STC-1 in inducing angiogenesis and tumorigeneisis.</p> <p>Method</p> <p>BGC/STC cells (high-expression of STC-1) and BGC/shSTC cells (low- expression of STC-1) were constructed to investigate the effect of STC-1 on the xenograft tumor growth and angiogenesis <it>in vitro </it>and <it>in vivo</it>. ELISA assay was used to detect the expression of vascular endothelial growth factor (VEGF) in the supernatants. Neutralizing antibody was used to inhibit VEGF expression in supernatants. The expression of phosphorylated -PKCβII, phosphorylated -ERK1/2 and phosphorylated -P38 in the BGC treated with STC-1protein was detected by western blot.</p> <p>Results</p> <p>STC-1 could promote angiogenesis <it>in vitro </it>and <it>in vivo</it>, and the angiogenesis was consistent with VEGF expression <it>in vitro</it>. Inhibition of VEGF expression in supernatants with neutralizing antibody markedly abolished angiogenesis induced by STC-1 <it>in vitro</it>. The process of STC-1-regulated VEGF expression was mediated via PKCβII and ERK1/2.</p> <p>Conclusions</p> <p>STC-1 promotes the expression of VEGF depended on the activation of PKCβII and ERK1/2 pathways. VEGF subsequently enhances tumor angiogenesis which in turn promotes the gastric tumor growth.</p

Pharmacokinetic/Pharmacodynamic Profiles of Tiamulin in an Experimental Intratracheal Infection Model of Mycoplasma gallisepticum

Mycoplasma gallisepticum is the most important pathogen in poultry among four pathogenic Mycoplasma species. Tiamulin is a pleuromutilin antibiotic that shows a great activity against M. gallisepticum and has been approved for use in veterinary medicine particularly for poultry. However, the pharmacokinetic/pharmacodynamics (PK/PD) profiles of tiamulin against M. gallisepticum are not well understood. Therefore, in the current studies, we investigated the in vivo PK/PD profiles of tiamulin using a well-established experimental intratracheal infection model of M. gallisepticum. The efficacy of tiamulin against M. gallisepticum was studied in 8-day-old chickens after intramuscular (i.m.) administration at 10 doses between 0-80 mg/kg. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to evaluate the PK parameters of tiamulin following i.m. administration at doses of 5, 40, and 80 mg/kg in Mycoplasma gallisepticum-infected neutropenic chickens. Real-time PCR (RT-PCR) was used for quantitative detection of M. gallisepticum. The MIC of tiamulin against M. gallisepticum strain S6 was 0.03 μg/mL. The PK/PD index, AUC24h/MIC, correlated well with the in vivo antibacterial efficacy. The in vivo data suggest that animal dosage regimens should supply AUC24h/MIC of tiamulin of 382.68 h for 2 log10 ccu equivalents M. gallisepticum reduction. To attain that goal, the administered dose is expected to be 45 mg/kg b.w. for treatment of M. gallisepticum infection with an MIC90 of 0.03 μg/mL