Membrane expression and significance of TRAIL death receptors DR4 and DR5 in Pancreatic cancer

Introduction: Tumor necrosis factor related-apoptosis-inducing ligand (TRAIL) is a powerful and selective activator of apoptosis in many cancer cells. We aim to investigate the expression and significance of TRAIL death receptor DR4 and DR5 in pancreatic cancer (PC) tissues. Method: Twenty-eight histologically verified samples of PC tissue were collected between 2018 and 2019. TRAIL death receptor expression profiles were determined by immunohistochemistry. Result: Death receptor DR4 and DR5 were expressed in the PC tissue and the adjacent non-cancerous pancreatic tissues, the expression of DR4 and DR5 in the PC tissue was significantly higher than that of the adjacent non-cancerous pancreatic tissues (p<0.05). Additionally, in both the tissue group, the expression of DR4 was significantly stronger than the DR5 (p<0.05). To assess the relationship between DR4 and DR5 expression, differentiation, and tumor staging of PC, the result reveals that the expression of DR4 and DR5 was significantly higher in stage I tumors than the stage II, III, IV tumors (p<0.05). In contrast, the expression of DR4 and DR5 was decreased with a decrease in the degree of differentiation of tumors. However, the difference was not statistically significant. Conclusion: The membrane expression of TRAIL death receptor DR4 and DR5 is greater in PC than in the adjacent non-cancerous pancreatic tissues. Furthermore, increased membrane expression of TRAIL death receptor DR4 and DR5 in stage I PC and well-differentiated PC may predict the prognosis and feasibility of using TRAIL gene therapy as a treatment option for early PC.&nbsp

Time-varying Reliability Analysis of Long-span Continuous Rigid Frame bridge under Cantilever Construction Stage based on the Monitored Strain Data

Abstract: In general, the material properties, loads, resistance of the prestressed concrete continuous rigid frame bridge in different construction stages are time-varying. So, it is essential to monitor the internal force state when the bridge is in construction. Among them, how to assess the safety is one of the challenges. As the continuous monitoring over a long-term period can increase the reliability of the assessment, so, based on a large number of monitored strain data collected from the structural health monitoring system (SHMS) during construction, a calculation method of the punctiform time-varying reliability is proposed in this paper to evaluate the stress state of this type bridge in cantilever construction stage by using the basic reliability theory. At the same time, the optimal stress distribution function in the bridge mid-span base plate is determined when the bridge is closed. This method can provide basis and direction for the internal force control of this type bridge in construction process. So, it can reduce the bridge safety and quality accidents in construction stages

Holiday Destination Choice Behavior Analysis Based on AFC Data of Urban Rail Transit

For urban rail transit, the spatial distribution of passenger flow in holiday usually differs from weekdays. Holiday destination choice behavior analysis is the key to analyze passengers’ destination choice preference and then obtain the OD (origin-destination) distribution of passenger flow. This paper aims to propose a holiday destination choice model based on AFC (automatic fare collection) data of urban rail transit system, which is highly expected to provide theoretic support to holiday travel demand analysis for urban rail transit. First, based on Guangzhou Metro AFC data collected on New Year’s day, the characteristics of holiday destination choice behavior for urban rail transit passengers is analyzed. Second, holiday destination choice models based on MNL (Multinomial Logit) structure are established for each New Year’s days respectively, which takes into account some novel explanatory variables (such as attractiveness of destination). Then, the proposed models are calibrated with AFC data from Guangzhou Metro using WESML (weighted exogenous sample maximum likelihood) estimation and compared with the base models in which attractiveness of destination is not considered. The results show that the ρ2 values are improved by 0.060, 0.045, and 0.040 for January 1, January 2, and January 3, respectively, with the consideration of destination attractiveness

Effect of Reaction and Regeneration on the Production of Pyridine Bases through Glycerol and Ammonia Route

The HZSM-22-At-acid and HZSM-5-At-acid catalysts were synthesized by alkaline-acid sequential treatment and the ZnO/HZSM-5-At-acid catalyst was synthesized by wet-impregnated method. Influence factors, including the types of reactors, impurities in glycerol and regeneration, were systematically investigated. The catalysts were characterized by XRD, TG, N2-physorption and NH3-TPD techniques. The catalytic evaluation showed that the total yield of pyridine bases in the series-connected two-stage reactors was significantly higher than that of the single reactor while the catalytic pair (HZSM-22-At-acid + ZnO/HZSM-5-At-acid) was employed in these reactors, respectively. It was found that the presence of methanol and sodium chloride in glycerol played a great negative effect on the total yield of pyridine bases. The coke was a key factor leading to the deactivation of catalyst. The catalytic activity was basically restored after the regeneration. The total yield of pyridine bases was increased up to 72% after the 6 th reaction, which was obviously higher than that of the similar reports. The characterization results demonstrated that the larger pore size and the declined concentration of acid site (particularly strong acid site) were main reasons for improving the catalytic activity

The DWT Power Spectrum of the two-degree Field Galaxy Redshift Survey

The power spectrum of the two-degree Field Galaxy Redshift Survey (2dFGRS) sample is estimated with the discrete wavelet transform (DWT) method. The DWT power spectra within $0.04 <k< 2.3 h$Mpc$^{-1}$ are measured for three volume-limited samples defined in connective absolute magnitude bins $-19 \sim -18$, $-20 \sim -19$ and $-21 \sim -20$. We show that the DWT power spectrum can effectively distinguish $\Lambda$CDM models of $\sigma_8=0.84$ and $\sigma_8=0.74$. We adopt maximum likelihood method to perform three-parameter fitting with bias parameter $b$, pairwise velocity dispersion $\sigma_{pv}$ and redshift distortion parameter $\beta=\Omega_m^{0.6}/b$ to the measured DWT power spectrum. Fitting results denotes that in a $\sigma_8=0.84$ universe the best fitted $\Omega_m$ given by the three samples are consistent in the range $0.28 \sim 0.36$, and the best fitted $\sigma_{pv}$ are $398^{+35}_{-27}$, $475^{+37}_{-29}$ and $550 \pm 20$km/s for the three samples, respectively. However in the model of $\sigma_8=0.74$, our three samples give very different values of $\Omega_m$. We repeat the fitting by using empirical formula of redshift distortion. The result of the model of low $\sigma_8$ is still poor, especially, one of the best value $\sigma_{pv}$ is as large as $10^3$km/s. The power spectrum of 2dFGRS seems in disfavor of models with low amplitude of density fluctuations.Comment: 11 pages, 9 figures. submitted to MNRAS. submitted to MNRA

Gold nanoparticles as high-resolution X-ray imaging contrast agents for the analysis of tumor-related micro-vasculature

<p>Abstract</p> <p>Background</p> <p>Angiogenesis is widely investigated in conjunction with cancer development, in particular because of the possibility of early stage detection and of new therapeutic strategies. However, such studies are negatively affected by the limitations of imaging techniques in the detection of microscopic blood vessels (diameter 3-5 μm) grown under angiogenic stress. We report that synchrotron-based X-ray imaging techniques with very high spatial resolution can overcome this obstacle, provided that suitable contrast agents are used.</p> <p>Results</p> <p>We tested different contrast agents based on gold nanoparticles (AuNPs) for the detection of cancer-related angiogenesis by synchrotron microradiology, microtomography and high resolution X-ray microscopy. Among them only bare-AuNPs in conjunction with heparin injection provided sufficient contrast to allow <it>in vivo </it>detection of small capillary species (the smallest measured lumen diameters were 3-5 μm). The detected vessel density was 3-7 times higher than with other nanoparticles. We also found that bare-AuNPs with heparin allows detecting symptoms of local extravascular nanoparticle diffusion in tumor areas where capillary leakage appeared.</p> <p>Conclusions</p> <p>Although high-Z AuNPs are natural candidates as radiology contrast agents, their success is not guaranteed, in particular when targeting very small blood vessels in tumor-related angiography. We found that AuNPs injected with heparin produced the contrast level needed to reveal--for the first time by X-ray imaging--tumor microvessels with 3-5 μm diameter as well as extravascular diffusion due to basal membrane defenestration. These results open the interesting possibility of functional imaging of the tumor microvasculature, of its development and organization, as well as of the effects of anti-angiogenic drugs.</p

Mapping codon usage of the translation initiation region in porcine reproductive and respiratory syndrome virus genome

<p>Abstract</p> <p>Background</p> <p>Porcine reproductive and respitatory syndrome virus (PRRSV) is a recently emerged pathogen and severely affects swine populations worldwide. The replication of PRRSV is tightly controlled by viral gene expression and the codon usage of translation initiation region within each gene could potentially regulate the translation rate. Therefore, a better understanding of the codon usage pattern of the initiation translation region would shed light on the regulation of PRRSV gene expression.</p> <p>Results</p> <p>In this study, the codon usage in the translation initiation region and in the whole coding sequence was compared in PRRSV ORF1a and ORFs2-7. To investigate the potential role of codon usage in affecting the translation initiation rate, we established a codon usage model for PRRSV translation initiation region. We observed that some non-preferential codons are preferentially used in the translation initiation region in particular ORFs. Although some positions vary with codons, they intend to use codons with negative CUB. Furthermore, our model of codon usage showed that the conserved pattern of CUB is not directly consensus with the conserved sequence, but shaped under the translation selection.</p> <p>Conclusions</p> <p>The non-variation pattern with negative CUB in the PRRSV translation initiation region scanned by ribosomes is considered the rate-limiting step in the translation process.</p