Determining cosmological-model-independent H0H_0 and post-Newtonian parameter with time-delay lenses and supernovae

Strong gravitational lensing provides a natural opportunity to test General Relativity (GR). We propose a model-independent method for simultaneous constraining on Hubble constant ($H_0$) and post-Newtonian parameter (${\gamma_{\rm{PPN}}}$) using strong lensing systems and observational SNe Ia. The time-delay measurements from strong lesning can directly determine the Hubble constant, and the lens distance inferred from the spectroscopic measurement of the stellar kinematics of the deflector galaxy can help us to constrain the post-Newtonian parameter. We seek the Pantheon dataset and reconstruct unanchored distances using Gaussian process regression to achieve the cosmological model-independent GR testing instead of assuming a specific model, which can reduce possible bias on GR testing and measurement of Hubble constant. Combining the reconstructed unanchored distances and the four H0LiCOW lenses datasets, our results are $H_0=72.9^{+2.0}_{-2.3} {\mathrm{~km~s^{-1}~Mpc^{-1}}}$ and ${\gamma_{\rm{PPN}}}=0.89^{+0.17}_{-0.15}$. All the lenses show that there is no obvious evidence to support GR deviation within observational uncertainties. In the subsequent analysis, we consider a ratio of distance ${D_{\Delta t}}/{D^{'}_{d}}$ method to further avoid the influence of $H_0$ on GR testing. The results show that, except J1206 within the $\sim1.2\sigma$ observational uncertainty, the remaining 3 lenses support GR holds within the $1\sigma$ observational uncertainties.Comment: 7 pages, 3 figures, submitted to MNRA

Flexural capacity of overloading damaged RC T-beams strengthened with CFRP subjected to wet-dry cycles

Overweight trucks are common on the highways in China, which presents fatigue damage problem for the reinforced concrete (RC) bridges. Externally bonding CFRP sheets is increasingly being used to repair the damaged bridges. The degradation of adhesive bonding in a wet-dry environment, however, may have a significant adverse effect on the long term durability of the repaired bridges. This paper presents an experimental study on the flexural capacity of damaged RC T-beams strengthened with CFRP sheets subjected to the wet-dry cycles. A total of 19 specimens in 8 series were tested. The specimens were damaged by constant fatigue loading which were equivalent to the repetitive loadings caused by the overweight trucks across a bridge in one year. The specimens subjected to wet-dry environment were exposed to a period of 3 months or 6 months. A wet-dry cycle was 24 h including a wet cycle (salt water) of 10 h and a dry cycle (hot air at 40 ℃) of 14 h. The experimental results showed that a slight reduction in stiffness was observed for the strengthened beams due to overloading damage or wet-dry exposure. The residual deflection and cracks caused by overloading damage reduced the effect of CFRP strengthening. The wet-dry cycles induced degradation to bond at the concrete/FRP interface. Only in the first 3 months, however, the wet-dry environmental exposure can obvious reduce the strength of the retrofitted beams

Guava leaf extracts alleviate fatty liver via expression of adiponectin receptors in SHRSP.Z-Leprfa/Izm rats

<p>Abstract</p> <p>Background</p> <p>In recent years, the number of people with metabolic syndrome has continued to rise because of changing eating habits, and accompanying hepatic steatosis patients have also increased. This study examined the effect of guava leaf extract on liver fat accumulation using SHRSP.Z-Leprfa/IzmDmcr rats (SHRSP/ZF), which are a metabolic syndrome model animal.</p> <p>Method</p> <p>Seven-week-old male SHRSP/ZF rats were divided into two groups, a control group and a guava leaf extract (GLE) group. We gave 2 g/kg/day GLE or water by forced administration for 6 weeks. After the experimental period, the rats were sacrificed and organ weight, hepatic lipids, serum aminotransferase and liver pathology were examined. To search for a possible mechanism, we examined the changes of key enzyme and transcriptional factors involved in hepatic fatty acid beta-oxidation.</p> <p>Results</p> <p>The triglyceride content of the liver significantly decreased in the GLE group in comparison with the control group, and decreased fat-drop formation in the liver tissue graft in the GLE group was observed. In addition, the improvement of liver organization impairments with fat accumulation restriction was suggested because blood AST and ALT in the GLE group significantly decreased. Furthermore, it was supposed that the activity of AMPK and PPARα significantly increased in the GLE group via the increase of adiponectin receptors. These were thought to be associated with the decrease of the triglyceride content in the liver because AMPK and PPARα in liver tissue control energy metabolism or lipid composition. On the other hand, insulin resistance was suggested to have improved by the fatty liver improvement in GLE.</p> <p>Conclusion</p> <p>Our results indicate that administration of GLE may have preventive effects of hepatic accumulation and ameliorated hepatic insulin resistance by enhancing the adiponectin beta-oxidation system. Guava leaf may be potentially useful for hepatic steatosis without the side effects of long-term treatments.</p

Study on Repaired Earthquake-Damaged Bridge Piers under Seismic Load

The concrete bridge pier damaged during earthquakes need be repaired to meet the design standards. Steel tube as a traditional material or FRP as a novel material has become popular to repair the damaged reinforced concrete (RC) bridge piers. In this paper, experimental and finite element (FE) studies are employed to analyze the confinement effectiveness of the different repair materials. The FE method was used to calculate the hysteretic behavior of three predamaged circle RC bridge piers repaired with steel tube, basalt fiber reinforced polymer (BFRP), and carbon fiber reinforced polymer (CFRP), respectively. Meanwhile, the repaired predamaged circle concrete bridge piers were tested by pseudo-static cyclic loading to study the seismic behavior and evaluate the confinement effectiveness of the different repair materials and techniques. The FE analysis and experimental results showed that the repaired piers had similar hysteretic curves with the original specimens and all the three repair techniques can restore the seismic performance of the earthquake-damaged piers. Steel tube jacketing can significantly improve the lateral stiffness and peak load of the damaged pier, while the BFRP and CFRP sheets cannot improve these properties due to their thin thickness

Guava Leaf Extracts Inhibit 3T3-L1 Adipocyte Differentiation Via Activating AMPK

The guava tree (psidium guajava linn.) is commonly used not only as food but also as folk medicine. In our previous studies, we showed that oral administration of guava leaf extracts (GLE) had beneficial anti-obesity effects using metabolic syndrome model rats. However, we did not clarify molecular mechanism by which GLE administration leads to anti-obesity effect. This study was designed to evaluate the mechanism of anti-obesity by GLE using 3T3-L1 pre-adipocyte cell lines. We found that GLE significantly inhibited 3T3-L1 differentiation via down-regulation of adipogenic transcription factors and markers. Mitotic clonal expansion, which is essential for adipose differentiation, was also depressed in the early phase. Interestingly, GLE increased the phosphorylation of AMPK on 3T3-L1 cells and, by pretreatment with AMPK siRNA, the GLE treatment group showed restored adipocyte differentiation. In conclusion, these results showed that GLE is capable of inhibiting adipocyte differentiation via AMPK activation and therefore it may prevent obesity in vivo