AXIAL CRUSHING ENERGY ABSORPTION CAPACITY OF ALUMINUM ALLOY THIN-WALLED MULTI-CORNER TUBES

The multi-corner tubes with extra concave corners in cross section were presented to improve energy absorption efficiency of aluminum alloy thin-walled tubes in this paper. The axial crushing energy absorption capacity of square and multicorner aluminum alloy thin-walled tubes was compared with the same cross-sectional perimeter and mass. The improved method of folding element was applied to predict the crushing forces of thin-walled tubes under axial impact. The corners on cross section were discussed for the effect on axial crushing energy absorption capacity of the thin-walled tubes. The results show that the increasing performance of energy absorption of aluminum alloy thin-walled tubes is due to the increasing number of corners on cross section. The number and size of corners both have important effect on the crushing force efficiency of multi-corner tubes.The maximum crushing force efficiency of multi-corner tubes is 11. 6% higher than that of square tubes with the same material consumption of thin-walled tubes. The multi-corner tubes with 12 corners show better energy absorption capacity than the tubes with more corners which could lead to the small size of corners or the unstable deformations. The high axial crushing energy absorption capacity of the multi-corner tubes prefers increasing the corner number and corner size of adjacent sides at the same time

Atorvastatin Attenuates Myocardial Hypertrophy in Spontaneously Hypertensive Rats via the C/EBPβ/PGC-1α/UCP3 Pathway

Background/Aims: Many clinical and experimental studies have shown that treatment with statins could prevent myocardial hypertrophy and remodeling induced by hypertension and myocardial infarction. But the molecular mechanism was not clear. We aimed to investigate the beneficial effects of atorvastatin on hypertension-induced myocardial hypertrophy and remodeling in spontaneously hypertensive rats (SHR) with the hope of revealing other potential mechanisms or target pathways to interpret the pleiotropic effects of atorvastatin on myocardial hypertrophy. Methods: The male and age-matched animals were randomly divided into three groups: control group (8 WKY), SHR (8 rats) and intervention group (8 SHR). The SHR in intervention group were administered by oral gavage with atorvastatin (suspension in distilled water, 10 mg/Kg once a day) for 6 weeks, and the other two groups were administered by gavage with equal quantity distilled water. Blood pressure of rats was measured every weeks using a standard tail cuff sphygmomanometer. Left ventricular (LV) dimensions were measured from short-axis views of LV under M-mode tracings using Doppler echocardiograph. Cardiomyocyte apoptosis was assessed by the TUNEL assay. The protein expression of C/EBPβ, PGC-1α and UCP3 were detected by immunohistochemistry or Western blot analysis. Results: At the age of 16 weeks, the mean arterial pressure of rats in three groups were 103.6±6.1, 151.8±12.5 and 159.1±6.2 mmHg respectively, and there wasn’t statistically significant difference between the SHR and intervention groups. Staining with Masson’s trichrome demonstrated that the increased interstitial fibrosis of LV and ventricular remodeling in the SHR group were attenuated by atorvastatin treatment. Echocardiography examination exhibited that SHR with atorvastatin treatment showed an LV wall thickness that was obviously lower than that of water-treated SHR. In hypertrophic myocardium, accompanied by increasing C/EBPβ expression and the percentage of TUNEL-positive cells, the expression of Bcl-2/Bax ratio, PGC-1α and UCP3 were reduced, all of which could be abrogated by treatment with atorvastatin for 6 weeks. Conclusion: This study further confirmed that atorvastatin could attenuate myocardial hypertrophy and remodeling in SHR by inhibiting apoptosis and reversing changes in mitochondrial metabolism. The C/EBPβ/PGC-1α/UCP3 signaling pathway might also be important for elucidating the beneficial pleiotropic effects of atorvastatin on myocardial hypertrophy

Association between the Hypertriglyceridemic Waist Phenotype, Prediabetes, and Diabetes Mellitus in Rural Chinese Population: A Cross-Sectional Study

Background: The objective was to evaluate the association of the hypertriglyceridemic waist (HTGW) phenotype with prediabetes and diabetes (DM) in rural Chinese population. Methods: In a cross-sectional study, 11,579 adults (5361 men and 6218 women) aged 35 years or older were recruited from rural areas of China. Anthropometric measurements, laboratory examinations and self-reported information were collected by trained personnel. The HTGW phenotype was defined as elevated triglycerides and elevated waist circumference. We used logistic regression analysis to evaluate the associations of interest. Results: Adults with the HTGW phenotype had a significantly higher prevalence of prediabetes and diabetes than those without the HTGW phenotype. Compared with the normal waist-normal triglycerides (NWNT) group, those in the HTGW group had a higher adjusted odds ratio of diabetes (OR: 2.10; 95% CI: 1.62–2.73). The association for diabetes was stronger for men (OR: 2.27; 95% CI: 1.52–3.40) than for women (OR: 1.86; 95% CI: 1.32–2.63). However, multivariate analysis indicated that the HTGW phenotype was not associated with prediabetes. Conclusions: This study demonstrated that the HTGW phenotype was associated with diabetes in a large rural Chinese population, and suggested this phenotype as a simple screening tool to identify adults with cardiometabolic conditions

DEFORMATION AND FRACTURE BEHAVIOR OF ALUMINUM ALLOY THIN-WALLED SQUARE TUBES UNDER AXIAL IMPACT

The tensile stress-strain response for 6016 aluminum alloy（ AA6016） sheet under different strain rates was presented in this paper. The data were fit to the Johnson-Cook constitutive model and fractured strain model. The energy absorbing performance of AA 6016 thin-walled square tubes under axial impact were analyzed. The results show that flow stress of AA6016 is insensitive to strain rate,while fractured strain is sensitive to strain rate. Thin-walled tubes show good energy absorbing performance with progressive buckling deformation under axial crushing. However,the energy absorbing performance decreases due to the mix buckling mode with the increasing thickness,length and impacting velocity of aluminum alloy thinwalled tubes

Association between Serum Uric Acid and Elevated Alanine Aminotransferase in the General Population

Background: Both the serum uric acid (SUA) level and elevated alanine aminotransferase (ALT) are related to metabolic syndrome. However, the association between SUA and elevated ALT has not been elucidated in the general population. The objective of this study was to investigate the association between SUA and elevated ALT in the general population of China; Methods: A total of 11,572 adults (≥35 years of age) participated in this survey. Elevated ALT was defined as >40 U/L. SUA ≥ 7.0 mg/dL in males or ≥6.0 mg/dL in females was defined as hyperuricemia. SUA within the reference range was divided into quartiles, and its associations with elevated ALT were evaluated by logistic regressions; Results: A total of 7.4% participants had elevated ALT. The prevalence of hyperuricemia was 14.9% in males and 7.3% in females. There was a significantly positive dose-response association between SUA levels and the prevalence of elevated ALT. After adjusting for potential confounders, a positive relationship for elevated ALT was observed in subjects with hyperuricemia (odds ratio [OR]: 2.032, 95% confidence interval [CI]: 1.443–2.861 for men; OR: 2.045, 95% CI: 1.221–3.425 for women, both p < 0.05). Within the reference range, the association between SUA and elevated ALT persisted in the fourth quartile (OR: 1.467, 95% CI: 1.063–2.025 for men; OR: 1.721, 95% CI: 1.146–2.585 for women, both p < 0.05); Conclusions: Our results indicated that an increased SUA level, even within the reference range, was independently associated with elevated ALT in Chinese adults

The Protective Role of the TOPK/PBK Pathway in Myocardial Ischemia/Reperfusion and H2O2-Induced Injury in H9C2 Cardiomyocytes

T-LAK-cell-originated protein kinase (TOPK) is a PDZ-binding kinase (PBK) that was recently identified as a novel member of the mitogen-activated protein kinase (MAPK) family. It has been shown to play an important role in many cellular functions. However, its role in cardiac function remains unclear. Thus, we have herein explored the biological function of TOPK in myocardial ischemia/reperfusion (I/R) and oxidative stress injury in H9C2 cardiomyocytes. I/R and ischemic preconditioning (IPC) were induced in rats by 3-hour reperfusion after 30-min occlusion of the left anterior descending coronary artery and by 3 cycles of 5-min I/R. Hydrogen peroxide (H2O2) was used to induce oxidative stress in H9C2 cardiomyocytes. TOPK expression was analyzed by western blotting, RT-PCR, immunohistochemical staining, and immunofluorescence imaging studies. The effects of TOPK gene overexpression and its inhibition via its inhibitor HI-TOPK-032 on cell viability and Bcl-2, Bax, ERK1/2, and p-ERK1/2 protein expression were analyzed by MTS assay and western blotting, respectively. The results showed that IPC alleviated myocardial I/R injury and induced TOPK activation. Furthermore, H2O2 induced TOPK phosphorylation in a time-dependent manner. Interestingly, TOPK inhibition aggravated the H2O2-induced oxidative stress injury in myocardiocytes, whereas overexpression relieved it. In addition, the ERK pathway was positively regulated by TOPK signaling. In conclusion, our results indicate that TOPK might mediate a novel survival signal in myocardial I/R, and that its effect on anti-oxidative stress involves the ERK signaling pathway

Comparative Pharmacokinetic Profiles of Puerarin in Rat Plasma by UHPLC-MS/MS after Oral Administration of Pueraria lobata Extract and Pure Puerarin

Puerarin is the main biologically active isoflavone in Pueraria lobata and has a wide range of biological activities. However, due to its poor water solubility and low oral bioavailability, its clinical applications are restricted. Compared with puerarin, the Pueraria lobata extract (PLE) has better water solubility, lower toxicity, and less side effects. In this study, the pharmacokinetics of orally administered puerarin (100 mg/kg) and PLE (763 mg/kg, equivalent to 100.0 mg/kg of puerarin) to rats was investigated by the UHPLC-MS/MS method. Results showed that when the rats were administered PLE, the area under the concentration-time curve from zero to infinity (AUC0-inf) dramatically increased from 219.83 ± 64.37 μg h/L to 462.62 ± 51.74 μg h/L (p<0.01). The elimination half-time (t1/2) also increased from 1.60 ± 0.38 h to 12.04 ± 5.10 h (p<0.01). The maximum concentration (Cmax) of puerarin decreased from 101.64 ± 41.82 ng/mL to 48.64 ± 21.47 ng/mL (p<0.01), and time to reach the maximum plasma concentration (Tmax) of puerarin decreased from 1.46 ± 1.08 h to 0.54 ± 0.30 h (p<0.01). Results indicated that the pharmacokinetics of puerarin in Pueraria lobata may be dramatically different from pure puerarin in the plasma of rat, and oral bioavailability of puerarin may be increased when PLE was administrated to rats