Determination of the water vapor transmission rate of cellulose-based papers by multiple headspace extraction analysis.

This paper presents a multiple headspace extraction (MHE) analysis technique to determine the water vapor transmission rate of cellulose-based papers. The water vapor passing through the sample in a closed headspace vial is determined by MHE-gas chromatography. The results show that the employed method offers good precision (the relative standard deviation < 3.49 %) and good accuracy. The method is rapid and accurate, and is promising for the determination of the water vapor transmission rate of cellulose-based papers in future studies.

Determination of carbonate content in barite ore by headspace gas chromatography.

This paper reports a method for determining the carbonate content in barite ore using headspace gas chromatography. Based on the acidification reaction, the carbonate in the barite ore was converted to CO2 in a closed headspace vial. When the carbonate content was significant, the pressure caused changes in the CO2 and O2 signals and affected the measurement accuracy. It was found that carbonate content is proportional to the intensity ratio of the CO2 to O2 signals. Thus, the carbonate content in barite ore can be measured indirectly using a theoretical model. The results showed that the carbonate in 3 g of barite ore sample with a particle size of 74 µm could react completely with a hydrochloric acid solution (2 mol/L) at 65°C for 5 min. The method described herein had good precision (relative standard deviation < 4.14%) and accuracy (relative differences < 6.12%). Further, the limit of quantification was 0.07 mol/L. Owing to its simplicity and speed, this method can be used for the batch determination of carbonate content in barite ore.

SUMOylation of SIRT1 activating PGC-1α/PPARα pathway mediates the protective effect of LncRNA-MHRT in cardiac hypertrophy.

Long noncoding RNA-Myosin heavy chain associated RNA transcript (LncRNA-MHRT) has been reported to prevent pathological cardiac hypertrophy. However, the underlying inhibition mechanism has not been fully elucidated. Further, whether MHRT inhibits hypertrophy by regulating post-translational modification of certain proteins remains unclear. Therefore, this study aims to find potential role of MHRT in inhibiting cardiac hypertrophy via regulating modification of certain proteins. Here, Angiotensin II (Ang II) -treated neonatal rat cardiomyocytes and transverse aortic constriction (TAC) mice were used to investigate the effect and mechanism of MHRT in cardiac hypertrophy in vitro and in vivo. Moreover, the regulatory effects of MHRT on SUMOylation of NAD-dependent protein deacetylase sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor γ coactivator-1 α (PGC-1α)/peroxisome proliferator-activated receptor-α (PPARα), specificity protein 1 (SP1)/histone deacetylase 4 (HDAC4) pathway were investigated. Here, we found that MHRT improved heart function by attenuating pathological cardiac hypertrophy in vivo and in vitro. MHRT also promoted the SUMOylation of SIRT1 protein that activated PGC1-α/PPAR-α pathway. Furthermore, MHRT enhanced SUMOylation of SIRT1 by upregulating SP1/HDAC4. Our findings suggested that SUMOylation of SIRT1 could mediate the protective effect of MHRT in cardiac hypertrophy. The new regulatory pathway provides a potential new therapeutic target for pathological cardiac hypertrophy.

The correlation between trimethylamine N-oxide, lipoprotein ratios, and conventional lipid parameters in patients with unstable angina pectoris.

PURPOSE: Trimethylamine N-oxide (TMAO) is recently the main risk factor for coronary heart disease (CHD). Plasma lipid levels are conventionally used to predict coronary risk, but the correlation between TMAO and plasma lipid levels in unstable angina pectoris (UAP) was unclear. Our objective was to compare the plasma level of TMAO to lipoprotein ratios and conventional lipid parameters in UAP patients. METHODS: A total of 114 control participants and 184 UAP patients were enrolled. Demographic characteristics were collected. Plasma levels of TMAO and lipid in all patients were measured and analyzed. The receiver operating characteristic analysis (ROC), univariate, and multivariate logistic regression analyses were carried out to examine the relationship between TMAO, lipoprotein ratios, conventional lipid parameters, and UAP. RESULTS: The plasma levels of TMAO were remarkably increased in UAP patients (3.28 ± 1.97 µM) compared with control participants (1.52 ± 0.59 µM, P < 0.01). TMAO was significantly correlated with lipid levels in UAP patients. The ROC, univariate and multivariate logistic regression analysis both showed that the TMAO significantly increased the risk for occurrence of UAP. CONCLUSIONS: Our data indicate that the TMAO is superior to lipoprotein ratios and conventional lipid parameters in predicting occurrence of UAP.