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Due to the complexity and the low concentrations of volatile components in aromatic plants, sample pretreatment is an important step in the whole analytical procedure.This study aimed to propose a novel, sensitive and fast approach to determine the volatile components in lavender.The 1-butyl-3-(propyltrimethoxysilane)imidazolium chloride ([BPtmsim]Cl) ionic liquid was introduced onto the surface of polydimethylsiloxane (PDMS) to prepare a novel PDMS/[BPtmsim]Cl sponge with large surface area, good sorption performance, and reusability. A solid-phase extraction method was developed based on PDMS/[BPtmsim]Cl sponge combined with gas chromatography-mass spectrometry (GC-MS).The effects of the various experimental parameters on the extraction efficiency were investigated. The optimal conditions were [BPtmsim]Cl amount of 0.3 g, 1:4 as the mass ratio of PDMS/[BPtmsim]Cl to lavender sample, microwave power of 700 W, microwave time of 10 min, and n-hexane as the desorption solvent. The method validation results showed good linearity (10-800 μg/ml), high correlation coefficient (RThe results showed that PDMS/[BPtmsim]Cl extraction is a rapid, highly efficient, and sensitive technique for the determination of volatile components in complex plant samples.

An adsorbent polydimethylsiloxane/graphene oxide/β-cyclodextrin sponge, which possessed the merits of high surface area, chemical stability, environment friendly, and excellent extraction capacity, was successfully fabricated. Based on the advantages, a novel microwave-assisted headspace solid-phase extraction method for lavender essential oil using polydimethylsiloxane/graphene oxide/β-cyclodextrin sponge as adsorbents was developed in this study. Various experimental parameters were studied. The optimal extraction conditions were as follows: 1 mg/mL as dopamine solution concentration, graphene oxide dosages of 30 mg, microwave power of 700 W, microwave irradiation time of 10 min, and desorption solvent of n-hexane. Under the optimal extraction condition, linearities ranging from 10 to 800 ng were achieved for six representative compounds with a correlation coefficients value of 0.99. The intra-day and inter-day precisions were in the ranges of 0.40-1.56 and 0.67-2.56%, respectively. Finally, the proposed technique was applied to analyze essential oil constituents in 14 samples of three lavender varieties, and 48 compounds were identified. Lavender varieties were distinguished using principal component analysis and partial least squares discriminant analysis. The results showed that the method developed in this study is a novel, simple, and sensitive method for the determination of essential oil in complex plant samples.

Different constitutive modeling methods lead to different prediction accuracy of stress-strain relationships for hot metal forming. The aim of this work is to establish constitutive model using two methods of double multiple nonlinear regression model (DMNR) and strain-compensated Arrhenius-type constitutive model (SACM) to describe the material flow behaviour of TC16 titanium alloy under hot compression in the strain rate range of 0.1 s − 1 ∼ 10.0 s − 1 and temperature range of 973 K ∼ 1373 K . A comparative study has been conducted on the prediction capability of DMNR model and SACM model under different temperature ranges, and their prediction accuracy was quantified by using standard statistical parameters such as correlation coefficient ( R ), average absolute error ( A A R E ) and root mean square error ( R M S E ). The results showed that the DMNR model has a better prediction accuracy to describe the stress-strain relationship than SACM model at temperature range of 973 K ∼ 1373 K . It indicates that DMNR model is more suitable in a wider range of deformation temperature. When the constitutive models of TC16 titanium alloy were developed at temperature range of 1173 K ∼ 1373 K , SACM model has more excellent predictability than DMNR model. It indicates that SACM model is more suitable to describe the stress-strain relationships in a narrow range of deformation temperature.

The expression of nearly all smooth muscle genes are controlled by serum response factor binding sites in their promoter regions. However, SRF alone is not sufficient for regulating smooth muscle cell development. It associates with other cardiovascular specific cofactors to regulate smooth muscle gene expression. Previously, we showed that the transcription co-factor CRP2 was a regulator of smooth muscle gene expression. Here, we report that CSRP2BP, a coactivator for CRP2, is a histone acetyltransferase and a driver of smooth muscle gene expression. CSRP2BP directly interacted with SRF, CRP2 and myocardin. CSRP2BP synergistically activated smooth muscle gene promoters in an SRF-dependent manner. A combination of SRF, GATA6 and CRP2 required CSRP2BP for robust smooth muscle gene promoter activity. Knock-down of Csrp2bp in smooth muscle cells resulted in reduced smooth muscle gene expression. We conclude that the CSRP2BP histone acetyltransferase is a coactivator for CRP2 that works synergistically with SRF and myocardin to regulate smooth muscle gene expression.