In order to determine hydrogen cyanide(HCN) in mainstream cigarette smoke with autoanalyzer more accurately,the effects of formaldehyde,acetaldehyde,acetone and acrolein,as well as the concentration of formaldehyde on the determination system were examined,and the stability of HCN in diluted and undiluted trapping solution for gas phase and extraction solution of particulate phase was investigated.The results showed that: 1) formaldehyde had notable influence,however,acetaldehyde,acetone and acrolein had little,negligible influence on the determination system;2) the determined value of hydrogen cyanide decreased by 7.38% and 13.51% in the presence of formaldehyde of 5.80 and 11.49 μg/mL,respectively;3) formaldehyde had notable influence on the stability of the sample,and the other three compounds' influence was negligible;4) the stability of HCN in undiluted trapping solution for gas phase and extract solution of particulate phase was poor,which was obviously improved in diluted solutions;5) the recovery of the method ranged from 100% to 104% with the relative standard deviation(RSD) of 1.11%,and the relative deviation between the HCN values by this method and ion chromatography was less than 5%.
In order to systemically evaluate the reliability of the method of predicting ionization energy with density functional method in quantum chemistry [B3LYP/6-311++G(d,p)] and composite ab initio(G3B3),70 chemical portions of known ionization energy in cigarette smoke were calculated and analyzed as the validation set,and some smoke portions of unknown ionization energy were calculated.Meanwhile,by synchrotron radiation photoionization mass spectrometry assisted with an in-house cigarette smoke sampler,the gas phase components in cigarette smoke were on-line analyzed.The photoionization mass spectra and photoionization efficiency spectra were measured,also obtained were the experimental values of the ionization energy of some smoke portions.The results showed that G3B3 method was competent for calculating ionization energy of various smoke portions,the accuracy was up to 0.06 eV,and the calculated results were suitable for the qualitative analysis of cigarette smoke components.
Introduction At now, the association between levels of physical activity and depression is not well understood, however depressive symptoms are common in patients with metabolic dysfunction associated fatty liver disease (MAFLD). Material and methods This study aims to investigate whether there is a correlation between MAFLD patients' levels of moderate to vigorous recreational exercise and depression. From the National Health and Nutrition Examination Survey (NHANES) database, 2656 individuals with MAFLD were included in this investigation. Depressive symptoms were examined in connection to varying degrees of entertainment activity using a generalized linear model that was weighted on numerous factors. Results After accounting for all potential confounding factors, the weighted generalized linear model revealed a negative correlation between moderate entertainment activity and depression (OR=0.599, 95% CI: 0.475-0.755; P<0.001). This correlation persisted even after controlling for other variables. In spite of this, after controlling for all potential confounding variables, there was still no correlation between the intensity of entertainment activity and depression. Females who engage in moderate amounts of amusement are less likely to suffer from depression, according to subgroup analysis (OR=0.657, 95% CI: 0.440-0.983; P =0.036). Conclusions This link persists after controlling for other variables; patients with MAFLD are more prone to depression, whereas those with higher levels of moderate recreational activity are less likely to suffer from depression. Their depressed symptoms may be treatable by modest recreational activity, according to these results.
The pyrolytic behavior of citric acid was investigated by thermogravimetric system coupled to Fourier transform infrared spectrometer(TG-FTIR).The TG curves,DTG curves,and relative contents of pyrolytic gas phase products of citric acid in oxygen of different concentrations were determined and compared.The formation rules of gas phase products and pyrolytic mechanism of citric acid were explored.The results showed that: 1) The main pyrolytic gas phase products of citric acid included CO2,H2O,CO,anhydride and ketone compounds,in which CO2 was the major,while CO was the minor,H2O emerged first,while anhydride the last.2) There might exist two pyrolytic pathways,in one of the pathways citric acid was dehydrated and then decarbonated to form anhydride,and in the other to form ketones mainly by decarbonation.At the initial pyrolytic stage,both pathways coexisted,increasing oxygen concentration would benefit the formation of ketones.While at higher temperature,anhydride formation dominated.
Lipoxygenases (LOXs) play significant roles in abiotic stress responses, and identification of LOX gene promoter function can make an important contribution to elucidating resistance mechanisms. Here, we cloned the CmLOX08 promoter of melon (Cucumis melo) and identified the main promoter regions regulating transcription in response to signalling molecules and abiotic stresses.The 2054-bp promoter region of CmLOX08 from melon leaves was cloned, and bioinformatic analysis revealed that it harbours numerous cis-regulatory elements associated with signalling molecules and abiotic stress. Five 5'-deletion fragments obtained from the CmLOX08 promoter-2054 (LP1), 1639 (LP2), 1284 (LP3), 1047 (LP4), and 418 bp (LP5)-were fused with a GUS reporter gene and used for tobacco transient assays. Deletion analysis revealed that in response to abscisic acid, salicylic acid, and hydrogen peroxide, the GUS activity of LP1 was significantly higher than that of the mock-treated control and LP2, indicating that the - 2054- to - 1639-bp region positively regulates expression induced by these signalling molecules. However, no deletion fragment GUS activity was induced by methyl jasmonate. In response to salt, drought, and wounding treatments, LP1, LP2, and LP4 promoted significantly higher GUS expression compared with the control. Among all deletion fragments, LP4 showed the highest GUS expression, indicating that - 1047 to - 1 bp is the major region regulating promoter activity and that the - 1047 to - 418-bp region positively regulates expression induced by salt, drought, and wounding, whereas the - 1284 to - 1047-bp region is a negative regulatory segment. Interestingly, although the GUS activity of LP1 and LP2 was not affected by temperature changes, that of LP3 was significantly induced by heat, indicating that the - 1284- to - 1-bp region is a core sequence responding to heat and the - 2054- to - 1284-bp region negatively regulates expression induced by heat. Similarly, the - 1047- to - 1-bp region is the main sequence responding to cold, whereas the - 2054- to - 1047-bp region negatively regulates expression induced by cold.We cloned the CmLOX08 promoter and demonstrated that it is a signalling molecule/stress-inducible promoter. Furthermore, we identified core and positive/negative regulatory regions responding to three signalling molecules and five abiotic stresses.
The present study investigated the influence of the cigarette smoke extract (CSE) on mammalian thioredoxin reductase (TrxR) activity. TrxR is a selenoenzyme with a selenocysteine (Sec) residue exposed on the enzyme’s surface. This unique Sec residue is particularly susceptible to modification by numerous types of electrophiles, leading to inactivation of TrxR and consequent cytotoxicity. Cigarette smoke contains various electrophiles, and the present study showed that CSE could inhibit intracellular TrxR through causing crosslinking and alkylation of TrxR1. TrxR inhibitory capacities of various CSEs were evaluated by using mouse-liver homogenate. Among the CSEs prepared from 18 commercial cigarette brands, TrxR inhibitory capacities of the maximum and the minimum had a 2.5-fold difference. Importantly, CSE’s inhibitory capacity greatly paralleled its cytotoxic potency in all cell lines used. Compared to cytotoxic assays, which have been widely used for evaluating cigarette toxicity but are not suitable for simultaneously examining a large number of cigarette samples, the present method was simple and rapid with a high-throughput feature and thus could be used as an auxiliary means to predict the cytotoxicity of a large number of cigarette samples, making it possible to extensively screen numerous agricultural and industrial measures that potentially affect cigarette safety.
The seedling provenance trial of Schima suoerba containing 37 seedlots collected from 6 provinces (zone) was conducted in Dexing, Anfu and Xinfeng Counties, Jiangxi Province. The results showed there were very significant differences in weight per 1 000 seeds,laboratory seed germination,seedling height, ground diamater and biomass of Schima suoerba provenance, and broad heritability of seedling traits were hight. The seedling height growth of Schima suoerba provenance displayed quick growing period in August and September, height increment was more than. 50% of the total height increment. The seedling height and ground diamater were even negative related to the latitude of the seedlots. 5 quick - growing provenances have been selected among the seedlings, they are Kaiping, Yangshan, Shaoguan, Hua' an and Shangyou.
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