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According to the normal production conditions, 13 kinds of n-alkanes were added to the core material sheet production process to prepare heated tobacco products, and a GC-MS analysis method suitable for re-alkanes in the core material, filter and mainstream smoke particulate matter of heated tobacco products was established. The transfer behavior of re-alkanes in heated tobacco products was studied by measuring the content, release and mouth-to-mouth release of re-alkanes in heated tobacco products. The results showed that: 1) The particle phase transfer rates of 13 re-alkanes in mainstream smoke were 0~53. 5 %, the filter interception rate was 12. 6% ~ 50. 0%, the smoke support retention rate was 0. 2% ~ 35. 4%, the smoke core residue rate was 6. 4% ~ 29. 3%, and the loss rate was 0. 6% ~ 81. 5%; With the increase of relative molecular mass and boiling point, the transfer rate of particulate matter and the interception rate of filter in mainstream smoke of n-alkane compounds increased first and then decreased, the residual rate of cigarette core increased gradually, and the retention rate of cigarette support increased first and then stabilized. The smoke retention rate and filter rejection rate showed a good positive correlation with the boiling point of the compound within a certain range. 2) With the increase of the number of suction ports, the release amount of re-alkanes increased first and then decreased, but the order of the maximum release amount was inconsistent. The lower the boiling point of the compound, the earlier the order of the maximum release amount. 3) The coefficient of variation of the puff-by-puff release of re-alkanes ranged from 0. 28 to 0. 44. The coefficient of variation of the puff-by-puff release of tridecane ( boiling point 235°C) and tetradecane ( boiling point 254 °C) was small, and the puff-by-puff release stability was good. Based on the evaluation data of the retention rate of re-alkanes in heated tobacco products, the transfer rate of particulate matter in mainstream smoke, and the stability of puff-by-puff release, the boiling point range of additives suitable for heated tobacco products was proposed to be about 250 °C. [ABSTRACT FROM AUTHOR]

Normal and slim cigarettes with different filter ventilation and cigarette paper air permeability were rolled. The effects of filter ventilation, cigarette paper ventilation and ventilation distribution on nine phenolic aroma components release from mainstream cigarette smoke were investigated. The results showed the filter ventilation rate, paper ventilation rate negatively correlated to the releases of nine phenolic aroma components in cigarette smoke, and with the increase of ventilation rate, the decrease rate of maltol with caramel flavour and smaller molecular weight was higher, while the decrease rate of eugenol with smoky flavor and larger molecular weight was lower. No matter normal or small cigarettes, the paper and filter ventilation rate have different effects on the decrease of smoke composition, and the paper ventilation rate has greater influence than the filter ventilation rate. The effects of filter ventilation rate, paper ventilation rate and ventilation distribution on the release of nine phenolic aroma components in conventional cigarette smoke were greater than those in slim cigarette smoke. When the total ventilation rate was the same, the release of 9 phenolic aroma components in cigarette smoke with high filter ventilation rate and low paper ventilation rate was higher than that with low filter ventilation rate and high paper ventilation rate. [ABSTRACT FROM AUTHOR]

To quantify water-soluble sugars in natural tobacco flavors, the analytical method described in YC/T 447-2012 was optimized, and an HPLC-ELSD method with water extraction was developed to determine 10 water-soluble sugars in natural tobacco flavors, namely rhamnose, stevioside, fructose, sorbitol, mannose, galactose, glucose, inositol, sucrose, maltose. The results showed that: 1) The sample solution with water extraction presented better stability compared with the control method with 0.02 mol/L NaOH extraction. 2) The retention time of the analytes was more stable after adding aqueous ammonia into the mobile phase. 3) The stabilities of ELSD peak areas of the ananlytes were improved at a gas flow rate of 2.20 L/min and a drift tube temperature of 80 °C. 4) The LODs of the 10 sugars were in the range of 4.19-12.30 µg/mL and the spiked recoveries ranged from 80.20% to 106.00% with good intra-day (RSD≤4.05%) and inter-day (RSD≤6.25%) precisions. 5) The contents of these sugars in 239 natural tobacco flavors were determined with the developed method, and the top five sugars were glucose, fructose, sucrose, maltose and sorbitol. [ABSTRACT FROM AUTHOR]

In order to explore the effects of ventilation distribution on the releases of ketones in mainstream cigarette smoke, the releases of ketones in mainstream smoke were determined by GC-MS with two chromatography columns. The results showed that: 1) A total of 56 ketones were identified qualitatively and quantitatively. Among them, the releases of 27 ketones were more than 1 µ g/cig, and their releases accounted for more than 91% of the total release of all 56 ketones, which suggested that these 27 ketones were important in mainstream cigarette smoke. 2) Both filter ventilation rate and cigarette paper ventilation rate negatively correlated to the total release of ketones in mainstream cigarette smoke with coefficients of determination (R²) more than 0.98, and the effect of filter ventilation rate was greater than that of cigarette paper ventilation rate. 3) The ventilation rate of cigarette paper negatively correlated to the releases of 56 ketones and their total release. 4) At the same total ventilation rate of cigarette, the total release of ketones increased with the increase of cigarette filter ventilation rate, and the same total release of ketones could be achieved by different combinations of filter ventilation rate and cigarette paper ventilation rate. [ABSTRACT FROM AUTHOR]

Cigarette smoke condensate is a complex chemical matrix, and analysis of its components is very difficult because of the limitation of the peak capacity and sensitivity of conventional chromatography and the extensive and laborious sample preparation that is frequently required. In this study, the acidic fraction of mainstream cigarette smoke condensate has been investigated by using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GCxGC/TOFMS). Different column systems were tested and compared under proper GCxGC/TOFMS conditions. Auto data processing by TOFMS software combined with manual identification was used to assign the components. Over 1000 compounds, with S/N [greater than or equal to] 100, including 139 organic acids and over 150 phenols were tentatively identified by the developed method.

In order to investigate the effect of different ventilation distribution on organic acid release from mainstream smoke of slim cigarette, the slim cigarette samples with different filter ventilation and cigarette paper air permeability were rolled, and the organic acid in mainstream smoke of samples were analyzed by GC-MS, the prediction models of organic acids release based on both filter and paper ventilation rate were established. The results were as follows: 26 kinds of organic acids were detected. With the increase of filter ventilation rate or paper ventilation rate, the decrease rate of organic acids with smaller molecular weight was higher, while that with larger molecular weight was smaller, and the effect of paper ventilation rate on the release of organic acids in cigarette smoke was greater than that of filter ventilation rate. When the total ventilation rate (V) was constant, the release of organic acids in cigarette smoke with high filter ventilation rate and low paper ventilation rate was higher than that with low filter ventilation rate and high paper ventilation rate. The prediction accuracy of the model of organic acid release was high, and the results further proved that the cigarette organic acid release was higher with the combination of high filter ventilation rate and low paper ventilation rate. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of filter ventilation on the releases of routine components and seven harmful components in mainstream smoke of slim cigarettes, slim cigarette samples with different filter ventilation rates and cigarette paper of different air permeabilities were prepared. The releases of routine smoke components and seven harmful components in mainstream smoke were analyzed under machine-smoking conditions. The results showed that: 1) The total ventilation rate, filter ventilation rate, paper ventilation rate negatively correlated to the releases of routine smoke components, the seven harmful components and the cigarette harmful index (H). 2) When the total ventilation rate, filter ventilation rate or paper ventilation rate increased by 1%, the reduction rates of CO, HCN and crotonaldehyde were higher. The influences of paper ventilation on the releases of TPM, tar, nicotine, CO, moisture, HCN, NNK, phenol and crotonaldehyde and the H index of slim cigarettes were greater than those of filter ventilation alone. 3) The influences of filter ventilation and paper ventilation on the releases of tar, nicotine, CO, HCN, ammonia and phenol and the H index of slim cigarettes were slighter than those of king-sized cigarettes. By optimizing the ventilation parameters, the releases of tar and seven harmful components in mainstream smoke of slim cigarettes could be reduced. [ABSTRACT FROM AUTHOR]

Introduction The comprehensive complication index (CCI) is a new index to comprehensively and systematically evaluate complication severity. The objective of this study was to evaluate the predictive ability of CCI on short—and long-term overall survival(OS) in patients with esophageal squamous cell carcinoma (ESCC) undergoing minimally invasive esophagectomy (MIE) based on a propensity Score Matching (PSM) analysis. Methods A total of 356 patients treated with radical MIE from 2013 to 2017 were included, and the primary outcome was OS, and the secondary outcomes were postoperative hospital stay and hospital costs. Firstly, the optimla cut-off value of CCI was determined by X-tile. PSM was used to balance the baseline characteristics. Second, we compared postoperative hospital stay and hospital costs between high- and low-CCI group. Third, the Kaplan–Meier survival curve was used to analyze survival difference. Fourth, univariate and multivariate Cox analysis was used to explore the independent risk factors of OS. Results The CCI > 24.2 was defined as high-CCI group and CCI≦24.2 was defined as low-CCI group. The high-CCI group had more hospital costs and longer hospital stay than the low-CCI group both before and after PSM (p < 0.001). The K-M analysis indicated that patients with high CCI had worse prognosis both before and after PSM (before matching: P < 0.001; after matching: P = 0.04). CCI was determined as independent prognostic factor both before and after PSM (before PSM, P = 0.002; after PSM, P = 0.025). Conclusion The CCI could quantify postoperative complications after esophagectomy. High CCI is associated with longer hospital stay and hospitalization costs, and is an independent risk factor for poor OS. [ABSTRACT FROM AUTHOR]

In order to investigate the puff-by-puff discipline of flavor components in the mainstream cigarette smoking, a 20-channel rotary disc smoker modified from a patent in laboratory was used to achieve the puff-by-puff smoking of cigarettes. A GC-MS quantitative analysis method for neutral and alkaline flavor components in single-mouthful particulate phase of mainstream cigarette smoke was established. By using the established analytical method, the puff-by-puff delivery discipline of flavor components and the effects of the permeability of cigarette paper and packaging paper were studied. The results showed that: 1) The established analytical method had a good precision and recovery and was suitable for the quantitative analysis of neutral and alkaline aroma substances in single-mouthful gaseous and granular phase of cigarette smoke. 2) The transport capacity of tar and nicotine in the mainstream cigarette smoke steadily increased with the increase in the number of suction mouths, and decreased with the increase in the permeability of cigarette paper and packaging paper. 3) The transmission of neutral and alkaline aroma components increased with the increase in the number of suction mouths, but the transmission of various flavor components was slightly different, and decreased with the increase of the permeability of cigarette paper and packaging paper. 4) The puff-by-puff contents of neutral and alkaline aroma components in gaseous and granular phase of the mainstream smoke per unit tar and nicotine were the lowest in the first puff, and then were in line with the number of suction puffs. [ABSTRACT FROM AUTHOR]

The CHIRALPAK-IC was used, and the mixed solution of V (re-hexane) : V (isopropanol) = 95 : 5 was used as the mobile phase, and diethylamine was used as the mobile phase additive. In normal phase chromatography mode, a chiral column-high performance liquid chromatography-diode array detector (HPLC-DAD ) method was developed for the separation and analysis of nicotine optical isomers in tobacco and tobacco products. The characterization and test results of this method indicated:) The linear relationship between S-( -)-nicotine and R-( +)-nicotine was in the range of 15 ~750 µg/mL and 0. 75 ~30. 00 µg/mL, respectively. The detection limit and limit of quantification were 0.2 mg/g and 0. 05 mg/g, respectively. 2) The precision of intra- and inter-day measurements of nicotine was less than 0. 85% and 4. 00%, respectively; the recovery rates of S-( - ) -nicotine and R-( + ) -nicotine were 94. 93% ~ 103. 70% and 92. 50% ~ 117. 50%, respectively. This indicated that the method had good precision and high recovery rate. Using this method to determine the nicotine optical isomers of 26 different types of tobacco and tobacco products, it was found that tobacco was mainly S-( - )-nicotine, only 6 samples were detected by R-( + )-nicotine. The proportion of nicotine quality was 0. 18% ~0.70% ; among the 10 finished cigarettes and their mainstream smoke, the proportion of R-( + )-nicotine in total cigarette smoke was higher than that of cigarette tobacco. [ABSTRACT FROM AUTHOR]

• Sulfonated functionalized magnetic COFs were prepared through a facile strategy. • The resultant composite featured mixed-mode and multiple interactions. • It exhibited excellent capture ability for β-agonists and fluoroquinolones. • Validated MSPE–LC–MS/MS method quantified β-agonists and fluoroquinolones in real samples. In this work, an efficient method for the determination of β-agonists and fluoroquinolones was established, based on a mixed-mode sorbent of magnetic sulfonated covalent organic framework composites. By coupling with HPLC–MS/MS, the main factors that affect the extraction procedure were optimized. Under the optimal conditions, the proposed HPLC–MS/MS method was successfully utilized for the extraction of β-agonists and fluoroquinolones in milk and pork meat samples. The method showed good linearities (R 2 ≥ 0.9916), and low LOQs of 0.1–0.2 ng g−1 for β-agonists and fluoroquinolones. The adsorption mechanism was investigated with the assistance of quantum chemistry calculation method, and it is worth noting that the sorbent relied mainly on the multiple adsorption mechanisms, including π–π stacking, hydrophobic, electrostatic attraction and hydrogen-bonding interactions. This work not only provides a simple method for the preparation of a mixed-mode sorbent, but also a routine analysis strategy for monitoring the illegal use of β-agonists and fluoroquinolones. [ABSTRACT FROM AUTHOR]

Purpose: Neoadjuvant chemoimmunotherapy (nICT) is a novel and promising therapy model for locally advanced esophageal squamous cell carcinoma.The objective of this study aimed to assessed the impact of additional neoadjuvant immunotherapy on patients' short-term outcomes, particularly the incidence of anastomotic leakage (AL) and pathological response., Methods: Patients with locally advanced esophageal squamous cell carcinoma who received neoadjuvant chemotherapy (nCT)/ nICT combination with radical esophagectomy were enrolled from three medical centers in China. The authors used propensity score matching (PSM, ration:1:1, caliper=0.01) and inverse probability processing weighting (IPTW) to balance the baseline characteristics and compare the outcomes. Conditional logistic regression and weighted logistic regression analysis were used to further evaluate whether additional neoadjuvant immunotherapy would increase the risk of postoperative AL., Results: A total of 331 patients getting partially advanced ESCC receiving nCT or nICT were enrolled from three medical centers in China. After PSM/IPTW, the baseline characteristics reached an equilibrium between the two groups. After matching, there were no significant difference in the AL incidence between the two groups ( P =0.68, after PSM; P =0.97 after IPTW), and the incidence of AL in the two groups was 15.85 versus 18.29%, and 14.79 versus 15.01%, respectively. After PSM/IPTW, both groups were similar in pleural effusion and pneumonia. After IPTW, the nICT group had a higher incidence of bleeding (3.36 vs. 0.30%, P =0.01), chylothorax (5.79 0.30%, P =0.001), and cardiac events (19.53 vs. 9.20%, P =0.04). recurrent laryngeal nerve palsy (7.85 vs. 0.54%, P =0.003). After PSM, both groups were similar in palsy of the recurrent laryngeal nerve (1.22 vs. 3.66%, P =0.31) and cardiac events (19.51 vs. 14.63%, P =0.41). Weighted logistic regression analysis showed that additional neoadjuvant immunotherapy was not responsible for AL (OR=0.56, 95% CI: [0.17, 1.71], after PSM; 0.74, 95% CI: [0.34,1.56], after IPTW). The nICT group had dramatically higher pCR in primary tumor than the nCT group ( P =0.003, PSM; P =0.005, IPTW), 9.76 versus 28.05% and 7.72 versus 21.17%, respectively., Conclusions: Additional neoadjuvant immunotherapy could benefit pathological reactions without increasing the risk of AL and pulmonary complications. The authors require further randomized controlled research to validate whether additional neoadjuvant immunotherapy would make a difference in other complications, and determine whether pathologic benefits could translate into prognostic benefits, which would require longer follow-up., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.)

Cigarette smoke condensate is a complex chemical matrix. Analysis of nitrogen-containing compounds present therein is very difficult because of the limitation of the peak capacity of conventional one-dimensional chromatography. Extensive and laborious sample preparation is frequently required or selective detectors are frequently used. In this study, the basic fraction of mainstream cigarette smoke condensate has been investigated by using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC x GC/TOFMS). Auto data processing by TOFMS software combined with manual identification was used to assign the components. 377 nitrogen-containing compounds, including 155 pyridine derivatives, 104 quinoline/isoquinoine derivatives, and 56 pyrazine derivatives were tentatively identified. By selecting appropriate unique masses and in the light of the component positions in the structured chromatogram, alkyl-substituted pyridines, pyrazines, and quinolines/isoquinolines were separately shown and further validated. The peaks of eight individual positional isomers of two-carbon-substituted pyridines and thirteen positional isomers of methyl-substituted quinolines/isoquinolines were further confirmed, based on linear incremental retention behavior in combination with TOFMS and the structured chromatogram of GC x GC.