Nicotine Levels Research Articles

Reactions to Messages About a Nicotine Reduction Policy: A Focus Group Study Among People Who Use Little Cigars and Cigarillos.

The U.S. Food and Drug Administration (FDA) has proposed rulemaking to reduce the nicotine content in cigarettes and other combusted tobacco products to non-addictive levels. This qualitative study documents reactions to messages communicating this policy among people who use little cigars and cigarillos (LCCs). We conducted eight focus groups with participants from four populations with the highest prevalence of cigar use (African American males and females, white males and females). Participants described their reactions to eight messages about the policy: Three messages about the equal risk of LCCs with regular and low nicotine levels; three quit efficacy messages about low nicotine LCCs being easier to quit; one "compensation" message to correct misperceptions about the policy causing people to smoke more to get desired nicotine; and one message about using alternative nicotine sources (eg, e-cigarettes). Participants perceived risk messages as the most motivating to quit, whereas efficacy messages made some participants feel that the policy would cause former users of LCCs to relapse. Many participants expressed favorable responses to the compensation message. The message about using alternative nicotine sources sparked intense responses, with many participants expressing outrage and mistrust of the message. Participants' beliefs that they were not addicted to LCCs dampened their perceptions of the effectiveness of the policy. Perceptions of the addictiveness and relative harms of LCCS influenced responses to policy messages. The FDA should consider using different messages to communicate with people who use LCCs because they perceive LCCs as different from cigarettes. This is the first study to document affective and cognitive responses to the FDA's reduced nicotine policy among people who use LCCs. The false belief that cigar products are less harmful than cigarettes may be influencing people's lack of support for the reduced nicotine policy and difficulty in understanding its potential positive impact. To maximize the public health benefit of the reduced nicotine policy, the FDA should include LCC products in the policy; however, it is crucial that they use educational messaging to clarify misperceptions regarding nicotine and harm as it applies to LCCs.

Polymorphisms in Glutathione S-Transferase (GST) Genes Modify the Effect of Exposure to Maternal Smoking Metabolites in Pregnancy and Offspring DNA Methylation.

Maternal smoking in pregnancy (MSP) affects the offspring's DNA methylation (DNAm). There is a lack of knowledge regarding individual differences in susceptibility to exposure to MSP. Glutathione S-transferase (GST) genes are involved in protection against harmful oxidants such as those found in cigarette smoke. This study aimed to test whether polymorphisms in GST genes influence the effect of MSP on offspring DNAm. Using data from the Isle of Wight birth cohort, we assessed the association of MSP and offspring DNAm in 493 mother-child dyads (251 male, 242 female) with the effect-modifying role of GST gene polymorphism (at rs506008, rs574344, rs12736389, rs3768490, rs1537234, and rs1695). MSP was assessed by levels of nicotine and its downstream metabolites (cotinine, norcotinine, and hydroxycotinine) in maternal sera. In males, associations of hydroxycotinine with DNAm at cg18473733, cg25949550, cg11647108, and cg01952185 and norcotinine with DNAm at cg09935388 were modified by GST gene polymorphisms (p-values < 0.05). In females, associations of hydroxycotinine with DNAm at cg12160087 and norcotinine with DNAm at cg18473733 were modified by GST gene polymorphisms (p-values < 0.05). Our study emphasizes the role of genetic polymorphism in GST genes in DNAm's susceptibility to MSP.

Impact of E-liquid Packaging on Vaping Product Perceptions Among Youth in England, Canada, and the United States: A Randomized Online Experiment.

Vaping is not risk-free but can help those who smoke to reduce harm to health and stop smoking. However, packaging of vaping products, including e-liquids, appeals to youth and might facilitate vaping among nicotine-naïve people. Standardized packaging of vaping products could moderate the appeal of vaping among youth. This study assessed how youth interest in trying and perceived health harms of using e-liquids are associated with branded or standardized (white or olive) e-liquid packaging with different nicotine levels displayed. A between-subject experiment with three packaging and two nicotine level conditions included youth (n = 13801) aged 16 to 19 from England, Canada, and the United States as a part of a cross-sectional online survey in August-September 2021. Participants' interest in trying and perceived harm of e-liquids were analyzed using logistic and multinomial regressions adjusted for age, sex, race or ethnicity, country, vaping, and smoking status. Compared with branded e-liquid packs, more youth reported no interest in trying e-liquids in white (aOR = 1.48, 95% CI = 1.34 to 1.64) or olive (aOR = 1.62, 95% CI: 1.47 to 1.80) standardized packs. Compared with branded e-liquid packs, more youth inaccurately perceived e-liquids in white (aOR = 1.22, 95% CI: 1.11 to 1.34) or olive (aOR = 1.29, 95% CI: 1.18 to 1.41) standardized packs as equally or more harmful than smoking. E-liquid nicotine levels displayed on packs were not associated with youth interest in trying or harm perceptions of using e-liquids. Among 16- to 19-year-old youth from England, Canada, and the United States, standardized packaging of e-liquids was associated with lower interest in trying and higher health risk perceptions. Branded packaging of vaping products appeal to youth and might prompt nicotine use among those who had never smoked. This study suggests that restricting branding elements on e-liquid packaging is associated with youth's lower interest in trying e-liquids and higher misperceptions that vaping is equally or more harmful than smoking. Standardized packaging might reduce appeal of vaping among youth, but its potential to discourage vaping for harm reduction should also be considered.

Determination of nicotine and cotinine in human hair using online solid phase extraction coupled with liquid chromatography-tandem mass spectrometry and their relation to hair cortisol and cortisone

Tobacco smoking is one of the critical public health threats all over the world. Since nicotine and its metabolite cotinine have been routinely used as the biomarkers to estimate the exposure to tobacco smoking, hair nicotine and cotinine analyses can provide of a retrospective index of nicotine and cotinine integrated over extended periods of several months prior to hair sampling to estimate the long-term exposure to tobacco smoking. Since the relationship between tobacco smoking and hypothalamic-pituitary-adrenal (HPA) axis is implicated in both stress response and nicotine addiction, better understanding of the association between hair nicotine, cotinine levels and hair cortisol, cortisone levels is an important prerequisite toward more adequate use of this method in future research. We here presented an online solid phase extraction (SPE) coupled with liquid chromatography- tandem mass spectrometry (LC-MS/MS) method for quantification of long-term integrated nicotine and cotinine in human hair. This method was applied to the analysis of hair nicotine and cotinine in 40 participants of smokers and nonsmokers (mean ± SD age: 46.25 ± 11.92 years; 40 % male) and the investigation of their association with hair cortisol and cortisone. Methanol together with glass tube was used for hair nicotine and cotinine extraction during the incubation time of 18-h. The limits of quantification were 1 pg/mg for nicotine as well as 0.1 pg/mg for cotinine. The inter- and intra-day coefficients of variation were below 15 %. The method recovery ranged between 90 % and 104 %. Group-level analyses revealed that smokers exhibited higher hair nicotine and cotinine levels compared to nonsmokers. Hair nicotine and cotinine levels showed significant positive associations with hair cortisol and cortisone levels in smokers (nicotine and cortisol: Spearman's ρ = 0.619, p = 0.005; cotinine and cortisol: Spearman's ρ = 0.468, p = 0.043; nicotine and cortisone: Spearman's ρ = 0.773, p = 0.000; cotinine and cortisone: Spearman's ρ = 0.531, p = 0.016), but not in nonsmokers. The presented online SPE LC-MS/MS method provides a simply and highly specific analytical strategy for the detection of nicotine and cotinine concentrations in human hair for the retrospective assessment of cumulative long-term nicotine and cotinine exposure. Furthermore, hair nicotine, cotinine levels correlate with hair cortisol, cortisone levels in smokers other than nonsmokers.

An epidemiological study of oral tobacco use amongst urban slum inhabitants in a town from central urban India

Background: Smokeless tobacco users receive levels of nicotine known to be addictive, and clinical symptoms of dependency and withdrawal for smokeless tobacco are identical to those for cigarettes. Smokeless tobacco usage patterns share significant parallels with patterns of use of other addictive drugs. Because everyone spits after using oral tobacco, there are more persons who spit in public due toits use. Use of smokeless tobacco during pregnancy increases the chance of low-birth-weight babies by two to three times and is linked to stillbirths. Other negative health implications of smokeless tobacco use include dental decay, gum recession, high blood pressure, oral sub-mucous fibrosis (OSF), a crippling disorder, and mouth and food pipe malignancies. This warrants the study of patterns of oral tobacco use and its determinants in urban slum areas. Objective: To estimate the prevalence and patterns of oral tobacco use and assess the motivating and demotivating factors associated with it amongst urban slum inhabitants. Methods: A community-based cross-sectional study will be conducted in the urban field practice area of a tertiary care hospital. A semi-structured questionnaire assessing the socio-demographic profile, prevalence and pattern associated factors for oral tobacco use among the study participants will be implemented. Study implications: This study will help to determine the prevalence and pattern of oral tobacco use, as well as the motivating and demotivating factors that contribute to oral tobacco use. Insights gained shall be useful to implement focussed prevention strategies.

CYP2A6 Gene Polymorphism Allele *4 Study in Hypertensive Patients with a History of Smoking

Nicotine is a specific CYP2A6 substrate found in cigarettes. Nicotine levels in the blood are affected by the metabolic rate of the CYP2A6 enzyme, which is known to have a high level of polymorphism. High levels of nicotine in the blood can result in an increased risk of cardiovascular disease through the mechanism of increasing lipolysis and causing an increase in triglyceride levels in the blood. This study is an observational study conducted on 31 hypertensive men with a history of smoking. The purpose of this study was to determine the frequency of the CYP2A6 allele *4 genes in hypertensive patients with a history of smoking. Result analysis was performed on PCR products using electrophoresis, then the frequency of each allele was determined. The results showed that there was a CYP2A6 allele *4 gene in hypertensive patients with a history of smoking in Yogyakarta with an allele frequency of 62.90%, and only 2 respondents (6.45%) had the CYP2A6*1/*1 genotype or wildtype.

Investigation of the relationship between nicotine and cotinine concentrations in human biological samples by a GC-MS method

In this study, a gas chromatography-mass spectrometry method was developed for the determination of nicotine and cotinine wherein human plasma, urine, and saliva. In addition, it was aimed to determine statistically the correlation between nicotine and cotinine levels in urine and saliva samples and nicotine and cotinine levels in blood samples. The limit of quantification was ≤0.83 ng/mL and precision were ≤4.91 and accuracy (RE%) was between (-4.93) and 4.90. Recovery was detected between 95.4% and 104.7%. The method was employed to determining the nicotine and cotinine concentrations in plasma, saliva, and urine total of 91 samples belong to non-smokers (n=37) and active smokers (n=54) who were healthy (n=65) and COPD patients (n=27) and the statistical relationship within the nicotine and cotinine values of the samples were investigated. It was found a correlation (r=0.752, p≤0.01) between plasma and saliva cotinine levels and estimation equation calculated as y=1.56x+43.24. Also, the correlation between plasma and urine cotinine levels was found (r=0.787, p≤0.01) by the equation that y=0.31x+34.59. The results show that by accurately determining the amount of cotinine in both saliva and urine, the exposure risks of both active smokers and those exposed to cigarette smoke with the ETS can be estimated.

Characterization of Ad Libitum Use Behavior of On! Nicotine Pouches.

Objectives: Actual use of nicotine pouch products is not well studied. The objectives of this study were to characterize on ® nicotine pouch (Test Products (TP)) use behavior, including association with cigarette and smokeless tobacco (ST) product use. Methods: Adults who smoke cigarettes (AS) and/or adults who use ST (ASTU) (N=1147) that were not planning to quit and had expressed interest in trying and using TP after a 5-day trial were offered ad libitum use of TPs (7 flavors at 5 nicotine levels) for 6 weeks. Results: Participants used a median of ~5-6 pouches/day of a variety of flavors and nicotine levels. In the final week of the study, 27% of AS and 71% of ASTU reported no use of cigarettes or ST respectively, while reporting continued use of TPs. Additionally, 39% of AS and 14% of ASTU reduced consumption of cigarettes or ST products respectively by 50%-99%, compared to reported use at screening. We found a statistically significant inverse relationship between TP flavor varieties and number of cigarettes/ST. Conclusions: These data suggest that TPs can be potential substitutes for cigarettes/ST products, and complete switching may offer harm reduction potential for AS and ASTU not interested in quitting.

Assessing the impact of protonating acid combinations in e-cigarette liquids: a randomised, crossover study on nicotine pharmacokinetics

The addition of protonating acids to e-cigarette liquid formulations (e-liquids) enhances nicotine bioavailability in e-cigarette use. However, little is known about the impact of different combinations of protonating acid on nicotine pharmacokinetics. The objectives of this study were to compare pharmacokinetics of nicotine absorption following use of a closed-system e-cigarette, containing e-liquids with two different nicotine levels and with different ratios of three common protonating acids—lactic, benzoic and levulinic. In a randomised, controlled, crossover study, nicotine pharmacokinetics and product liking were assessed for prototype e-liquids used in a Vuse e-cigarette containing either 3.5% or 5% nicotine and varying ratios of lactic, benzoic and/or levulinic acid. During an 8-day confinement period, 32 healthy adult current cigarette smokers/e-cigarette dual users used a single study e-liquid each day during 10-min fixed and ad libitum use periods after overnight nicotine abstinence. For most comparisons, Cmax and AUC0–60 following both fixed and ad libitum puffing were significantly higher for e-liquids containing 5% nicotine compared with 3.5% nicotine. However, Cmax and AUC0–60 were not statistically different for 5% nicotine e-liquids containing varying ratios of lactic, levulinic and benzoic acid when compared to an e-liquid containing lactic acid only. Mean scores for product liking were similar for all e-liquid formulations assessed, regardless of nicotine concentration, acid content, and whether the product was used in a fixed or ad libitum puffing regimen. While e-liquid nicotine concentration significantly affected users’ nicotine uptake, the different combinations of benzoic, levulinic and lactic acid in the e-liquids assessed had limited impact on nicotine pharmacokinetics and product liking scores.

"I Get the Flavors and It Makes Me Love Vaping More": How and Why Youth Users Modify Electronic Nicotine Delivery Systems.

Youth in the United States are using electronic nicotine delivery systems (ENDS) at a high rate. Modifications to ENDS by youth can introduce additional health hazards which have not been previously considered. To better understand these risks, we need more information on what these modifications are, the motivations behind them, and the sources of information on modifications. Utilizing a trained moderator, in 2020-2021, we conducted one-on-one interviews with 19 youth ENDS users aged 16-17 living in the United States and analyzed their responses using a qualitative description approach. The most prominent modification was to the e-liquid; youth indicated they mixed e-juices to create new flavors and added substances not intended for vaping, including illicit drugs such as cannabis and cocaine. Few youths from our sample were interested in achieving a specific nicotine level to vape, and modifications to the battery, coil and wick were less frequently mentioned. Some of these modifications were motivated by a desire to achieve specific experiences with their device. At other times, modifications were made due to necessity because of limited access to ENDS devices and supplies. YouTube and peers were the main sources of information about modifying. Youth are making modifications that are both intended and unintended by the manufacturer. Adding illicit drugs and other substances not made for vaping is of particular concern. Understanding how youth modify ENDS and how that changes their use is important to guide regulatory policy intended to reduce harm to youth from ENDS use. Youth from our study indicated that they make modifications to the ENDS devices, specifically to the e-liquid. These modifications are both intended by the manufacturer, such as changing the e-liquid and replacing coils, and unintended, such as adding substances not meant for vaping. Future policies aimed at reducing youth ENDS use should consider mandating better safeguards against modifications that appeal to youth.

367-OR: E-cigarette Vaping Exposure Increases Adipose 11ß-HSD1 Expression and Disturbs Glucose Homeostasis in Mice

Electronic cigarette (E-cigs) use may increase the prediabetic risk, but the underlying mechanisms remain underexplored. Pre-receptor activation of glucocorticoids (GCs) via 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in adipose tissues has been identified as an important mediator of insulin resistance and type 2 diabetes. However, little is known about the effects of E-cig vaping on 11β-HSD1 and glucose homeostasis. To address this issue, we conducted animal model studies with mice exposed to aerosolized PBS, nicotine-free or nicotine-containing E-cigs, with concurrent exposure to either vehicle or the GC receptor (GR) antagonist RU486. We observed that exposure of E-cig vaping nicotine for 4 weeks increased 11β-HSD1 expression and induced lipase HSL and ATGL abundance within the adipose tissues with induction of hypercortisolemia in response to elevated plasma nicotine levels in mice compared with those of aerosolized E-cig vaping vehicle or PBS controls. Induction of adipose 11β-HSD1 was correlated with elevated the expression of hepatic gluconeogenic enzymes PEPCK and G6Pase and corresponded to the elevated fasting glucose levels. Moreover, E-cig vaping nicotine also increased glucose intolerance, but decreased the glucose-lowing effects of insulin and elevated plasma FFA levels in mice compared with PBS controls. However, E-cig vapor without nicotine did not affect these metabolic parameters. Furthermore, RU486 treatment attenuated E-cig vaping nicotine-induced adipose 11β-HSD1 and lipase expression. In addition, RU486 also attenuated the E-cig-mediated activation of hepatic PEPCK and G6Pase and decreased plasma FFA levels, but did not change the elevated plasma corticosterone levels in mice on E-cig vaping nicotine. These data indicate that E-cig vapor exposure harmfully affects glucose homeostasis and these effects may arise, in part, from aerosol nicotine-induced adipose 11β-HSD1 and GR expression. Disclosure J.Wang: None. T.Friedman: None. M.Jiang: None. Y.Liu: None. J.Liu: None. Y.Wang: None. S.C.J.Kim: None. E.Espinal: None. R.Yang: None. H.Zhong: None. X.M.Shao: None. K.Lutfy: None. Funding Tobacco-Related Disease Research Program (T31IR1603)

Nicotine and Microvascular Responses in Skeletal Muscle from Acute Exposure to Cigarettes and Vaping.

Despite claims of safety or harm reduction for electronic cigarettes (E-cig) use (also known as vaping), emerging evidence indicates that E-cigs are not likely safe, or necessarily safer than traditional cigarettes, when considering the user's risk of developing vascular dysfunction/disease. E-cigs are different from regular cigarettes in that E-cig devices are highly customizable, and users can change the e-liquid composition (such as the base solution, flavors, and nicotine level). Since the effects of E-cigs on the microvascular responses in skeletal muscle are poorly understood, we used intravital microscopy with an acute (one-time 10 puff) exposure paradigm to evaluate the individual components of e-liquid on vascular tone and endothelial function in the arterioles of the gluteus maximus muscle of anesthetized C57Bl/6 mice. Consistent with the molecular responses seen with endothelial cells, we found that the peripheral vasoconstriction response was similar between mice exposed to E-cig aerosol or cigarette smoke (i.e., 3R4F reference cigarette); this response was not nicotine dependent, and endothelial cell-mediated vasodilation was not altered within this acute exposure paradigm. We also report that, regardless of the base solution component [i.e., vegetable glycerin (VG)-only or propylene glycol (PG)-only], the vasoconstriction responses were the same in mice with inhalation exposure to 3R4F cigarette smoke or E-cig aerosol. Key findings from this work reveal that some component other than nicotine, in inhaled smoke or aerosol, is responsible for triggering peripheral vasoconstriction in skeletal muscle, and that regardless of one's preference for an E-cig base solution composition (i.e., ratio of VG-to-PG), the acute physiological response to blood vessels appears to be the same. The data suggest that vaping is not likely to be 'safer' than smoking towards blood vessels and can be expected to produce and/or result in the same adverse vascular health outcomes associated with smoking cigarettes.

Rapid quantitative analysis of tobacco smoking in saliva using a TRPA1 ion channel-mediated bioelectronic tongue inspired by the human sensory system

To stop smoking is often hampered by the addictive nature of nicotine, even when smokers are aware of its harmful effects. Hence, healthcare providers should manage cessation programs for smokers. A quantitative method of analyzing tobacco use is needed to accurately diagnose addicted smokers and provide alternatives, such as nicotine patches. Although numerous sensors have been developed to measure levels of nicotine that reflect tobacco smoking, those that analyze saliva from smokers remains challenging in terms of on-site application. We therefore constructed a biomimetic system using the human smoking-responsive respiratory tract receptor, transient receptor potential ankyrin 1 (TRPA1), to quantify amounts of smoking. TRPA1-overexpressed nanovesicles (TRPA1-NV) were attached to a carbon nanotube (CNT) electrode coated with a Ca2+ ion selective membrane (TRPA1-NV/ISM-CNT) to prevent non-selective responses and detect TRPA1-mediated Ca2+ movement. The TRPA1-NV/ISM-CNT sensor detected pM levels of nicotine and crotonaldehyde in saliva from smokers and did not respond to capsaicin, glucose, and acetic acid, that are potential contaminants in saliva. Our sensor dose-dependently responded to artificial saliva exposed to tobacco smoke and to saliva from smokers, without complex preparatory processes. Our TRPA1-NV/ISM-CNT sensor rapidly and accurately quantified salivary nicotine and crotonaldehyde that indicate smoking habits in real time on-site.

Tobacco products and electronic cigarettes’ legislation violations - observational study in 31 European countries, 2005–2022

BackgroundEuropean Union (EU) law regulates the manufacture, presentation, and sale of tobacco and related products in all member states. This study examined whether legislation non-compliant tobacco products and electronic cigarettes were available for sale in the European market. MethodsWe queried the EU Rapid Information System for dangerous non-food products, covering 28 current and former EU member states and 3 associated countries, also known as Rapex, for non-compliant tobacco and related products reported between 2005 and 2022. FindingsDuring the operation of the Rapex system, 183 violations were reported (six on tobacco, three on traditional cigarettes, and 174 on e-cigarettes). Insufficient product safety information was found in 86% of the reports on e-cigarettes and 74% of the refills. Violations regarding the volume of the liquid container were observed in 26% of the e-cigarette reports and 20% of the refill reports. Approximately 15% of the reported e-cigarettes and 17% of refill liquids exceeded permissible nicotine levels. More serious standard violations were recorded for refills than for e-cigarettes. Approximately one-third of Rapex system countries submitted no notifications. InterpretationE-cigarettes were the most frequently reported items in the European market of tobacco and non-tobacco nicotine products. The most common concerns were inadequate product safety information, incorrect liquid container volume, and excessive nicotine concentration. Identifying the most recognized legal infringements did not require laboratory tests and was based only on packaging and the manufacturer's declaration analysis. Further studies are necessary to corroborate whether products available in countries where no violations have been reported meet EU safety standards.

Physical and chemical characterization of smokeless tobacco products in India

The rapid proliferation of smokeless tobacco (SLT) in India has occurred without adequate information on the possible dangers and toxicity of these products. Tobacco flavors as well as nicotine (both protonated and un-protonated) are responsible for health dangers and addiction. The study aimed to offer information on the physical characteristics of commonly used smokeless tobacco products (including microscopic analysis), along with nicotine content (both total and un-protonated), pH, moisture, and flavors. The Standard Operating Procedures (SOPs) validated by the World Health Organization (WHO) recognized Tobacco Testing Laboratory TobLabNet) were applied for the analysis of various constituents of the SLTs. The microscopic analysis indicated that some of the SLT products like khaini were finely processed and available in filter pouches for users’ convenience and prolonged use leading to prolonged retention and addiction potential. Nicotine absorption and availability (both protonated and un-protonated) are affected by moisture and pH. Essences provide a pleasant aroma and flavor, with an increased risk of misuse and other health problems. Few chewing tobacco and Zarda had the lowest levels of un-protonated nicotine (0.10–0.52% and 0.15–0.21%, respectively), whereas Gul, Gudhaku, and Khaini had the highest levels, ranging from 95.33 to 99.12%. Moisture and pH ranged from 4.54 to 50.19% and 5.25–10.07 respectively. Menthol (630.74–9681.42 µg/g) was the most popular flavour, followed by Eucalyptol (118.16–247.77 µg/g) and camphor (148.67 and 219.317 µg/g). SLT’s health concerns and addiction dangers are exacerbated by the high proportion of bioavailable nicotine coupled with flavors. The findings of this study have important implications for the regulation and use of SLT in countries where use of SLT is prevalent.

A Lightweight convolutional neural network for nicotine prediction in tobacco by near-infrared spectroscopy.

The content of nicotine, a critical component of tobacco, significantly influences the quality of tobacco leaves. Near-infrared (NIR) spectroscopy is a widely used technique for rapid, non-destructive, and environmentally friendly analysis of nicotine levels in tobacco. In this paper, we propose a novel regression model, Lightweight one-dimensional convolutional neural network (1D-CNN), for predicting nicotine content in tobacco leaves using one-dimensional (1D) NIR spectral data and a deep learning approach with convolutional neural network (CNN). This study employed Savitzky-Golay (SG) smoothing to preprocess NIR spectra and randomly generate representative training and test datasets. Batch normalization was used in network regularization to reduce overfitting and improve the generalization performance of the Lightweight 1D-CNN model under a limited training dataset. The network structure of this CNN model consists of four convolutional layers to extract high-level features from the input data. The output of these layers is then fed into a fully connected layer, which uses a linear activation function to output the predicted numerical value of nicotine. After the comparison of the performance of multiple regression models, including support vector regression (SVR), partial least squares regression (PLSR), 1D-CNN, and Lightweight 1D-CNN, under the preprocessing method of SG smoothing, we found that the Lightweight 1D-CNN regression model with batch normalization achieved root mean square error (RMSE) of 0.14, coefficient of determination (R 2) of 0.95, and residual prediction deviation (RPD) of 5.09. These results demonstrate that the Lightweight 1D-CNN model is objective and robust and outperforms existing methods in terms of accuracy, which has the potential to significantly improve quality control processes in the tobacco industry by accurately and rapidly analyzing the nicotine content.

Sensory appeal and puffing intensity of e-cigarette use: Influence of nicotine salts versus free-base nicotine in e-liquids

BackgroundIn the US, nicotine salts (with protonated nicotine instead of free-based nicotine) have been reported to lower the harshness and bitterness of e-cigarette aerosols, making it easier to inhale high levels of nicotine. This study aimed to determine whether nicotine salts also increase sensory appeal at lower concentrations (< 20mg/mL). Moreover, and novel, inhalation intensity of both types of e-liquids was compared. MethodsIn a randomized, double-blinded, within-participants design, healthy adults who use e-cigarettes (n=68) vaped tobacco-flavored e-liquids containing 12mg/mL of free-based nicotine or nicotine salt ad libitum, using their own device, during two online sessions (June-July 2021, Utrecht, The Netherlands). The sensory parameters perceived liking, nicotine intensity, harshness, and pleasantness were rated on a 100-unit visual analog scale. The intensity of use was determined by the recorded puff number, duration and interval. ResultsTest scores on appeal, harshness and puffing behavior parameters showed no significant differences between the nicotine salt and the free-base condition. The average inhalation time was 2.5seconds. Additional analyses found no significant effect of liquid order, age, gender, smoking status, vaping frequency and familiarity with nicotine salts. Significant positive correlations were found between the sensory parameters except for harshness. ConclusionsContrary to a previous study that used higher nicotine concentrations and standardized puffing conditions in a laboratory setting, we did not observe the effects of nicotine salts on sensory appeal in our real-life study paradigm. Moreover, we did not see effects on study parameters related to puffing intensity.

Comparative transcriptome analysis of conventionally cultivated tobacco and tobacco grafted to eggplant

AbstractTobacco (Nicotiana tabacum L.) grafted to eggplant (Solanum melongena L.) has been shown to limit nicotine content, however, the molecular mechanism of this graft combination remains unclear. In this study, we performed a genome‐wide transcriptional analysis of Zhongyan‐100 leaves, that were conventionally planted and grafted onto eggplant rootstocks, using high‐throughput sequencing. The nicotine content in the leaves of the tobacco/eggplant grafting group was significantly decreased compared to the tobacco group. A total of 2389 differentially expressed genes (DEGs) were identified between the tobacco/eggplant group and tobacco group. Functional annotation revealed that many DEGs were involved in glutathione and linoleic acid metabolism, and phenylpropanoid, sesquiterpenoid, and triterpenoid biosynthesis. To explore whether nicotine level in tobacco changes after grafting, the expression of PMT, QPT, A622, and BBLa in the roots and stems was elucidated using quantitative PCR. This study found that the expression of these genes in the roots of the tobacco/eggplant group was significantly lower than that in the tobacco group. In addition, the expression of PMT, A622, and BBLa in tobacco stems of the tobacco/eggplant group was significantly higher than those in tobacco stems of the tobacco group and leaves of the tobacco/eggplant group. Our comprehensive analysis provides basic information on the genes and metabolic signaling pathways involved in Zhongyan‐100/eggplant grafting. Additionally, this study found that the expression of nicotine‐related genes changed during the grafting process; however, the specific molecular mechanisms underpinning this effect requires further exploration.

Purchase Intent and Appeal of ENDS Products among Current, Former and Never Ever Users of Tobacco Products in the U.S.

SUMMARY Background and objectives The last decade has seen extensive research into electronic nicotine delivery systems (ENDS) such as e-cigarettes. Although some studies assess ENDS’ potential benefits, there is a paucity of studies that provide population-level estimates of purchase intent or product appeal among various tobacco user groups, or that have examined the impact of different product characteristics on those variables. Methods Purchase intent and product appeal ratings were analyzed from six online studies for multiple sub-brands of Vuse vapor products (including different flavors, nicotine levels, and device styles). The sample in each study was weighted to represent the adult U.S. population of current established, former established, and never established cigarette smokers on five key demographics; providing population-level estimates. Results Results for purchase intent and appeal are remarkably consistent. Ratings of purchase intent and appeal are higher for current tobacco users (current established cigarette smokers, current established non-cigarette tobacco users, and current tobacco experimenters) than for former and never ever tobacco users. Conclusions and scientific significance These findings show that varying sub-brands of an e-cigarette has little or no impact on population level purchase intent and appeal ratings across tobacco user groups. Additionally, greater variability in ratings among current tobacco experimenters than other tobacco user groups is discussed as well as correlations between measures. This paper provides the first population estimates of both purchase intent and product appeal for various ENDS products among adult tobacco users and nonusers; information that is critical for evaluating the impact on public health. [Contrib. Tob. Nicotine Res. 32 (2023) 34–42]

Controllable-Swelling Microneedle-Assisted Ultrasensitive Paper Sensing Platforms for Personal Health Monitoring.

Microneedle (MN) patches, which allow the extraction of skin interstitial fluid (ISF) without a pain sensation, are powerful tools for minimally invasive biofluid sampling. Herein, an MN-assisted paper-based sensing platform that enables rapid and painless biofluid analysis with ultrasensitive molecular recognition capacity is developed. First, a controllable-swelling MN patch is constructed through the engineering of a poly(ethylene glycol) diacrylate/methacrylated hyaluronic acid hydrogel; it combines rapid, sufficient extraction of ISF with excellent structural integrity. Notably, the analyte molecules in the needles can be recovered into a moist cellulose paper through spontaneous diffusion. More importantly, the paper can be functionalized with enzymatic colorimetric reagents or a plasmonic array, enabling a desired detection capacity-for example, the use of paper-based surface-enhanced Raman spectroscopy sensors leads to label-free, trace detection (sub-ppb level) of a diverse set of molecules (cefazolin, nicotine, paraquat, methylene blue). Finally, nicotine is selected as a model drug to evaluate the painless monitoring of three human volunteers. The changes in the nicotine levels could be tracked, with the levels varying significantly in response to metabolism of the drug in the different volunteers. This as-designed minimally invasive sensing system should open up new opportunities for precision medicine, especially for personal healthcare monitoring. This article is protected by copyright. All rights reserved.