Background: Prior studies have demonstrated that the e-cigarette market contains a large number of brands. Identifying these existing e-cigarette brands is a key element of market surveillance, which will further assist in policy making and compliance checks. Objective: To facilitate the surveillance of the diverse product landscape in the e-cigarette market, we constructed a semantic database of e-cigarette brands that have appeared in the US market as of 2020-2022. Methods: In order to build the brand database, we searched and compiled e-cigarette brands from a comprehensive list of retail channels and sources, including (1) e-liquid and disposable brands sold in web-based stores, (2) e-cigarette brands sold in brick-and-mortar stores and collected by the Nielsen Retail Scanner Data, (3) e-cigarette brands compiled by Wikipedia, (4) self-reported e-cigarette brands from the 2020 International Tobacco Control Four-Country Smoking and Vaping (ITC 4CV) US survey, and (5) e-cigarette brands on Twitter. We also estimated the top 5 e-cigarette brands by sales volume in brick-and-mortar stores, by the frequency and variety of offerings in web-based shops, and by the frequency of self-reported brands from the 2020 ITC 4CV US survey. Results: As of 2020-2022, a total of 912 e-cigarette brands have been sold by various retail channels. During 2020-2022, the top 5 brands are JUUL, vuse, njoy, blu, and logic in brick-and-mortar stores; blu, king, monster, twist, and air factory for e-liquids in web-based stores; hyde, pod mesh, suorin, vaporlax, and xtra for disposables sold in web-based stores; and smok, aspire, vaporesso, innokin, and eleaf based on self-reported survey data. Conclusions: As the US Food and Drug Administration enforces the premarket tobacco market authorization, many e-cigarette brands may become illegal in the US market. In this context, how e-cigarette brands evolve and consolidate in different retail channels will be critical for understanding the regulatory impacts on product availability. Our semantic database of e-cigarette brands can serve as a useful tool to monitor product and marketplace development, conduct compliance checks, assess manufacturers’ marketing behaviors, and identify regulatory impacts.

Introduction: Over 20 states and local jurisdictions in the United States have imposed e-cigarette taxes. It is important to evaluate how adult vapers, including those who also smoke respond to e-cigarette taxation. The purpose of this study is to examine factors associated with adult vapers’ cost comparison between e-cigarettes and cigarettes (ie, which one is perceived to be more expensive) and expenditures (ie, dollars spent) on these two products. Aims and Methods: We recruited a nationally representative sample of 801 adult e-cigarette users in the United States., who participated in an online survey in April–May 2023. Nested-ordered logit and ordinary least squares regressions were used in the analysis. Results: On average, adult vapers spent $82.22 per month on e-cigarettes, and dual users spent $118.77 per month on cigarettes. More frequent e-cigarette use, lower state-level e-cigarette taxes, age, and exclusive use of rechargeable tank systems with e-liquids were associated with considering e-cigarettes as less expensive than cigarettes. Exclusive use of tank systems was associated with lower e-cigarette spending. Adults who used e-cigarettes more frequently preferred to report weekly (vs. monthly) spending on e-cigarettes; among dual users, everyday smokers were more likely to think of weekly (vs. monthly) spending on cigarettes compared to someday smokers. Conclusions: Among U.S. adult vapers, tobacco use frequency, and e-cigarette device type are closely related to cost measures; e-cigarette taxes are associated with cost comparison between e-cigarettes and cigarettes, suggesting potential financial disincentive for vaping. Policymakers may consider imposing differential taxes on e-cigarette product types due to their different costs to consumers. Implications: This study provides supportive evidence that e-cigarette taxes may impact how vapers compare the costs of e-cigarettes relative to cigarettes. Given different expenditures and cost comparisons by e-cigarette device types, tax, and policy design may need to be taken into consideration of e-cigarette device types. We also found that indoor tobacco use restrictions in shared housing may reduce vaping, and future research is needed. The associations between sociodemographics and cost comparison and expenditures reflect known patterns in price responsiveness and vaping prevalence. Cost comparison and expenditures are related measures, which may further reflect product affordability.

Since the advent of digital PLLs (DPLLs), various techniques have been proposed for a low-power, low-noise fractional-N frequency synthesizer. Among the various innovations, a reference-multiplied architecture offers distinct advantages compared to conventional DPLLs [1]. First, low quantization noise (q-noise) can be achieved without complex q-noise cancellation schemes, since the delta-sigma modulator (DSM) has a high oversampling ratio and its q-noise is pushed to higher frequencies. Second, noise requirements of PLL building blocks become less stringent as the division value is reduced. For a digital PLL using a Nyquist-rate time-to-digital converter (TDC), if the reference is multiplied by N the time resolution of the TDC can be reduced by √N for the same noise level. Unfortunately, one drawback of the reference-multiplied PLL is the increase in power and complexity due to the reference-multiplying circuit. In this paper, we propose a reference-multiplied digital fractional-N PLL that has negligible overhead in the reference-multiplying circuit. To save power, a frequency-multiplied TDC (FMTDC) consisting of an open-loop multiplying DLL (MDLL) and a Vernier delay-line (VDL) TDC is proposed, which share their delay lines. High spurious tone coming from the open-loop MDLL is canceled by an adaptive filter located between TDC and loop filter.

Objectives: The government of the Republic of Korea (ie, South Korea) drastically increased cigarette prices by 80% in 2015. The exogenous regulatory change provided us with an opportunity to examine the effects of the cigarette price increase on smoking behavior. Methods: Utilizing 2011-2016 balanced panel data from the Korea Health Panel (3693 participants each year), we divided the sample into smokers and non-smokers and traced each individual's smoking behavior. Results: Overall smoking prevalence (OR = 0.476, p < .01) and daily cigarette consumption (IRR = 0.737, p < .01) were reduced after the cigarette price increase. However, although the cigarette price increase was inversely related to smokers' cigarette consumption (OR = 0.799, p < .01), we found no statistically significant impact on smoking cessation among smokers. On the other hand, the cigarette price increase was associated with decreased smoking onset among non-smokers (OR = 0.172, p < .01) and reduced cigarette consumption after they started smoking (IRR = 0.279, p < .01). Conclusions: The reduction in smoking prevalence after the increase of the cigarette price resulted from the fact that non-smokers did not start smoking rather than from a decrease in the number of existing smokers.