Smoking-Attributable Health Care Expenditures for US Adults With Chronic Lower Respiratory Disease.

Importance: Cigarette smoking is a primary risk factor for chronic lower respiratory disease (CLRD) and is associated with worse symptoms among people with CLRD. It is important to evaluate the economic outcomes of smoking in this population. Objective: To estimate smoking prevalence and cigarette smoking-attributable health care expenditures (SAHEs) for adults with CLRD in the US. Design, Setting, and Participants: This cross-sectional study used data from the 2014-2018 and 2020 National Health Interview Surveys (NHIS) and the 2020 Medical Expenditure Panel Survey. The final study population, stratified by age 35 to 64 years and 65 years or older, was extracted from the 2014-2018 NHIS data. The data analysis was performed between February 1 and March 31, 2024. Exposures: Cigarette smoking, as classified into 4 categories: current smokers, former smokers who quit less than 15 years ago, former smokers who quit 15 or more years ago, and never smokers. Main Outcomes and Measures: Smoking-attributable health care expenditures were assessed using a prevalence-based annual cost approach. Econometric models for the association between cigarette smoking and health care utilization were estimated for 4 types of health care services: inpatient care, emergency department visits, physician visits, and home health visits. Results: In the 2014-2018 NHIS study sample of 13 017 adults, 7400 (weighted 62.4%) were aged 35 to 64 years, 5617 (weighted 37.6%) were 65 years or older, and 8239 (weighted 61.9%) were female. In 2020, among 11 211 222 adults aged 35 to 64 with CLRD, 3 508 504 (31.3%) were current smokers and 3 496 790 (31.2%) were former smokers. Total SAHEs in 2020 for this age group were $13.6 billion, averaging $2752 per current smoker and $1083 per former smoker. In 2020, 7 561 909 adults aged 65 years or older had CLRD, with 1 451 033 (19.2%) being current smokers and 4 104 904 (54.3%) being former smokers. Total SAHEs in 2020 for the older age group were $5.3 billion, averaging $1704 per current smoker and $682 per former smoker. In sum, SAHEs for adults with CLRD aged 35 years or older amounted to $18.9 billion in 2020. Conclusions and Relevance: In this cross-sectional study of adults with CLRD, cigarette smoking was associated with a substantial health care burden. The higher per-person SAHEs for current smokers compared with former smokers suggest potential cost savings of developing targeted smoking cessation interventions for this population.

Association between tobacco product use and respiratory health and asthma-related interference with activities among U.S. Adolescents.

Tobacco use adversely affects long-term respiratory health. We examined the relationship between sole and dual tobacco product use and both respiratory health and respiratory-related quality of life during adolescence in the U.S. Using adolescent data (baseline age 12-17) from Waves 4.5 (data collected from December 2017-December 2018) and 5 (data collected from December 2018-November 2019) of the Population Assessment of Tobacco and Health Study, we examined the associations between combustible (i.e., cigarette or cigar), vaped, and dual (i.e., both cigar/cigarette and e-cigarette) tobacco/nicotine use at baseline and two respiratory symptoms (all adolescents, n = 11,748) and new asthma diagnosis (adolescents with no baseline diagnosis, n = 9,422) at follow-up. Among adolescents with asthma (Wave 5, n = 2,421), we estimated the association between current tobacco use and the extent to which asthma interfered with daily activities. At follow-up, 12.3 % of adolescents reported past 12-month wheezing/whistling, 17.4 % reported past 12-month dry cough, and 1.9 % reported newly diagnosed asthma. Baseline current cigarette/cigar smoking was associated with subsequent wheezing/whistling and baseline report of another tobacco product use pattern was associated with subsequent asthma diagnosis. Among adolescents with asthma, 5.7 % reported it interfering with activities some of the time and 3.1 % reported interference most/all of the time in the past 30 days. Past 30-day sole cigarette/cigar smoking and dual use was positively associated with asthma-related interference with activities compared to never tobacco use and sole e-cigarette use. Combustible and dual tobacco use pose direct risk to respiratory health and indirect risk to quality of life through respiratory health.

The association of current exclusive e-cigarette use and dual use of e-cigarettes and cigarettes with psychological distress among U.S. adults.

This observational study examines the association of current e-cigarette use and dual use of e-cigarettes and cigarettes (dual use) with psychological distress among U.S. adults. We differentiate dual use based on the smoking frequency and compare the relationship between dual use and psychological distress to that of exclusive cigarette smoking with the same smoking frequency. Using data from the 2015-2018 National Health Interview Surveys, we analyzed adults aged 18+ (N = 55,780) who currently use e-cigarettes or/and cigarettes and have no history of using other tobacco products, and adults who never used any tobacco. Multinomial logistic regression models estimate the association of current e-cigarette use and dual use with psychological distress severity (no/mild, moderate, and severe).In the sample, 15.3% and 2.9% of adults experienced moderate and severe psychological distress. Compared to never tobacco users, current exclusive e-cigarette users and dual users who smoke daily had higher odds of moderate and severe psychological distress. Dual users who smoke nondaily had higher odds of moderate, but not severe psychological distress than never tobacco users. Compared to exclusive daily smokers, dual users with daily smoking had higher odds of moderate and severe psychological distress. Compared to exclusive nondaily smokers, dual users with nondaily smoking had higher odds of moderate but not severe psychological distress. Our findings suggest that exclusive e-cigarette use is associated with psychological distress severity. Dual use is associated with higher odds of psychological distress severity compared to never tobacco users and exclusive cigarette smoking, and this association differs by smoking frequency.

Parabolic-Index Ring-Core Fiber Supporting High-Purity Orbital Angular Momentum Modes.

We design a graded-index ring-core fiber with a GeO2-doped silica ring core and SiO2 cladding. This fiber structure can inhibit the effect of spin-orbit coupling to mitigate the power transfer among different modes and eventually enhance the orbital angular momentum (OAM) mode purity. By changing the high-index ring core from the step-index to parabolic graded-index profile, the purity of the OAM1,1 mode can be improved from 86.48% to 94.43%, up by 7.95%. The proposed fiber features a flexible structure, which can meet different requirements for mode order, effective mode area, etc. Simulation results illustrate that the parabolic-index ring-core fiber is promising in enhancing the OAM mode purity, which could potentially reduce the channel crosstalk in mode-division-multiplexed optical communication systems.

Association between e-cigarette use and food insecurity among low-income adults.

INTRODUCTION: Previous research quantifying the relationship between tobacco use and food insecurity has focused on cigarette smoking. E-cigarette use has become popular in recent years. Drawing on large, population-based survey data, this study augments the previous research, considering the association of e-cigarette use with food insecurity among low-income adults. METHODS: We analysed data from the California Health Interview Survey in 2014-2019. The study sample consisted of 25 948 respondents aged 18-64 who lived in low-income (<200% of the Federal Poverty Level) households. Multivariable logistic regression models were estimated to examine the associations of e-cigarette use as well as dual use of e-cigarettes and cigarettes with food insecurity. RESULTS: Of California low-income adults, 6.4% identified as current e-cigarette users (3.0% dual users of e-cigarettes and cigarettes, and 3.4% sole e-cigarette users) and 43.0% reported food insecurity. After controlling for confounding factors, food insecurity was significantly more likely to be reported among current e-cigarette users (adjusted OR (AOR)=1.67; 95% CI 1.25 to 2.23) compared with never e-cigarette users, and among dual users (AOR=2.21; 95% CI 1.63 to 3.00), current sole e-cigarette users (AOR=1.66; 95% CI 1.15 to 2.40), and current sole cigarette smokers (AOR=1.46; 95% CI 1.22 to 1.76) compared with never tobacco users. The odds of food insecurity among dual users were significantly greater than sole cigarette smokers but not statistically different from sole e-cigarette users. CONCLUSIONS: Using e-cigarette is an associated risk factor for food insecurity among low-income adults. Dual use of e-cigarettes and cigarettes has a significantly greater risk of food insecurity compared with smoking cigarettes alone.

Healthcare utilisation and expenditures attributable to current e-cigarette use among US adults.

AIMS: This study estimated annual healthcare expenditures attributable to current e-cigarette use among US adults, including current exclusive and dual/poly e-cigarette use. METHODS: Analysing the 2015-2018 National Health Interview Survey data, we estimated the impacts of e-cigarette use on healthcare utilisation among adults aged 18+ years. Healthcare utilisation outcomes were hospital nights, emergency room (ER) visits, doctor visits and home visits. Current e-cigarette use was categorised as exclusive and dual/poly e-cigarette use. The econometric model included two equations: health status as a function of e-cigarette use and other independent variables, and healthcare utilisation as a function of health status, e-cigarette use, and other independent variables. Using an 'excess utilisation' approach, we multiplied the e-cigarette-attributable fraction derived from the model by annual health expenditures to calculate healthcare expenditures attributable to current exclusive and dual/poly e-cigarette use, the sum of which were expenditures attributable to all current e-cigarette use. RESULTS: Current exclusive and dual/poly e-cigarette use, with 0.2% and 3.5% prevalence in 2015-2018, were associated with higher odds of reporting poor health status than never tobacco users. Poor health status was associated with higher odds of using the four healthcare services and a greater number of ER and doctor visits. Annual healthcare expenditures attributable to all current e-cigarette use was $15.1 billion ($2024 per user) in 2018, including $1.3 billion attributable to exclusive e-cigarette use ($1796 per user) and $13.8 billion attributable to dual/poly e-cigarette use ($2050 per user). CONCLUSION: Adult current e-cigarette use was associated with substantial excess healthcare utilisation and expenditures.

Broadband dispersion compensating ring-core fiber for orbital angular momentum modes.

A well designed ring-core fiber can theoretically support numerous orbital angular momentum (OAM) modes with low crosstalk for space-division-multiplexing (SDM) data transmission, which is considered as a promising solution for overcoming the capacity crunch in optical communication network. However, the accumulated chromatic dispersion in OAM-fiber could limit the data speed and transmission distance of communication systems. A potential solution is to insert a dispersion compensation ring-core fiber with opposite-sign of dispersion in the transmission fiber along the fiber link. In this work, we propose a triple ring-core fiber with broadband negative dispersion. A highest negative dispersion of -24.47 ps/(nm·km) at 1550 nm and an average dispersion slope in the C band from -0.182 ps/(nm2·km) to 0.065 ps/(nm2·km) can be achieved to compensate multi-order dispersion. The effects of Ge-doping concentration fluctuation in the high-index ring core and fabrication errors on fiber geometric structures are also investigated. Furthermore, the effective mode area decreases as the widths of high-index rings increase due to the enhanced confinement ability. The designed triple ring-core fiber could offer potential for compensating OAM fiber links with positive dispersions.

Over-Two-Octave Supercontinuum Generation of Light-Carrying Orbital Angular Momentum in Germania-Doped Ring-Core Fiber.

In this paper, we design a silica-cladded Germania-doped ring-core fiber (RCF) that supports orbital angular momentum (OAM) modes. By optimizing the fiber structure parameters, the RCF possesses a near-zero flat dispersion with a total variation of <±30 ps/nm/km over 1770 nm bandwidth from 1040 to 2810 nm for the OAM1,1 mode. A beyond-two-octave supercontinuum spectrum of the OAM1,1 mode is generated numerically by launching a 40 fs 120 kW pulse train centered at 1400 nm into a 12 cm long designed 50 mol% Ge-doped fiber, which covers 2130 nm bandwidth from 630 nm to 2760 nm at −40 dB of power level. This design can serve as an efficient way to extend the spectral coverage of beams carrying OAM modes for various applications.

19-ring-air-core fiber supporting thousands of OAM modes for spatial division multiplexing.

We propose and design a 19-ring-air-core fiber that can support about 3000 orbital angular momentum (OAM) modes (156 modes in each ring) with <-80 dB inter-ring cross talk across the entire C and L bands after 100-km fiber propagation. Moreover, the eigenmodes are all separated from their adjacent modes by effective index differences >2.67 × 10-4 and mode groups by > 1.90 × 10-2, which can guarantee the stable transmission of OAM modes. This designed fiber is a potential candidate for applications in spatial division multiplexing (SDM) of optical channels to improve the capacity of next-generation high-speed optical communication systems, especially in short-distance applications. In this Letter, we also show the relationship between supported OAM mode numbers, total cross talk, and effective refractive index of intra-ring modes during the optimization of fiber through numerical simulations. It can provide a related reference for the future design of multi-ring-core fibers.

Harnessing Paenarthrobacter ureafaciens YL1 and Pseudomonas koreensis YL2 Interactions to Improve Degradation of Sulfamethoxazole.

Sulfamethoxazole (SMX) is a widespread and persistent pollutant in the environment. Although the screening and analysis of SMX-degrading bacteria have been documented, the interaction mechanisms of functional microorganisms are still poorly understood. This study constructed a consortium with strain YL1 and YL2 supplied with SMX as the sole carbon and energy source. The coexisting mechanism and the removal of SMX of the consortium were investigated. The total oxidizable carbon (TOC) removal rate of the combined bacterial system was 38.94% compared to 29.45% for the single bacterial system at the same biomass. The mixed bacterial consortium was able to resist SMX at concentrations up to 400 mg/L and maintained a stable microbial structure at different culture conditions. The optimum conditions found for SMX degradation were 30 °C, pH 7.0, a shaking speed of 160 r·min-1, and an initial SMX concentration of 200 mg·L-1. The degradation of SMX was accelerated by the addition of YL2 for its ability to metabolize the key intermediate, 4-aminophenol. The removal rate of 4-aminophenol by strain YL2 reached 19.54% after 5 days. Genome analysis revealed that adding riboflavin and enhancing the reducing capacity might contribute to the degradation of SMX. These results indicated that it is important for the bioremediation of antibiotic-contaminated aquatic systems to understand the metabolism of bacterial communities.

Changes in e-cigarette use and subsequent cigarette smoking cessation in the USA: evidence from a prospective PATH study, 2013-2018.

AIMS: To examine the relationship between changes in electronic cigarette (e-cigarette) use and subsequent cigarette smoking cessation. METHODS: Using data from the Population Assessment of Tobacco and Health Study (wave 1-wave 4), we analysed a study cohort of 3014 current adult cigarette smokers at wave 1 who tried to quit during the past 12 months. We categorised changes in e-cigarette use from wave 1 to wave 2 as: daily initiation, non-daily initiation, increase to daily use, increase to non-daily use, stable daily use, stable non-daily use, decrease from daily use, quit non-daily use and non-use. We estimated multivariable logistic regressions on short-term (≥1 month and <12 months) cigarette smoking cessation at wave 3 and long-term (≥12 months) cigarette smoking cessation at wave 4. We conducted sensitivity analyses using alternative study cohorts. RESULTS: Among the study cohort, 2.4% initiated daily, 7.5% initiated non-daily, 1.0% increased to daily, 1.4% increased to non-daily, 1.5% maintained daily, 3.0% maintained non-daily, 2.4% decreased from daily and 3.8% quit non-daily e-cigarette use between waves 1 and 2; 7.9% and 6.9% reported short-term and long-term cigarette smoking cessation. 15.1% of short-term and 16.3% of long-term cigarette quitters used e-cigarettes. Compared with non-users, smokers who initiated daily, increased to daily or quit non-daily e-cigarette use between waves 1 and 2 had higher odds of short-term cigarette smoking cessation at wave 3. These results are robust to different study cohort specifications. CONCLUSION: The findings suggest a complex relationship between changes in e-cigarette use and subsequent cigarette smoking cessation.

Xanthobacter dioxanivorans sp. nov., a 1,4-dioxane-degrading bacterium.

A Gram-stain-negative bacterium, designated as YN2T, that is capable of degrading 1,4-dioxane, was isolated from active sludge collected from a wastewater treatment plant in Harbin, PR China. Cells of strain YN2T were aerobic, motile, pleomorphic rods, mostly twisted, and contained the water-insoluble yellow zeaxanthin dirhamnoside. Strain YN2T grew at 10-40 °C (optimum, 30 °C), pH 5.0-8.0 (pH 7.0) and with 0-1 % (w/v) NaCl (0.1 %). It also could grow chemolithoautotrophically and fix N2 when no ammonium or nitrate was supplied. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain YN2T belongs to the genus Xanthobacter and shares the highest pairwise identity with Xanthobacter autotrophicus 7cT (98.6 %) and Xanthobacter flavus 301T (98.4 %). The major respiratory quinone was ubiquinone-10. Chemotaxonomic analysis revealed that the strain possesses C16 : 0, C19 : 0 cyclo ω8c and C18 : 1 ω7c as the major fatty acids. The DNA G+C content was 67.95 mol%. Based on genome sequences, the DNA-DNA hybridization estimate values between strain YN2T and X. autotrophicus 7cT, X. flavus 301T and X. tagetidis TagT2CT (the only three species of Xanthobacter with currently available genomes) were 31.70, 31.30 and 28.50 %; average nucleotide identity values were 85.23, 84.84 and 83.59 %; average amino acid identity values were 81.24, 80.23 and 73.57 %. Based on its phylogenetic, phenotypic, and physiological characteristics, strain YN2T is considered to represent a novel species of the genus Xanthobacter, for which the name Xanthobacter dioxanivorans sp. nov. is proposed. The type strain is YN2T (=CGMCC 1.19031T=JCM 34666T).

Adaption and Degradation Strategies of Methylotrophic 1,4-Dioxane Degrading Strain Xanthobacter sp. YN2 Revealed by Transcriptome-Scale Analysis.

Biodegradation of 1,4-dioxane (dioxane) contamination has gained much attention for decades. In our previous work, we isolated a highly efficient dioxane degrader, Xanthobacter sp. YN2, but the underlying mechanisms of its extraordinary degradation performance remained unresolved. In this study, we performed a comparative transcriptome analysis of YN2 grown on dioxane and citrate to elucidate its genetic degradation mechanism and investigated the transcriptomes of different dioxane degradation stages (T0, T24, T48). We also analyzed the transcriptional response of YN2 over time during which the carbon source switched from citrate to dioxane. The results indicate that strain YN2 was a methylotroph, which provides YN2 a major advantage as a pollutant degrader. A large number of genes involved in dioxane metabolism were constitutively expressed prior to dioxane exposure. Multiple genes related to the catabolism of each intermediate were upregulated by treatment in response to dioxane. Glyoxylate metabolism was essential during dioxane degradation by YN2, and the key intermediate glyoxylate was metabolized through three routes: glyoxylate carboligase pathway, malate synthase pathway, and anaplerotic ethylmalonyl-CoA pathway. Genes related to quorum sensing and transporters were significantly upregulated during the early stages of degradation (T0, T24) prior to dioxane depletion, while the expression of genes encoding two-component systems was significantly increased at late degradation stages (T48) when total organic carbon in the culture was exhausted. This study is the first to report the participation of genes encoding glyoxalase, as well as methylotrophic genes xoxF and mox, in dioxane metabolism. The present study reveals multiple genetic and transcriptional strategies used by YN2 to rapidly increase biomass during growth on dioxane, achieve high degradation efficiency and tolerance, and adapt to dioxane exposure quickly, which provides useful information regarding the molecular basis for efficient dioxane biodegradation.

Non-zero dispersion-shifted ring fiber for the orbital angular momentum mode.

As the dimension of orbital angular momentum (OAM) is orthogonal to the other degrees of freedom for photon, such as wavelength, it can be utilized to further increase data capacity in the wavelength division multiplexing (WDM) systems. However, the non-zero dispersion-shifted fiber (NZDSF) for the OAM mode has not yet been investigated or even proposed. In this work, we propose and design a ring fiber with low chromatic dispersion for the HE2,1 mode, which can serve as NZDSF for its corresponding OAM1,1 mode. A low dispersion of 3.3 ps/(nm·km) at 1550 nm and <2.9 ps/(nm·km) dispersion variation from 1530 to 1565 nm for the OAM1,1 mode is achieved in simulation, which satisfies the standard of the ITU-T G.655.C. The designed fiber with ring width from 1.5 µm to 3.5 µm can support the OAM1,1 mode within the C-band, and a large effective area of about 646 µm2 is obtained. We also note that the fiber with larger inner radius and ring width are more tolerant to the perturbations, such as fiber ellipticity and bending. In the fiber-based optical communication systems, the designed ring fiber could be used as a candidate for supporting OAM modes with low dispersion and reduced nonlinear effects.

Seven air-core fibers with germanium-doped high-index rings supporting hundreds of OAM modes.

In this paper, we propose and design a multi-orbital-angular-momentum multi-ring air-core fiber, which has seven high-index rings with each ring supporting 62 radially fundamental OAM modes across C and L bands (from 1530 nm to 1625 nm), i.e. 434 OAM modes in total. The designed fiber features >4×10-4 intra-ring modal indices difference for OAM modes with the same topological charge l in a ring across the C and L bands. Moreover, it can keep <-52 dB crosstalk between the OAM modes in the adjacent rings at 1550 nm, and <-24 dB crosstalk across C and L bands after 100-km fiber propagation. This kind of seven-air-core-ring fiber would be a robust candidate for transmitting efficient OAM modes and boosting the capacity of optical fiber communications systems.

The Association of California's Proposition 56 Tobacco Tax Increase With Smoking Behavior Across Racial and Ethnic Groups and by Income.

INTRODUCTION: On April 1, 2017, California Proposition 56 (Prop 56) was implemented, increasing the excise tax on cigarettes by $2/pack. This study compares the association of Prop 56 with smoking prevalence and smoking intensity across racial/ethnic groups, further examining distinctions across income subgroups within each racial/ethnic group. AIMS AND METHODS: The study used pooled cross-sectional data from the 2012-2018 California Behavioral Risk Factor Surveillance System. We examined two outcomes: current smoking prevalence and smoking intensity conditional on current smoking. A two-part econometric model was used to estimate the association of Prop 56 with smoking prevalence and intensity using multiple logistic regression and multiple linear regression, respectively. The two-part model was run separately for all adults (full sample) and each racial/ethnic group. Within each racial/ethnic group, we ran stratified analyses by income subgroups. RESULTS: The results indicated that Prop 56 was negatively associated with smoking prevalence among full sample, Hispanic, White, and African American adults and negatively associated with smoking intensity among full sample and White smokers. Stratified analyses by race/ethnicity and income showed that Prop 56 was negatively associated with smoking prevalence among low-income full sample and White adults and among middle-income smokers in the full, Hispanic, White, African American, and Asian samples. Prop 56 was negatively associated with smoking intensity among middle-income Hispanic and high-income White smokers. The association between Prop 56 and smoking intensity was positive among high-income African American smokers. CONCLUSION: Prop 56 was associated with a reduction in smoking prevalence across multiple racial/ethnic groups, particularly within the low- and middle-income subgroups. IMPLICATIONS: Our findings indicate that the reduction in smoking prevalence immediately following the implementation of Prop 56 tobacco tax increase was significant across a variety racial/ethnic groups, particularly low- and middle-income subgroups. We found differential responses in smoking prevalence across income groups among Whites but not among racial/ethnic minorities. We found no evidence of any significance association between Proposition 56 and smoking intensity among minorities and economically vulnerable populations, except for middle-income Hispanics. Researchers, policy makers, and advocates should consider the additional merits of targeted, community-based, noneconomic tobacco control interventions in reaching low- and middle-income groups within racial/ethnic minorities.

Differential price-responsiveness of smoking behaviors among non-Hispanic African Americans and non-Hispanic whites in the United States.

BACKGROUND AND AIMS: Non-Hispanic African Americans (African Americans) smoke fewer cigarettes per day (CPD) and are more likely to be non-daily smokers than non-Hispanic whites (whites). Little is known about how changes in cigarette prices might contribute to these differences. This study aimed to measure the price-responsiveness of smoking participation, non-daily smoking among current smokers and smoking intensity among daily or non-daily smokers for African Americans and compare the price-responsiveness estimates with those for whites. DESIGN: Analysis of data from the 2009-14 National Adult Tobacco Surveys and cigarette price data from the Tax Burden on Tobacco report. SETTING: United States. PARTICIPANTS: A total of 19 232 African American and 197 939 white adults aged 18+. MEASUREMENTS: We used a three-part econometric model of cigarette demand to estimate the price-responsiveness of smoking participation, daily versus non-daily smoking and smoking intensity. The model controlled for secular variation, state-level anti-smoking sentiment and smoke-free air laws and socio-demographics. FINDINGS: In 2009-14, 20.2% of African Americans and 17.7% of whites identified as current smokers; 70.2% of African American smokers and 81.4% of white smokers smoked daily. The price elasticity of smoking participation was significant for whites at -0.16 [95% confidence interval (CI) = -0.23, -0.09], indicating that a 10% increase in prices would reduce smoking participation by 1.6%, but not statistically significant for African Americans, and this racial/ethnic differential price responsiveness was not statistically significant. The price elasticity of smoking intensity was statistically significant for African American daily smokers at -0.29 (95% CI = -0.42, -0.16), but not statistically significant for white daily smokers, and this racial/ethnic differential price-responsiveness was statistically significant. The price elasticity of daily versus non-daily smoking among current smokers, and the price elasticity of smoking intensity among non-daily smokers were not statistically significant for either racial/ethnic group. CONCLUSION: In the United States, cigarette price increases may have stronger effects on decreasing daily smokers' consumption among African Americans than among non-Hispanic whites.

Degradation of 1,4-Dioxane by Xanthobacter sp. YN2.

1,4-Dioxane is a highly toxic and carcinogenic pollutant found worldwide in groundwater and soil environments. Several microorganisms have been isolated by their ability to grow on 1,4-dioxane; however, low 1,4-dioxane tolerance and slow degradation kinetics remain obstacles for their use in 1,4-dioxane bioremediation. We report here the isolation and characterization of a new strain, Xanthobacter sp. YN2, capable of highly efficient 1,4-dioxane degradation. High degradation efficiency and high tolerance to 1,4-dioxane make this new strain an ideal candidate for the biodegradation of 1,4-dioxane in various treatment facilities. The maximum degradation rate of 1,4-dioxane was found to be 1.10 mg-1,4-dioxane/h mg-protein. Furthermore, Xanthobacter sp. YN2 was shown to grow in the presence of higher than 3000 mg/L 1,4-dioxane with little to no degradation inhibition. In addition, Xanthobacter sp. YN2 could grow on and degrade 1,4-dioxane at pH ranges 5 to 8 and temperatures between 20 and 40 °C. Xanthobacter sp. YN2 was also found to be able to grow on a variety of other substrates including several analogs of 1,4-dioxane. Genome sequence analyses revealed the presence of two soluble di-iron monooxygenase (SDIMO) gene clusters, and regulation studies determined that all of the genes in these two clusters were upregulated in the presence of 1,4-dioxane. This study provides insights into the bacterial stress response and the highly efficient biodegradation of 1,4-dioxane as well as the identification of a novel Group-2 SDIMO.

Health Care Utilization of Menthol and Non-menthol Cigarette Smokers.

INTRODUCTION: To study the association between health care utilization and menthol cigarette use and whether the association differed between African American (AA) and non-AA smokers. METHODS: We analyzed the three most recent 2005, 2010, and 2015 National Health Interview Survey Cancer Control Supplements. After incorporating propensity score weights adjusting for observed differences between menthol and non-menthol users, we estimated Zero-Inflated Poisson models on hospital nights, emergency department visits, doctor visits, and home visits as a function of menthol use status and other covariates separately for current cigarette smokers and recent quitters (former smokers quitting cigarette smoking ≤ 4 years). RESULTS: Although current menthol smokers smoked fewer cigarettes per day than current non-menthol smokers, they did not differ from current non-menthol smokers in health care utilization. Among recent quitters, those who used to smoke menthol cigarettes had higher odds of having hospital nights than those who used to smoke non-menthol cigarettes. However, we did not find any significant association between menthol use and other health care utilization-emergency department visits, doctor visits, and home visits-among recent quitters. Moreover, compared with non-AA recent quitters, AA recent quitters had higher odds of having home visits, but fewer home visits, if they used to smoke menthol cigarettes. CONCLUSION: Menthol use was associated with greater hospitalization among recent quitters, and the association between home visits and menthol use differed between AA and non-AA recent quitters. IMPLICATIONS: This is the first study that used econometric models to study the association between health care utilization and menthol cigarette use and examine whether the association differed between AA and non-AA smokers. Our study found health care utilization did not differ by menthol use status for current smokers, although current menthol smokers smoked fewer cigarettes per day than current non-menthol smokers. However, we found menthol use was associated with higher odds of having hospital nights for recent quitters. We also found AA recent quitters had a different association between home visits and menthol use compared with non-AA recent quitters.

Biodiversity, isolation and genome analysis of sulfamethazine-degrading bacteria using high-throughput analysis.

Sulfamethazine (SM2) is one of the sulfonamide antibiotics that is frequently detected in aquatic environment. Given the complex structure of SM2 and its potential threat to the environment, it is necessary to determine the degradation behavior of high-concentration SM2. The mechanisms of community structure and diversity of activated sludge were analyzed. A novel SM2-degrading strain YL1 was isolated which can degrade SM2 with high concentration of 100 mg L-1. Strain YL1 was identified as Paenarthrobacter ureafaciens and there was also a significant increase in the genus during acclimation. Additional SM2 metabolic mechanisms and genomic information of YL1 were analyzed for further research. The succession of the community structure also investigated the effect of SM2 on the activated sludge. This result not only advances the current understanding of microbial ecology in activated sludge, but also has practical implications for the design and operation of the environmental bioprocesses for treatment of antimicrobial-bearing waste streams.