The effects of nicotine withdrawal on exercise-related physical ability and sports performance in nicotine addicts: a systematic review and meta-analysis.

BACKGROUND: Previous research has established that nicotine withdrawal can ameliorate cardiovascular and pulmonary function in smokers. Nevertheless, the impact on physical fitness and athletic performance remains under-investigated. OBJECTIVE: To evaluating the impacts of nicotine withdrawal on both exercise performance and exercise-associated physical capabilities in nicotine-dependent individuals. STUDY DESIGN: A comprehensive systematic review and meta-analysis. DATA SOURCES: The data was compiled from databases such as PubMed, Scopus, Web of Science, Cochrane Central, and EBSCO. STUDY SELECTION: The selection criteria required studies to elucidate the effects of nicotine withdrawal on exercise performance or exercise-related physical abilities. Moreover, the selected studies needed to provide discernible experimental results. DATA SYNTHESIS AND ANALYSIS: The random effects model was employed in data analysis, utilizing the standardized mean difference (SMD) and the 95% confidence intervals (95% CIs) to estimate participants' exercise performance and physical abilities, referencing the Mean ±SD during baseline and withdrawal states. RESULTS: Out of the selected studies, 10 trials were included, encompassing 13,538 participants aged 18 to 65 years. The findings suggest that nicotine withdrawal could potentially enhance sports performance (SMD = 0.45, 95% CI: 0.03 to 0.88; I^2 = 83%), particularly in terms of aerobic capacity. Short-term nicotine withdrawal (spanning 12 to 24 hours) might lead to a decline in participants' physical abilities in certain aspects like reaction time and sustained attention (SMD = -0.83, 95% CI: -1.91 to 0.25; I^2 = 79%), whereas long-term withdrawal (lasting 48 hours or more) demonstrated an opposing trend (SMD = 0.25, 95% CI: 0.12 to 0.39; I^2 = 81%). Overall, the results show that long-term nicotine withdrawal exhibited some positive impacts on sports performance and exercise-related physical ability, with the withdrawal duration being an indicator of subsequent physical performance. CONCLUSIONS: Mid- to long-term (≥3 months) nicotine withdrawal significantly improved the exercisers' exercise-related physical ability and sports performance. Conversely, short-term (≤24 hours) nicotine withdrawal considerably hampered exercisers' performance and physical cognition. It is suggested that exercises avoid abrupt nicotine cessation prior to competitions, as long-term nicotine withdrawal has been shown to significantly enhance exercise-related physiological capacities and athletic performance. By referring to existing literatures we also found that athletes with existing nicotine addiction may could consume nicotine 15-30 minutes before competition to enhance athletic performance and physical function.PROSPERO registration number CRD42023411381.

A dysregulated sebum-microbial metabolite-IL-33 axis initiates skin inflammation in atopic dermatitis.

Microbial dysbiosis in the skin has been implicated in the pathogenesis of atopic dermatitis (AD); however, whether and how changes in the skin microbiome initiate skin inflammation, or vice versa, remains poorly understood. Here, we report that the levels of sebum and its microbial metabolite, propionate, were lower on the skin surface of AD patients compared with those of healthy individuals. Topical propionate application attenuated skin inflammation in mice with MC903-induced AD-like dermatitis by inhibiting IL-33 production in keratinocytes, an effect that was mediated through inhibition of HDAC and regulation of the AhR signaling pathway. Mice lacking sebum spontaneously developed AD-like dermatitis, which was improved by topical propionate application. A proof-of-concept clinical study further demonstrated the beneficial therapeutic effects of topical propionate application in AD patients. In summary, we have uncovered that the dysregulated sebum-microbial metabolite-IL-33 axis might play an initiating role in AD-related skin inflammation, thereby highlighting novel therapeutic strategies for the treatment of AD.

Numerical modelling of magnetic characteristics of ferrite core taking account of both eddy current and displacement current.

In the magnetic field analysis of magnetic devices using a ferrite core, such as a pulse transformer, the frequency-domain analysis is often carried out using the measured complex permeability under different frequency range. However, the nonlinear magnetic characteristics cannot be considered in the frequency-domain analysis because of the harmonics caused by it cannot be represented. The nonlinear magnetic characteristics can be considered in the time-domain analysis, but suitable constant conductivity and permittivity taking account of the microstructure of ferrite core, which can represent the measured complex permeability under different frequencies, needs to be investigated for the time-domain analysis. In this paper, the effective permeability of a toroidal ferrite core is tried to be demonstrated by using the linear ac steady state magnetic field analysis taking account eddy currents and displacement currents. It is shown that the measured permeability can be realized roughly by using the modified constant conductivity and permittivity. The nonlinear time-domain magnetic field analysis can be carried out using the modified constant conductivity and permittivity obtained from this paper.

Erratum to "Numerical modelling of magnetic characteristics of ferrite core taking account of both eddy current and displacement current" [Heliyon Volume 5, Issue 8, August 2019, e02229].

[This corrects the article DOI: 10.1016/j.heliyon.2019.e02229.].