64 research outputs found
E-cigarette use causes a unique innate immune response in the lung, involving increased neutrophilic activation and altered mucin secretion
Rationale: E-cigarettes have become increasingly popular and little is known about their potential adverse health effects. Objectives: To determine the effects of e-cigarette use on the airways. Methods: Induced sputum samples from cigarette smokers, e-cigarette users, and nonsmokers were analyzed by quantitative proteomics, and the total and individual concentrations of mucins MUC5AC and MUC5B were determined by light scattering/refractometry and labeled mass spectrometry, respectively. Neutrophil extracellular trap (NET) formation rates were also determined for the same groups. Measurements and Main Results: E-cigarette users exhibited significant increases in aldehyde-detoxification and oxidative stress-related proteins associated with cigarette smoke compared with nonsmokers. The levels of innate defense proteins associated with chronic obstructive pulmonary disease, such as elastase and matrix metalloproteinase-9, were significantly elevated in e-cigarette users as well. E-cigarette users' sputum also uniquely exhibited significant increases in neutrophil granulocyte-related and NET-related proteins, such as myeloperoxidase, azurocidin, and protein-arginine deiminase 4, despite no significant elevation in neutrophil cell counts. Peripheral neutrophils from e-cigarette users showed increased susceptibility to phorbol 12-myristate 13-acetate-induced NETosis. Finally, a compositional change in the gel-forming building blocks of airway mucus (i.e., an elevated concentration of mucin MUC5AC) was observed in both cigarette smokers and e-cigarette users. Conclusions: Together, our results indicate that e-cigarette use alters the profile of innate defense proteins in airway secretions, inducing similar and unique changes relative to cigarette smoking. These data challenge the concept that e-cigarettes are a healthier alternative to cigarettes
Analysis of a single server batch arrival retrial queueing system with modified vacations and N-policy
In this paper, a batch arrival single server retrial queue with modified vacations under
N-policy is
considered. If an arriving batch of customers finds the server busy or on vacation, then
the entire batch joins the orbit in order to seek the service again. Otherwise, one
customer from the arriving batch receives the service, while the rest joins the orbit. The
customers in the orbit will try for service one by one when the server is idle with a
classical retrial policy with the retrial rate âjvâ, where âjâ is the size of the
orbit. At a service completion epoch, if the number of customers in the orbit is zero,
then the server leaves for a secondary job (vacation) of random length. At a vacation
completion epoch, if the orbit size is at least N, then the server remains in the system to render
service for the primary customers or orbital customers. On the other hand, if the number
of customers in the orbit is less than âNâ at a vacation completion epoch, the server
avails multiple vacations subject to maximum âMâ repeated vacations. After availing
âMâ
consecutive vacations, the server returns to the system to render service irrespective of
the orbit size. The model is studied using supplementary variable technique. For the
proposed queueing system, the probability generating function of the steady state queue
size distribution at an arbitrary time is obtained. Various performance measures are
derived. A cost model for the queueing system is developed. Numerical illustration is
provided
Analysis of a Bulk Queue with Unreliable Server and Single Vacation
Abstract In this paper, the operating characteristics of a
Analysis of a M
In this paper, a batch arrival general bulk service queueing system with interrupted
vacation (secondary job) is considered. At a service completion epoch, if the server finds
at least âaâ customers waiting for service say Ο, he
serves a batch of min (Ο, b) customers, where
b â„ a. On the other hand, if the queue length is at
the most âa-1â, the server leaves for a secondary job (vacation) of
random length. It is assumed that the secondary job is interrupted abruptly and the server
resumes for primary service, if the queue size reaches âaâ, during the
secondary job period. On completion of the secondary job, the server remains in the system
(dormant period) until the queue length reaches âaâ. For the proposed
model, the probability generating function of the steady state queue size distribution at
an arbitrary time is obtained. Various performance measures are derived. A cost model for
the queueing system is also developed. To optimize the cost, a numerical illustration is
provided
Collisional Dynamics of the First Excited States of Neon in the 590-670 nm Region using Laser Optogalvanic Spectroscopy
A mathematical rate equation model, incorporating the various processes contributing to the generation of optogalvanic signals in a discharge plasma, has been used to analyze the time-resolved waveforms of neon in the wavelength region 590â670 nm. Amplitudes, decay rates and the appropriate instrumental time constant have been determined using a non-linear least-squares fit of the observed time-resolved optogalvanic waveforms
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