Heat or Burn? Impacts of intrauterine tobacco smoke and E-Cigarette vapor exposure on the offspring's health outcome

© 2018 by the authors. Maternal smoking during pregnancy leads to gestational complications and organ disorders in the offspring. As nicotine replacement therapy is often ineffective for smoking cessation, pregnant women turn to alternatives such as heat-not-burn tobacco and e-cigarettes. Recently, the popularly of e-cigarettes has been increasing especially among the youth and pregnant women, mainly due to the advertisements claiming their safety. This has even led to some clinicians recommending their use during pregnancy. E-cigarettes heat e-liquid to produce an aerosol (e-vapor), delivering flavorings and nicotine to the user. However, e-vapor also contains toxins such as formaldehyde along with heavy metals and carcinogenic nitrosamines. In addition, specific flavoring compounds such as diacetyl can be toxic themselves or decompose into toxic compounds such as benzaldehydes. These compounds can induce toxicity, inflammation and oxidative stress in the mothers and can accumulate in the developing fetus, affecting intrauterine development. Recent animal studies suggest that maternal e-vapor exposure during pregnancy could cause respiratory and neurological disorders in the offspring. This review will examine the available literature to shed light on the current understanding of this problem-to-be from lessons learned in animal models

Doping effects on the phase separation in perovskite La0.67-xBixCa0.33MnO3

Effects of Bi, Cr, and Fe doping on phase separation of La0.67Ca0.33MnO3 have been experimentally studied. As proved by the electron-spin resonance and neutron-diffraction studies, partial replacement of La by Bi causes the simultaneous occurrence of ferromagnetic (FM) phase and charge-ordered antiferromagnetic phase. As a consequence, two subsequent magnetic transitions at ∼120 K and ∼230 K are resulted. A strong coupling between the coexisted phases is assumed, which is responsible for the insensitivity of Tc(L), the higher Curie temperature, to Bi doping after the appearance of phase separation, and consistent with the discontinuous variation of Tc(L) with Cr doping. As expected, the substitution of Cr for Mn in this case promotes the FM order, but its effects are significantly different for the two magnetic states. Each Cr drives ∼100 neighboring unit cells, for the high-moment state, and ∼60 unit cells, for the low-moment state, into the FM state. Two definite processes can be identified for the melting of the charge-ordered phase. The FM fraction increases rapidly in the initial stage of Cr doping, and then slowly when the FM population exceeds ∼90%. This could be a common feature of the phase-separated system suffering from random-phase fluctuation according to a theoretical analysis. Exactly opposite effects on phase constituent are produced by Cr doping and Bi doping, and 1% Cr are equivalent to ∼4.6% Bi. In contrast, both Cr doping and magnetic field promote the FM order. 1% Cr correspond to a field of ∼4.5 T for the low-moment state and 6 T for the high-moment state, reducing the energy difference between the charge ordering and the FM states by ∼0.96 meV/Mn and ∼1.3 meV/Mn, respectively.published_or_final_versio

Advances in Discrete-Time Sliding Mode Control Theory and Applications

The focus of this book is on the design of a specific control strategy using digital computers

PVC Sheathed Electrical Cable Fire Smoke Toxicity

The cone calorimeter, under free and restricted ventilation conditions, was used to investigate the toxic emissions from PVC cable fires. Toxic gases were measured using direct high temperature gas sampling from the exit of the cone calorimeter with a short chimney attached to the exit from the electrical cone. Toxic species CO and HCl were identified as a function of time using a heated Gasmet FTIR. The particle number was determined using the Cambustion DMS500 fast response particle sizer with a diluted sample taken from the diluted cone calorimeter exhaust flow at the same location as the optical obscuration smoke meter. The HCl concentrations from the Chlorine in the PVC sheath demonstrated HCl levels well above the LC50 concentration for HCl. The restricted ventilation reduced the peak fire heat release rate and the peak toxicity and HCl occurred later than for free ventilation. The equivalence ratio in the gases from the combustion zone, were both rich at 1.5 for free ventilation and 1.3-1.4 for restricted ventilation. The toxicity results showed the classic phases of compartment fires: growth, steady state burning and then fire decay. After flaming combustion was extinguished, slow char combustion continued with high CO emissions. The particle size distribution showed peak particle number, PN, nuclei mode particles at 10 nm and an accumulation mode at 100 nm. The number of particles at 10 nm for free and restricted ventilation were extremely high and showed that the freely ventilated fires had the highest PN, but later in the fire the restricted ventilation PN were higher. Nano-particle emissions < 50 nm from PVC fires are a health hazard that is currently unrecognized and unregulated

Smoke Particle Size Distribution in Pine Wood Fires

There is a growing concern about the impact of ultra- fine particulates released from fires on the health of humans in fires and the related environmental pollution. However, there is no requirement to measure particle mass or number from legislated test fires and hence there is minimum information in the literature on this toxic hazard in fires. This work compares particulates generated from freely ventilated and restricted ventilation pine wood fires using the cone calorimeter. The standard cone calorimeter with freely ventilated combustion was modified by adding a discharge pipe to the cone heater that enabled direct fire product sampling from the cone outlet. The controlled atmosphere cone calorimeter was used for the restricted ventilation fire with metered air fed to the enclosure around the test area. Both tests used a radiant heat flux of 35kW/m2. Real-time particulate number and size distribution were measured using the Cambustion DMS 500 particle electrical mobility spectrometer. The particulate size distribution showed a peak of ultra-fine aerosol particles of <100 nm in the early stage of the fire development and then changed to the larger size (100-1000 nm) with a peak of 200 nm as the fire progressed. The restricted ventilation fire generated more particles. There were high numbers of 20 nm particles throughout the fire and these have the greatest health risks. Toxic gases were also measured from the raw exhaust gases using a heated Gasmet FTIR gas analyser

Cinnamon as Dietary Supplement Caused Hyperlipidemia in Healthy Rats

ObjectiveCinnamon is a cooking spice and a medicinal herb. It is increasingly used as a health supplement due to its perceived benefit to prevent and or manage type 2 diabetes and metabolic disorders. However, it is unclear if regular consumption of this medicinal plant will interfere with normal physiological functions. Therefore, this study investigated the impact of daily cinnamon supplements on glucose and lipid metabolic profiles in healthy rats.MethodsMale rats (Sprague Dawley, 8 weeks) were supplied with cinnamon in their diet (equivalent to ∼1 g/day in humans) for two weeks. Blood glucose and lipid levels, as well as metabolic markers in both liver and abdominal white adipose tissue, were measured.ResultsCinnamon significantly increased fat mass and blood cholesterol and low-density lipoprotein (LDL) levels, but reduced fasting blood glucose level by 12%. Liver functional enzymes were normal in rats consuming cinnamon. However, several lipid metabolic markers were impaired which may contribute to dyslipidemia, including two main switches for energy metabolism (sirtuin 1 and peroxisome proliferator-activated receptor-gamma coactivator-1α) and the LDL receptor. However, de novo lipid synthesis enzymes and inflammatory markers were also reduced in the liver by cinnamon treatment, which may potentially prevent the development of steatosis. Markers for lipid oxidation were downregulated in fat tissue in cinnamon-treated rats, contributing to increased fat accumulation.ConclusionDaily low-dose cinnamon supplementation seems to promote abdominal adipose tissue accumulation and disturb lipid homeostasis in healthy rats, raising the concerns regarding daily use in healthy people

Replacing smoking with vaping during pregnancy: Impacts on metabolic health in mice.

Smoking is a significant risk factor for the development of metabolic diseases. Due to social pressures to quit smoking, many pregnant women are vaping as an alternative nicotine source. However, the metabolic consequences of replacing tobacco cigarettes with e-cigarettes during pregnancy are unknown. Therefore, in the mothers and their offspring, we investigated the metabolic and hepatic impacts of replacing cigarette smoke with e-vapour during pregnancy. Female BALB/c mice were either air-exposed or cigarette smoke-exposed (SE) from six weeks before pregnancy until lactation. At mating, a subset of the SE mice were instead exposed to e-vapour. Markers of glucose and lipid metabolism were measured in the livers and plasma, from the mothers and their male offspring (13 weeks). In the SE mothers, plasma insulin levels were reduced, leading to downstream increases in hepatic gluconeogenesis and plasma non-esterified fatty acids (NEFA). In the e-vapour replacement mothers, these changes were not as significant. In the SE offspring, there was impaired glucose tolerance, and increased plasma NEFA and liver triglyceride concentrations. E-vapour replacement restored lipid homeostasis but did not improve glucose tolerance. Therefore, in a murine model, low dose e-cigarette replacement during pregnancy is less toxic than cigarette smoke

A transient homotypic interaction model for the influenza A virus NS1 protein effector domain

Influenza A virus NS1 protein is a multifunctional virulence factor consisting of an RNA binding domain (RBD), a short linker, an effector domain (ED), and a C-terminal 'tail'. Although poorly understood, NS1 multimerization may autoregulate its actions. While RBD dimerization seems functionally conserved, two possible apo ED dimers have been proposed (helix-helix and strand-strand). Here, we analyze all available RBD, ED, and full-length NS1 structures, including four novel crystal structures obtained using EDs from divergent human and avian viruses, as well as two forms of a monomeric ED mutant. The data reveal the helix-helix interface as the only strictly conserved ED homodimeric contact. Furthermore, a mutant NS1 unable to form the helix-helix dimer is compromised in its ability to bind dsRNA efficiently, implying that ED multimerization influences RBD activity. Our bioinformatical work also suggests that the helix-helix interface is variable and transient, thereby allowing two ED monomers to twist relative to one another and possibly separate. In this regard, we found a mAb that recognizes NS1 via a residue completely buried within the ED helix-helix interface, and which may help highlight potential different conformational populations of NS1 (putatively termed 'helix-closed' and 'helix-open') in virus-infected cells. 'Helix-closed' conformations appear to enhance dsRNA binding, and 'helix-open' conformations allow otherwise inaccessible interactions with host factors. Our data support a new model of NS1 regulation in which the RBD remains dimeric throughout infection, while the ED switches between several quaternary states in order to expand its functional space. Such a concept may be applicable to other small multifunctional proteins

Exposure to Air Pollution Exacerbates Inflammation in Rats with Preexisting COPD.

Particulate matter with an aerodynamic diameter equal or less than 2.5 micrometers (PM2.5) is associated with the development of chronic obstructive pulmonary disease (COPD). The mechanisms by which PM2.5 accelerates disease progression in COPD are poorly understood. In this study, we aimed to investigate the effect of PM2.5 on lung injury in rats with hallmark features of COPD. Cardinal features of human COPD were induced in a rat model by repeated cigarette smoke inhalation and bacterial infection for 8 weeks. Then, from week 9 to week 16, some of these rats with COPD were subjected to real-time concentrated atmospheric PM2.5. Lung function, pathology, inflammatory cytokines, oxidative stress, and mucus and collagen production were measured. As expected, the COPD rats had developed emphysema, inflammation, and deterioration in lung function. PM2.5 exposure resulted in greater lung function decline and histopathological changes, as reflected by increased Mucin (MUC) 5ac, MUC5b, Collagen I, Collagen III, and the profibrotic cytokine α-smooth muscle-actin (SMA), transforming growth factor- (TGF-) β1 in lung tissues. PM2.5 also aggravated inflammation, increasing neutrophils and eosinophils in bronchoalveolar lavage fluid (BALF) and cytokines including Interleukin- (IL-) 1β, granulocyte-macrophage colony-stimulating factor (GM-CSF), and IL-4. The likely mechanism is through oxidative stress as antioxidants levels were decreased, whereas oxidants were increased, indicating a detrimental shift in the oxidant-antioxidant balance. Altogether, these results suggest that PM2.5 exposure could promote the development of COPD by impairing lung function and exacerbating pulmonary injury, and the potential mechanisms are related to inflammatory response and oxidative stress

Magnetoresistance in LaFe11.2Co0.7Si1.1 compound

Magnetoresistance has been studied in LaFe/sub 11.2/Co/sub 0.7/Si/sub 1.1/ compound. The ferromagnetic ordering at Curie temperature T/sub C/ of 274 K was found being accompanied by a drastic negative lattice expansion due to the strong structural and magnetic interplay. Such a simultaneous magnetic and lattice change would cause changes in transport properties. The measured transport properties indicate that the transition can be induced by temperature or applied magnetic field. The sample shows a metallic character below T/sub C/, whereas the electrical resistance decreases dramatically and then recovers the metal-like behavior above T/sub C/. Application of a magnetic field retains the transitions via increasing the ferromagnetic ordering temperature. An isothermal increase of field leads to an increase of resistance at temperatures near but above T/sub C/, which is a result of the field-induced metamagnetic transition from paramagnetic to ferromagnetic state.published_or_final_versio