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The Metabolic Cart
Published in Michael M. Rothkopf, Jennifer C. Johnson, Optimizing Metabolic Status for the Hospitalized Patient, 2023
Michael M. Rothkopf, Jennifer C. Johnson
The final aspect to interpreting a metabolic cart study is substrate oxidation (step 5). This area has two subcomponents, the general metabolic pattern and the specific fuel utilization. This method provides insight into what fuel your patient is burning to produce ATP. In the metabolism of carbon compounds as fuel, some compounds burn more efficiently than others, some less efficiently. This is partly based on the stoichiometry of the fuel’s reactions. Because some fuels contain more oxygen atoms, they require less gaseous O2 to burn. The chemical combustion formula describes how much oxygen is consumed and how much carbon dioxide and water are produced.
Answers
Published in Ken Addley, MCQs, MEQs and OSPEs in Occupational Medicine, 2023
Best fit. Carboxyhaemoglobin concentrations are typically less than 10% in smokers. Carbon monoxide results in the oxyhemoglobin dissociation curve shifting to the left impairing oxygen delivery to the tissues. Carbon monoxide is a by-product of incomplete combustion of carbon fuels. Carbon monoxide is generated in the human body by the catabolism of heme and results in the normal baseline human carboxyhemoglobin level of 0.4–1%.
How Nanoparticles Are Generated
Published in Antonietta Morena Gatti, Stefano Montanari, Advances in Nanopathology From Vaccines to Food, 2021
Antonietta Morena Gatti, Stefano Montanari
The third category of particulate matter created at high temperature is the secondary. Combustion releases different gases, depending on the composition of what is being burned: particularly carbon oxides, sulphur dioxide, nitrogen oxides, ammonia and a quantity of different volatile organic compounds. Once in the atmosphere, they find oxygen, also as its allotropic form ozone, free radicals, water vapour and a mixture of gases varying from place to place, from situation to situation and from time to time, occasionally changing in a matter of hours. In a time which in some instances takes days, catalysed by the sun and, more in particular, by the ultraviolet rays, a condensation reaction takes place among all those gases, forming new particles, precisely the secondary ones. Besides being definitely more numerous than filterable and condensable primary particles, the secondary ones have an important feature: organic pollutants, like, for instance, dioxins and furans, stick to them and are carried by them even to relatively long distances. Due to the time which condensation takes and because of diffusion phenomena, secondary particles can be found pretty far from the actual source of the substances by which they have been generated, and the pollutants adhering to them can have origins which have little or nothing to do with that of the particles themselves.
Prediction of spontaneous coal combustion tendency using multinomial logistic regression
Published in International Journal of Occupational Safety and Ergonomics, 2022
Nilufer Kursunoglu, Maruf Gogebakan
Spontaneous combustion has a complex structure and is caused by a combination of multiple factors. For this purpose, MLR was used in the present study to investigate the spontaneous combustion tendencies of the three coal mines in Zonguldak hardcoal basin. This method is capable of analyzing the interactions between the factors. The results of the MLR analysis indicated that three classes were obtained, and these classes were statistically divided into two clusters as Mine I and Mines II and III. It was observed that CH4, CO variables and CH4 × CO interaction were effective in the formation of clusters. Two fire levels were obtained as ‘normal situation’ and ‘potential combustion’ based on the MLR results. GR and the CO/CO2 index of the mines were also calculated. The combustion tendencies of the mines obtained by MLR were compared with the results of these indexes and the results supported each other. Mine II and Mine III have lower risk according to both methods, while Mine I is risky. Risk-reducing studies such as cement injection, rock dust dispersing and foam spraying behind the face should be intensified in Mine I. Besides, ventilation controls to minimize air leakages between intake and return airways should be performed more frequently.
A novel aqueous dimethyl trisulfide formulation is effective at low doses against cyanide toxicity in non-anesthetized mice and rats
Published in Clinical Toxicology, 2022
D. S. Lippner, D. M. Hildenberger, M. O. Rhoomes, J. N. Winborn, H. Dixon, J. McDonough, G. A. Rockwood
Cyanide (CN) is a metabolic poison that acts by inhibiting complex IV of metabolic respiration [1–3]. It is found naturally in various food sources, such as cassava root and bitter almonds [4–8], and can be formed as a product of manufacturing practices [9]. It is also a combustion byproduct of various plastic or nitrile-containing substances [10]. In industrialized countries, the most common route of exposure to CN is from commercial or domestic combustion fires [11–15]. Given its rapid toxicity and ability to incapacitate in many forms (as a powder or as a gas), CN has been used to adulterate medicine [16] and as a terrorism agent by many terrorist groups [17–21]. Two potent U.S. Food and Drug Administration (FDA)-approved CN antidotes, Nithiodote® and Cyanokit®, are effective for the treatment of confirmed or suspected CN poisonings [22–24]; however, both antidotes require intravenous administration over the course of many minutes (IV administration slowly over time), which presents limitations especially in cases of mass casualty exposures. The use of the Cyanokit® also requires reconstitution of hydroxocobalamin into saline and generous mixing, which can also delay treatment. Furthermore, the cost of both CN antidote kits is relatively high, potentially limiting the availability of these treatments, and there have been reports of undesired effects after administration of both compounds [25,26]. With these limitations in mind, a novel, safe and efficacious countermeasure that can be rapidly administered and is suitable for mass casualty situations is needed [27].
Numerical investigation of the effect of air supply on cook stove performance
Published in Inhalation Toxicology, 2021
Ankur Kaundal, Satvasheel Powar, Atul Dhar
Wood combustion is a complicated process of burning; combustion is the result of reactions between oxygen and gasses emitted from the feedstock, not solid feedstock. Upon heating solid feedstock releases gaseous components viz—pyrolysis gases with high oxygen affinity to react and create flames. Temperature due to this exothermic reaction is very high, making combustion luminous and flaming. Primary air and heating of the wood are responsible for releasing the volatiles. In short, it's called primary wood combustion. The remaining air supplied throughout the process is secondary air. Number of vents are placed on the horizontal sections of pipes (shown in Figure 1) inside the combustion chamber for the induction of secondary air. Oxygen in secondary air reacts with volatiles, resulting in flaming combustion. An appropriate mechanism for primary and secondary air intake is therefore essential for efficient cook stove operation.