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Indirect Calorimetry
Indirect calorimetry calculates heat that living organisms produce by measuring either their production of carbon dioxide and nitrogen waste (frequently ammonia in aquatic organisms, or urea in terrestrial ones), or from their consumption of oxygen. Indirect calorimetry estimates the type and rate of substrate utilization and energy metabolism in vivo starting from gas exchange measurements (oxygen consumption and carbon dioxide production during rest and steady-state exercise). This technique provides unique information, is noninvasive, and can be advantageously combined with other experimental methods to investigate numerous aspects of nutrient assimilation, thermogenesis, the energetics of physical exercise, and the pathogenesis of metabolic diseases.Ferrannini "The theoretical bases of indirect calorimetry: a review."Metabolism. 1988 Mar;37(3):287-301. Scientific background Indirect calorimetry measures O2 and nitrogen consumption and CO2 production. On the assumption that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indirect Calorimetry Laboratory With Canopy Hood
Indirect, the opposite of direct, may refer to: * Indirect approach, a battle strategy * Indirect DNA damage, caused by UV-photons * Indirect agonist or indirect-acting agonist, a substance that enhances the release or action of an endogenous neurotransmitter * Indirect speech, a form of speech *Indirect costs, costs that are not directly accountable to a particular function or product * Indirect self-reference, describes an object referring to itself indirectly *Indirect effect, a principle of European Community Law *Indirect finance, where borrowers borrow funds from the financial market through indirect means *Indirection In computer programming, an indirection (also called a reference) is a way of referring to something using a name, reference, or container instead of the value itself. The most common form of indirection is the act of manipulating a value through ..., the ability to reference something in computer programming * Indirect transmission, infections passing from on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Metabolic Rate
Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest.. In other words it is the energy required by body organs to perform normal It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a thermally neutral environment while in the post- absorptive state (i.e., not actively digesting food). In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Quotient
The respiratory quotient (RQ or respiratory coefficient) is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body, when the body is in a steady state. Such measurements, like measurements of oxygen uptake, are forms of indirect calorimetry. It is measured using a respirometer. The respiratory quotient value indicates which macronutrients are being metabolized, as different energy pathways are used for fats, carbohydrates, and proteins. If metabolism consists solely of lipids, the respiratory quotient is approximately 0.7, for proteins it is approximately 0.8, and for carbohydrates it is 1.0. Most of the time, however, energy consumption is composed of both fats and carbohydrates. The approximate respiratory quotient of a mixed diet is 0.8. Some of the other factors that may affect the respiratory quotient are energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracheal Tube
A tracheal tube is a catheter that is inserted into the trachea for the primary purpose of establishing and maintaining a patent airway and to ensure the adequate exchange of oxygen and carbon dioxide. Many different types of tracheal tubes are available, suited for different specific applications: * An endotracheal tube is a specific type of tracheal tube that is nearly always inserted through the mouth (orotracheal) or nose (nasotracheal). * A tracheostomy tube is another type of tracheal tube; this curved metal or plastic tube may be inserted into a tracheostomy stoma (following a tracheotomy) to maintain a patent lumen. * A tracheal button is a rigid plastic cannula about in length that can be placed into the tracheostomy after removal of a tracheostomy tube to maintain patency of the lumen. History Portex Medical (England and France) produced the first cuff-less plastic 'Ivory' endotracheal tubes. Ivan Magill later added a cuff (these were glued on by hand to make the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intensive Care Unit
An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensive care medicine. An intensive care unit (ICU) was defined by the task force of the World Federation of Societies of Intensive and Critical Care Medicine as "an organized system for the provision of care to critically ill patients that provides intensive and specialized medical and nursing care, an enhanced capacity for monitoring, and multiple modalities of physiologic organ support to sustain life during a period of life-threatening organ system insufficiency." Patients may be referred directly from an emergency department or from a ward if they rapidly deteriorate, or immediately after surgery if the surgery is very invasive and the patient is at high risk of complications. History In 1854, Florence Nightingale left for the Crimean War, where triage was used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Measurement
Flow measurement is the quantification of bulk fluid movement. Flow can be measured using devices called flowmeters in various ways. The common types of flowmeters with industrial applications are listed below: * Obstruction type (differential pressure or variable area) * Inferential (turbine type) * Electromagnetic * Positive displacement meter, Positive-displacement flowmeters, which accumulate a fixed volume of fluid and then count the number of times the volume is filled to measure flow. * Fluid dynamic (vortex shedding) * Anemometer * Ultrasonic flow meter * Mass flow meter (Coriolis force). Flow measurement methods other than positive-displacement flowmeters rely on forces produced by the flowing stream as it overcomes a known constriction, to indirectly calculate flow. Flow may be measured by measuring the velocity of fluid over a known area. For very large flows, tracer methods may be used to deduce the flow rate from the change in concentration of a dye or radioisotope. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parenteral Nutrition
Parenteral nutrition (PN), or intravenous feeding, is the feeding of nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by pharmaceutical compounding entities or standard pharmaceutical companies. The person receives a nutritional mix according to a formula including glucose, salts, amino acids, lipids and vitamins and dietary minerals. It is called total parenteral nutrition (TPN) or total nutrient admixture (TNA) when no significant nutrition is obtained by other routes, and partial parenteral nutrition (PPN) when nutrition is also partially enteric. It is called peripheral parenteral nutrition (PPN) when administered through vein access in a limb rather than through a central vein as in central venous nutrition (CVN). Medical uses Total parenteral nutrition (TPN) is provided when the gastrointestinal tract is nonfunctional because of an interruption in its continuity (it is blocked, or has a leak – a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermodynamics
Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of thermodynamics, which convey a quantitative description using measurable macroscopic physical quantity, physical quantities but may be explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to various topics in science and engineering, especially physical chemistry, biochemistry, chemical engineering, and mechanical engineering, as well as other complex fields such as meteorology. Historically, thermodynamics developed out of a desire to increase the thermodynamic efficiency, efficiency of early steam engines, particularly through the work of French physicist Nicolas Léonard Sadi Carnot, Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antoine Lavoisier
Antoine-Laurent de Lavoisier ( ; ; 26 August 17438 May 1794), When reduced without charcoal, it gave off an air which supported respiration and combustion in an enhanced way. He concluded that this was just a pure form of common air and that it was the air itself "undivided, without alteration, without decomposition" which combined with metals on calcination. After returning from Paris, Priestley took up once again his investigation of the air from mercury calx. His results now showed that this air was not just an especially pure form of common air but was "five or six times better than common air, for the purpose of respiration, inflammation, and ... every other use of common air". He called the air dephlogisticated air, as he thought it was common air deprived of its phlogiston. Since it was therefore in a state to absorb a much greater quantity of phlogiston given off by burning bodies and respiring animals, the greatly enhanced combustion of substances and the greater ease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Quotient
The respiratory quotient (RQ or respiratory coefficient) is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body, when the body is in a steady state. Such measurements, like measurements of oxygen uptake, are forms of indirect calorimetry. It is measured using a respirometer. The respiratory quotient value indicates which macronutrients are being metabolized, as different energy pathways are used for fats, carbohydrates, and proteins. If metabolism consists solely of lipids, the respiratory quotient is approximately 0.7, for proteins it is approximately 0.8, and for carbohydrates it is 1.0. Most of the time, however, energy consumption is composed of both fats and carbohydrates. The approximate respiratory quotient of a mixed diet is 0.8. Some of the other factors that may affect the respiratory quotient are energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Physiologica
''Acta Physiologica'' is a monthly peer-reviewed scientific journal that is published by Wiley-Blackwell on behalf of the Scandinavian Physiological Society. According to the ''Journal Citation Reports'', it has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 7.523. It is the official journal of the Federation of European Physiological Societies. The journal was established in 1889 as the ''Skandinavisches Archiv für Physiologie'' and renamed to ''Acta Physiologica Scandinavica'' in 1940, before obtaining its current name in 2006. References External links * {{Official website, http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1748-1716 Wiley-Blackwell academic journals Physiology journals English-language journals Monthly journals Public ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weir Formula
The Weir formula is a formula used in indirect calorimetry, relating metabolic rate to oxygen consumption and carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ... production. According to original source, it says: :Metabolic rate (kcal per day) = 1.440 (3.9 VO2 + 1.1 VCO2) where VO2 is oxygen consumption in litres per minute and VCO2 is the rate of carbon dioxide production in litres per minute. The formula can also be written for units of calories per day where VO2 is oxygen consumption expressed in millilitres per minute and VCO2 is the rate of carbon dioxide production in millilitres per minute. Another source gives :Energy (kcal/min) = (respiration in L/min times change in percentage oxygen) / 20 This corresponds to: :Metabolic rate (cal per minute) = 5 (VO2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
