Calcium Isotopes: Stable calcium atoms that have the same atomic number as the element calcium, but differ in atomic weight. Ca-42-44, 46, and 48 are stable calcium isotopes.Isotopes: Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)Chemical EngineeringMagic: Beliefs and practices concerned with producing desired results through supernatural forces or agents as with the manipulation of fetishes or rituals.Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.Neutron Diffraction: The scattering of NEUTRONS by matter, especially crystals, with accompanying variation in intensity due to interference effects. It is useful in CRYSTALLOGRAPHY and POWDER DIFFRACTION.Magnoliaceae: A plant family of the order Magnoliales, subclass Magnoliidae, class Magnoliopsida. They are trees and shrubs having an elongated conelike floral axis with fragrant flowers that have six tepals (sepals and petals that are not distinctly different) and many spirally arranged stamens.Invertebrates: Animals that have no spinal column.Perches: A common name for fish of the family Percidae, belonging to the suborder Percoidei, order PERCIFORMES.Elements: Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.Animal Shells: The hard rigid covering of animals including MOLLUSCS; TURTLES; INSECTS; and crustaceans.Electron Probe Microanalysis: Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.Alpha Particles: Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.Isotope Labeling: Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.Actinium: Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.Journalism, Medical: The collection, writing, and editing of current interest material on topics related to biomedicine for presentation through the mass media, including newspapers, magazines, radio, or television, usually for a public audience such as health care consumers.Nuclear Power Plants: Facilities that convert NUCLEAR ENERGY into electrical energy.Fukushima Nuclear Accident: Nuclear power accident that occurred following the Tohoku-Kanto earthquake of March 11, 2011 in the northern region of Japan.Television: The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)Radiation Monitoring: The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.Radiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Cesium Radioisotopes: Unstable isotopes of cesium that decay or disintegrate emitting radiation. Cs atoms with atomic weights of 123, 125-132, and 134-145 are radioactive cesium isotopes.Foraminifera: An order of amoeboid EUKARYOTES characterized by reticulating pseudopods and a complex life cycle with an alternation of generations. Most are less than 1mm in size and found in marine or brackish water.Carbonates: Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)Calcium Carbonate: Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Lithium Carbonate: A lithium salt, classified as a mood-stabilizing agent. Lithium ion alters the metabolism of BIOGENIC MONOAMINES in the CENTRAL NERVOUS SYSTEM, and affects multiple neurotransmission systems.Geology: The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Lithium: An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.Meteoroids: Any solid objects moving in interplanetary space that are smaller than a planet or asteroid but larger than a molecule. Meteorites are any meteoroid that has fallen to a planetary surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Radioactivity: The spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Oxygen Isotopes: Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.Solar System: The group of celestial bodies, including the EARTH, orbiting around and gravitationally bound by the sun. It includes eight planets, one minor planet, and 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as MINOR PLANETS (asteroids) and METEOROIDS. (From Academic American Encyclopedia, 1983)Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cosmic Dust: Finely divided solid matter with particle sizes smaller than a micrometeorite, thus with diameters much smaller than a millimeter, moving in interplanetary space. (NASA Thesaurus, 1994)Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

Effects of high compared with low calcium intake on calcium absorption and incorporation of iron by red blood cells in small children. (1/181)

BACKGROUND: The potential benefits of increasing calcium intake in small children must be balanced with the potential risk to iron utilization from high calcium intakes. OBJECTIVE: This study was designed to evaluate the relation between calcium intake and calcium absorption and iron incorporation into red blood cells. DESIGN: We performed a multitracer, crossover study of the absorption of calcium and red blood cell incorporation of iron in 11 preschool children aged 3-5 y who had been adapted for 5 wk to low- (502 +/- 99 mg) and high- (1180 +/- 117 mg) calcium diets. Stable-isotope studies were performed by using 44Ca and 58Fe given orally with meals and 46Ca given intravenously. RESULTS: Iron incorporation into red blood cells 14 d postdosing was similar (6.9 +/- 4.2% compared with 7.9 +/- 5.5%; NS) with the low- and high-calcium diets, respectively. Total calcium absorption (181 +/- 50 compared with 277 +/- 91 mg/d; P = 0.002) was greater in children with the higher calcium intake. CONCLUSIONS: Our findings indicate that small children may benefit from calcium intakes similar to those recommended for older children without adverse effects on dietary iron utilization.  (+info)

Characterization of prostanoid receptors in podocytes. (2/181)

Prostaglandins participate in the regulation of important glomerular functions and are involved in the pathogenesis of glomerular diseases. This study investigates the influence of prostaglandins on membrane voltage, ion conductances, cAMP accumulation, and cytosolic calcium activity ([Ca2+]i) in differentiated podocytes. Prostaglandin E2 (PGE2) caused a concentration-dependent depolarization and an increase of the whole cell conductance in podocytes (EC50 approximately 50 nM). Compared with PGE2, the EP2/EP3/EP4 receptor agonist 11-deoxy-PGE1 caused an equipotent depolarization, whereas the DP receptor agonist BW 245 C, the EP1/EP3 receptor agonist sulprostone, and the IP receptor agonist iloprost were at least 100 to 1000 times less potent than PGE2. The EP2 receptor agonist butaprost did not change membrane voltage of podocytes. The depolarizing effect of PGE2 was increased in an extracellular solution with a reduced Cl- concentration (from 145 to 32 mM). PGE2 and the prostaglandin agonists, but not the IP receptor agonist iloprost and the EP2 receptor agonist butaprost, induced a time- and concentration-dependent cAMP accumulation in podocytes. In fura-2 fluorescence experiments, PGE2, sulprostone, PGF2alpha, fluprostenol (a potent FP agonist), and U-46619 (a selective thromboxane A2 agonist) induced a biphasic increase of [Ca2+]i in 60 to 80% of podocytes. In reverse transcription-PCR studies, podocyte mRNA for the EP1, EP4, FP, and TP receptor could be amplified. These data indicate that in podocytes, PGE2 regulates distinct cellular functions via the EP1 and EP4 receptor, thereby increasing [Ca2+]i and cAMP, respectively. Furthermore, PGF1alpha and U-46619 increase [Ca2+]i via their specific receptors.  (+info)

Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates. (3/181)

Calcium from bone and shell is isotopically lighter than calcium of soft tissue from the same organism and isotopically lighter than source (dietary) calcium. When measured as the (44)Ca/(40)Ca isotopic ratio, the total range of variation observed is 5.5 per thousand, and as much as 4 per thousand variation is found in a single organism. The observed intraorganismal calcium isotopic variations and the isotopic differences between tissues and diet indicate that isotopic fractionation occurs mainly as a result of mineralization. Soft tissue calcium becomes heavier or lighter than source calcium during periods when there is net gain or loss of mineral mass, respectively. These results suggest that variations of natural calcium isotope ratios in tissues may be useful for assessing the calcium and mineral balance of organisms without introducing isotopic tracers.  (+info)

Isotopic evidence for variations in the marine calcium cycle over the Cenozoic. (4/181)

Significant variations in the isotopic composition of marine calcium have occurred over the last 80 million years. These variations reflect deviations in the balance between inputs of calcium to the ocean from weathering and outputs due to carbonate sedimentation, processes that are important in controlling the concentration of carbon dioxide in the atmosphere and, hence, global climate. The calcium isotopic ratio of paleo-seawater is an indicator of past changes in atmospheric carbon dioxide when coupled with determinations of paleo-pH.  (+info)

High bioavailability of calcium in fortified Horlicks. (5/181)

OBJECTIVE: To compare the bioavailability of calcium carbonate-fortified Horlicks with calcium naturally present in milk. DESIGN: Randomised crossover within-subject comparison using a double label stable isotope technique. SETTING: Institute of Food Research, Human Nutrition Unit. PARTICIPANTS: Sixteen pre-menopausal women aged 23-40 y, habituated to a high-calcium diet (mean 1240 mg/day). RESULTS: Mean true fractional calcium absorption was 38.8% (s.d.+/-14.5) from Horlicks and 21.2% (s.d.+/-4.6) from milk. Significantly more calcium was absorbed from a serving of Horlicks than from the same quantity of calcium present in 420 g semi-skimmed milk (P<0.001). CONCLUSIONS: Fortified Horlicks is a highly bioavailable source of calcium. A single serving, containing at least 500 mg calcium, provides half the reference nutrient intake for the population sub-group with the highest requirement (adolescent boys) and more than half for all others. SPONSORSHIP: SmithKline Beecham funded this research project.  (+info)

Calcium absorption measured by stable calcium isotopes ((42)Ca & (44)Ca) among Northern Chinese adolescents with low vitamin D status. (6/181)

An adequate calcium intake and vitamin-D status is important for bone mineralization in adolescents. In Northern China, calcium intake and plasma vitamin-D level of adolescents is low due to low consumption of dairy foods and inadequate sunshine exposure. True fractional calcium absorption (TFCA) in Chinese adolescents has never been performed. This study aims to evaluate nutritional adaptation namely, TFCA and urinary calcium excretion among Chinese adolescents in northern China.  (+info)

Overview of the 7th European symposium on calcium-binding proteins in normal and transformed cells. (7/181)

The strong feature of the meeting was the continuing efforts described in many papers to resolve the multiple ways in which calcium ions are released into cells via messenger signals and then interact with receptors to cause differential internal cellular activation and cell/cell communication. An easy general way to relate these studies to cell components is to start analysis from the genetic structures lying behind all cell activities and then to explore the RNA production, the proteome, the small substrates and calcium levels themselves in turn while referring to the environment of a particular cell, organ or organism. There is then of course the overall physiology. I shall summarize the papers in this order of their main interests.  (+info)

A novel dual radio- and stable-isotope method for measuring calcium absorption in humans: comparison with the whole-body radioisotope retention method. (8/181)

BACKGROUND: Dietary calcium absorption can be determined only with the use of isotope techniques. Currently used isotope techniques require exclusive equipment or are not true tracer approaches. OBJECTIVE: The objective was to compare a dual-isotope method combining radioisotopes and stable isotopes with a whole-body radioisotope retention method for measuring calcium absorption. DESIGN: Seven healthy adults aged 21-27 y consumed a test meal containing 63 +/- 14 (macro x +/- SD) mg Ca together with a water solution of (47)Ca (0.11 MBq). One hour after ingestion, 18 mg (44)Ca was administered intravenously. All feces and urine were collected for 5 and 6 d, respectively. Calcium absorption was estimated from whole-body retention of the radioisotope 12 times over 3 wk after ingestion and from the excretion of (47)Ca and (44)Ca in a 24-h urine sample collected on day 2. (44)Ca in urine was determined by inductively coupled plasma mass spectrometry. RESULTS: Mean (+/- SD) calcium absorption was 75 +/- 9% with the dual-isotope method and was 74 +/- 8% with the whole-body radioisotope retention method. There was a high degree of agreement between the methods. CONCLUSION: The dual-isotope method is a valid approach for measuring calcium absorption from a single meal.  (+info)

  • Here, we further test potential controls on the Permian-Triassic calcium isotope record by measuring calcium isotope ratios from shallow-marine carbonate successions spanning the Permian-Triassic boundary in Turkey, Italy, and Oman. (lu.se)
  • Physicists at the TU Darmstadt and their collaboration partners have performed laser spectroscopy on cadmium isotopes to confirm an improved model of the atomic nucleus. (idw-online.de)
  • CO2 release, including a temporary decrease in seawater δ44/40Ca due to short-lived ocean acidification and a more protracted increase in calcium isotope fractionation associated with a shift toward more primary aragonite in the sediment and, potentially, subsequently elevated carbonate saturation states caused by the persistence of elevated CO2 delivery from volcanism. (lu.se)
  • They have been attributed to the heavy calcium isotopes, including 48 Ca. One member of the triplet, Λ8542, had been either unavailable, or of poor quality in earlier spectra. (umich.edu)
  • The research group has now begun to investigate other chains in the neighbouring region of the cadmium isotopes in order to establish whether the theory can also be applied there with similar success. (idw-online.de)
  • The results indicate an intra-specimen δ44/40Ca variation ranging from 0.16 to 0.33‰, pointing to a fairly homogenous distribution of calcium isotopes in brachiopod shells. (uni-muenchen.de)
  • Consistency in the direction, magnitude, and timing of the calcium isotope excursion across these widely separated localities implies a primary and global δ44/40Ca signature. (lu.se)
  • Calcium ions outside cells are important for maintaining the potential difference across excitable cell membranes as well as proper bone formation. (wikipedia.org)
  • The primary goal of this project was to demonstrate whether the relationship between bone mineral balance (BMB) and changes in the natural isotope composition of blood and urine observed in Earth-based bed rest studies could also be observed in crewmembers in spaceflight, providing the basis for inflight measurements of BMB and evaluation of effectiveness of bone loss countermeasures in individual crewmembers. (data.gov)
  • Changes in Ca isotope composition are revealing details of the dynamics of BMB on previously inaccessible timescales, and offer new insights into bone biology. (data.gov)
  • In particular, while on Ca isotopes show what on average crewmembers lose bone during spaceflight, our data reveal striking differences between the responses of individual crewmembers. (data.gov)
  • Other reactor-produced radioisotopes continue to play a major role in research, and recent advances in many fields (such as molecular biology, including the Human Genome Project) could not have been accomplished without the use of 32 P. In addition, many of the isotopes useful for therapeutic applications, such as strontium-89 for the palliation of metastatic bone pain, are produced in reactors. (nap.edu)
  • Finally, current biomedical applications of Ca isotopes for the detection of bone loss during bed rest studies and during bone cancer are presented. (springer.com)
  • Channon MB, Gordon GW, Morgan JLL et al (2015) Using natural, stable calcium isotopes of human blood to detect and monitor changes in bone mineral balance. (springer.com)
  • Freeman SP, King JC, Vieira NE et al (1997) Human calcium metabolism including bone resorption measured with 41Ca tracer. (springer.com)
  • As a major material used in mineralization of bone , teeth and shells , calcium is the most abundant metal by mass in many animals . (wn.com)
  • Calcium levels in mammals are tightly regulated, with bone acting as the major mineral storage site. (wn.com)
  • Calcium ions , Ca 2+ , are released from bone into the bloodstream under controlled conditions. (wn.com)
  • Calcitriol, the active form of vitamin D 3 , promotes absorption of calcium from the intestines and the mobilization of calcium ions from bone matrix. (wn.com)
  • Trabecular bone readily gives up its minerals whenever blood calcium needs replenishing. (bartleby.com)
  • Furthermore, Ca isotope ratios were significantly correlated to other clinical parameters ([Ca]Urine, ([Ca]Urine/Creatinine)) and biomarkers (CRP, CTX/P1NP) associated with bone mineralization and demineralization. (geomar.de)
  • DXA reflects the bone mass density (BMD) of selected bones only (femur and spine) whereas the Ca isotope biomarker reflects bone Ca loss of the whole skeleton. (geomar.de)
  • In addition, the close correlation between Ca isotopes and biomarkers of bone demineralization suggest that early changes in bone demineralization are detected by Ca isotope values, long before radiological changes in BMD can manifest on DXA. (geomar.de)
  • We report a high resolution oxygen isotope (δ 18 O) record of animal teeth-bone phosphates from an archaeological trench itself at Bhirrana, NW India, preserving all cultural levels of this civilization. (nature.com)
  • Porous calcium phosphate implant compositions that approximate the chemical composition of natural bone mineral are provided. (google.es)
  • When introduced at an implant site, the calcium phosphate compositions are remodeled into bone. (google.es)
  • Methods for using the calcium phosphate compositions, e.g., to repair or replace bone, are also provided. (google.es)
  • Our bones are largely built of calcium, and the turnover of calcium can indicate the development of bone diseases such as osteoporosis and the cancer multiple myeloma . (medicalxpress.com)
  • These methods, using mass spectrometry, can discern the relative ratios of the calcium isotopes 42Ca and 44Ca in bone. (medicalxpress.com)
  • The researchers found that lighter calcium isotopes, such as 42Ca, are absorbed from the blood into the bone during bone formation . (medicalxpress.com)
  • Ariel Anbar said:"We were able to confirm that Ca isotopes of the shuttle shifted as expected, meaning that they we could see in more or less real time the ongoing bone loss. (medicalxpress.com)
  • Physicians treating osteoporosis and other calcium disorders of bone, including multiple myeloma, have very few tools at their disposal to quickly determine whether the treatments they're providing are actually making a difference. (medicalxpress.com)
  • And besides showing promise for determining bone loss, stable isotopes may be useful as biomarkers for a variety of other health problems. (earthmagazine.org)
  • It is not clear whether this occurs because parathyroid hormone release is inhibited or, more probably, because of a reduced sensitivity of the bone to parathyroid hormone, thus restricting withdrawal of calcium from the skeletal matrix. (fao.org)
  • Between 50 percent and 60 percent of body magnesium is located within bone, where it is thought to form a surface constituent of the hydroxyapatite (calcium phosphate) mineral component. (fao.org)
  • Calcium also serves as a structural element in bone. (gutenberg.org)
  • Strontium-90 acts like calcium, attracted to bone. (scientificamerican.com)
  • Calcium and vitamin D supplements were both not associated in protecting hip fractures and other bone breaks in the elderly, reveals a new study. (medindia.net)
  • Pawlowski J, Martin B, McCabe G, McCabe L, Jackson G, Peacock M, Barnes S, Weaver CM. Impact of equol producing capacity and soy isoflavone profiles of supplements on bone calcium retention in postmenopausal women: a partially randomized crossover trial. (purdue.edu)
  • Calcium and vitamin D intake maintained from pre-ovariectomy independently affect calcium metabolism and bone properties in Sprague Dawley rats. (purdue.edu)
  • Polyphenolic-rich extracts of plum, blueberry, grape seed, soy, and grape improve bone calcium retention in ovariectomized Sprague Dawley rats. (purdue.edu)
  • Parathyroid hormone, which causes transfer of exchangeable calcium from bone into the blood stream, maintains calcium homeostasis by preventing either calcium deficit or excess. (thefreedictionary.com)
  • Unlike cosmogenic isotopes that are produced in the atmosphere, 41Ca is produced by neutron activation of 40Ca. (wikipedia.org)
  • Unlike cosmogenic isotopes that are produced in the atmosphere , 41 Ca is produced by neutron activation of 40 Ca. Most of its production is in the upper metre or so of the soil column, where the cosmogenic neutron flux is still sufficiently strong. (wn.com)
  • After a recent application as a high-resolution mass separator for Penning-trap investigations (see idw press release "Laboratory Mass Measurement deepens Insight into Neutron Star Crusts" http://idw-online.de/en/news516628 ) the new device was successfully used to obtain the first mass measurements of calcium-53 and calcium-54. (idw-online.de)
  • Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications. (lanl.gov)
  • Researchers from Michigan State University and the RIKEN Nishina Center in Japan discovered eight new rare isotopes of the elements phosphorus, sulfur, chlorine, argon, potassium, scandium and, most importantly, calcium. (phys.org)
  • Like the other elements placed in group 2 of the periodic table, calcium has two valence electrons in the outermost s-orbital, which are very easily lost in chemical reactions to form a dipositive ion with the stable electron configuration of a noble gas , in this case argon . (wikipedia.org)
  • What isotopes of Argon are present on Earth? (nasa.gov)
  • What is the primary isotope of Argon on Earth? (nasa.gov)
  • Although not all of our analyses are completed, analysis of archived urine samples from 32 crewmembers from previous ISS missions clearly shows the same pattern of change in Ca isotope composition observed in bed rest and predicted in spaceflight. (data.gov)
  • Heuser A, Frings-Meuthen P, Rittweger J et al (2011b) Calcium isotopes in human urine under simulated microgravity conditions. (springer.com)
  • Over the next 24 hours, we will collect all urine for measurement of its calcium content. (clinicaltrials.gov)
  • Calcium isotope ratios in blood and urine: A new biomarker for the diagnosis of osteoporosis. (geomar.de)
  • Low fractional calcium absorption (FCA) contributes to osteoporosis but is not measured clinically, as the gold-standard method requires administration of two calcium tracers and a subsequent 24-h urine collection. (biomedcentral.com)
  • We measured subsequent calcium isotope concentrations in 24-h urine samples and serum collected 1, 3 and 5 h post tracer administration during an inpatient research stay. (biomedcentral.com)
  • While more efficient, the single isotope method might be less accurate than the 24-h urine method. (biomedcentral.com)
  • Working with NASA, the researchers measured calcium isotope ratios in urine from 30 shuttle astronauts, before, during, and after the flights. (medicalxpress.com)
  • Together, they have measured concentrations of calcium isotopes - specifically stable isotopes, which occur naturally and do not decay into other elements - in the urine of participants in a long-term bed-rest study run by NASA to mimic conditions seen in microgravity and study the effects on human anatomy. (earthmagazine.org)
  • Such particles are delivered as ion beams to the precision mass balance ISOLTRAP by the "isotope factory" ISOLDE at the European research centre CERN. (idw-online.de)
  • Obtain the fractional abundances for the two naturally occurring isotopes of europium. (bartleby.com)
  • Subsequent chapters cover nucleosynthetic anomalies in meteorites and early solar system chronology and the use of radiogenic isotopes in understanding the evolution of the Earth's mantle, crust, and oceans. (wiley.com)
  • Measuring the abundances of diverse trace elements and stable and radiogenic isotopes at micron scales. (whoi.edu)
  • Oxygen isotope analysis considers only the ratio of 18O to 16O present in a sample. (wikipedia.org)
  • Oxygen isotope ratios in barnacle shells change with ocean condition and allow scientists to chart the migration of the host whale, for example to warmer breeding grounds or colder feeding grounds. (eurekalert.org)
  • The study is comprised of 15 subjects orally administered immediately after breakfast a 600 mg gelatin capsules containing either 600 mg (2 capsules of 300 mg)of ACC (192 mg elemental calcium) of 480 mg CCC (192 mg elemental calcium), labeled with 15 mg of 44Ca (2 capsules of 300 mg). (clinicaltrials.gov)
  • 600 mg (2 capsules of 300 mg) for oral use of 480 mg CCC (192 mg elemental calcium) intrinsically labeled with 15 mg 44Ca and 120 mg of inactive filler, sucrose. (clinicaltrials.gov)
  • The results indicate an intra-specimen δ44/40Ca variation ranging from 0.16 to 0.33‰, pointing to a fairly homogenous distribution of calcium isotopes in brachiopod shells. (uni-muenchen.de)
  • Calcium isotopes are also used to study calcification rates (for the creation of shells and skeletons) and other processes. (iaea.org)
  • Of particular importance with respect to the pathologic effects of magnesium depletion is the role of this element in regulating potassium fluxes and its involvement in the metabolism of calcium ( 6-8 ). (fao.org)
  • osteoporosis group: 2.43 ± 0.10 mmol/l (SD, n = 14) and were also not correlated to their corresponding Ca isotope compositions. (geomar.de)
  • The δ44/42CaBlood and δ44/42CaUrine values correlated significantly (p = 0.004 to p = 0.031) with their corresponding DXA data indicating that both Ca isotope ratios are biomarkers for osteoporosis. (geomar.de)
  • Further studies are required to independently confirm that Ca isotope measurement provide a sensitive, non-invasive and radiation-free method for the diagnosis of osteoporosis. (geomar.de)
  • Unfortunately, clinicians do not routinely measure calcium absorption in patients with osteoporosis due to lack of an accurate, inexpensive and time-efficient method. (biomedcentral.com)
  • Worldwide Daily dose of calcium may differ in distinct regional patterns among people found a new study published in Osteoporosis International journal. (medindia.net)
  • A new clinical guide with the aim of raising awareness of the importance of calcium in lowering the risk of osteoporosis has been published by the European Menopause and Andropause Society (EMAS). (medindia.net)
  • Calcium Supplementation: Is protecting against osteoporosis counter to protecting against cardiovascular disease. (purdue.edu)
  • Analysis of these isotopes from sediment cores extracted directly off the North American Atlantic coast showed the earliest evidence for the Antarctic Intermediate Waters, which circulates strictly as a direct consequence of the ACC. (innovations-report.com)
  • Heuser A, Tütken T, Gussone N et al (2011a) Calcium isotopes in fossil bones and teeth-diagenetic versus biogenic origin. (springer.com)
  • We can answer these questions by looking at the shape of longbones, and by studying the isotopes and the DNA that can be found in human bones. (coursera.org)
  • Conversely, these light isotopes tend to be released into the bloodstream when bones break down. (medicalxpress.com)
  • People who are overweight or obese are vulnerable to losing unhealthful amounts of calcium from their bones when they go on weight-loss diets. (usda.gov)
  • But a study by Agricultural Research Service ( ARS ) scientists suggests that consuming about three times the recommended amount of dietary copper may help women retain calcium in their bones when dieting. (usda.gov)
  • The study showed that the women who were given 3 mg of additional copper were more likely to retain calcium in their bones. (usda.gov)
  • The body stores more than 99 percent of its calcium in the bones and teeth to help make and keep them strong. (medindia.net)
  • The most familiar calcium deficiency disease is rickets , in which the bones and teeth soften. (thefreedictionary.com)
  • Nematode infection increased leaf calcium contents but genotypes that were relatively tolerant of potato cyst nematodes ( Globodera pallida ) had lower leaf calcium concentrations on a particular sampling date. (springer.com)
  • Potassium citrate supplementation results in sustained improvement in calcium balance in older men and women. (purdue.edu)
  • When there is a deficit of ionized calcium, the nerve cells become more permeable, allowing leakage of sodium and potassium from the cells. (thefreedictionary.com)
  • Here, we present three household case studies to illustrate how lead hazard evaluations by an environmental specialist could be supplemented with routine lead isotope analyses of potential lead sources and blood. (thefreelibrary.com)
  • Typical analyses include investigation of the minerals that make up the meteorite, their relative locations, orientations and chemical compositions, analysis of isotope ratios and radiometric dating. (wikipedia.org)
  • Does Omeprazole Decrease Intestinal Calcium Absorption? (clinicaltrials.gov)
  • Existing literature makes it unclear whether proton pump inhibitor therapy truly decreases intestinal calcium absorption. (clinicaltrials.gov)
  • The primary study outcome is the change in intestinal calcium absorption following omeprazole therapy 40 mg daily for 30 days. (clinicaltrials.gov)
  • Can serum isotope levels accurately measure intestinal calcium absorption compared to gold-standard methods? (biomedcentral.com)
  • Intestinal calcium absorption decreases dramatically after gastric bypass surgery despite optimization of vitamin D status. (purdue.edu)