Calcium induction

Anderson, J. M., Charbonneau, H., and Cormier, M. J. (1974). Mechanism of calcium induction of Renilla bioluminescence. Involvement of a calcium-triggered luciferin binding protein. Biochemistry 13 1195-1200. 

A unique problem arises when reducing the fissile isotope The amount of that can be reduced is limited by its critical mass. In these cases, where the charge must be kept relatively small, calcium becomes the preferred reductant, and iodine is often used as a reaction booster. This method was introduced by Baker in 1946 (54). Researchers at Los Alamos National Laboratory have recently introduced a laser-initiated modification to this reduction process that offers several advantages (55). A carbon dioxide laser is used to initiate the reaction between UF and calcium metal. This new method does not requite induction heating in a closed bomb, nor does it utilize iodine as a booster. This promising technology has been demonstrated on a 200 g scale. 

Other drugs such as the neuroleptic, haloperidol, inhibit the induction of hsp70 mRNA in rodent neurons (Sharp et al.. 1992). Although this observation needs to be confirmed in the human population, it raises the possibility that an age-dependent defect in the production of HS proteins is exacerbated by a drug which is commonly used in demented elderly patients. The potential for certain pharmacologic agents to inhibit the HS response could increase the risk for untoward effects of atherosclerosis and hypoxia. A similar concern may be raised with certain calcium channel blockers which also have been found to reduce the synthesis of HS proteins in cardiac myocytes (Low-Friedrich and Schoeppe, 1991). 

Finally, at high temperatures ( 1000°C) calcium reacts violently with silicon after a short induction time. The products incandesce. 

This oxide catalyses the violent or even explosive decomposition of hydrogen peroxide. This reaction explains the numerous accidents mentioned involving the contact of hydrogen peroxide with rusted iron. Two accidents of this nature dealt with mixtures of hydrogen peroxide with ammonia and an alkaline hydroxide The detonations took place after a period of induction of respectively several hours and four minutes. Iron (III) oxide also catalyses the explosive decomposition of calcium hypochlorite. 

During ischaemia, NOS is activated by calcium influx or by cytokines like tumour necrosis factor (TNF) or by lipopolysaccharide (LPS) and NO is produced in excess. It has been proposed that the excitotoxic effect of glutamate, which contributes to ischaemia-induced neuronal damage, is mediated by increased production of NO via a chain of events that includes increases in intracellular calcium (via glutamate activation of NMDA receptors), calcium activation of NOS, production of NO and peroxynitrite, and induction of lipid peroxidation. In fact, N-nitro-L-atginine, a selective inhibitor of NOS, has been shown to prevent glutamate-induced neurotoxicity in cortical cell cultures (Dawson rf /., 1991). 

Current data suggest little benefit on clinical outcomes beyond symptom relief for calcium channel blockers in the setting of ACS.43 Moreover, the use of first-generation shortacting dihydropyridines, such as nifedipine, should be avoided because they appear to worsen outcomes through their negative inotropic effects, induction of reflex sympathetic activation, tachycardia, and increased myocardial ischemia.43 Therefore, calcium channel blockers should be avoided in the acute management of MI unless there is a clear symptomatic need or a contraindication to p-blockers. 

Interaction of calcium carbide with methanol to give calcium methoxide is very vigorous, but subject to an induction period of variable length. Once reaction starts, evolution of acetylene gas is very fast, and a wide-bore condenser and adequate ventilation are necessary. 

Detailed examination of another madder preparation proved that the sample can be premordanted with alum. [ 19] After hydrolysis performed with hydrochloric acid and extraction with M-amyl alcohol, only four colourants are found alizarin, purpurin, and probably lucidin and ruberythric acid. Additionally, signals at m/z 525 and 539 are observed in the mass spectrum. Analysis of the preparation by inductively coupled plasma mass spectrometry (ICP MS) shows that aluminium and calcium are the main inorganic components of the sample. This is why it was suggested that the signal at m/z 539 can be attributed to the complex of aluminium with alizarin, and the second one, observed at m/z 525, to an aluminium-calcium cluster. 

Brenner et al. [ 169] applied inductively coupled plasma atomic emission spectrometry to the determination of calcium (and sulfate) in brines. The principal advantage of the technique was that it avoided tedious matrix matching of calibration standards when sulfate was determined indirectly by flame techniques. It also avoided time-consuming sample handling when the samples were processed by the gravimetric method. The detection limit was 70 ig/l and a linear dynamic range of 1 g/1 was obtained for sulfate. 

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