Anaerobic endurance: the speed endurance sports
Nick Draper, Helen Marshall in Exercise Physiology, 2014
Lactate and H+ produced in muscle fibres during fast-rate glycolysis can diffuse across the sarcolemma to the blood. This provides the primary mechanism through which the effect of increasing H+ on cellular acidosis is delayed. Within the blood, where pH levels also require homeostatic control, carbonate (HCO3−) provides a buffer against H+ diffusing from the working muscles. Through carbonate buffering, the H+ binds with HCO3− to produce water and carbon dioxide. The equation for this reaction is: HCO3− + H+ ➞ CO2 + H2O
Procedures for Writing Formulas and Naming Compounds
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk in Survival Guide to General Chemistry, 2019
Example: Name K2CO3Potassium: Direct (unchanged) name of the metal that forms the positive ion.Potassium is in Group I and is a fixed-charged metal; no Roman numeral is required.The name carbonate matches the formula (CO3) as the negative ion (charges are not shown); the name is used directly with no change and is stated last in the complete name of the compound. Name: potassium carbonate
Chemistry of Mature Enamel
Colin Robinson, Jennifer Kirkham, Roger Shore in Dental Enamel, 2017
Why this gradient exists is not known. Since, however, carbonate is presumed to reflect metabolic activity of tissue, it may reflect the activity of the enamel-forming cells — the ameloblasts. Higher concentrations of CO2 would be expected to occur during the most active phase of enamel secretion. As ameloblast activity decreases toward maturation (see Chapter 2), less CO2 would be expected to be produced, leading to lower accumulation by the last apatite crystals to be formed near the finished enamel surface. Some support for this explanation derives from the fact that the concentrations of carbonate are relatively high during early secretion, falling somewhat as enamel is laid down.45
The oceans are changing: impact of ocean warming and acidification on biofouling communities
Published in Biofouling, 2019
Sergey Dobretsov, Ricardo Coutinho, Daniel Rittschof, Maria Salta, Federica Ragazzola, Claire Hellio
An increase in the level of atmospheric CO2 is leading to ocean acidification (Doney et al. 2009). Because the oceanic and atmospheric gas concentrations tend towards equilibrium, ̴ 30% of the added atmospheric CO2 has been taken up by the oceans, decreasing the average pH by ̴ 0.1 pH unit and ultimately changing water chemistry. The observed decrease in pH corresponds to a 26% increase in the hydrogen ion concentration of seawater (Feely et al. 2009). By 2100, the pH is expected to change by -0.13 (421 ppm under RCP2.6), -0.22 (538 ppm under RCP4.5), -0.28 (670 ppm under RCP6.0) and -00.42 pH unit (936 ppm under RCP8.5). Progress has been made in understanding the consequences of changes in pH, carbonate CO32- and the saturation state of CaCO3 for marine organisms and ecosystems (IPCC 2013; Wahl et al. 2015). These chemical and physical changes have direct implications for physiological processes such as photosynthesis, calcification, growth rates and internal pH regulation in a wide range of organisms (McCoy and Ragazzola 2014; Nannini et al. 2015; Evans et al. 2017; Fabricius et al. 2017; Okazaki et al. 2017) which will lead to a disruption of marine ecosystems and a reduction in biodiversity (Hoegh-Guldberg et al. 2007; Milazzo et al. 2014; Beaugrand et al. 2015).
Design, synthesis and cholinesterase inhibitory properties of new oxazole benzylamine derivatives
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2020
Ivana Šagud, Nikolina Maček Hrvat, Ana Grgičević, Tena Čadež, Josipa Hodak, Milena Dragojević, Kornelija Lasić, Zrinka Kovarik, Irena Škorić
Using the reaction of N-alkylation on the previously synthesised trans-chloro-arylethenyloxazole 120, new trans-amino-5-arylethenyl-oxazole derivatives trans-2–18 were synthesised (Scheme 1) with an aim to add a new functional group at the end of the oxazole derivative that resembles acetylcholine, the substrate of cholinesterase. The Buchwald-Hartwig reaction21 was utilised with two catalysts and the reaction was optimised for best conditions to enhance the yield. Change of base was crucial for the optimisation of this reaction. Sodium tert-butoxide was previously used as a base but the dehalogenation of the starting material was observed. Caesium carbonate improved yield and conversion. Temperature, solvent and catalyst used were independently varied to give the best conversion. The best conditions found are given in Scheme 1. The catalysed N-alkylation reaction is a complex coupling reaction and it gave a vast array of yields. Some of the substrates were optimised to excellent yields, while in the example of others only moderate to low yields were obtained. There is still some room for optimisation in the future with additional catalysts but at this time this was sufficient.
Non-destructive approaches for assessing biofouling of household reverse osmosis membranes
Published in Biofouling, 2018
Stephen D. Markwardt, Nirmala Ronnie, Anne K. Camper
Representative images from Phase 4 also illustrate the development of biofouling (Figure 3). The surface of the membrane fed with inorganics only had evidence of mineral solids. This was supported by testing for calcium carbonate using hydrochloric acid with the production of carbon dioxide gas bubbles. The average thickness of the scale was 23 µm ± 6 µm. The combined feedwater membrane had inorganic crystals coated with biological material resembling cells and extracellular biofilm matrix material. However, cryosectioning of this membrane was unsuccessful (separation of the membrane and fouling layer) and thickness could not be measured. The organics only surfaces had similar structures minus the crystals with a visible biofilm. The average thickness of the fouling layer was 40 µm ± 14 µm.
Related Knowledge Centers
- Carbonic Acid
- Ester
- Functional Group
- Monomer
- Organic Chemistry
- Polycarbonate
- Carbonyl Group
- Alkoxy Group
- Ether
- Dimethyl Carbonate