Bicarbonate Ion Concentration Research Articles

Microbial diversity of two natural CO2-rich springs with contrasting hydrochemical features

Microbial communities in CO2-rich springs have adapted to environmental pressure including low pH resulting from high concentrations of CO2. Microbial community composition and hydrochemical characteristics in the CO2-rich springs are important features affected by high levels of CO2 in groundwater ecosystems, and they may be useful indicators of CO2 leakage from carbon capture and storage (CCS) sites where CO2 is injected into deep geological reservoirs for the mitigation of climate change. To determine how long-term CO2 leakage affects the groundwater ecosystems, we analyzed the bacterial and archaeal community composition and hydrochemical features of two different natural CO2-rich springs, Hansil (HS) and Chosukol (CS), located in south-eastern Korea which are natural analog sites for groundwater ecosystems affected by CO2 leakage from geological CO2 storage sites. Analyses of hydrochemical characteristics and 16S rRNA gene amplicon sequencing of bacteria and archaea revealed a marked distinction between the two springs. The pH, the concentrations of bicarbonate ion (HCO3-), major cations including Ca2+ and Mg2+, and specific trace elements including Fe and Mn were higher in HS as compared to CS while no distinction in pCO2 between the two springs was observed. Microbial community composition was distinct between the two springs at the genus level. Specifically, the relative abundance of Gallionella, an iron-oxidizer, was significantly higher in HS whereas that of Albidiferax known as dissimilatory iron-reducing bacteria was higher in CS than HS, reflecting the difference of iron concentration in the two springs. In our study, microbial community composition appeared to be more strongly affected by the concentration of iron than that of CO2. Our results enhance the understanding of hydrochemical features and microbial communities in natural CO2-rich springs and suggest that microbial communities may be useful indicators of CO2 leakage from CCS sites.

Enteric-coated sodium bicarbonate supplementation improves high-intensity cycling performance in trained cyclists

PurposeEnteric-coated sodium bicarbonate (NaHCO3) can attenuate gastrointestinal (GI) symptoms following acute bicarbonate loading, although the subsequent effects on exercise performance have not been investigated. The purpose of this study was to examine the effects of enteric-coated NaHCO3 supplementation on high-intensity exercise performance and GI symptoms.MethodsEleven trained male cyclists completed three 4 km time trials after consuming; a placebo or 0.3 g∙kg–1 body mass NaHCO3 in enteric-coated or gelatin capsules. Exercise trials were timed with individual peak blood bicarbonate ion concentration ([HCO3–]). Blood acid–base balance was measured pre-ingestion, pre-exercise, and post-exercise, whereas GI symptoms were recorded pre-ingestion and immediately pre-exercise.ResultsPre-exercise blood [HCO3−] and potential hydrogen (pH) were greater for both NaHCO3 conditions (P < 0.0005) when compared to placebo. Performance time was faster with enteric-coated (− 8.5 ± 9.6 s, P = 0.044) and gelatin (− 9.6 ± 7.2 s, P = 0.004) NaHCO3 compared to placebo, with no significant difference between conditions (mean difference = 1.1 ± 5.3 s, P = 1.000). Physiological responses were similar between conditions, although blood lactate ion concentration was higher with gelatin NaHCO3 (2.4 ± 1.7 mmol∙L–1, P = 0.003) compared with placebo. Furthermore, fewer participants experienced GI symptoms with enteric-coated (n = 3) compared to gelatin (n = 7) NaHCO3.DiscussionAcute enteric-coated NaHCO3 consumption mitigates GI symptoms at the onset of exercise and improves subsequent 4 km cycling TT performance. Athletes who experience GI side-effects after acute bicarbonate loading may, therefore, benefit from enteric-coated NaHCO3 supplementation prior to exercise performance.

Development of a severity scoring system for acute haemorrhage in anaesthetized domestic cats: the CABSS score

ObjectiveTo determine whether physiological, haematological, biochemical or electrolyte variables can predict severe haemorrhage in cats. Study designRandomized crossover study whereby each cat underwent mild and severe haemorrhage, with a 2 month period between events. AnimalsA group of six domestic cats aged 21 ± 1 months and weighing 4.9 ± 1.2 kg, mean ± standard deviation. MethodsCats were anaesthetized (buprenorphine, alfaxalone, isoflurane in oxygen at a fixed end-tidal concentration of 1.7%) before the haemorrhage event. In total, 34 variables were measured twice (prehaemorrhage and posthaemorrhage). The difference and percent change for each variable were compared between haemorrhage events (paired t test). Significant variables were placed into 13 different ratios (posthaemorrhage value of one variable divided by a posthaemorrhage value of a second variable) and compared (paired t test), and Cohen’s d (d) was calculated. Receiver operating characteristic curves were plotted and cut-off values for weak, moderate and strong indicators of severe haemorrhage were obtained. ResultsThe blood loss was 4.5 ± 1.1 mL kg–1 and 26.8 ± 5.5 mL kg–1 for mild and severe haemorrhage events, respectively. The most significant variables with large effect sizes were heart rate (HR), systolic arterial blood pressure (SAP), end-tidal carbon dioxide (Pe′CO2), serum albumin, haematocrit and actual bicarbonate ion concentration [HCO3−(act)]. The most robust ratios were: 1) shock index (d = –2.8; HR:SAP); 2) HR:Pe′CO2 (d = –2.9); 3) serum albumin: haematocrit (d = 1.5); and 4) HR:HCO3−(act) (d = –1.6). These ratios were included in the final proposed Cat Acute Bleeding Scoring System (CABSS). Conclusionsand clinical relevance Cats subjected to mild and severe haemorrhage demonstrated statistically and clinically relevant changes whereby four ratios could be created to make up the CABSS. The ratios detected and quantified the presence of severe haemorrhage in anaesthetized cats.

Effect of peritoneal dialysis solution with different pyruvate concentrations on intestinal injury.

To investigate the effects of direct peritoneal resuscitation with pyruvate-peritoneal dialysis solution (Pyr-PDS) of different concentrations combined with intravenous resuscitation on acid–base imbalance and intestinal ischemia reperfusion injury in rats with hemorrhagic shock. Sixty rats were randomly assigned to group SHAM, group intravenous resuscitation, and four direct peritoneal resuscitation groups combined with intravenous resuscitation: group NS, LA, PY1, and PY2, that is, normal saline, lactate-PDS (Lac-PDS), lower concentration Pyr-PDS (Pyr-PDS1), and higher concentration Pyr-PDS (Pyr-PDS2), respectively. Two hours after hemorrhagic shock and resuscitation, the pH, oxygen partial pressure, carbon dioxide partial pressure (PCO2), base excess, and bicarbonate ion concentration (HCO3−) of the arterial blood were measured. The intestinal mucosal damage index and intercellular adhesion molecule 1 (ICAM-1), tumor necrosis factor-α, interleukin-6, zonula occludens-1, claudin-1, and occludin levels in intestinal issues were detected. Two hours after resuscitation, group PY2 had higher mean arterial pressure, pH, oxygen partial pressure, and base excess and lower PCO2of arterial blood than group PY1 ( P &lt; 0.05). Tumor necrosis factor-α and interleukin-6 levels in group PY2 were significantly lower than those in group PY1 ( P &lt; 0.05). Zonula occludens-1, claudin-1, and occludin expression levels were significantly higher in group PY2 than in group PY1 ( P &lt; 0.05). Direct peritoneal resuscitation with Pyr-PDS2 combined with intravenous resuscitation enhanced the hemodynamics, improved the acid–base balance, and alleviated intestinal ischemia reperfusion injury from hemorrhagic shock and resuscitation in rats. The mechanisms might include correction of acidosis, inhibition of inflammatory response, enhancement of systemic immune status, regulation of intestinal epithelial permeability, and maintenance of intestinal mucosal barrier function.Impact statementHemorrhagic shock is a life-threatening condition after trauma or during surgery. Acid–base imbalance and intestinal ischemia reperfusion injury are two significant causes in the pathogenetic process and multiple organ dysfunction. As a result, it is urgent and necessary to find an effective method of resuscitation in order to reverse the acid–base imbalance and protect organ function. This current study confirmed the protection against hypoxic acidosis and intestinal ischemia reperfusion injury by peritoneal resuscitation with pyruvate combined with intravenous resuscitation in rats with hemorrhagic shock. And the peritoneal dialysis solution with pyruvate of high concentration plays a crucial role in the process. It provided a new idea and possible direction of fluid resuscitation for alleviating organ injuries, protecting organ functions, and improving clinical prognosis after hemorrhagic shock and resuscitation.

Effect of Sign-Alternating Cyclic Polarisation and Hydrogen Uptake on the Localised Corrosion of X70 Pipeline Steel in Near-Neutral Solutions

The effect of sign-alternating cycling polarisation (SACP) on the localised corrosion of X70pipeline steel in solutions of various compositions was studied. Localised corrosion of steel at anodic potentials was accelerated with an increase in the duration of the cathodic half-cycle, in the presence of a promoter of hydrogen absorption in aqueous electrolyte, and with an increase in the concentrations of chloride and bicarbonate ions. It was pointed out that the corrosion rate is determined by the amount of hydrogen absorbed by the steel. A quantitative indicator to determine the intensity of localised corrosion under SACP was suggested.

The Influence of Elevated Brain Temperature on Intracranial Pressure during Exposure of RF Energy

Brain temperature (BT) and intracranial pressure (ICP) are crucial parameters in precise management of brain rejuvenation in the event of brain injury. In order to reduce medical costs and improve therapeutic effects, it is important to know that the dynamics of BT and ICP are affected due to various reasons. RF energy is also one of the major reason to increase the BT and ICP. In this work, a simple compartment based simulation model has been developed for coupling between RF energy and ICP, with an intention to improve the comprehension of ICP. The model incorporates the cardiovascular output, hemodynamic of cerebral arterial-arteriolar bed, oxygen, and carbon dioxide exchange mechanism between brain tissue and capillary, a non-linear pressure-volume relationship of subarachnoid space. It simulates the interaction between BT, the cerebral metabolic rate of oxygen (CMRO2), a concentration of bicarbonate ions (HCO3-), cerebral blood flow (CBF), cerebral blood volume (CBV) and ICP. The basic concept behind the model is the expansion or contraction of brain tissue which is affected underexposure of RF energy. The simulation results determine the following: 1) ICP becomes unstable underexposure of RF energy at higher specific absorption rate (SAR). 2) ICP and brain temperature has a direct relation during exposure of RF energy. The model elaborates the dynamics of ICP with less complexity.

Biomineralization of Carbonate Minerals Induced by The Moderate Halophile Staphylococcus Warneri YXY2

Although biomineralization of minerals induced by microorganisms has been widely reported, the mechanisms of biomineralization and the characteristics of the biominerals precipitated needs to be studied further. In this study, Staphylococcus warneri YXY2, a moderate halophile, was used to induce the precipitation of carbonate minerals at various Mg/Ca molar ratios. To investigate the biomineralization mechanism, the growth curve, pH changes, ammonia test, the concentration of bicarbonate and carbonate ions, and the activity of carbonic anhydrase (CA) and alkaline phosphatase (ALP) were determined. X-ray powder diffraction (XRD), scanning electron microscopy - energy disperse spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and stable carbon isotope analyses were used to characterize the minerals. The obtained biotic minerals were calcite, vaterite, Mg-rich calcite, and aragonite crystals. The crystallinity of aragonite decreased with increasing Mg/Ca ratios. The preferred orientation, diverse morphologies, organic substances, and more negative stable carbon isotope values proved the biogenesis of these carbonate minerals. The presence of Mg in the biotic aragonite crystals was likely related to the acidic amino acids which also facilitated the nucleation of minerals on/in the extracellular polymeric substances (EPS). Mg2+ and Ca2+ ions were able to enter into the YXY2 bacteria to induce intracellular biomineralization. Dynamics simulation using Material Studio software proved that different adsorption energies of Glutamic acid (Glu) adsorbed onto different crystal planes of aragonite led to the preferred orientation of aragonite. This study helps to deepen our understanding of biomineralization mechanisms and may be helpful to distinguish biotic minerals from abiotic minerals.

The mutual effects of injected fluid and rock during imbibition in the process of low and high salinity carbonated water injection into carbonate oil reservoirs

Abstract During water injection into oil reservoirs, interactions occur between injected water and the reservoir rock. The interactions are enhanced when dissolved carbon dioxide (CO2) is used in injectable fluid in enhanced oil recovery (EOR) process, especially in carbonate reservoirs. With the dissolution of CO2 in water, carbonic acid is formed. The formed acid reacts with the carbonate salts in the rock (calcium carbonate and magnesium carbonate) and dissolves them. The dissolution causes a change in the properties of the rock, including wettability, porosity and permeability. In this study, variations of porosity, permeability, rock mass and wettability during carbonated water imbibition were measured based on direct measurements of porosity, permeability, rock weight and contact angle. In addition, changes in the concentration of calcium, magnesium and bicarbonate ions from the dissolution of carbonate rocks in injected water were measured by sampling and titration of water. The experiments were carried out at a constant temperature and the pressure parameter was considered to be variable in order to investigate its effect on the cases discussed. The effect of base fluid salinity was investigated in two salinities equal to the initial salinity and salinity from the dilution of seawater. The carbonated water imbibition in oil-saturated plugs yields 48, 56, 69 and 75%, at pressures of 500, 1000, 1500, and 2000 psi, respectively, and low salinity resulted from the dilution of seawater as the base fluid. In addition to the dependence of changes in rock parameters on the pressure and salinity of the base fluid, the results show that porosity variations, permeability and, most importantly, wettability of the rock are so much that they can be effective in activating the process of the imbibition and increasing its power in oil production.

Electrolytes, Serum biochemical and Acid-Base Disturbances in Dogs with Foul-Smelling Bloody Diarrhoea

Metabolic alkalosis is an electrolyte abnormality accompanied by an elevation in bicarbonate ion concentration in blood and a rise in blood pH. This study aims to determine the serum concentration of electrolytes and levels of some biochemical parameters in dogs presented with profuse foul-smelling bloody watery diarrhoea. From October 2018 to February 2019, 60 client-owned dogs were presented at the University of Nigeria Veterinary Teaching Hospital (UNVTH) for vaccination, treatment and regular deworming. Five (5) out of 60 dogs had profuse foul-smelling watery diarrhoea and were sampled. A full history and physical examinations were undertaken for the sampled dogs. Clinical signs such as profuse foul-smelling bloody diarrhoea, vomiting, anorexia, weakness, dehydration, lethargy was observed in the affected dogs. Three dogs were 4 months old while two dogs are adults. Blood samples (2 ml) were collected from the cephalic vein of dogs with the above presentation, and sera were harvested for serum biochemical analysis. Standard procedures were followed in all the serum biochemistry determinations. The most common electrolyte and serum biochemical abnormalities in 5 dogs with profuse foul-smelling bloody watery diarrhoea were hypokalemia (100%), increased serum bicarbonate level (100%), hyponatremia (75%), and hypoglobulinemia (100%). Hypochloremia occurred in 20% of the cases, while hypoproteinemia, hypoglobulinemia, and low serum creatinine levels were recorded in 100% of the cases. Increased urea level was observed in 40% of the affected dogs. Our study demonstrated that all affected dogs developed hypokalemic metabolic alkalosis following loss of potassium through the gastrointestinal tract consequent upon severe watery diarrhoea.

Experimental Study on Diffusion Process of Sulfate Ion in Cemented Gangue Backfill Material

Cemented gangue backfill material (CGBM) is made of coal gangue, fly ash, cement, and water. The backfill body will be corroded by mine water that contains different kinds of corrosive ions. The paper mainly aimed to study the diffusion process of sulfate ion () in CGBM. Soluble salt solutions with different concentrations are prepared to simulate various mine water. The concentration was measured by layered sampling method and chemical analyzing method. The diffusion coefficient was calculated according to the second Fick’s law. Scanning electron microscope (SEM) and X‐ray diffraction (XRD) were used to analyze the degradation mechanisms. The experimental results showed that the concentration increases in CGBM when the external sulfate solutions concentration increases. With the increasing of magnesium ion (Mg2+) concentration and bicarbonate ion () concentration in the external corrosion solutions, the diffusion coefficient of was increased, and has more significant effects than Mg2+. reacting with CGBM produced ettringite and gypsum. The ettringite and gypsum changed the pore structure of hardened CGBM and affected the compressive strength of hardened CGBM. Studying the diffusion of can contribute to predicting the service life of CGBM.

Fluoride abundance and their release mechanisms in groundwater along with associated human health risks in a geologically heterogeneous semi-arid region of east India

The present study investigated the source, release mechanisms, mobility and controlling factors of fluoride in groundwater. It has been conducted in the semi-arid rural tract of Birbhum district, located in the eastern part of peninsular India which comprises of the granite genesis aquifers, soft to medium hard rocks with laterite and lateritic soils and alluvial aquifers. The groundwater fluoride level of the study area varied from 0.3 to 9.36 mg/L with an average value of 1.7 mg/L. In the granite region, weathering of granitic rocks, dissolution and iron-exchange processes are responsible for fluoride occurrence in groundwater and its concentration is controlled by the concentration of carbonate and bicarbonate ions. In clay, laterite soil and sedimentary aquifer regions, pH of the circulating water and clay/soil, surface charge characteristics of clay/soils, soil permeability and residence time control the groundwater fluoride through adsorption/desorption of fluoride by the clay and laterite soil. High evaporation rate of the study area also plays an important role to increase the groundwater fluoride concentration. The study also evaluated the health risks to the residents based on the dose-response characterization and USEPA human health risk assessment model through ingestion and dermal contact exposure pathways. The population of infants and children within the study area is more susceptible to the non-carcinogenic health hazards of fluoride than adults. This takes place mainly through direct ingestion route where the dominance order of the population is infants > children > men > women.

Approximation of bicarbonate concentration using serum total carbon dioxide concentration in patients with non-dialysis chronic kidney disease.

BackgroundWe investigated the relationship between serum total carbon dioxide (CO2) and bicarbonate ion (HCO3−) concentrations in pre-dialysis chronic kidney disease (CKD) patients and devised a formula for predicting low bicarbonate (HCO3−< 24 mmol/L) and high bicarbonate (HCO3− ≥ 24 mmol/L) using clinical parameters.MethodsIn total, 305 samples of venous blood collected from 207 pre-dialysis patients assessed by CKD stage (G1 + G2, 46; G3, 50; G4, 51; G5, 60) were investigated. The relationship between serum total CO2 and HCO3− concentrations was analyzed using Pearson’s correlation coefficient. An approximation formula was developed using clinical parameters correlated independently with HCO3− concentration. Diagnostic accuracy of serum total CO2 and the approximation formula was evaluated by receiver operating characteristic curve analysis and a 2 × 2 table.ResultsSerum total CO2 correlated strongly with HCO3− concentration (r = 0.91; P < 0.001). The following approximation formula was obtained by a multiple linear regression analysis: HCO3− (mmol/L) = total CO2 − 0.5 × albumin − 0.1 × chloride − 0.01 × (estimated glomerular filtration rate + blood glucose) + 15. The areas under the curves of serum total CO2 and the approximation formula for detection of low bicarbonate and high bicarbonate were 0.981, 0.996, 0.993, and 1.000, respectively. This formula had superior diagnostic accuracy compared with that of serum total CO2 (86.6% vs. 81.3%).ConclusionSerum total CO2 correlated strongly with HCO3− concentration in pre-dialysis CKD patients. An approximation formula including serum total CO2 showed superior diagnostic accuracy for low and high bicarbonate compared with serum total CO2.

Correlation between the Serum Chloride Levels and the Anion Gap Values in Initial Fluid Resuscitation with Normal Saline in Patients with Diabetic Ketoacidosis at RSUD dr. Saiful Anwar Malang

Introduction : Diabetic ketoacidosis (DKA) is characterized by uncontrolled hyperglycemia, ketonemia, and metabolic acidosis. Osmotic diuresis as a result of uncontrolled hyperglycemia causes intracellular dehydration and electrolyte deficits. Excessive production of ketone bodies in the blood instigates high anion gap metabolic acidosis (HAGMA). Fluid resuscitation with normal saline is the initial management of DKA frequently performed at Saiful Anwar Hospital because this infusion fluid is rich in chloride content. Hyperchloremia contributes to the occurrence of normal anion gap metabolic acidosis (NAGMA) after rehydration with large amounts of normal saline because an increase in the chloride levels is not counterbalanced by an increase in the bicarbonate ion concentrations in plasma. Although the anion gap values decrease, acidosis still occurs. A normal anion gap is a recovery sign of DKA. Therefore, research is needed to examine the description and correlation of changes in the serum chloride levels and changes in the anion gap values before and after fluid resuscitation with normal saline. Method : Analytic observational research with cross-sectional approach. A sample of 15 people was collected from July to December 2018 in the emergency department (ED) of Saiful Anwar Hospital. Results : Significant changes were found in the serum chloride levels (p = &lt;0.001) and in the anion gap values (p = 0.002) before and after fluid resuscitation with normal saline in patients with DKA. Correlation test results showed a significant relationship between changes in the serum chloride levels and changes in the anion gap values before and after fluid resuscitation with normal saline in patients with DKA (p = &lt;0.001, r = -0.848). Conclusions : Significant changes were found in the serum chloride levels and in the anion gap values before and after fluid resuscitation with normal saline in patients with DKA. The serum chloride levels tended to increase, whereas the anion gap values tended to decrease. Correlation test showed that there was a significant relationship between changes in the serum chloride levels and changes in the anion gap values. The relationship was strong, meaning that the more increasing changes in the serum chloride levels were, the more decreasing changes in the anion gap values would be or vice versa. Keywords : The chloride level, the anion gap, normal saline, 0.9% NaCl, diabetic ketoacidosis, changes in chloride, changes in the anion gap, correlation between chloride and the anion gap. DOI : 10.7176/JHMN/66-10 Publication date :September 30 th 2019

Presence and Distribution of Fluoride Ions in Groundwater for Human in a Semiconfined Volcanic Aquifer

Dental and emaciated fluorosis is derived from the chronic intake of fluoride ions (F−) by consumption of food, tooth products and drinking water from groundwater. Recent reports indicate that in some regions of Mexico, the incidence of fluorosis in temporary and permanent dentitions have increased in recent years. The purpose of the present investigation was to determine the presence and distribution of F− ions in semi-confined aquifers, located in the basins of Lerma-Chapala and Valley of México. Temperature (T), pH, electrical conductivity (EC) and alkalinity were determined in situ, in 27 groundwater wells. The hardness, chloride ions (Cl−), free chlorine (Cl2), total dissolved solids (TDS) and bicarbonates (HCO3−), were determined in the laboratory. The high content of bicarbonate ions (HCO3−) is associated with the alteration of silicates and the presence of chloride ions (Cl−) due to the anthropogenic activity. The highest value of fluoride ions (F−) (1.31 mg/L) was identified in a well of the Lerma-Chapala basin and in 25% of the samples (1.056 mg/L) of the Valley of México basin. The groundwater in the Lerma-Chapala basin is of the Ca-HCO3 type and the water in the Valley of Mexico basin is Na-HCO3 and Ca-HCO3. According to the Gibbs diagram, the water of the Toluca Valley aquifer is recharged by local meteoric precipitation and consequent the water-rock interaction occurs. The correlation analysis shows the significant relationship between F− and CE (R = 0.5933), F− and alkalinity (R = 0.6924), F− and HCO3− (R = 0.6924) and F− and TDS (R = 0.5933). The correlations confirm that the content of fluoride ions present in groundwater is associated with high concentrations of bicarbonate ions and the presence of sodium, due to a process of alteration of the silicates.

Experimental study of nanoparticles as catalyst in enhancing matrix acidizing for carbonate reservoir

Hydrochloric (HCl) acid is the most common stimulating fluid used in acidizing job due to its strong acidic property and low cost to create or enlarge existing wormhole within the reservoir. However, the HCl acid has rapid reaction with carbonate reservoir, and it is causing surface dissolution of the rock and lowering the penetration into the formation. Recent studies have shown the addition of nickel nanoparticles as catalyst to handle the problems in HCl acidizing. The nanoparticles are high-performance catalyst due to their high ratio of surface area to volume. The proposed method in this research is to mix the nanoparticles with the carbonate formation prior to the acid injection into the formation. The efficiency of the nanoparticles as catalyst depends on the thermodynamics property, which is surface energy of the materials used. The surface energy reduces as the size of particles become smaller. However, the effect of surface energy become insignificant on nanoparticles due to the small particles sizes, and the surface energy is based on the individual energy of the particles. Therefore, this research investigates the efficiency of silica, aluminum oxide, and zinc oxide besides nickel nanoparticles based on their thermodynamics property in accelerating the conversion of CO2 gas into carbonic acid. The approach consists of investigating the efficiency of nanoparticles in different concentrations of carbonate and mass of nanoparticles. Suitable nanoparticles are proposed based on efficiency and cost in retarding the HCl reactivity and rapid formation of in situ carbonic acid. The concentration of carbonic acid (H2CO3), bicarbonate ion (HCO3−), and carbonate ion (CO32−) is analyzed based on Henry’s law of solubility. The result shows that the silica has the best efficiency as catalyst in 6700 ppm Na2CO3 solution due to its high stability and dispersion in aqueous solution. The silica engages into rapid dissociation of water molecules and bind with OH− group to react with CO2 gas and form HCO3−. The nanoparticles reduce the reactivity of HCl through conversion of bicarbonate ions. However, ZnO gives better efficiency in 17,000 ppm of Na2CO3. The efficiency of silica in this concentration increased at 0.7 g, proving the minimum amount required as catalyst. In contrast, ZnO and Al2O3 have lower efficiency as acid retarder since changes in pH values affect the performance of the nanoparticles. The surface charge demonstrated by ZnO and Al2O3 depends on pH changes which makes these nanoparticles to perform inefficiently. The silica is chosen as the best catalyst due to high efficiency versus cost ratio.Graphical

How does aquatic macrophyte Salvinia auriculata respond to nanoceria upon an increased CO2 source? A Fourier transform-infrared photoacoustic spectroscopy and chlorophyll a fluorescence study

With the continued increase of technological uses of cerium oxide nanoparticles (CeO2 NPs or nanoceria) and their unregulated disposal, the accumulation of nanoceria in the environment is inevitable. Concomitantly, atmospheric carbon dioxide (CO2) levels continue to rise, increasing the concentrations of bicarbonate ions in aquatic ecosystems. This study investigates the influence of CeO2 NPs (from 0 to 100 μgL−1) in the presence and absence of an elevated bicarbonate (HCO3−) ion concentration (1 mM), on vibrational biochemical parameters and photosystem II (PSII) activity in leaf discs of Salvinia auriculata. Fourier transform-infrared photoacoustic spectroscopy (FTIR-PAS) was capable of diagnostic use to understand biochemical and metabolic changes in leaves submitted to the CeO2 NPs and also detected interactive responses between CeO2 NPs and HCO3− exposure at the tissue level. The results showed that the higher CeO2 NPs levels in the presence of HCO3− increased the non-photochemical quenching (NPQ) and coefficient of photochemical quenching in dark (qPd) compared to the absence of HCO3. Moreover, the presence of HCO3− significantly decreased the NPQ at all levels of CeO2 NPs demonstrating that HCO3− exposure may change the non-radiative process involved in the operation of the photosynthetic apparatus. Overall, the results of this study are useful for providing baseline information on the interactive effects of CeO2 NPs and elevated HCO3− ion concentration on photosynthetic systems.

The Effects of Endurance Exercise in Hypoxia on Acid-Base Balance, Potassium Kinetics, and Exogenous Glucose Oxidation.

PurposeTo investigate the carbohydrate metabolism, acid–base balance, and potassium kinetics in response to exercise in moderate hypoxia among endurance athletes.MethodsNine trained endurance athletes [maximal oxygen uptake (VO2max): 62.5 ± 1.2 mL/kg/min] completed two different trials on different days: either exercise in moderate hypoxia [fraction of inspired oxygen (FiO2) = 14.5%, HYPO] or exercise in normoxia (FiO2 = 20.9%, NOR). They performed a high-intensity interval-type endurance exercise consisting of 10 × 3 min runs at 90% of VO2max with 60 s of running (active rest) at 50% of VO2max between sets in hypoxia (HYPO) or normoxia (NOR). Venous blood samples were obtained before exercise and during the post-exercise. The subjects consumed 13C-labeled glucose immediately before exercise, and we collected expired gas samples during exercise to determine the 13C-excretion (calculated as 13CO2/12CO2).ResultsThe running velocities were significantly lower in HYPO (15.0 ± 0.2 km/h) than in NOR (16.4 ± 0.3 km/h, P < 0.0001). Despite the lower running velocity, we found a significantly greater exercise-induced blood lactate elevation in HYPO compared with in NOR (P = 0.002). The bicarbonate ion concentration (P = 0.002) and blood pH (P = 0.002) were significantly lower in HYPO than in NOR. There were no significant differences between the two trials regarding the exercise-induced blood potassium elevation (P = 0.87) or 13C-excretion (HYPO, 0.21 ± 0.02 mmol⋅39 min; NOR, 0.14 ± 0.03 mmol⋅39 min; P = 0.10).ConclusionEndurance exercise in moderate hypoxia elicited a decline in blood pH. However, it did not augment the exercise-induced blood K+ elevation or exogenous glucose oxidation (13C-excretion) compared with the equivalent exercise in normoxia among endurance athletes. The findings suggest that endurance exercise in moderate hypoxia causes greater metabolic stress and similar exercise-induced elevation of blood K+ and exogenous glucose oxidation compared with the same exercise in normoxia, despite lower mechanical stress (i.e., lower running velocity).

Acid‐Base Balance: Back to Basics

For decades students have struggled to understand the complexities of acid‐base balance. Facts must be learned, but more importantly concepts must be mastered. To complicate this issue, the student must appreciate the interactions between respiratory physiology, renal physiology, and the complexities involved in acid dissociation and buffering capability. The Davenport diagram provides a graphic representation of the Henderson‐Hasselbalch equation giving students a visual tool useful in understanding these complex interactions. One of the least understood components of this graph is the buffer line. The slope of the buffer line is determined by the amount of fixed buffers in the body which can decrease the extent to which new hydrogen ions alter pH. A rapid decrease in ventilation adds additional CO2 and produces acute respiratory acidosis. As can be seen on the ordinate of the Davenport diagram, the bicarbonate ion concentration can easily increase 3–4mEq/l. As this occurs, an equal amount of hydrogen ion is also produced. If it was not for the presence of fixed buffers, this would result in plasma pH≈3. The current teaching approach employs the van't Hoff Equation and the accepted rate of CO2 production in a normal individual. Using these values, it can be demonstrated that the amount of bicarbonate ions produced by reduced respiration is capable of increasing plasma bicarbonate ion by 3–4 mEq/l in several minutes. This increase in bicarbonate is independent of renal function.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The relationships among some chemical and physical soil traits and coastal dune plant species in Central Black Sea Region of Turkey

Coastal dunes are very prone to environmental changes and they are very vulnerable ecosystems. Coastal dune vegetation in the north of Turkey cover a comparatively wide area (149 km) and they include most of the characteristic coastal dune zones. However, they are threatened by disturbance factors and most significant of these are inundation and dune erosion especially in drift line. In the present study, the relationships between some chemical and physical traits and coastal dune species in characteristic dune zones were investigated in Central Black Sea Region of Turkey. Soil reaction (pH), sodium adsorption ratio (SAR), organic matter content (% OM), potassium ion (K+) concentration, bicarbonate ion (HCO3−) concentration and coarse and very fine sand contents were found to be the most significant abiotic factors along seashore to inland gradient in studied coastal dunes. Medium sand and OM contents were associated with main and transitional dunes, while pH and SAR were associated with drift line and embryonic dune zones.

Studies on novel nano-bimetal doped cellulose nanofibers derived from agrowaste towards deflouridation.

Cellulose nanofibers were extracted from sugarcane bagasse. Zerovalent‑iron (ZVI)/Zirconium(IV) (Zr)/ZVI-Zr doped cellulose nanofibers were prepared, characterized and evaluated for fluoride removal. The prepared nanofibers could effectively remove fluoride within a wide pH range of 3.0 to 8.0. The equilibrium reached within 3 h and the adsorption capacities followed the order ZrZVICNF > ZrCNF > ZVICNF. The Langmuir adsorption capacity of ZrZVICNF was 35.70 mg/g, much higher than various commercial adsorbents. Nitrate, chloride, sulphate, phosphate, has insignificant effect on fluoride adsorption and higher concentrations of bicarbonate and silicate ions affected fluoride sorption. Furthermore insignificant amount of Zr(IV) ions were leached during adsorption owing to its efficient complexation with hydroxyl groups of cellulose and the adsorbent could be successfully regenerated. Spectroscopic analysis revealed that fluoride ion complexed with both Zr(IV) and Fe(II)/Fe(III) ions. Thus high fluoride uptake capacity, faster kinetics, applicability at wide pH range, makes ZrZVICNF as attractive sorbent for defluoridation.