Addition Of Bicarbonate Research Articles

Effects of sodium bicarbonate on the gel properties, water distribution and mobility of low-salt pork batters

To study the potential use of sodium bicarbonate in low-salt pork batters, the gel properties, rheology and water holding capacity of pork batters with various amounts of sodium chloride (0.7–1.74%) and sodium bicarbonate (0–0.42%) were investigated. The results showed that the pH, salt-soluble protein concentration, cooking yield, b* values and G′ values at 80 °C were significantly (P < 0.05) increased in the batters with sodium bicarbonate. Their textural properties were significantly (P < 0.05) increased, except for 0.42% sodium bicarbonate. Partial replacement of sodium chloride by sodium bicarbonate increased the denaturation temperature of the myosin tails, and the relaxation times of T2b, T21 and T22 were faster (P < 0.05). The mobility of the water was lower, and the immobilized water was increased, except at 0.42% sodium bicarbonate. Excessive addition of sodium bicarbonate produced carbon dioxide that destroyed the gel structure during heating. Overall, partial replacement of sodium chloride by sodium bicarbonate enabled low-salt pork batters to have a better water holding capacity and textural properties.

Cassava Processing Into “Attiéké” (A West Africa Fast Food): Wastewater Quantification and Pretreatment Using Two Fermentative Additives (Saccharomyces Cerevisiae and Sodium Bicarbonate)

The need for alternative energy sources rises steeply researches on residual agricultural biomass. Artisanal processing of agricultural products in the agri-food chains represent an essential pollution source in most emerging countries and get interest also in the energy sector. The present study final objective enables to convert wastewater from cassava processing in Attiéké, a traditional food largely consumed in West Africa, to energy in a cheapest way. To achieve the purpose, cassava processing wastewater pH and biodegradability was improved to perform an anaerobic digestion. Hence, two common fermentive and cost effective additives were used. Yeast (organic compound) and Sodium bicarbonate (inorganic compound) effect were compared at different amounts mix with the same quantity of cassava wastewater. The experiments were carried out in triplicate. The best pH result was obtained from 7g of Saccharomyces cerevisiae per liter of cassava wastewater which increased the pH from 3.83 to 4.57. While 40 g Sodium bicarbonate per liter of cassava waster, increased the pH to maximum 4.17. In anaerobic environment after 15 days, Sodium bicarbonate addition (5g, 10g, 20g and 40g) increase the carbon fraction thus the mixture biodegradability but not gas production. The best additive was found to be Saccharomyces cerevisiae in comparison to Sodium bicarbonate. Results should help when to choose a cost effective additive for cassava wastewater pretreatment prior anaerobic co-digestion of cassava wastewater.

Adult cardiopulmonary bypass in Australian and New Zealand public hospitals: A survey of practice.

A telephone survey of cardiac anaesthetists and perfusionists at the 29 public hospitals providing adult cardiac surgical services in Australia and New Zealand was carried out between December 2019 and January 2020. The aim was to investigate current practice with regard to selected contentious elements of anaesthetic and perfusion management during cardiopulmonary bypass; primarily relating to bypass circuit priming, blood conservation methods and point-of-care coagulation testing. There was a 100% response rate. The average number of adult public cardiopulmonary bypass cases per hospital was 508 (160-1400). For cardiopulmonary bypass cases, ten hospitals (34%) routinely used a cell saver and the remainder used a cell saver selectively. Residual blood remaining in the cardiopulmonary bypass circuit was processed using a cell saver routinely in four hospitals (14%) and selectively in 23 (79%). Acute normovolaemic haemodilution was rarely used. Retrograde autologous priming was used routinely in seven hospitals (24%) and selectively in 16 (55%). All hospitals had access to point-of-care coagulation testing. The majority of hospitals targeted an activated clotting time of 480 s (range 400-500 s) prior to commencing cardiopulmonary bypass. There was marked geographic variation in access to fibrinogen concentrate. The cardiopulmonary bypass circuit prime solution was primarily a balanced crystalloid in most hospitals; however, there was significant variation regarding the addition of human albumin, mannitol, sodium bicarbonate and other medications. Many of the interventions examined were used on a case-by-case basis. These findings support the need for further research to define more evidence-based practice of these interventions.

Homoacetogenesis and solventogenesis from H2/CO2 by granular sludge at 25, 37 and 55 °C

CO2 fermentation is a promising process to produce biofuels like ethanol. It can be integrated in third generation biofuel production processes to substitute traditional sugar fermentation when supplied with cheap electron donors, e.g. hydrogen derived from wind energy or as surplus gas in electrolysis. In this study, granular sludge from an industrial wastewater treatment plant was tested as inoculum for ethanol production from H2/CO2 via non-phototropic fermentation at submesophilic (25 °C), mesophilic (37 °C) and thermophilic (55 °C) conditions. The highest ethanol concentration (17.11 mM) was obtained at 25 °C and was 5-fold higher than at 37 °C (3.36 mM), which was attributed to the fact that the undissociated acid (non-ionized acetic acid) accumulation rate constant (0.145 h−1) was 1.39 fold higher than at 25 °C (0.104 h−1). Methane was mainly produced at 55 °C, while neither acetic acid nor ethanol were formed. Ethanol production was linked to acetic acid production with the highest ethanol to acetic acid ratio of 0.514 at 25 °C. The carbon recovery was 115.7%, 131.2% and 117.1%, while the electron balance was almost closed (97.1%, 110.1% and 109.1%) at 25 °C, 37 °C and 55 °C, respectively. The addition of bicarbonate inhibited ethanol production both at 25 °C and 37 °C. Clostridium sp. were the prevalent species at both 25 and 37 °C at the end of the incubation, which possibly contributed to the ethanol production.

The combined effects of alkali treatment and ammonium bicarbonate addition on selected properties of MDF panels

Effects of alkali treatment and ammonium bicarbonate were studied relative to selected properties of medium-density fiberboard (MDF) panels. Wood fibers were subjected to alkali treatment with sodium hydroxide or sodium perborate monohydrate (SPM). The MDF panels were produced from untreated and alkali treated fibers with or without ammonium bicarbonate (ABC). The modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding (IB), thickness swelling (TS), water absorption (WA), and limiting oxygen index (LOI) of the MDF were analyzed. The mechanical, physical, and fire resistance properties of MDF samples showed differences depending on the experimental parameters used. The lowest TS and WA values were found in the untreated-control group. The highest value for MOR and MOE was found for the group with the addition of 8% ABC. The IB values generally were higher than the untreated-control value. The highest value was determined in the group ABC8. Remarkably higher LOI values were achieved in the LOI test, especially for the groups with the application of both alkali treatment and ammonium bicarbonate.

Carbon limitation in hypereutrophic, periphytic algal wastewater treatment systems.

Global eutrophication degrades water quality in freshwater ecosystems and limits the availability of freshwater for human consumption. While current wastewater treatment facilities (WWTF) remove pathogens and pollutants, many US WWTF continue to discharge nutrients that contribute to eutrophication. Traditional nutrient removal technologies can effectively reduce eutrophication risk, but can have unintended negative consequences on human and environmental health. Alternatives, such as algae-based treatment systems, improve the sustainability of the nutrient recovery process by producing biomass that can be converted to biofuel. However, research is needed to increase the productivity of algal treatment systems to improve their economic viability. Because algae in wastewater treatment systems are grown in wastewater rich in nutrients, the algae could become limited by dissolved inorganic carbon. This hypothesis was tested in 1.2 m long recirculating floways (n = 8 for each treatment/control) by quantifying algal dry mass and wastewater nutrient concentrations in 3 independent experiments: (1) carbon dioxide gas infused vs air infused control; (2) hydrochloric acid acidified vs neutralized solution control vs no chemical addition control; and (3) sodium bicarbonate addition vs no chemical control. Results showed increases in algal biomass after 18 days in wastewater augmented with dissolved inorganic carbon (carbon dioxide or sodium bicarbonate). In contrast, maintaining wastewater at near neutral pH with hydrochloric acid reduced algal productivity relative to controls. Nutrient reductions generally paralleled algal biomass increases except in the bicarbonate addition experiment. These findings provide evidence for the importance of carbon limitation in algal wastewater treatment floways. These results could help explain why carbon dioxide infusions stimulate algae in treatment systems. Furthermore, these results suggest that algae in nutrient enriched, sun-exposed streams (e.g., agricultural ditches or urbanized streams) may become carbon limited during peak periods of productivity. These findings could have important implications for ecosystems undergoing eutrophication as atmospheric carbon dioxide concentrations continue to rise.

Involvement of oviduct in sperm capacitation and oocyte development in pigs

An overview is presented on the structure and function of the pig oviduct in relation to sperm capacitation and oocyte development in vivo. In pigs, a functional sperm reservoir is established in the uterotubal junction-isthmus when sperm deposition occurs before ovulation. Capacitation is assumed to occur in this location, and spermatozoa progress towards the ampullaryisthmic junction at about the time of ovulation as a consequence of capacitation and hyperactivation. Preliminary data from our laboratory on viable spermatozoa retrieved from the sperm reservoir and the ampullaryisthmic junction of mated sows at pre- and periovulation oestrus showed that the largest subpopulation (60-90%) was of uncapacitated spermatozoa (using merocyanine-540), whereas 6-37% of the gated cells were capacitated spermatozoa. Incubation in a capacitation-inducing medium (bicarbonate-containing modified Brackett-Oliphant medium; mBO) for < 30 min effected capacitation readily, more markedly in ampullary-isthmic junction samples than in samples from the uterotubal junction, thereby indicating that uncapacitated spermatozoa responded to the addition of the effector bicarbonate at concentrations similar to those recorded in the periovulatory ampullary-isthmic junction in vivo. Addition of preovulatory isthmic oviductal fluid and hyaluronan under a similar incubation regimen maintained tubal sperm viability without obvious induction of capacitation. This finding indicates that, before ovulation, the intraluminal fluid of the sperm reservoir might delay sperm capacitation, perhaps because of its hyaluronan content. Evidence is presented that the sperm population in the oviduct undergoes capacitation under particular conditions in the upper tuba! compartments. The diverse response of spermatozoa to capacitation stimuli helps to ensure full rates of fertilization in vivo. Data are also provided on the importance of final zona pellucida maturation in the pig oviduct to warrant proper zona pellucida reaction after sperm penetration, which would address in part the abnormal occurrence of polyspermy in in vitro fertilization of pigs.

Effect of Sodium Bicarbonate Additions on the Physical, Mechanical and Bioactive Property of Sol-Gel Bioglass

Porous bioceramics are the materials of choice for non-load bearing bone implants. Calcium phosphates and bioglass are widely used due to excellent biocompability. The primary function of porous bioceramics are as filler material for bone defects. In this research, 10% amount of sodium bicarbonates (Na2HCO3) were mixed with sol-gel derived glass powder (SiO2-CaO-P2O5) and sintered at 700 °C for 3 hours. It was found that, additions of sodium bicarbonate induced a foaming effect during sintering of bioglass thus increased the porosity content of the glass-ceramics obtained. However, the increased in porosity significantly reduced the compressive strength of the crystallized glass. The increased in porosity content and formation of sodium related phases within the crystallized glass matrix after sintering resulted in enhancement of its in vitro bioactivity property when tested in SBF solution.

S0131 Addition of Serum Bicarbonate and Anion Gap to Bedside Index of Severity in Acute Pancreatitis Score Do Not Improve Its Predictive Performance

INTRODUCTION: Reliable and easy to use clinical prediction score is important in optimal management of acute pancreatitis. Currently, Bedside Index of Severity in Acute Pancreatitis (BISAP) score is the most accurate and easy to use clinical prediction score for acute pancreatitis (AP). Patients with AP are often hypovolemic at the time of presentation, which is a contributing factor to AP associated multi-organ dysfunction. We hypothesize that an elevated serum bicarbonate level and anion gap, which are readily available in most clinical settings, could improve performance of the BISAP score. Here, we assessed the performance of BISAP including serum bicarbonate in prognosticating moderate and severe acute pancreatitis. METHODS: Consecutive adults with acute pancreatitis admitted to our academic and two community hospitals between Jan 2014 and Dec 2019 were included in this study. We excluded patients with pregnancy or with diseases independently affecting their bicarbonate level (i.e., diabetic ketoacidosis, chronic renal failure stage 4 and 5). In cases of recurrent pancreatitis, only the initial episode was included. The severity of pancreatitis was defined based on the revised Atlanta classification: mild, moderate and severe. Performance of BISAP with and without bicarbonate levels and the anion gap was assessed using the ROC analysis. RESULTS: During the study period, 3 hospitals together had 653 admission for acute pancreatitis; a total of 444 unique patient admission were included. Of these, 316 patients had mild, 94 moderate and 34 patients had severe AP. Clinical characteristics of the cohort by severity of pancreatitis are summarized in Table 1. Bicarbonate levels were slightly lower in patients with moderate to severe acute pancreatitis, P = 0.038). The area under the curve (AUC) for BISAP score was 0.87 (95% CI 0.81–0.93) for severe and 0.72 (0.67–0.77) for moderate and severe pancreatitis combined. Inclusion of bicarbonate levels and the anion gap into BISAP improved AUC to 0.88 (0.81–0.95) and 0.89 (0.84–0.95), respectively (Table 2). This difference was not statistically significant. CONCLUSION: Inclusion of serum bicarbonate levels and the anion gap to the BISAP score did not improve its performance significantly.Table 1.: Clinical and laboratory characteristicsTable 2.: Discrimination by predictors—Two Revised Atlanta Classification

Experimental Study on the Dissolution Behavior of Calcium Fluoride

The presence of halogens has an adverse effect on the zinc extraction process through electrowinning, the last phase of the RLE (Roasting, Leaching and Electrowinning) zinc extraction route. Fluoride (F−) may be present as calcium fluoride (CaF2) and this is, for example, the case in double leached Waelz oxide (DLWO). Efficient removal of F− from primary and secondary raw materials for zinc extraction results in a simplified process and increases flexibility in the selection of raw materials. Understanding of the solubility behavior of pure CaF2 can give valuable information on treatment for maximized halogen removal. Dissolution of CaF2 was studied with the addition of sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3). Dissolution studies were combined with thermodynamic calculations to understand the solubility behavior of CaF2 under different conditions. Results from the experiments and the thermodynamic calculations show that Na2CO3 and NaHCO3 have similar behavior if the pH is controlled at the same value. The available carbonate (CO32−) ion in the system limits the concentration of calcium (Ca2+) ion by precipitation of CaCO3, which enhances the dissolution of CaF2. At higher temperatures and pH, calcite, vaterite, and aragonite were formed and co-precipitation of CaF2 along with calcium carbonate (CaCO3) was observed. At lower temperatures and lower pH levels, only calcite and vaterite were formed and a coating by CaCO3 on CaF2 was found to hinder complete dissolution reaction. The results of this study indicate that the temperature along with the reagents used for the dissolution tests have a significant impact on the CaCO3 polymorph mixture (calcite, vaterite and aragonite) formation.

Effect of Various Bicarbonate Supplements on Biodiesel Production and Valuable Biochemical Components of the Marine Eustigmatophyceae Nannochloropsis oculata (Droop)

Microbial breeding media must be cost-effective, enable high growth, meet exact requirements and be readily available. The effect of different levels of sodium bicarbonate (SB) [25, 50, 75 and 100%] in the growth medium on the biochemical constituents (protein, carbohydrates, lipids, fatty acids, and amino acids) of the Nannochloropsis oculata was assessed compared to the F/2 Guillard standard medium. The obtained results revealed that the chemical constituents of N. oculata were influenced by the used level of sodium bicarbonate. The highest total protein, carbohydrate contents, and the maximum percentage of essential amino acids (EAA) (59.68 %) were obtained by using the B1 medium (25% SB) as compared to the control (100% F/2). The highest total lipid content was achieved by using the B4 medium (100% SB) producing (20.09 %). In accordance, the highest total saturated fatty acids percentage (TSFA) of N. oculata was recorded by B4 medium. However, the highest total unsaturated fatty acids percentage (USFA) was exhibited by the B1 medium. The EN 14214 and ASTM D-6751 analyzes of the production of biodiesel have shown that the produced biodiesel by B4 medium (100% SB) and the control media of high quality. In conclusion, the addition of sodium bicarbonate is an excellent policy to increase chemical composition and lipid accumulation. The present study recommended taming results foreither biodiesel production or aquaculture feeding by using proposed B4 medium as a lipid promoter or B1 medium as a protein promoter.

The PsbT protein modifies the bicarbonate-binding environment of Photosystem II

ABSTRACT Photosystem II is the pigment–protein complex that oxidises water and reduces plastoquinone in oxygenic photosynthesis. Each Photosystem II complex contains four core proteins surrounded by 13 low-molecular-weight proteins. The 5-kDa PsbT protein is one of the subunits found at the interface of functional Photosystem II dimers. We previously observed that deletion of PsbT in the cyanobacterium Synechocystis sp. PCC 6803 slowed electron transfer and increased the susceptibility of Photosystem II to photodamage and that the addition of bicarbonate (or ) could prevent this photodamage. Bicarbonate is an essential Photosystem II cofactor that binds to a non-heme iron found between the QA and QB plastoquinone electron acceptors. Formate can bind to the non-heme iron thereby displacing bicarbonate and this results in blocked electron transfer and impaired oxygen evolution. We show Synechocystis sp. PCC 6803 cells lacking PsbT exhibit an enhanced sensitivity to formate addition, while formate inhibition of oxygen evolution in these cells is reversed by the addition of bicarbonate. Our results suggest that binding is weakened in ΔPsbT cells and that PsbT plays a key role in maintaining the HCO3 –-iron-quinone electron-acceptor complex of Photosystem II and consequently moderates the susceptibility of Photosystem II to high-light-induced photodamage.

Influence of substrate concentration and bicarbonate addition on the anaerobic digestion of an inulin-rich substrate as the ending stage in a dandelion biorefinery scheme

This study was focused on the suitability of dandelion plant as part of a biorefinery scheme in which anaerobic degradation (biomethanization) for biogas production is the ending process. Inulin as the main compound in the tuberous root was selected as substrate and tested at different concentrations (5, 10 and 15 g TS L−1). The presence of bicarbonate as a buffer on anaerobic digestion was assessed as well. Methane production curves were fitted with the modified Gompertz equation. Methane production yield (YCH4), specific maximum methane production rate (SRMAX) and the first-order hydrolysis constant (kH) were affected by the substrate concentration. Bicarbonate was found not to be determinant for the overall biomethanization process because no significant effect over the YCH4was achieved in the presence or absence of bicarbonate; between 0.19 to 0.23 m3 kg-1 VS added. However, kHand SRMAX were affected by the presence of this inorganic compound. Without the addition of bicarbonate, kHand SRMAX decreased as the TS increased. These results will be key for a dandelion biorefinery proof-of-concept under the proposed conditions.

Changes in pH and dissolved inorganic carbon in water affect the growth, saxitoxins production and toxicity of the cyanobacterium Raphidiopsis raciborskii ITEP-A1

Raphidiopsis raciborskii is a widely distributed, potentially toxic cyanobacterium described as a tropical-subtropical species. However, its occurrence in temperate regions has been expanding. Understanding the environmental factors underlying the expansion and colonization success of Raphidiopsis has been the object of numerous studies. However, less is known regarding its responses to pH and inorganic carbon in water. Thus, the aim of the present study was to investigate the effects of changes in pH and dissolved inorganic carbon on growth and saxitoxins production in the strain R. raciborskii ITEP-A1. We incubated batch cultures with different unbuffered and buffered pH (neutral-acid and alkaline) and inorganic carbon availability (CO2-rich air bubbling and the addition of NaHCO3) to assess the effect of these factors on the growth, toxin production as well as saxitoxins composition of the cyanobacterium. The carbon concentrating mechanism (CCM) system of ITEP-A1 was also characterized by an in silico analysis of its previously sequenced genome. The growth and saxitoxins production of R. raciborskii were affected. The addition of sodium bicarbonate and air bubbling enhanced the growth of the cyanobacterium in alkaline pH. In contrast, saxitoxins production and relative toxicity were decreased. Moreover, significant changes in the cellular composition of saxitoxins were strongly related to pH changes. ITEP-A1 potentially expresses the low-flux bicarbonate transporter BicA, an efficient CCM which uptakes most of its carbon from HCO3−. Hence, increasing the diffusion of CO2 in alkaline eutrophic lakes is likely to increase R. raciborskii dominance, but produce less toxic blooms.

Rapid and Positive Effect of Bicarbonate Addition on Growth and Photosynthetic Efficiency of the Green Microalgae Chlorella Sorokiniana (Chlorophyta, Trebouxiophyceae)

Bicarbonate ions are the primary source of inorganic carbon for autotrophic organisms living in aquatic environments. In the present study, we evaluated the short-term (hours) effects of sodium bicarbonate (NaHCO3) addition on the growth and photosynthetic efficiency of the green algae Chlorella sorokiniana (211/8k). Bicarbonate was added to nonaxenic cultures at concentrations of 1, 2, and 3 g L−1 leading to a significant increase in biomass especially at the highest salt concentration (3 g L−1) and also showing a bactericidal and bacteriostatic effect that helped to keep a reduced microbial load in the algal culture. Furthermore, bicarbonate stimulated the increase in cellular content of chlorophyll a, improving the photosynthetic performance of cells. Since microalgae of genus Chlorella spp. show great industrial potential for the production of biofuels, nutraceuticals, cosmetics, health, and dietary supplements and the use of bicarbonate as a source of inorganic carbon led to short-term responses in Chlorella sorokiniana, this method represents a valid alternative not only to the insufflation of carbon dioxide for the intensive cultures but also for the production of potentially bioactive compounds in a short period.

Severe Coastal Hypoxia Interchange with Ocean Acidification: An Experimental Perturbation Study on Carbon and Nutrient Biogeochemistry

Normally atmospheric CO2 is the major driver of ocean acidification (OA); however, local discharge/degradation of organic matter (OM) and redox reactions can exacerbate OA in coastal areas. In this work we study the response of nutrient and carbon systems to pH decrease in relation to hydrographically induced intermittent characteristics and examine scenarios for future ocean acidification in a coastal system. Laboratory microcosm experiments were conducted using seawater and surface sediment collected from the deepest part of Elefsis Bay; the pH was constantly being monitored while CO2 gas addition was adjusted automatically. In Elefsis Bay surface pCO2 is already higher than global present atmospheric values, while near the bottom pCO2 reaches 1538 μatm and carbonate saturation states were calculated to be around 1.5. During the experiment, in more acidified conditions, limited alkalinity increase was observed and was correlated with the addition of bicarbonates and OM. Ammonium oxidation was decelerated and a nitrification mechanism was noticed, despite oxygen deficiency, paralleled by reduction of Mn-oxides. Phosphate was found significantly elevated for the first time in lower pH values, without reprecipitating after reoxygenation; this was linked with Fe(II) oxidation and Fe(III) reprecipitation without phosphate adsorption affecting both available dissolved phosphate and (dissolved inorganic nitrogen) DIN:DIP (dissolved inorganic phosphate)ratio.

Effect of added calcium and heat setting on gel forming and functional properties of Sardinella fimbriata surimi.

Present study evaluates the effect of calcium and heat setting on gel characteristics of lesser sardine (Sardinella fimbriata) surimi. Total seven formulations were made namely, S. fimbriata minced meat without heat setting (A1), minced meat with heat setting (A2), S. fimbriata surimi control (without addition of calcium) without heat setting (B1), control (without addition of calcium) with heat setting (B2), surimi added with 0.3% calcium without heat setting (C1) and surimi added with calcium with heat setting (C2) and refiner meat without addition of calcium and with addition of sodium bicarbonate (D). C1 exhibited gel strength of 329gcm (Grade KA) whereas C2 sample exhibited gel strength of 556.2gcm (Grade AA) as a result of gel setting at 35°C for 45min. Textural parameters such as hardness, chewiness, gumminess and cohesiveness were improved in C2 when compared with all other formulations. Addition of calcium and sodium bicarbonate significantly improved whiteness of surimi with gel setting in comparison to other treatments (p < 0.05). C2 samples exhibited reduced thio barbituric acid (TBA) values indicating lower oxidation. Results indicated potential for use of fish species with high fat content and darker meat for surimi manufacture with gel setting of sol and addition of sodium bicarbonate and calcium as ingredients.

On Increasing Powder Carbon Steels Properties Using Activating Additives

In this paper, the possibility of increasing powder carbon steels properties by activation of carbon diffusion into the iron base during sintering process due to the introduction of the thermally split graphite (TSG), macromolecular compounds (MC) and sodium bicarbonate was investigated. It was found that the introduction of these additives allows obtaining homogeneous structures at a sintering temperature of 100–200 °C lower than that traditionally used for sintering of powder carbon steels. Such structures provide increased mechanical properties of powder carbon steels. The addition of sodium bicarbonate increases the diffusion rate of carbon into iron at a temperature of &lt;i&gt;950 C&lt;/i&gt; by 1.8 times, at &lt;i&gt;1000 °C&lt;/i&gt; by 1.5 times, and at 1100 °&lt;i&gt;C&lt;/i&gt; by 1.2 times.

Scope and Predictive Genetic/Phenotypic Signatures of Bicarbonate (NaHCO3) Responsiveness and β-Lactam Sensitization in Methicillin-Resistant Staphylococcus aureus.

Addition of sodium bicarbonate (NaHCO3) to standard antimicrobial susceptibility testing medium reveals certain methicillin-resistant Staphylococcus aureus (MRSA) strains to be highly susceptible to β-lactams. We investigated the prevalence of this phenotype (NaHCO3 responsiveness) to two β-lactams among 58 clinical MRSA bloodstream isolates. Of note, ∼75% and ∼36% of isolates displayed the NaHCO3 responsiveness phenotype to cefazolin (CFZ) and oxacillin (OXA), respectively. Neither intrinsic β-lactam MICs in standard Mueller-Hinton broth (MHB) nor population analysis profiles were predictive of this phenotype. Several genotypic markers (clonal complex 8 [CC8]; agr I and spa t008) were associated with NaHCO3 responsiveness for OXA.

Bicarbonate: the alternative buffer for peritoneal dialysis.

For a long time bicarbonate, the physiological buffer of the body, was suggested to be the best buffer for peritoneal dialysis. However, since the production of bicarbonate-containing solutions is associated with technical problems, lactate was favored. To avoid the well-known disadvantages of lactate solution concerning biocompatibility and possible metabolic side effects, different attempts have been made to use bicarbonate as a buffer in peritoneal dialysis. One of the major approaches was the total replacement of lactate by bicarbonate combined with storage of the fluid in a specially designed double-chamber bag. Further solutions of the above-mentioned problem were the on-line preparation of bicarbonate fluids for intermittent peritoneal dialysis, the addition of bicarbonate just before use, the combination of bicarbonate with organic acids, or its combination with the dipeptide glycylglycine as a stabilizing agent. By now, the beneficial effect of the neutral bicarbonate fluid, for example, on cell viability and cell functions, has been demonstrated in many different in vitro and animal studies. However, only few reports on clinical experience have been published. These investigations demonstrated independently that bicarbonate fluids diminish inflow pain, are well tolerated by the patients, and may correct metabolic acidosis of uremic patients. A controlled randomized multicenter trial using 34 mmol/L bicarbonate for at least three months confirmed that bicarbonate is as efficacious as lactate in equimolar concentrations. Concomitant investigations on energy metabolism and redox state of red blood cells and phospholipid secretion of mesothelial cells additionally demonstrated the improvement of cell function with bicarbonate solutions. For some patients with severe metabolic acidosis the bicarbonate concentration used in the multicenter trial seemed to be too low. Thus, a fluid containing a higher bicarbonate concentration was tested in a pilot study resulting in the expected significant increase of arterial bicarbonate levels. In summary, bicarbonate-containing peritoneal dialysis solutions are a promising alternative to lactate, especially if bicarbonate concentrations are adjusted individually to the patient's need.