Acid-base Parameters Research Articles

Bolus exposure as a novel predictor of postoperative symptom resolution after laparoscopic nissen fundoplication: A two-institutional retrospective cohort study.

Even in the absence of definite evidence of pathological acid reflux, antireflux surgery (ARS) can still effectively improve gastroesophageal reflux symptoms. Nonetheless, predicting postoperative reflux symptom improvement has been primarily dependent on acid-based parameters. No objective index reflecting both acid and non-acid reflux was identified to select ARS candidates. Prospectively collected data of 121 patients with gastroesophageal reflux disease (GERD), who underwent laparoscopic Nissen fundoplication from two institutions, were retrospectively reviewed. The patients reported preoperative and postoperative GERD symptoms using the Korean version of the GERD questionnaire, along with the gastroesophageal reflux disease-health-related quality of life (GERD-HRQL). The patients assessed for reflux symptoms using bolus exposure, acid exposure time (AET), and DeMeester score (DMS) as measurements were selected. For each reflux parameter, its association, correlation, and predictive capacity of the degree of postoperative symptom resolution were analyzed using chi-squared tests, point-biserial correlations, logistic regression analyses, and receiver operating characteristic curve analyses. 72 patients were eligible for this study. Bolus exposure was superior to the other parameters in terms of the degree of association and correlation with resolution of typical symptoms. Bolus exposure also showed a higher diagnostic accuracy in predicting the resolution of epigastric pain (area under the curve [AUC]=0.723, P=0.013) and regurgitation (AUC=0.981, P<0.001). Secondary analyses were performed in patients without pathological reflux, defined as the DMS-negative (DMS<14.7) or AET-negative (AET<6%) groups. In the secondary analyses, bolus exposure showed considerable diagnostic accuracy with statistical significance for all typical symptoms in both in the DMS-negative (heartburn: AUC=0.717, P=0.025; epigastric pain: AUC=0.717, P=0.025; regurgitation: AUC=0.975, P<0.001) and AET-negative (heartburn: AUC=0.681, P=0.045; epigastric pain: AUC=0.749, P=0.009; regurgitation: AUC=0.975, P<0.001) groups. Bolus exposure, a parameter of total reflux, was superior to AET or DMS in defining candidates for ARS. Further studies investigating the surgical indications for ARS in patients with non-acid reflux using bolus exposure are required.

Exploring the Application of Advanced Chromatographic Methods to Characterize the Surface Physicochemical Properties and Transition Phenomena of Polystyrene-b-poly(4-vinylpyridine)

The linear diblock copolymer polystyrene-b-poly(4-vinylpyridine) (PS-P4VP) is an important copolymer recently used in many applications such as optoelectronics, sensors, catalysis, membranes, energy conversion, energy storage devices, photolithography, and biomedical applications. (1) Background: The surface thermodynamic properties of PS-P4VP copolymers are of great importance in many chemical and industrial processes. (2) Methods: The inverse gas chromatography (IGC) at infinite dilution was used for the experimental determination of the retention volumes of organic solvents adsorbed on copolymer surfaces as a function of temperature. This led to the variations in the free energy of interaction necessary to the evaluation of the London dispersive and polar acid–base surface energies, the polar enthalpy and entropy, the Lewis acid–base constants, and the transition temperatures of the PS-P4VP copolymer. (3) Results: The application of the thermal Hamieh model led to an accurate determination of the London dispersive surface energy of the copolymer that showed non-linear variations versus the temperature, highlighting the presence of two transition temperatures. It was observed that the Lewis acid–base parameters of the copolymer strongly depend on the temperature, and the Lewis base constant of the solid surface was shown to be higher than its acid constant. (4) Conclusions: An important effect of the temperature on the surface thermodynamic properties of PS-P4VP was proven and new surface correlations were determined.

Hyperchloremic metabolic acidosis potentially benefiting sodium bicarbonate therapy: A multi-center cohort study

BackgroundThe use of sodium bicarbonate for metabolic acidosis has been a topic of debate, primarily due to the lack of clinical efficacy evidence. This study aims to identify which types of patients with various acid-base balance parameters can benefit from sodium bicarbonate therapy. MethodsPatients diagnosed with metabolic acidosis were screened from a large multi-center critical care database to form a retrospective cohort. Mortality curves, logistic regression analysis, simulation methods, and propensity scores were used to compare data between sodium bicarbonate (SOB group) and non-treated (Non-SOB group) patients. ResultsThere was an interaction between baseline chloride, anion gap levels and sodium bicarbonate therapy on patients' in-hospital death. As chloride levels increased, the in-hospital mortality curves of the SOB group and Non-SOB group gradually converged, with the difference narrowing from approximately 20 % to 10 %, and then gradually widened with the increase of the anion gap. Furthermore, when patients had high chloride levels (≥112 mmol/L), those in the SOB group exhibited a higher incidence of hypernatremia, hypokalemia, and hypocalcemia at 24 h, and a lower incidence of hyperchloremia. Patients in SOB group also had a lower simulated mortality. Among patients treated with sodium bicarbonate, those with low chloride had more difficulty in normalizing pH compared to those with high chloride. ConclusionsThis study identified an interaction between baseline chloride and sodium bicarbonate therapy on patient survival. Hyperchloremic metabolic acidosis may potentially benefit from sodium bicarbonate therapy. Further prospective randomized controlled studies are warranted.

Acid–base and electrolyte changes in dogs after packed red blood cell transfusion

AbstractBackgroundPacked RBC (pRBC) transfusions are often necessary to enhance organ perfusion and tissue oxygenation in cases of severe anemia.ObjectivesWe aimed to describe changes in acid–base and biochemical parameters in dogs after transfusion of pRBC and potential effects on the outcome.MethodsThe prospective observational study included anemic dogs requiring pRBC transfusions. Venous blood gas and electrolytes were measured pre‐transfusion and repeated within 1 h post‐transfusion. Signalment, pre‐existing conditions and underlying disease(s), number of days spent of hospitalization, the quantity of transfused pRBC units, and the outcome were also recorded. Associations between analytical values and all other parameters before and after transfusion were assessed using the Wilcoxon test. A generalized linear model was generated for each of the blood gas parameters post‐transfusion, including the pre‐transfusion values and the characteristics of the animal as fixed effects. The effect of the blood gas parameters on the mortality and hospitalization length was assessed using logistic regression and generalized linear models, respectively.ResultsTwenty‐six dogs with different causes of anemia were included in the study, with dogs remaining hospitalized for a median of 3 days (range: 0–11). Pre‐transfusion heart rate, respiratory rate, Angap, base excess, and lactate were higher than post‐transfusion values. Post‐transfusion results showed an increase in hematocrit, hemoglobin, HCO3‐, PCO2, tCO2, and chloride. Pre‐transfusion hypophosphatemia and receiving an increased volume of transfused pRBC were associated with a longer hospital stay, while higher pre‐transfusion lactate values were associated with higher mortality.ConclusionspRBC transfusion in anemic dogs was associated with an improvement in perfusion and acid–base parameters. Pre‐transfusion lactate may be an indicator of mortality in dogs.

Comparative Evaluation of 0.9% Normal Saline Versus Acetate-Gluconate-Based Balanced Solution on Acid-Base Status and Postoperative Liver Function in Donor Hepatectomy Patients.

Background Live donor liver transplantation, a widely practiced procedure, involves resecting a portion of a healthy donor's liver for transplantation. Despite advancements, it poses challenges like cardiovascular instability and electrolyte imbalances, with maintaining acid-base balance being critical. This study compares the effects of 0.9% normal saline and PlasmaLyte A® on acid-base status and postoperative liver function. Methodology This prospective observational study was conducted over one year among 40 healthy adults aged 18-60 years undergoing donor hepatectomy. Patients were alternately allocated to receive either 0.9% saline (Group 1; n = 20) or PlasmaLyte A® (Group 2; n = 20). Key parameters, including acid-base status, hemodynamic parameters, and postoperative liver function, were monitored at various intervals. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 25.0 (Released 2017; IBM Corp., Armonk, NY, USA), with appropriate statistical tests. A p-value <0.05 was considered statistically significant. Results The study included 40 patients, with 20 in each group. No significant differences were observed between the groups concerning age, gender, weight, hemodynamic parameters, and urine output. However, significant differences were found in acid-base parameters. Group 2 showed better preservation of acid-base balance with higher pH and HCO₃ levels. Patients in Group 1 exhibited a significant decrease in HCO₃ levels during surgery, while those in Group 2 maintained a more stable metabolic profile. Furthermore, nine patients in Group 1 required sodium bicarbonate supplementation for metabolic acidosis, compared to only three in Group 2. Postoperative liver function tests revealed no significant differences between the two groups, although a trend toward better outcomes was observed in Group 2. Conclusions PlasmaLyte A® demonstrated superior preservation of acid-base balance compared to 0.9% normal saline, with less need for bicarbonate supplementation. While liver function outcomes were similar, the balanced solution showed a trend toward better metabolic stability, suggesting it may offer safer and more effective fluid management in liver transplantation surgery.

Insights into the baseline blood pH homeostasis at admission and the risk of in-hospital mortality in COVID-19 patients.

Aim: A laboratory finding in critically ill COVID-19 patients is blood academia (pH <7.35). We investigated its cause in connection with the admission baseline blood pH homeostasis.Patients & methods: We retrospectively monitored the baseline blood pH homeostasis of 1215 COVID-19 patients who were admitted with pneumonia using data-driven knowledge. Two categories of patients were identified: non-survivors (107) and survivors (1108).Results: Non-survivors showed greater levels of lactate and lower blood pH, saturation, and partial pressure of oxygen than survivors. A bivariate Spearman's correlation matrix showed that the [HCO3-]/pCO2 and pCO2 of non-survivors exhibited an unmatched connection, but not in the survivor group. When comparing non-survivors to survivors, the dendrograms derived from the bivariate comparison matrix showed differences in gasometry parameters like blood pH, [HCO3-]/pCO2 ratio, anion gap and pO2.Conclusion: The little variations in the gasometry readings between survivors and non-survivors upon admission suggested abnormal changes in the complementary renal and respiratory systems that bring blood pH back to normal. In advanced COVID-19, modest blood acid-base imbalances could become blood acidemia if these compensatory strategies were overused. Data-driven monitoring of acid-base parameters may help predict abnormal blood pH and the advancement of metabolic acidemia before it is too late.

SERIAL CHANGES IN METABOLIC ACID-BASE STATUS IN THREE SPECIES OF ANESTHETIZED CAPTIVE LARGE FELID.

Determination of acid-base status contributes important information about patient health, including for patients under anesthesia. There is a paucity of information about the determinants of acid-base status of large felids managed under anesthesia, and advancement of such knowledge may contribute to patient safety. This study serially monitored the individual metabolic acid-base status of 11 large felids, including lions (Panthera leo), tigers (Panthera tigris), and cheetahs (Acinonyx jubatus), under general anesthesia. We analyzed the contributions of measured strong ions (sodium, chloride, potassium, lactate), weak acids and buffers (albumin, phosphate and bicarbonate), and unmeasured anions to standardized extracellular base excess (SBE). A general linear model assessed for species differences in these parameters, with time since immobilization, SBE, and mean arterial pressure as covariates. By employing a Stewart-based analytical approach, it was possible to separate chloremic and unmeasured anion contributions to metabolic acid base status. This provided a basis for identifying mixed metabolic processes, generating differentials for underlying causes. Using normal acid base parameters for domestic felids, metabolic acidosis was found to be prevalent. Frequent evidence of unmeasured anion accumulation was also found, with unmeasured anions occasionally exceeding 5mmol/L. These findings warrant further inquiry into the drivers and clinical significance of metabolic acidosis and unmeasured anion accumulations in anesthetized large felids, encouraging further anion identity studies to elucidate possible causes. Reference ranges need to be established for acid-base parameters in large felids as a foundation for interpreting more controlled, prospective research into determinants of metabolic acid-base status in these animals under anesthesia.

Determining lactate concentrations in Korean indigenous calves and evaluating its role as a predictor for acidemia in calf diarrhea

BackgroundCalf diarrhea leads to high mortality rates and decreases in growth and productivity, causing negative effects on the livestock industry. Lactate is closely associated with metabolic acidosis in diarrheic calves. However, there have been no reports on lactate concentrations in Korean indigenous (Hanwoo) calves, especially those with diarrhea. This study aimed to determine the reference range of L-lactate and D-lactate concentrations in Hanwoo calves and to better understand the utility of lactate as predictive factors for acidemia in diarrheic calves.ResultsL-lactate and D-lactate concentrations were measured in healthy (n = 44) and diarrheic (n = 93) calves, and blood gas analysis was performed on diarrheic calves. The reference range in healthy calves was 0.2–2.25 mmol/L for L-lactate and 0.42–1.38 mmol/L for D-lactate. Diarrheic calves had higher concentrations of L-lactate and D-lactate than healthy calves. In diarrheic calves, L-lactate and D-lactate each had weak negative correlation with pH (r = − 0.31 and r = − 0.35). In diarrheic calves with hyper-L-lactatemia, the combined concentrations of L-lactate and D-lactate had moderate correlation with pH (r = − 0.51) and anion gap (r = 0.55). Receiver operating characteristic analysis showed D-lactate had fair predictive performance (AUC = 0.74) for severe acidemia, with an optimal cut-off value of > 1.43 mmol/L. The combined concentrations of L-lactate and D-lactate showed fair predictive performance for predicting acidemia (AUC = 0.74) and severe acidemia (AUC = 0.72), with cut-off values of > 6.05 mmol/L and > 5.95 mmol/L.ConclusionsThe determined reference ranges for L-lactate and D-lactate in Hanwoo calves enable the identification of hyper-L-lactatemia and hyper-D-lactatemia. Diarrheic calves exhibited increased lactate concentrations correlated with acid-base parameters. While the concentrations of L-lactate and D-lactate have limitations as single diagnostic biomarkers for predicting acidemia or severe acidemia, their measurement remains important, and L-lactate has the advantage of being measurable at the point-of-care. Assessing lactate concentrations should be considered by clinicians, especially when used alongside other clinical indicators and diagnostic tests. This approach can improve calf diarrhea management, contributing positively to animal welfare and providing economic benefits to farms.

Local and Systemic Micro-Rheological Changes during Intestinal Anastomosis Operation: A Metabolic Dependence in an Experimental Model.

Hemorheological factors may show arterio-venous differences. Alterations in acid-base and metabolic parameters may also influence these factors. However, little is known about changes in micro-rheological parameters during abdominal surgery, influencing splanchnic circulation. In anesthetized pigs, the external jugular vein, femoral artery and vein were cannulated unilaterally, and paramedian laparotomy was performed. In the anastomosis group, after resecting a bowel segment, end-to-end jejuno-jejunostomy was completed. Blood samples (from cannulas and by puncturing the portal vein) were taken before and after the intervention. Hematological, acid-base and blood gas parameters, metabolites, red blood cell (RBC) deformability and aggregation were determined. The highest hematocrit was found in portal blood, increasing further by the end of operation. A significant pH decrease was seen, and portal blood showed the highest lactate and creatinine concentration. The highest RBC aggregation values were found in arterial, the lowest in renal venous blood. The RBC aggregation increased with higher lactate concentration and lower pH. Osmotic gradient deformability declined, with the lowest values in portal and renal venous samples. In conclusion, micro-rheological parameters showed arterio-venous and porto-renal venous differences, influenced by oxygenation level, pH and lactate concentration. The intestinal anastomosis operation caused an immediate micro-rheological deterioration with portal venous dominancy in this experiment.

Chelation of rare earth metals by perfluorinated β-diketones bearing nitrogen heterocycles rings

Aqueous equilibria of three substituted perfluorinated 1,3-diketones with pyrrole, pyrazole, and pyridine rings have been extensively studied in aqueous solutions. Thermodynamic characteristics of dissociation, protonation, and chelation processes have been investigated by UV–Vis spectroscopy using non-linear regression analysis. Acid-base parameters were discovered in the acidity range from highly acidic media (C(HCl) = 10 M) to alkaline pH region. Dissociation constants (pKa) have been determined in glycine-HCl, phosphate-citrate, and TRIS-HCl buffered media. Protonation activities were studied by the Cox-Yates approach in concentrated hydrochloric acid solutions. First formation constants of ML complex species with trivalent ions of Sc3+, Y3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Dy3+, Tb3+, Ho3+, Er3+, Tm3+, Yb3+, and Lu3+ have been obtained in the pH within 3.0–5.6 (I = 0.5 M, NaCl). True stability constants have been calculated using determined acid-base parameters considering side reactions. The “True” formation constants lie from 3.7 to 6.9 logarithmic units and have a linear relationship with the ionic (Coulomb) potential of metals. DFT and TD-DFT simulations have been performed for the modeling of the data obtained.

The Effects of Early-Phase, Low- or Standard-Intensity Continuous Renal Replacement Therapy on Acid-Base Control and Clinical Outcomes: An Observational Study

Introduction: The Kidney Disease Improving Global Outcomes (KDIGO) clinical practice guideline recommends administering an effluent volume of 20–25 mL/kg/h during continuous renal replacement therapy (CRRT) for acute kidney injury. Recent evidence on CRRT initiation showed that less intervention might be beneficial for renal recovery. This study aimed to explore the association between early-phase low CRRT intensity and acid-base balance corrections and clinical outcomes. Methods: This was a single-centre, retrospective, observational study at a tertiary intensive care unit (ICU) in Japan. All adult patients requiring CRRT in the ICU were included. Eligible patients were classified into the Low group (dialysate flow rate [QD] 10.0–19.9 mL/kg/h) and the Standard group (QD ≥20 mL/kg/h) by the intensity of CRRT at the beginning. The primary outcomes were acid-base parameters 6 h after CRRT initiation. We used an inverse probability of treatment weighting analysis to estimate the association between the intensity group and the outcomes. Results: Overall, 194 patients were classified into the Low group (n = 144) and the Standard group (n = 50). The Standard group presented with more severe acid-base disturbances, including lower pH and base excess (BE) at baseline. At 6 h after CRRT initiation, pH, BE, and strong ion difference values were comparable, even after adjusting for baseline severity. Despite the efficient correction, no evident differences were observed in clinical outcomes between the two groups. Conclusions: The initial standard intensity appeared to be efficient in correcting acid-base imbalance at the early phase of CRRT; however, further studies are needed to assess the impact on clinical outcomes.

#1430 Acid excretion is disturbed in calcium oxalate and calcium phosphate stone formers in the Swiss kidney stone cohort

Abstract Background and Aims Kidney stone is a highly prevalent disease worldwide that causes high morbidity and may increase the risk for chronic kidney disease. Urine pH influences the crystallization of some types of kidney stones, such as calcium phosphate and uric acid. This study aimed to identify whether other acid-base parameters are associated with stone formation in the Swiss kidney stone cohort. Method Urinary, serum, clinical, and anthropomorphic baseline data were obtained from the Swiss Kidney Stone Cohort, a prospective, longitudinal, and multi-centric observational study. We included 200 non-stone formers (NSF, determined by CT scan), and 265 calcium oxalate (CaOx) and 113 calcium phosphate (CaP) stone formers with complete data for urine pH (collected under oil). Titratable acids were calculated based on urine phosphate and creatinine levels and urine bicarbonate based on urine pH. Net acid excretion (NAE) was calculated and NAE capacity (NAEC), the NAE for a given urine pH, which reveals the ability of kidneys to excrete acids, was calculated from the residuals of the relation between urine pH and NAE. Logistic regression analyses were used to estimate the potential contributions of various acid-base variables to the occurrence of CaOx or CaP kidney stones. Odds ratio (OR) are reported as “OR [95% confidence interval]” Results CaOx stone formers were slightly older than NSF individuals and CaP stone formers (NSF = 42.9 ± 13.6 y.o., CaOx = 47.3 ± 14.3 y.o., CaP = 43.3 ± 12.9 y.o.), slightly more overweight (NSF = 25.0 ± 4.15, CaOx = 27.1 ± 4.72, CaP = 25.9 ± 4.55), and had a higher prevalence of males (NSF = 56.0%, CaOx= 72.1%, CaP = 59.3%), but had similar baseline estimated glomerular filtration rate (NSF = 97.1 ± 16.5, CaOx = 96.3 ± 18.3, CaP = 99.5 ± 18.0 ml/min/1.73 m2). Hypertension, type 2 diabetes, pyelonephritis, and nephrocalcinosis were more prevalent among people with either type of kidney stones in comparison with NSFs, while inflammatory bowel disease was more common among CaOx stone formers in comparison with NSF individuals. CaOx and CaP stone formers showed disturbed capacity of excreting acids in relation to NSF (NAEC NSF = 1.81 ± 8.21 µmol/min; CaOx = −1.35 ± 8.45, P &amp;lt; .001; CaP = −0.89 ± 7.66, P = .016) and lower 24 h urine excretion of ammonium (NSF = 19.8 ± 8.70 µmol/min; CaOx = 17.4 ± 8.54, P = .012; CaP = 16.5 ± 8.23, P = .005), but also of citrate, oxalate, and potassium (Table 1). In addition, CaOx exhibited a lower urine volume. In contrast, both CaOx and CaP excreted more calcium (NSF = 3.12 ± 1.85 µmol/min; CaOx = 3.82 ± 1.91 p &amp;lt;0.001; CaP = 4.63 ± 2.27, p &amp;lt;0.001). Urine pH was more acidic in CaOx (p &amp;lt; 0.001) in comparison with NSFs and CaP (P = .004), NSF = 6.05 ± 0.51; CaOx = 5.86 ± 0.53; CaP = 6.16 ± 0.62. The correlations between urine pH and both urine calcium and ammonium were disturbed in CaOx stone formers and shifted in CaP stone formers (Fig. 1). Logistic models including urine ammonium, pH, citrate, phosphate, potassium, calcium, magnesium, oxalate, protein, and volume showed that ammonium is negatively associated with both CaOx and CaP stone formation (unadjusted model OR 0.41[0.26-0.57], p&amp;lt; 0.001 for CaOx and OR 0.42[0.26–0.67], P &amp;lt; .001 for CaP) and urine calcium is positively associated with kidney stones (OR 2.37 [1.72-3.43], P &amp;lt; .001 for CaOx and OR 5.82 [3.6–10.1], P &amp;lt; .001 for CaP). Similar results were obtained after adjustment for age, sex, and BMI. Removing urine ammonium, pH, and phosphate from our logistic model and adding NAEC rendered comparable goodness of fit and model complexity. Holding all other independent variables constant, the odds of CaOx associated with NAEC were 0.45 [0.33–0.61], P &amp;lt; .001 and with calcium of 2.6 [1.91–3.64], P &amp;lt; .001. For CaP, NAEC was still associated with it, but urine magnesium showed a lower odds ratio value (0.44 [0.27–0.72], P = .001 vs 0.54 [0.36–0.80], P = .003). Urine citrate was only associated with CaOx stones. Conclusion Baseline urine ammonium and net acid excretion capacity are strongly associated with the occurrence of CaOx and CaP kidney stones. Reduced NAEC indicates that poor control of ammonium excretion is a hallmark of both types of kidney stones, although more strongly apparent in CaOx.

Effect of Tacticity on London Dispersive Surface Energy, Polar Free Energy and Lewis Acid-Base Surface Energies of Poly Methyl Methacrylate by Inverse Gas Chromatography

This research was devoted to study the effect of the tacticity on the surface physicochemical properties of PMMA. (1) Background: The determination of the surface free energy of polymers is generally carried out by inverse gas chromatography (IGC) at infinite dilution. The dispersive, polar and surface acid-base properties of PMMA at different tacticities were obtained via IGC technique with the help of the net retention time and volume of adsorbed. (2) Methods: The London dispersion equation was used to quantify the polar free energy of adsorption, while the London dispersive surface energy γsd(T) of PMMAs was determined using the thermal model. (3) Results: The results showed non-linear variations of γsd(T) of atactic, isotactic, and syndiotactic PMMAs with three maxima characterizing the three transition temperatures of PMMAs. The obtained values of the enthalpic and entropic Lewis’s acid-base parameters showed that the basicity of the atactic PMMA was about four times larger than its acidity. (4) Conclusions: A large difference in the behavior of the various PMMAs was proven in the different values of the polar acid and base surface energies of the three PMMAs with an important effect of the tacticity of PMMA on its acid-base surface energies.

Surface Thermodynamic Properties of Poly Lactic Acid by Inverse Gas Chromatography.

Poly lactic acid (PLA) is one of the most commonly used bio-derived thermoplastic polymers in 3D and 4D printing applications. The determination of PLA surface properties is of capital importance in 3D/4D printing technology. The surface thermodynamic properties of PLA polymers were determined using the inverse gas chromatography (IGC) technique at infinite dilution. The determination of the retention volume of polar and non-polar molecules adsorbed on the PLA particles filling the column allowed us to obtain the dispersive, polar, and Lewis's acid-base surface properties at different temperatures from 40 °C to 100 °C. The applied surface method was based on our recent model that used the London dispersion equation, the new chromatographic parameter function of the deformation polarizability, and the harmonic mean of the ionization energies of the PLA polymer and organic molecules. The application of this new method led to the determination of the dispersive and polar free surface energy of the adsorption of molecules on the polymeric material, as well as the glass transition and the Lewis acid-base constants. Four interval temperatures were distinguished, showing four zones of variations in the surface properties of PLA as a function of the temperature before and after the glass transition. The acid-base parameters of PLA strongly depend on the temperature. The accurate determination of the dispersive and polar surface physicochemical properties of PLA led to the work of adhesion of the polar organic solvents adsorbed on PLA. These results can be very useful for achieving reliable and functional 3D and 4D printed components.

Temperature Dependence of the Polar and Lewis Acid-Base Properties of Poly Methyl Methacrylate Adsorbed on Silica via Inverse Gas Chromatography.

The adsorption of polymers on solid surfaces is common in many industrial applications, such as coatings, paints, catalysis, colloids, and adhesion processes. The properties of absorbed polymers commonly vary with temperature. In this paper, inverse gas chromatography at infinite dilution was used to determine the physicochemical characterization of PMMA adsorbed on silica. A new method based on the London dispersion equation was applied with a new parameter associating the deformation polarizability with the harmonic mean of the ionization energies of the solvent. More accurate values of the dispersive and polar interaction energies of the various organic solvents adsorbed on PMMA in bulk phase and PMMA/silica at different recovery fractions were obtained, as well as the Lewis acid-base parameters and the transition temperatures of the different composites. It was found that the temperature and the recovery fraction have important effects on the various physicochemical and thermodynamic properties. The variations in all the interaction parameters showed the presence of three transition temperatures for the different PMMA composites adsorbed on silica with various coverage rates, with a shift in these temperatures for a recovery fraction of 31%. An important variation in the polar enthalpy and entropy of adsorption, the Lewis acid-base parameters and the intermolecular separation distance was highlighted as a function of the temperature and the recovery fraction of PMMA on silica.

Acid-Base Balance in Healthy Adults: Beneficial Effects of Bicarbonate and Sodium-Rich Mineral Water in a Randomized Controlled Trial: The BicarboWater Study.

Noncommunicable diseases (NCDs) are a global health challenge. The complex etiology of NCDs involves genetic, environmental, and lifestyle factors, including dietary habits. Chronic latent metabolic acidosis has been associated with an increased risk of NCDs. Alkalizing diets and mineral water consumption have shown promise in improving acid-base balance and potentially impacting NCDs. In this randomized controlled intervention study, the effect of drinking 1,500-2,000 mL of mineral water daily on acid-base balance was evaluated. Ninety-four healthy participants were divided into two groups: one consumed mineral water with a high bicarbonate and sodium content (HBS, n = 49) and the other consumed mineral water with a low bicarbonate and sodium content (LBS, n = 45). Changes in venous blood gas and urinary acid-base parameters were measured over a short-term (3 days) and long-term (28 days) intervention period. Potential renal acid load (PRAL) and nutrient intake were calculated at baseline and after 28 days. HBS water consumption led to increased urinary pH (24-hour urine and spontaneous urine, both p < 0.001) and bicarbonate levels (p < 0.001), accompanied by reduced titratable acids (p < 0.001) and ammonium (p < 0.001), resulting in a lower renal net acid excretion (p < 0.001). These changes occurred in the short term and persisted until the end of the study. LBS consumption showed no significant effects on urinary pH but led to a slight decrease in bicarbonate (p < 0.001) and NH4 + (p < 0.001), resulting in a slight decrease in NAE (p=0.011). Blood gas changes were modest in both groups. Mineral water consumption in the HBS group altered dietary intake of sodium and chloride, contributing to changes in PRAL values. The study demonstrates that the consumption of mineral water high in bicarbonate and sodium (1,500 mL-2,000 mL/day) can positively influence urinary acid-base parameters and reduce NAE, suggesting potential benefits in maintaining acid-base balance without adverse effects on human health. These findings highlight the importance of mineral water composition in acid-base regulation. This trial is registered with DRKS00025341.

Oxidative stress as one of the pathogenetic mechanisms of hepatopulmonary syndrome in patients with liver cirrhosis

Background. Hepatopulmonary syndrome is one of the most dangerous syntropies in case of liver cirrhosis. Consequently, it is important to determine the role of oxidative stress, acid-base balance and ventilation-perfusion disorders as factors of hepatopulmonary syndrome development in cirrhotic patients. Materials and methods. We included 44 cirrhotic patients with hepatopulmonary syndrome verified according to the patented Method for diagnosing degrees of hepatopulmonary syndrome severity in patients with liver cirrhosis. In addition to the traditional examinations, we determined the gas composition parameters in venous blood, acid-base balance parameters, catalase activity and malondialdehyde level in all the patients. The received material was processed on a personal computer using Excel 2010, Statistica 6.0, RStudio v. 1.1.442 and R Commander v. 2.4-4. Results. Analysis of blood gas parameters revealed the reliability of the difference for PCO2 (р = 0.03) depending on the class of liver cirrhosis severity. Also, with the liver cirrhosis severity increase, the malondialdehyde level increased, and catalase decreased. Moreover, significant inverse relationships between malondialdehyde content and PCO2 (p = 0.039), HCO3 (p = 0.039), TCO2 (p = 0.036), Beb (p = 0.049), BEecf (p = 0.043) were found resulting in hypocapnia and partially compensated metabolic acidosis. The found direct correlation between malondialdehyde level and AaDO2 (p = 0.044) indicates the arteriovenous pulmonary shunts, ventilation-perfusion disorders. The absence of catalase content changes can obviously be explained by the fact that its activity can be partially compensatory maintained. Conclusions. In patients with hepatopulmonary syndrome, the peroxidation activity enhances with an increase in the liver cirrhosis severity, resulting in the redox homeostasis imbalance, leading to the ventilation-perfusion disorders and partially compensated metabolic acidosis.

Acid base and metabolic parameters of the umbilical cord blood and cerebral oxygenation immediately after birth.

Aim was to investigate whether acid-base and metabolic parameters obtained from arterial umbilical cord blood affect cerebral oxygenation after birth in preterm neonates with respiratory support and in term neonates without respiratory support. This was a post-hoc analysis of secondary outcome parameters of a prospective observational study including preterm neonates with and term neonates without respiratory support. Non-asphyxiated neonates with cerebral oxygenation measured with near-infrared spectroscopy during the first 15 min and with blood gas analyses from arterial umbilical cord blood were included. Arterial oxygen saturation (SpO2) and heart rate (HR) were monitored with pulse oximetry. Potential correlations were investigated between acid-base and metabolic parameters (pH-value, bicarbonate, base-excess, and lactate) and crSO2/cFTOE 5 min after birth. Seventy-seven neonates were included: 14 preterm neonates with respiratory support (mean gestational age [GA] 31.4 ± 4.1 weeks; mean birth weight [BW] 1,690 ± 640 g) and 63 term neonates without respiratory support (GA 38.7 ± 0.8 weeks; BW 3,258 ± 443 g). Mean crSO2 5 min after birth was 44.0% ± 24.2% in preterm and 62.2% ± 20.01% in term neonates. Mean cFTOE 5 min after birth was 0.46 ± 0.06 in preterm and 0.27 ± 0.19 in term neonates. In preterm neonates with respiratory support higher lactate was significantly associated with lower crSO2 and SpO2 and tended to be associated with higher cFTOE. In term neonates without respiratory support no significant correlations were found. In non-asphyxiated preterm neonates with respiratory support, lactate levels were negatively associated with crSO2 and SpO2, whereas in term neonates without respiratory support no associations were observed.

Upgrading of Pyrolytic Char Generated from Waste Tyre Pyrolysis for Solid Tyre Industry

In Sri Lanka, accumulation of tons of low-quality pyrolytic char (PT-char) in pyrolysis plants is a significant issue in waste tyre management. Finding a solution to upgrade low-quality PT-char is urgent in Sri Lankan context as it initiates a method of finding a solution to the disposal issue of PT-char. As a result, the current study introduces an efficient and cost-effective routine for upgrading low grade PT-char into value-added products which is not being successful before. The upgrading method entails carefully regulating size reduction of the low-grade PT-char (particle size&lt;50 μm) and following optimization of acid-base demineralization parameters. After the size reduction of PT–char, demineralization procedure was introduced using low char: acid/base ratios (1:2), diluted acids and bases (2 M HCl and 2 M NaOH), low temperatures (30 0C-60 0C), and short reaction times (30-60 minutes). Purity and surface characteristics of upgraded char were investigated using XRD, elemental analysis, SEM, and TGA. Based on a CHN analysis, 67% (w/w) of initial carbon content of crude C-PT char was increased up to 91% (w/w) by washing it twice with 2 M HCl and once with 2 M NaOH (2 M H2+2 M S) while reducing ash content from 17.65% (w/w) to 3.59% (w/w). Significance removal of metals such as Zn (1.14% w/w) , Fe (0.34% w/w), Mg (0.25% w/w) and Ca (2.71% w/w) from C-PT char were observed after treating with 2 M H2+2M S (Zn 0.36%w/w , Fe 0.06%w/w, Mg 0.01%w/w and Ca 0.01% w/w). Removal of Zn from C-PT char further confirmed by XRD and surface modification was confirmed by SEM images. Additionally, the rheological and physico-mechanical properties of the upgraded char incorporated solid tyre base compounds were evaluated and compared with commercial grades of carbon black; N 330, and N 660. It was observed that tensile strength, tear strength, hardness and compression properties of purified PT-char incorporated rubber compounds were not significantly different and exhibit resemble properties to the samples prepared using commercial carbon black grades. Overall, it can be confirmed that upgraded PT char has a significant potential to be used as an economical alternative for reinforcement filler in solid tyre industry and upgrading procedure is efficient and economically viable than the conventional methods. &#x0D; Keywords: Pyrolytic char, Demineralization, Purification, Modification

Hematological, biochemical, and acid-base response of trotters to submaximal exercise at the end of the horse racing season

Depending on intensity, physical exercise in horses causes various changes in the parameters of hematological, biochemical, acid-base, and electrolyte status, which can affect the health and athletic performance of the horse. This study?s objective was to look at how submaximal exercise at the end of the racing season affected the horses? hematological, biochemical, acid-base, and electrolyte status markers. In this study, eight (n=8) trotters, aged 4?2 years, were involved. Venous blood samples were drawn from each horse by jugular puncture before and after exercise to determine hematologic, biochemical, acid-base and electrolyte parameters. The submaximal physical exercise in this study was two intervals of 2,000 m of slow trotting and two consecutive runs of 500 m at submaximal level. Hematocrit (HCT), red blood cell (RBC) and monocyte count, hemoglobin (HGB) concentration, aspartate aminotransferase (AST) activity, and glucose concentration increased significantly after the exercise. Additionally, significant decreases in venous blood pH, bicarbonate (HCO3-) and total CO2 (TCO2) concentration, base excess of the extracellular fluid (BEecf), and ionized Ca2+ (iCa2+) concentrations were established after exercise. In contrast, partial pressure of CO2 (pCO2), total concentration of weak acids (Atot), the anion gap (AG), and total protein and lactate concentrations were significantly higher after exercise. Considering the significant changes in the parameters of hematological, biochemical, and acid-base status after submaximal exercise, determining those parameters would be useful for monitoring the health and performance of trotters.