Acid-base Balance Research Articles

An azine‐based halochromic molecular chameleon

Halochromism has a plethora of uses in the textile industry, including wound treatments and protective apparel. Reactive dye’s fastness and a wide variety of hues, from bright to dull, make it ideal for coloring cotton and other regenerated cellulose fibers. It is also fundamentally paramount importance to determine the freshness of packaging foods. In this study, a halochromic probe, 4,4′-((1E,1′E,3E,3′E)-hydrazine-1,2-diylidenebis(prop-1-en-1-yl-3-ylidene))bis(N, N-dimethylaniline), HDBD, has been introduced utilizing a simple condensation reaction. Through the protonation and deprotonation process with the addition of acid and base in the non-aqueous medium, HDBD shows visual colorimetric as well as ratiometric UV–visible absorption spectral change. A colorimetric paper strip-based experiment has been demonstrated to detect trace amounts of acid and its reversibility with bases in non-aqueous solvents. Further, a dip-stick experiment was also carried out for the detection of acid-base vapor in a wide range of concentrations. Furthermore, the overlapping indicator method is explored to estimate acid dissociation constants in the non-aqueous medium. Moreover, we have constructed the INHIBIT (INH) and IMPLICATION (IMP) molecular logic gates exploring the reversibility of HDBD due to the cascade introduction of acid-base as chemical encoded inputs. Utilizing a reversible and reproducible detecting method, we have constructed a molecular-scale additional memory device that demonstrates binary logic “Writing-Reading-Erasing-Reading” and “Multi-write” functions. This finding provides a new way for designing acid-base indicators, which could estimate the acid dissociation constants of various acids in the non-aqueous environment which is fundamentally important in the field of acid-catalyzed organic synthesis.

The Rationale for Combining Normothermic Liver Machine Perfusion with Continuous Renal Replacement Therapy to Maintain Physiological Perfusate during Ex Vivo Organ Perfusion.

Background: The possibility of keeping liver grafts viable and functioning until transplantation has been explored since the 1950s. However, the current modalities of Normothermic Machine Perfusion (NMP) have shown several limitations, such as the inability to correct electrolytes and pH derangements efficiently. Combining NMP with continuous kidney replacement therapy (CKRT) might provide a promising new model to overcome these issues. Methods: An NMP that covers the organ perfusion, oxygenation, carbon dioxide removal, and thermal balance was connected to a CKRT circuit to ensure physiological hydro-electrolytes, acid-base balance, and catabolite removal from the perfusate. Results: The integration of NMP and CKRT maintains a neoplastic liver in a perfusion system with physiological perfusate for 100 h. CKRT re-established and maintained the hydro-electrolyte and acid-base status throughout the 100 h of perfusion. Significant limitations were the need for frequent monitoring of electrolytes and acid-base disorders and the loss of low molecular weight nutrients, which have to be replenished by manual infusion into the system. Conclusions: This novel CKRT-NMP integrated system may represent a practical and versatile model to support organs' perfusion and extend preservation times. Further experiments are needed to fix monitoring and adjusting processes.

Molecular docking, microwave-assisted synthesis, characterization, and preliminary evaluation of the anti-microbial activity of new sulfonamide derivatives of the 1, 2, 4-triazole-3-thiol ring system

A new sulfonamide derivative containing a 1,2,4-Triazole-3-thiol ring was synthesized and characterized using FT-IR and 1H-NMR. The microwave-assisted chemical synthesis of the 1,2,4-Triazole-3-thiol ring system resulted in good yield and purity. The synthetic compounds were then subjected to in vitro evaluation for antimicrobial study. All synthetic compounds show high activity against Gram-positive bacteria (S. aureus, S. pneumonia, and B. subtilis) and high activity against Gram-negative bacteria (P. aeruginosa, and H. pylori), with less activity against (N. gonorrhoeae, and E. coli). Also, it shows high activity against fungi (C. albicans). In this study, we utilized computational methods to design new derivatives that target the carbonic anhydrase enzyme of H. pylori (PDB: 4YGF). All the target compounds interact with the enzyme’s active site, resulting in a disturbance of the acid-base balance affecting the virulence and pathogenicity.

Dissolution Mechanisms and Surface Charge of Clay Mineral Nanoparticles: Insights from Kinetic Monte Carlo Simulations

The widespread use of clay minerals and clays in environmental engineering, industry, medicine, and cosmetics largely stems from their adsorption properties and surface charge, as well as their ability to react with water. The dissolution and growth of minerals as a function of pH are closely related to acid–base reactions at their surface sites and their surface charge. The vivid tapestry of different types of surface sites across different types of clay minerals generates difficulties in experimental studies of structure–property relationships. The aim of this paper is to demonstrate how a mesoscale stochastic kinetic Monte Carlo (kMC) approach altogether with atomistic acid-base models and empirical data can be used for understanding the mechanisms of dissolution and surface charge behavior of clay minerals. The surface charge is modeled based on equilibrium equations for de/protonated site populations, which are defined by the pH and site-specific acidity constants (pKas). Lowered activation energy barriers for these sites in de/protonated states introduce pH-dependent effects into the dissolution kinetics. The V-shaped curve observed in laboratory experiments is reproduced with the new kMC model. A generic rate law for clay mineral dissolution as a function of pH is derived from this study. Thus, the kMC approach can be used as a hypothesis-testing tool for the verification of acid–base models for clay and other minerals and their influence on the kinetics of mineral dissolution and growth.

Influence of pore structure on catalytic performance of Cs-Zr/SiO2 catalyst for methyl methacrylate synthesis from methyl propionate and formaldehyde

Methyl methacrylate (MMA) synthesis via aldol condensation of methyl propionate with formaldehyde over Cs-based supported catalysts is intensively investigated, while the effect of their pore structures on catalytic performance still lacks in-depth understanding. Herein, series of Cs-Zr/SiO2 catalysts with different pore structures were prepared for this aldol condensation. The physicochemical characteristics of as-prepared Cs-Zr/SiO2 catalysts were characterized using physical N2 adsorption–desorption isotherms and CO2–/NH3-TPD. In addition, the impact of pore structure on mass transfer, adsorption, and desorption of reactants and products was studied through in situ DRIFTS. The results show that the acid and base site densities elevated with the increasing pore volume. The mass transfer of reactants and products could be promoted with increasing pore size, while their adsorption energies exhibited a volcanic trend. As a result, the Cs-Zr/SiO2 catalysts having average pore diameter of 12–18 nm and acid-base balance was considered as the optimal candidate for MMA production.

Role of Kir5.1 (Kcnj16) Channels in Regulating Renal Ammonia Metabolism during Metabolic Acidosis in Dahl Salt-Sensitive Rats

Maintaining acid-base homeostasis is critical for normal physiological function. The kidneys are essential for regulating acid-base homeostasis through maintaining systemic bicarbonate concentration. Chronic metabolic acidosis is an independent risk factor for chronic kidney diseases. Renal inwardly rectifying potassium channel Kir5.1 plays an essential role in maintaining resting membrane potential. Patients with loss-of-function mutations in KCNJ16 gene, which encodes Kir5.1, reveal tubulopathy with hypokalemia, salt wasting, and hearing loss. Importantly, these mutations also disrupt acid-base balance, particularly causing metabolic acidosis. This study aimed to use Dahl salt-sensitive rats with a knockout of the Kcnj16 gene (SSKcnj16-/-) to investigate how the deletion of Kir5.1 affects the regulation of acid-base balance in salt-sensitive hypertension. Results indicated that SSKcnj16-/- rats displayed metabolic acidosis under a normal salt (NS) diet. Further analysis using RNA-Sequncing and Western blotting showed unchanged expression of proteins responsible for ammonia metabolism in the kidney of SSKcnj16-/- rats despite observed acidosis. However, there was a significant increase in the expression of bicarbonate transporter NBCe1 while a significant decrease in pendrin. In conclusion, the current study demonstrated that the loss of Kir5.1 impairs the sensitivity of ammonia metabolism in the kidney in response to metabolic acidosis, which provides mechanistic insights into developing potential therapeutics for conditions involving hypokalemia and acid-base abnormalities.

The effects of dietary cation-anion difference and dietary buffer for lactating dairy cattle under mild heat stress with night cooling

The objective of this study was to investigate the interactive effect of dietary cation-anion difference (DCAD) and dietary buffer supply on DMI, ruminal fermentation, milk and milk component yields, and gastrointestinal tract (GIT) permeability in lactating dairy cattle exposed to mild heat stress. Sixteen lactating Holstein cows, including 8 ruminally cannulated primiparous (80 ± 19.2 DIM) and 8 non-cannulated multiparous (136 ± 38.8 DIM) cows, were housed in a tie-stall barn programmed to maintain a temperature-humidity index (THI) between 68 and 72 from 0600 h to 1600 h followed by natural night cooling. The experimental design was a replicated 4 × 4 Latin rectangle (21-d periods) with a 2 × 2 factorial treatment arrangement. Diets contained a low DCAD (LD; 17.5 mEq/100g of DM) or high DCAD (HD; 39.6 mEq/100g of DM) adjusted using NH4Cl and Na-acetate, with low (LB; 0% CaMg(CO3)2) or high buffer (HB; 1% CaMg(CO3)2). In addition to measurement of feed intake, ruminal fermentation, and milk and milk component yields, a ruminal dose of Cr-EDTA and an equimolar abomasal dose of Co-EDTA were used to evaluate total and post-ruminal gastrointestinal tract permeability, respectively. Treatments had no effect on DMI, ruminal short-chain fatty acid concentrations, or ruminal pH. Feeding HD improved blood acid-base balance, increased urine volume by 4 ± 1.5 kg/d, and increased milk fat by 0.14 ± 0.044 percentage units and milk fat yield by 36.5 ± 16.71 g/d. HB reduced milk fat percentage by 0.11 ± 0.044 percentage units and had no effect on milk fat yield. The HB treatments reduced urinary excretion of Co by 27% and tended to reduce urinary Cr excretion by 10%. Across all treatments, 72% of the Cr recovery was represented by Co suggesting that much of the permeability responses were post-ruminal during mild heat stress. In conclusion, increasing DCAD through greater Na supply during mild heat stress improved blood acid-base balance and may increase milk fat yield. Dietary inclusion of CaMg(CO3)2 improved post-ruminal GIT barrier function despite a lack of low ruminal pH. As there appeared to be a limited interactive effect between DCAD and buffer, increased DCAD and provision of buffer seem to independently influence physiological and performance responses in lactating dairy cows exposed to mild heat with night cooling.

Open Access Data Repository and Common Data Model for Pulse Oximeter Performance Data.

The OpenOximetry Repository is a structured database storing clinical and lab pulse oximetry data, serving as a centralized repository and data model for pulse oximetry initiatives. It supports measurements of arterial oxygen saturation (SaO2) by arterial blood gas co-oximetry and pulse oximetry (SpO2), alongside processed and unprocessed photoplethysmography (PPG) data and other metadata. This includes skin color measurements, finger diameter, vital signs (e.g., arterial blood pressure, end-tidal carbon dioxide), and arterial blood gas parameters (e.g., acid-base balance, hemoglobin concentration). Data contributions are encouraged. All data, from desaturation studies to clinical trials, are collected prospectively to ensure accuracy. A common data model and standardized protocols for consistent archival and interpretation ensure consistent data archival and interpretation. The dataset aims to facilitate research on pulse oximeter performance across diverse human characteristics, addressing performance issues and promoting accurate pulse oximeters. The initial release includes controlled lab desaturation studies (CLDS), with ongoing updates planned as further data from clinical trials and CLDS become available.

Combined effect of intermittent hemostasis and a modified external hemorrhage control device in a lethal swine model

BackgroundNon-compressible torso hemorrhage (NCTH) presents the ultimate challenge in pre-hospital care. While external hemorrhage control devices (EHCDs) such as the Abdominal Aortic and Junctional Tourniquet (AAJT) and SAM Junctional Tourniquet (SJT) have been invented, the current design and application strategy requires further improvement. Therefore, researchers devised a novel apparatus named Modified EHCD (M-EHCD) and implemented intermittent hemostasis (IH) as a preventive measure against ischemia-reperfusion injury. The objective of this study was to ascertain the combined effect of M-EHCD and IH on the hemostatic effect of NCTH. MethodsEighteen swine were randomized to M-EHCD, AAJT or SJT. The NCTH model was established by inducing Class Ⅲ hemorrhagic shock and performing a hemi-transection of common femoral artery (CFA). EHCDs were rapidly fastened since the onset of free bleeding (T0min). The IH strategy was implemented by fully releasing M-EHCD at T40min, T70min and T100min, respectively, whereas AAJT and SJT maintained continuous hemostasis (CH) until T120min. All groups underwent CFA bridging at T110min, and EHCDs were removed at T120min. Reperfusion lasted for 60 min, after which euthanasia was performed. Hemodynamics, intra-vesical pressure (IVP), and blood samples were collected periodically. Histological examinations were also conducted. ResultsM-EHCD demonstrated the fastest application time (M-EHCD: 26.38 ± 6.32s vs. SJT: 30.84 ± 5.62s vs. AAJT: 54.28 ± 5.45s, P < 0.001) and reduced free blood loss (M-EHCD: 17.77 ± 9.85g vs. SJT: 51.80 ± 33.70g vs. AAJT: 115.20 ± 61.36g, P = 0.011) compared to SJT and AAJT. M-EHCD exhibited inhibitory effects on heart rate (M-EHCD: 91.83 ± 31.61bpm vs. AAJT: 129.00 ± 32.32bpm vs. SJT: 135.17 ± 21.24bpm, P = 0.041) and shock index. The device's external pressure was lowest in M-EHCD and highest in SJT (P = 0.001). The resultant increase in IVP were still the lowest in M-EHCD (M-EHCD: −0.07 ± 0.45 mmHg vs. AAJT: 27.04 ± 5.03 mmHg vs. SJT: 5.58 ± 2.55 mmHg, P < 0.001). Furthermore, M-EHCD caused the least colonic injury (M-EHCD: 1.17 ± 0.41 vs. AAJT: 2.17 ± 0.41 vs. SJT: 2.17 ± 0.41, P = 0.001). The removal of M-EHCD showed the slightest impact on pH (P < 0.001), while AAJT group was more susceptible to the lethal triad based on the arterial lactate and thrombelastogram results. ConclusionsM-EHCD + IH protected the organs and reduced the risk of the lethal triad by decreasing disruptions to IVP, hemodynamics, acid-base equilibrium and coagulation. M-EHCD + IH was superior to the hemostatic safety and efficacy of AAJT/SJT + CH.

Using systems modeling to facilitate undergraduate physiology student learning and retention of difficult concepts.

Physiology concepts, such as acid-base balance, may be difficult for students to understand. Systems modeling, a cognitive tool, allows students to visualize their mental model of the problem space to enhance learning and retention. Methods: We performed a within-subjects three-period randomized control comparison of systems modeling versus written discussion activities in an undergraduate asynchronous online Anatomy and Physiology II course. Participants (n=108) were randomized to groups with differing treatment orders across three course units: endocrine, immune, and acid-base balance. Participants demonstrated content understanding either through constructing systems modeling diagrams (M) or written discussion posts (W) in a MWM, MMW, or WMM sequence. Results: For each of three units, student performance was assessed on six standardized multiple-choice questions embedded within a 45-question exam. The same six questions per unit, eighteen questions total, was again assessed on the 75-question final exam. The groups demonstrated no significant difference in performance in the endocrine unit exam (mean difference, MD=-0.036). However, the modeling group outperformed the writing group in the immune unit exam (MD=0.209) and widened the gap in the acid-base balance unit exam (MD=0.243). On the final exam, performance was again higher for the modeling group on acid-base balance content as mean difference increased to 0.306 despite the final exam content for acid-base balance being significantly more difficult compared to other units (modeling: F(2)=29.882, p<.001; writing: F(2)=25.450, p<.001). Conclusions: These results provide initial evidence that participation in systems modeling activities enhance student learning of difficult physiology content as evidenced by improved multiple-choice question performance.

Reductive samarium (electro)catalysis enabled by SmIII-alkoxide protonolysis.

Samarium diiodide (SmI2) is a privileged, single-electron reductant deployed in diverse synthetic settings. However, generalizable methods for catalytic turnover remain elusive because of the well-known challenge associated with cleaving strong SmIII-O bonds. Prior efforts have focused on the use of highly reactive oxophiles to enable catalyst turnover. However, such approaches give rise to complex catalyst speciation and intrinsically limit the synthetic scope. Herein, we leveraged a mild and selective protonolysis strategy to achieve samarium-catalyzed, intermolecular reductive cross-coupling of ketones and acrylates with broad scope. The modularity of our approach allows rational control of selectivity based on solvent, pKa (where Ka is the acid dissociation constant), and the samarium coordination sphere and provides a basis for future developments in catalytic and electrocatalytic lanthanide chemistry.

The influence of insulin and incretin-based therapies on renal tubular transport.

The tubular function of the kidney is very complex and is finely regulated by many factors. These include a variety of hormonal signaling pathways which are involved in the expression, activation and regulation of renal transporters responsible for the handling of electrolytes. Glucose-lowering drugs such as insulin and incretin-based therapies, exert a well-known renal protective role in diabetic kidney disease, mainly acting at the glomerular level. In the literature, several studies have described the effect of insulin and the incretin hormones on tubular transport. Most of these studies focused on the variations in excretion and clearance of sodium but did not extensively and systematically investigate the possible variations that these hormones may induce in the tubular regulation of all the other electrolytes, urea metabolism, acid-base balance and urinary pH. While insulin action on the kidney is very well-described, the renal tubular impact of incretin-based therapies is less consistent and the results available are scarce. To our knowledge, this is the first review summarizing the effects induced on renal tubules by insulin, glucagon-like peptide-1 (GLP-1) receptor agonists and serine protease dipeptidyl peptidase-4 (DPP4) inhibitors in both healthy and diabetic human subjects. This is significant because it highlights the existence of a renal-gut and pancreas axis which also has a direct tubular effect and enables a deeper understanding of renal physiology.

Effects of Oral Lactate Supplementation on Acid-Base Balance and Prolonged High-Intensity Interval Cycling Performance.

Lactate is an important energy intermediate and metabolic buffer, and may be ergogenic. We investigated if lactate supplementation is an effective approach to enhance the exercise performance and acid-base balance of trained cyclists during exercise devised to simulate the demands of endurance road race cycling. Sixteen endurance-trained male cyclists (V·O2max 59 ± 7 mL·kg-1·min-1) consumed 120 mg·kg-1 body mass of lactate or a placebo 70 min prior to performing an exercise performance test, comprising five repeated blocks consisting of 1 km and 4 km time trials interspersed with 10 min of moderate-intensity exercise. Blood acid-base balance (including [H+] and [HCO3-]), heart rate, perceived exertion, and gastro-intestinal tolerance were assessed. There was no effect of lactate supplementation on exercise performance (p = 0.320), despite a reduction in RPE (p = 0.012) and increases in [SID] (p = 0.026) and [HCO3-] (p = 0.041). In addition, gastro-intestinal side effects were observed, but there was no effect on heart rate. Lactate supplementation did not improve exercise performance, despite positive changes in acid-base balance and RPE. This suggests that the alkalising effects of the supplement can reduce perceived effort, but these benefits do not translate into performance improvements.

Excited-State Dynamics of a Bright Fluorescent Dye with Precise Control of Emission Color Using Acid-Base Equilibrium, Intramolecular Charge Transfer, and Host-Guest Chemistry.

A fluorescent dye, a dithiophene-conjugated benzothiazole derivative (DTBz), was prepared to have high fluorescence emission quantum yields (ΦF) across various organic solvents. Its emission color modulation, from bright blue to deep red, was achieved through intramolecular charge transfer (ICT), acid-base equilibrium, and host-guest chemistry. Although it exhibits a weak solvatochromic effect, DTBz exhibited a bright fluorescence emission around 480 nm upon excitation at 390 nm in most solvents. In polar solvents, such as MeOH (methanol), EtOH (ethanol), DMF (N,N-dimethylforamide), and DMSO (dimethyl sulfoxide), an additional ICT emission band emerged around 640 nm, notably intense in DMSO, resulting in a bright greenish-white emission (ΦF = 0.67). The addition of 1,8-diazabicyclo[5,4.0]undec-7-ene (DBU) altered emission characteristics, reducing emission from the local excited (LE) state and enhancing ICT state emission. The degree of emission spectral change saturation with DBU addition varied with the solvent nature. Polar solvents with high dielectric constants, like DMSO and DMF, saw a complete disappearance of LE state emission with 5 equiv of DBU, resulting in a deep red emission (ΦFs of 0.53 and 0.48, respectively). Femtosecond transient absorption spectroscopy and time-resolved photoluminescence measurements elucidated the excited-state dynamics, revealing a long-lived excited state (τ-H = 10.3 ns) at a lower energy emission (640 nm), identified as DTBz-*, supported by transient absorption spectra analysis. Further analysis, including time-resolved fluorescence decay measurements and time-dependent density-functional theory (TD-DFT) calculations, underscored the role of deprotonation of DTBz's hydroxyl group in promoting the ICT process. The CIE coordination plot demonstrated wide linear emission color changes upon successive DBU additions in all solvents, while emission color precision was achieved through host-guest chemistry. Emission changes induced by DBU were reverted to the original state upon beta-cyclodextrin (β-CD) addition, with the 1H NMR study revealing the competition between acid-base equilibrium and host-guest complex formation as the cause of emission color change.

Bridging pyrimidine hemicurcumin and Cisplatin: Synthesis, coordination chemistry, and in vitro activity assessment of a novel Pt(II) complex

In the upcoming decades, the incidence and mortality rates of cancer are expected to rise globally, with colorectal and prostate cancers among the most prevalent types. Despite advancements in molecular targeted therapy, platinum-based chemotherapies remain the cornerstone of treatment, especially for colorectal and prostate cancer, with oxaliplatin and cisplatin being extremely effective due to their DNA-targeting capabilities. In our pursuit of new platinum-based chemotherapeutics that are potentially less toxic and more effective, we have explored the combination of the Pt-binding groups of the diaminocyclohexane ring used in oxaliplatin, with the stable amino-pyrimidine hemicurcumin moiety. This new derivative exhibit improved stability in physiological conditions and increased solubility in aqueous media, demonstrating promising effects on cell proliferation of both colorectal and prostate cells. We report herein the complete synthesis and chemical characterization in solution of the new derivative [(1R,2R)-N1-(3-(4-((E)-2-(2-Amino-6-methylpyrimidin-4-yl)vinyl)-2-methoxyphenoxy) propyl) cyclohexane-1,2-diamine] (MPYD). Our analysis includes an examination of its acid-base equilibria, speciation and stability in physiological conditions. The synthesis and in situ formation of Pt(II) complexes were investigated by nuclear magnetic resonance spectroscopy, while density functional theory calculations were employed to elucidate the chemical structure in solution. Results on the biological activity were obtained through cell viability assays on different colorectal and prostate cell lines (HCT116, HT29, PC3 and LNCaP).

The organization of pyridazine adsorbed on Au(1 1 1) electrode in sulfuric and perchloric acids – As probed by in situ STM

The adsorption of pyridazine (PD) on a gold electrode served as a model to study the orientation and arrangement of an organic adsorbate bearing a heterocyclic molecular structure at an electrified interface. Because the two N-ends of PD could interact with a Au electrode, the acid-base equilibrium of PD at an electrified interface can be different from that in a solution phase. Unprotonated and protonated PD interacted with the Au electrode differently, leading to dissimilar spatial structures on the Au(111) electrode. Moreover, having a large dipole moment of 4.22 D, PD adopted different adsorption configurations, as the Au potential was modulated. The indispensable anion present in the supporting electrolyte can compete with PD for surface sites on the Au electrode. Since the potential of a charged conductor is established by the physical contact with an electrolyte, the study of the adsorption of PD on a Au(111) electrode calls for the use of an in situ tool, such as a scanning tunneling microscope (STM), which provides sub-nanometer information of the interface in real-time and real-space. Different phases of adsorbed PD molecules on an ordered Au(111) electrode were revealed as a function of potential, pH and anion. The most notable event for PD adsorbed on Au(111) is attributed to the sharp transition from a disordered state to highly organized structures in 0.1 M H2SO4 and HClO4. The obtained STM images enabled a direct measurement of the spacing between PD admolecules, from which the molecular reorientations on the Au electrode were inferred. PD admolecules flipped from the horizontal to the upright configuration, tethered to Au substrate via the two N-ends, at positive potentials. Different ordered PD structures seen in H2SO4 and HClO4 imply anions were coadsorbed with PD molecule on the Au electrode. The acid-base equilibrium of PD at the Au electrode was examined with STM in pH 1 and 3 media.

Biochemical Approach of Acid-Base Disturbances: Diagnosis Algorithm

Context: The biochemical approach to acid-base balance classifies disturbances in two categories based on cellular mechanisms. The first one being cellular respiration (ATP), which presents high anion gap and changes in carbon dioxide levels, and the second one, cellular metabolism (ion transport through membrane channels), which evidences normal anion gap and changes in other cations and anions. Objective: To present a new diagnostic algorithm for acid-base disturbances, based on the biochemical approach. Method: Original research with systematic analysis and data organization, following biochemical processes that affect acid-base balance. Results: A simple, three-step algorithm which classifies information in a diagnostic table that connects blood gas analysis results (pH, anion gap or base excess, bicarbonate, carbon dioxide and unmeasured anions) with the biochemical cause and most probable clinical findings. Conclusions: The biochemical approach is considered the new model to understand, explain and diagnose acid-base balance and disturbances. All high anion gap disturbances occur in cellular respiration, while all normal anion gap disturbances occur in membrane channel function. The diagnosis algorithm simplifies and organizes the information to describe medical conditions with data from a blood gas analysis. This approach is the first model to establish a linear correlation between lab results, biochemical cause, and clinical findings of acid-base disturbances.

(Industrial Electrochemistry and Electrochemical Engineering Division H. H. Dow Memorial Student Achievement Award) Tailoring Electrode-Electrolyte Interfaces through Non-Covalent Interactions for Electrochemical Energy Storage and Conversion

Li-ion batteries and fuel cells play essential roles in electrifying transportation. Central to the electrochemical systems is the electrode-electrolyte interface, where (electro)chemical surface reactions or intercalation occur, and its thermodynamic and kinetic properties determine the energy density, power density, and lifetime of the electrochemical devices. However, the molecular structures at the electrical double layer and reaction mechanisms remain poorly understood, hindering the rational material design for more efficient electrochemical devices. This talk focuses on the mechanisms of (electro)chemical reactions and charges transfer kinetics at the electrode-electrolyte interface, providing design principles based on non-covalent interactions in electrolytes.First, an in situ Fourier-transform infrared spectroscopy (FTIR) method was developed for Li-ion batteries, which revealed unique evidence for dehydrogenation of carbonate electrolytes on Ni-rich lithium nickel, manganese and cobalt oxides (NMC), accounting for interface impedance build-up and battery capacity fading. Based on the proposed mechanism, strategies on suppressing electrode and electrolyte reactivity were demonstrated to improve battery cycling. Next, the kinetic mechanism for ion intercalation at the electrode-electrolyte interface will be discussed. Li-ion concentration-dependent intercalation kinetics was demonstrated from charge-adjusted electrochemical experiments and fit into a coupled ion-electron transfer mechanism, which governed the current-dependent maximum capacity and power density of intercalation batteries. Finally, for electrocatalytic reactions central to fuel cell technologies, we demonstrated tuning interfacial hydrogen bonding through protic ionic liquids with different acid dissociation constants and organic solvents with different donor numbers to tailor oxygen-reduction reaction (ORR) and hydrogen evolution reaction (HER). Strengthening hydrogen bonding between ORR products and ionic liquids, or between interfacial water molecules facilitated proton-coupled electron transfer kinetics, revealed by in situ surface-enhanced infrared absorption spectroscopy and density functional theory (DFT) calculations. The study can pave the way for the electrolyte and electrode design of electrochemical storage devices with improved energy and power density and cycle life.

Effects of volume management on free flap perfusion and metabolism in a large animal model study.

Free flap failure represents a substantial clinical burden. The role of intraoperative volume management remains controversial, with valid studies lacking. Here, using a large animal model, we investigated the influence of volume management on free flap perfusion and metabolism. Autotransfer of a musculocutaneous gracilis flap was performed on 31 German domestic pigs, with arterial anastomosis and catheterization of the pedicle vein for sequential blood sampling. Flap reperfusion was followed by induction of a hemorrhagic shock with maintenance for 30 min and subsequent circulation stabilization with crystalloid solution, crystalloid solution and catecholamine, autotransfusion or colloidal solution. Flap perfusion and oxygenation were periodically assessed using hyperspectral imaging. Flap metabolism was assessed via periodic blood gas analyses. Hyperspectral imaging revealed no difference in either superficial or deep tissue oxygen saturation, tissue hemoglobin or tissue water content between the test groups at any time point. Blood gas analyses showed that lactate levels were significantly increased in the group that received crystalloid solution and catecholamine, after circulatory stabilization and up to 2 h after. We conclude that, in hemorrhagic shock, volume management impacts acid-base balance in free flaps. Crystalloid solutions with norepinephrine increase lactate levels, yet short-term effects on flap perfusion seem minimal, suggesting that vasopressors are not detrimental.

Origins and molecular mechanisms underlying renal vascular development.

Kidneys play a crucial role in maintaining homeostasis within the body, and this function is intricately linked to the vascular structures within them. For vascular cells within the kidney to mature and perform their functions effectively, it is imperative that there is a meticulous and well-coordinated spatial alignment between the nephrons and the intricate network of blood vessels within the organ. This spatial arrangement ensures efficient filtration of blood and regulation of the electrolyte balance, blood pressure, and fluid levels. Additionally, the kidneys play a vital role in the regulation of acid-base balance and the production of hormones involved in erythropoiesis and blood pressure regulation. Thus, the close interaction between the vascular system and the kidney's structural organization is essential for maintaining overall physiological balance and health. This article focuses on the vascular development of the kidneys, summarizing the current understanding of the origin and formation of the renal vasculature, and the crucial molecules involved. By elucidating the cellular and molecular mechanisms governing renal vascular development, this article aims to promote advancements in renal regenerative medicine and provide potential avenues for therapeutic interventions to address kidney disease.