The liquid structure of protic ionic liquids (PILs) composed of the superbases 1,5-diazabicyclo(4.3.0)non-5-ene (DBN) and 1,8-diazabicycloundec-7-ene (DBU) combined with carboxylic acids (acetic acid (HAc) and octanoic acid (HOct)) has been investigated by vibrational spectroscopy (infrared (IR) and Raman). The spectroscopic studies have been assisted by quantum chemistry calculations and ab initio molecular dynamics (AIMD) simulations of clusters of ions and molecules. To cover a broad range of base : acid ratios, IR and Raman spectra of different mixtures have been investigated: 10 : 1, 4 : 1, 2 : 1, 1 : 1, 1 : 2, 1 : 4, and 1 : 10. Characteristic bands in the spectra indicate the protonation of the base with increasing amounts of the acid, however, a small percent of neutral base is still present in the 1 : 1 composition that corresponds to the PIL. The Raman spectra show that the acid-base equilibrium shifts, allowing for more proton transfer, as the PIL is cooled. The Raman spectra of mixtures containing excess of acid reveal that the ion pairs and extended structures like [DBNH][+]⋯[Ac][-]⋯[HAc] disrupt the acid liquid structure and decrease the population of cyclic acid dimers. The complex band shape characteristic of strong hydrogen bonds is seen in the high-frequency range of the IR spectra related to hydrogen stretching modes, which span the wide 1800-3600 cm[-1] range and depend heavily on the mixture's composition. Owing to the inherent anharmonic character of the vibrations in an AIMD simulation, the interpretation of the high-frequency range was aided by simulating clusters of ions and molecules of DBN : HAc, 4 : 4, 4 : 8, 2 : 8, and 1 : 10. In line with the experimental IR spectra, the AIMD simulations reproduce the decrease in intensity in the 3000-3500 cm[-1] range and the increase in intensity in the 1800-3000 cm[-1] range as the composition changes from 1 : 10 to 1 : 1. The AIMD simulations indicate that more mobile protons are responsible for this increased intensity in the lower-frequency side of the band. Direct inspection of N-H and O-H distances along the AIMD simulations reveals proton exchange between HAc and DBN in the 4 : 4 cluster, but prevalence of proton exchange between acetate and acetic acid in the other clusters with excess of acid.

This study evaluated the effects of dietary non-fiber carbohydrate to neutral detergent fiber ratio (NFC/NDF) and allicin supplementation on serum electrolytes, urinary biochemical indicators, nitrogen (N) and phosphorus excretion, and fecal microbiota in beef bulls. Forty 12-month-old beef bulls were assigned to a 2 × 2 factorial design based on dietary NFC/NDF (0.75 and 1.02) and allicin supplementation (0 and 0.04% on a DM basis), resulting in four treatment groups with 10 replicates per group. Increasing dietary NFC/NDF decreased serum pH and increased the anion gap (p < 0.05). An interaction between NFC/NDF and allicin supplementation was observed for the serum concentrations of non-ionized calcium and total calcium (p < 0.05), with the highest concentrations detected in cattle fed high-NFC/NDF diets supplemented with allicin. Serum uric acid was elevated by high NFC/NDF (p < 0.05). High dietary NFC/NDF also increased urine pH (p < 0.05). Significant interactions between dietary NFC/NDF and allicin supplementation were observed for allantoin, creatinine, and urease activity (p < 0.05). High NFC/NDF increased N excretion, total N excretion, and N excretion rate (p < 0.01). Additionally, allicin supplementation reduced fecal N excretion and N excretion rate and increased the apparent total-tract digestibility of N (p < 0.05). Fecal microbiota Alpha diversity analysis showed that high NFC/NDF decreased the Chao1, observed features, and Shannon (p < 0.05). At the phylum level, high NFC/NDF increased Pseudomonadota but decreased Cyanobacteriota, and a significant interaction between NFC/NDF and allicin was observed for Spirochaetota (p < 0.05). At the genus level, high NFC/NDF reduced unclassified_UCG-010 but increased Succinivibrio, unclassified_Muribaculaceae, and Methanobrevibacter (p < 0.05). Allicin increased Rikenellaceae_RC9_gut_group abundance (p < 0.05). In conclusion, dietary NFC/NDF and allicin supplementation modulate acid-base balance, N utilization, and fecal microbial composition in beef bulls, providing a scientific basis for improving feed efficiency.

Membrane-photoelectrode assemblies are a promising device configuration to directly electrolyse liquid water or water vapour into hydrogen and oxygen using solar energy. For the first time, we studied the performance and the stability of membrane-photoelectrode assemblies with BiVO4 photoanodes and CoPi co-catalysts on metallic felt at different temperatures. Upon illumination with simulated solar light, photocurrent densities of 0.23 mA cm[-2] at 1 V vs. RHE were obtained with the proton-exchange ionomer and 0.06 mA cm[-2] with the anion-exchange ionomer, all using liquid water at 30 °C. Operation with liquid water at 56 °C reduced the onset potential difference under light and in the dark due to more severe recombination of charges, independent of the choice of ionomer. The (photoelectro)chemical corrosion reactions resulted in the dissolution of Bi, V, Mo and Co, which was accelerated by temperature. The dissolved species formed solid particles mainly containing vanadium in the proton-exchange membranes. Operation of proton-exchange membrane-photoelectrode assemblies with water vapour resulted in an 85% decrease in the photocurrent density produced at 1 V vs. RHE as the hydration of the ionomer was reduced. The more acidic local pH at the ionomer-photoelectrode interface (compared to liquid water operation) accelerated the dissolution of the photoactive material in time, resulting in a faster decrease in the saturation current density. Membrane-photoelectrode assemblies have been demonstrated to expand practical device configurations beyond conventional planar setups. The remaining performance gap with respect to planar photoelectrodes highlights the gains that systematic optimisation of membrane-photoelectrode assemblies can still unlock.

Dietary, environmental, and physiological changes can challenge lamb health and performance during the feedlot transition. This study evaluated supplementation with a liquid direct-fed microbial (DFM; RSG Prime by BIO S.I.) on growth, fecal consistency, blood parameters, and fecal microbial populations in feedlot lambs fed a high-concentrate diet. Seventy-two Dorper × Katahdin lambs (60 d of age, initially 26.73 ± 0.35 kg BW) were fed for 63 d at Kansas State University. Lambs were randomly assigned by initial body weight to pens (3 lambs/pen) and allotted to one of two treatments during the treatment period (d 0-63), with 12 replications per treatment. Treatments were (1) control (CON, no DFM) or (2) DFM supplementation (15 mL/head, orally once daily at 08:00). The DFM contained Bacillus licheniformis (10 million CFU/mL), Bacillus subtilis (3.5 million CFU/mL), Lactobacillus acidophilus (3 million CFU/mL), and Bacillus pumilus (2 million CFU/mL). Lambs and feeders were weighed weekly to determine average daily gain (ADG), feed intake (ADFI), and gain-to-feed ratio (G: F). Feces were scored weekly (d 0-42). Blood was collected on d 0 and 21 from one lamb/pen, and fecal samples were collected for microbial analysis. No differences (P > 0.05) were observed for ADG, ADFI, or G: F. Fecal scores were unaffected by treatment (P > 0.05) but improved over time (P < 0.0001). No treatment × day interactions were detected for blood variables. Serum calcium tended to be lower (P = 0.06) in lambs supplemented with a DFM. Albumin and anion gap decreased significantly from d 0 to 21 (P ≤ 0.01), while glucose, urea nitrogen, globulin, magnesium, and bicarbonate increased (P ≤ 0.03). Calcium and potassium tended to be greater in the control group (P ≤ 0.10). Relative abundance of several genera in the feces showed a significant treatment effect (P ≤ 0.05) There were statistically significant shifts (P ≤ 0.05) in fecal microbial populations from d 0 to 21. Opitutae, Bifidobacteriales, Treponema, and Bifidobacterium showed treatment × day interactions (P ≤ 0.05). In summary, DFM supplementation did not significantly alter growth performance or fecal consistency in feedlot lambs. Lambs supplemented with a DFM had alterations in serum chemistry and changes in fecal microbial populations.

Excited-state ion radicals have recently attracted attention as powerful reductants or oxidants for electron-transfer photocatalysis. A key challenge in their application as photocatalysts is the short lifetime of their excited states, which directly impacts the efficiency of bimolecular photoinduced electron transfer. Here, we present a comprehensive photophysical study aimed at elucidating the factors that govern the lifetime of the doublet excited state in a series of 10 anion radicals derived from structurally related π-conjugated donor-acceptor-donor (DAD) molecules. In these systems, the acceptor is a 2,1,3-benzothiadiazole (BTD) unit flanked by arylene or oligo-(arylene) groups. The anion radicals, generated by chemical reduction in deoxygenated DMF, are stable and were characterized using UV-visible-near-IR absorption/emission spectroscopy and femtosecond transient absorption spectroscopy. Remarkably, the doublet excited state lifetimes vary by nearly 200-fold across the series, ranging from 2.9 to 565 ps. Nonradiative decay rates increase as the excited-state energy decreases, in a manner that is quantitatively consistent with the energy gap law for nonradiative decay. Faster decay is observed for anion radicals with highly delocalized π-systems, reflecting their lower excited-state energies. Finally, we demonstrate the catalytic utility of DAD anion radicals with long-lived doublet excited states in a consecutive photoinduced electron transfer (ConPET) process, using the photodebromination of 4-bromoacetophenone as a model reaction.

Type 4 renal tubular acidosis (RTA) is a common disorder characterized by hyperkalemic non-anion gap metabolic acidosis. Although type 4 RTA is generally attributed to impaired renal ammoniagenesis induced by hyperkalemia, whether defects in distal nephron acidification contribute to its pathophysiology remains unclear. Here, we investigated alterations in distal nephron acidification machinery in Kelch-like 3 knock-in (KLHL3-KI) mice, a genetically engineered model of pseudohypoaldosteronism type II. KLHL3-KI mice exhibited hyperkalemia, hyperchloremia, and reduced serum bicarbonate levels, consistent with type 4 RTA. Phosphoenolpyruvate carboxykinase (PEPCK), a key enzyme involved in proximal tubular ammoniagenesis, was significantly reduced in KLHL3-KI mice as compared with wild-type mice. In addition, ATP6V1B1, a subunit of the vacuolar H[+]-ATPase selectively expressed in intercalated cells, was significantly decreased in membrane fraction. Renal medullary expression of Rh C glycoprotein (RHCG), a major ammonia transporter in the distal nephron, was also reduced. To determine whether these changes were secondary to hyperkalemia, KLHL3-KI mice were fed a low-K[+] diet. Correction of hyperkalemia with a low-K[+] diet significantly increased RHCG abundance, whereas ATP6V1B1 levels remained unchanged. By immunostaining, we found that WNK1 bodies were detected in a subset of ATP6V1B1-positive cells. In sum, these findings demonstrate that distal nephron acidification pathways are dysregulated in KLHL3-KI mice. Whereas RHCG downregulation appears to be potassium-dependent, ATP6V1B1 reduction persists despite correction of hyperkalemia, suggesting the involvement of potassium-independent mechanisms. Our findings raise the possibility that dysregulated KLHL3 signaling contributes to impaired distal nephron acidification in type 4 RTA, which merits further investigation.

Bletilla striata is highly regarded in traditional Chinese medicine and has also gained widespread attention as a valuable medicinal plant resource. However, the molecular composition and bioactive potential of its polysaccharides present a significant knowledge gap. Herein, a specific glucomannan fraction, designated as BSP60, was purified from Bletilla striata tubers and subsequently subjected to structural, rheological, and biological evaluations. Comprehensive characterization via methylation-GC-MS, monosaccharide composition analysis, and 1D and 2D NMR techniques demonstrated that BSP60 possesses a β-(1 → 4)-linked backbone featuring alternating mannosyl and glucosyl units, with the mannose moieties exhibiting partial O-acetylation at their C-2 or C-3 positions (with an acetylation rate of 23.54%). Rheological studies showed that BSP60 aqueous solutions exhibit shear-thinning behavior and form an elastic-dominated viscoelastic network, with higher viscosity and storage modulus than dextran of comparable molecular weight, indicating enhanced intermolecular interactions. Biological assays revealed that the BSP60 effectively decreased the level of NO, IL-6, and TNF-α in LPS-triggered macrophages (RAW264.7). Furthermore, the scavenge ability of BSP60 to superoxide anion (O2[•-]) and ABTS[[+]•] radicals are significantly higher than that of hyaluronic acid. This study systematically characterizes the structural features of glucomannan derived from Bletilla striata, thereby establishing a robust scientific basis for its expanded utilization in the development of biomedical materials and functional cosmetic ingredients.

Metformin is the first-line oral anti-hyperglycemic agent for the treatment of type 2 diabetes mellitus due to its effectiveness, cost-efficiency, and acceptable safety profile. Although metformin possesses a favorable safety profile, a rare but serious adverse event known as metformin-associated lactic acidosis (MALA) may occur, particularly in patients with impaired renal clearance or predisposing comorbidities that favor drug retention. High anion-gap metabolic acidosis, increased concentrations of lactate (>5 mmol/L), and arterial pH of less than 7.35 are the hallmarks of MALA. MALA has a multifactorial pathophysiology, driven primarily by mitochondrial complex I inhibition, leading to an altered intracellular redox state and decreased hepatic lactate clearance. Crucially, MALA is fundamentally an accumulation disorder precipitated by an acute decline in kidney function rather than an intrinsic toxicity of metformin at therapeutic concentrations. Many precipitating factors, including acute kidney injury (AKI), chronic kidney disease (CKD), hepatic impairment, sepsis, hypoxia, and dehydration, substantially predispose individuals to this complication. Early identification of clinical signs, such as metabolic acidosis, tachypnea, hypotension, and altered mental status, is essential to a better patient outcome. Diagnostic assessment is based on arterial blood gas values, serum lactate, and renal function tests. Management aims at stopping metformin immediately, providing supportive care, and eliminating the medication through renal replacement therapy (RRT) in severe instances. Prevention measures focus on appropriate patient selection, renal monitoring, dose adjustment, and proactive temporary drug withdrawal during acute intercurrent illnesses ("sick-day rules"). MALA is not highly prevalent, and contemporary evidence demonstrates that mortality is highly context-dependent, with prompt extracorporeal interventions yielding robust survival rates.

Metformin-associated lactic acidosis (MALA) is a rare phenomenon mostly described in the setting of impaired renal elimination or following an acute overdose. While metformin is first-line treatment for type 2 diabetes mellitus, glucagon-like peptide-1 (GLP-1) receptor agonists and glucose-dependent insulinotropic polypeptide (GIP) and GLP-1 dual receptor agonists are frequent add-on agents. Both classes of medications share common gastrointestinal adverse reactions, including decreased appetite, nausea, vomiting, and abdominal pain. We present a series of four critically ill patients with type 2 diabetes mellitus on high-dose metformin who presented with severe MALA following the introduction or dose escalation of a GLP-1 or GIP/GLP-1 dual receptor agonist, or during an acute gastrointestinal illness while also on a maintenance dose of a GLP-1 receptor agonist, requiring acute renal replacement therapy. Prudence must be exercised when co-prescribing these 2 classes of medications with close monitoring of kidney function, possible reduction in metformin dose, and emphasis on sick day rule teaching.