Search Results (873)

Background: Idiopathic epilepsy (IE) is among the most frequent chronic neurological disorders of cats, but by definition it is associated with an unremarkable conventional brain MRI, leaving its temporal lobe pathophysiology poorly characterised. Objectives: To quantify interictal temporal lobe neurometabolite ratios in cats with IE using bilateral single-voxel ¹H-MRS and to compare them with healthy controls, and to explore relationships with seizure timing and signalment. Methods: In this prospective case–control study, 20 client-owned cats with idiopathic epilepsy and 20 healthy control cats underwent bilateral single-voxel ¹H-MRS (PRESS; TE 135 ms; 10 × 10 × 10 mm voxel centred on the mid-hippocampus and amygdala). N-acetylaspartate (NAA), total choline (tCho), and total creatine (tCr) were quantified and the NAA/tCr, NAA/tCho, tCho/tCr, and tCho/NAA ratios were compared (independent-samples t-tests; one-way ANOVA; Spearman correlation; α = 0.05). Results: Overall, no metabolite ratio differed significantly between groups across both hemispheres, and no ratio correlated with age, sex, breed, coat length, or neutering status. However, the right temporal lobe NAA/tCr ratio was significantly lower in epileptic cats (1.32 ± 0.29) than in controls (1.50 ± 0.20; p < 0.05). Seizure timing modulated the left-hemisphere spectrum: left tCho/tCr correlated negatively with the interval since the last seizure (Spearman r = −0.48; p = 0.035), and cats with ≤3 days between first and last seizures showed lower left NAA/tCho (0.89 ± 0.23 vs. 1.14 ± 0.24; p = 0.032) and higher left tCho/NAA (1.21 ± 0.40 vs. 0.91 ± 0.17; p = 0.039) than cats with a longer interval. Conclusions: Interictal ¹H-MRS detects temporal lobe metabolic disturbances, including a reduced right temporal lobe NAA/tCr ratio suggesting neuronal or metabolic dysfunction and seizure timing-dependent membrane turnover shifts, in cats with normal-appearing MRI. ¹H-MRS is therefore a promising non-invasive adjunct for characterising, monitoring, and potentially assisting in the localisation of metabolic abnormalities in feline IE and warrants validation in larger, longitudinally sampled cohorts. Full article

Maintaining sustainable production of healthy and nutritious food represents a major global challenge. Cultivated meat could reduce the environmental impact of livestock production, but it remains costly, largely due to the expense of fetal bovine serum, a common cell culture media supplement. Algal and cyanobacterial proteins, particularly phycobiliproteins, represent promising sustainable sources of potentially bioactive peptides that may contribute to the development of serum-reduced or serum-free culture media. This study investigated the potential of hydrolysates prepared using the protein extracts of the red alga Porphyra haitanensis and the cyanobacterium Arthrospira platensis as functional supplements for cell cultivation in a low-serum environment. Twelve hydrolysates were generated by treating protein extracts from Arthrospira platensis and Porphyra haitanensis with six proteolytic enzymes: pepsin, trypsin, chymotrypsin, subtilisin, thermolysin and proteinase K. The effects of these hydrolysates were studied in three cell models of mammalian (CHO-K1), avian (QM7), and fish (MACK1) origin. The effects of hydrolysates on cell viability, proliferation, and antioxidant activity were evaluated. A. platensis–chymotrypsin hydrolysate significantly improved QM7 cell viability compared to control in both 80% reduced-serum and tryptose phosphate broth conditions (p ≤ 0.0001). Additionally, peptide composition analysis and identification of amino acid sequences provided preliminary insights into potentially bioactive chromopeptides associated with the maintenance and promotion of cellular growth. Algae/cyanobacteria-derived hydrolysates positively regulated cell viability and proliferation in serum-reduced conditions, although effects were dependent on the algal species, enzymatic treatment, and cell type. These findings highlight their potential as sustainable supplements for alternative cell culture media. Full article

Growing demand for pavement maintenance promotes reclaimed asphalt pavement (RAP) recycling, yet multi-scale comparative research on rejuvenators remains limited. This study compared a commercial bio-based Rejuvenator A and a petroleum-based Rejuvenator B to reveal how chemical compositions control asphalt regeneration. Following JTG 3410-2025 standards, asphalt binders underwent extended RTFOT aging (75, 112.5, and 150 min) and were externally blended with rejuvenators at 5%, 7.5%, and 10% by binder mass. A multi-scale framework combining macro tests, interfacial characterization, SARA fraction analysis, ATR-FTIR, and molecular dynamics (MD) simulations was established. Results indicated that the two rejuvenators acted via different mechanisms. Rejuvenator B contained 31.64% saturates and restored aged asphalt mainly through physical dilution and softening. This rejuvenator formed 0–80 hydrogen bonds dominated by weak C–H···O interactions, and the corresponding rejuvenated asphalt yielded a CII of 0.293. It was effective for 75 min-aged binders yet produced more oxidation products after re-aging. Conversely, Rejuvenator A, characterized by 68.10% aromatics and 20.17% resins, exhibited a 3–5° lower equilibrium contact angle, and a roughly 13% shorter relative penetration time than Rejuvenator B. Its network of 150–250 hydrogen bonds effectively disrupted asphaltene aggregates, reducing the CII to 0.180. Consequently, Rejuvenator A successfully restored 112.5 min- and 150 min-aged asphalt with significantly lower secondary oxidation. These performance differences were governed by aromatic and polar fractions rather than feedstock origins. While quantitative findings are sample-specific, the established framework provides theoretical references for engineering rejuvenator selection and high-performance regenerant design. Full article

Background/Objectives: Pseudorabies virus (PRV) variant strains have caused widespread outbreaks in China since 2011, and currently available vaccines provide suboptimal protection. Glycoprotein D (gD), the principal target of virus-neutralizing antibodies, represents a promising antigen for subunit vaccine development. However, CHO cell-based production systems suitable for large-scale manufacturing remain insufficiently explored. This study aimed to develop a potentially scalable CHO cell-derived PRV gD subunit vaccine and evaluate its immunogenicity and protective efficacy in mice. Methods: A stable Chinese hamster ovary (CHO) suspension cell line secreting the extracellular domain of PRV gD was established through signal peptide optimization and stepwise serum-free adaptation. The recombinant gD protein was purified using Ni²⁺- Sepharose High-Performance affinity chromatography and subsequently formulated with MONTANIDE ISA 206 adjuvant. Immunogenicity and protective efficacy were assessed in BALB/c mice through serological analysis, neutralization assays, lethal challenge experiments, and quantitative PCR. Results: The gD subunit vaccine induced rapid seroconversion of gD-specific IgG antibodies as early as 7 days post immunization and exhibited a strong booster effect, maintaining high antibody levels. Neutralizing antibodies were first detected at 14 days and increased significantly after booster immunization, with titers markedly exceeding those induced by a commercial inactivated PRV vaccine at 42 days (p = 0.001). Following lethal challenge with 10⁴ TCID₅₀ of the highly virulent PRV-TJ variant strain, vaccinated mice achieved 100% survival without clinical signs. Viral genome copy numbers in the brain and spinal cord were reduced by approximately 3.3 to 4.4 log₁₀ relative to the PBS control group. Conclusions: The CHO cell-derived PRV gD subunit vaccine elicits robust humoral immune responses and provides complete protection against lethal PRV variant challenge in mice. These findings support its further evaluation in the natural swine host toward the development of a safe and scalable subunit vaccine for pseudorabies control. Full article

Background: To evaluate the effects of three lifestyle modification strategies—dietary supplementation with phenolic acid-rich Brussels chicory (Cho), Brussels chicory supplementation combined with supervised concurrent resistance exercise and high-intensity interval training (Cho-CT) or mindfulness-enhanced concurrent resistance exercise and high-intensity interval training (Cho-MeCT)—on high-density lipoprotein cholesterol efflux capacity (HDL-CEC) from macrophages and HDL subclass profiles (pre-β-HDL, HDL₃, HDL₂) in overweight adults. Methods: This study is an 8-week randomized controlled trial in which 97 overweight college students were randomized to Cho, Cho-CT, Cho-MeCT or control group. HDL-CEC from macrophages, the primary outcome, HDL subclass profiles, plasma activities of lecithin, such as cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) involved in remodeling HDL subclass profiles and plasma lipid profiles, and apolipoprotein AI were assessed at baseline and post-intervention. Results: Compared with the control treatment, all three lifestyle interventions comparably elicited a 1.18% to 1.78% elevations in HDL-CEC from macrophages (p < 0.001). Their improvements were accompanied by reductions in pre-β-HDL and HDL₃ concentrations and increased HDL₂ concentrations. However, there were no significant differences in plasma lipid profiles, apolipoprotein A-I, and plasma LCAT and CETP activities among the tested groups. Within the Cho, Cho-CT, and Cho-MeCT groups, changes in HDL-CEC from macrophages were positively correlated with changes in HDL₂ levels, whereas weak negative correlations were observed for pre-β-HDL and HDL₃, though these associations did not reach statistical significance. No comparable significant correlations were found in the control group. Conclusions: In overweight adults, sustained Brussels chicory supplementation, either alone or combined with concurrent exercise training, may yield comparable favorable changes in HDL-CEC from macrophages and HDL subclass profiles, though effect magnitudes appear modest in this pilot trial. Full article

Background/Objectives: Adherence to a low-carbohydrate diet induces distinct metabolic adaptations, yet the acute endocrine responses to individual macronutrients within this adapted state remain incompletely characterized. This study aimed to determine the acute, postprandial endocrine and glycemic kinetics following isolated isocaloric carbohydrate, protein, and fat boluses in healthy adults adapted to a low-carbohydrate diet. Methods: Participants (13 female, 11 male) completed three interventions which consisted of consuming an isovolumetric 300 kcal drink of either whey protein (PRO), dextrose (CHO), or olive oil (FAT) mixed with water. Blood was taken immediately prior to drink consumption and then every 30 min afterwards for 2 h in each condition. Continuous glucose monitoring occurred during each intervention. Results: Postprandial glucose remained stable following the FAT and PRO conditions, whereas the CHO condition significantly increased glucose concentrations over time (p < 0.01). Glucagon did not differ between FAT and CHO (p = 0.28) but increased following PRO compared to both FAT and CHO (p < 0.01). Insulin, C-peptide and amylin rose in the CHO condition, with smaller increases in PRO and minimal changes in FAT (p < 0.01). GLP-1 was elevated in the PRO condition compared to both FAT and CHO (p < 0.01), while GIP increased most in the CHO condition and differed across all treatments (p < 0.01). Ghrelin decreased after CHO and PRO, leptin did not significantly change across conditions, and both PP and PYY were lower in the CHO condition at later time points relative to FAT and PRO. Inflammatory markers showed minimal acute changes across conditions, although MCP-1 increased over time following PRO. Conclusions: In low-carbohydrate-adapted individuals, isolated macronutrient boluses elicit highly distinct, divergent endocrine signatures. The robust, acute glucagon response to pure protein does not cause short-term glycemic excursions, indicating that counter-regulatory incretin and insulinotropic pathways remain highly capable of preserving immediate glucose homeostasis. Full article

In the history of Buddhist literature, there have been two texts sharing the title Jātakastava (Birth Stories Hymn), one in Khotanese and the other in Sanskrit and Tibetan. These two texts exhibit similarities in genre, framework structure, thematic selection, and narrative logic, while diverging in the arrangement of specific materials, textual length, authorship, dissemination regions, and translation approaches. This study examines the Sanskrit–Tibetan bilingual Jātakastava—a text that has received limited scholarly attention—and undertakes a comparative analysis with the Khotanese Jātakastava to reassess the relationship between these two texts bearing the same title, as well as their associated authors and translators. Through the inclusion of stories such as the Elephant King Leaping off a Cliff and King Maitrībala sacrificing his flesh to feed the rākṣasas, the Sanskrit–Tibetan bilingual Jātakastava reinforces the sequence of the six perfections (pāramitās) and exhibits a more pronounced thematic progression in its arrangement, thus representing a concise model of classical Sanskrit hymns. The Sanskrit–Tibetan bilingual text is attributed to Jñānayaśas, who may be associated with the Northern Zhou translator Shénà Yēshě 闍那耶舍. The text was translated into Tibetan by the scholar Chos skyong bzang po of the Zhwa lu school, whose word-for-word rendering style possibly reflects a grammatical and commentarial approach characteristic of the Zhwa lu school’s linguistic studies. The Khotanese Jātakastava may be seen as an expanded recension of this Buddhist hymn tradition as it existed in Dunhuang around the tenth century, while the Sanskrit–Tibetan bilingual version represents an abridged form that reached Tibet in the fifteenth century. The similarities and differences between the two texts reveal the inherent tension between localized dissemination and standardized compilation in the transmission of Jātaka narratives. Full article

The sustainable reuse of industrial by-products in fermentation processes supports the transition toward a circular bioeconomy. This study evaluated the production yield of fungal chitosan (FuCho) by nine Mucorales strains, including novel species isolated from Brazilian biomes, cultivated in alternative culture media composed of corn steep liquor (CSL) and biodiesel-derived glycerol (GLY). Furthermore, the physicochemical properties, potential of irritation, and broad-spectrum antimicrobial activity of the extracted FuCho were investigated. Among the strains tested in CSL-GLY medium, FuCho yields ranged from $17.88\mathrm{mg}/\mathrm{g}$ (Absidia aguabelensis) to $126.56\mathrm{mg}/\mathrm{g}$ (Absidia caatinguensis). Optimization using a $2^2$ central composite rotatable design (CCRD) yielded maximum FuCho productions of $128.26\mathrm{mg}/\mathrm{g}$ for A. caatinguensis (center point condition) and $164.92\mathrm{mg}/\mathrm{g}$ for Cunninghamella elegans (lower CSL concentration). Physicochemical characterization revealed degrees of deacetylation of 85% (A. caatinguensis) and 75% (C. elegans), crystallinity indices of 36.74% and 37.93%, and viscometric molecular weights ($M_v$) of $1.6\times {10}^3\mathrm{g}/\mathrm{mol}$ and $2.0\times {10}^3\mathrm{g}/\mathrm{mol}$, respectively. In the HET-CAM assay, both FuCho samples were classified as non-irritating, exhibiting no inflammatory, vascular, or vasoconstrictive effects. FuCho demonstrated minimum inhibitory concentrations (MIC) against all tested pathogenic bacterial strains and Candida species, with A. caatinguensis FuCho displaying lower MIC values for the majority of microorganisms compared to C. elegans FuCho. Confocal laser scanning microscopy confirmed a significant reduction in microbial cell viability, driven by membrane disruption in Escherichia coli and Staphylococcus aureus. These findings validate the CSL-GLY mixture as a cost-effective, eco-friendly culture medium for producing high-value biopolymers with pharmaceutical potential, underscoring the biotechnological relevance of Brazilian Mucorales strains. Full article

Background/Objectives: Proximal glue migration toward the saphenofemoral junction (SFJ) and endovenous glue-induced thrombosis are recognised concerns during cyanoacrylate ablation. This exploratory pilot study compared standard and modified ultrasound-guided compression protocols. Methods: Thirty patients with incompetent great saphenous veins (GSVs) were allocated non-randomly, in two sequential cohorts, to a standard (n = 15) or modified (n = 15) protocol. The modified protocol added a “release-and-check” duplex assessment after the initial 3 min compression, a 1 min recompression, and an extra minute for veins > 5.5 mm. The primary outcome was glue migration distance from the compression level, measured immediately postoperatively. Clinical and thromboembolic outcomes were not systematically ascertained; follow-up was one week. Results: Baseline variables were comparable (standardised differences ≤ 0.31). Mean migration distance was lower with the modified protocol (0.80 ± 0.34 vs. 1.97 ± 0.51 cm; mean difference −1.17 cm, 95% CI −1.50 to −0.85; p < 0.0001), persisting after covariate adjustment. Residual stump length was greater (4.41 ± 0.34 vs. 2.49 ± 1.27 cm; p < 0.001), although this SFJ-referenced measure is confounded by the unrecorded compression distance. Deep venous extension occurred in 3/15 standard and 0/15 modified limbs (p = 0.22); all three were asymptomatic Cho grade III events, resolved at one week. Immediate migration was recorded in 7/15 versus 0/15 limbs (p = 0.006). Conclusions: In this small, non-randomised exploratory cohort, a “release-and-check” modification was associated with shorter immediate glue migration. These hypothesis-generating findings rest on an unblinded surrogate endpoint with one-week follow-up and do not establish clinical safety, effectiveness or durability; adequately powered randomised trials with blinded assessment and adjudicated endpoints are required. Full article

Alzheimer’s disease (AD) is characterized by the excessive production and aggregation of β-amyloid (Aβ), which serves as key pathological features of disease progression. Although Humulus japonicus Siebold & Zucc. is a traditional medicinal plant rich in flavonoids and phenolic compounds, its specific anti-amyloidogenic constituents remain to be fully elucidated. This study evaluated the effects of the aerial parts of H. japonicus on Aβ production and aggregation, and identified its active constituents through bioassay-guided isolation. The 80% ethanolic extract of H. japonicus aerial parts significantly reduced soluble amyloid precursor protein β (sAPPβ) levels and BACE1 protein expression in Chinese Hamster Ovary cells stably expressing amyloid precursor protein (APP-CHO cells). Furthermore, it inhibited Aβ aggregation and promoted fibril disaggregation in Thioflavin T assays. Among the solvent-partitioned fractions, the ethyl acetate fraction exhibited the most potent anti-amyloidogenic activity and was subjected to chromatographic isolation, leading to the characterization of fourteen compounds (7 flavonoids, 2 phenolic acids, 2 sesquiterpenoids, and 3 phenylpropanoids). Specifically, luteolin 7-O-β-d-glucopyranoside (2), orientin (3), vitexin (5), vomifoliol (8), abscisic acid (9), and p-hydroxyphenylethyl-p-coumarate (12) significantly decreased sAPPβ levels, as well as BACE1 and Presenilin-1 protein expression. Meanwhile, luteolin 7-O-β-d-glucopyranoside (2), orientin (3), vitexin (5), and quercetin 7-O-β-d-glucopyranoside trimer (7) effectively reduced Aβ aggregation and enhanced the disaggregation of pre-formed Aβ aggregates. Collectively, luteolin 7-O-β-d-glucopyranoside (2), orientin (3), and vitexin (5) exhibited the most consistent dual inhibitory effects on both Aβ production and aggregation, supporting their selection as key marker compounds. Among the extracts prepared with varying ethanol concentrations, the 100% ethanol extract yielded the highest levels of these flavonoid glycosides and exhibited the strongest anti-amyloidogenic activity. These findings suggest that the aerial parts of H. japonicus and its constituent flavonoid glycosides represent promising natural resources for modulating amyloidogenic APP processing and Aβ aggregation in AD. Full article

Background/Objectives: Innovative topical delivery systems are needed to improve the stability, loading capacity, and performance of poorly water-soluble bioactive compounds. TransfersomILs, hybrid nanosystems combining transfersomes with ionic liquids (ILs), represent a promising strategy for this purpose. This work assessed the effect of incorporating cholinium-based ILs into transfersomal formulations loaded with hydroxycinnamic acids (HCAs)—ferulic, caffeic, and p-coumaric acids. Methods: TransfersomILs were prepared by the thin-film hydration method followed by sonication, with or without HCA incorporation. Formulations were characterised in terms of physicochemical properties, storage stability and impact on keratinocyte viability. In vitro release, permeation, and occlusion studies were also performed. Results: IL incorporation significantly improved formulation performance. TransfersomILs showed smaller vesicle sizes and more negative zeta potential values than conventional transfersomes, indicating improved physicochemical characteristics. ILs also increased association efficiency and loading capacity for all HCAs, although the magnitude depended on both the IL and the compound. Release profiles were compound-dependent, reflecting distinct release kinetics due to variable HCA–IL–membrane interactions. Permeation studies showed enhanced HCA flux across both silastic and human epidermal membranes compared with aqueous solutions and/or conventional transfersomes, with [Cho][Gly] generally showing superior performance. All formulations demonstrated acceptable cytocompatibility and occlusive properties. Conclusions: The combination of transfersomes and cholinium-based ILs demonstrated a synergistic effect, highlighting transfersomILs as a versatile platform for improving the topical delivery of HCAs. Full article

Antrodia cinnamomea (AC) is a medicinal mushroom native to Taiwan. This study evaluated the genotoxicity and toxicity of red quinoa and barley-based solid-state fermented AC mycelium (RQBACM). The safety of RQBACM was evaluated via a 90-day repeated-dose oral toxicity study in rats and a battery of genotoxicity assays, including the Ames, CHO-K1 chromosomal aberration, and in vivo micronucleus tests. RQBACM exhibited no mutagenicity in the Ames test, regardless of S9 metabolic activation, nor did it induce chromosomal aberrations in CHO-K1 cells. In mice, no significant changes in reticulocyte or micronucleus frequency were observed at doses up to 5000 mg/kg. In the 90-day study, Sprague–Dawley rats receiving up to 3000 mg/kg/day showed no treatment-related adverse effects, except for a slight reduction in body weight in high-dose males. No significant changes were found in hematology, serum biochemistry, urinalysis, organ weights, or histopathology. The no-observed-adverse-effect level (NOAEL) was determined to be 3000 mg/kg/day, supporting the safety of RQBACM for potential human consumption. Full article

Seminal plasma regulates sperm function; oxidative stress (OS) and inflammation can impair semen biochemical homeostasis. This study investigated seminal biochemical/enzymatic compounds and Trolox Equivalent Antioxidant Capacity (TEAC) in seminal plasma and spermatozoa from normozoospermic men (>5th percentile) assessing their relationship with sperm quality. The strongest significant (p < 0.001 ***) negative correlations (r) were found for normal sperm morphology and albumin (ALB, r = −0.515 ***), cholesterol (CHO, r = −0.386 ***), lactate dehydrogenase (LDH, r = −0.514 ***), sperm TEAC (r = −0.438 ***) and homocysteine (Hcy; r = −0.381 ***); sperm progressive motility with ALB (r = −0.495 ***), CHO (r = −0.349 ***), LDH (r = −0.355 ***) and sperm TEAC (r = −0.295 ***); sperm vitality with creatine kinase (CK, r = −0.486 ***) and LDH (r = −0.380 ***). Total prostate-specific antigen (TPSA) was positively correlated with sperm quality. After stratification, subjects with low-normal sperm parameters showed significantly higher levels of ALB, CHO, CK, LDH, interleukin 6 (IL-6), Hcy and sperm TEAC vs. high-normal parameter subjects. ALB, Hcy and LDH were increased in individuals with progressive motility, normal morphology and vitality < 25th percentile indicating their involvement in OS, inflammation and accessory gland activity. These findings suggest that World Health Organization lower reference limits are not a strict cutoff between normal and abnormal semen quality but rather define a baseline of biochemical efficiency and sperm function, highlighting the synergy between spermatozoa and seminal plasma. Full article

Non-heme iron enzyme-catalyzed enantioselective alkene trifluoromethyl azidation represents a powerful strategy for constructing valuable chiral organofluorine compounds, yet the mechanistic origins of enantioselectivity controlled by the key residues in the enzyme’s chiral environment remain elusive. Herein, we integrate density functional theory (DFT) calculations, classical molecular dynamics (MD) simulations, and quantum mechanical/molecular mechanical (QM/MM) calculations to elucidate the mechanism and the origin of enantiocontrol in this transformation. Our computational study reveals that radical addition from the CF₃ radical to the 4-methoxystyrene substrate constitutes the enantioselectivity-determining step. The enantioselectivity arises from energetic differences driven by H···H repulsions and C-H···O and N-H···F interactions between the substrate and the binding pocket defined by key residues I335V, F188Q, and R324 near the active site, which stabilize the transition state leading to the major enantiomer. These findings provide mechanistic insights into non-heme iron enzyme-catalyzed asymmetric azido-trifluoromethylation of alkenes and establish a structural framework for rational biocatalyst design. Full article

Background/Objectives: Exogenous ketone supplementation has been proposed to enhance endurance performance by altering substrate metabolism and sparing muscle glycogen. Prolonged carbohydrate restriction may upregulate ketolytic capacity and could therefore modulate the response to exogenous ketone ingestion. This study investigated the impact of increasing circulating ketone bodies through exogenous ketone supplementation on endurance performance in athletes chronically adapted to a ketogenic diet. Methods: Participants (n = 9 recreationally active males, with ≥1 year of ketogenic adherence) visited the lab four times. The first visit determined their $\stackrel{.}{\mathrm{V}}$O₂max. The second visit accustomed them to test procedures. In a counterbalanced design, visits three and four tested the consumption of a 60 g carbohydrate beverage (CHO), or a beverage comprising 60 g carbohydrate and 0.5 g/kg 1,3-butanediol (CHO + BD). This was followed by a 60 min set-intensity exercise bout, followed by a 16.1 km time trial. Results: βHB significantly increased in the CHO + BD group (rest: 0.72 ± 0.33 mmol/L; post-exercise: 1.69 ± 0.30 mmol/L) compared to CHO (rest: 0.80 ± 0.53; post-exercise: 0.55 ± 0.30) (p < 0.001). There was no significant difference in time trial performance between groups (1606 ± 138 s; 1620 ± 134 s; p > 0.05). During set intensity exercise, there was no significant main effect of supplementation on lactate concentration, substrate oxidation, oxygen consumption at a fixed workload, RPE or heart rate (p > 0.05). However, glucose was significantly lower at minutes 40 and 60 of set intensity exercise in CHO + BD compared to CHO. Conclusions: No significant effect of 1,3-butanediol ingestion on endurance performance was detected in this sample of nine chronically ketogenic male athletes. βHB significantly increased from resting levels; however, time trial performance did not differ between conditions. Given the small sample and limited statistical power, these preliminary findings indicate no detectable ergogenic effect under the present conditions rather than evidence of no effect, and larger studies are warranted. Full article