Search PubMedSearch

SEARCH · Search PubMed

Results for “machine learning models”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

885 records · Page 15Linked to original sources

Distress Intolerance, Social Anxiety, and Depressive Symptoms in Adolescents: Evidence from Random-Intercept Cross-Lagged Panel and Cross-Lagged Panel Network Analyses.

Social anxiety and depressive symptoms frequently co-occur during adolescence, yet the mechanisms underlying their longitudinal associations remain insufficiently understood. Distress intolerance has been proposed as a transdiagnostic risk factor implicated across internalizing symptoms. However, it remains unclear whether distress intolerance is predicted by social anxiety and depressive symptoms, as well as the underlying mechanisms among these three constructs. The specific symptoms most centrally involved in these cross-domain associations remain poorly understood. The present study investigated the longitudinal associations among distress intolerance, social anxiety, and depressive symptoms using a dual-method framework combining random-intercept cross-lagged panel models (RI-CLPM) and cross-lagged panel network (CLPN) analyses. A total of 1,378 Chinese adolescents (Mage = 12.57, SDage = 0.63; 50.4% female) were assessed at three time points with six-month intervals between waves. The RI-CLPM analyses revealed that higher distress intolerance prospectively predicted subsequent increases in both social anxiety and depressive symptoms, whereas elevated social anxiety and depressive symptoms in turn predicted subsequent increases in distress intolerance. Moreover, distress intolerance mediated the longitudinal associations between social anxiety and depressive symptoms. Additionally, distress intolerance was also indirectly associated with its own subsequent levels through social anxiety and depressive symptoms. The CLPN analyses revealed that fear of negative evaluation and fatigue were the strongest predictors of other network nodes from T1 to T2 and from T2 to T3, respectively. In contrast, distress intolerance symptoms were predominantly predicted by other nodes in both cross-lagged networks. These findings extend prior views of distress intolerance as a unidirectional vulnerability by showing that distress intolerance is also predicted by social anxiety and depressive symptoms and accounts for part of their longitudinal associations across adolescence.

Humans

Development and validation of a liquid chromatography-tandem mass spectrometry method for the quantification of twenty-five steroids in equine serum.

Steroids are potential biomarkers for monitoring equine pregnancy. However, immunoassays currently used for their quantification suffer from cross-reactivity and limited specificity, thus requiring more accurate methods. This study reports the development and validation of a robust liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of 25 steroids covering the main biosynthetic pathways of progestogens, corticosteroids, androgens, and estrogens. Steroids were extracted by protein precipitation followed by evaporation, derivatization, and reconstitution before LC-MS/MS analysis. A surrogate matrix was used for calibration and validation to avoid endogenous interference. Validation was performed according to and partly adapted from Clinical and Laboratory Standards Institute guidelines (CLSI), including linearity, trueness, precision, limits of detection and quantification, measurement uncertainty, recovery, matrix effects, carryover, selectivity, and stability. Calibration curves were fitted using the best-performing weighted linear or quadratic regression model, yielding excellent linearity (R2&#xa0;>&#xa0;0.990), trueness between -9.0% and 2.3%, and intra- and inter-day precision <6.3%. Lower limits of quantification ranged from 2.07 to 2250&#xa0;pg/mL depending on physiological analytes concentration. Extraction recovery averaged 24.3-114.9%, matrix effects were acceptable, and accuracy ranged from 94.4% to 98.9%. No carryover or interferences were detected. Measurement uncertainty remained <15%. This study presents the first LC-MS/MS method partially validated per CLSI criteria for the quantification of 24 steroids in equine serum. The method offers a sensitive and specific alternative to immunoassays and provides a robust tool for equine steroid profiling with potential applications in pregnancy monitoring, placentitis diagnosis, and fetal sex determination.

Animals

Beyond species trees: pervasive gene flow limits phylogenomic resolution in the diversification of Juniperus from the Qinghai-Tibet Plateau.

Understanding how lineages diversify despite persistent ancestral polymorphism and recurrent gene flow remains a central challenge in evolutionary biology. Juniperus distributed across the Qinghai-Tibet Plateau provide an ideal system for addressing this question because repeated geological uplift and climatic oscillations have likely promoted cycles of lineage divergence, range shifts, and secondary contact. Here, we combined approximately 1.08 million genome-wide SNPs from 164 individuals representing thirteen Juniperus lineages with phylogenomic datasets comprising 3,381 nuclear single-copy genes and nearly complete plastomes. We detected extensive phylogenomic discordance and cytonuclear incongruence across genomic datasets. Topology weighting, coalescent simulations, quartet-based tests, and analyses of gene flow and reticulation collectively support the interpretation that these patterns were shaped by the combined effects of prolonged incomplete lineage sorting and gene flow during lineage diversification. Ecological niche analyses further provide a spatial and climatic context in which environmentally similar lineages may have had greater opportunities for secondary contact during historical range shifts. Collectively, our results reveal that the evolutionary history of Qinghai-Tibet Plateau Juniperus is characterized by reticulate diversification rather than strictly bifurcating evolution, and demonstrate how genome-wide discordance can provide biological insights into the evolutionary processes underlying lineage diversification.

Gene Flow

Formation of environmental persistent free radicals in soil of ammunition demolition site: Roles of 2,4,6-trinitrotoluene and heavy metals.

Environmental Persistent Free Radicals (EPFRs) are a particular type of contaminant present in soil. This study investigated the formation process, environmental behavior, and main influencing variables of EPFRs in soils contaminated with heavy metals and 2,4,6-trinitrotoluene (TNT) from an ammunition demolition site. The results showed that the concentration of total organic carbon (TOC) in the soil was negatively correlated with EPFRs (r = -0.29). In contrast, the content of TNT and copper was significantly positively correlated with EPFRs (r = 0.90 and 0.78, respectively), indicating that TNT acts as a precursor macromolecule in the formation of EPFRs in this type of contaminated soil. Transition metal Cu may be an essential carrier in EPFR production. In order to explore the possible formation mechanism of EPFRs, a simulation experiment was carried out under different temperature and light conditions. The results showed that the photolysis process of TNT was impacted by external energy sources such as heat and light. TNT was firstly adsorbed onto the surface of a transition metal (Cu), and then EPFRs were formed through further electron transfer. This is the first study to detect significant levels of EPFRs in the soil at ammunition demolition sites.

Trinitrotoluene

Three-dimensional porous nano-hydroxyapatite@gelatin composite as efficient adsorbent for uranyl ion removal from low-level radioactive wastewater.

The contamination of water resources by uranyl (UO22+) ions poses significant environmental and health risks, requiring the development of efficient and sustainable remediation strategies. Adsorption-based techniques have emerged as promising approaches in the field of UO22+ removal, but the design of cost-effective, high-capacity, and environmentally friendly adsorbents remains challenging. In this study, a three-dimensional porous nano-hydroxyapatite@gelatin (nHAP@Ge) composite was synthesized through glutaraldehyde cross-linking, combining the structural stability of Ge with the high uranium affinity of nHAP. The optimized nHAP@Ge, with a nHAP:Ge mass ratio of 1:0.5, exhibited exceptional UO22+ removal efficiency (97 %), along with high adsorption capacity (364.03 mg/g). Systematic characterizations using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) methods revealed that the porous structure and surface functional groups (-OH, Ca2+, and PO43-) of the material synergistically contributed to binding UO22+ species. Furthermore, the incorporation of nHAP into the Ge framework resulted in enhanced thermal stability while significantly improving the UO22+ adsorption performance. This work presents a scalable, eco-friendly, and recyclable strategy for the effective treatment of uranium-contaminated water, with potential applications in nuclear wastewater treatment and environmental remediation.

Adsorption

In Vivo Genome Editing Approach to Disrupt Hydroxyacid Oxidase 1 for the Treatment of Primary Hyperoxaluria Type 1.

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disorder that leads to kidney and liver failure. PH1 is caused by a mutation in the alanine glyoxylate aminotransferase (AGXT) gene, which encodes a key metabolic enzyme that converts glyoxylate to glycine in the liver. Inability to metabolize glyoxylate leads to oxalate overproduction, yielding insoluble calcium oxalate crystals; accumulation of these crystals leads to progressive organ failure. Here, we used a novel, minimally disruptive genome-editing approach to disrupt the mechanism of action of hydroxyacid oxidase 1 (HAO1), an upstream enzyme in the glyoxylate metabolic pathway. Successful gene editing and disruption of the HAO1 gene is expected to increase levels of glycolate, a harmless intermediate of the glycine metabolic pathway, thereby preventing the formation of calcium oxalate crystals. We intravenously administered an adeno-associated virus (AAV) vector expressing the M1HAO1 meganuclease to both wild-type and Agxt-/- mice, a mouse model of PH1. We observed >30% editing of HAO1 in Agxt-/- mice, correlating with a dose-dependent increase in serum glycolate levels. At the highest dose tested, urine glycolate levels increased by 79%, with a concomitant 75% decrease in urine oxalate levels. We also evaluated in&#xa0;vivo targeting in rhesus macaques injected with AAV expressing two different versions of the HAO1 meganuclease. Dose-dependent editing of hepatic DNA and RNA was achieved, and serum glycolate levels changed in a manner consistent with successful liver editing; additionally, the treatment was well tolerated. Our results indicate that AAV-delivered meganucleases can effectively target HAO1 in mice and nonhuman primates to achieve high levels of HAO1 gene editing. Moreover, increased glycolate levels in serum indicate that this intervention significantly impacts the HAO1-mediated glycolate-to-glyoxylate pathway. These data suggest that this approach may represent an effective treatment for PH1.

Hyperoxaluria, Primary

Unconfined compressive strength prediction for the ordinary Portland cement-steel slag-silica fume ternary system based on response surface methodology.

This research was undertaken to address environmental concerns associated with industrial solid waste and to reduce cement consumption in geotechnical engineering. It specifically investigates the feasibility of using steel slag (SS) and silica fume (SF) as partial substitutes for ordinary Portland cement (OPC) in soil stabilization. The effects of SS, SF, OPC, and initial moisture content on the unconfined compressive strength (UCS) of stabilized soil were investigated through single-factor experiments and response surface methodology (RSM). The results show that SS and SF can synergistically enhance the strength of stabilized soil, although their interaction effect was not statistically significant within the investigated ranges. Compared with soil stabilized solely with OPC, the addition of 18 % SS and 10 % SF reduced OPC consumption by 3 % without compromising strength. Microstructural and compositional analyses further revealed that SS mainly supplied calcium- and silica-bearing components, while SF provided highly reactive silica and micro-filling effects, jointly promoting hydration reactions and improving the compactness of the stabilized soil matrix. As a result, more hydration products were formed in the OPC/SS/SF-stabilized soil than in the OPC-stabilized soil, which contributed to pore filling and strength enhancement. This study provides useful guidance for the sustainable utilization of industrial solid waste and the low-carbon development of soil stabilization materials.

Construction Materials

Double-Axis Maxillary Skeletal Expander Suggests Higher Expansion Efficiency in Early Activation: A Finite Element Analysis.

INTRODUCTION: Conventional single-axis maxillary skeletal expanders (MSE) have some drawbacks, such as limited control over maxillary expansion and possible asymmetric expansion between the anterior nasal spine (ANS) and posterior nasal spine (PNS). This report introduces a double-axis maxillary skeletal expander (DAMSE) concept to overcome these drawbacks and enhance the efficiency of maxillary skeletal expansion. MATERIALS AND METHODS: Five different DAMSE designs were compared with a conventional single-axis MSE. Finite element analysis was performed to analyse their expansion efficiency, stress magnitude and distribution occurring in a simplified bone model. RESULTS: DAMSE outperformed the single-axis MSE and provided better control over ANS and PNS expansion. During early activation, the highest expansion efficiency (31.7%) was achieved by DAMSE Model V, 13% more efficient than the single-axis MSE. This efficiency was increased to 100.8% by combining the DAMSE Model V with midpalatal suture surgery. However, with the simplified bone model, the current study could not demonstrate that DAMSE can resolve the issue of asymmetric expansion between ANS and PNS. CONCLUSIONS: An appropriately designed DAMSE can be a promising tool for maxillary expansion treatment. DAMSE offers more efficient treatment than the conventional single-axis MSE while maintaining similar levels of patient comfort and invasiveness.

Finite Element Analysis

Development and validation of a novel LC-MS/MS method for simultaneous quantification of fidaxomicin and metabolite (OP-1118) from feces for gut pharmacobiome studies.

Fidaxomicin is a first-line antibiotic for treating Clostridioides difficile infection. While it has low systemic absorption and reaches high colonic concentrations, it is hydrolyzed to a less active metabolite, OP-1118. Few studies have completely described critical experimental details of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for quantifying fecal fidaxomicin and OP-1118. This study developed and validated a simple, fast, and sensitive LC-MS/MS method to quantify fidaxomicin and OP-1118 in human and mouse feces. This method simplified fecal sample preparation without the use of solid phase extraction and optimized LC-MS/MS parameters. A broad working range (0.3-1000&#xa0;ng/ml) in both diluted human and murine fecal matrices was achieved with good intra- and inter-day accuracy (93-107%), precision (1-7%), and recovery (70-105%) as well as little IS-normalized matrix effects. This method was utilized to quantify fidaxomicin and OP-1118 in human and murine fecal samples. This novel method was simple, fast, sensitive, and accurate in analyzing fecal fidaxomicin and OP-1118 and could be deployed to facilitate gut pharmacobiome research.

Feces

Vortex-assisted liquid-liquid microextraction based on natural deep eutectic solvents for the determination of pyrethroid pesticides in urine.

A novel, facile, and environmentally friendly analytical method was developed based on vortex-assisted liquid-liquid microextraction and high-performance liquid chromatography with diode-array detection for detecting pyrethroid pesticides (PPs) in urine. Natural deep eutectic solvents (NADESs) were prepared using plant essential oil-derived monoterpenoids (thymol, carvacrol, and menthol) combined with aromatic primary alcohols (benzyl alcohol, phenethyl alcohol, and phenylpropyl alcohol) as hydrogen bond donors and acceptors. These solvents served as environmentally benign extraction media, thereby avoiding the use of conventional volatile, toxic organic solvents. NADESs are naturally derived, easy to prepare, biodegradable, and environmentally friendly solvents. Hydrophobic and &#x3c0;-&#x3c0; interactions between the NADESs and PPs may contribute to enhancing the affinity of PPs toward the NADESs phase. Vortex technology, accelerating mass transfer between the sample and extractant phases, enables fast extraction of PPs. Under optimized conditions, the method achieved a low detection limit (0.002&#xa0;mg&#xa0;L-1), satisfactory precision with relative standard deviations (0.3%-2.4%), and acceptable recovery (80.7%-86.2%). The method demonstrated excellent performance in urine analysis and was feasible as a facile and green strategy for monitoring the content of PPs in biological matrices and assessing exposure risk.

Liquid Phase Microextraction

One-carbon metabolism and chemotherapy-induced toxicities in patients with stage II-III colorectal cancer: a prospective cohort study.

BACKGROUND: One-carbon metabolism (OCM) is a target of the chemotherapeutic agent capecitabine. OBJECTIVES: We investigated OCM biomarker concentrations in relation to capecitabine-induced toxicities in patients with stage II-III colorectal cancer. METHODS: Within a prospective cohort, 297 patients receiving adjuvant capecitabine-based chemotherapy were included. Pretreatment plasma concentrations of the OCM biomarkers folate, vitamin B2, vitamin B6, vitamin B12, total homocysteine, methionine, serine, and glycine were determined. We also investigated whether associations differed according to methylenetetrahydrofolate reductase (MTHFR) C677T genotypes. Chemotherapy-induced toxicities were defined as toxicity-induced modifications of capecitabine treatment. To allow for inspection of shapes of the associations, restricted cubic splines and Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) adjusted for age and sex. RESULTS: In total, 156 (53%) patients experienced toxicity-induced modifications of capecitabine treatment. Folate was not associated with toxicities in the overall population. Higher folate concentrations were associated with a lower risk of toxicities in patients with MTHFR C677T CT/TT genotype (HRperdoubling: 0.75; 95% CI: 0.57, 0.98) but not in patients with CC genotype (HRperdoubling: 1.17; 95% CI: 0.84, 1.63). Higher concentrations of vitamin B2 were associated with a lower risk of toxicities (HRperdoubling: 0.81; 95% CI: 0.67, 0.99), whereas higher glycine concentrations were associated with a higher risk of toxicities (HRperdoubling: 1.87; 95% CI: 1.18, 2.94). The association between vitamin B6 and vitamin B12 and toxicities appeared nonlinear. Homocysteine, methionine, and serine were not associated with toxicities. CONCLUSIONS: Future studies investigating whether nutrition-guided optimization of OCM biomarkers will result in improved treatment tolerance are warranted.

Humans

Sugar rationing during the first 1000 days and early onset cancer: a natural experiment.

BACKGROUND: The "first 1000 days" of life is a critical window for metabolic programming, while the long-term oncological consequences of nutritional exposures during this period remain understudied. OBJECTIVES: We aimed to evaluate whether restricted sugar intake in utero and during early childhood reduces risk of early onset cancer diagnosis and mortality in adulthood, utilizing a natural experiment. METHODS: We analyzed 63,819 United Kingdom Biobank participants born between October 1951 and March 1956, spanning the end of United Kingdom sugar rationing (September 1953). Leveraging a quasi-experimental birth cohort design, we compared participants exposed to sugar rationing in utero and during infancy with those unexposed. Early onset cancer incidence (&#x2264;50 y) and mortality were ascertained via integrated national Cancer Registry and hospital inpatient records. Multivariable Cox proportional hazards models (including Gompertz distribution) were used to estimate hazard ratios (HRs), with exploratory site-specific analyses. RESULTS: Among 63,819 participants (56.3% female), 40,397 were exposed to rationing and 23,422 were unexposed. Early life sugar restriction significantly reduced early onset cancer risk (HR: 0.66; 95% confidence interval: 0.53, 0.81; P < 0.001). A dose-response relationship was observed, with peak protection in individuals exposed for &#x2264;24 mo postnatally. This protection was observed systemically across solid tumors, independent of specific cancer sites. Specificity was corroborated by null associations with negative controls (herpes zoster and cataract). No significant difference was found for cancer-specific mortality. CONCLUSIONS: Restricting sugar intake during the first 1000 days is associated with a reduced risk of early onset cancer, extending the disease-free lifespan. The divergence between reduced incidence and unchanged mortality suggests early life metabolic environments primarily influence tumor latency rather than biological aggressiveness. These findings highlight the potential long-term public health implications of early life dietary guidelines against the rising burden of early onset cancer.

Humans

The incidence and descriptive factors of calcaneal malunion after surgical fixation of intra-articular calcaneal fractures using the sinus tarsi approach: A retrospective cohort study with binary logistic regression analysis.

BACKGROUND: This study evaluated the incidence of calcaneal malunion after minimally invasive sinus tarsi approach (MIS-STA) in displaced intra-articular calcaneal fractures (I-ACFs) and identified related descriptive factors of calcaneal malunion. METHODS: A retrospective review of 99 displaced I-ACFs treated with MIS-STA was conducted. Demographic data, pre-operative radiographs, and operative details were analyzed. Outcomes included numerical rating scale (NRS) pain scores at rest and during activities of daily living (ADL), Foot and Ankle Ability Measure (FAAM) for ADL and radiographic parameters. Logistic regression was used to identify descriptive factors associated with malunion. RESULTS: Malunion occurred in 33/99 cases (33.3%). The significant descriptive factors were the initial B&#xf6;hler angle <&#x202f;0.5 &#xb0;, time to surgery >&#x202f;12.5 days, and Sanders type &#x2265;&#x202f;III. Malunion patients had significantly worse NRS and FAAM scores (p&#x202f;&#x2264;&#x202f;0.001). CONCLUSION: Calcaneal malunion after MIS-STA occurred in one-third of cases, with three descriptive factors identified and poorer outcomes observed. LEVEL OF EVIDENCE: III, Comparative retrospective study with binary logistic regression analysis.

Humans

Anatomy and Biomechanics of the Deltoid Ligament Complex in Healthy Ankles: Protocol for a Systematic Review and Meta-Analysis.

INTRODUCTION: Up to one in two individuals who have a history of an ankle injury will develop chronic ankle instability, which subsequently increases the risk of osteoarthritis development. Although lateral ankle ligament injuries are the most common, recent research shows that concomitant injuries to the deltoid (medial collateral) ligament complex may be more prevalent than previously recognised. However, the anatomy and biomechanics of the deltoid ligament complex are reported inconsistently in the literature. This systematic review will summarise current evidence on the anatomy and biomechanics of the deltoid ligament complex in healthy adult ankles. METHODS: Searches will be conducted in Scopus, MEDLINE, Embase, CINAHL and SPORTDiscus. Our search strategy will cover terms associated with 'deltoid ligament', 'anatomy' and 'biomechanics'. We will only include dissection and imaging studies published in English that report any of the listed clinically relevant properties of the deltoid ligament in healthy adult human ankles. Two reviewers will independently perform screening and assess study quality using the anatomical quality assessment (AQUA) tool. One reviewer will extract relevant data, which will be independently verified by co-authors. Primary outcomes include band prevalence, length, width, cross-sectional area, maximum and/or failure load and elastic modulus. If three or more studies report a primary outcome, we will conduct a meta-analysis and report findings as pooled means with 95% confidence intervals. If a meta-analysis is not feasible, outcomes will be summarised as a narrative analysis. Measures will be taken during data synthesis to address anticipated methodological heterogeneity across included studies, and pooled estimates will be interpreted with caution. DISCUSSION: This protocol details a systematic review that aims to summarise the anatomy and biomechanics of the deltoid ligament complex. Our findings will inform computational modelling, clinical management and biomechanics for ankle pathologies, as well as identifying research gaps and directions for future research. TRIAL REGISTRATION: PROSPERO: CRD420251142867.

Humans

Association of Baloxavir Treatment Timing with Serial Interval and Household Transmission of Influenza through a Likelihood-Based Analysis.

BACKGROUND: Baloxavir treatment is associated with reduced influenza transmission within households, and the serial interval varies by treatment status. However, it remains unclear how baloxavir-induced changes in the serial interval relate to household transmission. We aimed to quantify the model-based association between baloxavir treatment timing and the serial interval and household transmission risk. METHODS: We conducted a household survey of influenza cases in Japan between October 2018 and February 2019. We defined the likelihood-based model integrating the serial interval distribution by treatment status and the secondary attack rate (SAR) using individual-level data from index cases. Using this model, we estimated the reduction in the serial interval associated with baloxavir treatment. RESULTS: Compared with untreated index cases, baloxavir-treated cases were estimated to have a serial interval density reduced by 21.42% following treatment. Treatment within 24 hours was associated with a 0.1685 reduction in the area under the curve, with smaller reductions as treatment was delayed. Earlier treatment was associated with a shorter, more concentrated distribution, whereas treatment 72 hours after onset resembled untreated cases. CONCLUSIONS: Our findings highlight that baloxavir treatment is associated with a shorter serial interval and lower estimated secondary household transmission risk. We provide model-based estimates suggesting that earlier administration is associated with a greater reduction in serial interval density and estimated transmission risk, which may inform public health strategies for infection control.

Influenza

Direct background subtraction LC-MS/MS assay for human plasma progesterone: Full validation and comparative application.

OBJECTIVE: To develop and validate a liquid chromatography-tandem mass spectrometry method based on direct background subtraction for the quantification of endogenous progesterone in human plasma. METHODS: Protein precipitation was used for sample preparation with deuterated progesterone as the internal standard. Chromatographic separation was performed on an ACQUITY C18 column using gradient elution with 0.1% formic acid in water and acetonitrile at a flow rate of 0.3&#xa0;mL/min. Mass spectrometry was operated in positive electrospray ionization mode with multiple reaction monitoring. Instead of using analyte-stripped matrix or surrogate matrix, authentic plasma was directly used for all validation experiments. Quantitation was achieved by subtracting the background signal, and results were compared with those from the classical method using stripped matrix. RESULTS: Excellent linearity was achieved over 0.1-100&#xa0;ng/mL (R2&#xa0;&#x2265;&#xa0;0.99). Precision, accuracy, recovery, matrix effect, and stability all met FDA and ICH M10 acceptance criteria. Compared with the classical method, the bias in Cmax and AUC0-t was within &#xb1;15%, indicating no significant difference between the two methods. CONCLUSION: The direct background subtraction method avoids laborious preparation of blank matrix, eliminates matrix effect discrepancies, and is simple, efficient, and low-cost. It can serve as a general strategy for endogenous substance determination.

Humans

Avian egg incubation period: Revisiting existing allometric relationships via surface area-to-volume ratio of an egg.

The incubation period (I) for bird eggs varies among species and is used in establishing allometric relationships. Research on variations in I shed light on the evolutionary mechanisms that gave rise to the differentiation of embryonic development in distinct taxa of birds. Here, using a sampling of 444 images from 444 avian species, 89 families and 30 orders, we calculated their major geometric dimensions: volume (V) and surface area (S). An assessment of the relationship between I and the measured and calculated egg parameters demonstrated the closest and most significant correlation (R&#xa0;=&#xa0;-0.760) between I and the S/V ratio that was adopted as a conditional indicator and reflects the embryo's metabolic rate. Approximation of the values of these parameters made it possible to derive a power-law dependence for the prediction of I depending on the S/V value of a particular egg (R2&#xa0;=&#xa0;0.757). The prediction accuracy was higher (R2&#xa0;=&#xa0;0.783) if the eggs of the family Procellariiformes (petrels), whose I value is characterized by a longer time, were removed from the general sampling computation. We conclude that the value of the S/V ratio can characterize both the metabolism of an embryo and the conditional thermal conductivity of an egg, which aids in ensuring the temperature regime of egg incubation.

Animals

Mitigating pH-induced instability in deruxtecan-based ADCs: an onboard-mixing icIEF approach for robust charge heterogeneity characterization.

Accurate charge variant analysis of antibody-drug conjugates (ADCs) is essential for understanding product heterogeneity and ensuring quality control. However, Deruxtecan (DXd)-based ADCs present a unique analytical challenge due to the intrinsic instability of the payload, where the lactone ring readily undergoes hydrolysis under alkaline conditions, resulting in time-dependent shifts in charge distribution during imaged capillary isoelectric focusing (icIEF). In this study, we describe the development of an onboard-mixing icIEF method designed to minimize pH-induced degradation during sample preparation. By separating ADC samples from carrier ampholytes (CAs) prior to injection and enabling real-time mixing within the instrument, this approach effectively suppresses premature lactone ring opening and stabilizes charge variant profiles. Comparative studies between conventional premixing and onboard-mixing approach demonstrated that the latter significantly enhances reproducibility, particularly for acidic variants that are highly sensitive to structural conversion. Comprehensive method validation confirmed excellent precision, linearity, and sensitivity, with consistent performance across run-to-run and intra-day analyses. The results underscore the importance of controlling microenvironmental pH exposure in the analysis of chemically instable ADCs. The proposed onboard-mixing strategy provides a robust and efficient solution for icIEF-based characterization, reducing analytical artifacts while simplifying method development. This approach is broadly applicable to ADCs and other biotherapeutics containing pH-sensitive functional groups.

Hydrogen-Ion Concentration