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461 papers

Decoding Preschool Social Dynamics: Automated Tracking of Spatial and Temporal Patterns to Investigate Social Interactions and Relationships in Peer Groups.

Markova G et al. · Jul 1, 2026

In this study, we applied machine learning tools to automatically track the positions of preschool children in a natural free play setting and derived spatial and temporal features from these data to identify social interactions between them. We observed a sample of 20 preschool children (10 female, 10 male; M ± SD = 3.95 ± 0.82 years) in groups of three children each. Friendship among children was assessed, and friend dyads were paired either with a mutual friend (n = 12 groups) or with a mutually disliked peer (n = 11 groups). We used a ceiling-mounted camera to record 10-min free play sessions of the 23 groups and used an automated keypoint tracking software to extract children's locations over time from the videos. From this data, we derived the following measures for each dyad within the group: distance, social orientation, and paired correlations of children's position and speed. Additionally, a human rater coded all occurrences of social interactions in the videos. Automated measures reliably predicted the occurrence of children's social interactions, validating our choice of spatial and temporal features. Friend dyads were closer, oriented more toward each other, and showed higher position and speed correlations than non-friends. Social orientation and speed correlation varied over time, and speed correlation increased in mixed-group contexts, especially among friends. These findings highlight the value of tracking-based approaches for detecting both fine-grained interactive behavior and affiliative ties, offering key insights into the spatial dynamics of young children's peer interactions.

Psychology

Methionine Synthase Interacts With the Methionine Adenosyl-Transferase MATα2 and the DNA Methyltransferase DNMT3b in the Nucleus.

Jeandel M et al. · Jul 1, 2026

Transmethylation reactions, which are crucial for regulating gene expression, require S-adenosyl-L-methionine (SAM) as methyl donor. The substrate for SAM synthesis is methionine, which can be produced by methionine synthase (MS) whose dysfunctions are associated with SAM synthesis alterations despite the presence of methionine in the milieu, suggesting a preferential use of the methionine produced de novo. This highlights the crucial role of MS activity and would imply nuclear import of SAM or MS nuclear localization, allowing protein-protein interactions with the methionine adenosyl-transferases (MAT) responsible for SAM production. Using subcellular fractions of human cells, biochemical and cellular approaches, including incorporation of 14 C-methyltetrahydrofolate, here we provide the experimental evidence of MS localization and activity in the nucleus where it interacts with MATα2, the catalytic subunit of MATII, and the methyltransferase DNMT3b. These results support the idea that spatial compartmentalization of one-carbon metabolism could play a major role in regulating the epigenome.

Medicine

Sense of School Belonging and School Reintegration for Students Hospitalized With Chronic or Complex Medical Diseases: Insights From a Grounded Theory Study.

Tomberli L et al. · Jul 1, 2026

Background A strong sense of school belonging (SoSB) supports students' emotional well-being, engagement, and adjustment. For students hospitalized because of chronic or complex conditions, maintaining SoSB is challenging yet essential for successful school reintegration. Methods Using a Grounded Theory approach, this study combined interviews with 16 parents, 32 mainstream teachers, 31 hospital teachers, and one association, alongside drawings from 14 hospitalized students. Data were collected pre- and post-COVID-19. Drawings were analyzed through a meaning-making approach, and all materials underwent iterative coding and constant comparison. Results Students reported strong emotional bonds with hospital teachers but felt forgotten by their mainstream schools. Peer contact was limited, and teachers felt unprepared to manage absences and reintegration. Structural gaps and weak communication between schools hindered continuity. Both formal (e.g., remote lessons) and informal (e.g., messages, drawings) exchanges, along with psychologists and associations, emerged as protective factors. Implications for school health policy, practice, and equity Findings highlight the need for integrated school-health policies, teacher training, and structured collaboration to ensure equitable relational continuity. Conclusions Promoting SoSB during hospitalization is crucial for recovery, resilience, and educational equity.

Medicine

Enzyme-catalysed synthesis of pyridines from biomass-derived feedstocks.

Sodré V et al. · Jul 1, 2026

Pyridines are found in many pharmaceuticals and agrochemicals, but are synthesised from fossil fuel conversion. 2,4- and 2,5-pyridinedicarboxylic acids have been reported as products from bioconversion of renewable lignin feedstocks using engineered strains of Rhodococcus jostii RHA1 (Z. Mycroft et al. , Green Chem. , 2015, 17 , 4974-4979), but previously it has been uncertain whether the formation of the pyridine ring was assisted by enzyme catalysis. The 4,5-extradiol ring fission product of protocatechuic acid, 4-carboxy-2-hydroxymuconate 6-semialdehyde (CHMS) shows structural similarity to α-ketoglutaric acid, the substrate for reductive amination by glutamate dehydrogenase (GDH). Testing of five glutamate dehydrogenase (GDH) isozymes from R. jostii RHA1 revealed that GDH5 catalyses NADH-dependent reductive amination of CHMS, and its cyclisation to form a dihydropyridine product. The dihydropyridine can be oxidised to 2,4-pyridinedicarboxylic acid using recombinant P. fluorescens dye-decolorizing peroxidase DyP1B, providing a route to substituted pyridines from a renewable feedstock.

Engineering

Towards optimized CT lung cancer screening scan protocols.

Iball GR et al. · Jul 1, 2026

Objectives To evaluate radiation dose and image quality for CT lung cancer screening protocols and to determine which reconstruction kernels deliver accurate nodule volumetry. Methods A variable size anthropomorphic chest phantom and a lung screening image quality phantom were scanned on 17 different scanner models. Dose metrics from the chest phantom scans were compared against international dose recommendations. Image quality phantom scans were used to assess whether the protocol yielded accurate nodule volumetry as per the Quantitative Imaging Biomarkers Alliance (QIBA) criteria, and to determine whether changes were needed to enable this. Results Doses varied by up to a factor of 7 for the largest phantom size. All protocols delivered doses below the UK standards but only 2 scanners met the European dose criteria. Many scanners failed to meet the QIBA criteria with lung reconstruction kernels, primarily due to excessive edge enhancement and insufficient 3D spatial resolution. With alternative reconstruction kernels, the QIBA criteria were met on all bar 2 scanners. Conclusions Standard lung screening CT protocols on contemporary scanners produce images of varying image quality, over a wide range of radiation doses. Scanner-specific reconstruction kernel selection is required to meet the QIBA criteria. The study findings enable the development of optimized CT scanning protocols for lung cancer screening program. Advances in knowledge Standard lung cancer screening scanning protocols demonstrate notable variations in dose. Lung reconstruction kernels often yield inaccurate measurements of nodule volume; instead, soft tissue kernels are necessary to obtain reliable results.

Medicine

When can AlphaFold predict the oligomeric states of proteins?

Lin Y et al. · Jul 1, 2026

Homooligomerisation is a prevalent and important process that many proteins undergo to form the quaternary structures required for biological function. However, determining oligomeric states and structures experimentally remains technically challenging and time-consuming for many proteins. Here, we show that the protein structure prediction tools AlphaFold2-Multimer and AlphaFold3 can be used to quickly and accurately predict oligomeric states and structures for a range of soluble and membrane proteins. Across over 4700 proteins, AlphaFold2-Multimer provides reliable oligomeric state predictions in the majority of cases, however accuracy is more limited for proteins lacking close structural representatives in the AlphaFold training set, highlighting the dependence of these methods on robust training data. Together, our results suggest both the utility and current limitations of AlphaFold-based oligomeric state prediction, highlight cases where multiple physiologically relevant assemblies may be plausible, and provide practical guidance for minimizing computational cost, identifying challenging cases, and applying these methods to proteins lacking experimental structural data.

Biochemistry, Genetics and Molecular Biology

"Desperate not to make the same mistakes": Couple adjustment to parenthood in the context of childhood maltreatment.

Martin LN et al. · Jul 1, 2026

This study explored how a history of childhood maltreatment shapes the transition to parenthood, with a focus on how partners jointly negotiate this adjustment within the couple relationship. Using Interpretative Phenomenological Analysis (IPA), in-depth semi-structured interviews were conducted with 11 heterosexual couples (22 individuals) living in the United States, in which at least one partner reported a history of childhood maltreatment. Interviews were analyzed for emergent themes related to adjustment to parenthood, relational functioning, and dyadic support processes. Four overarching dyadic themes emerged: (1) relational meaning-making of childhood maltreatment, (2) relational challenges activated by maltreatment history, (3) dyadic support as co-regulation for maltreatment-related vulnerability, and (4) couples' resilient and intentional orientation toward family life. Findings suggest that supportive romantic partnerships may function as a relational context through which parenting-related self-doubt is negotiated, emotional safety is fostered, and caregiving approaches distinct from participants' own childhood experiences are collaboratively constructed. These insights have implications for dyadic interventions during the transition to parenthood that aim to support reflective parenting and relational resilience.

Psychology

Investigating the Impact of Carboxylated Polystyrene Nanoplastics in the Liver Using Cell Lines and Precision-Cut Liver Slices.

Pandey N et al. · Jul 1, 2026

Background and aims Increasing reports of plastic accumulation in human tissue have raised concerns about potential adverse health outcomes. Evidence of negative effects of nanoplastics is heterogeneous and provides limited insights into the underlying pathogenic toxicity mechanisms in humans. Methods In the present study, carboxylate-modified fluorescently labelled polystyrene nanoparticles (PS NPs) were used to investigate uptake and cytotoxicity in three different hepatic models of varying complexity, including HepG2 cells, IHH cells, and human precision-cut liver slices (hPCLS). Results The results show model- and dose-dependent effects on hepatocytes. 74.2% ± 13.4% of the IHH cells showed PS NPs uptake at 0.1 μg/mL, which is considerably lower than the estimated plastic concentration in human blood (1.8-4.7 μg/mL). The viability of IHH cells decreased to 10.6% ± 9.1% after exposure to 100 μg/mL for 48 h. Early signs of hepatic injury were found in hPCLS at high concentrations. No changes were observed in the redox state and mitochondrial respiratory parameters of HepG2 cells after exposure. Conclusion The PS NPs exposure experiments show uptake across all three hepatic models and toxic effects in IHH cells and hPCLS. Overall, the study highlights the need for physiologically relevant human tissue models to understand the impact of nanoplastic pollution on human health.

Environmental Science

Impact of Breath Holding on Spleen Stiffness Measured by 100 Hz Vibration Controlled Transient Elastography.

Atzori S et al. · Jul 1, 2026

Backgrounds and aims Ultrasound-based spleen stiffness measurement (SSM) is a valid non-invasive tool to assess portal hypertension (PH) in chronic liver disease. Whereas the role of the respiratory phase during liver stiffness measurements is established, no study has specifically addressed how respiration influences SSM by transient elastography. Aims To evaluate the influence of respiration on SSM assessed with FibroScan 630 (Echosens, Paris, France). Methods Eighty-three patients with chronic liver disease of different aetiologies underwent SSM using vibration-controlled transient elastography (VCTE). Results SSM acquired during a normal respiratory cycle showed better diagnostic accuracy than measurements obtained during breath-hold after deep inspiration (AUROC 0.835 [95% CI 0.743-0.928] vs. 0.798 [95% CI 0.697-0.899]). Conclusion SSM by VCTE should be performed during quiet breathing, as it showed good diagnostic accuracy for predicting the presence of oesophageal varices (OV) in patients with chronic liver disease.

Medicine

Impact of Different Types of Sedentary Behaviour on Cognitive Function in Older Adults: A Systematic Review.

de Jesus Silva TR et al. · Jul 1, 2026

Issue addressed Sedentary behaviour (SB) is a relevant determinant of health in ageing, yet its effects on cognitive function remain inconclusive. The literature often treats SB as a homogeneous exposure, without considering that different sedentary activities may differentially affect cognitive domains. Accordingly, this study sought to identify how distinct types of SB influence cognition in older adults. Methods A systematic review was conducted and registered in PROSPERO (CRD42025637160), following PRISMA guidelines. Observational studies published between 2010 and 2025 were included if they involved participants aged 60 years or older and examined the relationship between specific types of SB and cognitive domains. Searches were performed in PubMed/MEDLINE, Web of Science and Scopus. Two independent reviewers carried out study selection, data extraction and quality assessment using Joanna Briggs Institute tools. Results The search yielded 1795 records, resulting in the inclusion of 13 studies encompassing 43 902 participants. Findings were heterogeneous: passive SB, particularly, television viewing, was more frequently associated with poorer cognitive performance. In contrast, cognitively stimulating sedentary activities involving complex tasks-such as reading, playing games and computer use-were positively associated with memory, executive function and processing speed. Some studies further suggested that cognitive engagement may mitigate potential negative effects of SB. Conclusions The findings indicate that the impact of SB on cognition depends more on the type of activity performed than on total sedentary time, underscoring the importance of context and mental demand. SO WHAT?: Identifying which types of SB are beneficial or harmful may inform health promotion strategies, encouraging older adults to replace passive SB with cognitively stimulating sedentary activities, thereby supporting healthier cognitive ageing.

Medicine