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PubMed2026

Recovery of polysaccharides from marc and pomace through sequential extractions assisted by ultrasound, enzymes and acid maceration.

This study evaluated the pilot-scale recovery of polysaccharides from Vitis vinifera pomace/marc using sequential extraction strategies combining high-power ultrasound (UAE), enzymes (EAE), and acid maceration (AAE). Laboratory-scale trials identified optimal conditions for enzyme dosage and liquid/solid ratio (L/S). Pilot-scale trials demonstrated that the extraction sequence and the processing byproducts influenced extraction efficiency, total soluble polysaccharide in the extract (TSP), and polysaccharide composition. Post-maceration at pH 3.2, with/without the maximum enzyme dose after UAE in a L/S of 1.3/1, improved structural polysaccharide extraction from Viura pomace, while Tempranillo marc showed better recovery of pectic families and TSP with UAE + EAE. Separating grape pomace extract (UAE) from the post-maceration stage at pH 3.2 produced two extracts: E1, with higher yield (19.9%), enriched in structural polysaccharides and oligosaccharides, and E2, enriched in high and medium molecular weight pectic polysaccharides (58.03%), a low degree of esterification (17.1%) and more complex rhamnogalacturan structures.

Polysaccharides↗
PubMed2026

Evolutionary architecture and lineage-specific diversification of Forkhead box transcription factors in Perna viridis.

The Forkhead box (Fox) transcription factors are evolutionarily conserved regulators of development, cell cycle, and apoptosis across metazoans. This study provides the first comprehensive genome-wide analysis of the Fox gene family in the Asian green mussel (Perna viridis). We identified 28 Fox genes distributed across 10 chromosomes. Comparative analysis reveals the absence of the FoxI, FoxQ1, FoxR and FoxS subfamily, consistent with other bivalves and indicative of lineage-specific gene loss during molluscan evolution. Notably, gene duplications in the FoxAB, FoxD, FoxH, FoxN1-4, FoxQ2 and FoxQD subfamilies may reflect functional diversification associated with environmental adaptation. Exon-intron structural variability, including intron loss in several paralogues, suggests structural diversification and potential regulatory variation. Phylogenetic reconstruction confirmed the monophyly of core Fox classes while highlighting divergent expansion patterns in lophotrochozoans. Selection analyses showed strong purifying selection across duplicated Fox paralogs, supporting functional conservation after lineage-specific expansion. Gene Ontology enrichment linked Fox genes to stress response, apoptosis, and transcriptional regulation. By integrating phylogenetic, structural, and transcriptomic analyses, this study provides a genomic framework for understanding Fox gene organisation, evolution, and tissue-associated expression patterns in Perna viridis and establishes a comparative resource for future functional studies in bivalves.

Animals↗
PubMed2026

Functions of tandem-repeat galectins and domain coordination governs galectin-4 activity in grass carp (Ctenopharyngodon idella).

Galectins are β-galactoside-binding lectins that play essential roles in innate immunity. Among them, tandem-repeat galectins (TrGals), typically composed of two distinct carbohydrate-recognition domains (CRDs) connected by a linker peptide, are well established as key regulators of pathogen recognition and host defense in mammals. However, their structural diversity and immunological functions in teleost fish remain poorly understood. In this study, five TrGals (Gal-4, Gal-8a, Gal-8b, Gal-9, and Gal-9like) were identified in grass carp. Sequence and structural analysis revealed that Gal-8a/b, Gal-9, and Gal-9like possess the canonical two-CRD architecture, whereas Gal-4 uniquely contains four highly similar tandem-repeat domains. All five TrGals were broadly expressed across examined tissues, with predominant expression in the liver. Upon Aeromonas hydrophila infection, Gal-4, Gal-8a, Gal-8b, and Gal-9 were rapidly up-regulated at early time points (3-6 h). To elucidate the functional significance of CRD number, recombinant full-length CiGal-4 (CiGal4-full) and three truncated variants containing one, two, or three CRDs (CiGal4-1CRD, CiGal4-2CRD, and CiGal4-3CRD) were generated and systematically characterized. All recombinant proteins contained the conserved β-sheet structure typical of galectin CRDs. Functional assays revealed that CiGal4-full displayed the strongest growth-inhibitory activity against all tested bacteria, whereas CiGal4-1CRD showed the weakest effect. Notably, CiGal4-2CRD exhibited the most potent bactericidal activity, surpassing the full-length protein, while CiGal4-3CRD showed no further enhancement. CiGal4-full and CiGal4-2CRD showed superior carbohydrate-binding activities compared with the other variants. Collectively, these results reveal that CRD copy number alone does not linearly determine galectin function. Instead, domain organization and conformational coordination are critical for optimizing antimicrobial activity. This study provides new insights into the structure-function relationships and evolutionary diversification of galectins in teleosts and highlights their potential as novel antimicrobial and immunomodulatory agents in aquaculture.

Animals↗
PubMed2026

Genome-wide scans reveal candidate genes associated with wing morph differentiation in Tetrix japonica.

Wing dimorphism is an important dispersal-related trait in insects, but its genomic basis remains poorly understood in pygmy grasshoppers. Here, we integrated genome-wide single-nucleotide polymorphism (SNP) analyses, population structure inference, selection scans, and functional annotation to investigate genomic differentiation between long- and short-winged Tetrix japonica. Principal component analysis (PCA), ADMIXTURE, and phylogenetic analyses revealed weak genome-wide separation between morphs, indicating differentiation on a largely shared genetic background. Genome-wide scans based on the fixation index (FST), nucleotide diversity ratios, and Tajima's D, using 50-kb non-overlapping windows and empirical top-5% outlier thresholds, identified multiple candidate regions across seven chromosomes. The broader long- and short-winged candidate sets spanned 9.35 Mb and 9.37 Mb and directly overlapped 82 and 77 genes, respectively. Candidate genes were associated with signaling/hormone regulation, membrane transport, metabolism, cytoskeletal organization, extracellular matrix structure, and development. Short-winged candidate genes were significantly enriched for ABC-type transporter activity and ATP hydrolysis activity. Because all individuals originated from a single laboratory-maintained population with weak genome-wide structure, these regions should be regarded as candidate loci from a screening-stage analysis that require validation in independent populations and by functional assays, rather than as confirmed targets of selection.

Animals↗
PubMed2026

Treatment-related associations of nucleus accumbens connectivity within mesocorticolimbic circuits in depression.

Pharmacological treatment remains a mainstay in managing depression, yet the neural correlates associated with treatment response remain incompletely understood. This study used multimodal neuroimaging to examine nucleus accumbens (NAc)-centered structural and functional alterations associated with fluoxetine and Shugan Jieyu Capsule (SG), a traditional Chinese medicine, in patients with mild-to-moderate depression (MMD). Sixty patients were randomized to an 8-week course of fluoxetine or SG. Depression severity was assessed using the 24-item Hamilton Depression Rating Scale (HAMD-24), and structural and functional MRI scans were acquired at baseline and endpoint. Both treatments were associated with significant symptom improvement. Neuroimaging analyses revealed structural and functional alterations involving the NAc. Changes in NAc-amygdala connectivity showed an exploratory association with symptom improvement in the SG group, whereas changes in NAc-rostral anterior cingulate cortex connectivity were associated with symptom improvement in the fluoxetine group and remained significant after correction for multiple comparisons. In addition, remitters exhibited stronger baseline connectivity between the NAc and ventral tegmental area and between the NAc and middle frontal gyrus compared with non-remitters. These findings suggest that NAc-centered connectivity may be relevant to treatment-related neural changes in depression and may inform future research on imaging-based candidate markers of treatment response and personalized treatment approaches. TRIAL REGISTRATION: The study is registered in https://www.chictr.org.cn/ with a registration number ChiCTR1900024988 (date: 08.06.2019).

Humans↗
PubMed2026

Genome-wide characterization of heat shock protein genes reveals thermal stress-responsive candidates in Litopenaeus vannamei.

Heat shock proteins (HSPs) are conserved molecular chaperones involved in protein folding, refolding, aggregation prevention, and degradation of damaged proteins. However, the genomic organization and thermal responsiveness of HSP genes in the Pacific white shrimp (Litopenaeus vannamei) remain incompletely understood. Here, we performed a genome-wide analysis of the HSP gene family and examined its phylogenetic relationships, structural features, duplication patterns, sequence variation, interaction networks, and transcriptional responses to acute heat stress. A total of 34 HSP genes were identified and classified into the HSP90, HSP70, HSP40/DNAJ, HSP60, and small HSP families. Phylogenetic, motif, gene structure, synteny, and subcellular localization analyses revealed evolutionary conservation and structural diversification among family members. Three duplicated gene pairs were identified, comprising two segmental duplications and one tandem duplication. All pairs exhibited Ka/Ks ratios below 1, consistent with purifying selection of varying strength. Sequence analysis identified 295 nonsynonymous single-nucleotide polymorphisms, of which 12 were consistently predicted to be deleterious by multiple algorithms. Protein-protein interaction analysis indicated enrichment of protein-folding and cellular stress-response functions. RT-qPCR analysis showed significant induction of HSPA4, HSP90AA1, TRAP1, BiP, and DNAJA1 after 6, 12, and 24 h of exposure to 34 °C, whereas DNAJC3 was significantly induced only at 12 h. All six genes reached their highest transcript abundance at 12 h. These findings may provide a genomic framework for HSP genes in L. vannamei and identify candidate genes and variants associated with thermal stress responses.

Animals↗
PubMed2026

Organizational bullying among nursing faculty: A systematic review of consequences, contributing factors, and interventions.

BACKGROUND: Organizational bullying among nursing faculty is a systemic and pervasive issue with profound psychological, professional, and institutional consequences. Despite increasing awareness, the literature remains fragmented, and a comprehensive synthesis is lacking. METHODS: This systematic review followed PRISMA guidelines and examined empirical studies on organizational bullying among nursing faculty, with no date restrictions applied. A structured search across five databases (PubMed, Scopus, Web of Science, CINAHL, and Embase) identified studies that met inclusion criteria related to the consequences, contributing factors, and interventions. The Mixed Methods Appraisal Tool (MMAT) was used to assess study quality. RESULTS: Fifteen studies meeting the quality threshold were included. Organizational bullying was consistently associated with psychological distress (e.g., anxiety, depression, burnout, suicidal ideation), professional disengagement, and intent to leave. Contributing factors were categorized into structural and organizational (e.g., hierarchical power imbalances, toxic workplace culture), managerial and HR-related (e.g., lack of leadership support, poor reporting mechanisms), and individual/social (e.g., gender or ethnic discrimination, early-career vulnerability). Intervention strategies identified included policy reforms, leadership training, supportive reporting systems, and psychological support services, though evidence on their effectiveness remains limited. CONCLUSIONS: Organizational bullying in nursing academia is a serious and multifaceted challenge with detrimental effects on individuals and institutions. Addressing it requires a comprehensive, evidence-based approach that includes structural reforms, leadership development, and psychosocial support systems. Academic institutions must prioritize the creation of safe, inclusive, and respectful environments to retain faculty and sustain the quality of nursing education.

Faculty, Nursing↗
PubMed2026

A systematic review of qualitative research on HIV and food insecurity in high-income countries.

OBJECTIVES: Food insecurity leads to adverse health outcomes in people living with HIV, including obesity, poor mental health and viral non-suppression. Qualitative studies in low- and middle-income countries have described the impact of food insecurity on medication adherence. However, limited qualitative research exists on the lived experiences of food insecurity among people living with HIV in high-income countries (HICs). We aimed to synthesize qualitative literature on food insecurity among people living with HIV in HICs. DESIGN: Systematic review and textual narrative synthesis. METHODS: We searched MEDLINE, CINAHL, Scopus, Embase, and PsycINFO, extracting data from included articles on a standardized form in Covidence. We synthesized literature using a textual narrative approach. We conducted quality appraisal (Critical Appraisal Skills Programme Qualitative Studies Checklist) and graded certainty of findings (GRADE-CERQual). RESULTS: We reviewed 2772 articles, reduced to 940 after deduplication, with 12 articles included after full text screening. Included articles reported on studies conducted in the United States ( n  = 7), and Canada ( n  = 5). We identified three key themes, each with their own sub-themes: the role of structural inequalities in shaping and navigating food insecurity; the impacts of food insecurity on health and wellbeing; and the labour of acquiring of food. CONCLUSIONS: Our review highlights the syndemic nature of food insecurity and HIV; intersecting experiences of multiple structural hardships constellate and interact synergistically to amplify poor health outcomes. Interventions should address the multiple and reinforcing social and structural conditions that shape food insecurity among people living with HIV.

Humans↗
PubMed2026

Neurocorrelates of nocturnal enuresis in pre-adolescent children.

INTRODUCTION: Nocturnal enuresis (NE) is a common neurodevelopmental condition, yet its underlying neural mechanisms remain unclear. This study leverages the large-scale Adolescent Brain Cognitive Development (ABCD) dataset to identify structural and functional brain correlates associated with active symptoms and the resolution of bedwetting. METHODS: Using cross-sectional data from 3472 participants aged 9-10 years, children were categorized into three groups: active nocturnal enuresis (ANE, n = 225), history of nocturnal enuresis (HNE, n = 1171), and healthy control groups (CG, n = 2076). Multimodal neuroimaging protocol evaluated macrostructural properties via structural MRI (sMRI), microstructural white matter integrity via diffusion MRI (dMRI), and functional connectivity via resting-state fMRI (fMRI). Group differences were evaluated using linear models within an ANCOVA framework, adjusting for intracranial volume and handedness with False Discovery Rate (FDR) correction. RESULTS: Compared to controls, the ANE group exhibited a significant volume deficit in the right caudate, decreased sulcal depth in the left insula, and lower internal correlation within the Cingulo-Opercular Network (CON). Conversely, the dry HNE group demonstrated significant structural adaptations, including bilaterally larger putamen volumes and increased right caudate volume compared to the ANE group. The HNE group also showed increased microstructural density (decreased mean diffusivity) in the bilateral hippocampus and an increased cortical surface area in the left insula. Both NE groups demonstrated persistently reduced functional coupling within the CON. CONCLUSIONS: Nocturnal enuresis appears to be associated with a potential complex central signaling deficits. Reduced internal correlation within the CON across both active and former bedwetters indicates a potential for impairment in processing internal homeostatic bladder signals during sleep.

Humans↗
PubMed2026

Oxygen-controlled gamma-irradiation and annealing enable terminal processing of collagen-based biomaterials.

Gamma irradiation is a widely adopted method for terminal sterilization of medical devices; however, its application to collagen-based extracellular matrix (ECM) materials remains limited due to radiation-induced degradation of structural integrity and mechanical performance. Here, we present an engineered terminal-processing strategy that combines oxygen controlled gamma irradiation (25-30 kGy) with post-irradiation dry-heat annealing to preserve ECM functionality while achieving effective sterilization. By modulating oxygen availability during irradiation, this approach alters radical reaction pathways, suppresses oxygen-mediated oxidative degradation, and generates a metastable radical-containing intermediate, which is subsequently converted into a structurally stabilized collagen network through thermal annealing. As a result, the treated matrices preserved ECM integrity and recovered clinically relevant mechanical properties. Furthermore, the process achieved cumulative viral reductions exceeding 6 log10 across a representative panel including enveloped and non-enveloped DNA and RNA viruses, demonstrating compatibility with sterility assurance and viral safety requirements for biologically derived medical devices. Notably, preliminary observations indicate that mechanical integrity can be partially preserved even at elevated irradiation doses up to 50 kGy, suggesting potential applicability to sterilization validation frameworks requiring higher assurance levels. Overall, this work establishes a mechanistically grounded terminal-processing paradigm that enables control of radical fate, decouples sterilization efficacy from material degradation, and integrates sterilization, viral safety, and functional preservation into a unified and scalable framework for collagen-based biomaterials. This concept repositions gamma-irradiation from a purely degradative process to a controllable tool for tuning collagen structure and performance.

Gamma Rays↗
PubMed2026

Integrated exome and mitochondrial genome sequencing reveals the genetic landscape of primary mitochondrial diseases: findings from a large Tunisian cohort.

Primary mitochondrial diseases are a heterogeneous group of neurometabolic disorders recognized as the most common metabolic genetic diseases. They manifest at any age, affecting any tissue or organ, especially those with high energy demands, and are caused by pathogenic variants in both mitochondrial and nuclear genomes. Here, we aimed to describe the genetic spectrum of a Tunisian pediatric cohort with suspected mitochondrial diseases. We recruited 47 unrelated families who underwent exome sequencing as a first-tier test followed by whole mitochondrial genome sequencing for unsolved cases. Dedicated bioinformatic pipelines and prediction tools were used to determine the potential disease-causing variants. Sanger sequencing confirmed the presence and segregation within parents. For the newly identified variants, structural modeling was conducted to study the impact of these variants on protein structure and motions. Dual genome sequencing yielded a molecular diagnosis in 33/47 families (70%) and 18/47 (38%) showed disease-causing variants in genes encoding mitochondrial proteins. Among them, four families disclosed novel variants in FASTKD2, SERAC1 and GATB, which were supported by in-depth in silico and structural analyses demonstrating their deleterious effect. The remaining families (32%, 15/47) disclosed other metabolic and neurological disorders. An exome-first strategy delivers a high diagnostic yield in Tunisia, where consanguinity remains high and simultaneously captures mitochondrial and non-mitochondrial etiologies. Mitochondrial sequencing remains indispensable in the case of an inconclusive exome. Thus, our data expand the clinical and genetic spectrum of primary mitochondrial diseases in Tunisia, an underrepresented and admixed population.

Humans↗
PubMed2026

The Impact of Video Game Experience on Surgical Performance: A Systematic Review.

OBJECTIVE: To assess whether video gaming experience is associated with improved surgical performance in the surgeon population across laparoscopic, robotic, and other surgical modalities, and evaluate its implications on surgical training and education. METHODS: A structured literature search was conducted across five databases on 29th November 2024 in adherence to PRISMA guidelines. Comparative studies evaluating surgical performance outcome data between surgeons with differing video game experience were eligible for inclusion. Outcomes evaluated were time to complete task, error rate, accuracy, economy of motion, and overall score. Included studies were assessed for risk of bias using ROBINS-I and RoB 2. RESULTS: 15 studies involving 641 participants were included, comprising one randomized controlled trial and 14 nonrandomized studies. All nonrandomized studies were judged to be at moderate or serious risk of bias, and the single randomized controlled trial was judged to be at serious risk of bias. Differences in study design and outcome measures meant that quantitative synthesis could not be performed. Across laparoscopic studies, video gaming experience was associated with improved overall score and time to task completion predominantly in the period prior to structured training interventions, with accuracy findings consistently favoring gamers in the two studies reporting this outcome. Error rate and economy of motion findings were inconsistent or predominantly nonsignificant. No meaningful association was identified across nonlaparoscopic modalities. CONCLUSIONS: Video gaming may be associated with improved surgical performance in surgeons, though this appears restricted to laparoscopic tasks and the pretraining intervention period. As a low-cost and accessible activity, video gaming may represent a practical informal adjunct to formal surgical training to help ease the transition into structured technical training. Surgical program directors need not alter existing selection criteria or training modules based on the available literature.

Video Games↗
PubMed2026

S-layer-phage interaction in Clostridioides difficile.

Successful infection by a bacteriophage requires the injection of the phage genome into the cytoplasm of the host bacterium. To achieve this, an infecting phage must traverse the layers of the host cell envelope, including the membrane(s) and the cell wall. This process is further complicated in bacterial species that produce a proteinaceous S-layer on the outermost surface of the cell. Surprisingly little is known about the mechanistic basis of these early stages in the phage lifecycle, and even less is known about infection of S-layer producing bacteria. Recent advances in structural biology, particularly in cryoEM, have dramatically improved our understanding of the structures of both bacterial S-layers and phage virions separately, but we still lack a molecular view combining both phage and S-layer in the process of infection. Here, we review our current understanding of phage-S-layer interactions, using the human pathogen Clostridioides difficile as an example host.

Clostridioides difficile↗
PubMed2026

Theta-range SEEG stimulation for intracranial mapping: extending conventional 1-Hz and 50-Hz protocols.

OBJECTIVE: Electrical brain stimulations (EBS) are central to epileptic network identification and functional mapping during stereo-electroencephalography, yet stimulation frequencies remain empirical, and standardized across patients and brain regions, producing false negatives and false positives, and potentially compromising surgical outcome. We prospectively investigated theta-range EBS (7 Hz) in the temporal lobe, a prominent physiological frequency band in this region, and compared it with conventional 1-Hz and 50-Hz protocols. METHODS: We analyzed 1,408 temporal EBS in 25 drug-resistant epileptic patients. Epileptic responses (afterdischarges, seizures) and clinical signs were assessed across the epileptic network and temporal structures (amygdala, hippocampus, neocortex, parahippocampal gyrus, white matter), and confronted to stimulation parameters (frequency, intensity, duration, total charge). RESULTS: At matched intensity and duration, 7-Hz EBS were associated with a higher occurrence of afterdischarges and clinical signs than 1-Hz EBS in several temporal structures. Effects on usual seizure induction were less consistent. Comparisons with 50 Hz showed no systematic significant differences, with responses observed at one or both frequencies depending on structure and outcome. When controlling for total charge, frequency-related differences were attenuated. Some effects were sporadically observed at both intermediate frequency and charge quantity. CONCLUSIONS: EBS responses emerge from the interaction between all electrical parameters and anatomical location and local excitability, and can hardly be disentangled. However, 7-Hz EBS can provide complementary clinical information during temporal-lobe mapping, with a targeted approach. SIGNIFICANCE: These findings support targeted evaluation of broader stimulation parameter spaces, including intermediate frequencies, rather than routine reliance on fixed low- and high-frequency protocols alone.

Humans↗
PubMed2026

Unravelling bioanalytical innovations, degradation processes, and impurity landscapes of VEGFR inhibitors.

From pre-formulation studies to clinical trials, VEGFR-targeted small-molecule tyrosine kinase inhibitors (TKIs) require rigorous analytical standards. Bioanalysis, stability-indicating studies, and impurity profiling are used to examine chromatographic advances for VEGFR-targeted TKIs like sunitinib, pazopanib, axitinib, sorafenib, cabozantinib, vandetanib, apatinib, lenvatinib, nintedanib, and regorafenib. An LC-MS/MS and UPLC-MS/MS routinely show sub ng/mL performance, as shown by LLOQs (0.2 ng/mL) for sunitinib and axitinib, 1 ng/mL for pazopanib, 5-7 ng/mL for sorafenib, 0.5-1.5 ng/mL for regorafenib metabolic products, and 0.1-0.5 ng/mL for lenvatinib. These approaches are used for pharmacokinetics and therapeutic drug monitoring due to their good correlation coefficient of 0.1-10,000 ng/mL, accuracy of 95%-108%, and precision of 15% RSD. UPLC-QTOF-MS/MS distinguishes degradants and metabolites during forced degradation studies, enabling structural elucidation following ICH M7 risk evaluation protocol. HPTLC/MLC offers fast, sensitive screenings, while RP-HPLC/DAD or HPLC-UV offer reliable, cost-effective routine quality-control solutions with LOD/LOQ in the μg/mL range and linearity of 10-240 μg/mL. This review lists the structures and CAS numbers of ten VEGFR-2 TKI degradants and metabolites, as well as pharmacopeial impurities in SMILES forms. It will be useful for future method development and regulatory applications. To ensure VEGFR-targeted TKI quality, safety, and therapeutic efficacy, LC-MS/MS for trace quantification and HRMS for structure elucidation provide a robust, future-oriented framework. To improve VEGFR-targeted TKI quality, safety, and regulatory compliance, analytical development should focus on HRMS-based impurity characterization, AI-assisted degradation prediction, green chromatography, and harmonized bioanalytical validation.

Humans↗
PubMed2026

What do we know about medical invalidation and related concepts? - A scoping review and thematic analysis about the definitions, measurements, causes, consequences and potential solutions for medical invalidation.

BACKGROUND: Medical invalidation, medical gaslighting, and related constructs have gained visibility in public discourse but remain inconsistently defined in scientific literature. Despite growing research-often focused on specific diseases- to date, no single review has comprehensively synthesized their definitions, causes, consequences, or methods of measurement. This scoping review addresses this gap by examining medical invalidation and related constructs. METHODS: Using a preregistered protocol, we systematically searched PubMed, CINAHL, Web of Science, Google Scholar, and ProQuest (dissertations) without year restrictions. Eligible sources included peer-reviewed empirical, theoretical, and conceptual work in English addressing invalidation, gaslighting, or closely related notions within healthcare. A total of 158 studies were identified through database searches and citation tracking. Data extraction followed a standardized schema, and findings were synthesized descriptively and through thematic analysis to clarify terminology, map determinants and outcomes, and identify existing measurement approaches. RESULTS: The results showed substantial inconsistency in how "invalidation," "not being taken seriously," and "gaslighting" were defined. Medical invalidation emerged as a multifactorial phenomenon driven by diagnostic challenges, structural and societal factors, provider and patient characteristics, stigma, misattribution, interactional dynamics, academic knowledge gaps, and disease-related complexity. Invalidation was associated with wide-ranging behavioural, emotional, cognitive, physical, relational, and systemic harms, while validation had consistently beneficial effects. Proposed solutions in the summarized studies included communication improvements, clinician training, patient support, targeted research, and structural and systemic changes. DISCUSSIONS: Medical invalidation represents a complex, systemic issue with significant implications for patient safety. The discussion highlights its multifactorial origins, its potential to cause both psychological and physical harm, and the need for clearer conceptualisation within the field. Advancing research requires validated instruments and longitudinal designs to examine underlying mechanisms and consequences. Addressing medical invalidation will demand multi-level interventions to improve communication, reduce structural barriers, and promote equitable, patient-centred care. OSF PREREGISTRATION: https://doi.org/10.17605/OSF.IO/MPE6U.

Humans↗
PubMed2026

Complexity in disguise: a systematic review of fractal analysis in psychiatric neuroimaging.

OBJECTIVES: Psychiatric diagnosis and fractal studies are complex processes that extend beyond clinical evaluation and require careful methodological considerations in neuroimaging. Over the years, fractals have helped reduce these complexities in research, but they still cannot grant clinical diagnoses. Thus, the main objective was a systematic review exploring the potential applications of fractal analysis in characterizing psychiatric conditions through neuroimaging techniques-including both functional and structural MRI. MATERIALS AND METHODS: A systematic literature review was conducted on PubMed, identifying thirty-nine original studies that met the inclusion criteria. Areas showing statistical significance (p&#x2009;<&#x2009;0.05) were reported. These studies were categorized according to DSM-V classification and examined for the description of psychiatric conditions through the fractal analysis. RESULTS: The review primarily focuses on young adults with psychiatric conditions compared to control groups. Schizophrenia and Autism Spectrum Disorder are major areas of investigation, and fractal dimension (FD) is the primary analysis method used to reflect brain patterns. Studies that calculated whole-brain FD may have underestimated local abnormalities due to the inclusion of a high percentage of tissue, potentially resulting in overlooked findings. Notably, abnormalities in the frontal cortex represent a common neurobiological feature across several psychiatric conditions. CONCLUSIONS: The findings from this systematic review shed light on the use of fractal analysis to quantify complex brain patterns in both psychiatric patients and healthy individuals. However, it is essential to recognize the need for further research to elucidate a fractal analysis protocol that allows for optimal extraction of psychiatric insights. KEY POINTS: Question Fractal analysis applied to structural and functional MRI help characterize brain alterations across psychiatric conditions. Findings This review shows consistent fractal patterns across multiple psychiatric disorders, especially in frontal regions. Despite heterogeneous methodologies, results highlight shared structural and functional abnormalities. Clinical relevance Fractal analysis may offer complementary characterization of subtle brain organization across psychiatric disorders. Its potential clinical utility-such as improving diagnostic characterization, earlier detection, among others-remains limited by the current absence of a standardized protocol.

Humans↗
PubMed2026

Distinct functions of mammalian RAD51 paralogs in genome maintenance.

RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) are evolutionarily conserved essential proteins for cell survival and genome maintenance. RAD51 paralogs were originally identified to play a role in homologous recombination-mediated repair of DNA double-strand breaks (DSBs). However, investigations over the last decade have uncovered new roles of RAD51 paralogs beyond DSB repair in replication stress responses, including replication fork progression, fork stability, and its restart. Recent structural studies have not only uncovered the molecular architecture of previously known RAD51 paralog complexes but also identified novel paralog complex assemblies, providing mechanistic insights into their various genome-maintenance functions. Additionally, a role for RAD51 paralogs in resolving R-loops has been identified, and studies with cancer-associated variants suggest that RAD51 paralogs are potential determinants of cancer susceptibility and therapeutic responses. In the present review, we highlight the recently deciphered structures and novel functions of RAD51 paralog complexes and discuss the clinical and therapeutic implications.

Rad51 Recombinase↗