Distinct Class Research Articles

Analysis of cerium substitution in Co–Sr based spinel ferrites for high frequency application

Spinel ferrites exhibit exceptional magnetic properties, making them a distinctive class of magnetic materials. The sol–gel technique was utilized for the synthesis of spinel ferrites with the chemical formula Co0.6Sr0.4CexFe2–xO4. Following that, a comprehensive X-ray diffraction analysis unveiled the crystalline cubic structure of the synthesized materials. Through the utilization of the M-H loop approach, the ferromagnetic attributes of ferrites were assessed, and the assimilation of rare earth elements led to substantial enhancements in saturation magnetization, remanence, and coercivity. Spinel ferrites with a high concentration of rare earth elements have improved direct current resistivity and activation energy. The logarithm of a material's resistance increased from 5.29 to 8.12 Ω⋅cm as cerium is added. With a change in the amount of cerium, the activation energy goes up from 0.19 to 0.29. By changing the frequency from 5.5 to 9.5 GHz, the dielectric characteristics were determined. As the frequency goes up, the dielectric constant goes down. Spinel ferrites that have been made better in every way can be used in high-frequency applications.

Laminations and 2-filling rays on infinite type surfaces

The loop graph of an infinite type surface is an infinite diameter hyperbolic graph first studied in detail by Juliette Bavard. An important open problem in the study of infinite type surfaces is to describe the boundary of the loop graph as a space of geodesic laminations. We approach this problem by constructing the first examples of 2-filling rays on infinite type surfaces. Such rays have strong filling properties while failing to correspond to points on the boundary of the loop graph. As such they may be thought of as “fake boundary points.” We give multiple constructions using both a hands-on combinatorial approach and an approach using train tracks and automorphisms of flat surfaces. In addition, our approaches are sufficiently robust to describe all 2-filling rays with certain other basic properties as well as to produce uncountably many distinct mapping class group orbits.

General construction scheme for geometrically nontrivial flat band models

A singular flat band (SFB), a distinct class of the flat band, has been shown to exhibit various intriguing material properties characterized by the quantum distance. We present a general construction scheme for a tight-binding model hosting an SFB, where the quantum distance profile can be controlled. We first introduce how to build a compact localized state (CLS), endowing the flat band with a band-touching point and a specific value of the maximum quantum distance. Then, we develop a scheme designing a tight-binding Hamiltonian hosting an SFB starting from the obtained CLS, with the desired hopping range and symmetries. We propose several simple SFB models on the square and kagome lattices. Finally, we establish a bulk-boundary correspondence between the maximum quantum distance and the boundary modes for the open boundary condition, which can be used to detect the quantum distance via the electronic structure of the boundary states.

Exploring a Special Class of Bi-Univalent Functions: q-Bernoulli Polynomial, q-Convolution, and q-Exponential Perspective

This research article introduces a novel operator termed q-convolution, strategically integrated with foundational principles of q-calculus. Leveraging this innovative operator alongside q-Bernoulli polynomials, a distinctive class of functions emerges, characterized by both analyticity and bi-univalence. The determination of initial coefficients within the Taylor-Maclaurin series for this function class is accomplished, showcasing precise bounds. Additionally, explicit computation of the second Hankel determinant is provided. These pivotal findings, accompanied by their corollaries and implications, not only enrich but also extend previously published results.

How things become red in Mandarin Chinese? A case study of deadjectival change of state predicates

This paper provides an HPSG analysis for the morphosyntax and the semantics of deadjectival change of state (CoS) verbs in Mandarin Chinese. We first show that adjectives are a distinct word class from verbs in Mandarin Chinese and argue for the derivation of CoS verbs from property concept adjectives. We then model this derivation with a lexical rule. Finally, since CoS verbs can be combined with another verb to form a resultative verb compound (RVC) to express caused CoS, we also propose a lexical rule to account for RVCs.

Omega‐Gate Silicon Nanowire Geometric Diodes with Reconfigurable Self‐Switching Operation and THz Rectification

AbstractGeometric diodes (GDs) represent a relatively unconventional class of diode that produces an asymmetric current response through carrier transport in an asymmetric geometry. Synthesized from the bottom up, Si nanowire‐based GDs are three‐dimensional, cylindrically symmetric nanoscale versions capable of room‐temperature rectification at GHz‐THz frequencies with near zero‐bias turn‐on voltages. Here, by fabricating three‐terminal n‐type Si nanowire GDs with axial contacts and an omega‐gate electrode, a distinct class of reconfigurable self‐switching geometric diodes (SSGDs) is reported. Single‐nanowire SSGD device measurements demonstrate a significant dependence of diode current and polarity on gate potential, where the diode polarity reverses at a gate potential of ≈−1 V under specific grounding conditions. Finite‐element modeling reproduces the experimental results and reveals that the gate potential—in combination with the morphology and dopant profile—produces an asymmetric potential along the nanowire axis that changes asymmetrically with axial bias, altering the effective conductive channel within the nanowire to yield diode behavior. The self‐switching effect is retained in two‐terminal SSGD devices, and modeling demonstrates that both three‐terminal and two‐terminal devices support rectification through THz frequencies. The results reveal a new mechanism of operation for nanowire‐based GDs and characterize a new type of self‐switching diode with reconfigurable polarity.

CoCrFeNiSi high entropy alloy: Synthesis, structural and radiation shielding properties

High entropy alloys (HEAs) have emerged as a distinct class of alloys with unique design strategies, different from traditional alloys. These alloys hold great promise for diverse applications, and the investigation of their nuclear radiation shielding properties has become an important and emerging area of research. In this experimental study, an equimolar CoCrFeNiSi HEA was prepared using the ball milling method. The focus was on characterizing the crystalline structure, morphological features, and radiation shielding properties of the synthesized HEA. X-ray diffraction analysis revealed that the HEA exhibited a face-centered cubic (FCC) phase structure. The crystallite size was significantly reduced from 23.63 nm to 3.22 nm, indicating the refinement of the microstructure. The homogeneity of the alloy was confirmed through scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), which showed that the five elements were uniformly distributed within the powder alloy. To evaluate the radiation shielding properties, linear attenuation coefficients (LAC) of the CoCrFeNiSi HEA powder were measured using a 662 keV gamma source and a NaI(Tl) detector system (ORTEC® 905–4). The experimental LAC values were determined to be 0.2140 ± 0.01 cm⁻1. Theoretical calculations using MCNP6.2 and XCOM code were also performed and showed good agreement with the experimental results. Comparing the CoCrFeNiSi HEA with common shield materials such as thin films, glass systems, and some composites, it was found that the HEA outperformed them in terms of radiation shielding effectiveness. This demonstrates the potential of the CoCrFeNiSi HEA as an advanced alternative to conventional shielding materials, with potential applications in various fields.

Nitrobindin versus myoglobin: A comparative structural and functional study

Most hemoproteins display an all-α-helical fold, showing the classical three on three (3/3) globin structural arrangement characterized by seven or eight α-helical segments that form a sandwich around the heme. Over the last decade, a completely distinct class of heme-proteins called nitrobindins (Nbs), which display an all-β-barrel fold, has been identified and characterized from both structural and functional perspectives. Nbs are ten-stranded anti-parallel all-β-barrel heme-proteins found across the evolutionary ladder, from bacteria to Homo sapiens. Myoglobin (Mb), commonly regarded as the prototype of monomeric all-α-helical globins, is involved along with the oligomeric hemoglobin (Hb) in diatomic gas transport, storage, and sensing, as well as in the detoxification of reactive nitrogen and oxygen species. On the other hand, the function(s) of Nbs is still obscure, even though it has been postulated that they might participate to O2/NO signaling and metabolism. This function might be of the utmost importance in poorly oxygenated tissues, such as the eye's retina, where a delicate balance between oxygenation and blood flow (regulated by NO) is crucial. Dysfunction in this balance is associated with several pathological conditions, such as glaucoma and diabetic retinopathy. Here a detailed comparison of the structural, spectroscopic, and functional properties of Mb and Nbs is reported to shed light on the similarities and differences between all-α-helical and all-β-barrel heme-proteins.

Coronal voids and their magnetic nature

Context. Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these coronal features is not well understood. Aims. We study the magnetic properties of the weakly emitting extended regions, which we name coronal voids. In particular, we aim to understand whether these voids result from a reduced heat input into the corona or if they are associated with mainly unipolar and possibly open magnetic fields, similar to coronal holes. Methods. We defined the coronal voids via an intensity threshold of 75% of the mean quiet-Sun (QS) EUV intensity observed by the high-resolution EUV channel (HRIEUV) of the Extreme Ultraviolet Imager on Solar Orbiter. The line-of-sight magnetograms of the same solar region recorded by the High Resolution Telescope of the Polarimetric and Helioseismic Imager allowed us to compare the photospheric magnetic field beneath the coronal voids with that in other parts of the QS. Results. The coronal voids studied here range in size from a few granules to a few supergranules and on average exhibit a reduced intensity of 67% of the mean value of the entire field of view. The magnetic flux density in the photosphere below the voids is 76% (or more) lower than in the surrounding QS. Specifically, the coronal voids show much weaker or no network structures. The detected flux imbalances fall in the range of imbalances found in QS areas of the same size. Conclusions. We conclude that coronal voids form because of locally reduced heating of the corona due to reduced magnetic flux density in the photosphere. This makes them a distinct class of (dark) structure, different from coronal holes.

Distinct HLA associations with autoantibody-defined subgroups in idiopathic inflammatory myopathies

In patients with idiopathic inflammatory myopathies (IIM), autoantibodies are associated with specific clinical phenotypes suggesting a pathogenic role of adaptive immunity. We explored if autoantibody profiles are associated with specific HLA genetic variants and clinical manifestations in IIM. We included 1348 IIM patients and determined the occurrence of 14 myositis-specific or -associated autoantibodies. We used unsupervised cluster analysis to identify autoantibody-defined subgroups and logistic regression to estimate associations with clinical manifestations, HLA-DRB1, HLA-DQA1, HLA-DQB1 alleles, and amino acids imputed from genetic information of HLA class II and I molecules. We identified eight subgroups with the following dominant autoantibodies: anti-Ro52, -U1RNP, -PM/Scl, -Mi2, -Jo1, -Jo1/Ro52, -TIF1γ or negative for all analysed autoantibodies. Associations with HLA-DRB1∗11, HLA-DRB1∗15, HLA-DQA1∗03, and HLA-DQB1∗03 were present in the anti-U1RNP-dominated subgroup. HLA-DRB1∗03, HLA-DQA1∗05, and HLA-DQB1∗02 alleles were overrepresented in the anti-PM/Scl and anti-Jo1/Ro52-dominated subgroups. HLA-DRB1∗16, HLA-DRB1∗07 alleles were most frequent in anti-Mi2 and HLA-DRB1∗01 and HLA-DRB1∗07 alleles in the anti-TIF1γ subgroup. The HLA-DRB1∗13, HLA-DQA1∗01 and HLA-DQB1∗06 alleles were overrepresented in the negative subgroup. Significant signals from variations in class I molecules were detected in the subgroups dominated by anti-Mi2, anti-Jo1/Ro52, anti-TIF1γ, and the negative subgroup. Distinct HLA class II and I associations were observed for almost all autoantibody-defined subgroups. The associations support autoantibody profiles use for classifying IIM which would likely reflect underlying pathogenic mechanisms better than classifications based on clinical symptoms and/or histopathological features. See a detailed list of funding bodies in the Acknowledgements section at the end of the manuscript.

Distinct Features of Plasma Ultrashort Single-Stranded Cell-Free DNA as Biomarkers for Lung Cancer Detection.

Using broad range cell-free DNA sequencing (BRcfDNA-Seq), a nontargeted next-generation sequencing (NGS) methodology, we previously identified a novel class of approximately 50 nt ultrashort single-stranded cell-free DNA (uscfDNA) in plasma that is distinctly different from 167 bp mononucleosomal cell-free DNA (mncfDNA). We hypothesize that uscfDNA possesses characteristics that are useful for disease detection. Using BRcfDNA-Seq, we examined both cfDNA populations in the plasma of 18 noncancer controls and 14 patients with late-stage nonsmall cell lung carcinoma (NSCLC). In comparison to mncfDNA, we assessed whether functional element (FE) peaks, fragmentomics, end-motifs, and G-Quadruplex (G-Quad) signatures could be useful features of uscfDNA for NSCLC determination. In noncancer participants, compared to mncfDNA, uscfDNA fragments showed a 45.2-fold increased tendency to form FE peaks (enriched in promoter, intronic, and exonic regions), demonstrated a distinct end-motif-frequency profile, and presented with a 4.9-fold increase in G-Quad signatures. Within NSCLC participants, only the uscfDNA population had discoverable FE peak candidates. Additionally, uscfDNA showcased different end-motif-frequency candidates distinct from mncfDNA. Although both cfDNA populations showed increased fragmentation in NSCLC, the G-Quad signatures were more discriminatory in uscfDNA. Compilation of cfDNA features using principal component analysis revealed that the first 5 principal components of both cfDNA subtypes had a cumulative explained variance of >80%. These observations indicate that the distinct biological processes of uscfDNA and that FE peaks, fragmentomics, end-motifs, and G-Quad signatures are uscfDNA features with promising biomarker potential. These findings further justify its exploration as a distinct class of biomarker to augment pre-existing liquid biopsy approaches.

Dimethyl itaconate selectively targets inflammatory and metabolic pathways in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) co-evolves with its own microenvironment where inflammatory stimuli including toll-like receptors (TLR) signaling can protect CLL cells from spontaneous and drug-induced apoptosis by upregulating IκBζ, an atypical co-transcription factor. To dissect IκBζ-centered signaling pathways, we performed a gene expression profile of primary leukemic cells expressing either high or low levels of IκBζ after stimulation, highlighting that IκBζ is not only an inflammatory gene but it may control metabolic rewiring of malignant cells thus pointing to a novel potential opportunity for therapy. We exploited the capacity of the dimethyl itaconate (DI), an anti-inflammatory electrophilic synthetic derivative of the metabolite Itaconate, to target IκBζ. CLL cells, murine leukemic splenocytes, and leukocytes from healthy donors were treated in vitro with DI that abolished metabolic activation and reduced cell viability of leukemic cells only, even in the presence of robust TLR prestimulation. RNA sequencing highlighted that in addition to the expected electrophilic stress signature observed after DI treatment, novel pathways emerged including the downregulation of distinct MHC class II complex genes. In conclusion, DI not only abrogated the proinflammatory effects of TLR stimulation but also targeted a specific metabolic vulnerability in CLL cells.

Meiofauna: Biodiversity, Ecology, and Role in Ecosystems

The meiofauna is currently considered to be a group of microscopic metazoans ranging in size from 30 to 1000–2000 μm, forming a distinct size class [...]

Trajectories of kidney function and risk of mortality.

We aimed to identify patterns within the rate of kidney function decline, determinants of these patterns and their association with all-cause mortality risk in the general population. Participants aged ≥ 45 years with at least one assessment of creatinine-based estimated glomerular filtration rate (eGFR) taken between 1997 and 2018 were selected from a population-based cohort study. Analyses were performed using several distinct latent class trajectory modelling methods. Cumulative incidences were calculated with 45 years of age as the starting point. In 12062 participants (85922 eGFR assessments, mean age 67.0 years, 58.7% women, median follow-up 9.6 years), four trajectories of eGFR change with age were identified: slow eGFR decline [rate of change in mL/min/1.73m2 per year (RC), -0.9; 95% CI, -0.9 to -0.9; reference group], intermediate eGFR decline (RC, -2.5; 95% CI, -2.7 to -2.5) and fast eGFR decline (RC, -4.3; 95% CI, -4.4 to -4.1), and an increase/stable eGFR (RC, 0.3; 95% CI, 0.3 to 0.4). Women were more likely to have an increase/stable eGFR [odds ratio (OR), 1.94; 95% CI, 1.53 to 2.46] whereas men were more likely to have a fast eGFR decline (OR, 1.86; 95% CI, 1.33 to 2.60). Participants with diabetes, cardiovascular disease (CVD) or hypertension were more likely to have an intermediate or fast eGFR decline. All-cause mortality risks (cumulative incidence at age of 70 years) were 32.3% (95% CI, 21.4 to 47.9, slow eGFR decline), 6.7% (95% CI, 3.5 to 12.4, intermediate eGFR decline), 68.8% (95% CI, 44.4 to 87.8, fast eGFR decline) and 9.5% (95% CI, 5.5 to 15.7, increase/stable eGFR). Sex, hypertension, diabetes and CVD were identified as trajectory membership determinants. Having fast eGFR decline was associated with the highest risk of all-cause mortality, highlighting the need for extensive monitoring and prevention of kidney function decline in individuals at risk of having fast eGFR decline.

Heterogeneity in the trajectories of psychological distress among late adolescents during the COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has constrained opportunities in social, educational and professional domains, leading to developmental challenges for adolescents initiating their transition to adulthood. Meta-analysis indicated that there was a small increase in psychological distress during the first year of the COVID-19 pandemic. However, significant heterogeneity in the psychological response to the COVID-19 pandemic was noted. Developmental antecedents as well as social processes may account for such heterogeneity. The goal of this study was to characterize trajectories of psychological distress in late adolescence during the COVID-19 pandemic. 5014 late adolescents born between 2000 and 2002 from the UK Millennium Cohort Study completed online self-reported assessments at three occasions during the first year of the COVID-19 pandemic (May 2020, September/October 2020 and February/March 2021). These surveys assessed psychological distress, loneliness, social support, family conflict, as well as other pandemic stressors. Information on developmental antecedents were obtained when cohort members were 17years of age. Four distinct trajectories class were identified. Normative class (52.13%) experienced low and decreasing levels of psychological distress, while moderately increasing class (31.84%) experienced a small, but significant increase in distress over time and increasing class (8.75%) exhibited a larger increase in distress after the first wave of the pandemic. Inverted U-shaped class (7.29%) experienced elevated psychological distress during the first wave of the pandemic, followed by a decrease in distress in subsequent waves of the pandemic. Larger longitudinal increases in loneliness were noted among individuals in the elevated distress trajectory, compared to other trajectories. Pre-pandemic psychopathology was associated with elevated distress early in the pandemic. The largest trajectory showed low and declining psychological distress, highlighting the resilience of the majority of late adolescents. However, a subgroup of adolescents experienced large increases in psychological distress, identifying a group of individuals more vulnerable to pandemic-related stress.

Direct observation of Néel-type skyrmions and domain walls in a ferrimagnetic DyCo3 thin film

Isolated magnetic skyrmions are stable, topologically protected spin textures that are at the forefront of research interests today due to their potential applications in information technology. A distinct class of skyrmion hosts are rare earth - transition metal (RE-TM) ferrimagnetic materials. To date, the nature and the control of basic traits of skyrmions in these materials are not fully understood. We show that for an archetypal ferrimagnetic material DyCo3 that exhibits a strong perpendicular anisotropy, the ferrimagnetic skyrmion size can be tuned by an external magnetic field. Moreover, by taking advantage of the high spatial resolution of scanning transmission X-ray microscopy (STXM) and utilizing a large x-ray magnetic linear dichroism (XMLD) contrast that occurs naturally at the RE resonant edges, we resolve the nature of the magnetic domain walls of ferrimagnetic skyrmions. We demonstrate that through this method one can easily discriminate between Bloch and Néel type domain walls for each individual skyrmion. For all isolated ferrimagnetic skyrmions, we observe that the domain walls are of Néel-type. This key information is corroborated with results of micromagnetic simulations and allows us to conclude on the nature of the Dzyaloshinskii-Moriya interaction (DMI) which concurs to the stabilisation of skyrmions in this ferrimagnetic system. Establishing that an intrinsic DMI occurs in RE-TM materials will also be beneficial towards a deeper understanding of chiral spin texture control in ferrimagnetic materials.

Long-molecule scars of backup DNA repair in BRCA1- and BRCA2-deficient cancers.

Homologous recombination (HR) deficiency is associated with DNA rearrangements and cytogenetic aberrations1. Paradoxically, the types of DNA rearrangements that are specifically associated with HR-deficient cancers only minimally affect chromosomal structure2. Here, to address this apparent contradiction, we combined genome-graph analysis of short-read whole-genome sequencing (WGS) profiles across thousands of tumours with deep linked-read WGS of 46 BRCA1- or BRCA2-mutant breast cancers. These datarevealeda distinct class of HR-deficiency-enriched rearrangements called reciprocal pairs. Linked-read WGS showed that reciprocal pairs with identical rearrangement orientations gave rise to one of two distinct chromosomal outcomes, distinguishable only with long-molecule data. Whereas one (cis) outcome corresponded to the copying and pasting of a small segment to a distant site, a second (trans) outcome was a quasi-balanced translocation or multi-megabase inversion with substantial (10 kb) duplications at each junction. We propose an HR-independent replication-restart repair mechanism to explain the full spectrum of reciprocalpair outcomes. Linked-read WGS also identified single-strand annealing as a repair pathway that is specific to BRCA2 deficiency in human cancers. Integrating these features in a classifier improved discrimination between BRCA1- and BRCA2-deficient genomes. In conclusion, our data reveal classes of rearrangements that are specific to BRCA1 or BRCA2 deficiency as a source of cytogenetic aberrations in HR-deficient cells.

Barriers to accessing internationally controlled essential medicines in sub-saharan Africa: A scoping review.

Access to internationally controlled essential medicines (ICEMs), medicines that are listed on both the World Health Organization's Essential Medicines List and one of three international drug control conventions, remains problematic in Sub-Saharan Africa (SSA). Previous reviews have focused only on specific ICEMs or ICEM-related healthcare fields, but none have focused on all ICEMs as a distinct class. This scoping review therefore aims to identify the barriers to accessing ICEMs across all relevant healthcare fields in SSA. A scoping review was conducted across indexing platforms Embase, PubMed, Scopus and Web of Science of studies published between January 1 2012 and February 1 2022. Articles were eligible if they mentioned barriers to accessing ICEMs and/or ICEM-related healthcare fields, if studies were conducted in SSA, or included data on an SSA country within a multi-country study. The review was guided by the Access to Medicines from a Health System Perspective framework. The search identified 5519 articles, of which 97 met the inclusion criteria. Many barriers to access were reported and were common across the ICEMs drug class. Main barriers were: at the individual level, the lack of knowledge about ICEMs; at the health service delivery level, low availability, stockouts, affordability, long distances to health facilities, insufficient infrastructure to store and distribute ICEMs, and lack of ICEM knowledge and training among healthcare workers; at the health sector level, lack of prioritisation of ICEM-related healthcare fields by governments and subsequent insufficient budget allocation. Cross-cutting, governance-related barriers pertained to lack of proper quantification systems, cumbersome procurement processes, and strict national laws controlling ICEMs, leading to overly restrictive prescription practices. This review showed that there are a multitude of barriers to accessing ICEMs in SSA across all health system levels. Many of the barriers identified are applicable to all ICEMs, highlighting the importance of tackling barriers for this entire class of drugs together.

The Trouble with Relational Values

This paper questions the conceptual and pragmatic worth of the category of relational values. Combining philosophical reasoning with ethnographic field-work in Wallmapu/Chile, I analyse a variety of ways in which people think about, value and behave toward the land. I thereby demonstrate that relational-ity is inherent to held, instrumental and intrinsic values. This means that there is no meaningful way in which to distinguish relational values from more familiar types of values. Yet, to be able to argue that a distinct class of relational values exists, those who have proposed the term have been compelled to silence or downplay the relational natures of those other values. This has the perverse effect of confining, rather than promoting, relational thinking.

Circular RNAs — a modern perspective on the molecular mechanisms of neurologic diseases in humans and prospects for therapeutic agents

In mammals, the brain exhibits significantly higher expression levels of various noncoding RNAs (ncRNAs) compared to other organs. Among these, circular RNAs (circRNAs) have recently emerged as a distinct class of ncRNAs. CircRNAs are formed by back-splicing and fusion of exons, introns, or both, resulting in covalently closed loops. Abundant in the brain, circRNAs levels increase during development and persist into adulthood. The functional significance and mechanisms of circRNA action are subjects of ongoing search, with indications that they regulate the transcription of host genes and sequestration of miRNAs and RNA binding proteins. Some circRNAs have also shown potential for translation, giving rise to peptides. In a healthy brain, circRNA expression and abundance are carefully regulated spatiotemporally. However, altered expression of circRNAs is associated with several disorders, including brain tumor growth and acute and chronic neurodegenerative disorders. This is believed to be through their impact on mechanisms such as angiogenesis, neuronal plasticity, autophagy, apoptosis, and inflammation. The unique properties of circRNAs make them promising molecular biomarkers, especially in the context of neurodegenerative diseases. This review provides a comprehensive overview of circRNAs, focusing on their role in the pathogenesis of major neurodegenerative disorders, namely, Alzheimers disease, frontotemporal dementia, Parkinsons disease, schizophrenia, and amyotrophic lateral sclerosis (ALS). Additionally, it discusses the potential utility of circRNAs in biomarker discovery for these debilitating conditions.