Axial Joints Research Articles

68Ga-FAPI and 18F-NaF PET/CT in psoriatic arthritis: a comparative study.

As fibroblast-like synoviocyte activation and bone formation are associated with psoriatic arthritis (PsA), positron emission tomography (PET) using the tracers of 68Ga-fibroblast activation protein inhibitor (FAPI) and 18F-sodium fluoride (NaF) may sensitively detect the disease. In this prospective study, we aimed to evaluate the performance of 68Ga-FAPI PET/CT in PsA and to compare it with 18F-NaF PET/CT. Sixteen participants (female 7/16, age 42.31 ± 10.66 years) with PsA were prospectively enrolled and underwent dual-tracer PET/CT, clinical assessment and ultrasonography. PET/CT images were scored for PET-positive lesions at the peripheral joints, entheses, and axial joints. The positivity rate of 68Ga-FAPI in peripheral joints is higher than that in entheses and axial joints (21.84% vs 12.15% vs 0%), whereas high positivity rates of 18F-NaF in peripheral joints, entheses, and axial joints were observed (85.23%, 78.13%, and 75%, respectively). The disease activity score 28 was higher in the PET-positive than in the PET-negative group with 68Ga-FAPI (5.25 ± 1.84 vs 2.55 ± 0.94, p= 0.037), but not with 18F-NaF. Besides, the PET joint count at 68Ga-FAPI PET/CT was positively correlated with the TJC (r = 0.604, p= 0.017), SJC (r = 0.773, p= 0.001), DAS28-CRP (r = 0.556, p= 0.032), PASDAS (r = 0.540, p= 0.038) and PsASon13 (r = 0.701, p= 0.005), while no correlation was observed in 18F-NaF PET/CT. The positivity rates of 68Ga-FAPI- and 18F-NaF PET/CT were different in patients with PsA in peripheral joints, entheses, and axial joints. The extent of joint involvement at 68Ga-FAPI PET/CT correlated with clinical and ultrasound variables as well as disease activity.

An Actual Insight into the Pathogenic Pathways of Ankylosing Spondylitis.

Spondyloarthritis refers to a broad group of conditions that include ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and enteropathic arthritis associated with Crohn's disease or ulcerative colitis. They have been classified by the ASAS group (ASsessment in Ankylosing Spondylitis) into axial spondyloarthritis and peripheral spondyloarthritis. Common features include the absence of autoantibodies, genetic predisposition, and clinical aspects such as axial joint involvement, peripheral manifestations, and extra-articular involvement. However, the pathogenic mechanisms remain complex and incompletely elucidated, despite the fact that the specialized literature has described several pathways that act in synergy: genetic predisposition, environmental factors (infections and mechanical stress), or innate and acquired immune mechanisms. Finally, an inflammatory response is triggered by the recruitment of a large number of inflammatory cells and the release of innate cytokines in the affected areas: joints or periarticular or extraarticular tissues. The current article aims to update and systematize the knowledge accumulated so far on this topic, focusing on the mechanisms that have been involved in the onset, progression, and severity of ankylosing spondylitis.

Unmet Needs in Spondyloarthritis: Pathogenesis, Clinical Trial Design, and Nonpharmacologic Therapy.

A program focused on pathogenesis, clinical trial design, and nonpharmacologic mind-body therapy for of spondyloarthritis (SpA) was presented at the Spondylitis Association of America Unmet Needs Conference IV. SpA pathogenesis is incompletely understood but involves a complex set of drivers, including genetics, biomechanical stress, and microbial factors. Affected tissues may include axial and peripheral joints, entheses, skin, uvea, and intestines. The specific role of key cytokines like interleukin (IL)-23, IL-17, and tumor necrosis factor in the phases of this inflammatory process remains unclear. New insights into pathogenesis will continue to generate targets for novel therapeutics. How to optimally evaluate those therapeutics in clinical trials, and for the various manifestations of SpA, remains less clear. Future trials need better generalizability, robust subgroup analyses to assess differential responses for distinct disease manifestations, a focus on comparative efficacy, and outcomes relevant to the clinician and the patient. Additionally, study designs need to leverage available technology to facilitate subject participation in trials. In view of the interplay between biologic, physical, and psychological aspects of disease, there is increasing attention to nonpharmacologic agents, with the aim of maximizing long-term health-related quality of life through the control of symptoms and inflammation. Recent studies provide encouraging evidence that mind-body interventions such as tai chi, qigong, yoga, and meditation have benefits for patients with SpA, particularly those with pain. The advances in our understanding of pathogenesis, novel therapeutics, and nonpharmacologic interventions have revolutionized the management of SpA, but numerous questions around optimal management remain.

Non-invasive regional parameter identification of degenerated human meniscus

Accurate identification of local changes in the biomechanical properties of the normal and degenerative meniscus is critical to better understand knee joint osteoarthritis onset and progression. Ex-vivo material characterization is typically performed on specimens obtained from different locations, compromising the tissue's structural integrity and thus altering its mechanical behavior. Therefore, the aim of this in-silico study was to establish a non-invasive method to determine the region-specific material properties of the degenerated human meniscus. In a previous experimental magnetic resonance imaging (MRI) study, the spatial displacement of the meniscus and its root attachments in mildly degenerated (n = 12) and severely degenerated (n = 12) cadaveric knee joints was determined under controlled subject-specific axial joint loading. To simulate the experimental response of the lateral and medial menisci, individual finite element models were created utilizing a transverse isotropic hyper-poroelastic constitutive material formulation. The superficial displacements were applied to the individual models to calculate the femoral reaction force in an inverse finite element analysis. During particle swarm optimization, the four most sensitive material parameters were varied to minimize the error between the femoral reaction force and the force applied in the MRI loading experiment. Individual global and regional parameter sets were identified. In addition to in-depth model verification, prediction errors were determined to quantify the reliability of the identified parameter sets. Both compressibility of the solid meniscus matrix (+141 %, p ≤ 0.04) and hydraulic permeability (+53 %, p ≤ 0.04) were significantly increased in the menisci of severely degenerated knees compared to mildly degenerated knees, irrespective of the meniscus region. By contrast, tensile and shear properties were unaffected by progressive knee joint degeneration. Overall, the optimization procedure resulted in reliable and robust parameter sets, as evidenced by mean prediction errors of <1 %. In conclusion, the proposed approach demonstrated high potential for application in clinical practice, where it might provide a non-invasive diagnostic tool for the early detection of osteoarthritic changes within the knee joint.

Serum Sclerostin as a Biomarker of Disease Activity in Ankylosing Spondylitis in Correlation with Radiographic Imaging

Abstract Background Ankylosing spondylitis (AS) is a chronic inflammatory autoimmune disease defined by the development of new bone in the spine, resulting in joint fusion and functional impairment. The role of sclerostin has been evaluated in AS pathogenesis to identify a possible link with bone formation. Objective Evaluating serum sclerostin level in AS patients and investigating the presence of any correlations with radiographic damage, disease activity and function. Patients and Methods A total of 20 patients diagnosed as ankylosing spondylitis according to Ankylosing Spondylitis International Society (ASAS) criteria were enrolled in addition to 20 healthy age matched control cases. All patients were subjected to skin, nail, hair, enthesitis, dactylitis, peripheral and axial joint examination. Also, assessment of disease activity was done by using Ankylosing Spondylitis Disease Activity Score, Bath Ankylosing Spondylitis Disease Activity Index and Bath Ankylosing Spondylitis Functional Index. Serum sclerostin level was measured in all cases and correlated with disease activity. Radiographs of the spine and pelvis performed within three months from the enrollment in the study were collected in all patients. Each radiograph was evaluated by an expert reader using the modified Stoke Ankylosing Spondylitis Spinal Score. Finally, MRI examinations for both sacroiliac joints and spine were performed. Results Positive correlation was noted between serum sclerostin level and both intermalleolar distance and cervical rotation. A negative correlation between serum sclerostin level and BASMI score. Hemoglobin and hematocrit levels were lower while ESR and CRP levels were higher among AS cases with significant correlations with serum sclerostin level. Negative correlation was reported between serum sclerostin level and SIJs SPARCC score, spine SPARCC score and total SPARCC score. Also, significant positive correlation was noted between mSASSS with BASMI score. Cutoff point ≤20 pmol/L had sensitivity 100% and specificity 100%. Conclusion Serum sclerostin was found to be an accurate biomarker with good discriminating power between ankylosing spondylitis cases and healthy control individuals. Finally, serum sclerostin is advised to be used as a routine, less invasive, cheap and valid biomarker in patients with ankylosing spondylitis.

Tibial acceleration alone is not a valid surrogate measure of tibial load in response to stride length manipulation

PurposeThis study aimed to evaluate the relationship between peak tibial acceleration and peak ankle joint contact forces in response to stride length manipulation during level-ground running. MethodsTwenty-seven physically active participants ran 10 trials at preferred speed in each of 5 stride length conditions: preferred, ±5 %, and ±10 % of preferred stride length. Motion capture, force platform, and tibial acceleration data were directly measured, and ankle joint contact forces were estimated using an inverse-dynamics-based static optimization routine. ResultsIn general, peak axial tibial accelerations (p < 0.001) as well as axial (p < 0.001) and resultant (p < 0.001) ankle joint contact forces increased with stride length. When averaged within the 10 strides of each stride condition, moderate positive correlations were observed between peak axial acceleration and joint contact force (r = 0.49) as well as peak resultant acceleration and joint contact force (r = 0.51). However, 37% of participants illustrated either no relationship or negative correlations. Only weak correlations across participants existed between peak axial acceleration and joint contact force (r = 0.12) as well as peak resultant acceleration and ankle joint contact force (r = 0.18) when examined on a step-by-step basis. ConclusionThese results suggest that tibial acceleration should not be used as a surrogate for ankle joint contact force on a step-by-step basis in response to stride length manipulations during level-ground running. A 10-step averaged tibial acceleration metric may be useful for some runners, but an initial laboratory assessment would be required to identify these individuals.

Sequencing of Targeted Therapy in Psoriasis: Does it Matter?

With the continued development of biologics for the treatment of psoriasis, some patients have achieved optimal control, but a recommended biologic sequence if a biologic fails to initially improve the skin, termed primary nonresponse, or loses efficacy after initial improvement, termed secondary nonresponse, is still lacking. Primary and secondary nonresponse can occur with any class of biologics, and the type of nonresponse can drive the choice of whether to switch within a biologic class or to a different biologic class. The choice of biologic can also be challenging when managing psoriasis and concomitant psoriatic arthritis, as treatment differs on the basis of the severity of both diseases and further classification of axial and peripheral joint involvement. When choosing a biologic, each patient's comorbidities and preferences are also taken into account to provide the optimal therapy. With this lack of anestablishedbiologic sequence after biologic failure, the objective of our review is to define a therapy sequence for the tumor necrosis factor (TNF), interleukin-17 (IL-17), and interleukin-23 (IL-23) inhibitor classes in the treatment of psoriasis and psoriatic arthritis. Our proposed biologic sequence was derived through an analysis of the efficacy of each biologic class, primary and secondary nonresponse rates from clinical trials, and clinical experience with expert opinion.

Clinical features of juvenile onset ankylosing spondylitis in Japanese patients.

This retrospective study aimed to examine the clinical features of juvenile onset ankylosing spondylitis (JoAS) in Japanese patients. We examined clinical symptoms (including initial symptoms) and the progression to diagnosis of AS in 17 Japanese JoAS patients at our institute between January 2004 and May 2023. Initial symptoms were considered pain at axial joints and/or extra-axial joints. Mean ages (± standard deviation) at onset and diagnosis of AS were 12.9 (± 2.0) years and 19.6 (± 9.6) years, respectively. The back was the most common site of initial symptoms (seven patients; 41.2%), followed by the hip (five patients; 29.4%) and knees (five patients; 29.4%). Initial symptoms were limited to extra-axial joints and axial joints in nine (52.9%) and seven (41.2%) patients, respectively. Nine patients (52.9%) were recognised as a musculoskeletal disease other than AS, such as oligoarticular juvenile idiopathic arthritis. Sites of initial symptoms were frequently the back, hip, and knees, with 52.9% of patients having initial symptoms limited to extra-axial joints. More than half of the patients were recognised musculoskeletal diseases other than AS.

Study on static performance and dynamic characteristics of a spoke cable-truss suspen-dome system

The proposed spoke cable-truss suspen-dome structure is a new structure system based on the traditional chord-supported dome structure. In this structure, the upper lattice shell is modified to a radial cable-truss structure. The lower part of the structure is a cable network structure composed of radial cables, ring cables and radial cables. There are few research results on the mechanical properties of the new structure, so a 1:10 scale model is established, multi-condition static loading test, local cable force failure test and natural vibration characteristic test are carried out, and the measured results are compared with the finite element results. The changes of axial force and joint displacement under different loads, the changes of static properties under cable damage and the dynamic characteristics of the structure are obtained. The results show that the loading method adopted meets the test accuracy requirements. Under the action of uniform load, the upper chord, the lower chord end and the inner ring truss of the main truss are in a pure compression state. The middle bar of the lower chord span and the outer ring truss change from the compression state to the tension state with the increase of load. The structure is still in the elastic stage when part of the cable fails, and the coordinated deformation ability is strong. The base frequency of the measured structure is 7.97 Hz, and the stiffness distribution is uniform.

COMPARISON of TEMPOROMANDIBULAR JOINT SPACE and ARTICULAR EMINENCE INCLINATION in VARIOUS SKELETAL ANOMALIES

Aim: This study aims to compare the values of joint spaces and articular eminence inclinations in individuals with various skeletal anomalies. Materials and Methods: A total of 60 individuals with Class I (n=20), Class II (n=20), and Class III (n=20) anomalies were included in the study, and their cone-beam computed tomography images were utilized. In each individual, the axial sectional joint spaces, including the articular disc, were calculated three-dimensionally using computer software for both the right and left condyles. Additionally, the articular eminence inclinations of both the right and left sides were measured for each individual. The obtained data were statistically compared among groups using one-way analysis of variance and within groups for the right and left values using paired t-tests (p

The incidence and prevalence of ankylosing spondylitis in Thailand using ministry of public health database

Ankylosing spondylitis (AS), an inflammatory condition affecting axial and peripheral joints, exhibits varying prevalence worldwide. This study sought to ascertain AS incidence and prevalence in Thailand from 2017 to 2020. Utilizing national databases, individuals aged 18 and above with primary AS diagnoses (ICD-10 code M45) were identified. AS prevalence and incidence were calculated with 95% confidence intervals. The total number of AS patients was 13,292 patients in 2017. The prevalence of AS was 20.4 per 100,000 populations (95% CI 20.0–20.7) in 2017. The number of new AS cases, identified during 2018–2020, was 6784, 6805, and 6791 patients, respectively. The incidences of AS in 2018, 2019, and 2020 were comparable with the incidence of 10.4 (95% CI 10.1–10.6) per 100,000-person-years. The peak age at diagnosis was 50–59 years of age between 2018 and 2020. The number of female patients was 57.8%, 57.0%, and 57.6%, in 2018, 2019, and 2020, respectively. In conclusion, AS was relatively rare among Thais and comparable between males and females. The prevalence and incidence of AS in Thailand were identified by the Thailand Database Ministry of Public Health. The epidemiological profile of AS in Thailand might help to plan better care, workforce needs, and public health budgets.

Analysis of experience in the clinical use of dual-energy computed tomography in patients with undifferentiated arthritis

Dual-energy computed tomography (DECT) is a radiation diagnostic method that is used in rheumatology to verify microcrystalline arthritis, but in Russia this method is little known and the experience of its use is rather scarce.Objective of the research. To analyze the experience of using DECT in patients with undifferentiated arthritis and lesions of the axial skeleton in clinical practice.Material and Methods. The retrospective study included 20 patients (14 men and 6 women) observed at the V. A. Nasonova Research Institute of Rheumatology, who underwent DECT for diagnostic purposes. 13 patients with undifferentiated arthritis underwent DECT of peripheral joints to diagnose gout; 7 patients with an established diagnosis of gout (based on the 2015 ACR/EULAR classification criteria for gout) – to clarify the genesis of lesions to the axial joints and spine. The study was performed on a Siemens SOMATOM Definition Flash computed tomograph.Results. Using DECT in patients with undifferentiated arthritis, deposits of monosodium urate crystals (MSUc) were detected in 7 out of 13 (54 %), which made it possible to verify the diagnosis of gout. In the second sample, 6 out of 7 patients (85 %) showed signs of MSUc deposition on DECT, which explained the genesis of the existing complaints. Among these 6 patients, in 1 person, DECT revealed the presence of MSUc and calcium pyrophosphate crystals in the shoulder joint, which made it possible to make two diagnoses at once – gout and calcium pyrophosphate deposition disease.Conclusion. DECT in patients with undifferentiated arthritis makes it possible to verify the diagnosis of gout in more than half of the cases (54 %). In 85 % of patients with gout and pain in the back and axial joints of unknown origin, urate deposits are detected according to DECT. This method may be a useful tool for identifying microcrystalline arthritis of the axial joints, but further research is needed to implement the method in routine practice.

Examining the Therapeutic Potential of CRISPR-Cas9 Gene Editing in Spondyloarthritis: Efficacy of TNF Inhibitor Adalimumab

Spondyloarthritis (SpA) encompasses a group of inflammatory rheumatic diseases characterized by axial and peripheral joint involvement, enthesitis, and extra-articular manifestations. Despite advancements in understanding the genetic and immunological underpinnings of SpA, current therapeutic options, including biologic therapies such as the TNF inhibitor adalimumab, primarily focus on symptom management and often show variable efficacy among patients. The advent of CRISPR-Cas9 gene editing technology presents a revolutionary opportunity to directly modify genetic contributors to SpA, potentially transforming the therapeutic landscape and enhancing the efficacy of adalimumab. This review investigates the feasibility and implications of utilizing CRISPR-Cas9 for targeted gene editing in SpA to improve patient response to adalimumab. We review the current knowledge on genetic mutations and polymorphisms associated with SpA pathogenesis, focusing on key genes involved in immune regulation and inflammatory pathways targeted by adalimumab. By leveraging CRISPR-Cas9, we aim to explore how precise genetic modifications can optimize the molecular targets of adalimumab, thereby enhancing its efficacy and reducing refractory cases. Preliminary studies in animal models and cell cultures demonstrate promising results, showcasing the potential of CRISPR-Cas9 to correct genetic abnormalities and synergize with adalimumab to restore normal cellular functions and reduce inflammation. However, translating these findings into clinical applications requires addressing significant challenges, including delivery methods, off-target effects, and long-term safety. Future research directions include optimizing CRISPR-Cas9 delivery systems, such as viral vectors and nanoparticle-based approaches, to enhance specificity and efficiency in conjunction with adalimumab. Additionally, comprehensive preclinical studies and early-phase clinical trials are essential to evaluate the combined therapeutic potential and safety profile of CRISPR-Cas9 and adalimumab in human subjects with SpA. This pioneering approach not only holds the promise of groundbreaking treatments for SpA but also sets the stage for broader applications of gene editing in rheumatology. By targeting the genetic roots of rheumatic diseases and optimizing adalimumab interactions, CRISPR-Cas9 could offer a new era of precision medicine, offering more effective and durable therapeutic outcomes.

E028 A differential diagnosis for treatment resistant psoriatic arthritis

Abstract Background/Aims This case involves a 45 year old gentleman with established psoriatic arthritis with axial and peripheral joint involvement. His disease was managed with subcutaneous methotrexate and etanercept. Despite improvement in axial symptoms and resolution of symptoms at other peripheral joints, he had ongoing severe monoarthritis of his right knee with significant pain and swelling. Methods In spite of several joint aspirations and intra-articular steroid injections [ten in total], escalation of dose of methotrexate, addition of sulfasalazine and switch of biologic to adalimumab, the patient’s right knee symptoms persisted. Further imaging was performed. An US scan showed chronic synovial hypertrophy with fatty metaplasia and an MRI scan showed frond like synovial thickening, suggestive of lipoma arborescens. Results The patient was referred to the orthopaedic surgeons and underwent excision synovectomy. The histopathology reported fibrofatty tissue with areas of chronic synovitis with presence of lymphoplasmacytic aggregates. The patient’s knee symptoms persisted for five years in total after clinical improvement at other joints; post-synovectomy, his right knee symptoms were improved. Lipoma arborescens is a benign progressive intra-articular lesion characterised by villous lipomatous proliferation of the synovium; it frequently affects the knee joint suprapatellar pouch. Villous proliferation of the synovium occurs, with subsequent replacement of synovial connective tissue by adipocytes. Conclusion Lipoma arborescens has been described occasionally in association with psoriatic arthritis. It is felt to occur as a reactive response to chronic synovial irritation; in this case from an inflammatory affront. Given the rarity of lipoma arborescens, coupled with the patient’s known underlying diagnosis of a seronegative arthritis, there was significant delay in his diagnosis. This case highlights the need to consider other causes of persistent joint pain and swelling when maximal therapeutic options have been unsuccessful. Disclosure A. Jacobs: None. M. Callan: None.

Increased Circulating CD14+ Monocytes in Patients with Psoriatic Arthritis Presenting Impaired Apoptosis Activity.

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis primarily affecting peripheral and axial joints. The osteolytic effect in the damaged joint is mediated by osteoclast activation. We aimed to investigate differential gene expression in peripheral CD14+ monocytes between patients with psoriatic arthritis (n = 15) and healthy controls (HCs; n = 15). Circulating CD14+ monocytes were isolated from peripheral blood mononuclear cells using CD14+ magnetic beads. Cell apoptosis was measured via Annexin V using flow cytometry. The gene expression profiling was analyzed via microarray (available in the NCBI GEO database; accession number GSE261765), and the candidate genes were validated using PCR. The results showed a higher number of peripheral CD14+ monocytes in patients with PsA than in the HCs. By analyzing the microarray data, identifying the differentially expressed genes, and conducting pathway enrichment analysis, we found that the apoptosis signaling pathway in CD14+ cells was significantly impaired in patients with PsA compared to the HCs. Among the candidate genes in the apoptotic signaling pathway, the relative expression level of cathepsin L was confirmed to be significantly lower in the PsAs than in the HCs. We concluded that the numbers of peripheral CD14+ monocytes increased, and their apoptosis activity was impaired in patients with PsA, which could lead to enhanced macrophage maturation and osteoclast activation. The resistance of apoptotic death in peripheral CD14+ monocytes may contribute to active joint inflammation in PsA.

An atypical presentation of axial spondyloarthritis with severe acute low back pain: A case report

Axial spondyloarthritis (axSpA) represents a chronic inflammatory condition primarily impacting axial joints, characterized by sacroiliitis and spondylitis. In axSpA patients, low back pain (LBP) typically assumes a chronic and inflammatory nature, where diagnostic delays can precipitate disability. However, atypical axSpA presentations pose challenges for early diagnosis and management. In the current study, we detail the case of a 39-year-old male presenting with acute, severe LBP and bilateral sacroiliitis. Initial treatment with non-steroidal anti-inflammatory drugs (NSAIDs), the standard first-line therapy, was discontinued due to severe gastrointestinal bleeding. Following a bone biopsy that excluded alternative etiologies, axSpA was confirmed based on diagnostic criteria. Elevated inflammatory markers, contraindications to NSAIDs, and magnetic resonance imaging findings prompted the initiation of anti-tumor necrosis factor (TNF) therapy. Remarkably, a marked improvement was observed in less than six weeks post anti-TNF therapy commencement. This case underscores the significance of recognizing atypical axSpA presentations and underscores the potential for swift and robust responses to anti-TNF agents. Optimal patient outcomes hinge upon effective disease pattern recognition and treatment selection.

A possible correlation between facet orientation and development of degenerative cervical spinal stenosis

BackgroundPrevious studies have demonstrated the relationship between sagittal facet orientation and cervical degenerative spondylolisthesis. However, the associations between facet orientation and cervical spinal stenosis (CSS) have rarely been studied.MethodsOne hundred twenty patients with CSS (CSS group) and 120 healthy participants (control group) were consecutively enrolled. The cervical facet angles and anteroposterior diameter (A-P diameter) of spinal canal at each subaxial cervical levels were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint.ResultsThe facet angles on the right side at C2- C3 and C3-C4 in CSS group and at C2- C3 in control group had significantly higher values than those of the other sides. Besides, the facet angles and A-P diameter of spinal canal in CSS group were significantly smaller than those in control group at all levels (p < 0.05).ConclusionsOur study demonstrated that patients with CSS have smaller axial cervical facet joint angles compared to the healthy individuals. Further studies are needed to elicit the specific underlying mechanism between sagittalization of the cervical facet joints and the pathology of CSS.

Technical solutions to reduce losses in magnetic cores and material consumption of three-phase transformer and reactor equipment

Purpose. The increase in energy costs and the need for further energy saving lead to an increase in requirements for reducing losses in the magnetic cores of transformers and reactors. Problem. The improvement of transformer and reactor equipment is traditionally carried out by applying the achievements of electrical materials science and new technologies to traditional designs and structures of electromagnetic systems. The basis of modern transformers is made up of laminated and twisted magnetic cores. The disadvantage of laminated magnetic cores is large additional losses in corner zones due to the texture of anisotropic steel. Disadvantage of twisted three-phase three-contour magnetic cores is large additional losses caused by the lack of magnetic coupling of three separate magnetic flux contours. The disadvantages of combined joint tape-plate magnetic cores are the unsatisfactory use of the active volume and increased losses, which are determined by the uneven distribution of the magnetic field and the negative impact of steel texture in the corner zones of the twisted parts. Aim. To determine the possibility of improving three-phase transformers and reactors. Methodology. The improvement is achieved by geometrical and structural transformations of the outer contours and elements of the varieties of magnetic cores. Results. The possibility of eliminating additional losses of a planar laminated magnetic core by a combination of anisotropic and isotropic steels at the appropriate location in the yoke-rod and corner sections is determined. With an octagonal outer contour of the combined magnetic core, a reduction in mass is achieved without an increase in losses. The mutually orthogonal position of the steel layers or the elements of the joint twisted and combined three-phase planar and spatial magnetic cores achieves magnetic coupling and elimination of additional losses of individual twisted contour sections. The hexagonal configurations of the inner contours of the twisted yoke-corner parts and the cross-sections of the laminated rods of the variants of the axial spatial joint magnetic core improve the magnetic flux density distribution and reduce the main losses of the yokes, as well as reduce the complexity of manufacturing rods from identical rectangular steel layers. Originality. The paper presents constructive and technological proposals and features of varieties of non-traditional planar and spatial, laminated, twisted and combined tape-plate joint magnetic cores, which differ in the combination of anisotropic, isotropic and amorphous steels, as well as the multifaceted geometric shape of contours and the spatial arrangement of elements. Based on the identity of the optimal geometric ratios of the variants of electromagnetic systems of transformers and reactors, with joint planar and spatial twisted and combined and tape-plate magnetic cores, the unification of the structure of transformer and reactor equipment with a capacity of I-III dimensions.

Kinematic responses of lead-caulked joints for cast iron pipelines subjected to strike-slip faulting

Buried cast iron pipelines are susceptible to damage at joints under fault movements. In this paper, a new three-dimensional soil-pipe continuum model for segmented pipelines undergoing fault rupture is introduced, in which both the nonlinear behavior of lead-caulked joints and post-peak softening behavior of dense sand are properly characterized. The rationality of the developed numerical model is validated against experimental results reported in the literature. Parametric analyses indicate that ignoring the strain softening behavior of soil would underestimate the maximum joint rotations, and the parameters of fault-pipe intersection angle, cast iron-lead adhesion, and burial depth play a notable role on the magnitude of joint kinematics. Numerical fault rupture analyses are then conducted for cast iron pipelines with nominal diameters ranging from 900 to 1500 mm. Based on the numerical results, predictive solutions are developed for estimating the maximum axial translations and joint rotations under fault movements. The residuals of the proposed solutions are generally unbiased. The proposed solutions can be used to evaluate the maximum joint kinematics in terms of axial translations and joint rotations for large-diameter cast iron pipelines with lead-caulked joints undergoing strike-slip fault ruptures.

Radiological Insights into Sacroiliitis: A Narrative Review.

Sacroiliitis is the inflammation of the sacroiliac joint, the largest axial joint in the human body, contributing to 25% of lower back pain cases. It can be detected using various imaging techniques like radiography, MRI, and CT scans. Treatments range from conservative methods to invasive procedures. Recent advancements in artificial intelligence offer precise detection of this condition through imaging. Treatment options range from physical therapy and medications to invasive methods like joint injections and surgery. Future management looks promising with advanced imaging, regenerative medicine, and biologic therapies, especially for conditions like ankylosing spondylitis. We conducted a review on sacroiliitis using imaging data from sources like PubMed and Scopus. Only English studies focusing on sacroiliitis's radiological aspects were included. The findings were organized and presented narratively.