Search Results (5,004)

Crimean–Congo hemorrhagic fever (CCHF) is a zoonotic viral disease endemic to parts of Africa, Asia and southeastern Europe. Bulgaria is one of the few European countries with the consistent annual reporting of human CCHF cases. This study provides a descriptive overview of 24 confirmed CCHF cases in Bulgaria between 2015 and 2024. Laboratory confirmation was performed by an enzyme-linked immunosorbent assay (ELISA) and/or real-time reverse transcriptase polymerase chain reaction (RT-qPCR) testing. Common findings included fever, fatigue, gastrointestinal symptoms, thrombocytopenia, leukopenia, liver dysfunction and coagulopathy. Two fatal cases were recorded. Two samples collected in 2016 and 2024 were subjected to whole-genome sequencing. Phylogenetic analysis showed that both strains clustered within the Turkish branch of the Europe 1 genotype and shared high genetic similarity with previous Bulgarian strains, as well as strains from neighboring countries. These findings suggest the long-term persistence of a genetically stable viral lineage in the region. Continuous molecular and clinical surveillance is necessary to monitor the evolution and public health impact of CCHFV in endemic areas. Full article

This research compares speech discrimination abilities between 17 children who are hard-of-hearing (CHH) and 13 children with normal hearing (CNH), aged 9 to 36 months, using either a conditioned head turn (CHT) or condition play paradigm, for two phoneme pairs /ba-da/ and /sa-ʃa/. As CHH were tested in the aided and unaided conditions, CNH were also tested on each phoneme contrast twice to control for learning effects. When speech discrimination abilities were compared between CHH, with hearing aids (HAs), and CNH, there were no statistical differences observed in performance on stop consonant discrimination, but a significant statistical difference was observed for fricative discrimination performance. Among CHH, significant benefits were observed for /ba-da/ speech discrimination while wearing HAs, compared to the no HA condition. All CHH were early-identified, early amplified, and were enrolled in parent-centered early intervention services. Under these conditions, CHH demonstrated the ability to discriminate speech comparable to CNH. Additionally, repeated testing within 1-month did not result in a change in speech discrimination scores, indicating good test–retest reliability of speech discrimination scores. Finally, this research explored the question of infant/toddler listening fatigue in the behavioral speech discrimination task. The CHT paradigm included returning to a contrast (i.e., /a-i/) previously shown to be easier for both CHH and CNH to discriminate to examine if failure to discriminate /ba-da/ or /sa-ʃa/ was due to listening fatigue or off-task behavior. Full article

Background: Dietary advice for Paralympic athletes (PAs) with a spinal cord injury (PAs-SCI) requires particular attention and has been widely studied. However, currently, no particular attention has been addressed to nutritional guidelines for athletes with an amputation (PAs-AMP). This study aimed at filling up this gap, at least partially, and compared veteran PAs-SCI with PAs-AMP. Methods: A sample of 25 male PAs (12 with SCI and 13 with AMP), recruited during two training camps, was submitted to the following questionnaires: allergy questionnaire for athletes (AQUA), Nordic Musculoskeletal Questionnaire (NMQ), Starvation Symptom Inventory (SSI), neurogenic bowel dysfunction (NBD), orthorexia (ORTO-15/ORTO-7), alcohol use disorders identification test (AUDIT), and Mediterranean diet adherence (MDS). The PAs were also submitted to the following measurements: dietary Oxygen Radical Absorbance Capacity (ORAC) and intakes, body composition, handgrip strength (HGS), basal energy expenditure (BEE), peak oxygen uptake (VO_2peak), peak power, peak heart rate (HR), post-exercise ketosis, and antioxidant response after a cardiopulmonary exercise test (CPET) to voluntary fatigue. Results: Compared to PAs-AMP, PAs-SCI had higher NBD and lower VO_2peak (p < 0.05), peak power, peak HR, peak lactate, phase angle (PhA) of the dominant leg (p < 0.05), and ORTO15 (p < 0.05). The latter was related to NBD (r = −0.453), MDS (r = −0.638), and ORAC (r = −0.529), whereas ORTO7 correlated with PhA of the dominant leg (r = 0.485). Significant differences between PAs-AMP and PAs-SCI were not found in the antioxidant response, glucose, and ketone levels after CPET, nor in dietary intake, AUDIT, AQUA, NMQ, SSI, BEE, HGS, and FM%. Conclusions: The present study showed that PAs-SCI and PAs-AMP display similar characteristics in relation to lifestyle, energy intake, basal energy expenditure, and metabolic response to CPET. Based on both the similarities with PAs-SCI and the consequences of the limb deficiency impairment, PAs-AMP and PAs-SCI require personalized nutritional advice. Full article

Friction stir lap welding has been utilized across research and industry for over a decade. However, difficulties in welding in the lap configuration without an interface-related defect have prevented the process from moving beyond low feed rates (generally less than 1.5 m per minute). As a means of making a huge leap in welding productivity, this study will evaluate friction stir welds made at 10 m per minute (mpm), detailing the changes to tool geometries and weld parameters that result in fully consolidated welds. Characterization of the subsequent material properties, namely through optical microscopy, CT scanning, microhardness testing, tensile and fatigue testing, hermetic seal pressure tests, and electron backscattered diffraction, is presented as a means of demonstrating the quality and repeatability of friction stir lap welds made at 10 mpm. Fully consolidated welds were produced at spindle speeds 5.5% faster and 2.9% slower than nominal values and weld depths ranging from 1% shallower to 8.2% deeper than nominal values. Additionally, the loading direction of the weld had a significant impact on tensile properties, with the advancing side of the weld measured to be 16% stronger in lap-shear tensile and 289% fatigue life improvement under all loading conditions measured when compared to the retreating side. Full article

The Statistics Anxiety Rating Scale (STARS) is a 51-item scale commonly used to measure college students’ anxiety regarding statistics. To date, however, limited empirical research exists that examines statistics anxiety among ethnically diverse or first-generation graduate students. We examined the factor structure and reliability of STARS scores in a diverse sample of students enrolled in graduate courses at a Minority-Serving Institution (n = 194). To provide guidance on assessing dimensionality in small college samples, we compared the performance of best-practice factor analysis techniques: confirmatory factor analysis (CFA), exploratory structural equation modeling (ESEM), and Bayesian structural equation modeling (BSEM). We found modest support for the original six-factor structure using CFA, but ESEM and BSEM analyses suggested that a four-factor model best captures the dimensions of the STARS instrument within the context of graduate-level statistics courses. To enhance scale efficiency and reduce respondent fatigue, we also tested and found support for a reduced 25-item version of the four-factor STARS scale. The four-factor STARS scale produced constructs representing task and process anxiety, social support avoidance, perceived lack of utility, and mathematical self-efficacy. These findings extend the validity and reliability evidence of the STARS inventory to include diverse graduate student populations. Accordingly, our findings contribute to the advancement of data science education and provide recommendations for measuring statistics anxiety at the graduate level and for assessing construct validity of psychometric instruments in small or hard-to-survey populations. Full article

Existing studies have shown that placing 3D-printed lattices in cement matrices can effectively improve the ductility of cement-based composites. However, the influence of thermal fatigue effect on the mechanical properties of 3D-printed lattice-reinforced cement-based composites during service remains to be studied. In this paper, cement-based materials without lattices were used as the control group, and the uniaxial compressive mechanical properties of 3D-printed lattice-reinforced cement-based composites after thermal fatigue treatment under a temperature difference of 60 °C were tested. The number of thermal fatigue cycles was set to 45, 90, and 145 times, respectively. During the test, two non-destructive testing technologies, AE and DIC, were used to analyze the strength degradation and deformation law of 3D-printed lattice-reinforced cement-based composites with the increase in cycles. AE adopted the threshold triggering mode, and the channel threshold was 100 mv. The experiment showed that the compressive strength of the control group after 45, 90, and 145 thermal cycles decreased to 72.47% and 49.44% of that of the specimen after 45 thermal cycles, respectively. The strength of RO lattices decreased to 91.07% and 82.14% of that of the specimen after 45 thermal cycles, respectively, while the strength of SO lattices decreased to 83.27% and 77.96% of that of the specimen after 45 thermal cycles, respectively. The compressive strengths of the two types of lattices were higher than that of the control group after three cycles, indicating that 3D-printed lattices can effectively mitigate the influence of environmental thermal fatigue on the mechanical properties of cement-based materials. Full article

Background: The implant–abutment joint is important for the long-term marginal tissue integrity in terms of biomimetic design that replicates the natural dentition under mastication forces. This study aimed to evaluate conical implant–abutment joints coupled at different tightening torque values through a mechanical fatigue test. Methods: Eighty conic implants (Ø: 3.8 mm L: 10 mm) with a 6° cone morse joint were embedded in resin blocks with an inclination of 30° ± 2°. The samples were divided into 8 groups (4 Test and 4 Control). The implant–abutment joints were coupled with different tightening torques: 25 Ncm (Group I), 30 Ncm (Group II), 35 Ncm (Group III) and 40 Ncm (Group IV). An in vitro cyclic loading test (1 × 10⁴ loads) was performed for 4 Test groups, while 4 Control groups did not receive any forces. All the samples were assessed with Scanning Electron Microscopy to compare the microfractures and microgaps on flexion and extension points. Results: Microscopy observation results showed significant differences among torque groups. We found that 30 Ncm had the best stability with less microgap. Conclusions: Tightening torque plays an important role in the distortion of the cone morse joint under mechanical forces. However, further studies should be conducted to validate the results using different implant–abutment joints for comparison. Full article

Background and Clinical Significance: Hemophagocytic lymphohistiocytosis (HLH) and autoimmune hemolytic anemia (AIHA) are both life-threatening hematologic syndromes that rarely present together outside of malignancy. Advanced acquired immunodeficiency syndrome (AIDS) creates a milieu of profound immune dysregulation and hyperinflammation, predisposing patients to atypical overlaps of these disorders. Case Presentation: A 30-year-old woman with poorly controlled AIDS presented with three weeks of jaundice, fever, and fatigue. Initial labs revealed pancytopenia, hyperbilirubinemia, and elevated ferritin level. Direct anti-globulin testing confirmed warm AIHA (IgG⁺/C3d⁺) with transient cold agglutinins. Despite intravenous immunoglobulin (IVIG), rituximab, and transfusions, she developed hepatosplenomegaly, extreme hyperferritinemia, and sIL-2R > 10,000 pg/mL, meeting HLH-2004 criteria. Bone marrow biopsy excluded malignancy; further work-up revealed Epstein–Barr virus (EBV) viremia and cytomegalovirus (CMV) reactivation. Dexamethasone plus reduced-dose etoposide transiently reduced soluble interleukin-2 receptor (sIL-2R) but precipitated profound pancytopenia, Acute respiratory distress syndrome (ARDS) from CMV/parainfluenza pneumonia, bilateral deep vein thrombosis (DVT), and an ST-elevation myocardial infarction (STEMI). She ultimately died of hemorrhagic shock after anticoagulation despite maximal supportive measures. Conclusions: This case underscores the diagnostic challenges of HLH-AIHA overlap in AIDS, where cytopenias and hyperferritinemia mask the underlying cytokine storm. Pathogenesis likely involved IL-6/IFN-γ overproduction, impaired cytotoxic T-cell function, and molecular mimicry. While etoposide remains a cornerstone of HLH therapy, its myelotoxicity proved catastrophic in this immunocompromised host, highlighting the urgent need for cytokine-targeted agents to mitigate treatment-related mortality. Full article

Objectives: To investigate the reliability and validity of the Singer Reflux Symptom Score (sRSS), a new patient-reported outcome questionnaire documenting the severity of reflux symptoms in singing voice is proposed. Methods: Amateur and professional singers consulting the European Reflux Clinic for laryngopharyngeal reflux disease (LPRD) symptoms and findings were prospectively recruited from January 2022 to February 2023. The diagnosis was based on a Reflux Symptom Score (RSS) > 13 and Reflux Sign Assessment (RSA) > 14. A control group of asymptomatic singer subjects was recruited from the University of Mons. The sRSS was rated within a 7-day period to assess test–retest reliability. Internal consistency was measured using Cronbach’s α in patients and controls. A correlation analysis was performed between sRSS and Singing Voice Handicap Index (sVHI) to evaluate convergent validity. Responsiveness to change was evaluated through pre- to post-treatment sRSS changes. The sRSS threshold for suggesting a significant impact of LPRD on singing voice was determined by receiver operating characteristic (ROC) analysis. Results: Thirty-three singers with suspected LPRD (51.5% female; mean age: 51.8 ± 17.2 years) were consecutively recruited. Difficulty reaching high notes and vocal fatigue were the most prevalent LPRD-related singing complaints. The sRSS demonstrated high internal consistency (Cronbach-α = 0.832), test–retest reliability, and external validity (correlation with sVHI: r = 0.654; p = 0.015). Singers with suspected LPRD reported a significant higher sRSS compared to 68 controls. sRSS item and total scores significantly reduced from pre-treatment to 3 months post-treatment except for the abnormal voice breathiness item. ROC analysis revealed superior diagnostic accuracy for sRSS (AUC = 0.971) compared to sRSS-quality of life (AUC = 0.926), with an optimal cutoff at sRSS > 38.5 (sensitivity: 90.3%; specificity: 85.0%). Conclusions: The sRSS is a reliable and valid singer-reported outcome questionnaire for documenting singing symptoms associated with LPRD leading to personalized management of Singers. Future large-cohort studies are needed to evaluate its specificity for LPRD compared to other vocal fold disorders in singers. Full article

In this work, the load spectra acting in the vertical direction on the hub carriers and in the horizontal longitudinal direction on the drawbar of a trailed variable chamber round baler were evaluated. To this end, each hub carrier was instrumented with appropriately calibrated strain gauge bridges. Similarly, the baler was equipped with a dynamometric towing pin, instrumented with strain gauge sensors and calibrated in the laboratory, which replaced the original pin connecting the baler and the tractor during the in-field load acquisitions. In both cases, the calibration tests returned the relationship between applied forces and output signals of the strain gauge bridges. Multiple in-field load acquisitions were carried out under typical maneuvers and operating conditions. The synchronous acquisition of a video via an onboard camera and Global Positioning System (GPS) signal allowed to observe the behaviour of the baler in correspondence of particular trends of the vertical and horizontal loads and to point out the most demanding maneuver in view of the fatigue resistance of the baler. Finally, through the application of a rainflow cycle counting algorithm according to ASTM E1049-85, the load spectrum for each maneuver was derived. Full article

This study systematically investigates 50 μm-diameter 631 stainless steel fine wires subjected to both sequential and simultaneous electrothermomechanical loading to simulate probe spring conditions in microelectronic test environments. Under cyclic current loading (~10⁴ A/cm²), the 50 μm 631SS wire maintained electrical integrity up to 0.30 A for 15,000 cycles. Above 0.35 A, rapid oxide growth and abnormal grain coarsening resulted in surface embrittlement and mechanical degradation. Current-assisted tensile testing revealed a transition from recovery-dominated behavior at ≤0.20 A to significant thermal softening and ductility loss at ≥0.25 A, corresponding to a threshold temperature of approximately 200 °C. These results establish the endurance limit of 631 stainless steel wire under coupled thermal–mechanical–electrical stress and clarify the roles of Joule heating, oxidation, and microstructural evolution in electrical fatigue resistance. A degradation map is proposed to inform design margins and operational constraints for fatigue-tolerant, electrically stable interconnects in high-reliability probe spring applications. Full article

Background and Objectives: Functional capacity assessment is essential in bariatric surgery candidates, but the Six-Minute Walk Test (6MWT) may be limited by fatigue, joint pain, and spatial constraints in individuals with severe obesity. Shorter tests such as the Two-Minute Walk Test (2MWT), Three-Minute Walk Test (3MWT), and One-Minute Sit-to-Stand Test (1MSTS) have been proposed as alternatives, yet comparative data in this population remain scarce. We aimed to evaluate the validity, reliability, and clinical utility of the 2MWT, 3MWT, and 1MSTS as substitutes for the 6MWT in patients preparing for bariatric surgery. Materials and Methods: In this cross-sectional study, 142 obese adults (BMI ≥ 30 kg/m²) underwent standardized 2MWT, 3MWT, 6MWT, and 1MSTS protocols. Correlation, linear regression, test–retest reliability (ICC), and ROC analyses were used to determine each test’s correlation and discriminative accuracy for impaired exercise tolerance (6MWT < 450 m). Results: The 3MWT showed the strongest correlation with the 6MWT (r = 0.930) and the highest explained variance (R² = 0.865), especially in individuals with BMI > 50. It also exhibited excellent reliability (ICC > 0.9) and a strong ROC profile (AUC = 0.931; 212 m cut-off). The 2MWT demonstrated acceptable concurrent validity but slightly lower agreement. The 1MSTS showed weak and inconsistent associations with 6MWT performance, suggesting limited value in assessing aerobic capacity in this population. Conclusions: The 3MWT appears to be a valid, reliable, and clinically practical alternative to the 6MWT in individuals with severe obesity. The 2MWT may be used when time or patient tolerance is limited. The 1MSTS, while safe and simple, may reflect strength and coordination more than aerobic capacity, limiting its utility in this context. Full article

With the rise of carbon capture and storage, liquefied carbon dioxide (LCO₂) has emerged as a promising medium for large-scale marine transport. This study evaluates the structural integrity of an IMO Type C cargo tank for a medium-range LCO₂ carrier under four conditions: ultimate limit state, accidental limit state, hydrostatic pressure test, and fatigue limit state, based on IGC Code and classification rules. Seventeen load cases were analyzed using finite element methods with multi-step loading to ensure stability. The highest stress occurred at the pump dome–shell junction due to geometric discontinuities, but all stress and buckling criteria were satisfied. The fatigue damage from wave-induced loads was negligible, with low-cycle fatigue from loading/unloading operations governing the fatigue life, which exceeded 31,000 years. The findings confirm the tank’s structural robustness and its suitability for safe, efficient medium-pressure LCO₂ transport. Full article

Addressing the need for contact load detection in wind turbine main bearings during service, a roller contact load measurement method is proposed. An analytical model characterizes the contact load-to-inner bore strain mapping relationship. To overcome the inherent low sensitivity of direct bore strain measurement, bore-to-measurement-point sensitivity analysis was optimized. Multiple structurally optimized sensor brackets were designed to enhance strain measurement sensitivity, and their performance was comparatively evaluated via simulation. To mitigate sensitivity fluctuations caused by roller rotation phase variations, a strain–phase–load calculation method incorporating real-time phase compensation was developed and verified through simulation analysis. A dedicated roller contact load testing system was constructed and experimental validation was conducted. Results demonstrate 95% accuracy in contact load acquisition. This method accurately obtains roller contact loads in wind turbine main bearings, proving crucial for studying bearing mechanical behavior, predicting fatigue life, optimizing structural design, and enhancing reliability. Full article

Background: As COVID-19 transitions to an endemic phase, long COVID symptoms remain a significant public health issue affecting both physical and mental health. A notable proportion of college students report symptoms such as fatigue, cough, and brain fog persisting for weeks or months post-infection. Objectives: This study explored the prevalence and contributing factors of long COVID symptoms among both infected and uninfected students in medicine-related departments. Methods: A cross-sectional study was conducted using online self-reported questionnaires completed by 1523 undergraduate and graduate students in medicine-related departments at a medical university. Participants who had tested positive for COVID-19 within the past three months were excluded. The survey assessed long COVID symptoms, with comparisons conducted between infected and uninfected groups. Multivariate logistic regression identified risk factors associated with long COVID symptoms. Results: Of the 1118 participants, 47.5% of those with a prior COVID-19 diagnosis reported long COVID symptoms within the past month. Significant differences between the infected and uninfected groups were observed in physical, cognitive, and psychological health. Logistic regression identified that prior COVID-19 diagnosis had an association with the presence of long COVID symptoms (odds ratio = 1.48, p = 0.024) after adjusted model analysis. Meanwhile, higher anxiety levels (odds ratio = 1.09, p < 0.001) and a BMI ≥ 24 (odds ratio = 4.50, p < 0.01) were identified as significant risk factors for post-infection syndrome among previously infected students. Sex and exercise habits also influenced symptom prevalence. Conclusions: Since late 2023, with those experiencing cumulative infections surpassing half of Taiwan’s population, long COVID symptoms have persisted as a widespread concern affecting both physical and mental health, continuing into 2025. This study underscores critical risk factors and symptom patterns among students in medicine-related departments, reinforcing the urgency of sustained surveillance and targeted interventions to facilitate comprehensive recovery. Full article