• Smart Structures and Systems
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• v.26 no.6
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• pp.809-817
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• 2020

In cells, the microtubules are surrounded by viscoelastic medium. Microtubules, though very small in size, perform a vital role in transportation of protein and in maintaining the cell shape. During performing these functions waves propagate and this propagation of waves has been investigated using nonlocal elastic theory. But the effect of surrounding medium was not taken into account. To fill this gap, this study considers the viscoelastic medium along with nonlocal elastic theory. The analytical formulas of the velocity of waves, and the results reveal that the presence of medium reduces the velocity. The axisymmetric and nonaxisymmetric waves are separately discussed. Furthermore, the results are compared with the results gained from the studies of free microtubules. The presence of medium around microtubules results in the increase of the flexural rigidity causing a significant decrease in radial wave velocity as compared to axial and circumferential wave velocities. The effect of viscoelastic medium is more obvious on radial wave velocity, to a lesser extent on torsional wave velocity and least on longitudinal wave velocity.

• Steel and Composite Structures
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• v.39 no.5
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• pp.599-614
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• 2021

This study deals with the Lateral-Torsional Buckling (LTB) of a mono-symmetric tapered I-beam, in which the cross-section is varying longitudinally. To obtain the buckling moment, two concentrated bending moments should be applied at the two ends of the structure. This structure is made of Functionally Graded Material (FGM). The Young's and shear modules change linearly along the longitudinal direction of the beam. It is considered that this tapered beam is laterally restrained continuously, by using torsional springs. Furthermore, two rotational bending springs are employed at the two structural ends. To achieve the buckling moment, Ritz solution method is utilized. The response of critical buckling moment of the beam is obtained by minimizing the total potential energy relation. The lateral and torsional displacement fields of the beam are interpolated by harmonic functions. These functions satisfy the boundary conditions. Two different support conditions are considered in this study. The obtained formulation is validated by solving benchmark problems. Moreover, some numerical studies are implemented to show the accuracy, efficiency and high performance of the proposed formulation.

• Advances in concrete construction
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• v.11 no.3
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• pp.255-260
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• 2021

Vibration of protein microtubules is investigated based upon Orthotropic Elastic Shell Model, considering the effect of thermal stresses. The complete analytical formulas of thermal vibration for microtubules are obtained. It is observed that the effects of thermal stresses on the vibrational frequency mode are more significant when the longitudinal and circumferential wave vectors are large enough. But when the length of wave vector reduces to 5 nm, these effects have no significant effects. The present results well agree with the lattice vibrations of microtubules. Moreover, the results show that the effects of thermal stresses due to small change in temperature are not so significant but with the increase in temperature its effects are obvious.

• Safety and Health at Work
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• v.13 no.2
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• pp.201-206
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• 2022

Background: The present objective was to verify whether burnout (emotional exhaustion [EE], depersonalization [DP] and low professional efficacy [PE]) is a risk factor for long-term sickness absence (LTSA; 30 consecutive days) from the teaching role. Methods: This was a prospective cohort study with two years of follow-up that investigated 509 elementary and high-school teachers. Burnout was identified by Maslach Burnout Inventory. Poisson regression with robust variance was used to adjust for possible confounders. Results: The incidence of LTSA was 9.4%. High EE levels were associated with LTSA in the crude analysis, but the association lost statistical significance after adjustments (for sex, age, perception of work-life balance, general self-rated health, chronic pain and depression). High DP levels were associated with this outcome, even after all adjustments (relative risk = 1.80; 95% confidence interval: 1.05-3.09). Low PE levels were not related to LTSA. Conclusion: The results reinforce the need to improve teachers' work conditions to reduce burnout, particularly DP, and its consequences.

• Nutrition Research and Practice
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• v.16 no.4
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• pp.505-516
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• 2022

BACKGROUND/OBJECTIVES: The association between nutritional status and health-related quality of life (HRQoL) among patients with type 2 diabetes mellitus (T2DM) is not fully understood. This study was conducted to understand the role of nutritional status on HRQoL among people with and without T2DM. SUBJECTS/METHODS: Structured survey and direct measurement of anthropometric data were conducted among people with and without T2DM. Nutritional status was measured with Mini Nutritional Assessment tool and HRQoL was measured with a 36-item Short Form Healthy Survey. Data collection was conducted in Chuncheon, South Korea with 756 participants who are older than 40 yrs of age. RESULTS: This study found that overall HRQoL were significantly lower in people with T2DM than people without T2DM after controlling for key covariates. When stratified by nutritional status, a greater degree of negative impact of T2DM on overall physical HRQoL was observed among well-nourished or at risk of malnutrition, whereas significant and more evident negative impact of diabetes on overall psychological HRQoL was observed only among malnourished. CONCLUSIONS: The study results suggest the role of nutritional status among people with T2DM on overall, especially psychological aspects of HRQoL. Future longitudinal or intervention studies are warranted to test the impact of nutritional status on HRQoL among people with T2DM.

• Clinical and Experimental Pediatrics
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• v.65 no.1
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• pp.21-28
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• 2022

Crohn disease (CD) is a multifactorial inflammatory disorder that can affect all segments of the gastrointestinal (GI) tract but typically involves the ileum and/or colon. To assess patient prognosis and choose appropriate treatment, it is necessary to accurately evaluate the factors influencing poor outcomes, including disease phenotype. Pediatric CD involving the upper GI (UGI) tract has become increasingly recognized with the introduction of routine upper endoscopy with biopsies for all patients and the increased availability of accurate small bowel evaluations. Most clinical manifestations are mild and nonspecific; however, UGI involvement should not be overlooked since it can cause serious complications. Although controversy persists about the definition of upper GI involvement, aphthoid ulcers, longitudinal ulcers, a bamboo joint-like appearance, stenosis, and fistula are endoscopic findings suggestive of CD. In addition, the primary histological findings, such as focally enhanced gastritis and noncaseating granulomas, are highly suggestive of CD. The association between UGI involvement and poor prognosis of CD remains controversial. However, the unstandardized definition and absence of a validated tool for evaluating disease severity complicate the objective assessment of UGI involvement in CD. Therefore, more prospective studies are needed to provide further insight into the standardized assessment of UGI involvement and long-term prognosis of CD. Our review summarizes the findings to date in the literature as well as UGI involvement in CD and its clinical implications.

• Journal of Astronomy and Space Sciences
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• v.39 no.3
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• pp.87-98
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• 2022

The Far-UltraViolet (FUV) imager onboard the Ionospheric Connection Explorer (ICON) spacecraft provides two-dimensional limb images of oxygen airglow in the nightside low-latitude ionosphere that are used to determine the oxygen ion density. As yet, no FUV limb imager has been used for climatological analyses of Equatorial Plasma Bubbles (EPBs). To examine the potential of ICON/FUV for this purpose, we statistically investigate small-scale (~180 km) fluctuations of oxygen ion density in its limb images. The seasonal-longitudinal variations of the fluctuation level reasonably conform to the EPB statistics in existing literature. To further validate the ICON/FUV data quality, we also inspect climatology of the ambient (unfiltered) nightside oxygen ion density. The ambient density exhibits (1) the well-known zonal wavenumber-4 signatures in the Equatorial Ionization Anomaly (EIA) and (2) off-equatorial enhancement above the Caribbean, both of which agree with previous studies. Merits of ICON/FUV observations over other conventional data sets are discussed in this paper. Furthermore, we suggest possible directions of future work, e.g., synergy between ICON/FUV and the Global-scale Observations of the Limb and Disk (GOLD) mission.

• Physical Therapy Rehabilitation Science
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• v.12 no.1
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• pp.72-79
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• 2023

Objective: Despite known associations between negative body image and health declines in chronic pain patients, few studies have examined longitudinal associations between psychological stress and perceived hand deformities. This study examined whether psychological distress was associated with hand deformities 4 years later and if rural and urban adults differed in the association. Design: A community-based cohort study. Methods: Community dwelling adults (mean age=51.97, 52.3% women) in a rural (n=2968) and urban area (n=2784) provided demographic data at baseline and, in the 4-year follow-up, responded to questionnaires about psychological distress. Perceived hand deformities were assessed at the 8-year follow-up. Linear regression was conducted to examine the effects of psychological distress on hand deformities and moderation by residential areas. Results: The perceived hand deformities were more likely among those with severe psychological stress, hand osteoarthritis, or any chronic disease condition (p<0.01) but less likely among those with younger age, higher education, or income (p<0.01). The regression results showed that psychological distress predicted more perceived hand deformities 4 years later even after adjusting for demographic and health covariates (p<0.01). The residential areas did not significantly moderate the association between distress and hand deformities. Conclusions: This study suggected that psychological distress may trigger later perception of hand deformities in both urband and rural adults. The findings indicate that stress management interventions that are customizable to regional contexts may be effective at preventing negative body image related health problems of community-dewelling adults.

• Journal of Oral Medicine and Pain
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• v.47 no.1
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• pp.67-71
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• 2022

Subchondral cysts are frequently encountered in patients with temporomandibular joint osteoarthritis (TMJ OA), particularly in advanced stage. Subchondral cysts within osteoarthritis are typically lying adjacent to the joint surface where initial load bearing occurs during activity and have been associated with greater pain and disease progression. Although the etiology of these cysts remains uncertain, recently studies report that the induction of the subchondral bone mechanical stress caused subchondral cysts. Repeated overloading leads to further deterioration of subchondral bone which render subchondral bone structure more fragile, increase the risk of osteoarthritis progress. The purpose of this study was to assess the effect of conservative treatment and longitudinal osseous changes of a large subchondral cyst in a mandibular condyle in a symptomatic TMJ OA patient.

• Computers and Concrete
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• v.31 no.6
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• pp.527-536
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• 2023

Fiber Reinforced Polymer (FRP) bar has emerged as a viable and sustainable replacement to steel in reinforced concrete (RC) under severe corrosive environment. The behavior of concrete columns reinforced with FRP bars, spirals, and hoops is an ongoing area of research. In this study, 3D nonlinear numerical modelling of circular concrete columns reinforced with Glass Fiber Reinforced Polymer (GFRP) bars and transversely confined with GFRP spirals were conducted using fracture-plastic model. The numerical models and experimental results are found to be in good agreement. The effectiveness of confinement was accessed through von-mises stresses, and it was found that the stresses in the concrete's core are higher with a 30 mm pitch (46 MPa) compared to a 60 mm pitch (36 MPa). The validated models are used to conduct parametric studies. In terms of axial load carrying capacity and member ductility, the effect of concrete strength, spiral pitch, and longitudinal reinforcement ratio are thoroughly investigated. The confinement effect and member ductility of a GFRP RC column increases as the spiral pitch decreases. It is also found that the confinement effect and member ductility decreased with increase in strength of concrete.