This paper aims to propose an alternative approach for response of viscoelastic cross-ply laminated shallow spherical shells. In the proposed approach, the governing differential equations of ...cross-ply laminated shallow spherical shell are derived using the dynamic version of the principle of virtual displacements. Following this Laplace transform is employed in the transient analysis of laminated shell problem. In the transformed domain damping can be incorporated very easily. The transformed time-independent problem in spatial coordinate is solved numerically by Gauss elimination. Inverse transformation of the results into the time domain is performed by the modified Durbin’s method. Verification of the presented method is carried out by comparing the results with those obtained by Newmark method and ANSYS finite element software. Materials of the shell laminates are assumed to be linear elastic or viscoelastic. The novelty of the present study lies in the fact that a combination of Laplace transform and Navier method is employed in the analysis of damped response of laminated shells. The numerical sample results have proved that the presented method constitutes a highly accurate and efficient solution and it can be easily applied to the laminated composite shell problems.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
BACKGROUND The aim of this study was to investigate the effects of coracoid morphology, coracohumeral distance, coracoglenoid angle, and coracohumeral angle variabilities on subcoracoid impingement ...development using magnetic resonance imaging (MRI). MATERIAL AND METHODS A total of 200 patients (87 males with mean age of 51.1±15.2 years and 113 females with mean age of 52.6±10.7 years) undergoing shoulder MRI were included in this retrospective study. All MRI studies were performed with standard positioning. Coracoid morphology and subscapularis tendon were evaluated. Coracohumeral distance, coracoglenoid angle and coracohumeral angle were measured in all subjects. One-way ANOVA was used to assess the difference between the groups. For binary comparisons, Tukey post hoc analysis was done. Pearson correlation analysis was performed between variables. RESULTS Type C coracoid was more frequent in the tendinosis and tendon tear groups. There was a significant difference between type C coracoid and the other coracoid types for coracohumeral distance values (P=0.016). There was a statistically significant decrease in coracoglenoid angle values and coracohumeral distance in patients with subscapularis tendon pathologies (P=0.000). A statistically insignificant increase in coracohumeral angle values was found in the subscapularis tendon pathologies. There was a positive correlation between coracohumeral distance and coracoglenoid angle (R=0.749 P=0.000). There was a negative correlation between coracohumeral distance and coracohumeral angle (R=-0.668 P=0.000) and between coracoglenoid angle and coracohumeral angle (R=-0.605 P=0.000). CONCLUSIONS In subscapularis tendon pathologies, decrease in coracohumeral distance and coracoglenoid angle was observed. A new approach uses coracohumeral angle to evaluate subcoracoid impingement. A statistically insignificant increase in coracohumeral angle was noted.
Purpose
The purpose of this study was to describe the elastic properties of the medial rectus muscle and optic nerve in Graves’ patients without clinically apparent ophthalmopathy using strain ...elastography (SE) and shear wave elastography (SWE) and to determine whether these elastic properties could be used to aid in the diagnosis of the medial rectus muscle or optic nerve involvement.
Materials and methods
Thirty participants diagnosed with Graves’ disease without ophthalmopathy and 30 healthy volunteers (control group) were prospectively examined between November 2018 and August 2019. SE and SWE findings in both groups were compared using the
χ
2
test and the independent samples
t
test.
Results
A statistically significant softening of the medial rectus muscle was observed in the SE patterns of the Graves’ patients (
p
= 0.009). A statistically appreciable distinction was observed between the medial rectus muscle (7.64 ± 2.1 and 9.20 ± 1.7 kPa,
p
= 0.000) and the optic nerve (8.35 ± 2.8 and 9.37 ± 1.5 kPa,
p
= 0.019) in the SWE modulus of the Graves’ patients and healthy volunteers.
Conclusion
SE and SWE can be used to identify structural alterations to the medial rectus muscle and optic nerve before clinically apparent Graves’ ophthalmopathy has developed.
We investigated senile volume and density changes in infraorbital fat to evaluate by computed tomography (CT).
CT examinations of a total of 120 patients (60 males and 60 females) were included in 3 ...age groups: 18–29 (group 1), 30–49 (group 2), and 50 years and older (group 3). Body weight and height and BMI were recorded, and infraorbital fat tissue volume and density were measured on CT.
Body weight and BMI of ≥50 years of age were significantly higher than the younger ones. In overweight and obesity groups, infraorbital fat volume increased and density decreased compared to the underweight and normal weight groups. In ≥50 years of age group, infraorbital fat volume was higher; density was lower than 18–29 years of age. Female's infraorbital fat volume was higher; density was lower than males. In each age group, the infraorbital fatty tissue density of the females was significantly lower than those in the males. There was a negative correlation between infraorbital fat volume and density. In older patients and as age groups, body weight and BMI increased, infraorbital fat volume increased, and infraorbital fat density decreased.
By aging, BMI and body weight and infraorbital fat volume increased, and infraorbital fat density decreased, especially at ≥50 years of age that is thought to be one of the factors that play a role in the downward bulging of infraorbital fat tissue. Females’ higher infraorbital fat volume and infraorbital fat density may be a reason for the females’ bulging in the infraorbital fat region.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present study, we investigated the distance between adenoid tissue and internal carotid artery (ICA) in children with adenoid hypertrophy by magnetic resonance imaging.
Cranial magnetic ...resonance images of 200 children with adenoid hypertrophy between the ages of 5 and 15 were included. In group 1 (5-9 years of age), there were 100 children, and in group 2 (10-15 years of age), there were 100 children. In both groups, adenoid thickness, adenoid/nasopharynx) ratio, and superior, middle, and inferior adenoid-ICA distances were measured.
Adenoid thickness is significantly higher in the 10-to-15 years age group than in the 5-to-9 years age group (P < 0.05). Adenoid-ICA distance got lower from the superior to the inferior part in both age groups and in both sexes: inferior < middle < superior adenoid-ICA distance. In the 5-to-9 years age group, the minimum adenoid-ICA distances were 2.40 mmsuperior, 0.90 mmmiddle, and 1.20 mminferior. In 10-to-15 years age group, the minimum adenoid-ICA distances were 2.50 mmsuperior, 1.00 mmmiddle, and 0.90 mminferior. As adenoid thickness increased, the inferior adenoid-ICA distance decreased bilaterally (P < 0.05). As the age got older, adenoid thickness increased, and the left superior and middle adenoid ICA distances and bilateral inferior adenoid-ICA distances decreased (P < 0.05).
The distance between adenoid and ICA decreased from superior to inferior. In 10- to 15-year-old children, the distance between adenoid and ICA was determined as lower than in the 5- to 9-year-old children. The minimum distances between adenoid and ICA were found to be between 0.9 and 2.5 mm in the 10-to-15 age group and between 0.9 and 2.4 mm in the 5-to-9 age group. It should be remembered that ICA can be very close to the adenoid tissue. In addition, because thermal injury can cause deeper damage to the tissue, bipolar cautery should be used with caution in this area and unipolar cautery should not be used.
In this study, quinoxaline-linked bis(benzimidazolium) salts were synthesized as bis-
N
-heterocyclic carbene (NHC) precursors. These bis(NHC) precursors were used as multidentate ligands for the ...construction of bi(hetero)aryls by palladium-catalyzed direct C-H activation process. The in situ prepared palladium complexes by mixtures of the Pd(OAc)
2
and the bis(NHC) precursors were used as the catalyst for direct C-H activation of heteroarenes. These catalytic system exhibited a modest catalytic activity in the direct C-H activation of five-membered heteroarenes with a wide range of (hetero)aryl bromides.
Graphic Abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In this paper, the viscoelastic damped response of cross-ply laminated shallow spherical shells is investigated numerically in a transformed Laplace space. In the proposed approach, the governing ...differential equations of cross-ply laminated shallow spherical shell are derived using the dynamic version of the principle of virtual displacements. Following this, the Laplace transform is employed in the transient analysis of viscoelastic laminated shell problem. Also, damping can be incorporated with ease in the transformed domain. The transformed time-independent equations in spatial coordinate are solved numerically by Gauss elimination. Numerical inverse transformation of the results into the real domain are operated by the modified Durbin transform method. Verification of the presented method is carried out by comparing the results with those obtained by the Newmark method and ANSYS finite element software. Furthermore, the developed solution approach is applied to problems with several impulsive loads. The novelty of the present study lies in the fact that a combination of the Navier method and Laplace transform is employed in the analysis of cross-ply laminated shallow spherical viscoelastic shells. The numerical sample results have proved that the presented method constitutes a highly accurate and efficient solution, which can be easily applied to the laminated viscoelastic shell problems.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The presence of the internal carotid artery (ICA) near tonsils can also cause severe bleeding during a tonsillectomy. We investigated the relationship between tonsil width and volume; and superior, ...middle and inferior tonsil-ICA distances in 5–9 and 10–15 years of age children.
Cranial MRI images of 200 children between 5 and 15 years of age were evaluated retrospectively. There were 100 children in group 1 (5–9 years of age) and 100 children in group 2 (10–15 years of age). Palatine tonsil width and volume; and superior, middle and inferior tonsil-internal carotid artery (ICA) measurements were performed bilaterally.
Our results showed that bilateral tonsil width and volume; and left superior, middle and inferior tonsil-ICA distance of 5–9 years of age group were lower than those of the 10-15 year-of age group (p < 0.05). The nearest distance between ICA and palatine tonsil is at the inferior tonsil-ICA distance side in both age groups. Especially mean inferior and middle tonsil-ICA distances were lower than 8 mm in 5–9 years of age group and lower than 9 mm in 10–15 years of age group. Minimum middle tonsil-ICA distances were 2.0–2.50 mm in smaller children and 2.0–3.50 mm in older children. Similarly, the minimum inferior tonsil-ICA distances were 2.00 mm in smaller children and 2.20–3.00 mm in older children. There were positive correlations between tonsil width, volume, and superior tonsil-ICA distance; and middle and inferior tonsil-ICA distances (p < 0.05).
In younger children, lower tonsil width; and in all children, lower tonsil volume can be a warning sign in terms of lower tonsil superior-ICA distance. During tonsillectomies, working at the middle and inferior tonsillary fossa, maximum attention must be performed for the possibility of the ICA being very closer to the tonsil to avoid unwanted bleedings.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Objectives
To investigate the optic nerve's elastic properties using shear wave and strain elastography in patients with migraine compared to healthy individuals.
Methods
The migraine group consisted ...of 30 patients (16 with visual auras and 14 without auras) who had previously had a diagnosis of migraine. These were age and sex matched with healthy participants to form the control group. The findings from shear wave and strain elastography in the groups were compared. The elastographic examination was performed with a 6–15‐MHz multifrequency linear array transducer.
Results
The evaluation involved 30 patients with migraine (3 male and 27 female), whose mean age ± SD was 34.63 ± 10 years, and 30 healthy participants (3 males, 27 females), whose mean age was 36.4 ± 10.5 years. In strain elasticity patterns, a statistically insignificant hardening of the optic nerve in the patients with migraine was observed (P = .052). Analysis of the shear wave elastic modulus values (9.8 ± 3.34 and 12.3 ± 5.25 kPa; P = .03) revealed that differences between the healthy participants and patients with migraine were statistically significant. The results for elasticity patterns and the shear modulus suggested that the differences between migraines with and without visual auras were insignificant (P > .05). A positive correlation was discovered between the duration of the disease and the shear modulus in the patients with migraine (r = 0.496; P < .01).
Conclusions
Histopathologic changes in the optic nerve may be seen in patients with migraine due to possible fibrotic changes. Elastographic techniques can be useful diagnostic tools for investigating these changes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Objective
We investigated the effects of vitamin D deficiency in the peripheral and central smell regions by magnetic resonance imaging (MRI).
Methods
This retrospective study included 29 ...patients (12 males, 17 females) with 25-dihydroxy vitamin D3 25(OH)
2
D
3
deficiency (group 1) and 34 subjects without 25(OH)
2
D
3
deficiency (14 males, 20 females) (group 2). Using cranial MRIs, the peripheral (olfactory bulb OB volume and olfactory sulcus OS depth) and central (insular gyrus and corpus amygdala) smell regions were evaluated.
Results
The OB volume and OS depth values of the 25(OH)
2
D3 deficiency group were significantly lower than those of the control group (
p
< 0.05). For the central smell regions, the insular gyrus and corpus amygdala areas of the 25(OH)
2
D3 deficiency group were nonsignificantly lower than those in the control group (
p
> 0.05). There were positive correlations between OB volumes, OS depths, and insular gyrus and corpus amygdala areas bilaterally in the 25(OH)
2
D3 deficiency group separately and in all subjects (groups 1 and 2) (
p
< 0.05). In the 25(OH)
2
D3 deficiency group, as the 25(OH)
2
D3 values became lower, the insular gyrus area values decreased bilaterally (
p
< 0.05). In females, the corpus amygdala area values were lower than in males (
p
< 0.05).
Conclusion
Since vitamin D3 deficiency affected the peripheral and central smell regions negatively, we recommend evaluating patients' vitamin D levels as a health policy to prevent vitamin D3 deficiency-related cranial smell region problems. Moreover, sunlight exposure is very important to increase vitamin D levels, and the public should be informed about this topic.
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