Wall Thickness Values Research Articles

The predictive value of relative wall thickness on the prognosis of the patients with ST-segment elevation myocardial infarction

ObjectiveThe study aimed to evaluate the prognostic value of relative wall thickness (RWT) in the patients with ST-segment elevation myocardial infarction (STEMI).MethodsA total of 866 patients with STEMI admitted in Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School from November 2010 to December 2018 were enrolled in the current study retrospectively. Three methods were used to calculate RWT: RWTPW, RWTIVS+PW and RWTIVS. The included patients were divided according to the median values of RWTPW, RWTIVS+PW, and RWTIVS, respectively. Survival analysis were performed with Kaplan–Meier plot and multivariate Cox proportional hazard model was established to evaluate the adjusted hazard ratio of the three kinds of RWT for all cause death, cardiac death and MACE (major adverse cardiac death).ResultsThere was no significance for the survival analysis between the low and high groups of RWTPW, RWTIVS+PW and RWTIVS at 30 days and 12 months. Nonetheless, the cumulative incidence of all cause death and cardiac death in the low group of RWTPW and RWTIVS+PW was higher than those in the high group at 60 months. The cumulative incidence of MACE in the low group of RWTPW was higher than the high group at 60 months. Multivariate Cox regression model showed that RWTPW were inversely associated with long-term cardiac death and MACE in STEMI patients. In the subgroup analysis, three calculations of RWT had no predictive value for the patients with anterior myocardial infarction. By contrast, RWTPW was the most stable independent predictor for the long-term outcomes of the patients with non-anterior myocardial infarction.ConclusionRWTPW, RWTIVS+PW and RWTIVS had no predictive value for the long-term clinical outcomes of patients with anterior myocardial infarction, whereas RWTPW was a reliable predictor for all cause death, cardiac death and MACE in patients with non-anterior myocardial infarction.

Evidence in Clinical Studies for the Role of Wall Thickness in Ascending Thoracic Aortic Aneurysms: A Scoping Review.

Ascending thoracic aortic aneurysm is a chronic degenerative pathology characterized by dilatation of this segment of the aorta. Clinical guidelines use aortic diameter and growth rate as predictors of rupture and dissection. However, these guidelines neglect the effects of tissue remodeling, which may affect wall thickness. The present study aims to systematically review observational studies to examine to what extent wall thickness is considered and measured in clinical practice. Using PubMed and Web of Science, studies were identified with data on ascending aortic wall thickness, morphology, aortic diameter, and measurement techniques. 15 included studies report several methods by which wall thickness is measured. No association was observed between wall thickness and aortic diameter across included studies. Wall thickness values appear not materially different between aneurysmatic aortas and non-aneurysmal aortas. The effects on and consequences of wall thickness changes during ATAA formation are ill-defined. Wall thickness values for aneurysmatic aortas can be similar to aortas with normal diameters. Given the existing notion that wall thickness is a determinant of mechanical stress homeostasis, our review exposes a clear need for consistent as well as clinically applicable methods and studies to quantify wall thickness in ascending aortic aneurysm research.

GOLD stage-specific phenotyping of emphysema and airway disease using quantitative computed tomography.

In chronic obstructive pulmonary disease (COPD) abnormal lung function is related to emphysema and airway obstruction, but their relative contribution in each GOLD-stage is not fully understood. In this study, we used quantitative computed tomography (QCT) parameters for phenotyping of emphysema and airway abnormalities, and to investigate the relative contribution of QCT emphysema and airway parameters to airflow limitation specifically in each GOLD stage. Non-contrast computed tomography (CT) of 492 patients with COPD former GOLD 0 COPD and COPD stages GOLD 1-4 were evaluated using fully automated software for quantitative CT. Total lung volume (TLV), emphysema index (EI), mean lung density (MLD), and airway wall thickness (WT), total diameter (TD), lumen area (LA), and wall percentage (WP) were calculated for the entire lung, as well as for all lung lobes separately. Results from the 3rd-8th airway generation were aggregated (WT3-8, TD3-8, LA3-8, WP3-8). All subjects underwent whole-body plethysmography (FEV1%pred, VC, RV, TLC). EI was higher with increasing GOLD stages with 1.0 ± 1.8% in GOLD 0, 4.5 ± 9.9% in GOLD 1, 19.4 ± 15.8% in GOLD 2, 32.7 ± 13.4% in GOLD 3 and 41.4 ± 10.0% in GOLD 4 subjects (p < 0.001). WP3-8 showed no essential differences between GOLD 0 and GOLD 1, tended to be higher in GOLD 2 with 52.4 ± 7.2%, and was lower in GOLD 4 with 50.6 ± 5.9% (p = 0.010 - p = 0.960). In the upper lobes WP3-8 showed no significant differences between the GOLD stages (p = 0.824), while in the lower lobes the lowest WP3-8 was found in GOLD 0/1 with 49.9 ± 6.5%, while higher values were detected in GOLD 2 with 51.9 ± 6.4% and in GOLD 3/4 with 51.0 ± 6.0% (p < 0.05). In a multilinear regression analysis, the dependent variable FEV1%pred can be predicted by a combination of both the independent variables EI (p < 0.001) and WP3-8 (p < 0.001). QCT parameters showed a significant increase of emphysema from GOLD 0-4 COPD. Airway changes showed a different spatial pattern with higher values of relative wall thickness in the lower lobes until GOLD 2 and subsequent lower values in GOLD3/4, whereas there were no significant differences in the upper lobes. Both, EI and WP5-8 are independently correlated with lung function decline.

Macleaya cordata extract phytogenic additive: A safe alternative for horses that influences intestinal wall thickness

Macleaya cordata extract (MCE), a phytogenic additive, is used in various species because of its multiple biological effects. These effects are linked especially to its major active compound sanguinarine, an isoquinoline alkaloid. To date, there is little information on its effects on horses. Our objectives were to determine whether a commercial MCE phytogenic additive is safe for horses and evaluate the effects of increasing inclusion rates of it on gut health and systemic inflammation of horses fed with a high-starch diet. The study design was a contemporary double 4 × 4 Latin square design. Eight healthy gelding ponies were used (8 experimental units per treatment, and a total of 32 experimental units). Dry matter intake was 1.75% body weight (BW) and starch intake was 2.2 g/kg BW per meal. Horses were randomly assigned into four treatments: Control, without MCE; S1, 1 mg MCE/kg BW; S1.5, 1.5 mg MCE/kg BW; and S2, 2 mg MCE/kg BW. Feed safety was determined by hemogram, leucogram, serum biochemical, and oxidative stress analyses. Systemic inflammation was measured by fibrinogen and gene expression of interleukins (IL) 6 and 10 in peripheral blood mononuclear cells (PBMC). The thickness of the right dorsal colon (RDC) wall was examined by abdominal ultrasonography as a variable related to gut health. Data were analyzed by PROC MIXED of SAS, and the means were compared using Tukey's test at 5% significance. RDC wall thickness, fibrinogen, IL-6, and IL-10 were analyzed by orthogonal polynomials and Pearson correlation. Serum albumin presented a lower value in S2 (2.97 g/dL) when compared to Control (3.10 g/dL) (P = 0.005), but albumin/globulin relation was not different among treatments. In orthogonal polynomial analyses, there were no differences among the systemic inflammatory variables; only RDC wall thickness values presented a linear response (R² = 0.223; P = 0.001). Pearson correlation showed a strong positive and significant correlation between IL-6 and IL-10 (R = 0.818; P < 0.001). The commercial MCE is safe for horses up to doses of 2 mg/kg. No systemic anti-inflammatory effects were observed, but the thinner intestinal wall in supplemented horses showed that the phytogenic additive had a local effect. We suggest that further studies must be done using this commercial MCE for horses.

Investigating Complex Geometrical Features in LPBF-Produced Parts: A Material-Based Comparison Between Different Titanium Alloys

The Ti–6Al–4V (Ti64) alloy is a well-established material to be processed via laser powder bed fusion (LPBF). Recently, other α + β titanium alloys are receiving attention, such as Ti–6Al–2Sn–4Zr–6Mo (Ti6246). Their typical industrial fields of application (aerospace, automotive), often require critical design choices, such as low wall thicknesses and hollow channels. Thus, a comparative analysis between these two competitor alloys in terms of processability was conducted in this work. To do so, specific sample designs were developed. The specimens were analyzed in terms of geometrical compliance with the initial design, porosity, and microstructure. A correlation between the width of the specimens and their porosity, microstructure and hardness was found. Overall, both the alloys proved to be well processable, even for very low wall thickness (300 μm) and channel diameter (1 mm) values. Nevertheless, the Ti6246 alloy seemed to behave better in specific scenarios. For instance, some Ti64 specimens provided delamination. The hollow channels proved to be challenging for both materials, mainly due to the high amount of residual powder particles adhered to the upper part of the holes. This works aims at giving a materials perspective on process-related issues, considering the LPBF-induced defectology and microstructural variations in these Ti alloys.Graphical

Diagnostic performance of magnetic resonance imaging for diagnosing acute appendicitis during pregnancy.

This retrospective study evaluated the diagnostic efficacy of magnetic resonance imaging (MRI) for identifying acute appendicitis during pregnancy. This retrospective study enrolled a total of 46 pregnant patients with clinically suspected acute appendicitis who underwent 1.5 T MRI and received a final pathological diagnosis. We evaluated the imaging characteristics associated with patients diagnosed with acute appendicitis, including the appendix diameter, the appendix wall thickness, intra-appendiceal fluid collection, and peri-appendiceal fat infiltration. A bright appendix on T1-weighted 3-dimensional imaging was identified as a negative sign for appendicitis. Peri-appendiceal fat infiltration had the highest specificity of 97.1% for diagnosing acute appendicitis, whereas increasing appendiceal diameter had the highest sensitivity of 91.7%. The cut-off values for increasing appendiceal diameter and appendiceal wall thickness were 6.55 mm and 2.7 mm, respectively. Using these cut-off values, appendiceal diameter had a sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) of 91.7%, 91.2%, 78.4%, and 96.9%, respectively, whereas these values for appendiceal wall thickness were 75.0%, 91.2%, 75.0%, and 91.2%. The combination of increasing appendiceal diameter and appendiceal wall thickness resulted in an area under the receiver operating characteristic curve value of 0.958 with Se, Sp, PPV, and NPV values of 75.0%, 100.0%, 100.0%, and 91.9%, respectively. All five MRI signs examined in this study had significant diagnostic value for detecting acute appendicitis during pregnancy, with p-values <0.01. The combined use of increasing appendiceal diameter and appendiceal wall thickness displayed the excellent ability to diagnose acute appendicitis in pregnant women.

Prediction of internal fixation failure of femoral trochanteric fracture by external wall morphology

To investigate the relationship between the shape of the lateral wall and the early failure of internal fixation in the fracture of the femoral trochanteric region(FFT). Total 295 patients with femoral trochanteric fracture underwent internal fixation from January 2015 to January 2020 were selected. The patients were divided into two groups according to whether there was early internal fixation failure after surgery, 19 patients in the failure group and 276 patients in the normal group. Gender, affected side, age, AO classification, body mass index(BMI), preoperative hemoglobin, X-ray measurement of lower lateral wall thickness, preoperative internal diseases, intraoperative blood loss, postoperative tip apex distance(TAD), postoperative neck shaft angle, operation time and other data were compared between two groups. The shape of the lateral wall was compared between two groups, and the correlation between the shape of the lateral wall and the early internal fixation failure of femoral trochanteric fracture was analyzed. All patients were followed up for more than 1 year. There was no significant difference between two groups in terms of intraoperative blood loss, operation time, postoperative TAD, and postoperative neck shaft angle(P>0.05). At the latest follow-up, the visual anaglue scale (VAS) of the failure group was higher than that of the normal group(P<0.01), and the Harris score of the failure group was lower than that of normal group(P<0.05). The receiver operator characteristic (ROC) curve between shape of lateral wall and failure of early internal fixation of femoral trochanteric fracture was drawn. The critical value of the midpoint lateral wall thickness was 16.5 mm, and the area under the ROC curve was 0.845;The critical value of average sidewall thickness was 16.5 mm, and the area under ROC curve was 0.838;The critical value of the axial area of the sidewall was 7.5 mm, and the area under the ROC curve was 0.826. The shape of the lateral femoral wall measured by CT could be used as a predictive factor for the early failure of internal fixation of femoral trochanteric fractures. For patients at risk, more reasonable surgical plans and postoperative preventive measures should be developed.

Design and research of soft-body cavity-type detonation drivers

According to the high-energy-density movement characteristics of animals during jumping, soft-body cavity-type detonation driver that combines the explosive chemical reaction mechanism of hydrogen and oxygen is designed, in order to control the robot in jump to achieve output optimization. Then, combined with the theoretical values of the detonation dynamic equation and experimental data for the performance parameters, the influences of the mixing ratio of hydrogen (H2) and oxygen (O2), the volume of mixed hydrogen and oxygen in the cavity, and the shape, wall thickness, and area ratio value of the soft-body cavity on the output performance of the detonation driver are analyzed. When gas volume is 20:10mL, the jump height reaches 2.5m. In addition, the upper and lower area ratio of cavity is optimized to 2:1, improving the output performance by 21.6% on average. Therefore, the above research results provide reference for the driver structure design of jumping robot.

Submucosal fat accumulation in Crohn's disease: evaluation with sonography.

The study objective is to investigate the ultrasound features that allow suspecting the presence of submucosal fat deposition, called the fat halo sign (FHS), in the intestinal wall of patients with Crohn's disease. Computed tomography (CT) examinations over a period of 10 years were reviewed for the presence of the FHS in the bowel wall. A measurement of less than -10 Hounsfield units was regarded as indicative of fat. We included only patients who had undergone ultrasound examinations 3 months before or after CT. The study cohort group comprised 68 patients. Wall and submucosal thickness were measured on longitudinal ultrasound sections. A receiver operating characteristic curve was constructed to determine the best cutoff of ultrasound submucosal wall thickness value for predicting FHS in the bowel wall determined on CT. The FHS was present in 22 patients (31%) on CT. There were significant differences between submucosal thickness of patients with FHS and patients without FHS (4.19 mm vs. 2.41 mm). From the receiver operating characteristic curve, a threshold value of 3.1 mm of submucosal thickness had the best sensitivity and specificity to suspect FHS (95.5% and 89.1%, respectively; area under the curve, 0.962), with an odds ratio of 172. All of 16 patients with a submucosal thickness >3.9 mm had FHS. FHS in patients with Crohn's disease can be suspected on ultrasound in cases with marked thickening of the submucosa layer. In these cases, the activity of the disease should be measured by other parameters such as the color Doppler.

Left ventricular wall thickness and severity of cardiac disease in women and men with transthyretin amyloidosis.

Cardiac amyloidosis (CA) is due to a deposition of amyloid fibrils in the heart causing an increase in wall thickness. A left ventricular (LV) wall thickness ≥12 mm plus at least one red flag should raise the suspicion of CA. As normal values of LV wall thickness are lower in women, the adoption or the same cut-off values for men and women could lead to underdiagnosis or delayed diagnosis in women. We investigated the relationship between LV wall thickness and the severity of cardiac involvement in women and men with transthyretin (ATTR) CA. We evaluated 330 consecutive patients diagnosed with ATTR-CA at three centres (Pisa, n=232; Brescia, n=69; Trieste, n=29). Interventricular septum (IVS) and posterior wall (PW) thickness values were lower in women (n=53, 16%) than men, but most differences were abolished when indexing by body surface area (BSA), height, or height2.7 , suggesting similar disease severity when accounting for the smaller body size of women. PW thickness indexed for height2.7 was even higher in women. We also searched for correlations between IVS and PW thickness and other indicators of the severity of cardiac disease. IVS values indexed by height2.7 displayed tighter associations with N-terminal pro-B-type natriuretic peptide values than non-indexed IVS values. Similarly, indexed values displayed closer relationships with relative wall thickness, E/e' ratio, and tricuspid annular plane systolic excursion. Indexed LV wall thickness values, particularly by height2.7 , reflect more accurately the severity of cardiac involvement than non-indexed values.

Value of preoperative ureteral wall thickness in prediction of impaction of ureteric stones stratified by size in laser ureteroscopic lithotripsy

ObjectivesTo evaluate the role of preoperative UWT in the prediction of impaction of ureteral stones stratified according to stone size in ureteroscopic laser lithotripsy.Patient and methodsThis study included 154 patients submitted to URSL for ureteral stones. Radiological data comprised the presence of hydronephrosis, anteroposterior pelvic diameter (PAPD), proximal ureteric diameter (PUD), and maximum UWT at the stone site. Collected stone characteristics were stone size, side, number, site, and density.ResultsThe study included 154 patients subjected to URSL. They comprised 74 patients (48.1%) with impacted stones and 80 (51.9%) with non-impacted stones. Patients were stratified into those with stone size ≤ 10 mm and others with stone size > 10 mm. In the former group, we found that stone impaction was significantly associated with higher PAPD, PUD, and UWT. In patients with stone size > 10 mm, stone impaction was related to higher UWT, more stone number, and higher frequency of stones located in the lower ureter. ROC curve analysis revealed good power of UWT in discrimination of stone impaction in all patients [AUC (95% CI) 0.65 (0.55–0.74)] at a cut-off of 3.8 mm, in patients with stone size ≤ 10 mm [AUC (95% CI) 0.76 (0.61–0.91)] at a cut-off of 4.1 mm and in patients with stone size > 10 mm [AUC (95% CI) 0.72 (0.62–0.83)] at a cut-off of 3.0 mm.ConclusionsStratifying ureteric stones according to size would render UWT a more practical and clinically-oriented approach for the preoperative prediction of stone impaction.

710 NEW PROSPECTIVES IN THE USE OF ELECTROCARDIOGRAM IN ANDERSON-FABRY DISEASE ON AND OFF SPECIFIC DISEASE THERAPY: EARLY DIAGNOSIS AND RESPONSE TO THERAPY

Abstract Background Anderson Fabry disease (AFD) is a rare X-linked lysosomal storage disorder caused by deficient activity of α-galactosidase A bringing to intracellular accumulation of globotriaosylceramide (Gb3) in affected tissues, including heart. Progressive cardiac involvement has shown to cause electrocardiographic modifications in these patients. Treatment with enzyme replacement therapy (ERT) or chaperone therapy has demonstrated to decrease Gb3 levels in the heart, but little is known about its influence on ECG evolution. Purpose to gain new insights about ECG evolution in AFD patients on and off specific disease therapy and to assess its potential role in the diagnosis and the follow-up of these patients. Methods we analysed the ECG evolution of a multicentre study cohort of 170 patients with a diagnosis of AFD (64 males 38%, median age 46±15 years) for a median follow-up of 64±48 months, dividing them into patients off (group A, N=63) and on (group B, N= 107) specific therapy. Results the two groups did not differ as regard age at baseline (47±14 vs 44±12 years; p=0,171) but patients off specific disease therapy (group A) showed lower prevalence of male sex [13(21%) vs 51(48%); p=&amp;lt;0,001], classic phenotype [36(57%) vs 82(77%); p&amp;lt;0,001)] and lower values of maximal wall thickness [11±3 vs 13±4 mm; p=&amp;lt;0,0001]. At baseline group A presented more frequently a normal ECG [44(70%) vs 41(38%), p=0,0001] showing lower prevalence of repolarization anomalies [16(25%) vs 51(48%), p=0,005] and left ventricular hypertrophy [14(22%) vs 51(48%), p=0,001]. During follow-up we observed ECG progression in 9 patients in group A (14%), characterized by the development of repolarization anomalies (N=5; 8%), incomplete right bundle branch block (N=4; 6%), shortening of PR interval (N=2; 3%), left ventricular hypertrophy (N=2; 3%), left atrial enlargement (N=2; 3%) and complete right bundle branch block (N=1; 2%). Differently, in group B an ECG evolution was observed in 31 patients (29%) characterized by the development of repolarization anomalies (N=19; 18%), left atrial enlargement (N=12; 12%), complete right bundle branch block (N=8; 8%), left anterior fascicular hemiblock (N=4; 4%) and left ventricular hypertrophy (N=3; 3%).We observed an improvement in ECG features with a regression of repolarization anomalies only in 1 patient off therapy, which could be explained by the presence of transient overload anomalies. We didn't detect any left bundle brunch block among the patients of the two groups. Conclusion We observed ECG progression despite specific disease therapy in 29% of patients of group B showing a potential role of ECG as a marker of cardiac specific response to therapy in these patients. Differently we detected ECG progression in 14% of patients off specific therapy, which is consistent with their less advanced cardiac involvement (lower prevalence of male sex, classic phenotype and lower maximum wall thickness), suggesting that ECG could be an important tool to detect an initial cardiac involvement in these patients even in absence of hypertrophy. The absence of left bundle branch blocks in the two groups compared with a significant prevalence of complete and incomplete right conduction delay could suggest a prevalent involvement of the right bundle branch in these patients and could represent a red flag for the diagnosis of AFD.

Measurement of Rectal Diameter and Anterior Wall Thickness by Ultrasonography in Children with Chronic Constipation.

Measurement of rectal diameter by ultrasonography helps the clinician in the diagnosis of chronic constipation in children for whom rectal examination cannot be performed. The aim of the study is to determine the rectal diameter and anterior wall thickness values in constipated and healthy children and to evaluate the feasibility of ultrasonography in the diagnosis of functional constipation in children who refuse digital rectal examination. One hundred forty constipated and 164 healthy children participated in the study. All patients were divided into 4 subgroups according to their ages (≤3 years [group I], 3.1-6 years [group II], 6.1-12 years [group III], and >12 years [group IV]) and were referred to the radiology department. The measurement was made from above the symphysis pubis, under the ischial spine, and at the bladder neck. Anterior wall thickness measurement was performed. The measurements were recorded according to the presence or absence of fecal mass in the rectum. Constipated children with fecal mass positive group III was found to have significant difference in all of the planes in rectal diameter measurement. Rectum anterior wall thickness measurement was found to be higher in constipated patients with fecal mass (+) compared to the control. Its measurements in constipated patients in group II, group III, and group IV with no fecal mass were found to be statistically higher than the control group. The measurement of rectal diameter and anterior wall thickness by ultrasonography as a noninvasive method was per formed in children who did not want the digital rectal examination, and it may be useful in the diagnosis of constipation.

Wall Thickness Ratio-A New Magnetic Resonance Parameter-Is Associated With the Outcome of Biological Therapy in Patients With Ileal and Ileocolonic Crohn's Disease.

The present study was aimed at identifying a new magnetic resonance enterography (MRE) parameter assessing the clinical outcome of biological therapy in patients with active ileal/ileocolonic Crohn's disease (CD). Transmural healing (TH) has been associated with improved outcomes in CD. However, some patients with clinical remission and inactive disease at endoscopy do not achieve TH. Ileal/ileocolonic CD patients scheduled for biological therapy were prospectively evaluated, at baseline (T0) and after 1 year of treatment (T1), with Harvey Bradshaw Index score, blood tests, ileocolonscopy, and MRE. Clinical activity was assessed after 2 years of treatment (T2). Wall thickness ratio (WTR) was calculated in the same affected ileal segment, as the ratio between the ileum wall thickness value at T1 and the ileum wall thickness value at T0. A total of 103 patients were included. Mean WTR at T1 in nonresponders was significantly higher than in responders. At receiver operating characteristic analysis, WTR values were significantly associated to biological therapy responsiveness. A WTR cutoff value of 0.77mm was identified to discriminate responders from nonresponders (sensitivity: 79%; specificity: 67%). In responders, the proportion of patients with a WTR<0.77 was significantly higher than the proportion of patients achieving TH at T1. Among patients achieving endoscopic remission, 11/29 (37.9%) presented TH, while 20/29 (68.9%) presented WTR<0.77 ( P : 0.035). At multivariate logistic regression analysis, WTR<0.77 was significantly associated to biological therapy response. WTR index represents an easy-to-calculate MRE parameter and seems to be a promising tool for monitoring therapeutic response in CD patients during biological therapy.

Multiobjective Optimization System of Extrusion Process Parameters for Targeted Microtubes Based on RSM and NSGA-II

An optimization system of extrusion process parameters was designed to rapidly extrude a microtube with a target diameter and wall thickness for forming medical balloons with personalized size characteristics. Firstly, the double convected pom-pom (DCPP) model was selected for the numerical simulation of the tube extrusion process, and different parameter combinations and their corresponding simulation results were extracted based on orthogonal experiments. Secondly, the nonlinear functional relationships between microtube diameter and wall thickness with extrusion parameters were established based on the response surface model (RSM). Finally, the nondominated sorting genetic algorithm II (NSGA-II) and response surface model (RSM) were mixed to find the optimal parameters of the tube extrusion. The extrusion experiment results, taking three microtubes with different target size characteristics (1, 0.15), (1, 0.2), and (1.5, 0.2) as examples, show that the average error between the actual and predicted values of diameter and wall thickness of three microtubes is 6.53%, where the average diameter error is 7.3%, the wall thickness error is 5.77%, the maximum value is 9%, and the minimum value is only 1.3%.

Mechanical performance of hexagonal close-packed hollow sphere infill structures with shared walls under compression load

Infill structures of additive manufactured components give not only stability, but can be used as a design feature regarding lightweight and mechanical properties. In this study, an infill structure was investigated which consists of hollow spheres in a hexagonal closed packing. An additional characteristic is, that the contact between the spheres is modelled as an intersection. A script-based design approach was used for generating the structure within a cylinder. Thus, the sphere diameter, the sphere wall thickness and the outer shell thickness can be varied. The deformation behavior was studied using the Finite Element Method (FEM). Compression tests on additive manufactured cylindrical specimens verify the FEM results: (1) appropriate modelling of the contact between the spheres enhances the stability to the structure. (2) Increasing the relative density increases the mechanical properties. (3) Lower values for the relative sphere wall thickness result in an improved ductility.

B-mode and color Doppler ultrasonography of normal external jugular vein in donkeys (Equus asinus)

BackgroundAlthough the jugular vein is a major important blood vessel in equine, the literature lacks this vessel's normal B-mode and Doppler ultrasonographic examinations in donkeys. Therefore, this study aimed to determine the reference ranges of B-mode and Doppler ultrasonographic indices of jugular veins in healthy adult donkeys (Equus asinus) and the possible effect of examination side (left and right), gender, and body condition on the ultrasonographic measurements of this vessel. B-mode and Doppler ultrasound imaging of the external jugular vein was conducted on 20 adult healthy donkeys of both sexes.ResultsIn all donkeys, the jugular vein was 4.01 to 8.1 mm from the body surface. The longitudinal and transverse venous diameters ranged from 3.94 to 10.5 mm and from 0.88 to 1.9 cm, respectively. Moreover, the vein areas varied from 0.61 to 2.83 cm2. The reference values of superficial and deep wall thickness (SWT and DWT) were 0.56 ± 0.2 and 0.6 ± 0.13 mm, respectively. The blood velocity, blood follow rate, and congestion index of the external jugular vein can be expected in adult healthy donkeys as a range value from 8.4 to 13.5 cm/sec, from 0.33 to 1.78 ml/min, and from 0.06 to 0.27 cm.sec, respectively. Generally, the vein showed laminar monophasic waveforms. The examination side and gender have no significant effect on the ultrasound measurements of the vein (P > 0.05). Donkeys with a body condition score (BCS) ≥ 3 revealed increases in the depth of the vein (P < 0.05).ConclusionsThe results of this study can be used as reference values and provide a basis for comparison when evaluating donkeys with diseases that affect blood flow in the external jugular vein.

Bladder wall thickness measured by CT can predict bladder outlet obstruction in men: a retrospective cohort study.

To evaluate whether bladder wall thickness (BWT) measured by CT can be used to predict bladder outlet obstruction in men with low urinary tract symptoms (LUTS). From 2015 to 2018, a total of 120 men with lower urinary tract symptoms who underwent both urodynamic studies and CT tests of the lower abdomen or pelvis were involved. Bladder wall thickness values were measured by CT scanning. Based on the urodynamic studies, 120 men were categorized into two groups, including 70/120 men (58.3%) in the bladder outlet obstruction (BOO) group and 50/120 men (41.7%) in the non-BOO group. The mean BWT was thicker in the BOO group than in the non-BOO group (3.87 vs. 2.75mm, p < 0.001). The mean maximum bladder capacity (MBC) was lower in the BOO group than in the non-BOO group (263.42 vs. 308.96ml, p < 0.001). The mean detrusor pressure at maximum urinary flow rate (PdetQmax) was higher in the patients in the BOO group than in those in the non-BOO group (102.28 vs. 49.25 cmH2O, p < 0.001). The ROC curve showed that BWT was a good predictor with an AUC of 0.855 (95% CI 0.785-0.924, p < 0.001). At the cutoff value of 3.20mm, the predictive sensitivity of BWT for BOO was 72.9%, and the specificity was 90%. Increased bladder wall thickness was correlated with bladder outlet obstruction in men with LUTS. Bladder wall thickness measured by CT scans may be a noninvasive parameter to predict bladder outlet obstruction in men with LUTS.

Association between lower uterine wall thickness measured at 18–22 weeks of gestation and risk of Preterm Birth: a prospective cohort study

BackgroundPreterm labour prediction has been relied on history of previous preterm birth and cervical length of current pregnancy. However, universal cervical length measurement has some limitation. We aim to find a surrogate marker of cervical length to close the gap in preterm prevention program and lower uterine wall thickness seems promising. We generate the nomogram of lower uterine wall thickness during 18–22 weeks of gestation and evaluate the accuracy of LUW thickness as a predictor of preterm delivery before 37 weeks.MethodsThis prospective cohort study included 524 Thai singleton pregnant women at 18–22 weeks of gestation between November 2016 and October 2017. After signing informed consent, transabdominal ultrasonography was performed to examine fetal anatomical structures and to measure LUW thickness. The results were blinded to the caregivers. The outcomes of all pregnancies were followed. The LUW thickness at 10th percentiles was established and was correlated with the outcomes of pregnancy. The performance of LUW thickness at 10th percentile as a predictor of preterm delivery was calculated. The intra-observer and inter-observer reliability of measurement were assessed by intraclass correlation coefficient and Bland-Altman plot.ResultsOf the 524 pregnant women, 64 (12.2%) delivered before 37 weeks of gestation. The reference value of lower uterine wall thickness at 18–22 weeks was established. Mean and 10th percentile of LUW thickness were 6.2 and 4.5 mm respectively. The inter-observer and intra-observer variation of measurement were small (intraclass correlation coefficient = 0.926 and 0.989 respectively). Using LUW thickness at less than 4.5 mm as a predictor of preterm delivery, we found a 2.37 folds increased risk of preterm delivery after adjustment of other factors (p = 0.037). Sensitivity, specificity, positive predictive value and negative predictive value were 14% (95% CI: 6.64–25.02), 92.8% (95% CI: 90.06–95.12), 22.5% (95% CI: 12.66–36.76) and 88% (95% CI: 86.92–89.08) respectively.ConclusionsThe measurement of LUW thickness by transabdominal ultrasonography is feasible and reproducible. The risk of delivery before 37 weeks of gestation is increased significantly if the LUW thickness at 18–22 weeks is less than 4.5 mm.Trial registrationThe study protocol was approved by institutional ethical committee (COA No. Si 657/2016).

Sonographic Evaluation of Urinary Bladder Wall Thickness in Healthy Adults

The urinary bladder is distensible empty viscous with thick muscular walls organ in the pelvis. For normal urination the wall thickness of the bladder should be normal in the range. Objective: To determine urinary bladder wall thickness using ultrasound in normal adults. Methods: It was a cross-sectional study conducted over 4 months from December 2021 to March 2022 in the private sector hospital in Gujranwala, Pakistan. A sample size of 60 was collected using the convenient sampling approach from taking mean of sample sizes of previous related study. Participants with no disease were included after informed consent. Data were analyzed and entered using SPSS version 20.0. Results: The mean age of participants was 33.41 ± 11.9, the mean weight was 75.51 ± 13.9 and height was 171.08 ± 12.5. The mean body mass index was 25.00 ± 3.9. The mean of anterior wall thickness was 2.85 ± 0.405 and posterior wall thickness was 2.86 ± 0.430. Regarding lateral wall thickness, mean right lateral was 2.78 ± 0.464 and left lateral was 2.80 ± 0.430. The participants categorized into normal, overweight and obese showed very slight differences in the mean values of anterior, posterior and lateral wall thickness of bladder. Conclusion: In conclusion, ultrasound is the best modality for measuring the wall thickness of the urinary bladder in both males and females. The age and gender do not affect BWT. A small change is noted in thickness of anterior, posterior and lateral walls of urinary bladder.