Segmental Wall Research Articles

Application of Computational Fluid Dynamic Simulation of Parent Blood Flow in the Embolization of Unruptured A1 Aneurysms

To investigate the effect of microcatheter shaping based on the parent artery mainstream line of blood flow simulated using the computational fluid dynamics (CFD) technique on embolization of unruptured aneurysms on the posterior wall of the anterior cerebral artery (ACA) A1 segment. Patients with unruptured cerebral aneurysms on the posterior wall of the ACA A1 segment were retrospectively enrolled and treated with endovascular embolization after microcatheter shaping. The clinical, embolization and follow-up data were analyzed. Eight patients were enrolled and treated with endovascular embolization. Eight microcatheters were steam shaped in vitro and were all successfully navigated to the right location in the in vitro experiment. During the embolization procedure, seven microcatheters were successfully navigated to the right location for embolization. In the remaining one patient who had tortuous cerebral arteries, reshaping of the microcatheter based on the parent artery mainstream of blood flow made successful navigation of the microcatheter to the right place. Complete occlusion was obtained in seven (87.5%) aneurysms and residual aneurysm neck in the remaining one (12.5%). At angiographic follow-up in 6 (75%) patients, the Raymond grade was I in 5 (83.3%) and II in the rest one (16.7%). Use of CFD simulation of parent artery blood flow for microcatheter shaping in the embolization of unruptured aneurysms on the posterior wall of the ACA A1 segment is safe and effective in navigating the microcatheter to the right location for embolization, resulting in good stability and support for the embolization.

POLYCORE: Polygon-based contour refinement for improved Intravascular Ultrasound Segmentation

Segmentation of the coronary vessel wall in intravascular ultrasound is a fundamental step in guiding coronary intervention. However, it is an challenging task, even for highly skilled cardiologists, due to image artefacts and shadowed regions caused by calcified plaque, guide wires and vessel side branches. Recently, dense-based neural networks have been applied to this task, however, they often fail to predict anatomically plausible contours in these low-signal areas. We propose a novel methodology called Polygon-based Contour Refiner (POLYCORE) that addresses topological error in dense-based segmentation networks using a relational inductive bias through higher-order connections between vertices to learn anatomically rational contours. Our approach remedies the over-smoothing phenomena common in polygon networks by introducing a new vector field refinement module which enables pixel-level detail to be added in an iterative process. POLYCORE is enhanced with augmented polygon aggregation which we show is more effective than typical dense-based test-time augmentation strategies. We achieve state-of-the-art results on two diverse datasets, observing particular improvements when segmenting the lumen structure and in topologically-challenging regions containing shadow artefacts. Our source code is available here: http://orcid.org/https://github.com/kitbransby/POLYCORE.

Multi-functional additively constructed honeycomb walls for housing and sheltering

Honeycomb designs have become increasingly popular in additive manufacturing due to their great mechanical properties. The honeycomb infill pattern has allowed the creation of lightweight objects without sacrificing the strength of solid objects. Honeycombs have been utilized in different applications, including architecture, aerospace, and automotive. However, there is a lack of honeycomb designs within the construction industry. With the growth of concrete additive construction, there is an opportunity to introduce honeycomb designs into construction practices. This paper proposes a methodology for manufacturing multi-functional walls through additive construction. The methodology includes several key steps, from material development and quality control testing to wall assembly and experimental investigation. Two multi-functional wall segments were additively constructed, reaching a height of 1180 mm, a width of 610 mm, and a thickness of 90 mm. These measurements led to the manufacturing of seven distinct cellular sections per wall, comprising three main, two intermediate, and two end cellular units. In addition, a columnar unit was additively constructed for corner connection, featuring two vertical octagonal cells with end brackets. A preliminary wall system made up of honeycomb wall segments was assembled using various additional materials such as sealant, clamping systems, and insulative materials. Furthermore, an additional wall segment with end connections was designed and manufactured to test its load-carrying capacity. The wall segment performed well compared to wooden stud walls and showed sufficient load-carrying capacity. Unlike traditional un-reinforced concrete structures, which are brittle and experience small plastic deformations before failing, the honeycomb wall structure experienced large plastic deformation before failure due to the use of insulation foam and silicon rubber. The preliminary testing showed that the honeycomb wall system could be an alternative to traditional housing construction, especially for shelters.

Percutaneous revascularization in late-presenting STEMI with absence of viability: effects on left ventricular remodeling and scar

Abstract Introduction In patients with ST-elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI) should be conducted within 12 hours of symptom onset. The potential benefits attributable to late reperfusion in STEMI fall under the "open artery hypothesis" where the stunned peri-infarction zone after revascularization would restore blood supply and contractility. Purpose To estimate the differences on the LV ejection fraction (LVEF), indexed LV end-systolic volume (iLVESV) and scar in patients with STEMI without viabilitity randomized to optimal medical therapy (OMT) alone or OMT and a late percutaneous coronary intervention (PCI) performed between 24 hours and 30 days after the event. Methods Patients with non-reperfused STEMI were evaluated from September 2021 to June 2022 at a tertiary cardiology hospital. The patients underwent Cardiac Magnetic Resonance (CMR) to assess myocardial viability and were classified as non-viable if they had only 1 wall segment with less than fifty percent thickness of the affected wall with late gadolinium enhancement. The patients were randomized to PCI or OMT alone. CMR was repeated at 6 months to evaluate LVEF, iLVESV and fibrosis. This summary presents a planned partial analysis of the 6-month results (N=51). Descriptive statistics analysis included central and dispersion estimators, or absolute and relative frequencies. To explore the differences between groups and time, Mann-Whitney and Wilcoxon tests were run, and results were given as point-estimates and confidence intervals at 95% (95% CI). A significance level of 5% was adopted for inferential analysis. Results 51 patients (60±11 years, 71% male) were included in the analysis. Of this total, 24 were randomized to PCI + OMT, and 27 to isolated OMT. The groups showed balanced distribution regarding clinical characteristics and initial CMR parameters (LVEF, iLVESV, and fibrosis). The difference in LVEF at the end of 6 months between the OMT and PCI groups was 2.07%, favoring the OMT group; however, this difference was not significant (p= 0.677, 95% CI: -5 to 10). Between the groups, the difference at the end of 6 months in iLVESV was -6.82 ml/m², also without statistical significance (p= 0.858, 95% CI: -19 to 11). There was a significant reduction in the amount of fibrosis in both PCI group with -14.68g (p= 0.011) and in the OMT group with -12.57g (p= 0.009). Detailed results are presented in Table 1. Conclusion Despite a significant reduction in fibrosis in both groups, there was no superiority observed in late PCI compared to isolated OMT in reducing reverse remodeling and fibrosis in patients with non-viable STEMI when compared to isolated OMT.Remodeling changes.

Right atrio-ventricular strain as a predictor of death in left-sided heart failure

Abstract Background Right ventricular (RV) strain is an established outcome predictor in heart failure (HF). However, the role of right atrial (RA) strain in the setting of left-sided HF is incompletely understood. Purpose We sought to evaluate the RV, RA and combined right atrio-ventricular (RAV) strain using speckle-tracking echocardiography in a cohort of patients with left-sided HF and to assess their prognostic role. Methods 121 consecutive patients (mean age 59±14 years, 74% men) with HF with reduced ejection fraction (HFrEF) referred to our echocardiography department were prospectively enrolled. The main endpoint was all-cause death. RV strain was measured as the average longitudinal strain of the basal, mid, and apical segments of the RV free wall and was reported as a positive value, thus a lower RV strain reflecting a greater longitudinal dysfunction. RA strain was defined as the maximal longitudinal displacement of the atrial wall at end-systole, corresponding to atrial reservoir function. RAV strain was defined as the sum of RV strain and RA strain. Results During a median follow-up of 19±11 months, 26 patients (21%) died. Patients who reached the endpoint had lower left ventricular ejection fraction (LVEF) (21±7% vs. 26±7%, p=0.001), lower tricuspid annular plane systolic excursion (16±3 vs. 18±5, p=0.02) and lower RA strain (13± 10% vs. 18±11%, p=0.03). In univariable Cox regression, RV, RA and RAV strain were all predictors of death: HR=1.05 [95% CI, 1.00-1.11], p=0.045 for RV strain, HR=0.95 [95% CI, 0.91-0.99], p=0.02 for RA strain, HR=0.97 [95% CI, 0.94-0.99], p=0.01 for RAV strain. We constructed a multivariable model with well-established event predictors in HFrEF and one strain index at a time. After adjustment for LVEF, maximal left atrial volume, tricuspid regurgitation severity and pulmonary artery systolic pressure, only RAV strain remained an independent predictor of death (HR=0.97 [95% CI, 0.94-1.00], p=0.04), while RV strain and RA strain did not (p=0.07 for both). LVEF did not emerge as a predictor of death in multivariable regression (p=0.57). Conclusion In left-sided HF, RV and RA strain were predictors of death. Combining the longitudinal strain of both right heart chambers might improve risk stratification, since RAV strain remained the only independent predictor of adverse outcome after adjustment for confounders.

Verification of intra- and inter-atrial conduction during Bachmann's bundle pacing using longitudinal bi-atrial strain

Abstract Introduction Although atrial septal pacing has been reported to reduce atrial fibrillation (AF) burden, there is less evidence regarding its effect on the prevention of permanent AF and the improvement of long-term clinical outcomes. However, Bachmann's bundle pacing (BBp), which features P-wave morphology similar to sinus rhythm and shortened P-wave duration (PWD), was reported to significantly reduce permanent AF recurrences and occurrences compared with right atrial appendage pacing (RAAp) and non-specific right septal pacing. Purpose Possible mechanisms for AF suppression with BBp are that fast inter-atrial conduction through BB decreases global atrial activation time and the dispersion of the overall atrial refractoriness, and it prevents the decrease in left ventricular filling and increase in left atrial pressure associated with delayed left atrial contraction. Intra-and inter-atrial conduction during BBp was evaluated using longitudinal bi-atrial strain. Methods In patients with successful BBp implantation defined by electrocardiographic criteria using SelectSecure pacing lead and C315 delivery catheter (Medtronic, Inc), both left atrium (LA) and right atrium (RA) global longitudinal strain (GLS) in simultaneous phases were measured using Philips Ultrasound Workspace 2D Strain in apical 4-chamber view during atrial pacing to assess intra- and inter-atrial conduction delay. The atrial GLS were measured semi-automatically, and the strain rate was analyzed in the three segments of septal wall, lateral wall, and roof and their average. The negative peak of strain rate during atrial systole was the starting point of atrial contraction, and time to peak (TTP) was measured. The difference in TTP between septal and lateral walls in each atrium was measured as intra-atrial conduction delay and the difference in average TTP between LA and RA as inter-atrial conduction delay. Results Ten patients who underwent successful BBp were enrolled (Sick sinus syndrome: 3, advanced atrioventricular block: 2, complete atrioventricular block: 5). At implantation, bipolar atrial electrogram amplitude was 2.03±0.93 mV, atrial lead impedance was 632.7±157.6 Ω, and atrial pacing threshold was 0.7±0.2 V at 0.4 ms. The PWD during sinus rhythm on the 12-lead ECG was 132.8±10.6 ms, while during BBp it was 108.0±11.9 ms, which was significantly shorter in the BBp group (p<0.001). The intra-atrial conduction delay in RA and LA was 10.9 ± 12.1 ms and 12.1 ± 17.3 ms, respectively, and the inter-atrial conduction delay was 6.6 ± 8.6 ms. On the other hand, for the 10 RAAp and 10 sinus rhythm patients as control groups, the inter-atrial conduction delay was 29.7±13.8 ms and 8.5±9.5 ms, respectively. BBp had significantly less inter-atrial conduction delay than RAAp (p=0.005) and was comparable to sinus rhythm (p=0.719). Conclusion Longitudinal bi-atrial strain suggested that BBp significantly reduced inter-atrial delay and it might be effective in AF suppression.Longitudinal bi-atrial strain

Toward assessment of rupture risk predictors in abdominal aortic aneurysms including intraluminal thrombus based on 3D+t ultrasound images.

Image-based patient-specific rupture risk analysis for abdominal aortic aneurysms (AAAs) has shown considerable promise. However, clinical translation has been hampered by the use of invasive and costly imaging modalities. Despite being a promising alternative, ultrasound (US) makes a full analysis, including intraluminal thrombus (ILT), not trivial. This study explored the feasibility of assessing AAA rupture risk parameters, e.g., peak wall stress (PWS) and peak wall rupture index (PWRI), using US-based models of the AAA wall, finally including ILT. Three-dimensional US data were segmented from a group of AAA patients whose CT data were available within 30 days. The segmented vessel wall and ILT boundaries were converted into a mesh including and excluding ILT to evaluate the effect of adding ILT on the model output. US-based rupture risk parameters (PWS and PWRI) were compared to CT-based results. The US-based PWS and PWRI, including ILT, showed good agreement with CT-based results, and the model excluding ILT showed no significant bias in wall stress or rupture index. When including ILT, a lower US-based wall stress and rupture index of 7.2% and 3.8% were found, respectively. The intraclass correlation coefficient (ICC) of PWS was 0.60. The highest ICC was found for the PWRI (ICC = 0.86), indicating good absolute agreement. This study showed that PWRI can be estimated with US when including the ILT, yielding comparable results to CT, and good absolute agreement. Future work should focus on improving the contrast of ILT in US, since this will be essential to performing large-scale studies in AAA cohorts.

Clinical profile and outcomes of patients with chronic kidney disease on chronic hemodialysis hospitalized for acute coronary syndrome in a tertiary public hospital in the Philippines

Abstract Introduction Acute coronary syndrome (ACS) and end-stage renal disease (ESRD) are both prevalent globally. Of the many risk factors for ACS, chronic kidney disease (CKD) remains to be of great concern because the interplay of cardiac and renal disease is inherently complicated. Cardiovascular mortality rates are 10-30 times higher in the ESRD population. The risk for cardiovascular disease in CKD extends beyond the traditional risk factors. Purpose The guidelines for ACS may not be applicable to the ESRD population because the landmark ACS trials mostly excluded ESRD patients. Due to the gaps in knowledge regarding ACS in ESRD, our study sought to explore the clinical profile and outcomes of these patients in the our institution. Methods We did a retrospective cohort study among ESRD patients presenting with ACS in our institution from May 2021 to November 2023. The data was analyzed using univariate and bivariate statistics using PRISM software. Results A total of 48 patients with ESRD were admitted for ACS in this study - 8 with STEMI and 40 with NSTEMI. The mean age was 61 years old and 33 (68.8%) were male. The average length of hospital stay was 12 days. The most common comorbidities were hypertension (91.7%), heart failure (83.3%), and diabetes mellitus (60.4%). The most common cause of ESRD in our cohort is concomitant hypertensive and diabetic kidney disease (45.8%) with an average length of hemodialysis at 31 months. The most common chief complaints were chest pain (39.6%), dyspnea (29.2%), and decreased sensorium (10.4%). On admission, 18 (37.5%) presented with systolic BP >160mmHg, 7 (14.6%) presented with shock, and 4 (8.3%) presented with cardiac arrest. On electrocardiogram, 21 (43.8%) had left ventricular hypertrophy while 34 (70.8%) had cardiomegaly on chest radiography. On two-dimensional echocardiogram, the average left ventricular ejection fraction was 46% and 27 (90%) had segmental wall motion abnormalities. The most common angiographic finding was 3-vessel coronary artery disease (50%). Only 5 patients (10.4%) had an LDL-C greater than 55mg/dL. Among those with STEMI, 6 (75%) presented with Kilip II or more. While among those with NSTEMI, 27 (67.5%) had a TIMI risk score >2. Almost all patients received dual-antiplatelet therapy, high dose statin, and beta-blocker. The mortality rate was 43.8% with acute coronary syndrome being the most common cause of death. Conclusion Our study did not show significant associated predictors of mortality possibly due to the low sample size. Despite this, our study portrays that patients admitted for ACS with ESRD present with higher risk features reflected by derangement in vital signs, abnormal laboratories, significant imaging abnormalities, high prognostication scores, and high in-hospital morbidity.Predictors of Mortality

The effect of the floor-wall interaction on the post-elastic rocking behaviour of segmented CLT shear walls

This paper investigates the impact of floor-wall interaction on the lateral rocking behaviour of two-panel segmented Cross-Laminated Timber (CLT) shear walls through experimental testing and numerical analyses. The study extends a simplified equivalent spring modelling approach to the post-elastic domain to accurately simulate the effects of floor-wall interaction. Experimental withdrawal tests on four types of floor-to-wall connections, utilizing Fully Threaded Screws (FTSs) and Partially Threaded Screws (PTSs) at varying inclinations, revealed that FTSs exhibited higher stiffness and load-carrying capacity but lower deformation capacity compared to PTSs. The maximum force of FTS connections was about twice that of PTS connections, while PTS connections achieved ultimate displacements up to seven times greater. Numerical analyses using a parametric framework showed that floor-wall interaction increases the stiffness and lateral load-carrying capacity of segmented shear walls, with a significant reduction in deformation capacity. These analyses also demonstrated that the equivalent spring can effectively replicate the influence of floor-wall interaction on shear wall lateral response. Expressions for calculating the strength and ductility of this equivalent spring were developed, considering a limited set of geometric and mechanical parameters. These expressions provide a simplified yet accurate method for estimating the effects of floor-wall interaction. The findings suggest that understanding the interaction between floor and wall elements is crucial for optimizing the performance of segmented CLT shear walls in seismic and lateral load scenarios.

Failure analysis and deformation characteristics of shield tunnel obliquely crossing ground fissure under earthquake

In order to study the deformation law and failure characteristics of shield tunnel obliquely crossing ground fissure under earthquake action, taking the shield tunnel of Xi ’an Metro Line 8 crossing f3 ground fissure as the engineering background, the 1: 20 shaking table model test method was used to analyze the strain of shield tunnel, the contact pressure with surrounding rock soil, the dislocation of segment and the axial force of bolt in detail, and the seismic damage mechanism and failure characteristics of shield tunnel obliquely crossing ground fissure were obtained. The test results show that under the action of earthquake, the shield tunnel has complex three-dimensional deformation characteristics, among which the vertical deformation is the most obvious. The deformation is mainly concentrated in the location of the ground fissure. The tensile strain and contact pressure of the hanging wall of the tunnel segment are greater than the strain value and contact pressure of the footwall. Because the vertical deformation of the tunnel is the largest, the bolts at the vault and the arch bottom are most obviously pulled. Excavation after the test, it can be seen that the tunnel appeared the phenomenon of ring joint opening, lining cracking and other damage. Under the action of the earthquake, the shield tunnel across the ground fissure is mainly subjected to tensile failure. The failure area is within 10 m from the ground fissure in the hanging wall and footwall, and the total length is 20 m. The closer to the ground fissure, the more serious the damage. The research results provide a scientific and reasonable reference for the subsequent construction and disaster prevention and mitigation design of Xi ’an Metro.

PID Controller with an Override Mode for a Wall-Following Robot with a Rotating Sensor Compartment

This paper presents the design of a wall-following robot (WFR) with a rotating sensor compartment to reduce the number of distance sensors used. Two infrared (IR) sensors were fitted in the compartment that rotates back and forth at 45°, producing four measurement values at each rotation cycle. The WFR was regulated using a novel control scheme of PID controller with an override mode. A discrete PID controller in position form was used to run the WFR to follow straight wall segments or walls turning left, while an override mode governed the WFR to follow walls turning right. The sampling time was set to 300 ms. The parameters of the PID controller were tuned using a trial-and-error method. The Mean Absolute Errors (MAE) was selected as the cost function. The WFR conducted twelve trial runs along a trial track with a length of 200 cm, consisting of one right turn and one left turn. The parameters that yielded the lowest MAE of 0.90 cm were used for further tests. Subsequently, a closed track for testing was constructed with a length of 845 cm, consisting of 7 right turns and 2 left turns. The WFR completed five test runs successfully, each elapsing the test track twice. The lowest MAE during the tests was 1.06 cm. The favorable performance of the proposed WFR strengthens future development efforts to equip the robot with more hardware to fulfill specific tasks and to put the completion time into optimization consideration.

Comparison of efficiency of PFA catheter designs by computer modeling.

Various catheter designs are appearing for Pulsed Field Ablation (PFA). It is unclear if they differ in terms of safety and efficiency. PFA studies have reported hemolysis, kidney injury, high troponin, among other side effects. Using a CT-derived computer model, we compared catheter designs using two metrics: (1) efficiency: power delivered to an atrial wall target, expressed as a percent of total generator power; and (2) safety: electric current to achieve 90% transmurality (since more energy causes more collateral effects), as well as the corresponding electrode current density (ECD), a heat and bubble metric. The following catheter designs were compared: penta-spline basket, Nitinol spheres (focal 9 mm and large 1-shot), circular, balloon, and flex-circuit. Target was a 6 × 47 mm circumferential segment of atrial wall at LPV antrum. Transmurality was defined as percent of target having >600 volts per centimeter (V/cm) electric field needed for electroporation. Efficiency was 0.9, 1.4, 2.7, 5.9, 10, and 12% for the large 1-shot and 9 mm Nitinol spheres, penta-spline, circular, flex spline, and balloon catheters, respectively. Regarding safety, currents for 90% transmurality were 70, 39,36,12.5, 5.3, and 4 Amps for the same respective catheters, with less being safer. ECD was 124, 25, 74, 83, 41, and 31 A/cm2, respectively. Computer models demonstrated a remarkable range in efficiency among catheters studied. Those having less atrial blood exposure had the highest efficiencies, with factors of up to 13X more efficiency compared to exposed ones. Higher efficiency designs have less collateral current and are safer. Confirmatory in-vivo studies are required.

Exploring Anatomical Variations in the Bony Architecture of the Greater Palatine Canal in Dry Bones.

Introduction The greater palatine canal (GPC) holds significant clinical importance due to its role in providing access to the branches of the maxillary division of the trigeminal nerve. Anatomical variations within this posterior maxillary region can complicate the surgical anatomy, making the identification of vital structures challenging. Therefore, a thorough understanding of both normal anatomy and common anatomical variations of the GPC is essential to minimize perioperative complications during surgical procedures.This study aims to investigate the bony architecture of the GPC in dry bones to identify anatomical variations and address significant lacunae in our current understanding of this structure. Despite its impact on the management of various dental and surgical procedures, there remains a limited and sometimes inconsistent knowledge of the normal and variant anatomy of the GPC.Existing literature often lacks comprehensive detail regarding the range of anatomical variations and their implications for surgical approaches. By systematically documenting these variations, this study aims to bridge these gaps in knowledge, justify the need for continued research in this area, and highlight its potential clinical implications. Materials and methods In total, 30 dried and intact adult skull specimens were selected, consisting of 19 males (63.3%) and 11 females (36.7%). The selection criteria included an intact hard palate with fully erupted third molars and an intact lateral nasal wall on both sides. The presence of erupted third molars was used to assess the degree of bone resorption, ensuring that only specimens with minimal bone loss were included. The exclusion criteria ruled out specimens with major craniofacial deformities, excessive bone resorption, and signs of advanced age. The bony walls of the GPC were observed by passing a black wire made of rubber material with a consistent diameter (approximately 5 mm), allowing us to qualitatively assess the bore of the canal. Results In four out of 30 specimens (13.3%), significant variations were noted in the bony medial wall of the GPC. Of these, three specimens were male (75%) and one was female (25%). These variations have been categorized into four distinct types for clarity and analysis. Type 1, in a male specimen, showed a deficiency in the lower segment of the bony medial wall of the left GPC above the greater palatine foramen. Type 2, in a male specimen, had a small bar of bone in the left GPC midway between the foramen and the pterygopalatine fossa. Type 3, in a female specimen, exhibited a small bar of bone above the greater palatine foramen on the right side, with no wall above it. Type 4, in a male specimen, displayed a bar of bone above the greater palatine foramen on the right side, with the medial wall completely absent on the left side. Conclusion The study identified anatomical variations in the bony architecture of the GPCbased on dry bone specimens. While these findings offer insights into potential variations that could affect surgical procedures, their clinical implications need validation through patient-based studies. Understanding these variations is crucial for improving preoperative planning and reducing surgical risks, but recommendations should be cautious given the limited sample size. Further research with larger samples and clinical validation is needed to fully understand the embryological basis and potential impact on surgical practice.

Lung Structure and Longitudinal Change in Cardiac Structure and Function: The MESA COPD Study.

Lung structure and cardiac structure and function are associated cross-sectionally. The classic literature suggests relationships of airways disease to cor pulmonale and emphysema to reduced cardiac output (CO) but longitudinal data are lacking. The Multi-Ethnic Study of Atherosclerosis Chronic Obstructive Pulmonary Disease (COPD) Study was a multi-center longitudinal COPD case-control study of participants 50-79 years with ≥10 pack-years smoking without clinical cardiovascular disease. Segmental airway wall area (WA) and percent emphysema were measured on computed tomography. Right and left ventricle (RV, LV) parameters were assessed on magnetic resonance imaging (MRI) in exams six years apart. Longitudinal and period cross-sectional associations were evaluated with mixed models adjusted for demographics, body size, and smoking. The 187 participants with repeated MRI were 67±7 years old; 42% had COPD; 22% currently smoked; and the race/ethnicity distribution was 54% white, 30% Black, 14% Hispanic, and 3% Asian. Greater WA at enrollment was associated with longitudinal increase in RV mass (3.5 g per 10mm2 WA, 95% CI: 1.1, 5.9). Greater percent emphysema was associated with stably lower LV end diastolic volume (-7.8 mL per 5% emphysema, 95% CI: -10.3, -3.0) and CO (-0.2 L·min-1 per 5% emphysema, 95% CI: -0.4, -0.1). Cardiac associations varied by lung structure over six years in this multi-ethnic study. Greater WA at enrollment was associated with longitudinal increases in RV mass; whereas greater percent emphysema was associated with stable decrements in LV filling and CO.

Моделирование краниофациальных повреждений, анализ сроков регенерации и показаний к хирургической коррекции

The purpose of the experiment. Experimental modeling of craniofacial injuries, analysis of oculomotor function and regeneration in the post-traumatic period. Materials and methods. In the experiment, 48 sexually mature males of the Wistar breed were hit with a blunt hammer on a pre-determined area on the muzzle. According to the MS CT data, the nature of the displacement of bone fragments and the presence of muscle interposition were visualized. In the post-traumatic period, behavioral activity in the Actimeter device was analyzed. Results and discussion. Taking into account the thickness of the bone, the localization of the buttress at the place of applied force in the rodent, the hypothesis of energy absorption with its propagation through the bone structures of the orbits, and their subsequent displacement, was confirmed. Conclusions. In 38% of animals (groups 2 and 4), after impact to the postero lateral segment of the lower wall of the orbit, type 2 fracture of the cheekbone-orbital complex was recorded. In the posttraumatic period, a violation of behavioral activity was registered, which required prompt correction of displaced fragments. Upon impact to the central segment, in 50% of cases, 1 type of fracture was formed, without deviations in behavioral activity and without the need for surgical treatment.

The unseen spread: a case of disseminated tuberculosis with renal manifestation in a healthy adult

Disseminated tuberculosis (TB), resulting from the hematogenous spread of tubercle bacilli, typically affects immunocompromised individuals, such as those infected with the human immunodeficiency virus. However, risk factors in immunocompetent populations are not well understood. Here, we report a rare case of disseminated TB with CD4+ T-cell depletion in a previously healthy 35-year-old man. The patient presented with a 2-month history of intermittent gross hematuria, dysuria, loose stools, and weight loss. His medical history was unremarkable except for a herpes zoster infection 4 years prior to presentation. Laboratory tests revealed microscopic hematuria and pyuria; however, the urine culture was negative. Urine specimens tested positive for TB-polymerase chain reaction. Abdominal computed tomography revealed a focal filling defect in the left kidney, segmental wall thickening of the terminal ileum, and multiple enlarged lymph nodes with central necrosis. Chest computed tomography revealed active pulmonary TB. Colonoscopy confirmed intestinal TB in the terminal ileum and ileocecal valve, with positive TB-polymerase chain reaction results from sputum and ileal ulcer tissue. The patient was diagnosed with disseminated TB and was treated with standard anti-TB drugs. Although the human immunodeficiency virus test results were negative, the patient’s CD4+ T-cell count was significantly low (278/μL). Follow-up tests after 1 month showed negative TB cultures; however, the patient’s CD4+ T-cell depletion persisted, with counts remaining low after 1 year. This case highlights the rare occurrence of disseminated TB in immunocompetent individuals with CD4+ T-cell depletion and emphasizes the importance of CD4+ T-cell assessment in healthy patients presenting with disseminated TB.

Basalt fibers corrosion in concrete: New perspectives originating from computational modelling techniques employment

Most of engineering disciplines or research areas have recently witnessed strategic changes leading to formulation of new challenges and revision of existing activities. Promoting the environmental aspects to the highest priority level was mostly in common. Seeking for energy efficient solutions, concrete society has mentioned basalt as a promising candidate having a potential to replace steel in the future. The chemical disharmony between basalt and alkaline environment of concrete, however, represents the most challenging tasks that obstructs the replacement procedure due to durability issues. Since only 3.3 % of the research priorities in this area deals with the corrosion and degradation problems, while the mainstream (57.0 %) prefers determination of various material properties, this problem seems to be undervalued. Additionally, computational modelling approaches are surprisingly not applied as frequently (6.1 %) as in other disciplines, although they could provide the essential long-term research. Simplified methods therefore still dominate these estimations approaches. This paper therefore brings an overview on basalt fiber corrosion in concrete, while summarizing the most topical gaps slowing down the basalt application progress. Since these gaps originate mostly from the simplifications adopted, specific solutions are proposed respectively, exploiting the unique advantages and possibilities of computational modelling approaches that are omitted. The topicality as well as the potential of the advanced approach is demonstrated on a critical example dealing with corrosion analysis evaluation in a specific wall segment. Highlighting the differences between simplified- and advanced techniques outputs, the main findings are concluded, and the most topical gaps are identified.

Diagnostic value and efficacy evaluation value of transvaginal color doppler ultrasound parameters for uterine scar pregnancy and sub-type after cesarean section

ObjectiveWe aimed to probe the diagnostic value of transvaginal color Doppler ultrasound (TV-CDU) parameters in cesarean scar pregnancy (CSP) and CSP sub-types, and the relevant factors affecting patients’ surgical effects.MethodsSeventy-five CSP patients (all requested termination of pregnancy) were selected as the observation group, and 75 normal pregnant women with a history of cesarean section were selected as the control group. All the study subjects underwent TV-CDU and their cesarean scar muscle (CSM) thickness, minimum sagittal muscle thickness and resistance index (RI) of blood flow in the anterior wall of the lower uterine segment were calculated. The diagnostic value of CSM, minimum sagittal muscle thickness, and RI for CSP and CSP sub-types was analyzed. The patients in the observation group were grouped into the effective group and the ineffective group according to whether the surgical treatment was effective or not, and the independent factors affecting CSP efficacy were analyzed.ResultsThe observation group had lower CSM, minimum sagittal muscle thickness and RI than the control group. CSM, RI, and minimum sagittal thickness in patients with type II CSP were lower than those in patients with type I, and these indicators in patients with type III were lower than those in patients with type II. The area under the curve (AUC) of CSM, RI and minimum sagittal muscle thickness in combination for CSP diagnosis and the AUC for CSP sub-types were higher than those of each indicator alone. Gestational sac size and CSM were independent factors affecting CSP treatment.ConclusionChanges in TV-CDU parameters facilitates CSP diagnosis after cesarean section. CSM, minimum sagittal muscle thickness changes, and RI in combination possesses high value for CSP diagnosis and CSP sub-types. Gestational sac size and CSM are independent factors affecting CSP treatment.

Using imagination and the contents of memory to create new scene and object representations: A functional MRI study

Humans can use the contents of memory to construct scenarios and events that they have not encountered before, a process colloquially known as imagination. Much of our current understanding of the neural mechanisms mediating imagination is limited by paradigms that rely on participants' subjective reports of imagined content. Here, we used a novel behavioral paradigm that was designed to systematically evaluate the contents of an individual's imagination. Participants first learned the layout of four distinct rooms containing five wall segments with differing geometrical characteristics, each associated with a unique object. During functional MRI, participants were then shown two different wall segments or objects on each trial and asked to first, retrieve the associated objects or walls, respectively (retrieval phase) and then second, imagine the two objects side-by-side or combine the two wall segments (imagination phase). Importantly, the contents of each participant's imagination were interrogated by having them make a same/different judgment about the properties of the imagined objects or scenes. Using univariate and multivariate analyses, we observed widespread activity across occipito-temporal cortex for the retrieval of objects and for the imaginative creation of scenes. Interestingly, a classifier, whether trained on the imagination or retrieval data, was able to successfully differentiate the neural patterns associated with the imagination of scenes from that of objects. Our results reveal neural differences in the cued retrieval of object and scene memoranda, demonstrate that different representations underlie the creation and/or imagination of scene and object content, and highlight a novel behavioral paradigm that can be used to systematically evaluate the contents of an individual's imagination.

Seismic Behavior of Cluster-Connected Prefabricated Shear Walls under Different Axial Compression Ratios

This study analyzes the nonlinear seismic behavior of cluster-connected prefabricated shear walls under varying axial compression ratios. The investigation focuses on the connectivity of shear wall segments assembled using cluster connections rather than separate walls connected by beams. Using the finite element software ABAQUS, this study simulates monotonic horizontal displacement loading to evaluate the yield strength, peak strength, and deformation capacity of the shear walls. The results demonstrate that the horizontal load-bearing capacity of the shear wall significantly improves with an increase in axial compression ratio, while the axial compression ratio also influences ductility. The numerical simulations are validated against experimental data, confirming the accuracy of the model. These findings provide essential insights for optimizing the seismic design of precast shear walls.