Minimal Area Research Articles

Sclerosing mucoepidermoid carcinoma of salivary glands.

Sclerosing mucoepidermoid carcinoma (SMEC) of the salivary glands is a rare variant of low-grade mucoepidermoid carcinoma with scanty cellular atypia characterized by marked fibrosis/sclerosis and a rich inflammatory infiltrate. Herein, we report 25 unpublished cases of SMEC, two of them with prominent eosinophilia (2/25; 8%) and three with abundant IgG4-positive plasma cells (3/25; 12%). In our series of salivary SMEC, molecular analysis using fluorescence in situ hybridization (FISH) and/or next-generation sequencing (NGS) provided evidence of MAML2 gene rearrangement in 18 cases of the 21 analyzable cases tested (86%), while this gene locus was intact in 3 cases (14%). This study focuses on the diagnostic criteria of salivary SMEC given its challenge of abundant collagenous stroma, minimal residual neoplastic areas, and inconspicuous mucous cells. Follow-up data of our cases indicate that salivary SMECs have favorable outcomes. Molecular analysis for MAML2 gene rearrangement suggests that SMECs of salivary glands represent a rare variant of conventional low-grade MECs of salivary glands. In contrast, SMECs of the thyroid gland are genetically distinct from salivary-type thyroid MECs.

Pattern formation on regular polygons and circles

We investigate the formation of Turing patterns on regular polygonal domains, as the number of edges grow, leading to the limiting case of the circle. Using linear and weakly nonlinear analysis, and evidence by simulations, we demonstrate how the domain shape can fundamentally change the expected bifurcation structure. Specifically, on the square domain we are able to derive pitchfork bifurcations for stripe and spot solutions, as well as show that both branches cannot bifurcate to produce stable patterns. This compares with the case of the equilateral triangle domain that causes the Turing bifurcation to be generically transcritical and, in some cases, none of the bifurcating branches are stable. Moreover, we find a monotonically increasing, but nonlinear relationship, between the minimal bifurcation area and the number of edges. Thus, patterns can occur on triangles with much smaller areas than circles. Overall, this work raises questions for researchers who are simulating applications on domains with simple shapes. Specifically, even small changes to domain geometry can have large impacts on the produced patterns; thus, domain perturbations should be considered in any sensitivity analyses.

Efficacy of Clarithromycin Combined with Fluticasone Propionate on Nasal Function, Nasal Mucociliary Transport Function, and Serum Inflammatory Markers in Chronic Rhinosinusitis Patients After Functional Endoscopic Sinus Surgery.

Objective: This study aims to assess the efficacy of clarithromycin (CAM) combined with fluticasone propionate (FP) in patients with chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS), focusing on nasal function, nasal mucociliary transport (MCT) function, and serum inflammatory markers. Methods: The control group (n = 48) was treated with FESS alone, while the study group (n = 48) was treated with FESS plus CAM combined with FP. The clinical effects, symptom scores, nasal function, nasal MCT function, serum inflammatory marker levels, and the occurrence of adverse reactions were compared. Results: The total efficacy rate of the study group (95.83%) was significantly higher than that of the control group (83.33%). After treatment, the study group showed lower symptom scores for nasal congestion, runny nose, sneezing and dizziness, and headache compared to those in the control group. The study group also had lower nasal airway resistance, shorter distance from the minimal cross-sectional area to the nostril, and lower T&T olfactory scores. In contrast, their nasal cavity volume and minimal cross-sectional area were higher than those of the control group. Additionally, the nasal mucociliary clearance and MCT rates were higher in the study group. Serum levels of interleukin-6, interleukin-8, tumor necrosis factor-α, and procalcitonin were significantly lower in the study group compared to the control group (all P < .05). Conclusion: The use of CAM combined with FP in patients after FESS for CRS is effective, leading to the relief of clinical symptoms, improvement of nasal function, enhancement of MCT function, and reduction of inflammatory response, without increasing the incidence of adverse reactions.

Porous mesh manifold for enhanced boiling performance

High-performance electronics are continuously demanding cooling of higher heat fluxes. Phase-change cooling, including pool boiling, is a useful approach to address this challenge; however, competition between liquid and vapor flows generally limit the heat fluxes that can be dissipated. A range of strategies to control these flows have been investigated previously, including capillary guides. Here a manifold structure formed from a metallic mesh is investigated to control the disposition of liquid and vapor phases above a pool fed boiling surface enhanced with porous structures. Copper mesh forms defined liquid flow paths, using capillary action to guide and distribute liquid evenly over the heated surface, along with open channels to facilitate vapor escape. The mesh provides a novel structure for liquid guidance that imposes low resistance to liquid flow while occluding a minimal area of heated surface underneath. The manifold performance is characterized in boiling fed by a pool of water above a laser-textured aluminum nitride heat dissipation surface with pin–fin structures having heights of 110 µm and spacing of 30 µm with a heated area of 5mm x 5mm. A maximum heat flux of 490 W/cm2 is reached with the manifold in the pool fed configuration, representing an increase of more than 65% over the porous pin fin surface alone. The maximum stable superheat observed for the manifold of 36K is 14K higher than that for the porous surface without the manifold. The factors limiting performance of the manifold are analyzed. High superheat is attributed to partial flooding of the boiling surface as suggested by the reduction in superheat using external suction. Similar systems and structures for enhanced two-phase cooling are compared.

Intravascular Ultrasound Assessment of Distal Trans-Radial Access in Patients Undergoing Percutaneous Coronary Intervention.

Distal trans-radial access (dTRA) for percutaneous coronary interventions (PCI) is increasingly gaining attention due to its potential to mitigate radial artery occlusion (RAO). However, a comprehensive understanding of the mechanical impact of the devices on the radial artery (RA) wall remains limited. Using a complete intravascular ultrasound (IVUS) evaluation of the RA, including also the vascular access site, we aimed to evaluate all the consequences related to the catheterization on the RA wall, starting from the vascular access, comparing conventional sheath and sheathless approaches. This is an observational, prospective, multicenter study aimed to assess the entire RA wall immediately after IVUS-guided PCI via-dTRA. IVUS assessment included quantitative measurements (minimal lumen area [MLA], minimal vessel area [MVA]) and qualitative observations (dissections, vasospasm). Study objectives included delineating RA wall structure post-PCI and comparing findings between conventional and sheathless approaches. Fifty patients (21 [42%] with conventional sheath, 29 [58%] sheathless) were enrolled between March 2023 and February 2024. Female patients were more prevalent in the convention sheath group (38% vs. 7%, p < 0.001). Sheathless approach utilized 7-French guiding catheters more frequently (33% vs. 86%, p < 0.001). Post-procedural IVUS identified dissections in 12% of cases, with no significant difference between approaches. Arterial vasospasm was present in a quarter of patients, numerically higher in the conventional sheath group (29% vs. 21%, p = 0.5). MLA and MVA were comparable between groups, though MLA and MVA were lowest at the proximal segment of the RA only in the conventional sheath group (p < 0.001). No RAO was documented during the IVUS evaluation. The intravascular assessment of dTRA after coronary interventions, utilizing either conventional or sheathless approaches, including large-bore guiding catheters, demonstrated a relatively low incidence of access-related complications such as dissection and vasospasm, without affecting the flow and patency of the proximal RA.

Assessment of Cutting-Balloon Angioplasty with Novel Bioabsorbable Polymer-Coated Everolimus-Eluting Stent in Treating Calcified Coronary Lesions Guided by Intravascular Ultrasound (CUPID Trial): study design and protocol

BackgroundVarious devices and techniques have been used for plaque modification in the treatment of severe coronary artery calcification. This prospective, multicenter, randomized, open-label study aims to evaluate the safety and efficacy of cutting balloon angioplasty using a novel bioabsorbable polymer-coated everolimus-eluting coronary stent for treating various degrees of calcified coronary lesions.MethodsWe outline the trial design aimed at assessing whether the cutting balloon (Wolverine™) is non-inferior to the non-compliant balloon in treating patients with calcified lesions, encompassing both de novo and in-stent restenosis (ISR) lesions. We aim to enroll 250 patients who have undergone bioabsorbable polymer-coated everolimus-eluting coronary stent (Synergy™) implantation. The primary endpoint is the minimal stent cross-sectional area at the calcium site as determined by intravascular ultrasonography. The secondary endpoints include major adverse cardiac events and target lesion revascularization at 12 months, alongside procedural convenience and operator-centric parameters, such as the number of balloons used, procedure time, and total contrast medium volume used.DiscussionIn this study, we will evaluate the efficacy and safety of Wolverine™ and non-compliant balloon in patients with calcified coronary lesions and provide a rationale for which type of balloons will optimally modify calcium lesions. In addition, we will attempt to expand the indications of the cutting balloon for treating mild-to-severe calcified coronary lesions. As the scope of insurance coverage for cutting balloons remains limited in some countries, this study may provide evidence for extending insurance coverage to the treatment of de novo calcified and ISR lesions.Trial registrationClinicalTrials.gov NCT06177808. Registered on January 1, 2024.

Intravascular lithotripsy in the management of underexpanded stents

Abstract Introduction Stent underexpansion significantly heightens the risk of major adverse cardiac events (MACE), and available treatment options for this condition remain limited. Intravascular Lithotripsy (IVL) technology disrupts superficial and deep calcium by using localized pulsative sonic pressure waves, emerges as a promising tool for underexpanded stents. Methods Following PRISMA guidelines, we systematically explored PubMed, SCOPUS, and Cochrane databases up to September 3, 2023, for studies evaluating IVL's safety and efficacy in treating underexpanded stents. We gathered angiographic (QCA) and intracoronary imaging (OCT or IVUS) data, examining the stent's minimal diameter stenosis (MDS), minimal lumen diameter (MLD), minimal stent area (MSA), and minimal lumen area (MLA) pre- and post-IVL application. Procedural success constituted the efficacy endpoint, while peri-procedural complications, in-hospital-30-days and long-term mortality, and MACE were safety endpoints Results This meta-analysis comprised 21 studies including 669 patients and 673 treated lesions in underexpanded stent. The mean age was 73.2 ± 2.1 years, with an overall IVL procedural success rate of 93% [(95% Confidence Interval (CI): 88%-96%, I2=29%), while the in-hospital-30-days and long-term mortality incidence were 1% (95% CI: 1%-3%, I2=0%) and 3% (95% CI: 2%-6%, I2=0), respectively. The 30-days target lesion revascularization (TLR) was approximately 6% (95% CI: 3%-12%, I2=50%). There was a significant increase in the MDS [Standardized Mean Difference (SMD): +50.52%, 95% CI: 39.4-61.6, I2=94%)] and in MSA (SMD: +3.52, 95% CI: 2.47 to -4.58, I2=83%) immediately after IVL application. It was observed a significant increase in MLD (SMD: +1.54, 95% CI: 1.09 to 1.98, I2=95%) and in the MLA (SMD: +3.64, 95% CI: 2.62-4.66, I2=5%). Major procedural and device related complications were 3% (95% CI: 1%-6%, I2=0%) and 1% (95% CI: 0%-2%, I2=85%) respectively. Notably low rates were observed for stent thrombosis (0%, 95% CI: 0%-2%, I2=0%), dissections (1%, 95% CI: 1%-4%, I2=0%), perforations (1%, 95% CI: 1%-3%, I2=0%) and no-reflow (0%, 95% CI: 0%-1%, I2=0%). Conclusions IVL demonstrates promise as a safe and effective strategy for underexpanded stent treatment, characterized by low rates of periprocedural complications. Future prospective studies are now warranted to compare IVL to other lesion preparation strategies.30day All-Cause Mortality after IVL use.Minimum Stent Diameter after IVL use.

Impact of ultra-high-resolution on cardiac CT assessment of coronary artery stenoses, plaque burden/composition, and pericoronary adipose tissue attenuation

Abstract Background Conventional coronary computed tomography angiography (CCTA) overestimates stenoses within stents and calcified arteries due to "blooming" artifacts. Ultra-high-resolution coronary CT (UHR-CT) may overcome this limitation because of higher spatial resolution. Purpose To investigate differences in coronary arterial lumen volume, stenosis severity, and plaque composition, between CCTA and UHRCT in patients with stents and/or high coronary calcium scores. Methods As part of a prospective pilot study, 14 patients referred for invasive coronary angiography for evaluation of obstructive CAD underwent UHRCT (Canon Precision, 160 x 0.25mm slices) prior to catheterization. Images of identical cardiac phases were reconstructed in two badges for comparison: 1) Ultra-high resolution using a 1,024 x 1,024 matrix, 0.25 mm, and 2) conventional resolution with a 524 x 524 matrix, 0.5 mm. All images were reconstructed using iterative reconstruction algorithm (AIDR 3D) and a sharp kernel (FC05). For the left main and three coronary arteries, an automated contour analysis using a dedicated software (QAngioCT RE 3.2, Medis, Netherlands) was performed to compare conventional CCTA vs. UHR-CT resolution images across common vascular and plaque metrics, including lumen and vessel volume, plaque burden/volume, plaque composition based upon predefined fixed intensity cut-off values of CT attenuation, minimal and maximal plaque thickness, pericoronary adipose tissue attenuation (PCAT), minimal lumen area and diameter, and diameter stenosis. All lumen and vessel contours were generated by the software, without manual editing. The segment model proposed by the SCCT was used as reference and the lesions classified as greater than 25% stenosis by visual assessment were recorded. The quality of the images was subjectively assessed using a 5-point Likert scale. Vessel segments with scores 1 (severe artifacts) and 2 (pronounced artifacts) were not included in the analysis. Results The mean patient age was 68.5 years (±6.8), 2 were female (14.3%), 6 patients had stents (11 stented segments) and the mean Agatston score was 947.6 (±449) among the 8 non-stented patients. A total of 56 vessels, 133 segments, and 57 lesions were analyzed. Eight segments (6%) were excluded from the analysis due to poor quality. Results on a per segment and per lesion basis were summarized in the table. The mean PCAT value was significantly lower for the UHRCT images compared to NR reconstruction in both segment (p&amp;lt;0.001) and lesion based (p=0.002) analyses. Plaque differentiation varied by UHRCT resulted in a lower fibrous plaque volumes but higher necrotic (low attenuation) plaque volumes. Conclusions Ultra-high-resolution CT image analysis results in significantly different coronary artery plaque volume and PCAT assessment vs. conventional resolution CCTA. These findings have implications for evaluating high-risk plaque features and perivascular inflammation in patients.Table 1

Prognostic value of diffuse high-risk plaque in patients with acute myocardial infarction: a three-vessel optical coherence tomography study

Abstract Background Existing evidence has identified that high-risk plaque (HRP) characterized by a thin-cap fibroatheroma and/or a minimal lumen area ≤ 3.5 mm² were indicative of future cardiovascular events. Diffuse coronary artery disease also contributes to the poor prognosis. Purpose The present study aims to assess the prognostic value of diffuse HRP in patients with acute myocardial infarction (AMI) by using three-vessel optical coherence tomography (OCT). Methods A total of 674 patients with AMI who underwent OCT examination of three major epicardial arteries between January 2017 and December 2018 were consecutively studied. Among 2843 nonculprit lesions detected by OCT, 1375 (48.4%) HRPs were identified and divided into diffuse HRP group (lesion length &amp;gt;20mm, n=443) and focal HRP group (lesion length ≤20mm, n=932). Patients were followed up for a median period of 5 years. Major adverse cardiovascular event (MACE) was defined as the composite of cardiac death, nonculprit lesion-related nonfatal myocardial infarction, and unplanned coronary revascularization. Results The average age of all enrolled patients is 56.7±11.4 years, with 74.9% of male. As compared with focal HRP group, diffuse HRP group had longer lesion length [25.8(23.0,30.8) mm vs. 13.2(9.8,16.1) mm, P&amp;lt;0.001], longer lipid length [18.6(12.3,24.9) mm vs. 7.0(4.5,10.5) mm, P&amp;lt;0.001], and thinner minimal fibrous cap thickness [73.3(53.3,106.7) μm vs. 93.3(60.0,130.0) μm, P&amp;lt;0.001], whereas mean lipid arc was comparable between the two groups. The prevalence of nonculprit plaque rupture (14.2% vs. 7.8%, P&amp;lt;0.001) was significantly higher in diffuse HRP group than that in the focal HRP group. Nonculprit lesions in diffuse HRP group had higher incidence of macrophage accumulation, microvessels, cholesterol crystals, calcification, and layered plaque phenotype than those in focal HRP group (all P&amp;lt;0.001). The incidence of nonculprit lesion-related MACE was 4.7% in diffuse HRP group and 1.7% in focal HRP group [HR: 3.155, 95% confidence interval: 1.579 to 6.301, P=0.002]. Conclusions In patients with AMI, diffuse HRP at nonculprit segment has higher levels of plaque vulnerability and is predictive of future adverse cardiovascular events. Further studies are warranted to investigate the individual treatment strategy of diffuse and focal HRP.Figure 1.Nonculprit plaque vulnerabilityFigure 2.MACE

Association of non-invasive assessed anatomical features with functional testing in coronary artery anomalies - NARCO trial

Abstract Introduction Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital condition believed to carry an increased risk for myocardial ischemia. However, correlation between anatomical characteristics and ischemia remains unclear. Therefore, this study aimed to assess: 1. The difference of invasive fractional flow reserve (FFR) and intravascular ultrasound (IVUS)-based minimal lumen area (MLA) between baseline and stress. 2. The association of coronary computed tomography angiography (CCTA)-based anatomical characteristics to invasively measured hemodynamics and IVUS in AAOCA. Methods Consecutive patients with AAOCA and presence of ≥1 anatomical high-risk features (i.e. intramural course (IM), slit-like ostium, acute take-off angle or proximal narrowing), were systematically evaluated as part of the NARCO trial using CCTA, FFR using adenosine (140 µg/kg/min), dobutamine-volume stress (20-40mcg/kg/min, 0.5-1mg atropine and 3L of saline solution) and IVUS- MLA of IM. Anatomic high-risk features were quantified by CCTA including ostial lumen area and IM-MLA, IM-width, IM-height, IM-elliptic ratio, take-off angle, proximal narrowing and IM length of the anomalous coronary segment. Results A total of 94 patients with AAOCA were screened, whereas 48 showed high-risk anatomic features and underwent the complete stress protocol. Mean age was 54±12 years and 36 (75%) were male and 39 (81%) presented with symptoms. FFRstress was significantly lower than FFRadenosine (0.88 [0.81-0.91] vs. 0.91 [0.87-0.94], p&amp;lt;0.001) (Figure 1). FFRadenosine was ≤0.8 in 5 patients (10%), and FFRdobutamine was ≤0.8 in 12 patients (25%), resulting in 7 (15%) with FFRadenosine &amp;gt;0.8 while FFRdobutamine was ≤0.8. IVUS-MLA was decreased from 6.3 (5.4-8.2) mm2 to 5.4 (4.2-7.1) mm2 during stress (p&amp;lt;0.001) (Figure 2), while elliptic ratio increased from 2.6 (2.1-3.4) to 3.3 (2.5-4.4) (p&amp;lt;0.001). Logistic regression analysis for body surface area adjusted CCTA derived high-risk features showed, that only ostial lumen area, IM-MLA, -elliptic ratio and -width could predict FFRstress ≤0.8. Receiver operating curve analysis showed that ostial width had the greatest AUC with 0.86 (accuracy 83%, sensitivity 83%, and specificity 83%). Eight out of 12 (67%) patients with hemodynamic relevance underwent surgery, 2 (17%) underwent stenting and 2 (17%) were treated with medication. Conclusion In patients with AAOCA and anatomic high-risk features, only one quarter are hemodynamic relevant. FFR during dobutamine-volume stress showed to be the more sensitive stress modality as compared to FFRadenosine. CCTA derived ostial and IM anatomical severity is associated with ischemia under stress. Comprehensive functional and anatomical assessment of AAOCA helps to optimize patient management and avoid unnecessary revascularization.Figure 1:FFRadenosine vs FFRstressFigure 2:IVUS-MLArest vs IVUS-MLAstress

Stent Underexpansion Is an Underestimated Cause of Intrastent Restenosis: Insights From RESTO Registry.

Despite improvement in devices, in-stent restenosis remains a frequent and challenging complication of percutaneous coronary interventions. The RESTO (Morphological Parameters of In-Stent Restenosis Assessed and Identified by OCT [Optical Coherence Tomography]; study NCT04268875) was a prospective multicenter registry including patients presenting with coronary syndromes related to in-stent restenosis. All patients underwent preintervention OCT analysis, which led to analysis of in-stent restenosis phenotype, number of strut layers, and presence of stent underexpansion. The primary end point was the in-stent restenosis type according to the OCT morphological classification. The 1-year incidence of target vessel failure (a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization) was assessed. The study included 297 patients. The culprit stent was a drug-eluting stent in 74.2% of cases. OCT analysis revealed the presence of neoatherosclerosis in 57% (52% calcified), neointimal hyperplasia in 43% (58% homogeneous), stent underexpansion (minimal stent area <4.5 mm2) in 43%, and multiple stent layers in 30%. The prepercutaneous coronary intervention OCT analysis modified the operator's strategy for management in 30% of cases. Treatment involved drug-eluting stent implantation in 61.6% and drug-eluting balloon angioplasty in 36.1% of cases with only 63.2% optimal results. The 1-year target vessel failure incidence was 11% (95% CI, 9%-13%). Residual postpercutaneous coronary intervention stent underexpansion was associated with significantly higher target vessel failure incidence (19% [95% CI, 14%-24%] versus 7% [95% CI, 5-9], P=0.01). OCT identified neoatherosclerosis and neointimal hyperplasia in comparable proportions. Stent underexpansion was frequent and favored subsequent adverse clinical outcomes.

High-Performance Composite Membranes: Embedding Yttria-Stabilized Zirconia in Polyphenylene Sulfide Fabric for Enhanced Alkaline Water Electrolysis Efficiency.

Due to their excellent alkali resistance and chemical stability, polyphenylene sulfide (PPS) fabric membranes are widely used in alkaline water electrolysis (AWE) for hydrogen production. However, traditional PPS membranes suffer from poor hydrophilicity, low airtightness, and high area resistance, resulting in high energy consumption and reduced safety in industrial applications. This study addresses the aforementioned issues by coupling 3-(2,3-epoxy propoxy) propyl trimethoxy silane (KH560) via self-condensation to the PPS membrane and blending it with self-synthesized yttrium-stabilized zirconia nanoparticles (YSZNPs). The YSZNPs are loaded onto the modified PPS fiber surface through dip-coating and hot-pressing processes, forming a micro-mechanical interlocking structure that enhances the overall performance of the membrane in practical hydrogen production applications. The findings indicate that the developed composite membrane demonstrate outstanding hydrophilicity, minimal area resistance (0.21 Ω cm2), and elevated bubble point pressure (2.93224bar). Significantly, tests on gas purity indicate that the produced hydrogen and oxygen attain purities of 99.90% and 99.75%, respectively, when evaluated at a current density of 1.5 A cm-2. Moreover, after 500h of electrolysis testing in a simulated industrial environment, minimal decline in membrane performance is observed, highlighting the competitive edge of this composite membrane in the current AWE market.

Construction of cellulose 3D network composite membrane supported by hydroxylated boron nitride with high surface charge density to achieve high-efficiency osmotic energy harvesting

Ion selectivity and mechanical persistence are critical properties of membranes to harvest osmotic energy. Two-dimensional nanofluidic membranes have been studied to enhance those properties, whereas they are usually constrained due to unsatisfactory mass transfer performances. Herein, a ternary three-dimensional membrane (T-CNF/PVDF/BN-OH composite membrane, abbreviated as CPBN) with distinct mechanical strength and high surface charge density (−2.65 mC·m−2) for sustainable osmotic energy harvesting is designed. In CPBN, negatively charged TEMPO-oxidized cellulose acts as a scaffold and constructs a 3D network structure together with the hydroxylated boron nitride (BN-OH) via a self-assembly process. The affluent nano-constrained ion channels effectively enhance the controllability and effectiveness of ion transport. The abundant ionized carboxyl groups extremely facilitate the selective transportation of the cations, while the BN-OH also assist this process, promoting the one-way transmission of cations in the channel. Additionally, the participation of PVDF polymer forms a network interlock structure, which significantly improves mechanical performances and stability in water. The membrane demonstrates a high power density (10.6 W/m2), measured in minimal testing areas, and an average power density around 1 W/m2 in larger areas, with an energy conversion efficiency of up to 30.7 %. This study provides a promising exploration of replacing traditional two-dimensional layered structure with three-dimensional network structure of cellulose for osmotic energy harvesting.

Differences in vascular tissue response after stent implantation between biolimus-eluting and everolimus-eluting stents: a sub-study of the NEXT study.

NEXT [NOBORI biolimus-eluting stent (BES) versus XIENCE/PROMUS everolimus-eluting stent (EES) trial] was a multicenter, randomized, prospective trial that included 3235 patients with 8-12months of follow-up imaging at 18 centers. IB-IVUS images were analyzed at an interval of 0.5mm using a motorized pull-back system in each plaque that required stent implantation. We analyzed seven cross-sections at the site of minimal lumen area and ten cross-sections in proximal and distal peripheral sites prior to the procedure, after stent implantation and after 8months. We averaged the relative blue volume, relative green volume, relative yellow volume, and relative red volume across seven cross-sections using the manufacturer's default setting. Fifty-four lesions in 50 patients were analyzed. There were 28 lesions in 25 patients in the EES group and 26 lesions in 25 patients in the BES group. The patient characteristics did not differ significantly between the two groups except high-density lipoprotein cholesterol. There were no significant differences before and after stent implantation after 8months in relative red volume, relative yellow volume, relative green volume or relative blue volume. Although the present study was likely underpowered for statistical analyses and larger populations are needed to confirm the conclusions, the vascular response regarding tissue characterization was similar between EES and BES, even though the thickness and releasing materials differed between the stents.

Low-Dose Whole-Chest Dynamic CT for the Assessment of Large Airway Collapsibility in Patients with Suspected Tracheobronchial Instability.

Purpose To quantify tracheal collapsibility using low-dose four-dimensional (4D) CT and to compare visual and quantitative 4D CT-based assessments with assessments from paired inspiratory-expiratory CT, bronchoscopy, and spirometry. Materials and Methods The authors retrospectively analyzed 4D CT examinations (January 2016-December 2022) during shallow respiration in 52 patients (mean age, 66 years ± 12 [SD]; 27 female, 25 male), including 32 patients with chronic obstructive pulmonary disease (mean forced expiratory volume in 1 second percentage predicted [FEV1%], 50% ± 27), with suspected tracheal collapse. Paired CT data were available for 27 patients and bronchoscopy data for 46 patients. Images were reviewed by two radiologists in consensus, classifying patients into three groups: 50% or greater tracheal collapsibility, less than 50% collapsibility, or fixed stenosis. Changes in minimal tracheal lumen area, tracheal volume, and lung volume from inspiration to expiration were quantified using YACTA software. Tracheal collapsibility between groups was compared employing one-way analysis of variance (ANOVA). For related samples within one group, ANOVA with repeated measures was used. Spearman rank order correlation coefficient was calculated for collapsibility versus pulmonary function tests. Results At 4D CT, 25 of 52 (48%) patients had tracheal collapsibility of 50% or greater, 20 of 52 (38%) less than 50%, and seven of 52 (13%) had fixed stenosis. Visual assessment of 4D CT detected more patients with collapsibility of 50% or greater than paired CT, and concordance was 41% (P < .001). 4D CT helped identify more patients with tracheal collapsibility of 50% or greater than did bronchoscopy, and concordance was 74% (P = .39). Mean collapsibility of tracheal lumen area and volume at 4D CT were higher for 50% or greater visually assessed collapsibility (area: 53% ± 9 and lumen: 52% ± 10) compared with the less than 50% group (27% ± 9 and 26% ± 6, respectively) (P < .001), whereas both tracheal area and volume were stable for the fixed stenosis group (area: 16% ± 12 and lumen: 21% ± 11). Collapsibility of tracheal lumen area and volume did not correlate with FEV1% (rs = -0.002 to 0.01, P = .99-.96). Conclusion The study demonstrated that 4D CT is feasible and potentially more sensitive than paired CT for central airway collapse. Expectedly, FEV1% was not correlated with severity of tracheal collapsibility. Keywords: CT-Quantitative, Tracheobronchial Tree, Chronic Obstructive Pulmonary Disease, Imaging Postprocessing, Thorax Supplemental material is available for this article. © RSNA, 2024.

Spatial patterns of high-risk biomechanical metrics in plaques with abnormal vs. normal physiological flow indices

BackgroundPlaques associated with abnormally low physiological flow reserve indices are appropriate for percutaneous coronary intervention (PCI). However, recent trials demonstrate that PCI of ischemia-producing lesions does not reduce major adverse cardiac events (MACE). Low endothelial shear stress (ESS) or high ESS gradient (ESSG) are associated with MACE wherever they occur along the plaque. This study aims to determine the presence of high-risk ESS metrics in obstructive coronary plaques with high-risk (<0.80) vs. borderline-risk (0.80–0.89) vs. normal Instantaneous Wave-free Ratio (iFR) (>0.89). MethodsWe included 50 coronary arteries (50 patients) with variable iFR values who underwent coronary angiography and optical coherence tomography (OCT), followed by 3D reconstruction and computational fluid dynamics calculations of ESS/ESSG. The cohort was divided into 3 groups: iFR < 0.80, iFR 0.80–0.89, and iFR > 0.89. Spatial distribution of ESS metrics was reported along the course of each plaque, and high-risk ESS metrics and their location were compared among the 3 iFR subgroups. ResultsHigh-risk ESS features (Minimal ESS, Maximum ESSG) were similarly distributed along the course of the atherosclerotic plaque in the three iFR subgroups, both in absolute value and in location: Min ESS: 0.5 ± 0.3 vs. 0.4 ± 0.2 vs. 0.4 ± 0.2 Pa respectively (p = 0.60); Max ESSG any direction: 13.7 ± 9.4 vs. 10.4 ± 10.6 vs. 10.0 ± 7.8 Pa/mm respectively (p = 0.30). ESS metrics were spatially located up to ≥18 mm from the plaque minimal luminal area (MLA) in both directions. ConclusionHigh-risk ESS metrics are similarly observed in plaques with normal or abnormal iFR, both in absolute value and spatial location in reference to the MLA. Utilizing iFR to identify plaques likely to cause MACE would miss the majority of plaques mechanistically at high-risk to destabilize and cause future adverse cardiac events.

Scalar Quasi-Normal Modes of a loop quantum black hole

We compute the Quasi-Normal Mode (QNM) frequencies for scalar perturbations for modified Schwarzschild black holes in Loop Quantum Gravity. We study the singularity-free polymerized metric characterized by two parameters encoding loop quantum effects: the minimal area gap a 0 and the polymeric deformation parameter P. We perform numerical computations using Leaver's continued fraction method and compare our results to other semi-analytical methods and existing literature. We study the effects on the QNM spectrum of variation of both deformation parameters and systematically compare to the standard Schwarzschild case. In particular we find that the scalar fundamental mode is modified from the third decimal for values of P in accordance with the most recent astrophysical constraints. We also show that qualitative differences arise for highly damped modes: on the one hand, a new crossing of the imaginary axis occurs for high values of a 0 and, on the other hand, increasing P produces a positive shift of the real part and an increase of the spacing in imaginary part between modes.

A Temperature-Robust Envelope Detector Receiving OOK-Modulated Signals for Low-Power Applications

This paper presents a passive Envelope Detector (ED) to be used for reception of OOK-modulated signals, such as in Wake-Up Receivers employed within Wireless Sensor Networks, widely used in the IoT. The main goal is implementing a temperature compensation mechanism in order to keep the passive ED input resistance roughly constant over temperature, making it a constant load for the preceding matching network and ultimately keeping the overall receiving chain sensitivity constant over temperature. The proposed ED was designed using STMicroelectronics 90 nm CMOS technology to receive 1 kbps OOK-modulated packets with a 433 MHz carrier frequency and a 0.6 V supply. The use of a block featuring a Proportional-to-Absolute Temperature (PTAT) current yields a 5 dB reduction in sensitivity temperature variation across the −40 °C to 120 °C range. Moreover, two different implementations were compared, one targeting minimal mismatch and the other one targeting minimal area. The minimal area version appears to be better in terms of estimated overall chain sensitivity at all temperatures despite a higher sensitivity spread.

Baseline Survey of Plant Species Along Salang Road in Afghanistan

The Salang Road, a critical transportation corridor, serves as a vital link connecting the northern and southern parts of Afghanistan. In response to the government's decision to upgrade this road, assessing and documenting the plant species in the region is crucial. This study was conducted to catalog the plant species along the Salang Road, aiming to establish a comprehensive understanding of the area's botanical diversity. Plants were recorded using the quadrate sampling method at 35 sampling points. A transect line was set up at each sampling point, 5 quadrats were established along each line, and the occurrence of plants within the quadrat frame was recorded. Quadrat sizes, determined using the minimal area method, were 10×10 m for trees, 2×5 m for shrubs, and 1 m2 for herbs. Plants were identified with the help of literature and by comparing with the deposited specimen of Kabul University Faculty of Sciences Herbarium (KUFS). Data were analyzed using Microsoft Excel. 135 diverse species, including trees, shrubs, and herbs, representing various ecological niches were documented. These species belong to 46 plant families, and the most abundant ones were Asteraceae, Apiaceae, Rosaceae, Lamiaceae, Fabaceae, and Polygonaceae. The survey additionally examined road construction's impact on plant species' distribution and diversity. The survey provides valuable insights into the Salang corridor area's botanical diversity and ecological significance, serving as a foundational dataset for future environmental conservation and land management efforts. The information obtained from this study can support qualified decision-making and sustainable development practices in the region.

Unraveling the complex interplay between abnormal hemorheology and shape asymmetry in flow through stenotic arteries

Background and Objective:Stenosis or narrowing of arteries due to the buildup of plaque is a common occurrence in atherosclerosis and coronary artery disease (CAD), limiting blood flow to the heart and posing substantial cardiovascular risk. While the role of geometric irregularities in arterial stenosis is well-documented, the complex interplay between the abnormal hemorheology and asymmetric shape in flow characteristics remains unexplored. Methods:This study investigates the influence of varying hematocrit (Hct) levels, often caused by conditions such as diabetes and anemia, on flow patterns in an idealized eccentric stenotic artery using computational fluid dynamics simulations. We consider three physiological levels of Hct, 25%, 45%, and 65%, representing anemia, healthy, and diabetic conditions, respectively. The numerical simulations are performed for different combinations of shape eccentricity and blood rheological parameters, and hemodynamic indicators such as wall shear stress (WSS), oscillatory shear index (OSI), are relative residence time (RRT) are calculated to assess the arterial health. Results:Our results reveal the significant influence of Hct level on stenosis progression. CAD patients with anemia are exposed to lower WSS and higher OSI, which may increase the propensity for plaque progression and rupture. However, for CAD patients with high Hct level—as is often the case in diabetes—the WSS at the minimal lumen area increases rapidly, which may also lead to plaque rupture and cause adverse events such as heart attacks. These disturbances promote endothelial dysfunction, inflammation, and thrombus formation, thereby intensifying cardiovascular risk. Conclusions:Our findings underscore the significance of incorporating hemorheological parameters, such as Hct, into computational models for accurate assessment of flow dynamics. We envision that insights gained from this study will inform the development of tailored treatment strategies and interventions in CAD patients with common comorbidities such as diabetes and anemia, thus mitigating the adverse effects of abnormal hemorheology and reducing the ever-growing burden of cardiovascular diseases.