bluuebunny/crossref_metadata_2025 huggingface dataset:
Airworthiness Compliance Verification of Bird Strike on Civil Aircraft Windshield Frame
Authors: Hai Lan Xing
Published: November 2023

With the frequent occurrence of bird strikes, minimizing the impact damage effect of birdstrike on flight always is the goal of airworthiness certification. As a large windward component in front of the aircraft, the windshield, and frame have more probability to be suffered from birdstrike. This paper introduces the common connection forms of the windshield frame structure of civil aircraft, and through the interpretation of the airworthiness requirements related to windshield in CCAR-25, puts forward the process and method of compliance verification of windshield frame birdstrike. Based on the SPH method, the dynamic analysis of bird impact on windshield window frame is carried out, the test is carried out to verify that the analysis method is reasonable and conservative, and the results show that the bird impact performance of the windshield frame structure meets the airworthiness requirements.
Anti-vibration Design of the Civil Aircraft’s Horizontal Tail Trailing Edge Compartment
Authors: Lyu Yuanzhou , Yu Fengli , Chen Yin
Published: November 2023

The horizontal tail trailing edge compartment is a vital component of civil aircraft, situated between the horizontal tail beam and elevator. Its primary function is to connect the elevator and meet the aerodynamic sealing requirements of the unflapped elevator, and to transfer the aerodynamic and inertial load of the elevator to the outboard wing box of the horizontal tail in concentrated form. Under aerodynamic or other excitation, the horizontal tail trailing edge compartment may experience vibration, increasing the risk of structural damage. This study aims to enhance the anti-vibration capability of the horizontal tail trailing edge compartment via parametric finite element analysis. This analysis examines various design elements of the horizontal tail end cabin and compares the first-order modal frequency to deduce the influence of factors on the stiffness. The results provide a reference for the anti-vibration design of the horizontal tail trailing edge compartment in civil aircraft.
Random Error Analysis of Launch and Injection Positions for Distributed Multi Micro-nano Satellite System
Authors: Wu Huanqin , Wang Maocai , Song Zhiming , Chen Xiaoyu , Dai Guangming , Zheng Wei , Zhou Qingrui
Published: November 2023

Accurate satellite orbit calculation has always been a focus in the aerospace field. Especially, the error distribution of the orbit involving various internal and external factors in the satellite launch process has an important influence on the effectiveness of the satellite cluster. To qualitatively and quantitatively analyze the cooperative efficiency of multi-satellite clusters involving various random errors, this paper analyzes the random error sources in the launch process of micro-nano satellites and studies the distribution law of these satellite orbit position errors. Based on the parameter estimation and the central limit theorem of probability theory, the expression of the error function for the satellite’s orbit position is also constructed. In addition, the probability distribution model of the satellites in a certain range is designed, and the relationship between the number of satellites and the overall errors is proposed. Finally, the result is verified by the simulation experiment, which provides the rationale behind the position and altitude adjustment and constellation optimization of micro-nano satellites.
Design, construction and commissioning of a technological prototype of a highly granular SiPM-on-tile scintillator-steel hadronic calorimeter
Authors: White A. , Yu J. , Eigen G. , Zalieckas J. , Dannheim D. , Elsener K. , Grefe C. , Klempt W. , Linssen L. , Sailer A. , Sicking E. , Lai S. , Utehs J. , Wilhahn A. , Bach O. , Brianne E. , Ebrahimi A. , Gadow K. , Göttlicher P. , Hartbrich O. , Heuchel D. , Irles A. , Krüger K. , Laudrain A. , Lu S. , Neubüser C. , Provenza A. , Reinecke M. , Sefkow F. , Schuwalow S. , De Silva M. , Sudo Y. , Tran H.L. , Buhmann E. , Buhmann P. , Garutti E. , Huck S. , Laurien S. , Lomidze D. , Martens S. , Matysek M. , Rolph J. , Briggl K. , Eckert P. , Munwes Y. , Schultz-Coulon H.-Ch. , Shen W. , Stamen R. , Kawagoe K. , Kuhara M. , Onoe T. , Suehara T. , Tsumura S. , Yoshioka T. , Wing M. , Grenier G. , Büscher V. , Chau P. , Krause S. , Liu Y. , Masetti L. , Schäfer U. , Tapprogge S. , Wanke R. , Weitzel Q. , Corriveau F. , Freund B. , Emberger L. , Gabriel M. , Graf C. , Hummer F. , Sasikumar K.S. , Simon F. , Wagner M. , Windel H. , Bilokin S. , Bonis J. , Breton D. , Cornebise P. , Gallas A. , Jeglot J. , Maalmi J. , Pöschl R. , Thiebault A. , Richard F. , Zerwas D. , Callier S. , Dulucq F. , de la Taille Ch. , Martin-Chassard G. , Raux L. , Seguin-Moreau N. , Cvach J. , Janata M. , Kovalcuk M. , Kvasnicka J. , Polak I. , Smolik J. , Vrba V. , Zalesak J. , Zuklin J. , Fujita Y. , Itoh H. , Kanzaki I. , Kotera K. , Takeshita T. , Terada R. , Ootani W. , Liu L. , Masuda R. , Mori T. , Murata T. , Torimaru T. , Tsuji N. , Ueda Y. , Elkhalii A. , Götze M. , Zeitnitz C. , Chadeeva M. , Danilov M. , Popova E. , Rusinov V. , Tarkovsky E. ,   The CALICE Collaboration
Published: November 2023

The CALICE collaboration is developing highly granular
electromagnetic and hadronic calorimeters for detectors at future
energy frontier electron-positron colliders. After successful tests
of a physics prototype, a technological prototype of the Analog
Hadron Calorimeter has been built, based on a design and
construction techniques scalable to a collider detector. The
prototype consists of a steel absorber structure and active layers
of small scintillator tiles that are individually read out by
directly coupled SiPMs. Each layer has an active area of
72 × 72 cm^2 and a tile size of
3 × 3 cm^2. With 38 active layers, the prototype
has nearly 22,000 readout channels, and its total thickness
amounts to 4.4 nuclear interaction lengths. The dedicated readout
electronics provide time stamping of each hit with an expected
resolution of about 1 ns. The prototype was constructed in
2017 and commissioned in beam tests at DESY. It recorded muons,
hadron showers and electron showers at different energies in test
beams at CERN in 2018. In this paper, the design of the prototype,
its construction and commissioning are described. The methods used
to calibrate the detector are detailed, and the performance achieved
in terms of uniformity and stability is presented.
Multi-scale analysis of urbanization and gross primary productivity during 2000–2018 in Beijing, China
Authors: Liu Xiaoyan , Cui Yaoping , Xiao Xiangming , Shi Zhifang , Li Mengdi , Li Nan , Dong Jinwei
Published: November 2023

Urban vegetation experiences multiple natural and human impacts during urbanization, including land conversion, local environmental factors, and human management, which may bring positive or negative impacts on vegetation gross primary productivity (GPP) at multiple scales. In this study, we analyzed the spatial-temporal changes of GPP and three urbanization factors: land urbanization (impervious surface coverage), population urbanization (Population), and economic urbanization Gross domestic product (GDP) at city-district-grid scales in Beijing during 2000–2018. Overall, both GPP and three urbanization factors showed an increased trend. The relationships between GPP and urbanization factors exhibit diverse characteristics at multiple scales: unlike the linear relationship observed at city scale, the relationships at district and grid scales all demonstrated nonlinear relationship, even a U shape between GPP and population/GDP. Furthermore, the positive impact of urbanization on GPP increased and offset the negative impact of land conversion from 9.9% in 2000 to 35% in 2018, indicating that urban management and climate during urbanization effectively promote vegetation photosynthesis and neutralize the negative impact of urban area expansion. Our findings highlight the increased growth offset by urbanization on vegetation and the importance of analysis at a finer scale. Understanding these urbanization types’ impact on vegetation is pivotal in formulating comprehensive strategies that foster sustainable urban development and preserve ecological balance.
The sharing economy is not always greener: a review and consolidation of empirical evidence
Authors: Meshulam Tamar , Goldberg Sarah , Ivanova Diana , Makov Tamar
Published: November 2023

The digital sharing economy is commonly seen as a promising circular consumption model that could potentially deliver environmental benefits through more efficient use of existing product stocks. Yet whether sharing is indeed more environmentally benign than prevalent consumption models and what features shape platforms’ sustainability remains unclear. To address this knowledge gap, we conduct a systematic literature review of empirical peer reviewed and conference proceeding publications. We screen over 2200 papers and compile a dataset of 155 empirical papers, and consolidate reported results on the environmental impacts of the sharing economy. We find that sharing is not inherently better from an environmental perspective. The type of resource shared, logistic operations, and the ways in which sharing influences users’ consumption more broadly affect environmental outcomes. Sharing goods is generally associated with better environmental outcomes compared to shared accommodations or mobility. Within mobility, shared scooters and ride-hailing emerge as particularly prone to negative environmental outcomes. Contrary to previous suggestions, peer-to-peer sharing (vs. centralized ownership) does not seem to be a good proxy for environmental performance. As sharing becomes intertwined with urbanization, efforts to steer digital sharing towards environmental sustainability should consider system levels effects and take into account platform operations as well as potential changes in consumer behavior.
Quantum gravity through geometric algebra
Authors: Wolk Brian Jonathan
Published: November 2023

Geometric Algebra is used to construct a model of quantum gravity in which the 4D spacetime manifold is built from qubitic quantum entangled spacetime elements of geometric algebraic nature. This is achieved by first investigating the spontaneous decomposition of the spacetime continuum’s metric structure at Planck distances as one approaches what otherwise would become the Universe’s initial singularity. Considering this metric deconstruction within the model one finds that the reverse induced emergence of the spacetime continuum is generated by a coupling action triggered by the embedding action between distinct pre-spacetime manifolds. Further uncovered in this re-engineering of spacetime is a Poincaré-constrained quantum foam existing at infra-Planck scales.
Transfer learning for clustering single-cell RNA-seq data crossing-species and batch, case on uterine fibroids
Authors: Wang Yu Mei , Sun Yuzhi , Wang Beiying , Wu Zhiping , He Xiao Ying , Zhao Yuansong
Published: November 2023

Due to the high dimensionality and sparsity of the gene expression matrix in single-cell RNA-sequencing (scRNA-seq) data, coupled with significant noise generated by shallow sequencing, it poses a great challenge for cell clustering methods. While numerous computational methods have been proposed, the majority of existing approaches center on processing the target dataset itself. This approach disregards the wealth of knowledge present within other species and batches of scRNA-seq data. In light of this, our paper proposes a novel method named graph-based deep embedding clustering (GDEC) that leverages transfer learning across species and batches. GDEC integrates graph convolutional networks, effectively overcoming the challenges posed by sparse gene expression matrices. Additionally, the incorporation of DEC in GDEC enables the partitioning of cell clusters within a lower-dimensional space, thereby mitigating the adverse effects of noise on clustering outcomes. GDEC constructs a model based on existing scRNA-seq datasets and then applying transfer learning techniques to fine-tune the model using a limited amount of prior knowledge gleaned from the target dataset. This empowers GDEC to adeptly cluster scRNA-seq data cross different species and batches. Through cross-species and cross-batch clustering experiments, we conducted a comparative analysis between GDEC and conventional packages. Furthermore, we implemented GDEC on the scRNA-seq data of uterine fibroids. Compared results obtained from the Seurat package, GDEC unveiled a novel cell type (epithelial cells) and identified a notable number of new pathways among various cell types, thus underscoring the enhanced analytical capabilities of GDEC.

Availability and implementation: https://github.com/YuzhiSun/GDEC/tree/main
DeepFold: enhancing protein structure prediction through optimized loss functions, improved template features, and re-optimized energy function
Authors: Lee Jae-Won , Won Jong-Hyun , Jeon Seonggwang , Choo Yujin , Yeon Yubin , Oh Jin-Seon , Kim Minsoo , Kim SeonHwa , Joung InSuk , Jang Cheongjae , Lee Sung Jong , Kim Tae Hyun , Jin Kyong Hwan , Song Giltae , Kim Eun-Sol , Yoo Jejoong , Paek Eunok , Noh Yung-Kyun , Joo Keehyoung
Published: November 2023

Motivation

Predicting protein structures with high accuracy is a critical challenge for the broad community of life sciences and industry. Despite progress made by deep neural networks like AlphaFold2, there is a need for further improvements in the quality of detailed structures, such as side-chains, along with protein backbone structures.

Results

Building upon the successes of AlphaFold2, the modifications we made include changing the losses of side-chain torsion angles and frame aligned point error, adding loss functions for side chain confidence and secondary structure prediction, and replacing template feature generation with a new alignment method based on conditional random fields. We also performed re-optimization by conformational space annealing using a molecular mechanics energy function which integrates the potential energies obtained from distogram and side-chain prediction. In the CASP15 blind test for single protein and domain modeling (109 domains), DeepFold ranked fourth among 132 groups with improvements in the details of the structure in terms of backbone, side-chain, and Molprobity. In terms of protein backbone accuracy, DeepFold achieved a median GDT-TS score of 88.64 compared with 85.88 of AlphaFold2. For TBM-easy/hard targets, DeepFold ranked at the top based on Z-scores for GDT-TS. This shows its practical value to the structural biology community, which demands highly accurate structures. In addition, a thorough analysis of 55 domains from 39 targets with publicly available structures indicates that DeepFold shows superior side-chain accuracy and Molprobity scores among the top-performing groups.

Availability and implementation

DeepFold tools are open-source software available at https://github.com/newtonjoo/deepfold.
Organization of pRF size along the AP axis of the hippocampus and adjacent medial temporal cortex is related to specialization for scenes versus faces
Authors: Leferink Charlotte A , DeKraker Jordan , Brunec Iva K , Köhler Stefan , Moscovitch Morris , Walther Dirk B
Published: November 2023

The hippocampus is largely recognized for its integral contributions to memory processing. By contrast, its role in perceptual processing remains less clear. Hippocampal properties vary along the anterior–posterior (AP) axis. Based on past research suggesting a gradient in the scale of features processed along the AP extent of the hippocampus, the representations have been proposed to vary as a function of granularity along this axis. One way to quantify such granularity is with population receptive field (pRF) size measured during visual processing, which has so far received little attention. In this study, we compare the pRF sizes within the hippocampus to its activation for images of scenes versus faces. We also measure these functional properties in surrounding medial temporal lobe (MTL) structures. Consistent with past research, we find pRFs to be larger in the anterior than in the posterior hippocampus. Critically, our analysis of surrounding MTL regions, the perirhinal cortex, entorhinal cortex, and parahippocampal cortex shows a similar correlation between scene sensitivity and larger pRF size. These findings provide conclusive evidence for a tight relationship between the pRF size and the sensitivity to image content in the hippocampus and adjacent medial temporal cortex.
Spatial simulation of autologous cell defection for cancer treatment
Authors: Choi Jibeom
Published: November 2023

Cancer cells are highly cooperative in a nepotistic way and evolutionarily dynamic. Present cancer treatments often overlook these aspects, inducing the selection of resistant cancer cells and the corresponding relapse. As an alternative method of cancer elimination, autologous cell defection (ACD) was suggested by which modified cancer cells parasitically reliant on other cancer cells are implemented to the cancer cluster. Specifically, modified cancer cells should not produce costly growth factors that promote the growth of other cancer cells while receiving the benefit of exposure to such growth factors. Analytical models and rudimentary experiments up to date provide the medical feasibility of this method. In this study, I built comprehensive spatial simulation models by embracing the effects of the multiple growth factors, the Warburg effect, mutations and immunity. The simulation results based on planar spatial structures indicate that implementation of the defective modified tumours may replace the existing cancer cluster and defective cells would later collapse by themselves. Furthermore, I built a mathematical model that compares the fitness of the cells adjacent to the hypertumour–cancer interface. I also calculated whether anticancer drugs that reduce the effects of the growth factors promote or demote the utility of ACD under diverse fitness functions. The computational examination implies that anticancer drugs may impede the therapeutic effect of ACD when there is a strong concavity in the fitness function. The analysis results could work as a general guidance for effective ACD that may expand the paradigm of cancer treatment.
Hemodynamics analysis and computational fluid dynamics simulations to identify potential location of rupture in abdominal aortic aneurysm
Authors: Al-Thani H , Yalcin H , Mutlu O , El-Menyar A
Published: November 2023

Background

Abdominal Aortic Aneurysm (AAA) rupture is the most severe consequence of aneurysmal disease, with an overall death rate of 80%. Early diagnosis and appropriate follow-up and management of AAA will significantly reduce the risk of rupture and mortality. Rupture risk assessment of AAA has a critical role for the early warning.

Purpose

To Predict of the course of an AAA and determine the rupture risk and location from a biomechanical point of view. AAA hemodynamics were investigated to clarify the relation between the hemodynamic parameters and the AAA rupture.

Methods

Computed tomography (CT) images of one healthy aorta and 23 patients’ aorta with aneurysms were analyzed. WSS-related hemodynamic parameters of time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), endothelial cell activation potential (ECAP), and relative residence time (RRT) are investigated in patient-specific AAA geometries by performing computational fluid dynamics (CFD) simulations (Figure 1). Patient-specific AAA geometries are identified using medical imaging techniques and realistic boundary conditions are determined using Doppler ultrasonography.

Results

AAA rupture locations predicted by CFD simulations were in good agreement with the actual rupture locations of retrospective data. The rupture locations had relatively low TAWSS, high OSI, high ECAP, and high RTT levels. High risk of rupture is expected in regions with a local minimum of TAWSS, and a local maximum of OSI, ECAP, and RRT.

Conclusions

Examining the spatial distribution of the hemodynamic parameters was a powerful approach for rupture risk assessment of AAA. Predicting the rupture location using a single hemodynamic parameter is not feasible, and the accuracy of AAA rupture risk assessment can be improved by using multiple WSS-related parameters by identifying the common intersection regions of low TAWSS, high OSI, high ECAP, and high RRT.Figure 1
Risks and benefits of antiplatelet therapy in patients with abdominal aortic aneurysm without symptomatic atherosclerotic disease: a nationwide cohort study
Authors: Nicolajsen C , Soegaard M , Eldrup N , Larsen T B , Goldhaber S Z , Behrendt C A , Nielsen P B
Published: November 2023

Background

Patients with abdominal aortic aneurysm (AAA) suffer a high risk of ischemic events associated with concomitant atherosclerotic cardiovascular disease, and current clinical practice guidelines recommend antiplatelet therapies to mitigate this risk. However, in patients with AAA and no symptomatic atherosclerosis, the benefit of antiplatelet is sparsely investigated.

Purpose

To assess the effectiveness of antiplatelets vs no antiplatelets on the risk of ischemic events (composite of myocardial infarction and ischemic stroke) and bleeding in individuals with AAA who had no concomitant atherosclerotic vascular disease.

Methods

We designed a target trial to compare outcomes among treatment initiators and non-initiators and emulated the trial contingent on patient eligibility at time of inclusion, utilizing Danish nationwide observational data from January 2010 through August 2021. Confounding was handled by means of inverse probability treatment weighting based on the propensity score. The emulated sequential trial results for all possible trial months were pooled by means of pooled logistic regression models to estimate the intention-to-treat average treatment effects, and the 5-year associated treatment differences were expressed as hazard ratio (HR) with 95% confidence intervals (CI) and estimated event-free survival.

Results

A total of 6,344 patients provided 131,047 trial participants: 3,363 of these were new initiators of antiplatelet therapy, while 127,684 were non-initiators. During a median follow-up of 24 months, 173 and 369 ischemic events occurred among initiators and non-initiators, respectively. The corresponding HR of 0.91 (CI 95% 0.73 to 1.17) and an estimated absolute event-free survival difference of -0.6% (Figure 1). For bleeding, the HR was 1.26 (CI 0.97 to 1.58) and the event-free survival difference was 1.0%.

Conclusion

This target trial emulation, using nationwide observational data on all patients with AAA and no record of symptomatic atherosclerotic disease, did not find evidence of antiplatelets to lower the risk of ischemic events, but also no evidence of substantial higher bleeding risk. The observed differences between the treatment groups were minimal, suggesting limited clinically relevance of this treatment.ischemia- and bleeding free survival
Cerebral Embolic Protection Device protects against stroke during Transcatheter Aortic Valve Replacement (TAVR): An Updated Meta-Analysis
Authors: Basit J , Fatima M , Zaheer Z , Ebad Ur Rehman M , Ahmed N , Lee Q , Saeed S , Leung C , Maqbool S , Malik J , Tse G
Published: November 2023

Background

Cerebral Embolic Protection Device (CEPD) is used to capture emboli during Transcatheter Aortic Valve Replacement (TAVR). Previous meta-analyses have yielded conflicting results regarding efficacy and safety of CEPD in TAVR. With recently published pivotal trial and multiple Cohort studies reporting new data, there is a need of re-calibration of available statistical evidence.

Aims

The aim of our study was to explore the effects of using CEPD on TAVR outcomes.

Methods

A systematic literature search was conducted across Pubmed, Cochrane, Embase, and clinicaltrials.gov from inception till February 2023. Dichotomous outcomes were pooled using Odds Ratio (OR) while continuous outcomes were pooled using Standardized Mean Difference (SMD). Revman 5.4 was used to pool the data using random effects model With Mantel-Haenszel method. Subgroup analysis for study type (RCT vs NRS) was conducted. Sensitivity analysis using leave one out method and multiple exit method was conducted to find out, if unadjusted cohort studies had an impact on the pooled outcomes.

Results

The initial search revealed 870 articles. After primary and secondary screening, data was included from 17 studies (6 RCTs, 11 cohorts, n= 180187). Use of CEPD was associated with 50% reduced odds of stroke (OR=0.50, 95% CI=0.03-0.75, p=<0.01, I2=32%). There was no significant difference in 30 days mortality between the two groups (OR=0.76, 95% CI=0.44-1.31, p=0.33, I2=18%). On Diffusion Weighted Magnetic Resonance Imaging (DW-MRI), the two groups did not have any significant differences in volume per lesion (SMD=-0.07,CI=-0.28-0.14, p=0.52,I2=71%), Total volume of lesions (SMD=-0.08, p=0.73, CI=-0.53,0.17, I2=84%) and Number of lesions per patient (SMD=-0.15, p=0.45, CI=-0.23,0.10, I2=84%). On subgroup analysis, RCTs were found to have high heterogeneity while NRS had zero heterogeneity. The pooled analysis revealed no significant association with either of the group regarding Acute Kidney Injury (OR=0.84, p=0.43,I2=0%), risk of pacemaker implantation (OR=1.17,p=0.35,I2=0%), major bleed (OR=0.97,p=0.94,I2=62%), Worsening National Institute of Health Stroke Scale (NIHSS) (OR=0.46,p=0.36,I2=76%), and Vascular complications VC (OR=0.85,p=0.35,I2=0%). The results remained insignificant for subgroup analysis for study type and sensitivity analysis using leave one out and exit multiple methods for unadjusted cohort studies.

Conclusion

The use of CEPD during TAVR was found to be associated with reduced risk of stroke, however, there was no significant association with mortality, DW-MRI findings, AKI, major bleed, minor bleed, risk of pacemaker implantation, worsening NIHSS score and vascular complications. Further, large scale prospective trials are needed to provide definitive evidenceFig 1:Plots for mortality and strokeFig 2:Plots for VC and AKI
Prevalence and prognostic effects of comorbid coronary artery disease detected in patients undergoing carotid endarterectomy
Authors: Nakajima H , Momose T , Misawa T
Published: November 2023

Introduction

Coronary artery disease (CAD) shares common risk factors with carotid artery stenosis and is a known perioperative risk factor for carotid endarterectomy (CEA). It is feasible to perform CEA with continuation of antiplatelet drugs, including dual antiplatelet therapy. Differing opinions exist with respect to detection of CAD prior to CEA. To support the discussions, we aimed to assess recent prevalence and prognostic effects of comorbid CAD in patients undergoing CEA without known CAD.

Methods

This single-center prospective cohort study included patients scheduled for elective CEA between 2013 and 2021. Of these, 108 patients without a medical history of CAD (mean age 76.6±7.3 years, 73.1% men) underwent coronary computed tomography angiography (CCTA). Coronary angiography (CAG) and subsequent fractional flow reserve (FFR) estimation were performed where necessary. CAD was defined as total or subtotal occlusion observed on CCTA, ≥75% stenosis on CAG, or lesions with FFR ≤ 0.80 in the major coronary arteries. Optimal medical therapy and/or coronary revascularization was added according to the presence, severity, and extent of CAD. The primary endpoint was MACE (the composite of all-cause mortality, myocardial infarction, or stroke) after CEA.

Results

The prevalence of comorbid CAD was 19.4% (21 of 108 patients). During a mean follow-up of 4.0 years, the incidence of MACE and stroke was significantly higher in patients with CAD (adjusted HR: 3.10, 95% CI: 1.43–6.71, p=0.0042 and HR: 2.76, 95% CI 1.08–7.31, p=0.041, respectively). Other than patient age, only CAD was a significant predictor of MACE.

Conclusions

CAD is commonly detected in patients undergoing CEA, and it predicts future MACE and stroke event.
Imaging signs of vulnerability, neurological events and cognitive impairment in asymptomatic carotid artery stenosis: results from the Carotid Artery Multi-modality imaging Prognostic (CAMP) study
Authors: Gargani L , Masini G , Baldini M , Napoli V , Orlandi G , Lucchi G , Totaro P , D'amelio C , Galeotti G G , Ghicopulos I , Nilsson I , Goncalves I , Palombo C , Cosottini M , De Caterina R
Published: November 2023

Background

Carotid artery plaques with imaging signs of vulnerability, such as ulceration, intraplaque haemorrhage (IPH) or a lipid-rich necrotic core (LRNC), are associated with a high risk of ischemic stroke, and are reported to be considered for invasive treatment if % diameter stenoses ≥60. Little is known about their fate in patients with <60% stenoses.

Purpose

To evaluate the prevalence of ulceration, IPH and LRNC and their characteristics in patients with asymptomatic, non-significant (<60%) carotid artery stenoses.

Methods

One hundred and twenty-one patients with asymptomatic, unilateral, mild/moderate (40-60%) carotid artery stenoses at Doppler ultrasound (DUS), were prospectively evaluated with computed tomography angiography (CTA), magnetic resonance angiography (MRA) and brain magnetic resonance imaging (MRI). IPH and LRNC were defined at MRA, while ulceration was defined at CTA. Verbal and memory skills were tested by the Fifteen Reye’s Words and other standardized tests.

Results

At least one sign of vulnerability (IPH, LRNC or ulceration) was detected in 51.6% patients. Signs of vulnerability were more frequent in patients with ≥50% stenoses compared with those with <50% at DUS (62.5% vs 27.6%, p=0.002). No difference in the prevalence of cardiovascular risk factors was present in those with and without signs of vulnerability (Table). An ulceration at CTA was significantly associated with presence of IPH or LRNC even after adjustment for the degree of stenosis (OR 4.2, 95% CI 1.3-13.2; OR 4.0, 95% CI 1.4-11.2). Subclinical embolic brain infarctions were found in 10% of patients. A higher prevalence of LRNC was found in patients with brain infarctions (50% vs 17%, p<0.05). Patients with either IPH or LRNC performed worse at standardized tests of cognitive impairment (score 1.6±1.1 vs 2.2±1.4, p<0.05).

Conclusions

Imaging signs of vulnerability are highly prevalent in patients with asymptomatic intermediate carotid artery stenosis, and can be detected in more than one fourth of patients with a non-significant plaque in terms of degree of stenosis. Plaque ulceration at CTA is independently associated with LRNC and IPH at MRA, independent of the degree of stenosis. Plaques with LRNC are associated with subclinical embolic brain infarcts and a worse cognitive performance.TableFigure
Combined predictive value of pre-procedural protein-energy wasting and inflammation status for amputation and/or mortality after lower extremity revascularization in patients on hemodialysis
Authors: Takahashi H , Kumada Y , Ito R , Oshima Y , Murohara T , Izawa H , Ozaki Y , Ishii H
Published: November 2023

Background

Although lower extremity revascularization has been commonly performed in chronic hemodialysis (HD) patients with peripheral artery disease (PAD), poorer prognosis after revascularization still remains major problems. Recently, protein-energy wasting (PEW) or malnutrition have been considered to be strongly associated with chronic inflammation and advanced atherosclerosis in HD patients. We investigated the association of geriatric nutritional risk index (GNRI) as a surrogate marker of the PEW, C-reactive protein (CRP) and their joint role with prediction of amputation and/or mortality after lower extremity revascularization in HD patients.

Method

We enrolled a total of 800 HD patients (age 67±10 years, diabetes 63.3% and critical limb ischemia 52.9%) who successfully underwent lower extremity revascularization [535 with endovascular therapy (EVT) and 265 with bypass surgery]. Patients were divided into tertiles according to pre-procedural GNRI levels; tertile 1 (T1): <88.1, T2: 88.1-96.7and T3: >96.7, and CRP levels; T1: <2.0mg/l, T2: 2.0-12.6mg/l and T3: >12.6mg/l, respectively. Primary outcome was amputation-free survival (AFS). They were followed up for up to 8 years.

Results

During follow-up period (median: 43 months), 56 (7.0%) patients needed major amputation and 183 (22.9%) patients died. Kaplan-Meier analysis shows that the AFS rates for 8 years were 47.0%, 56.9% and 69.5% in T1, T2 and T3 of GNRI, and were 65.8%, 58.7% and 33.2% in T1, T2 and T3 of CRP, respectively (p<0.0001 in both). After adjustment for male, age, previous coronary artery disease, procedure (EVT vs. bypass surgery), below-knee artery disease and ulcer/gangrene as covariates with p<0.05 by univariate analysis, declined GNRI [hazard ratio (HR) 2.18, 95% confidence interval (CI) 1.57-3.07, p<0.0001 for T1 vs. T3] and elevated CRP (HR 1.78, 95%CI 1.24-2.59, p=0.0016 for T3 vs. T1) were identified as independent predictors of amputation and/or mortality. In the combined setting of both variables, the risk of amputation and/or mortality was 3.77-fold higher (95%CI 1.97-7.69, p<0.0001) in the group with T1 of GNRI and T3 of CRP than in that with T3 of GNRI and T1 of CRP (Figure). Addition of GNRI and CRP in a predicting model with established risk factors improved C-statistics (0.661 to 0.716, p=0.0021) greater than that of each alone.

Conclusion

Among HD patients undergoing lower extremity revascularization for PAD, those with pre-procedural declined GNRI and elevated CRP frequently experienced amputation and/or mortality, furthermore, combination of both variables could more accurately stratify the risk of amputation and/or mortality.
Inflammatory activity of vulnerable plaques in asymptomatic, non-hemodynamically significant carotid artery stenoses: preliminary results of the carotid artery multi-modality imaging prognostic study
Authors: Masini G , Gargani L , Baldini M , Aghakhanyan G , Volterrani D , Erba P A , Marciano A , Napoli V , Cosottini M , Lucchi G , D'angelo G , Morizzo C , Orlandi G , Palombo C , De Caterina R
Published: November 2023

Background

[18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a valid technique to quantify carotid plaque inflammation and can improve identification of patients at high risk for stroke. There are few data on the inflammatory plaque activity in asymptomatic patients and of its association with other characteristics of plaque vulnerability.

Purpose

To assess the inflammatory carotid plaque activity and its correlations with patient characteristics and features of plaque vulnerability detected by other imaging techniques in a population of patients with asymptomatic mild/moderate degree of stenosis.

Methods

Seventy-five asymptomatic patients with 40-60% unilateral carotid stenosis at Doppler ultrasound (DUS) were prospectively evaluated with [18F]FDG-PET, computed tomography angiography (CTA), and magnetic resonance angiography (MRA). Regions of interests were drawn using fused PET/CT slices on the most diseased segment (MDS), defined as the single hottest slice of [18F]FDG uptake. Background blood pool activity was obtained from regions of interests placed in the lumen of the jugular vein. The target-to-background ratio (TBR) was calculated by dividing maximum standardized uptake value (SUVmax) of the MDS to SUVmax of ipsilateral blood pool activity. Plaque vulnerability was defined as the presence of an echolucent plaque at DUS, plaque ulceration at CTA, intraplaque hemorrhage, and lipid-rich necrotic core at MRA.

Results

Patients with a TBR ≥median (1.75), compared with those below the median, were significantly more frequently male and on statin therapy, had higher prevalence of ulcerated plaque at CTA (61% vs 35%, p=0.03) and intraplaque hemorrhage at MRA (33% vs 10%, p=0.03), while the prevalence of a lipid-rich necrotic core at MRA was not significantly different (p=0.16). TBR and SUVmax of the MDS were similar in those with or without a ≥50% stenosis, and peak velocities indices at DUS were not significantly correlated with TBR or SUVmax. Log(TBR) was significantly higher in ulcerated, rather than non-ulcerated, plaque (0.27 vs 0.21, p=0.03) and numerically higher in plaques with an intraplaque hemorrhage (0.22 vs 0.30, p=0.06). Log(TBR) and Log(SUVmax) were similar in plaques with and without a lipid-rich necrotic core (p=0.86 for both).

Conclusions

Higher TBR or SUVmax, indicating a high inflammatory activity, are associated with an ulcerated plaque and the presence of intraplaque hemorrhage but not with either the degree of stenosis or the presence of a lipid-rich necrotic core.
Interdisciplinary rendez-vous approach in endovascular stroke treatment a new concept to accelerate mechanical thrombectomy in primary stroke centers
Authors: Braun H , Knez A , Krug N , Auerbach H M , Bodenberger S , Eglseder B , Wunderlich S , Boy S , Zimmer C , Henninger J , Maegerlein C
Published: November 2023

Background/Introduction

Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge especially in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC).

Purpose

To address this problem, we present a new concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional cardiologists and neuroradiologists: the Rendez-Vous approach.

Methods

Twenty-seven patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes. The crucial aspect of the concept is that the patient is not transferred for the intervention but is treated on site and the cardiologist actively starts the intervention while the neurointerventionalist rushes to the site as soon as possible.

Results

Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p=0.57). The time from diagnosis of LVO to groin puncture was reduced by 68.3 minutes with the Rendez-Vous concept (p<0.01). Regarding the clinical outcome, a functionally independent status was achieved in 37.0 % in the Rendez-Vous group and in 19.4% in the control group (p=0.012).

Conclusion

Interdisciplinary teamwork between cardiology and interventional neuroradiology in rural PSCs leads to shorter times to successful reperfusion in patients with severe ischemic stroke due to LVO. This has a potentially positive impact on the clinical outcome of stroke patients and should be considered as a possible care concept in similar stroke networks.Rendez-Vous concept in stroke management
The effectiveness of direct oral anticoagulant therapy on stroke severity and functional prognosis for very elderly cardioembolic stroke patients at high bleeding risk
Authors: Saito K , Hagii J , Soma T , Washima S , Yamada N , Shiroto H , Saito S , Kamada T , Takanashi S , Tomita H
Published: November 2023

Background

The All Nippon AF In the Elderly (ANAFIE) Registry showed that taking any DOACs was associated with reduced stroke/systemic embolisms and was not associated with increased major bleeding in very elderly (≥80 years) patients with nonvalvular atrial fibrillation (NVAF) at high bleeding risk (1). However, the relationship between very elderly (≥80 years) cardioembolic stroke (CES) patients with NVAF at high bleeding risk and direct oral anticoagulant (DOAC) therapy before stroke onset remains unknown.

Methods

During a 10-year period from April 2011 to March 2021, 364 CES patients (≥80 years) with NVAF admitted to our hospital within 48 hours after stroke onset and with a modified Rankin Scale (mRS) score of 0 or 1 before onset were studied. High bleeding risk was defined as having any following factors; a bleeding history, renal dysfunction (creatinine clearance <30 ml/min), low body weight (≤45 kg), use of antiplatelet or nonsteroidal anti-inflammatory drugs. They were divided into two groups: high bleeding risk group (H group) (n=214; median 85 years [82-88]; 144 women [67%]) and non-high bleeding risk group (Non-H group) (n=150; median 84 years [82-87]; 69 women [46%]). We compared stroke severity between the two groups and evaluated effect of DOAC treatment on stroke severity and functional outcome.

Results

CHADS₂ score was significantly higher in the H group than in the Non-H group (median 4 [3-4] versus 3 [2-4], p=0.002). NIHSS (National Institutes of Health Stroke Scale) score on admission and proportion of mortality (mRS:6) were relatively higher in H group than in Non-H group, but there were no significant differences among the two groups. However, mRS score at discharge was worse in the H group than in the Non-H group (median 4 [2-5] versus 3 [1-4], p=0.002). The patients in the H group were further divided into three groups based on the treatment with OAC before stroke onset: DOAC therapy (n=20), no-OAC (n=148) and warfarin therapy (n=46). The number of patients with NIHSS (≥8) on admission and mRS (≥5) at discharge were 8 (40%), 104 (70%), and 30 (65%) (p=0.03) and 3 (15%), 60 (41%) and 23 (50%) (p=0.03), respectively. Multivariate analysis confirmed that DOAC therapy had a lower odds ratio (OR) for severe stroke (NIHSS ≥8) on admission (OR to no-OAC=0.22; 95% confidence interval [CI]=0.08-0.62; p=0.005) and poor functional outcome (mRS ≥5) at discharge (OR=0.20; 95% CI=0.05-0.80; p=0.02), when no-OAC was used as a reference after adjusting for confounders.

Conclusion

Very elderly (≥80 years) CES patients with NVAF at high bleeding risk have severe CES than those at non-high bleeding risk. However, DOAC therapy before stroke onset may be associated with reduced stroke severity on admission and poor functional outcome at discharge in very elderly (≥80 years) CES patients with NVAF at high bleeding risk.
Risks of cardiovascular events after acute ischemic stroke and intra-cranial hemorrhage
Authors: Chao T , Lip G Y H , Chen S A
Published: November 2023

Background

The occurrence of acute ischemic stroke and intra-cranial hemorrhage (ICH) would result in severe stress for patients which may trigger cardiovascular (CV) events. In the present study, we aimed to report and compare the risks of CV events of patients who experienced ischemic stroke and ICH. Also, we analyzed the associations between the severities of stroke/ICH and risks of CV events.

Methods

A total of 413,000 and 131,313 patients who experienced acute ischemic stroke and ICH and did not have past history of acute myocardial infarction (AMI), heart failure (HF), atrial fibrillation (AF) and ventricular arrhythmia (VA) were identified from the Taiwan National Health Insurance Research Database, respectively. Risks of CV events within 90 days after stroke and ICH were analyzed and compared.

Results

There were 2.77% and 1.75% of patients who suffered from CV events after ischemic stroke and ICH, respectively. The risks of AMI (odds ratio [OR] 0.702, 95%CI 0.618-0.798), HF (OR 0.708, 95%CI 0.661-0.759), AF (OR 0.534, 95%CI 0.502-0.569) and any events (OR 0.626, 95%CI 0.598-0.655) were lower for patients with ICH compared to those with ischemic stroke (Figure 1). For patients with acute ICH, the risks of CV events expect for AF significantly increased from mild to severe ICH (Figure 2). For patients with acute ischemic stroke, all the risks of CV events were higher among patients with severe stroke.

Conclusions

When managing patients with acute ischemic stroke and ICH, the risks of acute CV events should also be kept in mind. The impacts of acute CV events on the long-term prognosis of these patients deserve a further study.
Agreement between direct Fick and bolus thermodilution measurements of cardiac output during right heart catheterisation and the impact on haemodynamic classifications
Authors: Hamilton G W , Fletcher L , Harley W , Azzopardi R , Fulcher J , Chan R K , Horrigan M
Published: November 2023

Background/Introduction

When measuring cardiac output (CO) during right heart catheterisation (RHC), both direct Fick (DF) and bolus thermodilution (TD) methods are endorsed by pulmonary hypertension (PH) guidelines (1). Agreement between these techniques in contemporary practice is not well understood, nor are the diagnostic consequences of disagreement.

Purpose

To investigate the real-world agreement between DF and TD techniques for measuring CO during contemporary RHC, and evaluate the impact of disagreement on patients’ haemodynamic classification.

Methods

This was a single-centre study including 182 patients who had CO measured simultaneously by DF and TD methods during RHC. Oxygen consumption (VO2) was measured with an indirect calorimeter. The primary outcome was the agreement between DF and TD derived CO using Bland-Altman analysis. Secondary outcomes included the impact of specific clinical variables on CO agreement, and the frequency of disagreement in determining patients’ haemodynamic classification.

Results

Disagreement between DF and TD measures of CO was noted, with the DF technique tending to overestimate CO relative to the TD measurement (median DF-CO 5.42 L/min [interquartile range (IQR) 3.90 – 7.41] vs median TD-CO 4.10 L/min [IQR 3.47 – 5.10], p<0.001). For CO values between 3-7 L/min, the error between DF and TD measurements ranged from -4.75% to +44.5%, and limits of agreement were between -69.9% and +101% (Figure 1). Disagreement was increased by 19.2% in patients with at least moderate-to-severe tricuspid regurgitation, and by 16.0% in those with irregular heart rhythms (Table1). The agreement between DF and TD derived pulmonary vascular resistance (PVR) was equally poor. Nonetheless, in 86.3% of patients, the techniques agreed in classifying the PVR as abnormally elevated (> 2 Wood Units), with disagreement occurring more frequently in patients with less severe PH.

Conclusions

In this real-world study there was poor agreement between DF and TD derived CO, resulting in more than 10% of patients having discrepant haemodynamic classifications. This data highlight that both methods should be utilised in clinical practice, particularly in borderline cases or when the haemodynamic assessment influences treatment eligibility or operative risk assessment. The two techniques should not be used interchangeably for serial surveillance, and the impact of our findings on invasive assessments of valvular pathologies needs further investigation.