Transcatheter Aortic Valve Implantation Outcomes and Challenges in Asia: A Systematic Review and Meta-Analysis.

Background: Aortic stenosis (AS) is the world's most prevalent heart valve disease. Transcatheter aortic valve replacement (TAVR) or Implantation (TAVI) is widely available yet adopting this procedure in Asia has been slow due to high device cost, the need for specific training programs, and the lack of specialized heart teams and dedicated infrastructures. The limited number of randomized controlled trials describing TAVI outcomes among the Asian population hampered the approval for medical reimbursements as well as acceptance among surgeons and operators in some Asian countries. Methods: A comprehensive medical literature search on TAVI and/or TAVR performed in Asian countries published between January 2015 and June 2022 was done through MEDLINE and manual searches of bibliographies. The full text of eligible articles was obtained and evaluated for final analysis. The event rates for key efficacy and safety outcomes were calculated using the data from the registries and randomized controlled trials. Results: A total of 15,297 patients were included from 20 eligible studies. The mean patient age was 82.88 ± 9.94 years, with over half being females (62.01%). All but one study reported Society of Thoracic Surgeons (STS) scores averaging an intermediate risk score of 6.28 ± 1.06%. The mean logistic European Systems for Cardiac Operations Risk Evaluation (EuroSCORE) was 14.85. The mean baseline transaortic gradient and mean aortic valve area were 50.93 ± 3.70 mmHg and 0.64 ± 0.07 cm 2 , respectively. The mean procedural success rate was 95.28 ± 1.51%. The weighted mean 30-day and 1-year all-cause mortality rate was 1.66 ± 1.21% and 8.79 ± 2.3%, respectively. The mean average for stroke was 1.98 ± 1.49%. The acute kidney injury (AKI) rate was 6.88 ± 5.71%. The overall major vascular complication rate was 2.58 ± 2.54%; the overall major bleeding rate was 3.88 ± 3.74%. Paravalvular aortic regurgitation rate was 15.07 ± 9.58%. The overall rate of pacemaker insertion was 7.76 ± 4.6%. Conclusions: Compared to Americans and Europeans, Asian patients who underwent TAVI had lower all-cause mortality, bleeding, and vascular complications, however, had a higher rate of postprocedural aortic regurgitation. More studies with greater sample sizes are needed among Asian patients for a more robust comparison.

Recent developments in X-ray diffraction/scattering computed tomography for materials science.

X-ray diffraction/scattering computed tomography (XDS-CT) methods are a non-destructive class of chemical imaging techniques that have the capacity to provide reconstructions of sample cross-sections with spatially resolved chemical information. While X-ray diffraction CT (XRD-CT) is the most well-established method, recent advances in instrumentation and data reconstruction have seen greater use of related techniques like small angle X-ray scattering CT and pair distribution function CT. Additionally, the adoption of machine learning techniques for tomographic reconstruction and data analysis are fundamentally disrupting how XDS-CT data is processed. The following narrative review highlights recent developments and applications of XDS-CT with a focus on studies in the last five years. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'.

Effect of thermal treatment on the stability of Na-Mn-W/SiO2 catalyst for the oxidative coupling of methane.

In this study, we investigate the effect of thermal treatment/calcination on the stability and activity of a Na-Mn-W/SiO2 catalyst for the oxidative coupling of methane. The catalyst performance and characterisation measurements suggest that the W species are directly involved in the catalyst active site responsible for CH4 conversion. Under operating conditions, the active components, present in the form of a Na-W-O-Mn molten state, are highly mobile and volatile. By varying the parameters of the calcination protocol, it was shown that these molten components can be partially stabilised, resulting in a catalyst with lower activity (due to loss of surface area) but higher stability even for long duration OCM reaction experiments.

In situ X-ray diffraction computed tomography studies examining the thermal and chemical stabilities of working Ba0.5Sr0.5Co0.8Fe0.2O3-δ membranes during oxidative coupling of methane.

In this study we present the results from two in situ X-ray diffraction computed tomography experiments of catalytic membrane reactors (CMRs) using Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) hollow fibre membranes and Na-Mn-W/SiO2 catalyst during the oxidative coupling of methane (OCM) reaction. The negative impact of CO2, when added to the inlet gas stream, is seen to be mainly related to the C2+ yield, while no evidence of carbonate phase(s) formation is found during the OCM experiments. The main degradation mechanism of the CMR is suggested to be primarily associated with the solid-state evolution of the BSCF phase rather than the presence of CO2. Specifically, in situ XRD-CT and post-mortem SEM/EDX measurements revealed a collapse of the cubic BSCF phase and subsequent formation of secondary phases, which include needle-like structures and hexagonal Ba6Co4O12 and formation of a BaWO4 layer, the latter being a result of chemical interaction between the membrane and catalyst materials at high temperatures.

Exploring cycling induced crystallographic change in NMC with X-ray diffraction computed tomography.

This study presents the application of X-ray diffraction computed tomography for the first time to analyze the crystal dimensions of LiNi0.33Mn0.33Co0.33O2 electrodes cycled to 4.2 and 4.7 V in full cells with graphite as negative electrodes at 1 µm spatial resolution to determine the change in unit cell dimensions as a result of electrochemical cycling. The nature of the technique permits the spatial localization of the diffraction information in 3D and mapping of heterogeneities from the electrode to the particle level. An overall decrease of 0.4% and 0.6% was observed for the unit cell volume after 100 cycles for the electrodes cycled to 4.2 and 4.7 V. Additionally, focused ion beam-scanning electron microscope cross-sections indicate extensive particle cracking as a function of upper cut-off voltage, further confirming that severe cycling stresses exacerbate degradation. Finally, the technique facilitates the detection of parts of the electrode that have inhomogeneous lattice parameters that deviate from the bulk of the sample, further highlighting the effectiveness of the technique as a diagnostic tool, bridging the gap between crystal structure and electrochemical performance.

Spatially Resolving Lithiation in Silicon-Graphite Composite Electrodes via in Situ High-Energy X-ray Diffraction Computed Tomography.

Optimizing the chemical and morphological parameters of lithium-ion (Li-ion) electrodes is extremely challenging, due in part to the absence of techniques to construct spatial and temporal descriptions of chemical and morphological heterogeneities. We present the first demonstration of combined high-speed X-ray diffraction (XRD) and XRD computed tomography (XRD-CT) to probe, in 3D, crystallographic heterogeneities within Li-ion electrodes with a spatial resolution of 1 µm. The local charge-transfer mechanism within and between individual particles was investigated in a silicon(Si)-graphite composite electrode. High-speed XRD revealed charge balancing kinetics between the graphite and Si during the minutes following the transition from operation to open circuit. Subparticle lithiation heterogeneities in both Si and graphite were observed using XRD-CT, where the core and shell structures were segmented, and their respective diffraction patterns were characterized.

X-ray physico-chemical imaging during activation of cobalt-based Fischer-Tropsch synthesis catalysts.

The imaging of catalysts and other functional materials under reaction conditions has advanced significantly in recent years. The combination of the computed tomography (CT) approach with methods such as X-ray diffraction (XRD), X-ray fluorescence (XRF) and X-ray absorption near-edge spectroscopy (XANES) now enables local chemical and physical state information to be extracted from within the interiors of intact materials which are, by accident or design, inhomogeneous. In this work, we follow the phase evolution during the initial reduction step(s) to form Co metal, for Co-containing particles employed as Fischer-Tropsch synthesis (FTS) catalysts; firstly, working at small length scales (approx. micrometre spatial resolution), a combination of sample size and density allows for transmission of comparatively low energy signals enabling the recording of 'multimodal' tomography, i.e. simultaneous XRF-CT, XANES-CT and XRD-CT. Subsequently, we show high-energy XRD-CT can be employed to reveal extent of reduction and uniformity of crystallite size on millimetre-sized TiO2 trilobes. In both studies, the CoO phase is seen to persist or else evolve under particular operating conditions and we speculate as to why this is observed.This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

Early child health in Africa: do ICT and democracy matter?

This article examines the effect of information and communication technologies (ICT) and democracy on early child health using data from 51 African countries. We first specify and estimate a panel data model using ordinary least squares and two-stage least squares over the period 2001-2019. We apply the Hodrick-Prescott filter before analysis. Our results show that the extension of mobile phone use significantly contributes to the improvement of early child health in Africa. This effect is indifferent to the state or the level of democracy. Also, the internet diffusion plays a positive role in early child health when the democracy environment improves and becomes better. We suggest policies in favour of a large access to ICT tools and internet infrastructure as well as the promotion of democracy in Africa to better prevent infant mortality.

Impact of a peer-support programme to improve loneliness and social isolation due to COVID-19: does adding a secure, user friendly video-conference solution work better than telephone support alone? Protocol for a three-arm randomised clinical trial.

INTRODUCTION: The COVID-19 pandemic has forced the implementation of physical distancing and self-isolation strategies worldwide. However, these measures have significant potential to increase social isolation and loneliness. Among older people, loneliness has increased from 40% to 70% during COVID-19. Previous research indicates loneliness is strongly associated with increased mortality. Thus, strategies to mitigate the unintended consequences of social isolation and loneliness are urgently needed. Following the Obesity-Related Behavioural Intervention Trials model for complex behavioural interventions, we describe a protocol for a three-arm randomised clinical trial to reduce social isolation and loneliness. METHODS AND ANALYSIS: A multicentre, outcome assessor blinded, three-arm randomised controlled trial comparing 12 weeks of: (1) the HOspitals WoRking in Unity ('HOW R U?') weekly volunteer-peer support telephone intervention; (2) 'HOW R U?' deliver using a video-conferencing solution and (3) a standard care group. The study will follow Consolidated Standard of Reporting Trials guidelines.We will recruit 24-26 volunteers who will receive a previously tested half day lay-training session that emphasises a strength-based approach and safety procedures. We will recruit 141 participants ≥70 years of age discharged from two participating emergency departments or referred from hospital family medicine, geriatric or geriatric psychiatry clinics. Eligible participants will have probable baseline loneliness (score ≥2 on the de Jong six-item loneliness scale). We will measure change in loneliness, social isolation (Lubben social network scale), mood (Geriatric Depression Score) and quality of life (EQ-5D-5L) at 12-14 weeks postintervention initiation and again at 24-26 weeks. ETHICS AND DISSEMINATION: Approval has been granted by the participating research ethics boards. Participants randomised to standard care will be offered their choice of telephone or video-conferencing interventions after 12 weeks. Results will be disseminated through journal publications, conference presentations, social media and through the International Federation of Emergency Medicine. TRIAL REGISTRATION NUMBER: NCT05228782.

Sex differences in trends and outcomes of acute myocardial infarction with mechanical complications in the United States.

BACKGROUND: Mechanical complications (MC) are rare but significant sequelae of acute myocardial infarction (AMI). Current data on sex differences in AMI with MC is limited. METHODS: We queried the National Inpatient Sample database to identify adult patients with the primary diagnosis of AMI and MC. The main outcome of interest was sex difference in-hospital mortality. Secondary outcomes were sex differences in the incidence of acute kidney injury (AKI), major bleeding, use of inotropes, permanent pacemaker implantation (PPMI), performance of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), surgery (VSD repair and MV surgery), pericardiocentesis, use of mechanical circulatory support (MCS), ischemic stroke, and mechanical ventilation. RESULTS: Among AMI-MC cohort, in-hospital mortality was higher among females compared to males (41.24% vs 28.13%: aOR 1.39. 95% CI 1.079-1.798; p = 0.01). Among those who had VSD, females also had higher in-hospital mortality compared to males (56.7% vs 43.1%: aOR 1.74, 95% CI 1.12-2.69; p = 0.01). Females were less likely to receive CABG compared to males (12.03% vs 20%: aOR 0.49 95% CI 0.345-0.690; p < 0.001). CONCLUSION: Despite the decreasing trend in AMI admission, females had higher risk of MC and associated mortality. Significant sex disparities still exist in AMI treatment.

A laboratory system for element specific hyperspectral X-ray imaging.

X-ray tomography is a ubiquitous tool used, for example, in medical diagnosis, explosives detection or to check structural integrity of complex engineered components. Conventional tomographic images are formed by measuring many transmitted X-rays and later mathematically reconstructing the object, however the structural and chemical information carried by scattered X-rays of different wavelengths is not utilised in any way. We show how a very simple; laboratory-based; high energy X-ray system can capture these scattered X-rays to deliver 3D images with structural or chemical information in each voxel. This type of imaging can be used to separate and identify chemical species in bulk objects with no special sample preparation. We demonstrate the capability of hyperspectral imaging by examining an electronic device where we can clearly distinguish the atomic composition of the circuit board components in both fluorescence and transmission geometries. We are not only able to obtain attenuation contrast but also to image chemical variations in the object, potentially opening up a very wide range of applications from security to medical diagnostics.

Architecture of industrial Bi-Mo-Co-Fe-K-O propene oxidation catalysts.

Industrial heterogeneous catalysts show high performance coupled with high material complexity. Deconvoluting this complexity into simplified models eases mechanistic studies. However, this approach dilutes the relevance because models are often less performing. We present a holistic approach to reveal the origin of high performance without losing the relevance by pivoting the system at an industrial benchmark. Combining kinetic and structural analyses, we show how the performance of Bi-Mo-Co-Fe-K-O industrial acrolein catalysts occurs. The surface BiMoO ensembles decorated with K supported on ß-Co1-xFexMoO4 perform the propene oxidation, while the K-doped iron molybdate pools electrons to activate dioxygen. The nanostructured vacancy-rich and self-doped bulk phases ensure the charge transport between the two active sites. The features particular to the real system enable the high performance.

Paramedic supportive discharge programmes to improve health system efficiency and patient outcomes: a scoping review protocol.

INTRODUCTION: Discharging older adults with frailty home from the emergency department (ED) poses unique challenges due to multiple interacting physical and social problems. Paramedic supportive discharge services help overcome these challenges by adding in-home assessment and/or interventions. Our objective is to describe existing paramedic programmes designed to support discharge from the ED or hospital to avoid unnecessary hospital admissions. A comprehensive description of paramedic supportive discharge services will be conducted by mapping the literature to describe: (1) why such programmes are needed; (2) who is being targeted, making referrals and delivering the services and (3) what assessments and interventions are offered. METHODS AND ANALYSIS: We will include studies that focus on expanded paramedic roles (community paramedicine) and extended scope postdischarge from the ED or hospital. All study designs will be included with no limit by language. We will include peer-reviewed articles and preprints and a targeted search of grey literature from January 2000 to June 2022. The proposed scoping review will be conducted in accordance with the Joanna Briggs Institute methodology. We will use a search strategy designed by a health science librarian to search MEDLINE All (Ovid), CINAHL Full Text (EBSCO), Embase (Elsevier) and Scopus (Elsevier) for eligible studies from 2000 to present. Two independent reviewers will conduct screening and full-text review. Data extraction will be conducted by one reviewer and verified by another. We will report our findings descriptively by charting trends in the research. ETHICS AND DISSEMINATION: Research ethics review is not required as this is a scoping review comprised published studies. The results of this research will be published in a manuscript and presented at national and international geriatric and emergency medicine conferences. This research will inform future implementation studies on community paramedic supportive discharge services. REGISTRATION: This scoping review protocol was registered in Open Science Framework and can be found here: https://doi.org/10.17605/OSF.IO/X52P7.

Sex differences in permanent pacemaker implantation after transcatheter aortic valve replacement: a systematic review and meta-analysis.

BACKGROUND: There is limited evidence on the effect of sex on permanent pacemaker implantation (PPMI) after transcatheter aortic valve replacement (TAVR). The primary objective of this meta-analysis was to determine the role of sex among patients requiring PPMI post-TAVR. METHODS: A literature search was conducted using the SCOPUS, MEDLINE, and CINAHL databases for studies published until October 2022. Eligible studies included published randomized controlled trials (RCTs) and Observational Cohort Studies (OCS) articles that reported PPMI as an outcome of pacemaker status following TAVR. This study was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Guidelines. Publication bias was estimated using a Funnel plot and Egger's test. Data were pooled using a random-effects model. The primary endpoint was the sex difference in PPMI after TAVR, with odds ratios and 95% confidence intervals (CIs) extracted. RESULTS: Data was obtained from 63 studies, and a total of 79,655 patients were included. The cumulative PPMI rate was 15.5% (95% CI, 13.6%-17.7%). The pooled analysis revealed that while there were more females than males undergoing TAVR (51.6%, 95% CI 50.4%-52.8%), males have a 14.5% higher risk for post-TAVR PPMI than females (OR 1.145, 95% CI 1.047-1.253, P < 0.01). CONCLUSIONS: Males are more likely to experience PPMI after TAVR than females. Further research needs to be done to better explain these observed differences in outcomes.

A new approach to synchrotron energy-dispersive X-ray diffraction computed tomography.

A new data collection strategy for performing synchrotron energy-dispersive X-ray diffraction computed tomography has been devised. This method is analogous to angle-dispersive X-ray diffraction whose diffraction signal originates from a line formed by intersection of the incident X-ray beam and the sample. Energy resolution is preserved by using a collimator which defines a small sampling voxel. This voxel is translated in a series of parallel straight lines covering the whole sample and the operation is repeated at different rotation angles, thus generating one diffraction pattern per translation and rotation step. The method has been tested by imaging a specially designed phantom object, devised to be a demanding validator for X-ray diffraction imaging. The relative strengths and weaknesses of the method have been analysed with respect to the classic angle-dispersive technique. The reconstruction accuracy of the method is good, although an absorption correction is required for lower energy diffraction because of the large path lengths involved. The spatial resolution is only limited to the width of the scanning beam owing to the novel collection strategy. The current temporal resolution is poor, with a scan taking several hours. The method is best suited to studying large objects (e.g. for engineering and materials science applications) because it does not suffer from diffraction peak broadening effects irrespective of the sample size, in contrast to the angle-dispersive case.

Adverse events related to ultrasound-guided regional anesthesia performed by Emergency Physicians: Systematic review protocol.

The use of ultrasound-guided regional anesthesia for pain management has become increasingly prevalent in Emergency Medicine, with studies noting excellent pain control while sparing opioid use. However, the use of ultrasound-guided regional anesthesia may be hampered by concern about risks for patient harm. This systematic review protocol describes our approach to evaluate the incidence of adverse events from the use of ultrasound-guided regional anesthesia by Emergency Physicians as described in the literature. This project will also seek to document the scope of ultrasound-guided regional anesthesia applications being performed in Emergency Medicine literature, and potentially serve as a framework for future systematic reviews evaluating adverse events in Emergency Medicine.

Chemical imaging of catalytic solids with synchrotron radiation.

Heterogeneous catalysis is a term normally used to describe a group of catalytic processes, yet it could equally be employed to describe the catalytic solid itself. A better understanding of the chemical and structural variation within such materials is thus a pre-requisite for the rationalising of structure-function relationships and ultimately to the design of new, more sustainable catalytic processes. The past 20 years has witnessed marked improvements in technologies required for analytical measurements at synchrotron sources, including higher photon brightness, nano-focusing, rapid, high resolution data acquisition and in the handling of large volumes of data. It is now possible to image materials using the entire synchrotron radiative profile, thus heralding a new era of in situ/operando measurements of catalytic solids. In this tutorial review we discuss the recent work in this exciting new research area and finally conclude with a future outlook on what will be possible/challenging to measure in the not-too-distant future.

Cycling Rate-Induced Spatially-Resolved Heterogeneities in Commercial Cylindrical Li-Ion Batteries.

Synchrotron high-energy X-ray diffraction computed tomography has been employed to investigate, for the first time, commercial cylindrical Li-ion batteries electrochemically cycled over the two cycling rates of C/2 and C/20. This technique yields maps of the crystalline components and chemical species as a cross-section of the cell with high spatiotemporal resolution (550 × 550 images with 20 × 20 × 3 µm3 voxel size in ca. 1 h). The recently developed Direct Least-Squares Reconstruction algorithm is used to overcome the well-known parallax problem and led to accurate lattice parameter maps for the device cathode. Chemical heterogeneities are revealed at both electrodes and are attributed to uneven Li and current distributions in the cells. It is shown that this technique has the potential to become an invaluable diagnostic tool for real-world commercial batteries and for their characterization under operating conditions, leading to unique insights into "real" battery degradation mechanisms as they occur.

Point-of-care ultrasound-guided regional anaesthesia in older ED patients with hip fractures: a study to test the feasibility of a training programme and time needed to complete nerve blocks by ED physicians after training.

OBJECTIVES: Point-of-care ultrasound-guided regional anaesthesia (POCUS-GRA) provides safe, rapid analgesia for older people with hip fractures but is rarely performed in the emergency department (ED). Self-perceived inadequate training and time to perform POCUS-GRA are the two most important barriers. Our objective is to assess the feasibility of a proposed multicentre, stepped-wedge cluster randomised clinical trial (RCT) to assess the impact of a knowledge-to-practice (KTP) intervention on delirium. DESIGN: Open-label feasibility study. SETTING: An academic tertiary care Canadian ED (annual visits 60 000). PARTICIPANTS: Emergency physicians working at least one ED shift per week, excluding those already performing POCUS-GRA more than four times per year. INTERVENTION: A KTP intervention, including 2-hour structured training sessions with procedure bundle and email reminders. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary feasibility outcome is the proportion of eligible physicians that completed training and subsequently performed POCUS-GRA. Secondary outcome is the time needed to complete POCUS-GRA. We also test the feasibility of the enrolment, consent and randomisation processes for the future stepped-wedge cluster RCT (NCT02892968). RESULTS: Of 36 emergency physicians, 4 (12%) were excluded or declined participation. All remaining 32 emergency physicians completed training and 31 subsequently treated at least one eligible patient. Collectively, 27/31 (87.1%) performed 102 POCUS-GRA blocks (range 1-20 blocks per physician). The median (IQR) time to perform blocks was 15 (10-20) min, and reduction in pain was 6/10 (3-7) following POCUS-GRA. There were no reported complications. CONCLUSION: Our KTP intervention, consent process and randomisation were feasible. The time to perform POCUS-GRA rarely exceeded 30 min, Our findings reinforce the existing data on the safety and effectiveness of POCUS-GRA, mitigate perceived barriers to more widespread adoption and demonstrate the feasibility of trialling this intervention for the proposed stepped-wedge cluster RCT. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov #02892968.

Voltage-sensitive dye imaging of neuronal populations under hyperbaric conditions: preliminary results obtained using a new technique.

We used voltage-sensitive dye imaging to study the properties of transient large-scale neuronal populations under hyperbaric conditions using a newly-developed high-pressure optical cell. In our experiments we investigated propagation of neuronal voltage wave depolarization along the CA2-CA1 Schaffer collateral pathway in rat hippocampal slices. The voltage-sensitive dye responses were studied at pressures up to 20 atmospheres (atm) over a range in which changes in excitability and pressure-reversal of narcosis/anesthesia have been described to occur in animals. An electrode placed in the CA2 region was used to evoke a signal along the Schaffer collateral neuronal circuit toward CA1 using a paired pulse paradigm (PPF). Initial inspection of the data indicates that the signal amplitude of the excitation following the second PPF event is enhanced at high pressure. Data analysis using MatLab software revealed a range of conductance velocities between different layers within the Schaffer collateral and for sites at different distances from the stimulating electrode. The estimated value of the conductance velocity along the trajectory of maximum flow is in good agreement with previous determinations of axonal propagation along the Schaffer collateral.