Voltage control of magnetic single domains in Ni discs on ferroelectric BaTiO<inf>3</inf>

For 1 μm diameter Ni discs on a BaTiO3 substrate, the local magnetization direction is determined by ferroelectric domain orientation as a consequence of growth strain, such that single domain discs lie on single ferroelectric domains. On applying a voltage across the substrate, ferroelectric domain switching yields non volatile magnetization rotations of 90°, while piezoelectric effects that are small and continuous yield non volatile magnetization reversals that are non-deterministic. This demonstration of magnetization reversal without ferroelectric domain switching implies reduced fatigue, and therefore represents a step towards applications

Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality

Background and purpose: Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. Methods: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). Results: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P&lt;0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P&lt;0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. Conclusions: During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT

Global Impact of the COVID-19 Pandemic on Cerebral Venous Thrombosis and Mortality.

BACKGROUND AND PURPOSE: Recent studies suggested an increased incidence of cerebral venous thrombosis (CVT) during the coronavirus disease 2019 (COVID-19) pandemic. We evaluated the volume of CVT hospitalization and in-hospital mortality during the 1st year of the COVID-19 pandemic compared to the preceding year. METHODS: We conducted a cross-sectional retrospective study of 171 stroke centers from 49 countries. We recorded COVID-19 admission volumes, CVT hospitalization, and CVT in-hospital mortality from January 1, 2019, to May 31, 2021. CVT diagnoses were identified by International Classification of Disease-10 (ICD-10) codes or stroke databases. We additionally sought to compare the same metrics in the first 5 months of 2021 compared to the corresponding months in 2019 and 2020 (ClinicalTrials.gov Identifier: NCT04934020). RESULTS: There were 2,313 CVT admissions across the 1-year pre-pandemic (2019) and pandemic year (2020); no differences in CVT volume or CVT mortality were observed. During the first 5 months of 2021, there was an increase in CVT volumes compared to 2019 (27.5%; 95% confidence interval [CI], 24.2 to 32.0; P<0.0001) and 2020 (41.4%; 95% CI, 37.0 to 46.0; P<0.0001). A COVID-19 diagnosis was present in 7.6% (132/1,738) of CVT hospitalizations. CVT was present in 0.04% (103/292,080) of COVID-19 hospitalizations. During the first pandemic year, CVT mortality was higher in patients who were COVID positive compared to COVID negative patients (8/53 [15.0%] vs. 41/910 [4.5%], P=0.004). There was an increase in CVT mortality during the first 5 months of pandemic years 2020 and 2021 compared to the first 5 months of the pre-pandemic year 2019 (2019 vs. 2020: 2.26% vs. 4.74%, P=0.05; 2019 vs. 2021: 2.26% vs. 4.99%, P=0.03). In the first 5 months of 2021, there were 26 cases of vaccine-induced immune thrombotic thrombocytopenia (VITT), resulting in six deaths. CONCLUSIONS: During the 1st year of the COVID-19 pandemic, CVT hospitalization volume and CVT in-hospital mortality did not change compared to the prior year. COVID-19 diagnosis was associated with higher CVT in-hospital mortality. During the first 5 months of 2021, there was an increase in CVT hospitalization volume and increase in CVT-related mortality, partially attributable to VITT

Appariement entre un registre régional de pratiques en cardiologie interventionnelle et la base médico-administrative d’hospitalisation française : développement et validation d’un algorithme d’appariement déterministe

PROBLÉMATIQUE: Afin de reconstruire le parcours de soins hospitalier des patients ayant bénéficié d’un acte de coronarographie ou d’angioplastie coronaire, un appariement entre le registre de pratiques aquitain de cardiologie interventionnelle ACIRA et la base pseudonymisée du Programme de médicalisation du système d’information (PMSI) de la région ex-Aquitaine a été réalisé. L’objectif de cette étude était de développer et valider un algorithme d’appariement déterministe entre ces bases de données exhaustives et complémentaires. MÉTHODES: Après une phase de prétraitement des bases pour standardiser les 11 variables d’appariement identifiées, un algorithme d’appariement déterministe a été développé sur les séjours ACIRA des patients hospitalisés entre décembre 2011 et décembre 2014 dans neuf centres de cardiologie interventionnelle et les données des bases PMSI consolidées de la région ex-Aquitaine des années 2011 à 2014. L’appariement a été effectué en 12 étapes successives, la première consistant en un appariement strict sur les 11 variables. Les performances de l’algorithme ont été analysées en termes de sensibilité, spécificité, valeur prédictive positive (VPP) et valeur prédictive négative (VPN) et testées en faisant varier l’algorithme initial selon des stratégies complémentaires (modification de l’ordre des variables et du prétraitement des bases). L’analyse comparative des patients appariés/non appariés a permis d’explorer les potentielles causes de non-appariement. RÉSULTATS: L’algorithme a permis de retrouver au final 97,2 % des 31 621 séjours ACIRA avec une sensibilité de 99,9 % (IC 95 % [99,9 ; 99,9]), une spécificité de 97,9 % (IC 95 % [97,7 ; 98,1]), une VPP de 99,9 % (IC 95 % [99,9 ; 99,9]) et une VPN de 96,9 % (IC 95 % [96,7 ; 97,1]). Les stratégies complémentaires n’ont pas permis d’obtenir de meilleurs résultats. Les patients non appariés étaient plus âgés, avaient majoritairement été hospitalisés en 2012 et dans deux centres de cardiologie interventionnelle. CONCLUSION: Cette étude a montré la faisabilité et la validité d’un appariement indirect déterministe pour faire le lien en routine entre un registre de pratiques utilisant des données hospitalières et les bases médico-administratives pseudonymisées. Cette méthode, extrapolable à d’autres événements de santé donnant lieu à une hospitalisation, permet de façon efficace de reconstruire le parcours de soins hospitalier des patients.BACKGROUND: To recreate the in-hospital healthcare pathway for patients treated with coronary angiography or percutaneous coronary intervention, we linked the interventional cardiology registry (ACIRA) and the pseudonymized French hospital medical information system database (PMSI) in the Aquitaine region. The objective of this study was to develop and validate a deterministic merging algorithm between these exhaustive and complementary databases. METHODS: After a pre-treatment phase of the databases to standardize the 11 identified linking variables, a deterministic linking algorithm was developed on ACIRA hospital stays between December 2011 and December 2014 in nine interventional cardiology centers as well as the data from the consolidated PMSI databases of the Aquitaine region from 2011 to 2014. Merging was carried out through 12 successive steps, the first consisting in strict linking of the 11 variables. The performance of the algorithm was analyzed in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Strategies complementary to the initial algorithm (change in the order of variables and base preprocessing) were tested. Comparative analysis of merged/unmerged patients explored potential causes of mismatch. RESULTS: The algorithm found 97.2% of the 31,621 ACIRA stays to have sensitivity of 99.9% (95% CI [99.9; 99.9]), specificity of 97.9% (95% CI [97.7; 98.1]), PPV of 99.9% (95% CI [99.9; 99.9]) and NPV of 96.9% (95% CI [96.7; 97.1]). Complementary strategies did not yield better results. The unmerged patients were older, and hospitalized mostly in 2012 in two interventional cardiology centers. CONCLUSION: This study underscored the feasibility and validity of an indirect deterministic pairing to routinely link a registry of practices using hospital data to pseudonymized medico-administrative databases. This method, which can be extrapolated to other health events leading to hospitalization, renders it possible to effectively reconstruct patients' hospital healthcare pathway

Voltage control of magnetic single domains in Ni discs on ferroelectric BaTiO3

For 1 μm-diameter Ni discs on a BaTiO3substrate, the local magnetization direction is determined by ferroelectric domain orientation as a consequence of growth strain, such that single-domain discs lie on single ferroelectric domains. On applying a voltage across the substrate, ferroelectric domain switching yields non-volatile magnetization rotations of 90°, while piezoelectric effects that are small and continuous yield non-volatile magnetization reversals that are non-deterministic. This demonstration of magnetization reversal without ferroelectric domain switching implies reduced fatigue, and therefore represents a step towards applications

Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: A 1-Year Follow-up

BACKGROUND AND OBJECTIVES: Declines in stroke admission, IV thrombolysis (IVT), and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the effect of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), IVT, and mechanical thrombectomy over a 1-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020). METHODS: We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, IVT treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. RESULTS: There were 148,895 stroke admissions in the 1 year immediately before compared with 138,453 admissions during the 1-year pandemic, representing a 7% decline (95% CI [95% CI 7.1-6.9]; p < 0.0001). ICH volumes declined from 29,585 to 28,156 (4.8% [5.1-4.6]; p < 0.0001) and IVT volume from 24,584 to 23,077 (6.1% [6.4-5.8]; p < 0.0001). Larger declines were observed at high-volume compared with low-volume centers (all p < 0.0001). There was no significant change in mechanical thrombectomy volumes (0.7% [0.6-0.9]; p = 0.49). Stroke was diagnosed in 1.3% [1.31-1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82-2.97], 5,656/195,539) of all stroke hospitalizations. DISCUSSION: There was a global decline and shift to lower-volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared with the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year. TRIAL REGISTRATION INFORMATION: This study is registered under NCT04934020

Global Impact of COVID-19 on Stroke Care and IV Thrombolysis

OBJECTIVE: To measure the global impact of COVID-19 pandemic on volumes of IV thrombolysis (IVT), IVT transfers, and stroke hospitalizations over 4 months at the height of the pandemic (March 1 to June 30, 2020) compared with 2 control 4-month periods. METHODS: We conducted a cross-sectional, observational, retrospective study across 6 continents, 70 countries, and 457 stroke centers. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. RESULTS: There were 91,373 stroke admissions in the 4 months immediately before compared to 80,894 admissions during the pandemic months, representing an 11.5% (95% confidence interval [CI] -11.7 to -11.3, p &lt; 0.0001) decline. There were 13,334 IVT therapies in the 4 months preceding compared to 11,570 procedures during the pandemic, representing a 13.2% (95% CI -13.8 to -12.7, p &lt; 0.0001) drop. Interfacility IVT transfers decreased from 1,337 to 1,178, or an 11.9% decrease (95% CI -13.7 to -10.3, p = 0.001). Recovery of stroke hospitalization volume (9.5%, 95% CI 9.2-9.8, p &lt; 0.0001) was noted over the 2 later (May, June) vs the 2 earlier (March, April) pandemic months. There was a 1.48% stroke rate across 119,967 COVID-19 hospitalizations. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was noted in 3.3% (1,722/52,026) of all stroke admissions. CONCLUSIONS: The COVID-19 pandemic was associated with a global decline in the volume of stroke hospitalizations, IVT, and interfacility IVT transfers. Primary stroke centers and centers with higher COVID-19 inpatient volumes experienced steeper declines. Recovery of stroke hospitalization was noted in the later pandemic months. © 2021 American Academy of Neurology

Global Impact of the COVID-19 Pandemic on Stroke Volumes and Cerebrovascular Events: One-Year Follow-up.

Declines in stroke admission, intravenous thrombolysis, and mechanical thrombectomy volumes were reported during the first wave of the COVID-19 pandemic. There is a paucity of data on the longer-term effect of the pandemic on stroke volumes over the course of a year and through the second wave of the pandemic. We sought to measure the impact of the COVID-19 pandemic on the volumes of stroke admissions, intracranial hemorrhage (ICH), intravenous thrombolysis (IVT), and mechanical thrombectomy over a one-year period at the onset of the pandemic (March 1, 2020, to February 28, 2021) compared with the immediately preceding year (March 1, 2019, to February 29, 2020). We conducted a longitudinal retrospective study across 6 continents, 56 countries, and 275 stroke centers. We collected volume data for COVID-19 admissions and 4 stroke metrics: ischemic stroke admissions, ICH admissions, intravenous thrombolysis treatments, and mechanical thrombectomy procedures. Diagnoses were identified by their ICD-10 codes or classifications in stroke databases. There were 148,895 stroke admissions in the one-year immediately before compared to 138,453 admissions during the one-year pandemic, representing a 7% decline (95% confidence interval [95% CI 7.1, 6.9]; p&lt;0.0001). ICH volumes declined from 29,585 to 28,156 (4.8%, [5.1, 4.6]; p&lt;0.0001) and IVT volume from 24,584 to 23,077 (6.1%, [6.4, 5.8]; p&lt;0.0001). Larger declines were observed at high volume compared to low volume centers (all p&lt;0.0001). There was no significant change in mechanical thrombectomy volumes (0.7%, [0.6,0.9]; p=0.49). Stroke was diagnosed in 1.3% [1.31,1.38] of 406,792 COVID-19 hospitalizations. SARS-CoV-2 infection was present in 2.9% ([2.82,2.97], 5,656/195,539) of all stroke hospitalizations. There was a global decline and shift to lower volume centers of stroke admission volumes, ICH volumes, and IVT volumes during the 1st year of the COVID-19 pandemic compared to the prior year. Mechanical thrombectomy volumes were preserved. These results suggest preservation in the stroke care of higher severity of disease through the first pandemic year. This study is registered under NCT04934020