60 research outputs found

    Nanostructured Bimetallic Block Copolymers as Precursors to Magnetic FePt Nanoparticles

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    Phase-separated block copolymers (BCPs) that function as precursors to arrays of FePt nanoparticles (NPs) are of potential interest for the creation of media for the next-generation high-density magnetic data storage devices. A series of bimetallic BCPs has been synthesized by incorporating a complex containing Fe and Pt centers into the coordinating block of four different poly­(styrene-<i>b</i>-4-vinylpyridine)­s (PS-<i>b</i>-P4VPs, <b>P1–P4</b>). To facilitate phase separation for the resulting metalated BCPs (<b>PM1–PM4</b>), a loading of the FePt-bimetallic complex corresponding to ca. 20% was used. The bulk and thin-film self-assembly of these BCPs was studied by transmission electron microscopy (TEM) and atomic force microscopy, respectively. The spherical and cylindrical morphologies observed for the metalated BCPs corresponded to those observed for the metal-free BCPs. The products from the pyrolysis of the BCPs in bulk were also characterized by TEM, powder X-ray diffraction, and energy-dispersive X-ray spectroscopy, which indicated that the FePt NPs formed exist in an fct phase with average particle sizes of ca. 4–8 nm within a carbonaceous matrix. A comparison of the pyrolysis behavior of the metalated BCP (<b>PM3</b>), the metalated <b>P4VP</b> homopolymer (<b>PM5</b>), and the molecular model organometallic complex revealed the importance of using a nanostructured BCP approach for the synthesis of ferromagnetic FePt NPs with a smaller average NP size and a close to 1:1 Fe/Pt stoichiometric ratio

    Effects of loading positions on the activation of trunk and hip muscles during flywheel and dumbbell single-leg Romanian deadlift exercises

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    Objective: The study compared the activities of the surface electromyography (sEMG) of trunk and hip muscles during single-leg Romanian deadlift (SLRDL) exercises using a flywheel and dumbbell with different loading positions (ipsilateral and contralateral).Method: Twelve active male subjects with at least 2 years of strength training experience (age: 26.7 ± 3.3 years; weight: 73.9 ± 6.2 kg) participated in this study. sEMG in the percentage of maximum voluntary isometric contraction of four SLRDL exercises (ipsilateral and contralateral loading position for dumbbell and flywheel) in a randomized order for superior gluteus maximus (SGM), inferior gluteus maximus (IGM), gluteus medius (GM), biceps femoris (BF), erector spinae (ES), external oblique (EO), and adductor longus (AL) were measured. One-way repeated measure ANOVA with Bonferroni adjustment (statistical significance at 0.05) and the non-clinical magnitude-based decision with a standardized difference were performed for statistical analysis.Results: The overall results demonstrated a very high level of SGM (105.4%–168.6%) and BF (69.6%–122.4%) muscle activities. A significant moderate increase of sEMG signals in GM, IGM, and ES (dominant side) and a large increase in SGM activity during concentric action when the loading position of flywheel SLRDL was changed from ipsilateral to the contralateral side. No significant difference was observed between flywheel and dumbbell SLRDL exercises.Conclusion: Strength coaches may adopt dumbbell or flywheel SLRDL exercises using the contralateral loading position to simultaneously strengthen the hip extensors and trunk stabilizers effectively

    Association between the risk of seizure and COVID-19 vaccinations: A self-controlled case-series study

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    OBJECTIVE: The risk of seizure following BNT162b2 and CoronaVac vaccinations has been sparsely investigated. This study aimed to evaluate this association. METHOD: Patients who had their first seizure-related hospitalization between February 23, 2021 and January 31, 2022 were identified in Hong Kong. All seizure episodes happening on the day of vaccination (day 0) were excluded since clinicians validated that most of the cases on day 0 were syncopal episodes. Within-individual comparison using a modified self-controlled case series analysis was applied to estimate the incidence rate ratio (IRR) with 95% confidence intervals (CI) of seizure using conditional Poisson regression. RESULTS: We identified 1656 individuals who had their first seizure-related hospitalization (BNT162b2: 426; CoronaVac: 263; unvaccinated: 967) within the observation period. The incidence of seizure was 1.04 (95% CI: 0.80-1.33) and 1.11 (95% CI: 0.80-1.50) per 100,000 doses of BNT162b2 and CoronaVac administered respectively. 16 and 17 individuals received second dose after having first seizure within 28 days after first dose of BNT162b2 and CoronaVac vaccinations, respectively. None had recurrent seizures after the second dose. There was no increased risk during day 1-6 after the first (BNT162b2: IRR=1.39, 95% CI=0.75-2.58; CoronaVac: IRR=1.19, 95% CI=0.50-2.83) and second doses (BNT162b2: IRR=1.36, 95% CI 0.72-2.57; CoronaVac: IRR=0.71, 95% CI=0.22-2.30) of vaccinations. During 7-13, 14-20- and 21-27-days post-vaccination, no association was observed for both vaccines. SIGNIFICANCE: The findings demonstrated no increased risk of seizure following BNT162b2 and CoronaVac vaccinations. Future studies will be warranted to evaluate the risk of seizure following COVID-19 vaccinations in different populations with subsequent doses to ensure the generalizability

    Comparing hybrid and regular COVID-19 vaccine-induced immunity against the Omicron epidemic

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    Evidence on the effectiveness of COVID-19 vaccines among people who recovered from a previous SARS-CoV-2 infection is warranted to inform vaccination recommendations. Using the territory-wide public healthcare and vaccination records of over 2.5 million individuals in Hong Kong, we examined the potentially differential risk of SARS-CoV-2 infection, hospitalization, and mortality between those receiving two homologous doses of BNT162b2 or CoronaVac versus those with a previous infection receiving only one dose amid the Omicron epidemic. Results show a single dose after a SARS-CoV-2 infection is associated with a lower risk of infection (BNT162b2: adjusted incidence rate ratio [IRR] = 0.475, 95% CI: 0.410–0.550; CoronaVac: adjusted IRR = 0.397, 95% CI: 0.309–0.511) and no significant difference was detected in the risk of COVID-19-related hospitalization or mortality compared with a two-dose vaccination regimen. Findings support clinical recommendations that those with a previous infection could receive a single dose to gain at least similar protection as those who received two doses without a previous infection

    Disease Burden, Risk Factors, and Trends of Leukaemia: A Global Analysis.

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    Leukaemia accounted for approximately 2.5% of all new cancer incidence and 3.1% of cancer-related mortality. The investigation of its risk factors and epidemiologic trends could help describe the geographical distribution and identify high-risk population groups. This study aimed to evaluate the global incidence, mortality, associated risk factors, and temporal trends of leukaemia by sex, age, and country. We extracted incidence and mortality of leukaemia from GLOBOCAN, CI5, WHO mortality database, NORDCAN, and SEER. We searched the WHO Global Health Observatory data repository for the age-standardised prevalence of lifestyle and metabolic risk factors. We tested the trends by calculating Average Annual Percentage Change (AAPC) from Joinpoint regression. The age-standardized rate of incidence and mortality were 5.4 and 3.3 per 100,000 globally. The incidence and mortality of leukaemia were associated with Human Development Index, Gross Domestics Products per capita, prevalence of smoking, physical activity, overweight, obesity, and hypercholesterolaemia at the country level. Overall, more countries were showing decreasing trends than increasing trends in incidence and mortality. However, an increasing trend of leukaemia incidence was found in Germany, Korea, Japan, Canada and the United Kingdom (AAPC, 2.32-0.98) while its mortality increased in the Philippines, Ecuador, Belarus, and Thailand (AAPC, 2.49-1.23). There was a decreasing trend of leukaemia for the past decade while an increase in incidence and mortality was observed in some populations. More intensive lifestyle modifications should be implemented to control the increasing trends of leukaemia in regions with these trends. Future studies may explore the reasons behind these epidemiological transitions

    Distribution, Risk Factors, and Temporal Trends for Lung Cancer Incidence and Mortality: A Global Analysis

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    BACKGROUND: Lung cancer ranks second for cancer incidence and first for cancer mortality. Investigation into its risk factors and epidemiologic trends could help describe geographical distribution and identify high-risk population groups. RESEARCH QUESTION: What is the global incidence, mortality, associated risk factors, and temporal trends of lung cancer by sex, age, and country? STUDY DESIGN AND METHODS: Data on incidence and mortality were retrieved from the Global Cancer Observatory (GLOBOCAN), Cancer Incidence in Five Continents series I-X, World Health Organization (WHO) mortality database, the Nordic Cancer Registries (NORDCAN), and the Surveillance, Epidemiology, and End Results Program (SEER). We searched the WHO Global Health Observatory data repository for age-adjusted prevalence of current smoking. The Average Annual Percentage Change (AAPC) of the trends were obtained by Joinpoint Regression. RESULTS: The age-standardized rate of incidence and mortality were 22.4 and 18.0 per 100,000 globally. The lung cancer incidence and mortality were associated with Human Development Index (HDI), Gross Domestic Products (GDP), and prevalence of smoking. For incidence, more countries had increasing trends in females but decreasing trends in males (AAPC, 1.06 to 6.43 for female; -3.53 to -0.64 for male). A similar pattern was found in those 50 years or older, whereas those aged younger than 50 years had declining incidence trends in both sexes in most countries. For mortality, similar to incidence, 17 of 48 countries showed decreasing trends in males and increasing trends in females (AAPC, -3.28 to -1.32 for male, 0.63 to 3.96 for female). INTERPRETATION: Most countries had increasing trends in females but decreasing trends in males and in lung cancer incidence and mortality. Tobacco related measures and early cancer detection should be implemented to control the increasing trends of lung cancer in females, and in regions identified as having these trends. Future studies may explore the reasons behind these epidemiological transitions

    Sex-based differences in risk of ischaemic stroke or systemic embolism after BNT162b2 or CoronaVac COVID-19 vaccination in patients with atrial fibrillation: a self-controlled case series and nested case-control study

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    AIMS: Patients with atrial fibrillation (AF) have a higher risk of ischemic stroke or systemic embolism with a greater risk for female patients. This study aims to evaluate the risk of ischemic stroke or systemic embolism and bleeding following COVID-19 vaccination in patients with AF and the sex differences. METHODS AND RESULTS: Self-controlled case series (SCCS) analysis was conducted to evaluate the risk of ischemic stroke or systemic embolism and bleeding following BNT162b2 or CoronaVac in patients with AF, using the territory-wide electronic medical records from the Hospital Authority and vaccination records from the Department of Health in Hong Kong. Patients with a primary diagnosis of ischemic stroke or systemic embolism or bleeding in the inpatient setting between February 23, 2021 and March 31, 2022 were included. A nested case-control analysis was also conducted with each case randomly matched with ten controls according to sex, age, Charlson comorbidity index and date of hospital admission. Conditional Poisson regression was used in the SCCS analysis and conditional logistic regression was used in nested case-control analysis to assess the risks and all analyses were stratified by sex and type of vaccines. Among 51 158 patients with AF, we identified an increased risk of ischemic stroke or systemic embolism after the first dose of BNT162b2 in SCCS analysis during 0-13 days (incidence rate ratio 6.60[95% CI 1.51-28.77]) and 14-27 days (6.53[95% CI 1.31-32.51]), and nested case-control analysis during 0-13 days (adjusted odds ratio 6.21 [95% CI 1.14-33.91]) and 14-27 days (5.52 [95% CI 1.12-27.26]) only in female patients. The increased risk in female patients following the first dose of CoronaVac was only detected during 0-13 days (3.88 [95% CI 1.67-9.03]) in the nested case-control analysis. No increased risk of ischemic stroke or systemic embolism was identified in male patients and no increased risk of bleeding was detected in all patients with AF for both vaccines. An increased risk of ischemic stroke or systemic embolism after COVID-19 was also observed in both females (17.42 [95% CI 5.08-59.73]) and males (6.63 [95% CI 2.02-21.79]). CONCLUSIONS: The risk of ischemic stroke or systemic embolism after COVID-19 vaccination was only increased in female patients with AF. However, as the risk after COVID-19 was even higher, proactive uptake of COVID-19 vaccines is recommended to prevent the potential severe outcomes after infection

    Global incidence and mortality trends of corpus uteri cancer and associations with gross domestic product, human development index, lifestyle, and metabolic risk factors

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    OBJECTIVE: To evaluate the worldwide distribution, risk factors, and temporal trends of corpus uteri cancer for different countries and age groups. METHOD: Data relating to corpus uteri cancer in 2020 were retrieved from the Global Cancer Observatory database. Data from Cancer Incidence in Five Continents and the WHO mortality database were used for trend analysis. Age-standardized rates (ASR, per 100 000 persons) were calculated for incidence and mortality. Joinpoint regression analysis was used to estimate the 10-year annual average percent change (AAPC). RESULTS: A total of 417 367 new cases and 97 370 new deaths of corpus uteri cancer were reported globally in 2020. The highest incidence was observed in high-income countries. Higher ASR of mortality of corpus uteri cancer was associated with a higher gross domestic product per capita, higher Human Development Index, and higher prevalence of smoking, alcohol drinking, physical inactivity, obesity, hypertension, diabetes, and lipid disorders. There was a substantial increasing trend of corpus uteri cancer, with the largest AAPC in incidence found in Japan, followed by India, Chile, Korea, and Thailand. CONCLUSION: The incidence and mortality of corpus uteri cancer have been increasing substantially for the past 10 years. Intensive lifestyle modifications are needed, especially among younger women
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