Solubility of iron(Ⅲ) and nickel(Ⅱ) acetylacetonates in supercritical carbon dioxide

As a common precursor for supercritical CO_(2)(scCO_(2))deposition techniques,solubility data of organometallic complexes in scCO_(2)is crucial for the preparation of nanocomposites.Recently,metal acetylacetonates have shown great potential for the preparation of single-atom catalytic materials.In this study,the solubilities of iron(Ⅲ)acetylacetonate(Fe(acac)3)and nickel(Ⅱ)acetylacetonate(Ni(acac)2)were measured at the temperature from 313.15 to 333.15 K and in the pressure range of 9.5–25.2 MPa to accumulate new solubility data.Solubility was measured using a static weight loss method.The semi-empirical models proposed by Chrastil and Sung et al.were used to correlate the solubility data of Fe(acac)3 and Ni(acac)2.The equations obtained can be used to predict the solubility of the same system in the experimental range.

面向鸟鸣声识别任务的深度学习技术

在生态系统中,鸟类是重要的组成部分,对调节生态环境和监测生物多样性至关重要,甚至可以通过监测鸟群动向与监听鸟群异常鸣声对地震、海啸等自然灾害进行辅助预测和防范,为此,鸟鸣声识别和异常鸣声监测成为热门的研究方向。然而,由于传统鸟鸣声识别方法存在特征提取不充分等问题,导致识别率不高。本文采用融合特征的方法结合深度学习技术提取鸟鸣声特征,融合特征选择改良后的对数梅尔谱差分参数同原始信号参数拼接所得的特征;深度学习方法是基于Dense Net121网络结构,并融入自注意力模块与中心损失函数进行鸟鸣声识别。自注意力模块部分提高了关键通道的特征表达能力;中心损失函数可解决类内特征不紧凑问题。我们通过消融实验对比验证,对在Xeno-Canto世界野生鸟类声音公开数据集上选取的10种鸟类声音进行识别,准确率达到96.9%。代码已开源至Github:https://github.com/Carrie X6/-Xeno-Canto-.git。

Trend of declining stroke mortality in China:reasons and analysis

Introduction There is a downward trend of stroke-related mortality in the USA.By reviewing all published articles on stroke mortality in China,we analysed its trend and possible factors that have influenced the trend.Methods Both English and Chinese literatures were searched on the mortality of stroke or cerebrovascular diseases in China.Potential papers related to this topic were identified from PubMed,Medline,Embase,Cochrane Library,Wanfang Database,SINOMED and China National Knowledge Infrastructure databases.Results Comparing the results from the most recent population-based epidemiological survey and databank from the national Center for Disease Control and Prevention,the age-adjusted stroke mortality rate has shown a downward trend among both urban and rural population in the past 30 years in China.Comparing with 30 years ago,the rate of stroke mortality has decreased by more than 31%in urban/suburban population and 11%in rural population.In men,the age-adjusted stroke mortality rate decreased by 18.9%and in women by 24.9%between 1994 and 2013.Factors that may have contributed to the trend of decreased stroke mortality rate include(1)improved healthcare coverage and healthcare environment;(2)improved treatment options and medical technology;(3)support by government to educate the public on stroke and stroke prevention;and(4)improved public knowledge on stroke.Conclusions The age-adjusted stroke mortality rate in China has shown a downward trend among both urban and rural population in the past 30 years.The major influencing factors that helped in reducing stroke mortality in China included improved healthcare coverage,healthcare environment,the updated treatment options and modern medical technology.

Chinese Stroke Association guidelines for clinical management of cerebrovascular disorders:executive summary and 2019 update of the management of high-risk population

Aim Cerebrovascular disease is the leading cause of death and disability in China,causing a huge burden among patients and their families.Hence,stroke prevention is critical,especially in the high-risk population.Here,we present the evidence-based guideline suitable for the Chinese population.Methods Literature search of PubMed and Cochrane library(from January 1964 to June 2019)was done.After thorough discussion among the writing group members,recommendations were listed and summarised.This guideline was reviewed and discussed by the fellow writing committees of the Chinese Stroke Association’s Stroke.Results This evidence-based guideline was written in three parts:controlling the risk factors of stroke,utilisation of antiplatelet agents and assessing the risks of first-ever stroke.All recommendations were listed along with the recommending classes and levels of evidence.Conclusions This guideline provides recommendations for primary prevention of cerebrovascular disease among high-risk population in China.Controlling related risk factors,appropriately using antiplatelet agents,assessing the risk of developing first-ever stroke should help reduce the rate of cerebrovascular disease in China.

Tranexamic acid for acute intracerebral haemorrhage growth based on imaging assessment (TRAIGE): a multicentre, randomised, placebo- controlled trial

Background Studies show tranexamic acid can reduce the risk of death and early neurological deterioration after intracranial haemorrhage.We aimed to assess whether tranexamic acid reduces haematoma expansion and improves outcome in intracerebral haemorrhage patients susceptible to haemorrhage expansion.Methods We did a prospective,double-blind,randomised,placebo-controlled trial at 10 stroke centres in China.Acute supratentorial intracerebral haemorrhage patients were eligible if they had indication of haemorrhage expansion on admission imaging(eg,spot sign,black hole sign or blend sign),and were treatable within 8 hours of symptom onset.Patients were randomly assigned(1:1)to receive either tranexamic acid or a matching placebo.The primary outcome was intracerebral haematoma growth(>33% relative or>6 mL absolute)at 24 hours.Clinical outcomes were assessed at 90 days.Results Of the 171 included patients,124(72.5%)were male,and the mean age was 55.9±11.6 years.89 patients received tranexamic acid and 82 received placebo.The primary outcome did not differ significantly between the groups:36(40.4%)patients in the tranexamic acid group and 34(41.5%)patients in the placebo group had intracranial haemorrhage growth(OR 0.96,95% CI 0.52 to 1.77,p=0.89).The proportion of death was lower in the tranexamic acid treatment group than placebo group(8.1%vs 10.0%),but there were no significant differences in secondary outcomes including absolute intracranial haemorrhage growth,death and dependency.Conclusions Among patients susceptible to haemorrhage expansion treated within 8 hours of stroke onset,tranexamic acid did not significantly prevent intracerebral haemorrhage growth.Larger studies are needed to assess safety and efficacy of tranexamic acid in intracerebral haemorrhage patients.

Haemostatic therapy in spontaneous intracerebral haemorrhage patients with high-risk of haematoma expansion by CT marker: a systematic review and meta- analysis of randomised trials

Background and purpose Current randomised controlled trials(RCTs)showed an uncertain benefit of haemostatic therapy on preventing haematoma expansion and improving the outcome in patients with intracerebral haemorrhage(ICH).This meta-analysis aims to systematically evaluate the effect of haemostatic agents on the prevention of haemorrhage growth in patients with high-risk spontaneous ICH predicted by CT signs in RCTs.Methods A comprehensive search of PubMed,EMBASE and Cochrane library from 1 January 2005 to 30 June 2021 was conducted.RCTs that compared haemostatic agents with placebo for the treatment of spontaneous patients with ICH with high-risk haemorrhage growth were included.The primary endpoint was haematoma expansion at 24 hours.Other major endpoints of interest included 90-day functional outcome and mortality.Results The meta-analysis included four RCTs that randomised 2666 patients with ICH with high-risk haemorrhage growth.Haemostatic therapy reduced the rate of haematoma expansion at a marginally statistically significant level when compared with placebo(OR 0.84;95% CI 0.70 to 1.00;p=0.051).Subgroup analysis for patients with black hole sign on CT revealed a significant reduction of haematoma expansion with haemostatic therapy(OR 0.61;95% CI 0.39 to 0.94;p=0.03).However,both the primary analysis and subgroup analyses showed that haemostatic therapy could not reduce the rate of poor functional outcome(modified Rankin Scale>3)or death.Conclusions Haemostatic therapy showed a marginally significant benefit in reducing early haematoma expansion in patients with high-risk spontaneous ICH predicted by markers on CT scan.However,no significant improvement in functional outcome or reduction of mortality was observed.