Speckle-tracking echocardiography for detecting myocardial dysfunction in sepsis and septic shock patients:A single emergency department study

BACKGROUND:Septic cardiomyopathy(SCM)occurs in the early stage of sepsis and septic shock,which has implications for treatment strategies and prognosis.Additionally,myocardial involvement in the early stages of sepsis is difficult to identify.Here,we assess subclinical myocardial function using laboratory tests and speckle-tracking echocardiography(STE).METHODS:Emergency department patients diagnosed with sepsis or septic shock were included for analysis.Those with other causes of acute or pre-existing cardiac dysfunction were excluded.Transthoracic echocardiography(TTE),including conventional echocardiography and STE,were performed for all patients three hours after initial resuscitation.Samples for laboratory tests were taken around the time of TTE.RESULTS:Left ventricular functions of 60 patients were analyzed,including 21 septic shock patients and 39 sepsis patients.There was no significant difference in global longitudinal strain(GLS),global circumferential strain(GCS),or global radical strain(GRS)between patients with sepsis and septic shock(all with P>0.05).However,GLS and GCS were significantly less negative in patients with abnormal troponin levels or in patients with abnormal left ventricular ejection fraction(LVEF)values(all with P<0.05).There were also moderate correlations between GLS and levels of cTnI(r=0.40,P=0.002)or N-terminal pro-B-type natriuretic peptide(NT-proBNP)(r=0.44,P=0.001)in sepsis and septic shock patients.CONCLUSION:Myocardial dysfunction,e.g.,lower LVEF or less negative GLS in patients with sepsis or septic shock,is more affected by myocardial injury.GLS could be incorporated into mainstream clinical practice as a supplementary LVEF parameter,especially for those with elevated troponin levels.

Detection and Prevention of Environmental Hormone

The sorts and detection methods of environmental hormone were analyzed firstly,and then the effects of environmental hormone on organisms and humanity were discussed. Finally the control measures of environmental hormone pollution,such as reducing the use of goods and pesticide and the study of new substitutes and degradation technology are advanced.

世界建筑导报SOM领导力专访:在瞬息万变的世界中持续创新

Q1:SOM是上个世纪九十年代第一批进入中国市场的国际建筑事务所,您能否简单回顾一下SOM在此期间的成长和转变?放眼未来,SOM又是如何规划未来十年在中国的发展?傅萱:作为一家国际性的、有着多专业设计服务的建筑设计事务所,SOM在过去的四十多年里,在中国与当地政府、开发商及其他顾问公司精诚合作,将跨专业综合设计方法运用到各种规模的项目设计中,在契合国家制定总体发展目标的同时,共同创造可持续发展的城市环境。

Inhomogeneous Natural Network Promoting Strain-induced Crystallization:A Mesoscale Model of Natural Rubber

Although synthetic rubbers show continuously improved mechanical properties,natural rubber (NR) remains irreplaceable in the rubber family due to its superior mechanical properties.A mainstream viewpoint regarding the superiority of NR is that NR possesses a natural network formed by linking the poly(cis-l,4-isoprene) chain terminals to protein and phospholipid aggregates;after vulcanization,the natural network additionally contributes to rubber mechanics by both increasing the network density and promoting the strain-induced crystallization (SIC) behavior.However,the reason why the natural network promotes SIC is still unclear;in particular,only using the increased network density cannot explain our finding that the NR shows smaller onset strain of SIC than Gel (the gel component of NR with higher network density) and even vulcanized NR.Herein,we point out that the inhomogeneous chain deformation is the alternative reason why SIC of NR takes place at smaller strain than that of Gel.More specifically,although the natural network is homogenous on the subchain length scale based on the proton double-quantum NMR results,it is essentially inhomogeneous on mesoscale (100 nm),as revealed by the small angle X-ray scattering analysis.This inhomogeneous network also leads to the mesoscale deformation inhomogeneity,as detected by the orientation of stearic acid (SA) probe,thus resulting in the smaller onset strain of SIC of NR.Based on the experimental results,a mesoscale model is proposed to qualitatively describe the crucial roles of inhomogeneous structure and deformation of natural network in NR?s mechanical properties,providing a clue from nature to guide the development of high-performance rubbers with controlled structures at mesoscale.

Super Strong and Tough Elastomers Enabled by Sacrificial Segregated Network

The integration of high strength and toughness concurrently is a vital requirement for elastomers from the perspective of long-term durability and reliability. Unfortunately, these properties are generally conflicting in artificial materials. In the present work, we propose a facile strategy to simultaneously toughen and strengthen elastomers by constructing 3 D segregated filler network via a simple latex mixing method.The as-fabricated elastomers are featured by a microscopic 3 D interconnected segregated network of rigid graphene oxide(GO) nanosheets and a continuous soft matrix of sulfur vulcanized natural rubber(NR). We demonstrate that the interconnected segregated filler network ruptures preferentially upon deformation, and thus is more efficient in energy dissipation than the dispersed filler network. Therefore, the segregated filler network exhibits better reinforcing effects for the rubber matrix. Moreover, the excellent energy dissipating ability also contributes to the outstanding crack growth resistance through the release of concentrated stress at the crack tip. As a result, the strength, toughness and fatigue resistance of the nanocomposites are concurrently enhanced. The methodology in this work is facile and universally applicable, which may provide new insights into the design of elastomers with both extraordinary static and dynamic mechanical performance for practical applications.