The role of temperature as a driver of metabolic flexibility in the Red-billed Leiothrix(Leiothrix lutea)

Background:The thermoregulatory ability of animals is strongly influenced by the temperature of their environment.Acclimation to cold requires a range of physiological and morphological adjustments.In this study,we tested the hypothesis that a small passerine,the Red-billed Leiothrix(Leiothrix lutea),can maintain homeothermy in cold conditions by adjusting the physiology and biochemistry of its tissue and organs and return to its former physiological and biochemical state when moved to a warm temperature.Methods:Phenotypic variation in thermogenic activity of the Red-billed Leiothrixs(Leiothrix lutea)was investigated under warm(35℃),normal(25℃)or cold(15℃)ambient temperature conditions.Oxygen consumption was measured using an open-circuit respirometry system.Mitochondrial state-4 respiration and cytochrome-c oxidase(COX)activity in liver,kidney heart and pectoral muscle were measured with a Clark electrode.Results:Birds acclimated to an ambient temperature of 15℃ for 4 weeks significantly increased their basal metabolic rate(BMR)compared to a control group kept at 25℃.Birds acclimated to 35℃ decreased their BMR,gross energy intake(GEI)and digestible energy intake(DEI).Furthermore,birds acclimated to 15℃ increased state-4 respiration in their pectoral muscles and cytochrome-c oxidase(COX)activity in their liver and pectoral muscle,compared to the 25℃ control group.Birds acclimated to 35℃ also displayed lower state-4 respiration and COX activity in the liver,heart and pectoral muscles,compared to those kept at 25℃.There was a positive correlation between BMR and state-4 respiration,and between BMR and COX activity,in all of the above organs except the liver and heart.Conclusions:Our study illustrates that the morphological,physiological,and enzymatic changes are associated with temperature acclimation in the Red-billed Leiothrix,and supports the notion that the primary means by which small birds meet the energetic challenges of cold conditions is through metabolic adjustments.

An ICME impact on the Martian hydrogen corona

The Martian hydrogen exosphere extends out of the bow shock, forming a "hydrogen corona". The solar wind interacts directly with the hydrogen corona. During an ICME event on 7 March 2015, the SWIA instrument onboard Mars Atmosphere and Volatile Evolution mission (MAVEN) observed that the pick-up H+ fluxes in upstream solar wind were enhanced. Also increased were the penetrating H+ fluxes in the Martian atmosphere. Quantitatively, these penetrating H+ fluxes cannot increase by a factor of 5 simply due to a factor of 3 increase in the solar wind density, suggesting that the increased abundance of exospheric hydrogen upstream of the bow shock was a consequence of the passage of the ICME. A denser outer hydrogen corona at high altitudes suggests that the expansion of the neutral atmosphere was caused by the ICME. The excited and heated hydrogen exosphere probably indicates an elevated hydrogen escape rate during an ICME.

Influencing factors of using behaviour for computational advertising under the theoretical model of UTAUT

Based on the UTAUT theoretical model, this paper discusses the applicability of the model incomputational advertising situations. Computational advertising relies on artificial intelligencetechnologies such as big data, cloud computing, new algorithms, and blockchain. Results showthat: performance expectation, effort expectation, and social impact have a positive influence onthe acceptance intention of computational advertising;stimulus has no significant influence onthe using behaviour of computational advertising;the acceptance intention of computationaladvertising has a positive influence on the using behaviour of computational advertising. Fourpoints should be paid attention to in the future computational advertising: paying attention tothe needs of users and realising accurate advertising;improving efforts and expectations andoptimising user experience;enhancing user interaction and user stickiness;protecting user privacyand improving user satisfaction. The core of computational advertising research in the fieldof humanities and social sciences is not dislocated from the traditional user-centred problemconsciousness.

快速射电暴脉冲研究进入高统计性时代

快速射电暴(fast radio burst,FRB)是在宇宙空间中发生的持续时标为毫秒量级的射电脉冲信号,瞬时辐射流量峰值可达数十央斯基(Jy),爆发的总能量相当于太阳几天甚至几个月内辐射的总能量.快速射电暴于2007年被Lorimer等人[1]首次发现并报道之后,经历了初期的真实性质疑.

有机添加剂调控铜互连结构电生长及信号传输损耗的研究

铜互连结构的粗糙度严重制约高频信号传输的完整性.研究了含不同有机添加剂的镀液体系对电生长铜层粗糙度的影响;采用分子模拟仿真和电化学测试,调控了有机添加剂在铜面的竞争吸附行为,探究了引起铜电生长差异的可能机制.结果表明,与仅用单一有机添加剂的镀液体系相比,含聚二硫二丙烷磺酸钠、聚氧乙烯聚丙乙烯嵌段共聚物和健那绿的镀液体系可电生长出表面形貌平整的铜层,且其插入损耗值为−8.9 dB@20 GHz.因此,采用有机添加剂调控铜互连结构电生长的低粗糙度,降低传输损耗,可有效保障高频信号传输完整性.

QRS score:A simple marker to quantify the extent of myocardial scarring in patients with chronic total arterial occlusion

Background:Chronic total occlusion(CTO)is a critical and unique subgroup of coronary lesions.This study aimed to investigate the correlation between the Selvester QRS score and late gadolinium enhancement cardiac magnetic resonance imaging(LGE-CMRI)in quantifying myocardial scarring to provide a simple and feasible method for treating CTO.Methods:The medical records of 134 patients with absolute CTO who underwent coronary angiography between May 1,2014 and December 30,2017 were retrospectively reviewed.All patients were grouped according to the CTO location(right coronary artery[RCA]CTO,left artery descending[LAD]CTO,left circumflex[LCX]CTO,and multivessel CTO groups).The degree of myocardial scarring was determined according to the Selvester QRS score and using the LGE-CMRI.All patients were followed up for at least 12 months.Results:Among the 62 CTO patients,55 had occlusion of a single vessel and seven had occlusion of multiple vessels,of which 27(43.55%)were in the RCA CTO group,16(25.81%)in the LAD CTO group,12(19.35%)in the LCX CTO group,and 7(11.29%)in the multivessel CTO group.The area under the receiver operating characteristic curve for the QRS score that was used to determine the degree of myocardial scarring was 0.806,with a sensitivity and specificity of 94.7%and 42.1%,respectively.The Selvester QRS score and LGE-CMRI measures of scar size were correlated in the RCA CTO,LCX CTO,and multivessel CTO groups(r=0.466,0.593,and 0.775,respectively).Conclusion:The Selvester QRS score was feasible for detecting myocardial scarring in patients with CTO.

Lactoferrin improves hepatic pyroptosis in mice after irradiation

Objective:To investigate the effects of lactoferrin(Lf)on hepatic pyroptosis(an inflammatory form of programmed cell death)in mice exposed to radiation.Methods:A total of thirty-six BALB/c male mice were randomly divided into four groups,namely the control group,5 Gy group,5 Gyþ2 mg Lf group,and 5 Gyþ4 mg Lf group.The mice were administered whole-body ionizing radiation using a PRIMUS accelerator,with a single dose of 5 Gy and an absorbed dose rate of 2.0 Gy/min at a source-skin distance of 100 cm.Lf solution was intraperitoneally injected into the mice 2 h before and per day after radiation.The mice were sacrificed 1,3,and 9 d after radiation,and their livers were used for histopathologic examination,immunohistochemistry analysis,and Western blot analysis for absent in melanoma 2(AIM2)inflammasome pathway.Results:Histopathologic examination showed the disorder of the hepatocellular structure and the accumulation of inflammatory cells after radiation.Lf intervention inhibited hepatocellular proliferation and decreased the infiltration of inflammatory cells.Immunohistochemistry analysis indicated that AIM2 overexpression was significantly attenuated by 4 mg of Lf(t=3.065,P<0.05)3 d after radiation and by 2 mg and 4 mg of Lf(t=4.032,t=2.786,P<0.05)9 d after radiation.Western blot analysis showed that Lf downregulated the hepatic overexpression of AIM2,apoptosis-associated speck-like protein containing a caspase activation and recruitment domain(ASC),IL-1β,and IL-18.2 mg of Lf significantly downregulated the abovementioned protein expression 3 d(t=7.934,4.092,5.193,2.916,P<0.05)and 9 d after radiation(t=5.016,3.882,9.528,P<0.05 for AIM2,ASC,IL-1β).Conclusions:Lf intervention suppressed the hepatic pyroptosis in mice exposed to ionizing radiation by downregulating the protein expression of AIM2 inflammasome.