干眼与睡眠障碍关系的研究进展

近年来,由于社会经济发展、电子产品的普及和工作压力增加,造成人们睡眠障碍和干眼的患病率不断增加。这既影响了人们的身心健康,也给社会经济造成一定负担。有研究认为睡眠障碍与干眼有明显相关性,睡眠障碍是干眼的独立危险因素之一。因此,在干眼的诊疗中需要考虑睡眠因素的影响。目前关于睡眠障碍如何导致干眼及眼表损伤的机制是领域内的前沿课题。本文具体分析了睡眠障碍与干眼之间的相关性,总结了这种相关性的机制,并进一步分析了改善睡眠对干眼的影响,以期为眼科医生提供新的诊疗思路。

Spaceflight-associated neuro-ocular syndrome:a review of potential pathogenesis and intervention

With the continuing progress in space exploration,a new and perplexing condition related to spaceflight ocular syndrome has emerged in the past four decades.National Aeronautics and Space Administration(NASA) has named this condition "spaceflight-associated neuro-ocular syndrome"(SANS).This article gives an overview of the current research about SANS and traditional Chinese medicine(TCM) by analyzing the existing publications on Pub Med and CNKI and reports from NASA about SANS,summarizing the potential pathogenesis of SANS and physical interventions for treating SANS,and discussing the feasibility of treating SANS with TCM.Due to the unique characteristics of the space environment,it is infeasible to conduct large-scale human studies of SANS.SANS may be the result of the interaction of multiple factors,including inflammation and fluid displacement in the optic nerve sheath and cerebrospinal fluid.We should pay attention to SANS.Visual function is not only related to the health of astronauts but also closely related to space operations.TCM has antioxidative stress and antiapoptotic effects and is widely used for optic nerve diseases.TCM has great potential to prevent SANS.

Photodynamics of Methyl-Vinyl Criegee Intermediate:Different Conical Intersections Govern the Fates of Syn/Anti Configurations

Methyl vinyl ketone oxide,an unsaturated four-carbon Criegee intermediate produced from the ozonolysis of isoprene has been recognized to play a key role in determining the tropospheric OH concentration.It exists in four configurations(anti-anti,anti-syn,synanti,and syn-syn)due to two different substituents of saturated methyl and unsaturated vinyl groups.In this study,we have carried out the electronic structure calculation at the multi-configurational CASSCF and multi-state MS-CASPT2 levels,as well as the trajectory surface-hopping nonadiabatic dynamics simulation at the CASSCF level to reveal the different fates of syn/anti configurations in photochemical process.Our results show that the dominant channel for the S1-state decay is a ring closure,isomerization to dioxirane,during which,the syn(C-O)configuration with an intramolecular hydrogen bond shows slower nonadiabatic photoisomerization.More importantly,it has been found for the first time in photochemistry of Criegee intermediate that the cooperation of two heavy groups(methyl and vinyl)leads to an evident pyramidalization of C3 atom in methyl-vinyl Criegee intermediate,which then results in two structurally-independent minimal-energy crossing points(CIs)towards the syn(C-O)and anti(C-O)sides,respectively.The preference of surface hopping for a certain CI is responsible for the different dynamics of each configuration.

Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring

We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal.

Correlation of huamn cytomegalovirus infection with inflammatory factor secretion and myocardial cell injury in patients with acute myocardial infarction

Objective:To study the correlation of human cytomegalovirus infection (HCMV) with inflammatory factor secretion and myocardial cell injury in patients with acute myocardial infarction.Methods: A total of 80 patients with acute myocardial infarction who were treated in our hospital between September 2015 and September 2017 were selected as the acute myocardial infarction (AMI) group of the research, and 60 healthy volunteers who received physical examination in our hospital during the same period were selected as the control group of the research. The serum was collected to qualitatively determine HCMV, and quantitatively determine the inflammatory factors and myocardial injury indicators.Results: Serum IL-10 and TGF-β1 levels of AMI group were significantly lower than those of control group whereas IL-1β, IL-6, CD62P, CCL21, CK-MB, cMyBP-C, sLOX-1, Caspase-3 and MDA levels were significantly higher than those of control group;serum IL-10 and TGF-β1 levels of AMI group of patients with HCMV infection were lower than those of patients with non-HCMV infection whereas IL-1β, IL-6, CD62P, CCL21, CK-MB, cMyBP-C, sLOX-1, Caspase-3 and MDA levels were higher than those of patients with non-HCMV infection. Conclusion: Cytomegalovirus infection can promote and aggravate the inflammatory factor secretion and myocardial cell injury in patients with acute myocardial infarction.

Mechanism study on direct synthesis of glycerol carbonate from CO_(2)and glycerol over shaped CeO_(2)model catalysts

Direct synthesis of glycerol carbonate(GC)from CO_(2)and glycerol(a byproduct of biodiesel production)is a route to obtain a high-value chemical from waste and low-cost byproducts but has not yet industrialized due to the lack of efficient catalysts.Ceria(CeO_(2))exhibits the highest catalytic activity and GC selectivity among the heterogeneous catalysts studied so far.However,the mechanism of this reaction over CeO_(2)catalysts has not been studied in detail.Herein,we synthesized CeO_(2)nanocrystals with different morphologies as model catalysts that can predominantly expose(111),(110),and(100)facets,and their surface acid-base properties were characterized using high-sensitivity temperature-programmed desorption of NH3 and CO_(2)with quadrupole mass spectrometry as detector(NH3-TPD-QMS and CO_(2)-TPD-QMS).We found that the catalytic performance(GC formation rate)is strictly linearly dependent on the density of basic sites,which is relevant to the adsorption and activation of CO_(2).In addition,to illustrate a more microscopic reaction mechanisms underlying the formation of GC from CO_(2)and glycerol on all three low-index surfaces(111),(110)and(100),we also performed comprehensive first principles calculations.A three-step Langmuir-Hinshelwood(LH)mechanism was identified in which the annulation reaction is the rate-limiting step.The CeO_(2)(11)surface exhibits the lowest overall activation energy,which agrees well with the catalytic performance that the CeO_(2)nano-octahedra,predominantly exposing(111)facets,have the highest GC formation rate.This work is the first to combine experiments on shaped CeO_(2)model catalysts with first-principles calculations to gain insight into the mechanism of direct synthesis of GC from CO_(2)and glycerol,and will aid in the development of catalysts with improved performance.

基于改进大脑情感学习模型的车辆纵向跟随

为提高无人驾驶车辆纵向跟随控制算法的安全性,在大脑情感学习模型的基础上,删除了情感暗示信号,并结合径向基神经网络良好的非线性逼近特性,提出了一种间接自适应脑情绪神经鲁棒控制器(iARBERC)和一种证明该控制系统稳定性的Lyapunov分析方法。将其运用到单级倒立摆仿真中,并与径向基神经网络、ARBENC进行数值比较,仿真结果表明:iARBERC具有最快的响应速度、最小的跟踪误差和最优的鲁棒性能,虽然总控制能量有所提高,但偏差在4%以内。最后,将iARBERC应用到无人驾驶车辆跟随控制系统半物理仿真台架中,结果表明,搭载iARBERC的车辆对频繁变化的纵向速度有较好的跟随能力。