Müller cells are activated in response to retinal outer nuclear layer degeneration in rats subjected to simulated weightlessness conditions

A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.

Correlation between heart rate variability and pupillary reflex in healthy adult subjects under the influence of alcohol

This study explored the association between pupil area variation, heart rate variability, and fatigue, caused by alcohol consumption. Sixteen healthy young male volunteers were enrolled in this study for a series of structured physical examinations. Individual drinking volume was strictly assessed in accordance with the normalized experimental design. The motions of the subjects＇ pupils, as well as electrocardiograms were recorded by a computerized recording system, both before and after drinking alcohol. After alcohol intake, the pupil diameter, and both low frequency and standard deviation of all heartbeat interval indices of heart rate variability showed significant variations compared with the baseline. In addition, time- and frequency-domain indices of heart rate variability were negatively associated with pupil area. Thus the current study suggests that fatigue status may be determined by significant changes in pupil area and heart rate variability.

Visual electrophysiological examination in diagnosis of hepatic encephalopathy

Clinical observation of the neuropsychiatric condition, psychometric tests, and EEG recordings has been used to diagnose hepatic encephalopathy. However, no standardization for the diagnosis of minimal hepatic encephalopathy (MHE) has been achieved. According to the study in normal subjects, visual electrophysiology testing is a method of simple, objective record for the medical examination, which includes visual evoked potentials (VEP), electroretinograms (ERG), etc. 23 hepatic encephalopathy patients prospectively underwent visual electrophysiology testing and laboratory serum analysis, and it was found that 22 visual electrophysiology abnormalities which showed that the amplitudes were decreased and the implicit times were prolonged compared with the normal. The relationship between biochemical parameters and visual electrophysiology parameters showed that visual recording was related to the damage of the liver. On the basis of this preliminary study, we could conclude that this method can be as a way to predict for hepatic encephalopathy and it appears to be a method in the recognition of the MHE.

Uncovering the CO_(2)emissions of vehicles:A well-to-wheel approach

Carbon dioxide(CO_(2))from road traffic is a non-negligible part of global greenhouse gas(GHG)emissions,and it is a challenge for the world today to accurately estimate road traffic CO_(2)emissions and formulate effective emission reduction policies.Current emission inventories for vehicles have either low-resolution,or limited coverage,and they have not adequately focused on the CO_(2)emission produced by new energy vehicles(NEV)considering fuel life cycle.To fill the research gap,this paper proposed a framework of a high-resolution well-to-wheel(WTW)CO_(2)emission estimation for a full sample of vehicles and revealed the unique CO_(2)emission characteristics of different categories of vehicles combined with vehicle behavior.Based on this,the spatiotemporal characteristics and influencing factors of CO_(2)emissions were analyzed with the geographical and temporal weighted regression(GTWR)model.Finally,the CO_(2)emissions of vehicles under different scenarios are simulated to support the formulation of emission reduction policies.The results show that the distribution of vehicle CO_(2)emissions shows obvious heterogeneity in time,space,and vehicle category.By simply adjusting the existing NEV promotion policy,the emission reduction effect can be improved by 6.5%-13.5%under the same NEV penetration.If combined with changes in power generation structure,it can further release the emission reduction potential of NEVs,which can reduce the current CO_(2)emissions by 78.1%in the optimal scenario.

Switch of substrate specificity of hyperthermophilic acylaminoacyl peptidase by combination of protein and solvent engineering

The inherent evolvability of promiscuous enzymes endows them with great potential to be artificially evolved for novel functions.Previously,we succeeded in transforming a promiscuous acylaminoacyl peptidase(apAAP)from the hyperthermophilic archaeon Aeropyrum pernix K1 into a specific carboxylesterase by making a single mutation.In order to fulfill the urgent requirement of thermostable lipolytic enzymes,in this paper we describe how the substrate preference of apAAP can be further changed from p-nitrophenyl caprylate(pNP-C8)to p-nitrophenyl laurate(pNP-C12)by protein and solvent engineering.After one round of directed evolution and subsequent saturation mutagenesis at selected residues in the active site,three variants with enhanced activity towards pNP-C12 were identified.Additionally,a combined mutant W474V/F488G/R526V/T560W was generated,which had the highest catalytic efficiency(kcat/Km)for pNP-C12,about 71-fold higher than the wild type.Its activity was further increased by solvent engineering,resulting in an activity enhancement of 280-fold compared with the wild type in the presence of 30%DMSO.The structural basis for the improved activity was studied by substrate docking and molecular dynamics simulation.It was revealed that W474V and F488G mutations caused a significant change in the geometry of the active center,which may facilitate binding and subsequent hydrolysis of bulky substrates.In conclusion,the combination of protein and solvent engineering may be an effective approach to improve the activities of promiscuous enzymes and could be used to create naturally rare hyperthermophilic enzymes.

The effects of parental relationships,and gender and grade differences on depressive disorder in Chinese adolescents:the evidence from multiple cross-sectional surveys(1999-2016)

This study aims to investigate the impacts of parental relationships,gender,and grade differences on depressive disorder among Chinese adolescents over a time period of nearly 20 years.The first survey took place in 1999 and involved 852 stu-dents;subsequent follow-up surveys took place in 2006,2009 and 2016,with 3345 students involved in total.Depressive disorder was measured by SCL-90-R(Chi-nese version).The surveys also collected social-demographic information about the respondents.Three indicators of parental relationships were examined-parental quarrels,parental disharmony and parental divorce.The results show that gender was significantly associated with adolescents’depressive disorder and that there was a higher prevalence of depressive disorder among senior middle school students than among junior middle school students,except in 1999.Troubled parental rela-tionships were associated with high risks of depressive disorder.Coefficients and 95%CI were adjusted for the survey years(1999,2006,2009,2016),school grades(junior or senior middle school students),gender(girls/boys),parental quarrels(yes/no),parental disharmony(yes/no),and parental divorce(yes/no).Logistic regres-sion indicated that parental divorce and gender were the two strongest predictors of the presence of depressive disorder.In summary,there was a higher prevalence of depressive disorder among girls and senior middle school students.Adolescents are vulnerable to depressive disorder in cases of parental divorce.Therefore,good parental relationships may be considered an important and necessary factor that affects the susceptibility of Chinese adolescents to depressive disorder.