产前应激对发育海马神经元及其超微结构的影响

目的 :观察产前应激 (PS)对子鼠海马神经元和神经元超微结构是否有损伤作用 ,以及这种损伤是否与氧化物的过度生成有关。方法 :采用束缚应激模型 ,观察出生后 1个月雄性子鼠的海马神经元数量、神经元超微结构及神经型一氧化氮合酶 (nNOS)表达的变化。结果 :晚期应激 (LS)引起子鼠海马CA1和CA4区的细胞数量明显减少 ;电镜可见PS使子鼠海马CA1区神经元超微结构发生改变 ,表现为线粒体肿大、边界不清、电子密度不均 ,脂褐素增多 ,偶见核变形 ;中期应激 (MS)使子鼠海马CA1、CA2、CA3区和DG内nNOS阳性表达量显著升高 ,LS使子鼠海马CA1、CA2、CA3、CA4区和DG内nNOS阳性表达量也显著升高。结论 :结果提示 ,PS对子鼠海马神经元及神经元超微结构有损伤作用 ,这种损伤可能由氧化物过度生成引起。

Intelligent Building Load Scheduling Based on Multi-Objective Multi-Verse Algorithm

In the multi-objective of intelligent building load scheduling, aiming at the problem of how to select Pareto frontier scheme for multi-objective optimization algorithm, the current optimal scheme mechanism combined with multi-objective multi-verse algorithm is used to optimize the intelligent building load scheduling. The update mechanism is changed in updating the position of the universe, and the process of correction coding is omitted in the iterative process of the algorithm, which reduces the com-putational complexity. The feasibility and effectiveness of the proposed method are verified by the optimal scheduling experiments of residential loads.

Exercise promotes angiogenesis by enhancing endothelial cell fatty acid utilization via liver-derived extracellular vesicle miR-122-5p

Background:Angiogenesis constitutes a major mechanism responsible for exercise-induced beneficial effects.Our previous study identified a cluster of differentially expressed extracellular vesicle microRNAs(miRNAs)after exercise and found that some of them act as exerkines.However,whether these extracellular vesicle miRNAs mediate the exercise-induced angiogenesis remains unknown.Methods:A 9-day treadmill training was used as an exercise model in C57BL/6 mice.Liver-specific adeno-associated virus 8 was used to knock down microRNA-122-5p(miR-122-5p).Human umbilical vein endothelial cells were used in vitro.Results:Among these differentially expressed extracellular vesicle miRNAs,miR-122-5p was identified as a potent pro-angiogenic factor that activated vascular endothelial growth factor signaling and promoted angiogenesis both in vivo and in vitro.Exercise increased circulating levels of miR-122-5p,which was produced mainly by the liver and shuttled by extracellular vesicles in mice.Inhibition of circulating miR-122-5p or liver-specific knockdown of miR-122-5p significantly abolished the exercise-induced pro-angiogenic effect in skeletal muscles,and exerciseimproved muscle performance in mice.Mechanistically,miR-122-5p promoted angiogenesis through shifting substrate preference to fatty acids in endothelial cells,and miR-122-5p upregulated endothelial cell fatty-acid utilization by targeting 1-acyl-sn-glycerol-3-phosphate acyltransferase(AGPAT1).In addition,miR-122-5p increased capillary density in perilesional skin tissues and accelerated wound healing in mice.Conclusion:These findings demonstrated that exercise promotes angiogenesis through upregulation of liver-derived extracellular vesicle miR-122-5p,which enhances fatty acid utilization by targeting AGPAT1 in endothelial cells,highlighting the therapeutic potential of miR-122-5p in tissue repair.

Effect of Hole Density and Confining Pressure on Mechanical Behavior of Porous Specimens:An Insight from Discrete Element Modeling

Hole-like defects are very common in natural rock or coal mass,and play an important role in the failure and mechanical behaviors of rock or coal mass.In this research,multi-holed coal specimens are constructed numerically and calibrated based on UDEC-GBM models.Then,the strength,deformation and failure behavior of the porous specimens are analyzed,with consideration of hole density(P)and confining pressure(σ_(3)).The simulation results are highly consistent with those available experiment results,and show that the compressive strength decreases exponentially with the increasing hole density.The strength loss is mainly caused by the reduction of cohesion when P<P_(cr)(critical hole density)and the reduction of frictional angle when P>P_(cr).Also,the increasing hole density linearly reduces the tangent and secant modulus and causes greater nonlinear deformation of multi-holed specimens.Finally,the failure patterns,coalescence mechanism and damage behavior of the multi-holed specimens are revealed based on the analysis of mesoscopic displacement fields and stress distribution around holes.This research promotes a better understanding of the effects of hole density and confining pressure on the failure and mechanical behavior of porous geomaterials.

Temperature stress analysis for bi-modulus beam placed on Winkler foundation

The materials with different moduli in tension and compression are called bi-modulus materials. Graphene is such a kind of materials with the highest strength and the thinnest thickness. In this paper, the mechanical response of the bi-modulus beam subjected to the temperature effect and placed on the Winkler foundation is studied. The differential equations about the neutral axis position and undetermined parameters of the normal strain of the bi-modulus foundation beam are established. Then, the analytical expressions of the normal stress, bending moment, and displacement of the foundation beam are derived. Simultaneously, a calculation procedure based on the finite element method （FEM） is developed to obtain the temperature stress of the bi-modulus struc- tures. It is shown that the obtained bi-modulus solutions can recover the classical modulus solution, and the results obtained by the analytical expressions, the present FEM proce- dure, and the traditional FEM software are consistent, which verifies the accuracy and reliability of the present analytical model and procedure. Finally, the difference between the bi-modulus results and the classical same modulus results is discussed, and several reasonable suggestions for calculating and optimizing the certain bi-modulus member in practical engineering are presented.

Sexual differences of the effects of prenatal stress on the expression of extracellular signal-regulated kinaseas in the hippocampus of offspring rats

BACKGROUND： Prenatal stress has been shown to inhibit cell proliferation in the dentate gyrus and hippocampus, reduce hippocampal volume, and cause neuronal loss and oxidative damage in the hippocampus of offspring rats, but the sexual difference of the effects on offsprings is seldom referred to. OBJECTIVE： To observe the effect of prenatal stress to adult pregnant rats on expression of extracellular signal-regulated kinases （ERK） in hippocampus of the offspring rats of different genders. DESIGN ： A randomized and control animal experiment.SETTING： Department of Physiology and Pathophysiology, School of Medicine, Xi＇an Jiaotong University. MATERIALS ： The experiments were carried out in the Key Laboratory of Environment and Gene Related Diseases （Xi＇an Jiaotong University）, Ministry of Education between October 2005 and March 2006. Fifteen female and five male adult Sprague-Dawley rats were adopted. Female rats weighing 230-250 g and male rats weighing 280-350 g were used. METHODS： The virgin female rats were placed overnight with adult male rats （3：1） for mating. A total of twelve pregnant rats were randomly assigned to prenatal stress group （PNS group, n=6） and control group （n=6）. The pregnant rats of the PNS group were exposed to restraint stress on days 14-20 of pregnancy three times a day, 45 minutes for each time . The restraint device was a transparent plastic tube （6.8 cm in diameter） with air holes for breathing and closed end. The length could be adjusted to accommodate the size of the animals. To prevent habituation of animals to the daily procedure, restraint periods were randomly shifted within certain time periods （8：00-11：00, 11：00-14：00, and 16：00-19：00）. After birth, offsprings of all groups were culled to 8-10 litters in each group and housed in the same animal room, and kept together with their biologic mothers. The pregnant rats of the control group were left undisturbed. On day 21, after all the offspring were weaned, male and female pups were separated and housed four in each cage respectively until test at 30 days of age. At the end of postnatal day 30, one male and female offspring rats from the same dam were selected with a random choice and a total of 24 animals from 12 different dams were used. The experimental rats were sacrificed by decapitation under anesthesia. Bilateral hippocampal tissues were isolated and homogenized in cold condition. Alkaline carbonate buffer （BCA） method was used to detect the concentration of extracellular signal-regulated kinases （ERK）, then mixed with loading buffer, the constant voltage was 100 V. Finally, BCIP/NBT staining and electrDphoresis were performed, the absorbance （A） value for the bands was detected with the Bandscan analytical software, and the expression of ERK in hippocampus of offspring rats of different genders in each group was quantitatively analyzed. MAIN OUTCOME MEASURES： The level of ERK expression in hippocampus of offspring rats of different genders in each group was observed.RESULTS： All the 24 offspring rats were involved in the analysis of results. ① The staining results of ERP activity in the extract of brain tissue detected with Western blotting technique and specific antibody analysis showed that the ERP in hippocampus of offspring rats had two subtypes of ERK-1 and ERK-2, and the latter was the main type.② Standardized by the average A value in the control group, the quantitative data of the general A value of total ERK showed that the expression of ERK-2 in hippocampus of female offspring rats was obviously higher in the PNS group than in the control group （A value： 126±6.76,100±4.89,P〈 0.01）. ③The expression of ERK-2 had no obvious difference between the female and male offspring rats in the control group.④ The expression of ERK-2 in hippocampus of male offspring rats was a little higher in the PNS group than in the control group （A value： 104±6.27,102±5.48,P 〉 0.05）. CONCLUSION ： PNS significantly affects the increase of ERK expression in hippocampus of female offspring rats, but has no obvious influence on that of male ones.

Safety of high-carbohydrate fluid diet 2 h versus overnight fasting before non-emergency endoscopic retrograde cholangiopancreatography:A single-blind,multicenter,randomized controlled trial

Background:Although overnight fasting is recommended prior to endoscopic retrograde cholangiopancreatography(ERCP),the benefits and safety of high-carbohydrate fluid diet(CFD)intake 2 h before ERCP remain unclear.This study aimed to analyze whether high-CFD intake 2 h before ERCP can be safe and accelerate patients’recovery.Methods:This prospective,multicenter,randomized controlled trial involved 15 tertiary ERCP centers.A total of 1330 patients were randomized into CFD group(n=665)and fasting group(n=665).The CFD group received 400 mL of maltodextrin orally 2 h before ERCP,while the control group abstained from food/water overnight(>6 h)before ERCP.All ERCP procedures were performed using deep sedation with intravenous propofol.The investigators were blinded but not the patients.The primary outcomes included postoperative fatigue and abdominal pain score,and the secondary outcomes included complications and changes in metabolic indicators.The outcomes were analyzed according to a modified intention-to-treat principle.Results:The post-ERCP fatigue scores were significantly lower at 4 h(4.1±2.6 vs.4.8±2.8,t=4.23,P<0.001)and 20 h(2.4±2.1 vs.3.4±2.4,t=7.94,P<0.001)in the CFD group,with least-squares mean differences of 0.48(95%confidence interval[CI]:0.26-0.71,P<0.001)and 0.76(95%CI:0.57-0.95,P<0.001),respectively.The 4-h pain scores(2.1±1.7 vs.2.2±1.7,t=2.60,P=0.009,with a least-squares mean difference of 0.21[95%CI:0.05-0.37])and positive urine ketone levels(7.7%[39/509]vs.15.4%[82/533],χ^(2)=15.13,P<0.001)were lower in the CFD group.The CFD group had significantly less cholangitis(2.1%[13/634]vs.4.0%[26/658],χ^(2)=3.99,P=0.046)but not pancreatitis(5.5%[35/634]vs.6.5%[43/658],χ^(2)=0.59,P=0.444).Subgroup analysis revealed that CFD reduced the incidence of complications in patients with native papilla(odds ratio[OR]:0.61,95%CI:0.39-0.95,P=0.028)in the multivariable models.Conclusion:Ingesting 400 mL of CFD 2 h before ERCP is safe,with a reduction in post-ERCP fatigue,abdominal pain,and cholangitis during recovery.Trail Registration:ClinicalTrials.gov,No.NCT03075280.

A regime-switching stochastic SIR epidemic model with a saturated incidence and limited medical resources

The stochastic switching SIR epidemic model with saturated incidence and limited medical treatment is investigated in this paper.By using Lyapunov methods and Ito formula,we first prove that the system has a unique global positive solution with any positive initial value.Then combining inequality technique and the ergodic property of Markov switching,the suficient conditions for extinction and persistence in the mean of the disease are established.The results demonstrate that increasing medical resources and improving supply efficiency can accelerate the transition from the persistent state to the extinct state.Meanwhile,the high incidence rate will slow down the extinction of the disease.Specially,the switching noise can induce the system to toggle between the extinct and persistent states.Finally,some numerical simulations are carried out to confirm the analytical results.

带有黏性阻尼的波动方程的一致指数镇定和状态重构

通过有限时间的输出观测信息,以向前-向后观测器为基础的时间反转法可以用于无穷维能量守恒系统的状态重构.本文利用Lyapunov函数法将上述结果推广到具有一般黏性和边界观测的一维波动方程,给出上述方法的数值逼近格式和收敛于初值的迭代序列.对于任何初始猜想值,迭代序列都强收敛到初值,进而实现状态重构的数值逼近.其中在状态重构的数值逼近的时间反转法中,离散系统和向前观测系统的误差系统的一致指数稳定性(关于离散步长)具有重要作用,因而先讨论相关系统的一致指数稳定性.本文通过将port-Hamilton理论和有限差分格式相结合,得到一种降阶型差分格式,利用与连续系统同样的验证方法得到离散系统的一致指数稳定性.

The COVID-19 pandemic and physical activity

The SARS-CoV-2-caused COVID-19 pandemic has resulted in a devastating threat to human society in terms of health,economy,and lifestyle.Although the virus usually first invades and infects the lung and respiratory track tissue,in extreme cases,almost all major organs in the body are now known to be negatively impacted often leading to severe systemic failure in some people.Unfortunately,there is currently no effective treatment for this disease.Pre-existing pathological conditions or comorbidities such as age are a major reason for premature death and increased morbidity and mortality.The immobilization due to hospitalization and bed rest and the physical inactivity due to sustained quarantine and social distancing can downregulate the ability of organs systems to resist to viral infection and increase the risk of damage to the immune,respiratory,cardiovascular,musculoskeletal systems and the brain.The cellular mechanisms and danger of this“second wave”effect of COVID-19 to the human body,along with the effects of aging,proper nutrition,and regular physical activity,are reviewed in this article.

Seasonal variation and longitudinal distribution of copepods in the main river area of the Three Gorges Reservoir

The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake(reservoir)ecosystem after impoundment in June 2003.We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem.From Jiangjin to Maoping,eight copepod species were collected and classified into Calanoida(2),Harpacticoida(1),and Cyclopoida(5).Among them,Mesocyclops pehpeiensis,M.leuckarti and Sinocalanus dorrii had a relatively wide distribution.No distinct difference in species number was found among the sampling sites,but the species composition was different.Species composition,distribution and density of copepods showed significant seasonal variations.In addition,copepod density showed an obvious gradient with the distance from the reservoir dam:the nearer to the dam,the denser the copepods.