Performance of the CENDL-3.2 and other major neutron data libraries for criticality calculations

Nuclear data are the cornerstones of reactor physics and shielding calculations.Recently,China released CENDL-3.2 in 2020,and the US released ENDF/B-VIII.0 in 2018.Therefore,it is necessary to comprehensively evaluate the criticality computing performance of these newly released evaluated nuclear libraries.In this study,we used the NJOY2016 code to generate ACE format libraries based on the latest neutron data libraries(including CENDL-3.2,JEFF3.3,ENDF/B-VIII.0,and JENDL4.0).The MCNP code was used to conduct a detailed analysis of fission nuclides,including^(235)U,^(233)U,and^(239)Pu,in different evaluated nuclear data libraries based on 100 benchmarks.The criticality calculation performance of each library was evaluated using three statistical parameters:δk/σ,χ^(2),and<|Δ|>.Analysis of theδk/σparameter showed that CENDL-3.1 and JENDL-4.0 both had>10 benchmarks that exceeded 3r,whereas CENDL3.2,ENDFB-VIII.0,and JEFF-3.3 had,7,5,and 4 benchmarks,respectively,exceeding 3r.The ENDF/B-VII.1 library performed best,with only two benchmarks exceeding 3r.Compared to CENDL-3.1,CENDL-3.2 offers an improvement in criticality calculations.Compared to the JEFF-3.3 and ENDF/B-VIII.0 libraries,CENDL3.2 performs better in the calculation of the^(233)U assemblies,but it performs poorly in the pusl11 series case calculation of the^(239)Pu assemblies,and thus further improvement is needed.

Recurrent Seizures Manifestations in a Case of Congenital Hypoparathyroidism:a Case Report

HYPOPARATHYROIDISM is characterized by hypocalcemia, hyperphosphatemia and low or inappropriately normal levels of parathyroid hormone （PTH）. PTH is a key calcium regulatinghormone essential for calcium homeostasis, vitamin D-dependent calcium absorption, renal calcium reabsorption and renal phosphate clearance. Hypoparathyroidism may be due to congenital or acquired disorders. Causes include autoimmune diseases, genetic abnormalities, destruction or infiltrative disorders of the parathyroid glands.

The Role of Ozone Depletion in the Lack of Cooling in the Antarctic Upper Stratosphere during Austral Winter

Temperature trends in the upper stratosphere are investigated using satellite measurements from Stratospheric Sounding Unit(SSU)outputs and simulations from chemistry-climate models(CCMs)and the Coupled Model Intercomparison Project Phase 6(CMIP6).Observational evidence shows a lack of cooling in the Antarctic,in contrast to strong cooling at other latitudes,during austral winter over 1979-97.Analysis of CCM simulations for a longer period of1961-97 also shows a significant contrast in the upper stratospheric temperature trends between the Antarctic and lower latitudes.Results from two sets of model integrations with fixed ozone-depleting substances(ODSs)and fixed greenhouse gases(GHGs)at their 1960 levels suggest that the ODSs have made a major contribution to the lack of cooling in the Antarctic upper stratosphere.Results from CMIP6 simulations with prescribed GHGs and ozone confirm that changes in the dynamical processes associated with observed ozone depletion are largely responsible for the lack of cooling in the Antarctic upper stratosphere.The lack of cooling is found to be dynamically induced through increased upward wave activity into the upper stratosphere,which is attributed mainly to ODSs forcing.Specifically,the radiative cooling caused by the ozone depletion results in a stronger meridional temperature gradient between middle and high latitudes in the upper stratosphere,allowing more planetary waves propagating upward to warm the Antarctic upper stratosphere.These findings improve our understanding of the chemistry-climate coupling in the southern upper stratosphere.

Effect of autaptic delay signal on spike-timing precision of single neuron

Experimental and theoretical studies have reported that the precise firing of neurons is crucial for sensory representation.Autapse serves as a special synapse connecting neuron and itself,which has also been found to improve the accuracy of neuronal response.In current work,the effect of autaptic delay signal on the spike-timing precision is investigated on a single autaptic Hodgkin–Huxley neuron in the present of noise.The simulation results show that both excitatory and inhibitory autaptic signals can effectively adjust the precise spike time of neurons with noise by choosing the appropriate coupling strength g and time delay of autaptic signalτ.The g–τparameter space is divided into two regions:one is the region where the spike-timing precision is effectively regulated;the other is the region where the neuronal firing is almost not regulated.For the excitatory and inhibitory autapse,the range of parameters causing the accuracy of neuronal firing is different.Moreover,it is also found that the mechanisms of the spike-timing precision regulation are different for the two kinds of autaptic signals.

Effect of temperature on tribofilm growth and the lubrication of the piston ring-cylinder liner system in two-stroke marine engines

This study is an optimized extension based on the authors’previous research on the tribo-chemical reaction under constant temperature field of two-stroke internal combustion engines(ICEs).It establishes a coupled analysis model that considers the tribo-chemical reactions,dynamic contact,and interface lubrication of the piston ring-cylinder liner(PRCL)system under transient temperature conditions.In this study,for the first time,the prediction of the tribofilm thickness and its influence on the surface micro-topography(the comprehensive roughness)are coupled in the working temperature field of the PRCL system,forming an effective model framework and providing a model basis and analytical basis for subsequent research.This study findings reveal that by incorporating temperature and tribofilm into the simulation model,the average friction deviation throughout the stroke decreases from 8.92%to 0.93%when compared to experimental results.Moreover,the deviation during the combustion regime reduces from 39.56%to 7.34%.The proposed coupled model provides a valuable tool for the evaluation of lubrication performance of the PRCL system and supports the analysis software forward design in two-stroke ICEs.

公共服务参与会增加个体的获得感吗?——基于政府透明度与信任的调节作用分析

从自我决定理论和需求层次理论的视角来看,个体在公共服务供给过程中的参与表现是其获得感提升的重要影响因素,但二者的关系机制会受到哪些条件的影响呢?通过来自3个省、40个社区(村)的1944份实证数据,论文分析了公共服务参与对个体获得感的影响机制及边界条件,并特别关注了政府透明度和政府信任在其中的调节作用。结果显示:在公共服务参与对个体获得感提升的正向影响中,政府透明度和政府信任分别表现出显著的调节作用和高阶调节作用。具体来看,只有当政府具有较高的透明度时,个体的公共服务参与才会对其获得感表现出显著的正向影响;而当个体对政府信任和政府透明度的评价水平都比较低时,其公共服务参与对获得感的影响作用将不再显著。论文聚焦于公共服务供给的参与环节,拓展了个体获得感提升的研究视角,对把握政民互动情境中的获得感提升路径、营建共建共治共享的现代化治理格局具有实践启示。

村社认同如何影响政治信任?——公民参与和个人传统性的作用

【问题】政治信任是支撑政治系统运行的重要心理基础,对推进政民良性互动、提升公众的政府支持具有重要意义。村、社区是公众的社会生活共同体和国家治理的基本单元,人们对村社的认同如何转化为对政治系统的信任以及此过程受到何种条件的影响,这将是本研究尝试探究的问题。【方法】论文基于95个行政村和城镇社区的5040份有效数据,将村社认同作为高层级变量,运用多水平结构方程模型和贝叶斯可信区间估计,对所提出的跨层级的“有调节的中介模型”进行检验。【发现】村社认同对个体的政治信任水平具有显著的正向预测作用,且公民参与在二者关系中具有部分中介作用。同时,个人传统性不仅在村社认同和公民参与关系中具有显著的负向影响,也能进一步调节村社认同与政治信任的间接关系。具体来看,在不同水平的个人传统性下,村社认同差异通过公民参与对政治信任影响的间接效应表现出来。【贡献】论文从政治心理学的视角出发,揭示了“村社认同→公民参与→政治信任”这一中介作用路径,并进一步分析了个体传统性变量对上述影响机制作用发挥的边界效应,为理解和分析本土情境下公众的政治信任发生机制提供了可鉴路径,对激发公民参与、提升政治信任和推动基层治理转型的治理实践具有启示。

A comprehensive review of bioactive compounds and processing technology of sesame seed

Sesame seeds are promulgated as traditional high-quality edible oil crops,rich in lipid(40–65%),protein(19–35%),and bioactive compounds.The review starts with bioactive components(fatty acid,tocopherol,phytosterol,sesamin,sesamolin,and sesamol)of sesame seeds.It considers processing techniques for extracting oil(aqueous extraction and pressing)from seeds.Novel technologies,such as enzyme-assisted aqueous,supercritical CO_(2),and microwave-assisted solvent extraction,are also discussed.The methods of utilization of sesame seed cake are also analyzed.In the future,the processing technology of sesame seed will be further developed in the direction of improving comprehensive utilization rate to meet new consumption demand.

Effects of preoperative trimetazidine application on myocardial injury indexes and oxidative stress indexes in patients with AMI after PCI

Objective:To investigate the effects of preoperative trimetazidine application on myocardial injury indexes and oxidative stress indexes in patients with AMI after PCI.Methods:A total of 70 patients with AMI who received emergency PCI in this hospital between January 2015 and January 2018 were divided into the control group (n=35) (received no trimetazidine) and the trimetazidine group (n=35) (received trimetazidine) according to the application of trimetazidine before PCI or not. The differences in the contents of myocardial injury markers, inflammatory factors and oxidative stress indexes were compared between the two groups immediately after admission and after surgery.Results: Immediately after admission, the differences in serum levels of myocardial injury markers, inflammatory factors and oxidative stress indexes were not statistically significant between the two groups of patients. Twenty-four hours after surgery, serum myocardial injury markers CK-MB, cTnⅠ, Myo and h-FABP levels of trimetazidine group were lower than those of control group;inflammatory factors hs-CRP, Neopterin and IL-1β levels were lower than those of control group;oxidative stress index SOD level was higher than that of control group whereas MDA and LHP levels were was lower than those of control group.Conclusion: Trimetazidine treatment before PCI can effectively optimize the postoperative cardiac function and reduce the oxidative stress response in patients with AMI.

Transformation:how do nematode sperm become activated and crawl?

Nematode sperm undergo a drastic physiological change during spermiogenesis(sperm activation).Unlike mammalian flagellated sperm,nematode sperm are amoeboid cells and their motility is driven by the dynamics of a cytoskeleton composed of major sperm protein(MSP)rather than actin found in other crawling cells.This review focuses on sperm from Caenorhabditis elegans and Ascaris suum to address the roles of external and internal factors that trigger sperm activation and power sperm motility.Nematode sperm can be activated in vitro by several factors,including Pronase and ionophores,and in vivo through the TRY-5 and SPE-8 pathways.Moreover,protease and protease inhibitors are crucial regulators of sperm maturation.MSP-based sperm motility involves a coupled process of protrusion and retraction,both of which have been reconstituted in vitro.Sperm motility is mediated by phosphorylation signals,as illustrated by identification of several key components(MPOP,MFPs and MPAK)in Ascaris and the characterization of GSP-3/4 in C.elegans.

Modulation of Beta Oscillations for Implicit Motor Timing in Primate Sensorimotor Cortex during Movement Preparation

Motor timing is an important part of sensorimotor control. Previous studies have shown that beta oscillations embody the process of temporal perception in explicit timing tasks. In contrast, studies focusing on beta oscillations in implicit timing tasks are lacking. In this study, we set up an implicit motor timing task and found a modulation pattern of beta oscillations with temporal perception during movement preparation. We trained two macaques in a repetitive visually-guided reach-to-grasp task with different holding intervals. Spikes and local field potentials were recorded from microelectrode arrays in the primary motor cortex, primary somatosensory cortex, and posterior parietal cortex. We analyzed the association between beta oscillations and temporal interval in fixedduration experiments(500 ms as the Short Group and1500 ms as the Long Group) and random-duration experiments(500 ms to 1500 ms). The results showed that the peak beta frequencies in both experiments ranged from15 Hz to 25 Hz. The beta power was higher during the hold period than the movement(reach and grasp) period.Further, in the fixed-duration experiments, the mean poweras well as the maximum rate of change of beta power in the first 300 ms were higher in the Short Group than in the Long Group when aligned with the Center Hit event. In contrast, in the random-duration experiments, the corresponding values showed no statistical differences among groups. The peak latency of beta power was shorter in the Short Group than in the Long Group in the fixed-duration experiments, while no consistent modulation pattern was found in the random-duration experiments. These results indicate that beta oscillations can modulate with temporal interval in their power mode. The synchronization period of beta power could reflect the cognitive set maintaining working memory of the temporal structure and attention.

Microstructural Depictions of Austenite Dynamic Recrystallization in a Low-Carbon Steel:A Cellular Automaton Model

A mesoscopic cellular automaton model that takes into account grain deformation during hot deformation has been developed to quantitatively depict the microstructural evolution of the austenite dynamic recrystallization （DRX） in a low-carbon steel. Both the grain deformation and the concept of DRX cycle are introduced, allowing accurate depictions of the grain structures, the overall microstructural properties and the flow stress evolutions that involving in the austenite DRX. The simulation results are compared with the experimental results and the predictions by the macroscopic DRX model and are found to be in good agreement.

Neurons in Primary Motor Cortex Encode Hand Orientation in a Reach-to-Grasp Task

It is disputed whether those neurons in the primary motor cortex（M1） that encode hand orientation constitute an independent channel for orientation control in reach-to-grasp behaviors. Here, we trained two monkeys to reach forward and grasp objects positioned in the frontal plane at different orientation angles, and simultaneously recorded the activity of M1 neurons. Among the 2235 neurons recorded in M1, we found that 18.7% had a high correlation exclusively with hand orientation, 15.9% with movement direction, and 29.5% with both movement direction and hand orientation. The distributions of neurons encoding hand orientation and those encoding movement direction were not uniform but coexisted in the same region. The trajectory of hand rotation was reproduced by the firing patterns of the orientation-related neurons independent of the hand reaching direction. These resultssuggest that hand orientation is an independent component for the control of reaching and grasping activity.

Pyridoxal 5'-phosphate alleviates prenatal pyridaben exposureinduced anxiety-like behaviors in offspring

Pyridaben(PY)is a widely used organochlorine acaricide,which can be detected in the peripheral blood of pregnant women.Available evidence suggests that PY has reproductive toxicity.However,it remains uncertain whether prenatal PY exposure impacts neurobehavioral development in offspring.Here,we administered PY to pregnant mice at a dose of 0.5 and 5 mg kg^(-1)day^(-1)via gavage and observed anxietylike behaviors in PY offspring aged five weeks.We then integrated the metabolome and transcriptome of the offspring's brain to explore the underlying mechanism.Metabolome data indicated that the vitamin B6 metabolism pathway was significantly affected,and the pyridoxal 50-phosphate(PLP)concentration and the active form of vitamin B6 was significantly reduced.Moreover,the transcriptome data showed that both PLP generation-related Pdxk and anxiety-related Gad1 were significantly down-regulated.Meanwhile,there was a decreasing trend in the concentration of GABA in the hippocampal DG region.Next,we supplemented PLP at a dose of 20 mg kg^(-1)day^(-1)to the PY offspring via intraperitoneal injection at three weeks.We found up-regulated expression of Pdxk and Gad1 and restored anxiety-like behaviors.This study suggests that prenatal exposure to PY can disrupt vitamin B6 metabolism,reduce the concentration of PLP,down-regulate the expression levels of Pdxk and Gad1,inhibit the production of GABA,and ultimately lead to anxiety-like behaviors in offspring.

An enhanced network of energy metabolism,lysine acetylation,and growth-promoting protein accumulation is associated with heterosis in elite hybrid rice

Heterosis refers to the superior performance of a hybrid compared with its parental lines.Although several genetic and molecular models have been proposed to explain heterosis,it remains unclear how hybrid cells integrate complementary gene expression or activity to drive heterotic growth.In this work,we show that accumulation of growth-promoting and energy metabolism proteins,enhanced energy metabolism activities,and increased protein lysine acetylation were associated with superior growth of the panicle meristem in the elite hybrid rice Shanyou 63 relative to its parental varieties.Metabolism of nuclear/cytosolic acetylcoenzyme A was also enhanced in the hybrid,which paralleled increases in histone H3 acetylation to selectively target the expression of growth-promoting and metabolic genes.Lysine acetylation of cellular proteins,including TARGET OF RAPAMYCIN complex 1,ribosomal proteins,and energy metabolism enzymes,was also augmented and/or remodeled to modulate their activities.The data indicate that an enhanced network of energy-producing metabolic activity and growth-promoting histone acetylation/gene expression in the hybrid could contribute to its superior growth rate and may constitute a model to explain heterosis.

心血管磁共振分子影像研究现状与进展

在心血管影像发展中,磁共振多模态成像技术具备在体评估心肌组织学特征的优势,有较高的临床应用价值,其"一站式"成像在心血管疾病诊断、鉴别诊断以及预后判断和危险分层中发挥了重要作用,其在分子影像学领域也在不断发展。该文从动脉粥样硬化、心肌梗死、干细胞疗法3个方面介绍磁共振分子探针及其成像技术的应用。

Ordovician integrative stratigraphy and timescale of China

In this chapter, starting with a brief review of the research history and current status in the studies of the Ordovician chronostratigraphy in China, the subdivision of the Ordovician System, definition and recognition of its series and stage boundaries, and possible stratigraphic gaps are discussed in details in order to establish a multidisciplinary stratigraphic correlation through an integrated approach including lithostratigraphy, biostratigraphy, radiometric dating, chemostratigraphy and magnetostratigraphy. Being internationally accepted, the Ordovician System is now subdivided into three series and seven stages, in ascending order, Lower(Tremadocian, Floian), Middle(Dapingian, Darriwilian) and Upper series(Sandbian, Katian,Hirnantian). Three of the seven "Golden Spikes" defining the bases of the Ordovician stages, which were established in 1997–2007, are located in China. As a regionally applied chronostratigraphy, the Ordovician System was subdivided in China into Lower(Xinchangian, Yiyangian), Middle(Dapingian, Darriwilian) and Upper series(Neichiashanian, Chientangkiangian,Hirnantian). This scheme agrees largely with the standard international classification, which can actually be directly applied to China, except for some special circumstances where the Neichiashanian and Chientangkiangian stages of the Upper Ordovician are used. Based on the new studies in recent years and distinctions and differences recognized in the development of the Ordovician System in the constituent terranes of China, a new framework for correlation among the major Chinese palaeoplates or terranes, e.g. South China, North China(including Tarim and Qaidam) and Xizang(Tibet)-western Yunnan, has been established. However, it has been recognized herein that uncertainties still remain on defining the base of the Tremadocian,Dapingian and Katian, and on the correlation between different mega-facies. More specifically, for the Tremadocian, the precise correlation of its base will depend on the better-defined conodont taxonomy, while for the Dapingian and Katian, on the correlation between different mega-facies. It is worthwhile to note that the chemostratigraphic studies of the Ordovician System in China produced the carbonate δ13 C curves for the Darriwilian(Middle Ordovician) and Katian(Upper Ordovician), which show significant differences from the composite global curve. Record of the Ordovician isotopic dating is relatively rare in China, with only three reliable ages from zircons that are all from the upper Katian to Hirnantian of the Upper Ordovician.Abundant bentonite beds in the Upper Ordovician of South China will also provide unique opportunities to advance the isotopic dating and related researches. Studies on the Ordovician magnetostratigraphy need to be significantly enhanced in China, as currently all the available results are restricted to the Lower Ordovician of North China, although they can be correlated with those known from other parts of the world. The analysis of the durational unevenness of the seven stages in the Ordovician supports the possibility to further subdivide the long-durational Tremadocian, Darriwilian and Katian stages, each into two substages.

Extensive profiling of the expressions of tRNAs and tRNA-derived fragments(tRFs)reveals the complexities of tRNA and tRF populations in plants

Evidence is emerging that t RNA-derived fragments(t RFs)are regulatory molecules.Studies of t RFs in plants have been based on conventional small RNA sequencing,and focused on profiling of t RF-5 and t RF-3 species.A more comprehensive and quantitative analysis of the entire t RF population is highly necessary.Here,we employ t RNA-seq and YAMAT-seq,and develop a bioinformatics tool to comprehensively profile the expressions of t RNAs and t RFs in plants.We show that in Arabidopsis,approximately half of t RNA genes are extremely weakly expressed,accounting for only 1%of total t RNA abundance,while~12%of t RNA genes contribute to~80%of t RNA abundance.Our t RNA sequencings in various plants reveal that t RNA expression profiles exhibit a cross-species conserved pattern.By characterizing the composition of a highly heterogeneous t RF population,we show that t RNA halves and previously unnoticed 10–16-nt tiny t RFs represent substantial portions.The highly accumulated 13-nt and 16-nt tiny t RFs in Arabidopsis indicate that tiny t RFs are not random t RNA degradation products.Finally,we provide a user-friendly database for displaying the dynamic spatiotemporal expressions of t RNAs and t RFs in the model plants Arabidopsis and rice.

Plant transfer RNA-derived fragments:Biogenesis and functions

Processing of mature transfer RNAs(tRNAs)produces complex populations of tRNA-derived fragments(tRFs).Emerging evidence shows that tRFs have important functions in bacteria,animals,and plants.Here,we review recent advances in understanding plant tRFs,focusing on their biological and cellular functions,such as regulating stress responses,mediating plant-pathogen interactions,and modulating post-transcriptional gene silencing and translation.We also review sequencing strategies and bioinformatics resources for studying tRFs in plants.Finally,we discuss future directions for plant tRF research,which will expand our knowledge of plant non-coding RNAs.

Cotton variant genomes—a breakthrough in population genetics analysis

Cotton is not only an important cash crop for its fiber,but also an excellent model system for studying polyploidization,cell elongation and cell wall biosynthesis(Yang et al.,2014;Fang et al.,2017;Wang et al.,2016;Zou et al.,2016).A focus for scientists is to dissect the genetic basis underlying important agronomic traits(Gong et al.,2018;Huang et al.,2016).The advent of high-throughput sequencing technologies has boosted unveiling the cotton genome(Wang et al.,2012;Li et al.,2014;Li et al.,2015).