The Ecophysiological Roles of Arbuscular Mycorrhizal Fungi in Phosphorus Nutrition and Cadmium Resistance of Kandelia obovata (S., L.) Yong

红树林湿地生态系统分布于陆地生态系统和海洋生态系统的交错带，属于生态脆弱敏感区域。由于生境营养元素如磷(P)的限制以及工农业发展导致的河口重金属污染等的影响，红树林退化与消失的趋势相当严重，因此红树林的保育恢复已成为我国环境保护工作的重点。近年来，红树林湿地丛枝菌根真菌(AMF)资源的调查评估，为我们开辟了一条红树林保育恢复工作的新思路。本研究立足于AMF与红树植物的共生关系，以红树植物秋茄(K.obovata)为试材，以前期红树林湿地调查筛选出的4种AMF优势种作为混合接种对象，通过室内盆栽试验研究了AMF在红树植物磷营养及抗镉(Cd)胁迫中的作用，率先揭示AMF在红树植物营养缺乏和重金属污...Mangrove wetland ecosystem locates in the ecotone between terrestrial and marine ecosystem, therefore is a fragile eco-sensitive zone. Due to nutrient elements restriction such as phosphorus (P) deficiency in the habitat, and estuarine heavy metal pollution resulted from industrial and agricultural development, mangroves have degenerated dramatically in China. As a result, mangrove conservation an...学位：理学博士院系专业：生命科学学院生物学系_生态学学号：2172009015354

Effects of Arbuscular Mycorrhizal Inoculation and Cd Stress on the Growth and Antioxidant Enzyme System of Kandelia obovata

近年来,由于工农业发展导致的河口重金属污染等的影响,红树林退化与消失的趋势相当严重,红树林的保育恢复已成为我国环境保护工作的重点.立足于丛枝菌根真菌(ArbuSCulAr MyCOrrHIzAl fungI,AMf)与红树植物的共生关系,以红树植物秋茄(kAndElIA ObOVATA(S.,l.)yOng)为试材,在施加重金属Cd(0,5,10,20,40Mg/kg)的条件下,通过接种与不接种混合AMf,对比研究从红树林生境中筛选扩繁的优势AMf菌种对秋茄幼苗生长与抗氧化酶系统的影响.研究表明:接种AMf使得秋茄幼苗的生物量增加,但株高未出现明显变化.Cd胁迫引起了秋茄叶片和根系丙二醛(MdA)含量的持续上升,且超氧化物歧化酶(SOd)、过氧化物酶(POd)、过氧化氢酶(CAT)活性表现为低含量下刺激,高含量下抑制的效应.接种AMf使得MdA含量显著减少,SOd、POd、CAT活性显著增加,从而能够更好地清除活性氧,减轻Cd胁迫下秋茄的膜脂过氧化程度,保护植物.研究揭示AMf在红树林湿地生态系统中潜在的抗重金属污染生理生态功能,为红树林污染的生物修复提供了一条新思路.In recent decades,mangroves have degenerated dramatically in China due to estuarine heavy metal pollution resulting from industrial and agricultural development.As a result,mangrove conservation and restoration have become the priority of environmental protection.Based on the symbiotic relationships of AMF and mangrove plant,the effect of AMF on the growth and antioxidant enzyme system of Kandelia obovata(S.,L.) Yong under cadmium(Cd) stress(0,5,10,20,40 mg/kg) was studied,with or without the inoculation of four dominant AMF species selected from mangrove habitat as the mixed inocula.The results showed that AMF inoculation increased the biomass of K.obovata,while no variation was observed in plant height.Cd stress caused a continuous increase of malondialdehyde(MDA) content in leaves and roots of K.obovata,and the activities of superoxide dismutase(SOD),peroxidase(POD),and catalase(CAT) showed a stimulation effect under low Cd treatment strength and an inhibition effect under high Cd treatment strength.AMF inoculation significantly decreased the MDA content,meanwhile,the activities of SOD,POD,and CAT were increased,thus could scavenge more reactive oxygen species(ROS),alleviate the degree of membrane lipid peroxidation,and protect the plant cells.This research disclosed the potential function of AMF in mangrove plant against heavy metal stress for the first time,and provided a new method of mangrove pollution bioremediation.国家自然科学基金项目(31170471;30970527

Effect of Electroacupuncture Stimulation of "Huantiao"(GB 30) on Walking Ability and Touch Sensation in Rabbits with Lumbar Intervertebral Disc Protrusion

目的:观察电针“环跳“穴对实验性腰椎间盘突出症(lIdP)家兔步态、触觉功能和坐骨神经超微结构的影响,探讨电针对lIdP的修复作用。方法:40只新西兰家兔随机分为正常组、模型组、环跳组和非穴组。采用lIdP动物病理模型造模器将家兔腰6、7的椎间盘组织推出到后纵韧带右前方建立模型。环跳组和非穴组予电针治疗,每次20MIn,每日1次,共7d。神经功能评分法检测家兔治疗前后步态、触觉功能的变化,透射电镜检测坐骨神经超微结构。结果:造模后家兔步态、触觉功能减弱;环跳组的步态、触觉功能治疗前后积分值的差值显著高于正常组、模型组、非穴组(P<0.01)。模型组坐骨神经纤维广泛洋葱状变性,雪旺氏细胞坏死、水肿;环跳组神经纤维大多数趋于正常,雪旺氏细胞丰富;非(组)旺氏细胞线粒体广泛水肿、空泡化。结论:电针“环跳“穴对实验性lIdP的损伤具有很好的修复作用。Objective To observe the effect of electroacupuncture(EA) stimulation of "Huantiao"(GB 30) on the wal-king ability and touch sensation in rabbits with lumbar intervertebral disc protrusion(LIDP).Methods Forty New Zealand rabbits were equally randomized into normal control,model,EA-GB 30 and EA-non-acupoint groups.The LIDP model was established by surgical operation under anesthesia.EA(30 Hz/100 Hz,2-4 V,0.5 ms in pulse duration) was applied to bilateral "Huantiao"(GB 30) or non-acupoint.The rabbits' walking ability was assessed according to a 4-points scoring standard: 0 point: complete paralysis;1 point: paralysis with muscular contraction and mild joint movement;2 points: weaker strength of the affected limbs with bradykinesia and instable walking;3 points: able to walk with only interphalangeal joint dyskinesia;4 points: complete recovery.The rabbit's touch sensation was assessed according to another 4-points scoring standard: 0 point: no any response to cotton swab stimulation;1 point: very mild response;2 points: sluggish response;3 points: relatively swifter response but weaker than the healthy limb;4 points: normal.The ultrostructure changes of the sciatic nerve were analyzed by transmission electron microscope.Results Following modeling,the scores for walking ability and touch sensation were significantly reduced in the model,EA-GB 30 and EA-non-acupoint groups(P<0.01).While compared with the model group,both walking ability score and touch sensation score of the EA-GB 30 group were obviously increased(P<0.01),rather than in the EA-non-acupoint group.Outcomes of the ultrastructure showed that in the model group,extensive onion-like state of the myelin sheath of the sciatic nerve fibers,shrink or disappearance of the axon,kytoplasm edema or lysis of Schwann cells tending to necrosis,and mitochondrium vacuolization of the Schwann cells were found.In the EA-GB 30 group,majority of the nerve fibers and vascular endothelium were normal,with delamination and vacuolization of partial myelin sheath,edema of partial mitochondria and vacuolization of Schwann cells were found.In the EA-non-acupoint group,delamination and twist of partial myelin sheath,Schwann cellular plasma edema and mitochondrial edema of the axon with vacuolization change were found,suggesting a poorer effect of EA of non-acupoint.Conclusion EA-GB 30 can improve LIDP rabbits' walking ability and touch sensation function and reduce ultrastructure of sciatic nerve.国家自然科学基金项目(No.30960484

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies