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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China

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Journal of Forestry Research 2024年第2期35卷 197-208页

作者： Jinkuan li Jianfeng Peng xiaoxu Wei Meng Peng Xuan li Yameng liu Jiaxin li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People’s Republic of China

Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.

关键词： Tree ring width Lubanling Pinus armandii Franch Slope direction Climate response

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Climate-growth relationships of Pinus tabuliformis along an altitudinal gradient on Baiyunshan Mountain,Central China

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Journal of Forestry Research 2024年第1期35卷 202-212页

作者： xiaoxu Wei Jianfeng Peng Jinbao li Jinkuan li Meng Peng Xuan li Yameng liu Jiaxin li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of He’nan Province Kaifeng 475004People’s Republic of China Department of Geography University of Hong KongPokfulamHong Kong SARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China

A set of standard chronologies for tree-ring width(TRW),earlywood width(EWW)and latewood width(LWW)in Pinus tabuliformis Carr.along an altitudi-nal gradient(1450,1400,and 1350 m a.s.l.)on Baiyunshan Mountain,Central China to analyze the effect of varying temperature and precipitation on growth along the gradi-ent.Correlation analyses showed that at all three altitudes and the TRW and EWW chronologies generally had signifi-cant negative correlations with mean and maximum tem-peratures in the current April and May and with minimum temperatures in the prior July and August,but significant positive correlations with precipitation in the current May.Correlations were generally significantly negative between LWW chronologies and all temperatures in the prior July and August,indicating that the prior summer temperature had a strong lag effect on the growth of P.tabuliformis that increased with altitude.The correlation with the standard-ized precipitation evapotranspiration index(SPEI)confirmed that wet conditions in the current May promoted growth of TR and EW at all altitudes.Significant altitudinal differences were also found;at 1400 m,there were significant positive correlations between EWW chronologies and SPEI in the current April and significant negative correlations between LWW chronologies and SPEI in the current September,but these correlations were not significant at 1450 m.At 1350 m,there were also significant negative correlations between the TRW and the EWW chronologies and SPEI in the prior October and the current July and between LWW chronology and SPEI in the current August,but these cor-relations were not significant at 1400 m.Moving correlation results showed a stable response of EWW in relation to the SPEI in the current May at all three altitudes and of LWW to maximum temperature in the prior July-August at 1400 m from 2002 to 2018.The EWW chronology at 1400 m and the LWW chronology at 1450 m were identified as more suitable for climate reconstruction.These results provide a strong scientific basis f

关键词： Tree rings Climate response Altitudinal gradient Baiyunshan Mountain Pinus tabuliformis Carr

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Application of epoxy resin in cultural relics protection

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Chinese Chemical Letters 2024年第4期35卷 31-42页

作者： Zhaoru Chen xiaoxu liu Haonan Chen Jialong li Xiaofeng Wang Jianfeng Zhu Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials School of Material Science and EngineeringShaanxi University of Science and TechnologyXi'an 710021China College of Mechanical&Electrical Engineering Shaanxi University of Science and TechnologyXi'an 710021China

Cultural relics have their unique artistic, cultural and historical value, and the protection of important cultural relics is conducive to the inheritance of historical culture. As a kind of cementing agent and binder commonly seen in cultural relics protection, epoxy resin is widely used in the bonding and consolidation of various materials in cultural relics, which has important practical application value. In this review, a systematic classification of commonly used epoxy resins, including their molecular structures, synthesis reactions and properties are provided, the problems and solutions of epoxy resin in cultural relics protection are summarized. The solutions are classified into three aspects: functional epoxy resin, blending modification, and other modification. Representative application examples of epoxy resin are listed in the field of cultural relics protection, and the development direction of epoxy resin in cultural relics protection in the future is proposed, which provides useful guidance for the modification of epoxy resin and its application in cultural relics protection in the future.

关键词： Epoxy resin Cultural relics Modified UV resistance

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Microenvironmental effects on growth response of Pinus massoniana to climate at its northern boundary in the Tongbai Mountains,Central China

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Journal of Forestry Research 2024年第1期35卷 44-57页

作者： Jianfeng Peng Jiayue Cui Jinbao li Meng Peng Yongtao Ma xiaoxu Wei Jinkuan li Xuan li Yamen liu Jiaxin li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People’s Republic of China Department of Geography University of Hong KongHong KongSARPeople’s Republic of China HKU Shenzhen Institute of Research and Innovation Shenzhen 518057People’s Republic of China Henan Academy of Forestry Zhengzhou 450000People’s Republic of China

The Tongbai Mountains is an ecologically sensi-tive region and the northern boundary of Pinus massoniana Lamb.To analyze the effect of different microenvironments on tree growth response to climate factors,we developed standard chronologies for earlywood width(EWW),late-wood width(LWW),and total ring width(TRW)of P.massoniana at two sampling sites on slopes with different orientations,then analyzed characteristics of the chronolo-gies and their correlations with climate variables from five stations in the region and with a regional normalized differ-ence vegetation index(NDVI).Statistical results showed that the TRW/EWW/LWW chronology consistency and charac-teristics(mean sensitivity,signal to noise ratio,expressed population signal)for trees growing on the southeastern slope were much higher than for trees on the northeastern slope.Correlations indicated that temperature in current March and August has a significant positive effect on TRW/EWW/LWW formation,and the effect on the northeastern slope was weaker than on the southeastern slope.Compared to temperature,precipitation has more complicated effects on tree growth,but the effect on the northeastern slope was also generally weaker than on the southeastern slope.Step-wise linear regression analyses showed that temperature in August was the main limiting factor at the two sampling sites.Similarly,the response of tree growth on the southeast-ern slope as determined by the NDVI is better than on the northeastern slope,and the TRW/EWW/LWW chronologies for the southeastern slope explained over 50%of the total NDVI variances in June.Overall,the results indicate that the difference in the climate response of P.massoniana at two sampling sites is clearly caused by differences in the microenvironment,and such differences should be properly considered in future studies of forest dynamics and climate reconstructions.

关键词： Tree-rings Pinus massoniana lamb Microenvironment Radial growth Climate-growth response

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Antidepressant effects of Peiyuan Jieyu formula in a mouse model of chronic stress in conjunction with lipopolysaccharide-induced depression

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Journal of Traditional Chinese Medical Sciences 2024年第1期11卷 111-119页

作者： Qin Tang Yu li Tao Yang xiaoxu Fan lina li Hongsheng Chang School of Chinese Materia Medica Beijing University of Chinese MedicineBeijing 102488China Institute of Chinese Materia Medica China Academy of Chinese Medical SciencesBeijing 100700China Chinese Medicine Department Tianjin Institute of Pharmaceutical InspectionTianjin 300070China School of Chinese Medicine Beijing University of Chinese MedicineBeijing 102488China

Objective:To explore the mechanism of the Peiyuan Jieyu formula in treating depression by assessing its impact on a lipopolysaccharide-induced(LPS-induced)depression mouse model.Methods:We created a mouse model of depression by exposing mice that had previously received chronic stress to intraperitoneal LPS injections.The mice were divided into the following groups:control,model,fluoxetine,Tiansi Yin,Sini powder,and low-,medium-,and high-dose Peiyuan Jieyu formula groups.Forced swim and tail suspension tests were used to assess the efficacy of the depression(despair)model,and weight gain rates were also measured.Furthermore,serum levels of various depression and inflammation-associated molecules,including tumor necrosis factor-a(TNF-a),interferon-γ(IFN-γ),tryptophan,5-hydroxytryptamine,kynurenine(KYN),and kynurenic acid(KA)were assessed.Furthermore,the expression levels of ionic calcium-binding adaptor molecule-1(IBA-1)and indoleamine 2,3-dioxygenase(IDO)mRNA in hippocampal microglia were measured.Results:The model group displayed greater despair-associated immobility,which was shortened in response to various doses of Peiyuan Jieyu formula.Furthermore,formula administration significantly reduced serum TNF-a levels and hippocampal IDO mRNA expression.The high formula dose also reduced IFN-γand IBA-1 levels,the latter was also decreased in response to the medium formula dose.However,the low formula dose reduced serum KYN level and KYN/tryptophan(TRP)and KYN/KA ratios.Conclusion:The Peiyuan Jieyu formula holds immense potential in treating depression in a mouse model,potentially inhibiting inflammation and improving TRP-KYN metabolic disorders.

关键词： Peiyuan Jieyu formula Depression Chronic stress lipopolysaccharide Inflammation Tryptophan pathway

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CLE14 functions as a "brake signal" to suppress age-dependent and stress-induced leaf senescence by promoting JUB1-mediated ROS scavenging in Arabidopsis

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Molecular Plant 2022年第1期15卷 179-188页

作者： Zenglin Zhang Cheng liu Kui li xiaoxu li Mengmeng Xu Yongfeng Guo Tobacco Research Institute Chinese Academy of Agricultural SciencesQingdaoShandong 266101China

Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-cence as an adaptive mechanism to ensure a complete life cycle.Upon initiation,the senescence process is fine-tuned through the coordination of both positive and negative regulators.Here,we report that the small secreted peptide CLAVATA3/ESR-RELATED 14(CLE14)functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis.Expression of the CLE14-encoding gene in leaves was signifi-cantly induced by age,high salinity,abscisic acid(ABA),salicylic acid,and jasmonic acid.CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence,whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence.CLE14 pep-tide treatments also delayed ABA-induced senescence in detached leaves.Further analysis showed that over-expression of CLE14 led to reduced.ROS levels in leaves,where higher expression of ROS scavenging genes was detected.Moreover,CLE14 signaling resulted in transcriptional activation of JUB1,a NAC family tran-scription factor previously identified as a negative regulator of senescence.Notably,the delay of leaf senes-cence,reduction in H202 level,and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1.Collectively,these results suggest that the small peptide CLE14 serves as a novel"brake signal"to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.

关键词： CLE14 peptide signal leaf senescence salt stress ABA ROS JUB1

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High-static-low-dynamic stiffness isolator based on an electromagnetic negative stiffness spring with long linear stroke

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Science China(Technological Sciences) 2024年第3期67卷 740-752页

作者： YUAN ShuJin WU YaJun SONG DaiPing PU HuaYan MOU liSheng HOU Lei ZHAO JingLei li XuePing LUO Jun WU Jie HUANG xiaoxu State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China China Aerodynamics Research and Development Center Mianyang 621000China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Negative stiffness mechanisms can improve low-frequency vibration isolation performance and have been widely used in the vibration isolation of precision equipment. However, the negative stiffness mechanism usually introduces a nonlinear stiffness,resulting in a nonlinear response and worsening the vibration isolation performance, especially under large amplitude vibration.In this paper, an electromagnetic spring with linear negative stiffness(ESLNS) is proposed, in which the antagonistic ampere forces of the energized coils are used to generate negative stiffness within a long linear stroke. The magnetic field distribution is improved through the design of the magnetic circuit, thereby increasing the stiffness generation efficiency. The stiffness can be adjusted bidirectionally by current within the range of positive and negative stiffness. An electromagnetic stiffness model was established based on the equivalent magnetic circuit method. Experimental measurements verified the accuracy of the model and proved the linearity of the electromagnetic spring. A vibration isolator with high static and low dynamic stiffness(HSLDS) based on the ESLNS is designed and tested. The experimental results prove that the introduction of the ESLNS can effectively expand the isolation frequency band without changing the equilibrium position. Moreover, the vibration isolator with ESLNS does not produce nonlinear response. The proposed electromagnetic spring with linear negative stiffness extends the application range of HSLDS isolators to a large amplitude vibration environment.

关键词： linear negative stiffness mechanism low-frequency vibration isolation electromagnetic spring vibration control

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Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains, China

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Journal of Forestry Research 2024年第3期 88-99页

作者： Jinkuan li Jianfeng Peng xiaoxu Wei Meng Peng Xuan li Yameng liu Jiaxin li College of Geography and Environmental Science Henan University Key Laboratory of Earth System Observation and Simulation of Henan Province

Global warming will affect growth strategies and how trees will adapt. To compare the response of tree radial growth to climate warming in different slope directions, samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains. Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July. The difference of the climate response to slopes was small but not negligible. Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures, while that of the LBL02 site was affected by maximum temperatures. With regards to moisture, radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July, while on the western slope, it was affected by the relative humidity in the previous June–August, the current May–July and the precipitation in the current May–July. With the change in climate, the effects of the main limiting factors on growth on different slopes were visible to a certain extent, but the differences in response of trees on different slopes gradually decreased, which might be caused by factors such as different slope directions and the change in diurnal temperature range. These results may provide information for forest protection and ecological construction in this region, and a scientific reference for future climate reconstruction.

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Stability assessment of tree ring growth of Pinus armandi Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China

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Journal of Forestry Research 2024年第3期35卷 87-98页

作者： Jinkuan li Jianfeng Peng xiaoxu Wei Meng Peng Xuan li Yameng liu Jiaxin li College of Geography and Environmental Science Henan UniversityKaifeng 475004People's Republic of China Key Laboratory of Earth System Observation and Simulation of Henan Province Kaifeng 475004People's Republic of China

Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and tree-ring chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June-August and the com-bination of temperatures and moisture in the current May-July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBLO1 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBLO2 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May-July,while on the western slope,it was affected by the relative humidity in the previous June-August,the current May-July and the precipitation in the current May-July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.

关键词： Tree ring width Lubanling Pinus armandi Franch Slope direction Climate response

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Transcranial Magneto-Acoustic Stimulation Attenuates Synaptic Plasticity Impairment through the Activation of Piezo1 in Alzheimer’s Disease Mouse Model

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Research 2024年第1期2023卷 81-95页

作者： Fangxuan Chu Ruxin Tan Xin Wang Xiaoqing Zhou Ren Ma xiaoxu Ma Ying li Ruixu liu Chunlan Zhang Xu liu Tao Yin Zhipeng liu Institute of Biomedical Engineering Chinese Academy of Medical Sciences and Peking Union Medical CollegeTianjin300192China Tianjin Institutes of Health Science Tianjin301600China Neuroscience Center Chinese Academy of Medical Science&Peking Union Medical CollegeBeijing100730China

The neuropathological features of Alzheimer’s disease include amyloid plaques.Rapidly emerging evidence suggests that Piezo1,a mechanosensitive cation channel,plays a critical role in transforming ultrasound-related mechanical stimuli through its trimeric propeller-like structure,but the importance of Piezo1-mediated mechanotransduction in brain functions is less appreciated.However,apart from mechanical stimulation,Piezo1 channels are strongly modulated by voltage.We assume that Piezo1 may play a role in converting mechanical and electrical signals,which could induce the phagocytosis and degradation of Aβ,and the combined effect of mechanical and electrical stimulation is superior to single mechanical stimulation.Hence,we design a transcranial magneto-acoustic stimulation(TMAS)system,based on transcranial ultrasound stimulation(TUS)within a magnetic field that combines a magnetoacoustic coupling effect electric field and the mechanical force of ultrasound,and applied it to test the above hypothesis in 5xFAD mice.Behavioral tests,in vivo electrophysiological recordings,Golgi–Cox staining,enzyme-linked immunosorbent assay,immunofluorescence,immunohistochemistry,real-time quantitative PCR,Western blotting,RNA sequencing,and cerebral blood flow monitoring were used to assess whether TMAS can alleviate the symptoms of AD mouse model by activating Piezo1.

关键词： stimulation Alzheimer Piezo1

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