The radial growth of trees plays a crucial role in determining forest carbon sequestration capacity. Understanding the growth dynamics of trees and their response to environmental factors is essential for predicting forest\'s carbon sink potential under future climate change. Coniferous forest trees are particularly sensitive to climate change, with growth dynamics responding rapidly to environmental shifts. We collected and analyzed data from 99 papers published between 1975 and 2023, and examined the effects of exogenous factors (such as temperature, water, and photoperiod) and endogenous factors (including tree age and species) on cambial activity and radial growth in conifers. We further explored the mechanisms underlying these effects. The results showed that climate warming had the potential to advance the onset while delayed the end of xylem differentiation stages in conifers in temperate and boreal regions. Water availability played a crucial role in regulating the timing of cambial phenology and wood formation by influencing water potential and cell turgor. Additionally, the photoperiod not only participated in regulating the start and end times of growth, but also influenced the timing of maximum growth rate occurrence. Future climate warming was expected to extend the growing season, leading to increase in growth of conifers in boreal regions and expanding forests to higher altitudes or latitudes. However, changes in precipitation patterns and increased evapotranspiration resulting from temperature increases might advance the end of growing season and reduce growth rate in arid areas. To gain a more comprehensive understanding of the relationship between radial growth and climatic factors, it is necessary to develop process-based models to elucidate the physiological mechanisms underlying wood formation and the response of trees to climatic factors.
树木径向生长是森林固碳的主要方式,明确树木生长动态及其与环境要素的响应关系对于预测气候变化背景下森林固碳能力具有重要意义。针叶树生长对气候变化非常敏感,其生长动态能够快速响应气候变化。本文收集了1975—2023年的99篇文献,评述了外源因素(温度、水分和光周期)和内在因素(树龄、树种)对针叶树形成层活动和径向生长的影响及其机制。结果表明:气候变暖可能会导致温带和北方针叶树木质部分化的各阶段开始时间提前,生长停止时间推迟;水分条件参与调控形成层活动的开始并通过影响水势和细胞膨压进而调节树木生长;光周期除了可以参与调节生长开始、结束时间外,也对最大生长速率发生时间产生重要影响。未来气候变暖可能会使北方针叶树生长季延长、生长量增加,并使森林向更高海拔或高纬度地区迁移。同时,未来降水格局改变以及温度升高导致的蒸散发加剧可能会使干旱区树木生长季提前结束,生长速率下降。在未来研究中,还需进一步开发树木生长过程模型,量化径向生长与气候要素的关系,以便进一步明确树木生长对气候要素响应的生理机制。.

BACKGROUND: As studies on ethnic disparities in metabolic syndrome and its risk factors in Taiwan are still rare, the aims of this study were: (1) to detect the differences in the rates of metabolic syndrome, obesity and health behaviors between two ethnic groups (indigenous Tsou and nonindigenous Han) living in the same area and with similar age and sex distributions; (2) to examine whether ethnicity per se plays a significant role in the occurrence of metabolic syndrome, while taking other risk factors including sociodemographic characteristics, obesity and health behaviors into consideration.
METHODS: This is a cross-sectional study using data from a community survey conducted in Chiayi County in southwestern Taiwan. A frequency matching strategy by age and sex with a ratio of 1 (Tsou) to 3 (Han) was applied to select a comparable sample between both ethnic groups (667 Tsou and 2001 Han) from among the survey participants. Furthermore, participants with cardiometabolic diseases diagnosed before the surveyed day were excluded to avoid confounding any associated risk factors for developing metabolic syndrome (MS). A final analytic sample of 1482 remained. The used information included sociodemographic characteristics, medical histories, health behaviors, and the concentrations of triglycerides, cholesterol, and glucose.
RESULTS: Indigenous Tsou had significantly higher rates of metabolic syndromes, obesity and unhealthy behaviors than their Han counterparts (MS: 54.0% vs. 29.1%, obesity: 54.0% vs. 23.2%, drinking alcohol: 17.5% vs. 13.6%, and higher intake of fried food: 6.4% vs. 4.4%), even though they were similar in age and sex distributions. The significant risk factors for subsequently developing MS included being indigenous Tsou (adjusted POR = 2.62, P < 0.001), older, single, and obese. Stratified analyses on the risk factors for developing MS by health behaviors and by obese problems also indicated increased risks of being indigenous Tsou.
CONCLUSIONS: There existed ethnic differences in the rates of metabolic syndrome, obesity, and health behaviors. Ethnicity per se did play a significant role in developing MS; in particular indigenous Tsou people had increased risks, suggesting possible biological reasons rooted in their origins that need further exploration. In addition, unhealthy behaviors may potentially have an indirect effect on developing MS via their effect on obesity.

Tree growth is the main way of carbon sequestration in forest ecosystems, which is influenced by climatic and non-climatic factors. The long-term location monitoring of cambial phenology and wood formation dynamics (xylogenesis) is an important method to clarify the responses of radial growth to climate change. Here, we reviewed studies on cambial phenology and xylogenesis by microcoring method. Firstly, we reviewed the effects of climatic factors on cambial phenology. The onset and cessation of xylogenesis were determined by temperature in cold and humid conditions. Temperature and water availability collectively modulated the onset of xylogenesis under dry conditions, and the later determined the end of xylogenesis. The radial increment was regulated by rate and duration of cell production, with the maximum of growth rate occurring around the summer solstice. Short-term N addition did not affect wood formation dynamics. Secondly, we reviewed the roles of biological factors in regulating xylogenesis. The onset of xylogenesis differred among species, ages, and inter-specific competition. Seasonal dynamics of non-structural carbohydrates were coupled with wood formation. Finally, we reviewed the response mechanisms of xylogenesis to the interaction of climatic and biological factors. In conclusion, we put forward problems in current studies and prospected future development to provide reference for further scientific research.
树木生长是森林生态系统固碳的主要方式,树木生长过程受到气候与非气候因素的共同作用。树木径向生长长期定位监测是明确树木生长对气候变化响应的重要研究手段。本文对运用微树芯法的树木形成层活动及径向生长过程研究进行了总结。首先,综述了气候因素对树木形成层活动的影响: 寒冷湿润区温度决定树木生长开始和停止,干旱半干旱区水分和温度共同决定生长开始,水分决定生长停止;生长速率和持续时间共同决定生长量,最大生长速率出现在夏至前后;短期施氮并不能影响树木径向生长动态。其次,探讨了生物因素对树木径向生长过程的调控: 形成层活动开始时间因树种、树龄、竞争关系而有所差异;非结构性碳水化合物的季节动态与径向生长过程相耦合。最后,阐述了气候因素和生物因素交互作用下树木次生生长的响应机制。针对以上进展,本文提出了目前研究尚存在的问题并展望了未来的发展前景,以期为进一步的科学研究提供参考。.

The effects of biological factors including dissolved oxygen (DO), pH, carbon/nitrogen (C/N) and hydraulic retention times (HRT) on the performance of simultaneous nitrification and denitrification (SND) in a moving bed sequencing batch reactor (MBSBR) were investigated. A low DO was found to be advantageous to the SND in that nitrification was not inhibited, while pH and C/N ratio were shown to have positive effects on SND, and HRT needed to be controlled in a suitable range. A desirable SND efficiency was obtained at a DO of 2.5 mg L-1, pH of approximately 8.0, C/N ratio of 10 and HRT of 10 h in the MBSBR. High-throughput sequencing analysis showed that different operating conditions impacted microbial communities, resulting in different nitrogen removal mechanisms. Autotrophic and heterotrophic nitrification together contributed to the good nitrification performance, while denitrification was conducted by combined anoxic and aerobic processes. Furthermore, the results of principal component analyses (PCA) and the abundance of the predominant nitrification and denitrification genera both showed that DO and HRT might be regarded as the dominant variable factors influencing community structure analysis during SND, while the linear discriminant analysis (LDA) effect size (LEfSe) algorithm showed differences in abundance among the biofilm microbial communities with different DO. Overall, the results of this study improve our understanding of the bacterial community structure with different operating conditions in MBSBRs.

Using the Li-8150 multichannel automatic soil CO2 efflux system, soil respiration was measured continuously over a one-year period in a coastal wetland in the Yellow River Delta, China. Environmental and biological factors were measured simultaneously, including temperature, soil water content, aboveground biomass and leaf area index. The results showed that the diurnal variation of soil respiration presented a single-peak curve, but it appeared as multiple peaks when disturbed by soil freezing and surface flooding. Soil respiration showed obvious seasonal dynamics and a single peak curve. The average annual soil respiration was 0.85 μmol CO2·m-2·s-1, and the mean soil respiration rate was 1.22 μmol CO2·m-2·s-1 during the growing season. On one-year scale, soil temperature was a major factor influencing soil respiration in the coastal wetland, which explained 87.5% of the variation in soil respiration. On the growing season scale, soil water content and leaf area index accounted for 85% of the seasonal variation of soil respiration.
采用Li-8150多通道土壤呼吸自动测量系统对黄河三角洲滨海湿地土壤呼吸进行全年连续测定,同步测量了温度、土壤含水量、地上生物量以及叶面积指数等环境因子和生物因子.结果表明: 土壤呼吸日动态在全年尺度上多呈单峰型,但在受到土壤封冻和地表积水干扰时,土壤呼吸日动态呈多峰型.土壤呼吸具有明显的季节动态特征,总体呈单峰型,年平均土壤呼吸速率为0.85 μmol CO2·m-2·s-1,生长季平均土壤呼吸速率为1.22 μmol CO2·m-2·s-1.在全年尺度上,土壤温度是滨海湿地土壤呼吸的主要控制因子,可解释全年土壤呼吸87.5%的变化.在生长季尺度上,土壤含水量和叶面积指数对土壤呼吸的协同影响达到85%.

As a kind of globally widely distributed soil microorganism, arbuscular mycorrhizal (AM) fungi form the symbiosis with the majority of land plants, which is important for plant nutrition and ecosystem functioning. Few vascular species are considered to be nonmycorrhizal, especially those within the families Amaranthaceae, Chenopodiaceae, Carophyllaceae and Brassicaceae. At present, the interactions between these non-host plants and AM fungi are few and scattered, lacking systematic summary. In this paper, the type of non-host plants, the reason of low mycotrophy, and the effect of AM network formed by neighbor plants on AM fungi colonization on the non-host, and the possible interaction between AM fungi and non-host, as well as the material exchange between plants and AM fungi and their possible ecological functions were reviewed in order to give some new ideas on the function of the nonmycorrhizal plants in the fragile ecosystems.
丛枝菌根(AM)真菌作为一类在全球分布广泛的土壤微生物,能够与陆地上大多数的维管植物形成专性共生关系,对于植物营养吸收和生态系统功能具有重要作用.而较少量的维管植物如苋科、黎科、石竹科、十字花科等植物被认为是非菌根植物.目前,对于这些非菌根植物与AM 真菌之间的相互作用关系研究少且分散,缺乏系统总结.本文综述了非菌根植物的类型以及低侵染的原因,邻体植物形成的菌丝网络对AM真菌侵染非菌根植物的影响,并探讨AM真菌和非菌根植物之间可能存在的相互作用,以及植物-AM真菌之间的物质交换及可能存在的生态功能,旨在为进一步发挥非菌根植物在脆弱生态系统的功能潜力提供新思路.

A rat model of acute ocular hypertension was established by enhancing the perfusion of balanced salt solution in the anterior chamber of the right eye. Minocycline (90 mg/kg) was administered intraperitoneally into rats immediately after the operation for 3 consecutive days. Immunofluorescence, western blot assay and PCR detection revealed that the expression of the precursor form of nerve growth factor, nerve growth factor and the p75 neurotrophin receptor, and the mRNA expression of nerve growth factor and the p75 neurotrophin receptor, increased after acute ocular hypertension. The number of double-labeled CD11B- and precursor form of nerve growth factor-positive cells, glial fibrillary acidic protein- and p75 neurotrophin receptor-positive cells, glial fibrillary acidic protein- and caspase-3-positive cells in the retina markedly increased after acute ocular hypertension. The above-described expression decreased after minocycline treatment. These results suggested that minocycline inhibited the increased expression of the precursor form of nerve growth factor in microglia, the p75 neurotrophin receptor in astroglia, and protected cells from apoptosis.

Ototoxic drug-induced apoptosis of inner ear cells has been shown to be associated with calpain expression. Cisplatin has severe ototoxicity, and can induce cochlear cell apoptosis. This study assumed that cisplatin activated calpain expression in apoptotic cochlear cells. A mouse model of cisplatin-induced ototoxicity was established by intraperitoneal injection with cisplatin (2.5, 3.5, 4.5, 5.5 mg/kg). Immunofluorescence staining, image analysis and western blotting were used to detect the expression of calpain 1 and calpain 2 in the mouse cochlea. At the same time, the auditory brainstem response was measured to observe the change in hearing. Results revealed that after intraperitoneal injection with cisplatin for 5 days, the auditory brainstem response threshold shifts increased in mice. Calpain 1 and calpain 2 expression significantly increased in outer hair cells, the spiral ganglion and stria vascularis. Calpain 2 protein expression markedly increased with an increased dose of cisplatin. Results suggested that calpain 1 and calpain 2 mediated cisplatin-induced ototoxicity in BALB/c mice. During this process, calpain 2 plays a leading role.

Neurotrophin-3 (NT-3) can promote the repair of central nervous system and retinal damage. In previous reports, NT-3 has been expressed by viral vectors. However, plasmid vectors have a safer profile compared with viral vectors in clinical studies. This study recombined amplified human retinal NT-3 with a eukaryotic expression plasmid containing green fluorescent protein (GFP) to construct an NT-3 expression plasmid, pEGFP-N1-NT-3. The transfection efficiency 48 hours after pEGFP-N1-NT-3 transfection to 293T cells was 50.06 ± 2.78%. Abundant NT-3-GFP was expressed in 293T cells as observed by fluorescence microscopy, suggesting the construct pEGFP-N1-NT-3 effectively expressed and secreted NT-3-GFP. Secretory vesicles containing NT-3-GFP were observed in a constant location in cells by laser scan confocal microscopy, indicating the expression and secretion processes of NT-3 in eukaryotic cells were in accordance with the physical synthesis processes of secreted proteins. Western blot assay showed that pro-NT-3-GFP had a molecular weight of 56 kDa, further confirming NT-3-GFP expression. At 48 hours after transfection, the concentration of NT-3 in culture medium was 22.3 ng/mL, suggesting NT-3 produced by pEGFP-N1-NT-3 was efficiently secreted. This study constructed a human retinal-derived NT-3 eukaryotic expression plasmid that efficiently expressed and secreted NT-3.

In this study, PC12 cells were induced to differentiate into neuron-like cells using nerve growth factor, and were subjected to oxygen-glucose deprivation. Cells were treated with 0, 10, 20, 30, 50, 100 ng/mL exogenous Activin A. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide assay and Hoechst 33324 staining showed that the survival percentage of PC12 cells significantly decreased and the rate of apoptosis significantly increased after oxygen-glucose deprivation. Exogenous Activin A significantly increased the survival percentage of PC12 cells in a dose-dependent manner. Reverse transcription-PCR results revealed a significant increase in Activin receptor IIA, Smad3 and Smad4 mRNA levels, which are key sites in the Activin A/Smads signaling pathway, in neuron-like cells subjected to oxygen-glucose deprivation, while mRNA expression of the apoptosis-regulation gene caspase-3 decreased. Our experimental findings indicate that exogenous Activin A plays an anti-apoptotic role and protects neurons by means of activating the Activin A/Smads signaling pathway.