Relationships between stem growth and climatic and edaphic factors,notably air temperatures and soil moisture for different slopes,are not completely understood.Stem radial variations were monitored at the bottom and ...Relationships between stem growth and climatic and edaphic factors,notably air temperatures and soil moisture for different slopes,are not completely understood.Stem radial variations were monitored at the bottom and top slope positions in a Larix principis-rupprechtii plantation during the 2017 and 2018 growing seasons.Total precipitation during the growing season in 2017 and 2018 was 566 mm and 728 mm,respectively.Stem contractions typically occurred after mid-morning followed by swelling in the late afternoon in both plots,reflecting the diurnal cycle of water uptake and loss.Trees at the two locations showed the same growth initiation(mid-May)because of the small differences in air and soil temperatures.There were no significant differences in cumulative stem radial growth between the bottom plot(1.57±0.34 mm)and the top plot(1.55±0.26 mm)in 2018.However,in 2017,the main growth period of the bottom plot ceased 17 days earlier than in the top plot,while cumulative seasonal growth of the bottom plot(1.08±0.25 mm)was significantly less than the top plot(1.54±0.43 mm).Maximum daily stem shrinkage was positively correlated with air and soil temperatures,solar radiation,vapor pressure deficits,and negatively correlated with volumetric soil moisture content.The maximum daily shrinkage reflected transpiration rates as affected by environmental factors.Daily radial stem increment was correlated with precipitation and volumetric soil moisture in both years,but with air temperatures only in 2017.The seasonal growth of L.principis-rupprechtii Mayr thus shows interannual dynamics,while precipitation constitutes a key driving factor.展开更多
文摘目的探讨RUNX3、P16和DAPK基因启动子DNA甲基化与非小细胞肺癌(non-small cell lung cancer,NSCLC)化疗敏感性的关系。方法选取2023年2月至2025年2月于株洲市中心医院接受铂类化疗的初治晚期NSCLC患者116例为研究对象,根据化疗疗效将其分为敏感组(n=81)和耐受组(n=35)。比较两组患者的病灶组织标本RUNX3、P16、DAPK基因启动子DNA甲基化情况、基因转录水平绝对定量,采用受试者操作特征曲线(receiver operating characteristic curve,ROC曲线)评估RUNX3、P16、DAPK基因表达水平对铂类化疗耐药的预测价值。结果耐受组患者肺癌组织的RUNX3、P16和DAPK基因启动子DNA甲基化比例均显著高于敏感组(P<0.05)。耐受组患者肺癌组织的RUNX3、P16和DAPK基因转录水平均显著低于敏感组(P<0.05)。ROC曲线显示,肺癌组织RUNX3、P16、DAPK基因转录水平预测NSCLC患者化疗敏感的最佳截断值分别为2.93×10^(6)、5.22×10^(4)、6.420×10^(5),曲线下面积(area under the curve,AUC)分别为0.726、0.748、0.763。三者联合预测NSCLC患者化疗敏感的AUC为0.883,敏感度为81.82%、特异性为78.05%。结论RUNX3、P16、DAPK基因甲基化可能是晚期NSCLC患者铂类化疗耐药的原因之一,早期测定此类基因转录水平对预估化疗耐药、制定个体化治疗方案具有积极作用。
基金supported by the Ningxia Hui Autonomous Region(QCYL-2018-12)the National Key Research and Development Program of China(2016YFC0501603,2017YFC0504602)the National Natural Science Foundation of China(41671025).
文摘Relationships between stem growth and climatic and edaphic factors,notably air temperatures and soil moisture for different slopes,are not completely understood.Stem radial variations were monitored at the bottom and top slope positions in a Larix principis-rupprechtii plantation during the 2017 and 2018 growing seasons.Total precipitation during the growing season in 2017 and 2018 was 566 mm and 728 mm,respectively.Stem contractions typically occurred after mid-morning followed by swelling in the late afternoon in both plots,reflecting the diurnal cycle of water uptake and loss.Trees at the two locations showed the same growth initiation(mid-May)because of the small differences in air and soil temperatures.There were no significant differences in cumulative stem radial growth between the bottom plot(1.57±0.34 mm)and the top plot(1.55±0.26 mm)in 2018.However,in 2017,the main growth period of the bottom plot ceased 17 days earlier than in the top plot,while cumulative seasonal growth of the bottom plot(1.08±0.25 mm)was significantly less than the top plot(1.54±0.43 mm).Maximum daily stem shrinkage was positively correlated with air and soil temperatures,solar radiation,vapor pressure deficits,and negatively correlated with volumetric soil moisture content.The maximum daily shrinkage reflected transpiration rates as affected by environmental factors.Daily radial stem increment was correlated with precipitation and volumetric soil moisture in both years,but with air temperatures only in 2017.The seasonal growth of L.principis-rupprechtii Mayr thus shows interannual dynamics,while precipitation constitutes a key driving factor.
