Soil moisture is essential for plant growth in terrestrial ecosystems.This study investigated the visible-near infrared(Vis-NIR)spectra of three subgroups of purple soils(calcareous,neutral,and acidic)from western Cho...Soil moisture is essential for plant growth in terrestrial ecosystems.This study investigated the visible-near infrared(Vis-NIR)spectra of three subgroups of purple soils(calcareous,neutral,and acidic)from western Chongqing,China,containing different water contents.The relationship between soil moisture and spectral reflectivity(R)was analyzed using four spectral transformations,and estimation models were established for estimating the soil moisture content(SMC)of purple soil based on stepwise multiple linear regression(SMLR)and partial least squares regression(PLSR).We found that soil spectra were similar for different moisture contents,with reflectivity decreasing with increasing moisture content and following the order neutral>calcareous>acidic purple soil(at constant moisture content).Three of the four spectral transformations can highlight spectral sensitivity to SMC and significantly improve the correlation between the reflectance spectra and SMC.SMLR and PLSRmethods provide similar prediction accuracy.The PLSR-based model using a first-order reflectivity differential(R?)is more effective for estimating the SMC,and gave coefficient of determination(v2),root mean square errors of validation(RMSEV),and ratio of performance to inter-quartile distance(RPIQ)values of 0.946,1.347,and 6.328,respectively,for the calcareous purple soil,and 0.944,1.818,and 6.569,respectively,for the acidic purple soil.For neutral purple soil,the best prediction was obtained using the SMLR method with R?transformation,yieldingv2,RMSEV and RPIQ values of 0.973,0.888 and 8.791,respectively.In general,PLSR is more suitable than SMLR for estimating the SMC of purple soil.展开更多
腰痛(low back pain,LBP)是影响人类健康的最常见疾病之一,患病率高且治愈率低下。其发病机制尚不清楚,可能与多种因素有关,如椎间盘退变、关节突关节损伤、肌肉筋膜炎症等。建立恰当的动物模型有助于研究和了解LBP的发病机制、探索预...腰痛(low back pain,LBP)是影响人类健康的最常见疾病之一,患病率高且治愈率低下。其发病机制尚不清楚,可能与多种因素有关,如椎间盘退变、关节突关节损伤、肌肉筋膜炎症等。建立恰当的动物模型有助于研究和了解LBP的发病机制、探索预防及治疗方法。本文就可诱发腰痛的动物模型研究进展综述如下。展开更多
目的通过对比细胞凋亡辅助脱细胞法与化学脱细胞法,探究制备马尾神经细胞外基质(ECM)的最佳方案。方法分别采用喜树碱(细胞凋亡辅助脱细胞法)和十二烷基硫酸钠(SDS,化学脱细胞法)制备大鼠马尾神经ECM,采用扫描电子显微镜(SEM)、DNA含量...目的通过对比细胞凋亡辅助脱细胞法与化学脱细胞法,探究制备马尾神经细胞外基质(ECM)的最佳方案。方法分别采用喜树碱(细胞凋亡辅助脱细胞法)和十二烷基硫酸钠(SDS,化学脱细胞法)制备大鼠马尾神经ECM,采用扫描电子显微镜(SEM)、DNA含量测定、组织学等方法评价两种方案的脱细胞效果。分别将大鼠雪旺细胞(SC)及背根神经节(DRG)接种在两种脱细胞方案制备的马尾神经ECM上进行培养,运用免疫细胞化学、细胞增殖实验(CCK-8)、实时荧光定量反转录聚合酶链反应(qRT-PCR)及酶联免疫吸附测定(ELISA)等方法评价两种方案所制备马尾神经ECM的生物相容性、促进SC增殖、髓鞘化、分泌及DRG轴突再生、细胞迁移的能力。结果与化学脱细胞法相比,细胞凋亡辅助脱细胞法制备的马尾神经ECM的DNA残留量更低[48 h DNA残留量(23.898±1.259)ng/mg比(30.200±1.442)ng/mg,P<0.05],基底膜管结构保留更加完整,促BDNF分泌更强[(365.1±12.24)pg/ml比(307.1±16.36)pg/ml,P<0.05],促DRG的轴突再生更长[(1589.1±33.74)μm比(1433.2±37.69)μm,P<0.05],促DRG中的SC迁移更远[迁移距离(1589.1±33.74)μm比(1433.2±37.69)μm,P<0.05]。结论利用细胞凋亡辅助脱细胞法制备马尾神经ECM的效果显著优于化学脱细胞法,该方案将为以马尾神经ECM为基础的组织工程神经移植物的构建提供更为合理有效的脱细胞策略。展开更多
基金funded by Chongqing Talent Program(CQYC201905009)Chongqing Education Commission(KJZD-K201800502,KJQN201800531)Science Fund for Distinguished Young Scholars of Chongqing(cstc2019jcyjjq X0025)。
文摘Soil moisture is essential for plant growth in terrestrial ecosystems.This study investigated the visible-near infrared(Vis-NIR)spectra of three subgroups of purple soils(calcareous,neutral,and acidic)from western Chongqing,China,containing different water contents.The relationship between soil moisture and spectral reflectivity(R)was analyzed using four spectral transformations,and estimation models were established for estimating the soil moisture content(SMC)of purple soil based on stepwise multiple linear regression(SMLR)and partial least squares regression(PLSR).We found that soil spectra were similar for different moisture contents,with reflectivity decreasing with increasing moisture content and following the order neutral>calcareous>acidic purple soil(at constant moisture content).Three of the four spectral transformations can highlight spectral sensitivity to SMC and significantly improve the correlation between the reflectance spectra and SMC.SMLR and PLSRmethods provide similar prediction accuracy.The PLSR-based model using a first-order reflectivity differential(R?)is more effective for estimating the SMC,and gave coefficient of determination(v2),root mean square errors of validation(RMSEV),and ratio of performance to inter-quartile distance(RPIQ)values of 0.946,1.347,and 6.328,respectively,for the calcareous purple soil,and 0.944,1.818,and 6.569,respectively,for the acidic purple soil.For neutral purple soil,the best prediction was obtained using the SMLR method with R?transformation,yieldingv2,RMSEV and RPIQ values of 0.973,0.888 and 8.791,respectively.In general,PLSR is more suitable than SMLR for estimating the SMC of purple soil.
文摘腰痛(low back pain,LBP)是影响人类健康的最常见疾病之一,患病率高且治愈率低下。其发病机制尚不清楚,可能与多种因素有关,如椎间盘退变、关节突关节损伤、肌肉筋膜炎症等。建立恰当的动物模型有助于研究和了解LBP的发病机制、探索预防及治疗方法。本文就可诱发腰痛的动物模型研究进展综述如下。
文摘目的通过对比细胞凋亡辅助脱细胞法与化学脱细胞法,探究制备马尾神经细胞外基质(ECM)的最佳方案。方法分别采用喜树碱(细胞凋亡辅助脱细胞法)和十二烷基硫酸钠(SDS,化学脱细胞法)制备大鼠马尾神经ECM,采用扫描电子显微镜(SEM)、DNA含量测定、组织学等方法评价两种方案的脱细胞效果。分别将大鼠雪旺细胞(SC)及背根神经节(DRG)接种在两种脱细胞方案制备的马尾神经ECM上进行培养,运用免疫细胞化学、细胞增殖实验(CCK-8)、实时荧光定量反转录聚合酶链反应(qRT-PCR)及酶联免疫吸附测定(ELISA)等方法评价两种方案所制备马尾神经ECM的生物相容性、促进SC增殖、髓鞘化、分泌及DRG轴突再生、细胞迁移的能力。结果与化学脱细胞法相比,细胞凋亡辅助脱细胞法制备的马尾神经ECM的DNA残留量更低[48 h DNA残留量(23.898±1.259)ng/mg比(30.200±1.442)ng/mg,P<0.05],基底膜管结构保留更加完整,促BDNF分泌更强[(365.1±12.24)pg/ml比(307.1±16.36)pg/ml,P<0.05],促DRG的轴突再生更长[(1589.1±33.74)μm比(1433.2±37.69)μm,P<0.05],促DRG中的SC迁移更远[迁移距离(1589.1±33.74)μm比(1433.2±37.69)μm,P<0.05]。结论利用细胞凋亡辅助脱细胞法制备马尾神经ECM的效果显著优于化学脱细胞法,该方案将为以马尾神经ECM为基础的组织工程神经移植物的构建提供更为合理有效的脱细胞策略。
