The present study was designed to isolate and evaluate the antibacterial activity of the compounds from the whole plant of Euphorbia helioscopia L.. Various chromatographic techniques were used to isolate and purify t...The present study was designed to isolate and evaluate the antibacterial activity of the compounds from the whole plant of Euphorbia helioscopia L.. Various chromatographic techniques were used to isolate and purify the compound. The structure of the compound was elucidated on basis of spectral data(1H NMR, 13 C NMR, 1H-1H COSY, HSQC, HMBC, NOESY, IR, and HR-ESI-MS). A new jatrophone-type diterpenoid(14α,15β-diacetoxy-3β-benzoyloxy-7β-nicotinoyloxy-9-oxo-jatropha-5E,11E-diene), named euphoheliosnoid E(1), was isolated from the whole plant of E. helioscopia L. Compound 1 showed significant anti-microbial activity against oral pathogens.展开更多
A proper excitation wavelength and strong hot-spot effect are of great importance for the application of surface-enhanced Raman spectroscopy(SERS)in the field of biochemistry.As a popular SERS substrate,noble metal na...A proper excitation wavelength and strong hot-spot effect are of great importance for the application of surface-enhanced Raman spectroscopy(SERS)in the field of biochemistry.As a popular SERS substrate,noble metal nanoparticles dimer is analyzed systematically in this paper.The hot-spot effect and the resonance peak position with varying geometric parameters of metal nanoparticles are investigated.Moreover,the excitation wavelength of bimetallic structure is discussed as well.The conclusions can provide reference for the selection of metal material at different excitation wavelengths.展开更多
Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically...Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically accompanied by substantial alterations in nitrogen fertilizer application and irrigation practices,is an important influencing factor.This study evaluated the changes in NO_(3)^(-)accumulation and transport in the deep vadose zone(DVZ,below the root zone),and the groundwater NO_(3)^(-)content associated with ALUC from grain to vegetable fields in the North China Plain(NCP).The ALUC from grain to vegetable resulted in nitrate–nitrogen(NO_(3)^(-)-N)accumulation in DVZ increased by 235.5 kg ha^(-1)m^(-1)(163.2%)in the piedmont plain and 224.9 kg ha^(-1)m^(-1)(102.7%)in the central plain,respectively.This change accelerated downward transport velocity in the DVZ(from 0.81±0.47 to 0.89±0.55 m yr^(-1)in the piedmont plain,and from 0.24±0.12 to 0.92±0.12 m yr^(-1)in the central plain)and increased NO_(3)^(-)leaching fluxes.High transport velocity and leaching fluxes resulted in chemical N-fertilizer entering the aquifer in several areas in the piedmont plain.The impact of the agricultural activity intensity changes,accompanied by the ALUC,on groundwater quantity and quality should be considered in similar regions.展开更多
目的利用分子对接技术预测金莲花中牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、荭草素-2"-O-β-L-半乳糖苷、藜芦酸、金莲花碱的抗病毒和抗炎机制。方法运用Discovery Studio 2.5软件和药物化学数据库,将金莲花的6个活性成...目的利用分子对接技术预测金莲花中牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、荭草素-2"-O-β-L-半乳糖苷、藜芦酸、金莲花碱的抗病毒和抗炎机制。方法运用Discovery Studio 2.5软件和药物化学数据库,将金莲花的6个活性成分与Toll样受体蛋白(TLRs)及神经氨酸酶(NA)靶点进行分子对接,通过模拟运算,分析对接结果及其功能区域的相互作用关系。结果牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、藜芦酸、金莲花碱均作用于1种或多种TLR,而荭草素-2"-O-β-L-半乳糖苷与3种TLR均无相互作用;黄酮类化合物,即牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、荭草素-2"-O-β-L-半乳糖苷均可与NA结合,而藜芦酸和金莲花碱与NA无相互作用。结论金莲花的6个活性成分中,5个成分可影响TLRs介导的信号通路,TLR3、4、7是其抗病毒抗炎作用的潜在靶点;4个黄酮类化合物可通过作用于NA而影响流感病毒活性。本研究可为探讨金莲花的抗病毒和抗炎有效成分及其进一步开发利用提供依据。展开更多
针对城市地物的特点,本文基于两种不同空间分辨率的遥感数据,利用原始与改进后的CASA估算了徐州城区的NPP,探讨了CASA模型的改进和遥感影像的空间分辨率对城市尺度NPP估算结果的影响。研究结果表明:①城市建筑用地对城市NPP的估算结果...针对城市地物的特点,本文基于两种不同空间分辨率的遥感数据,利用原始与改进后的CASA估算了徐州城区的NPP,探讨了CASA模型的改进和遥感影像的空间分辨率对城市尺度NPP估算结果的影响。研究结果表明:①城市建筑用地对城市NPP的估算结果有较大的影响。改进的CASA模型将建筑用地的光合有效辐射(FPAR)归零,其估算值降至15.503 g C·m-2·month-1,有效去除了建筑用地对城区NPP估算的影响。②低空间分辨率的遥感数据对城市尺度的NPP存在高估现象。MOD13Q1+改进的CASA模型估算的NPP均值为18.607 g C·m-2·month-1,比Landsat 8 OLI+改进的CASA模型估算结果高出了3.104 g C·m-2·month-1。该研究结果可为城市尺度NPP估算提供新的方法,为城市碳汇估算提供科学依据。展开更多
基金supported by the Fundamental Research Funds for the Central Universities(No.JB-ZR1226)the National Natural Science Foundation of China(No.81202940)
文摘The present study was designed to isolate and evaluate the antibacterial activity of the compounds from the whole plant of Euphorbia helioscopia L.. Various chromatographic techniques were used to isolate and purify the compound. The structure of the compound was elucidated on basis of spectral data(1H NMR, 13 C NMR, 1H-1H COSY, HSQC, HMBC, NOESY, IR, and HR-ESI-MS). A new jatrophone-type diterpenoid(14α,15β-diacetoxy-3β-benzoyloxy-7β-nicotinoyloxy-9-oxo-jatropha-5E,11E-diene), named euphoheliosnoid E(1), was isolated from the whole plant of E. helioscopia L. Compound 1 showed significant anti-microbial activity against oral pathogens.
基金supported by the National Natural Science Foundation of China(No.61905100)the Fundamental Research Funds for the Central Universities(No.lzujbky-2020-65)。
文摘A proper excitation wavelength and strong hot-spot effect are of great importance for the application of surface-enhanced Raman spectroscopy(SERS)in the field of biochemistry.As a popular SERS substrate,noble metal nanoparticles dimer is analyzed systematically in this paper.The hot-spot effect and the resonance peak position with varying geometric parameters of metal nanoparticles are investigated.Moreover,the excitation wavelength of bimetallic structure is discussed as well.The conclusions can provide reference for the selection of metal material at different excitation wavelengths.
基金National Natural Science Foundation of China,No.41930865Project for Innovative Capacity Improvement in Hebei Province,No.225A4201D。
文摘Nitrate(NO_(3)^(-))accumulation and transport processes in the thick vadose zone affect the evolution of the groundwater NO_(3)^(-)content in intensive agricultural regions.Agricultural land-use change(ALUC),typically accompanied by substantial alterations in nitrogen fertilizer application and irrigation practices,is an important influencing factor.This study evaluated the changes in NO_(3)^(-)accumulation and transport in the deep vadose zone(DVZ,below the root zone),and the groundwater NO_(3)^(-)content associated with ALUC from grain to vegetable fields in the North China Plain(NCP).The ALUC from grain to vegetable resulted in nitrate–nitrogen(NO_(3)^(-)-N)accumulation in DVZ increased by 235.5 kg ha^(-1)m^(-1)(163.2%)in the piedmont plain and 224.9 kg ha^(-1)m^(-1)(102.7%)in the central plain,respectively.This change accelerated downward transport velocity in the DVZ(from 0.81±0.47 to 0.89±0.55 m yr^(-1)in the piedmont plain,and from 0.24±0.12 to 0.92±0.12 m yr^(-1)in the central plain)and increased NO_(3)^(-)leaching fluxes.High transport velocity and leaching fluxes resulted in chemical N-fertilizer entering the aquifer in several areas in the piedmont plain.The impact of the agricultural activity intensity changes,accompanied by the ALUC,on groundwater quantity and quality should be considered in similar regions.
文摘目的利用分子对接技术预测金莲花中牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、荭草素-2"-O-β-L-半乳糖苷、藜芦酸、金莲花碱的抗病毒和抗炎机制。方法运用Discovery Studio 2.5软件和药物化学数据库,将金莲花的6个活性成分与Toll样受体蛋白(TLRs)及神经氨酸酶(NA)靶点进行分子对接,通过模拟运算,分析对接结果及其功能区域的相互作用关系。结果牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、藜芦酸、金莲花碱均作用于1种或多种TLR,而荭草素-2"-O-β-L-半乳糖苷与3种TLR均无相互作用;黄酮类化合物,即牡荆素、荭草素、牡荆素-2"-O-β-L-半乳糖苷、荭草素-2"-O-β-L-半乳糖苷均可与NA结合,而藜芦酸和金莲花碱与NA无相互作用。结论金莲花的6个活性成分中,5个成分可影响TLRs介导的信号通路,TLR3、4、7是其抗病毒抗炎作用的潜在靶点;4个黄酮类化合物可通过作用于NA而影响流感病毒活性。本研究可为探讨金莲花的抗病毒和抗炎有效成分及其进一步开发利用提供依据。
文摘针对城市地物的特点,本文基于两种不同空间分辨率的遥感数据,利用原始与改进后的CASA估算了徐州城区的NPP,探讨了CASA模型的改进和遥感影像的空间分辨率对城市尺度NPP估算结果的影响。研究结果表明:①城市建筑用地对城市NPP的估算结果有较大的影响。改进的CASA模型将建筑用地的光合有效辐射(FPAR)归零,其估算值降至15.503 g C·m-2·month-1,有效去除了建筑用地对城区NPP估算的影响。②低空间分辨率的遥感数据对城市尺度的NPP存在高估现象。MOD13Q1+改进的CASA模型估算的NPP均值为18.607 g C·m-2·month-1,比Landsat 8 OLI+改进的CASA模型估算结果高出了3.104 g C·m-2·month-1。该研究结果可为城市尺度NPP估算提供新的方法,为城市碳汇估算提供科学依据。
