Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target m...Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety.展开更多
Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by esta...Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by establishing a mechanistic drifting forecast model based on kinetic analysis. Taking tide–wind–wave into consideration, the forecast model is validated against in situ drifting experiment in the Radial Sand Ridges. Model results show good performance with respect to the measured drifting features, characterized by migrating back and forth twice a day with daily downwind displacements. Trajectory models are used to evaluate the influence of the individual hydrodynamic forcing. The tidal current is the fundamental dynamic condition in the Radial Sand Ridges and has the greatest impact on the drifting distance. However, it loses its leading position in the field of the daily displacement of the used drifter. The simulations reveal that different hydrodynamic forces dominate the daily displacement of the used drifter at different wind scales. The wave-induced mass transport has the greatest influence on the daily displacement at Beaufort wind scale 5–6; while wind drag contributes mostly at wind scale 2–4.展开更多
针对低渗透油藏注入性差、洗油效率低,水驱无法有效提高采收率等问题,提出了一种低界面张力小分子驱油剂(LST溶液)提高低渗透油藏采收率新技术,评价了该驱油剂的界面活性、增黏性、乳化性、润湿性及其油藏环境适应性和驱油效果。结果表...针对低渗透油藏注入性差、洗油效率低,水驱无法有效提高采收率等问题,提出了一种低界面张力小分子驱油剂(LST溶液)提高低渗透油藏采收率新技术,评价了该驱油剂的界面活性、增黏性、乳化性、润湿性及其油藏环境适应性和驱油效果。结果表明,该驱油剂具有良好的界面活性和增黏性。在6788.23 mg/L的矿化水中,质量分数为0.4%时的LST溶液的油水界面张力为0.012 m N/m,且黏度与油藏原油黏度(3.4 m Pa·s)相近。LST溶液具有较好的油水乳化能力,可改善油藏水润湿性。在47.2℃、油水比为1∶1的条件下,LST乳状液的稳定时间为120 min。岩心经LST溶液处理后,水相接触角由57.0°降至12.5°,油相接触角由24.3°增至38.6°。LST溶液具有良好的静态抗吸附性能,经岩心3次吸附后,LST残液与原油间的界面张力仍能达到10^(-2)m N/m数量级,黏度达2.895 m Pa·s,乳状液静置10、120 min的析水率分别为38.6%、73.4%。LST溶液的耐盐性能较好。在矿化度为16570 mg/L的环境下,其油水界面张力低于7×10^(-2)m N/m、黏度为3.06 m Pa·s。LST溶液的驱油效果较好,可有效封堵高渗透孔道,启动低渗透孔道残余油。注入0.4 PV 0.4%LST溶液可使均质岩心(0.05μm^(2))的水驱驱油效率提高11.21百分点,非均质岩心(级差3~10)水驱后的综合采收率提高6.55百分点~19.41百分点。LST溶液可以实现低剂量或低成本有效提高水驱采收率,在低渗透非均质油藏化学驱提高采收率方面具有较好的应用前景。展开更多
基金supported by the National Key R&D Program of China(2017YFC1600603)the Funds for Huangshan Professorship of Hefei University of Technology(407-037019).
文摘Food safety is a major issue to public health and have attracted global attention.Fast,sensitive,and reliable detection methods for food hazardous substances is highly desirable.Aptamers which can bind to the target molecules with high affinity and specificity represent an attractive tool for the recognition of food hazardous substances,which play an important role in the development and application of new food safety detection technology.But current assays for characterizing small molecule-aptamer binding are limited by either the mass sensitivity or the size differentiation ability.Herein,we proposed a comprehensive method for assessing the dissociation equilibria of small molecule-aptamer,which is immobilized-free under ambient conditions.The design employs the Le Chatelier’s principle and could be used to effectively measure small molecule-aptamer interactions.ATP binding aptamer and anti-aflatoxin B1 aptamer were used as the model system to determine their affinity,in which their dissociation equilibria measurements are in excellent close to their previous work.Due to the simplicity and sensitivity of this new method,we believe that it could be recommended as an effective tool for characterizing small molecule-aptamer interactions and promote the further application of small molecular aptamer in food safety.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFC0405401)the National Science&Technology Pillar Program(Grant No.2012BAB03B01)+1 种基金the Fundamental Research Funds for the Central Universities,Hohai University(Grant No.2014B30914)the Natural Science Foundation of Jiangsu Province(Grant No.BK2012411)
文摘Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by establishing a mechanistic drifting forecast model based on kinetic analysis. Taking tide–wind–wave into consideration, the forecast model is validated against in situ drifting experiment in the Radial Sand Ridges. Model results show good performance with respect to the measured drifting features, characterized by migrating back and forth twice a day with daily downwind displacements. Trajectory models are used to evaluate the influence of the individual hydrodynamic forcing. The tidal current is the fundamental dynamic condition in the Radial Sand Ridges and has the greatest impact on the drifting distance. However, it loses its leading position in the field of the daily displacement of the used drifter. The simulations reveal that different hydrodynamic forces dominate the daily displacement of the used drifter at different wind scales. The wave-induced mass transport has the greatest influence on the daily displacement at Beaufort wind scale 5–6; while wind drag contributes mostly at wind scale 2–4.
文摘针对低渗透油藏注入性差、洗油效率低,水驱无法有效提高采收率等问题,提出了一种低界面张力小分子驱油剂(LST溶液)提高低渗透油藏采收率新技术,评价了该驱油剂的界面活性、增黏性、乳化性、润湿性及其油藏环境适应性和驱油效果。结果表明,该驱油剂具有良好的界面活性和增黏性。在6788.23 mg/L的矿化水中,质量分数为0.4%时的LST溶液的油水界面张力为0.012 m N/m,且黏度与油藏原油黏度(3.4 m Pa·s)相近。LST溶液具有较好的油水乳化能力,可改善油藏水润湿性。在47.2℃、油水比为1∶1的条件下,LST乳状液的稳定时间为120 min。岩心经LST溶液处理后,水相接触角由57.0°降至12.5°,油相接触角由24.3°增至38.6°。LST溶液具有良好的静态抗吸附性能,经岩心3次吸附后,LST残液与原油间的界面张力仍能达到10^(-2)m N/m数量级,黏度达2.895 m Pa·s,乳状液静置10、120 min的析水率分别为38.6%、73.4%。LST溶液的耐盐性能较好。在矿化度为16570 mg/L的环境下,其油水界面张力低于7×10^(-2)m N/m、黏度为3.06 m Pa·s。LST溶液的驱油效果较好,可有效封堵高渗透孔道,启动低渗透孔道残余油。注入0.4 PV 0.4%LST溶液可使均质岩心(0.05μm^(2))的水驱驱油效率提高11.21百分点,非均质岩心(级差3~10)水驱后的综合采收率提高6.55百分点~19.41百分点。LST溶液可以实现低剂量或低成本有效提高水驱采收率,在低渗透非均质油藏化学驱提高采收率方面具有较好的应用前景。
