We conduct optical-tweezers experiments to investigate the average potential energies of passive plates harmonically trapped in bacterial suspensions.Our results show that the mean potential energies along both the ma...We conduct optical-tweezers experiments to investigate the average potential energies of passive plates harmonically trapped in bacterial suspensions.Our results show that the mean potential energies along both the major and minor axes increase with bacterial concentration but decrease with trap stiffness.Notably,the average potential energy along the major axis consistently exceeds that along the minor axis.This discrepancy from equilibrium systems is primarily attributed to the distinct bacterial flow fields and direct bacterium–plate collisions near the major and minor axes,as evidenced by the higher orientational order around the plate along the major compared to the minor axis,despite identical bacterial densities in these regions.Our findings highlight the critical role of hydrodynamic interactions in determining the potential energy of passive objects immersed in an active bath.展开更多
目的探讨腹型超重者CTA检查过程中采用80 k V管电压对图像质量及患者接受的有效辐射剂量(ED)的影响。方法选取腹型超重的拟诊冠心病患者105例,随机分为高剂量组(A组)、中剂量组(B组)、低剂量组(C组)各35例。应用Phillips 64排128层螺旋C...目的探讨腹型超重者CTA检查过程中采用80 k V管电压对图像质量及患者接受的有效辐射剂量(ED)的影响。方法选取腹型超重的拟诊冠心病患者105例,随机分为高剂量组(A组)、中剂量组(B组)、低剂量组(C组)各35例。应用Phillips 64排128层螺旋CT,A、B、C组分别采用120、100、80 k V/800 m As管电压行冠状动脉CTA检查。将冠状动脉分为右冠状动脉(RCA)近中段,左主干(LMA),左前降支(LAD)近、中段,左回旋支(LCX)近段共6个主要诊断节段进行主观评分评价;测量RCA近段、LM、LAD近段、LCX近段的增强后血管中心的SD值,评价图像噪声,计算噪声比(CNR)、信噪比(SNR)。计算CTA检查过程中各组患者接受的ED。结果 A、B组间各冠状动脉节段主观评分均高于C组(P均<0.05),A、B组间各冠状动脉节段主观评分差异无统计学意义(P均>0.05)。C组RCA近段、LM、LAD近段、LCX近段SD、CNR均高于A、B组(P均<0.05)。A、B、C组ED分别为(13.61±1.16)、(8.41±0.88)、(5.74±1.28)m Sv,C组ED少于A、B组(P均<0.05)。结论对腹型超重者CTA检查过程中采用80 k V管电压,所获得的CT图像质量符合诊断要求,并可降低对患者的ED。展开更多
基金supports of the National Natural Science Foundation of China(Grant Nos.12304245,12374205,12475031,and 12364029)the Science Foundation of China University of Petroleum,Beijing(Grant Nos.2462023YJRC031 and 2462024BJRC010)+4 种基金the National Key Laboratory of Petroleum Resources and Engineering(Grant No.PRE/DX-2407)the Natural Science Foundation of Shandong Province(Grant No.ZR2024YQ017)the Young Elite Scientist Sponsorship Program by BAST(Grant No.BYESS2023300)the Beijing Institute of Technology Research Fund Program for Young ScholarsThis work was also supported by Beijing National Laboratory for Condensed Matter Physics(Grant Nos.2023BNLCMPKF014 and 2024BNLCMPKF009).
文摘We conduct optical-tweezers experiments to investigate the average potential energies of passive plates harmonically trapped in bacterial suspensions.Our results show that the mean potential energies along both the major and minor axes increase with bacterial concentration but decrease with trap stiffness.Notably,the average potential energy along the major axis consistently exceeds that along the minor axis.This discrepancy from equilibrium systems is primarily attributed to the distinct bacterial flow fields and direct bacterium–plate collisions near the major and minor axes,as evidenced by the higher orientational order around the plate along the major compared to the minor axis,despite identical bacterial densities in these regions.Our findings highlight the critical role of hydrodynamic interactions in determining the potential energy of passive objects immersed in an active bath.
文摘目的探讨腹型超重者CTA检查过程中采用80 k V管电压对图像质量及患者接受的有效辐射剂量(ED)的影响。方法选取腹型超重的拟诊冠心病患者105例,随机分为高剂量组(A组)、中剂量组(B组)、低剂量组(C组)各35例。应用Phillips 64排128层螺旋CT,A、B、C组分别采用120、100、80 k V/800 m As管电压行冠状动脉CTA检查。将冠状动脉分为右冠状动脉(RCA)近中段,左主干(LMA),左前降支(LAD)近、中段,左回旋支(LCX)近段共6个主要诊断节段进行主观评分评价;测量RCA近段、LM、LAD近段、LCX近段的增强后血管中心的SD值,评价图像噪声,计算噪声比(CNR)、信噪比(SNR)。计算CTA检查过程中各组患者接受的ED。结果 A、B组间各冠状动脉节段主观评分均高于C组(P均<0.05),A、B组间各冠状动脉节段主观评分差异无统计学意义(P均>0.05)。C组RCA近段、LM、LAD近段、LCX近段SD、CNR均高于A、B组(P均<0.05)。A、B、C组ED分别为(13.61±1.16)、(8.41±0.88)、(5.74±1.28)m Sv,C组ED少于A、B组(P均<0.05)。结论对腹型超重者CTA检查过程中采用80 k V管电压,所获得的CT图像质量符合诊断要求,并可降低对患者的ED。
