The interlayer spacing(i.e.,d-spacing)plays a crucial role in determining the selectivity and permeability of nanofiltration membranes.A high-throughput directional filtration can be achieved by designing and controll...The interlayer spacing(i.e.,d-spacing)plays a crucial role in determining the selectivity and permeability of nanofiltration membranes.A high-throughput directional filtration can be achieved by designing and controlling the d-spacing.In this study,the d-spacing of a graphene oxide(GO)membrane was tuned and fixed to the desired value(approximately 0.79 nm)using a solution of polyethyleneimine(PEI)and GO at a PEI/GO mass ratio of15:1.The resultant PEI/GO was deposited on a polyacrylonitrile(PAN)substrate to form a robust composite nanofiltration membrane(a PEI/GO@PAN membrane).The as-prepared membrane exhibited an ultrahigh flux of117.8 L·m^(-2)·h^(-1),and the rejection values for Direct Red80(DR80)and Na_(2)SO_(4)reached 99.7%and<1.7%,respectively;these are desirable values for dye/salt separation.The PEI/GO@PAN membrane exhibited an excellent filtration performance,and had a longer lifespan and excellent reusability because of its reinforced nature.This work suggested that tuning the d-spacing with PEI would be an effective strategy to achieve the anticipated functions of nanofiltration membranes.展开更多
目的:评价磁共振成像(MRI)三维可变翻转角快速自旋回波(3D-sampling perfection with applicationoptimized contrasts by using different filp angle evolutions,3D-SPACE)序列结合不同图像融合技术获得的图像对垂体大腺瘤术前评估的...目的:评价磁共振成像(MRI)三维可变翻转角快速自旋回波(3D-sampling perfection with applicationoptimized contrasts by using different filp angle evolutions,3D-SPACE)序列结合不同图像融合技术获得的图像对垂体大腺瘤术前评估的应用价值。方法:收集中南大学湘雅医院43例术后证实为垂体大腺瘤患者的MRI资料,包括常规MRI平扫+增强、3D-SPACE T2WI和3D-SPACE T1WI+C(增强)的影像资料。3D-SPACE T2WI/3D-SPACE T1WI+C序列分别采用正相+正相、反相+正相、正相+反相、反相+反相以及正相伪彩+正相、正相+正相伪彩6种组合方式融合,由两名放射科高年资主治医生采用半定量方法对不同组合方式图像质量进行评价及比较,得到最佳融合模式;并根据肿瘤对视交叉、动眼神经、海绵窦血管的侵袭程度,按照三级评分制对MRI平扫+增强(常规MRI增强组),3DSPACE T2WI,3D-SPACE T1WI+C及2种3D-SPACE序列融合(融合组)的图像进行评估,以术中观察结果为金标准,采用Fisher概率确切法比较4组图像显示垂体大腺瘤对周围组织侵袭程度与金标准的一致性。结果:Kruskal-Wallis H秩和检验结果显示6种图像融合模式中,以3D-SPACE T1WI+C正相伪彩与3D-SPACE T2WI正相融合图像质量最优(P<0.05)。比较肿瘤对动眼神经侵袭程度I,II,III级关系一致性时,MRI增强组、3D-SPACE T1WI+C组、3DSPACE T2WI组、融合组4组图像差异均无统计学意义(均P>0.05);比较肿瘤对视交叉侵袭程度I级关系一致性时,4组图像差异均无统计学意义(均P>0.05),比较侵袭程度II,III级关系一致性时,融合组图像与3D-SPACE T2WI组差异无统计学意义(P>0.05),但均明显优于常规MRI增强组(均P<0.01)和3D-SPACE T1WI+C组(均P<0.05);比较肿瘤对海绵窦血管侵袭程度I,III级关系一致性时,4组图像差异均无统计学意义(均P>0.05),比较侵袭程度II级关系一致性时,融合组图像与3D-SPACE T1WI+C组差异无统计学意义(P>0.05),但均明显优于常规MRI增强组(均P<0.01)和3D-SPACE T2WI组(均P<0.05)。结论:MRI 3D-SPACE序列结合图像融合技术在显示垂体大腺瘤对颅底血管神经的侵袭程度上明显优于常规MRI序列,在显示肿瘤与视交叉II,III级侵袭关系及肿瘤与海绵窦血管II级侵袭关系上明显优于单独的3D-SPACE序列,对于手术前的风险评估及手术方案的制订有良好的应用前景。展开更多
基金financially supported by Griffith University Ph.D.Scholarshipthe National Natural Science Foundation of China(No.21808094)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions,Natural Science Foundation of Jiangsu Province(No.BK20170237)Startup Funding for Introduced Talents of Jiangsu Normal University(No.16XLR015)。
文摘The interlayer spacing(i.e.,d-spacing)plays a crucial role in determining the selectivity and permeability of nanofiltration membranes.A high-throughput directional filtration can be achieved by designing and controlling the d-spacing.In this study,the d-spacing of a graphene oxide(GO)membrane was tuned and fixed to the desired value(approximately 0.79 nm)using a solution of polyethyleneimine(PEI)and GO at a PEI/GO mass ratio of15:1.The resultant PEI/GO was deposited on a polyacrylonitrile(PAN)substrate to form a robust composite nanofiltration membrane(a PEI/GO@PAN membrane).The as-prepared membrane exhibited an ultrahigh flux of117.8 L·m^(-2)·h^(-1),and the rejection values for Direct Red80(DR80)and Na_(2)SO_(4)reached 99.7%and<1.7%,respectively;these are desirable values for dye/salt separation.The PEI/GO@PAN membrane exhibited an excellent filtration performance,and had a longer lifespan and excellent reusability because of its reinforced nature.This work suggested that tuning the d-spacing with PEI would be an effective strategy to achieve the anticipated functions of nanofiltration membranes.
