A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found t...A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green,red and blue emitters.While the luminance enhancements of blue and red phosphorescent microcavity devices are small,a current efficiency as high as 224 cd A21 is obtained in the green phosphorescent microcavity OLEDs.展开更多
AIM: To determine whether the photopic negative response(Ph NR) elicited by transient white flash on white background is characterizing for glaucoma model in rabbits.METHODS: Glaucoma was induced in twelve rabbits by ...AIM: To determine whether the photopic negative response(Ph NR) elicited by transient white flash on white background is characterizing for glaucoma model in rabbits.METHODS: Glaucoma was induced in twelve rabbits by subconjunctival injection of 0.05 m L of betamethasone in right eyes(each 1 m L contain betamethasone dipropionate5 mg and betamethasone sodium phosphate 2 mg).The intraocular pressure(IOP), electroretinogram(ERG) and visual evoked potential(VEP) were measured successively prior and on the 3, 7d, two weeks and four weeks postglaucoma induction. After four weeks, the animals were sacrificed and the globes were histopathologically examined.RESULTS: The IOP increased significantly after one week(P =0.0001), then it gradually returned to the control level. In ERG examination, the means of a and b wave amplitude and latency were not affected significantly.Ph NR amplitude decreased significantly within one week(P =0.0001), but its latency was not affected significantly(P =0.132). The means of VEP latency and amplitude were significantly affected after two weeks and four weeks of glaucoma induction(P =0.0001 and 0.02,respectively). The histopathologic examination of the globes showed reduced number of cells in the retinal ganglion cell layer with multiple vacuoles in the retinal nerve fibre layer.There was significant positive correlation between ganglion cell layer cells and Ph NR amplitude( r =0.8, P =0.002).CONCLUSION: The rise in IOP resulted in irreversible changes or incomplete recovery of VEP and Ph NR amplitude. Both Ph NR and VEP represented good additional tools in early diagnosis of glaucoma.展开更多
A series of opaque and semitransparent polymer solar cells(PSCs)were fabricated with PM6:Y6 as active layers,and 100 nm Al or 1 nm Au/(20,15,10 nm)Ag layer as electrode,respectively.The power conversion efficiency(PCE...A series of opaque and semitransparent polymer solar cells(PSCs)were fabricated with PM6:Y6 as active layers,and 100 nm Al or 1 nm Au/(20,15,10 nm)Ag layer as electrode,respectively.The power conversion efficiency(PCE)of opaque PSCs arrives to 15.83%based on the optimized active layer with a thickness of 100 nm,resulting from the well-balanced photon harvesting and charge collection.Meanwhile,the 100 nm PM6:Y6 blend film exhibits a 50.5%average visible transmittance(AVT),which has great potential in preparing efficient semitransparent PSCs.The semitransparent electrodes were fabricated with 1 nm Au and different thick Ag layers,exhibiting a relatively high transmittance in visible light range and relatively low transmittance in near infrared range.The PCE and AVT of the semitransparent PSCs can be adjusted from 14.20%to 12.37%and from 8.9%to 18.6%along with Ag layer thickness decreasing from 20 to 10 nm,respectively,which are impressive values among the reported semitransparent PSCs.展开更多
AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the o...AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022.All of them had eye health and normal visual function and could have refractive errors or not.Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition.The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured.Also,visual acuity,stereopsis and contrast sensitivity(in five spatial frequencies of 1.5,3,6,12,and 18 cycles per degree),were measured first in photopic light condition and then in mesopic light condition,by Snellen control vision chart,stereo butterfly test and the M&S technology monitor test respectively.RESULTS:In the 48 student subjects with an average age of 22.69±3.56y,mean of refractive error as sphere equivalent,visual acuity and stereopsis were-1.25±1.74 diopters,0 logMAR,44.37±13.03 seconds of arc,respectively in photopic light condition while in mesopic light was equal to-1.56±1.75 diopters,0.12±0.09 logMAR and 50.62±33.35 seconds of arc,respectively.The mean of contrast sensitivity measured at spatial frequencies of 1.5,3,6,12,and 18 cycles per degree in photopic condition was equal to 2.38±0.04,2.37±0.07,2.04±0.21,1.27±0.32,0.82±0.27 logarithm of contrast sensitivity,respectively and in mesopic lighting condition was equal to 2.34±0.12,2.30±0.16,1.84±0.28,1.02±0.28,0.63±0.24 logarithm of contrast sensitivity,respectively.Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables[refractive error(P<0.001),visual acuity(P<0.001),stereopsis(P=0.008)and contrast sensitivity(P<0.001)].CONCLUSION:The refractive error of the student subjects in展开更多
I am Dr. David P Pifiero from the Department of Optics, Pharmacology and Anatomy of the University of Alicante and from the Department of Ophthalmology of Vithas Medimar （Oftalmar） and Vithas Virgen del Carmen （Qv...I am Dr. David P Pifiero from the Department of Optics, Pharmacology and Anatomy of the University of Alicante and from the Department of Ophthalmology of Vithas Medimar （Oftalmar） and Vithas Virgen del Carmen （Qvision） hospitals in Spain.展开更多
Background:Cataract,a leading cause of vision impairment,is due to the lens becoming excessively optically dense.Change in the lens optical density(LOD)could be a useful indicator of incipient nuclear cataract and wou...Background:Cataract,a leading cause of vision impairment,is due to the lens becoming excessively optically dense.Change in the lens optical density(LOD)could be a useful indicator of incipient nuclear cataract and would necessitate the development of accurate measurement techniques.Mapcat sf^(TM) is a heterochromatic flicker photometer for measuring macular pigment optical density(MPOD)under photopic conditions.In the process,it also measures LOD that is needed in the calculation of MPOD.LOD is then converted by the instrument to“lens equivalent age”(LEA).However,varying cone photoreceptor ratios among individuals could affect the LEA measurement.Scotopic vision is mediated by rod photoreceptors;therefore,LEA measurement under scotopic conditions potentially provides a reliable standard for assessing other methods.The study was conducted to test the level of agreement between the LEA data obtained under photopic and scotopic conditions for a sample population.We also comment on factors that might contribute to any disagreement.Methods:LEAs were obtained by Mapcat sf for 25 subjects and compared with those obtained under absolute scotopic threshold conditions.Results:The mean scotopic LEA for the subjects was 2.7 years higher than the mean photopic LEA,but this difference was not statistically significant.Measurements by the two methods were reasonably correlated(r 2=0.59,p<0.0001).Significant individual differences in LEA by the two methods were found for six of the 25 subjects.Although our calculations included a standard long-to medium-wavelength-sensitive cone ratio,we found that different ratios could be found that rendered the differences in LEA insignificant for two of these six subjects.Variability in pupil diameter during scotopic measurements was considered another potential source of discrepancy between LEAs by the two methods.Conclusion:The absolute threshold technique,with long adaptation times,is probably impractical for routine lens density measurement,whereas Mapcat sf provided a rapid,straight展开更多
背景玻璃体腔注射曲安奈德（TA）对于视网膜中央静脉阻塞（CRVO）患者黄斑区水肿的消退以及视力的维持和提高作用较明显，明视负向反应（PhNR）可以反映视网膜内层视网膜神经节细胞（RGCs）及其轴突的功能，两者间是否存在联系是尚待解...背景玻璃体腔注射曲安奈德（TA）对于视网膜中央静脉阻塞（CRVO）患者黄斑区水肿的消退以及视力的维持和提高作用较明显，明视负向反应（PhNR）可以反映视网膜内层视网膜神经节细胞（RGCs）及其轴突的功能，两者间是否存在联系是尚待解决的问题。目的比较分析CRVO黄斑水肿患者玻璃体腔内注射TA前后视网膜电图（ERG）的PhNR的变化，探讨PhNR作为治疗过程中监测视网膜功能的价值。方法收集比较CRVO伴黄斑水肿者12例13眼，于玻璃体腔内注射TA（0．1ml，4mg）前1d及注射后4周分别用标准小数视力表、光学相干断层扫描仪（OCT）、德国Roland RETI scan3．15系统检查视力、黄斑区视网膜厚度和PhNR。结果接受TA玻璃体腔注射后4周，12例患者13眼中有12眼视力提高，1眼视力不变。与玻璃体腔注射TA前比较，玻璃体腔注射TA后4周OCT显示黄斑区神经上皮细胞层水肿明显减轻，厚度减小；闪光视网膜电图（F—ERG）显示PhNR在玻璃体腔注射TA后波形明显改善。玻璃体腔注射前后患眼的视力分别为0．32±0．12和0．48±0．09，差异有统计学意义（t=6．325，P=0．000）；玻璃体腔注射后患眼黄斑区神经上皮层厚度与注射前比较明显下降[（459．46±131．31）μmvs（297．54±43．31）μm]，差异有统计学意义（t=5．961，P=0．000），玻璃体腔注射前后患眼的PhNR平均振幅值分别为（61．28±20．16）μV和（80．23±22．96）μV，差异有统计学意义（t=4．438，P=0．001）。玻璃体腔注射TA前后黄斑区神经上皮层厚度与PhNR振幅间均无明显的相关性（注射前：r=0．587，P=0．035；注射后：r=一0．011，P=0．971）。结论CRVO黄斑水肿患者行玻穗蚀日奉内沣射TA后，PhNR可以做为监测患者内层视网膜功能变化的有效指标。展开更多
文摘A systematic study has been conducted on microcavity organic light emitting diodes(OLEDs)based on green,red and blue phosphorescent emitters to elucidate the microcavity effects for different color emitters.We found that the luminance output is determined by the reflectivity of the semitransparent electrode and the photopic response of the green,red and blue emitters.While the luminance enhancements of blue and red phosphorescent microcavity devices are small,a current efficiency as high as 224 cd A21 is obtained in the green phosphorescent microcavity OLEDs.
文摘AIM: To determine whether the photopic negative response(Ph NR) elicited by transient white flash on white background is characterizing for glaucoma model in rabbits.METHODS: Glaucoma was induced in twelve rabbits by subconjunctival injection of 0.05 m L of betamethasone in right eyes(each 1 m L contain betamethasone dipropionate5 mg and betamethasone sodium phosphate 2 mg).The intraocular pressure(IOP), electroretinogram(ERG) and visual evoked potential(VEP) were measured successively prior and on the 3, 7d, two weeks and four weeks postglaucoma induction. After four weeks, the animals were sacrificed and the globes were histopathologically examined.RESULTS: The IOP increased significantly after one week(P =0.0001), then it gradually returned to the control level. In ERG examination, the means of a and b wave amplitude and latency were not affected significantly.Ph NR amplitude decreased significantly within one week(P =0.0001), but its latency was not affected significantly(P =0.132). The means of VEP latency and amplitude were significantly affected after two weeks and four weeks of glaucoma induction(P =0.0001 and 0.02,respectively). The histopathologic examination of the globes showed reduced number of cells in the retinal ganglion cell layer with multiple vacuoles in the retinal nerve fibre layer.There was significant positive correlation between ganglion cell layer cells and Ph NR amplitude( r =0.8, P =0.002).CONCLUSION: The rise in IOP resulted in irreversible changes or incomplete recovery of VEP and Ph NR amplitude. Both Ph NR and VEP represented good additional tools in early diagnosis of glaucoma.
基金financially supported by the National Natural Science Foundation of China(61675017,61975006)Beijing Natural Science Foundation(4192049).
文摘A series of opaque and semitransparent polymer solar cells(PSCs)were fabricated with PM6:Y6 as active layers,and 100 nm Al or 1 nm Au/(20,15,10 nm)Ag layer as electrode,respectively.The power conversion efficiency(PCE)of opaque PSCs arrives to 15.83%based on the optimized active layer with a thickness of 100 nm,resulting from the well-balanced photon harvesting and charge collection.Meanwhile,the 100 nm PM6:Y6 blend film exhibits a 50.5%average visible transmittance(AVT),which has great potential in preparing efficient semitransparent PSCs.The semitransparent electrodes were fabricated with 1 nm Au and different thick Ag layers,exhibiting a relatively high transmittance in visible light range and relatively low transmittance in near infrared range.The PCE and AVT of the semitransparent PSCs can be adjusted from 14.20%to 12.37%and from 8.9%to 18.6%along with Ag layer thickness decreasing from 20 to 10 nm,respectively,which are impressive values among the reported semitransparent PSCs.
文摘AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022.All of them had eye health and normal visual function and could have refractive errors or not.Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition.The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured.Also,visual acuity,stereopsis and contrast sensitivity(in five spatial frequencies of 1.5,3,6,12,and 18 cycles per degree),were measured first in photopic light condition and then in mesopic light condition,by Snellen control vision chart,stereo butterfly test and the M&S technology monitor test respectively.RESULTS:In the 48 student subjects with an average age of 22.69±3.56y,mean of refractive error as sphere equivalent,visual acuity and stereopsis were-1.25±1.74 diopters,0 logMAR,44.37±13.03 seconds of arc,respectively in photopic light condition while in mesopic light was equal to-1.56±1.75 diopters,0.12±0.09 logMAR and 50.62±33.35 seconds of arc,respectively.The mean of contrast sensitivity measured at spatial frequencies of 1.5,3,6,12,and 18 cycles per degree in photopic condition was equal to 2.38±0.04,2.37±0.07,2.04±0.21,1.27±0.32,0.82±0.27 logarithm of contrast sensitivity,respectively and in mesopic lighting condition was equal to 2.34±0.12,2.30±0.16,1.84±0.28,1.02±0.28,0.63±0.24 logarithm of contrast sensitivity,respectively.Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables[refractive error(P<0.001),visual acuity(P<0.001),stereopsis(P=0.008)and contrast sensitivity(P<0.001)].CONCLUSION:The refractive error of the student subjects in
文摘I am Dr. David P Pifiero from the Department of Optics, Pharmacology and Anatomy of the University of Alicante and from the Department of Ophthalmology of Vithas Medimar （Oftalmar） and Vithas Virgen del Carmen （Qvision） hospitals in Spain.
文摘Background:Cataract,a leading cause of vision impairment,is due to the lens becoming excessively optically dense.Change in the lens optical density(LOD)could be a useful indicator of incipient nuclear cataract and would necessitate the development of accurate measurement techniques.Mapcat sf^(TM) is a heterochromatic flicker photometer for measuring macular pigment optical density(MPOD)under photopic conditions.In the process,it also measures LOD that is needed in the calculation of MPOD.LOD is then converted by the instrument to“lens equivalent age”(LEA).However,varying cone photoreceptor ratios among individuals could affect the LEA measurement.Scotopic vision is mediated by rod photoreceptors;therefore,LEA measurement under scotopic conditions potentially provides a reliable standard for assessing other methods.The study was conducted to test the level of agreement between the LEA data obtained under photopic and scotopic conditions for a sample population.We also comment on factors that might contribute to any disagreement.Methods:LEAs were obtained by Mapcat sf for 25 subjects and compared with those obtained under absolute scotopic threshold conditions.Results:The mean scotopic LEA for the subjects was 2.7 years higher than the mean photopic LEA,but this difference was not statistically significant.Measurements by the two methods were reasonably correlated(r 2=0.59,p<0.0001).Significant individual differences in LEA by the two methods were found for six of the 25 subjects.Although our calculations included a standard long-to medium-wavelength-sensitive cone ratio,we found that different ratios could be found that rendered the differences in LEA insignificant for two of these six subjects.Variability in pupil diameter during scotopic measurements was considered another potential source of discrepancy between LEAs by the two methods.Conclusion:The absolute threshold technique,with long adaptation times,is probably impractical for routine lens density measurement,whereas Mapcat sf provided a rapid,straight
文摘背景玻璃体腔注射曲安奈德（TA）对于视网膜中央静脉阻塞（CRVO）患者黄斑区水肿的消退以及视力的维持和提高作用较明显，明视负向反应（PhNR）可以反映视网膜内层视网膜神经节细胞（RGCs）及其轴突的功能，两者间是否存在联系是尚待解决的问题。目的比较分析CRVO黄斑水肿患者玻璃体腔内注射TA前后视网膜电图（ERG）的PhNR的变化，探讨PhNR作为治疗过程中监测视网膜功能的价值。方法收集比较CRVO伴黄斑水肿者12例13眼，于玻璃体腔内注射TA（0．1ml，4mg）前1d及注射后4周分别用标准小数视力表、光学相干断层扫描仪（OCT）、德国Roland RETI scan3．15系统检查视力、黄斑区视网膜厚度和PhNR。结果接受TA玻璃体腔注射后4周，12例患者13眼中有12眼视力提高，1眼视力不变。与玻璃体腔注射TA前比较，玻璃体腔注射TA后4周OCT显示黄斑区神经上皮细胞层水肿明显减轻，厚度减小；闪光视网膜电图（F—ERG）显示PhNR在玻璃体腔注射TA后波形明显改善。玻璃体腔注射前后患眼的视力分别为0．32±0．12和0．48±0．09，差异有统计学意义（t=6．325，P=0．000）；玻璃体腔注射后患眼黄斑区神经上皮层厚度与注射前比较明显下降[（459．46±131．31）μmvs（297．54±43．31）μm]，差异有统计学意义（t=5．961，P=0．000），玻璃体腔注射前后患眼的PhNR平均振幅值分别为（61．28±20．16）μV和（80．23±22．96）μV，差异有统计学意义（t=4．438，P=0．001）。玻璃体腔注射TA前后黄斑区神经上皮层厚度与PhNR振幅间均无明显的相关性（注射前：r=0．587，P=0．035；注射后：r=一0．011，P=0．971）。结论CRVO黄斑水肿患者行玻穗蚀日奉内沣射TA后，PhNR可以做为监测患者内层视网膜功能变化的有效指标。
