AIM: To quantify the changes in the lens profile with accommodation in different age groups. METHODS: The Pentacam HR system was used to obtain the images of the anterior eye segment from 23 young and 15 presbyopic em...AIM: To quantify the changes in the lens profile with accommodation in different age groups. METHODS: The Pentacam HR system was used to obtain the images of the anterior eye segment from 23 young and 15 presbyopic emmetropic subjects in unaccommodated (with an accommodation stimulus of 0.0D) and accommodated (with an accommodation stimulus of 5.0D for the young group and 1.0D for the presbyopic group) states. The phakic crystalline lens shape, including curvature of crystalline lens and central lens thickness (CLT), and the measurements of anterior segment length (ASL), central anterior chamber depth (CACD) were investigated. The anterior chamber volume (ACV) was also measured. RESULTS: The reduction of CACD and ACV were significant in both groups after accommodation stimulus. From the profile of anterior eye segment, a significant decrease in anterior crystalline lens radii of curvature (-2.52mm) and a mean increase in CLT (0.222mm) and ASL (0.1138mm) were found in the. young group with an accommodation stimulus of 5.0D. However, no statistically significant changes of CLT, ASL, or crystalline lens radii of curvature were found in the presbyopic group. CONCLUSION: Our data showed that the shallowing of anterior chamber during accommodation was caused by the forward bulging of the anterior lens surface, rather than by anterior shifting of lens position in either young or presbyopic subjects.展开更多
Compared to regular conjugated polymers,the random conjugated terpolymers are usually not beneficial to achieve highly efficient non-fullerene(NF)-based polymer solar cells(PSCs)due to their disordered chemical struct...Compared to regular conjugated polymers,the random conjugated terpolymers are usually not beneficial to achieve highly efficient non-fullerene(NF)-based polymer solar cells(PSCs)due to their disordered chemical structures.In this work,we report two random terpolymer donors(PBNB80 and PBNB50)by tuning the molar ratio of electron-accepting units of 1,3-di(thiophen-2-yl)naphtho[2,3-c]thiophene-4,9-dione(NTD)and 1,3-bis(4-chlorothiophen-2-yl)-4 H,8 H-benzo[1,2-c:4,5-c’]dithiophene-4,8-dione(ClBDD),at the same time,the parent polymers(PBNB100 and PBNB00)are also compared to study.These four polymer donors exhibit similar optical bandgaps and gradually deepen highest occupied molecular orbital levels.Importantly,aggregation and self-organization properties of the random terpolymer donors are optimized,which result in the better morphology and crystal coherence length after blending with NF acceptor of BO-4 Cl.Particularly,a PBNB80:BO-4 Cl blend forms an optimal nanoscale phase-separation morphology,thereby producing an outstanding power conversion efficiency of 16.0%,which is much higher than those(12.8%and 10.7%)of their parent binary polymer donor-based devices.This work demonstrates that rational using terpolymerization strategy to prepare random terpolymer is a very important method to achieve highly efficient NF-PSCs.展开更多
The current research was carried out to verify if low-temperature spreading treatments(CK,natural spreading;LTD,low temperature+dark;LTY,low temperature+yellow light;LTCD,low temperature+CO_(2))had a positive effect o...The current research was carried out to verify if low-temperature spreading treatments(CK,natural spreading;LTD,low temperature+dark;LTY,low temperature+yellow light;LTCD,low temperature+CO_(2))had a positive effect on the aroma quality of green tea products under the premise of prolonging the spreading period of picked tea leaves.Compared to CK,LTY significantly improved the aroma quality in green tea products.The spreading leaves with LTY treatment showed the highest relative content of terpene volatiles and amino acid-derived volatiles.Furthermore,terpene precursor synthesis genes,such as linalool synthase genes(CsLIS2,CsLIS3,CsLIS4)and farnesene synthase genes(CsFS5,CsFS10)were significantly up-regulated in spreading leaves after LTY treatment.This research furthers our understanding of volatile metabolism in postharvest tea leaves and provides a genetic metabolic basis for the application of low-temperature spreading in green tea processing.展开更多
基金Supported by National Natural Science Foundation of China (No. 81070747)Research Award for New Century Excellent Talents in University (No. NCET08-0586)in ChinaScience and Technology Planning Project of Guangdong Province, China (No.2010B090400416)
文摘AIM: To quantify the changes in the lens profile with accommodation in different age groups. METHODS: The Pentacam HR system was used to obtain the images of the anterior eye segment from 23 young and 15 presbyopic emmetropic subjects in unaccommodated (with an accommodation stimulus of 0.0D) and accommodated (with an accommodation stimulus of 5.0D for the young group and 1.0D for the presbyopic group) states. The phakic crystalline lens shape, including curvature of crystalline lens and central lens thickness (CLT), and the measurements of anterior segment length (ASL), central anterior chamber depth (CACD) were investigated. The anterior chamber volume (ACV) was also measured. RESULTS: The reduction of CACD and ACV were significant in both groups after accommodation stimulus. From the profile of anterior eye segment, a significant decrease in anterior crystalline lens radii of curvature (-2.52mm) and a mean increase in CLT (0.222mm) and ASL (0.1138mm) were found in the. young group with an accommodation stimulus of 5.0D. However, no statistically significant changes of CLT, ASL, or crystalline lens radii of curvature were found in the presbyopic group. CONCLUSION: Our data showed that the shallowing of anterior chamber during accommodation was caused by the forward bulging of the anterior lens surface, rather than by anterior shifting of lens position in either young or presbyopic subjects.
基金the financial support from the National Natural Science Foundation of China(Grant Nos.51703228,51673201,21835006)Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-201903)。
文摘Compared to regular conjugated polymers,the random conjugated terpolymers are usually not beneficial to achieve highly efficient non-fullerene(NF)-based polymer solar cells(PSCs)due to their disordered chemical structures.In this work,we report two random terpolymer donors(PBNB80 and PBNB50)by tuning the molar ratio of electron-accepting units of 1,3-di(thiophen-2-yl)naphtho[2,3-c]thiophene-4,9-dione(NTD)and 1,3-bis(4-chlorothiophen-2-yl)-4 H,8 H-benzo[1,2-c:4,5-c’]dithiophene-4,8-dione(ClBDD),at the same time,the parent polymers(PBNB100 and PBNB00)are also compared to study.These four polymer donors exhibit similar optical bandgaps and gradually deepen highest occupied molecular orbital levels.Importantly,aggregation and self-organization properties of the random terpolymer donors are optimized,which result in the better morphology and crystal coherence length after blending with NF acceptor of BO-4 Cl.Particularly,a PBNB80:BO-4 Cl blend forms an optimal nanoscale phase-separation morphology,thereby producing an outstanding power conversion efficiency of 16.0%,which is much higher than those(12.8%and 10.7%)of their parent binary polymer donor-based devices.This work demonstrates that rational using terpolymerization strategy to prepare random terpolymer is a very important method to achieve highly efficient NF-PSCs.
基金the National Key R&D Program of China(Project No.2018YFD1000600)the Fundamental Research Funds for the Central Universities,Huazhong Agricultural University(Project No.2662017PY053).
文摘The current research was carried out to verify if low-temperature spreading treatments(CK,natural spreading;LTD,low temperature+dark;LTY,low temperature+yellow light;LTCD,low temperature+CO_(2))had a positive effect on the aroma quality of green tea products under the premise of prolonging the spreading period of picked tea leaves.Compared to CK,LTY significantly improved the aroma quality in green tea products.The spreading leaves with LTY treatment showed the highest relative content of terpene volatiles and amino acid-derived volatiles.Furthermore,terpene precursor synthesis genes,such as linalool synthase genes(CsLIS2,CsLIS3,CsLIS4)and farnesene synthase genes(CsFS5,CsFS10)were significantly up-regulated in spreading leaves after LTY treatment.This research furthers our understanding of volatile metabolism in postharvest tea leaves and provides a genetic metabolic basis for the application of low-temperature spreading in green tea processing.
