Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damage...Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.展开更多
Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) suppo...Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.展开更多
Efficient translation mediated by the 5'untranslated region(5'UTR)is essential for the robust efficacy of mRNA vaccines.However,the N1-methyl-pseudouridine(m1)modification of mRNA can impact the translation ef...Efficient translation mediated by the 5'untranslated region(5'UTR)is essential for the robust efficacy of mRNA vaccines.However,the N1-methyl-pseudouridine(m1)modification of mRNA can impact the translation efficiency of the 5'UTR.We discovered that the optimal 5'UTR for m1y-modified mRNA(m1y-5'UTR)differs significantly from its unmodified counterpart,high-lighting the need for a specialized tool for designing mly-5'UTRs rather than directly utilizing high-expression endogenous gene 5'UTRs.In response,we developed a novel machine learning-based tool,Smart5UTR,which employs a deep generative model to identify superior m1y-5'UTRs in silico.The tailored loss function and network architecture enable Smart5UTR to overcome limitations inherent in existing models.As a result,Smart5UTR can successfully design superior 5'UTRs,greatly benefiting mRNA vaccine development.Notably,Smart5UTR-designed superior 5'UTRs significantly enhanced antibody titers induced by COVID-19 mRNA vaccines against the Delta and Omicron variants of SARS-CoV-2,surpassing the performance of vaccines using high-expression endogenous gene 5'UTRs.展开更多
Utilizing CO_(2)for the production of bulky and valuable chemicals presents an attractive solution to address environmental and fossil energy crises.Among the various approaches,direct carboxylation of alcohols with C...Utilizing CO_(2)for the production of bulky and valuable chemicals presents an attractive solution to address environmental and fossil energy crises.Among the various approaches,direct carboxylation of alcohols with CO_(2)stands out as an eco-friendly process capable of efficiently producing carboxylic acids in a sustainable manner.However,the high dissociation energy of the C–O bond poses a significant challenge in this process.Over the past few decades,several strategies have been developed to activate alcohols and establish efficient catalytic systems for carboxylation with CO_(2).Nevertheless,the sporadic nature of reported approaches makes it difficult to determine the most effective one.This perspective aims to provide an overview of the current state-of-the-art catalytic protocols for carboxylating alcohols with CO_(2),encompassing esterification,halogenation,and photocatalysis,while considering their respective advantages and limitations.We aim to discern the most promising avenues for future development in this field.The insights presented in this perspective will contribute to the advancement of efficient and sustainable carboxylation methods using CO_(2),leading to the production of valuable chemicals in future.展开更多
Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent M...Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and CO.The Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold further.The finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.展开更多
After the appalling ＂Wuxi Drinking Water Crisis＂, increasing investigations concerning the contaminations of cyanobacterial blooms and their toxins in Lake Taihu have been performed and reported in the last two year...After the appalling ＂Wuxi Drinking Water Crisis＂, increasing investigations concerning the contaminations of cyanobacterial blooms and their toxins in Lake Taihu have been performed and reported in the last two years. However, information regarding these issues before the crisis in 2007 remained insufficient. To provide some background data for further comparisons, the present study reported our investigations conducted in 2004, associated with the cyanotoxin contaminations as well as the eutrophication status in Lake Taihu. Results from the one-year-study near a drinking water resource for Wuxi City indicated that, unlike the status in recent two years, cyanobacteria and chlorophyta are the co-dominance species throughout the year. The highest toxin concentration （34.2 ng/mL） in water columns occurred in August. In bloom biomass, the peak value of intracellular toxin （0.59 μg/mg DW） was determined in October, which was lag behind that in water column. In addition, MC-RR was the major toxin variant throughout the year. During the study period, nutrients levels of total nitrogen and phosphorus were also recorded monthly. Results from the present study will lead to a better understanding of the eutrophication status and the potential risks before ＂Wuxi Drinking Water Crisis＂.展开更多
Ocular drug delivery remains a significant challenge that is limited by poor corneal retention and permeation,resulting in low ocular bioavailability(<5%).Worse still,the most convenient and safe route of ocular dr...Ocular drug delivery remains a significant challenge that is limited by poor corneal retention and permeation,resulting in low ocular bioavailability(<5%).Worse still,the most convenient and safe route of ocular drug administration,topical administration results in a drug bioavailability of less than 1%.iRGD modified drug delivery strategies have been developed for cancer therapy,however active targeting iRGD platforms for ocular drug delivery have yet to be explored.Herein,an iRGD modified liposomes was developed for ocular drug delivery via topical administration.The results indicated that iRGD modified liposomes could prolong the corneal retention time and enhance corneal permeability in an iRGD receptor mediated manner.These findings provided a novel strategy for topical ocular drug delivery for the treatment of posterior ocular diseases.展开更多
Timely and accurate mapping of rice planting areas is crucial under China's current cropping structure. This study proposes a new paddy rice mapping method by combining phenological parameters and a decision tree ...Timely and accurate mapping of rice planting areas is crucial under China's current cropping structure. This study proposes a new paddy rice mapping method by combining phenological parameters and a decision tree model.Six phenological parameters were developed to identify paddy rice areas based on the analysis of the Moderate Resolution Imaging Spectroradiometer (MODIS)Enhanced Vegetation Index (EVI)time series and the Land Surface Water Index (LSWI)time series.The six phenological parameters considered the performance of different land cover types during specific phenological phases (EVI1 and EVI2),one-half of or the entire rice growing cycle (LSWI1 and LSWI2),and the shape of the LSWI time series (KurtosisLSWI and SkewnessLSWI).A hierarchical decision tree model was designed to classify paddy rice areas according to the potential separability of different land cover types in paired phenological parameter spaces.Results showed that the decision tree model was more sensitive to LSWI1,LSWI2,and SkewnessLswi than the other phenological parameters.A paddy rice map of Jiangsu Province for 2015 was generated with an optimal threshold set of(0.4,0.42,9,19,1.5,-1.7,0.0)with a total accuracy of 93.9%.The MODIS-derived paddy rice map generally agreed with the paddy land fraction map from the National Land Cover Dataset project,but there were regional discrepancies because of their different definitions of land use and the inability of MODIS to map paddy rice at a fragmental level.The MODIS-derived paddy rice map showed high correlation (R^2=0.85)with county-level agricultural statistics.The results of this study indicate that the phenological parameter-based paddy rice mapping algorithm could be applied at larger spatial scales.展开更多
Sensitivity analyses were conducted for the retrieval of vegetation leaf area index （LAI） from multi- angular imageries in this study. Five spectral vegetation indices （VIs） were derived from Compact High Resoluti...Sensitivity analyses were conducted for the retrieval of vegetation leaf area index （LAI） from multi- angular imageries in this study. Five spectral vegetation indices （VIs） were derived from Compact High Resolution Imaging Spectrometer onboard the Project for On Board Autonomy （CHRIS/PROBA） images, and were related to LAI, acquired from in situ measurement in Jiangxi Province, China, for five vegetation communities. The sensitivity of LAI retrieval to the variation of VIs from different observation angles was evaluated using the ratio of the slope of the best-fit linear VI-LAI model to its root mean squared error. Results show that both the sensitivity and reliability of VI-LAI models are influenced by the heterogeneity of vegetation communities, and that perfor- mance of vegetation indices in LAI estimation varies along observation angles. The VI-LAI models are more reliable for tall trees than for low growing shrub-grasses and also for forests with broad leaf trees than for coniferous forest. The greater the tree height and leaf size, the higher the sensitivity. Forests with broad-leaf trees have higher sensitivities, especially at oblique angles, while relatively simple-structured coniferous forests, shrubs, and grasses show similar sensitivities at all angles. The multi-angular soil and/or atmospheric parameter adjustments will hope- fully improve the performance of VIs in LAI estimation, which will require further investigation.展开更多
The discovery that supported gold catalysts can promote CO/H2O-mediated reduction at ambient temperatures is important to chemoselective synthesis and has gained significant attention in recent years.Whether the alter...The discovery that supported gold catalysts can promote CO/H2O-mediated reduction at ambient temperatures is important to chemoselective synthesis and has gained significant attention in recent years.Whether the alternative Pt group metal （PGM） catalysts can exhibit such exceptional performance is thus an interesting research issue.So far,no PGM catalyst shows activity for CO/H2O-mediated reduction at ambient temperatures.Here,we demonstrate that it is possible to transform nonactive into highly active and selective catalysts for CO/H2O-mediated reduction by modulating the interfacial structure and electronic properties at the metal-support interfaces.Thus,highly active and chemoselective hydrogenation Pt,Ir,Rh and Pd catalysts can be prepared by decorating the exposed metal faces with partially reduced support species by means of a simple catalyst activation procedure.In this way,it has been possible to dramatically facilitate the previously unappreciated PGM-catalyzed activation of CO molecules under mild conditions,which can make a significant contribution not only to reveal the intrinsic catalytic potential of supported PGMs but also to establish a more sustainable and industrially-relevant process.展开更多
Qinghai Province is one of the four largest pastoral regions in China.Timely monitoring of grass growth and accurate estimation of grass yields are essential for its ecological protection and sustainable development.T...Qinghai Province is one of the four largest pastoral regions in China.Timely monitoring of grass growth and accurate estimation of grass yields are essential for its ecological protection and sustainable development.To estimate grass yields in Qinghai,we used the normalized difference vegetation index(NDVI)time-series data derived from the Moderate-resolution Imaging Spectroradiometer(MODIS)and a pre-existing grassland type map.We developed five estimation approaches to quantify the overall accuracy by combining four data pre-processing techniques(original,Savitzky-Golay(SG),Asymmetry Gaussian(AG)and Double Logistic(DL)),three metrics derived from NDVI time series(VImax,VIseason and VImean)and four fitting functions(linear,second-degree polynomial,power function,and exponential function).The five approaches were investigated in terms of overall accuracy based on 556 ground survey samples in 2016.After assessment and evaluation,we applied the best estimation model in each approach to map the fresh grass yields over the entire Qinghai Province in 2016.Results indicated that:1)For sample estimation,the crossvalidated overall accuracies increased with the increasing flexibility in the chosen fitting variables,and the best estimation accuracy was obtained by the so called“fully flexible model”with R2 of 0.57 and RMSE of 1140 kg/ha.2)Exponential models generally outperformed linear and power models.3)Although overall similar,strong local discrepancies were identified between the grass yield maps derived from the five approaches.In particular,the two most flexible modeling approaches were too sensitive to errors in the pre-existing grassland type map.This led to locally strong overestimations in the modeled grass yields.展开更多
Traditional Chinese medicine(TCM)with a long history in China has demonstrated unique advantages in treating a variety of cardiovascular diseases,with promising prospects.We exemplify the TCM advantages with 3 major c...Traditional Chinese medicine(TCM)with a long history in China has demonstrated unique advantages in treating a variety of cardiovascular diseases,with promising prospects.We exemplify the TCM advantages with 3 major cardiovascular diseases:coronary heart disease,hypertension,and chronic heart failure.With both national and international guidelines,consensus,systematic reviews,and randomized controlled trials as evidence,we used the modified Jadad and AMSTAR-1 scales to evaluate the evidence quality and then systematically evaluated the clinical effects and benefits of TCM on cardiovascular diseases,aiming to provide fresh insights into the research methodologies and future development directions for TCM-dominant diseases.展开更多
Chronic liver disease(CLD)entails elevated risk of COVID-19 severity and mortality.The effectiveness of the booster dose of inactivated SARS-CoV-2 vaccine in stimulating antibody response in CLD patients is unclear.Th...Chronic liver disease(CLD)entails elevated risk of COVID-19 severity and mortality.The effectiveness of the booster dose of inactivated SARS-CoV-2 vaccine in stimulating antibody response in CLD patients is unclear.Therefore,we conducted a cross-sectional study involving 237 adult CLD patients and 170 healthy controls(HC)to analyze neutralizing antibodies(NAbs)against SARS-CoV-2 prototype and BA.4/5 variant,anti-receptor binding domain(RBD)IgG,and total anti-SARS-CoV-2 antibodies.Serum levels of the total anti-SARS-CoV-2 antibodies,anti-RBD IgG and inhibition efficacy of NAbs were significantly elevated in CLD patients after the booster dose compared with the pre-booster dose,but were relatively lower than those of HCs.Induced humoral responses decreased over time after booster vaccination.The neutralization efficiency of the serum against BA.4/5 increased but remained below the inhibition threshold.All four SARS-CoV-2 antibodies,including total anti-SARS-CoV-2 antibodies,anti-RBD IgG and NAbs against prototype and BA.4/5,were lower in patients with severe CLD than those with non-severe CLD.After booster shot,age and time after the last vaccine were the risk factors for seropositivity of NAb against BA.4/5 in CLD patients.Additionally,white blood cell counts and hepatitis B core antibodies were the protective factors,and severe liver disease was the risk factor associated with seropositivity of total anti-SARS-CoV-2 antibodies.Overall,our data uncovered that antibody responses were improved in CLD patients and peaked at 120 days after the booster vaccines.All antibodies excepting total anti-SARS-CoV-2 antibodies declined after peak.CLD patients exhibited impaired immunologic responses to vaccination and weakened NAbs against BA.4/5,which hindered the protective effect of the booster shot against Omicron prevalence.Cellular immune responses should be further evaluated to determine the optimal vaccine regimen for CLD patients.展开更多
基金supported by the National Natural Science Foundation of China(21273044,21473035,and 91545108)SINOPEC(X514005)the Open project of State Key Laboratory of Chemical Engineering(SKL-Ch E-15C02)
文摘Biobutanol is attracting increasingly interest as a source of renewable energy and biofuels because of its many advantages over bioethanol that include higher energy density, fuel efficiency, and reduced engine damages. Currently, there is a growing interest in producing biobutanol from bioethanol, in view of the tremendous potential benefits of this transformation for the bulk production of biobutanol in a target specific manner. This perspective paper describes recent progress for the ethanol to butanol process. The different catalysts, including homogeneous and heterogeneous catalytic systems, for ethanol to butanol are outlined and compared, and the key issues and requirements for future developments are highlighted. A major challenge for further development and application of ethanol to butanol process is to find an optimal balance between different catalytic functions and to suppress the formation of side products that has plagued most catalytic bioethanol upgrading systems. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved.
文摘Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.
基金This work was financially supported by the Postdoctoral Research Foundation of National Key S&T Special Projects(2018ZX09201018-024,China)Sichuan Province Science and Technology Support Program(2022YFH0001 and 2021YFH0003,China).
文摘Efficient translation mediated by the 5'untranslated region(5'UTR)is essential for the robust efficacy of mRNA vaccines.However,the N1-methyl-pseudouridine(m1)modification of mRNA can impact the translation efficiency of the 5'UTR.We discovered that the optimal 5'UTR for m1y-modified mRNA(m1y-5'UTR)differs significantly from its unmodified counterpart,high-lighting the need for a specialized tool for designing mly-5'UTRs rather than directly utilizing high-expression endogenous gene 5'UTRs.In response,we developed a novel machine learning-based tool,Smart5UTR,which employs a deep generative model to identify superior m1y-5'UTRs in silico.The tailored loss function and network architecture enable Smart5UTR to overcome limitations inherent in existing models.As a result,Smart5UTR can successfully design superior 5'UTRs,greatly benefiting mRNA vaccine development.Notably,Smart5UTR-designed superior 5'UTRs significantly enhanced antibody titers induced by COVID-19 mRNA vaccines against the Delta and Omicron variants of SARS-CoV-2,surpassing the performance of vaccines using high-expression endogenous gene 5'UTRs.
基金Financial support from the National Natural Science Foundation of China(No.22271060)the Department of Chemistry at Hehai UniversityNanjing Forestry University。
文摘Utilizing CO_(2)for the production of bulky and valuable chemicals presents an attractive solution to address environmental and fossil energy crises.Among the various approaches,direct carboxylation of alcohols with CO_(2)stands out as an eco-friendly process capable of efficiently producing carboxylic acids in a sustainable manner.However,the high dissociation energy of the C–O bond poses a significant challenge in this process.Over the past few decades,several strategies have been developed to activate alcohols and establish efficient catalytic systems for carboxylation with CO_(2).Nevertheless,the sporadic nature of reported approaches makes it difficult to determine the most effective one.This perspective aims to provide an overview of the current state-of-the-art catalytic protocols for carboxylating alcohols with CO_(2),encompassing esterification,halogenation,and photocatalysis,while considering their respective advantages and limitations.We aim to discern the most promising avenues for future development in this field.The insights presented in this perspective will contribute to the advancement of efficient and sustainable carboxylation methods using CO_(2),leading to the production of valuable chemicals in future.
基金supported by the Ministry of Science and Technology of China (2022YFA1503804)National Natural Science Foundation of China (22272031, 22102033)+1 种基金Science&Technology Commission of Shanghai Municipality (22ZR1408000, 22QA1401300)the Fundamental Research Funds for the Central Universities (20720220008)。
文摘Effective and mild activation of O_(2) is essential but challenging for aerobic oxidation. In heterogeneous catalysis, high-valence manganese oxide(e.g., +4) is known to be active for the oxidation, whereas divalent MnO is ineffective due to its limited capacity to supply surface oxygen and its thermodynamically unstable structure when binding O_(2) in reaction conditions. Inspired by natural enzymes that rely on divalent Mn^(2+), we discovered that confining Mn^(2+) onto the Mn_(2)O_(3) surface through a dedicated calcination process creates highly active catalysts for the aerobic oxidation of 5-hydroxymethylfurfural, benzyl alcohol, and CO.The Mn_(2)O_(3)-confined Mn^(2+) is undercoordinated and efficiently mediates O_(2) activation, resulting in 2–3 orders of magnitude higher activity than Mn_(2)O_(3) alone. Through low-temperature infrared spectroscopy, we distinguished low-content Mn^(2+) sites at Mn_(2)O_(3) surface, which are difficult to be differentiated by X-ray photoelectron spectroscopy. The combination of in-situ energydispersive X-ray absorption spectroscopy and X-ray diffraction further provides insights into the formation of the newly identified active Mn^(2+) sites. By optimizing the calcination step, we were able to increase the catalytic activity threefold further.The finding offers promising frontiers for exploring active oxidation catalysts by utilizing the confinement of Mn^(2+)and oftenignored calcination skills.
基金supported by the National Basic Research Program(973)of China:"Water environmental quality evolution and water quality criteria in lakes"(No.2008CB418200)the National High Technology Research and Development Program(863)of China(No.2007AA10Z344)
文摘After the appalling ＂Wuxi Drinking Water Crisis＂, increasing investigations concerning the contaminations of cyanobacterial blooms and their toxins in Lake Taihu have been performed and reported in the last two years. However, information regarding these issues before the crisis in 2007 remained insufficient. To provide some background data for further comparisons, the present study reported our investigations conducted in 2004, associated with the cyanotoxin contaminations as well as the eutrophication status in Lake Taihu. Results from the one-year-study near a drinking water resource for Wuxi City indicated that, unlike the status in recent two years, cyanobacteria and chlorophyta are the co-dominance species throughout the year. The highest toxin concentration （34.2 ng/mL） in water columns occurred in August. In bloom biomass, the peak value of intracellular toxin （0.59 μg/mg DW） was determined in October, which was lag behind that in water column. In addition, MC-RR was the major toxin variant throughout the year. During the study period, nutrients levels of total nitrogen and phosphorus were also recorded monthly. Results from the present study will lead to a better understanding of the eutrophication status and the potential risks before ＂Wuxi Drinking Water Crisis＂.
基金supported by the National Key S&T Special Projects(No.2018ZX09201018-024)Sichuan Province Science and Technology Plan(2019YFH0115).
文摘Ocular drug delivery remains a significant challenge that is limited by poor corneal retention and permeation,resulting in low ocular bioavailability(<5%).Worse still,the most convenient and safe route of ocular drug administration,topical administration results in a drug bioavailability of less than 1%.iRGD modified drug delivery strategies have been developed for cancer therapy,however active targeting iRGD platforms for ocular drug delivery have yet to be explored.Herein,an iRGD modified liposomes was developed for ocular drug delivery via topical administration.The results indicated that iRGD modified liposomes could prolong the corneal retention time and enhance corneal permeability in an iRGD receptor mediated manner.These findings provided a novel strategy for topical ocular drug delivery for the treatment of posterior ocular diseases.
基金the National Natural Science Foundation of China (Grant No.41401494)China Postdoctoral Science Foundation (No.2014M552475)Foundation of Shaanxi Educational Committee (No.14JK1745).
文摘Timely and accurate mapping of rice planting areas is crucial under China's current cropping structure. This study proposes a new paddy rice mapping method by combining phenological parameters and a decision tree model.Six phenological parameters were developed to identify paddy rice areas based on the analysis of the Moderate Resolution Imaging Spectroradiometer (MODIS)Enhanced Vegetation Index (EVI)time series and the Land Surface Water Index (LSWI)time series.The six phenological parameters considered the performance of different land cover types during specific phenological phases (EVI1 and EVI2),one-half of or the entire rice growing cycle (LSWI1 and LSWI2),and the shape of the LSWI time series (KurtosisLSWI and SkewnessLSWI).A hierarchical decision tree model was designed to classify paddy rice areas according to the potential separability of different land cover types in paired phenological parameter spaces.Results showed that the decision tree model was more sensitive to LSWI1,LSWI2,and SkewnessLswi than the other phenological parameters.A paddy rice map of Jiangsu Province for 2015 was generated with an optimal threshold set of(0.4,0.42,9,19,1.5,-1.7,0.0)with a total accuracy of 93.9%.The MODIS-derived paddy rice map generally agreed with the paddy land fraction map from the National Land Cover Dataset project,but there were regional discrepancies because of their different definitions of land use and the inability of MODIS to map paddy rice at a fragmental level.The MODIS-derived paddy rice map showed high correlation (R^2=0.85)with county-level agricultural statistics.The results of this study indicate that the phenological parameter-based paddy rice mapping algorithm could be applied at larger spatial scales.
文摘Sensitivity analyses were conducted for the retrieval of vegetation leaf area index （LAI） from multi- angular imageries in this study. Five spectral vegetation indices （VIs） were derived from Compact High Resolution Imaging Spectrometer onboard the Project for On Board Autonomy （CHRIS/PROBA） images, and were related to LAI, acquired from in situ measurement in Jiangxi Province, China, for five vegetation communities. The sensitivity of LAI retrieval to the variation of VIs from different observation angles was evaluated using the ratio of the slope of the best-fit linear VI-LAI model to its root mean squared error. Results show that both the sensitivity and reliability of VI-LAI models are influenced by the heterogeneity of vegetation communities, and that perfor- mance of vegetation indices in LAI estimation varies along observation angles. The VI-LAI models are more reliable for tall trees than for low growing shrub-grasses and also for forests with broad leaf trees than for coniferous forest. The greater the tree height and leaf size, the higher the sensitivity. Forests with broad-leaf trees have higher sensitivities, especially at oblique angles, while relatively simple-structured coniferous forests, shrubs, and grasses show similar sensitivities at all angles. The multi-angular soil and/or atmospheric parameter adjustments will hope- fully improve the performance of VIs in LAI estimation, which will require further investigation.
文摘The discovery that supported gold catalysts can promote CO/H2O-mediated reduction at ambient temperatures is important to chemoselective synthesis and has gained significant attention in recent years.Whether the alternative Pt group metal （PGM） catalysts can exhibit such exceptional performance is thus an interesting research issue.So far,no PGM catalyst shows activity for CO/H2O-mediated reduction at ambient temperatures.Here,we demonstrate that it is possible to transform nonactive into highly active and selective catalysts for CO/H2O-mediated reduction by modulating the interfacial structure and electronic properties at the metal-support interfaces.Thus,highly active and chemoselective hydrogenation Pt,Ir,Rh and Pd catalysts can be prepared by decorating the exposed metal faces with partially reduced support species by means of a simple catalyst activation procedure.In this way,it has been possible to dramatically facilitate the previously unappreciated PGM-catalyzed activation of CO molecules under mild conditions,which can make a significant contribution not only to reveal the intrinsic catalytic potential of supported PGMs but also to establish a more sustainable and industrially-relevant process.
基金This research was supported by the National Natural Science Foundation of China(Grant No.41401494)National Key Research and Development Plan(No.2017YFC0404302)Talented Youth Project of Hebei Education Department(No.BJ2018043).
文摘Qinghai Province is one of the four largest pastoral regions in China.Timely monitoring of grass growth and accurate estimation of grass yields are essential for its ecological protection and sustainable development.To estimate grass yields in Qinghai,we used the normalized difference vegetation index(NDVI)time-series data derived from the Moderate-resolution Imaging Spectroradiometer(MODIS)and a pre-existing grassland type map.We developed five estimation approaches to quantify the overall accuracy by combining four data pre-processing techniques(original,Savitzky-Golay(SG),Asymmetry Gaussian(AG)and Double Logistic(DL)),three metrics derived from NDVI time series(VImax,VIseason and VImean)and four fitting functions(linear,second-degree polynomial,power function,and exponential function).The five approaches were investigated in terms of overall accuracy based on 556 ground survey samples in 2016.After assessment and evaluation,we applied the best estimation model in each approach to map the fresh grass yields over the entire Qinghai Province in 2016.Results indicated that:1)For sample estimation,the crossvalidated overall accuracies increased with the increasing flexibility in the chosen fitting variables,and the best estimation accuracy was obtained by the so called“fully flexible model”with R2 of 0.57 and RMSE of 1140 kg/ha.2)Exponential models generally outperformed linear and power models.3)Although overall similar,strong local discrepancies were identified between the grass yield maps derived from the five approaches.In particular,the two most flexible modeling approaches were too sensitive to errors in the pre-existing grassland type map.This led to locally strong overestimations in the modeled grass yields.
基金This work was supported by the National Natural Science Foundation of China(Key Program)(no.82230124)National Natural Science Foundation of China(General Program)(no.81974556)+1 种基金Traditional Chinese Medicine Inheritance and Innovation“Ten Million”Talent Project-Qihuang Project Chief Scientist Project(0201000401)State Administration of Traditional Chinese Medicine 2nd National Traditional Chinese Medicine Inheritance Studio Construction Project(Official Letter of the State Office of Traditional Chinese Medicine[2022],no.245).
文摘Traditional Chinese medicine(TCM)with a long history in China has demonstrated unique advantages in treating a variety of cardiovascular diseases,with promising prospects.We exemplify the TCM advantages with 3 major cardiovascular diseases:coronary heart disease,hypertension,and chronic heart failure.With both national and international guidelines,consensus,systematic reviews,and randomized controlled trials as evidence,we used the modified Jadad and AMSTAR-1 scales to evaluate the evidence quality and then systematically evaluated the clinical effects and benefits of TCM on cardiovascular diseases,aiming to provide fresh insights into the research methodologies and future development directions for TCM-dominant diseases.
基金This work was supported by the Beijing Natural Science Foundation(M23008)the National Key Research and Development Program of China(2018YFE0207300)+2 种基金Beijing Municipal Science&Technology Commission(Z211100002521021)the National High Level Hospital Clinical Research Funding(2022-PUMCH-B-124)Key Research and Development Plan of Hebei Province,Special Health Innovation Project(22377744D).
文摘Chronic liver disease(CLD)entails elevated risk of COVID-19 severity and mortality.The effectiveness of the booster dose of inactivated SARS-CoV-2 vaccine in stimulating antibody response in CLD patients is unclear.Therefore,we conducted a cross-sectional study involving 237 adult CLD patients and 170 healthy controls(HC)to analyze neutralizing antibodies(NAbs)against SARS-CoV-2 prototype and BA.4/5 variant,anti-receptor binding domain(RBD)IgG,and total anti-SARS-CoV-2 antibodies.Serum levels of the total anti-SARS-CoV-2 antibodies,anti-RBD IgG and inhibition efficacy of NAbs were significantly elevated in CLD patients after the booster dose compared with the pre-booster dose,but were relatively lower than those of HCs.Induced humoral responses decreased over time after booster vaccination.The neutralization efficiency of the serum against BA.4/5 increased but remained below the inhibition threshold.All four SARS-CoV-2 antibodies,including total anti-SARS-CoV-2 antibodies,anti-RBD IgG and NAbs against prototype and BA.4/5,were lower in patients with severe CLD than those with non-severe CLD.After booster shot,age and time after the last vaccine were the risk factors for seropositivity of NAb against BA.4/5 in CLD patients.Additionally,white blood cell counts and hepatitis B core antibodies were the protective factors,and severe liver disease was the risk factor associated with seropositivity of total anti-SARS-CoV-2 antibodies.Overall,our data uncovered that antibody responses were improved in CLD patients and peaked at 120 days after the booster vaccines.All antibodies excepting total anti-SARS-CoV-2 antibodies declined after peak.CLD patients exhibited impaired immunologic responses to vaccination and weakened NAbs against BA.4/5,which hindered the protective effect of the booster shot against Omicron prevalence.Cellular immune responses should be further evaluated to determine the optimal vaccine regimen for CLD patients.
