High-resolution satellite data have been playing an important role in agricultural remote sensing monitoring. However, the major data sources of high-resolution images are not owned by China. The cost of large scale u...High-resolution satellite data have been playing an important role in agricultural remote sensing monitoring. However, the major data sources of high-resolution images are not owned by China. The cost of large scale use of high resolution imagery data becomes prohibitive. In pace of the launch of the Chinese ＂High Resolution Earth Observation Systems＂, China is able to receive superb high-resolution remotely sensed images （GF series） that equalizes or even surpasses foreign similar satellites in respect of spatial resolution, scanning width and revisit period. This paper provides a perspective of using high resolution remote sensing data from satellite GF-1 for agriculture monitoring. It also assesses the applicability of GF-1 data for agricultural monitoring, and identifies potential applications from regional to national scales. GF-1＇s high resolution （i.e., 2 m/8 m）, high revisit cycle （i.e., 4 days）, and its visible and near-infrared （VNIR） spectral bands enable a continuous, efficient and effective agricultural dynamics monitoring. Thus, it has gradually substituted the foreign data sources for mapping crop planting areas, monitoring crop growth, estimating crop yield, monitoring natural disasters, and supporting precision and facility agriculture in China agricultural remote sensing monitoring system （CHARMS）. However, it is still at the initial stage of GF-1 data application in agricultural remote sensing monitoring. Advanced algorithms for estimating agronomic parameters and soil quality with GF-1 data need to be further investigated, especially for improving the performance of remote sensing monitoring in the fragmented landscapes. In addition, the thematic product series in terms of land cover, crop allocation, crop growth and production are required to be developed in association with other data sources at multiple spatial scales. Despite the advantages, the issues such as low spectrum resolution and image distortion associated with high spatial resolution and wide swath width, might pose challenges for GF-1 data applications and need to be addressed in future agricultural monitoring.展开更多
Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results...Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results showed that the ee value of （S）-1- phenylethanol and （R）-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.展开更多
The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Amon...The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candida rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150r·min-1 and 20℃ to 30℃, respectively. The enantiomeric excess of the remaining (5)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30℃, 150r·min-1 for 12 h.展开更多
Soil moisture plays an important role in crop yield estimation,irrigation management,etc.Remote sensing technology has potential for large-scale and high spatial soil moisture mapping.However,offline remote sensing da...Soil moisture plays an important role in crop yield estimation,irrigation management,etc.Remote sensing technology has potential for large-scale and high spatial soil moisture mapping.However,offline remote sensing data processing is time-consuming and resource-intensive,and significantly hampers the efficiency and timeliness of soil moisture mapping.Due to the high-speed computing capabilities of remote sensing cloud platforms,a High Spatial Resolution Soil Moisture Estimation Framework(HSRSMEF)based on the Google Earth Engine(GEE)platform was developed in this study.The functions of the HSRSMEF include research area and input datasets customization,radar speckle noise filtering,optical-radar image spatio-temporal matching,soil moisture retrieving,soil moisture visualization and exporting.This paper tested the performance of HSRSMEF by combining Sentinel-1,Sentinel-2 images and insitu soil moisture data in the central farmland area of Jilin Province,China.Reconstructed Normalized Difference Vegetation Index(NDVI)based on the Savitzky-Golay algorithm conforms to the crop growth cycle,and its correlation with the original NDVI is about 0.99(P<0.001).The soil moisture accuracy of the random forest model(R 2=0.942,RMSE=0.013 m3/m3)is better than that of the water cloud model(R 2=0.334,RMSE=0.091 m3/m3).HSRSMEF transfers time-consuming offline operations to cloud computing platforms,achieving rapid and simplified high spatial resolution soil moisture mapping.展开更多
Experiments including C-13 spin-lattice relaxation, C-13 heteronuclear dipolar dephasing and H-1 spin diffusion are performed on poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). The results show that the rotation of the...Experiments including C-13 spin-lattice relaxation, C-13 heteronuclear dipolar dephasing and H-1 spin diffusion are performed on poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). The results show that the rotation of the methyl groups in solid PPO is partially restricted, which results in a surprisingly efficient spin diffusion between the aromatic proton and methyl proton characterized by a diffusion time of 150 mu s. The results also show that the aromatic ring in solid PPO is rigid and twisted, which causes all aromatic carbons to be chemically unequivalent.展开更多
BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon e...BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.展开更多
10, 11-Dihydro-10-hydroxycyproheptadine was synthesized in a new and facile synthetic route and resolved by L-（-）-2-（1, 3）-dioxo-1, 3-dihydroisoindol-2-yl）-propionic acid and D-（＋）-tartaric acid, respectively....10, 11-Dihydro-10-hydroxycyproheptadine was synthesized in a new and facile synthetic route and resolved by L-（-）-2-（1, 3）-dioxo-1, 3-dihydroisoindol-2-yl）-propionic acid and D-（＋）-tartaric acid, respectively. The free base of the two enantiomers has the same absolute specific rotation value.展开更多
Structural characteristics of Alo.55 Gao.45N epilayer were investigated by high resolution x-ray diffraction（HRXRD）and transmission electron microscopy（TEM）;the epilayer was grown on GaN/sapphire substrates using ...Structural characteristics of Alo.55 Gao.45N epilayer were investigated by high resolution x-ray diffraction（HRXRD）and transmission electron microscopy（TEM）;the epilayer was grown on GaN/sapphire substrates using a high-temperature A1 N interlayer by metal organic chemical vapor deposition technique.The mosaic characteristics including tilt,twist,heterogeneous strain,and correlation lengths were extracted by symmetric and asymmetric XRD rocking curves as well as reciprocal space map（RSM）.According to Williamson-Hall plots,the vertical coherence length of AlGaN epilayer was calculated,which is consistent with the thickness of AlGaN layer measured by cross section TEM.Besides,the lateral coherence length was determined from RSM as well.Deducing from the tilt and twist results,the screw-type and edge-type dislocation densities are 1.0×10~8 cm^（-2） and 1.8×10^（10） cm^（-2）,which agree with the results observed from TEM.展开更多
Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood cl...Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood clots have been shown to elicit secondary brain injury after germinal matrix hemorrhage,by disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage causing post-hemorrhagic hydrocephalus development.Current evidence suggests that rapid hematoma resolution is necessary to improve neurological outcomes after hemorrhagic stroke.Various articles have demonstrated the beneficial effects of stimulating the polarization of microglia cells into the M2 phenotype,as it has been suggested that they play an essential role in the rapid phagocytosis of the blood clot after hemorrhagic models of stroke.N-formyl peptide receptor 2(FPR2),a G-protein-coupled receptor,has been shown to be neuroprotective after stroke.FPR2 activation has been associated with the upregulation of phagocytic macrophage clearance,yet its mechanism has not been fully explored.Recent literature suggests that FPR2 may play a role in the stimulation of scavenger receptor CD36.Scavenger receptor CD36 plays a vital role in microglia phagocytic blood clot clearance after germinal matrix hemorrhage.FPR2 has been shown to phosphorylate extracellular-signal-regulated kinase 1/2(ERK1/2),which then promotes the transcription of the dual-specificity protein phosphatase 1(DUSP1)gene.In this review,we present an intrinsic outline of the main components involved in FPR2 stimulation and hematoma resolution after germinal matrix hemorrhage.展开更多
We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein...We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final（S）-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.展开更多
基金financed by the National Natural Science Foundation of China (41501111 and 41271112)the National Non-profit Institute Research Grant of Chinese Academy of Agricultural Sciences (CAAS) (IARRP-2015-10)
文摘High-resolution satellite data have been playing an important role in agricultural remote sensing monitoring. However, the major data sources of high-resolution images are not owned by China. The cost of large scale use of high resolution imagery data becomes prohibitive. In pace of the launch of the Chinese ＂High Resolution Earth Observation Systems＂, China is able to receive superb high-resolution remotely sensed images （GF series） that equalizes or even surpasses foreign similar satellites in respect of spatial resolution, scanning width and revisit period. This paper provides a perspective of using high resolution remote sensing data from satellite GF-1 for agriculture monitoring. It also assesses the applicability of GF-1 data for agricultural monitoring, and identifies potential applications from regional to national scales. GF-1＇s high resolution （i.e., 2 m/8 m）, high revisit cycle （i.e., 4 days）, and its visible and near-infrared （VNIR） spectral bands enable a continuous, efficient and effective agricultural dynamics monitoring. Thus, it has gradually substituted the foreign data sources for mapping crop planting areas, monitoring crop growth, estimating crop yield, monitoring natural disasters, and supporting precision and facility agriculture in China agricultural remote sensing monitoring system （CHARMS）. However, it is still at the initial stage of GF-1 data application in agricultural remote sensing monitoring. Advanced algorithms for estimating agronomic parameters and soil quality with GF-1 data need to be further investigated, especially for improving the performance of remote sensing monitoring in the fragmented landscapes. In addition, the thematic product series in terms of land cover, crop allocation, crop growth and production are required to be developed in association with other data sources at multiple spatial scales. Despite the advantages, the issues such as low spectrum resolution and image distortion associated with high spatial resolution and wide swath width, might pose challenges for GF-1 data applications and need to be addressed in future agricultural monitoring.
基金financially supported by the National Natural Science Foundation of China(No.50662004)the State Key Program of Fundamental Research(No.2004CCA05900).
文摘Pseudomonas cepacia lipase （PSL） immobilized on the carboxyl-functionalized meso-cellular foams （HOOC-MCF） was used for the transesterification resolution of （R,S）-l-phenylethanol in organic solvent. The results showed that the ee value of （S）-1- phenylethanol and （R）-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.
基金Supported by the National Natural Science Foundation of China (No. 20076019) the Natural Science Foundation of Guangdong Province (No. 000444).
文摘The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candida rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150r·min-1 and 20℃ to 30℃, respectively. The enantiomeric excess of the remaining (5)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30℃, 150r·min-1 for 12 h.
基金Under the auspices of National Key Research and Development Project of China(No.2021YFD1500103)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28100500)+2 种基金National Natural Science Foundation of China(No.4197132)Science and Technology Development Plan Project of Jilin Province(No.20210201044GX)Land Observation Satellite Supporting Platform of National Civil Space Infrastructure Project(No.CASPLOS-CCSI)。
文摘Soil moisture plays an important role in crop yield estimation,irrigation management,etc.Remote sensing technology has potential for large-scale and high spatial soil moisture mapping.However,offline remote sensing data processing is time-consuming and resource-intensive,and significantly hampers the efficiency and timeliness of soil moisture mapping.Due to the high-speed computing capabilities of remote sensing cloud platforms,a High Spatial Resolution Soil Moisture Estimation Framework(HSRSMEF)based on the Google Earth Engine(GEE)platform was developed in this study.The functions of the HSRSMEF include research area and input datasets customization,radar speckle noise filtering,optical-radar image spatio-temporal matching,soil moisture retrieving,soil moisture visualization and exporting.This paper tested the performance of HSRSMEF by combining Sentinel-1,Sentinel-2 images and insitu soil moisture data in the central farmland area of Jilin Province,China.Reconstructed Normalized Difference Vegetation Index(NDVI)based on the Savitzky-Golay algorithm conforms to the crop growth cycle,and its correlation with the original NDVI is about 0.99(P<0.001).The soil moisture accuracy of the random forest model(R 2=0.942,RMSE=0.013 m3/m3)is better than that of the water cloud model(R 2=0.334,RMSE=0.091 m3/m3).HSRSMEF transfers time-consuming offline operations to cloud computing platforms,achieving rapid and simplified high spatial resolution soil moisture mapping.
文摘Experiments including C-13 spin-lattice relaxation, C-13 heteronuclear dipolar dephasing and H-1 spin diffusion are performed on poly (2,6-dimethyl-1,4-phenylene oxide) (PPO). The results show that the rotation of the methyl groups in solid PPO is partially restricted, which results in a surprisingly efficient spin diffusion between the aromatic proton and methyl proton characterized by a diffusion time of 150 mu s. The results also show that the aromatic ring in solid PPO is rigid and twisted, which causes all aromatic carbons to be chemically unequivalent.
基金supported in part by a BMBF grant(TOMCAT)given to H.K.the Molecular Imaging North Competence Center(MOIN-CC)
文摘BACKGROUND:The specificity in discriminating pancreatitis is limited in the positron emission tomography(PET)using Fluorine-18-fluorodeoxyglucose.Furthermore,PET is not widely available compared to the single photon emission computed tomography(SPECT).Since amino acids play a minor role in metabolism of inflammatory cells,the potential of the SPECT tracer,3-[ 123 I]iodo-L-α-methyltyrosine(123I-IMT),for detecting pancreatic cancer was examined in xenotransplantation models of human pancreatic carcinoma in mice. METHODS: 123 I-IMT was injected to eight mice inoculated with subcutaneous or orthotopic pancreatic tumors.Fused high-resolution-micro-SPECT(Hi-SPECT)and magnetic resonance imaging were performed.The gene expression level of L amino acid transport-system 1(LAT1)was analyzed and correlated with tumor uptake of 123 I-IMT. RESULTS:A high uptake of 123 I-IMT was detected in all tumor-bearing mice.The median tumor-to-background ratio (T/B)was 12.1(2.0-13.2)for orthotopic and 8.4(1.8-11.1)for subcutaneous xenotransplantation,respectively.Accordingly, the LAT1 expression in transplanted Colo357 cells was increased compared to non-malignant controls.CONCLUSIONS:Our mouse model could show a high 123 I-IMT uptake in pancreatic cancer.Fused MRI scans facilitate precise evaluation of uptake in the specific regions of interest.Further studies are required to confirm these findings in tumors derived from other human pancreatic cancer cells.Since amino acids play a minor role in the metabolism of inflammatory cells,the potential for application of 123 I-IMT to distinguish pancreatic tumor from inflammatory pancreatitis warrants further investigation.
文摘10, 11-Dihydro-10-hydroxycyproheptadine was synthesized in a new and facile synthetic route and resolved by L-（-）-2-（1, 3）-dioxo-1, 3-dihydroisoindol-2-yl）-propionic acid and D-（＋）-tartaric acid, respectively. The free base of the two enantiomers has the same absolute specific rotation value.
基金Project supported by the National Key Research and Development Project of China(Grant No.2016YFB0400100)the Hi-tech Research Project of China(Grant Nos.2014AA032605 and 2015AA033305)+5 种基金the National Natural Science Foundation of China(Grant Nos.61274003,61422401,51461135002,and61334009)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BY2013077,BK20141320,and BE2015111)the Project of Green Young and Golden Phenix of Yangzhou City,the Postdoctoral Sustentation Fund of Jiangsu Province,China(Grant No.1501143B)the Project of Shandong Provinceial Higher Educational Science and Technology Program,China(Grant No.J13LN08)the Solid State Lighting and Energy-saving Electronics Collaborative Innovation Center,Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Research Funds from NJU–Yangzhou Institute of Opto-electronics
文摘Structural characteristics of Alo.55 Gao.45N epilayer were investigated by high resolution x-ray diffraction（HRXRD）and transmission electron microscopy（TEM）;the epilayer was grown on GaN/sapphire substrates using a high-temperature A1 N interlayer by metal organic chemical vapor deposition technique.The mosaic characteristics including tilt,twist,heterogeneous strain,and correlation lengths were extracted by symmetric and asymmetric XRD rocking curves as well as reciprocal space map（RSM）.According to Williamson-Hall plots,the vertical coherence length of AlGaN epilayer was calculated,which is consistent with the thickness of AlGaN layer measured by cross section TEM.Besides,the lateral coherence length was determined from RSM as well.Deducing from the tilt and twist results,the screw-type and edge-type dislocation densities are 1.0×10~8 cm^（-2） and 1.8×10^（10） cm^（-2）,which agree with the results observed from TEM.
基金supported in part by the National Institutes of Health grant 5R01NS117364-02(to JT)。
文摘Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood clots have been shown to elicit secondary brain injury after germinal matrix hemorrhage,by disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage causing post-hemorrhagic hydrocephalus development.Current evidence suggests that rapid hematoma resolution is necessary to improve neurological outcomes after hemorrhagic stroke.Various articles have demonstrated the beneficial effects of stimulating the polarization of microglia cells into the M2 phenotype,as it has been suggested that they play an essential role in the rapid phagocytosis of the blood clot after hemorrhagic models of stroke.N-formyl peptide receptor 2(FPR2),a G-protein-coupled receptor,has been shown to be neuroprotective after stroke.FPR2 activation has been associated with the upregulation of phagocytic macrophage clearance,yet its mechanism has not been fully explored.Recent literature suggests that FPR2 may play a role in the stimulation of scavenger receptor CD36.Scavenger receptor CD36 plays a vital role in microglia phagocytic blood clot clearance after germinal matrix hemorrhage.FPR2 has been shown to phosphorylate extracellular-signal-regulated kinase 1/2(ERK1/2),which then promotes the transcription of the dual-specificity protein phosphatase 1(DUSP1)gene.In this review,we present an intrinsic outline of the main components involved in FPR2 stimulation and hematoma resolution after germinal matrix hemorrhage.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA11030404),the Key Project from Chinese Academy of Sciences(KGZD-EW-606)the National Natural Science Foundation of China(21302199)Guangzhou Science and Technology Plan Projects(201510010012)
文摘We previously functionally characterized a novel marine microbial GDSL lipase MT6 and identified that the stereo-selectivity of MT6 was opposite to that of other common lipases in trans-esterification reactions.Herein,we have investigated the use of MT6 in stereo-selective biocatalysis through direct hydrolysis reactions.Notably,the stereo-selectivity of MT6 was also demonstrated to be opposite to that of other common lipases in hydrolysis reactions.Parameters,including temperature,organic co-solvents,pH,ionic strength,catalyst loading,substrate concentration,and reaction time,affecting the enzymatic resolution of racemic 1-phenylethyl acetate were further investigated,with the e.e.of the final（S）-l-Phenylethanol product and the conversion being 97%and 28.5%,respectively,after process optimization.The lengths of side chains of 1-phenylethyl esters greatly affected the stereo-selectivity and conversion during kinetic resolutions.MT6 is a novel marine microbial GDSL lipase exhibiting opposite stereo-selectivities than other common lipases in both trans-esterification reactions and hydrolysis reactions.
