Crown development is closely related to the biomass and growth rate of the tree and its width(CW)is an important covariable in growth and yield models and in forest management.To date,various CW models have been propo...Crown development is closely related to the biomass and growth rate of the tree and its width(CW)is an important covariable in growth and yield models and in forest management.To date,various CW models have been proposed.However,limited studies have explicitly focused on additive and inherent correlation of crown components and total CW as well as the influence of competition on crown radius from the corresponding direction.In this study,two model systems were used,i.e.,aggregation method system(AMS)and disaggregation method system(DMS),to develop crown width additive model systems.For calculating spatially explicit competition index(CI),four neighbor tree selection methods were evaluated.CI was decomposed into four cardinal directions and added into the model systems.Results show that the power model form was more proper for our data to fit CW growth.For each crown radius and total CW,height to the diameter at breast height(HDR)and basal area of trees larger than the subject tree(BAL)significantly contributed to the increase of prediction accuracy.The 3-m fixed radius was optimal among the four neighborhoods selection ways.After adding decomposed competition Hegyi index into model systems AMS and DMS,the prediction accuracy improved.Of the model systems evaluated,AMS based on decomposed CI provided the best performance as well as the inherent correlation and additivity properties.Our study highlighted the importance of decomposed CI in tree CW modelling for additive model systems.This study focused on methodology and could be applied to other species or stands.展开更多
In this paper,an ultraviolet C-band laser diode lasing at 277 nm composed of B0.313Ga0.687N/B0.40Ga0.60N QW/QB heterostructure on Mg and Si-doped AlxGa1-xN layers was designed,as well as a lowest reported substitution...In this paper,an ultraviolet C-band laser diode lasing at 277 nm composed of B0.313Ga0.687N/B0.40Ga0.60N QW/QB heterostructure on Mg and Si-doped AlxGa1-xN layers was designed,as well as a lowest reported substitutional accepter and donor concentration up to NA=5.0×10^17 cm^-3 and ND=9.0×10^16 cm^-3 for deep ultraviolet lasing was achieved.The structure was assumed to be grown over bulk AIN substrate and operate under a continuous wave at room temperature.Although there is an emphasizing of the suitability for using boron nitride wide band gap in the deep ultraviolet region,there is still a shortage of investigation about the ternary BGaN in aluminum-rich AIGaN alloys.Based on the simulation,an average local gain in quantum wells of 1946 cm^-1,the maximum emitted power of 2.4 W,the threshold current of 500 mA,a slope efficiency of 1.91 W/A as well as an average DC resistance for the V-I curve of(0.336Ω)had been observed.Along with an investigation regarding different EBL,designs were included with tapered and inverse tapered structure.Therefore,it had been found a good agreement with the published results for tapered EBL design,with an overweighting for a proposed inverse tapered EBL design.展开更多
Diabetes Mellitus is a systematic disease with complications in multi-organs,including decreased implant osseointegration and a high failure rate of dental transplants.Accumulating evidence indicates that the signalin...Diabetes Mellitus is a systematic disease with complications in multi-organs,including decreased implant osseointegration and a high failure rate of dental transplants.Accumulating evidence indicates that the signaling pathway directly impacts the process of bone metabolism and inflammatory response implicated with dental implants in diabetic patients.This review summarizes the recent advance in signaling pathways regulate osseointegration and inflammatory response in dental transplantation,aiming to identify the potential therapeutic target to reduce the dental transplant failure in diabetes patients,with emphasis on the surface characteristics of the implant,inflammatory signaling,AMPK,PPARγ,WNT,ROS,and adiponectin signaling.展开更多
Pine wilt disease(PWD)is currently one of the main causes of large-scale forest destruction.To control the spread of PWD,it is essential to detect affected pine trees quickly.This study investigated the feasibility of...Pine wilt disease(PWD)is currently one of the main causes of large-scale forest destruction.To control the spread of PWD,it is essential to detect affected pine trees quickly.This study investigated the feasibility of using the object-oriented multi-scale segmentation algorithm to identify trees discolored by PWD.We used an unmanned aerial vehicle(UAV)platform equipped with an RGB digital camera to obtain high spatial resolution images,and multiscale segmentation was applied to delineate the tree crown,coupling the use of object-oriented classification to classify trees discolored by PWD.Then,the optimal segmentation scale was implemented using the estimation of scale parameter(ESP2)plug-in.The feature space of the segmentation results was optimized,and appropriate features were selected for classification.The results showed that the optimal scale,shape,and compactness values of the tree crown segmentation algorithm were 56,0.5,and 0.8,respectively.The producer’s accuracy(PA),user’s accuracy(UA),and F1 score were 0.722,0.605,and 0.658,respectively.There were no significant classification errors in the final classification results,and the low accuracy was attributed to the low number of objects count caused by incorrect segmentation.The multi-scale segmentation and object-oriented classification method could accurately identify trees discolored by PWD with a straightforward and rapid processing.This study provides a technical method for monitoring the occurrence of PWD and identifying the discolored trees of disease using UAV-based high-resolution images.展开更多
INTRODUCTION Pangolin is the common name for animals in the Family Pholidota,Mammalia,which consists of eight extant species.All pangolin species have been listed as critically endangered(CR),endangered(EN),or vulnera...INTRODUCTION Pangolin is the common name for animals in the Family Pholidota,Mammalia,which consists of eight extant species.All pangolin species have been listed as critically endangered(CR),endangered(EN),or vulnerable(VU)species in the International Union for Conservation of Nature(IUCN)Red List of Threatened Species(Challender et al.2020).In June 2020,the Chinese government upgraded the Chinese pangolin(Manis pentadactyla Linnaeus,1758)from a national second-class protected animal to a national first-class protected animal.In February 2021,the Sunda pangolin(Manis javanica Desmarest,1822)and the Indian pangolin(Manis crassicaudata Geoffroy,1803)were added to the list of national first-class protected animals.However,the number of species of pangolins naturally distributed in China varies in the literature:Some sources have recorded only one species,namely the Chinese pangolin(Nowak&Paradiso 1983;Sheng 1999),while most have recorded two species,namely the Chinese pangolin and Indian pangolin(Allen 1938;Zhang 1997;Wang 2003;Wu et al.2005a;Hu&Hu 2017).展开更多
We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface ...We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface system modeling(FTESM). The Beijing-Tianjin-Hebei(BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling(HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-meansquare error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM.展开更多
Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with...Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.展开更多
Hydroxyapatite nanoparticles(HANPs)have been increasingly regarded and reported due to their potential anti-tumor ability.Previously,we found that the rod-like HANPs had good application potential for cutaneous melano...Hydroxyapatite nanoparticles(HANPs)have been increasingly regarded and reported due to their potential anti-tumor ability.Previously,we found that the rod-like HANPs had good application potential for cutaneous melanoma(CMM).To satisfy the actual requirements in repairing post-operative skin defects and inhibiting CMM recurrence after tumorectomy,we constructed a novel chitosan/alginate(CS/Alg)hydrogel containing the aforementioned HANPs.The in vitro cell experiments confirmed that activated mitochondrial-dependent apoptosis was tightly related to the anti-tumor ability of HANPs.Specifically,we further discovered several target proteins might be involved in abnormal activating Wnt,proteoglycans in cancer,oxidative phosphorylation and p53 signaling pathways.The in vivo animal experiments demonstrated that the HANPsloaded CS/Alg hydrogel(CS/Alg/HANPs)had a similar effect on inhibiting tumor growth as HANPs,and CS/Alg hydrogel as well as phosphate buffered saline(PBS)group(control)not showed any effect,proving the key role of HANPs.The immunohistochemical staining demonstrated a tumor inhibition via the mitochondria-mediated apoptosis pathway,consistent with the in vitro evaluation.Moreover,CS/Alg/HANPs exhibited no additional biosafety risk to the functions of major organs.Overall,this CS/Alg/HANPs hydrogel has substantial application potential for treating CMM.展开更多
Surfactant residues in recycled wood fiber from the deinking process can have impact on the subsequent bleaching and papermaking processes by increasing bleaching agents and disturbing papermaking wet-end chemistry.In...Surfactant residues in recycled wood fiber from the deinking process can have impact on the subsequent bleaching and papermaking processes by increasing bleaching agents and disturbing papermaking wet-end chemistry.In this paper,the fundamental mechanism of surfactants adsorption characteristics on secondary fiber surface was studied.The adsorption isotherms and kinetics of an anionic surfactant,sodium dodecyl benzene sulfonate(SDBS)and a non-ionic surfactant,Triton X-100(TX-100)on secondary fiber surface with or without the presence of electrolytes(Mg^(2+)ions)were studied by using spectrophotometric methods.Results showed that the adsorption isotherm of SDBS could be subdivided into four regions,and the adsorption of SDBS was increased with the presence of Mg^(2+)ions.While for TX-100,the adsorption isotherm showed typically Langmuir-type adsorption,and its adsorption was decreased with the presence of Mg^(2+)ions.Kinetic analysis indicated that the adsorption processes both fit pseudo-second-order model well.The adsorption rate of both surfactants was affected by the initial surfactant concentration,electrolyte and temperature.The activation parameters confirmed that the adsorption processes of both surfactants were typically diffusion-controlled and endothermic at a temperature range commonly used for current flotation deinking processes.SDBS and TX-100 mainly adsorbed to the hydrophobic sites of secondary fibers surface,which decreased the fiber hydrophobicity and reduced the fiber loss in the flotation deinking process.The results suggested that the concentration of Mg^(2+)ions should be maintained at a low level when SDBS was used in the flotation process.展开更多
基金supported by the National Natural Science Foundation of China,“Study on crown models for L arix olgensis based on tree growth” (No.31870620)。
文摘Crown development is closely related to the biomass and growth rate of the tree and its width(CW)is an important covariable in growth and yield models and in forest management.To date,various CW models have been proposed.However,limited studies have explicitly focused on additive and inherent correlation of crown components and total CW as well as the influence of competition on crown radius from the corresponding direction.In this study,two model systems were used,i.e.,aggregation method system(AMS)and disaggregation method system(DMS),to develop crown width additive model systems.For calculating spatially explicit competition index(CI),four neighbor tree selection methods were evaluated.CI was decomposed into four cardinal directions and added into the model systems.Results show that the power model form was more proper for our data to fit CW growth.For each crown radius and total CW,height to the diameter at breast height(HDR)and basal area of trees larger than the subject tree(BAL)significantly contributed to the increase of prediction accuracy.The 3-m fixed radius was optimal among the four neighborhoods selection ways.After adding decomposed competition Hegyi index into model systems AMS and DMS,the prediction accuracy improved.Of the model systems evaluated,AMS based on decomposed CI provided the best performance as well as the inherent correlation and additivity properties.Our study highlighted the importance of decomposed CI in tree CW modelling for additive model systems.This study focused on methodology and could be applied to other species or stands.
基金National Key Research and Development Program (Nos. NKRDP 2016YFE0118400)the Key project of Science and Technology of Henan Province (No. 172102410062)+1 种基金National Natural Science Foundation of China (No. 61176008)National Natural Science Foundation of China Henan Provincial Joint Fund Key Project (No. U1604263)
文摘In this paper,an ultraviolet C-band laser diode lasing at 277 nm composed of B0.313Ga0.687N/B0.40Ga0.60N QW/QB heterostructure on Mg and Si-doped AlxGa1-xN layers was designed,as well as a lowest reported substitutional accepter and donor concentration up to NA=5.0×10^17 cm^-3 and ND=9.0×10^16 cm^-3 for deep ultraviolet lasing was achieved.The structure was assumed to be grown over bulk AIN substrate and operate under a continuous wave at room temperature.Although there is an emphasizing of the suitability for using boron nitride wide band gap in the deep ultraviolet region,there is still a shortage of investigation about the ternary BGaN in aluminum-rich AIGaN alloys.Based on the simulation,an average local gain in quantum wells of 1946 cm^-1,the maximum emitted power of 2.4 W,the threshold current of 500 mA,a slope efficiency of 1.91 W/A as well as an average DC resistance for the V-I curve of(0.336Ω)had been observed.Along with an investigation regarding different EBL,designs were included with tapered and inverse tapered structure.Therefore,it had been found a good agreement with the published results for tapered EBL design,with an overweighting for a proposed inverse tapered EBL design.
文摘Diabetes Mellitus is a systematic disease with complications in multi-organs,including decreased implant osseointegration and a high failure rate of dental transplants.Accumulating evidence indicates that the signaling pathway directly impacts the process of bone metabolism and inflammatory response implicated with dental implants in diabetic patients.This review summarizes the recent advance in signaling pathways regulate osseointegration and inflammatory response in dental transplantation,aiming to identify the potential therapeutic target to reduce the dental transplant failure in diabetes patients,with emphasis on the surface characteristics of the implant,inflammatory signaling,AMPK,PPARγ,WNT,ROS,and adiponectin signaling.
基金supported by the National Natural Science Foundation of China(No.31870620)the National Technology Extension Fund of Forestry([2019]06)the Fundamental Research Funds for the Central Universities(No.PTYX202107)。
文摘Pine wilt disease(PWD)is currently one of the main causes of large-scale forest destruction.To control the spread of PWD,it is essential to detect affected pine trees quickly.This study investigated the feasibility of using the object-oriented multi-scale segmentation algorithm to identify trees discolored by PWD.We used an unmanned aerial vehicle(UAV)platform equipped with an RGB digital camera to obtain high spatial resolution images,and multiscale segmentation was applied to delineate the tree crown,coupling the use of object-oriented classification to classify trees discolored by PWD.Then,the optimal segmentation scale was implemented using the estimation of scale parameter(ESP2)plug-in.The feature space of the segmentation results was optimized,and appropriate features were selected for classification.The results showed that the optimal scale,shape,and compactness values of the tree crown segmentation algorithm were 56,0.5,and 0.8,respectively.The producer’s accuracy(PA),user’s accuracy(UA),and F1 score were 0.722,0.605,and 0.658,respectively.There were no significant classification errors in the final classification results,and the low accuracy was attributed to the low number of objects count caused by incorrect segmentation.The multi-scale segmentation and object-oriented classification method could accurately identify trees discolored by PWD with a straightforward and rapid processing.This study provides a technical method for monitoring the occurrence of PWD and identifying the discolored trees of disease using UAV-based high-resolution images.
基金funded by the National Key Program of Research and Development,Ministry of Science and Technology(No.2022YFF1301500)the National Nature Science Foundation of China(No.32070522)。
文摘INTRODUCTION Pangolin is the common name for animals in the Family Pholidota,Mammalia,which consists of eight extant species.All pangolin species have been listed as critically endangered(CR),endangered(EN),or vulnerable(VU)species in the International Union for Conservation of Nature(IUCN)Red List of Threatened Species(Challender et al.2020).In June 2020,the Chinese government upgraded the Chinese pangolin(Manis pentadactyla Linnaeus,1758)from a national second-class protected animal to a national first-class protected animal.In February 2021,the Sunda pangolin(Manis javanica Desmarest,1822)and the Indian pangolin(Manis crassicaudata Geoffroy,1803)were added to the list of national first-class protected animals.However,the number of species of pangolins naturally distributed in China varies in the literature:Some sources have recorded only one species,namely the Chinese pangolin(Nowak&Paradiso 1983;Sheng 1999),while most have recorded two species,namely the Chinese pangolin and Indian pangolin(Allen 1938;Zhang 1997;Wang 2003;Wu et al.2005a;Hu&Hu 2017).
基金supported by the National Natural Science Foundation of China (Grant Nos. 41930647, 41590844, 41421001 & 41971358)the Strategic Priority Research Program (A) of the Chinese Academy of Sciences (Grant No. XDA20030203)+1 种基金the Innovation Project of LREIS (Grant No. O88RA600YA)the Biodiversity Investigation, Observation and Assessment Program (2019–2023) of the Ministry of Ecology and Environment of China。
文摘We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface system modeling(FTESM). The Beijing-Tianjin-Hebei(BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling(HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-meansquare error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM.
基金This work was supported by the Shenzhen Municipal Science and Technology Innovation Council(JCYJ20180504165819965)the National Natural Science Foundation of China(No.21874063)The authors acknowledge the technical support from SUSTech Core Research Facilities。
文摘Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.
基金financially supported by National Key Research and Development Program of China(2017YFB0702600,2017YFB0702604)Sichuan Science and Technology Program(2020YFS0038).
文摘Hydroxyapatite nanoparticles(HANPs)have been increasingly regarded and reported due to their potential anti-tumor ability.Previously,we found that the rod-like HANPs had good application potential for cutaneous melanoma(CMM).To satisfy the actual requirements in repairing post-operative skin defects and inhibiting CMM recurrence after tumorectomy,we constructed a novel chitosan/alginate(CS/Alg)hydrogel containing the aforementioned HANPs.The in vitro cell experiments confirmed that activated mitochondrial-dependent apoptosis was tightly related to the anti-tumor ability of HANPs.Specifically,we further discovered several target proteins might be involved in abnormal activating Wnt,proteoglycans in cancer,oxidative phosphorylation and p53 signaling pathways.The in vivo animal experiments demonstrated that the HANPsloaded CS/Alg hydrogel(CS/Alg/HANPs)had a similar effect on inhibiting tumor growth as HANPs,and CS/Alg hydrogel as well as phosphate buffered saline(PBS)group(control)not showed any effect,proving the key role of HANPs.The immunohistochemical staining demonstrated a tumor inhibition via the mitochondria-mediated apoptosis pathway,consistent with the in vitro evaluation.Moreover,CS/Alg/HANPs exhibited no additional biosafety risk to the functions of major organs.Overall,this CS/Alg/HANPs hydrogel has substantial application potential for treating CMM.
基金support of the Natural Natural Science Foundation of China (NSERC),Grant No.31000282the Program for High School Excellent Talent of Liaoning Province,Grant No.LJQ2011053.
文摘Surfactant residues in recycled wood fiber from the deinking process can have impact on the subsequent bleaching and papermaking processes by increasing bleaching agents and disturbing papermaking wet-end chemistry.In this paper,the fundamental mechanism of surfactants adsorption characteristics on secondary fiber surface was studied.The adsorption isotherms and kinetics of an anionic surfactant,sodium dodecyl benzene sulfonate(SDBS)and a non-ionic surfactant,Triton X-100(TX-100)on secondary fiber surface with or without the presence of electrolytes(Mg^(2+)ions)were studied by using spectrophotometric methods.Results showed that the adsorption isotherm of SDBS could be subdivided into four regions,and the adsorption of SDBS was increased with the presence of Mg^(2+)ions.While for TX-100,the adsorption isotherm showed typically Langmuir-type adsorption,and its adsorption was decreased with the presence of Mg^(2+)ions.Kinetic analysis indicated that the adsorption processes both fit pseudo-second-order model well.The adsorption rate of both surfactants was affected by the initial surfactant concentration,electrolyte and temperature.The activation parameters confirmed that the adsorption processes of both surfactants were typically diffusion-controlled and endothermic at a temperature range commonly used for current flotation deinking processes.SDBS and TX-100 mainly adsorbed to the hydrophobic sites of secondary fibers surface,which decreased the fiber hydrophobicity and reduced the fiber loss in the flotation deinking process.The results suggested that the concentration of Mg^(2+)ions should be maintained at a low level when SDBS was used in the flotation process.
