Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim ...Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare.展开更多
A novel lectin(termed PML)was purified from fruiting bodies of the edible mushroom Phellodon melaleucus(division Basidiomycota)by ion exchange,hydrophobic interaction,and gel filtration chromatographies,with overall t...A novel lectin(termed PML)was purified from fruiting bodies of the edible mushroom Phellodon melaleucus(division Basidiomycota)by ion exchange,hydrophobic interaction,and gel filtration chromatographies,with overall titer recovery~60%and 20-fold purification.PML displayed hemagglutination activity 13319 units/mg toward rabbit erythrocytes.SDS-PAGE and gel filtration analyses revealed that PML is a homodimeric lectin with a molecular weight of 28.8 kDa.PML hemagglutination activity was not inhibited by various simple sugars or their derivatives,but was enhanced by cations Ca^(2+),Mg^(2+),Zn^(2+),and Cu^(2+).The activity was stable in pH range 6–9 and in the temperature range 20–60°C.Circular dichroism(CD)spectroscopic analysis showed that PML was composed primarily ofβ-sheets with lowα-helix content.In a B16 melanoma mouse model,PML treatment significantly inhibited tumor growth,and increased cytokine IL-10 content.Our findings suggest that PML is a potential anticancer therapeutic agent.展开更多
Arundinaria spanostachya is the main bamboo species on which giant pandas forage.Information on its regeneration capacity to meet the foraging demands of pandas is important to ensure the long-term survival of pandas....Arundinaria spanostachya is the main bamboo species on which giant pandas forage.Information on its regeneration capacity to meet the foraging demands of pandas is important to ensure the long-term survival of pandas.In 2014,2 plot types(grazed versus control)were selected in the winter habitat used by one wild giant panda.Various morphological and regeneration characteristics of the bamboo were assessed in the respective plots during 2014 and 2015.The panda avoided feeding on bamboo with a basal diameter of<6 mm,preferentially feeding on intermediate-sized bamboo.The density of new shoots and the recruitment rate of shoots were significantly higher in the grazed plots compared to the control plots.The annual recruitment rate of shoots was markedly higher than the annual mortality rate in the same plot type.After grazing,the basal diameter and height of new bamboo were similar between the 2 plots.In the grazed plots,the basal diameter of new bamboo was similar to that of the stumps.Innutrition and foraging by insects were the main factors influencing the survival of new shoots.Our results showed that grazing by giant pandas helped the clonal regeneration of A.spanostachya populations,with the basal diameter of new bamboo shoots meeting the foraging demand of pandas.However,information on the carrying capacity of A.spanostachya is necessary to ensure sufficient forage matter is available for reintroduced giant pandas.Furthermore,fertilization and insect control measures should be implemented during the shooting period to optimize A.spanostachya resources.展开更多
Fe^(2+)is of considerable importance in plant growth and crop production.However,most Fe elements in nature favor existing in the trivalent state,which often causes the deficiency of Fe^(2+)in plants.Here,we report th...Fe^(2+)is of considerable importance in plant growth and crop production.However,most Fe elements in nature favor existing in the trivalent state,which often causes the deficiency of Fe^(2+)in plants.Here,we report the Fe valence state change from Fe^(3+)to Fe^(2+)by using leaves.This valence state change was confirmed by x-ray photoelectron spectroscopy in Fe-Cl@leaves.Fourier transform infrared and ultraviolet-visible spectroscopy demonstrated that aromatic ring groups were included in leaves,and cation-π𝜋interactions between Fe cations and the components containing aromatic rings in leaves were measured.Further,density functional theory calculations revealed that the most stable adsorption site for hydrated Fe^(3+)cation was the region where hydroxyl groups and aromatic rings coexist.Moreover,molecular orbital and charge decomposition analysis revealed that the aromatic rings took the major part(59%)of the whole net charge transfer between leaves and Fe cations.This work provides a high-efficiency and eco-friendly way to transform the Fe valence state from Fe^(3+)to Fe^(2+),and affords a new insight into the valance change between plant organisms with cations.展开更多
This paper investigates fault tolerant attitude control theory and experiment for underactuated spacecraft with one reaction wheel completely broken and two others suffering actuator faults of partial loss of effectiv...This paper investigates fault tolerant attitude control theory and experiment for underactuated spacecraft with one reaction wheel completely broken and two others suffering actuator faults of partial loss of effectiveness or bias.A non-smooth robust adaptive fault tolerant control law is proposed under the zero-momentum and input saturation conditions.It shows that the available reaction wheels need to produce sufficient control torque for the fault tolerance.Such a new control method is implemented in a semi-physical simulation system of an air-bearing platform.Experimental results show the effectiveness of the proposed method in spacecraft practical engineering.展开更多
In this paper,an optical pulse amplitude modulation with 4 levels(PAM-4)using a fiber combiner is proposed to enhance the data rate of a field-programmable gate-array-based long-distance real-time underwater wireless ...In this paper,an optical pulse amplitude modulation with 4 levels(PAM-4)using a fiber combiner is proposed to enhance the data rate of a field-programmable gate-array-based long-distance real-time underwater wireless optical communication system.Two on-off keying signals with different amplitudes are used to modulate two pigtailed laser diodes,respectively,and the generated optical signals are superimposed into optical PAM-4 signals by a fiber combiner.The optical PAM-4scheme can effectively alleviate the nonlinearity,although it reduces the peak-to-peak value of the emitting optical power by 25%.A real-time data rate of 187.5 Mbit/s is achieved by using the optical PAM-4 with a transmission distance of 50 m.The data rate is increased by about 25%compared with the conventional electrical PAM-4 in the same condition.展开更多
This paper presents an improved method for imaging in turbid water by using the individual strengths of the quadrature lock-in discrimination(QLD)method and the retinex method.At first,the high-speed QLD is performed ...This paper presents an improved method for imaging in turbid water by using the individual strengths of the quadrature lock-in discrimination(QLD)method and the retinex method.At first,the high-speed QLD is performed on images,aiming at capturing the ballistic photons.Then,we perform the retinex image enhancement on the QLD-processed images to enhance the contrast of the image.Next,the effect of uneven illumination is suppressed by using the bilateral gamma function for adaptive illumination correction.The experimental results depict that the proposed approach achieves better enhancement than the existing approaches,even in a high-turbidity environment.展开更多
CHINAS EVOLVING NATIONAL PARK DESIGNATIONS AND SINGLE LARGE PROTECTED AREA OR SEVERAL SMALL PROTECTED AREAS(SLOSS)DEBATE As of 2021,the International Union for Conservation of Nature estimated that there are over 6,00...CHINAS EVOLVING NATIONAL PARK DESIGNATIONS AND SINGLE LARGE PROTECTED AREA OR SEVERAL SMALL PROTECTED AREAS(SLOSS)DEBATE As of 2021,the International Union for Conservation of Nature estimated that there are over 6,000 national parks(NPs)in more than 100 countries,most of which are strongly focused on endangered species.1 Over the past 6 years,China has invested US$20million in developing the Giant Panda National Park(GPNP)and a furtherUS$16million in establishing theNortheast China Tiger and Leopard National Park(NCTLNP).展开更多
We report on the first study to track the spatial behaviors of wild giant pandas(Ailuropoda melanoleuca)using high-resolution global positioning system(GPS)telemetry.Between 2008 and 2009,4 pandas(2 male and 2 fe-male...We report on the first study to track the spatial behaviors of wild giant pandas(Ailuropoda melanoleuca)using high-resolution global positioning system(GPS)telemetry.Between 2008 and 2009,4 pandas(2 male and 2 fe-male)were tracked in Foping Reserve,China for an average of 305 days(±54.8 SE).Panda home ranges were larger than those of previous very high frequency tracking studies,with a bimodal distribution of space-use and distinct winter and summer centers of activity.Home range sizes were larger in winter than in summer,although there was considerable individual variability.All tracked pandas exhibited individualistic,unoriented and multi-phasic movement paths,with a high level of tortuosity within seasonal core habitats and directed,linear,large-scale movements between habitats.Pandas moved from low elevation winter habitats to high elevation(>2000 m)summer habitats in May,when temperatures averaged 17.5°C(±0.3 SE),and these large-scale movements took<1 month to complete.The peak in panda mean elevation occurred in Jul,after which they began slow,large-scale movements back to winter habitats that were completed in Nov.An adult female panda made 2 long-distance movements during the mating season.Pandas remain close to rivers and streams during winter,possi-bly reflecting the elevated water requirements to digest their high-fiber food.Panda movement path tortuosity and first-passage-time as a function of spatial scale indicated a mean peak in habitat search effort and patch use of approximately 700 m.Despite a high degree of spatial overlap between panda home ranges,particularly in winter,we detected neither avoidance nor attraction behavior between conspecifics.展开更多
The giant panda(Ailuropoda melanoleuca David,1869)is an iconic species for global conservation,yet field research has only recently advanced to the point where adaptive management is possible.Here,we review recent dev...The giant panda(Ailuropoda melanoleuca David,1869)is an iconic species for global conservation,yet field research has only recently advanced to the point where adaptive management is possible.Here,we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation forward.Because of scientific,funding,political,and logistical hurdles,few endangered species management programs have embraced adaptive management,wherein management decisions are shaped iteratively by targeted scientific research.Specific threats,such as habitat destruction,anthropogenic disturbance and fragmented nonviable populations,need to be addressed simultaneously by researchers,managers and policy-makers working in concert to understand and overcome these obstacles to species recovery.With the backing of the Chinese Govern-ment and the conservation community,the giant panda can become a high-profile test species for this much touted,but rarely implemented,approach to conservation management.展开更多
Earthquakes not only result in a great loss of human life and property,but also have profound effects on the Earth’s biodiversity.The Lushan earthquake occurred on 20 Apr 2013,with a magnitude of 7.0 and an intensi&#...Earthquakes not only result in a great loss of human life and property,but also have profound effects on the Earth’s biodiversity.The Lushan earthquake occurred on 20 Apr 2013,with a magnitude of 7.0 and an intensity of 9.0 degrees.A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined.Making use of research on the Wenchuan earthquake(with a magnitude of 8.0),which occurred approximately 5 years ago,we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat.An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death.In addition,an earthquake can damage conservation facilities for pandas,and result in further habitat fragmentation and degradation.However,from a historical point of view,the impacts of human activities on giant pandas and their habitat may,in fact,far outweigh those of natural disasters such as earthquakes.Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas,not those of humans.展开更多
基金supported by the Inner Mongolia Autonomous Region Science and Technology Revitalization Foundation (2021CG0029)the National Natural Science Foundation of China (22178070)
文摘Glabridin is the main ingredient of hydrophobic fraction in licorice extract and has been shown to have anti-melanogenesis activity in skins.However,the underlying mechanism(s)remain not completely understood.The aim of this study is thus to elucidate the possible mechanisms related to the melanogenesis suppression by glabridin in cultured B16 murine melanoma cells and in UVA radiation induced hyperpigmentation model of BALB/c mice as well.Molecular docking simulations revealed that between catalytic core residues and the compound.The treatment by glabridin significantly downregulated both transcriptional and/or protein expression of melanogenesis-related factors including melanocyte stimulating hormone receptor(MC1R),microphthalmia-associated transcription factor(MITF),tyrosinase(TYR),TYR-related protein-1(TRP-1)and TRP-2 in B16 cells.Both PKA/MITF and MAPK/MITF signaling pathways were found to be involved in the suppression of melanogenesis by glabridin in B16 cells.Also in vivo glabridin therapy significantly reduced hyperpigmentation,epidermal thickening,roughness and inflammation induced by frequent UVA exposure in mice skins,thus beneficial for skin healthcare.These data further look insights into the molecular mechanisms of melanogenesis suppression by glabridin,rationalizing the application of the natural compound for skin healthcare.
基金supported by grants from the China Agriculture Research System(CARS-20-01A)。
文摘A novel lectin(termed PML)was purified from fruiting bodies of the edible mushroom Phellodon melaleucus(division Basidiomycota)by ion exchange,hydrophobic interaction,and gel filtration chromatographies,with overall titer recovery~60%and 20-fold purification.PML displayed hemagglutination activity 13319 units/mg toward rabbit erythrocytes.SDS-PAGE and gel filtration analyses revealed that PML is a homodimeric lectin with a molecular weight of 28.8 kDa.PML hemagglutination activity was not inhibited by various simple sugars or their derivatives,but was enhanced by cations Ca^(2+),Mg^(2+),Zn^(2+),and Cu^(2+).The activity was stable in pH range 6–9 and in the temperature range 20–60°C.Circular dichroism(CD)spectroscopic analysis showed that PML was composed primarily ofβ-sheets with lowα-helix content.In a B16 melanoma mouse model,PML treatment significantly inhibited tumor growth,and increased cytokine IL-10 content.Our findings suggest that PML is a potential anticancer therapeutic agent.
基金supported by National Natural science Foundation of China(No.31370367)
文摘Arundinaria spanostachya is the main bamboo species on which giant pandas forage.Information on its regeneration capacity to meet the foraging demands of pandas is important to ensure the long-term survival of pandas.In 2014,2 plot types(grazed versus control)were selected in the winter habitat used by one wild giant panda.Various morphological and regeneration characteristics of the bamboo were assessed in the respective plots during 2014 and 2015.The panda avoided feeding on bamboo with a basal diameter of<6 mm,preferentially feeding on intermediate-sized bamboo.The density of new shoots and the recruitment rate of shoots were significantly higher in the grazed plots compared to the control plots.The annual recruitment rate of shoots was markedly higher than the annual mortality rate in the same plot type.After grazing,the basal diameter and height of new bamboo were similar between the 2 plots.In the grazed plots,the basal diameter of new bamboo was similar to that of the stumps.Innutrition and foraging by insects were the main factors influencing the survival of new shoots.Our results showed that grazing by giant pandas helped the clonal regeneration of A.spanostachya populations,with the basal diameter of new bamboo shoots meeting the foraging demand of pandas.However,information on the carrying capacity of A.spanostachya is necessary to ensure sufficient forage matter is available for reintroduced giant pandas.Furthermore,fertilization and insect control measures should be implemented during the shooting period to optimize A.spanostachya resources.
基金supported by the National Natural Science Foundation of China(Grant Nos.11974366,12004110,and 12147169)the Fundamental Research Funds for the Center Universities.
文摘Fe^(2+)is of considerable importance in plant growth and crop production.However,most Fe elements in nature favor existing in the trivalent state,which often causes the deficiency of Fe^(2+)in plants.Here,we report the Fe valence state change from Fe^(3+)to Fe^(2+)by using leaves.This valence state change was confirmed by x-ray photoelectron spectroscopy in Fe-Cl@leaves.Fourier transform infrared and ultraviolet-visible spectroscopy demonstrated that aromatic ring groups were included in leaves,and cation-π𝜋interactions between Fe cations and the components containing aromatic rings in leaves were measured.Further,density functional theory calculations revealed that the most stable adsorption site for hydrated Fe^(3+)cation was the region where hydroxyl groups and aromatic rings coexist.Moreover,molecular orbital and charge decomposition analysis revealed that the aromatic rings took the major part(59%)of the whole net charge transfer between leaves and Fe cations.This work provides a high-efficiency and eco-friendly way to transform the Fe valence state from Fe^(3+)to Fe^(2+),and affords a new insight into the valance change between plant organisms with cations.
基金supported by the National Natural Science Foundation of China(Nos.62073165 and 62233009)the 111 Project,China(No.B20007).
文摘This paper investigates fault tolerant attitude control theory and experiment for underactuated spacecraft with one reaction wheel completely broken and two others suffering actuator faults of partial loss of effectiveness or bias.A non-smooth robust adaptive fault tolerant control law is proposed under the zero-momentum and input saturation conditions.It shows that the available reaction wheels need to produce sufficient control torque for the fault tolerance.Such a new control method is implemented in a semi-physical simulation system of an air-bearing platform.Experimental results show the effectiveness of the proposed method in spacecraft practical engineering.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61971378)Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22030208)Zhoushan-Zhejiang University Joint Research Project(No.2019C81081)。
文摘In this paper,an optical pulse amplitude modulation with 4 levels(PAM-4)using a fiber combiner is proposed to enhance the data rate of a field-programmable gate-array-based long-distance real-time underwater wireless optical communication system.Two on-off keying signals with different amplitudes are used to modulate two pigtailed laser diodes,respectively,and the generated optical signals are superimposed into optical PAM-4 signals by a fiber combiner.The optical PAM-4scheme can effectively alleviate the nonlinearity,although it reduces the peak-to-peak value of the emitting optical power by 25%.A real-time data rate of 187.5 Mbit/s is achieved by using the optical PAM-4 with a transmission distance of 50 m.The data rate is increased by about 25%compared with the conventional electrical PAM-4 in the same condition.
基金supported in part by the National Key Research and Development Program of China(Nos.2022YFC2808200 and 2022YFB2903403)the National Natural Science Foundation of China(NSFC)(No.61971378)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA22030208).
文摘This paper presents an improved method for imaging in turbid water by using the individual strengths of the quadrature lock-in discrimination(QLD)method and the retinex method.At first,the high-speed QLD is performed on images,aiming at capturing the ballistic photons.Then,we perform the retinex image enhancement on the QLD-processed images to enhance the contrast of the image.Next,the effect of uneven illumination is suppressed by using the bilateral gamma function for adaptive illumination correction.The experimental results depict that the proposed approach achieves better enhancement than the existing approaches,even in a high-turbidity environment.
基金provided by the Joint Fund of the National Natural Science Foundation of China and the Karst Science ResearchCenter ofGuizhou Province(U1812401)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB13000000)and the Major Science and Technology Projects of the Science and Technology Department of Sichuan Province(2022YFS0484 and 2021YFS0280).
文摘CHINAS EVOLVING NATIONAL PARK DESIGNATIONS AND SINGLE LARGE PROTECTED AREA OR SEVERAL SMALL PROTECTED AREAS(SLOSS)DEBATE As of 2021,the International Union for Conservation of Nature estimated that there are over 6,000 national parks(NPs)in more than 100 countries,most of which are strongly focused on endangered species.1 Over the past 6 years,China has invested US$20million in developing the Giant Panda National Park(GPNP)and a furtherUS$16million in establishing theNortheast China Tiger and Leopard National Park(NCTLNP).
基金This work was funded by the Na-tional Natural Science Foundation of China(31230011,30970382)the Knowledge Innovation Program of the Chinese Academy of Sciences(KSCX2-EW-Z-4)the San Diego Zoo Global Wildlife Conservancy.
文摘We report on the first study to track the spatial behaviors of wild giant pandas(Ailuropoda melanoleuca)using high-resolution global positioning system(GPS)telemetry.Between 2008 and 2009,4 pandas(2 male and 2 fe-male)were tracked in Foping Reserve,China for an average of 305 days(±54.8 SE).Panda home ranges were larger than those of previous very high frequency tracking studies,with a bimodal distribution of space-use and distinct winter and summer centers of activity.Home range sizes were larger in winter than in summer,although there was considerable individual variability.All tracked pandas exhibited individualistic,unoriented and multi-phasic movement paths,with a high level of tortuosity within seasonal core habitats and directed,linear,large-scale movements between habitats.Pandas moved from low elevation winter habitats to high elevation(>2000 m)summer habitats in May,when temperatures averaged 17.5°C(±0.3 SE),and these large-scale movements took<1 month to complete.The peak in panda mean elevation occurred in Jul,after which they began slow,large-scale movements back to winter habitats that were completed in Nov.An adult female panda made 2 long-distance movements during the mating season.Pandas remain close to rivers and streams during winter,possi-bly reflecting the elevated water requirements to digest their high-fiber food.Panda movement path tortuosity and first-passage-time as a function of spatial scale indicated a mean peak in habitat search effort and patch use of approximately 700 m.Despite a high degree of spatial overlap between panda home ranges,particularly in winter,we detected neither avoidance nor attraction behavior between conspecifics.
文摘The giant panda(Ailuropoda melanoleuca David,1869)is an iconic species for global conservation,yet field research has only recently advanced to the point where adaptive management is possible.Here,we review recent developments in giant panda conservation science and propose a strategic plan for moving panda conservation forward.Because of scientific,funding,political,and logistical hurdles,few endangered species management programs have embraced adaptive management,wherein management decisions are shaped iteratively by targeted scientific research.Specific threats,such as habitat destruction,anthropogenic disturbance and fragmented nonviable populations,need to be addressed simultaneously by researchers,managers and policy-makers working in concert to understand and overcome these obstacles to species recovery.With the backing of the Chinese Govern-ment and the conservation community,the giant panda can become a high-profile test species for this much touted,but rarely implemented,approach to conservation management.
基金This project was supported by the National Natural Science Foundation of China(31270570)the Planned Project for New-Century Excellent Talents of the Chinese Chinese Education Ministry(NCET-11-1060)the International Cooperation Foundation for Giant Pandas of the State Forestry Administration(Sichuan 2010-01).
文摘Earthquakes not only result in a great loss of human life and property,but also have profound effects on the Earth’s biodiversity.The Lushan earthquake occurred on 20 Apr 2013,with a magnitude of 7.0 and an intensity of 9.0 degrees.A distance of 17.0 km from its epicenter to the nearest distribution site of giant pandas recorded in the Third National Survey was determined.Making use of research on the Wenchuan earthquake(with a magnitude of 8.0),which occurred approximately 5 years ago,we briefly analyze the impacts of the Lushan earthquake on giant pandas and their habitat.An earthquake may interrupt ongoing behaviors of giant pandas and may also cause injury or death.In addition,an earthquake can damage conservation facilities for pandas,and result in further habitat fragmentation and degradation.However,from a historical point of view,the impacts of human activities on giant pandas and their habitat may,in fact,far outweigh those of natural disasters such as earthquakes.Measures taken to promote habitat restoration and conservation network reconstruction in earthquake-affected areas should be based on requirements of giant pandas,not those of humans.
