To determine light requirement and adaptability of Fraxinus mandshurica seedlings, the seasonal variations of photosynthetic variables were measured in 3-year-old seedlings grown under four light levels （100%, 60%, 3...To determine light requirement and adaptability of Fraxinus mandshurica seedlings, the seasonal variations of photosynthetic variables were measured in 3-year-old seedlings grown under four light levels （100%, 60%, 30%, and 15% of full sunlight） with a LI-6400 portable photosynthesis system. The leaf chlorophyll content, special leaf weight, annual height and basal diameter increment of seedlings were also observed. The maximum and minimum values of net photosynthetic rate, maximum rate of carboxylation, and maximum rate of electron transport of F. mandshurica seedlings were detected with 60% and 15% of full sunlight treatments, respectively. With the decrease of light level, both light saturation point and special leaf weight significantly declined （p 0.05）, but leaf chlorophyll content significantly increased （p 0.05）. Annual height and basal diameter increments of seedlings grown under 60% of full sunlight treatment were significantly greater than those of seedlings under other treatments （p 0.05）. It was concluded that F. mandshurica seedlings can adapt to a wide range of light environments from 15% to 100% of full sunlight by adjusting light saturation point, leaf chlorophyll content and special leaf weight. According to the maximum of relative growth, 60% of full sunlight treatment is the optimum light level for the growth of 3-year-old F. mandshurica seedlings.展开更多
Plants of the genus Camellia are widely cultivated throughout the world as ornamentals because of their bright and large flowers.The widely cultivated varieties are mainly derived from the mutant lines and hybrid prog...Plants of the genus Camellia are widely cultivated throughout the world as ornamentals because of their bright and large flowers.The widely cultivated varieties are mainly derived from the mutant lines and hybrid progenies of Camellia japonica Linn.and Camellia reticulata Lindl.While their geographical distributions and environmental adaptabilities are significantly different,no systematic comparison has been conducted between these two species.To investigate differences in how these plants have adapted to their environments,we measured photosynthesis and 20 leaf functional traits of C.japonica and C.reticulata grown under the same conditions.Compared with C.japonica,C.reticulata showed higher values for light saturation point,light-saturated photo synthetic rate,leaf dry mass per unit area and stomatal area,but lower values for apparent quantum efficiency,leaf size,stomatal density and leaf nitrogen content per unit mass.Stomatal area was positively correlated with light-saturated photosynthetic rate and light saturation point,but negatively correlated with stomatal density.The differences between C.reticulata and C.japonica were mainly reflected in their adaptations to light intensity and leaf morphological traits.C.reticulata is better adapted to high light intensity than C.japonica.This difference is related to the two species’ differing life fo rms.Thus,leaf morphological traits have played an important role in the light adaptation of C.reticulata and C.japonica,and might be first noticed and selected during the breeding process.These findings will contribute to the cultivation of camellia plants.展开更多
Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-...Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.展开更多
Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination.Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation....Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination.Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation.However,various types of neurons and glial cells exist in the retina,and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation.Therefore,we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice.The results demonstrated that,in addition to photoreceptors,other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation.Importantly,Müller glial cells(MGs)were identified as hub cells for intercellular interactions,displaying complex cell‒cell communication with other retinal cells.Furthermore,light increased the transcription of the deiodinase Dio2 in MGs,which converted thyroxine(T4)to active triiodothyronine(T3).Subsequently,light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions.As cones specifically express the thyroid hormone receptor Thrb,they responded to the increase in T3 by adjusting light responsiveness.Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones.These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.展开更多
Our adaptive optics system based on a non-modulation pyramid wavefront sensor is integrated into a 1.8 m astronomical telescope installed at the Yunnan Observatory in LiJiang, and the first light with high-resolution ...Our adaptive optics system based on a non-modulation pyramid wavefront sensor is integrated into a 1.8 m astronomical telescope installed at the Yunnan Observatory in LiJiang, and the first light with high-resolution imaging of an astronomical star is successfully achieved. In this Letter, the structure and performance of this system are introduced briefly, and then the observation results of star imaging are reported to show that the angular resolution of an adaptive optics system using a non-modulation pyramid wavefront sensor can approach the diffraction limit quality of a 1.8 m telescope.展开更多
Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communic...Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communication system is highly desired for achieving target-oriented beamforming and accommodating high-speed data service.However,an efficient solution to integrated sensing and light communication remains challenging.Here,we demonstrate an integrated system that concurrently accomplishes high-precision sensing and high-speed data transmission by spatio-temporal modulation of the illumination and computational reconstruction.We developed a compressive angular projection imaging scheme to achieve rapid three-dimensional localization with high resolution,and a jointly optimized waveform design ensures slight sacrifice in the transmission data rate on the integrated system.We experimentally demonstrated a resolving resolution of 1 mm in lateral and 4 cm in depth within 0.6 m×0.6 m×0.6 m volume over 2 m distance at the sensing speed of 39 Hz in both static and dynamic conditions.This capability enables adaptive beamforming,which significantly enhances the data rate by 184%to permit errorless transmission of high-throughput virtual reality videos.Our work offers a promising route for intelligent wireless light communication systems with spatial perception capability,presenting the possibility of cable-free,immersive virtual reality experiences.展开更多
Photosystem I(PSI)is one of two photosystems involved in oxygenic photosynthesis.PSI of cyanobacteria exists in monomeric,trimeric,and tetrameric forms,in contrast to the strictly monomeric form of PSI in plants and a...Photosystem I(PSI)is one of two photosystems involved in oxygenic photosynthesis.PSI of cyanobacteria exists in monomeric,trimeric,and tetrameric forms,in contrast to the strictly monomeric form of PSI in plants and algae.The tetrameric organization raises questions about its structural,physiological,and evolutionary significance.Here we report the3.72 A˚resolution cryo-electron microscopy structure of tetrameric PSI from the thermophilic,unicellular cyanobacterium Chroococcidiopsis sp.TS-821.The structure resolves 44 subunits and 448 cofactor molecules.We conclude that the tetramer is arranged via two different interfaces resulting from a dimer-of-dimers organization.The localization of chlorophyll molecules permits an excitation energy pathway within and between adjacent monomers.Bioinformatics analysis reveals conserved regions in the PsaL subunit that correlate with the oligomeric state.Tetrameric PSI may function as a key evolutionary step between the trimeric and monomeric forms of PSI organization in photosynthetic organisms.展开更多
基金supported by National Nature Science Foundation of China (30830085)
文摘To determine light requirement and adaptability of Fraxinus mandshurica seedlings, the seasonal variations of photosynthetic variables were measured in 3-year-old seedlings grown under four light levels （100%, 60%, 30%, and 15% of full sunlight） with a LI-6400 portable photosynthesis system. The leaf chlorophyll content, special leaf weight, annual height and basal diameter increment of seedlings were also observed. The maximum and minimum values of net photosynthetic rate, maximum rate of carboxylation, and maximum rate of electron transport of F. mandshurica seedlings were detected with 60% and 15% of full sunlight treatments, respectively. With the decrease of light level, both light saturation point and special leaf weight significantly declined （p 0.05）, but leaf chlorophyll content significantly increased （p 0.05）. Annual height and basal diameter increments of seedlings grown under 60% of full sunlight treatment were significantly greater than those of seedlings under other treatments （p 0.05）. It was concluded that F. mandshurica seedlings can adapt to a wide range of light environments from 15% to 100% of full sunlight by adjusting light saturation point, leaf chlorophyll content and special leaf weight. According to the maximum of relative growth, 60% of full sunlight treatment is the optimum light level for the growth of 3-year-old F. mandshurica seedlings.
基金the National Natural Science Foundation of China,China(31670342,31760229)the Scientific and Technological Leading Talent Project of Yunnan Province(2016HA005)project for Construction of International Flower Technology Innovation Center and Achievement Industrialization。
文摘Plants of the genus Camellia are widely cultivated throughout the world as ornamentals because of their bright and large flowers.The widely cultivated varieties are mainly derived from the mutant lines and hybrid progenies of Camellia japonica Linn.and Camellia reticulata Lindl.While their geographical distributions and environmental adaptabilities are significantly different,no systematic comparison has been conducted between these two species.To investigate differences in how these plants have adapted to their environments,we measured photosynthesis and 20 leaf functional traits of C.japonica and C.reticulata grown under the same conditions.Compared with C.japonica,C.reticulata showed higher values for light saturation point,light-saturated photo synthetic rate,leaf dry mass per unit area and stomatal area,but lower values for apparent quantum efficiency,leaf size,stomatal density and leaf nitrogen content per unit mass.Stomatal area was positively correlated with light-saturated photosynthetic rate and light saturation point,but negatively correlated with stomatal density.The differences between C.reticulata and C.japonica were mainly reflected in their adaptations to light intensity and leaf morphological traits.C.reticulata is better adapted to high light intensity than C.japonica.This difference is related to the two species’ differing life fo rms.Thus,leaf morphological traits have played an important role in the light adaptation of C.reticulata and C.japonica,and might be first noticed and selected during the breeding process.These findings will contribute to the cultivation of camellia plants.
基金the support from Optoseeker Biotechnology(Shenzhen)Co.,Ltd.to help build the OET system and provide Optobot 500 to carry out the experiment shown in supplementary Movie S4.National Key R&D Program of China(2023YFE0112400,2022YFA1207100,2024YFC3406900)National Natural Science Foundation of China(62103050,62473245,61933008)+6 种基金Beijing Municipal Natural Science Foundation(4242060,L246030)the Chongqing Municipal Natural Science Foundation(Grant No.2024NSCQJQX0192,CSTB2024NSCQ-JQX0034)the BIT Research and Innovation Promoting Project(Grant No.2023CX01002)Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-09-E0013)Shanghai Science and Technology plan project(23ZR1422300)Shenzhen Science and Technology Program(KJZD20240903101359020)Open Research Fund of Guangdong Provincial Key Laboratory of Advanced Biomaterials(Southern University of Science and Technology,Grant No.KLAB202404002).
文摘Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.
文摘Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination.Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation.However,various types of neurons and glial cells exist in the retina,and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation.Therefore,we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice.The results demonstrated that,in addition to photoreceptors,other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation.Importantly,Müller glial cells(MGs)were identified as hub cells for intercellular interactions,displaying complex cell‒cell communication with other retinal cells.Furthermore,light increased the transcription of the deiodinase Dio2 in MGs,which converted thyroxine(T4)to active triiodothyronine(T3).Subsequently,light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions.As cones specifically express the thyroid hormone receptor Thrb,they responded to the increase in T3 by adjusting light responsiveness.Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones.These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.
基金supported by the National Natural Science Foundation of China under Grant No.61008038
文摘Our adaptive optics system based on a non-modulation pyramid wavefront sensor is integrated into a 1.8 m astronomical telescope installed at the Yunnan Observatory in LiJiang, and the first light with high-resolution imaging of an astronomical star is successfully achieved. In this Letter, the structure and performance of this system are introduced briefly, and then the observation results of star imaging are reported to show that the angular resolution of an adaptive optics system using a non-modulation pyramid wavefront sensor can approach the diffraction limit quality of a 1.8 m telescope.
基金National Key Research and Development Program of China(2023YFB2804701)National Natural Science Foundation of China(62401156,61925104,62201157,62231018)。
文摘Visible light communication plays an essential role in the next-generation 6G network due to its extremely high bandwidth and ultrafast transmission speed.Incorporating position sensing functionality into the communication system is highly desired for achieving target-oriented beamforming and accommodating high-speed data service.However,an efficient solution to integrated sensing and light communication remains challenging.Here,we demonstrate an integrated system that concurrently accomplishes high-precision sensing and high-speed data transmission by spatio-temporal modulation of the illumination and computational reconstruction.We developed a compressive angular projection imaging scheme to achieve rapid three-dimensional localization with high resolution,and a jointly optimized waveform design ensures slight sacrifice in the transmission data rate on the integrated system.We experimentally demonstrated a resolving resolution of 1 mm in lateral and 4 cm in depth within 0.6 m×0.6 m×0.6 m volume over 2 m distance at the sensing speed of 39 Hz in both static and dynamic conditions.This capability enables adaptive beamforming,which significantly enhances the data rate by 184%to permit errorless transmission of high-throughput virtual reality videos.Our work offers a promising route for intelligent wireless light communication systems with spatial perception capability,presenting the possibility of cable-free,immersive virtual reality experiences.
基金Support has been provided by the Gibson Family Foundation,the Bredesen Center for Interdisciplinary Research and Education,the Dr Donald L.Akers Faculty Enrichment Fellowship,and National Science Foundation(DGE-0801470 and EPS-1004083)support to B.D.B.In addition,J.M.and B.D.B.have been supported via a JDRD award from University of Tennessee(UTK)/Oak Ridge National Lab Science Alliance to B.D.B.,M.L.has been supported as a CIRE Fellow at University of Tennessee,Knoxville,C.J.C.was supported by a UTK NSF GFRP award(grant no.2017219379)K.S.has been supported by the Tickle College of Engineering,UTK.
文摘Photosystem I(PSI)is one of two photosystems involved in oxygenic photosynthesis.PSI of cyanobacteria exists in monomeric,trimeric,and tetrameric forms,in contrast to the strictly monomeric form of PSI in plants and algae.The tetrameric organization raises questions about its structural,physiological,and evolutionary significance.Here we report the3.72 A˚resolution cryo-electron microscopy structure of tetrameric PSI from the thermophilic,unicellular cyanobacterium Chroococcidiopsis sp.TS-821.The structure resolves 44 subunits and 448 cofactor molecules.We conclude that the tetramer is arranged via two different interfaces resulting from a dimer-of-dimers organization.The localization of chlorophyll molecules permits an excitation energy pathway within and between adjacent monomers.Bioinformatics analysis reveals conserved regions in the PsaL subunit that correlate with the oligomeric state.Tetrameric PSI may function as a key evolutionary step between the trimeric and monomeric forms of PSI organization in photosynthetic organisms.
