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T-cell receptor-CD3 complex （TCR） is a versatile signaling machine that can initiate antigen-specific immune re- sponses based on various biochemical changes of CD3 cytoplasmic domains, but the underlying structural basis remains elusive. Here we developed biophysical approaches to study the conformational dynamics of CD3ε cytoplasmic domain （CD3εCD）. At the single-molecule level, we found that CD3εCD could have multiple conformational states with different openness of three functional motifs, i.e., ITAM, BRS and PRS. These conformations were generated because different regions of CD3εCD had heterogeneous lipid-binding properties and therefore had heterogeneous dynamics. Live-cell imaging experiments demonstrated that different antigen stimulations could stabilize CD3εCD at different conformations. Lipid-dependent conformational dynamics thus provide structural basis for the versatile signaling property of TCR.

For the therapy and regeneration of bone defects resulting from malignant bone tumors, it is necessary to develop multifunctional biomaterials that are able to deliver therapeutic drugs, monitor drug release, and stimulate bone formation. Herein, a multifunctional mesoporous bioactive glass （MBG）/upconversion nanoparticle （UCNP） nanocomposite [UCNPs@SiO2@mSiO2-XCa （X = 0, 5, 10, 15, and 20）] with the ability to deliver anti-cancer drugs, monitor drug release, and stimulate osteogenic differentiation of bone marrow stromal cells （BMSCs） was successfully prepared using a layer-by-layer strategy. The nanocomposite spheres possess a core--sheU structure composed of UCNPs and a mesoporous SiO2/Ca layer with a uniform size distribution of 100 nm. The incorporation of Ca into the nanocomposites induced phase transformation from a pure hexagonal phase to a cubic phase, and facilitated the occurrence of red emission, which significantly improved fluorescence penetration for deep tissue imaging. In addition, since the red emission strongly overlaps with the maximum absorbance of the anti-cancer drug zinc phthalocyanine （ZnPc）, red luminescence could be strongly quenched by ZnPc. Consequently, drug release could be quantified by monitoring changes in fluorescence intensity. Furthermore, the incorporation of Ca into MBG/UCNP nanocomposites remarkably improved bioactivity, i.e., it stimulated apatite mineralization in simulated body fluids and enhanced cell proliferation and bone-related gene expression in BMSCs for the concentration range of 200-500 ~g/mL. Our results suggest that the prepared MBG/UCNP nanocomposites are useful for the therapy and regeneration of bone defects resulting from malignant bone tumors owing to their distinct multifunctionality, including strong red emission and functions in drug-delivery monitoring and osteostimulation.

Multiferroic charge-transfer crystals have drawn significant interest due to their simultaneous dipolar and spin ordering. Numerous theoretical and experimental studies have shown that the molecular stacking between donor and acceptor complexes plays an important role in tuning charge-transfer enabled multifunctionality. Herein, we show that the charge-transfer interactions can be controlled by the segregated stack, consisting of polythiophene donor- and fuUerene acceptor-based all-conjugated block copolymers. Room temperature magnetic field effects, ferroelectricity, and anisotropic magnetism are observed in charge-transfer crystals, which can be further controlled by photoexcitation and charge doping. Furthermore, the charge-transfer segregated stack crystals demonstrate external stimuli controlled polarization and magnetization, which opens up their multifunctional applications for all-organic multiferroics.

The excessive expansion of urbanized areas has resulted in haphazard land utili- zation, immoderate consumption of superior agricultural land and water resources, significant fragmentation of agricultural landscape, and gradual deterioration of the agro-ecological en- vironment. Combined, these factors cause poor land use efficiency. Under these circum- stances, comprehensively assessing land use efficiency for urban agriculture is a key issue in land use research. Currently, evaluation methods for agricultural land use efficiency narrowly concentrate on aspects of economic input and output. However, urban agro-ecosystems can provide diverse economic, social, and ecological services and functions. In particular, the social and ecological services and functions originating from agricultural land, which have a higher value than economic services, play a significant role in ensuring regional social, eco- logical, and environmental security. However, recent research has rarely taken these benefits into consideration. Therefore, land use value has been greatly underestimated, which has resulted in mishandled and poor land use policies. In this study, we apply Landsat imagery and social and economic statistical data for the Xi＇an metropolitan zone （XMZ） to investigate agricultural multi-functionality. We develop an evaluation framework for urban agricultural land use efficiency and identify agro-ecosystem services and functions as important outputs from agricultural land. The land use efficiency of urban agriculture is then evaluated using ecosystem services models, providing a mechanism for assessing spatial-temporal changes in land use efficiency in the XMZ from 1999 to 2015. Four important conclusions are reached from this analysis. First, the rapid urbanization and agricultural transformation from traditional cereal cultivation to modern urban agriculture has resulted in steadily increasing costs, out- puts, and land use efficiency of urban agriculture. The total output value increased 41% and land use efficiency per hectare increased by 33.13% on average. Second, the spatial patterns of comprehensive output and land use efficiency were dominated by economic outputs from agricultural land. Areas near cities, which are dominated by orchard and arable land, provide more economic functions. These areas support and regulate services due to the transforma- tion from extensive cereal production to intensive modern urban agriculture; therefore, they have higher output value and land use efficiency. In contrast, areas distant from cities, towns, and high traffic roads, namely, remote rural areas, provide more support and regulating ser- vices, but have relatively lower economic function due to inaccessibility tO urban markets and slow agricultural transformation. Therefore, these areas have lower output value and land use efficiency. The spatial change in agricultural output and land use efficiency in urban areas is strongly dependent on the degree of urbanization and agricultural transformation. Third, the total output value and land use efficiency of urban agriculture measured with our approach are much higher than evaluations using traditional methods. However, the spatial patterns measured using the two approaches are in agreement. The evaluation framework integrates ecological services and economic and social functions into a comprehensive output from agricultural land. This approach is more methodical and accurate for evaluating the compre- hensive efficiency of land use based on quantities and spatial scale because they are at the pixel scale. Finally, the evaluation results have important implications for enhancing current agricultural subsidies and even implementing ecological payment policies in China. Most importantly, they can be directly applied to agricultural transformation regulations, decision-making, and guidance for rational land utilization.

Cultivated land protection （CLP） entered the new era of macro administration in 1999 in China. This paper presents a holistic analysis of cultivated land use change concerning the three goals of the CLP, i.e., grain security, ecological security and harmonizing regional development. Farmers＇ willingness to grow grain has been the key factor in safeguarding grain security. Grain-for-green policy has contributed to improving ecological state especially in the western provinces. Effects of the land macro-control of the CLP on harmonizing regional development were significant. Moi＇eover, cultivated land use change in 1999-2007 points out the way of the evolving poliey in the future. From the viewpoint of normative concept of multifunctionality, we discuss development of the three land functions, i.e., production function, environmental function and carrier function. Finally, we propose to emphasize multifunctional land management based on regional differences to promote transition of the CLP.

Cap-dependent translation is initi- ated by the binding of elF4E to the cap structure at the 5＇ end of mRNAs. During hypoxic stress, global translation decreases because elF4E is inac- tivated. In a recent article in Nature, Lee and colleagues show that residual hypoxic translation is maintained by a specialized isoform of elF4E, which binds to target mRNAs in complex with a hypoxia-induced RNP.