Nature's contributions to people (NCP) encompass both the beneficial and detrimental effects of living nature on human quality of life, including regulatory, material, and non-material contributions. Globally, vital NCPs have been deteriorating, accelerated by changes in both natural and anthropogenic drivers over recent decades. Despite the often inevitable trade-offs between NCPs due to their spatially and temporally uneven distributions, few studies have quantitatively assessed the impacts of different drivers on the spatial and temporal changes in multiple NCPs and their interrelationships. Here we evaluate the effects of precipitation, temperature, population, gross domestic product, vegetation restoration, and urban expansion on four key regulatory NCPs-habitat maintenance, climate regulation, water quantity regulation, and soil protection-in Nei Mongol at the county level. We observe increasing trends in climate regulation and soil protection from 2000 to 2019, contrasted with declining trends in habitat maintenance and water quantity regulation. We have identified the dominant positive and negative drivers influencing each NCP across individual counties, finding that natural drivers predominantly overpowered anthropogenic drivers. Furthermore, we discover significant spatial disparities in the trade-off or synergy relationships between NCPs across the counties. Our findings illustrate how the impacts of various drivers on NCPs and their interrelationships can be quantitatively evaluated, offering significant potential for application in various spatial scales. With an understanding of trade-offs and scale effects, these insights are expected to support and inform policymaking at both county and provincial levels.
Transition-metal-catalyzed enantioselective nitrene transfer to sulfides has emerged as one of the most powerful strategies for rapid construction of enantioenriched sulfimides. However, achieving stereocontrol over highly active earth-abundant transition-metal nitrenoid intermediates remains a formidable challenge compared with precious metals. Herein, we disclose a chiral iron(II)/N,N'-dioxide-catalyzed enantioselective imidation of dialkyl and alkyl aryl sulfides using iminoiodinanes as nitrene precursors. A series of chiral sulfimides were obtained in moderate-to-good yields with high enantioselectivities (56 examples, up to 99% yield, 98:2 e.r.). The utility of this methodology was demonstrated by late-stage modification of complex molecules and synthesis of the chiral insecticide sulfoxaflor and the intermediates of related bioactive compounds. Based on experimental studies and theoretical calculations, a water-bonded high-spin iron nitrenoid species was identified as the key intermediate. The observed stereoselectivity was original from the steric repulsion between the amide unit of the ligand in the chiral cave and the bulky substituent of sulfides. Additionally, dioxazolones proved to be suitable acylnitrene precursors in the presence of an iron(III)/N,N'-dioxide complex, resulting in the formation of enantioselectivity-reversed sulfimides (14 examples, up to 81% yield, 97:3 e.r.).
Relationships between plant diversity and soil properties are important for restoring ecosystem function to adapt climate change in drylands. Taxonomic, functional and phylogenetic diversity are widely used for understanding community assembly and the responses of plant communities to environmental change. However, one dimension of diversity index is difficult to reflect the multiple dimensional plant diversity, and their effects on soil properties (i.e., moisture, nutrients, and texture characteristics) along aridity gradient in drylands are limitedly understood. In this study, we proposed a holistic biodiversity (HB) index to integrate all the characteristics of plant diversity, and investigated the relationships between plant diversity and soil properties across 41 sites along aridity gradient (from hyperarid to arid and semiarid levels) in drylands of northern China. The results showed that the taxonomic diversity and phylogenetic diversity increased significantly while most of functional diversity indices did not differ significantly along the aridity gradient. The functional diversity was more important than taxonomic and phylogenetic diversity to plant communities, and the importance of taxonomic and phylogenetic diversity varied greatly and inversely along the aridity gradient. The HB index could much better reflect the positive or negative exponential relationships with soil properties compared to the single diversity index. Further, the aridity weakened the positive effects of plant diversity on several soil properties (including soil water content, soil organic carbon and soil total nitrogen), and indirectly strengthened the accumulation of soil total phosphorus, as well as intensified the soil coarsening by limiting the negative effects of plant diversity on soil sand content. Our findings suggest that the holistic biodiversity index can represent the overall traits of plant diversity in drylands, and guide a further step to understand the role of plant diversity in plant-soil relationships of dryland ecosystems.
α-Chiral alkyl phosphines are privileged structural motifs with a wide application in organic and medical synthesis. It is highly desirable to develop stereoselective methods to prepare these enantioenriched molecules. The incorporation of C(sp3)âH functionalization and chiral phosphine chemistry is much less explored, probably because of the weak reactivity of C(sp3)âH bonds and/or the challenging site- and stereoselectivity issues. Herein, we disclose a synergistic catalysis system to enable an enantioselective radical addition process of α-substituted vinylphosphine oxides. An array of diverse α-chiral alkyl phosphors compounds is smoothly accessed by using the readily available chemicals as the inert C(sp3)âH bond reagent, such as sulfides, amines, alkenes, and toluene derivatives, exerting remarkable chemo-, site-, and enantioselectivity. On the basis of the mechanistic studies, both the C(sp3)âH bond activation and the stereochemistry-determining step are proposed to involve a single-electron transfer/proton transfer process.
Azide compounds are widely present in natural products and drug molecules, and their easy-to-transform characteristics make them widely used in the field of organic synthesis. The merging of transition-metal catalysis with radical chemistry offers a versatile platform for radical carboazidation of alkenes, allowing the rapid assembly of highly functionalized organic azides. However, the direct use of readily available hydrocarbon feedstocks as sp3-hybridized carbon radical precursors to participate in catalytic enantioselective carboazidation of alkenes remains a significant challenge that has yet to be addressed. Herein, we describe an iron-catalyzed asymmetric three-component radical carboazidation of electron-deficient alkenes by direct activation of aliphatic C-H bonds. This approach involves intermolecular hydrogen atom transfer between a hydrocarbon and an alkoxy/aryl carboxyl radical, leading to the formation of a carbon-centered radical. The resulting radical then reacts with electron-deficient alkenes to generate a new radical species that undergoes chiral iron-complex-mediated C-N3 bond coupling. An array of valuable chiral azides bearing a quaternary stereocenter were directly accessed from widely available chemical feedstocks, and their synthetic potential is further demonstrated through more facile transformations to give other valuable enantioenriched building blocks.
Given the challenges in accurately replicating the surface of the pufferfish, this study employed three-dimensional (3D) printing to create a model based on inverse modeling. The morphology of the pufferfish exhibits a streamlined configuration, characterized by a gradual widening from the anterior oral region to the central ocular area, followed by a progressive narrowing from the midabdominal region toward the caudal extremity. The RNG k-ε turbulence simulation results demonstrate that the streamlined body surface of the pufferfish diminishes differential pressure resistance. This enhancement promotes laminar flow formation, delays fluid separation, minimizes turbulence-induced vortices, and reduces frictional resistance. Moreover, the pufferfish's supple and uneven outer epidermis was simplified into a flexible, nonsmooth planar film to conduct fluid-solid coupling simulations. These revealed that the pufferfish's unique skin can absorb turbulent energy and minimize momentum transfer between the fluid and the solid film, lowering the fluid resistance during swimming. In summary, The high-efficiency swimming capacity of pufferfish stems not only from their streamlined body surface but also significantly from the unique structural characteristics and mechanical properties of their flexible skin. This research provides critical theoretical underpinnings for the design of functional bionic surfaces aimed at drag reduction.
Tetraodontiformes , Animals , Surface Properties , Printing, Three-Dimensional
Climate change and anthropogenic activities are reshaping dryland ecosystems globally at an unprecedented pace, jeopardizing their stability. The stability of these ecosystems is crucial for maintaining ecological balance and supporting local communities. Yet, the mechanisms governing their stability are poorly understood, largely due to the scarcity of comprehensive field data. Here we show the patterns of community temporal stability and its determinants across an aridity spectrum by integrating a transect survey across China's drylands with remote sensing. Our results revealed a U-shaped relationship between community temporal stability and aridity, with a pivotal shift occurring around an aridity level of 0.88. In less arid areas (aridity level below 0.88), enhanced precipitation and biodiversity were associated with increased community productivity and stability. Conversely, in more arid zones (aridity level above 0.88), elevated soil organic carbon and biodiversity were linked to greater fluctuations in community productivity and reduced stability. Our study identifies a critical aridity threshold that precipitates significant changes in community stability in China's drylands, underscoring the importance of distinct mechanisms driving ecosystem stability in varying aridity contexts. These insights are pivotal for developing informed ecosystem management and policy strategies tailored to the unique challenges of dryland conservation.
The asymmetric desymmetrizing [3+2] annulation reaction of p-quinamines and arylalkylketenes to synthesize hydroindoles was realized. Catalyzed by chiral bisguanidinium hemisalt via multiple hydrogen bond interactions, enantiomerically enriched products with reversal of diastereoselectivity in comparison with the racemic version were afforded in good yields under mild reaction conditions. Diaryl-substituted hydroindoles could also perform the Friedel-Crafts type of addition to give more complicated multicycles. Density functional theory calculations revealed that the enantio- and diastereoselectivity stem from varied hydrogen-bonding manners.
Global estimates of the size, distribution, and vulnerability of soil inorganic carbon (SIC) remain largely unquantified. By compiling 223,593 field-based measurements and developing machine-learning models, we report that global soils store 2305 ± 636 (±1 SD) billion tonnes of carbon as SIC over the top 2-meter depth. Under future scenarios, soil acidification associated with nitrogen additions to terrestrial ecosystems will reduce global SIC (0.3 meters) up to 23 billion tonnes of carbon over the next 30 years, with India and China being the most affected. Our synthesis of present-day land-water carbon inventories and inland-water carbonate chemistry reveals that at least 1.13 ± 0.33 billion tonnes of inorganic carbon is lost to inland-waters through soils annually, resulting in large but overlooked impacts on atmospheric and hydrospheric carbon dynamics.
Over an extended period of evolution and natural selection, a multitude of species developed a diverse array of biological interface features with specific functions. These biological structures provide a rich source of inspiration for the design of bionic structures on superhydrophobic surfaces. Understanding the functional mechanism of plant leaves is of paramount importance for the advancement of new engineering materials and the further promotion of engineering applications of bionic research. The hierarchical structure of microcrater-covered nanograss (MCNG) on the surface of E. helioscopia L. leaf provided the inspiration for the bionic MCNG surface, which was successfully prepared on a copper substrate by hybrid laser micromachining technology and chemical etching. The combined action of texture structure and surface chemistry resulted in a contact angle of 169° ± 1° for MCNG surface droplets and a rolling angle of less than 1°. Notably, the condensation-induced adhesion force does not augment with the increase of the temperature difference, which facilitated the shedding of hot droplets from the surface. The microscope observation revealed a high density of condensed droplets on the MCNG surface and the tangible jumping behavior of the droplets. The fabricated MCNG also demonstrated excellent antifrost/anti-icing abilities in low-temperature and high-humidity environments. Finally, the study confirmed the exceptional mechanical durability and reusability of the MCNG surface through various tests, including scratch damage, sandpaper wear, water flow impact and flushing, and condensation-drying cycle tests. The nanograss can be effectively protected within the microcrater structure. This research presents a promising approach for preventing and/or removing unwanted droplets in numerous engineering applications.
Euphorbia , Plant Leaves , Surface Properties , Euphorbia/chemistry , Plant Leaves/chemistry , Nanostructures/chemistry , Hydrophobic and Hydrophilic Interactions , Particle Size
The catalytic asymmetric [3 + 2] cycloaddition of racemic norcaradienes with quinones to construct multicyclic hydrodibenzofurans was achieved by the use of chiral N,N'-dioxide/metal complex catalysts. Kinetic resolution of norcaradienes accompanied by partial racemization occurred, and one enantiomer in prior acted as the C2 synthon to participate in diastereoselective cycloaddition. An enantiodivergent synthesis via a switch of metal ions was observed when naphthoquinone was used as the partner. DFT calculations revealed the profiles of the cycloaddition processes.
Asymmetric synthesis of 3-sulfonylated 3-substituted oxindoles through the addition of sodium sulfinate salts to 3-bromo-3-substituted oxindoles has been achieved using chiral nickel complexes of N,N'-dioxides. This method facilitates the creation of diverse chiral sulfonyl oxindoles, several of which display promising anticancer properties. Notably, the catalyst demonstrates remarkable tolerance to water, crucial for maintaining enantioselectivity. Furthermore, the utilization of topographic steric maps of the catalysts offers valuable insights into the mechanism underlying enantioselection reversal.
As one of the most promising renewable energies, wind energy is abundant in the natural environment. However, it is still challenging to effectively collect wind energy because of its variable wind speed and unpredictable direction. Here, a triboelectric nanogenerator, which is inspired by ancient Chinese wind bells, has been developed to collect energy from variable-speed and multi-directional wind. The wind-bell-inspired triboelectric nanogenerator (W-TENG) has the capability to generate electricity even at a very low wind speed of 0.5 m s-1. Furthermore, it is able to harvest wind energy effectively from all directions (0-360 degrees). The parameter-optimized W-TENG achieves a maximum output voltage of 9.3 V and a maximum current of 0.63 µA. Electronic devices including a digital watch and 40 light-emitting diodes (LEDs) are successfully powered by the designed W-TENG, demonstrating its applicability. In this study, it is believed that a novel and effective strategy is provided to harvest energy from variable-speed and multi-directional wind.
Water possesses unique advantages, including abundance, environmental friendliness and mild effects. Undoubtedly, it is an ideal solvent or reagent in chemical syntheses. Water also shows unique abilities in catalytic asymmetric synthesis. It can accelerate reaction rates, improve diastereo- or enantioselectivities, initiate reactions, diversify chemo, diastereo- or enantioselectivities through various effects (hydrophobic, hydrogen bonding, protonation). Several reviews have demonstrated the positive effects of water in asymmetric synthesis. In this review, we summarize water-enabling strategies in the last decade, and focus on advances which reveal how water affects a reaction.
The anti-icing and drag-reduction properties of diverse microstructured surfaces have undergone extensive study over the past decade. Nonetheless, tough environments enforce stringent demands on the composite characteristics of superhydrophobic surfaces (SHS). In this study, fresh composite structures were fabricated on a metal substrate by nanosecond laser machining technology, drawing inspiration from the hardy plant Iridaceae. The prepared sample surface mainly consists of a periodic microrhombus array and irregular nanosheets. To comprehensively investigate the effect of its special structure on surface properties, three surfaces with different sizes of rhombic structures were used for comparative analysis, and the results show that the SH-S2 sample is optimal. This can significantly delay the freezing time by an impressive 1404 s at -10 °C while revealing the sample surface anti-icing strategy. In addition, the rheological experiments determined over 300 µm of slip length for the SH-S2 sample, and the drag reduction rate of the surface reaches nearly 40%, which is well aligned with the results of the delayed icing experiments. Finally, the mechanical durability of the SH-S2 surface was investigated through scratch damage, sandpaper abrasion, reparability trials, and icing and melting cycle tests. This research presents a new approach and methodology for the application of SHS on polar ship surfaces.
Chimeric antigen receptor-T (CAR-T) cell has been developed as a promising agent for patients with refractory or relapsed lymphoma and leukemia, but not all the recipients could achieve a long-lasting remission. The limited capacity of in vivo expansion and memory differentiation post activation is one of the major reasons for suboptimal CAR-T therapeutic efficiency. Nitric oxide (NO) plays multifaceted roles in mitochondrial dynamics and T cell activation, but its function on CAR-T cell persistence and anti-tumor efficacy remains unknown. Herein, we found the continuous signaling from CAR not only promotes excessive NO production, but also suppressed S-nitrosoglutathione reductase (GSNOR) expression in T cells, which collectively led to increased protein S-nitrosylation, resulting in impaired mitochondrial fitness and deficiency of T cell stemness. Intriguingly, enforced expression of GSNOR promoted memory differentiation of CAR-T cell after immune activation, rendered CAR-T better resistance to mitochondrial dysfunction, further enhanced CAR-T cell expansion and anti-tumor capacity in vitro and in a mouse tumor model. Thus, we revealed a critical role of NO in restricting CAR-T cell persistence and functionality, and defined that GSNOR overexpression may provide a solution to combat NO stress and render patients with more durable protection from CAR-T therapy.
Immunotherapy, Adoptive , Mitochondria , Receptors, Chimeric Antigen , Animals , Mice , Mitochondria/metabolism , Receptors, Chimeric Antigen/metabolism , Receptors, Chimeric Antigen/genetics , Humans , Immunotherapy, Adoptive/methods , Aldehyde Oxidoreductases/genetics , Aldehyde Oxidoreductases/metabolism , T-Lymphocytes/metabolism , T-Lymphocytes/immunology , Nitric Oxide/metabolism , Cell Line, Tumor , Xenograft Model Antitumor Assays , Lymphocyte Activation , Signal Transduction
To enhance the slagging efficiency of the lime-based slag system during the pre-treatment stage of hot metal, a composite calcium ferrite flux based on aluminum industry solid waste was developed in this study. The melting characteristics of the flux and its application in the pre-treatment of hot metal were investigated. The results indicated that the main phases of the composite calcium ferrite were CaFe2O4, Ca2Fe2O5, and Ca2(Fe,Al)2O4. It exhibited high oxidation, high alkalinity, and a low melting point, thereby achieving excellent melting performance. Simulations of various dephosphorization fluxes in the pre-treatment of high-phosphorus hot metal, ordinary hot metal, and kilogram-scale dephosphorization experiment processes were conducted. Under the same experimental conditions, the composite calcium ferrite flux was able to achieve a dephosphorization rate of over 90% and a final phosphorus content of less than 0.02 wt% under high carbon content ([%C] = 3.2 wt%). In the application of hot metal pre-dephosphorization, this flux was able to achieve efficient melting and rapid slagging of lime at a lower temperature, and its slagging time was 50% faster than that of calcium ferrite flux. In addition, this flux enhanced the utilization efficiency of lime during the steelmaking process, effectively prevented the agglomeration of slag, and achieved efficient slag-metal separation. These characteristics were significantly better than the application effect of calcium ferrite flux. This flux has significant implications for the industrial application of deep dephosphorization in the pre-treatment stage of hot metal or the early stage of converter steelmaking.
The asymmetric catalytic inverse-electron-demand hetero-Diels-Alder reaction of dioxopyrrolidines with a variety of simple olefins has been accomplished, significantly expanding the applicability of this cyclization to both cyclic hetero-dienes and dienophiles. A new type of strong Lewis acid catalyst of ferric salt enables the LUMO activation of dioxopyrrolidines via formation of cationic species, this method yields a range of bicyclic dihydropyran derivatives with exceptional outcomes, including high yields (up to 99%), diastereoselectivity (up to 99 : 1) and enantioselectivity (up to 99% ee) under mild conditions. This facile protocol was available for the late-stage modification of several bioactive molecules and transformation into macrocycle molecules as well. The origins of enantioselectivity were elucidated based on control experiments.
Northern China has experienced a significant increase in vegetation cover over the past few decades. It lacks a comprehensive understanding of how greening impacts local hydrothermal conditions. To address this issue, in our study, the RegCM-CLM45 model was used to conduct a thorough assessment of the impacts of greening on temperature, vapor pressure deficit (VPD), precipitation, and soil moisture. The findings revealed that the local climatic effects of greening varied across different drought gradients based on the aridity index (AI). In drier regions with AI<0.3, the increased energy induced by greening tended to dissipate as sensible heat, exacerbating both warming and drought conditions. Conversely, in wetter regions with AI>0.3, a greater proportion of energy was lost through evapotranspiration, attenuating warming. Additionally, greening enhanced precipitation and soil moisture in drier regions and moderated their decline in wetter regions. Significantly, our research emphasized the effectiveness of grassland expansion and conservation as prime strategies for ecological restoration, particularly in drylands, where they could effectively alleviate soil drought. Given the diverse responses of different land cover transformations to local hydrothermal conditions in drylands, there is an urgent need to address potential adverse effects arising from inappropriate ecological restoration strategies and to develop an optimal restoration framework for the future.
In pneumonia, the deficient or delayed pathogen clearance can lead to pathogen proliferation and subsequent overactive immune responses, inducing acute lung injury (ALI). While screening human genome coding genes using our peripheral blood cell chemotactic platform, we unexpectedly find SLP adaptor and CSK interacting membrane protein (SCIMP), a protein with neutrophil chemotactic activity secreted during ALI. However, the specific role of SCIMP in ALI remains unclear. In this study, we investigate the secretion of SCIMP in exosomes (SCIMPexo) by macrophages after bacterial stimulation, both in vitro and in vivo. We observe a significant increase in the levels of SCIMPexo in bronchoalveolar lavage fluid and serum of pneumonia patients. We also find that bronchial perfusion with SCIMPexo or SCIMP N-terminal peptides increases the survival rate of the ALI model. This occurs due to the chemoattraction and activation of peripheral neutrophils dependent on formyl peptide receptor 1/2 (FPR1/2). Conversely, exosome suppressors and FPR1/2 antagonists decrease the survival rate in the lethal ALI model. Scimp-deficient and Fpr1/2-deficient mice also have lower survival rates and shorter survival times than wild-type mice. However, bronchial perfusion of SCIMP rescues Scimp-deficient mice but not Fpr1/2-deficient mice. Collectively, our findings suggest that the macrophage-SCIMP-FPRs-neutrophil axis plays a vital role in the innate immune process underlying ALI.
Acute Lung Injury , Neutrophils , Animals , Humans , Mice , Adaptor Proteins, Signal Transducing , Genome, Human , Macrophages , Membranes
