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Ionizable lipid nanoparticles have demonstrated remarkable success as mRNA vaccine carriers and represent one of the most promising gene drug delivery vehicles. However, polyethylene glycol (PEG), one of the major components, can cause immunogenic reactions, anaphylaxis and increased blood clearance, leading to toxic side effects and reduced efficacy. In this study, we utilize polysorbate 80 (PS80) as a PEG alternative in formulating eGFP mRNA-loaded ionizable lipid nanoparticles (PS80-iLNPs), aiming to enhance stealth properties, uptake efficiency, and biosafety. Our findings revealed that PS80-iLNPs enhanced the stealthiness and resistance to serum interference. Compared to PEG-containing ionizable lipid nanoparticles (PEG-iLNPs), PS80-iLNPs showed a 1.14-fold increase in stealthiness. Moreover, at a total lipid concentration of 50 µg mL-1, PS80-iLNPs exhibited 1.12 times higher cell viability compared to PEG-iLNPs. Notably, under serum interference, PEG-iLNPs showed a 44.97% uptake reduction, whereas PS80-iLNPs exhibited a modest 30.55% decrease, underscoring its superior serum resistance. This work demonstrated that PS80 could serve as a suitable substitute for PEG, thus signifying an excellent basis for the development of PEG-free ionizable lipid nanoparticles.
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Neurodiversity is a perspective on cognition which suggests a non-pathological view of individual cognitive differences. Aesthetics research on neurodivergent brains has generally been limited to neuropsychological cases. Although this research has been integral to establishing the neurological correlates of aesthetic experience, it is crucial to expand this paradigm to more psychologically complex disorders. We offer a review of research on aesthetic preference in neurodivergent brains beyond neuropsychological cases: across populations with psychotic disorder, anhedonia and depression, anxiety disorder, and autism. We identify stable patterns of aesthetic bias in these populations, relate these biases to symptoms at perceptual, emotional, and evaluative levels of cognition, review relevant neurological correlates, and connect this evidence to current neuroaesthetics theory. Critically, we synthesize the reviewed evidence and discuss its relevance for three brain networks regularly implicated in aesthetic processing: the mesocorticolimbic reward circuit, frontolimbic connections, and the default mode network. Finally, we propose that broadening the subject populations for neuroaesthetics research to include neurodiverse populations is instrumental for yielding new insights into aesthetic processing in the brain.
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Encéfalo , Estética , Humanos , Encéfalo/fisiologia , Transtornos Mentais/fisiopatologiaRESUMO
Vegetation restoration is an effective measure to cope with global climate change and promote soil carbon sequestration. However, during vegetation restoration, the turnover and properties of carbon within various aggregates change. The effects of plant source carbon input on surface soil and subsurface soil may be different. Thus, the characteristics of carbon components in aggregates are affected. Therefore, the research object of this study is the Robinia pseudoacacia forest located in 16-47a of the Loess Plateau, and compared with farmland. The change characteristics of organic carbon functional groups in 0-20 cm, 20-40 cm, and 40-60 cm soil layers were analyzed by Fourier near infrared spectroscopy, and the relationship between the chemical structure of organic carbon and the content of organic carbon components in soil aggregates was clarified, and the mechanism affecting the distribution of organic carbon components in soil aggregates was revealed in the process of vegetation restoration. The results show the following: (1) The stability of surface aggregates is sensitive, while that of deep aggregates is weak. Vegetation restoration increased the surface soil organic carbon content by 1.97~3.78 g·kg-1. (2) After vegetation restoration, the relative contents of polysaccharide functional groups in >0.25 mm aggregates were significantly reduced, while the relative contents of aromatic and aliphatic functional groups of organic carbon were significantly increased. The opposite is true for aggregates smaller than 0.25 mm. (3) With the increase in soil depth, the effect of litter on organic carbon gradually decreased, while the effect of root input on the accumulation of inert carbon in deep soil was more lasting.
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The chemical vapor deposition (CVD) method holds promise for the scalable and controlled synthesis of high-quality borophene. However, the current lack of an atomistic understanding of intricate kinetic pathways from precursors to borophene impedes process optimization. Here, we employ first-principles simulations to systematically explore the pyrolytic decomposition pathways of the most used precursor diborane (B2H6) to borophene on various transition metal surfaces. Our results reveal that B2H6 on various metal substrates exhibits different dissociation behaviors. Meanwhile, the activity of the examined metal substrates is quite anisotropic and surface direction-dependent, where the estimated overall catalytic activity order of these metals is found to be Pd ≈ Pt ≈ Rh > Ir ≈ Ru ≈ Cu > Au ≈ Ag. Our study provides atomistic insights into the dissociation kinetics of diborane precursors on various transition metal surfaces, serving as a guide for experimental growth of borophene.
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How to develop contrast agents for cancer theranostics is a meaningful and challenging endeavor, and rare earth nanoparticles (RENPs) may provide a possible solution. In this study, we initially modified RENPs through the application of photodynamic agents (ZnPc) and targeted the bevacizumab antibody for cancer theranostics, which was aimed at improving the therapeutic targeting and efficacy. Subsequently, we amalgamated anthocyanin with the modified RENPs, creating a potential cancer diagnosis platform. When the spectral data were obtained from the composite of cells, the crucial information was extracted through a competitive adaptive reweighted sampling feature algorithm. Then, we employed a machine learning classification model and classified both the individual spectral data and fused spectral data to accurately predict distinctions between breast cancer and normal tissue. The results indicate that the amalgamation of fusion techniques with machine learning algorithms provides highly precise predictions for molecular-level breast cancer detection. Finally, in vitro and in vivo experiments were carried out to validate the near-infrared luminescence and therapeutic effectiveness of the modified nanomedicine. This research not only underscores the targeted effects of nanomedicine but also demonstrates the potent synergy between optical spectral technology and machine learning. This innovative approach offers a comprehensive strategy for the integrated treatment of breast cancer.
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Neoplasias da Mama , Aprendizado de Máquina , Metais Terras Raras , Nanomedicina Teranóstica , Humanos , Metais Terras Raras/química , Feminino , Neoplasias da Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/terapia , Neoplasias da Mama/metabolismo , Animais , Camundongos , Linhagem Celular Tumoral , Nanopartículas/química , Nanopartículas/uso terapêutico , Bevacizumab/química , Bevacizumab/uso terapêutico , Antocianinas/química , Antocianinas/farmacologiaRESUMO
BACKGROUND: Automated test assembly (ATA) represents a modern methodology that employs data science optimization on computer platforms to automatically create test form, thereby significantly improving the efficiency and accuracy of test assembly procedures. In the realm of medical education, large-scale high-stakes assessments often necessitate lengthy tests, leading to elevated costs in various dimensions (such as examinee fatigue and expenses associated with item development). This study aims to augment the design of the medical education assessments by leveraging modern ATA approaches. METHODS: To achieve the objective, a four-step process employing psychometric methodologies was used to calibrate and analyze the item pool of the Standardized Competence Test for Clinical Medicine Undergraduates (SCTCMU), a nationwide summative test comprising 300 multiple-choice questions (MCQ) in China. Subsequently, two modern ATA approaches were employed to determine the optimal item combination, accounting for both statistical and content requirements specified in the test blueprint. The qualities of the assembled test form, generated using modern ATA approaches, underwent meticulous evaluation. RESULTS: Through an exploration of the psychometric properties of the SCTCMU as a foundational step, the evaluation revealed commendable quality in the item properties. Furthermore, the evaluation of the quality of assembled test form using modern ATA approaches indicated the ability to ascertain the optimal test length within the predefined measurement precision. Specifically, this investigation demonstrates that the application of modern ATA approaches can substantially reduce the test length of assembled test form, while simultaneously maintaining the required statistical and content standards specified in the test blueprint. CONCLUSIONS: This study harnessed modern ATA approaches to facilitate the automatic construction of test form, thereby significantly enhancing the efficiency and precision of test assembly procedures. The utilization of modern ATA approaches offers medical educators a valuable tool to enhance the efficiency and cost-effectiveness of medical education assessment.
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Educação de Graduação em Medicina , Avaliação Educacional , Psicometria , Humanos , Avaliação Educacional/métodos , Educação de Graduação em Medicina/normas , China , Estudantes de Medicina , Competência Clínica/normasRESUMO
In this study, based on the self-assembly strategy, we fused CipA with carbonyl reductase LXCARS154Y derived from Leifsonia xyli by gene coding, and successfully performed the carrier-free immobilization of LXCARS154Y. The immobilized enzyme was then characterized using scanning electron microscope (SEM), dynamic light scattering (DLS) and fourier transform infrared spectroscopy (FTIR). Compared with the free enzyme, the immobilized LXCARS154Y exhibited a 2.3-fold improvement in the catalytic efficiency kcat/km for the synthesis of a chiral pharmaceutical intermediate (R)-3,5-bis(trifluoromethyl)phenyl ethanol ((R)-BTPE) by reducing 3,5-bis(trifluoromethyl)acetophenone (BTAP). Moreover, the immobilized enzyme showed the enhanced stability while maintaining over 61 % relative activity after 18 cycles of batch reaction. Further, when CipA-fused carbonyl reductase was employed for (R)-BTPE production in a continuous flow reaction, almost complete yield (97.0 %) was achieved within 7 h at 2 M (512.3 g/L) of BTAP concentration, with a space-time yield of 1717.1 g·L-1·d-1. Notably, we observed the retention of cofactor NADH by CipA-based enzyme aggregates, resulting in a higher total turnover number (TTN) of 4815 to facilitate this bioreductive process. This research developed a concise strategy for efficient preparation of chiral intermediate with cofactor self-sufficiency via continuous flow biocatalysis, and the relevant mechanism was also explored.
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Oxirredutases do Álcool , Enzimas Imobilizadas , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Oxirredutases do Álcool/química , Oxirredutases do Álcool/metabolismo , Oxirredutases do Álcool/genética , Reatores Biológicos , Cinética , Álcoois/química , Biocatálise , Coenzimas/química , Coenzimas/metabolismo , EstereoisomerismoRESUMO
Climate change is exacerbating drought in arid and semi-arid forest ecosystems worldwide. Soil microorganisms play a key role in supporting forest ecosystem services, yet their response to changes in aridity remains poorly understood. We present results from a study of 84 forests at four south-to-north Loess Plateau sites to assess how increases in aridity level (1- precipitation/evapotranspiration) shapes soil bacterial and fungal diversity and community stability by influencing community assembly. We showed that soil bacterial diversity underwent a significant downward trend at aridity levels >0.39, while fungal diversity decreased significantly at aridity levels >0.62. In addition, the relative abundance of Actinobacteria and Ascomycota increased with higher aridity level, while the relative abundance of Acidobacteria and Basidiomycota showed the opposite trend. Bacterial communities also exhibited higher similarity-distance decay rates across geographic and environmental gradients than did fungal communities. Phylogenetic bin-based community assembly analysis revealed homogeneous selection and dispersal limitation as the two dominant processes in bacterial and fungal assembly. Dispersal limitation of bacterial communities monotonically increased with aridity levels, whereas homogeneous selection of fungal communities monotonically decreased. Importantly, aridity also increased the sensitivity of microbial communities to environmental disturbance and potentially decreased community stability, as evidenced by greater community similarity-environmental distance decay rates, narrower habitat niche breadth, and lower microbial network stability. Our study provides new insights into soil microbial drought response, with implications on the sustainability of ecosystems under environmental stress.
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Bactérias , Mudança Climática , Florestas , Fungos , Microbiologia do Solo , Fungos/classificação , Bactérias/classificação , Microbiota , Clima Desértico , Secas , Biodiversidade , Ecossistema , Solo/químicaRESUMO
Overcoming tumor apoptosis resistance is a major challenge in enhancing cancer therapy. Pyroptosis, a lytic form of programmed cell death (PCD) involving inflammasomes, Gasdermin family proteins, and cysteine proteases, offers potential in cancer treatment. While photodynamic therapy (PDT) can induce pyroptosis by generating reactive oxygen species (ROS) through the activation of photosensitizers (PSs), many PSs lack specific subcellular targets and are limited to the first near-infrared window, potentially reducing treatment effectiveness. Therefore, developing effective, deep-penetrating, organelle-targeted pyroptosis-mediated phototherapy is essential for cancer treatment strategies. Here, we synthesized four molecules with varying benzene ring numbers in thiopyrylium structures to preliminarily explore their photodynamic properties. The near-infrared-II (NIR-II) PS Z1, with a higher benzene ring count, exhibited superior ROS generation and mitochondria-targeting abilities, and a large Stokes shift. Through nano-precipitation method, Z1 nanoparticles (NPs) also demonstrated high ROS generation (especially type-I ROS) upon 808â nm laser irradiation, leading to efficient mitochondria dysfunction and combined pyroptosis and apoptosis. Moreover, they exhibited exceptional tumor-targeting ability via NIR-II fluorescence imaging (NIR-II FI) and photoacoustic imaging (PAI). Furthermore, Z1 NPs-mediated phototherapy effectively inhibited tumor growth with minimal adverse effects. Our findings offer a promising strategy for cancer therapy, warranting further preclinical investigations in PDT.
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Apoptose , Raios Infravermelhos , Mitocôndrias , Técnicas Fotoacústicas , Fármacos Fotossensibilizantes , Piroptose , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/síntese química , Piroptose/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Humanos , Apoptose/efeitos dos fármacos , Camundongos , Animais , Fotoquimioterapia , Espécies Reativas de Oxigênio/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Estrutura MolecularRESUMO
Plant litter is an important source of soil organic carbon (SOC) in terrestrial ecosystems, and the pattern of litter inputs is also influenced by global change and human activities. However, the current understanding of the impact of changes in litter inputs on SOC dynamics remains contentious, and the mechanisms by which changes in litter inputs affect SOC have rarely been investigated from the perspective of microbial carbon use efficiency (CUE). We conducted a 1-year experiment with litter treatments (no aboveground litter (NL), natural aboveground litter (CK), and double aboveground litter (DL)) in Robinia pseudoacacia plantation forest on the Loess Plateau. The objective was to assess how changes in litter input affect SOC accumulation in forest soils from the perspective of microbial CUE. Results showed that NL increased soil microbial C limitation by 77.11 % (0-10 cm) compared to CK, while it had a negligible effect on nitrogen and phosphorus limitation. In contrast, DL had no significant effect on soil microbial nutrient limitation. Furthermore, NL was found to significantly increase microbial CUE and decrease microbial metabolic quotient (QCO2), while the opposite was observed with DL. It is noteworthy that NL significantly contributed to an increase in SOC of 30.72 %, while DL had no significant effect on SOC. Correlation analysis showed that CUE was directly proportional to SOC and inversely proportional to QCO2. The partial least squares pathway model indicated that NL indirectly regulated the accumulation of SOC, mainly through two pathways: promoting microbial CUE increase and reducing QCO2. Overall, this study elucidates the mechanism and novel insights regarding SOC accumulation under changes in litter input from the perspective of microbial CUE. These findings are critical for further comprehension of soil carbon dynamics and the terrestrial C-cycle.
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Carbono , Microbiologia do Solo , Solo , Carbono/análise , Solo/química , Florestas , Nitrogênio/análise , China , Ciclo do Carbono , RobiniaRESUMO
Photocatalytic oxidation technology is one of the most efficient and green methods to convert highly toxic As(III) into lowly toxic As(V) for arsenic-polluted wastewater. However, the obtained As(V) may be reduced to As(III) again in the environment, causing secondary pollution. In order to resolve these issues, a bifunctional composite consisting of needle-like α-FeOOH-modified Sn/N-codoped TiO2 granules (SNT-FeOOH) has been synthesized. After modifying, the band gap of SNT-FeOOH narrowed from 2.94 eV (SNT) to 2.29 eV. When the composites were applied to As(III) removal, 10 mg of SNT-FeOOH could totally photocatalytically oxidize 40 mL of As(III) solution with a concentration of 10,000 µg/L within 15 min and synchronously achieve complete adsorption of the produced As(V), which is much more efficient than pure Sn/N-codoped TiO2 [21 min for As(III) photocatalytic oxidation and only 20.01% of total arsenic removal efficiency]. Based on the characterizations, α-FeOOH modification plays a significant role in the promoted performances of photocatalytic oxidation and adsorption of SNT-FeOOH, leading to arsenic removal. On one hand, the Fe-O-Ti interfacial chemical interactions formed between α-FeOOH and Sn/N-codoped TiO2 can further boost the separation rate of photogenerated carriers, hence increasing the photocatalytic oxidation efficiency. On the other hand, α-FeOOH surface hydroxyl groups adsorb the generated As(V) by forming Fe-O-As bonds. The SNT-FeOOH bifunctional composites, prepared in this paper, with dual performances of photocatalytic oxidation and adsorption provide a new strategy to achieve arsenic removal from wastewater.
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Guided nanowires grown on polymer surfaces facilitate their seamless integration as flexible devices without post-growth processing steps. However, this is challenging due to the inability of polymer films to provide the required lattice-matching effect. In this work, this challenge is addressed by replicating highly aligned nanogrooves from a compact disc (CD) onto a casted flexible polydimethylsiloxane (PDMS) surface. Leveraging the replicated nanogrooves, copper hexadecafluorophthalocyanine (F16CuPc) and various metal phthalocyanines are guided into large-area, self-aligned nanowires. Subsequently, by employing specifically designed shadow masks during electrode deposition, these nanowires are seamlessly integrated as either a monolithic flexible photodetector with a large sensing area or on-chip flexible photodetector arrays. The resulting flexible photodetectors exhibit millisecond and long-term stable response to UV-vis-NIR light. Notably, they demonstrate exceptional bending stability, retaining stable and sensitive photoresponse even at a curvature radius as low as 0.5 cm and after enduring 1000 bending cycles. Furthermore, the photodetector array showcases consistent sensitivity and response speed across the entire array. This work not only proves the viability of guided nanowire growth on flexible polymer surfaces by replicating CD nanogrooves but also underscores the potential for large-scale monolithic integration of guided nanowires as flexible devices.
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The recent theory-driven discovery of a class of clathrate hydrides (e.g., CaH6, YH6, YH9, and LaH10) with superconducting critical temperatures (Tc) well above 200 K has opened the prospects for "hot" superconductivity above room temperature under pressure. Recent efforts focus on the search for superconductors among ternary hydrides that accommodate more diverse material types and configurations compared to binary hydrides. Through extensive computational searches, we report the prediction of a unique class of thermodynamically stable clathrate hydrides structures consisting of two previously unreported H24 and H30 hydrogen clathrate cages at megabar pressures. Among these phases, LaSc2H24 shows potential hot superconductivity at the thermodynamically stable pressure range of 167 to 300 GPa, with calculated Tcs up to 331 K at 250 GPa and 316 K at 167 GPa when the important effects of anharmonicity are included. The very high critical temperatures are attributed to an unusually large hydrogen-derived density of states at the Fermi level arising from the newly reported peculiar H30 as well as H24 cages in the structure. Our predicted introduction of Sc in the La-H system is expected to facilitate future design and realization of hot superconductors in ternary clathrate superhydrides.
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Room-temperature superconductivity has been a long-held dream of mankind and a focus of considerable interest in the research field of superconductivity. Significant progress has recently been achieved in hydrogen-based superconductors found in superhydrides (hydrides with unexpectedly high hydrogen contents) that are stabilized under high-pressure conditions and are not capturable at ambient conditions. Of particular interest is the discovery of a class of best-ever-known superconductors in clathrate metal superhydrides that hold the record for high superconductivity (e.g. T c = 250-260 K for LaH10) among known superconductors and have great promise to be those that realize the long-sought room-temperature superconductivity. In these peculiar clathrate superhydrides, hydrogen forms unusual 'clathrate' cages containing encaged metal atoms, of which such a kind was first reported in a calcium hexa-superhydride (CaH6) showing a measured high T c of 215 K under a pressure of 170 GPa. In this review, we aim to offer an overview of the current status of research progress on the clathrate metal superhydride superconductors, discuss the superconducting mechanism and highlight the key features (e.g. structure motifs, bonding features, electronic structure, etc.) that govern the high-temperature superconductivity. Future research direction along this line to find room-temperature superconductors will be discussed.
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Hydrides are promising candidates for achieving room-temperature superconductivity, but a formidable challenge remains in reducing the stabilization pressure below a megabar. In this study, we successfully synthesized a ternary lanthanum borohydride by introducing the nonmetallic element B into the La-H system, forming robust B-H covalent bonds that lower the pressure required to stabilize the superconducting phase. Electrical transport measurements confirm the presence of superconductivity with a critical temperature (Tc) of up to 106 K at 90 GPa, as evidenced by zero resistance and Tc shift under an external magnetic field. X-ray diffraction and transport measurements identify the superconducting compound as LaB2H8, a nonclathrate hydride, whose crystal structure remains stable at pressures as low as â¼ half megabar (59 GPa). Stabilizing superconductive stoichiometric LaB2H8 in a submegabar pressure regime marks a substantial advancement in the quest for high-Tc superconductivity in polynary hydrides, bringing us closer to the ambient pressure conditions.
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Investigations into the compositional model of the Earth, particularly the atypical concentrations of volatile elements within the silicate portion of the early Earth, have attracted significant interest due to their pivotal role in elucidating the planet's evolution and dynamics. To understand the behavior of such volatile elements, an established 'volatility trend' has been used to explain the observed depletion of certain volatile elements. However, elements such as Se and Br remain notably over-depleted in the silicate Earth. Here we show the results from first-principles simulations that explore the potential for these elements to integrate into hcp-Fe through the formation of substitutional alloys, long presumed to be predominant constituents of the Earth's core. Based on our findings, the thermodynamic stability of these alloys suggests that these volatile elements might indeed be partially sequestered within the Earth's core. We suggest potential reservoirs for volatile elements within the deep Earth, augmenting our understanding of the deep Earth's composition.
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Artificial forest restoration is widely recognized as a crucial approach to enhance the potential of soil carbon sequestration. Nevertheless, there is still limited understanding regarding the dynamics of aggregate organic carbon (OC) and the underlying mechanisms driving these dynamics after artificial forest restoration. To address this gap, we studied Pinus tabuliformis forests and adjacent farmland in three recovery periods (13, 24 and 33 years) in the Loess Plateau region. Samples of undisturbed soil from the surface layer were collected and divided into three aggregate sizes: >2 mm (large aggregate), 0.25-2 mm (medium aggregate), and <0.25 mm (small aggregate). The aim was to examine the distribution of OC and changes in enzyme activity within each aggregate size. The findings revealed a significant increase in OC content for all aggregate sizes following the restoration of Pinus tabuliformis forests. After 33 years of recovery, the OC of large aggregates, medium aggregates and micro-aggregates increased by (30.23 ± 9.85)%, (36.71 ± 21.60)% and (37.88 ± 16.07)% respectively compared with that of farmland. Moreover, the restoration of Pinus tabuliformis forests lead to increased activity of hydrolytic enzymes and decreased activity of oxidative enzymes. It is noteworthy that the regulation of carbon in all aggregates is influenced by soil P-limitation. In large aggregates, P-limitation promotes the enhancement of hydrolytic enzyme activity, thereby facilitate OC accumulation. Conversely, in medium and small aggregates, P-limitation inhibits the increase in oxidative enzyme activity, resulting in OC accumulation. The results emphasize the importance of P-limitation in regulating OC accumulation during the restoration of Pinus tabulaeformis forest, in which large aggregates play a leading role.
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Carbono , Florestas , Pinus , Solo , Solo/química , Carbono/análise , Carbono/metabolismo , Sequestro de Carbono , ChinaRESUMO
The halogenase-based catalysis is one of the most environmentally friendly methods for the synthesis of halogenated products, among which flavin-dependent halogenases (FDHs) have attracted great interest as one of the most promising biocatalysts due to the remarkable site-selectivity and wide substrate range. However, the complexity of constructing the NAD+-NADH-FAD-FADH2 bicoenzyme cycle system has affected the engineering applications of FDHs. In this work, a coenzyme self-sufficient tri-enzyme fusion was constructed and successfully applied to the continuous halogenation of L-tryptophan. SpFDH was firstly identified derived from Streptomyces pratensis, a highly selective halogenase capable of generating 6-chloro-tryptophan from tryptophan. Then, using gene fusion technology, SpFDH was fused with glucose dehydrogenase (GDH) and flavin reductase (FR) to form a tri-enzyme fusion, which increased the yield by 1.46-fold and making the coenzymes self-sufficient. For more efficient halogenation of L-tryptophan, a continuous halogenation bioprocess of L-tryptophan was developed by immobilizing the tri-enzyme fusion and attaching it to a continuous catalytic device, which resulted in a reaction yield of 97.6% after 12 h reaction. An FDH from S. pratensis was successfully applied in the halogenation and our study provides a concise strategy for the preparation of halogenated tryptophan mediated by multienzyme cascade catalysis.
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Halogenação , Triptofano , Coenzimas , Oxirredutases/genética , Oxirredutases/metabolismo , Flavinas/metabolismoRESUMO
Perturbations in soil microbial communities caused by climate warming are expected to have a strong impact on biodiversity and future climate-carbon (C) feedback, especially in vulnerable habitats that are highly sensitive to environmental change. Here, we investigate the impact of four-year experimental warming on soil microbes and C cycling in the Loess Hilly Region of China. The results showed that warming led to soil C loss, mainly from labile C, and this C loss is associated with microbial response. Warming significantly decreased soil bacterial diversity and altered its community structure, especially increasing the abundance of heat-tolerant microorganisms, but had no effect on fungi. Warming also significantly increased the relative importance of homogeneous selection and decreased "drift" of bacterial and fungal communities. Moreover, warming decreased bacterial network stability but increased fungal network stability. Notably, the magnitude of soil C loss was significantly and positively correlated with differences in bacterial community characteristics under ambient and warming conditions, including diversity, composition, network stability, and community assembly. This result suggests that microbial responses to warming may amplify soil C loss. Combined, these results provide insights into soil microbial responses and C feedback in vulnerable ecosystems under climate warming scenarios.