搜索结果：Sheng li xue bao : [Acta physiologica Sinica]

Chiral amines as pivotal intermediates in organic synthesis are widely utilized in the production of pharmaceuticals, fine chemicals, and bioactive molecules, holding significant industrial value. The asymmetric synthesis of chiral amines has always gained great attention. NAD(P)H-dependent imine reductases (IREDs) with wide substrate ranges, high activity, and high enantiomeric selectivity can be used for asymmetric reduction of imines to chiral amines. Our study aims to develop an efficient and stable immobilized dual-enzyme system through the fusion expression of imine reductase and formate dehydrogenase, in order to address the challenge of coenzyme regeneration and enhance catalytic efficiency, thereby providing a novel strategy for the green synthesis of chiral amines. The constructed system was applied to catalyze the asymmetric reduction of 1-methyl-3,4-dihydroisoquinoline to synthesize (S)-1-methyl-1,2,3,4-tetrahydroisoquinoline. Comparative analysis indicated that the catalytic efficiency of this fusion expression system exceeded that of both co-expression and standalone dual-enzyme systems. Furthermore, mesoporous silica nanoflowers were utilized as carriers to immobilize the fusion-expressed dual enzymes through a covalent method. In the case of covalent binding duration of 1.5 h and an initial enzyme concentration of 2.5 mg/mL, the protein loading achieved 193.2 mg/g. The immobilized enzymes demonstrated excellent pH, thermal, and storage stability. When the immobilized enzymes were employed to catalyze asymmetric reduction reactions of other cyclic imines, such as 1-ethyl-3,4-dihydroisoquinoline, 5-phenyl-3,4-dihydro-2H-pyrrole, 2,3,3-trimethyl-3H-indole, 2,3,3,5-tetramethylindole, and myosmine, the conversion rates exceeded 95%, and the values of e.e. surpassed 96%. The data confirm the application potential of the immobilized fusion enzymes in the green and efficient synthesis of chiral amines. Our study provides a novel strategy for the industrial biosynthesis of chiral amines, and the developed fused-enzyme immobilization approach holds significant theoretical and practical value for addressing common technical challenges in cofactor-dependent biocatalytic processes. 手性胺作为关键的有机合成中间体，广泛应用于药物、精细化学品及生物活性分子的合成，具有重要的工业价值。手性胺的不对称合成一直备受关注，NAD(P)H依赖型亚胺还原酶(imine reductase, IRED)具有底物范围广、高活性和立体选择性的特点，可用于不对称还原合成手性胺。本研究旨在通过构建一种高效、稳定的IRED与甲酸脱氢酶(formate dehydrogenase, FDH)双酶融合表达与固定化体系，解决辅酶再生难题并提升催化效率，为手性胺的绿色合成提供新策略。该体系用于催化1-甲基-3,4-二氢异喹啉不对称还原合成(S)-1-甲基-1,2,3,4-四氢异喹啉。通过对比发现，融合表达体系的催化效果优于共表达和单独表达双酶的体系。其次，利用介孔氧化硅纳米花(mesoporous silica nanoflowers, MSN)作为载体，共价法固定化融合表达双酶，固定化时间为1.5 h且初始酶浓度为2.5 mg/mL时，蛋白负载量为193.2 mg/g。固定化酶展现出良好的pH稳定性、热稳定性和储藏稳定性。将制备的固定化酶应用于催化其他环状亚胺如1-乙基-3,4-二氢异喹啉、5-苯基-3,4-二氢-2H-吡咯、2,3,3-三甲基-3H-吲哚、2,3,3,5-四甲基吲哚和麦斯明等的不对称还原反应，转化率高于95%，对映体过量值(enantiomeric excess, e.e.)高于96%，验证了固定化融合酶催化体系在手性胺绿色高效合成中的应用潜力。本研究为手性胺的工业化生物合成提供了新思路，所开发的融合酶固定化策略对解决辅酶依赖型生物催化过程中的共性技术难题具有重要的理论与应用价值。.

Phage therapy has the potential for broad application in the treatment of mastitis in dairy cows and the control of drug-resistant bacterial infections because of its precise targeting, efficient lytic activity, self-replicating nature, and excellent biocompatibility. This review summarized the challenges and future prospects in the utilization of phage therapy for bovine mastitis. The review encompassed the isolation and identification of phages targeting major mastitis pathogens (including Staphylococcus aureus and Escherichia coli) and the evaluation of in vivo (animal models and dairy cows) and in vitro (bacteriostatic effects, biofilm clearance, etc.) effectiveness. The findings indicate that specific phages or cocktail preparations are effective in controlling target pathogens. Phage genomic analysis is instrumental in elucidating the cleavage mechanism and evaluating potential virulence/lysogenic genes, thereby ensuring the safety of the treatment. Concurrently, the review delves into the prevailing challenges in this domain, encompassing the limited spectrum of phage hosts, the intricacies of pharmacokinetics and optimization of drug delivery in vivo, substantial-scale manufacturing concerns, and stability considerations. Notwithstanding the numerous challenges, innovative directions, such as phage engineering, phage-antibiotic synergistic application, and new delivery systems (such as nanocarriers), provide important ideas for future development. This review aims to offer theoretical foundations and practical references for further research and application of phage therapy in the prevention and control of bovine mastitis, promoting the translation of this green treatment strategy into clinical practice. 噬菌体疗法因精准靶向性、高效裂解性、自我增殖性及良好生物相容性，在奶牛乳房炎治疗和耐药菌感染控制领域具有广阔的应用前景。本文综述了在利用噬菌体治疗奶牛乳房炎过程中所面临的挑战与未来前景，总结了主要乳房炎病原体(金黄色葡萄球菌、大肠杆菌等)噬菌体的分离鉴定方法以及已开展的体内(实验动物模型及奶牛)和体外(抑菌效果、细菌生物膜清除等)有效性评价研究，归纳了特定噬菌体或鸡尾酒制剂在控制目标病原体方面的效果，阐述了噬菌体基因组学分析在理解裂解机制、评估潜在毒力/溶原性基因中起的关键作用。同时，深入探讨了该领域当前面临的挑战，包括噬菌体宿主范围相对狭窄、体内药代动力学及给药方案优化困难、规模化生产与稳定性问题等。尽管挑战众多，但是噬菌体工程改造、噬菌体-抗生素协同应用、新型递送系统(如纳米载体)等创新方向仍为未来发展提供了重要研究思路。本文为噬菌体疗法在奶牛乳房炎防控中的进一步研究与应用提供了理论依据和实践参考，推动该绿色治疗策略向临床转化。.

This study aimed to explore the regulatory effect and mechanism of 3β-hydroxy-Δ5-C27-steroid oxidoreductase (HSD3B7) on bovine follicular development. Bovine primary granulosa cells (GCs) with HSD3B7 knockdown and overexpression were constructed, and the proliferation efficiency of GCs was examined by the cell counting kit-8 (CCK-8) method. Annexin V-EGFP/PI double staining was performed to detect the apoptosis level of GCs. The concentration of estradiol (E2) in the culture medium and that of 2-methoxyestrone in GCs were determined by enzyme-linked immunosorbent assay (ELISA). The relative expression levels of the CCND2, Bim, Caspase-3, CYP19A1 and STAR were determined by qRT-PCR. The protein levels of related genes were determined by Western blotting. The results showed that HSD3B7 knockdown decreased the proliferation efficiency and CCND2 expression level of primary bovine follicular GCs, promoted the apoptosis, and increased Bim and Caspase-3 expression in GCs. Additionally, it decreased E2 secretion and CYP19A1 and STAR expression, and increased the concentration of 2-methoxyestrone, the main metabolite of E2. The opposite results were obtained after HSD3B7 overexpression. These results suggested that HSD3B7 positively regulated the development of bovine follicles by promoting the proliferation and E2 secretion and inhibiting the apoptosis of GCs. The results provide a new theoretical basis for further understanding the molecular regulatory network of bovine follicle development, and also lay a foundation for related research and practical application to improve bovine reproductive efficiency. 本研究旨在探究3β-羟基-Δ5-C27-类固醇氧化还原酶(3β-hydroxy-Δ5-C27-steroid oxidoreductase, HSD3B7)对牛卵泡发育的调节作用及其机制。构建敲降和过表达HSD3B7基因的牛原代颗粒细胞(granulosa cells, GCs)，用细胞计数试剂-8 (cell counting kit-8, CCK-8)法检测GCs增殖效率，用Annexin V-EGFP/PI双染法检测GCs凋亡水平，用酶联免疫吸附试验(enzyme-linked immunosorbent assay, ELISA)技术检测培养液中雌二醇(estradiol, E2)和胞内2-甲氧基雌酮的浓度，用实时荧光定量PCR (real-time quantitative-polymerase chain reaction, qRT-PCR)技术检测CCND2、Bim、Caspase-3、CYP19A1、STAR的相对表达水平，用Western blotting技术检测相关基因蛋白水平的表达情况。结果显示，HSD3B7敲降后降低了牛卵泡原代GCs增殖效率和CCND2蛋白的表达水平;促进了GCs凋亡和Bim蛋白、Caspase-3蛋白的表达;减少E2的分泌量和CYP19A1蛋白、STAR蛋白的表达量;增加E2主要代谢物2-甲氧基雌酮的浓度。HSD3B7过表达后取得相反结果。本研究结果表明，HSD3B7通过促进牛GCs增殖和E2分泌、抑制GCs凋亡，正向调控牛卵泡发育进程。研究结果为深入解析牛卵泡发育的分子调控网络提供了新的理论依据，也为提高牛繁殖效率的相关研究和实践应用奠定了基础。.

This study aimed to investigate the differential roles of GluN2A and GluN2B subunits of N-methyl-D-aspartate receptor (NMDAR) in the medial prefrontal cortex (mPFC) and their downstream signaling pathways in a mouse model of chronic constrictive injury of the infraorbital nerve (CION)-induced pain and anxiety/depression-like behaviors. A mouse model of trigeminal neuropathic pain was established under CION surgery. Behavioral tests were conducted to assess mechanical thresholds and anxiety/depression-like behaviors. The protein expression levels of GluN2A, GluN2B, ERK and mTOR in the mPFC were detected by Western blot. GluN2A antagonist (PEAQX) and GluN2B antagonist (Ifenprodil) were microinjected into the mPFC to observe their behavioral effects and underlying molecular mechanisms. CION mice developed persistent pain and anxiety/depression-like behaviors, accompanied by increased GluN2B expression in the mPFC. Behavioral results showed that compared with the vehicle group, GluN2A antagonist PEAQX ameliorated anxiety/depression-like behaviors, but not pain hyperalgesia. However, GluN2B antagonist Ifenprodil significantly alleviated pain and depressive-like symptoms instead of anxiety-like behaviors. Western blot analysis revealed that PEAQX significantly increased the expression of phosphorylation of ERK1 and ERK2, while reduced the expression of both total ERK1 and total ERK2. On the other hand, Ifenprodil decreased the expression of total mTOR protein. Neither antagonist had a significant effect on phospho-mTOR levels. Taken together, our findings suggest that GluN2A and GluN2B subunits in the mPFC differentially contribute to chronic pain and anxiety/depressive-like behaviors through their respective intracellular signaling. This study provides novel insights into the mechanisms underlying chronic pain and emotional comorbidity, and offers experimental evidence for developing targeted therapeutic strategies against specific NMDAR subunits.

We report a measurement of the cosmic ray helium energy spectrum in the energy interval 0.16-13 PeV, derived by subtracting the proton spectrum from the light component (proton and helium) spectrum obtained with observations made by the Large High Altitude Air Shower Observatory (LHAASO) under a consistent energy scale. The helium spectrum shows a significant hardening centered at E≃1.1  PeV, followed by a softening at ∼7  PeV, indicating the appearance of a helium "knee." Comparing the proton and helium spectra in the LHAASO energy range reveals some remarkable facts. In the lower part of this range, in contrast to the behavior at lower energies, the helium spectrum is significantly softer than the proton spectrum. This results in protons overtaking helium nuclei and becoming the largest cosmic ray component at E≃0.7  PeV. A second crossing of the two spectra is observed at E≃5  PeV, above the proton knee, when helium nuclei overtake protons to become the largest cosmic ray component again. These results have important implications for our understanding of the Galactic cosmic ray sources.

The Qinling Mountains contain the largest forest ecosystem in central China. Examining the spatiotemporal variations of urban carbon lock-in and the pathways for unlocking it on the northern and southern piedmont of the Qinling hinterland is of great significance for achieving carbon balance in central and western China. Based on panel data from seven cities on the northern and southern piedmont of the Qinling Mountains from 2008 to 2022, we mea-sured regional carbon lock-in levels and carbon budgets from a land-use perspective, and investigated the spatio-temporal trends. We applied fuzzy-set qualitative comparative analysis to identify the high-carbon and low-carbon configuration effects of regional carbon lock-in at both macro and micro levels. The results showed that the degree of carbon lock-in in cities on the northern and southern piedmont of the Qinling Mountains increased from 1.79 to 5.61 and exhibited a certain degree of spatial clustering between 2008 and 2022. Net carbon emissions ranged from 31.22 Mt to 113.14 Mt, while carbon sinks remained in the range of 18 Mt to 21 Mt. The ratio of total carbon emission from construction land to that from cropland was 2.96:1. At the macro scale, regional carbon lock-in could be attributed to three configuration types: weak carbon sink function, gap in regulatory function, and misaligned industrial structure. At the micro scale, we identified nine high-carbon and ten low-carbon configurations. The main drivers of carbon emissions from natural ecosystem, construction land, and cropland were environmental regulation, industrial structure, and cropping structure, respectively. The degree of carbon lock-in in cities on the northern and southern piedmont of the Qinling Mountains followed a "slow-fast-slow" growth pattern. Spatially, it was characterized by lower in the south and higher in the north, with clustering that diffused from core cities to surrounding areas. On the basis of implementing overarching environmental policies, each region should select appropriate enhancement pathways in line with resource endowments and carbon lock-in drivers, so as to achieve the goal of carbon unlocking. 秦岭是我国中部最大的森林生态系统,开展秦岭腹地南北麓城市碳锁定的时空演变和碳解锁路径研究,对中国中西部区域碳平衡具有重要意义。本研究基于2008—2022年秦岭南北麓7个城市的面板数据,通过土地利用视角测度各地区碳锁定水平和碳收支情况,并探究其时空变化趋势,最后,运用模糊集定性比较方法从宏观和微观两个维度探究区域碳锁定的高碳(低碳)组态效应。结果表明: 2008—2022年间,秦岭南北麓城市碳锁定程度从1.79上涨至5.61,并存在一定的空间聚集现象,净碳排放量为3122.03万～11314.43万t,碳汇量保持在1800万～2100万t,建设用地与耕地总碳排放之比为2.96∶1。在宏观上,区域碳锁定成因可归纳为碳汇功能乏力、监管功能缺失以及产业结构失调3个组态类型。在微观上,共识别出9条高碳和10条低碳组态构型,其中,自然生态系统、建设用地、耕地的碳排放驱动因素分别为环境规制、产业结构、农作物种植结构。秦岭南北麓城市碳锁定程度在研究期间上呈“慢-快-慢”的增长趋势,在空间上表现为南低北高、中心城市向四周发散的聚集特征,各区域在落实宏观环境政策的基础上,应根据自己的资源禀赋和碳锁定驱动因子,选择适当的提升路径从而达到碳解锁的目标。.

Chondroitinase ABC (ChABC) holds significant value in biomedical applications and polysaccharide structure analysis. However, the poor thermostability of this enzyme severely limits its industrial production and utilization. Focusing on the multidomain characteristics of PvChABC derived from Proteus vulgaris and targeting the loop region connecting the N-terminal domain and the catalytic domain, we obtained an optimized mutant M3 with significantly improved thermostability through a computer-aided rational design strategy. M3 exhibited a half-life of (48.12±1.85) h at 45 ℃, which represented a 13.7-fold increase over that of the wild type. It showed the specific activity 110.5% of that in the wild type, which indicated no loss of enzymatic activity. Molecular dynamics simulations revealed that the mutation in the loop region introduced hydrophobic interaction and hydrogen bond network, thereby enhancing the inter-domain binding and stabilizing the overall protein conformation. Notably, the enhanced thermostability enabled efficient heterologous expression at 37 ℃, with M3 showing a 14.84-fold higher yield than the wild type under industrial fermentation conditions. This work not only establishes a foundation for the industrial production of PvChABC but also provides a generalizable strategy for engineering other multidomain proteins. 硫酸软骨素裂解酶ABC (chondroitinase ABC, ChABC)在生物医药及多糖结构解析等领域具有重要应用价值，但其较差的热稳定性严重限制了该酶的工业化生产及应用。本研究针对来源于普通变形杆菌(Proteus vulgaris)的PvChABC的多结构域特征，以该酶N端结构域与核心催化结构域之间的loop区域为靶点，采用计算机辅助的理性设计策略对其进行分子改造，获得稳定性显著提升的优势突变体M3。该突变体在45 ℃下的半衰期达到(48.12±1.85) h，是野生型的13.7倍，且其比酶活为野生型的110.5%，没有表现出酶活性的损失。分子动力学模拟揭示，loop区域的突变通过引入关键疏水相互作用与氢键网络，增强了结构域间的结合能力，从而稳定了整体蛋白构象。此外，PvChABC热稳定性的提升有助于异源表达该酶的工程菌株在37 ℃下发酵产酶，该温度下M3的产量较野生型提高14.84倍，更适合工业化生产应用。本研究不仅为PvChABC的工业生产和应用奠定了基础，也为其他多结构域蛋白的分子改造提供了思路。.

In 2025, synthetic biology and biomanufacturing have demonstrated remarkable progress characterized by intelligent integration, systematic optimization, and diversified applications. Artificial intelligence has evolved from an auxiliary tool into a core driving force, deeply embedded throughout the entire pipeline from biomolecular design to fermentation process control, catalyzing a fundamental shift from "experience-driven" to "data- and model-driven" research paradigms. Breakthroughs in enzyme engineering and protein design continue to expand the functional boundaries of biocatalysis, while cell factory construction is advancing from single-target modification toward global systematic optimization. The synergistic development of traditional and emerging chassis hosts enables efficient biosynthesis of high-value chemicals and novel proteins. Environmental bioremediation is transitioning from functional strain engineering to the rational design of synthetic microbial consortia, marking a new era of predictable and controllable remediation strategies. Meanwhile, advances in interdisciplinary frontiers, such as artificial cells, are continuously expanding the horizons of biomanufacturing. Looking forward, the deep integration of artificial intelligence with automation platforms, a deeper understanding of biological complexity, and industrial applications aligned with carbon neutrality goals and human health demands will define the future trajectory of the field. Synthetic biomanufacturing is evolving from "understanding life by creating life and creating life for applications" toward "creating life for good and creating life for the future", offering indispensable solutions to address global challenges in resources, environment, and health. 2025年，合成生物学与生物制造领域呈现出“智能融合、系统优化、应用多元”的鲜明特征。人工智能已从辅助工具演变为核心驱动力，深度融入从生物元件设计到发酵过程控制的全链条，推动研发范式从“经验驱动”向“数据与模型驱动”的根本性转变。酶工程与蛋白质设计的突破不断拓展生物催化的功能边界，细胞工厂的构建正从单靶点改造迈向全局系统优化，传统底盘与新型底盘协同发展，推动高值化学品与新质蛋白的高效生物合成。环境生物修复从功能菌株改造走向人工合成微生物组的理性设计，标志着生物修复迈向可预测、可调控的新阶段。与此同时，人工细胞等前沿交叉领域的突破持续拓展着生物制造的边界与想象空间。展望未来，人工智能与自动化平台的深度集成、对生命系统复杂性的深入解析以及面向碳中和目标与人民健康需求的产业应用，将是领域发展的核心方向。合成生物制造正从“造物致知、造物致用”走向“造物致善、造物致远”，为人类社会应对资源、环境与健康等世纪挑战贡献不可替代的解决方案。.

Bovine viral diarrhea virus (BVDV), a major pathogen in the global bovine industry, causes diarrhea, fever, and reproductive disorders, leading to substantial economic losses. Developing the methods for rapid and accurate detection of BVDV is crucial for epidemic control. Current detection methods have notable limitations. PCR-based nucleic acid amplification techniques rely on sophisticated instruments and complex procedures. CRISPR-Cas13a systems, despite their high specificity, still require nucleic acid pre-amplification, which results in cumbersome workflows and contamination risks. To establish a simpler and more efficient on-site detection method for BVDV, this study integrated the CRISPR-Cas13a system characterized by specific recognition with electrochemical sensing praised for efficient signal transduction to establish a novel nucleic acid amplification-free method for the detection of BVDV. Through optimization of key parameters, including CRISPR RNA (crRNA) combination, buffer components, and Cas13a/crRNA concentration ratio, the biosensor achieved a detection limit of 3 090 copies/μL-representing a 4-5 order of magnitude improvement in sensitivity compared with conventional Cas13a fluorescence-based detection-and completed the entire process from sample loading to result output within 35 min. Specificity tests demonstrated that the sensor exclusively detected BVDV without cross-reactivity to other common bovine viruses (bovine parainfluenza virus type 3, bovine respiratory syncytial virus, bluetongue virus, and foot-and-mouth disease virus). Clinical validation with 22 samples demonstrated 100% specificity and sensitivity. The developed CRISPR-Cas13a-based electrochemical biosensor offers the advantages of being nucleic acid amplification-free and operationally simple, serving as a powerful new tool for rapid on-site BVDV detection with significant potential for veterinary diagnostics and epidemic prevention and control. 牛病毒性腹泻病毒(bovine viral diarrhea virus, BVDV)是危害全球养牛业的重要病原体，可导致腹泻、发热及繁殖障碍，造成严重经济损失。建立快速、精准的BVDV检测方法对疫情防控具有重要意义。现有检测方法存在明显局限:PCR等核酸扩增技术需精密仪器且操作复杂;而CRISPR-Cas13a系统虽特异性强，却仍需核酸预扩增，导致检测流程繁琐和污染风险。为开发更简便高效的BVDV现场快速检测技术，本研究将CRISPR-Cas13a系统的特异性识别能力与电化学传感技术的高效信号转换特性相结合，建立了一种免核酸扩增的BVDV检测新方法。通过优化CRISPR RNA (crRNA)组合、反应缓冲液组分及Cas13a/crRNA浓度比等关键参数，该传感器检测限达3 090 copies/μL，较传统Cas13a荧光检测方法灵敏度提升4-5个数量级，可在35 min内完成从加样到结果输出的全过程。特异性实验表明，该方法仅对BVDV产生特异性检测信号，而对其他常见牛源病毒(包括对牛副流感病毒3型、牛呼吸道合胞病毒、蓝舌病病毒和口蹄疫病毒)均未产生可检测的交叉反应信号。22份临床样本验证结果显示，该传感器的特异性和灵敏度均达到100%。本研究建立的CRISPR-Cas13a电化学生物传感器具有免核酸扩增、操作简便等优势，为BVDV的现场快速检测提供了新型高效工具，在临床诊断和疫情防控中具有重要应用价值。.

This study investigated the proteomic characteristics and biological functions of hypoxic exosomes derived from hypoxia-preconditioned feline adipose-derived mesenchymal stem cells (ADMSCs), aiming to reveal the remodeling effect of hypoxic preconditioning on the protein composition of exosomes derived from feline ADMSCs and its potential applications. CoCl2 was used to mimic a hypoxic environment for ADMSCs, and exosomes were isolated by differential ultracentrifugation. The physical properties of the exosomes were characterized by transmission electron microscopy, nanoparticle tracking analysis, and Western blotting. Proteomic analysis revealed that hypoxic preconditioning significantly altered the exosomal proteomic profile, identifying 120 differentially expressed proteins (116 upregulated and 4 downregulated). Bioinformatic analysis indicated significant enrichment of key pathways including the hypoxia-inducible factor-1 (HIF-1) signaling pathway, adenosine monophosphate-activated protein kinase (AMPK) signaling pathway, autophagy, and proteasome function. Gene ontology (GO) functional annotation demonstrated significant enrichment of biological processes such as metabolic processes, cell cycle regulation, and signal transduction in the hypoxia-preconditioned group. Kyoto encyclopedia of genes and genomes (KEGG) analysis further suggested potential biological functions through the regulation of pathways including the cell cycle and renin-angiotensin system. Notably, hypoxia-responsive proteins such as HMOX1 and TFRC were upregulated, while pathways related to the renin-angiotensin system were suppressed. This study systematically elucidates, for the first time, the remodeling effect of hypoxic preconditioning on the proteome of exosomes derived from feline ADMSCs, providing new molecular insights into exosome-mediated intercellular communication. 本研究旨在揭示低氧预处理对猫脂肪间充质干细胞(adipose-derived mesenchymal stem cells, ADMSCs)外泌体蛋白质组成的重塑作用及潜在应用。探讨了低氧预处理猫ADMSCs来源外泌体的蛋白质组特征及其生物学功能，通过CoCl{L-End} 2模拟低氧环境处理ADMSCs，采用差速超速离心法分离外泌体，经透射电镜、纳米颗粒追踪分析和蛋白质印迹鉴定其物理特性。蛋白质组学分析显示，低氧预处理诱导外泌体蛋白质组发生显著改变，共鉴定出120个差异表达蛋白质(116个上调、4个下调)。生物信息学分析表明，差异蛋白质显著富集于低氧诱导因子-1 (hypoxia-inducible factor-1, HIF-1)信号通路、腺苷酸活化蛋白激酶(adenosine monophosphate-activated protein kinase, AMPK)信号通路、自噬和蛋白酶体功能等关键通路。基因本体(gene ontology, GO)功能注释显示，低氧预处理组代谢过程、细胞周期调控和信号转导等生物学过程显著富集。京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes, KEGG)分析进一步揭示其可能通过调控细胞周期、肾素-血管紧张素系统等多条通路发挥生物学功能。值得注意的是，差异蛋白质中HMOX1、TFRC等低氧应答蛋白质表达上调，而肾素-血管紧张素系统相关通路受到抑制。本研究首次系统阐明了低氧预处理对猫ADMSCs来源外泌体蛋白质组的重塑作用，为深入理解外泌体介导的细胞间通讯提供了新的理论基础。.

Soil microbial carbon use efficiency (CUE), defined as the proportion of assimilated carbon allocated to microbial growth versus maintenance, is a key parameter regulating terrestrial soil organic carbon (SOC) storage. The response of CUE to climate change and its feedbacks profoundly affect global carbon cycle and soil carbon sequestration. At present, there are substantial uncertainties regarding the mechanisms underlying the responses of CUE to climate change and the ecological consequences. We synthesized research progress on soil microbial CUE over the past 20 years. First, we clarified the basic concept and computational approaches of CUE, and compared the principles, strengths, and limitations of three mainstream measurement techniques (isotope labeling method, stoichiometric model, and thermodynamic efficiency method). Second, we summarized the key biotic and abiotic factors influencing CUE. Focused on the mechanisms underlying the main and interactive effects of elevated atmospheric CO2 concentration, climate warming, and altered precipitation patterns on microbial CUE, and based on a "resource-cost trade-off" framework, we discussed the potential mechanisms underlying the heterogeneous responses of CUE across different ecosystems, and summarized the bottlenecks and challenges that still existed in current research regarding methodological standardization, the analysis of deep soil processes, the quantification of multi-factor interaction effects, and the application of CUE in earth system models (ESMs). We proposed an integrative research framework spanning from micro-scale metabolic mechanisms to macro-scale carbon cycling patterns, emphasizing the need for methodological innovation, multi-scale networked observations, and model-experiment integration, to thoroughly reveal the dynamics and adaptive mechanisms of CUE under climate change. 土壤微生物碳利用效率(CUE),即微生物将吸收的碳分配于生长与维持的比例,是调控陆地土壤有机碳(SOC)储量的关键参数。CUE对气候变化的响应及其反馈过程深刻影响着全球碳循环和土壤碳汇功能。然而,当前关于CUE对气候变化的响应机制及其生态后果仍存在诸多不确定性。本文梳理了近20年关于土壤微生物CUE的研究进展: 首先,明确了CUE的基本概念及计算方法,并比较了3种主流测定技术(同位素标记法、计量学模型和热力学效率法)的原理、优势与局限性;其次,总结了影响CUE变化的关键生物与非生物因子,重点评述了大气CO2浓度升高、气候变暖和降水格局改变对微生物CUE的单独及交互作用机制,并基于“资源-成本权衡”理论框架,探讨了不同生态系统中CUE响应异质性的潜在机制;概括了当前研究在方法学标准化、深层土壤过程解析、多因子交互效应量化以及CUE在地球系统模型(ESM)应用等方面仍存在的瓶颈与挑战;提出了从微观代谢机制到宏观碳循环格局的整合性研究框架,强调通过方法学创新、多尺度联网观测以及模型-试验融合,深入揭示气候变化背景下CUE的动态变化与适应性机制。.

In this study, we conducted a two-year nitrogen and phosphorus addition experiment with six treatments: control (0 kg N·hm-2·a-1, 0 kg P·hm-2·a-1), phosphorus (30 kg P·hm-2·a-1), low nitrogen (30 kg N·hm-2·a-1), low nitrogen + phosphorus (30 kg N·hm-2·a-1, 30 kg P·hm-2·a-1), high nitrogen (90 kg N·hm-2·a-1), and high nitrogen + phosphorus (90 kg N·hm-2·a-1, 30 kg P·hm-2·a-1). We investigated the decomposition of different litter components of aboveground (leaf, branch, fruit) and fine root litter (class Ⅰ-Ⅲ roots) in Pinus massoniana plantation, examined their relationships with soil chemical factors (e.g., pH, organic carbon, total nitrogen) and hydrolytic enzyme activities (e.g., α-1,4-glucosidase). We further quantified the relative contributions of soil factors to nutrient residue (e.g., soluble sugars, starch) and decomposition coefficients (k) following variation partitioning analysis. The results showed that decomposition coefficients varied significantly among litter components in the same treatment, with branches (k=0.42-0.49) being lower than leaves and fruits, and first-order roots (k=0.42-0.51) being lower than higher-order roots. Compared with single-nutrient addition, the low nitrogen + phosphorus treatment significantly enhanced litter decomposition and nutrient release. In contrast, high nitrogen treatment reduced soil pH by 23.1% and markedly inhibited decomposition. The high nitrogen + phosphorus treatment raised pH by 13.9%, effectively mitigating the adverse effect of high nitrogen. Soil enzyme activity and chemical factors jointly drove litter decomposition, with the independent contribution of enzyme activity (5.1%-15.2%) being overall higher than that of chemical factors (0.7%-6.5%). Soil enzyme activity was the key driving factor for the decomposition of litter influenced by exogenous nutrient input. In the management of P. massoniana plantations, it was necessary to avoid excessive or single application of nitrogen, and should appropriately apply phosphorus fertilizer based on the soil conditions. This was to enhance soil biological activities and promote litter decomposition and nutrient return. 本研究基于为期2年的氮、磷添加试验,设置对照(0 kg N·hm-2·a-1,0 kg P·hm-2·a-1)、磷(30 kg P·hm-2·a-1)、低氮(30 kg N·hm-2·a-1)、低氮+磷(30 kg N·hm-2·a-1,30 kg P·hm-2·a-1)、高氮(90 kg N·hm-2·a-1)、高氮+磷(90 kg N·hm-2·a-1,30 kg P·hm-2·a-1)6个处理,研究了马尾松人工林地上不同组分凋落物(叶、枝、果)和细根凋落物(Ⅰ～Ⅲ级根)的分解过程,分析了其与土壤pH、有机碳、全氮等化学因子及α-1,4-葡糖苷酶等水解酶活性的关系,并采用方差分解法量化了土壤因子对凋落物可溶性糖、淀粉等养分残留率及分解系数的相对贡献。结果表明: 同一处理下,不同组分凋落物的分解系数(k)存在显著差异,枝条(k=0.42～0.49)整体上低于叶和果,Ⅰ级细根(k=0.42～0.51)整体上显著低于Ⅱ级和Ⅲ级。与单一养分添加相比,低氮+磷处理显著促进了凋落物的分解和养分释放;高氮处理使土壤pH降低23.1%,从而显著抑制分解,而高氮+磷处理则将高氮处理下pH提升13.9%,有效缓解了高氮的不利效应。土壤酶活性与化学因子共同驱动了凋落物分解过程,其中酶活性因子的独立解释率(5.1%～15.2%)整体上高于化学因子(0.7%～6.5%)。土壤酶活性是外源养分输入影响凋落物分解的关键驱动因子。在马尾松人工林经营管理中,应避免单一或过量施氮,并依据土壤状况合理配施磷肥,以通过增强土壤生物活性促进凋落物的分解和养分归还。.

This study aimed to investigate the effects of lipocalin-2 (LCN2) gene knockout (LCN2KO) on cecal ligation and perforation (CLP)-induced lung injury and ferroptosis in septic mice, and further to clarify the potential role of the Toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB) pathway. A CLP model was established using LCN2KO mice. The levels of serum interleukin-6 (IL-6) and IL-1β were measured by ELISA. The contents of malondialdehyde (MDA) and glutathione (GSH) in lung tissue were determined using the corresponding assay kits. Reactive oxygen species (ROS) levels in lung tissue were detected using dihydroethidium (DHE) fluorescent probe. The expression levels of ferroptosis-related proteins in lung tissue were assessed by Western blot. The results showed that, compared to wild-type (WT)-Sham group, WT-CLP group exhibited significant lung tissue damage, elevated serum IL-6 and IL-1β levels, increased MDA content and ROS level, decreased GSH content, up-regulated protein expression levels of LCN2 and TLR4, increased p-P65/P65 ratio, and significantly down-regulated protein expression levels of ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4). LCN2KO reversed these changes induced by CLP. Both TLR4 inhibitor TAK-242 and NF-κB inhibitor PDTC down-regulated lung LCN2 protein expression, reversed sepsis-induced ferroptosis and lung injury, which is similar to the role of LCN2KO. These results suggest that LCN2KO may ameliorate lung injury in sepsis-induced mouse model by attenuating ferroptosis through modulating the TLR4/NF-κB signaling pathway.

To investigate the efficiency of utilization of cultivated land (EGLU) and its influencing factors in Shanxi Province under the context of carbon neutrality, we established a comprehensive evaluation index system from three dimensions: input, expected output, and unexpected output. We employed the super-efficiency model to measure the EGLU, applied kernel density estimation and spatial autocorrelation analysis to examine the spatiotemporal variations, and used a Tobit regression model to identify the key influencing factors. The results showed that the EGLU in Shanxi Province exhibited a generally fluctuating upward trend from 2008 to 2022, which increased from 1.11 to 1.19. Among the regions, the southern part of Shanxi experienced the highest annual average growth rate (0.077), while the northern part recorded the lowest (0.072). The trend surface fitting curve of EGLU shifted from an east-higher-west-lower pattern in 2008 to a west-higher-east-lower configuration by 2022. The difference between nor-thern and southern regions had gradually narrowed, while the pattern of regional differentiation was highly evident. Panel Tobit regression analysis revealed that the fertilizer application rate per unit cultivated land area and total agricultural machinery power exhibited significant negative correlation with EGLU, while the multiple cropping index, crop planting structure, and per capita cultivated land area showed a significant positive correlation with EGLU. The correlation between the irrigation index and EGLU presented a negative-to-positive change pattern, whereas per capita disposable income of rural residents exhibited a relatively weak correlation with EGLU. Our findings would provide a reference for formulating effective green and low-carbon utilization policies for cultivated land and promoting sustainable cultivated land development in Shanxi Province. 为探究碳中和背景下山西省耕地利用效率及影响因素,本研究从投入、期望产出和非期望产出3个视角构建指标体系,利用超效率模型测算了绿色低碳理念下山西省耕地利用效率,通过核密度估计和空间自相关法剖析其时空分异格局,最后使用Tobit回归模型分析其影响因素。结果表明: 2008—2022年,山西耕地利用效率整体呈波动上升趋势,由1.11上升至1.19,其中,晋南地区年均增长幅度最大(0.077),晋北地区年均增长幅度最小(0.072)。耕地利用效率趋势面拟合曲线由2008年的东高西低变为2022年的西高东低,南北差异缩小,地域分异规律显著。采用面板Tobit回归系数分析发现,单位耕地面积化肥施用量、农业机械总动力与耕地利用效率呈显著负相关;复种指数、农作物种植结构、劳均耕地面积与耕地利用效率呈显著正相关;灌溉指数与耕地利用效率的相关性呈先负后正变化;农村居民人均可支配收入与耕地利用效率相关性较弱。本研究结果可为山西省制定有效的耕地利用政策及耕地可持续发展提供参考。.

The assessment of lymphatic drainage function is essential for understanding the role of the lymphatic system in fluid homeostasis, immunosurveillance and disease processes. Conventional methods of evaluation rely on dynamic visualization with tracers, such as X-ray lymphangiography, lymphoscintigraphy and magnetic resonance lymphangiography. However, these methods have limitations in terms of invasiveness and resolution, and other aspects. Recent advances in optical technologies and nanomaterials technology have enabled the development of noninvasive, high-precision testing methods, such as photoacoustic imaging and optical coherence tomography, which have made it possible to visualize and analyze lymphatic flow rates, tracer clearance rates and functional abnormalities. In addition, the application of artificial intelligence-assisted analysis, multimodal imaging, and targeted nanoprobes has significantly improved the precision and clinical applicability of these methods. In this article, we systematically review the principles, characteristics, clinical applications and preclinical research progress of nine classical or novel lymphatic drainage function testing techniques. We also discuss the advantages and limitations of each technique and explore the future development trend, aiming to provide insights for basic research and clinical practice.

This study aimed to investigate the potential health hazards and molecular mechanisms of nanoplastic (NP) pollutants. Polystyrene nanoplastics (PS-NPs), which are prevalent in the environment and can enter the human body, have been closely associated with the risk of cardiovascular diseases, yet their impact on cholesterol metabolism remains unclear. In this study, proteomic analysis revealed that PS-NPs specifically adsorbed 1 676 proteins following their interaction with macrophages. Bioinformatic analysis indicated that these adsorbed proteins were significantly enriched in the cholesterol metabolism pathway, with apolipoprotein E (APOE) being the most prominently adsorbed. Further molecular docking and molecular dynamics simulations demonstrated that polystyrene molecules could inhibit the interaction between APOE and cholesterol by competitively binding to key amino acid residues (e.g., LEU-202 and TRP-228) of APOE. Cell experiments confirmed that exposure to 100 μg/mL PS-NPs for 24 h significantly induced lipid accumulation in macrophages. This study reveals, from a molecular interaction perspective, a novel mechanism by which PS-NPs disrupt lipid metabolism by interfering with APOE function. It provides key evidence for elucidating the toxicological mechanism through which PS-NPs promote atherosclerosis and holds significant scientific importance for assessing their health risks. 本研究旨在探究污染物纳米塑料(nanoplastics, NPs)对人体健康的潜在危害及其分子机制。聚苯乙烯纳米塑料(polystyrene nanoplastics, PS-NPs)在环境中广泛存在并可进入人体，与心血管疾病风险密切相关，但其对胆固醇代谢的影响尚未明确。本研究通过蛋白质组学技术分析发现，PS-NPs与巨噬细胞相互作用后，可特异性吸附1 676个蛋白质;生物信息学分析表明，这些吸附蛋白显著富集于胆固醇代谢通路，其中对载脂蛋白E (apolipoprotein E, APOE)的吸附最为突出。进一步的分子对接和分子动力学模拟显示，聚苯乙烯分子能够通过竞争性结合APOE的关键氨基酸残基(如LEU-202、TRP-228)，抑制其与胆固醇的相互作用。细胞实验证实，100 μg/mL PS-NPs暴露24 h可显著诱导巨噬细胞内脂质蓄积。本研究从分子互作层面揭示了PS-NPs通过干扰APOE功能影响脂质代谢的新机制，为阐明其促动脉粥样硬化发生的毒理机制提供了关键证据，对评估其健康风险具有重要科学意义。.

Monensin, a polyether ionophore antibiotic produced by Streptomyces cinnamonensis, is widely used in the livestock industry. To address the yield bottleneck caused by insufficient intracellular reducing power (NADPH/NADH) during industrial fermentation, we employed a multi-pathway collaborative metabolic engineering strategy. We fused the genes zwf (encoding glucose-6-phosphate dehydrogenase) and gnd (encoding 6-phosphogluconate dehydrogenase) from the pentose phosphate pathway with fadB (encoding 3-hydroxyacyl-ACP dehydratase) from the fatty acid β-oxidation pathway to construct a synthetic expression cassette. This cassette was cloned into the integrative vector pSET152 under the control of the strong ermE promoter and fd terminator and then introduced into S. cinnamonensis SDSL6002 (WT) via intergeneric conjugation, yielding the recombinant strain S-zwf-gnd-fadB. Shake-flask fermentation demonstrated that the engineered strain achieved the intracellular NADPH/NADH level 1.8 folds of that in the wild type, with a monensin titer of 22.6 g/L (a 51.7% increase). The yield remained stable after five generations of antibiotic-free subculturing. Further scale-up validation in 50 L and 5 m3 industrial fermenters demonstrated that the engineered strain achieved monensin titers of 37.2 g/L and 40.4 g/L, which represented 16.3% and 18.8% improvements, respectively, over that of the control strain. These results highlight the exceptional scalability and industrial production potential of the engineered strain. This study establishes a multi-gene co-expression system to reinforce the reducing power network, providing a high yield engineered strain and a feasible metabolic engineering approach for industrial biosynthesis of monensin. 莫能菌素是由肉桂地链霉菌(Streptomyces cinnamonensis)合成的一种聚醚类离子载体抗生素，在畜牧领域应用广泛。为解决其工业发酵中胞内还原力(NADPH/NADH)供给不足导致的产量瓶颈，本研究采用多途径协同代谢工程策略进行理性改造。通过将磷酸戊糖途径基因zwf (编码葡萄糖-6-磷酸脱氢酶)和gnd (编码6-磷酸葡萄糖酸脱氢酶)，与脂肪酸β-氧化途径基因fadB (编码3-羟酰基-ACP脱水酶)串联构建融合表达盒，克隆至含ermE强启动子和fd终止子的整合型载体pSET152中，并通过属间接合转移导入肉桂地链霉菌SDSL6002 (WT)，获得重组菌株S-zwf-gnd-fadB。摇瓶发酵结果显示，工程菌胞内NADPH与NADH总量约为野生型的1.8倍，莫能菌素效价达22.6 g/L，产量提高51.7%，在无抗性传代5代后产量保持稳定。进一步在50 L和5 m3生产规模发酵罐中进行放大验证，工程菌株效价达37.2 g/L和40.4 g/L，较对照菌株分别提升16.3%和18.8%，展现出优异的工艺放大适应性与规模化生产潜力。本研究通过多基因协同表达系统强化了还原力供给网络，为莫能菌素的工业生物制造提供了具有应用潜力的高产工程菌株和可行的代谢工程策略。.

To address the delayed heating and insufficient thermophilic phase caused by early mass transfer limitations and local oxygen shortage in aerobic composting, this study investigated the impacts of electric field intervention on the microbial ecological network and functional phenotypes. Composting experiments were conducted in 30 L reactors under different electric field intensities (0 V, 2 V, and 5 V). Physicochemical measurements, 16S rRNA-based community profiling, co-occurrence network analysis, and BugBase phenotype predictions were integrated to elucidate the coupling mechanism of electric field-microorganisms-process. The results demonstrated that electric field application markedly accelerated temperature rise and extended the thermophilic phase, with early-stage current dynamics tightly coupled to temperature. Although temporal succession remained the primary driver of microbial community structure, electric field treatments exerted significant additional effects, resulting in distinct community structures on days 7 and 18. At the genus level, electric field application enriched key taxa associated with electron transfer and fermentation (e.g., Pseudomonas, Proteiniphilum, Bacteroides, Methanocorpusculum, and Peptococcus). The network structure shifted from a "low-aggregation, short-path" pattern to a "high-aggregation, long-path" configuration, with the electric field reshaping the module affiliations and roles of dominant taxa and connectors. Weak fields promoted cross-module cooperation, whereas strong fields enhanced module compartmentalization and hub connectivity. The phenotypic level of BugBase showed periodic migration, and the 5-V electric field reshaped the bacteria to predict the phenotype spectrum effect stronger and earlier. The electric field treatment group was more inclined to enrich the phenotypes of aerobic bacteria, Gram-negative bacteria, biofilm formation, and stress tolerance, while tending to decrease Gram-positive phenotype. Collectively, the electric field enhanced microscale mass transfer and electron acceptor availability, thereby intensifying early metabolic and exothermic processes and restructuring the microbial network, achieving a state of acceleration without directional change. This study elucidates the microbial ecological mechanisms underlying electric-field regulation of aerobic composting, thereby providing a theoretical basis and technical framework for physical-field-enabled, precision modulation of microbial community functions and for the targeted optimization of composting processes. 为缓解好氧堆肥早期传质受限与局部缺氧导致的升温滞后与高温期不足，厘清电场介入对微生物生态网络与功能表型的影响，本研究设置不同强度(0 V、2 V、5 V)的电场施加于30 L反应器的堆肥过程，结合理化指标、16S rRNA细菌群落结构分析、共现网络与BugBase表型预测，解析电场堆肥下微生物群落组成与功能演替机制。研究结果显示:电场能够显著加速升温并延长高温期，前期电流与温度呈紧密耦合;堆肥时间是细菌群落结构的主要影响因素，但在控制时间后，电场效应依旧显著，且在第7天和第18天形成了显著分化的群落结构。属水平上，电场富集了与电子转移/发酵相关的关键类群，例如假单胞菌属(Pseudomonas)、嗜蛋白质菌属(Proteiniphilum)、拟杆菌属(Bacteroides)、甲烷粒菌属(Methanocorpusculum)、消化球菌属(Peptococcus)等，富集了发酵菌和电活性菌;网络结构由“低聚集、短路径”重组为“高聚集、长路径”，电场改变了优势菌与连接者的模块归属和相对位置，弱电场增强跨模块协同，强电场强化模块分区与枢纽连接。BugBase表型层面呈现阶段性迁移，且5 V电场对细菌表型谱的调控效应更强、更早出现。电场处理组更倾向于富集需氧型、革兰氏阴性、生物膜形成与应激耐受等表型，同时革兰氏阳性表型倾向降低。综上，电场通过改善微尺度传质与电子受体可用性，放大了前期代谢与放热过程，微生物网络结构重组，实现了“加速而不改向”。本研究阐明了电场调控好氧堆肥进程的微生物生态学机制，为通过物理场精准调控菌群功能、定向优化堆肥工艺提供了新的理论与技术路径。.

Pruritus, a complex multidimensional sensation accompanying diverse dermatological and systemic disorders, affects a substantial global population. Nevertheless, the pathophysiological mechanisms underlying chronic pruritus remain incompletely understood. Standardized experimental paradigms for inducing pruritus are essential for establishing a foundational understanding of chronic pruritus. This study aimed to develop a standardized laboratory protocol for pruritus induction, investigate the relationships between sensitivities to different pruritus modalities, and explore the associations of pruritus sensitivities with pain sensitivity and other somatosensory sensitivities, thereby exploring the potential neural mechanisms. This work recruited 124 healthy participants and employed three validated pruritus induction paradigms: mechanical stimulation via calibrated feather brushing, chemical stimulation via epicutaneous application of 1% histamine dihydrochloride solution, and electrically evoked pruritus using high-frequency, low-intensity transcutaneous electrical nerve stimulation. Concurrent Quantitative Somatosensory Testing assessed subjective itch intensity and its correlation with other somatosensory profiles. All three paradigms effectively evoked significant pruritic sensations. Critically, no statistically significant differences were observed in subjective intensity ratings across the induction methods. Correlational analysis revealed significant positive associations between intensities evoked by feather brushing and histamine application, and between feather brushing and electrical stimulation. However, no significant correlation was found between histamine-evoked and electrically evoked itch intensities. This dissociation suggests both shared and distinct neural substrates mediate processing of different pruritus modalities. Furthermore, the study identified complex interactions between pruritus and other somatosensory modalities. Feather-evoked mechanical itch intensity demonstrated a significant negative correlation with mechanical pain thresholds. Similarly, histamine-evoked chemical itch intensity showed a significant negative correlation with heat pain threshold as well as heat pain tolerance thresholds. This work establishes a rigorous methodological foundation for future mechanistic research into pruritus and facilitates the development of targeted therapeutic strategies. The established paradigm in this study can serve as a core tool for objectively assessing an individual's itch sensitivity, deepen the understanding of itch perception, and act as an objective indicator for evaluating the progression of chronic itch disorders and the efficacy of their treatment in clinical practice.