Synthesis of 2-Acyltryptamines through an Unexpected Brønsted Acid Catalyzed Formal 1,5-Migration of Functional Group from Indole-Tethered Ynamides.

Herein, we have developed a Brønsted acid catalyzed 1,5-migration of functional groups from indole-tethered ynamides to prepare a variety of 2-acyltryptamines in good to excellent yields with high site-selectivity at the C2-position of indoles. Mechanistic studies revealed that the reaction underwent an intramolecular cyclization, 1,2-migration of the vinyl group, and C-N bond cleavage by hydrolysis in a one pot. The reaction features broad substrate scope, good functional group compatibility, 1,5-migration of functional groups, C-N bond cleavage to form C-C bond, and diverse 2-acyltryptamine scaffolds.

Environmental Stresses Constrain Soil Microbial Community Functions by Regulating Deterministic Assembly and Niche Width.

Increasing evidence indicates that the loss of soil microbial α-diversity triggered by environmental stress negatively impacts microbial functions; however, the effects of microbial α-diversity on community functions under environmental stress are poorly understood. Here, we investigated the changes in bacterial and fungal α- diversity along gradients of five natural stressors (temperature, precipitation, plant diversity, soil organic C and pH) across 45 grasslands in China and evaluated their connection with microbial functional traits. By quantifying the five environmental stresses into an integrated stress index, we found that the bacterial and fungal α-diversity declined under high environmental stress across three soil layers (0-20 cm, 20-40 cm and 40-60 cm).

Ultrasonic-assisted separation and extraction of submicron and nano-sized straw particles: Reconstruction of physicochemical characteristics and a promising breakthrough in overcoming technical bottlenecks of straw return to the field.

Addressing the issues of slow decomposition and low nutrient release efficiency associated with traditional straw returning, this study innovatively applied ultrasound-assisted centrifugal separation technology to prepare submicron/nano-straw particles and systematically conducted a multi-scale investigation from microscopic to macroscopic levels. The core finding reveals that when the particle size reaches the 1 μm threshold, ultrasonic cavitation vigorously disrupts the straw structure, leading to efficient lignin removal (77.45 %) and a significant reduction in cellulose crystallinity, thereby fundamentally enhancing the degradation rate.

Recyclable Cu-Catalyzed -Methylation and C5-Methylthiomethylation of Isatins with DMSO.

An unprecedented recyclable system of copper-catalyzed C-C/N coupling of isatins and DMSO without any oxidant and acidic/basic additive has been unlocked. The -isatins occur tandem -methylation and C5-methylthiomethylation in order, while -substituted isatins proceed C5-methylthiomethylation only. DMSO serves as Me and MeSCH sources as well as the solvent.

C/N-Driven Synergies: Earthworms optimize CO/NO mitigation and soil quality in floral waste recycling.

The expansion of floriculture has increased the need for sustainable floral waste management to support agricultural carbon neutrality. This study assessed the impact of carnation, lily, and rose straw amendments (with varying C/N ratios, lignin, and cellulose) on GHG emissions and soil quality with earthworm (Eisenia fetida). Controlled microcosm experiments were conducted to examine the effects of straw types and earthworms on CO and NO fluxes, as well as soil properties, enzyme activities, and microbial functions.

Stimuli-activable hollow CuO@C/N doped paste for the prevention of white spot lesions in orthodontic treatments.

White spot lesions (WSLs) are the most common complication of orthodontic treatment, compromising dental health and significantly affecting aesthetics. To address this clinical challenge, this study aims to develop a dual-functional therapeutic strategy that simultaneously promotes the remineralization of demineralized enamel and inhibits the activity of cariogenic bacteria, thereby achieving effective prevention and treatment of WSLs. A hollow double-shell structured CuO@N/C nanozyme (H-CuO@N/C) was synthesized using a one-step hydrothermal method.

Antibiotic-induced perturbations in C-N metabolic networks, and associated gene pathways in soybean (Glycine max) seedlings.

Antibiotic contamination in agricultural systems via organic fertilizer application and livestock wastewater irrigation are threats to crop physiology. However, the phytotoxic mechanisms affecting the pivotal carbon-nitrogen (C-N) metabolic nexus remain unclear. In this study, we investigated florfenicol-induced perturbations in C-N metabolic networks and associated gene regulatory pathways in soybean (Glycine max) seedlings.

The compound risk of decabromodiphenyl ethane and cadmium to soil nutrient cycling in agroecosystems: Linking the enzyme, microbial community, gene networks to plant stress.

Soil serves as the habitat for numerous organisms and is increasingly threatened from co-pollution of novel brominated flame retardant (NBFRs) and heavy metals (HMs). Focusing on Deca-bromodiphenyl ethane (DBDPE) and cadmium (Cd) as the targets, we constructed a soil-lettuce-earthworm microcosm to explore co-pollution effects in rhizosphere soils. Results showed that DBDPE increased bioavailable Cd fraction to amplified its ecological risks.

Nitrogen-Driven Orchestration of Lateral Root Development: Molecular Mechanisms and Systemic Integration.

N, as plants' most essential nutrient, profoundly shapes root system architecture (RSA), with LRs being preferentially regulated. This review synthesizes the intricate molecular mechanisms underpinning N sensing, signaling, and its integration into developmental pathways governing LR initiation, primordium formation, emergence, and elongation. We delve deeply into the roles of specific transporters (NRT1.

Microorganisms Enhance Denitrification of Low Carbon-to-Nitrogen Ratio Municipal Wastewater and Reduce NO Emission: Metabolites Promote Carbon Flux to Nitrate Bioreduction.

Denitrifying carbon source is mainly used for microbial growth and proliferation, substrate transport, and nitrate bioreduction. This paper reported a new approach to dramatically promote denitrification and reduce NO emission of low carbon-to-nitrogen ratio (C/N) municipal wastewater by introducing two microorganisms to increase carbon flux to nitrate bioreduction without increasing the external carbon source. At a C/N of 3, the total nitrogen removal efficiency of the model denitrifier () was increased from 48.

Electrocatalytic synthesis of methylamine from nitrate and carbon dioxide on a heterometallic polyphthalocyanine.

Electrocatalytic coreduction of nitrate and CO provides an opportunity for the synthesis of organonitrogen chemicals. The major challenge is to realize the simultaneous reduction of nitrate and CO into active intermediates for C-N bond formation. In this work, methylamine is synthesized from nitrate and CO on a polyphthalocyanine electrocatalyst with heterometal centers (CoCuPPc).

Does abnormal weight affect sperm quality? A case-control study based on bioelectrical impedance analysis.

Introduction: Weight gain can lead to metabolic, circulatory, and systemic changes. Obesity has been confirmed to induce various physical and mental illnesses. The relationship between abnormal weight and male fertility has become a research focus, although the findings regarding their correlation remain controversial.

Recent Advances in Microenvironment Engineering for Selective Electrochemical C-N Coupling.

Electrochemical C-N coupling via the coreduction of CO and nitrogenous species (N/NO) presents a sustainable route to synthesize value-added C-N compounds under mild conditions. However, competing pathways and mismatched intermediate kinetics hinder the selective formation of products like urea, amines, and amides. Recent advances reveal that rational modulation of the electrochemical microenvironment can effectively steer reaction pathways and stabilize coupling-relevant intermediates.

Effect of target tree management on soil extracellular enzyme activities and fungal community structure in stands.

Target tree management can adjust stand structure, alleviate tree competition, and improve soil quality. Taking natural forest as the control, we explored the characteristics of soil fungal communities by high-throughput sequencing technology and investigated the relationships among fungal communities, physicochemical properties, and soil extracellular enzyme activities of . plantations managed by the target tree and that not managed by the target tree.

Synthesis of γ‑Lactams by Intermolecular (3 + 2) Annulation of Siloxy Alkynes and 3‑Aminooxetanes.

A silver-catalyzed intermolecular (3 + 2) annulation of siloxy alkynes and 3-aminooxetanes has been developed. This process provides mild and convenient access to useful γ-butyrolactams with high regio- and stereoselectivity. Mechanistically, intermolecular C-N bond formation likely precedes oxetane ring opening.

Traceability of etomidate and its analogs in biological samples using "specific" metabolites.

With the regulation of etomidate (ETO), criminals continue to use chemical modifications to derive various ETO analogues as substitutes to enter the illegal market in order to evade punishment, and the phenomenon of substitution abuse is becoming increasingly serious. After these substitutes are ingested by the human body, the prototype drug is almost undetectable in the biological samples. It is necessary to search for "characteristic" metabolite traceability prototype drugs to effectively prevent misjudgment of cases.

Planar tetra-, hexa-, octa-, and deca-coordinate Heavier alkaline-earth metals: covalent interactions of d orbitals with carbon chains.

The involvement of d-orbitals and the large atomic radii of heavier alkaline-earth metals (Ae = Ca, Sr, Ba) have significantly expanded the boundaries of planar coordination chemistry, enabling unprecedented configurations up to pentadeca-coordination. However, these same properties present challenges in isolating low-coordinated analogues. Here, we explore the potential energy surfaces of neutral AeC ( = 4-12) complexes, composed of Ae atoms coordinated by carbon chains, to identify planar hypercoordinate Ae (phAe) species.

Long-term nitrogen addition enhanced soil carbon sequestration through coupled physicochemical and microbial mechanisms in a temperate forest.

As critical carbon (C) sinks in terrestrial ecosystems, temperate forests exhibit complex responses to atmospheric nitrogen (N) deposition. Through a 13-year controlled field experiment, we systematically investigated the effects of three N forms (NO-N, NH-N, NHNO-N) at two deposition levels (50/150 kg N·ha·yr) on soil organic C (SOC) dynamics. The experimental data revealed a three-phase SOC accumulation pattern, with aggregate-associated C showing 6.

Ecological stoichiometry between leaves, litter and soil of dominant species in the forest community of rock-stream periglacial landforms in Mt. Laotudingzi.

This study investigates the ecological stoichiometric characteristics of carbon (C), nitrogen (N), and phosphorus (P) across the leaf-litter-soil continuum in the block stream forest community of Laotudingzi Mountain, a representative paleo-periglacial landform in northeastern China. Utilizing X-ray fluorescence spectroscopy (XRF), we analyzed 13 dominant tree species (10 broadleaf, 3 coniferous) to unravel nutrient limitation mechanisms and cross-media coupling in this oligotrophic cryogenic ecosystem. Results indicate that P is the primary limiting nutrient, with mean N: P ratios in leaves (12.

Non-metal single atoms anchored on defective MoS: a novel electrocatalyst for NO reduction to NH.

The electrocatalytic nitric oxide reduction reaction (eNORR) is a highly significant because it provides a sustainable and cost-effective way to combine the elimination of nitric oxide (NO) with synthesis of ammonia (NH). This study comprehensively investigates the performance of single non-metal atom catalysts (NM@MoS), which are composed of single non-metal atoms that are embedded in vacancy defects in MoS. Our results demonstrate that eight NM@MoS catalysts (NM = B, C, N, O, P, Si, Se, and Te) exhibit remarkable thermodynamic stability.

Sub-2 nm Cu and Co Codoping SnO Ultrathin Nanosheet with Mesoporous Structure for Efficient Electrocatalytic Urea Synthesis.

The production of urea through C-N coupling via the electrochemical coreduction of CO and NO represents an environmentally friendly and promising approach. However, the C-N coupling reaction encompasses multiple reactants and complex pathways, necessitating a catalyst that exhibits a high efficiency in both CO and NO reduction. Herein, the sub-2 nm Cu and Co codoped SnO ultrathin nanosheet (SnOCuCo) with mesoporous structure is synthesized for the electrochemical coreduction of CO and NO for urea synthesis, and the thickness of SnOCuCo is only 1.

Evaluation of soil quality and analysis of drivers of different vegetation patterns in the loess region of Northern Shaanxi.

Evaluating the effects of different vegetation patterns on soil quality and clarifying the soil quality drivers in the loess area of northern Shaanxi are highly important for the future land use and vegetation optimization in this area. In this work, eight typical vegetation patterns in the loess area of northern Shaanxi were used as research objects, and the main soil physicochemical indicators were screened out using principal component analysis, the soil quality evaluation model was established using fuzzy comprehensive evaluation method, and the soil quality (SQ) was comprehensively evaluated. Finally, structural equation modeling (SEM) was used to explore the key factors affecting soil quality.

Alkaline stress suppresses soybean waterlogging tolerance by exacerbating energy expenditure and ROS accumulation.

To clarify the synergistic inhibition mechanisms of saline-alkali and waterlogging combined stress on soybean physiology, this study systematically analyzed phenotypic traits, photosynthetic characteristics, reactive oxygen species (ROS) metabolism, and energy metabolism under saline-alkali (A + NW), waterlogging (NA + W), and combined stress (A + W). Results demonstrated that saline-alkali stress significantly impaired waterlogging-induced morphological adaptations, with A + W reducing dry weight and adventitious root number compared to W alone. Synergistic photosynthetic damage was observed: net photosynthetic rate (Pn) under A + W decreased markedly versus controls, while chlorophyll b content increased, suggesting PSII light-harvesting complex reorganization to mitigate photoinhibition.

Photocatalytic Co-Reduction of CO and Nitrate over Porphyrin Metal-Organic Frameworks: Dual Atomic Active Site and Nanostructure Synergy Enhances C-N Coupling for Urea Production.

The photocatalytic co-reduction of NO and CO (NitRR&CRR) offers a sustainable approach for urea synthesis and environment remediation. However, there is a lack of high-performance photocatalysts. Herein, we report a nanoflower-like bimetallic porphyrin metal-organic framework superstructure (Cu-TCPP(Co)-NF, TCPP = tetrakis(4-carboxyphenyl)porphyrin) as an efficient NitRR&CRR photocatalyst for urea production.

Single-atom catalysts toward electrocatalytic urea synthesis C-N coupling reactions.

Urea, with a global annual production that exceeds 200 million tons, occupies an irreplaceable position in agriculture, pharmaceuticals, and materials science. The conventional Haber-Bosch process and its derivatives are constrained by high energy consumption and considerable carbon emissions. Global urea production, for instance, utilizes approximately 1.