Diverse Functional Groups Research Articles

Climate regulates the effect of land‐use change on the diversity of soil microbial functional groups and soil multifunctionality

Abstract Although studies have explored how soil microbial diversity and soil multifunctionality respond to land‐use change at local scales, they have rarely been explored at larger scales and across different climatic and soil environmental conditions. By sampling 40 paired sites of land‐use change from natural forests to agricultural lands (including croplands and orchards) along the middle and lower Yangtze River, combined with a global meta‐analysis, we investigated the effects of land‐use change and climate on the alpha and beta diversity of soil bacterial and fungal functional groups (FGs) and their associated soil multifunctionality at a regional scale. Our results showed that land‐use change strongly changed the diversity of soil bacterial and fungal FGs and decreased multifunctionality, which was supported by our meta‐analysis at a global scale. Direct effects of land‐use change and climate and their interaction, together with changes in soil environmental variables, were the main determinants of the land‐use change‐induced changes in the diversity of soil bacterial or fungal FGs. The land‐use change‐induced decrease in multifunctionality was mainly associated with the direct effect of forest conversion, soil fertility and diversity of fungal FGs. Furthermore, climate also regulated the effects of land‐use change on multifunctionality by affecting soil fertility and fungal FGs diversity along the Yangtze River. Synthesis and applications. Taken together, our findings highlight the important effects of land‐use change, climate and their interactions on microbial diversity and multifunctionality and suggest that effective land‐use management and climate change mitigation strategies should be adopted to protect biodiversity and ecosystem function in the Yangtze River Basin.

Radical-Chain Hydrosilylation of Alkenes Enabled by Triplet Energy Transfer.

Development of mild, robust and metal-free catalytic approach for the hydrosilylation of alkenes is critical to the advancement of modern organosilicon chemistry given their powerful capacity in the construction of various C-Si bonds. Herein, we wish to disclose a visible light-triggered organophotocatalytic strategy, which proceeds via a triplet energy transfer (EnT)-enabled radical chain pathway. Notably, this redox-neutral protocol is capable of accommodating a broad spectrum of electron-deficient and -rich alkenes with excellent functional group compatibility. Electron-deficient alkenes are more reactive and the reaction could be finished within a couple of minutes even in PBS solution with extremely low concentration, which suggests its click-like potential in organic synthesis. The preparative power of the transformations has been further highlighted in a number of complex settings, including the late-stage functionalization and scale-up experiments. Furthermore, although only highly reactive (TMS)3SiH is suitable hydrosilane substrate, our studies revealed the great reactivity and versatility of (TMS)3Si- group in diverse C-Si and Si-Si bond cleavage-based transformations, enabling the rapid introduction of diverse functional groups and the facile construction of valuable quaternary silicon architectures.

Miniaturized 3D-printed hand-operable dispersive sample pretreatment device with replaceable chitosan/polydopamine thin film metal sorbent for enhanced metal analysis

To address the increasing demand for sensitive and selective sample preparation methods for metal analysis; preconcentration of intended analyte from complex sample matrices before analysis is required to improve the performance of analysis instruments. In this study, we have engineered a sustainable and portable syringe-based hand-operable three-dimensionally (3D) printed sample pretreatment apparatus equipped with a replaceable bio-based thin- film metal sorbent. This device effectively addresses the challenges of sample matrix interference in metal analysis. A metal sorbent film composed of chitosan (CS) and polydopamine (PDA) leveraged the diverse functional groups in the CS/PDA matrix to significantly enhance the extraction efficiency for various metals. Our approach demonstrated excellent analytical performance, with coefficients of determination (R2) of 0.9982 for copper (Cu) and 0.996 for chromium (Cr). The method achieved low limits of detection (LOD) of 0.3 μg L−1 for Cr and 0.7 μg L−1 for Cu. Precision and practicality assessments using actual urine samples yielded satisfactory relative standard deviations (RSD%) ranging from of 1.6 %–8.5 % for both metals, indicating minimal interference from the sample matrix. Moreover, our approach exhibited robust performance even after seven consecutive extraction and desorption cycles, highlighting its sustainability and practical applicability for laboratory and on-site sample pretreatment.

The critical role of organic matter for cadmium-lead interactions in soil: Mechanisms and risks

Understanding the interaction mechanisms between complex heavy metals and soil components is a prerequisite for effectively forecasting the mobility and availability of contaminants in soils. Soil organic matter (SOM), with its diverse functional groups, has long been a focal point of research interest. In this study, four soils with manipulated levels of SOM, cadmium (Cd) and lead (Pb) were subjected to a 90-day incubation experiment. The competitive interactions between Cd and Pb in soils were investigated using Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray adsorption near-edge structure (XANES) analysis. Our results indicate that Pb competed with Cd for adsorption sites on the surface of SOM, particularly on carboxyl and hydroxyl functional groups. Approximately 22.6 % of Cd adsorption sites on humus were occupied by Pb. The use of sequentially extracted exchangeable heavy metals as indicators for environment risk assessments, considering variations in soil physico-chemical properties and synergistic or antagonistic effects between contaminants, provides a better estimation of metal bioavailability and its potential impacts. Integrating comprehensive contamination characterization of heavy metal interactions with the soil organic phase is an important advancement to assess the environmental risks of heavy metal dynamics in soil compared to individual contamination assessments.

Synthesis of Fully Substituted Pyrazoles with a Dicyanomethyl Group via DBU/Lewis Acid-Mediated Annulation of D-A Cyclopropanes with Arylhydrazines.

The efficient synthesis of fully substituted pyrazoles with a dicyanomethyl group was developed via an annulation reaction of 2-aroyl D-A cyclopropanes with arylhydrazines in the presence of DBU/AlCl3 reaction systems. This synthetic approach featured a wide range of readily available aroyl-substituted D-A cyclopropanes with diverse functional groups and a diversity of substituents on pyrazole products and had operationally simple and mild reaction conditions.

Symmetric Anion Mediated Dynamic Kinetic Asymmetric Knoevenagel Reaction for N-C and N-N Atropisomers Synthesis.

A symmetric anion mediated dynamic kinetic asymmetric Knoevenagel reaction was established as a general and efficient method for accessing both N-C and N-N atropisomers. The resulting highly enantio-pure pyridine-2,6(1H,3H)-diones exhibit diverse structures and functional groups. The key to excellent regio- and remote enantiocontrol could be owed to the hydrogen bond between the enolate anion and triflamide block of the organocatalyst. This connected the enolate anion and iminium cation by a chiral backbone. The mechanism investigation via control experiments, correlation analysis, and density functional theory calculations further revealed how the stereochemical information was transferred from the catalyst into the axially chiral pyridine-2,6(1H,3H)-diones. The synthetic applications also demonstrated the reaction's potential.

Symmetric Anion Mediated Dynamic Kinetic Asymmetric Knoevenagel Reaction for N−C and N−N Atropisomers Synthesis

A symmetric anion mediated dynamic kinetic asymmetric Knoevenagel reaction was established as a general and efficient method for accessing both N−C and N−N atropisomers. The resulting highly enantio‐pure pyridine‐2,6(1H,3H)‐diones exhibit diverse structures and functional groups. The key to excellent regio‐ and remote enantiocontrol could be owed to the hydrogen bond between the enolate anion and triflamide block of the organocatalyst. This connected the enolate anion and iminium cation by a chiral backbone. The mechanism investigation via control experiments, correlation analysis, and density functional theory calculations further revealed how the stereochemical information was transferred from the catalyst into the axially chiral pyridine‐2,6(1H,3H)‐diones. The synthetic applications also demonstrated the reaction's potential.

Annulation of 2-Aroyl D-A Cyclopropanes via Selectively Ring-Opening Process with o-Benzenediamines to Access Quinoxaline Derivatives.

An annulation reaction of 2-aroyl D-A cyclopropanes with o-benzenediamines via selective cleavage of C-C bonds of cyclopropane in the presence of DBU/Sc(OTf)3 reaction systems was developed for the direct preparation of 2-aryl-3-benzylquinoxalines. This synthetic approach tolerated a wide range of readily available aroyl-substituted D-A cyclopropanes with diverse functional groups and had operationally simple and mild reaction conditions.

Transition-Metal-Free Hydrodefluoroamination of Trifluoromethyl Enones for the Synthesis of α-Fluoroenamides.

A three-component strategy was developed to enable hydrodefluoroamination of β-trifluoromethyl enones by selectively activating two C(sp3)-F bonds in the trifluoromethyl group. The method involved a sequence of carbonyl reduction, hydrodefluorination, and defluoroamination under transition-metal-free conditions. Synthetically useful (E)-stereospecific α-fluoroenamides were obtained in good yields with diverse functional group tolerance, which could be easily transformed into valuable organofluorides and heterocycles. The carbonyl auxiliary exerts both electronic and steric impacts on the CF3-alkenes, allowing for controllable and selective defluorination.

Assessing the combined effects of catchment land use and runoff on estuarine fish assemblages

Connectivity between land and sea through the movement of species, energy and nutrients means that land-based impacts can affect the structure and functioning of nearby coastal ecosystems. As the interface between land and sea, estuaries are often faced with increasing pressures from catchment modifications (e.g. the removal of terrestrial vegetation) which can alter the overall health of estuaries (e.g. the degradation of coastal water quality due to an increase in terrestrial runoff) and change the value of habitat for many marine species. These landscape-scale impacts can, however, be mediated through variations in the context and connectivity of seascapes (e.g. greater extent of vegetated ecosystems help to filter nutrients). We surveyed fish across five estuaries over four years using underwater videography and sought correlations between fish biodiversity and abundance with variables indexing catchment land use, seascape connectivity, and coastal water quality. Fish assemblages were more abundant and diverse at sites which had lower chlorophyll-a concentrations and were nearer to the estuary mouth, in conjunction with catchments containing higher percent of natural land and heterogenous seascapes. Sites with lower concentrations of chlorophyll-a supported indicator species from more diverse functional groups that had greater fisheries values, in comparison to indicator species from sites with high concentrations of chlorophyll-a. This research can help direct coastal management to better prioritise management in coastal ecosystems, thereby enhancing fish richness and abundance, functional group richness and fisheries value.

MiDAS 5: Global diversity of bacteria and archaea in anaerobic digesters

Anaerobic digestion of organic waste into methane and carbon dioxide (biogas) is carried out by complex microbial communities. Here, we use full-length 16S rRNA gene sequencing of 285 full-scale anaerobic digesters (ADs) to expand our knowledge about diversity and function of the bacteria and archaea in ADs worldwide. The sequences are processed into full-length 16S rRNA amplicon sequence variants (FL-ASVs) and are used to expand the MiDAS 4 database for bacteria and archaea in wastewater treatment systems, creating MiDAS 5. The expansion of the MiDAS database increases the coverage for bacteria and archaea in ADs worldwide, leading to improved genus- and species-level classification. Using MiDAS 5, we carry out an amplicon-based, global-scale microbial community profiling of the sampled ADs using three common sets of primers targeting different regions of the 16S rRNA gene in bacteria and/or archaea. We reveal how environmental conditions and biogeography shape the AD microbiota. We also identify core and conditionally rare or abundant taxa, encompassing 692 genera and 1013 species. These represent 84–99% and 18–61% of the accumulated read abundance, respectively, across samples depending on the amplicon primers used. Finally, we examine the global diversity of functional groups with known importance for the anaerobic digestion process.

Microbial Community Shifts in Tea Plant Rhizosphere under Seawater Stress: Enrichment of Beneficial Taxa.

Seawater intrusion has a significant impact on the irrigation quality of agricultural water, thereby posing a threat to plant growth and development. We hypothesized that the rhizosphere of tea plants harbors beneficial microorganisms, which may improve the tolerance of tea plants to seawater stress. This study utilized 16s and ITS techniques to analyze microbial community shifts in the tea plant rhizosphere and non-rhizosphere under seawater stress conditions. The findings suggest that seawater stress leads to a reduction in microbial diversity, although the rhizosphere microbial diversity in stressed soils showed a relatively higher level. Moreover, the rhizosphere of the tea plant under seawater stress exhibited an enrichment of plant growth-promoting rhizobacteria alongside a higher presence of pathogenic fungi. Network analysis revealed that seawater stress resulted in the construction of a more complex and stable rhizosphere microbial network compared to normal conditions. Predictions of bacterial potential functions highlighted a greater diversity of functional groups, enhancing resource utilization efficiency. In general, the rhizosphere microorganisms of tea plants are jointly selected by seawater and the host. The microorganisms closely related to the rhizosphere of tea plants are retained and, at the same time, attract beneficial microorganisms that may alleviate stress. These findings provide new insights into plant responses to saline stress and have significant implications for leveraging vegetation to enhance the resilience of coastal saline soils and contribute to economic progress.

Estimating bee distributions and their functional range to map important areas for protecting bee species and their functions

The decline of wild bee populations causes the decline of bee-pollinated plant populations through the deterioration of pollination services. Since high bee species richness generally involves high functional group diversity, protecting areas of high bee species richness will help to maintain pollination services for plants. However, those areas do not always include the habitats of bee species with specialized functions that expand the range of plants being pollinated. To map important areas for protecting native bee species and their functions, we estimated the distributions and functional range of 13 bumble bee species and 1 honey bee species in Japan. The distributions were estimated from an ensemble of six species distribution models using bee occurrence data and environmental data. The functional range of bee species was estimated by combining the estimated distributions and proboscis length, which frequently corresponds to the floral shape of the plant species they pollinate. The estimated species richness was high in western Hokkaido and the estimated functional range was wide in central Honshu. Our method is useful to see whether areas important for high species richness of pollinators differ from those for rare species or their functions.

Recent progress in covalent organic frameworks for flexible electronic devices

AbstractCovalent organic frameworks (COFs) are porous materials with good crystallinity, highly ordered stacking, tunable channels, and diverse functional groups that have been demonstrated to show great potential applications in flexible electronic devices, including flexible energy storage devices (batteries and supercapacitors), memristors and sensors. Although great research progress on the usage of COFs as active elements in flexible electronics has been witnessed, the summary in this direction is rare. Thus, it is the right time to write a review on COFs‐based flexible electronics. In this review, we will first discuss the different synthesis strategies to prepare COF materials. Then, the applications of COFs in flexible electronic devices are summarized. Finally, the future performance improvement and development directions of COFs in the field of flexible electronic devices are briefly outlined. This review could provide basic concepts and some guidelines to stimulate novel applications of COFs in diverse flexible electronic devices.

Comprehensive insights into the impact of magnetic biochar on protein hydrolysis in sludge anaerobic digestion: Protein structures, microbial activities and syntrophic metabolisms

The addition of composite conductive materials is being increasingly recognized as a promising strategy to enhance anaerobic digestion (AD) performance. However, the influence of these materials on protein hydrolysis has been poorly documented. Here, a novel magnetic biochar derived from oil sludge and straw was synthesized using different iron sources and successfully applied in sludge AD. Experimental results revealed that magnetic biochar modified by Fe2+ exhibited excellent electron transfer capacity, moderate magnetization, diverse functional groups (e.g. C=O, C-O=O-), and abundant iron distribution. These characteristics significantly enhanced the hydrolysis of tryptophan-like components, leading to increased methane production (144.44 mL gVS−1vs 79.72 mL gVS−1 in the control test). Molecular docking analysis revealed that the binding of magnetic biochar related Fe2+ and Fe3+, onto sludge proteins via hydrogen bond played a key role in promoting subsequent protein hydrolysis. Additionally, the noteworthy conservation of protein structures from α-helix and β-sheet to random coil, along with the breakdown of the amide I-associated C=O group and amide III-related CN and NH bonds following the addition of magnetic biochar, accelerated the degradation of sludge protein. Observation of variations in protease activity, coenzyme F420, electron transfer system (ETS), and conductivity within the AD systems, particularly the enrichment of Methanospirillum and Methanosaeta archaea, as well as the Petrimonas, Comamonas, and Syntrophomonas bacteria, suggested that magnetic biochar facilitated a conducive environment by improving hydrolysis-acidification and the direct interspecies electron transfer (DIET) process for acetoclastic methanogens. Moreover, metabolic pathways further proved that tryptophan metobalism and acetoclastic methanogenesis were both facilitated by magnetic biochar. This study provides an in-depth understanding of the impact of magnetic biochar on protein hydrolysis in sewage sludge AD.

Optical properties and antimicrobial of ionic chitosan-MgO-SiO2@ aminolsilane nanocomposites

This investigation involved synthesizing a nanocomposite heterostructure, Chitosan-MgO-SiO2@aminosilane, using the physical blending of chitosan-MgO-silica with aminosilane using the sol–gel technique. The prepared nanocomposites were characterized using x-ray diffraction (XRD), Scanning/Transmission Electron Microscope (SEM-EDX/TEM), Fourier Transform Infrared Spectroscopy (FTIR), and optical analysis to investigate the microstructural and spectroscopic properties. XRD results confirmed the formation of orthorhombic Mg2SiO4 within the fabricated system. FTIR analysis verified interactions among chitosan, MgO-silica, and aminosilane, leading to the development of diverse functional groups, including M-O bonds, silanol-hydroxyl ions, and heteropolymeric-O-M within the chitosan-MgO-SiO2@aminosilane nanocomposite. Optical studies demonstrated that aminosilane-incorporated samples have two distinct absorption bands around 215 nm and 419 nm, corresponding to the electronic transitions π–π* (k-band) and n–π* (R-band), respectively. The absorption band at 400 nm is ascribed to localized surface plasmon resonance (SPR). The incorporation of aminosilane resulted in a decrease in the direct transition energy gap from 2.677 to 2.399 eV. The nanocomposites displayed significant antimicrobial activity against pathogenic microorganisms such as Gram-positive Staphylococcus aureus, Gram-negative Pseudomonas aeruginosa, and pathogenic fungi Candida albicans and Aspergillus niger. The positive antimicrobial response of the fabricated nanocomposites candidates them for various applications, including wound dressings and food packaging.

Green synthesis, characterization, antidiabetic, antioxidant and antibacterial applications of silver nanoparticles from Syzygium caryophyllatum (L.) Alston leaves

Syzygium caryophyllatum (L.) Alston, an ethnobotanically acclaimed antidiabetic plant, was utilized for the first time in this study to synthesize silver nanoparticles (SC-AgNPs). Characterization revealed spherical SC-AgNPs (∼30 nm) with a silver content of 49.10 %, displaying diverse functional groups and significant antibacterial activity against Staphylococcus aureus and Proteus vulgaris. SC-AgNPs exhibited notable antidiabetic properties by inhibiting α-amylase and α-glucosidase activities, while enhancing glucose uptake in L6 and yeast cells. Moreover, SC-AgNPs demonstrated profound antioxidant activities by scavenging reactive oxygen species, which led to increased catalase activity and decreased glutathione-S-transferase activity. These properties surpassed those of the plant extract. SC-AgNPs were found to show low toxicity towards L6 cells when compared to the contemporary silver nanoparticles. The eco-friendly synthesis method and comprehensive biological assessments highlight the value of this work in advancing nanomedicine for diabetes management.

Merging σ-Bond Metathesis with Polymerization Catalysis: Insights into Rare-Earth Metal Complexes, End-Group Functionalization, and Application Prospects.

Polymers with well-defined structures, synthesized through metal-catalyzed processes, and having end groups exhibiting different polarity and reactivity than the backbone, are gaining considerable attention in both scientific and industrial communities. These polymers show potential applications as fundamental building blocks and additives in the creation of innovative functional materials. Investigations are directed toward identifying the most optimal and uncomplicated synthetic approach by employing a combination of living coordination polymerization mediated by rare-earth metal complexes and C-H bond activation reaction by σ-bond metathesis. This combination directly yields catalysts with diverse functional groups from a single precursor, enabling the production of terminal-functionalized polymers without the need for sequential reactions, such as termination reactions. The utilization of this innovative methodology allows for precise control over end-group functionalities, providing a versatile approach to tailor the properties and applications of the resulting polymers. This perspective discusses the principles, challenges, and potential advancements associated with this synthetic strategy, highlighting its significance in advancing the interface of metalorganic chemistry, polymer chemistry, and materials science.

An Efficient Propylphosphonic Anhydride (T3P®)-Mediated MW-induced Solvent-free Rapid Synthesis of Enamino Esters and Ketones including 5, 5-Dimethyl-3-aminocyclohex-2-enones

Abstract: This work presents a clean and convenient synthesis of various β-enaminones including 5,5- dimethyl-3-aminocyclohex-2-enones, in satisfactory to excellent yields from the condensation reaction of primary amines with β -dicarbonyls by employing T3P® as a catalyst and performing the reaction under microwave irradiation and solvent-free conditions. These rapid reactions launched readily and stood a diversity of organic functional groups. A mixture of 1,3-dicarbonyl compound, primary amine and T3P® (50% in AcOEt) was irradiated for an appropriate time under microwave at 80°C. After completing the reaction (TLC) and cooling to r.t., ethyl acetate and saturated aqueous NaHCO3 solution were added. The aqueous phase was extracted ethyl acetate. The combined organic layer was washed with brine, dried over Na2SO4, and filtered, and the solvent was removed under reduced pressure to afford the product, which was recrystallized from diisopropyl ether. The presented results exhibit a better catalytic activity of T3P in the synthesis of enaminones. It could be concluded that T3P is the best catalyst as it took only a few minutes for the completion of the reaction with an excellent yield of product, which indicates T3P is more efficient, compared to other catalysts. A comparison of the efficiency of the present procedure with some heterogeneous solid catalysts was evaluated as well. Clearly, a higher yield was established in this procedure compared to other catalysts. Furthermore, the reaction of amines with dimedone was investigated as well, delivering excellent yields. The reaction catalyzed by T3P under microwave irradiation supplies a comprehensive method for the synthesis of enaminones. In this work, T3P is an effective, efficient and green catalyst, which forms the procedure economic, suitable, and safe with widespread application in the synthesis of enaminones. background: This work presents a clean and convenient synthesis of various β-enaminones incuding 5,5-dimethyl-3-aminocyclohex-2-enones in good to excellent yields from the reaction of different primary amines with 1,3-dicarbonyl compounds by employing T3P® as a catalyst and performing the reaction under microwave irradiation and solvent-free conditions. This one-pot rapid reaction proceeded readily and tolerated a variety of functional groups.

Land-use intensification exerts a greater influence on soil microbial communities than seasonal variations in the Taihu Lake region, China

The Taihu Lake region has undergone intensive land-use conversions from natural wetlands (NW) to conventional rice-wheat rotation fields (RW) and further to greenhouse vegetable fields (GH). Nevertheless, the effects of these conversions on soil microbes, particularly in wetland ecosystem, are not well explicit. To explore the impact of land-use intensification on soil microbial communities, monthly soil samples were obtained from replicate plots representing three land-use types (NW, RW, and GH) in subtropical wetlands and then subjected to amplicon sequencing. Land-use intensification had direct effects on bacterial and fungal community composition, with a more pronounced impact on bacteria than on fungi. These changes in bacterial communities were closely correlated with variations in soil environmental variables, such as NO3−-N, pH, and electrical conductivity. Land-use intensification led to a decrease in bacterial deterministic processes, with an opposing trend observed in the fungal community. In addition, arable lands (RW and GH), which are affected by anthropogenic activities, exhibited more complex networks. Potential metabolic functional groups in GH had higher absolute abundance. Seasonal variations significantly influenced microbial diversity, composition, and potential metabolic functional groups within each land-use type, particularly in summer, although the magnitude of this impact was much smaller than the impact of land-use intensification. Our findings emphasize the importance of comprehending the ecological consequences of land-use intensification in wetlands for sustainable resource management and biodiversity conservation.