Trivalent manganese in dissolved forms: Occurrence, speciation, reactivity and environmental geochemical impact.

The cycling processes of elemental manganese (Mn), including the redox reactions of dissolved Mn(III) (dMn(III)), directly and indirectly influences the biogeochemical processes of many elements. Though increasing evidence indicates the widespread presence of dMn(III) mediates the fate of many elements, its role may be currently underestimated. There is both a lack of clear understanding of the historical research framework of dMn(III) and a systematic overview of its geochemical properties and detection methods. Therefore, the primary aim of this review is to outline the understanding of dMn(III) in multiple fields, including soil science, analytical chemistry, biochemistry, geochemistry, and water treatment, and summarize the formation pathways, species forms, and detection methods of dMn(III) in aquatic systems. This review considers how the characteristics of dMn(III), the intermediate formed in the single-electron reaction processes of Mn(II) oxidation and Mn(IV) reduction, determines its participation in environmental geochemical processes. Its widespread presence in diverse water systems and active redox properties coupling with various elements confirm its significant role in natural elemental geochemistry cycle and artificial water treatment processes. Therefore, further investigation into the role of dissolved Mn(III) in aquatic systems is warranted to unravel unexplored coupled elemental redox reaction processes mediated by dissolved Mn(III), filling in the gaps in our understanding of manganese environmental geochemistry, and providing a theoretical basis for recognizing the role of dMn(III) role in water treatment technologies.

Gas-phase and air-solid interface behavior of phthalate plasticizer and ozone: The influence of indoor mineral dust.

Indoor environments serve as reservoirs for a variety of emerging pollutants (EPs), such as phthalates (PAE), with intricate interactions occurring between these compounds and indoor oxidants alongside dust particles. However, the precise mechanisms governing these interactions and their resulting environmental implications remain unclear. By theoretical simulations, this work uncovers multi-functional compounds and high oxygen molecules as important products arising from the interaction between DEP/DEHP and O3, which are closely linked to SOA formation. Further analysis reveals a strong affinity of DEP/DEHP for mineral dust surfaces, with an adsorption energy of 22.11/30.91 kcal mol-1, consistent with a higher concentration of DEHP on the dust surface. Importantly, mineral particles are found to inhibit every step of the reaction process, albeit resulting in lower product toxicity compared to the parent compounds. Thus, timely removal of dust in an indoor environment may reduce the accumulation and residue of PAEs indoors, and further reduce the combined exposure risk produced by PAEs-dust. This study aims to enhance our understanding of the interaction between PAEs and SOA formation, and to develop a fundamental reaction model at the air-solid surface, thereby shedding light on the microscopic behaviors and pollution mechanisms of phthalates on indoor dust surfaces.

Clicking gallic acid into chitosan prolongs its antioxidant activity and produces intracellular Ca2+ responses in rat brain cells.

Gallic acid is a vegetable-derived and highly bioactive phenolic acid, but its antioxidant capacity is sensitive to environmental conditions. Chitosan is a biopolymer capable of exerting significant protection to various molecules, including phenolic compounds. A chitosan derivative that extends the antioxidant activity of gallic acid was synthesized by click chemistry and characterized by FT-IR, 1H NMR, and antioxidant capacity assays. Our results show that synthesized polymeric solutions and nanoparticles of N-(gallic acid) chitosan were both internalized by rat brain cells, processes that were modulated by extracellular Ca2+ and Na+. Their internalization was supported by dynamic light scattering and ζ-potential analyses, while Ca2+ imaging recordings performed in brain cells revealed the potential biological effect of N-(gallic acid) chitosan. We conclude that the synthesis of an N-(gallic acid) chitosan derivative through click chemistry is viable and may serve as strategy to prolong its antioxidant activity and to study its biological effects in vivo.

Designing intelligent bioorthogonal nanozymes: Recent advances of stimuli-responsive catalytic systems for biomedical applications.

Bioorthogonal nanozymes have emerged as a potent tool in biomedicine due to their unique ability to perform enzymatic reactions that do not interfere with native biochemical processes. The integration of stimuli-responsive mechanisms into these nanozymes has further expanded their potential, allowing for controlled activation and targeted delivery. As such, intelligent bioorthogonal nanozymes have received more and more attention in developing therapeutic approaches. This review provides a comprehensive overview of the recent advances in the development and application of stimuli-responsive bioorthogonal nanozymes. By summarizing the design outlines for anchoring bioorthogonal nanozymes with stimuli-responsive capability, this review seeks to offer valuable insights and guidance for the rational design of these remarkable materials. This review highlights the significant progress made in this exciting field with different types of stimuli and the various applications. Additionally, it also examines the current challenges and limitations in the design, synthesis, and application of these systems, and proposes potential solutions and research directions. This review aims to stimulate further research toward the development of more efficient and versatile stimuli-responsive bioorthogonal nanozymes for biomedical applications.

MolGC: molecular geometry comparator algorithm for bond length mean absolute error computation on molecules.

Density Functional Theory (DFT) is extensively used in theoretical and computational chemistry to study molecular and crystal properties across diverse fields, including quantum chemistry, materials physics, catalysis, biochemistry, and surface science. Despite advances in DFT hardware and software for optimized geometries, achieving consensus in molecular structure comparisons with experimental counterparts remains a challenge. This difficulty is exacerbated by the lack of automated bond length comparison tools, resulting in labor-intensive and error-prone manual processes. To address these challenges, we propose MolGC, a Molecular Geometry Comparator algorithm that automates the comparison of optimized geometries from different theoretical levels. MolGC calculates the mean absolute error (MAE) of bond lengths by integrating data from various DFT software. It provides interactive and customizable visualization of geometries, enabling users to explore different views for enhanced analysis. In addition, it saves MAE computations for further analysis and offers a comprehensive statistical summary of the results. MolGC effectively addresses complex graph labeling challenges, ensuring accurate identification and categorization of bonds in diverse chemical structures. It achieves a 98.91% average rate in correct bond label assignments on an antibiotics dataset, showcasing its effectiveness for comparing molecular bond lengths across geometries of varying complexity and size. The executable file and software resources for running MolGC can be downloaded from https://github.com/AbimaelGP/MolGC/tree/main .

Application progress of deep generative models in de novo drug design.

The deep molecular generative model has recently become a research hotspot in pharmacy. This paper analyzes a large number of recent reports and reviews these models. In the central part of this paper, four compound databases and two molecular representation methods are compared. Five model architectures and applications for deep molecular generative models are emphatically introduced. Three evaluation metrics for model evaluation are listed. Finally, the limitations and challenges in this field are discussed to provide a reference and basis for developing and researching new models published in future.

Protocol for siRNA-mediated U1 snRNA knockdown using fluorinated α-helical polypeptide in vitro and in vivo.

Here, we present a protocol for small interfering RNA (siRNA)-mediated U1 small nuclear RNA (snRNA) knockdown using fluorinated α-helical polypeptide in macrophages and mouse lungs, providing a dependable approach to silence U1 snRNA in vitro and in vivo. We describe steps for preparing P7F7/siRNA polyplexes and silencing U1 snRNA with P7F7/siRNA polyplexes in macrophages and mouse lungs. Knockdown efficiency is validated through reverse-transcription quantitative real-time PCR analysis. This protocol is applicable for studying the physiological or pathophysiological function of U1 snRNA. For complete details on the use and execution of this protocol, please refer to Zhang et al.1.

Multifunctional Modification of the Buried Interface in Mixed Tin-Lead Perovskite Solar Cells.

Mixed tin-lead perovskite solar cells can reach bandgaps as low as 1.2 eV, offering high theoretical efficiency and serving as base materials for all-perovskite tandem solar cells. However, instability and high defect densities at the interfaces, particularly the buried surface, have limited performance improvements. In this work, we present the modification of the bottom perovskite interface with multifunctional hydroxylamine salts. These salts can effectively coordinate the different perovskite components, having critical influences in regulating the crystallization process and passivating defects of varying nature. The surface modification reduced traps at the interface and prevented the formation of excessive lead iodide, enhancing the quality of the films. The modified devices presented fill factors reaching 81% and efficiencies of up to 23.8%. The unencapsulated modified devices maintained over 95% of their initial efficiency after 2000 h of shelf storage.

CF3-Substituted Ethylene Carbonates for High-Voltage/High-Energy Rechargeable Lithium Metal-LiNi0.8Co0.1Mn0.1O2 Batteries.

The development of advanced liquid electrolytes for high-voltage/high-energy rechargeable Li metal batteries is an important strategy to attain an effective protective surface film on both the Li metal anode and the high-voltage composite cathode. Herein, we report a study of two CF3-substituted ethylene carbonates as components of the electrolyte solutions for Li metal|NCM811 cells. We evaluated trifluoromethyl ethylene carbonate (CF3-EC) and trans-ditrifluoromethylethylene carbonate Di-(CF3)-EC as cosolvents and additives to the electrolyte solutions. Using CF3-substituted ethylene carbonates as additives to a fluoroethylene carbonate (FEC)-based electrolyte solution enables improved capacity retention of high-power Li metal|NCM811 cells. The composition of the products from the transformations of CF3-EC and Di-(CF3)-EC in Li|NCM811 cells was studied by FTIR, XPS, and 19F NMR spectroscopy. We concluded that fluorinated Li alkyl carbonates are the main reaction products formed from these cyclic carbonates during the cycling of Li|NCM 811 cells, and fragmentation of the ring with the formation of CO2, CO, or olefins is not characteristic of CF3-substituted ethylene carbonates. The NCM 811 cathodes and Li metal anodes were characterized by X-ray diffraction, SEM, XPS, and FTIR spectroscopy. The role of CF3-substituted ethylene carbonate additives in stabilizing high energy density secondary batteries based on Li metal anodes was discussed. A bright horizon for developing sustainable rechargeable batteries with the highest possible energy density is demonstrated.

Electromagnetic Enantiomer: Chiral Nanophotonic Cavities for Inducing Chemical Asymmetry.

Chiral molecules, a cornerstone of chemical sciences with applications ranging from pharmaceuticals to molecular electronics, come in mirror-image pairs called enantiomers. However, their synthesis often requires complex control of their molecular geometry. We propose a strategy called "electromagnetic enantiomers" for inducing chirality in molecules located within engineered nanocavities using light, eliminating the need for intricate molecular design. This approach works by exploiting the strong coupling between a nonchiral molecule and a chiral mode within a nanocavity. We provide evidence for this strong coupling through angular emission patterns verified by numerical simulations and with complementary evidence provided by luminescence lifetime measurements. In simpler terms, our hypothesis suggests that chiral properties can be conveyed on to a molecule with a suitable chromophore by placing it within a specially designed chiral nanocavity that is significantly larger (hundreds of nanometers) than the molecule itself. To demonstrate this concept, we showcase an application in display technology, achieving efficient emission of circularly polarized light from a nonchiral molecule. The electromagnetic enantiomer concept offers a simpler approach to chiral control, potentially opening doors for asymmetric synthesis.

Accelerated Development of Pharmaceuticals Past, Present, and Future.

This paper reviews the accelerated development of pharmaceuticals, exploring past, present, and future perspectives. It provides a historical overview of early strategies used to expedite development, beginning with initiatives from the 1990s. The work of Gardner and Byrn in accelerated development analysis during this era is highlighted. The narrative progresses to the 2000s, discussing the emergence of PK/PD in accelerating pharmaceutical development. The paper further examines case studies in the accelerated development field, including the INDIGO and Chorus programs. It concludes with an analysis of the current state of the field, referencing the NIPTE conference, which focused on the industrial perspective of accelerated development. Additionally, the paper outlines strategies for the rapid development of Solid Lipid Nanoparticle manufacturing and vaccine production.

Sustainable approaches to analyzing phenolic compounds: a green chemistry perspective.

Innovative and eco-friendly methodologies for the determination of phenolic compounds, showing a paradigm shift in analytical chemistry toward sustainability. Phenolic compounds, valued for their diverse health benefits, have historically been analyzed using methods that often involve hazardous solvents and energy-intensive processes. This review focuses on green analytical chemistry principles, emphasizing sustainability, reduced environmental impact, and analytical efficiency. The use of DES, specifically Ch: Chl-based DES, emerges as a prominent green alternative for extracting phenolic compounds from various sources. The integration of UAE with DES enhances extraction efficiency, contributing to a more sustainable analytical approach. Furthermore, the review highlights the significance of DLLME and SPME in reducing solvent consumption and simplifying extraction procedures. These techniques exemplify the commitment to making phenolic compound analysis environmentally friendly. The incorporation of portable measurement tools, such as smartphones, into analytical methodologies is a notable aspect discussed in the review. Techniques like UA-DLLME leverage portable devices, making phenolic compound determination more accessible and versatile. Anticipating the future, the review foresees ongoing advancements in sustainable analytical approaches, driven by collaborative efforts across diverse disciplines. Novel solvents, extraction techniques, and portable measurement methods are expected to play pivotal roles in the continuous evolution of green analytical methodologies for the analysis of phenolic compounds. The review encapsulates a transformative journey toward environmentally responsible and efficient analytical practices, paving the way for further research and application in diverse analytical settings.

Eco-friendly Approaches to Chromene Derivatives: A Comprehensive Review of Green Synthesis Strategies.

Synthetic routes of chromene are an area of thrust research due to its wide application as pigments, agrochemicals, cosmetics, and an important nucleus scaffold for various pharmaco-logically active drugs. The chromene nucleus is an important moiety for the discovery of new drug candidates owing to its broad range of pharmacological actions like antitumor, anti-inflammatory, antiviral, and many others. However, traditional synthesis techniques frequently use unsafe reagents and produce hazardous waste, presenting environmental issues. The eco-friendly production of chromene derivatives utilizes sustainable raw materials, non-toxic cata-lysts, and gentle reaction conditions to reduce ecological consequences. Innovative methods like microwave irradiation, ultrasound synthesis, the use of environmentally friendly solvents, a cata-lyst-based approach with minimal environmental impact, and mechanochemistry-mediated syn-thesis are implemented. These approaches provide benefits in scalability, cost-effectiveness, and ease of purification. This review compiles and presents various recently reported green synthetic strategies of chromene and its derivatives and gives the reader a clear idea of the detailed and crit-ical aspects of various synthetic protocols described.

Rapid start-up of carbon-free H2 production by ammonia oxidative decomposition over Co/Ce0.5Zr0.5O2 with microwave irradiation.

Hydrogen is a promising combustion improver for use with ammonia fuels, but a cost-effective method for easily producing hydrogen from ammonia at a high rate has yet to be developed. Here, we show that microwave irradiation instantly triggers oxidative decomposition of ammonia over a Co/Ce0.5Zr0.5O2 catalyst to produce hydrogen at a high rate. The microwave irradiation rapidly heats the inside of the catalyst from room temperature to the catalytic auto-ignition temperature of ammonia, thus initiating exothermic oxidative decomposition of ammonia to produce hydrogen. This method provides a highly efficient means of producing hydrogen for potential use in a carbon-free, ammonia-fueled power generation process.

Synthesis, crystal structure and Hirshfeld surface analysis of [1-(4-bromo-phen-yl)-1H-1,2,3-triazol-4-yl]methyl 2-(4-nitro-phen-oxy)acetate.

The title compound, C17H13BrN4O5, was synthesized by a Cu2Br2-catalysed Meldal-Sharpless reaction between 4-nitro-phen-oxy-acetic acid propargyl ether and para-bromo-phenyl-azide, and characterized by X-ray structure determination and 1H NMR spectroscopy. The mol-ecules, with a near-perpendicular orientation of the bromo-phenyl-triazole and nitro-phen-oxy-acetate fragments, are connected into a three-dimensional network by inter-molecular C-H⋯O and C-H⋯N hydrogen bonds (confirmed by Hirshfeld surface analysis), π-π and Br-π inter-actions.

2-Heteroarylethylamines in medicinal chemistry: a review of 2-phenethylamine satellite chemical space.

The concept of bioisostere replacement is of paramount importance in medicinal chemistry, as it can be employed as a rational to expand bioactive chemical space to tackle lead optimization issues like lack of potency, efficacy, and selectivity or pharmacokinetic/dynamic issues. One of the most important building blocks (in the sense of participating in a vast area of chemical space of biological importance) in medicinal chemistry is the 2-phenethyl moiety, a key component of diverse drug-like entities. Although the core 2-phenethylamine structure has been recognized by the drug discovery community, little attention has been given to the various ring-based rescaffolding procedures that can be conducted with this unit. In this regard, a review on the use of 2-heteroarylethylamines displaying pharmacological activity is reported. A detailed description of flexible, amine-opened motifs is provided, that describes therapeutic targets and other potent bioactive examples, which will be a valuable repository of phenyl, heteroaryl, and other replacement units of high value to the drug discovery community.

Hetero-polycyclic aromatic systems: A data-driven investigation of structure-property relationships.

Polycyclic aromatic systems (PASs) are pervasive compounds that have a substantial impact in chemistry and materials science. Although their specific structure-property relationships hold the key to the design of new functional molecules, a detailed understanding of these relationships remains elusive. To elucidate these relationships, we performed a data-driven investigation of the newly generated COMPAS-2 dataset, which contains ~500k molecules consisting of 11 types of aromatic and antiaromatic rings and ranging in size from one to ten rings. Our analysis explores the effects of electron count, geometry, atomic composition, and heterocyclic composition on a range of electronic molecular properties of PASs.

Efficient and environmentally friendly spectrofluorimetric determination of cariprazine: An analytical and green chemistry approach.

Cariprazine represents a new generation of antipsychotic medication, characterized by its heightened affinity for the D3 receptor. It has recently obtained approval as an adjunctive treatment option for patients diagnosed with major depressive disorder. In this study, a novel approach utilizing fluorescence spectroscopy was developed to analyze cariprazine. The methodology involves the transformation of cariprazine into a fluorescent compound by means of chemical derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl). Following excitation at 470 nm, the fluorescent derivative displayed peak fluorescence emission at 550 nm. The factors influencing the derivatization process were optimized. Upon reaching the optimal reaction conditions, a linear correlation (r2 = 0.9995) was observed between the fluorescence intensity and concentrations of cariprazine ranging from 20 to 400 ng/ml. Detection and quantitation limits were determined to be 5.85 and 17.74 ng/ml, respectively. The approach was accurate and precise, with percent recovery values ranging from 98.14% to 99.91% and relative standard deviations of less than 2%. Application of the method to the analysis of cariprazine in bulk and commercial capsules forms yielded accurate results. Moreover, adherence to environmentally friendly analytical practices was evident through alignment with the principles of green analysis, as demonstrated by the analytical eco-scale, AGREE, and GAPI greenness assessment tools.

Recyclable Biomimetic Sunflower Pollen-based Photocatalyst for Enhanced Degradation of Pharmaceuticals.

Recent trends in addressing the impending water crisis focus on the development of innovative water treatment methods. This work utilizes pollen as a core template to synthesize highly efficient onion-like photocatalysts for pollutant mineralization. The study showcases a novel electrochemical synthesis method that maintains the structural integrity of pollen, resulting in increased surface area and enhanced photocatalytic activity. After 90-min of visible light irradiation, over 99% mineralization is achieved. These hybrid photocatalysts demonstrate exceptional stability and efficacy in degrading pollutants. The used photocatalysts can be recycled into biopellets with an ash content of less than 7% (weight), moisture content of less than 8% (weight), and a calorific value of ≈22.1 ± 0.3 MJ kg-1. Additionally, the resulting ashes serve as effective peroxymonosulphate activators for pollutant mineralization. This process offers sustainable waste management while minimizing waste production, providing a practical solution for water purification. The efficacy of this approach in pollutant removal is underscored by mineralization rates exceeding 99%.

Ag20 Nanoclusters with Surface Azides as an Easily Functionalized Platform for Diverse Chemical Applications.

Modifying atomically precise nanocluster surfaces while maintaining the cluster core remains a key challenge. Herein, the synthesis, structure, and properties of two targeted Ag20 nanoclusters (NCs) with eight surface azide moieties, [CO3@Ag20(StBu)10(m-N3-C6H4COO)8(DMF)4] (1-m) and [CO3@Ag20(StBu)10(p-N3-C6H4COO)8(DMF)4] (1-p) are reported, where DMF is N,N-dimethylformamide. These AgNCs are designed to undergo cluster surface strain-promoted azide-alkyne cycloaddition (CS-SPAAC) reactions, introducing new functionality to the cluster surface. Reactivity is screened using model strained cyclooctynes. Reaction products and parent clusters are characterized by UV-vis, FT-IR, and NMR spectroscopies. The structure of the parent clusters and presence of surface azides is confirmed by single crystal X-ray diffraction (SCXRD) analysis. Clusters 1-m and 1-p are found to be amenable to CS-SPAAC reactions with retention of the NC frameworks, opening new routes for efficient modification of AgNC for applications.