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The gene editing and synthetic biological tools have led to the implementation of diverse metabolic engineering approaches to enhance the production of specific enzymes. Microbial keratinases can convert keratin wastes into valuable compounds for mankind. Since the market for keratinases cannot be satisfied by production from wild hosts, it is obligatory to develop hosts with high keratinase yields. The intention of this review is to evaluate microbial keratinase advancement through protein engineering, breeding techniques, and fermentation optimization. The main aim of protein engineering is to improve the heat resistance ability and catalytic activity of keratinases by employing mutagenesis methods. Moreover, modifying the expression elements and host engineering are also two unique ways to augment the keratinase yield. Intending to accelerate the production of modified keratinase, this review attempts to highlight the optimization of expression elements, such as promoter engineering, UTR, signal peptide, and codon optimization. Moreover, the approaches of host engineering including strengthening precursor supply, membrane surface engineering, and optimization of secretion pathways were also explained here. Furthermore, it is also essential to optimize the medium composition and fermentation condition for high keratinase yield. This review also addressed the present advancements, difficulties, and tendencies in the field of microbial keratinase production, along with its potential.

Tebufenozide, an efficient insect growth regulator (IGR) against lepidopteran pests, presents a novel mode of action with minimal non-target impact. By competing with ecdysteroids for ecdysone receptor (EcR) binding, it regulates insect growth precisely. This study explores tebufenozide's potential as a multitarget IGR, targeting both EcR and Ostrinia furnacalis chitinase I (OfChtI). The inhibitory activity against OfChtI is comparable to that of substrates (GlcNAc)5, with an IC50 of 45.77 ​μM. Our computational findings indicate that tebufenozide binds at the subsite −1 to +1 of OfChtI through various interactions. Notably, tebufenozide establishes a pi-pi interaction with the flipped sidechain of Trp107, enabling tebufenozide to deeply penetrate into the S1 pocket, thereby obstructing substrate binding to OfChtI. These insights highlight the potency of multitarget strategies, laying the groundwork for innovative IGR designs that offer comprehensive pest management solutions.

Carbofuran insecticide is one of the insecticides most often used by Indonesian farmers. The United Nations Environment Program (UNEP) 2011 in the decision of UNEP/FAO/RC/CRC.11/6, agreed that the active ingredient Carbofuran is dangerous to human health and the environment. P. fluorescens bacteria are known to be able to remediate carbofuran-contaminated soil. This study examines more deeply the biodegradation and biotransformation processes of Carbofuran in P. fluorescens bacteria. The research was carried out at the Laboratory of Plant Diseases, Faculty of Agriculture, Brawijaya University; Analytical Chemistry Laboratory, State Polytechnic of Malang; and Analytical Chemistry Laboratory, Udayana University from February to August 2020. The results showed that P. fluorescens was able to degrade the insecticide Carbofuran in liquid media up to 82 % and the growth of P. fluorescens bacteria reached 2.9 x 1012 CFU/mL, bacteria P. fluorescens is able to degrade the insecticide Carbofuran in a mixture of soil and compost up to 85 % and the growth of P. fluorescens bacteria reaches 7.5 x 1013 CFU/mL, resulting in Carbofuran insecticide derivatives from the biotransformation process, there are 3-hydroxy-7-phenol; 2,3-dihydro-1-benzofuran-2,2,7-triol; (2Z)-2-[(2Z)-pent-2-en-1-ylidene]butane-1,4,4-trio; 7-phenol; 2,2,3-trihydroxy-2,3-dihydro-1-benzofuran-7-yl hydrogen carbonate; 2,2-dimethyl-2,3-dihydro-1-benzofuran-7-yl acetate; 7-(hydroxymethoxy)-2,3-dihydro-1-benzofuran-2,2,3,5-tetrol; 3-hidroksi-2-fenilpropil Carbamat; 2-(3-hydroperoxy-2-hydroxyphenyl)ethane-1,1-diol, 3-keto-7-fenol; 4-hydroxy-2,2-dimethyl-2,3-dihydro-1H-inden-1-one; 3-hydroxy-carbofuran; and 7-methoxy-2,2-dimethyl-2,3-dihydro-1-benzofuran-3,5-diol. Carbofuran derivative compounds from the biodegradation of P. fluorescens bacteria are less toxic than the active ingredient Carbofuran.

A series of quinoxalinone-1,2,3-triazole derivatives have been synthesized and tested for antifungal activity against phytopathogenic fungus through mycelial growth inhibition in vitro, spore germination inhibition in vitro and control effect in vivo. The results showed that the pharmacophore quinoxalinone and 1,2,3-triazole displayed promising antifungal activity. The EC50 value against C. gloeosporioides of 6a-1 was 1.17 μg/mL and the compound 6c-1 showed the good bioactivity against C. fragariae Brooks and P. oryzae Cav., displaying EC50 values of 5.56, 4.62 μg/mL, respectively. The inhibitory of spore germination by 6a-1 was performed with EC50 value of 1.91 μg/mL. In addition, the in vivo bioassay indicated that 6a-1 possessed effective control against Pepper Anthrax Disease in protective treatment. For given activity data of target compounds, structure-activity relationship (SAR) study was operated, hoping for optimizing the target structure to find lead compound with higher activity.

Fungicides are an indispensable tool in plant disease control. Various modes of action (MOAs) have been identified in different fungicides to suppress plant pathogens. The combined use of fungicides with distinct MOAs has been recommended to prevent the development of pathogen resistance. In studying MOAs, metabolomics has been proven to be a robust and high-throughput method. Because metabolites are unique and distinct depending on the biological activities of an organism, MOAs can be identified and classified by establishing metabolic fingerprinting and metabolic profiles. Similarly, if fungicide resistance is developed in a pathogen, the metabolome will change, which can be identified. In this review, we have discussed the principles and advanced applications of metabolomics in the study of MOAs and resistance mechanisms of fungicides, and the potential of metabolic data in understanding the interaction between fungicides and pathogens. Challenges are also discussed in the application of metabolomics, improvement of the study on the mechanism of fungicides in their functions against pathogens and advancing the development of novel fungicides.

A novel coated urea (MVCU) was prepared, and its application effect was verified by field trials of oilseed rape in three main cultivation areas. Meanwhile, the nutrient release and coating layer changes of MVCU in static water at 25 °C and different soils were systematically evaluated. MVCU showed a long nutrient release time under static water (77 days) and soil incubation (140 days) conditions due to the slow degradation of the coating layer in MVCU, and its nitrogen release coincided well with oilseed rape nitrogen demand. The above results were further confirmed by FT-IR spectra and SEM analysis. Compared with conventional urea (U), the field trials of MVCU in the three main cultivation areas showed high nitrogen utilization efficiency and yield advantages in oilseed rape. The field trials results indicated that the MVCU significantly enhanced the aboveground dry matter (28.7%), the seed nitrogen concentration (9.5%) and aboveground nitrogen accumulation (42.5%) of oilseed rape at the mature stage as compared to that of the U. The oilseed rape yield enhanced by 932.8 kg/hm2, the average growth rate was 65.1%, and nitrogen utilization efficiency increased by 21.2%. In short, MVCU has the advantages of excellent slow-release performance and strong applicability, and its yield-increasing effect on oilseed rape could reach or even be better than that of traditional fertilization.

Plant growth-promoting rhizobacteria (PGPR) such as Bacillus and Pseudomonas have drawn broad attention and interest due to their agricultural benefits. One of the major benefits of PGPR lies at their biocontrol capabilities against various plant pathogens. The biocontrol capability of PGPR is closely related to its capability of producing various kinds of antimicrobial substances. Major antimicrobial secondary metabolites secreted by PGPR include non-ribosomal lipopeptides (NRLPs), polyketides, ribosomal peptides, phenazines, pyrrolnitrins, etc. This review focuses on the major antimicrobial secondary metabolites produced by Bacillus and Pseudomonas including their classifications, structures, mechanisms of action and genetic regulations. We have also discussed their applications in plant biocontrol and provided insights into future development of improved biocontrol strains using synthetic biology approaches.

Boscalid is a pesticide with the advantages of broad spectrum bactericidal activity, high efficiency, low toxicity, and no cross-resistance with other fungicides currently available on the market. Herein, we report the synthesis of 4′-chloro-2-nitrobiphenyl, a key intermediate of Boscalid using a palladium-catalyzed Suzuki-Miyaura cross-coupling employing the 2-aryl-substituted indenyl phosphine ligand. 4′-Chloro-2-nitrobiphenyl was prepared in 94 % yield on a 100 g scale. This method allows for the industrial production of alimide and active substances bearing a biphenyl moiety.

Δ3-carene is a prominent monoterpene in the atmosphere, contributing significantly to secondary organic aerosol (SOA) formation. However, knowledge about Δ3-carene oxidation pathways, particularly regarding their ability to form highly oxygenated organic molecules (HOMs), is still limited. In this study, we present HOM measurements during Δ3-carene ozonolysis under various conditions in two simulation chambers. We identified numerous HOMs (monomers: C7−10H10−18O6−14; dimers: C17−20H24−34O6−18) using a chemical ionization mass spectrometer (CIMS). Δ3-carene ozonolysis yielded higher HOM concentrations than α-pinene, with a distinct distribution, indicating differences in formation pathways. All HOM signals decreased considerably at lower temperatures, reducing the estimated molar HOM yield from ∼ 3 % at 20 °C to ∼ 0.5 % at 0 °C. Interestingly, the temperature change altered the HOM distribution, increasing the observed dimer-to-monomer ratios from roughly 0.8 at 20 °C to 1.5 at 0 °C. HOM monomers with six or seven O atoms condensed more efficiently onto particles at colder temperatures, while monomers with nine or more O atoms and all dimers condensed irreversibly even at 20 °C. Using the gas- and particle-phase chemistry kinetic multilayer model ADCHAM, we were also able to reproduce the experimentally observed HOM composition, yields, and temperature dependence.

Coffee is a significant commodity trend, with numerous coffee shops rapidly established in Indonesia. The development of this industry has led to an increased discharge of coffee grounds into the environment. The discarded grounds contain oil which can be optimized using various methods and serve as a raw material for biodiesel. Therefore, this study aimed to compare the maceration and ultrasonic methods of extracting coffee grounds. The comparison focused on yield, mass transfer value (diffusivity), and extraction speed constant based on the proposed mathematical model. The results showed a yield of 12.1% and 16%, for the maceration and ultrasonic methods, respectively. Diffusivity value was registered at 9.99 x 10-11 m2/min and 9.8 x 10-10 m2/min, while extraction speed constant values were discovered to be 0.2 m/min and 1.798 m/min, respectively. Additionally, the energy evaluation of ultrasonic extraction produced a Gibbs energy value of -3765.72 Joules.

Solubility in penetrating the follicles is the main obstacle in the formulation of hair growth serum preparation with chemicals derived from natural or synthetic materials. Therefore, a delivery system is needed to deliver more chemical compounds into the follicles. Nanoparticles and nanoliposomes are potential chemical compound delivery systems in hair growth serum. Specifically, nanoparticles with a particle size of less than 200 nm can increase the transport of serum chemical compounds into the scalp. The small particle size makes the interaction between atoms and molecules faster and prevents clumping with the repulsive force of dispersed particles. Meanwhile, nanoliposomes with lipids as encapsulation in the delivery of lipophilic or hydrophilic chemical compounds with nanosizes can significantly increase serum diffusion on the scalp.

Biobriquettes are a biomass fuel with high calorific value. This study aims to determine the optimal conditions for the particle size of husk charcoal and the addition of vinasse waste as an independent variable, using the Response Surface Methodology and the Central Composite Design (CCD) method on Design Expert 13 software. The sample mixed with tapioca starch (8:1), which acts as an adhesive, and add vinasse waste in 3, 6, 9, and 12 mL amounts. Carbonization process, which is then mashed and sieved according to particle sizes of 20, 30, 40, 50, and 60 mesh. Then, the sample is mixed with tapioca starch as adhesive with the ratio of charcoal and adhesive 8:1 as well as vinasse waste in volumes of 3, 6, 9, and 12 mL. The resulting briquette samples were tested in the form of water content, ash content, and calorific value tests. The optimum conditions that have a significant effect on the response variable are the combination of particle size variables of 35.152 mesh and the volume of vinasse waste of 6.049 mL. The moisture content obtained was 6.696%., The ash content was 5.450%, and the calorific value was 5003.399 cal/g with a desirability value of 0.927 in the quadratic model.

The Copernicus Atmosphere Monitoring Service (CAMS) provides daily analyses and forecasts of the composition of the atmosphere, including the reactive gases such as O3, CO, NO2, HCHO and SO2; aerosol species; and greenhouse gases. The global CAMS analysis system (IFS-COMPO) is based on the ECMWF Integrated Forecasting System (IFS) for numerical weather prediction (NWP) and assimilates a large number of composition satellite products on top of the meteorological observations ingested in IFS. The CAMS system receives regular upgrades, following the upgrades of IFS. The last upgrade, Cy48R1, operational since 27 June 2023, was major with a large number of code changes, both for IFS-COMPO and for NWP. The main IFS-COMPO innovations include the introduction of full stratospheric chemistry; a major update of the emissions; a major update of the aerosol model, including the representation of secondary organic aerosol; several updates of the dust life cycle and optics; updates to the inorganic chemistry in the troposphere; and the assimilation of Visible Infrared Imaging Radiometer Suite (VIIRS) aerosol optical depth (AOD) and TROPOspheric Monitoring Instrument (TROPOMI) CO. The CAMS Cy48R1 upgrade was validated using a large number of independent measurement datasets, including surface in situ, surface remote sensing, routine aircraft, and balloon and satellite observations. In this paper we present the validation results for Cy48R1 by comparing them with the skill of the previous operational system (Cy47R3), with the independent observations as reference, for the period October 2022 to June 2023, during which daily forecasts from both cycles are available. Major improvements in skill are found for the ozone profile in the lower–middle stratosphere and for stratospheric NO2 due to the inclusion of full stratospheric chemistry. Stratospheric trace gases compare well with the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) observations between 10 and 200 hPa, with larger deviations between 1 and 10 hPa. The impact of the updated emissions is especially visible over East Asia and is beneficial for the trace gases O3, NO2 and SO2. The CO column assimilation is now anchored by the Infrared Atmospheric Sounding Interferometer (IASI) instead of the Measurements Of Pollution in The Troposphere (MOPITT) instrument, which is beneficial for most of the CO comparisons, and the assimilation of TROPOMI CO data improves the model CO field in the troposphere. In general the aerosol optical depth has improved globally, but the dust evaluation shows more mixed results. The results of the 47 comparisons are summarised in a scorecard, which shows that 83 % of the evaluation datasets show a neutral or improved performance of Cy48R1 compared to the previous operational CAMS system, while 17 % indicate a (slight) degradation. This demonstrates the overall success of this upgrade.

Lockdown restrictions in response to the COVID-19 pandemic led to the curtailment of many activities and reduced emissions of primary air pollutants. Here, we applied positive matrix factorisation to particle size distribution (PSD) data from six monitoring sites (three urban background and three roadside) between four European cities (Helsinki, Leipzig, Budapest, and London) to evaluate how particle number concentrations (PNCs) and their sources changed during the respective 2020 lockdown periods compared to the reference years 2014–2019. A number of common factors were resolved between sites, including nucleation, road traffic semi-volatile fraction (road trafficsvf), road traffic solid fraction (road trafficsf), diffuse urban (wood smoke + aged traffic), ozone-associated secondary aerosol (O3-associated SA), and secondary inorganic aerosol (SIA). Nucleation, road traffic, and diffuse urban factors were the largest contributors to mean PNCs during the reference years and respective lockdown periods. However, SIA factors were the largest contributors to particle mass concentrations, irrespective of environment type. Total mean PNCs were lower at two of the urban-background and all roadside sites during lockdown. The response of nucleation and road trafficsvf factors to lockdown restrictions was highly variable, although road trafficsf factors were consistently lower at roadside sites. The responses of diffuse urban factors were largely consistent and were mostly lower at urban-background sites. Secondary aerosols (O3-associated SA and SIA) exhibited extensive reductions in their mean PNCs at all sites. These variegated responses to lockdowns across Europe point to a complex network of sources and aerosol sinks contributing to PSDs.

Aerosol effective radiative forcing (ERF) has persisted as the most uncertain aspect of anthropogenic forcing over the industrial period, limiting our ability to constrain estimates of climate sensitivity and to confidently predict 21st century climate change. Aerosol–cloud interactions are the most uncertain component of aerosol ERF. The 2014–2015 Holuhraun volcanic eruption acted as a large source of sulfur dioxide, providing an opportunistic experiment for studying aerosol–cloud interactions at a climatically relevant scale. We evaluate the observed aerosol-induced perturbation to marine liquid cloud properties inside the volcanic plume in the first month of the eruption and compare the results to those from UKESM1 (UK Earth System Model). In the first 2 weeks, as expected, we find an in-plume shift to smaller and more numerous cloud droplets in both the observations and the simulations. We find an observed increase in liquid water path (LWP) values inside the plume that is not captured in UKESM1. However, in the third week, the in-plume shift to smaller and more numerous cloud droplets is neither observed nor modelled, and there are discrepancies between the observed and modelled response in the fourth week. An analysis of the model simulations and trajectory modelling reveals that air mass history and background meteorological factors can strongly influence aerosol–cloud interactions between the weeks of our analysis. Overall, our study supports the findings of many previous studies: the aerosol impact on cloud effective radius is significant, with differences in the observed and modelled response for in-cloud LWP.

The fraction of urban volatile organic compound (VOC) emissions attributable to fossil fuel combustion has been declining in many parts of the world, resulting in a need to better constrain other anthropogenic sources of these emissions. During the National Institute of Environmental Research (NIER) and National Aeronautics and Space Administration (NASA) Korea-United States Air Quality (KORUS-AQ) field study in Seoul, South Korea, during May–June 2016, air quality models underestimated ozone, formaldehyde, and peroxyacetyl nitrate (PAN), indicating an underestimate of VOCs in the emissions inventory. Here, we use aircraft observations interpreted with the GEOS-Chem chemical transport model (version 13.4.0) to assess the need for increases in VOC emissions and for a revised chemical mechanism to improve treatment of VOC speciation and chemistry. We find that the largest needed VOC emissions increases are attributable to compounds associated with volatile chemical products, liquefied petroleum gas (LPG) and natural gas emissions, and long-range transport. Revising model chemistry to better match observed VOC speciation together with increasing model emissions of underestimated VOC species increased calculated OH reactivity by +2 s−1 and ozone production by +2 ppb h−1. Ozone increased by +6 ppb below 2 km and +9 ppb at the surface, and formaldehyde and acetaldehyde increased by +30 % and +120 % aloft, respectively, all in better agreement with observations. The larger increase in acetaldehyde was attributed to ethanol emissions, which we found to be as important for ozone production as isoprene or alkenes. The increased acetaldehyde significantly reduced the model PAN bias. The need for additional unmeasured VOCs, however, was indicated by a remaining model bias of −0.8 ppb in formaldehyde and a −57 % and −52 % underestimate in higher peroxynitrates (PNs) and alkyl nitrates (ANs), respectively. We added additional chemistry to the model to represent an additional six PNs from observed VOCs but were unable to account for the majority of missing PNs. However, four of these PNs were modeled at concentrations similar to other commonly measured PNs (> 2 % of PAN) indicating that these should be measured in future campaigns and considered from other VOC emission sources (e.g., fires). We hypothesize that emissions of oxygenated VOCs (OVOCs) such as ≥ C5 aldehydes from cooking and/or alkenes associated with volatile chemical products could produce both PNs and ANs and improve remaining model biases. Emerging research on the emissions and chemistry of these species will soon allow for modeling of their impact on local and regional photochemistry.

Ozone (O3) is an important secondary pollutant that impacts air quality and human health. Eastern Asia has high regional O3 background due to the numerous sources and increasing and rapid industrial growth, which also impacts the Seoul Metropolitan Area (SMA). However, the SMA has also been experiencing increasing O3 driven by decreasing NOx emissions, highlighting the role of the local in situ O3 production on the SMA. Here, comprehensive gas-phase measurements collected on the NASA DC-8 during the National Institute of Environmental Research (NIER)/NASA Korea–United States Air Quality (KORUS-AQ) study are used to constrain the instantaneous O3 production rate over the SMA. The observed NOx oxidized products support the importance of non-measured peroxy nitrates (PNs) in the O3 chemistry in the SMA, as they accounted for ∼49 % of the total PNs. Using the total measured PNs (ΣPNs) and alkyl and multifunctional nitrates (ΣANs), unmeasured volatile organic compound (VOC) reactivity (R(VOC)) is constrained and found to range from 1.4–2.1 s−1. Combining the observationally constrained R(VOC) with the other measurements on the DC-8, the instantaneous net O3 production rate, which is as high as ∼10 ppbv h−1, along with the important sinks of O3 and radical chemistry, is constrained. This analysis shows that ΣPNs play an important role in both the sinks of O3 and radical chemistry. Since ΣPNs are assumed to be in a steady state, the results here highlight the role that ΣPNs play in urban environments in altering the net O3 production, but ΣPNs can potentially lead to increased net O3 production downwind due to their short lifetime (∼1 h). The results provide guidance for future measurements to identify the missing R(VOCs) and ΣPN production.

Through the Bayesian lens of four-dimensional variational (4D-Var) data assimilation, uncertainty in model parameters is traditionally quantified through the posterior covariance matrix. However, in modern settings involving high-dimensional and computationally expensive forward models, posterior covariance knowledge must be relaxed to deterministic or stochastic approximations. In the carbon flux inversion literature, (Chevallier et al., 2007) proposed a stochastic method capable of approximating posterior variances of linear functionals of the model parameters that is particularly well suited for large-scale Earth-system 4D-Var data assimilation tasks. This note formalizes this algorithm and clarifies its properties. We provide a formal statement of the algorithm, demonstrate why it converges to the desired posterior variance quantity of interest, and provide additional uncertainty quantification allowing incorporation of the Monte Carlo sampling uncertainty into the method's Bayesian credible intervals. The methodology is demonstrated using toy simulations and a realistic carbon flux inversion observing system simulation experiment.

Using spaceborne lidar and radar observations, this study identifies deep convection systems (DCSs), including deep convection cores (DCCs) and anvils, over the Tibetan Plateau (TP) and tropical Indian Ocean (TO) and finds that DCSs over the TP are less frequent, exhibiting narrower and thinner DCCs and anvils compared to those over the TO. The thinner DCCs over the TP exert weaker radiative cooling effects at the top of atmosphere (TOA) compared to the TO. But, the shortwave TOA cloud radiative effect (CRE) of TP anvils is stronger than that of the TO possibly due to more densely packed cloud tops over the TP. It results in a stronger TOA CRE of DCSs over the TP than that of TO. In particular, the longwave CRE of DCSs over the TP is notably greater at surface and low-level atmosphere due to the distinct lower temperature and less water vapour. The width of DCSs shows a positive correlation with wind shear and atmospheric instability, and the underlying mechanisms are discussed. We also find that the impact of aerosols on cloud top heights and precipitation displays significant discrepancies between the two regions. It is because that the aerosol invigoration effect is less efficient on the TP DCSs, mainly attributed to the significantly colder cloud base. Due to competition between invigoration and direct/semi-direct radiative effects of aerosols, the correlation between precipitation and aerosols over the TP is not obvious. However, precipitation in the TO experiences invigoration followed by suppression with increasing aerosols, due to the dominance of aerosol radiative effects and enhancement entrainment under polluted conditions.

Carvone belongs to the chemical family of terpenoids and is the main component of various plant oils. Carvone and its hydrogenated products are used in the flavouring and food industries. A quantitative thermodynamic analysis of the general network of carvone hydrogenation reactions was performed based on the thermochemical properties of the starting carvone and all possible intermediates and end products. The enthalpies of vaporisation, enthalpies of formation, entropies and heat capacities of the reactants were determined by complementary measurements and a combination of empirical, theoretical and quantum chemical methods. The energetics and entropy change in the hydrogenation and isomerisation reactions that take place during the conversion of carvone were derived, and the Gibbs energies of the reactions were estimated. It was shown that negative Gibbs energies are recorded for all reactions that may occur during the hydrogenation of carvone, although these differ significantly in magnitude. This means that all these reactions are thermodynamically feasible in a wide range from ambient temperature to elevated temperatures. Therefore, all these reactions definitely take place under kinetic and not thermodynamic control. Nevertheless, the numerical Gibbs energy values can help to establish the chemoselectivity of catalysts used to convert carvone to either carvacarol or to dihydro- and terahydrocarvone, either in carvotanacetone or carveol.

Eleven new differently substituted N,7-diphenylpyrimido [4,5-d]pyrimidin-4-amines 4a–k were synthesized from readily available reagents in a simple and inexpensive two-step procedure with yields up to 57%. Neuroprotective analysis against H2O2 and analysis using ORAC assays identified compounds 4g, 4i and 4j as promising antioxidant compounds. These compounds also showed potent inhibition of Aβ1–42 self-aggregation, and suitable physicochemical properties predicted by Datawarior software V6.1.0, this biological activity and physicochemical property being of great interest for pathologies linked to oxidative stress, such as Alzheimer’s disease.

“Are we asking the right questions?” seems cliché, but for ChatGPT, it is a pivotal tool to ensure the accuracy of responses. While ChatGPT-3.5’s training on the vast database promises to revolutionize STEM education and research, this investigation shows the importance of precise communication and prompt engineering in guiding ChatGPT-3.5 toward reliable and accurate responses, particularly in chemistry. For instance, emphasizing context, clearly defining symbols, and focusing on field-specific instructions can dramatically improve its performance. Furthermore, avoiding open-ended prompts and strategically using repetition can further enhance its accuracy. The iterative prompt design, demonstrated through a series of adjustments, illustrates how seemingly minor refinements, such as substituting “least” for “lowest”, profoundly impact the output. This study highlights the essential role of human oversight, including the construction of well-crafted prompts, in guarding reliable information and nurturing a productive “Human–AI” (HAI) partnership.

Three amidine-based ligands were used in the crystal design of a series of mononuclear Zn(II) complexes. Interaction of zinc chloride, ZnCl2, with N-2-pyridylimidoyl-2-pyridylamidine (Py2ImAm) resulted in complexes [Zn(Py2ImAm)2] (1) and [ZnCl2(Py2ImAm)] (2). In [Zn(Py2ImAm)2] (1, monoclinic, P21/c), the metal ion was coordinated with the bidentate pocket of the anionic form of Py2ImAm, while in [ZnCl2(Py2ImAm)] (2, monoclinic, P21/n), the tridentate coordination to a neutral Py2ImAm was completed by two chloride anions. This structural variation was achieved by a pH-controlling strategy using the weak base triethylamine (TEA). Otherwise, three ionic complexes were obtained with 2-amidinopyridine (PyAm) and Zinc(II), [ZnCl(PyAm)2]Cl (3, triclinic, P-1), [ZnCl(PyAm)2]2[ZnCl4]·C2H5OH (4, monoclinic, P21/n), and [ZnCl(PyAm)2]2Cl·CH3OH (5, triclinic, P-1). They comprised the same [ZnCl(PyAm)2]+ monocation with a butterfly-like shape provided by the bidentate chelate coordination of two PyAm neutral entities and a chloride ligand. In a similar butterfly shape, ionic complex [ZnCl(PmAm)2]2[ZnCl4] (6, monoclinic, C2/c) comprised the mononuclear [ZnCl(PmAm)2]+ cations with two bidentate chelate-coordinated 2-amidinopyrimidine (PmAm) as neutral ligands. The Zn(II) pentacoordinated arrangement in 3–6 was variable, from square pyramidal to trigonal bipyramidal. The reported compounds’ synthetic protocols, crystal structures and photoluminescence properties are discussed.

Aaptamine (8,9-dimethoxy-1H-benzo[de][1,6]naphthyridine), an alkaloid obtained from marine sponges of the genus Aaptos (Demospongiae, Suberitida, Suberitidae), has attracted significant attention as a promising scaffold for the development of antioxidant, antibacterial, and anticancer agents. This review offers an extensive overview of updated research on aaptamine, focusing on its multifaceted pharmacological properties. The antioxidant potential of aaptamine reflects its potential ability for use in the DPPH free radical scavenging assay, for suppressing ROS, and subsequently deactivating the MAPK and AP-1 signaling pathway. Moreover, it demonstrates notable antibacterial activity against pathogenic bacteria, including mycobacterial active and dormant states, making it a potential candidate for combating bacterial infections. Additionally, aaptamine shows promising anticancer activity by inhibiting cancer cell proliferation, apoptosis induction, and suppressing tumor growth through various signaling pathways, including the regulation of PTEN/PI3K/Akt and CDK2/4, and the regulation of cyclin D1/E in cell cycle arrest. The unique chemical structure of aaptamine offers opportunities for structural modifications aimed at enhancing its antioxidant, antibacterial, and anticancer activities. The exploration of aaptamine as a scaffold in the development of novel therapeutic agents offers great promise for addressing various challenges associated with oxidative stress, bacterial infections, and cancer. This article underscores the potential of aaptamine as a valuable marine-derived scaffold in the fields of antioxidant, antibacterial, and anticancer therapy.

A set of Pd-containing composites was prepared by the deposition of Pd on the following carriers: polyaniline (PANI); PANI doped by H2SO4; Norit GSX activated carbon or Aerosil (SiO2) coated by PANI or by H2SO4-doped PANI; PANI after thermal treatment at 300 °C in an atmosphere of H2. One sample was also prepared by the in situ polymerization of aniline in the presence of Pd2+· The decomposition of Pd was carried out via deposition from the solutions of Pd2+ salts or decomposition of Pd0 complex Pd2(dba)3, where dba is dibenzylideneacetone. The composites were studied by powder X-ray diffraction, transmission electron microscopy, IR and Raman spectroscopy. The hydrogenation of quinoline in the presence of composites was carried out; the catalytic performance of the composites was evaluated by the yield of 1,2,3,4-tetrahydroquinoline. It was found that the doping of PANI by H2SO4, inclusion of Norit GSX activated carbon as a component of the carrier or thermal treatment of PANI prior to the deposition of Pd led to significant increase in the catalytic performance of the composites in the hydrogenation of quinoline.

A novel dicoumarol-based copolyester was synthesized via a one-step polycondensation reaction using titanium tetraisopropoxide (TTIP) as a catalyst. The copolyester was characterized using Fourier transform infrared spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) spectroscopy (1H and 13C), and Differential Scanning Calorimetry (DSC). Scanning electron microscopy (SEM) was used to examine the surface morphology before and after degradation. The synthesized copolyester exhibited toxicity against MCF-7 breast cancer cells, with an IC50 value of 62.5 μg/mL, and demonstrated potential as a drug carrier with a consistent drug-release rate. The combination of dicoumarol, itaconic acid, and 1,12-dodecanediol in the copolyester enhances its biomedical capabilities, with dicoumarol providing anticancer properties, itaconic acid offering biocompatibility and mechanical stability, and 1,12-dodecanediol ensuring structural integrity and responsiveness. This study presents the first example of a dicoumarol-substituted copolyester, which was thoroughly characterized and shown to have promising biocompatibility for targeted anticancer therapy. The synthesis of this novel copolyester from renewable sources highlights the growing interest in sustainable materials for pharmaceutical and biomedical applications, particularly in drug delivery and tissue engineering for cancer treatment.

A pyridine–tricarboxylic acid, 4-(6-carboxy-pyridin-3-yl)-isophthalic acid (H3cpia), was used as a versatile building block to synthesize three novel coordination polymers under hydrothermal conditions and formulated as [Mn8(μ3-Hcpia)2 (μ6-cpia)4(Hbiim)2(H2O)6]n·6nH2O (1), [Cu3(μ4-cpia)2(bipy)2(H2O)2]n·4nH2O (2), and [Ni3(μ3-cpia)2(dpe)3(H2O)2]n·4nH2O (3). Three supporting ligands, 2,2′-biimidazole (H2biim), 2,2′-bipyridine (bipy), and 1,2-di(4-pyridyl)ethane (dpe), were used in the synthesis. The structures of the studied products 1–3 varied significantly, ranging from a 1D chain (2) to 2D sheets (1 and 3). Furthermore, these compounds were evaluated as heterogeneous catalysts for the Henry reaction, achieving high product yields under optimized conditions. In addition, we investigated various reaction parameters and substrate scopes, and assessed the feasibility of catalyst recycling. This thorough investigation’s results highlight the versatility of H3cpia as a tricarboxylate building block in the formation of functional coordination polymers.

Organometallic ruthenium complexes with p-cymene = 1-methyl-4-(1-methylethyl)-benzene and N^N = bidentate polypyridyl ligands constitute interesting candidates with biological and catalytic properties. Towards this aim, we have synthesized four ruthenium(II)–arene complexes of the type [Ru(η6-p-cymene)(N^N)Cl][X] (N^N = Br-Qpy = 6-bromo-4-phenyl-2-pyridin-2-yl-quinoline, X = Cl− (1a); PF6− (1b); N^N = OH-Ph-Qpy = 4-(4-phenyl-2-(pyridin-2-yl)quinolin-6-yl)phenol, X = Cl− (2a); PF6− (2b)). This is the first report of ruthenium(II) p-cymene complexes incorporating substituted pyridine–quinoline ligands, with –Br and –C6H4OH groups in the 6-position of quinoline. We also refer to the cytotoxicity of the ligands and their possible effect of modulating the activity of the ruthenium(II) complexes. These were characterized by a combination of spectroscopic methods (ATR-IR, UV–Vis, multinuclear NMR), elemental analysis, and conductivity measurements. The solid-state structure of 2b, determined by single-crystal X-ray diffraction, reveals a three-legged piano-stool geometry. The in vitro cytotoxic activities of the new complexes were evaluated in HEK293T (human embryonic kidney cells) and in HeLa cells (cervical cancer cells), via the MTT assay. Poor in vitro anticancer activities were observed for the HeLa cancer cell line, with 2a being the most potent (IC50 = 75 μΜ). The cytotoxicity of Br-Qpy in HEK293T is comparable to that of cisplatin. Both complexes 1a and 1b successfully catalyze the transfer hydrogenation of benzophenone to benzhydrol by 2-propanol at 82 °C. The catalytic performance of 1a in the ratio of S:Cat:B = 400:1:40 (S = substrate, Cat = catalyst, B = base = KOiPr) leads to a conversion of 94%, within 3 h of reaction. Presumably, catalytic transformation takes place via ruthenium(II) hydride species being the active catalyst.

Ammonia (NH3) has major effects on the environment and climate. In situ measurements of NH3 concentrations taken between June 2009 and July 2020 at an urban site in Beijing were analyzed to study its long-term behavior, responses to meteorological conditions, and influences on the formation of secondary inorganic aerosols (SIAs). The 11-year average NH3 mixing ratio was 26.9±19.3 ppb (median 23.5 ppb). The annual average NH3 mixing ratio increased from 2009 to 2017 by 50 % and then decreased by 49 % from 2017 to 2020. Notably, the long-term trend for NH3 at the ground level did not align with the trends derived from satellite observations and emission estimates. The NH3 concentration exhibited a stronger correlation with the daily variation in water vapor (H2O) concentration than with air temperature. Thermodynamic modeling revealed the nonlinear response of SIAs to NH3, with increased sensitivity when its concentration was reduced to 40 % of the initial level. Although reducing NH3 concentrations can improve air quality during winter, controlling acid gas concentrations has a greater effect than controlling NH3 concentrations on reducing SIA concentrations, until NH3 and acidic gas concentrations are reduced below 80 % of their current levels. Nevertheless, the increased mass proportion of ammonium salts in SIAs during the observation period indicates that future control measures for NH3 concentrations may need to be prioritized in Beijing.

The optical, physical, and chemical properties of aerosol particles have been previously studied in the United Arab Emirates (UAE), but there is still a gap in the knowledge of particle sources and in the horizontal and vertical transport of aerosol particles and their precursors in the area. To investigate how aerosol particle and SO2 concentrations at the surface responded to changes in horizontal and vertical transport, we used data from a 1-year measurement campaign at a background site where local sources of SO2 were expected to be minimal. The measurement campaign provided a combination of in situ measurements at the surface and the boundary layer evolution from vertical and horizontal wind profiles measured by a Doppler lidar. The diurnal structure of the boundary layer in the UAE was very similar from day to day, with a deep, well-mixed boundary layer during the day transitioning to a shallow nocturnal layer, with the maximum boundary layer height usually being reached around 14:00 local time. Both SO2 and nucleation-mode aerosol particle concentrations were elevated for surface winds coming from the east or western sectors. We attribute this to oil refineries located on the eastern and western coasts of the UAE. The concentrations of larger cloud condensation nuclei (CCN)-sized particles and their activation fraction did not show any clear dependence on wind direction, but the CCN number concentration showed some dependence on wind speed, with higher concentrations coinciding with the weakest surface winds. Peaks in SO2 concentrations were also observed despite low surface wind speeds and wind directions unfavourable for transport. However, winds aloft were much stronger, with wind speeds of 10 m s−1 at 1 km common at night and wind directions favourable for transport; surface-measured concentrations increased rapidly once these particular layers started to be entrained into the growing boundary layer, even if the surface wind direction was from a clean sector. These conditions also displayed higher nucleation-mode aerosol particle concentrations, i.e. new particle formation events occurring due to the increase in the gaseous precursor.

Aerosol hygroscopic growth and activation under high-relative-humidity (RH) conditions significantly influence the physicochemical properties of submicron aerosols (PM1). However, this process remains poorly characterized due to limited measurements. To address this gap, we deployed an advanced aerosol–fog sampling system that automatically switched between PM1, PM2.5 and total suspended particulate (TSP) inlets at a rural site in the North China Plain in the cold season. The results revealed that aerosol swelling due to water vapor uptake influenced aerosol sampling under high-RH conditions by shifting the cut-off size of impactors. At subsaturated high RH (> 90 %), over 25 % of aerosol mass with dry diameters below 1 µm resided in supermicron ranges, while in supersaturated foggy conditions, more than 70 % of submicron aerosol migrated to supermicron ranges. Hygroscopic growth and activation particularly affected highly hydrophilic inorganic salts, shifting a significant number of submicron sulfate and nitrate particles to supermicron ranges, with 27 %–33 % at 95 % ≤ RH ≤ 99 % and more than 78 % under supersaturated foggy conditions. Moreover, more than 10 % of submicron biomass burning organic aerosols grew beyond 2.5 µm during fog events, while fossil-fuel-related organic aerosol (FFOA) remained dominantly in submicron ranges, suggesting inefficient aqueous conversion of FFOA. The two secondary organic aerosol (SOA) factors (OOA1 and OOA2) behaved differently under supersaturated conditions, with OOA2 exhibiting a higher activated fraction despite a lower oxygen / carbon ratio. A substantial increase in organic nitrate and organosulfur mass concentrations in activated droplets during fog events suggested aqueous conversions and formations of brown carbon with potential radiative impacts. Overall, our study highlights remarkably different cloud and fog processing behaviors between primary and secondary aerosols, which would benefit a better understanding of aerosol–cloud interactions under distinct atmospheric conditions.

Norpinonic acid has been known as an important α-pinene atmospheric secondary organic aerosol (SOA) component. It is formed in the reaction of α-pinene, β-pinene or verbenone with atmospheric oxidizing reagents. In the presented study, tandem mass spectrometry techniques were used to determine the exact norpinonic acid fragmentation pathway in the gas phase. The precursor anion – deprotonated norpinonic acid (m/z 169), generated in an electrospray (ESI) source – was introduced into the collision cell of the mass spectrometer and fragmented using the energy-resolved collision-induced dissociation (ER-CID) technique. The experimental energy values of degradation processes were determined via analysis of the breakdown curves. Quantum chemical calculations of the reaction models were also constructed, including calculation of all transition states. Comparison between the experimental and the theoretical threshold energies calculated at a ωB97XD/6-311+G(2d,p) theoretical level has shown a good correlation. Two basic pathways of the fragmentation of the parent anion [M-H]− (m/z 169) were observed. Firstly this leads to the decarboxylation product (m/z 125) and secondly to the loss of a neutral molecule (C4H6O), together with the formation of the anion m/z 99. On the other hand, the breakdown of the anion m/z 125 gives rise to the m/z 69, 57 and 55 ions. To confirm structures formed during ER-CID experiments, the gas-phase proton transfer reactions were examined of all norpinonic acid anionic fragments with a series of neutral reagents, characterized by proton affinity (PA) values. Based on PA difference analysis, the most possible chemical structures were proposed for the observed fragment anions.

Clouds play a vital role in regulating Earth's energy balance and are impacted by anthropogenic aerosol concentration (Na) and sea surface temperature (SST) alterations. Traditionally, these factors, aerosols and SST, are investigated independently. This study employs cloud-resolving, radiative–convective-equilibrium (RCE) simulations to explore aerosol–cloud interactions (ACIs) under varying SSTs. ACIs are found to be SST-dependent even under RCE conditions. Notably, changes in cloud radiative effects for both longwave radiation and shortwave radiation lead to a decrease in top-of-atmosphere (TOA) energy gain with increasing Na. The changes in TOA shortwave flux exhibit greater sensitivity to underlying SST conditions compared to longwave radiation. To comprehend these trends, we perform a linear decomposition, analyzing the responses of different cloud regimes and contributions from changes in the cloud's opacity and occurrence. This breakdown reveals that ice and shallow clouds predominantly contribute to the radiative effect, mostly due to changes in the cloud's opacity and due to the Twomey effect, which is proportional to the baseline cloud fraction. Moreover, with an increase in Na, we observe an increase in latent heat release at the upper troposphere associated with heightened production of snow and graupel. We show that this trend, consistently across all SSTs, affects the anvil cloud cover by affecting the static stability at the upper troposphere via a similar mechanism to the stability iris effect, resulting in an increase in outgoing longwave radiation. In conclusion, under the ongoing climate change, studying the sensitivity of clouds to aerosols and SST should be conducted concomitantly as mutual effects are expected.