Direct Detection of Viral Infections from Swab Samples by Probe‐Gated Silica Nanoparticle‐Based Lateral Flow Assay

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Direct Detection of Viral Infections from Swab Samples by Probe-Gated Silica Nanoparticle-Based Lateral Flow Assay

Here, universal-modifiable probe-gated silica nanoparticles (SNPs) based lateral flow assay (LFA) is developed in the interest of the rapid and early detection of viral infections. The most superior advantage of the rapid assay is its utility in detecting various sides of the virus directly from the human swab samples and its adaptability to detect various types of viruses. The NSP12, NSP9, and E gene targets of CoV-2 were used as detection targets.


Abstract

Point-of-care diagnosis is crucial to control the spreading of viral infections. Here, universal-modifiable probe-gated silica nanoparticles (SNPs) based lateral flow assay (LFA) is developed in the interest of the rapid and early detection of viral infections. The most superior advantage of the rapid assay is its utility in detecting various sides of the virus directly from the human swab samples and its adaptability to detect various types of viruses. For this purpose, a high concentration of fluorescein and rhodamine B as a reporting material was loaded into SNPs with excellent loading capacity and measured using standard curve, 4.19 μmol ⋅ g−1 and 1.23 μmol ⋅ g−1, respectively. As a model organism, severe acute respiratory syndrome coronavirus-2 (CoV-2) infections were selected by targeting its nonstructural (NSP9, NSP12) and envelope (E) genes as target sites of the virus. We showed that NSP12-gated SNPs-based LFA significantly outperformed detection of viral infection in 15 minutes from 0.73 pg ⋅ mL−1 synthetic viral solution and with a dilution of 1 : 103 of unprocessed human samples with an increasing test line intensity compared to steady state (n=12). Compared to the RT-qPCR method, the sensitivity, specificity, and accuracy of NSP12-gated SNPs were calculated as 100 %, 83 %, and 92 %, respectively. Finally, this modifiable nanoparticle system is a high-performance sensing technique that could take advantage of upcoming point-of-care testing markets for viral infection detections.

Mikania micrantha Kunth: An Ethnopharmacological Treasure Trove of Therapeutic Potential

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Mikania micrantha Kunth: An Ethnopharmacological Treasure Trove of Therapeutic Potential


Abstract

Mikania micrantha is utilized as a therapeutic for the treatment of various human ailments including insect bites, rashes and itches of skin, chicken pox, healing of sores and wounds, colds and fever, nausea, jaundice, rheumatism, and respiratory ailments. This study aimed at summarizing the traditional uses, phytochemical profile, and biological activities of M. micrantha based on obtainable information screened from different databases. An up-to-date search was performed on M. micrantha in PubMed, Science Direct, clinicaltrials.gov, and Google Scholar databases with specific keywords. No language restrictions were imposed. Published articles, theses, seminar/conference papers, abstracts, and books on ethnobotany, phytochemistry and pharmacological evidence were considered. Based on the inclusion criteria, this study includes 53 published records from the above-mentioned databases. The results suggest that fresh leaves and whole plant are frequently used in folk medicine. The plant contains more than 150 different phytochemicals under the following groups: essential oils, phenolics and flavonoids, terpenes, terpene lactones, glycosides, and sulfated flavonoids. It contains carbohydrates and micronutrients including vitamins and major and trace minerals. M. micrantha possesses antioxidant, anti-inflammatory, anti-microbial, anti-dermatophytic, anti-protozoal, anthelmintic, cytotoxic, anxiolytic, anti-diabetic, lipid-lowering and antidiabetic, spasmolytic, memory-enhancing, wound-healing, anti-aging, and thrombolytic activities. No clinical studies have been reported to date. M. micrantha might be one of the potential sources of phytotherapeutic compounds against diverse ailments in humans. Studies are required to confirm its safety profile in experimental animals prior to initiating clinical trials. Moreover, adequate investigation is also crucial to clarify exact mechanism of action for each biological effect.

Exploring the Substrate Switch Motif of Aromatic Ammonia Lyases

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Exploring the Substrate Switch Motif of Aromatic Ammonia Lyases

Using a bioinformatic approach, we identified novel substrate switch motifs of aromatic ammonia lyases. These alternative amino acids were introduced into a tyrosine ammonia lyase (TAL rpc ). The characterization of these enzyme variants revealed a significant (up to 20-fold) improvement in the activity for phenylalanine. A computational analysis could explain these experimental results.


Abstract

Aromatic ammonia lyases (AALs) are important enzymes for biocatalysis as they enable the asymmetric synthesis of chiral l-α-amino acids from the corresponding α,β-unsaturated precursors. AALs have very similar protein structures and active site pockets but exhibit strict substrate specificity towards tyrosine, phenylalanine, or histidine. Herein, through systematic bioinformatics and structural analysis, we discovered eight new motifs of amino acid residues in AALs. After introducing them – as well as four already known motifs – into different AALs, we learned that altering the substrate specificity by engineering the substrate switch motif in phenylalanine ammonia lyases (PALs), phenylalanine/tyrosine ammonia lyases (PTALs), and tyrosine ammonia lyases (TALs) was only partially successful. However, we discovered that three previously unknown residue combinations introduced a substrate switch from tyrosine to phenylalanine in TAL, which was converted up to 20-fold better compared to the wild-type TAL enzyme.

Flower‐like Fe(OH)3 as sulfur hosts for high‐performance lithium–sulfur batteries

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Lithium–sulfur batteries are considered one of the next generation potential candidates for electrochemical energy storage devices owing to their high energy density. However, their practical application presents several challenges that need to be addressed. In this study, a flower-like Fe(OH)3 was obtained using a simple and environmentally friendly one-step injection method, intended to be used as sulfur host in lithium–sulfur batteries. The polar hydroxyl groups in Fe(OH)3 capture free polysulphides in the electrolyte via chemisorption and the unique structure of the material physically entraps polysulphides, thus preventing the shuttle effect. Benefiting from functional group and spatial shape advantages, the resultant S@FH electrode yielded an initial capacity of 1187.6 mAh g−1 at 0.1 C. When the batteries are tested for 100 cycles,the reversible capacity remained at 635.2 mAh g−1 and the coulomb efficiency was nearly 100%.

Study of the Antioxidant, Antimicrobial, and Wound Healing Properties of Raw Hydrolyzed Extract from Nile Tilapia Skin (Oreochromis niloticus)

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Study of the Antioxidant, Antimicrobial, and Wound Healing Properties of Raw Hydrolyzed Extract from Nile Tilapia Skin (Oreochromis niloticus)


Abstract

Oreochromis niloticus (Nile tilapia) skin is a by-product of Brazilian fish farming, rich in collagen. The present study aims to evaluate the wound healing, antioxidant, and antimicrobial potential of the raw hydrolyzed extract of Nile tilapia skin, as well as the identification of the main compounds. The in vitro activity was performed using antioxidant, antimicrobial and scratch wound healing assays. An in vivo experiment was performed to evaluate the wound healing potential. On days 1, 7, 14 and 21, the lesions were photographed to assess wound retraction and on the 7th, 14th and 21st days the skins were removed for histological evaluation and the blood of the animals was collected for glutamic oxaloacetic transaminase and glutamic pyruvic transaminase determination. The chemical study was carried out through liquid chromatography-tandem mass spectrometry and de novo sequencing of peptides. The in vitro assays showed a reduction of the gap area in 24 h, dose-dependent antimicrobial activity for both bacteria, and antioxidant activity. The chemical analysis highlighted the presence of active biopeptides. The histological evaluation showed that the raw hydrolyzed extract of Nile tilapia skin has a healing potential, and does not present toxicological effects; therefore, is promising for the treatment of wounds.

Cellular Mechanistic Considerations on Cytotoxic Mode of Action of Phosphino Ru(II) and Ir(III) Complexes

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Cellular Mechanistic Considerations on Cytotoxic Mode of Action of Phosphino Ru(II) and Ir(III) Complexes

Our study proved that in the case of Ru(II) complexes the intense ROS generation is mainly responsible for the resulting cytotoxicity. The corresponding Ir(III) complexes trigger simultaneously at least three different cytotoxic pathways i. e., depletion of mitochondrial potential, activation of caspases-dependent apoptosis, and ROS-associated oxidation.


Abstract

Two piano-stool ruthenium(II) complexes Ru(η6-p-cymene)Cl2PPh2CH2OH (RuPOH) and Ru(η6-p-cymene)Cl2P(p-OCH3Ph)2CH2OH (RuMPOH) and two half-sandwich iridium(III) complexes Ir(η 5-Cp*)Cl2PPh2CH2OH (IrPOH) and Ir(η 5-Cp*)Cl2P(p-OCH3Ph)2CH2OH (IrMPOH) have been studied in terms of potential anticancer activity on previously selected cell line (human lung adenocarcinoma). Based on experimental results obtained in monoculture in vitro model mechanistic considerations on the possible cellular modes of action have been carried out. ICP-MS analysis revealed the higher cellular uptake for less hydrophobic Ir(III) complexes in comparison to the corresponding Ru(II) compounds. Cytometric analysis showed a predominance of apoptosis over the other types of cell death for all complexes. The apoptotic pathway was confirmed by a decrease in mitochondrial membrane potential and the activation of caspases-3/9 for both Ru(II) and Ir(III) complexes. It was concluded that in the case of Ru(II) complexes the intense ROS generation is mainly responsible for the resulting cytotoxicity. The corresponding Ir(III) complexes trigger simultaneously at least three different cytotoxic pathways i. e., depletion of mitochondrial potential, activation of caspases-dependent apoptosis, and ROS-associated oxidation. Thus, it can be assumed that the final accumulation of toxic effects over time via parallel activation of different pathways results in the highest cytotoxicity in vitro exhibited by Ir(III) complexes when compared with Ru(II) complexes.

Reversible Binding of Hydrogen and Styrene Coordination on a Manganese Phosphenium Complex

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Reversible Binding of Hydrogen and Styrene Coordination on a Manganese Phosphenium Complex

Co-photolysis of two simple N-heterocyclic phosphenium complexes with H2 proceeds in one case under cooperative addition of H2 across the P=Mn double bond and in the other case via decarbonylation without participation of H2. The origin of this divergence and preliminary results on the passing on of the H2 molecule to styrene are discussed.


Abstract

The reactions of two complexes [(RNHP)Mn(CO)4] (RNHP=N-arylated N-heterocyclic phosphenium) with H2 at elevated pressure (≈4 bar) were studied by NMR spectroscopy. Irradiation with UV light initialized in one case (5 a, R=Dipp) the unselective formation of (RNHP-H)MnH(CO)4] (6 a) via cooperative addition of H2 across the Mn=P double bond. In the other case (5 b, R=Mes), addition of H2 was unobservable and the reaction proceeded via decarbonylation to a dimeric species [(RNHP)2Mn2(CO)7] (7 b) that was isolated and identified spectroscopically. Taking into account the outcome of further reaction studies under various conditions in the absence and presence of H2, both transformations can be explained in the context of a common mechanism involving decarbonylation to 7 a,b as the first step, and the different outcome is attributable to the fact that 7 b is unreactive towards both H2 and CO while 7 a is not. DFT studies relate this divergence to deviations in the molecular constitution and stability arising from a different level of steric congestion. Preliminary studies suggest further that 5 a/H2 as well as 6 a enable the photo-induced hydrogenation of styrene to ethyl benzene, even if the mechanism and possibly catalytic nature of this process remain yet unknown.

Reduced Graphene Oxide Modulated FeSe/C Anode Materials for High‐Stable and Long‐Life Potassium‐Ion Batteries

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Reduced Graphene Oxide Modulated FeSe/C Anode Materials for High-Stable and Long-Life Potassium-Ion Batteries

The rGO layer on electrode exhibits robust adsorption energies towards EC, DEC, and K+-ions, regulating the EDL around electrode. The special behavior changes the SEI and markedly improves the reaction kinetics. Meanwhile, rGO with robust mechanical properties remains the integrity of SEI and FeSe/C@rGO electrode. Under these synergies, the anode exhibits excellent potassium storage properties.


Abstract

Reduced graphene oxide (rGO) has been demonstrated to effectively enhance the potassium storage performance of transition metal selenides due to its robust mechanical properties and high conductivity. However, the impact of rGO on the electrode-electrolyte interface, a crucial factor in the electrochemical performance of potassium-ion batteries (PIBs), requires further exploration. In this study, we synthesized a seamless architecture of rGO on FeSe/C nanocrystals (FeSe/C@rGO). Comparative analysis between FeSe/C and FeSe/C@rGO reveals that the rGO layer exhibits robust adsorption energies towards EC and DEC, inducing the formation of organic-rich solid-electrolyte interphase (SEI) without damage to the structural integrity. Furthermore, incorporating rGO triggers K+-ions into the double electrode layer (EDL), markedly improving the transport of K+-ions. As a PIB anode, FeSe/C@rGO exhibits a reversible capacity of 332 mAh g−1 at 200 mA g−1 after 300 cycles, along with excellent long-term cycling stability, showcasing an ultralow decay rate of only 0.086 % per cycle after 1900 cycles at 1000 mA g−1.

Cooperative Dinitrogen Activation: Identifying the Push‐Pull Effects of Transition Metals and Lewis Acids in Molecular Orbital Diagrams

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Cooperative Dinitrogen Activation: Identifying the Push-Pull Effects of Transition Metals and Lewis Acids in Molecular Orbital Diagrams

The cooperative “push-pull” effects of ReI, Mo0, W0 complexes and borane Lewis acids on the dinitrogen bond are evaluated in molecular orbital diagrams: we extract electronic design principles in terms of orthogonal σ and π “push-pull” paths that may guide the design of complexes towards the desired thermal, electrochemical or photochemical reactivity of N2.


Abstract

The sustainable fixation of atmospheric N2 and its conversion into industrially relevant molecules is one of the major current challenges in chemistry. Besides nitrogen activation with transition metal complexes, a “push-pull” approach that fine-tunes electron density along the N−N bond has shown success recently. The “pushing” is performed by an electron rich entity such as a transition metal complex, and the “pulling” is achieved with an electron acceptor such as a Lewis acid. In this contribution, we explore the electronic structure implications of this approach using the complex trans-[ReICl(N2)(PMe2Ph)4] as a starting point. We show that borane Lewis acids exert a pull-effect of increasing strength with increased Lewis acidity via a π-pathway. Furthermore, the ligand trans to dinitrogen can weaken the dinitrogen bond via a σ-pathway. Binding a strong Lewis acid is found to have electronic structure effects potentially relevant for electrochemistry: dinitrogen-dominated molecular orbitals are shifted into advantageous energetic positions for redox activation of the dinitrogen bond. We show how these electronic structure design principles are rooted in cooperative effects of a transition metal complex and a Lewis acid, and that they can be exploited to tailor a complex towards the desired thermal, electrochemical or photochemical reactivity.