At a crucial time with rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant globally, the United States Food and Drug Administration has issued an ...emergency use authorization for 2 oral antivirals, molnupiravir (in persons aged ≥18 years) and nirmatrelvir-ritonavir (Paxlovid) (in persons aged ≥12 years weighing ≥40 kg), for the outpatient treatment of patients with mild to moderate coronavirus disease 2019 (COVID-19) who are at risk for progression. Molnupiravir is a nucleoside analogue, whereas nirmatrelvir is a SARS-CoV-2 main protease inhibitor, and ritonavir is a human immunodeficiency virus type 1 protease inhibitor. Drug interactions are a major concern for nirmatrelvir-ritonavir. Nirmatrelvir-ritonavir demonstrated a greater risk reduction in hospitalization and death than molnupiravir compared to placebo. Both drugs need to be started within 5 days of symptoms onset and given for 5 days' duration. This article reviews the 2 oral COVID-19 antiviral drugs including the mechanisms of action, antiviral activity, pharmacokinetics, drug interactions, clinical experience including trials, adverse events, recommended indications, and formulary considerations.
Designing metal hydroxide electrocatalysts with high efficiency to overcome the slow reaction kinetics of the oxygen evolution reaction (OER) is considered as a significant approach for renewable ...energy resources. We report here a simple methodology to synthesize 2D thin nickel hydroxide/nickel oxyhydroxide sheets that show efficient activity towards OER. Further, by doping with a heteroatom, Fe, thinner sheets of nickel hydroxide/nickel oxyhydroxide are developed, which exhibit enhanced electrocatalytic activity towards OER with high durability. Fe‐doped Ni(OH)2/NiOOH requires only 200 mV overpotential to produce 10 mA/cm2, whereas bare Ni(OH)2/NiOOH needs 290 mV overpotential. Moreover, Fe‐doped nickel hydroxide/nickel oxyhydroxide shows a minimal Tafel value of 48 mV/decade, which is even lower than RuO2/CC (82 mV/decade). X‐ray photoelectron spectroscopy indicates that in the case of Fe‐doped Ni(OH)2/NiOOH, the Ni3+ signal enhances, which indicates the favourable stabilization of Ni3+ in the presence of Fe3+ dopant. Under electrochemical OER conditions, in Fe‐doped Ni(OH)2/NiOOH, Fe3+ species help to generate more Ni3+, which function as the active species. Fe0.06Ni0.94(OH)2/NiOOH shows long‐term stability for at least 24 hours in alkaline medium. This work unveils a green strategy for Fe‐doping in 2D thin sheets of Ni(OH)2/NiOOH, which show improved electrocatalytic activity compared to bare Ni(OH)2/NiOOH. The mechanism of OER activity enhancement after Fe‐doping is proposed here.
Fe‐doping in Ni(OH)2/NiOOH enhances the electrocatalytic activity by tuning the morphology, modulating the electronic structure of the catalyst, and finally improving the conductivity by decreasing the charge‐transfer resistance, which results in a fast reaction rate. In−Fe doped Ni(OH)2/NiOOH, the Ni3+ signal is enhanced, which indicates the favorable stabilization of Ni3+ in the presence of the Fe3+ dopant. Under electrochemical OER conditions in Fe‐doped Ni(OH)2/NiOOH, the Fe3+ species help to generate more Ni3+ ions, which function as the active species.
Development of cost-effective, efficient electrocatalyst for oxygen evolution reaction (OER) is a challenging issue as OER has sluggish reaction kinetics due to transfer of multi-electrons. In this ...study, a new strategy has been developed for the synthesis of 2D nanostructures of CoFe2O4 and NiFe2O4 following a wet-chemical route followed by calcination. Following this method nanoplates of CoFe2O4 and nanosheets of NiFe2O4 have been successfully synthesized. These interconnected 2D structures are very efficient for oxygen evolution reaction and it is observed that CoFe2O4 nanoplates and NiFe2O4 nanosheets are catalytically more active compared to nanocubes and nanobipyramids of CoFe2O4 and NiFe2O4. CoFe2O4 nanoplates require only 1.64 V vs. RHE for generating current density of 10 mA/cm2 whereas nanocubes of CoFe2O4 require 1.68 V vs. RHE. Similarly, NiFe2O4 nanosheets require 1.69 V to generate current density 10 mA/cm2 and NiFe2O4 nanobipyramids require 1.77 V vs. RHE to engender 10 mA/cm2 current density. 2D sheet or Plate-like structure with more exposed surface atoms faces more electrolyte to adsorb and react which results in higher electrocatalytic activity.
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Solar water splitting devices with high efficiency need to be developed, utilizing low cost and efficient materials. For this purpose, ZnO@CdS heterostructure nanosheets are developed herein as an ...efficient photoanode for solar water splitting. 2D nanosheets of ZnO are synthesized vertically on fluorine doped tin oxide (FTO) through a simple electrochemical deposition technique. The ZnO nanosheets can generate a photocurrent density of 0.212 mA cm −2 at 0 V vs. Ag/AgCl. The vertically grown interconnected 2D sheets help to enhance light absorbance and allow larger amounts of electrolyte to penetrate inside the anode. ZnO is a wide bandgap (3.3 eV) material and it suffers from low solar light absorbance. To enhance the optical activity under visible light and to ensure efficient charge carrier separation, the surfaces of the ZnO nanosheets are modified with CdS, which has a bandgap of 2.4 eV, using a successive ionic layer adsorption and reaction (SILAR) technique. The amount of CdS on the ZnO surface is varied by increasing the SILAR cycle number and a maximum photocurrent density is observed in the case of ZnO@CdS/20. ZnO@CdS/20 can generate a photocurrent density of 1.15 mA cm −2 at 0 V vs. Ag/AgCl under continuous light illumination. The observed photoconversion efficiency ( η ) is maximal in the case of ZnO@CdS/20, a value of 0.754%. After the decoration of CdS on ZnO, the carrier density also increases nearly 30 times compared to bare ZnO, which further indicates the higher photoactivity of the heterostructures.
Advances in biocontrol potentials and fungicide resistance are highly desirable for Trichoderma. Thus, it is profitable to use mutagenic agents to develop superior strains with enhanced biocontrol ...properties and fungicide tolerance in Trichoderma. This study investigates the N-methyl-n-nitro-N-nitrosoguanidine (NTG) (100 mg/L) induced mutants of Trichoderma asperellum. Six NTG (3 each from 1st & 2nd round) induced mutants were developed and evaluated their biocontrol activities and carbendazim tolerance. Among the mutant N2-3, N2-1, N1 and N2-2 gave the best antagonistic and volatile metabolite activities on inhibition of chickpea F. oxysporum f. sp. ciceri, B. cinerea and R. bataticola mycelium under in vitro condition. Mutant N2-2 (5626.40 μg/ml) showed the highest EC50 value against carbendazim followed by N2-3 (206.36 μg/ml) and N2-1 (16.41 μg/ml); and succeeded to sporulate even at 2000 μg/ml of carbendazim. The biocontrol activity of N2-2 and N2 with half-dose of carbendazim was evaluated on chickpea dry root rot under controlled environment. Disease reduction and progress of the dry root rot was extremely low in T7 (N2-2 + with half-dose of carbendazim) treatment. Further, carbendazim resistant mutants demonstrated mutation in tub2 gene of β-tubulin family which was suggested through the 37 and 183 residue changes in the superimposed protein structures encoded by tub2 gene in N2 and N2-2 with WT respectively. This study conclusively implies that the enhanced carbendazim tolerance in N2-2 mutant did not affect the mycoparasitism and plant growth activity of Trichoderma. These mutants were as good as the wild-type with respect to all inherent attributes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Biofabrication of gold nanoparticles (AuNPs) using the aromatic essential oils is highlighted due to its simple, economical, low toxicity, and eco-friendly nature. Essential oil of
...Cymbopogon flexuosus
(
CF
), an economically valuable medicinal plant, exhibits anti-inflammatory, anti-tumor, antioxidant, and antimicrobial activities. For the first time, this research accounts for the biosynthesis, physicochemical, photocatalytic, antifungal, antibacterial properties of biogenic AuNPs, fabricated using CF essential oil collected from different altitudes (S1-Palampur, S2-Haryana, S3-Dehradun). The altitudinal disparity in the phytochemical composition of essential oils is highlighted. The average crystallite size ranged from 10 to 32 nm and was influenced by CF samples used in the synthesis. The spectroscopic outcomes revealed the involvement of bioactive reagents from CF essential oil in the fabrication and stabilization of AuNPs. The fabricated AuNPs exhibited excellent antimicrobial activities against all tested strains (
Staphyloccucs aureus
,
Escherichia coli, Fusarium oxysporum
), showing their efficacy as an antimicrobial agent to treat infectious diseases. Moreover, AuNPs exhibited excellent photocatalytic efficacy of around 91.8% for the degradation of methylene blue under exposure of direct sunlight for 3 h without the assistance of an external reducing agent. The outcomes highlight a potential economic and environmentally friendly strategy to fabricate biogenic AuNPs for diversified industrial applications where antimicrobial and photocatalytic efficacies are the key requirements.
Abstract
Emergent application of antimicrobial strategies as symptomatic treatment in coronavirus disease (COVID-19) and linkage of severe acute respiratory syndrome coronavirus2 with microbial ...infections, has created colossal demand for antimicrobials. For the first time, this communication explore the physicochemical, antifungal, antibacterial, and photocatalytic properties of biogenic magnesium nanoparticles (MgNPs), synthesized using essential oil of
Cymbopogon flexuosus's
as an efficient multifunctional reducing and stabilizing/capping reagent. It is observed that MgNPs (ranging in size: 8–16 nm) of varying phytochemical compositions (MgS1, MgS2, MgS3) exhibited various useful physicochemical, antimicrobial, and photocatalytic properties. FTIR outcomes highlight the functional biomolecules-assisted reduction of Mg from Mg
+
to Mg
0
. Among all, MgS3-Nps owing to the smallest particle size exhibited superior photocatalytic efficacy (91.2%) for the methylene blue degradation upon direct exposure to the sunlight for 3 h without using any reducing agents. Fabricated MgNPs also exhibited excellent antifungal (against
Fusarium oxysporum
) and antibacterial (versus
Staphylococcus aureus
and
Escherichia coli
) efficacies compared to state-of-the-art antimicrobial agents deployed for the treatment of infectious diseases. Based on this investigated greener approach, imperative from economic and environmental viewpoint, such essential oil based-MgNPs can be a potential nanosystem for various industrial applications where photocatalytic, and biomedical attributes are the key requirements.
For the construction of galactose biosensor, chitosan was electropolymerised onto the pencil graphite electrode. This chitosan modified pencil graphite electrode acts as good matrix for ...immobilization of enzyme nanoparticles of galactose oxidase. Development of this nanocomposite was further confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. The presence of chitosan makes the present galactose biosensor more efficient, reproducible and stable. The sensitivity was reported 7 × 10−3 mA/mM/cm2 with linear range from 0.05 to 25 mM and better detection limit of 0.05 mM. When the solution of galactose was spiked with 0.5 mM and 1 mM, the analytical recoveries were found 98.6% and 97.6%. A better storage stability was achieved (90days) when compared to earlier reported biosensors.
Schematic representation of GalOxNPs/CHIT/PGE biosensor. Display omitted
•Constructed an improved amperometric galactose biosensor based on GalOxNPs/CHIT) modified PGE.•Biosensor showed optimum current within 2 s, pH 6.5 and temperature 35 °C.•The limit of detection and working range of present biosensor were 0.05 mM and 0.05–25 mM respectively.•The enzyme electrode lost 40% of its initial activity following 90 days of its normal uses, when stored at 4 °C.•Biosensor measured galactose level in different samples of baby food products.
Ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Labr. is an important and widespread disease of chickpea (Cicer arietinum L.) worldwide. The disease is particularly severe under cool and ...humid weather conditions. Breeding for host resistance is an efficient means to combat this disease. In this paper, attempts have been made to summarize the progress made in identifying resistance sources, genetics and breeding for resistance, and genetic variation among the pathogen population. The search for resistance to AB in chickpea germplasm, breeding lines and land races using various screening methods has been updated. Importance of the genotype × environment (GE) interaction in elucidating the aggressiveness among isolates from different locations and the identification of pathotypes and stable sources of resistance have also been discussed. Current and modern breeding programs for AB resistance based on crossing resistant/multiple resistant and high-yielding cultivars, stability of the breeding lines through multi-location testing and molecular marker-assisted selection method have been discussed. Gene pyramiding and the use of resistant genes present in wild relatives can be useful methods in the future. Identification of additional sources of resistance genes, good characterization of the host–pathogen system, and identification of molecular markers linked to resistance genes are suggested as the key areas for future study.
Fusarium oxysporum (Fo) is ubiquitous in soil and forms a species complex of pathogenic and putatively non-pathogenic strains. Pathogenic strains cause disease in over 150 plant species. Fusarium ...oxysporum f. sp. ciceris (Foc) is a major fungal pathogen causing Fusarium wilt in chickpeas (Cicer arietinum). In some countries such as Australia, Foc is a high-priority pest of biosecurity concern. Specific, sensitive, robust and rapid diagnostic assays are essential for effective disease management on the farm and serve as an effective biosecurity control measure. We developed and validated a novel and highly specific PCR and a LAMP assay for detecting the Indian Foc race 1 based on a putative effector gene uniquely present in its genome. These assays were assessed against 39 Fo formae speciales and found to be specific, only amplifying the target species, in a portable real-time fluorometer (Genie III) and qPCR machine in under 13 min with an anneal derivative temperature ranging from 87.7 to 88.3 °C. The LAMP assay is sensitive to low levels of target DNA (> 0.009 ng/µl). The expected PCR product size is 143 bp. The LAMP assay developed in this study was simple, fast, sensitive and specific and could be explored for other Foc races due to the uniqueness of this marker to the Foc genome.
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