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1.
《印度化学会志》2023,100(1):100866
The advancement in nanotechnology, nanoparticles are reported to have applications in various fields. Their positive role in the environment, especially in plant ecosystem, is extensively studied nowadays. Among the metal nanoparticles, the silver nanoparticles (AgNPs) are receiving special attention because of their ability to increase the growth and yield in many crops. Although many studies are found that shows the toxic effects of AgNPs, the perspective of the present review is to collect the information about their positive roles in growth and yield enhancement of crops. During this overview, there are many methods of synthesizing silver AgNPs nanoparticles discussed, including chemical, bacterial-induced, fungal-derived and plant-mediated synthesis. There are numerous approaches towards the synthesis of AgNPs, including biological and chemical methods. Because of the use of reducing agents such as sodium borohydride in the synthesis of AgNPs, conventional methods have opened a path that threatens environmental sustainability. The chemical synthesis of silver colloids is the consequence of increased aggregation as storage time increases. AgNPs possess unique properties which has many applications such as antimicrobial and anticancer activities. It was concluded that cautious and sensible use of nanotechnology can warrant food security through boosting agricultural production. This review is aimed at providing an insight into the syntheses of AgNPs, its significant applications in various fields, and characterization techniques involved.  相似文献   

2.

In recent years, progress of biological synthesis of nanoparticles is inevitable due to its important applications. In this research, a new and simple method for the synthesis of AgNPs from plant extracts is presented. The extract from shoots of the plant Tribulus terrestris L. was mixed with AgNO3 with the aim of biologically synthesizing AgNPs. The biomolecules existing in the extract were accountable for the fast reduction of silver ions (Ag+) to AgNPs. Characterization of biosynthesized AgNPs was performed by UV–Vis, TEM, DLS, and XRD. The AgNPs exhibit a strong peak at 434 nm, and sphere-shaped AgNPs were found to be ~?25 nm. The biosynthesized silver nanoparticles have demonstrated high antibacterial effect against pathogenic bacteria (i.e., Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa). In addition, the in vitro cytotoxicity effect of biosynthesized silver nanoparticles was also investigated and was detected to be up to 15.62 μg/mL in the treated Neuro2A cells. The plant-mediated biosynthesis of AgNPs has comparatively rapid, eco-friendly, inexpensive and wide-ranging application in modern medicine and the food industry.

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3.
《Arabian Journal of Chemistry》2020,13(12):8662-8670
New and improved approaches are urgently needed to fight the increasing number of multi-drug resistant bacteria. The antibacterial effect of silver nanoparticles (AgNPs) prepared by standardized chemical and biological syntheses is compered here. Biological systems included extracts of Opuntia ficus-indica mucilage and extracellular growth broth of Aspergillus niger and Bacillus megaterium. The nanoparticles were characterized by infrared spectroscopy, IR, and transmission electron microscopy. All of the AgNPs shared characteristic IR peaks and had an average size of 20–60 nm. The AgNPs were mainly spherical regardless of synthetic path. The synthesis based on the extracellular broth of the fungus, due to the highest biomass and active compounds concentration, resulted in a high yield of nanoparticle formation. These AgNPs also exhibited the highest inhibition zone against Salmonella typhimurium and Staphylococcus aureus. The syntheses reported here have no significant influence on AgNPs physical characteristics, as compared to literature, but represent processes with shorter reaction time. Additionally, the fungal based nanoparticles have superior antibacterial characteristics.  相似文献   

4.
Due to environmentally friendly and cost- effective issues, biological methods for silver nanoparticles (AgNPs) synthesis are advantageous over chemical and physical ones. In this study, AgNPs synthesized using Lavandula stoechas extract as a reductant and its antioxidant capacity, antibacterial property and cytotoxicity effect were investigated. The phyto-synthesized AgNPs were characterized using various analyses such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) as well as Fourier transform infrared (FT-IR). The prepared nanoparticles were spherical on shape with the size about 20–50 nm. Antibacterial studies through agar disk diffusion method confirmed the antibacterial potential of phyto-synthesized AgNPs toward two clinical Staphylococus aureus and Pseudomonas aeruginosa bacteria, although MTT assay demonstrated that S. aureus (MIC = 125 μg/ml) was more susceptible to AgNPs than P. aeruginosa (MIC = 250 μg/ml). Moreover, the cytotoxicity assay of phyto-synthezied AgNPs showed a low cytotoxic effect on RAW264 cell line at 62.5 μg/ml as an effective concentration. Also the considerable antioxidant capacity of the AgNPs confirmed through DPPH assay. Great antibacterial and antioxidant properties along with biocompatibility make the suggested phyto-synthesized AgNPs a great candidate for different biomedical applications including wound healing.  相似文献   

5.
Uses of plants extracts are found to be more advantageous over chemical, physical and microbial (bacterial, fungal, algal) methods for silver nanoparticles (AgNPs) synthesis. In phytonanosynthesis, biochemical diversity of plant extract, non-pathogenicity, low cost and flexibility in reaction parameters are accounted for high rate of AgNPs production with different shape, size and applications. At the same time, care has to be taken to select suitable phytofactory for AgNPs synthesis based on certain parameters such as easy availability, large-scale nanosynthesis potential and non-toxic nature of plant extract. This review focuses on synthesis of AgNPs with particular emphasis on biological synthesis using plant extracts. Some points have been given on selection of plant extract for AgNPs synthesis and case studies on AgNPs synthesis using different plant extracts. Reaction parameters contributing to higher yield of nanoparticles are presented here. Synthesis mechanisms and overview of present and future applications of plant-extract-synthesized AgNPs are also discussed here. Limitations associated with use of AgNPs are summarised in the present review.  相似文献   

6.
A simple, eco-friendly, cost-effective and rapid microwave-assisted method has been developed to synthetize dendritic silver nanostructures, composed of silver nanoparticles (AgNPs), using white grape pomace aqueous extract (WGPE) as both reducing and capping agent. With this aim, WGPE and AgNO3 (1 mM) were mixed at different ratio, and microwave irradiated at 700 W, for 40 s. To understand the role of bioactive compounds involved in the green synthesis of AgNPs, preliminary chemical characterization, FT-IR analysis and 1H NMR metabolite profiling of WGPE were carried out. The effects of bioactive extract concentration and stability over time on AgNPs formation were also evaluated. WGPE-mediated silver nanostructures were then characterized by UV–vis, FTIR analyses, and scanning electron microscopy. Interestingly, the formation of dendritic nanostructures, originated from the self-assembly of Ag rounded nanoparticles (average diameter of 33 ± 6 nm), was observed and ascribed to the use of microwave power and the presence of organic components within the used WGPE, inducing an anisotropic crystal growth and promoting a diffusion-limited aggregation mechanism. The bio-dendritic synthetized nanostructures were also evaluated for potential applications in bio-sensing and agricultural fields. Cyclic voltammetry measurements in 0.5 M phosphate + 0.1 M KCl buffer, pH 7.4 showed that green AgNPs possess the electroactive properties typical of AgNPs produced using chemical protocol. The biological activity of synthetized AgNPs was evaluated by in-vitro antifungal activity against F. graminearum. Additionally, a phytotoxicity evaluation of synthetized green nanostructures was carried out on wheat seed germination. Results highlighted the potential of WGPE as green agent for bio-inspired nanomaterial synthesis, and of green Ag nanostructures, which can be used as antifungal agent and in biosensing applications.  相似文献   

7.
The importance of green synthesis was revealed with advantages such as: eliminating the use of expensive chemicals; consume less energy; and generate environmentally benign products. With this aim, silver nanoparticles (AgNPs) were synthesized by using isolated eugenol from clove extract. Its antimicrobial potential was determined on three different microorganisms. Clove was extracted and eugenol was isolated from this extract. Green synthesis was performed and an anti‐microbial study was performed. All extraction and isolation analyses were performed by high‐performance liquid chromatography (HPLC); identification and confirmation were achieved using liquid chromatography–mass spectrometry (LC–MS); and scanning electron microscopy was used for characterization. Both HPLC and LC–MS analyses showed that eugenol obtained purely synthesized AgNPs and 20‐25‐nm‐sized and homogeneous shaped particles seen in images. The antimicrobial effects of AgNPs at eight concentrations were determinated against Staphylococcus aureus, Escherichia coli and Candida albicans, and maximum inhibition zone diameters were found as 2.6 cm, 2.4 cm and 1.5 cm, respectively. The results of the antimicrobial study showed that eugenol as a biological material brought higher antimicrobial effect to AgNPs in comparison to the other materials found in the literature.  相似文献   

8.
The demand for nanoparticles is increasing day by day due to their wide range of applications in various areas including pharmaceutical industry. Nanoparticles are formally synthesized by chemical methods in which the toxic and flammable chemicals are used. Synthesis of nanoparticles from various biological systems has been reported, but among all, biosynthesis of nanoparticles from plants is considered as the most suitable method. The current study confirms the potential of aqueous extract of Melissa officinalis grown under in vitro condition for the green synthesis of silver nanoparticles (AgNPs). Also, we revealed the cytotoxicity, antioxidant, and anti-acute myeloid leukemia effects of AgNPs compared to mitoxantrone in a leukemic mouse model. The synthesized AgNPs were characterized using several techniques including UV–Vis., FT-IR, TEM, FE-SEM, and EDS. In vivo experiment, induction of acute myeloid leukemia was done by DMBA in 75 mice. The obtained results were fed into SPSS-22 software and analyzed by one-way ANOVA. By quantitative real-time PCR, S1PR1 and S1PR5 mRNA expression in lymphocytes were significantly (p ≤ 0.01) increased by treating the leukemic mice with the AgNPs and mitoxantrone. Also, AgNPs similar to mitoxantrone, significantly (p ≤ 0.01) enhanced the platelet, lymphocyte, and RBC parameters and the anti-inflammatory cytokines (IL4, IL5, IL10, IL13, and IFNα) and reduced the total WBC, blast, monocyte, neutrophil, eosinophil, and basophil counts and the pro-inflammatory cytokines (IL1, IL6, IL12, IL18, IFNY, and TNFα) as compared to the untreated mice. In vitro experiment, AgNPs similar to mitoxantrone had low cell viability dose-dependently against murine C1498, human HL-60/vcr, and 32D-FLT3-ITD cell lines without any cytotoxicity on HUVEC cell line. Furthermore, the DPPH assay showed similar antioxidant potentials for AgNPs and mitoxantrone. Above results approve the excellent anti-acute myeloid leukemia, cytotoxicity, and antioxidant properties of AgNPs compared to mitoxantrone.  相似文献   

9.
Silver nanoparticles (AgNPs) attract a great deal of attention for potent antibacterial capacity, but their use is challenged by limited stability. Inspired by the adhesive and redox properties of the mussel foot proteins containing L -3,4-dihydroxyphenylalanine (DOPA), a facile strategy for in situ synthesis of AgNPs using DOPA-containing fibroin is developed. Tyrosine residues in fibroin are transformed into DOPA via biomimetic synthesis method with content of 0.55 mol%. In situ synthesis generates stable and small AgNPs through DOPA bound in fibroin as a reducing and stabilizing agent. Narrow size distribution with average diameter of 20 nm and excellent monodispersity are obtained. Cross-linking with lysine increases the content of β-sheet to form hydrogel and achieves gradual release of silver. The material exhibits excellent antibacterial properties against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria. It can be potentially applied in biological and medical fields to treat bacterial infections.  相似文献   

10.
《Arabian Journal of Chemistry》2020,13(12):9139-9144
Silver nanoparticles (AgNPs) from silver nitrate solution are carried out using the flower extract of Calotropis gigantea. Silver nanoparticles were characterized by UV–vis spectrophotometer, X-Ray diffractometer (XRD). Reduction of silver ions in the aqueous solution of silver during the reaction was observed by UV–vis spectroscopy. Crystalline nature of synthesized silver nanoparticles was studied by XRD pattern, refraction peak using the Scherrer’s equation. Antibacterial activity of the silver nanoparticles was performed by disc diffusion method against Bacillus subtilis, Pseudomonas putida and Escherichia coli. The antibacterial activity of synthesized silver nanoparticles by flower extract of C. gigantea was found against B. subtilis (10 mm). Synthesised AgNPs has the efficient antibacterial activity against Gram positive bacteria.  相似文献   

11.
The present study investigates the green synthesis of stable silver nanoparticles using Juniperus communis leaf aqueous extract at room temperature. Synthesized silver nanoparticles (AgNPs) were characterized with different techniques such as UV–vis spectroscopy, Fourier transforms infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), Scanning electron microscopy (SEM-EDAX) and electrochemical method. Photocatalytic and anti-bacterial activities of synthesized AgNPs are evaluated based on the obtained result showed an efficient inhibition growth for gram negative P. Aeruginosa, E. Coli, and gram positive bacteria S.aureus. The AgNPs exhibited an excellent photocatalytic activity toward the degradation of methylene blue both indoor and outdoor, under sunlight, an efficiency of 95% was achieved. As an easy and environmentally friendly process, AgNPs based on Juniperus communis leaf extract could be applied for the degradation of pollutants and wastewater treatment.  相似文献   

12.
Pongamia pinnata – a plant used since olden times in Ayurvedic treatment – is reported to have diverse functions including antibacterial, antidiabetic, antineurodegenerative, antiepileptic, antiulcer, etc. In this study, our objective was to prepare silver nanoparticles (AgNPs) by green synthesis mediated by methanolic seed extract of P. pinnata and to determine their antimicrobial and antioxidant potential and wound healing activity. AgNPs were characterized for particle size and shape and for antioxidant potential. Further, the AgNPs were incorporated in a gel. The wound healing activity was investigated using an excision wound healing model in Wistar rats. The AgNP‐loaded gel was applied topically to the wounded rats daily for 30 days. The wound contraction was calculated and histopathological studies of the healed tissues were conducted. Karanjin content of the extract was found to be 349 ± 2.16 mg g?1. Formation of AgNPs was confirmed using transmission and scanning electron microscopies and X‐ray diffraction. AgNPs showed good antioxidant potential and were active against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa. Significant wound healing activity (p < 0.05) was shown by the AgNP gel as compared to 5% Betadine ointment. Thus, the prepared AgNPs have antimicrobial and wound healing effects that may be useful in treatment of topical infections especially in wounds.  相似文献   

13.
《中国化学会会志》2017,64(10):1164-1171
A green biogenic, nontoxic, high‐yielding synthetic method is introduced for the synthesis of silver nanoparticles (AgNPs) using ionic‐liquid‐based, microwave‐assisted extraction (ILMAE) from Polygonum minus . The aqueous ionic liquid (1‐butyl‐3‐methylimidazolium chloride [BMIM]Cl)‐based plant extract was used as reducing agent to reduce silver ions to AgNPs. The synthesis of AgNPs was confirmed by UV–visible spectrophotometry. Fourier transforms infrared (FTIR) spectra showed that the plant bioactive compounds capped the AgNPs. The particle size and morphology of Ag NPs were characterized by dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM), respectively. Elemental analysis was carried out by energy‐dispersive X‐ray (EDX) spectroscopy. Photodegradation studies showed that the AgNPs degraded 98% of methylene blue in 12 min.  相似文献   

14.
In this work, we present a fast and simple approach for detection of silver nanoparticles (AgNPs) in biological material (parsley) by solid sampling high-resolution–continuum source atomic absorption spectrometry (HR-CS AAS). A novel evaluation strategy was developed in order to distinguish AgNPs from ionic silver and for sizing of AgNPs. For this purpose, atomisation delay was introduced as significant indication of AgNPs, whereas atomisation rates allow distinction of 20-, 60-, and 80-nm AgNPs. Atomisation delays were found to be higher for samples containing silver ions than for samples containing silver nanoparticles. A maximum difference in atomisation delay normalised by the sample weight of 6.27?±?0.96 s mg?1 was obtained after optimisation of the furnace program of the AAS. For this purpose, a multivariate experimental design was used varying atomisation temperature, atomisation heating rate and pyrolysis temperature. Atomisation rates were calculated as the slope of the first inflection point of the absorbance signals and correlated with the size of the AgNPs in the biological sample. Hence, solid sampling HR-CS AAS was proved to be a promising tool for identifying and distinguishing silver nanoparticles from ionic silver directly in solid biological samples.
Figure
Fast and simple approach for direct identification and sizing of silver nanoparticles in biological material (parsley) applying solid sampling high-resolution continuum source atomic absorption spectrometry and a novel data evaluation strategy  相似文献   

15.
The chemical structure of newly synthesized cationic surfactants based on Schiff base was confirmed using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and mass spectroscopy. The synthesized surfactants were used in the synthesis of silver nanoparticles by a simple one-step method. The silver nanoparticle (AgNPs) formation was confirmed using transmission electron microscopy (TEM), electron diffraction (SAED), dynamic light scattering (DLS), and energy dispersive X-ray spectroscopy (EDX). The structure of the surfactant played an important role in the synthesis process. Increasing the hydrophobic chain length, the stability, and the amount of surfactant increased the quantity of AgNPs formed. The surface activity of the synthesized cationic surfactants was determined using surface tension measurements at three different temperatures. The synthesized surfactants showed a high tendency toward adsorption and micellization. Increasing the hydrophobic chain length of the synthesized surfactant increased its adsorption. Screening the synthesized cationic surfactants and their nano-form against bacteria and fungi showed that they are highly effective. The silver nanoparticles enhanced the biological activity of the synthesized cationic surfactants.  相似文献   

16.
Biologically synthesized silver nanoparticles are emerging as attractive alternatives to chemical pesticides due to the ease of their synthesis, safety and antimicrobial activities in lower possible concentrations. In the present study, we have synthesized silver nanoparticles (AgNPs) using the aqueous extract of the medicinal plant Euphorbia wallichii and tested them against the plant pathogenic bacterium Xanthomonas axonopodis, the causative agent of citrus canker, via an in vitro experiment. The synthesized silver nanoparticles were characterized by techniques such as UV-Vis spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and transmission electron microscopy. Moreover, the plant species were investigated for phenolics, flavonoids and antioxidant activity. The antioxidant potential of the extract was determined against a DPPH radical. The extract was also evaluated for phenolic compounds using the HPLC technique. The results confirmed the synthesis of centered cubic, spherical-shaped and crystalline nanoparticles by employing standard characterization techniques. A qualitative and quantitative phytochemical analysis revealed the presence of phenolics (41.52 mg GAE/g), flavonoids (14.2 mg QE/g) and other metabolites of medicinal importance. Different concentrations (1000 µg/mL to 15.62 µg/mL—2 fold dilutions) of AgNPs and plant extract (PE) alone, and both in combination (AgNPs-PE), exhibited a differential inhibition of X. axanopodis in a high throughput antibacterial assay. Overall, AgNPs-PE was superior in terms of displaying significant antibacterial activity, followed by AgNPs alone. An appreciable antioxidant potential was recorded as well. The observed antibacterial and antioxidant potential may be attributed to eight phenolic compounds identified in the extract. The Euphorbia wallichii leaf-extract-induced synthesized AgNPs exhibited strong antibacterial activity against X. axanopodis, which could be exploited as effective alternative preparations against citrus canker in planta in a controlled environment. In addition, as a good source of phenolic compounds, the plant could be further exploited for potent antioxidants.  相似文献   

17.
The focus of the study is to compare the antibacterial efficacy of silver nanoparticles (AgNPs) fabricated by exploiting biological (a mangrove plant, Rhizophora apiculata) and chemical means (Glucose). The synthesized nanoparticles were characterised using UV-visible absorption spectrophotometry (UV-vis), Fourier transform Infra-red Spectroscopy (FTIR) and Transmission electron microscopy (TEM). Biologically synthesized silver nanoparticles (BAgNPs) were observed at 423 nm with particle sizes of 19-42 nm. The chemically synthesized silver nanoparticles (CAgNPs) showed a maximum peak at 422 nm with particle sizes of 13-19 nm. An obvious superiority of the antibacterial potency of BAgNPs compared to the CAgNPs as denoted by the zone of inhibition (ZoI) was noted when the nanoparticles were treated against seven different Microbial Type Culture Collection (MTCC) strains. The current study therefore elucidates that the synthesized AgNPs were efficient against the bacterial strains tested.  相似文献   

18.
Recently, green synthesis of silver nanoparticles has attracted much curiosity in the field of life science research. In the present study, we have reported a green method for synthesis of silver nanoparticles (AgNPs) using aqueous seed extract of Phoenix sylvestris L. The green synthesized nanoparticles were characterized by aids of dynamic light scattering, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform-infrared. Further, the study demonstrate the comparative phytochemical analysis as well as antioxidant and antibacterial activity of the extract and Phoenix sylvestris seed generated nanoparticles against acne-causing pathogens, that is, by using a DPPH-scavenging assay and broth microdilution method as well as Kirby–Bauer Disk diffusion method (recommended by CLSI), respectively. Moreover, a concentration-dependent time-kill kinetic studies were also carried out to determine their antimicrobial activity. The seed extract was found a better antioxidant and AgNPs exhibited highly biocidal agent against both the test pathogens, when compared to aqueous extracts. The results obtained indicate that seed extract of P. sylvestris is suitable for synthesizing stable silver nanoparticles, which act as excellent antimicrobial agents with promising treatments for cosmetics embarrassment.  相似文献   

19.
ABSTRACT

The present work reports a method for green synthesis of silver nanoparticles (AgNPs) by reducing Ag ions from silver nitrate solution using alcoholic, aqueous and alcoholic-aqueous Stevia rebaudiana extracts. Depending on a particular extract different sizes of AgNPs could be observed – 40?nm in aqueous and aqueous-alcoholic extracts and significantly bigger 170?nm in case of alcoholic extract. Synthesis of AgNPs was analyzed within spectra range of 300–700?nm. The performed research provided information that aqueous and aqueous-alcoholic extracts are excellent sources for synthesis of AgNPs; however AgNPs were unstable in the case of alcoholic extract. The aqueous-alcoholic extract showed the best properties during studies. Antioxidant potential, antimicrobial properties and cytotoxicity were determined. The 2,2-diphenyl-1-(2,4,6-triphenyl-hydrazyl) method showed that antioxidant activity of an extract containing AgNPs was higher compared to Stevia extract alone. Bacterial inhibition studies had shown substantial antibacterial properties of AgNPs, which was much higher than Stevia extract alone and silver nitrate.  相似文献   

20.
Distinguishing the toxic effects of nanoparticles (NPs) themselves from the well-studied toxic effects of their ions is a critical but challenging measurement for nanotoxicity studies and regulation. This measurement is especially difficult for silver NPs (AgNPs) because in many relevant biological and environmental solutions, dissolved silver forms AgCl NPs or microparticles. Simulations predict that solid AgCl particles form at silver concentrations greater than 0.18 and 0.58 μg/mL in cell culture media and moderately hard reconstituted water (MHRW), respectively. The AgCl NPs are usually not easily separable from AgNPs. Therefore, common existing total silver techniques applied to measure AgNP dissolution, such as inductively coupled plasma mass spectrometry (ICP-MS) or atomic absorption, cannot accurately measure the amount of silver remaining in AgNP form, as they cannot distinguish Ag oxidation states. In this work, we introduce a simple localized surface plasmon resonance (LSPR) UV–visible absorbance measurement as a technique to measure the amount of silver remaining in AgNP form for AgNPs with constant agglomeration states. Unlike other existing methods, this absorbance method can be used to measure the amount of silver remaining in AgNP form even in biological and environmental solutions containing chloride because AgCl NPs do not have an associated LSPR absorbance. In addition, no separation step is required to measure the dissolution of the AgNPs. After using ICP-MS to show that the area under the absorbance curve is an accurate measure of silver in AgNP state for unagglomerating AgNPs in non-chloride-containing media, the absorbance is used to measure dissolution rates of AgNPs with different polymer coatings in biological and environmental solutions. We find that the dissolution rate decreases at high AgNP concentrations, 5 kDa polyethylene glycol thiol coatings increase the dissolution rate, and the rate is much higher in cell culture media than in MHRW.  相似文献   

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