27 research outputs found
The surface modification of spherical ZnO with Ag nanoparticles: A novel agent, biogenic synthesis, catalytic and antibacterial activities
Nowadays, the industrial wastewater pollutants including toxic dyes and pathogenic microbes have caused serious environmental contaminations and human health problems. In the present study, eco-friendly and facile green synthesis of Ag modified ZnO nanoparticles (ZnO-Ag NPs) using Crataegus monogyna (C. monogyna) extract (ZnO-Ag@CME NPs) is reported. The morphology and structure of the as-biosynthesized product were characterized by field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), differential reflectance spectroscopy (DRS), dynamic light scattering (DLS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDS) techniques. TEM and FESEM images confirmed the oval and spherical-like structure of the products with a size of 55ā70 nm. The EDS analysis confirmed the presence of Zn, Ag, and O elements in the biosynthesized product. The photocatalytic results showed ZnO-Ag@CME NPs were degraded (89.8% and 75.3%) and (94.2% and 84.7%) of methyl orange (MO) and basic violet 10 (BV10), under UV and sunlight irradiations, respectively. The Ag modified ZnO nanoparticles exhibited enhanced catalytic activity towards organic pollutants, and showed better performance than the pure ZnO nanoparticles under UV and sunlight irradiations. This performance was probably due to the presence of silver nanoparticles as a plasmonic material. Antibacterial activity was performed against different bacteria. ZnO-Ag@CME NPs showed high antibacterial activity against K. pneumoniae, S. typhimurium, P. vulgaris, S. mitis, and S. faecalis with MIC values of 50, 12.5, 12.5, 12.5, and 12.45 Āµg/mL, respectively. All in all, the present investigation suggests a promising method to achieve high-efficiency antibacterial and catalytic performance
Sustainable green synthesis of silver nanoparticles using Sambucus ebulus phenolic extract (AgNPs@SEE): Optimization and assessment of photocatalytic degradation of methyl orange and their in vitro antibacterial and anticancer activity
The biogenic approach in the synthesis of nanoparticles provides an efficient alternative to the chemical synthesis system. Furthermore, the ecofriendly synthesis of metallic nanoparticles is developing rapidly due to its wide applications in sciences. In this research, metallic silver nanoparticles (AgNPs) were biosynthesized using Sambucus ebulus (S. ebulus; AgNPs@SEE) extract for the evaluation of efficient antibacterial, anticancer, and photocatalyst activities. The reaction parameters including temperatures, contact time, and AgNO3 concentration were discussed and optimized. The optimized nanoparticles (AgNPs@SEE) showed cubic structure, spherical morphology with the average size of 35ā50 nm. The photocatalytic performance of AgNPs was assessed by degradation of methyl orange at different concentrations of AgNPs@SEE (10 and 15 Āµl) under sun-light irradiation. About 95.89% of the pollutant was degraded (after 11 min), when 10 Ī¼l of nanocatalyst used. Also, the degradation of contaminant increased (about 95.47% after 7 min) by increasing the nanoparticle concentration to 20 Ī¼l. All in all, the results showed that the percentage of pollutant degradation increased with increasing the concentration of nanocatalyst. Furthermore, anticancer activity of AgNPs@SEE on human cancer cell lines (AGS and MCF-7), and antibacterial activity on both Gram-positive and Gram-negative microorganisms were studied. The synthesized AgNPs@SEE exhibited superior performance on cancer cell lines and effective antibacterial properties against Gram-positive microorganisms (like MIC value of 1.5 Āµg/ml for S. aureus) than Gram-negative microorganisms. All these investigations revealed that silver nanoparticles synthesized by natural extract have the potential to use as low-cost and efficient nanoparticles for environmental and biomedical applications
Optimization and evaluation of anticancer, antifungal, catalytic, and antibacterial activities: Biosynthesis of spherical-shaped gold nanoparticles using Pistacia vera hull extract (AuNPs@PV)
In the past years, use of plant sources for the biosynthesis of nanoparticles has become very important. Gold nanoparticles with unique biological properties are one of these materials which are being investigated extensively. In the present study, the aqueous extract of Pistacia vera hull was utilized to fabrication of gold nanoparticles (AuNPs@PV) in a facile, environmentally friendly, and affordable way. Then the anticancer, antifungal, antibacterial, and photocatalytic potentials of AuNPs@PV were also investigated. The results of various techniques applied, including XRD, UVāvis, TEM, FT-IR, EDS, and FESEM showed the biological reduction of AuĀ³āŗ ions to Auā°. Antibacterial studies were performed on a wide range of bacteria including seven strains of ATCC and seven strains of drug-resistant pathogens. According to the findings of this research, it seems that biosynthesized gold nanoparticles had good antibacterial activity against ATCC and drug-resistant strains of bacteria. The MIC values of E. coli, S. aureus, P. mirabilis, P. aeruginosa, E. faecalis, K. pneumonia, A. baumannii were 34.37, 4.2, 8.59, 4.29, 0.5, 34.37, and 8.59 Ī¼g/mL, respectively. The result of the antifungal investigation showed that two pathogenic fungi, Candida albicans (IFRC1873) and Candida albicans (IFRC1874) were susceptible to AuNPs@PV with MIC values of 550 and 137 Ī¼g/mL, respectively. Furthermore, AuNPs@PV revealed noteworthy anticancer efficacy against AGS-3 and MCF-7 cell lines with IC50 values of 58.31 and 148.1 Ī¼g/mL, respectively. The results of the cytotoxicity effect of AuNPs@PV on BEAS-2B as a normal cell line indicated the selectivity of AuNPs@PV on cancerous cells. Furthermore, the fabricated AuNPs@PV under UV irradiation exhibited significant potential in the decolorization of methylene orange (MO) with a percent decolorization of 91.5 % after 20 min. Therefore, it can be concluded that biosynthesized gold nanoparticles as a photocatalyst, anti-bacterial, antifungal, and anti-cancer agents have potential applications in the fields of environment and biology
Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the Global Burden of Disease Study 2021
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corrected. The corrected version
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on September 28, 2023BACKGROUND : Diabetes is one of the leading causes of death and disability worldwide, and affects people regardless of country, age group, or sex. Using the most recent evidentiary and analytical framework from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD), we produced location-specific, age-specific, and sex-specific estimates of diabetes prevalence and burden from 1990 to 2021, the proportion of type 1 and type 2 diabetes in 2021, the proportion of the type 2 diabetes burden attributable to selected risk factors, and projections of diabetes prevalence through 2050. METHODS : Estimates of diabetes prevalence and burden were computed in 204 countries and territories, across 25 age groups, for males and females separately and combined; these estimates comprised lost years of healthy life, measured in disability-adjusted life-years (DALYs; defined as the sum of years of life lost [YLLs] and years lived with disability [YLDs]). We used the Cause of Death Ensemble model (CODEm) approach to estimate deaths due to diabetes, incorporating 25 666 location-years of data from vital registration and verbal autopsy reports in separate total (including both type 1 and type 2 diabetes) and type-specific models. Other forms of diabetes, including gestational and monogenic diabetes, were not explicitly modelled. Total and type 1 diabetes prevalence was estimated by use of a Bayesian meta-regression modelling tool, DisMod-MR 2.1, to analyse 1527 location-years of data from the scientific literature, survey microdata, and insurance claims; type 2 diabetes estimates were computed by subtracting type 1 diabetes from total estimates. Mortality and prevalence estimates, along with standard life expectancy and disability weights, were used to calculate YLLs, YLDs, and DALYs. When appropriate, we extrapolated estimates to a hypothetical population with a standardised age structure to allow comparison in populations with different age structures. We used the comparative risk assessment framework to estimate the risk-attributable type 2 diabetes burden for 16 risk factors falling under risk categories including environmental and occupational factors, tobacco use, high alcohol use, high body-mass index (BMI), dietary factors, and low physical activity. Using a regression framework, we forecast type 1 and type 2 diabetes prevalence through 2050 with Socio-demographic Index (SDI) and high BMI as predictors, respectively. FINDINGS : In 2021, there were 529 million (95% uncertainty interval [UI] 500ā564) people living with diabetes worldwide, and the global age-standardised total diabetes prevalence was 6Ā·1% (5Ā·8ā6Ā·5). At the super-region level, the highest age-standardised rates were observed in north Africa and the Middle East (9Ā·3% [8Ā·7ā9Ā·9]) and, at the regional level, in Oceania (12Ā·3% [11Ā·5ā13Ā·0]). Nationally, Qatar had the worldās highest age-specific prevalence of diabetes, at 76Ā·1% (73Ā·1ā79Ā·5) in individuals aged 75ā79 years. Total diabetes prevalenceāespecially among older adultsāprimarily reflects type 2 diabetes, which in 2021 accounted for 96Ā·0% (95Ā·1ā96Ā·8) of diabetes cases and 95Ā·4% (94Ā·9ā95Ā·9) of diabetes DALYs worldwide. In 2021, 52Ā·2% (25Ā·5ā71Ā·8) of global type 2 diabetes DALYs were attributable to high BMI. The contribution of high BMI to type 2 diabetes DALYs rose by 24Ā·3% (18Ā·5ā30Ā·4) worldwide between 1990 and 2021. By 2050, more than 1Ā·31 billion (1Ā·22ā1Ā·39) people are projected to have diabetes, with expected age-standardised total diabetes prevalence rates greater than 10% in two super-regions: 16Ā·8% (16Ā·1ā17Ā·6) in north Africa and the Middle East and 11Ā·3% (10Ā·8ā11Ā·9) in Latin America and Caribbean. By 2050, 89 (43Ā·6%) of 204 countries and territories will have an age-standardised rate greater than 10%. INTERPRETATION : Diabetes remains a substantial public health issue. Type 2 diabetes, which makes up the bulk of diabetes cases, is largely preventable and, in some cases, potentially reversible if identified and managed early in the disease course. However, all evidence indicates that diabetes prevalence is increasing worldwide, primarily due to a rise in obesity caused by multiple factors. Preventing and controlling type 2 diabetes remains an ongoing challenge. It is essential to better understand disparities in risk factor profiles and diabetes burden across populations, to inform strategies to successfully control diabetes risk factors within the context of multiple and complex drivers.Bill & Melinda Gates Foundation.http://www.thelancet.comam2024School of Health Systems and Public Health (SHSPH)SDG-03:Good heatlh and well-bein
Novel CoFeāOā@ZnO-CeOā ternary nanocomposite: Sonochemical green synthesis using Crataegus microphylla extract, characterization and their application in catalytic and antibacterial activities
In this study, CoFeāOā@ZnO-CeOā magnetic nanocomposite (CoFe@Zn-Ce MNC) was successfully prepared by facile sonochemical method for the first time. CoFe@Zn-Ce MNC was obtained by green and cost-effective process in the presence of Crataegus microphylla (C. microphylla) fruit extract. Influence of some parameters like capping agents (C. microphylla, SDS and CTAB), sonication time (10, 30 and 60 min) and sonication power (40, 60 and 80 W) were studied to achieve optimum condition. The as-obtained products were characterized by FT-IR, FESEM, TEM, DRS, VSM, EDS, TGA and XRD analysis. Results showed that high magnetic properties (20.38 emugā1), 70ā80 nm size and spherical morphology were unique characteristics of synthesized nanocomposite. Antibacterial activity of CoFe@Zn-Ce MNC was examined against E. coli, P. aeruginoss and S. aureus bacteria. Among theme, S. aureus as gram-positive bacteria showed excellent antibacterial activity. Furthermore, photocatalytic performance of the CoFe@Zn-Ce MNC was investigated by degradation of humic acid (HA) molecules under visible and UV light irradiations. The influence of morphology of products and incorporation of cerium oxide with CoFeāOā@ZnO on photocatalytic activity of CoFeāOā@ZnO was performed. After 100 min illumination, the decomposition of HA pollutant by magnetic nanocomposite were 97.2% and 72.4% under exposure of UV and visible light irradiations, respectively. Also, CoFe@Zn-Ce MNC demonstrated high stability in the cycling decomposition experiment after six times cycling runs
Enhanced catalytic and antibacterial efficiency of biosynthesized Convolvulus fruticosus extract capped gold nanoparticles (CFE@AuNPs)
Scientists are interested in biosynthesis of gold nanoparticles owing to their catalytic and biological features. In this research, the extract of Convolvulus fruticosus (C. fruticosus; CFE) extract was applied to synthesize spherical-like gold nanoparticles (CFE@AuNPs). As-prepared CFE@AuNPs was characterized by TEM, FE-SEM, XRD, FT-IR, EDS, UVāVis and DLS analysis. Identification analysis revealed that the properties of as-prepared CFE@AuNPs with spherical morphology were homogeneous, regular, high dispersibility and low agglomeration. The particle size of biogenic gold nanoparticles (about 35 nm) was obtained using FE-SEM, TEM and DLS techniques. Photocatalytic experiment of CFE@AuNPs determined by degradation of basic violet 10 (BV10), basic blue 9 (BB9) and acid red 51 (AR51) pollutants with percent degradation of 94.3%, 90.2%, 85.4% under UV and 80.6%, 79.8%, 73.3% under visible light irradiation, respectively. As well as, as-prepared CFE@AuNPs illustrated as a significant inhibitory influence against ATCC strain for both gram-positive and gram-negative bacteria. Owing to the antibacterial results, CFE@AuNPs enhanced antibacterial activity against E. coli, A. baumannii, P. aeruginosa, S. aureus, K. pneumonia, P. mirabilis and E. faecalis with MIC of 0.075, 0.075, 0.075, 0.075, 0.15, 0.075 and 0.037 mg/ml, respectively. All in all, results of the findings showed that C. fruticosus capped gold nanoparticles can find applications in the various arena including biological and removal of toxic pollutants for water purification
How does tissue regeneration influence the mechanical behavior of additively manufactured porous biomaterials?
Although the initial mechanical properties of additively manufactured porous biomaterials are intensively studied during the last few years, almost no information is available regarding the evolution of the mechanical properties of implant-bone complex as the tissue regeneration progresses. In this paper, we studied the effects of tissue regeneration on the static and fatigue behavior of selective laser melted porous titanium structures with three different porosities (i.e. 77, 81, and 85%). The porous structures were filled with four different polymeric materials with mechanical properties in the range of those observed for de novo bone (0.7 GPaAccepted Author ManuscriptBiomaterials & Tissue Biomechanic
Comparison of drying methods for the extraction of essential oil from dragonhead (Dracocephalum moldavica L., Lamiaceae)
In the present study, the effect of six different drying methods on the essential oil content and compositions of aerial parts of Iranian dragonhead was assessed. The highest and lowest essential oil contents (1.85 and 0.45%, respectively), were achieved in freeze-drying method and oven drying at 60Ā°C, respectively. Essential oil analyses showed that the main constituents were geranyl acetate (56.5ā33.2%), geranial (10.8ā27.9%), neral (7.3ā20.3%), and geraniol (6.7ā13.5%). The high- est percentages of geranyl acetate (56.5%) and geraniol (13.5%) were obtained with oven drying at 60Ā°C. Cluster analysis of the essential oil constituents demonstrated three main groups based on drying methods. Freeze drying of aerial parts of dragonhead was the most suitable method allowing high-essential oil yields and short drying time. On the other hand, the highest level of marker compounds such as geranyl acetate and geraniol was obtained with oven drying at 60Ā°C
Stem cell- and gene-based therapies as potential candidates in Alzheimer's therapy
Alzheimer's disease (AD) isa progressive neurodegenerative disorder, which is associated with impairments of memory, thinking, language, and reasoning. Despite extensive research aiming at the treatment of AD, durable and complete remissions are rare. Hence, new therapeutic approaches are required. Among various therapeutic approaches, stem cells (ie, neural stem cells, mesenchymal stem cells, and embryonic stem cells) and delivery of protective genes such asencoding nerve growth factor, APOE, and glial cell-derived neurotrophic factor have generated promise in AD therapy. Here, we summarized a variety of effective therapeutic approaches (ie, stem cells, and genes) in AD therapy