Gold Silver Research Articles

Raman spectrum combined with deep learning for precise recognition of Carbapenem-resistant Enterobacteriaceae.

Carbapenem-resistant Enterobacteriaceae (CRE) is a major pathogen that poses a serious threat to human health. Unfortunately, currently, there are no effective measures to curb its rapid development. To address this, an in-depth study on the surface-enhanced Raman spectroscopy (SERS) of 22 strains of 7 categories of CRE using a gold silver composite SERS substrate was conducted. The residual networks with an attention mechanism to classify the SERS spectrum from three perspectives (pathogenic bacteria type, enzyme-producing subtype, and sensitive antibiotic type) were performed. The results show that the SERS spectrum measured by the composite SERS substrate was repeatable and consistent. The SERS spectrum of CRE showed varying degrees of species differences, and the strain difference in theSERS spectrum of CRE was closely related to the type of enzyme-producingsubtype. The introduced attention mechanism improved the classification accuracy of the residual network (ResNet) model. The accuracy of CRE classification for different strains and enzyme-producing subtypes reached 94.0% and 96.13%, respectively. The accuracy of CRE classification by pathogen sensitive antibiotic combination reached 93.9%. This study is significant for guiding antibiotic use in CRE infection, as the sensitive antibiotic used in treatment can be predicted directly by measuring CRE spectra. Our study demonstrates the potential of combining SERS with deep learning algorithms to identify CRE without culture labels and classify its sensitive antibiotics. This approach provides a new idea for rapid and accurate clinical detection of CRE and has important significance for alleviating the rapid development of resistance to CRE.

Study on Ecological Environment Control in the Three Gorges Reservoir Area—A Case Study of Water Level Zone Control

On ecological environment governance, the General Secretary has repeatedly put forward the ecological concept of "green mountain is gold mountain and silver mountain". After the completion of the Three Gorges Dam and the storage of the reservoir, a water-level zone with a drop of up to 30m has been formed. This paper discusses a series of problems in the treatment of water-level zone, such as the slow progress of the work, the existence of secondary pollution and the lack of relevant support, and puts forward measures to strengthen management, environmental monitoring and vegetation restoration in view of the existing problems.

On the plasmonic properties of a graphene nanoribbon and noble metal composite array

Graphene, composed of sp2 hybrid orbitals, is a hexagonal nanomaterial with a two-dimensional honeycomb lattice structure. Nowadays, thanks to its great electronic, optical, and thermal properties, there have been many promising applications based on graphene nanostructures. Under irradiations of external electromagnetic fields, the free electrons on graphene surfaces can be excited to oscillate collectively, resulting in highly localized surface plasmons. This phenomenon may provide foundations for designs of tunable plasmonic devices, therefore, graphene-based nanostructures have been widely studied so far. Besides, investigations on noble metals is another hot topic in the plasmonic community. With irradiations of incident lights, collective oscillations of free electrons on noble metals’ surfaces can also be induced, forming surface plasmons. The plasmonic characteristics can be adjusted by varying the parameters of the metals, including the geometries, thicknesses, as well as dimensions, etc. In this paper, a composite array consisting of graphene nanoribbons and noble metals is proposed, and its plasmonic properties are studied at mid-infrared wavelengths. In the structure, graphene nanoribbons are placed in between two SiO2 layers, and gold semi-cylinders and silver nanofilms are placed above the upper SiO2 layer, respectively. Using the finite difference time domain method, the light transmittance and electric field of the array are investigated, by varying the graphene’s Fermi energy and layer number, the noble metals’ sizes, as well as the period of the array, respectively. The results show that a plasmonic resonance feature is revealed in the 4–18 μm wavelength range, and the resonance characteristics can be tuned by adjusting the above parameters. The composite array structure proposed in this work may provide us with a new platform for the design of plasmonic devices in the mid-infrared regime.

Features of the Mineralogy of the Ores of the Southern Flank of the Mutnovskoe Gold–Silver–Polymetallic Deposit (Southern Kamchatka)

Features of the Mineralogy of the Ores of the Southern Flank of the Mutnovskoe Gold–Silver–Polymetallic Deposit (Southern Kamchatka)

Porphyry Copper and Epithermal Gold–Silver Mineralization of the Baimka Ore Zone, Western Chukotka, Russia

Porphyry Copper and Epithermal Gold–Silver Mineralization of the Baimka Ore Zone, Western Chukotka, Russia

In situ synthesis of long tubular water-dispersible polyaniline with core/shell gold and silver@graphene oxide nanoparticles for gas sensor application

Gold nanoparticles (Au NPs) with graphene oxide (GO) shell (Au@GO), silver nanoparticles (Ag NPs) with GO shell (Ag@GO), and gold silver nanoparticles (AuAgNPs) with GO shell (AuAg@GO) were synthesized employing a cationic surfactant. The prepared core@shell structures were used for in situ synthesis of long tubular polyaniline structures employing cetyl trimethyl ammonium bromide (CTAB) as a soft template. This process led to a notable enhancement in the tubular nanostructure of PANI, extending its length beyond 10 μm, in the case of using core/shell Au@GO, Ag@GO, and AuAg@GO structures. To evaluate their applicability and compatibility, the dispersibility of these nanocomposites was assessed in three distinct solvents: water, dimethyl sulfoxide (DMSO), and N-Methyl-2-pyrrolidone (NMP). Subsequently, the dedoping of PANI within the prepared nanocomposites was scrutinized using UV–Visible (UV–Vis) spectroscopy, which revealed a reduction in the I750/I315 ratio from 1.00 to 0.66 when subjected to water and NMP solvents, respectively. Notably, the dedoping of the AuAg@GO/PANI nanocomposite was predominantly observed in NMP, attributable to the presence of hydrogen bonding interactions and the basic properties of NMP. In terms of ionic conductivity, it was observed that the prepared nanocomposite exhibited its highest conductivity in a water-based medium, registering at 1982 μs. Furthermore, the AuAg@GO/PANI nanocomposite exhibited superior sensing capabilities in comparison to PANI-based gas sensor devices, particularly when exposed to acetone, CO2, NO2, and H2S. Remarkably, at room temperature (25 °C), the AuAg@GO/PANI nanocomposite displayed rapid response and recovery times, with values of 279 s, 431 s, 335 s, and 509 s for 1 ppm concentrations of CO2, NO2, H2S, and acetone, respectively. The sensitivity of these sensors towards acetone, CO2, NO2, and H2S, was quantified by analyzing the slope of the response versus the target gas concentration, revealing the AuAg@GO/PANI nanocomposite to exhibit the highest sensitivity, particularly towards NO2.

Near-Infrared Fluorescent Silica Nanoparticles Based on Gold-Silver Alloy Nanoclusters for Clinical Diagnosis.

In clinical diagnosis, fluorescent particles are applied to detect analytes in biofluids, such as blood and saliva. However, current fluorescence detection methods have not been optimized to account for the overlapping autofluorescence peaks of biological substances. Gold and silver nanoclusters are known to the novel fluorescent materials and their emission wavelengths depend on cluster size. In this study, we developed fluorescent silica nanoparticles using gold-silver alloy nanoclusters and chitosan (CS) (NH2-SiO2@Au@CS@AuAg) by the layer-by-layer method. Under UV-light irradiation at 365 nm, the emission wavelength of NH2-SiO2@Au@CS@AuAg reached 750 nm in the near-IR region. Scanning electron microscopy images revealed that the shape of NH2-SiO2@Au@CS@AuAg was uniform and spherical. The fluorescence spectrum of horse blood obtained in the presence of NH2-SiO2@Au@CS@AuAg contained a specific fluorescence peak attributed to NH2-SiO2@Au@CS@AuAg, which was distinguishable from the autofluorescence peaks. These results showed that NH2-SiO2@Au@CS@AuAg has advantageous fluorescence properties for clinical diagnostic applications.

The Response of Rapeseed (Brassica napus L.) Seedlings to Silver and Gold Nanoparticles

With the advancement of nanotechnology and the increasing utilization of nanoparticles (NPs), their production and release into the environment are on the rise. Consequently, it is crucial to continuously monitor the toxicity of nanoparticles for humans, animals, and plants, as well as their impact on the environment. This is particularly significant in relation to human health and food production, given the escalating use of nanomaterials in agriculture and horticulture. The aim of the study was to investigate the response of rapeseed seedlings to silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) over different periods of exposure. This research analyzed the impact of these nanoparticles on the biochemical response of rapeseed seedlings after 7, 14, and 21 days of growth in their presence. This study assessed the activity of guaiacol peroxidase (GPOX), pyrogallol peroxidase (PPOX), superoxide dismutase (SOD), and free protein content, as well as the interactions between key elements responsible for oxidative stress and the antioxidant response. The findings demonstrated a significant effect of AgNPs and AuNPs on stimulating the response of rapeseed seedlings, with the activity of PPOX, GPOX, and SOD being dependent on the exposure time and the type and dose of nanoparticles used. Enzyme activity increased with the length of exposure time, while the content of free protein decreased over the weeks. The most intense reaction of seedlings was observed in the case of GPOX, with the lowest activity observed in PPOX and SOD. High effects of the nanoparticle type and rate were also observed in the correlation matrix. This study suggests that a comprehensive analysis of plant reactions to nanoparticles could have a significant impact on the proper and effective use of nanoparticles in agriculture and horticulture. This could lead to the environmentally friendly production of high-quality plant material.

Effect of hot electron induced charge transfer generated by surface plasmon resonance on Ag@Au/ITO/PNTP systems

The present study discusses the fabrication of a bimetallic material consisting of silver nanorods and gold nanospheres (designated Ag@Au), and its surface modification with 4-nitrothiophenol (PNTP) after deposition on an indium tin oxide (ITO) glass sheet, followed by laser irradiation at various wavelengths. The results indicate that the reduction of PNTP is more complete under irradiation at 532 nm due to the surface plasmon resonance (SPR) effects of the gold and silver nanomaterials. Moreover, the surface enhanced Raman scattering (SERS) of the PNTP adsorbed on the Ag@Au/ITO is found to be significantly stronger than that of PNTP adsorbed on Ag@Au alone, due to charge transfer (CT) at the interface. In addition, the SERS enhancement effect of the PNTP molecules on the Ag@Au/ITO substrate is optimal under 532 nm laser irradiation due to the hot electron-induced CT generated by the SPR effect. Thus, the system constructed herein combines the effects of SPR and CT, thereby assisting in a further understanding of the enhancement mechanism of SERS and, hence, the further development SERS research in metal-semiconductor-molecular systems.

Characteristics and evolution of quartz-calcite-sulfide veins in the Nazca-Ocoña belt, Peru

The Nazca-Ocoña metallogenic belt in southern Peru host about 70 recognized Au-Ag and base metal (Pb-Cu-Zn) deposits such as Orión, Caravelí, Ishihuica, Calpa, Arirahua, Mollehuaca, and San Juan de Chorunga. These deposits are spatially associated with Cretaceous intrusive rocks of the coastal Batholith in a zone that extends more than 350 km along the Central to Southern part of Peru. Gold and silver are structurally controlled in mineralized NW-SE, N-S and W-E-trending fault-fill veins that are less than one-meter wide, crosscutting granodiorite and diorite bodies. The origin of the veins is still debated, and they may be classified as intrusion-related gold deposits (IRGD), orogenic or mesothermal deposits. In this study, we focus on two representative deposits in the Nazca-Ocoña metallogenic belt: Mollehuaca and San Juan de Chorunga. At both sites, the mineralization is composed of quartz-calcite sulfide veins hosted in Cretaceous Coastal Batholith intrusions. Petrographic and chemical analyses on pyrite were performed with field-emission scanning electron microscopy (FE-SEM), electron microprobe analysis (EMPA), nano-scale secondary ion mass spectrometry (NanoSIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).Native gold and Au-rich silver are disseminated throughout the veins as micro to sub-micron inclusions in pyrite and chalcopyrite, and in pyrite as cavity and fracture fill. The are three pyrite generations and these have complex internal zonation and are host to precious (Au, Ag) and base metals (Co, Ni, Cu) metals, and also metalloids (As, Sb) as lattice-bound impurities and micron inclusions. The San Juan de Chorunga pyrite has δ34S values ranging from 0.4 to 1.4 ‰, and the Mollehuaca pyrite δ34S from 5.8 to 7.4 ‰. In both San Juan de Chorunga and Mollehuaca, the highest Au concentrations occur in pyrite zones with the heaviest δ34S values. Fluid inclusion petrography of these veins shows recrystallized, wispy quartz with implosion and explosion fluid inclusion textures, indicative of pressure variations during quartz vein formation. The presence of CO2 in these inclusions requires mid-crustal pressure conditions. However, the main stage of gold mineralization occurs with carbonate, chlorite, and euhedral quartz crystals lacking post-entrapment recrystallization textures or CO2. Our observations suggest that most of the gold in these veins formed in association with a shallower hydrothermal event, potentially in association with the emplacement of batholiths and shallower intrusions in the Late Cretaceous.

How Do Intracompetition Strategies Differ Between Para Powerlifting Podium and Nonpodium Athletes? A Retrospective, Cross-Sectional Analysis.

Beaumont, P, Garrett, J, and van den Hoek, D. How do intracompetition strategies differ between para powerlifting podium and nonpodium athletes? A retrospective, cross-sectional analysis. J Strength Cond Res 38(3): 584-591, 2024-This study aimed to investigate the intracompetition strategies used by para powerlifters and quantify and report them for application by coaches and athletes to improve their odds of competitive success. A cross-sectional retrospective analysis was conducted using a public powerlifting database. Primary analysis categorized athletes as either podium (POD) or nonpodium (NPOD), and a subanalysis classified athletes as either gold medalists (GMs) or silver and bronze medalists (SBMs). Analyses of variance were used to assess the significance of the difference between groups. Pearson's correlations were used to evaluate the magnitude of the relationships and binary logistic regressions were used to quantify the variables. Results are reported as odds ratios, and an alpha level of p < 0.05 was considered statistically significant. There was a significant difference in mean age (POD = 1.6 years younger; p < 0.001), body mass (POD = 2.7 kg heavier; p = 0.006), and best lift (POD = 19.5 kg greater; p < 0.001) for female POD athletes compared with NPOD athletes. For male POD athletes compared with NPOD athletes, there was a difference in mean age (POD = 0.6 years younger; p = 0.035) and best lift (POD = 28.4 kg greater; p < 0.001). Comparing GMs with SBMs showed a significant difference in the mean best lift in both men (GM = 17.4 kg greater; p < 0.001) and women (GM = 11.1 kg greater; p < 0.001). A positive relationship was seen in both the primary and subanalysis between the number of successful lifts (of 3) and an increase in the odds of competitive success (i.e., winning). The findings of this research indicate that high-performing para powerlifters tend to choose attempt weights that prioritize the successful completion of all 3 intracompetition lifts to win a competition.

Electrochemical Sensors based on Gold-Silver Core-Shell Nanoparticles Combined with a Graphene/PEDOT:PSS Composite Modified Glassy Carbon Electrode for Paraoxon-ethyl Detection.

Herein, a nonenzymatic detection of paraoxon-ethyl was developed by modifying a glassy carbon electrode (GCE) with gold-silver core-shell (Au-Ag) nanoparticles combined with the composite of graphene with poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS). These core-shell nanoparticles (Au-Ag) were synthesized using a seed-growth method and characterized using UV-vis spectroscopy and high-resolution transmission electron microscopy (HR-TEM) techniques. Meanwhile, the structural properties, surface morphology and topography, and electrochemical characterization of the composite of Au-Ag core-shell/graphene/PEDOT:PSS were analyzed using infrared spectroscopy, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS) techniques. Moreover, the proposed sensor for paraoxon-ethyl detection based on Au-Ag core-shell/graphene/PEDOT:PSS modified GCE demonstrates good electrochemical and electroanalytical performance when investigated with cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry techniques. It was found that the synergistic effect between Au-Ag core-shell nanoparticles and the composite of graphene/PEDOT:PSS provides a higher conductivity and enhanced electrocatalytic activity for paraoxon-ethyl detection at an optimum pH of 7. At pH 7, the proposed sensor for paraoxon-ethyl detection shows a linear range of concentrations from 0.2 to 100 μM with a limit of detection of 10 nM and high sensitivity of 3.24 μA μM-1 cm-2. In addition, the proposed sensor for paraoxon-ethyl confirmed good reproducibility, with the possibility of being further developed as a disposable electrode. This sensor also displayed good selectivity in the presence of several interfering species such as diazinon, carbaryl, ascorbic acid, glucose, nitrite, sodium bicarbonate, and magnesium sulfate. For practical applications, this proposed sensor was employed for the determination of paraoxon-ethyl in real samples (fruits and vegetables) and showed no significant difference from the standard spectrophotometric technique. In conclusion, this proposed sensor might have a potential to be developed as a platform of electrochemical sensors for pesticide detection.

Magnetic-assisted sequential templated self-assembly of hybrid colloid nanoparticle systems.

The assembly of hybrid nanoparticles is a pioneering route for developing nanoscale functional devices, enabling breakthroughs in various fields, including electronics, photonics, energy, sensing, and biomedical applications. Here, we focus on the templated assembly of nano-sized colloidal systems using a combination of silica-coated superparamagnetic beads (MBs) and polymer-coated gold nanoparticles (AuNPs) or silver nanoparticles (AgNPs). These hybrid nanoparticles introduce new functionalities that allow them to be used as nanomachines with numerous possible applications. Using sequential capillarity-assisted particle assembly (sCAPA), we deposit MBs with activating nano-transducers made of PNIPAm@AuNPs, which respond to specific external stimuli such as temperature variations. We deposit MBs with surface-enhanced Raman scattering (SERS) AgNPs, which have the ability to detect molecules at low concentrations. A key achievement of our study is demonstrating the successful CAPA assembly of nanoparticles with ingenious surface chemistry and retrieving these assembled structures from nanotraps in a liquid medium. This ability highlights the potential of hybrid colloids in precisely targeted drug delivery systems and highly effective mobile sensors. It represents a significant leap forward in using nanotechnology to create more complex and responsive nanoscale assemblies.

Experimental study on mineral processing of shallow oxidation ore in a hydrothermal metasamatic sulfide gold mine

The ore produced by a gold mine in Fujian province belongs to hydrothermal metasomatism sulfide type gold (silver) ore, and the shallow oxidized ore of the deposit has a gold grade of 0.91g/t. In order to understand the selectability of this oxidized ore, the selectability test study is carried out. Through the beneficiation test study, the concentration of-0.074mm is 70%, the concentration of isoopyl yellow is 150g/t, the concentration of butyl ammonium black is 50g/t, and the concentrate products of 16.98g/t can be obtained, and the gold recovery rate is 74.04%.

Antitumor efficacy of synthesized Ag–Au nanocomposite loaded with PEG and ascorbic acid in human lung cancer stem cells

Lung cancer is the leading cause of mortality worldwide of which non-small cell lung carcinoma constitutes majority of the cases. High mortality is attributed to early metastasis, late diagnosis, ineffective treatment and tumor relapse. Chemotherapy and radiotherapy form the mainstay of its treatment. However, their associated side effects involving kidneys, nervous system, gastrointestinal tract, and liver further adds to dismal outcome. These disadvantages of conventional treatment can be circumvented by use of engineered nanoparticles for improved effectiveness with minimal side effects.In this study we have synthesized silver gold nanocomposite (Ag–Au NC) using polyethylene glycol and l-ascorbic acid as surfactant and reducing agent respectively. Synthesized nanocomposite was characterized by ultraviolet–visible absorption, dynamic light scattering, scanning and transmission electron microscopy. Compositional analysis was carried out by energy dispersive X-ray analysis and average pore diameter was estimated using Barrett-Joyner-Halenda method. In-silico molecular docking analysis of the synthesized NC against active regions of epidermal growth factor receptor revealed good binding energy. Subsequently, we investigated the effect of NC on growth and stem cell attributes of A549 lung cancer cells. Results showed that NC was effective in inhibiting A549 cell proliferation, induced DNA damage, G2/M phase arrest and apoptosis. Further, tumor cell migration and spheroid formation were also negatively affected. NC also enhanced reactive oxygen species generation and mitochondrial depolarization. In addition, the effect of NC on putative cancer stem cells in A549 cells was evaluated. We found that Ag–Au NC at IC50 targeted CD44, CD24, CD166, CD133 and CD326 positive cancer stem cells and induced apoptosis. CD166 positive cells were relatively resistance to apoptosis.Together our results demonstrate the anticancer efficacy of Ag–Au NC mediated by a mechanism involving cell cycle arrest and mitochondrial derangement.

Complementary imaging of nanoclusters interacting with mitochondria via stimulated emission depletion and scanning transmission electron microscopy

The emerging stress caused by nanomaterials in the environment is of great concern because they can have toxic effects on organisms. However, thorough study of the interactions between cells and diverse nanoparticles (NPs) using a unified approach is challenging. Here, we present a novel approach combining stimulated emission depletion (STED) microscopy and scanning transmission electron microscopy (STEM) for quantitative assessment, real-time tracking, and in situ imaging of the intracellular behavior of gold–silver nanoclusters (AuAgNCs), based on their fluorescence and electron properties. The results revealed an aggregated state of AuAgNCs within the mitochondria and an increase in sulfur content in AuAgNCs, presumably owing to their reaction with thiol-containing molecules inside the mitochondria. Moreover, AuAgNCs (100 μg/mL) induced a 75% decline in mitochondrial membrane potential and a 12-fold increase of mitochondrial reactive oxygen species in comparison to control. This mitochondrial damage may be triggered by the reaction of AuAgNCs with thiol, which provides direct imaging evidence for uncovering the action mechanism of AuAgNCs on the mitochondria. The proposed dual-imaging strategy using STED and STEM is a potential tool to offer valuable insights into cytotoxicity between subcellular structures and diverse NPs, and can serve as a key strategy for nanomaterial biosafety assessment.

Deep Structure of Epithermal Deposits in Youxi Area: Insights from CSAMT and Dual-Frequency IP Data

Epithermal deposits represent a significant category of gold occurrences, with their subsurface structure playing a key role in reserve assessments. Fujian Province, characterized by extensive Mesozoic volcanic activities, stands out as a noteworthy region for shallow hydrothermal mineralization in China. This paper focus on the Youxi area within Fujian Province, employing the dual-frequency induced polarization method (DFIP) and controlled-source audio-frequency magnetotelluric method (CSAMT) to investigate the target ore. The DFIP results revealed predominant northeast-oriented zones with high polarizability and notable apparent resistivity. The CSAMT data were inverted using the SCS2D software. Two-dimensional resistivity profiles reveal a three-layer electrical structure, comprising subsurface banded rhyolites influenced by fault zones, intermediate-low resistivity sandstone layers, and deep-seated high-resistivity conglomerates. The resistivity gradient zones and highly polarizable locations align closely with known local faults. We interpreted these resistivity gradient zones as prospective target areas for mineralization, a hypothesis subsequently validated by drilling results. Combining geochemical analyses of epithermal gold deposits with the electrical resistivity structure, we propose an explanatory model for the mechanism of the formation of epithermal gold–silver deposits in the Youxi area. The magmatic hydrothermal fluids ascended along the fault, underwent convection-driven interaction with meteoric waters, and subsequently metasomatized the host rocks. This integrated approach provides valuable insights into the geological processes governing epithermal gold–silver deposit formation in the Youxi region.

Mechanism of the cytotoxic effect of noble metal polyacrylates on tumor cells

The present study was carried out to investigate and compare the cytotoxic activities and mechanism of action of gold polyacrylates (aurumacryl) and silver polyacrylates (argacryl) using human tumor cell line (MCF-7 cell culture). The tested compounds showed high cytotoxic activity. It was found that argacryl is 20 times more effective than aurumacryl. It was established that apoptosis represents the dominant mechanism by which tumor cells undergo cell death induced by aurumacryl and argacryl. Differences in the effect of drugs on the DNA structure in tumor cells were found.

Antibacterial efficacy of NanoCare, Fullerene (C60) activated by UV light, and Morinda Oleifera against S.Mutans and bond integrity of composite resin to caries affected dentin

AimAssessment of the impact of contemporary disinfection techniques Moringa Oleifera (M. Oleifera), NanoCare Plus Silver Gold® (Nanocare), and Fullerene (C60) on survival rates of S.Mutans and shear bond strength (SBS) of composite to the carious affected dentin (CAD) Material and methodsSixty mandibular molars having caries progression till the middle 1/3rd of the dentin were disinfected. The CAD surface of twenty samples was inoculated with S.mutans. Based on different disinfection regimens samples were arbitrarily assigned to four groups (n:15) Group 1: 2 % CHX, Group 2:NanoCare, Group 3:Fullerene (C60), and Group 4 (M. Oleifera. This was followed by calculating the survival rate of S.mutans. Ten samples from each group were then restored with composite restoration and thermocycled. Assessment of SBS and failure mode was performed using a universal testing machine and stereomicroscope at 40X magnification. Statistical significance among groups was assessed using analysis of variance (ANOVA) and Tukey's test at a significance level of p = 0.05 ResultsGroup 2 samples treated with NanoCare exhibited the lowest survival rate (0.39 ± 0.02 CFU/ml) of S.Mutans. However, Group 1 (CHX) samples exhibited the highest survival count (0.51±0.10 CFU/ml). Furthermore, the highest composite to CAD bond was observed in Group 3 Fullerene(C60) (18.44±0.25 MPa) samples and the lowest SBS was observed in Group 1 (CHX) (12.48±1.69 MPa) CONCLUSIONFullerene(C60) and Moringa Oleifera extract hold promise as potential substitutes for chlorhexidine (CHX) in clinical applications, offering the potential for improved S.Mutans elimination and enhanced bond strength to CAD surface

Bimetallic nanoparticles green synthesis from litchi leaf extract: a promising approach for breast cancer treatment

Noble metal nanoparticles have demonstrated promising biomedical and nanomedicine applications, and their bimetallic equivalents from the green synthesis approach are expected to be more promising. This study concerns bimetallic nanoparticle’s synthesis, characterization, and structure-function analysis for their potential application in breast cancer. Silver core (SCNPs) and Gold core (GCNPs) bimetallic nanoparticles were synthesized using Litchi Chinesis leaf extract (LCLE) and characterized using various physio-chemical techniques. The results revealed the successful synthesis of SCNPs and GCNPs with distinct surface plasmon resonance peaks at 551 nm and 531 nm, hydrodynamic sizes of 66 nm and 53 nm, and Zeta potential values of −26.0 mV and −20.6 mV. XRD analysis confirmed the presence of silver and gold phases, while HR-TEM images revealed spherical shapes for SCNPs and heterogenous shapes for GCNPs. Both nanoparticles demonstrated dose and time-dependent inhibition of breast cancer cell growth, with GCNPs requiring a higher concentration than SCNPs at 48 h compared to 24 h. Cell cycle evaluation indicated a cell cycle arrest in the G2M phase for both nanoparticles, an impact on the S phase distribution, and reactive oxygen species (ROS) generation, further contributing to their antiproliferative effects.