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1.
Heliyon ; 10(11): e32147, 2024 Jun 15.
Article in English | MEDLINE | ID: mdl-38947480

ABSTRACT

Barrier layers against intermetallic diffusion are a fundamental part on engineering electroplated coatings as they improve the lifetime of goods reducing wastes and improving the sustainability of the production chain. This study aims to set a cost-effective methodology to characterize barrier systems by evaluating the effectiveness with a recent approach based on XRF and EDS and characterize the kinetic of diffusion processes with X-ray diffractometry. Several high fashion barrier systems were tested highlighting that anticorrosion systems are not automatically suited as barrier layers for intermetallic diffusion, as opposed to industrial practice. Investigations on gold coatings obtained varying the current density revealed a correlation between the activation energy of the diffusion process, roughness, and crystallite size.

2.
J Funct Biomater ; 15(6)2024 Jun 19.
Article in English | MEDLINE | ID: mdl-38921542

ABSTRACT

Nanoparticle (NP)-based solutions for oncotherapy promise an improved efficiency of the anticancer response, as well as higher comfort for the patient. The current advancements in cancer treatment based on nanotechnology exploit the ability of these systems to pass biological barriers to target the tumor cell, as well as tumor cell organelles. In particular, iron oxide NPs are being clinically employed in oncological management due to this ability. When designing an efficient anti-cancer therapy based on NPs, it is important to know and to modulate the phenomena which take place during the interaction of the NPs with the tumor cells, as well as the normal tissues. In this regard, our review is focused on highlighting different approaches to studying the internalization patterns of iron oxide NPs in simple and complex 2D and 3D in vitro cell models, as well as in living tissues, in order to investigate the functionality of an NP-based treatment.

3.
Bioengineering (Basel) ; 11(6)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38927857

ABSTRACT

Magnesium-based multicomponent alloys with different compositions, namely Mg60Al20Zn5Cu10Mn5 (Mg60 alloy), Mg70Al15Zn5Cu5Mn5 (Mg70 alloy), and Mg80Al5Cu5Mn5Zn5 (Mg 80) alloys, were prepared using the disintegrated melt deposition technique. The DMD technique is a distinctive method that merges the benefits from gravity die casting and spray forming. This approach facilitates high solidification rates, process yields, and reduced metal wastage, resulting in materials with a fine microstructure and minimal porosity. Their potential as biodegradable materials was assessed through corrosion in different simulated body fluids (SBFs), microstructure, and cytotoxicity tests. It was observed that the Mg60 alloy exhibited low corrosion rates (~× 10-5 mm/year) in all SBF solutions, with a minor amount of corrosive products, and cracks were observed. This can be attributed to the formation of the Mg32(AlZn)49 phase and to its stability due to Mg(OH)2 film, leading to excellent corrosion resistance when compared to the Mg70 and M80 alloys. Conversely, the Mg80 alloy exhibited high corrosion rates, along with more surface degradation and cracks, due to active intermetallic phases, such as Al6Mn, Al2CuMg, and Al2Cu phases. The order of corrosion resistance for the Mg alloy was found to be ASS > HBSS > ABP > PBS. Further, in vitro cytotoxicity studies were carried out using MDA-MB-231 tumor cells. By comparing all three alloys, in terms of proliferation and vitality, the Mg80 alloy emerged as a promising material for implants, with potential antitumor activity.

4.
J Oral Biol Craniofac Res ; 14(4): 435-440, 2024.
Article in English | MEDLINE | ID: mdl-38832295

ABSTRACT

Background: Fluoridated mouth rinses improve anti-cariogenic environment but decrease oral pH below critical value, affecting orthodontic bracket surface topography and causing corrosive changes over prolonged use. This invitro study aimed to quantitatively and qualitatively assess the surface topography and metallic ion release of the stainless steel (SS) brackets at varying acidic and alkaline pH. Materials and methods: Forty unused SS brackets were divided into four groups (Group A, B, C, D) and immersed for 48- hours in solutions of artificial saliva and sodium fluoride (0.2 %) mouth rinse at varying pH of 5.5,6.7,7 and 8. The surface morphologic changes were analyzed under scanning electron microscope (SEM) at 50×, 150×, and 500× magnification. The changes in slot area were scored using the customized scale. The Energy Dispersive Xray Spectroscopy Analysis (EDAX) was used to estimate the probed elements' atomic and weight percentage. Results: The mean score of the scale was 3.4 for the brackets immersed in the acidic solution which was statistically significant (p = 0.00)and for alkaline and neutral solutions (p = 0.00). Chromium was found to be significantly higher in the alkaline solution (p = 0.016) followed by the neutral solution. Carbon was found excess in acidic solution than the neutral and alkaline solution. Conclusion: Quantitative and qualitative analysis of the ion release in stainless steel brackets using SEM and EDAX revealed the corrosive effect of fluoride ion causing maximum surface changes in acidic medium and chromium release in alkaline pH.

5.
Article in English | MEDLINE | ID: mdl-38861199

ABSTRACT

The trio elements found in Gunshot Residue (GSR) are considered the key elements that are characteristic of GSR. To date, most forensic laboratories have mainly concentrated on employing carbon stubs analyzed by Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) to find IGSR on the hands and clothing of a person. A little elevated from the normal practice, this work is focused on the evaluation of compositional and morphological variations of GSR collected from muzzle end, trajectory, and target obtained by firing the ammunition of choice (9×19 mm Indian ammunition). Even though there may be variations in IGSR compositions within various locations of a weapon, this hasn't been investigated or documented up to this point. To ascertain whether it is possible to identify any variation in GSR particles gathered from these three different locations, the objective of this study is to investigate the structural characteristics and elemental composition of GSR to identify the distinctive parameters that allow for comparison and to establish the composition of the primer. The study also focuses on assessing any possible surface modification that may occur to GSR upon striking the target and establishing a correlation between GSR particles and propellant powder. The collected GSR samples were analyzed using a digital microscope, SEM/EDS, and EDXRF. It was discovered that the primer type showed a strong correlation to the elemental composition and morphology of GSR. By analyzing the GSR particles collected from the various sites as mentioned above, it was possible to identify the primer mixture used in the ammunition and its diversity in elemental concentration. The obtained GSR samples were not spherical but showed an elongated structure and possessed a diameter ranging from 695.4 µm-1.640 mm, 536.2 µm-1.412 mm, and 775.8 µm-1.772 mm respectively. However, the morphology and the size distribution of the particles collected from all three different points showed slight deviation as moving from ME towards TG. The obtained results could identify the primer mixture and diversity in its elemental concentration. The morphology and size distribution of GSR collected from three different points showed deviations.

6.
Materials (Basel) ; 17(10)2024 May 15.
Article in English | MEDLINE | ID: mdl-38793413

ABSTRACT

The resistance of nickel-titanium endodontic instruments against cyclic fatigue failure remains a significant concern in clinical settings. This study aimed to assess the cyclic fatigue strength of five nickel-titanium rotary systems, while correlating the results with the instruments' geometric and metallurgical characteristics. A total of 250 new instruments (sizes S1/A1, S2/A2, F1/B1, F2/B2, F3/B3) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-Files systems underwent mechanical testing. Prior to experimental procedures, all instruments were meticulously inspected to identify irregularities that could affect the investigation. Using a stereomicroscope, design characteristics such as the number of spirals, length, spirals per millimeter, and average helical angle of the active blade were determined. The surface finishing characteristics of the instruments were examined using a scanning electron microscope. Differential scanning calorimetry was employed to establish the instruments' phase transformation temperatures, while energy-dispersive X-ray spectroscopy was utilized to analyze the elemental composition of the alloy. The instruments were subjected to cyclic fatigue testing within a stainless steel non-tapered artificial canal featuring a 6 mm radius and 86 degrees of curvature. Appropriate statistical tests were applied to compare groups, considering a significance level of 0.05. The assessed design characteristics varied depending on the instrument type. The least irregular surface finishing was observed in U-Files and Premium Taper Gold files, while the most irregular surface was noted in Go-Taper Flex. All instruments exhibited near-equiatomic proportions of nickel and titanium elements, whereas ProTaper Universal and U-Files instruments demonstrated lower phase transformation temperatures compared to their counterparts. Larger-sized instruments, as well as ProTaper Universal and U-Files, tended to display lower cyclic fatigue strength results. Overall, the design, metallurgical, and cyclic fatigue outcomes varied among instruments and systems. Understanding these outcomes may assist clinicians in making more informed decisions regarding instrument selection.

7.
Aust Endod J ; 2024 May 21.
Article in English | MEDLINE | ID: mdl-38773855

ABSTRACT

To use scanning electron microscopy and energy dispersive X-ray spectroscopy to evaluate the metallurgical-chemical changes of WaveOne Gold (WOG) and R-Motion (RM), after multiple uses. The instruments were divided into groups (n = 8): WOG and RM-control groups, new instruments; WOG1 and RM1; WOG2 and RM2; WOG3 and RM3 after instrumentation of 1, 2 or 3 molars, respectively. Burrs occurred mainly in the control group and after the first use. The RM files were found to have a higher nickel content, which increased during reuse, and a decrease in oxygen content with increasing reuse, in addition to calcium impregnation, which occurred in greater amounts in the corrosion areas in the WOG files. The presence of topographic and chemical changes was demonstrated, indicating that caution should be taken when reusing endodontic instruments to avoid fractures.

8.
Cureus ; 16(4): e58709, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38779263

ABSTRACT

Background Electrochemical sensing is a versatile field that uses electrochemistry concepts to detect and measure various substances. It finds applications in clinical diagnostics and environmental monitoring. Scientists are currently working on creating reliable electrochemical sensing devices that can accurately detect ascorbic acid. Iron sulfide (FeS) has emerged as a promising material for these sensors due to its excellent electrical conductivity, catalytic activity, and stability.  Materials and methods The FeS nanoparticles were synthesized through the hydrothermal method of synthesis. The glassy carbon electrode (GCE) with a surface area of 0.071 cm2 was modified with FeS before the working electrode was mechanically polished with 1 µm, 0.3 µm, and 0.05 µm alumina pastes for mirror finishing. Then it was subjected to ultrasonication in double distilled water for a few minutes to clean the surface of GCE. The FeS suspension was prepared by dispersing 5 mg of FeS in 10 mL of ethanol during 20 minutes of ultrasonic agitation then the GCE was coated with 10 µL of the suspension by drop coating method and dried in air. Results In this study, FeS nanoparticles were synthesized by the hydrothermal method of synthesis, and it was tested for their electrochemical sensing properties by various tests. Based on the field emission-scanning electron microscope (FE-SEM) analysis, scan rate effect test, cyclic voltammetric test, X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) spectroscopy analysis done and results obtained, it was seen that the synthesized FeS nanoparticles are highly pure and have a crystalline structure. FeS has an even morphology. The synthesized particles also showed highly sensitive and specific sensing toward ascorbic acid when compared to unmodified 10.1 µA electrodes with a sensing value of 12.51 µA, thereby fulfilling the aim of this study. Conclusion Based on the outcomes of the diverse tests carried out, it is evident that the sample displayed a high crystalline nature as indicated by the XRD test. Additionally, the sample exhibited a uniform morphology, exceptional stability, and remarkable sensitivity. The developed FeS-based electrochemical sensor was found to be exceptionally pure and showed excellent performance, showcasing both high sensitivity and selectivity toward ascorbic acid.

9.
Biomolecules ; 14(5)2024 May 20.
Article in English | MEDLINE | ID: mdl-38786012

ABSTRACT

BACKGROUND: Enamel plays an essential role in protecting the underlying layers of the human tooth; therefore, preserving it is vital. This experimental study aimed to evaluate the potential ability of L. brevis to counteract the action of a demineralizing agent on dental enamel morphology and mineral composition in vitro. METHODS: The sample consisted of 12 healthy human posterior teeth. The coronal portion of each tooth was subdivided into two equal parts longitudinally. The specimens were randomly divided into four groups: artificial saliva, L. brevis suspension, demineralizing agent (DA), and DA plus L. brevis. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to evaluate the surface micromorphology and the mineral content, respectively. The statistical analysis was conducted using a one-way ANOVA, followed by Tukey's post hoc test. RESULTS: SEM analysis did not highlight significant changes in the enamel microstructure of L. brevis-treated specimens compared to the control. DA-induced damage to the enamel structure was drastically reduced when the specimens were contextually exposed to the probiotic. The treatment with DA substantially reduced the weight % of crucial enamel minerals, i.e., Ca and P. Notably, the probiotic was able to reverse the demineralization process, bringing Ca and P weight % back to basal levels, including the Ca/P ratio. CONCLUSIONS: The findings indicate that L. brevis is able to efficiently protect the dental enamel surface from the damage caused by DA and increase the enamel resistance to demineralization. Overall, L. brevis confirms its efficacy in preventing or counteracting the action of carious lesions through a novel mechanism that protects the tooth surface under a chemical challenge that mimics the caries process.


Subject(s)
Dental Enamel , Probiotics , Tooth Demineralization , Humans , Dental Enamel/drug effects , Tooth Demineralization/prevention & control , Microscopy, Electron, Scanning , Spectrometry, X-Ray Emission , Surface Properties , In Vitro Techniques
10.
Front Microbiol ; 15: 1367658, 2024.
Article in English | MEDLINE | ID: mdl-38737410

ABSTRACT

Introduction: Nitrososphaeria, formerly known as Thaumarchaeota, constitute a diverse and widespread group of ammonia-oxidizing archaea (AOA) inhabiting ubiquitously in marine and terrestrial environments, playing a pivotal role in global nitrogen cycling. Despite their importance in Earth's ecosystems, the cellular organization of AOA remains largely unexplored, leading to a significant unanswered question of how the machinery of these organisms underpins metabolic functions. Methods: In this study, we combined spherical-chromatic-aberration-corrected cryo-electron tomography (cryo-ET), scanning transmission electron microscopy (STEM), and energy dispersive X-ray spectroscopy (EDS) to unveil the cellular organization and elemental composition of Nitrosopumilus maritimus SCM1, a representative member of marine Nitrososphaeria. Results and Discussion: Our tomograms show the native ultrastructural morphology of SCM1 and one to several dense storage granules in the cytoplasm. STEM-EDS analysis identifies two types of storage granules: one type is possibly composed of polyphosphate and the other polyhydroxyalkanoate. With precise measurements using cryo-ET, we observed low quantity and density of ribosomes in SCM1 cells, which are in alignment with the documented slow growth of AOA in laboratory cultures. Collectively, these findings provide visual evidence supporting the resilience of AOA in the vast oligotrophic marine environment.

11.
Materials (Basel) ; 17(3)2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38591374

ABSTRACT

This paper reviews quantitative characterization via transmission electron microscopy (TEM) and its application to interfacial phenomena based on the results obtained through the studies. Several signals generated by the interaction between the specimen and the electron beam with a probe size of less than 1 nm are utilized for a quantitative analysis, which yields considerable chemical and physical information. This review describes several phenomena near the interfaces, e.g., clear solid-vapor interface (surface) segregation of yttria in the zirconia nanoparticles by an energy-dispersive X-ray spectroscopy analysis, the evaluation of the local magnetic moment at the grain boundary in terms of electron energy loss spectroscopy equipped with TEM, and grain boundary character dependence of the magnetism. The direct measurement of the stress to the dislocation transferred across the grain boundary and the microstructure evolution focused on the grain boundary formation caused by plastic deformation are discussed as examples of material dynamics associated with the grain boundary. Finally, the outlook for future investigations of interface studies, including the recent progress, is also discussed.

12.
Nanotechnology ; 35(29)2024 May 01.
Article in English | MEDLINE | ID: mdl-38631325

ABSTRACT

We report on the fabrication of a novel design of GaAs/(In,Ga)As/GaAs radial nanowire heterostructures on a Si 111 substrate, where, for the first time, the growth of inhomogeneous shells on a lattice mismatched core results in straight nanowires instead of bent. Nanowire bending caused by axial tensile strain induced by the (In,Ga)As shell on the GaAs core is reversed by axial compressive strain caused by the GaAs outer shell on the (In,Ga)As shell. Progressive nanowire bending and reverse bending in addition to the axial strain evolution during the two processes are accessed byin situby x-ray diffraction. The diameter of the core, thicknesses of the shells, as well as the indium concentration and distribution within the (In,Ga)As quantum well are revealed by 2D energy dispersive x-ray spectroscopy using a transmission electron microscope. Shell(s) growth on one side of the core without substrate rotation results in planar-like radial heterostructures in the form of free standing straight nanowires.

13.
Clin Oral Investig ; 28(2): 147, 2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38351377

ABSTRACT

BACKGROUND: Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ. MATERIAL AND METHODS: A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control. RESULTS: CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression. CONCLUSION: PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.


Subject(s)
Bisphosphonate-Associated Osteonecrosis of the Jaw , Bone Density Conservation Agents , Temporomandibular Joint Disorders , Humans , Bisphosphonate-Associated Osteonecrosis of the Jaw/pathology , Core Binding Factor Alpha 1 Subunit , Retrospective Studies , Jaw , Diphosphonates/therapeutic use
14.
J Oral Sci ; 66(1): 50-54, 2024.
Article in English | MEDLINE | ID: mdl-38233154

ABSTRACT

PURPOSE: The aim of the present study was to develop a novel method for distinguishing white spot lesions (WSLs) from sound enamel in human premolars using micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and to examine differences in surface morphology, chemical composition, and mineral density (MD) between these two areas. METHODS: Fourteen premolars with natural WSLs on the enamel surface of the crowns were examined. After sectioning the teeth, each specimen containing WSLs adjacent to intact enamel was examined for MD, surface morphology, and atomic percentages (At%) of chemical components using micro-CT and SEM/EDS, respectively. Differences between these areas of the same specimen were analyzed statistically using paired t-test. RESULTS: SEM images highlighted increased roughness and irregularity in the lesion area. EDS analysis revealed significant reductions in calcium (Ca), phosphorus (P), fluorine (F), chlorine (Cl), and sodium (Na) levels at the lesion surface in comparison to intact enamel (P < 0.05). The decreases in the MD of the lesions were statistically significant in comparison to sound enamel (P < 0.05). CONCLUSION: These findings provide standard measurements for evaluating the essential characteristics of WSLs and intact enamel, being vital for assessment of treatment outcomes and development of innovative biomaterials for management of hypo-mineralized enamel lesions.


Subject(s)
Dental Caries , Dental Enamel , Humans , X-Ray Microtomography/methods , Bicuspid/diagnostic imaging , Bicuspid/chemistry , Bicuspid/pathology , Microscopy, Electron, Scanning , Dental Enamel/diagnostic imaging , Dental Enamel/pathology , Minerals/analysis , Spectrometry, X-Ray Emission , Dental Caries/pathology
15.
Photobiomodul Photomed Laser Surg ; 42(1): 81-89, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38252494

ABSTRACT

Objective: The aim of this study is to evaluate the efficacy of two different fluoride varnishes used alone or in combination with laser treatment on permanent and primary tooth enamel. Methods: Ninety-six primary and 96 permanent molar samples were divided into six groups. The levels of calcium, phosphorus, fluoride, and silver ions of each sample were analyzed using energy-dispersive X-ray spectroscopy (EDS). Six different treatments were applied to 12 different groups (n = 15) as control (g1/G1), fluoride varnish (g2/G2), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-fluoride varnish (g3/G3), laser (g4/G4), laser+fluoride varnish (g5/G5), and laser+CPP-ACP-fluoride varnish (g6/G6). After the procedures, ion levels were reanalyzed with EDS. The teeth were subjected to the artificial caries-forming procedure and ion levels were again evaluated by EDS. One sample from each group was prepared separately for the focused ion beam-scanning electron microscope measurement; initial and final images were recorded. The obtained data were statistically analyzed with the SPSS 23.0 program. Results: Compared with the initial measurement, phosphorus percentages increased in most of the groups in the last measurement. Calcium percentages of primary teeth increased in the last measurement, except for the g1 group, but in permanent teeth, there was an increase only in the G6 group. There was a statistically significant difference between g1/G1 and g6/G6 groups in the last measurement of phosphorus and calcium percentages. Conclusions: The combined use of laser with CPP-ACP-fluoride varnish enhanced remineralization in the primary and permanent teeth. However, in permanent teeth, the use of laser alone was not as effective as in primary teeth. Therefore, combined usage with CPP-ACP-fluoride varnish can enhance its efficacy. This in vitro study was approved by the local ethics committee of Hacettepe University (Project No.: GO 20/441).


Subject(s)
Lasers, Solid-State , Humans , Calcium , Fluorides, Topical , Minerals , Phosphorus , Ions , Dental Enamel
16.
Int J Mol Sci ; 25(2)2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38256176

ABSTRACT

Advancements in polymer science and nanotechnology hold significant potential for addressing the increasing demands of food security, by enhancing the shelf life, barrier properties, and nutritional quality of harvested fruits and vegetables. In this context, biopolymer-based delivery systems present themselves as a promising strategy for encapsulating bioactive compounds, improving their absorption, stability, and functionality. This study provides an exploration of the synthesis, characterization, and postharvest protection applications of nanocarriers formed through the complexation of chitosan oligomers, carboxymethylcellulose, and alginate in a 2:2:1 molar ratio. This complexation process was facilitated by methacrylic anhydride and sodium tripolyphosphate as cross-linking agents. Characterization techniques employed include transmission electron microscopy, energy-dispersive X-ray spectroscopy, infrared spectroscopy, thermal analysis, and X-ray powder diffraction. The resulting hollow nanospheres, characterized by a monodisperse distribution and a mean diameter of 114 nm, exhibited efficient encapsulation of carvacrol, with a loading capacity of approximately 20%. Their suitability for phytopathogen control was assessed in vitro against three phytopathogens-Botrytis cinerea, Penicillium expansum, and Colletotrichum coccodes-revealing minimum inhibitory concentrations ranging from 23.3 to 31.3 µg·mL-1. This indicates a higher activity compared to non-encapsulated conventional fungicides. In ex situ tests for tomato (cv. 'Daniela') protection, higher doses (50-100 µg·mL-1, depending on the pathogen) were necessary to achieve high protection. Nevertheless, these doses remained practical for real-world applicability. The advantages of safety, coupled with the potential for a multi-target mode of action, further enhance the appeal of these nanocarriers.


Subject(s)
Chitosan , Cymenes , Solanum lycopersicum , Carboxymethylcellulose Sodium , Alginates
17.
Trends Microbiol ; 32(3): 219-220, 2024 03.
Article in English | MEDLINE | ID: mdl-38281864

ABSTRACT

Iron is an essential nutrient for bacterial pathogenesis. In their study, Skaar and colleagues (Pi et al.) discovered and determined the detailed structure of ferrosomes within Clostridioides difficile, the iron-storage organelles that form under iron-limited conditions in anticipation of future iron overload.


Subject(s)
Bacterial Proteins , Ferric Compounds , Iron , Bacterial Proteins/metabolism , Iron/metabolism , Gene Expression Regulation, Bacterial
18.
Small ; 20(21): e2308001, 2024 May.
Article in English | MEDLINE | ID: mdl-38100205

ABSTRACT

Y3Al5O12:Ce (YAG:Ce) phosphors are extensively used in the field of white light-emitting diodes (LEDs) due to their efficient luminescent properties. To optimize the performance of YAG:Ce phosphors, a comprehensive understanding of their synthesis and structural evolution is essential. This paper presents a direct in situ transmission electron microscopy (TEM) /scanning TEM (STEM) investigation on the transformation process of a precursor comprising nanocrystalline CeO2 dispersed in an amorphous Y-Al oxide matrix into crystalline YAG:Ce particles. The study reveals that nanocrystalline CeO2 particles dissolve completely in the Y-Al oxide matrix at a temperature above 900 °C, while YAlO3 (YAP)-type crystalline particles with Al2O3 phase in grain boundaries are observed above 1000 °C. Finally, YAG:Ce-type crystalline particles are formed above 1180 °C. Atomic-resolution energy-dispersive X-ray spectroscopy (EDS) elemental mapping demonstrates that the doped cerium (Ce) atoms occupy the same atomic sites as yttrium (Y). Photoluminescence measurements validate the efficient luminescent properties of the obtained YAG:Ce phosphor.

19.
Pharmaceuticals (Basel) ; 16(11)2023 Nov 13.
Article in English | MEDLINE | ID: mdl-38004463

ABSTRACT

Eimeria stiedae (E. stiedae) is a common coccidian species that infects the liver and causes economic losses for the rabbit industry. This study aimed to determine the efficiency of green tea aqueous extract (GTE) as a natural treatment for eimeriosis caused by E. stiedae. Male rabbits Cuniculus L. (Oryctolagus) of the New Zealand White rabbit strain (4-4.5 months) were used, as they are suitable for research and conducting experiments. Thirty rabbits were allocated into six groups, with five rabbits in each group; the G1 group (non-infected untreated) served as a negative control group; the G2 group was not infected and treated with 250 mg GTE; the G3 group was not infected and treated with 500 mg GTE; the G4 group was untreated and was infected with 3 × 104 Sporulated E. stiedae oocysts, which served as a positive control group; the G5 group was infected and treated with 250 mg GTE; and the G6 group was infected and treated with 500 mg GTE. The hematological and biochemical analyses of each group of rabbit sera were carried out. Phytochemical analysis was performed to evaluate the active components in GTE leaves using the following methods: IR spectroscopy, liquid chromatography-mass spectrometry (LC-MS), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy. The infected rabbit groups treated with GTE at both doses of 250 and 500 mg/kg exhibited a significant decrease in the extent of E. stiedae oocyst shedding compared with the infected untreated group at 14, 21, and 28 days post-infection. Also, treatment with green tea showed improvement in liver weight compared with the enlarged livers of infected, untreated rabbits. The disturbance in serum liver enzymes' gamma-glutamyl transferase (GGT) and aspartate aminotransferase (AST/GOT) levels, as well as serum glucose, potassium, uric acid, cholesterol, and urea levels, were improved after the treatment of infected rabbit groups with green tea compared with the infected untreated group. Moreover, in this study, the images of the egg stages of the parasite were taken using a fluorescence microscope at 25 µm and 26 µm magnifications. This study provides promising results for the effective cell absorption of the aqueous extract of green tea, which was confirmed in the analyzed images using a scanning electron microscope at 5 µm and 20 µm magnifications.

20.
Toxics ; 11(10)2023 Sep 24.
Article in English | MEDLINE | ID: mdl-37888657

ABSTRACT

The chemical composition of COVID test swabs has not been examined beyond the manufacturer's datasheets. The unprecedented demand for swabs to conduct rapid lateral flow tests and nucleic acid amplification tests led to mass production, including 3D printing platforms. Manufacturing impurities could be present in the swabs and, if so, could pose a risk to human health. We used scanning electron microscopy and energy dispersive X-ray (EDX) spectroscopy to examine the ultrastructure of seven assorted brands of COVID test swabs and to identify and quantify their chemical elements. We detected eight unexpected elements, including transition metals, such as titanium and zirconium, the metalloid silicon, as well as post-transition metals aluminium and gallium, and the non-metal elements sulphur and fluorine. Some of the elements were detected as trace amounts, but for others, the amount was close to reported toxicological thresholds for inhalation routes. Experimental studies have shown that the detrimental effects of unexpected chemical elements include moderate to severe inflammatory states in the exposed epithelium as well as proliferative changes. Given the massive testing still being used in the context of the COVID pandemic, we urge caution in continuing to recommend repeated and frequent testing, particularly of healthy, non-symptomatic, individuals.

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