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Materials (Basel, Switzerland) Jun 2024This article presents the research results of depositing anti-friction coatings (Babbitt) using three different casting methods: static casting, flame soldering, and...
This article presents the research results of depositing anti-friction coatings (Babbitt) using three different casting methods: static casting, flame soldering, and clad welding. Babbitt alloy coatings deposited with different casting methods are discussed and explained in terms of changes in the coating properties, such as the microstructure, hardness, strength, and chemical composition. The results showed significant differences in the aforementioned properties, depending on the chosen coating deposition method. The results of the tests confirmed the importance of using shielding gas during deposition to ensure the chemical composition of the coating. The analysis revealed that decreases in the amounts of antimony and copper in the Babbitt coating compared with the initial concentrations were influenced by selective evaporation, oxidation, and the coating process parameters associated with different coating methods. To maintain the desired balance of mechanical properties in Babbitt coatings, it is important to control the antimony and copper contents. Clad welding deposition using a non-consumable tungsten electrode and argon shielding gas achieved a chemically stable coating quite close to the initial chemical composition of the Babbitt alloy.
PubMed: 38893926
DOI: 10.3390/ma17112662 -
Acta Tropica Jun 2024Owing to the persistent number of parasitic deaths, Visceral leishmaniasis continues to haunt several economically weaker sections of India. The disease causes over...
Owing to the persistent number of parasitic deaths, Visceral leishmaniasis continues to haunt several economically weaker sections of India. The disease causes over 30,000 deaths and threatens millions annually on a global scale. The standard pentavalent antimonials, on the other hand, are associated with health adversities and disease relapse. The current study is focused on the search for the most potential natural bioactive phytocompound from the bark extract of the Northeastern Indian plant, Garcinia cowa, that shows potent anti-leishmanial properties. The High Resonance Liquid Chromatography followed by Mass Spectrometry (HR-LCMS) study followed by an in silico molecular docking using computational tools revealed that α-mangostin might potentially possess antiparasitic activity. To validate the anti-leishmanial efficacy of the compound, a cell viability assay was performed, which demonstrated the parasite-specific inhibitory activity of α-mangostin; with IC values ranging from 4.95 - 7.37 µM against the different forms of Leishmania donovani parasite. The flow cytometric analysis of the phytocompound treated parasites indicated an oxidative and nitrosative stress-mediated apoptotic cell death in the parasites, by the suggestive surge in nuclear fragmentation and mitochondrial dysfunction. Simultaneously, a cytokine profiling study suggested approximate two-to-three-fold upregulated levels of pro-inflammatory cytokines post-compound treatment, which is predicted to actively contribute to parasite-killing. α-mangostin was also found to reduce the chances of parasite survival by inhibiting arginase enzyme activity, which in favorable conditions facilitates its sustenance. This study thereby substantiates that α-mangostin significantly possesses anti-leishmanial potentiality that can be developed into a cure for this infectious disease.
PubMed: 38889863
DOI: 10.1016/j.actatropica.2024.107291 -
Analytical Methods : Advancing Methods... Jun 2024A poly(luminol--anisidine--toluidine) terpolymer was synthesized, characterized, and modified with GNPs and ZnO NPs. The nanocomposites were then examined for their...
Development of an efficient electrochemical sensing platform based on ter-poly(luminol--anisidine--toluidine)/ZnO/GNPs nanocomposites for the detection of antimony (Sb) ions.
A poly(luminol--anisidine--toluidine) terpolymer was synthesized, characterized, and modified with GNPs and ZnO NPs. The nanocomposites were then examined for their electroactivity and potential use as cationic electrochemical sensors for detecting Sb ions in phosphate buffer on the surface of a glassy carbon electrode (GCE). Among the different compositions and the terpolymer, the GCE adapted with the PLAT/ZnO/GNPs-5% nanocomposite displayed the highest current response. The fabricated nanocomposite sensor exhibited high sensitivity, with a value of 21.4177 μA μM cm, and a low detection limit of 95.42 pM. The analytical performance of the sensor was evaluated over the linear dynamic range (LDR) of 0.1 nM to 0.01 mM. The proposed sensor is effective in detecting and measuring carcinogenic Sb ions in real environmental samples using an electrochemical approach, making it a promising tool for environmental monitoring.
PubMed: 38888440
DOI: 10.1039/d4ay00472h -
Environmental Science & Technology Jun 2024Antimony (Sb) isotopic fractionation is frequently used as a proxy for biogeochemical processes in nature. However, to date, little is known about Sb isotope...
Antimony (Sb) isotopic fractionation is frequently used as a proxy for biogeochemical processes in nature. However, to date, little is known about Sb isotope fractionation in biologically driven reactions. In this study, sp. J1 was selected for Sb isotope fractionation experiments with varying initial Sb concentration gradients (50-200 μM) at pH 7.2 and 30 °C. Compared to the initial Sb(III) reservoir (δSb = 0.03 ± 0.01 ∼ 0.06 ± 0.01‰), lighter isotopes were preferentially oxidized to Sb(V). Relatively constant isotope enrichment factors (ε) of -0.62 ± 0.06 and -0.58 ± 0.02‰ were observed for the initial Sb concentrations ranging between 50 and 200 μM during the first 22 days. Therefore, the Sb concentration has a limited influence on Sb isotope fractionation during Sb(III) oxidation that can be described by a kinetically dominated Rayleigh fractionation model. Due to the decrease in the Sb-oxidation rate by sp. J1, observed for the initial Sb concentration of 200 μM, Sb isotope fractionation shifted toward isotopic equilibrium after 22 days, with slightly heavy Sb(V) after 68 days. These findings provide the prospect of using Sb isotopes as an environmental tracer in the Sb biogeochemical cycle.
PubMed: 38887934
DOI: 10.1021/acs.est.3c10271 -
National Science Review Jul 2024Superconductivity (SC) was experimentally observed for the first time in antimony polyhydride. The diamond anvil cell combined with a laser heating system was used to...
Superconductivity (SC) was experimentally observed for the first time in antimony polyhydride. The diamond anvil cell combined with a laser heating system was used to synthesize the antimony polyhydride sample at high pressure and high temperature. - high pressure transport measurements as a function of temperature with an applied magnetic field were performed to study the SC properties. It was found that the antimony polyhydride samples show superconducting transition with critical temperature 116 K at 184 GPa. The investigation of SC at magnetic field revealed the superconducting coherent length of ∼40 Å based on the Ginzburg Landau (GL) equation. Antimony polyhydride superconductor has the second highest in addition to sulfur hydride among the polyhydrides of elements from main groups IIIA to VIIA in the periodic table.
PubMed: 38883292
DOI: 10.1093/nsr/nwad241 -
ACS Nano Jun 2024Nonlead low-dimensional halide perovskites attract considerable attention as X-ray scintillators. However, most scintillation screens exhibit pronounced light...
Nonlead low-dimensional halide perovskites attract considerable attention as X-ray scintillators. However, most scintillation screens exhibit pronounced light scattering, which detrimentally reduces the quality of X-ray imaging. Herein, we employed a simple and straightforward solvent-free melt-quenching method to fabricate a large-area zero-dimension (0D) antimony-based perovskite transparent medium, namely (CHP)SbCl (CHP = ethyltriphenylphosphine). The transparency is due to the large steric hindrance of CHP, which hinders the formation of crystals during the quenching process, thus forming a glass with low refractive index and uniform structure. This medium exhibits a high transmittance exceeding 80% in the range of 450-800 nm and shows a large Stokes shift of 245 nm, thereby minimizing light scattering, mitigating self-absorption, and enhancing the clarity of X-ray imaging. Moreover, it exhibits a high radioluminescence light yield of ∼12,535 photons MeV and displays a high X-ray spatial resolution of 30 lp mm owing to its high transparency. This study presents an alternative candidate for achieving high-quality X-ray detection and extends the applicability of transparent perovskite scintillators.
PubMed: 38876985
DOI: 10.1021/acsnano.4c01761 -
Langmuir : the ACS Journal of Surfaces... Jun 2024Plasmonic metal oxides are promising photocatalysts for the artificial photosynthesis of green ammonia due to localized surface plasmon resonance (LSPR) enhanced...
Plasmonic metal oxides are promising photocatalysts for the artificial photosynthesis of green ammonia due to localized surface plasmon resonance (LSPR) enhanced photoconversion and rich surface oxygen vacancies improved chemisorption and activation of dinitrogen molecules. However, these oxygen vacancies are unstable during the photocatalytic process and could be oxidized by photogenerated holes, leading to the vanishing of the LSPR. Here, we fabricated antimony-doped molybdenum trioxide nanosheets with stable plasmonic absorption extending into the near-infrared (NIR) range, even after harsh treatment in oxidative atmospheric conditions at high temperatures. For undoped plasmonic MoO nanosheets, the LSPR originates from the abundant oxygen vacancies that vanish after heat treatment at high temperatures in air, leading to the disappearance of the LSPR absorption. Sb doping does not significantly increase the concentration of oxygen vacancies while donating more free electrons because Sb can keep a lower oxidation state. Heat treatment diminished the oxygen vacancies while not affecting the low oxidation state of Sb. As a result, heat-treated Sb-doped MoO nanosheets still show strong LSPR absorption in the NIR range. Both experimental results and theoretical calculations demonstrated that add-on states close to the Fermi level are formed due to the Sb doping and high concentration of oxygen vacancies. The prepared samples were used for photocatalytic nitrogen reduction and showed an LSPR-dependent photocatalytic performance. The present work has provided an effective strategy to stabilize the LSPR of plasmonic semiconductor photocatalysts.
PubMed: 38875214
DOI: 10.1021/acs.langmuir.4c01135 -
Chemistry (Weinheim An Der Bergstrasse,... Jun 2024Boron subphthalocyanines with chloride and fluoride axial ligands and three antimony complexes chelated by corroles that differ in size and electron-richness were...
Boron subphthalocyanines with chloride and fluoride axial ligands and three antimony complexes chelated by corroles that differ in size and electron-richness were examined as electrocatalysts for reduction of protons to hydrogen. Experiment- and computation-based investigations revealed that all redox events are ligand-centered and that the meso-C of the corroles and the peripheral N atoms of the subphthalocyanines are the largely preferred proton-binding sites.
PubMed: 38869100
DOI: 10.1002/chem.202402145 -
Dalton Transactions (Cambridge, England... Jun 2024We report on the synthesis, structure and reactivity of [{NCN}Sb(CH-Bu-3,5-O-4)] (3), an organoantimony(III)-oxyaryl species obtained upon C-H bond activation in a...
We report on the synthesis, structure and reactivity of [{NCN}Sb(CH-Bu-3,5-O-4)] (3), an organoantimony(III)-oxyaryl species obtained upon C-H bond activation in a phenolate ligand and stabilised by the monoanionic pincer {NCN}. The mechanism leading to the formation of 3 is highly sensitive to steric considerations. It was probed experimentally and by DFT calculations, and a number of intermediates and related complexes were identified. All data agree with successive heterolytic bond cleaving and bond forming processes involving charged species, rather than a pathway involving free radicals as previously exemplified with congeneric bismuth species. The nucleophilic behaviour of the oxyaryl ligand in 3, a complex that features both zwitterionic and quinoidal attributes, was illustrated in derivatisation reactions. In particular, insertion of CS in the Sb-C bond generates [{NCN}Sb(SC-CH-Bu-3,5-O-4)].
PubMed: 38868997
DOI: 10.1039/d4dt01400f -
Journal of Arthropod-borne Diseases Dec 2023Current medications especially the pentavalent antimonial compounds have been used as the first line treatment of cutaneous leishmaniasis (CL), but they have limitations...
Anti-Leishmanial Effects of a Novel Biocompatible Non-Invasive Nanofibers Containing Royal Jelly and Propolis against Iranian Strain of (MRHO/IR/75/ER): an In-Vitro Study.
BACKGROUND
Current medications especially the pentavalent antimonial compounds have been used as the first line treatment of cutaneous leishmaniasis (CL), but they have limitations due to serious side effects such as drug resistance, cardio and nephrotoxicity, and high costs. Hence, the demand to find more usable drugs is evident. Synthesis and development of natural, effective, biocompatible, and harmless compounds against is the principal priority of this study.
METHODS
By electrospinning method, a new type of nanofiber were synthesized from royal jelly and propolis with different ratios. Nanofibers were characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Thermogravimetric Analysis (TGA), Contact angle, and Fourier-transform infrared spectroscopy (FTIR). The Half-maximal inhibitory concentration (IC), Half-maximal effective concentration (EC) and the 50% cytotoxic concentration (CC) for different concentrations of nanofibers were determined using quantitative calorimetric methods. Inductively coupled plasma-optical emission spectrometry (ICP-OES) and flow cytometry were performed as complementary tests.
RESULTS
The results showed that the proposed formulas provide a new achievement that, despite the significant killing activity on , has negligible cytotoxicity on the host cells. Royal jelly nanofibers have significantly shown the best 72 hours results (IC= 35 μg/ml and EC=16.4 μg/ml) and the least cytotoxicity.
CONCLUSION
This study presents a great challenge to introduce a new low-cost treatment method for CL, accelerate wound healing, and reduce scarring with minimal side effects and biocompatible materials. Royal jelly and propolis nanofibers significantly inhibit the growth of .
PubMed: 38868671
DOI: 10.18502/jad.v17i4.15294