Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
3,739 result(s) for "Antimony - chemistry"
Sort by:
Efficacy of pentavalent antimoniate intralesional infiltration therapy for cutaneous leishmaniasis: A systematic review
The mainstays of cutaneous leishmaniasis (CL) treatment, in several world regions, are pentavalent antimony (Sbv) compounds administered parenterally, despite their recognized toxicity, which requires frequent laboratory monitoring and complicates their use in areas with scarce infrastructure. As result of these drawbacks, the WHO Expert Committee on leishmaniasis has expanded the recommendations for the use of local therapies, including Sbv intralesional infiltration (IL-Sbv), as CL therapy alternatives even in the New World. However, the efficacy of these approaches has never been compiled. The aim of this study was to critically and systematically assess the efficacy of IL-Sbv for CL treatment. The PRISMA guidelines for systematic reviews and the Cochrane manual were followed. The sources used were the MEDLINE and LILACS databases and the International Clinical Trials Registry Platform of the World Health Organization. The outcome of interest was a clinical cure, defined as complete re-epithelialization of all lesions. The IL-Sbv pooled cure rate was estimated for several subgroups and direct comparisons were performed when possible. Thirty nine articles (40 studies) involving 5679 patients treated with IL-Sbv infiltration were included. In direct comparison, only three studies involving 229 patients compared IL-Sbv infiltration versus placebo and no difference was observed (OR: 1,9; 95%IC 0,93 to 3,82) based on cure rate 69.6% (95%CI 17.6-96.1%) and 83,2% (95%CI 66-92.7%) for placebo and IL-Sbv, respectively. In an alternative and non-comparative analysis, gathering all study arms using the intervention, the pooled IL-Sbv efficacy rate was 75% (95%CI 68-81%). In the Old World, the observed overall IL-Sbv efficacy rate was 75% (95%CI 66-82%), and the cure rates were significantly higher with sodium stibogluconate (SSG) than with meglumine antimoniate (MA): 83% (95%CI 75-90%) versus 68% (95%CI 54-79%), p = 0.03. Studies directly comparing IL-Sbv with topical 15% paromomycin ointment, IL hypertonic saline, radiofrequency-induced heat therapy, topical trichloroacetic acid and cryotherapy showed no significant difference in efficacy between the interventions. The analyses suggested a higher efficacy of IL-Sbv combined with cryotherapy (81.8%, 95%IC 62.4-92.4%) when compared with IL-Sbv alone (53.3%, 95%IC 46.1-66%), OR: 3.14 (95%CI 1.1-8.9), p = 0.03. In the New World, the global IL-Sbv efficacy was 77%(95%CI 66-85%). In contrast with the Old World, a significant difference favoring MA in relation to SSG was observed: 61% (95%CI 49-73%) versus 82% (95%CI 70-89%).By comparing IL infiltration schedules, it was determined that patients submitted to IL-Sbv treatments longer than 14 days had higher cure rates. Despite the high heterogeneity and low methodological quality of studies, an indirect comparison shows that the antimony infiltration efficacy rate is similar to that reported for antimony systemic use. The evidence gathered thus far is insufficient to identify the ideal IL therapeutic regime or estimate the rates of adverse events and mucosal late complications.
Antimony efflux underpins phosphorus cycling and resistance of phosphate-solubilizing bacteria in mining soils
Microorganisms play crucial roles in phosphorus (P) turnover and P bioavailability increases in heavy metal-contaminated soils. However, microbially driven P-cycling processes and mechanisms of their resistance to heavy metal contaminants remain poorly understood. Here, we examined the possible survival strategies of P-cycling microorganisms in horizontal and vertical soil samples from the world’s largest antimony (Sb) mining site, which is located in Xikuangshan, China. We found that total soil Sb and pH were the primary factors affecting bacterial community diversity, structure and P-cycling traits. Bacteria with the gcd gene, encoding an enzyme responsible for gluconic acid production, largely correlated with inorganic phosphate (Pi) solubilization and significantly enhanced soil P bioavailability. Among the 106 nearly complete bacterial metagenome-assembled genomes (MAGs) recovered, 60.4% carried the gcd gene. Pi transportation systems encoded by pit or pstSCAB were widely present in gcd -harboring bacteria, and 43.8% of the gcd -harboring bacteria also carried the acr3 gene encoding an Sb efflux pump. Phylogenetic and potential horizontal gene transfer (HGT) analyses of acr3 indicated that Sb efflux could be a dominant resistance mechanism, and two gcd -harboring MAGs appeared to acquire acr3 through HGT. The results indicated that Sb efflux could enhance P cycling and heavy metal resistance in Pi-solubilizing bacteria in mining soils. This study provides novel strategies for managing and remediating heavy metal-contaminated ecosystems.
Actinidia Deliciosa mediated synthesis of antimony oxide nanoparticles and their incorporation into chitosan matrix for enhanced antibacterial and photocatalytic activity
This study examines the synthesis and characterization of antimony oxide (Sb 2 O 3 ) nanoparticle and its combination with chitosan (Cs) to make Sb 2 O 3 -Cs nanocomposites. The green chemistry method of the Sb 2 O 3 nanoparticles synthesis was supported by the Actinidia deliciosa (kiwi) extract that serves as reducing agent and stabilizing agent. The nanoparticles obtained were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) analysis, X-ray Diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) to study their morphology, elemental composition, crystallinity and functional groups respectively. The SEM images indicated a more compact, heterogeneous structure when the Sb 2 O 3 nanoparticles were incorporated into the chitosan matrix to form Sb 2 O 3 -Cs nanocomposites, with the nanoparticles uniformly distributed in the chitosan matrix. XRD results established the formation of a pure senarmontite cubic phase of Sb 2 O 3 in pure nanoparticles and nanocomposites. The findings indicated that the dispersion of Sb 2 O 3 nanoparticles was highly enhanced by the presence of chitosan and this minimized aggregation and increased the stability of the material. The synthesized materials were tested against Staphylococcus aureus and Escherichia coli by zone of inhibition (ZOI) method of antibacterial activity as well as tested for photocatalytic degradation of rhodamine-B (rhB) under visible light. This study explains that Sb 2 O 3 nanoparticles, and Sb 2 O 3 -Cs nanocomposites, possess significant potential in biomedical and pollution remediation applications.
Ultrasensitive detection of miRNA with an antimonene-based surface plasmon resonance sensor
MicroRNA exhibits differential expression levels in cancer and can affect cellular transformation, carcinogenesis and metastasis. Although fluorescence techniques using dye molecule labels have been studied, label-free molecular-level quantification of miRNA is extremely challenging. We developed a surface plasmon resonance sensor based on two-dimensional nanomaterial of antimonene for the specific label-free detection of clinically relevant biomarkers such as miRNA-21 and miRNA-155. First-principles energetic calculations reveal that antimonene has substantially stronger interaction with ssDNA than the graphene that has been previously used in DNA molecule sensing, due to thanking for more delocalized 5 s /5 p orbitals in antimonene. The detection limit can reach 10 aM, which is 2.3–10,000 times higher than those of existing miRNA sensors. The combination of not-attempted-before exotic sensing material and SPR architecture represents an approach to unlocking the ultrasensitive detection of miRNA and DNA and provides a promising avenue for the early diagnosis, staging, and monitoring of cancer. Label-free molecular-level quantification of MicroRNA (miRNA) remains challenging. Here, the authors develop a new surface plasmon resonance sensor based on two-dimensional nanomaterial of antimonene for the specific label-free detection of clinically relevant biomarkers such as miRNA-21 and miRNA-155.
Degradable mesoporous semimetal antimony nanospheres for near-infrared II multimodal theranostics
Metallic and semimetallic mesoporous frameworks are of great importance owing to their unique properties and broad applications. However, semimetallic mesoporous structures cannot be obtained by the traditional template-mediated strategies due to the inevitable hydrolytic reaction of semimetal compounds. Therefore, it is yet challenging to fabricate mesoporous semimetal nanostructures, not even mention controlling their pore sizes. Here we develop a facile and robust selective etching route to synthesize monodispersed mesoporous antimony nanospheres (MSbNSs). The pore sizes of MSbNSs are tunable by carefully controlling the partial oxidation of Sb nuclei and the selective etching of the as-formed Sb 2 O 3 . MSbNSs show a wide absorption from visible to second near-infrared (NIR-II) region. Moreover, PEGylated MSbNSs are degradable and the degradation mechanism is further explained. The NIR-II photothermal performance of MSbNSs is promising with a high photothermal conversion efficiency of ~44% and intensive NIR-II photoacoustic signal. MSbNSs show potential as multifunctional nanomedicines for NIR-II photoacoustic imaging guided synergistic photothermal/chemo therapy in vivo. Our selective etching process would contribute to the development of various semimetallic mesoporous structures and efficient multimodal nanoplatforms for theranostics. The properties of mesoporous nanomaterials have been exploited for several applications, including drug delivery and NIR-II photoacoustic imaging. Here, the authors design monodispersed semimetallic mesoporous antimony nanospheres with photothermal conversion efficiency in the second near-infrared range and drug loading capacity, showing their potential for cancer photothermal/chemo therapy.
Group VA Aromatic Thiosemicarbazone Complexes: Synthesis, Characterization, Biological Activity, and Topological Studies
The antiproliferative and antibacterial activities of thiosemicarbazones increase markedly with the presence of metal ions. One of the factors determining the activity of metal thiosemicarbazone complexes is the coordination structure. In this study, the biological effects of new antimony (III) and bismuth (III) thiosemicarbazone complexes with different binding modes and geometrical structures were demonstrated. Three new complexes, with the formulae [SbCl3(µ2-S-Hacptsc)(η1-S-Hacptsc)], 2/3H2O,1/3CH2Cl2, [SbCl3(κ2-S,N-Hacpmtsc)(η1-S-Hacpmtsc)2CH2Cl2], and[BiCl3(η1-S-Hbzmtsc)3]·C2H5OH, where Hacptsc: acetophenone thiosemicarbazone, Hacpmtsc: acetophenone-N-methyl thiosemicarbazone, Hbzmtsc: benzaldehyde-N-methyl thiosemicarbazone) were elucidated by different methods and deeply analyzed in accordance with their structure by X-ray structure analysis and Atoms-In-Molecules topological analysis. This analysis provided a deeper understanding of the coordination spheres of the Sb/Bi complexes. For instance, the first reported two binding modes of the same ligand are observed in a single crystal structure of antimony (III) halide complexes. Additionally, in one of the complexes, a solid-to-solid phase transition was detected and analyzed in detail. Those complexes, very unique in terms of their geometry, have also been tested for their in vitro cytotoxic activity against human adenocarcinoma cervical cancer (HeLa) cells, whereas antimony (III) complex 1is the most active complex of this study. Further, the antibacterial activity of the complexes has been screened against two Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and two Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) pathogenic bacteria. From the results, it is found that all the complexes exhibited significant activity against the Gram-negative pathogenic bacteria.
Optimizing Antimony Speciation Analysis via Frontal Chromatography–ICP-MS to Explore the Release of PET Additives
Antimony (Sb) contamination poses significant environmental and health concerns due to its toxic nature and widespread presence, largely from anthropogenic activities. This study addresses the urgent need for an accurate speciation analysis of Sb, particularly in water sources, emphasizing its migration from polyethylene terephthalate (PET) plastic materials. Current methodologies primarily focus on total Sb content, leaving a critical knowledge gap for its speciation. Here, we present a novel analytical approach utilizing frontal chromatography coupled with inductively coupled plasma mass spectrometry (FC-ICP-MS) for the rapid speciation analysis of Sb(III) and Sb(V) in water. Systematic optimization of the FC-ICP-MS method was achieved through multivariate data analysis, resulting in a remarkably short analysis time of 150 s with a limit of detection below 1 ng kg−1. The optimized method was then applied to characterize PET leaching, revealing a marked effect of the plastic aging and manufacturing process not only on the total amount of Sb released but also on the nature of leached Sb species. This evidence demonstrates the effectiveness of the FC-ICP-MS approach in addressing such an environmental concern, benchmarking a new standard for Sb speciation analysis in consideration of its simplicity, cost effectiveness, greenness, and broad applicability in environmental and health monitoring.
Chemistry of Antimony in Radiopharmaceutical Development: Unlocking the Theranostic Potential of Sb Isotopes
Antimony‐119 (119Sb) holds promise for radiopharmaceutical therapy (RPT), emitting short‐range Auger and conversion electrons that can deliver cytotoxic radiation on a cellular level. While it has high promise theoretically, experimental validation is necessary for 119Sb in vivo applications. Current 119Sb production and separation methods face robustness and compatibility challenges in radiopharmaceutical synthesis. Limited progress in chelator development hampers targeted experiments with 119Sb. This review compiles literature on the toxicological, biodistribution and redox properties of Sb, along with existing Sb complexes, evaluating their suitability for radiopharmaceuticals. Sb(III) is suggested as the preferred oxidation state for radiopharmaceutical elaboration due to its stability in vivo and lack of skeletal uptake. While Sb complexes with both hard and soft donor atoms can be achieved, Sb thiol complexes offer enhanced stability and compatibility with the desired Sb(III) oxidation state. For 119Sb to find application in RPT, scientists need to make discoveries and advancements in the areas of isotope production, and radiometal chelation. This review aims to guide future research towards harnessing the therapeutic potential of 119Sb in RPT. Antimony‐119 for radiopharmaceutical therapy: Antimony‐119 (119Sb, t1/2=38.19 h) is a promising candidate for radiopharmaceutical therapy using Auger electrons. Available literature on 119Sb is scarce, with only one successful case of chelation, and no reported in vivo applications. This review compiles relevant information on fundamental chemistry of antimony from the lens of the radiopharmaceutical development process (see picture).
Dissolved organic matter-generated photoelectrons enable microbial antimonate reduction in mine stream sediments
Antimony contamination in mining-impacted river basins poses persistent environmental risks, yet the microbial processes governing antimony redox transformation under anoxic sediments remain poorly understood. Here, we report that photoelectrons generated by naturally occurring dissolved organic matter can support microbial antimonate reduction. Natural dissolved organic matter exhibits sustained photocurrent responses under illumination. In anoxic microcosms, indigenous sediment communities achieve 50–70% antimonate reduction with photoelectron supply, thereby constraining purely abiotic reduction or alternative electron-donor explanations under our experimental conditions. Multi-omics further identify non-phototrophic taxa (e.g., Sphingomonas and Bosea ) with elevated antimony reduction/detoxification pathways and respiratory electron-transfer components under photoelectron exposure. The consistent presence of photosensitive dissolved organic matter and candidate taxa across mining-impacted sediments suggests broader environmental relevance. These findings indicate that photosensitive dissolved organic matter may provide a photoelectron flux that influences microbial antimony redox transformations in anoxic sediments. Sunlight-exposed dissolved organic matter generates photoelectrons that microbes capture to reduce antimonate in anoxic sediments, revealing an overlooked electron supply route that may shape antimony cycling in mining-impacted streams.
Effects of antimony on redox activities and antioxidant defence systems in sunflower (Helianthus annuus L.) plants
The alterations induced by the toxicity of antimony (Sb) in the roots and leaves of sunflower plants were determined. The plants were grown hydroponically with different concentrations of Sb, a heavy metal which reduces biomass production and growth. There was preferential accumulation of Sb in the tissues of the roots, with the concentrations in the leaves being much lower. The accumulation of other mineral elements was also altered, especially that of Fe and Zn. Chlorophyll content declined, as also did the photosynthetic efficiency, but the carotenoid content remained unaltered. The total content of phenolics, flavonoids, and phenylpropanoid glycosides rose, evidence of their participation in the defence response. Increases were observed in the amount of superoxide anion in both roots and leaves, and in lipid peroxidation levels, especially with the highest Sb concentration of 1.0 mM. The induced oxidative stress leads to a strong increase in the SOD, POX and APX antioxidant activities, while the GR activity was only increased in the leaves and at the 1.0 mM Sb concentration. In contrast, the DHAR activity increased considerably in both organs. The GSNOR activity increased only in roots, and the total RSNOs increased. The total amount of AsA + DHA increased in roots and remained unaltered in leaves, whereas that of GSH + GSSG decreased considerably in all cases. As a whole, these results are evidence for the development of a strong oxidative stress induced by Sb, with there being a clear imbalance in the content of the compounds that constitute the AsA/GSH cycle. 0.5 mM Sb enhances GST expression, especially in leaves. This, together with the increase that was observed in the amount of GSH, may play an important part in detoxification. This oxidative stress affects both the phenolic and the ROS/RNS metabolic processes, which seems to implicate their involvement in the plant's defence and response to the stress.