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1.
Food Chem ; 399: 134008, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36037693

RESUMO

The Tyndall Effect assay (TEA) has been applied into colorimetric metal ion detection since 2019. However, the TEA-based sensor for pesticide detection has never been reported till now. Herein, a facile fluorescent organic nanoparticle (FON)-based sensor is firstly developed for fluorine-containing pesticide detection through ratiometric fluorescence assay (FLA) and TEA. For FLA, the intensity of the second-order Tyndall scattering peak (STS590nm) and the fluorescence peak of the FON-based sensor would increase and remain unchanged respectively when adding bifenthrin, flufenoxuron, and diflubenzuron. The detection limits were respectively 9.34, 6.91, and 3.60 µg/kg. For TEA, the increased STS590nm intensity displayed a bright and visible light beam. An economical, simple, and portable device was then constructed to visually monitor the analytes. The sensor was successfully used to detect the analytes in teas through FLA and TEA with the recoveries and RSD ranging from 86.27-100.00 %, and 0.00-5.68 %, respectively.


Assuntos
Diflubenzuron , Nanopartículas , Praguicidas , Corantes Fluorescentes , Fluoretos , Flúor , Compostos de Fenilureia , Piretrinas , Chá
2.
Braz. j. biol ; 83: e242703, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1285636

RESUMO

Abstract Oral diseases caused by various microorganisms are common around the world. Scientific research has now been focusing on novel medicines to overcome bacterial resistance and antibiotics side effects; therefore, the current study was designed to assess the efficacy of certain antibiotics, toothpaste, and medicinal plant extracts (Ajuga bracteosa and Curcuma longa) versus the bacterial pathogens isolated from the human oral cavity. A total of 130 samples were collected from Khyber Teaching Hospital Peshawar, Pakistan, among those 27 species isolated, and eight bacterial species were identified from the samples. Among all the bacterial species, Staphylococcus aureus (29.62%) and Proteus mirabilis (22.2%) were found to be more prevalent oral pathogens. In comparison, the least pervasive microbes were Proteus vulgaris, Shigella sonnei, Escherichia coli and Aeromonas hydrophila. The study also suggested that dental problems were more prevalent in males (41-50 years of age) than females. Among the eight antibiotics used in the study, the most promising results were shown by Foxicillin against A. hydrophila. The survey of TP1 revealed that it showed more potent antagonist activity against Proteus vulgaris as compared TP2 and TP3 that might be due to the high content of fluoride. The Curcuma longa showed more significant activity than Ajuga bracteosa (Stem, leaves and root) extracts. The data obtained through this study revealed that antibiotics were more effective for oral bacterial pathogens than toothpaste and plant extracts which showed moderate and low activity, respectively. Therefore, it is suggested that the active compounds in individual medicinal plants like Curcuma longa and Ajuga bracteosa could replace the antibiotics when used in daily routine as tooth cleansers or mouth rinses.


Resumo As doenças bucais causadas por vários microrganismos são comuns em todo o mundo. A pesquisa científica agora tem se concentrado em novos medicamentos para superar a resistência bacteriana e os efeitos colaterais dos antibióticos; portanto, o presente estudo foi desenhado para avaliar a eficácia de certos antibióticos, pasta de dente e extratos de plantas medicinais (Ajuga bracteosa e Curcuma longa) contra os patógenos bacterianos isolados da cavidade oral humana. No total, 130 amostras foram coletadas do Khyber Teaching Hospital Peshawar, Paquistão, entre essas, 27 espécies foram isoladas e oito espécies bacterianas foram identificadas a partir das amostras. Entre todas as espécies bacterianas, Staphylococcus aureus (29.62%) e Proteus mirabilis (22.2%) foram os patógenos orais mais prevalentes. Em comparação, os micróbios menos difundidos foram Proteus vulgaris, Shigella sonnei, Escherichia coli e Aeromonas hydrophila. O estudo também sugeriu que os problemas dentários eram mais prevalentes em homens (41-50 anos de idade) do que em mulheres. Entre os oito antibióticos usados ​​no estudo, os resultados mais promissores foram mostrados pelo Foxicillin contra A. hydrophila. A pesquisa de TP1 revelou que ele mostrou atividade antagonista mais potente contra Proteus vulgaris em comparação a TP2 e TP3, o que pode ser devido ao alto teor de flúor. A Curcuma longa apresentou atividade mais significativa em relação aos extratos de Ajuga bracteosa (caule, folhas e raiz). Os dados obtidos neste estudo revelaram que os antibióticos foram mais eficazes para os patógenos bacterianos orais do que os dentifrícios e os extratos vegetais que apresentaram atividade moderada e baixa, respectivamente. Portanto, sugere-se que os compostos ativos em plantas medicinais individuais como Curcuma longa e Ajuga bracteosa possam substituir os antibióticos quando usados ​​na rotina diária como limpadores de dentes ou enxaguatórios bucais.


Assuntos
Humanos , Masculino , Feminino , Cremes Dentais , Fluoretos , Paquistão , Extratos Vegetais/farmacologia , Testes de Sensibilidade Microbiana , Antibacterianos
3.
Biomed Res Int ; 2022: 7380324, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36046439

RESUMO

Objective: To explore the function and mechanism of Sirt-1 in fluorine-induced liver injury. Method: Fluorosis rats were first established. The fluorine content, pathological structure, collagen fibers, and fibrosis in liver tissues were tested through the fluoride ion selective electrode method, H&E, Masson, and Sirius red staining; alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin 18 (IL-18), and tumor necrosis factor-α (TNF-α) levels in rat serum were also analyzed using ELISA kits. Then, the fluorosis cell model was built, which was also alleviated with NaF, Sirt-1 siRNAs, or endoplasmic reticulum stress (ERS) alleviator (4-PBA). CCK-8 also assessed cell proliferation; RT-qPCR or Western blots detect sirtuin-1 (Sirt-1), protein kinase R- (PKR-) like endoplasmic reticulum kinase (PERK), and endoplasmic reticulum stress (ERS) and apoptosis-related protein levels in liver tissue. Results: Our results uncovered that fluorine exposure could aggravate the pathological damage and fibrosis of rat liver tissues and increase indicators related to liver injury. And fluoride exposure also could downregulate Sirt-1 and upregulate ERS-related proteins (PERK, 78-kD glucose-regulated protein (GRP-78), and activating transcription factor 6 (ATF6)) and apoptosis-related protein (caspase-3 and C/EBP-homologous protein (CHOP)) in rat liver tissues. Besides, we proved that fluoride exposure could suppress proliferation and enhances ERS and apoptotic pathways in AML12 cells by downregulating Sirt-1. Moreover, we revealed that ERS alleviator (4-PBA) could induce proliferation and prevent ERS and apoptosis in fluorine-exposed AML12 cells. Conclusions: We suggested that fluorine exposure can induce hepatocyte ERS and apoptosis through downregulation of Sirt-1.


Assuntos
Estresse do Retículo Endoplasmático , Fluoretos , Animais , Apoptose , Proliferação de Células , Fibrose , Fluoretos/toxicidade , Flúor , Hepatócitos , Ratos , Sirtuína 1
4.
Huan Jing Ke Xue ; 43(9): 4513-4521, 2022 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-36096592

RESUMO

Pollution characteristics and spatial distributions of perfluoroalkyl substances (PFASs) in surface water samples were investigated in Taihu Lake in 2010 and 2019, respectively. A hybrid model based on the positive matrix factorization (PMF) and the health risk assessment model were employed for quantifying the contributions of sources to PFASs concentrations and the source risks. The method contained two stages:1 the sources of PFASs were apportioned using the PMF model, and 2 the contribution of health risks from each source was quantitively estimated. Three factors (source categories) were extracted using PMF, including:coating industry sources, textile and electroplating sources, and fluoride-processing industry sources. Their contributions to PFASs concentration were 29.59%, 25.68%, and 44.72% for 2010 and 67.69%, 10.26%, 22.05%, for 2019, respectively. The health risk of PFASs in the water assessed by the health risk assessment (HRA) model was 4.56E-07 for 2010 and 2.69E-07 for 2019, which was lower than 1E-06. The source contributions to health risks estimated by the PMF-HRA hybrid model were:64.86% (2010) and 92.48% (2019) for textile and electroplating sources, 31.30% (2010) and 5.04% (2019) for coating industry sources, and 3.84% (2010) and 2.48% (2019) for fluoride-processing industry sources. For the two years, the concentrations of PFOA and PFOS were reduced significantly, indicating the effective control of their emissions during the past ten years in Taihu Lake. However, it was also shown that the concentrations of PFBS and PFHxS were increased. These findings suggest that the above short chain-PFCs species should be the focus for further control and management, and their health risks should be studied in future research.


Assuntos
Fluorcarbonetos , Poluentes Químicos da Água , Monitoramento Ambiental/métodos , Fluoretos , Fluorcarbonetos/análise , Lagos , Água , Poluentes Químicos da Água/análise
6.
Proc Natl Acad Sci U S A ; 119(37): e2208540119, 2022 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-36070343

RESUMO

Diversity Oriented Clicking (DOC) is a discovery method geared toward the rapid synthesis of functional libraries. It combines the best attributes of both classical and modern click chemistries. DOC strategies center upon the chemical diversification of core "SuFExable" hubs-exemplified by 2-Substituted-Alkynyl-1-Sulfonyl Fluorides (SASFs)-enabling the modular assembly of compounds through multiple reaction pathways. We report here a range of stereoselective Michael-type addition pathways from SASF hubs including reactions with secondary amines, carboxylates, 1H-1,2,3-triazole, and halides. These high yielding conjugate addition pathways deliver unprecedented ß-substituted alkenyl sulfonyl fluorides as single isomers with minimal purification, greatly enriching the repertoire of DOC and holding true to the fundamentals of modular click chemistry. Further, we demonstrate the potential for biological function - a key objective of click chemistry - of this family of SASF-derived molecules as covalent inhibitors of human neutrophil elastase.


Assuntos
Química Click , Fluoretos , Elastase de Leucócito , Proteínas Secretadas Inibidoras de Proteinases , Ácidos Sulfínicos , Química Click/métodos , Fluoretos/síntese química , Fluoretos/química , Fluoretos/farmacologia , Humanos , Elastase de Leucócito/antagonistas & inibidores , Proteínas Secretadas Inibidoras de Proteinases/síntese química , Proteínas Secretadas Inibidoras de Proteinases/química , Proteínas Secretadas Inibidoras de Proteinases/farmacologia , Ácidos Sulfínicos/síntese química , Ácidos Sulfínicos/química , Ácidos Sulfínicos/farmacologia
7.
J Org Chem ; 87(18): 12182-12195, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36069733

RESUMO

Nowadays, design of the new chiral ligands for organometallic catalysts is often based on the step-by-step increase in their complexity to improve efficiency. Herein we describe that simple in situ addition of the fluoride source to the asymmetric organometallic catalyst can improve not only activity but also enantioselectivity. Bromide-nickel diimine complexes were found to catalyze asymmetric Michael addition in low yields and ee, but activation with fluoride leads to a significant improvement in catalyst performance. The developed approach was applied to prepare several enantioenriched GABA analogues.


Assuntos
Malonatos , Níquel , Brometos , Catálise , Fluoretos , Ácido gama-Aminobutírico
8.
J Dent ; 125: 104273, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36058347

RESUMO

OBJECTIVE: To assess the clinical evidence for professionally applied fluoride therapy to prevent and arrest caries in older adults. DATA/SOURCES: Two independent researchers searched the English literature published up to 31st Dec 2021 in five databases (PubMed, Scopus, the Cochrane Library, EMBASE, and Web of Science) for clinical trials with a comparison group on professionally applied fluoride therapy for caries prevention or arrest at older adults aged ≥60 years with any follow-up period. The outcomes were the mean difference in the number of new caries/caries-prevented fraction and caries arrest rate. The Cochrane guidelines were used for the risk of bias assessment. STUDY SELECTION/RESULTS: Five hundred and twenty-seven studies were identified, and seven studies were finally included. Five studies were rated as having 'low risk'. The root caries-prevented fraction of 38% silver diamine fluoride (SDF) solution, 5% sodium fluoride (NaF) varnish, and 1.23% acidulated phosphate fluoride (APF) gel were 25-71%, 64%, and 32%, respectively. Meta-analysis indicated a decrease in the number of new root caries by 0.55 (95% CI: 0.32-0.78; p < 0.001) and an overall proportion of arrested root caries of 42% (95% CI: 33% to 49%; p < 0.001) after receiving 38% SDF application at the 24-month follow-up. CONCLUSIONS: According to the findings, 5% NaF varnish and 1.23% APF gel prevented root caries, whereas 38% SDF solution prevented and arrested root caries in older adults. More well-designed clinical trials should be conducted to investigate various methods in caries prevention and arrest in older adults. CLINICAL SIGNIFICANCE: Preventive measures effective in other age groups may not suit older adults, as caries type and associated risk factors vary. To date, no systematic review has evaluated professionally applied fluoride therapy in older adults. Evidence from clinical trials in older adults could aid clinical practice and public health measures. The International Prospective Register of Systematic Reviews (PROSPERO) registration number: CRD42022307025.


Assuntos
Cárie Dentária , Cárie Radicular , Fluoreto de Fosfato Acidulado , Idoso , Cariostáticos/uso terapêutico , Cárie Dentária/tratamento farmacológico , Cárie Dentária/prevenção & controle , Fluoretos/uso terapêutico , Fluoretos Tópicos/uso terapêutico , Humanos , Compostos de Amônio Quaternário/uso terapêutico , Cárie Radicular/tratamento farmacológico , Cárie Radicular/prevenção & controle , Compostos de Prata , Fluoreto de Sódio/uso terapêutico , Revisões Sistemáticas como Assunto
9.
Nutrients ; 14(17)2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36079765

RESUMO

The recollections of a former public health officer and research scientist who maintained good relations with both pro- and anti-fluoridationists over the course of a 60-year career in which fluoride has gone from being a "nutrient" to a suspected neurotoxin.


Assuntos
Cárie Dentária , Médicos , Fluoretos , Humanos , Rememoração Mental , Neurotoxinas , Nutrientes
10.
Molecules ; 27(16)2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-36014385

RESUMO

Copper ions (Cu2+) and sulfur ions (S2-) are important elements widely used in industry. However, these ions have the risk of polluting the water environment. Therefore, rapid and quantitative detection methods for Cu2+ and S2- are urgently required. Using 2,4-difluorobenzoic acid and L-lysine as precursors, nitrogen and fluorine co-doped dots (N, F-CDs) were synthesized in this study via a hydrothermal method. The aqueous N, F-CDs showed excellent stability, exhibited satisfactory selectivity and excellent anti-interference ability for Cu2+ detection. The N, F-CDs, based on the redox reactions for selective and quantitative detection of Cu2+, showed a wide linear range (0-200 µM) with a detection limit (215 nM). By forming the N, F-CDs@Cu2+ sensing platform and based on the high affinity of S2- to Cu2+, the N, F-CDs@Cu2+ can specifically detect S2- over a linear range of 0-200 µM with a detection limit of 347 nM. In addition, these fluorescent probes achieved good results when used for Cu2+ and S2- detection in environmental water samples, implying the good potential for applications.


Assuntos
Carbono , Pontos Quânticos , Cobre , Corantes Fluorescentes , Fluoretos , Flúor , Íons , Nitrogênio , Espectrometria de Fluorescência/métodos , Sulfetos , Água
11.
Inorg Chem ; 61(34): 13627-13636, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-35980758

RESUMO

Excessive content of fluoride ions (F-) in water will lead to water pollution and endanger human health, so the research on the method of low-cost, rapid, and efficient detection of F- is of particular significance. In this work, an amino-functionalized ligand with an appropriate triplet energy excited state, 2'-amino-[1,1':4',1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid (H4TPTC-NH2), was selected to construct a luminescent single-lanthanide metal-organic framework, EuTPTC-NH2, with uncoordinated amino groups for the detection of F-. Based on host-guest interactions, that is, hydrogen bonds formed between the free amino groups and F- ions, EuTPTC-NH2 was developed as a ratiometric fluorescence probe for F- detection with good anti-interference ability, low detection limit, high water stability, and selectivity. It was found that EuTPTC-NH2 has an excellent linear response to F- in the concentration range of 0-80 µM with high sensitivity and a low detection limit of 11.26 µM. A hydrogel membrane based on the combination of EuTPTC-NH2 and agarose was also prepared for the quantitative visual detection of F- in water.


Assuntos
Elementos da Série dos Lantanídeos , Estruturas Metalorgânicas , Corantes Fluorescentes , Fluoretos , Flúor , Humanos , Água
12.
J Contemp Dent Pract ; 23(5): 520-526, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35986460

RESUMO

AIM: This study was conducted to evaluate the remineralization potential of Remin Pro Forte vs Remin Pro remineralizing agents on white spot lesions (WSLs) post-orthodontic treatment. MATERIALS AND METHODS: Twenty patients with post-orthodontic WSLs were divided into the following two equal groups based on treatment (n = 10): (1) A 3-month program of hydroxyapatite, fluoride, xylitol, ginger, curcuma-containing cream (Remin Pro Forte) as intervention group; (2) A 3-month cream regimen including hydroxyapatite and fluoride, xylitol (Remin Pro) as control group. The main outcomes including caries regression (assessed by ICDAS II), mineral content (assessed by VistaCam iX camera), and color of WSLs (assessed by digital image analysis by Adobe photoshop) were measured at the time of enrollment and 1, 2, and 3 months afterward. Mann-Whitney test used to compare between tested groups. The statistical significance was set at p <0.05. RESULTS: Both Remin Pro Forte and Remin Pro elicited much better caries regression and significantly higher mineral content in WSLs over a 3-month period (p <0.05). However, the difference in mineral content of WSLs between groups did not reach statistical significance (p = 0.414). In both experimental groups, the appearance of WSLs improved significantly (p <0.05). CONCLUSION: Both Remin Pro Forte and Remin Pro were successful in reducing caries, increasing mineral content, and enhancing the appearance of demineralized enamel, indicating that both products could be suggested for post-orthodontic WSL management. CLINICAL SIGNIFICANCE: Natural herbal products could be employed as remineralizing agents and included into tooth preventive measures. It is a less harmful alternative to traditional chemical remineralization methods.


Assuntos
Cárie Dentária , Remineralização Dentária , Cariostáticos/farmacologia , Cariostáticos/uso terapêutico , Cárie Dentária/prevenção & controle , Fluoretos/uso terapêutico , Humanos , Hidroxiapatitas/uso terapêutico , Remineralização Dentária/métodos , Xilitol/farmacologia , Xilitol/uso terapêutico
13.
J Contemp Dent Pract ; 23(5): 548-551, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35986465

RESUMO

AIM: The current study was carried out to assess the impact on the mechanical properties of orthodontic wires such as the nickel-titanium (NiTi) and copper-nickel-titanium (CuNiTi) wires by fluoride available in various prophylactic products. MATERIALS AND METHODS: Fifty-six wire specimens were randomly divided into two groups-control group in which deionized water was used as a medium and study group in which Phos-Flur gel was used. Both study group and control group were divided into two subgroups-NiTi wire group: 0.019 × 0.025 inch NiTi archwires (14 specimens) and CuNiTi wire group: 0.019 × 0.025 inch CuNiTi archwires (14 specimens). Testing of all the wires was done under a universal force testing machine. RESULTS: Mean loading force among NiTi wire group and CuNiTi wire group specimens with deionized water as a medium was 682.6 and 397.4 MPa, respectively, while the mean loading force among NiTi wire group and CuNiTi wire group specimens with Phos-Flur gel as a medium was 596.1 and 368.4 MPa, respectively. While comparing between study group and control group among NiTi wires, significant results were obtained. Also, while comparing between study group and control group among CuNiTi wires, significant results were obtained. CONCLUSION: Following exposure to fluoride agents, NiTi wires and CuNiTi wires are significantly associated with reduced mechanical properties. CLINICAL SIGNIFICANCE: Although fluoride acts as a vital adjunct in maintaining oral hygiene, particularly among patients undergoing fixed orthodontic treatment, its influence on the mechanical properties of the wires is an area to be explored further; thereby, its use is to be monitored.


Assuntos
Níquel , Fios Ortodônticos , Cobre , Ligas Dentárias , Fluoretos , Humanos , Teste de Materiais , Fluoreto de Sódio , Propriedades de Superfície , Titânio , Água
14.
Sci Rep ; 12(1): 13985, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35978074

RESUMO

This randomized, parallel, controlled trial assessed the effect of fluoride varnish, ozone and octenidine on white spot lesions (WSLs) and caries during orthodontic treatment. Patients were enrolled between 1st September 2017 and 31st August 2020 at initiation of orthodontic treatment in Department of Interdisciplinary Dentistry Pomeranian Medical University in Szczecin, Poland. All participants were randomly assigned to four study and one control groups using number random generator. However, investigators were not blinded due to the nature of the study. Groups I, II, III, IV had professional cleaning and varnishing (5% NaF) every 4 weeks. Groups II and IV had in-office ozone therapy before varnishing, groups III and IV received domestic octenidine mouthrinse. Group K had no professional hygienic or prophylactic procedures. WSLs were assessed at T0 and then every 4 weeks (T1-T4) and caries-at T0 and T4. The specific objective was to assess the influence of fluoride varnish, ozone and octenidine on the incidence of white spot lesions and caries during orthodontic treatment. The primary outcome of this report was the highest number of WSLs in group K and the lowest percentage of patients with WSLs in group IV. Each group comprised 30 randomized participants; they were all analyzed. No WSLs were found at T0, but they were stated in all groups at T4. The numbers of patients with WSLs significantly increased between T0-T4 in groups I and K. Group IV had the lowest percentage of patients with WSLs in T1-T4. WSLs in group IV were found no earlier than at T2. Group K had the highest percentage of WSLs at T4: 26%. At T0 all the groups had DMFs above 0 with a significant increase at T4. No side effects of the introduced prophylaxis were observed in any group. Caries is an important problem of fixed orthodontic treatment. Even an extremely intensive prophylaxis could not completely prevent WSLs and caries. Simultaneous application of fluoride varnish, ozone gas exposure and octenidine appears to have a beneficial effect in limiting the development of WSLs.Trial registration: NCT04992481.


Assuntos
Cárie Dentária , Ozônio , Cariostáticos , Cárie Dentária/epidemiologia , Cárie Dentária/etiologia , Cárie Dentária/prevenção & controle , Suscetibilidade à Cárie Dentária , Fluoretos , Fluoretos Tópicos/uso terapêutico , Humanos , Iminas , Incidência , Ozônio/efeitos adversos , Piridinas
15.
Environ Monit Assess ; 194(10): 682, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35976461

RESUMO

To evaluate the fluoride concentration and pH of tea derived from Camellia sinensis produced and commercialized in Argentina. Forty-eight varieties of tea (black (n = 16), green (n = 21), red (n = 7), and white (n = 4)) commercialized in the form of leaves or tea bags were acquired. One bag or 2.0 ± 0.05 g of each product was infused for 5 min in 200 mL of distilled boiled water. The F- concentration was determined using an ion-selective electrode and pH was measured using a pH meter. The found fluoride concentrations ranged from 0.1 to 9.7 µg/mL and the pH ranged from 2.7 to 5.1. A higher fluoride concentration was observed in the leaves group (2.75 ± 2.65 µg/mL) compared to tea bags (1.10 ± 0.82 µg/mL) (p < 0.05). Regarding the type of tea, green and black tea were richer in F- than red and white tea. Fluoride and pH appeared not to be correlated (Pearson test). All the studied tea samples presented fluoride concentrations greater than the threshold recommended for drinking water. The pH proved to be low, which could be a risk for erosive tooth wear.


Assuntos
Camellia sinensis , Argentina , Monitoramento Ambiental , Fluoretos/análise , Chá
16.
Oper Dent ; 47(4): E174-E187, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35917241

RESUMO

OBJECTIVE: The aim of the present in vitro study was to examine the caries-inhibiting effect of a pit and fissure sealant (PFS) containing ion-releasing microcapsules under cariogenic conditions in a biofilm artificial mouth. METHODS AND MATERIALS: Forty-eight human third molars were divided into four groups (n=12 per group). Fissures were extended with burs and sealed with experimental PFS. The four groups of specimens were treated as follows: 1) EPFS 1: EPFS (Premier Dental) of increasing viscosity, containing microcapsules loaded with remineralizing agents (calcium, phosphate, and fluoride ions); 2) US: fluoride-releasing PFS (UltraSeal XT plus, UltraDent Products, South Jordan, UT, USA); 3) EPFS 2: experimental PFS of constant viscosity containing microcapsules loaded with calcium, phosphate, and fluoride ions; and 4) FT: glass ionomer cement (GIC) (GC Fuji Triage CAPSULE WHITE glass ionomer cement, GC Europe NV, Leuven, Belgium). FT and US were used as control groups. EPFS 1 and EPFS 2 were the experimental groups. Specimens were stored in distilled water for 14 days at 37°C, subjected to 10,000 thermocycles (5°C and 55°C) and finally exposed to microbiological cycling in a Streptococcus mutans-based artificial mouth for 10 days. Replicas were made for scanning electron microscopic (SEM) evaluation and specimens were cut for fluorescence microscopy. RESULTS: Overall demineralization depths at the margin of Fuji Triage were significantly shallower than in the other groups (p<0.05). Overall demineralization depths adjacent to the experimental pit and fissure sealant EPFS 2 (59±15 µm) were comparable to the values of the resin-based pit and fissure sealant UltraSeal XT plus (58±10 µm, p≥0.05). SEM revealed surface roughness of the GIC-based PFS. CONCLUSIONS: The experimental PFS with microcapsules containing active components for remineralization did not show a caries-inhibiting effect compared to a fluoride-releasing resin-based PFS. Lower demineralization depths adjacent to GIC sealants indicate an anticariogenic effect through fluoride ion release.


Assuntos
Cárie Dentária , Selantes de Fossas e Fissuras , Cálcio , Cápsulas , Cariostáticos , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Suscetibilidade à Cárie Dentária , Fluoretos , Cimentos de Ionômeros de Vidro , Humanos , Fosfatos , Selantes de Fossas e Fissuras/uso terapêutico
17.
Ecotoxicol Environ Saf ; 242: 113954, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35999768

RESUMO

High fluoride water is a crucial driving factor for endemic fluorosis. As an important research content of hydrogeochemistry, the enrichment of fluorine in alkaline water has received a fair amount of scholarly attention, but the understanding of the migration and enrichment of fluorine in acid mine drainage (AMD) in karst area remains very limited. An analysis of 13 consecutive periods of hydrochemical samples (312 samples in total) revealed that the weathering of carbonates and sulfide-rich coal measures induced a pH as low as 2.29 in the Chetian River in Jinsha, Southwest China. The highest content of fluorine in AMD was 23.8 mg/L, and the average content in the basin was 1.4 mg/L. In terms of the seasonal variation in the whole basin, the fluorine content were higher in the rainy season than in the dry season. The mineral saturation index shows that the dissolution of fluorapatite and fluorite is an important source of fluorine. The chloro-alkaline indices displayed a strong ion exchange process in the basin, promoting the release of fluorine in silicate minerals. In comparison, the contribution of external inputs, such as atmospheric deposition, was less. Additionally, evaporation was shown to have a limited influence on fluorine enrichment. Meanwhile, pH was an essential factor driving the dynamic transformation of the mode of occurrence of fluorine in water. In the upstream alkaline water, the main occurrence form of fluorine was free F-, while the F/Al ratio for most of the acidic samples was ≤ 1.0, indicating the main occurrence form of fluorine was likely AlF2+. The conclusion of this study provides a new understanding for deepening the geochemical characteristics of fluorine in karst surface water.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Ácidos/análise , China , Monitoramento Ambiental , Fluoretos/análise , Flúor , Água Subterrânea/química , Concentração de Íons de Hidrogênio , Minerais/análise , Água/análise , Poluentes Químicos da Água/análise
18.
Biomater Adv ; 136: 212763, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35929306

RESUMO

Up-conversion nanoparticles (UCNPs) of sodium yttrium fluoride with ytterbium and erbium ions as sensitizer and activator (ß-NaYF4/Yb3+/Er3+) have been synthesised by a solvothermal method. The synthesised particles were found to be highly uniform in size (~50 nm) and of hexagonal crystal phase producing strong up-conversion luminescence dominated in the green wavelength region. During the synthesis, photoluminescence properties of the reaction mixture were monitored at regular intervals to ensure the required particle size distribution and luminescence efficiency. The hydrophobic particles thus obtained were modified by coating with silica, yielding particles that were stable in aqueous media. The silica coated UCNPs were further modified with maleimide-polyethylene glycol-silane (mal-PEG-silane) to provide thiol reactive surface groups. The silanized, maleimide-bearing UCNPs were effective for conjugating to reductively-cleaved half antibodies against ofloxacin, a veterinary antibiotic, to produce photoluminescent nanobiosensors for its detection and quantification. The speed and minimum detection concentration (~10 nM) that we report for a competitive assay of ofloxacin in this study is promising for developing sensors for this and other biomolecules.


Assuntos
Fluoretos , Nanopartículas , Fluoretos/química , Maleimidas , Nanopartículas/química , Ofloxacino , Dióxido de Silício , Fluoreto de Sódio
19.
Environ Sci Technol ; 56(17): 12336-12346, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-35972505

RESUMO

The photolysis of pesticides with different fluorine motifs was evaluated to quantify the formation of fluorinated products in buffered aqueous systems, advanced oxidation (AOP) and reduction processes (ARP), and river water. Simulated sunlight quantum yields at pH 7 were 0.0033, 0.0025, 0.0015, and 0.00012 for penoxsulam, florasulam, sulfoxaflor, and fluroxypyr, respectively. The bimolecular rate constants with hydroxyl radicals were 2 to 5.7 × 1010 M-1 s-1 and, with sulfate radicals, 1.6 to 2.6 × 108 M-1 s-1 for penoxsulam, florasulam, and fluroxypyr, respectively. The rate constants of sulfoxaflor were 100-fold lower. Using quantitative 19F-NMR, complete fluorine mass balances were obtained. The maximum fluoride formation was 53.4 and 87.4% for penoxsulam and florasulam under ARP conditions, and 6.1 and 100% for sulfoxaflor and fluroxypyr under AOP conditions. Heteroaromatic CF3 and aliphatic CF2 groups were retained in multiple fluorinated photoproducts. Aryl F and heteroaromatic F groups were readily defluorinated to fluoride. CF3 and CF2 groups formed trifluoroacetate and difluoroacetate, and yields increased under oxidizing conditions. 19F-NMR chemical shifts and coupling analysis provided information on hydrogen loss on adjacent bonds or changes in chirality. Mass spectrometry results were consistent with the observed 19F-NMR products. These results will assist in selecting treatment processes for specific fluorine motifs and in the design of agrochemicals to reduce byproduct formation.


Assuntos
Flúor , Praguicidas , Fluoretos , Radical Hidroxila/química , Fotólise
20.
Chem Commun (Camb) ; 58(72): 10008-10011, 2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-35975686

RESUMO

Octa(dimethylsiloxy)silica cages (Q8M8H) undergo rapid self-polymerization in the presence of a fluoride catalyst to form complex 3D porous structural network materials with specific surface areas up to 650 m2 g-1. This establishes a new method to form bio-derived high inorganic content soft silicas with potential applications in filtration, carbon capture, catalysis, or hydrogen source.


Assuntos
Fluoretos , Dióxido de Silício , Catálise , Polimerização , Porosidade , Dióxido de Silício/química
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