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1.
Artículo en Chino | MEDLINE | ID: mdl-34074089

RESUMEN

Objective: To analyze the health hazards of fluorine and its inorganic compounds to workers exposed to fluorine, and to provide technical support for the protection of workers exposed to fluorine and the revision of occupational disease diagnostic standards. Methods: In January 2019, 677 workers exposed to fluorine in a fluorine chemical company in Hunan Province were selected by cluster sampling, and occupational health examination was conducted. The suspected occupational poisoning workers were diagnosed as occupational diseases, which were divided into poisoning group and non-poisoning group. T test and Pearson χ(2) test were used for statistical analysis. Results: A total of 73 occupational chronic fluorosis patients were diagnosed. 93.15% (68/73) of the skeletal lesions were multiple, and the most frequent sites were the upper tibia and fibula. 35.00% (21/60) , 50.00% (18/36) and 58.82% (10/17) of the tibia, fibula, ulna and radius had periosteal changes only on one side. Other abnormal results were mainly dental calculus (60.71%, 411/677) , fatty liver (48.89%, 331/677) , abnormal electrocardiogram (44.17%, 299/677) , decreased bone mass (33.53%, 227/677) and increased ALT (13.15%, 89/677) . Compared with non-poisoning group, the age, length of service exposed to fluoride and fatty liver detection rate of poisoning group were higher, and the differences were statistically significant (P<0.01) . Conclusion: The changes of long bone caused by inorganic fluoride only occur in one side, so the basic location of occupational health examination should include bilateral long bone to avoid missed diagnosis. It is difficult to diagnose occupational poisoning with single slight periosteal ossification, it is suggested that the standard should be revised to specify the degree.


Asunto(s)
Intoxicación por Flúor , Enfermedades Profesionales , Exposición Profesional , Salud Laboral , Intoxicación por Flúor/diagnóstico , Fluoruros , Flúor , Humanos
2.
Braz Oral Res ; 35(suppl 01): e053, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34076077

RESUMEN

Identifying the risk factors for dental caries is vital in epidemiology and clinical practices for developing effective preventive strategies, both, at the individual and collective levels. Different causality/determination models have been proposed to understand the development process of dental caries. In the present review, we designed a model inspired by the world-known social determinants models proposed in the 90s and more recently in the 10s, wherein the contextual factors are placed more externally and encompass the individual factors. The contextual factors included those related to the cultural and societal values, as well as the social and health government policies. The individual factors were classified into the following categories: socioeconomic (social class, occupation, income, and education level), demographic characteristics (age, sex, and ethnicity), behavioral factors (non-use of fluoride dentifrice, sugar consumption, poor oral hygiene, and lack of preventive dental care), and biological factors (recent caries experience/active caries lesions, biofilm retentive factors, developmental defects of the enamel, disabilities, saliva amount and quality, cariogenic biofilm). Each of these variables was addressed, while focusing on the current evidence from studies conducted in Latin American and Caribbean countries (LACC). Based on the proposed model, educational aspects were addressed, and individual caries risk assessment and management decisions were proposed; further, implications for public health policies and clinical practice were described. The identification of modifiable risk factors for dental caries should be the basis for multi-strategy actions that consider the diversity of Latin American communities.


Asunto(s)
Caries Dental , Región del Caribe , Caries Dental/epidemiología , Caries Dental/etiología , Caries Dental/prevención & control , Fluoruros , Humanos , América Latina/epidemiología , Factores de Riesgo
3.
Braz Oral Res ; 35: e066, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34076191

RESUMEN

This study developed experimental gels containing titanium tetrafluoride (TiF4) combined with commercial 35% hydrogen peroxide (HP), and evaluated bleaching efficacy and pH of the gels, and mineral content and morphology of enamel submitted to these treatments. In phase-1, different stock gels mixed with TiF4 were combined with HP. In phase-2, the selected gels were tested on enamel/dentin specimens (n=8): HP; HP and Natrosol+TiF4 (HPnT); HP and Natrosol+Chemygel+TiF4 (HPncT); HP and Aristoflex+TiF4 (HPaT). Bleaching was performed in four sessions (3x15min-application/session). Color (CIEL*a*b*) and whiteness index (WID) were measured after each session, whereas whiteness index differences (ΔWID), color alteration (CIELab-ΔE, CIEDE2000-ΔE00), enamel morphology and pH, at end of bleaching therapy. The change in Knoop microhardness (ΔKHN) was compared before and after bleaching. Data were analyzed by two-way repeated measures ANOVA and Bonferroni (CIEL*, a*, b*), one-way ANOVA and Tukey (ΔWID, ΔE, ΔE00), and LSD (ΔKHN) tests (α=5%). SEM and pH measurements were submitted to descriptive analysis. No differences were observed in lightness (L*) or WID among the groups (p > 0.05), but HP exhibited lower b* values (p<0.05), higher ΔWID than HPnT, and the highest ΔE among the groups (p < 0.05). No differences in ΔE00 were observed between HP and HPncT (p > 0.05), and HPncT showed higher ΔKHN than HP (p < 0.05). HP presented pH values closer to neutral (6.9), whereas experimental agents showed acidic pH values (2.3-3.9). No morphological changes were observed in HP or HPncT groups. HPncT was able to bleach the enamel and maintain enamel microhardness and surface integrity, even at low pH.


Asunto(s)
Blanqueadores , Blanqueadores Dentales , Blanqueamiento de Dientes , Fluoruros , Peróxido de Hidrógeno , Titanio
4.
Wiad Lek ; 74(5): 1120-1124, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34090275

RESUMEN

OBJECTIVE: The aim: A study of the impact of drinking water quality on the state of dental health in schoolchildren who permanently live in areas of biogeochemical deficiency of fluorine and iodine. PATIENTS AND METHODS: Material and methods: The composition of the drinking water of the city of Uzhhorod and the city of Rakhiv has been investigated. The prevalence and intensity of dental caries in children is determined, drinking water is taken in accordance with Uzhhorod and Rakhiv. RESULTS: Results: The regional features of the composition of drinking water of the mountain Rakhivsky district of the Transcarpathian region are the high variety of combinations of mineral components and the frequent excess of the normative content of dry residue components, namely nitrates, sulfates, chlorides, magnesium and calcium.Water oxidation, total stiffness and total alkalinity were significantly different. The established drinking water quality indicators have a direct dependence on the prevalence and intensity of dental caries in children, that is, a significant increase in the number of carious temporary, carious and distant permanent teeth and a decrease in filled temporary and permanent teeth (p < 0. 05) were diagnosed. CONCLUSION: Conclusions: One of the most pressing problems in water hygiene is the urgent need to review and improve regulations, State sanitary regulations, standards and other regulations in the field of drinking water, including through the development of regional drinking water quality standards.


Asunto(s)
Caries Dental , Agua Potable , Fluorosis Dental , Niño , Caries Dental/epidemiología , Fluoruros , Humanos , Prevalencia
5.
BMC Oral Health ; 21(1): 234, 2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33947382

RESUMEN

BACKGROUND: Dental caries is the most prevalent non-communicable health condition globally. The surface-based susceptibility hierarchy indicates that surfaces in the same group have similar susceptibility to caries, where the most susceptible group consists of occlusal surfaces of first molars and buccal surfaces of lower first molars, and the least susceptible surfaces are smooth and proximal surfaces of first premolars, canines and incisors. Therefore, fluoride in the drinking water could impact one group more than the other group. The present study examined the association between fluoride levels in the drinking water and dental caries experience in adults in the context of varying tooth surface susceptibility. METHODS: Data from the cross-sectional National Lithuanian Oral Health Survey conducted in 2017-2019 included a stratified random sample of 1398 35-74-year-olds (52% response rate). Dental caries experience in dentine was measured at a surface level. The surfaces were grouped according to their caries susceptibility (group 1 being the most and group 4 the least susceptible), and dental caries experience was calculated separately for each susceptibility group, creating four outcomes. Information about explanatory variable, fluoride levels in the drinking water, was provided by the water suppliers. The questionnaire inquired about potential determinants: sociodemographic characteristics and oral health-related behaviors. Chi-square, Mann-Whitney U and Kruskal Wallis tests were used for descriptive statistics, and linear regression analyses to examine the association between fluoride levels and four outcomes. RESULTS: The proportions of median decayed, missing, filled surfaces decreased following the surface-based susceptibility hierarchy (group 1-33%, group 2-28%, group 3-24%, group 4-15%). When adjusted for potential determinants, higher-level fluoride (≥ 0.7 ppm vs < 0.7 ppm) in the drinking water associated with lower dental caries experience in all surface-based susceptibility hierarchy groups; Group 1: ß = - 0.23 (95 %CI - 0.44; - 0.001), Group 2: ß = - 0.44 (95 %CI - 0.82; - 0.07), Group 3: ß = - 1.14 (95 %CI - 1.88; - 0.41) and Group 4: ß = - 6.28 (95 %CI - 9.29; - 3.30). CONCLUSIONS: The higher-level fluoride in the drinking water associated with lower dental caries experience in adults and this was observed in all surface-based susceptibility groups. However, there is a need to validate the surface-based susceptibility hierarchy in longitudinal adult studies.


Asunto(s)
Caries Dental , Agua Potable , Adulto , Estudios Transversales , Caries Dental/epidemiología , Fluoruros , Humanos , Diente Molar
7.
Mater Sci Eng C Mater Biol Appl ; 124: 111937, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33947528

RESUMEN

Dual labeled contrast agents could provide better complementary information for bioimaging than available solely from a single modality. In this paper we investigate the suitability of Yb3+ and Er3+-doped BaYF5 upconversion nanoparticles (UCNPs) as both optical and X-ray micro computed tomography (µCT) contrast agents. Stable, aqueous UCNP dispersions were synthesised using a hydrothermal method with the addition of polyethyleneimine (PEI). UCNPs were single crystal and had a truncated cuboidal and/or truncated octahedral morphology, with average particle size of 47 ±9 nm from transmission electron microscopy which was further used to characterize the structure and composition in detail. A zeta potential value of +51 mV was measured for the aqueous nanoparticle dispersions which is beneficial for cell permeability. The outer hydrated PEI layer is also advantageous for the attachment of proteins for targeted delivery in biological systems. The prepared UCNPs were proven to be non-toxic to endothelial cells up to a concentration of 3.5 mg/mL, when assessed using an MTT assay. The particles showed intense green upconversion photoluminescence when excited at a wavelength of 976 nm using a diode laser. Quantitative X-ray µCT contrast imaging confirmed the potential of these UCNPs as X-ray contrast agents and confirming their dual modality for bioimaging.


Asunto(s)
Nanopartículas , Itrio , Bario , Medios de Contraste , Células Endoteliales , Fluoruros , Microtomografía por Rayos X
8.
J Contemp Dent Pract ; 22(1): 4-8, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34002700

RESUMEN

AIM: The 75th anniversary of community water fluoridation in the United States was celebrated in 2020. However, there are studies that stimulate polarized discussion over the use of fluoride in dentistry. The purpose of this study was to evaluate dental and dental hygiene students' knowledge and perception of fluoride use in dentistry. MATERIALS AND METHODS: A survey was conducted to gauge participant's knowledge and perception of fluoride and their opinion on the need for developing viable alternatives to fluoride. An Institutional Review Board (IRB# 5190496) application was filed and approved. A hard copy survey was distributed to all student classes at Loma Linda University School of Dentistry (U.S.) between January 13, 2020, and February 5, 2020. Descriptive data were compiled and analyzed. Knowledge-based questions were compared using Kruskal-Wallis procedure to evaluate correct percentage among different classes. Perception questions were analyzed using a Likert scale and also a Chi-squared test. All tests were two-sided with α at 0.05. RESULTS: Out of 482 students, 282 students responded (58.5%). The mean of correct responses for knowledge ranged from 49 to 69%. There was a statistically significant difference among the classes. Overall the perception of the use of fluoride in dentistry was positive, and it changed with exposure to lectures on fluoride over the years. CONCLUSION: There was a correlation between knowledge and the perception of the use of fluoride in dentistry, indicating the importance of adequate delivery of didactic teaching on knowledge of fluoride to dental and dental hygiene students. CLINICAL SIGNIFICANCE: The oral healthcare provider plays a pivotal role in communicating pertinent information on the benefits of fluoride in preventing dental caries to the general public, prompting adequate delivery of didactic teaching on this topic in dental education.


Asunto(s)
Caries Dental , Fluoruros , Actitud del Personal de Salud , Humanos , Higiene Bucal , Percepción , Estudiantes de Odontología
9.
Dental Press J Orthod ; 26(2): e212020, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33950083

RESUMEN

INTRODUCTION: After debonding, white spot may appear on the area below the bracket, which is the early clinical sign of carious lesion. There is increased caries risk underneath and adjacent to orthodontic bands and brackets, which call for maximum use of caries preventive procedures using various fluoride application methods. OBJECTIVE: The aim of the study was to evaluate alterations in the mechanical properties (modulus of elasticity and yield strength) in loading and unloading phases for different orthodontic archwires (nickel-titanium [NiTi] and copper-nickel-titanium [CuNiTi]) when exposed routinely to fluoride prophylactic agents for a predetermined period of time. METHODS: Preformed rectangular NiTi and CuNiTi wires were immersed in fluoride solution and artificial saliva (control) for 90 minutes at 37ºC. After immersion, specimens were tested using a 3-point bend test on a universal testing machine. RESULTS: There is a significant reduction in the unloading yield strength when the NiTi and CuNiTi wires were exposed to APF gel. CONCLUSION: The result suggests that use of topical fluoride agents affect the mechanical properties of the wires, leading to increase in treatment duration. Fluoride prophylactic agents must be used with caution in patients undergoing orthodontic treatment. Injudicious use of these agents may cause corrosive effects on the orthodontic wire surfaces, with alteration in their mechanical properties.


Asunto(s)
Níquel , Alambres para Ortodoncia , Cobre , Aleaciones Dentales , Fluoruros , Humanos , Ensayo de Materiales , Níquel/efectos adversos , Propiedades de Superficie , Titanio
10.
Am J Dent ; 34(2): 87-90, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33940665

RESUMEN

PURPOSE: To assess the gingivitis reduction efficacy of a novel stannous-containing fluoride dentifrice relative to a negative control. METHODS: 100 generally healthy adults with 10 or more gingival bleeding sites based on the Mazza Modification of the Papillary Bleeding Index (Mazza GI) were enrolled into a 2-week randomized, controlled, double-blind, single-center, two-treatment, parallel group clinical study. The subjects were randomly assigned to the stannous-containing dentifrice group (experimental group) or the sodium fluoride dentifrice group (negative control group). An oral examination and Mazza GI examination were conducted at Baseline, Day 3 and Week 2 post-baseline by a qualified dental examiner. RESULTS: 98 subjects completed the study. The experimental group provided a significant reduction in Mazza GI scores and number of bleeding sites relative to baseline at Day 3 and Week 2 (P< 0.0001). The negative control did not provide significant reductions versus baseline for either measure at either timepoint (P> 0.3). At Day 3, the experimental group provided a statistically significant reduction of Mazza GI scores and number of bleeding sites compared with the negative control group (P< 0.0001). At Week 2, the experimental group showed 24.11% lower Mazza GI scores and 54.81% fewer bleeding sites than the negative control group (P< 0.0001). CLINICAL SIGNIFICANCE: The results demonstrated that the novel stannous-containing fluoride dentifrice had a superior anti-gingivitis effect compared to the sodium fluoride negative control dentifrice, which was evident as quickly as 3 days after use and further improved after 2 weeks of usage.


Asunto(s)
Dentífricos , Gingivitis , Adulto , Dentífricos/uso terapéutico , Fluoruros , Gingivitis/tratamiento farmacológico , Gingivitis/prevención & control , Humanos , Índice Periodontal , Fluoruros de Estaño/uso terapéutico
11.
Adv Exp Med Biol ; 1306: 121-127, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33959910

RESUMEN

Analysis of fluoride in body fluids (urine and serum) is essential for fluorosis diagnosis. Although 24-h urine collection is adopted to assess community defluoridation/fluoride supplementation program/research studies, but not feasible for Clinical/Pathological laboratories. Patients are reluctant to bring 24-h urine samples. Hence, spot urine samples are collected in clean, dry polypropylene bottles (not glass) without any preservative and analyzed on the same day by the Ion analyzer (ISE method). Equal volumes of Total Ionic Strength Adjustment Buffer (TISAB) solution are then added with body fluids before analysis and mixed well to eliminate interference from other ions besides pH adjustment and to provide a constant ionic strength. Results are reported as mg of Fluoride/l (ppm). High fluoride level in body fluids is an indication of confirmed cases of fluorosis. Two interventions, e.g. withdrawal of fluoride intake and intake of nutritive diet was introduced for prevention and control of fluorosis. The present study is to provide useful guidelines for monitoring of fluorosis disease in human beings, those who are at the risk of fluoride exposure.


Asunto(s)
Líquidos Corporales , Fluorosis Dental , Fluoruros , Fluorosis Dental/diagnóstico , Humanos , Electrodos de Ion-Selectivo , Concentración Osmolar
12.
Ecotoxicol Environ Saf ; 217: 112225, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33864983

RESUMEN

Long-term exposure to excessive fluoride causes chronic damage in the body tissues and could lead to skeletal and dental fluorosis. Cartilage damage caused by excessive fluoride intake has gained wide attention, but how fluoride accumulation blocks the development of chondrocytes is still unclear. Here, we report a negative correlation between the length and growth plate width after NaF treatments via apoptosis and autophagy, with shrinkage of cells, nuclear retraction, dissolution of chondrocytes. Whereas, fluoride exposure had no significant effect on the number and distribution of the osteoclasts which were well aligned. More importantly, fluoride exposure induced apoptosis of tibial bone through CytC/Bcl-2/P53 pathways via targeting Caspase3, Caspase9, Bak1, and Bax expressions. Meanwhile, the Beclin1, mTOR, Pakin, Pink, and p62 were elevated in NaF treatment group, which indicated that long-term excessive fluoride triggered the autophagy in the tibial bone and produced the chondrocyte injury. Altogether, fluoride exposure induced the chondrocyte injury by regulating the autophagy and apoptosis in the tibial bone of ducks, which demonstrates that fluoride exposure is a risk factor for cartilage development. These findings revealed the essential role of CytC/Bcl-2/P53 pathways in long-term exposure to fluoride pollution and block the development of chondrocytes in ducks, and CytC/Bcl-2/P53 can be targeted to prevent fluoride induced chondrocyte injury.


Asunto(s)
Condrocitos/fisiología , Patos/fisiología , Fluoruros/toxicidad , Animales , Apoptosis/efectos de los fármacos , Autofagia/efectos de los fármacos , Beclina-1/metabolismo , Condrocitos/efectos de los fármacos , Condrogénesis , Fluoruros/metabolismo , Placa de Crecimiento
13.
Chemosphere ; 277: 130222, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33794430

RESUMEN

Fluorine (F) and its compounds produced from industrial production and coal combustion can cause air, water and soil contamination, which can accumulate in animals, plants and humans via food chain threatening public health. Fluoride exposure affects liver, kidney, gastrointestinal and reproductive system in humans and animals. Literature regarding fluoride influence on intestinal structure and microbiota composition in ducks is scarce. This study was designed to investigate these effects by using simple and electron microscopy and 16S rRNA sequencing techniques. Results indicated an impaired structure with reduced relative distribution of goblet cells in the fluoride exposed group. Moreover, the gut microbiota showed a significant decrease in alpha diversity. Proteobacteria, Firmicutes and Bacteroidetes were the most abundant phyla in both control and fluoride-exposed groups. Specifically, fluoride exposure resulted in a significant decrease in the relative abundance of 9 bacterial phyla and 15 bacterial genera. Among them, 4 phyla (Latescibacteria, Dependentiae, Zixibacteria and Fibrobacteres) and 4 genera (Thauera, Hydrogenophaga, Reyranella and Arenimonas) weren't even detectable in the gut microbiota of the ducks. In summary, higher fluoride exposure can significantly damage the intestinal structure and gut microbial composition in ducks.


Asunto(s)
Microbioma Gastrointestinal , Microbiota , Animales , Patos , Fluoruros/toxicidad , Humanos , ARN Ribosómico 16S/genética
15.
Nanoscale ; 13(16): 7638-7647, 2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33928960

RESUMEN

Herein, we developed a novel strategy for the shape-controlled synthesis of iron oxide nanostructures with superior r2 values through the introduction of fluoride ions as a morphology controlling agent and dopant. The selective adsorption of fluoride ions onto the specified crystal planes of iron oxide nanocrystals leads to the formation of octapod nanoparticles (ONPs) and cubic nanocrystal clusters (CNCs). Both ONPs and CNCs present high r2 values (526.5 and 462.2 mM-1 s-1, respectively) due to the synergistic effect of a larger effective radius, clustering and fluorine doping. The in vivo MRI results show significant enhancement in T2-weighted images of the liver after the intravenous injection of ONPs and CNCs, suggesting their great potential as efficient T2-weighted MRI contrast agents. This new approach of achieving anisotropic fluorine-doped iron oxide nanostructures with high r2 relaxivity provides an alternative strategy for the development of highly sensitive T2 contrast agents for MRI.


Asunto(s)
Flúor , Nanoestructuras , Medios de Contraste , Compuestos Férricos , Fluoruros , Imagen por Resonancia Magnética
16.
Biosens Bioelectron ; 182: 113172, 2021 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-33812282

RESUMEN

Rising global concerns posed by chemical and biological threat agents highlight the critical need to develop reliable strategies for the real-time detection of such threats. While wearable sensing technology is well suited to fulfill this task, the use of on-body devices for rapid and selective field identification of chemical agents is relatively a new area. This work describes a flexible printed textile-based solid-contact potentiometric sensor for the selective detection of fluoride anions liberated by the biocatalytic hydrolysis of fluorine-containing G-type nerve agents (such as sarin or soman). The newly developed solid-contact textile fluoride sensor relies on a fluoride-selective bis(fluorodioctylstannyl)methane ionophore to provide attractive analytical performance with near-Nernstian sensitivity and effective discrimination against common anions, along with excellent reversibility and repeatability for dynamically changing fluoride concentrations. By using stress-enduring printed inks and serpentine structures along with stretchable textile substrates, the resulting textile-based fluoride sensor exhibits robust mechanical resiliency under severe mechanical strains. Such realization of an effective textile-based fluoride-selective electrode allowed biosensing of the nerve-agent simulant diisopropyl fluorophosphate (DFP), in connection to immobilized organophosphorus acid anhydrolylase (OPAA) or organophosphorus hydrolase (OPH) enzymes. A user-friendly portable electronic module transmits data from the new textile-based potentiometric biosensor wirelessly to a nearby smartphone for alerting the wearer instantaneously about potential chemical threats. While expanding the scope of wearable solid-contact anion sensors, such a textile-based potentiometric fluoride electrode transducer offers particular promise for effective discrimination of G-type neurotoxins from organophosphate (OP) pesticides, toward specific field detection of these agents in diverse defense settings.


Asunto(s)
Técnicas Biosensibles , Agentes Nerviosos , Dispositivos Electrónicos Vestibles , Fluoruros , Textiles
17.
Anal Chim Acta ; 1159: 338439, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33867030

RESUMEN

A PDMS (Polydimethylsiloxane) microfluidic channel coupled with UV-vis fibre-optic spectrometer and new synthesized colorimetric probe was integrated into an optofluidic based Lab-on-a-chip device for highly sensitive and real-time quantitative measurements of fluoride ions (F¯). An 'S' shaped microchannel in a microfluidic device was designed to act as microreactor to facilitate the continuous reaction between synthetized colorimetric probe (sensor) and F¯ ions. Following this reaction, the UV-vis optical probe in the downstream detection zone of the microfluidic device was used to capture their spectrum and present as F¯ concentration in real-time conditions. An initial study of the developed colorimetric probe with multi-colour change with several binding and chromophore groups such as -OH, -NH and -NO2 groups confirmed its high sensitivity and selectivity for F¯ ions with a detection limit of 0.79 ppm. The performance of the developed optofluidic device was evaluated for the selective, sensitive detection of F¯ ions including real samples out-performing conventional methods. The technology has advantages such as low sample consumption, rapid analysis, high sensitivity and portability. Presented new Lab-on-a-chip device provides many competitive advantages for the real-time analysis of F¯ ions needed across broad sectors.


Asunto(s)
Fluoruros , Dispositivos Laboratorio en un Chip , Colorimetría , Microfluídica
18.
Rev Esp Salud Publica ; 952021 Apr 08.
Artículo en Español | MEDLINE | ID: mdl-33828069

RESUMEN

OBJECTIVE: The use of fluoridated toothpastes is considered the most rational method in dental caries control, and it is recommended for all ages people, but for this they must be established at a minimum concentration of 1,000 ppm of total soluble fluoride, in pediatric patients. The objective of the study was to determine the concentration of total and soluble fluoride present in toothpastes marketed in Spain for pediatric use. METHODS: A descriptive and cross-sectional study was carried out throughout 2019, analyzing 11 toothpastes for pediatric use marketed in Murcia, Spain. The concentration of fluoride (ppm F=mg F/Kg) total (FT), soluble (FTS) and fluoride ion (F) and MFP (FPO32-) was analyzed using an ion-specific electrode coupled to an ion analyzer. A descriptive study was carried out to determinate mean and standard deviations for each variable analyzed. RESULTS: Among the analyzed toothpastes, 45% contained NaF (sodium fluoride), 45% MFP (sodium monofluorophosphate) and 10% both types of salts. The abrasive used was silica. 98% of the analyzed toothpastes showed total fluoride contents similar to those described by the manufacturer, only 3 toothpastes had fluoride concentrations lower than those described. The range obtained from FT oscillated between 398 -1,474.6 ppm F, and 100% of the toothpastes did not show differences between values of total fluoride and soluble fluoride. CONCLUSIONS: Most of the analyzed toothpastes contain a concentration of soluble fluoride between 1,000-1,500 ppm Fluoride, corresponding to the values described by the manufacturers However, there are still toothpastes with values lower than those recommended, minimum 1,000 ppm F, that do not allow effective anticaries activity from a public health point of view.


Asunto(s)
Fluoruros/análisis , Pastas de Dientes/química , Niño , Estudios Transversales , Humanos , España
19.
Bioresour Technol ; 333: 125154, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33895669

RESUMEN

This study investigated the influence of different carbon to nitrogen (C/N) ratios on the bio-removal efficiency of aquatic pollutants like calcium (Ca2+), fluoride (F-), and nitrate (NO3-N) in a quartz sand-filled biofilm reactor (QSBR) to treat the low C/N wastewater using Acinetobacter sp. H12 at pH 6.50. The simultaneous bio-removal rate of Ca2+, F-, and NO3- reached 56.31%, 96.33, and 96.95 respectively. Nitrogen gas (N2) was produced with no evidence of N2O emission. Moreover, the morphological study of strain H12 and biological precipitates through SEM revealed that strain H12 provides the nucleation sites for microbially induced calcium precipitation to remove Ca2+ and F-. Besides, XPS and XRD peak spectra implicated that Ca2+ and F- were removed as CaF2 and Ca5(PO4)3F co-precipitates. The 16S rRNA sequencing analyses revealed that H12 belongs to Acinetobacter and has stronger MICP and denitrification potential as compared with other strains under low C/N conditions.


Asunto(s)
Acinetobacter , Nitratos , Acinetobacter/genética , Biopelículas , Reactores Biológicos , Calcio , Carbono , Desnitrificación , Fluoruros , Nitrógeno , Cuarzo , ARN Ribosómico 16S/genética , Arena
20.
Biosensors (Basel) ; 11(4)2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33918524

RESUMEN

A plasmonic material-coated circular-shaped photonic crystal fiber (C-PCF) sensor based on surface plasmon resonance (SPR) is proposed to explore the optical guiding performance of the refractive index (RI) sensing at 1.7-3.7 µm. A twin resonance coupling profile is observed by selectively infiltrating liquid using finite element method (FEM). A nano-ring gold layer with a magnesium fluoride (MgF2) coating and fused silica are used as plasmonic and base material, respectively, that help to achieve maximum sensing performance. RI analytes are highly sensitive to SPR and are injected into the outmost air holes of the cladding. The highest sensitivity of 27,958.49 nm/RIU, birefringence of 3.9 × 10-4, resolution of 3.70094 × 10-5 RIU, and transmittance dip of -34 dB are achieved. The proposed work is a purely numerical simulation with proper optimization. The value of optimization has been referred to with an experimental tolerance value, but at the same time it has been ensured that it is not fabricated and tested. In summary, the explored C-PCF can widely be eligible for RI-based sensing applications for its excellent performance, which makes it a solid candidate for next generation biosensing applications.


Asunto(s)
Técnicas Biosensibles , Refractometría , Simulación por Computador , Fluoruros , Oro , Compuestos de Magnesio , Nanoestructuras , Fotones , Plata/química , Resonancia por Plasmón de Superficie
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