RESUMEN
The mode of action, bioaccumulation potential and toxicity of Rare Earth Elements (REE), with several applications in the technology, medical and agricultural fields, are still understudied. The nitrates acute effects on single exposures, binary and ternary mixtures of lanthanum (La), neodymium (Nd) and samarium (Sm) on Lactuca sativa lettuce seed germination and wet biomass in an artificial soil (AS) and an Ultisol were assessed. Germination (EC50), wet biomass (IC50) and germination inhibition (% GI) were evaluated. EC50 values show La was the most toxic in Ultisol, Sm in AS, and Nd appears with intermediate values on both substrates. The IC50, both single and mixed, decreased from 3- to 181-fold with increasing test concentrations in relation to the control in AS, while increases in Ultisol were observed, followed by decreases at higher doses which may be associated with the low-dose stimulation effect (hormesis). Our findings may be used to subsidize REE risk assessment studies and reinforce the hormesis effect to prevent the use of high application of REE fertilizers, avoiding the accumulation of REE in agricultural soils.
Asunto(s)
Germinación , Lactuca , Lantano , Semillas , Contaminantes del Suelo , Lactuca/efectos de los fármacos , Lactuca/crecimiento & desarrollo , Germinación/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Lantano/toxicidad , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Metales de Tierras Raras/toxicidad , Suelo/química , Neodimio/toxicidadRESUMEN
A large Argentine tegu (Salvator merianae) presented with anorexia. Initial radiographs revealed a metallic foreign body in the stomach. The tegu vomited and became inactive two days later. A follow-up radiograph revealed the persistence of the foreign body in the same region. The foreign body was identified as a cluster of multiple magnets resembling neodymium magnets reported missing by the owner. An emergent laparotomy was performed due to gastrointestinal perforations caused by the multiple magnets. The surgical intervention revealed perforations in the walls of the stomach and small intestine and progressing acute peritonitis. Three magnets were extracted from the abdominal cavity and the tegu showed recovery. At 200 days postoperatively, the tegu continued to demonstrate good appetite and energy levels.
Asunto(s)
Cuerpos Extraños , Neodimio , Animales , Cuerpos Extraños/cirugía , Cuerpos Extraños/veterinaria , Imanes , Estómago/cirugía , Estómago/lesiones , Masculino , Perforación Intestinal/veterinaria , Perforación Intestinal/cirugía , Perforación Intestinal/etiologíaRESUMEN
The antioxidant capabilities of nanoparticles are contingent upon various factors, including their shape, size, and chemical composition. Herein, novel Nd-doped CeO2 nanoparticles were synthesized and the neodymium content was varied to investigate the synergistic impact on the antioxidant properties of CeO2 nanoparticles. Incorporating Nd3+ induced changes in lattice parameters and significantly altered the morphology from nanoparticles to nanorods. The biological activity of Nd-doped CeO2 was examined against pathogenic bacterial strains, breast cancer cell lines, and antioxidant models. The antibacterial and anticancer activities of nanoparticles were not observed, which could be associated with the Ce3+/Ce4+ ratio. Notably, the incorporation of neodymium improved the antioxidant capacity of CeO2. Machine learning techniques were employed to forecast the antioxidant activity to enhance understanding and predictive capabilities. Among these models, the random forest model exhibited the highest accuracy at 96.35%, establishing it as a robust computational tool for elucidating the biological behavior of Nd-doped CeO2 nanoparticles. This study presents the first exploration of the influence of Nd3+ on the structural, optical, and biological attributes of CeO2, contributing valuable insights and extending the application of machine learning in predicting the therapeutic efficacy of inorganic nanomaterials.
Asunto(s)
Nanopartículas , Nanoestructuras , Antioxidantes/farmacología , Antioxidantes/química , Neodimio , Nanopartículas/química , Antibacterianos/farmacología , Antibacterianos/químicaRESUMEN
Capsulotomy with neodymium-doped yttriumaluminum-garnet (Nd:YAG) laser is an effective treatment for posterior capsule opacification following cataract surgery. A wide opening of the posterior capsule associated with the ruptured anterior hyaloid can cause anterior chamber vitreous prolapse. Two patients who developed angle-closure glaucoma associated with vitreous prolapse following Nd:YAG laser posterior capsulotomy were successfully treated with antiglaucoma medication and peripheral iridotomies. Patient identification for potential risk factors and a careful postoperative follow-up are essential to avoid these serious complications.
Asunto(s)
Opacificación Capsular , Extracción de Catarata , Glaucoma de Ángulo Cerrado , Terapia por Láser , Láseres de Estado Sólido , Cápsula del Cristalino , Humanos , Cápsula del Cristalino/cirugía , Neodimio , Glaucoma de Ángulo Cerrado/etiología , Glaucoma de Ángulo Cerrado/cirugía , Capsulotomía Posterior , Itrio , Extracción de Catarata/efectos adversos , Prolapso , Terapia por Láser/efectos adversos , Complicaciones Posoperatorias/etiología , Láseres de Estado Sólido/efectos adversosRESUMEN
In this study, we emphasize the critical role of sample pretreatment. We report on the behavior of NdFeB magnet samples exposed to four different acid media for digestion. NdFeB magnets are becoming a significant source of neodymium, a rare-earth element critical to many technologies and a potential substitute for traditional mining of the element. To address this, we meticulously tested nitric acid, hydrochloric acid, acetic acid, and citric acid, all at a concentration of 1.6 M, as economical and environmentally friendly alternatives to the concentrated mineral acids commonly used in the leaching of these materials. The pivotal stage involves the initial characterization of samples in the solid state using SEM-EDX and XPS analysis to obtain their initial composition. Subsequently, the samples are dissolved in the four aforementioned acids. Finally, neodymium is quantified using ICP-OES. Throughout our investigation, we evaluated some analytical parameters to determine the best candidate for performing the digestion, including time, limits of detection and quantification, accuracy, recovery of spike samples, and robustness. After careful consideration, we unequivocally conclude that 1.6 M nitric acid stands out as the optimal choice for dissolving NdFeB magnet samples, with the pretreatment of the samples being the critical aspect of this report.
Asunto(s)
Metales de Tierras Raras , Neodimio , Neodimio/química , Imanes , Espectrofotometría AtómicaRESUMEN
The increasing use of Rare Earth Elements (REE) in emerging technologies, medicine and agriculture has led to chronic aquatic compartment contamination. In this context, this aimed to evaluate the acute toxic effects of lanthanum (La), neodymium (Nd) and samarium (Sm), as both single and binary and ternary mixtures on the survival of the microcrustacean Daphnia similis. A metal solution medium with (MS) and without EDTA and cyanocobalamin (MSq) as chelators was employed as the assay dilution water to assess REE bioavailability effects. In the single exposure experiments, toxicity in the MS medium decreased following the order La > Sm > Nd, while the opposite was noted for the MSq medium, which was also more toxic than the MS medium. The highest MS toxicity was observed for the binary Nd + La (1:1) mixture (EC50 48 h of 11.57 ± 1.22 mg.L-1) and the lowest, in the ternary Sm + La + Nd (2:2:1) mixture (EC50 48 h 41.48 ± 1.40 mg.L-1). The highest toxicity in the MSq medium was observed in the single assays and in the binary Sm + Nd (1:1) mixture (EC50 48 h 10.60 ± 1.57 mg.L-1), and the lowest, in the ternary Sm + La + Nd (1:2:2) mixture (EC50 48 h 36.76 ± 1.54 mg.L-1). Concerning the MS medium, 75 % of interactions were additive, 19 % antagonistic, and 6 % synergistic. In the MSq medium, 56 % of interactions were synergistic and 44 % additive. The higher toxicity observed in the MSq medium indicates that the absence of chelators can increase the concentrations of more toxic free ions, suggesting that the MS medium should be avoided in REE assays. Additive interactions were observed in greater or equivalent amounts in both media and were independent of elemental mixture ratios. These findings improve the understanding of environmental REE effects, contributing to the establishment of future guidelines and ecological risk calculations.
Asunto(s)
Daphnia , Metales de Tierras Raras , Animales , Metales de Tierras Raras/toxicidad , Samario , Lantano/toxicidad , Neodimio/farmacología , Quelantes/farmacologíaRESUMEN
This work studied the feasibility of using a novel microreactor based on torus geometry to carry out a sample pretreatment before its analysis by graphite furnace atomic absorption. The miniaturized retention of total arsenic was performed on the surface of a magnetic sorbent material consisting of 6 mg of magnetite (Fe3O4) confined in a very small space inside (20.1 µL) a polyacrylate device filling an internal lumen (inside space). Using this geometric design, a simulation theoretical study demonstrated a notable improvement in the analyte adsorption process on the solid extractant surface. Compared to single-layer geometries, the torus microreactor geometry brought on flow turbulence within the liquid along the curvatures inside the device channels, improving the efficiency of analyte-extractant contact and therefore leading to a high preconcentration factor. According to this design, the magnetic solid phase was held internally as a surface bed with the use of an 8 mm-diameter cylindric neodymium magnet, allowing the pass of a fixed volume of an arsenic aqueous standard solution. A preconcentration factor of up to 60 was found to reduce the typical "characteristic mass" (as sensitivity parameter) determined by direct measurement from 53.66 pg to 0.88 pg, showing an essential improvement in the arsenic signal sensitivity by absorption atomic spectrometry. This methodology emulates a miniaturized micro-solid-phase extraction system for flow-through water pretreatment samples in chemical analysis before coupling to techniques that employ reduced sample volumes, such as graphite furnace atomic absorption spectroscopy.
Asunto(s)
Arsénico , Grafito , Microextracción en Fase Líquida , Arsénico/análisis , Óxido Ferrosoférrico , Cromatografía de Gases y Espectrometría de Masas , Grafito/química , Microextracción en Fase Líquida/métodos , Fenómenos Magnéticos , Neodimio , Espectrofotometría Atómica/métodos , Agua/químicaRESUMEN
BACKGROUND: Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars. OBJECTIVES: To assess the effects of laser therapy for treating hypertrophic and keloid scars. SEARCH METHODS: In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting. SELECTION CRITERIA: We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements. MAIN RESULTS: We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare. AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.
Asunto(s)
Cicatriz Hipertrófica , Hipopigmentación , Queloide , Terapia por Láser , Telangiectasia , Corticoesteroides/uso terapéutico , Adulto , Aluminio , Atrofia , Dióxido de Carbono , Niño , Cicatriz Hipertrófica/etiología , Cicatriz Hipertrófica/radioterapia , Dimetilpolisiloxanos , Erbio , Fluorouracilo , Helio , Humanos , Hipertrofia , Hipopigmentación/etiología , Queloide/etiología , Queloide/radioterapia , Terapia por Láser/efectos adversos , Neodimio , Neón , Dolor/etiología , Geles de Silicona , Telangiectasia/etiología , Triamcinolona Acetonida , Verapamilo , Cicatrización de Heridas , ItrioRESUMEN
INTRODUCTION AND AIMS: Endoscopic submucosal dissection (ESD) is a well-established treatment for superficial gastrointestinal tumors and enables en bloc resection. Adequate tissue tension is important for safe and effective dissection. Simplified magnetic anchor-guided ESD (MAG-ESD) with a neodymium magnet has potential benefits, compared with other current traction methods. We evaluated the feasibility of simplified MAG-ESD in an ex vivo porcine model. MATERIALS AND METHODS: An experimental study was conducted, utilizing the standard ESD technique. An external magnet and an internal magnet, both neodymium magnets, were used for the magnetic anchoring. The internal magnet was attached to an arm of a hemoclip with a 2-0 silk suture. After the incision, the clip with the internal magnet was placed at the edge of the lesion. The external magnet was maneuvered around the surface to apply adequate tension. RESULTS: A total of 15 en bloc ESDs (5 with no magnetic anchoring and 10 with magnetic anchoring) were carried out. Traction and dissection were feasible in all cases and the procedures were completed in fewer than 90min. Lesion size ranged from 15 to 50mm (mean 30mm). Two cases in the group with magnetic anchoring presented with punctate perforation (13.3%). CONCLUSIONS: Our study demonstrated the feasibility of simplified MAG-ESD and en bloc resection in an ex vivo porcine model.
Asunto(s)
Resección Endoscópica de la Mucosa , Animales , Disección , Humanos , Fenómenos Magnéticos , Imanes , Neodimio , PorcinosRESUMEN
The impact of cerium (Ce) and neodymium (Nd) rare-earth metal doping of TiO2 prepared by the hydrothermal method was investigated to tailor effective photocatalytic degradation of coloured wastewater under UV or visible illumination. The hydrothermal treatment of TiO2 decreased the pHpzc from 6.3 to 3.1-3.8 favouring the affinity for cationic water contaminants. Doping with Ce and Nd modified the crystallinity and the morphology of the photocatalysts and significantly increased the BET surface area and the adsorption capacity of cationic dyes. The photocatalytic activity under UV light irradiation decreased due to shielding of the catalyst active area by excessive amount of dye adsorbed. Conversely, the photocatalytic activity of the Ce and Nd doped TiO2 increased under visible light irradiation by 1.2 times as a result of the dye photosensitization effect. It was demonstrated that two-steps dark adsorption and photocatalytic reaction or one-step simultaneous adsorption and reaction can produce significantly different results for the photocatalytic degradation of dyes in coloured waters, the rate being controlled by the competitive adsorption of the reacting organics and the H2O/OH- species. The reaction is driven by the radical oxygen species (ROS) formed on the catalyst surface the nature of which, differs under UV or visible light irradiation. The Ce-doped TiO2 and Nd-doped TiO2 photocatalysts with 0.5% rare-earth content were found to be efficient in the degradation of MB in aqueous solution, removing the colour and reducing the toxicity of wastewaters.
Asunto(s)
Cerio , Aguas Residuales , Catálisis , Color , Luz , Neodimio , TitanioRESUMEN
La ingesta accidental de más de un imán puede producir complicaciones graves. Los protocolos actuales recomiendan la extracción endoscópica de ser posible. El objetivo de este trabajo es presentar un caso clínico de una ingesta de dos imanes y la técnica endoscópica de extracción. Niño de 11 años que acudió a Urgencias tras la ingesta de dos imanes, asintomático. En la radiografía de abdomen, se identificaron dos cuerpos extraños radiopacos, aparentemente unidos, en la cámara gástrica. Se realizó una endoscopía bajo anestesia general en quirófano. Para facilitar la extracción, se colocó, encima de la pared abdominal, a nivel gástrico, un imán de neodimio. En la endoscopía, se observaron dos pequeños imanes localizados y fijados en la cara anterior del estómago. Una vez localizados, se retiró el imán externo y se procedió a su extracción con cesta
The ingestion of more than one magnet can cause multiple complications. Current protocols recommend endoscopic extraction if possible. We report a patient who swallowed two magnets and the endoscopic extraction technique. An 11-yearold boy presented at the Emergency Room after ingesting two small magnets, being asymptomatic. In the abdominal x-ray two radiopaque bodies were identified at the gastric chamber, apparently together. A gastroscopy was done in the operating room under general anaesthesia. To enable the extraction, a neodymium magnet was placed externally at the abdominal wall. In the endoscopic image, the two magnets were fixed to the anterior gastric wall. Once located, the neodymium magnet was removed and the two magnets were retrieved with an endoscopic basket.
Asunto(s)
Humanos , Masculino , Adolescente , Imanes , Cuerpos Extraños/diagnóstico por imagen , Endoscopía del Sistema Digestivo , NeodimioRESUMEN
Abstract Purpose: To determine the impact of neodymium:YAG (Nd:YAG) laser posterior capsulotomy on quality of life and visual acuity in adults. Methods: A prospective study that included patients over 65 years old with clinical indications for Nd: YAG laser capsulotomy. On the day of the procedure, corrected distance visual acuity tests, slit-lamp examination and posterior capsule opacification (PCO) photo documentation were performed, followed by application of the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). The PCO rate was evaluated with Evaluation of Posterior Capsule opacification (EPCO 2000) software. Four weeks after the posterior capsulotomy, corrected distance visual acuity was measured, and the NEI-VFQ-25 was applied again. Complications were also reported. Results : Sixty eyes from 45 patients were enrolled in the study. The mean age was 71.51 ± 6.38 years (65 to 93). Comparing the results before and after the Nd:YAG laser capsulotomy, there was a statistically significant improvement in quality of life according to the NEI-VFQ-25 (p<0.001) and in visual acuity (p=0.0). The mean score in NEI-VFQ-25 Questionnaire before capsulotomy was 62.07 ± 20.90 (16.81-95.90) and after was 83.95±19.49 (20.68 - 100.0). The mean CDVA before the procedure was 0.75 ± 0.35 LogMAR (0.1-1.3) and after was 0.21 ± 0.20 LogMAR (0.0-1.3). The mean PCO rate measured by the EPCO software was 0.688 ± 0.449. There was a positive correlation between the EPCO score and the total score of quality of life after Nd: YAG laser capsulotomy (r=0.845, p=0.00). Damage to intraocular lens was the only complication observed in six eyes (10%). Conclusion: Nd: YAG laser capsulotomy, in addition to improving visual acuity, is able to improve quality of life.
Resumo Objetivo: Determinar o impacto da capsulotomia posterior com laser de neodímio: YAG (Nd: YAG) na qualidade de vida e na acuidade visual em adultos. Métodos: Estudo prospectivo que incluiu pacientes acima de 65 anos com indicação clínica para capsulotomia com laser de Nd: YAG. No dia do procedimento, foram realizados testes de acuidade visual corrigida, exame com lâmpada de fenda e fotodocumentação da opacificação da cápsula posterior (OCP), seguido da aplicação do National Eye Institute Visual Function Questionnaire (NEI-VFQ-25). A taxa de OCP foi avaliada utilizando o software de avaliação de opacificação de cápsula posterior (EPCO 2000). Quatro semanas após a capsulotomia posterior, a acuidade visual corrigida foi medida, e o NEI-VFQ-25 foi aplicado novamente. Complicações também foram relatadas. Resultados: Sessenta olhos de 45 pacientes foram incluídos no estudo. A idade média foi de 71,51±6,38 anos (65 to 93). Comparando os resultados antes e após a capsulotomia com laser Nd: YAG, houve melhora estatisticamente significante na qualidade de vida de acordo com o NEI-VFQ-25 (p <0,001) e na acuidade visual (p = 0,0). A média do escore total do questionário NEI-VFQ-25 pré capsulotomia foi de 62.07 ± 20.90 (16.81-95.90) e pós foi de 83.95 ±19.49 (20.68 - 100.0). A AVCC antes do procedimento foi 0.75 ± 0.35 LogMAR (0.1-1.3) e após foi 0.21 ± 0.20 LogMAR (0.0-1.3). A taxa média de OCP medida pelo software EPCO foi de 0,688 ± 0,449. Houve correlação positiva entre o escore EPCO e o escore total de qualidade de vida após a capsulotomia com laser de Nd: YAG (r = 0,845, p = 0,00). O dano à lente intraocular foi a única complicação observada em seis olhos (10%). Conclusão: A capsulotomia com laser Nd: YAG, além de melhorar a acuidade visual, é capaz de melhorar a qualidade de vida.
Asunto(s)
Humanos , Masculino , Femenino , Anciano , Anciano de 80 o más Años , Calidad de Vida , Opacificación Capsular/cirugía , Capsulotomía Posterior/psicología , Extracción de Catarata , Agudeza Visual , Estudios Prospectivos , Encuestas y Cuestionarios , Implantación de Lentes Intraoculares , Terapia por Láser/métodos , Láseres de Estado Sólido , Cápsula Posterior del Cristalino/cirugía , Cápsula Posterior del Cristalino/patología , Capsulotomía Posterior/métodos , Lentes Intraoculares , NeodimioRESUMEN
This in vitro study aimed to analyze the physical and chemical characteristics of the hypersensitive human dentin-like surface after application of a bioactive glass (BG) paste (BG/Ac) irradiated or not with high-power lasers. Dentin specimens were treated with 17% Ethylenediamine tetraacetic acid (EDTA) solution to mimic a hypersensitive dentin and then submitted to neodymium: yttrium-aluminum-garnet (Nd:YAG) laser or CO2 laser irradiation prior and after application of BG/Ac. Characterizations were performed by using X-ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results suggested that application of BG/Ac by itself caused some obstructions of dentinal tubules. Nd:YAG laser irradiation reduced the opening of the dentinal tubules with no changes in the collagen structure. CO2 laser irradiation caused dentin melting and resolidification along with cracks and chemical changes in collagen fibers. However, when BG/Ac paste was irradiated with lasers, a sequence of surface reactions between glass and dentin interface led to the formation of an amorphous hydroxyapatite layer, similar to that of an inorganic component of the normal dentin. Moreover, BG/Ac was able to prevent the formation of cracks and degradation of collagen fibers caused by CO2 irradiation. Overall, this study supports that application of BG/Ac paste irradiated by high-power laser could represent an effective and long-lasting therapeutic approach for dentin hypersensitivity.
Asunto(s)
Sensibilidad de la Dentina/terapia , Dentina/química , Vidrio , Rayos Láser , Aluminio , Dióxido de Carbono , Colágeno/química , Ácido Edético/química , Humanos , Técnicas In Vitro , Microscopía Electrónica de Rastreo , Diente Molar , Neodimio/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , ItrioRESUMEN
Human provenance studies employing isotopic analysis have become an essential tool in forensic and archaeological sciences, with multi-isotope approaches providing more specific location estimates compared to single isotope studies. This study reports on the human provenancing capability of neodymium isotopes (143Nd/144Nd), a relatively conservative tracer in the environment. Neodymium isotope ratios have only recently been determined on human remains due to low concentrations in human dental enamel (ppb range), requiring thermal ionisation mass spectrometry (TIMS) using 1013â¯Ω resistors. Dental elements (third molars) from 20 individuals born and raised in the Netherlands were analysed for Nd concentration (nâ¯=â¯12) and Nd isotope ratios (nâ¯=â¯15). The geological control on Nd isotope composition was examined using coupled Nd-Sr isotope analysis of the same third molar. Teeth from different geological environments were also analysed (Caribbean, Columbian, and Icelandic, nâ¯=â¯5). Neodymium elemental concentrations in dental elements ranged between 0.1 and 7.9â¯ppb (median 0.5â¯ppb). The Dutch 143Nd/144Nd ratios of the provinces of Limburg and Friesland were between 0.5118 and 0.5121, with Dutch 87Sr/86Sr ratios in agreement with the previously established local range (0.708-0.710). The current findings were compared to previously published results on Nd concentration and composition from Dutch individuals. The concentration of Nd and 143Nd/144Nd ratios were weakly correlated (R2â¯=â¯0.47, nâ¯=â¯17) in Dutch human dental enamel. The majority (nâ¯=â¯25, 83.3%) of individuals had Nd and Sr isotope values isotopically indistinguishable from the geological environment in which their third molars formed and mineralised. However, the Nd isotope ratios of the Icelandic individual and several Dutch individuals (nâ¯=â¯4) suggested that Nd in enamel is not solely influenced by geological environment. In order for neodymium isotopes to be quantitatively applied in forensic and archaeological settings further analyses of individuals from various geographical regions with well-defined dietary Nd isotope data are required.
Asunto(s)
Esmalte Dental/química , Isótopos/análisis , Espectrometría de Masas , Tercer Molar/química , Neodimio/análisis , Radioisótopos/análisis , Adolescente , Región del Caribe , Niño , Colombia , Dieta , Impedancia Eléctrica , Odontología Forense/métodos , Humanos , Islandia , Países Bajos , Dinámica Poblacional , Isótopos de Estroncio/análisisRESUMEN
The design of organometallic complexes used as selective intercalators to bind and react at DNA mismatch sites has concentrated efforts in the last few years. In this context, lanthanides have received attention to be employed as active optical centers due to their spectroscopic properties. Despite the fact that there are several experimental data about synthesis and DNA binding of these compounds, theoretical analyses describing their interaction with DNA are scarce. To understand the binding to regular and mismatched DNA sequences as well as to determine the effect of the intercalation on the spectroscopic properties of the complexes, a complete theoretical study going from classical to relativistic quantum mechanics calculations has been performed on some lanthanide complexes with phenanthroline derivatives synthesized and characterized herein, viz. [Nd(NO3)3(H2O)(dppz-R)] with R = H, NO2-, CN- and their [Nd(NO3)3(H2O)(dpq)] analogue, which was computationally modeled. The results were in correct agreement with the available experimental data showing that dppz complexes have higher binding affinities to DNA than dpq one and supporting the idea that these complexes are not selective to mismatch sites in the sampled time scale. Finally, the spectroscopic analysis evidence an intercalative binding mode and made possible the elucidation of the emission mechanism of these systems. This approach is proposed as a benchmark study to extend this methodology on similar systems and constitutes the first theoretical insight in the interaction between DNA and lanthanide complexes.
Asunto(s)
ADN/química , ADN/genética , Teoría Funcional de la Densidad , Neodimio/química , Secuencia de Bases , Modelos Moleculares , Conformación de Ácido NucleicoRESUMEN
We studied the time course of changes of cytochrome oxidase (CytOx) blob spatial density and blob cross-sectional area of deprived (D) and nondeprived (ND) portions of V1 in four capuchin monkeys after massive and restricted retinal laser lesions. Laser shots at the border of the optic disc produced massive retinal lesions, while low power laser shots in the retina produced restricted retinal lesions. These massive and restricted retinal lesions were intended to simulate glaucoma and diabetic retinopathy, respectively. We used a Neodymium-YAG dual frequency laser to make the lesions. We measured Layer III blobs in CytOx-reacted tangential sections of flat-mounted preparations of V1. The plasticity of the blob system and that of the ocular dominance columns (ODC) varied with the degree of retinal lesions. We found that changes in the blob system were different from that of the ODC. Blob sizes changed drastically in the region corresponding to the retinal lesion. Blobs were larger and subjectively darker above and below the non deprived ODC than in the deprived columns. With restricted lesions, blobs corresponding to the ND columns had sizes similar to those from non-lesioned areas. In contrast, blobs corresponding to the deprived columns were smaller than those from nonlesioned areas. With massive lesions, ND blobs were larger than the deprived blobs. Plastic changes in blobs described here occur much earlier than previously described.
Asunto(s)
Complejo IV de Transporte de Electrones/análisis , Terapia por Láser/efectos adversos , Plasticidad Neuronal/fisiología , Retina/fisiología , Corteza Visual/fisiología , Animales , Haplorrinos , Terapia por Láser/métodos , Neodimio/toxicidad , Retina/química , Retina/lesiones , Sapajus apella , Corteza Visual/química , Corteza Visual/citologíaRESUMEN
La enfermedad de Dowling-Degos (DDD), conocida también como 'anomalía reticulada y pigmentada de las flexuras' es una rara genodermatosis autosómica dominante. Se caracteriza por la aparición de máculas hiperpigmentadas de configuración reticulada; afectando principalmente los grandes pliegues como las axilas e ingles. Pudiendo, además, comprometer otros pliegues como cervicales, antecubitales, submamarios e interglúteos. Otras características asociadas son las lesiones tipo comedones y los pits palmo-plantares. Presentamos el caso de una familia con enfermedad de Dowling-Degos sin respuesta al tratamiento con laser Nd:YAG y CO2. Se realiza una revisión de la literatura de los tratamientos disponibles.
Dowling-Degos disease (DDD), also known as "reticulate pigmented anomaly of the flexures", is a rare autosomal dominant genodermatosis. DDD is characterized by an acquired reticular skin hyperpigmentation which begins in the axillae and groin. It later involves other body folds, including neck, inner aspects of the arms and thighs, inframammary, and intergluteal folds. Associated features include comedolike lesions on the neck or back, pitted facial or perioral scars, and epidermoid cysts. Herein we present a family (proband, mother, grandmother) with DDD that were treated with Q-switched Nd:YAG laser and CO2 laser without response. Treatment options are discussed and the available literature is reviewed.
Asunto(s)
Humanos , Femenino , Adulto , Enfermedades Cutáneas Genéticas/terapia , Enfermedades Cutáneas Papuloescamosas/terapia , Hiperpigmentación/terapia , Láseres de Estado Sólido/uso terapéutico , Enfermedades Cutáneas Genéticas/patología , Dióxido de Carbono , Enfermedades Cutáneas Papuloescamosas/patología , Hiperpigmentación/patología , NeodimioRESUMEN
The recent development of core/shell engineering of rare earth doped luminescent nanoparticles has ushered a new era in fluorescence thermal biosensing, allowing for the performance of minimally invasive experiments, not only in living cells but also in more challenging small animal models. Here, the potential use of active-core/active-shell Nd(3+)- and Yb(3+)-doped nanoparticles as subcutaneous thermal probes has been evaluated. These temperature nanoprobes operate in the infrared transparency window of biological tissues, enabling deep temperature sensing into animal bodies thanks to the temperature dependence of their emission spectra that leads to a ratiometric temperature readout. The ability of active-core/active-shell Nd(3+)- and Yb(3+)-doped nanoparticles for unveiling fundamental tissue properties in in vivo conditions was demonstrated by subcutaneous thermal relaxation monitoring through the injected core/shell nanoparticles. The reported results evidence the potential of infrared luminescence nanothermometry as a diagnosis tool at the small animal level.
Asunto(s)
Mediciones Luminiscentes/instrumentación , Nanopartículas/química , Neodimio/química , Termómetros , Iterbio/química , Administración Cutánea , Animales , Temperatura Corporal , Rayos Infrarrojos , Luminiscencia , Ratones , Nanopartículas/administración & dosificación , Neodimio/administración & dosificación , Fenómenos Fisiológicos de la Piel , Iterbio/administración & dosificaciónRESUMEN
The continuous development of nanotechnology has resulted in the actual possibility of the design and synthesis of nanostructured materials with pre-tailored functionabilities. Nanostructures capable of simultaneous heating and local thermal sensing are in strong demand as they would constitute a revolutionary solution to several challenging problems in bio-medicine, including the achievement of real time control during photothermal therapies. Several approaches have been demonstrated to achieve simultaneous heating and thermal sensing at the nanoscale. Some of them lack of sufficient thermal sensitivity and others require complicated synthesis procedures for heterostructure fabrication. In this study, we demonstrate how single core/shell dielectric nanoparticles with a highly Nd(3+) ion doped shell and an Yb(3+),Er(3+) codoped core are capable of simultaneous thermal sensing and heating under an 808 nm single beam excitation. The spatial separation between the heating shell and sensing core provides remarkable values of the heating efficiency and thermal sensitivity, enabling their application in single beam-controlled heating experiments in both aqueous and tissue environments.
Asunto(s)
Europio/química , Neodimio/química , Iterbio/química , Espectroscopía de Resonancia por Spin del Electrón , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Transmisión , Nanopartículas/química , Espectrometría por Rayos X , TemperaturaRESUMEN
One possible undesirable consequence of orthodontic therapy is the development of incipient caries lesions of enamel around brackets. The aim of this study was to compare the effects of CO2 (λ = 10.6 µm) and Nd:YAG (λ = 1,064 nm) lasers associated or not with topical fluoride application on the prevention of caries lesions around brackets. Brackets were bonded to the enamel of 65 premolars. The experimental groups (n = 13) were: G1--application of 1.23% acidulated fluoride phosphate gel (AFP, control); G2--Nd:YAG laser irradiation (0.6 W, 84.9 J/cm(2), 10 Hz, 110 µs, contact mode); G3--Nd:YAG laser irradiation associated with AFP; G4--CO2 laser irradiation (0.5 W, 28.6 J/cm(2), 50 Hz, 5 µs, and 10 mm focal distance); and G5--CO2 laser irradiation associated with AFP. Quantitative light-induced fluorescence was used to assess enamel demineralization. The data were statistically compared (α = 5%). The highest demineralization occurred in the Nd:YAG laser group (G2, 26.15% ± 1.94). The demineralization of all other groups was similar to that of the control group. In conclusion, CO2 laser alone was able to control enamel demineralization around brackets at the same level as that obtained with topical fluoride application.