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1.
J Fish Biol ; 92(2): 537-542, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29431221

RESUMEN

Occurrence of multiple whitetip reef sharks Triaenodon obesus in the Atlantic Ocean is reported for the first time from near a sunken ferry off the Paraná coast in south-eastern Brazil. This occurrence is hypothesized to have been caused by either a human introduction or a remarkably long oceanic displacement.


Asunto(s)
Distribución Animal , Tiburones , Animales , Océano Atlántico , Brasil , Humanos , Masculino
2.
J Fish Biol ; 89(3): 1873-9, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27397557

RESUMEN

Based on material deposited in collections, photographic records and other reports from fishermen and divers, the occurrence of the hogfish Lachnolaimus maximus (Labridae) is confirmed in the south-western Atlantic Ocean, near the Brazilian coast as far south as southern Brazil. The recognized range of this species should therefore be extended c. 3000 km further south.


Asunto(s)
Perciformes , Animales , Océano Atlántico , Brasil , Fotograbar
3.
Eur J Neurol ; 22(2): 305-12, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25220687

RESUMEN

BACKGROUND AND PURPOSE: Handicap has not been explored as a patient-centred outcome measure in Parkinson's disease (PD). The clinical features and medication use in late stages of PD (LS-PD) were reported previously. METHODS: Handicap, medical conditions, use of healthcare resources and the impact of LS-PD upon caregivers were characterized in a cross-sectional study of LS-PD stages 4 or 5 of Hoehn and Yahr (H&Y). Handicap was measured using the London Handicap Scale (LHS: 0, maximal handicap; 1, no handicap). RESULTS: The mean LHS score in 50 patients was 0.33 (SD ±0.15). The presence of dementia, the Unified Parkinson's Disease Rating Scale part I score and the H&Y stage in 'off' independently predicted the LHS score (adjusted R(2) = 0.62; P = 0.000). Comorbidities and past medical conditions were frequent. Thirty-five patients lived at their house. Forty-five received unpaid care. Mean visits to the family doctor in the preceding 6 months were 2.2 (SD ±3.0) and to a neurologist 1.7 (SD ±1.0). Use of other health resources was low. Unpaid caregivers spent much time with patients and reported a high burden. CONCLUSION: Handicap could be measured in LS-PD and the LHS was easily completed by patients and caregivers. The high handicap in our cohort was mostly driven by the presence of dementia, behavioural complaints and the severity of non-dopaminergic motor features. Patients visited doctors infrequently and made low use of health resources, whilst unpaid caregivers reported a high burden.


Asunto(s)
Demencia/fisiopatología , Personas con Discapacidad , Enfermedad de Parkinson/fisiopatología , Anciano , Anciano de 80 o más Años , Cuidadores , Costo de Enfermedad , Estudios Transversales , Demencia/etiología , Evaluación de la Discapacidad , Progresión de la Enfermedad , Femenino , Humanos , Masculino , Enfermedad de Parkinson/complicaciones , Portugal , Índice de Severidad de la Enfermedad , España
4.
Asian-Australas J Anim Sci ; 27(11): 1584-92, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25358318

RESUMEN

The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p<0.05), whereas the time spent on activities like rumination, idleness, trough and total chewing time were quadratically affected (p<0.05). Bite rate and number of bites/day were quadratically influenced (p<0.05). The number of bites/swallowed cud and the number of bites/minute, however, increased linearly (p<0.05). Although the time spent on each cud and number of chews per cud were not affected (p>0.05). The number of rumination periods reduced linearly (p<0.05), whereas the number of grazing, idle and trough periods, and the times per grazing, idle, rumination and trough periods were quadratically affected (p<0.05). The feed and rumination efficiencies of the dry matter, non-fibrous carbohydrates, pasture dry matter and concentrate were quadratically affected (p>0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies.

5.
J Hazard Mater ; 465: 133041, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38043423

RESUMEN

The solubility and transport of Cr(VI) is primarily controlled by adsorption-desorption reactions at the surfaces of soil minerals such as iron oxides. Environmental properties such as pH, ionic strength, and ion competition are expected to affect the mobility and fate of Cr(VI). Sea level rise (SLR), and consequent seawater intrusion, is creating a new biogeochemical soil environment at coastal margins, potentially impacting Cr(VI) retention at contaminated sites. We employed in-situ ATR-FTIR spectroscopy and DFT calculations to investigate at the molecular level the adsorption of Cr(VI) on the hematite surface and its desorption by sulfate, as a function of pH and ionic strength. We further used a batch experiment to assess Cr(VI) desorption at varying artificial seawater (ASW) concentrations. IR results demonstrate the complexity of Cr(VI) adsorption, showing a combination of monodentate inner-sphere complexation at high pH and dichromate outer-sphere (∼75%) at low pH. The Cr(VI)-complexes exhibited desorption induced by increasing pH values (58% of desorption) and sulfate competition (∼40% desorption). ASW desorbed ∼20% more Cr(VI), even at just 1% concentration. Our findings provide insight into Cr(VI)-adsorption complexation that controls the retention and remobilization of Cr(VI) on Fe-oxide minerals. The results point to an elevated risk of Cr(VI) mobilization in contaminated soils affected by SLR.

6.
Sci Total Environ ; 916: 170223, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38266730

RESUMEN

Agriculture in highly weathered tropical soils often requires considerable application of lime and fertilizers to ensure satisfactory plant nutrient levels. The consequences of these continue long-term applications is not well understood may induce changes in soil chemical properties, the abundance, and speciation of potentially toxic trace element and as well as of micronutrients in agriculture soils. In this study, we evaluated the adsorption (at pH 5) and speciation of Zn in tropical soils (both agricultural and native vegetation) as a function of fertilization and contact time using chemical fractionation analyses and X-ray absorption spectroscopy. The soils overall had high Zn adsorption capacities (∼ 700 mg kg-1), but the agricultural soil was approximately 30 % higher than of the soil under native vegetation, and the proportion of Zn in the mobile fraction was 35 % in native vegetation and 21 % in agricultural soils. Zn speciation via linear combination analysis showed a strong relationship with soil mineralogical composition and reveled that Zn associated with organic matter decreased while Zn associated with P increased after the conversion of soils from native vegetation to highly fertilized soil. Aluminosilicate soil minerals were identified as major sinks of soil Zn, accounting for 34 % of total Zn retention regardless of soil origin and land use. Association of Zn with phosphate (i.e., hopeite) was observed in the agricultural soil samples, which might be an unexpected Zn-bearing mineral in highly weathered tropical soils and could have impacts on Zn plant nutrition.


Asunto(s)
Contaminantes del Suelo , Oligoelementos , Suelo/química , Zinc/análisis , Verduras , Agricultura/métodos , Oligoelementos/análisis , Minerales , Contaminantes del Suelo/análisis
7.
Eur J Neurol ; 20(1): 5-15, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23279439

RESUMEN

OBJECTIVE: To summarize the 2010 EFNS/MDS-ES evidence-based treatment recommendations for the management of Parkinson's disease (PD). This summary includes the treatment recommendations for early and late PD. METHODS: For the 2010 publication, a literature search was undertaken for articles published up to September 2009. For this summary, an additional literature search was undertaken up to December 2010. Classification of scientific evidence and the rating of recommendations were made according to the EFNS guidance. In cases where there was insufficient scientific evidence, a consensus statement ('good practice point') is made. RESULTS AND CONCLUSIONS: For each clinical indication, a list of therapeutic interventions is provided, including classification of evidence.


Asunto(s)
Manejo de la Enfermedad , Guías como Asunto , Enfermedad de Parkinson/diagnóstico , Enfermedad de Parkinson/terapia , Bases de Datos Factuales/estadística & datos numéricos , Europa (Continente) , Medicina Basada en la Evidencia , Humanos
8.
Oper Dent ; 48(1): 51-58, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36534034

RESUMEN

PURPOSE: To evaluate the effect of short curing time using a high-radiant emittance light on polymerization shrinkage vectors in different consistency bulk-fill composites (BFRCs) using micro-computed tomography. METHODS AND MATERIALS: Radiopaque zirconia fillers were homogeneously incorporated and functioned as radiopaque tracers into two regular-paste: TBFill (Tetric EvoCeram Bulk Fill) and TPFill (Tetric PowerFill), and two flowable (n=6): TBFlow (Tetric EvoFlow Bulk Fill) and TPFlow (Tetric PowerFlow) resin composites. Class I cavities (4 mm depth × 4 mm length × 4 mm width) were 3D-printed and filled in a single increment: TBFill and TBFlow were light-activated using a Bluephase Style 20i (10 seconds in high-mode); TPFill and TPFlow were light-activated using a Bluephase PowerCure (three seconds). The same adhesive system (Adhese Universal) was used for all groups. Microcomputed tomography scans were obtained before and after light-activation. Filler particle movement was identified by polymerization shrinkage vectors at five depths (from 0-4 mm): top, top-middle, middle, middle-bottom and bottom. RESULTS: TPFlow showed the lowest total vector displacement, followed by TBFlow, TBFill and TPFill, significantly different among each other (p<0.05). Generally, BFRCs showed decreased vector displacement with increased depth, and higher displacement at the top-surface (p<0.05). Qualitative analysis showed a similar pattern of vector magnitude and displacement for groups TBFill and TPFill, with displacement vectors on occlusal (top) surfaces toward the center of the restoration from the top to middle areas, and relatively limited displacement at the bottom. TBFlow and TPFlow showed more displacement on the occlusal (top). CONCLUSIONS: Short curing time with high-radiant emittance on fast-curing BFRCs was shown to be a feasible option in terms of vector displacement. Flowable BFRCs presented lower vector displacement than their regular-viscosity versions.


Asunto(s)
Resinas Compuestas , Caries Dental , Humanos , Microtomografía por Rayos X , Polimerizacion , Ensayo de Materiales , Curación por Luz de Adhesivos Dentales
9.
Environ Pollut ; 323: 121302, 2023 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-36804144

RESUMEN

Sea level rise (SLR) is estimated to impact 25% of the world's population along coastal areas leading to an increase in saltwater intrusion. Consequently, changes in the soil biogeochemistry of currently non-saline and/or well-drained soils due to saltwater intrusion are of major concern. Saltwater intrusion is expected to affect farmland across large broiler producer regions, where large amounts of manure containing organic arsenicals were applied over the past decades. To determine how SLR may impact the speciation and mobility of adsorbed inorganic and organic As, we used in situ real-time attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) to determine the adsorption and desorption mechanisms of As(V) and 4-aminophenylarsonic (p-ASA, a poultry feed additive) on ferrihydrite (Fh) in the presence of sulfate at varying pH. The adsorption of As(V) and p-ASA increased at lower pH, with As(V) showing IR features consistent with the formation of inner-sphere of As-Fh surface complexes, while p-ASA also formed others structures as H-bonded As-surface complexes, likely mediated by outer-sphere complexes, based on our FTIR and batch experiments data. No observable As(V) or p-ASA desorption from the Fh surface was promoted by sulfate, however sulfate adsorption on the Fh surface was remarkably larger for p-ASA than for As(V). Complimentary, we carried out batch studies of As(V) and p-ASA desorption by Fh, using artificial seawater (ASW) at varying concentrations. The 1% ASW desorbed ∼10% of initially sorbed p-ASA, while at 100% ASW desorbed ∼40%. However, <1% of As(V) was desorbed by 1% ASW solution and only ∼7.9% were desorbed at 100% ASW. The spectroscopic data support the more extensive desorption of p-ASA compared to As(V) observed in batch experiments, suggesting that organoarsenicals may be easily desorbed and, after conversion to inorganic forms, pose a risk to water supplies.


Asunto(s)
Ácido Arsanílico , Arseniatos , Animales , Ácido Arsanílico/química , Adsorción , Sulfatos , Elevación del Nivel del Mar , Pollos , Compuestos Férricos/química , Suelo/química , Espectroscopía Infrarroja por Transformada de Fourier , Óxidos de Azufre , Concentración de Iones de Hidrógeno
10.
Meat Sci ; 204: 109286, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37494740

RESUMEN

We aimed to evaluate the impact of nutrient supplementation of beef female calves at pre-weaning on adipogenic determination. Thirty-four female calves were assigned to two experimental treatments: Control (CON, n = 17), where animals were supplemented only with mineral mixture; Supplemented (SUP, n = 17), where animals received energy-protein supplement containing minerals (5 g/kg of BW per day) of their body weight. Animals were supplemented from 100 to 250 days of age, and muscle samples were biopsied at the end of the supplementation period. Regarding the performance variables, there were no differences between treatments for initial body weight (P = 0.75). The final body weight (P = 0.07), average daily gain (P = 0.07), rib eye area (P = 0.03), and rib fat thickness (P = 0.08) were greater in SUP female calves compared with CON treatment. The number of fibro-adipogenic progenitor cells (P = 0.69) did not differ between treatments, while a greater number of intramuscular pre-adipocytes were observed in SUP than CON female calves (P = 0.01). The expression of miRNA-4429 (P = 0.20) did not differ between treatments, while the expression of miRNA-129-5p (P = 0.09) and miRNA-129-2-3p (P = 0.05) was greater in CON than SUP female calves. Our results suggest that nutrient supplementation at early postnatal stages of development enhances the commitment of fibro-adipogenic progenitor cells into the adipogenic lineages allowing to an increase in intramuscular fat deposition potential of the animals later in life.


Asunto(s)
Dieta , MicroARNs , Bovinos , Animales , Femenino , Dieta/veterinaria , Destete , Alimentación Animal/análisis , Suplementos Dietéticos , Peso Corporal , Nutrientes
11.
Sci Total Environ ; 807(Pt 1): 150711, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-34626622

RESUMEN

Chemical stabilization is an in-situ remediation that uses amendments to reduce contaminant availability in polluted soils. Rates of phosphate, lime, biochar, and biosolids were evaluated as affecting Pb speciation and mobility in soil samples of a mining area located in Vazante, state of Minas Gerais, Brazil. Chemical and mineralogical characterization, desorption kinetics, sequential extraction, leaching evaluation in columns and speciation using X-ray absorption near edge structure were performed. Pb adsorbed on bentonite and on anglesite were the predominant species in the unamended soil. The treatments with phosphate and lime transformed part of the Pb species to pyromorphite. Conversely, part of Pb species was transformed to Pb adsorbed on citrate in the soil amended with biochar, while PbCl2 was formed in soil samples amended with biosolids. Phosphate and lime increased the Pb extracted in the residual fraction, thus showing that more recalcitrant species, such as pyromorphite, were formed. Biosolids and biochar treatments decreased the Pb in the residual fraction, and the fraction associated to organic matter increased after the addition of biosolids. Phosphate and lime were effective to immobilize Pb and to decrease Pb desorption kinetics, but the organic amendments increased the desorption kinetics of Pb in all rates applied. The soil amended with phosphate decreased the Pb leached in the experiment with leaching columns.


Asunto(s)
Contaminantes del Suelo , Suelo , Cinética , Plomo , Contaminantes del Suelo/análisis , Espectroscopía de Absorción de Rayos X
12.
Med Phys ; 38(7): 4147-53, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21859016

RESUMEN

PURPOSE: The invariance of the total direct strand break yield when DNA is irradiated by different types of particles and energies has been reported by previous works. This study is intended to explain the physical causes of this behavior. METHODS: The GEANT4-DNA extension of the GEANT4 general purpose Monte Carlo simulation toolkit has been used to determine direct strand break yields induced by protons and alpha particles impacting on a B-DNA geometrical model, including five organization levels of the human genetic material. The linear energy transfer (LET) of such particles ranges from 4.8 keV/microm (10 MeV protons) to about 235 keV/microm (2 MeV alpha particles), at 5.225 pm depth (near the center of the region of interest). Direct total, single and double strand break probabilities have been determined in a liquid water homogeneous medium with a 1.06 g/cm3 density. The energetic spectra of single strand breaks (SSB), the number of energy deposition events, and the SSB/event ratio were determined. RESULTS: The target-hit probability was found to be independent of both the type and the energy of the incident particle, even if this latter is a secondary electron. This probability is determined by the geometrical properties of the system. The total strand break yield and the number of energy deposition events required to reach a certain absorbed dose were found nearly independent of the type and energy of the incident ion (proton or alpha). In contrast, the double strand break (DSB) yield was found strongly dependent on the LET of the incident radiation. CONCLUSIONS: The SSB generation process is homogeneous and independent of the LET of the particles involved, at least within the proton and alpha particle energy range here studied. The target-hit probability is only determined by the ratio between the total volume occupied by targets and that of the ROI where the radiation deposits its energy. The maximum separation distance between two adjacent SSBs to produce a DSB is the parameter that breaks the homogeneity of the target-hit process, making the DSB production process strongly heterogeneous.


Asunto(s)
Daño del ADN , ADN/genética , ADN/efectos de la radiación , Modelos Químicos , Simulación por Computador , ADN/química , Relación Dosis-Respuesta en la Radiación , Humanos , Dosis de Radiación
13.
Adv Tech Stand Neurosurg ; 36: 139-85, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21197610

RESUMEN

The prophylactic administration of antibiotics to prevent infection and the prophylactic administration of anticonvulsants to prevent first seizure episodes are common practice in neurosurgery. If prophylactic medication therapy is not indicated, the patient not only incurs the discomfort and the inconvenience resulting from drug treatment but is also unnecessarily exposed to adverse drug reactions, and incurs extra costs. The main situations in which prophylactic anticonvulsants and antibiotics are used are described and those situations we found controversial in the literature and lack further investigation are identified: anticonvulsants for preventing seizures in patients with chronic subdural hematomas, antiepileptic drugs for preventing seizures in those suffering from brain tumors, antibiotic prophylaxis for preventing meningitis in patients with basilar skull fractures, and antibiotic prophylaxis for the surgical introduction of intracranial ventricular shunts.In the following we present systematic reviews of the literature in accordance with the standard protocol of The Cochrane Collaboration to evaluate the effectiveness of the use of these prophylactic medications in the situations mentioned. Our goal was to efficiently integrate valid information and provide a basis for rational decision-making.


Asunto(s)
Profilaxis Antibiótica/métodos , Anticonvulsivantes/uso terapéutico , Epilepsia/prevención & control , Complicaciones Posoperatorias/prevención & control , Infección de la Herida Quirúrgica/prevención & control , Neoplasias Encefálicas/cirugía , Hematoma Subdural Crónico/cirugía , Humanos , Neurocirugia , Fractura Craneal Basilar/cirugía
14.
Eur Arch Paediatr Dent ; 22(5): 979-984, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34536205

RESUMEN

PURPOSE: To evaluate the type and the amount of fluoridated dentifrice applied on children's toothbrushes by parents/guardians according to descriptions typically recommended by scientific societies, as well as to assess the influence of demographic and socioeconomic variables on dentifrice use. METHODS: Parents/guardians of children (0-7 years old; n = 306; convenience sample) attending vaccination centres from Araçatuba (Brazil), answered to a structured questionnaire comprising items related to interviewees' education, child's age, gender, brushing habits and use of fluoridated dentifrice. The amount of toothpaste used by children during toothbrushing was estimated using a portable scale. Similarly, the interviewees were requested to apply dentifrices on toothbrushes according to eight descriptions, ranging from "smear" to "all bristles", following a random sequence. Data were submitted to Mann-Whitney's, Kruskal-Wallis' and Friedman's tests, and Spearman's correlation coefficient (p < 0.05). RESULTS: The type of toothpaste and the amount of product used at home were not affected by the respondents' educational level or family income. However, child's age was significantly correlated with the amount of toothpaste placed on the toothbrush (r = 0.324, p < 0.001). Also, the amount of toothpaste placed on the toothbrush increased according to what would be expected from the descriptions, although wide variations were observed within each description, with large interquartile and overall ranges. CONCLUSION: The amount and the type of dentifrice used by children were influenced by their age, while parents/caregivers' interpretation on verbal instructions regarding appropriate dentifrice quantities varied widely. This reinforces the need for educative measures on the appropriate use by dentifrices by children.


Asunto(s)
Dentífricos , Brasil , Cariostáticos , Niño , Preescolar , Fluoruros/análisis , Hábitos , Humanos , Lactante , Recién Nacido , Cepillado Dental
15.
Eur J Dent ; 15(3): 433-439, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34041726

RESUMEN

OBJECTIVES: This in vitro study aimed to characterize the superficial and subsurface morphology of dental enamel treated with fluoridated gels containing different biomimetic compounds after erosive challenge. MATERIALS AND METHODS: Bovine incisor teeth were sectioned to obtain enamel blocks (4 mm × 4 mm × 6 mm; n = 5) that were demineralized to create an artificial caries lesion and treated by pH cycling interspersed with exposure to fluoridated toothpaste slurries under agitation. During pH cycling (demineralization and remineralization for 2 and 22 hours, respectively) for 6 days, the enamel blocks were exposed to toothpaste slurries under agitation with one of the dental gels: Regenerate Enamel Science (NR-5 technology), Daily Regenerator Dental Clean (REFIX technology), and Sensodyne Repair & Protect (Novamin technology). The enamel blocks were subjected to an erosive challenge, immersed in 50% citric acid for 2 minutes, and then washed with plenty of distilled water. The surface and cross-sectional micromorphology were assessed using scanning electron microscope (SEM). The elemental analyses (weight percentage) were determined with an energy-dispersive X-ray spectroscopy (EDS). RESULTS: Enamel treated with the product containing REFIX technology presented a smoother surface morphology compared to the other treatments. The higher resistance to the erosive challenge can be attributed to a silicon-enriched mineral layer formed on the enamel induced by the REFIX-based toothpaste. This was not observed in the specimens treated with the other technology-containing toothpastes. CONCLUSION: The REFIX technology seemed to be the most promising compared to the Novamin and NR-5 technologies. In addition to forming a surface mineralized layer, the enamel treated with REFIX technology associated with the pH cycling resisted a subsequent erosive challenge.

16.
Oper Dent ; 45(4): E167-E175, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-32216725

RESUMEN

CLINICAL RELEVANCE: Secondary caries are the main reason for the failure of restorations, class II being the most affected. Techniques that promote less gap percentage are important. Flowable bulk fill composites used at such locations have been shown to decrease gap formation while being a faster procedure than an incremental technique.


Asunto(s)
Caries Dental , Restauración Dental Permanente , Resinas Compuestas , Adaptación Marginal Dental , Humanos , Microtomografía por Rayos X
17.
Oper Dent ; 45(1): 71-79, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31226004

RESUMEN

PURPOSE: This study aimed to characterize and analyze the number of voids and the percentage of void volume within and between the layers of class II composite restorations made using the bulk fill technique or the incremental technique by optical coherence tomography (OCT). METHODS AND MATERIALS: Class II cavities (4×4×2 mm) were prepared in 48 human third molars (n=24 restorations per group, two class II cavities per tooth). Teeth were divided into four groups and restored as follows: group 1 (FOB), bulk filled in a single increment using Filtek One Bulk Fill (3M Oral Care); group 2 (FXT), incrementally filled using four oblique layers of Filtek Z350 XT (3M Oral Care); group 3 (FBF+FXT), bulk filled in a single increment using Filtek Bulk Fill Flowable Restorative (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care), and group 4 (FF+FXT), incrementally filled using Filtek Z350 XT Flow (3M Oral Care) covered with two oblique layers of Filtek Z350 XT (3M Oral Care). After the restorative procedure, specimens were immersed into distilled water and stored in a hot-air oven at 37°C. Forty-eight hours later, thermal cycling was conducted (5000 cycles, 5°C to 55°C). Afterward, OCT was used to detect the existence of voids and to calculate the number of voids and percentage of voids volume within each restoration. Data were submitted to chi-square and Kruskal-Wallis tests (α=0.05). Comparisons were made using the Dunn method. RESULTS: Voids were detected in all groups, ranging from 0.000002 (FBF+FXT and FF+FXT) to 0.32 mm3 (FBF+FXT). FF + FXT presented voids in all of the restorations and had a significantly higher number of voids per restoration when compared to the other groups (p<0.05), but restorations with the presence of voids were significantly higher only when compared to FXT (p<0.05). FBF + FXT presented a significantly higher percentage of voids volume than that of FXT (p<0.05). When comparing restorations made using high-viscosity resin-based composites (FOB and FXT), no significant differences regarding number of voids or percentage of voids volume were detected (p≥0.05). CONCLUSIONS: The use of flowable resin-based composites can result in an increased number of voids and percentage of voids volume in restorations, and this appears to be more related to voids present inside the syringe of the material than to the use of incremental or bulk fill restorative techniques.


Asunto(s)
Caries Dental , Tomografía de Coherencia Óptica , Resinas Compuestas , Materiales Dentales , Restauración Dental Permanente , Humanos , Ensayo de Materiales
18.
Appl Radiat Isot ; 156: 108972, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31732425

RESUMEN

A new approach to the calibration procedure is presented, as there is no need to discount bismuth from lead spectrum when constructing the efficiency curve. This work presents two calibration methods: one considering mostly lead spectrum contributions and other that considers both lead and bismuth contributions. Both methodologies provide consistent results when evaluated in an intercomparison program. Furthermore, this methodology allows simultaneous analysis of several samples and is suitable for any type of sample after proper digestion in liquid form.

19.
Oper Dent ; 45(5): 496-505, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-32101499

RESUMEN

CLINICAL RELEVANCE: Shortened light curing does not affect volumetric polymerization shrinkage or cohesive tensile strength but negatively affects the shear bond strength of some bulk-fill resin composites. When performing shortened light curing, clinicians should be aware of the light output of their light-curing units. SUMMARY: Purpose: To evaluate volumetric polymerization shrinkage (VPS), shear bond strength (SBS) to dentin, and cohesive tensile strength (CTS) of bulk-fill resin composites (BFRCs) light activated by different modes.Methods and Materials: Six groups were evaluated: Tetric EvoCeram bulk fill + high mode (10 seconds; TEC H10), Tetric EvoFlow bulk fill + high mode (TEF H10), experimental bulk fill + high mode (TEE H10), Tetric EvoCeram bulk fill + turbo mode (five seconds; TEC T5), Tetric EvoFlow bulk fill + turbo mode (TEF T5), and experimental bulk fill + turbo mode (TEE T5). Bluephase Style 20i and Adhese Universal Vivapen were used for all groups. All BFRC samples were built up on human molar bur-prepared occlusal cavities. VPS% and location were evaluated through micro-computed tomography. SBS and CTS tests were performed 24 hours after storage or after 5000 thermal cycles; fracture mode was analyzed for SBS.Results: Both TEC H10 and TEE H10 presented lower VPS% than TEF H10. However, no significant differences were observed with the turbo-curing mode. No differences were observed for the same BFRC within curing modes. Occlusal shrinkage was mostly observed. Regarding SBS, thermal cycling (TC) affected all groups. Without TC, all groups showed higher SBS values for high mode than turbo mode, while with TC, only TEC showed decreased SBS from high mode to turbo modes; modes of fracture were predominantly adhesive. For CTS, TC affected all groups except TEE H10. In general, no differences were observed between groups when comparing the curing modes.Conclusions: Increased light output with a shortened curing time did not jeopardize the VPS and SBS properties of the BFRCs, although a decreased SBS was observed in some groups. TEE generally showed similar or improved values for the tested properties in a shortened light-curing time. The VPS was mostly affected by the materials tested, whereas the SBS was affected by the materials, curing modes, and TC. The CTS was not affected by the curing modes.


Asunto(s)
Resinas Compuestas , Luces de Curación Dental , Humanos , Curación por Luz de Adhesivos Dentales , Ensayo de Materiales , Diente Molar , Polimerizacion , Resistencia al Corte , Microtomografía por Rayos X
20.
Sci Rep ; 10(1): 13441, 2020 08 10.
Artículo en Inglés | MEDLINE | ID: mdl-32778712

RESUMEN

Proteins are of ubiquitous interest in the Life Sciences but are of interest in the Geosciences as well because of the significant role these compounds play in the biogeochemical cycling of trace and nutrient elements. Structural changes resulting from the adsorption of proteins onto mineral surfaces may alter protein biological function and other environmental interactions. Iron oxides are major sinks of a range of environmental elements including organic compounds. In this study, the adsorption of the broadly studied model protein BSA onto the hematite mineral surface was characterized as a function of pH, ionic strength, and BSA concentration using in-situ Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. BSA lost the α-helix and gain ß-sheets in the secondary structure during adsorption on hematite. BSA adsorption was maximum at pH 5, a value close to the BSA isoelectric point (~ pH 5), and lower at pH 4 and pH 7. Increasing ionic strength decreased to total BSA adsorption. Two-dimensional correlation spectroscopy analysis of the ATR-FTIR spectra revealed that higher initial BSA concentration and the consequent higher BSA surface loading enhanced BSA adsorption by protein-protein interaction, which less ordered structures changes into more compact forms decrease, hence compacting the structural arrangement and could promoting multilayers/aggregation formation on the mineral surface. The activity of enzymes following adsorption on mineral surfaces requires further study.


Asunto(s)
Adsorción/fisiología , Compuestos Férricos/química , Albúmina Sérica Bovina/química , Análisis de Fourier , Concentración de Iones de Hidrógeno , Punto Isoeléctrico , Conformación Proteica , Estructura Secundaria de Proteína , Proteínas/química , Espectroscopía Infrarroja por Transformada de Fourier , Propiedades de Superficie
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