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1.
J Colloid Interface Sci ; 611: 617-628, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34974225

RESUMO

HYPOTHESIS: Electrostatic extraction of particles from a bed to a pendent droplet to form liquid marbles has previously been investigated with respect to particle conductivity, size and shape, however, interparticle forces have not been specifically interrogated. If cohesion is the dominant force within the particle bed, then particles will be more readily extracted with reduced surface free energy. EXPERIMENTS: Glass particles were surface-modified using various alkyltrichlorosilanes. The surface free energy was measured for each sample using colloid probe atomic force microscopy (AFM) and sessile drop measurements on similarly modified glass slides. The ease of electrostatic particle extraction of each particle sample to a pendent droplet was compared by quantifying the electric field force required for successful extraction as a function of the measured surface free energy. FINDINGS: Surface free energy calculated from sessile droplet measurements and AFM were not in agreement, as work of adhesion of a liquid droplet on a planar substrate is not representative of the contact between particles. Ease of electrostatic extraction of particles was observed to generally decrease as a function of AFM-derived surface free energy, confirming this is a critical factor in electrostatic delivery of particles to a pendent droplet. Roughness was also shown to inhibit particle extraction.


Assuntos
Coloides , Vidro , Microscopia de Força Atômica , Tamanho da Partícula , Eletricidade Estática
2.
Gen Dent ; 70(1): 46-50, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34978990

RESUMO

This study evaluated the influence of different combinations of 3 final endodontic irrigation techniques (positive-pressure irrigation [PPI], passive ultrasonic irrigation [PUI], and continuous ultrasonic irrigation [CUI]) and 2 irrigants (5.25% sodium hypochlorite [NaOCl] and 2% chlorhexidine [CHX]) on the push-out resistance of glass fiber posts. Ninety bovine roots were prepared and divided into 6 groups (n = 15): PPIN, PPI with 5.25% NaOCl; PUIN, PUI with 5.25% NaOCl; CUIN, CUI with 5.25% NaOCl; PPIC, PPI with 2% CHX; PUIC, PUI with 2% CHX; and CUIC, CUI with 2% CHX. In the PPI groups, a 30-gauge needle was used to deliver the irrigating solution. In the PUI groups, a 30-gauge needle was used to deliver the irrigating solution, which was activated for 10 seconds by means of a stainless steel file mounted on an ultrasonic unit. In the CUI groups, delivery and continuous agitation of the irrigating solution for 10 seconds were performed using a stainless steel file mounted on the ultrasonic unit. After canal preparation was completed, glass fiber posts were cemented with a dual-cure resin cement. The roots were sectioned into 1-mm-thick slices (coronal, middle, and apical thirds). After 7 days' storage in distilled water, the slices were submitted to a push-out test. The mean bond strength values were compared using 2-way analysis of variance and Tukey post hoc test (P < 0.05). The mean (SD) overall bond strength values of the specimens were as follows: PPIN, 4.46 (1.43) MPa; PUIN, 6.13 (2.35) MPa; CUIN, 7.41 (1.83) MPa; PPIC, 3.59 (1.70) MPa; PUIC, 5.49 (1.41) MPa; and CUIC, 6.0 (1.63) MPa. Irrespective of the irrigating solution, continuous ultrasonic irrigation achieved significantly greater push-out bond strengths for glass fiber posts, mainly at the apical third of the root specimens (P < 0.05).


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Animais , Bovinos , Cavidade Pulpar , Dentina , Vidro , Humanos , Teste de Materiais , Cimentos de Resina , Irrigantes do Canal Radicular , Preparo de Canal Radicular
3.
Gen Dent ; 70(1): 65-71, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34978994

RESUMO

The objective of this study was to evaluate the effect of cement thickness and luting cement type on the push-out bond strength of glass fiber posts (GFPs) to root dentin. Sixty human maxillary root-filled canines or premolars with single straight roots were randomly divided into 6 groups (n = 10) according to the GFP configuration (conventional or relined with composite resin) and the cement used (RelyX U200, Ketac Cem, or Allcem Core). After endodontic treatment and GFP cementation, all of the roots were sectioned perpendicular to their long axis to obtain 1.0-mm-thick slices (n = 6 per group), which were mounted on a universal testing machine and submitted to a push-out test. The data (n = 45 to 51 specimens per group because of pretest failures) were analyzed by means of 2-way analysis of variance (ANOVA) and Tukey tests (α = 0.05). The type of failure was determined under a stereomicroscope, and representative specimens were observed with scanning electron microscopy. Significant interactions between the cements and GFP configurations were detected in the coronal and apical thirds (P < 0.05; 2-way ANOVA). For the coronal third, both RelyX U200 cement groups exhibited the greatest push-out bond strengths but were not significantly different from the Allcem Core relined group. For the middle third, no statistically significant interactions were observed between the cements and GFP configurations (P = 0.232; 2-way ANOVA). Adhesive failure between the dentin and cement layer was the most frequently observed failure mode. As expected, because of the composite resin added to relined GFPs, the cement layer was thinner in those groups. The type of cement used played an important role in the push-out bond strength.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Dentina , Vidro , Humanos , Teste de Materiais , Cimentos de Resina/uso terapêutico
4.
J Mech Behav Biomed Mater ; 125: 104948, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34775291

RESUMO

Bioactive glasses can be used to coat titanium implants to promote osseointegration. However, incorporating elements such as magnesium, zinc and fluoride into bioactive glasses might have a negative effect on bioactivity or the coefficient of thermal expansion of the glass. In this study, the impact of substituting MgO for CaO on physical properties and bioactivity of glass containing 1 mol % MgF2 was assessed. Seven glasses were produced by melt-quenched route. The glasses comprise (SiO2, CaO, Na2O, MgO, MgF2, K2O and P2O5) and were characterized utilizing XRD, DSC, FTIR and dilatometry analyses. The bioactivity of these glasses was investigated in biological fluids. The results showed that these glasses have wide sintering windows, low TECs and low glass transition and softening temperatures. The bioactive glasses containing up to 13.3 mol% MgO were able to form surface apatite within a short time period; whereas glasses containing ≥16.13 mol% demonstrated only structural variations with no clear sign of apatite precipitation.


Assuntos
Implantes Dentários , Titânio , Vidro , Pós , Dióxido de Silício
5.
Environ Pollut ; 292(Pt A): 118338, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637836

RESUMO

Marine litter is an ever-increasing problem that demands immediate reduction plans and mitigation actions that should act synergically to efficiently meet ambitious goals. Since the seafloor has been recognized as the major sink for marine debris, the study of litter accumulation dynamics represent a fundamental tool to evaluate possible removal actions. We analysed a 7 years (2013-2019) standardized data series collected along Sardinian fishing grounds through MEDiterranean International Trawl Survey, for which estimates of density and weight of seafloor macro-litter were calculated for over 707 hauls. Results show the absence of any temporal trend in seafloor macro-litter density and weight, but rather indicate a spatial and bathymetric segregation of different litter categories. Our data showed how different sources and physical features of macro-litter items (i.e., plastic and fishing gear, rubber, glass, metals, and cloth) led to spatially segregated accumulation hotspots. We also point out here how the identification of seafloor macro-litter hotspots using aggregated data that include plastic items could obscure the identification of other segregated but yet relevant hotspots of other macro-litter categories accumulated in the marine environment. These hotspots often occurred at shallower depths and closer to coastlines, thus representing potential spots where eventual future litter removal action could be prioritized.


Assuntos
Monitoramento Ambiental , Plásticos , Vidro , Mar Mediterrâneo , Metais , Borracha , Resíduos/análise
6.
Chemosphere ; 286(Pt 1): 131652, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34315075

RESUMO

Glass fiber and liquid-modified polyvinyl alcohol polymer (SH Polymer) are used to reinforce granite residual soil. In this paper, scanning electron microscopy (SEM) tests and drop-weight tests were used to study the microscopic interaction mechanism and impact resistance of granite residual soil specimens reinforced by glass fiber and SH Polymer. Combined with the equivalent confining pressure theory, Mohr-Coulomb intensity lines were used to quantitatively analyze the reinforcement effect of glass fiber. The SEM results showed that the granite residual soil solidified by a 3.5 % SH polymer had a tighter bond between the flake clay particles. In addition, with the incorporation of glass fiber, these flake clay particles were cemented on the glass fiber along the long axis, forming a cementing system of flake clay particles and glass fiber. When the glass fiber content was 3.0 %, the impact resistance of the specimen reached its maximum, 32.16 kN. Using the equivalent confining pressure theory, the reinforcement effect of glass fiber on soil could be quantified by Δσ3.


Assuntos
Polímeros , Álcool de Polivinil , Vidro , Teste de Materiais , Dióxido de Silício , Solo , Estresse Mecânico
7.
Georgian Med News ; (320): 143-147, 2021 Nov.
Artigo em Russo | MEDLINE | ID: mdl-34897061

RESUMO

The materials used in the construction of implants contacting with blood should be resistant to thrombus formation. One of the stages of a thrombogenicity assessment of materials is to determine the number of platelets adhered to its surface during the exposure to flowing blood under ex viAvo conditions. The aim of this study was to develop a modified test for screening assessment of materials for their thrombogenicity in contact with native blood. For the purpose of the study, flow chambers of were developed, allowing to mountain simultaneously 16 material samples. The chamber was connected to the circulatory system of the experimental animal through arterial and venous ports in such a way that blood, passing through the chamber, returned to the animal. The exposure time was 1 min. After perfusion the samples were rinsed and stained. The number of platelets adhered per unit area was calculated automatically that allowed significant error diminution. A total of 9 experiments were carried out on pigs under ex vivo conditions. The method was validated using standard samples of pyrolytic carbon, VT-6 titanium, glass, and polytetrafluorethylene as reference materials. New materials for synthetic vascular prostheses have been investigated. The developed technique makes it possible to study the thrombogenicity of polymeric materials with sufficient reliability.


Assuntos
Plaquetas , Trombose , Animais , Prótese Vascular , Vidro , Reprodutibilidade dos Testes , Suínos , Trombose/diagnóstico
8.
Evid Based Dent ; 22(4): 128-129, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34916635

RESUMO

Aim The aim of this randomised clinical trial based on cost-minimisation analysis was to assess and compare four post-retained restorative strategies for endodontically treated teeth.Methods A total of 225 endodontically treated teeth in 141 patients were evaluated annually between 2009 and 2018. In this sense, the teeth were divided into four groups according to the treatment strategy, where three groups were treated with glass fibre posts in combination with composite resin restorations or single metal-ceramic crown with or without ferrules, and one group was treated with cast metal posts with metal-ceramic crowns. According to the outcome of the treatment during follow-up, the teeth received additional treatments, which ranged from restoration repair, re-cementation, endodontic retreatment, apical surgery, post/crown replacement to tooth extraction and replacement through metal-ceramic implant-supported crown. Thus, cost-minimisation analysis was based on November 2018 values from the Brazilian Public Health System, considering the primary costs related to the post, restoration or crown, and incremental costs related to the outcomes during follow-up.Results Primary treatment costs were lower for the group using glass fibre posts in combination with composite resin restorations (US$27.11), while the highest costs were for the group using cast metal post with metal-ceramic crown (US$153,14). In turn, the incremental costs due to tooth removal, implant placement and metal-ceramic crown (US$363.92) were the highest, while the lowest costs were related to procedures for crown re-cementation (US$6.11) followed by repair of the resin restoration (US$16.47). In this regard, the highest percentage of failures was related to restoration fractures in the glass fibre posts in combination with the composite resin restorations group. However, the average annual cost was significantly lower in the group that used glass fibre posts in combination with composite resin restorations (p <0.001) when compared to the other groups, with or without ferrules.Conclusions The treatment of endodontically treated teeth using glass fibre posts in combination with composite resin restorations presented a significantly lower average annual cost when compared to treatments that consider the use of cast metal posts, metal-ceramic crowns, with or without ferrules.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Resinas Compostas , Falha de Restauração Dentária , Vidro , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
10.
Anticancer Res ; 41(11): 5817-5820, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34732456

RESUMO

AIM: Novel glass membrane pumping emulsification devices (GMDs) enable the formation of a high-percentage water-in-oil emulsion with homogeneous and stable droplets. Although GMDs are expected to improve therapeutic effects in transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC), clinical outcomes are not yet available. PATIENTS AND METHODS: A total of 26 patients with unresectable HCC who underwent TACE using a GMD were analyzed retrospectively. Ethiodized oil was mixed with epirubicin solution using a GMD. The emulsion was injected into the tumor-feeding artery, followed by embolization. RESULTS: The median size of HCCs was 28 (range=15-60) mm, and 15 nodules were solitary. Overall treatment effects were complete response in 18 cases (90%) and partial response in two (10%). The local recurrence rate at 6 months was 24.2%. No major complication was observed except for grade 4 elevations of liver enzymes in one case. CONCLUSION: TACE using a GMD is effective and safe in clinical practice.


Assuntos
Antineoplásicos/administração & dosagem , Carcinoma Hepatocelular/tratamento farmacológico , Quimioembolização Terapêutica , Sistemas de Liberação de Medicamentos/instrumentação , Epirubicina/administração & dosagem , Óleo Etiodado/administração & dosagem , Vidro , Neoplasias Hepáticas/tratamento farmacológico , Membranas Artificiais , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/patologia , Quimioembolização Terapêutica/efeitos adversos , Emulsões , Epirubicina/efeitos adversos , Desenho de Equipamento , Óleo Etiodado/efeitos adversos , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento , Carga Tumoral
11.
J Contemp Dent Pract ; 22(8): 876-881, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34753838

RESUMO

AIM AND OBJECTIVE: This study aimed to evaluate the effect of ozonated water used as an irrigant and dentin-cleaning solution on the bond strength of fiberglass pins in vitro, comparing it with the commonly used solutions. MATERIAL AND METHODS: Seventy-seven bovine roots were randomly divided into seven groups according to the irrigant and dentin-cleaning solution to be used: HP/HP, 2.5% sodium hypochlorite; DA/DA, distilled water; CHX/CHX, 2% chlorhexidine; OA/OA, 4 ppm ozonated water; HP/DA; HP/CHX; and HP/OA. In each group, the root canals were endodontically prepared by using the corresponding irrigant and stored in DA; after 7 days, they were cleared and cleaned with the corresponding cleaning solution. The fiberglass pins were cemented by using self-adhesive cement. After 7 days, the roots were sectioned (six discs each) and submitted to the push-out test. The type of fracture was analyzed with a 4.5x stereoscopic magnifying glass. The data were analyzed by the analysis of variance and the Tukey test at a 5% significance level. RESULTS: The OA/OA (11.67), HP/HP (11.21), and HP/OA (9.71) groups showed the highest mean push-out bond strength (MPa) in the cervical third. The same trend was maintained in the middle and apical thirds. CONCLUSION: Ozonated water and 2.5% sodium hypochlorite are the most relevant solutions for root dentin treatment. CLINICAL RELEVANCE: Teeth treated with ozonated water, sodium hypochlorite, and a combination of the two showed greater bond strength than those treated with other solutions.


Assuntos
Colagem Dentária , Técnica para Retentor Intrarradicular , Animais , Bovinos , Cavidade Pulpar , Dentina , Vidro , Teste de Materiais , Cimentos de Resina , Irrigantes do Canal Radicular , Água
12.
Biomater Sci ; 9(23): 7748-7798, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34755730

RESUMO

Amorphous calcium phosphates (ACPs) represent a metastable amorphous state of other calcium orthophosphates (abbreviated as CaPO4) possessing variable compositional but rather identical glass-like physical properties, in which there are neither translational nor orientational long-range orders of the atomic positions. In nature, ACPs of a biological origin are found in the calcified tissues of mammals, some parts of primitive organisms, as well as in the mammalian milk. Manmade ACPs can be synthesized in a laboratory by various methods including wet-chemical precipitation, in which they are the first solid phases, precipitated after a rapid mixing of aqueous solutions containing dissolved ions of Ca2+ and PO43- in sufficient amounts. Due to the amorphous nature, all types of synthetic ACPs appear to be thermodynamically unstable and, unless stored in dry conditions or doped by stabilizers, they tend to transform spontaneously to crystalline CaPO4, mainly to ones with an apatitic structure. This intrinsic metastability of the ACPs is of a great biological relevance. In particular, the initiating role that metastable ACPs play in matrix vesicle biomineralization raises their importance from a mere laboratory curiosity to that of a reasonable key intermediate in skeletal calcifications. In addition, synthetic ACPs appear to be very promising biomaterials both for manufacturing artificial bone grafts and for dental applications. In this review, the current knowledge on the occurrence, structural design, chemical composition, preparation, properties, and biomedical applications of the synthetic ACPs have been summarized.


Assuntos
Materiais Biocompatíveis , Fosfatos de Cálcio , Animais , Apatitas , Calcificação Fisiológica , Vidro
13.
Braz Dent J ; 32(3): 56-64, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34755790

RESUMO

It aims on evaluate the effect of the test environment on static fatigue behavior of lithium disilicate-based (LD), and yttrium oxide-stabilized zirconia (YSZ) ceramics. Specimens of LD (IPS e.max CAD, Ivoclar Vivadent) and YSZ (IPS e.max ZirCAD MO, 3 mol% Y2O3, Ivoclar Vivadent) were randomly allocated into three groups: tested in air, inert (paraffin oil, Sigma Aldrich) or distilled water. The static fatigue test (n=15) was performed using a piston-on-three ball assembly, adapted from ISO 6872, as follows: starting load 100 N for LD and 300 N for YSZ; loading application time set to 1 hour for each loading step; step size of 50 N for LD and 100 N for YSZ, applied successively until fracture. Data from static fatigue strength (MPa) and time to fracture (hours) were recorded. Fractographic analysis was executed. Survival analysis corroborates absence of influence of environment on static fatigue outcomes (fatigue strength, time to fracture and survival rates) for YSZ. For LD, specimens tested in air presented statistically superior survival rate and static fatigue strength (p= 0.025). In regards of time to fracture, LD tested in air were superior than when tested in distilled water (p=0.019) or inert (p=0.017) environments. No statistical differences for Weibull modulus were observed. Failures started on the tensile stress surface. Thus, the test environment did not affect slow crack growth (SCG) mechanisms during static fatigue test of YSZ ceramics, but it plays a significant role for the static fatigue behavior of lithium disilicate-based glass ceramics, indicating a high susceptibility to SCG.


Assuntos
Cerâmica , Porcelana Dentária , Desenho Assistido por Computador , Análise do Estresse Dentário , Vidro , Teste de Materiais , Propriedades de Superfície , Zircônio
14.
J Indian Prosthodont Soc ; 21(4): 425-429, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34810372

RESUMO

Aims: To evaluate the flexural properties of computer-aided design-computer-aided manufacturing (CAD-CAM) milled posts fabricated from the experimental fibre-reinforced composite disks in different fibre direction, and to compare the flexural properties of the CAD-CAM milled posts to those of commercial prefabricated posts, RelyX and FRC PostecPlus. Settings and Design: In vitro comparative study. Materials and Methods: E-glass fibre was used to fabricate the CAD-CAM composite disks. The fibres were prepared in unidirectional and multidirectional arrangements into the epoxy resin, at 70% by weight. The disk was milled by the Cerec InLab CAD-CAM system to fabricate a post. Ten posts for each type of disk were prepared. Two types of commercial fibre posts, RelyX fibre post, and FRC PostecPlus were used as control. The three-point bending test was performed. Statistical Analysis Used: The data were analysed using one-way ANOVA and Game-Howell post-hoc test. Results: The results indicated that both commercial fibre posts had the highest flexural strength and flexural modulus. The unidirectional experimental post yielded significantly lower values in both flexural strengths (739.1 ± 24.1 MPa) and flexural modulus (21.0 ± 3.5 GPa) compared to the control posts, while the multidirectional experimental posts had extremely low flexural strength and flexural modulus. Conclusions: The direction of the fibres significantly influenced the mechanical properties of the posts. The experimental unidirectional fibre-reinforced composite disk showed the potential to be used as a CAD-CAM disk for post and core fabrication.


Assuntos
Resinas Compostas , Vidro , Desenho Assistido por Computador , Teste de Materiais
15.
Sensors (Basel) ; 21(21)2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34770297

RESUMO

Fourier transform infrared (FTIR) micro-spectroscopy has been attracting the interest of many cytologists and histopathologists for several years. This is related to the possibility of FTIR translation in the clinical diagnostic field. In fact, FTIR spectra are able to detect changes in biochemical cellular components occurring when the cells pass to a pathological state. Recently, this interest has increased because it has been shown that FTIR spectra carried out just in the high wavenumber spectral range (2500-4000 cm-1), where information mainly relating to lipids and proteins can be obtained, are able to discriminate cell lines related to different tissues. This possibility allows to perform IR absorption measurements of cellular samples deposited onto microscopy glass slides (widely used in the medical environment) which are transparent to IR radiation only for wavenumber values larger than 2000 cm-1. For these reasons, we show that FTIR spectra in the 2800-3000 cm-1 spectral range can discriminate three different cell lines from breast tissue: a non-malignant cell line (MCF10A), a non-metastatic adenocarcinoma cell line (MCF7) and a metastatic adenocarcinoma cell line (MDA). All the cells were grown onto glass slides. The spectra were discriminated by means of a principal component analysis, according to the PC1 component, whose values have the opposite sign in the pairwise score plots. This result supports the wide studies that are being carried out to promote the translation of the FTIR technique in medical practice, as a complementary diagnostic tool.


Assuntos
Mama , Vidro , Linhagem Celular , Análise de Componente Principal , Espectroscopia de Infravermelho com Transformada de Fourier
16.
Biomater Sci ; 9(23): 7876-7894, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34676835

RESUMO

Bioactive glasses (BGs) are attractive materials for bone tissue engineering because of their bioactivity and osteoinductivity. In this study, we report the synthesis of a novel phosphorous pentoxide-free, silicate-based bioactive glass (52S-BG) composed of 52.1% SiO2, 23.2% Na2O and 22.6% CaO (wt%). The glass was thoroughly characterized. The biocompatibility and osteogenic properties of 52S-BG particles were analyzed in vitro with human adipose-derived mesenchymal stem cells (AdMSCs) and human osteoblasts. 52S-BG particles were biocompatible and induced mineralized matrix deposition and the expression of osteogenic markers (RunX2, alkaline phosphatase, osteocalcin, osteopontin, collagen I) and the angiogenic marker vascular endothelial growth factor (VEGF). Angiogenic properties were additionally confirmed in a zebrafish embryo model. 52S-BG was added to poly-ε-caprolactone (PCL) to obtain a composite with 10 wt% glass content. Composite PCL/52S-BG scaffolds were fabricated by additive manufacturing and displayed high porosity (76%) and pore interconnectivity. The incorporation of 52S-BG particles increased the Young's modulus of PCL scaffolds from 180 to 230 MPa. AdMSC seeding efficiency and proliferation were higher in PCL/52S-BG compared to PCL scaffolds, indicating improved biocompatibility. Finally, 52S-BG incorporation improved the scaffolds' osteogenic and angiogenic properties by increasing mineral deposition and inducing relevant gene expression and VEGF protein secretion. Overall, 52S-BG particles and PCL/52S-BG composites may be attractive for diverse bone engineering applications requiring concomitant angiogenic properties.


Assuntos
Dióxido de Silício , Peixe-Zebra , Animais , Vidro , Humanos , Osteogênese , Fator A de Crescimento do Endotélio Vascular
17.
J Avian Med Surg ; 35(3): 313-324, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34677030

RESUMO

Birds are among the most visually proficient group of animals on the planet; however, their inability to visualize and discriminate translucent glass structures results in an extreme number of deaths worldwide from high-speed collisions. Despite reports of avian glass collisions in North America, only a few studies have been developed to understand this problem in South America, and none evaluated radiographic and postmortem findings. One hundred cadavers were examined radiographically and postmortem, and data from 186 collision reports were analyzed for seasonality (website and manual reports and cadavers). A total of 34 different species of birds within 22 families were evaluated for this study, with the rufous-bellied thrush (Turdus rufiventris; n = 12), eared dove (Zenaida auriculata; n = 12), and ruddy ground dove (Columbina talpacoti; n = 10) being the most common species. Only 6 (27.7%) migratory species were reported: Sick's swift (Chaetura meridionalis), small-billed elaenia (Elaenia parvirostris), Black Jacobin (Florisuga fusca), Great kiskadee (Pitangus sulphuratus), Double-collared seedeater (Sporophila caerulescens), and Creamy-bellied thrush (Turdus amaurochalinus). Males (51) were more frequently reported than females (5), and 50.1% of the males had active gonads. Sex was unable to be determined in 44 birds. The most common radiographic lesion, noted in 16 of 82 (19.5%) animals, was loss of coelomic definition, suggestive of hemorrhage. Prevalent postmortem findings included skull hemorrhages (58/75, 77.3%) and encephalic contusions (47/73, 64.4%), followed by coelomic hemorrhages (33/81, 40.7%). Most of the window collisions (61/186, 32.8%) occurred during spring, the most common breeding season of avian species in Brazil. Cranioencephalic trauma was identified as the primary cause of mortality associated with birds flying into glass windows. Migration does not appear to be the main predisposing factor for window collisions by birds in Brazil. Increased activity and aggression related to breeding season, especially in males, may be a more important predisposing factor for window collision accidents.


Assuntos
Passeriformes , Aves Canoras , Animais , Brasil , Fatores Epidemiológicos , Feminino , Vidro , Masculino
18.
Sensors (Basel) ; 21(20)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34696068

RESUMO

Visible and infrared reflectance imaging spectroscopy is one of the several non-invasive techniques used during Operation Night Watch for the study of Rembrandt's iconic masterpiece The Night Watch (1642). The goals of this project include the identification and mapping of the artists' materials, providing information about the painting technique used as well as documenting the painting's current state and ultimately determining the possible conservation plan. The large size of the painting (3.78 m by 4.53 m) and the diversity of the technical investigations being performed make Operation Night Watch the largest research project ever undertaken at the Rijksmuseum. To construct a complete reflectance image cube at a high spatial resolution (168 µm2) and spectral resolution (2.54 to 6 nm), the painting was imaged with two high-sensitivity line scanning hyperspectral cameras (VNIR 400 to 1000 nm, 2.54 nm, and SWIR 900 to 2500 nm, 6 nm). Given the large size of the painting, a custom computer-controlled 3-D imaging frame was constructed to move each camera, along with lights, across the painting surface. A third axis, normal to the painting, was added along with a distance-sensing system which kept the cameras in focus during the scanning. A total of 200 hyperspectral image swaths were collected, mosaicked and registered to a high-resolution color image to sub-pixel accuracy using a novel registration algorithm. The preliminary analysis of the VNIR and SWIR reflectance images has identified many of the pigments used and their distribution across the painting. The SWIR, in particular, has provided an improved visualization of the preparatory sketches and changes in the painted composition. These data sets, when combined with the results from the other spectral imaging modalities and paint sample analyses, will provide the most complete understanding of the materials and painting techniques used by Rembrandt in The Night Watch.


Assuntos
Pinturas , Algoritmos , Diagnóstico por Imagem , Vidro , Análise Espectral
19.
PLoS One ; 16(10): e0258534, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34644356

RESUMO

OBJECTIVE: This ex vivo study aimed to evaluate the strengthening effect of different ferrule and reattachment designs with fiber and adhesive materials on vertically fractured teeth. METHODS: Ninety extracted single-root premolars were instrumented and divided into nine groups (two control groups and seven experimental groups; n = 10). The negative control (NC) group comprised of intact teeth, while the positive control (PC) group comprised of root canal-treated teeth. The roots of the teeth in the experimental groups were vertically fractured into two equal fragments. The fragments were reattached with one of the followings: 4-methacryloxyethyl trimellitate anhydride/methacrylate-tri-n-butyl borane (4-META/MMA-TBB) resin, 4-META/MMA-TBB + quartz fiber post, 4-META/MMA-TBB + glass fiber bundles, 4-META/MMA-TBB + quartz fiber post + 1 mm ferrule, 4-META/MMA-TBB + glass fiber bundles + 1 mm ferrule, 4-META/MMA-TBB + quartz fiber post + 2 mm ferrule, and 4-META/MMA-TBB + glass fiber bundles + 2 mm ferrule. The core build-ups were made with composite resin. The specimens were subjected to compressive loading until failure occurred. Mean load necessary to fracture each sample and the fracture types of these samples were recorded. RESULTS: The highest mean fracture load was recorded in the NC group (1,036.7 N), which was not significantly higher than the PC group (989.66 N) (p > 0.05). The roots reattached with quartz fiber post demonstrated significantly less fracture strength (871.9 N) as compared to the other test and control groups (p < 0.05). There was no significant difference between the PC group and reattached fragments with different ferrule designs in terms of fracture resistance (p > 0.05). CONCLUSIONS: The customized fiber bundles may be more suitable for reattachment of vertically fractured teeth than the rigid fiber posts. For reattachment procedures, the ferrule design may be preferred to increase the fracture strength of vertically fractured teeth.


Assuntos
Resinas Compostas/uso terapêutico , Planejamento de Prótese Dentária , Fraturas dos Dentes/terapia , Compostos de Boro/química , Estudos de Casos e Controles , Cimentos Dentários/química , Análise do Estresse Dentário , Vidro/química , Humanos , Metacrilatos/química , Quartzo/química , Fraturas dos Dentes/patologia
20.
BMJ Case Rep ; 14(10)2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34610955

RESUMO

An endoscope is a useful adjunct for the retinal surgeon to overcome haze of a compromised anterior segment. It allows early surgery in trauma and infections which translates to better results. Intraocular glass foreign body is a challenging condition, demanding highly skilled surgical expertise. We present endoscopic removal of an intraocular foreign glass body in a badly traumatised and infected eye. The surgical challenge was accentuated by an imaging misdiagnosis of 'twin metallic foreign bodies'.


Assuntos
Endoftalmite , Corpos Estranhos no Olho , Ferimentos Oculares Penetrantes , Criança , Endoftalmite/diagnóstico , Endoscópios , Corpos Estranhos no Olho/diagnóstico por imagem , Corpos Estranhos no Olho/cirurgia , Ferimentos Oculares Penetrantes/diagnóstico por imagem , Ferimentos Oculares Penetrantes/cirurgia , Vidro , Humanos , Masculino
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