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2.
Prev Vet Med ; 181: 105063, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32593083

RESUMEN

Ectoparasitic salmon louse (Lepeophtheirus salmonis) infestations are costly for Atlantic salmon (Salmo salar) farmers in Norway. As a result, there is a strong desire for solutions to prevent and control infestations, and new technologies are typically developed and commercialised rapidly, without rigorous validation. Here, we tested the efficacy of a new commercially available control measure-delousing by underwater lasers-using a replicated design at full commercial scale. Laser delousing was used in combination with a preventive method (snorkel cages), with laser nodes deployed in 3 of the 6 sea cages at the site. The trial ran for 54 days, after which time there was no difference in infestation density of mobile salmon louse stages (pre-adult, adult male or adult female) in cages with or without laser nodes installed. By the end of the trial, adult female lice numbers in all cages were close to the legislated trigger for mandatory delousing (0.5 adult female lice per fish). The laser nodes delivered a large number of pulses relative to the number of lice in the cages, indicating that a lack of lethality rather than a lack of target detection was the limiting factor. If all pulses had been effective, they should have removed between 4-38 % of mobile lice each day. There was no effect on salmon welfare indicators such as skin condition or eye status. Our results highlight the importance of rigorous validation of new technologies across a range of conditions before widespread implementation by industry.


Asunto(s)
Acuicultura/métodos , Copépodos/fisiología , Infestaciones Ectoparasitarias/veterinaria , Enfermedades de los Peces/prevención & control , Rayos Láser/estadística & datos numéricos , Salmo salar , Animales , Infestaciones Ectoparasitarias/parasitología , Infestaciones Ectoparasitarias/prevención & control , Enfermedades de los Peces/parasitología , Noruega
3.
J Vis Exp ; (136)2018 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-30010669

RESUMEN

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser (laser-SARPES), and demonstrate a power of this technique for studying solid state physics. Laser-SARPES achieves two great capabilities. Firstly, by examining orbital selection rule of linearly polarized lasers, orbital selective excitation can be carried out in SAPRES experiment. Secondly, the technique can show full information of a variation of the spin quantum axis as a function of the light polarization. To demonstrate the power of the collaboration of these capabilities in laser-SARPES, we apply this technique for the investigations of spin-orbit coupled surface states of Bi2Se3. This technique affords to decompose spin and orbital components from the spin-orbit coupled wavefunctions. Moreover, as a representative advantage of using the direct spin detection collaborated with the polarization-variable laser, the technique unambiguously visualizes the light polarization dependence of the spin quantum axis in three-dimension. Laser-SARPES dramatically increases a capability of photoemission technique.


Asunto(s)
Rayos Láser/estadística & datos numéricos , Espectroscopía de Fotoelectrones/métodos
4.
J Vis Exp ; (135)2018 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-29912185

RESUMEN

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (Cu variant) entropy-stabilized oxides. Phase pure and chemically homogeneous (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (x = 0.20, 0.27, 0.33) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (x = 0.11, 0.27) ceramic pellets are synthesized and used in the deposition of ultra-high quality, phase pure, single crystalline thin films of the target stoichiometry. A detailed methodology for the deposition of smooth, chemically homogeneous, entropy-stabilized oxide thin films by pulsed laser deposition on (001)-oriented MgO substrates is described. The phase and crystallinity of bulk and thin film materials are confirmed using X-ray diffraction. Composition and chemical homogeneity are confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The surface topography of thin films is measured with scanning probe microscopy. The synthesis of high quality, single crystalline, entropy-stabilized oxide thin films enables the study of interface, size, strain, and disorder effects on the properties in this new class of highly disordered oxide materials.


Asunto(s)
Rayos Láser/estadística & datos numéricos , Óxidos/química , Entropía
5.
J Vis Exp ; (135)2018 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-29863678

RESUMEN

As the field of tissue engineering has continued to mature, there has been increased interest in a wide range of tissue parameters, including tissue shape. Manipulating tissue shape on the micrometer to centimeter scale can direct cell alignment, alter effective mechanical properties, and address limitations related to nutrient diffusion. In addition, the vessel in which a tissue is prepared can impart mechanical constraints on the tissue, resulting in stress fields that can further influence both the cell and matrix structure. Shaped tissues with highly reproducible dimensions also have utility for in vitro assays in which sample dimensions are critical, such as whole tissue mechanical analysis. This manuscript describes an alternative fabrication method utilizing negative master molds prepared from laser etched acrylic: these molds perform well with polydimethylsiloxane (PDMS), permit designs with dimensions on the centimeter scale and feature sizes smaller than 25 µm, and can be rapidly designed and fabricated at a low cost and with minimal expertise. The minimal time and cost requirements allow for laser etched molds to be rapidly iterated upon until an optimal design is determined, and to be easily adapted to suit any assay of interest, including those beyond the field of tissue engineering.


Asunto(s)
Sistemas de Liberación de Medicamentos/métodos , Hidrogeles/metabolismo , Rayos Láser/estadística & datos numéricos , Ingeniería de Tejidos/métodos
6.
J Trop Pediatr ; 64(2): 146-150, 2018 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28673047

RESUMEN

Anthropometric measurements, including height and length, are routinely needed for health research worldwide. Measurement boards are the current gold standard for obtaining the height and length of children. In community-based research, however, the size and weight of the measurement boards make them difficult and cumbersome to carry in the field. In addition, children and infants may express an unwillingness to be placed onto the measurement board. Electronic measuring tools commonly used in industry and contracting work are precise and portable. This study piloted a protocol to use an adapted laser measurement tool, the anthropometric measurement assist (AMA), to obtain height and recumbent length in children in Western Kenya. Intra- and inter-observer variability were determined and compared with measurement board measurements. Results of this initial pilot indicated that the AMA may be a viable alternative to measurement boards. The AMA can measure height/length accurately and reliably, is portable and is equivalent in price to measuring boards, making it a viable option for fieldwork in low-resourced countries.


Asunto(s)
Antropometría/instrumentación , Rayos Láser/estadística & datos numéricos , Salud Pública/métodos , Niño , Preescolar , Femenino , Humanos , Lactante , Kenia , Masculino , Variaciones Dependientes del Observador , Proyectos Piloto , Reproducibilidad de los Resultados
7.
São José dos Campos; s.n; 2018. 65 p. il., tab., graf..
Tesis en Portugués | BBO - Odontología | ID: biblio-968872

RESUMEN

O objetivo deste estudo foi avaliar a eficácia de diferentes parâmetros de energia do Nd:YAG laser, associados ou não a um fotoabsorvedor na redução da desmineralização por cárie artificial, sobre a superfície de esmalte dental. De coroas de incisivos bovinos foram obtidos 80 espécimes circulares com 6 mm de diâmetro e 2 mm de altura (1 mm de esmalte e 1 mm de dentina), o esmalte foi polido com lixas de carbeto de silício. Em cada espécime foi delimitada uma metade na qual o esmalte ficou exposto. As amostras foram avaliadas em Microdurômetro e FTIR para verificação inicial, e distribuídas de forma aleatória em oito grupos (n=10), que receberam os seguintes tratamentos de superfície sobre o esmalte: G1 (controle negativo): não recebeu tratamento de superfície; G2 (controle positivo): aplicação tópica de fluorfosfato acidulado 1,23% gel por 4 min; G3 (Nd:YAG 60 mJ / pulso, 10Hz, 48 J/cm2 , não contato); G4 (fotoabsorvedor + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulso, 10Hz, 64 J/cm2 , não contato); G6 (fotoabsorvedor + Nd:YAG 80 mJ); G7 (Nd:YAG 100 mJ / pulso, 10Hz, 80 J/cm2 , não contato); G8 (fotoabsorvedor + Nd:YAG 100 mJ). Após os tratamentos as amostras foram submetidas ao ciclo de des-remineralização para indução artificial de cárie, sendo então avaliadas em Interferômetro de luz branca, Microdurômetro e FTIR. Os resultados de microdureza foram submetidos à Análise de variância (ANOVA) sob 2 fatores (laser e fotoabsorvedor); ao teste de Tukey e ao teste de Dunnett, com nível de significância de 5% (=0,05). Diferenças estatisticamente significantes foram obtidas no fator fotoabsorvedor individualmente e na interação entre os fatores laser e fotoabsorvedor. Houve menor porcentagem de perda de microdureza nos grupos com fotoabsorvedor comparados aos grupos sem fotoabsorvedor e no grupo G8 comparado aos demais grupos experimentais, o qual apresentou ainda média de microdureza semelhante ao grupo G2. Os dados do FTIR foram submetidos ao Teste T, com nível de significância de 5% (=0,05). Comparadas com G2 foram encontradas maiores concentrações de carbonato em G4, G6 e G8; de fosfato em G8; menor concentração de Amida I em G8 e maior relação Carbonato/Fosfato em G4 e G6. Os resultados de interferometria foram submetidos à ANOVA a três fatores de medidas repetidas, com nível de significância de 5% (=0,05). Houve diferenças estatisticamente significantes no fator fotoabsorvedor individualmente e no fator tempo. Concluiu-se que o emprego de fotoabsorvedor diminuiu a desmineralização, os parâmetros de Nd:YAG laser sem fotoabsorvedor foram menos efetivos que o flúor na prevenção da desmineralização, o parâmetro de 100 mJ do Nd:YAG laser com fotoabsorvedor foi tão efetivo quanto o flúor na redução da desmineralização e a aplicação do Nd:YAG laser, associado ou não ao fotoabsorvedor, não foi mais eficaz que o flúor na redução da desmineralização por cárie artificial(AU)


The aim of this study was to evaluate the effectiveness of different energy parameters of the Nd:YAG laser, associated or not to a photoabsorber in the reduction of demineralization by artificial caries, on the surface of dental enamel. From the crowns of bovine incisors, 80 circular specimens with 6 mm diameter and 2 mm height (1 mm of enamel and 1 mm of dentin) were obtained, the enamel was polished with silicon carbide sandpapers. In each specimen surface was delimited a half in which the enamel was exposed. The samples were evaluated in Microdurometer and FTIR for initial verification, and randomly distributed in eight groups (n = 10), which received the following surface treatments on the enamel: G1 (negative control): no surface treatment; G2 (positive control): topical application of acidulated fluorophosphate 1.23% gel for 4 min; G3 (Nd:YAG 60 mJ / pulse, 10 Hz, 48 J / cm2 , non-contact); G4 (photoabsorber + Nd:YAG 60 mJ); G5 (Nd:YAG 80 mJ / pulse, 10 Hz, 64 J / cm2 , non-contact); G6 (photoabsorber + Nd:YAG 80 mJ); G7 (Nd: YAG 100 mJ / pulse, 10 Hz, 80 J / cm2 , non-contact); G8 (photoabsorber + Nd:YAG 100 mJ). After the treatments, the samples were submitted to the deremineralization cycle for artificial induction of caries, and were then evaluated in White Light Interferometer, Microdurometer and FTIR. The microhardness results were submitted to Analysis of Variance (ANOVA) under 2 factors (laser and photoabsorber); to the Tukey test and the Dunnett test, with a significance level of 5% ( = 0.05). Statistically significant differences were obtained in the photoabsorber factor individually and in the interaction between the laser and photoabsorber factors. There was a lower percentage of microhardness loss in the photoabsorber groups compared to the non-photoabsorber groups and in the G8 group compared to the other experimental groups, which also presented a microhardness average similar to the G2 group. The FTIR data were submitted to the T test, with a significance level of 5% ( = 0.05). Compared with G2, higher concentrations of carbonate were found in G4, G6 and G8; phosphate in G8; lower Amide I concentration at G8 and higher Carbonate / Phosphate ratio at G4 and G6. The interferometry results were submitted to ANOVA under three factors of repeated measures, with a significance level of 5% ( = 0.05). There were statistically significant differences in the photoabsorber factor individually and in the time factor. It was concluded that the use of photoabsorber decreased the demineralization, the non-photoabsorber Nd:YAG laser parameters were less effective than fluoride in the prevention of demineralization, the parameter of 100 mJ of the Nd:YAG laser with photoabsorber was as effective as fluoride in the reduction of demineralization and the application of Nd:YAG laser, associated or not to the photoabsorber, was no more effective than fluoride in the reduction of artificial caries demineralization.5% ( = 0.05) (AU)


Asunto(s)
Humanos , Esmalte Dental , Desmineralización Dental/complicaciones , Caries Dental , Rayos Láser/estadística & datos numéricos
8.
Curr Protoc Immunol ; 119: 5.8.1-5.8.38, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29091263

RESUMEN

The immune system consists of a complex network of cells, all expressing a wide range of surface and/or intracellular proteins. Using flow cytometry, these cells can be analyzed by labeling with fluorophore-conjugated antibodies. The recent expansion of fluorescence flow cytometry technology, in conjunction with the ever-expanding understanding of the complexity of the immune system, has led to the generation of larger high-dimensional fluorescence flow cytometry panels. However, as panel size and complexity increases, so too does the difficulty involved in constructing high-quality panels, in addition to the challenges of analyzing such high-dimensional datasets. As such, this unit seeks to review the key principles involved in building high-dimensional panels, as well as to guide users through the process of building and analyzing quality panels. Here, cytometer configuration, fluorophore brightness, spreading error, antigen density, choosing the best conjugates, titration, optimization, and data analysis will all be addressed. © 2017 by John Wiley & Sons, Inc.


Asunto(s)
Anticuerpos/metabolismo , Citometría de Flujo/métodos , Colorantes Fluorescentes , Rayos Láser/estadística & datos numéricos , Análisis de la Célula Individual , Animales , Antígenos/inmunología , Antígenos/metabolismo , Conjuntos de Datos como Asunto , Citometría de Flujo/instrumentación , Fluorescencia , Colorantes Fluorescentes/química , Humanos
9.
J Vis Exp ; (124)2017 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-28715366

RESUMEN

An original method to heat cultured cells using a 1.94 µm continuous-wave thulium laser for biological assessment is introduced here. Thulium laser radiation is strongly absorbed by water, and the cells at the bottom of the culture dish are heated through thermal diffusion. A laser fiber with a diameter of 365 µm is set about 12 cm above the culture dish, without any optics, such that the laser beam diameter is almost equivalent to the inner diameter of the culture dish (30 mm). By keeping a consistent amount of culture medium in each experiment, it is possible to irradiate the cells with a highly reproducible temperature increase. To calibrate the temperature increase and its distribution in one cell culture dish for each power setting, the temperature was measured during 10 s of irradiation at different positions and at the cellular level. The temperature distribution was represented using a mathematical graphics software program, and its pattern across the culture dish was in Gaussian form. After laser irradiation, different biological experiments could be performed to assess temperature-dependent cell responses. In this manuscript, viability staining (i.e., distinguishing live, apoptotic, and dead cells) is introduced to help determine the threshold temperatures for cell apoptosis and death after different points in time. The advantages of this method are the preciseness of the temperature and the time of heating, as well as its high efficiency in heating cells in a whole cell culture dish. Furthermore, it allows for study with a wide variety of temperatures and time durations, which can be well-controlled by a computerized operating system.


Asunto(s)
Células Cultivadas/metabolismo , Terapia por Láser/métodos , Rayos Láser/estadística & datos numéricos , Tulio/química , Células Cultivadas/citología , Calefacción
10.
Methods Mol Biol ; 1607: 273-294, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28573577

RESUMEN

Time-resolved macromolecular crystallography unifies protein structure determination with chemical kinetics. With the advent of fourth generation X-ray sources the time-resolution can be on the order of 10-40 fs, which opens the ultrafast time scale to structure determination. Fundamental motions and transitions associated with chemical reactions in proteins can now be observed. Moreover, new experimental approaches at synchrotrons allow for the straightforward investigation of all kind of reactions in biological macromolecules. Here, recent developments in the field are reviewed.


Asunto(s)
Cristalografía por Rayos X/métodos , Proteínas/ultraestructura , Cristalografía por Rayos X/instrumentación , Cinética , Rayos Láser/estadística & datos numéricos , Conformación Proteica , Proteínas/química , Sincrotrones/instrumentación , Termodinámica , Factores de Tiempo , Difracción de Rayos X
11.
Artículo en Inglés | MEDLINE | ID: mdl-28374983

RESUMEN

We show the use of a new endoscopic drill for the management of web-like tracheal stenosis. Our device creates radial holes within stenosis that facilitate the use of scissors for cutting the scar tissue and the subsequent mechanical dilatation.


Asunto(s)
Dilatación/métodos , Endoscopía/instrumentación , Estenosis Traqueal/cirugía , Broncoscopía/instrumentación , Broncoscopía/métodos , Endoscopía/métodos , Humanos , Intubación Intratraqueal/efectos adversos , Rayos Láser/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Estenosis Traqueal/etiología , Traqueostomía/efectos adversos , Resultado del Tratamiento
12.
Rev. cuba. oftalmol ; 30(1): 0-0, ene.-mar. 2017.
Artículo en Español | LILACS | ID: biblio-901349

RESUMEN

La aplicación del femtoláser en la cirugía de catarata podría ser una de las grandes revoluciones contemporáneas ocurridas en el campo del tratamiento de la catarata. Si el uso de esta tecnología provocara una eficacia y seguridad muy superiores sobre la facoemulsificación convencional, justificaría el alto costo que genera para la cirugía de catarata en la actualidad. En revisiones de estudios comparativos no se han encontrado diferencias significativas entre los resultados visuales de ambos procedimientos al final del período de seguimiento posoperatorio. Una mejor circularidad de la capsulorrexis, unido a disminución en la emisión de energía ultrasónica y del tiempo efectivo de faco, son atribuidos como las grandes ventajas del uso del femtoláser en la facoemulsificación. Sin embargo, en cuanto a la pérdida de células endoteliales, el edema corneal posoperatorio y el edema macular posquirúrgico no se han registrado grandes diferencias entre ambas técnicas quirúrgicas, mientras que el costo de la cirugía se incrementa considerablemente con la utilización del femtoláser. Por tanto, se necesitan estudios de gran tamaño de muestra bien diseñados que proporcionen evidencias más fiables respecto al uso del femtoláser en la cirugía de catarata actual(AU)


The application of femtoláser in cataract surgery could be one of the great contemporary revolutions occurred in the field of treatment of cataract. If the use of this technology would cause a very superior efficacy and safety over conventional phacoemulsification, it justifies the high cost it generates for cataract surgery today. In reviews of comparative studies we have not found significant differences between the visual results of both procedures at the end of the period of postoperative follow-up. Better circularity of the capsulorhexis, coupled with decrease in the emission of ultrasonic energy and effective phacoemulsification time, are attributed as the major advantages of using femtoláser in phacoemulsification. However in terms of endothelial cell loss, postoperative corneal edema and macular edema after surgery they have not been recorded big differences between the two surgical techniques, while the cost of surgery is considerably increased with the use of femtoláser. Therefore studies of large sample size, well-designed to provide more reliable evidence regarding the use of femtoláser in current cataract surgery are needed(AU)


Asunto(s)
Humanos , Extracción de Catarata/métodos , Facoemulsificación/métodos , Rayos Láser/estadística & datos numéricos , Desarrollo Tecnológico/análisis
13.
Artículo en Inglés | MEDLINE | ID: mdl-28106972

RESUMEN

We propose the use of a new endoscopic drill for management of web-like tracheal stenosis. Our device allows creating radial holes within stenosis that facilitates the use of the scissors for cutting the  scar and the subsequent mechanical dilatation.


Asunto(s)
Broncoscopía/instrumentación , Dilatación/métodos , Endoscopía/instrumentación , Estenosis Traqueal/cirugía , Broncoscopía/métodos , Endoscopía/métodos , Humanos , Intubación Intratraqueal , Rayos Láser/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Estenosis Traqueal/etiología
14.
São José dos Campos; s.n; 2017. 94 p. il., tab., graf..
Tesis en Portugués | BBO - Odontología | ID: biblio-905204

RESUMEN

O objetivo deste estudo foi avaliar in vitro o efeito do tratamento com a associação de fosfato de cálcio, laser de Nd:YAG e sistema adesivo na permeabilidade dentinária e na resistência de união. Foram utilizados 60 discos de dentina com aproximadamente 6 mm de diâmetro e 1,5 mm de altura, obtidos de molares humanos hígidos. Os espécimes foram divididos em dois grupos de acordo com a prévia aplicação ou não do fosfato de cálcio (TeethMate Desensitizer - Kuraray Notitake Dental Inc.). Cada grupo foi dividido em três subgrupos conforme o tratamento realizado (n=10): A- Adesivo (Single Bond Universal - 3M-ESPE), AL- Adesivo + Laser (Nd: YAG 60 mJ) , LALLaser + Adesivo + Laser. A permeabilidade foi mensurada em três momentos: com smear layer presente (inicial), após a abertura dos túbulos (máxima) e depois do tratamento (final). O percentual da permeabilidade inicial e final foi calculada em relação a permeabilidade máxima. Após a fotopolimerização do adesivo foi aplicado uma camada de 3 mm com a resina composta Filtek Z350 XT (3M-ESPE) com técnica incremental. Os espécimes foram submetidos a 5000 ciclos térmicos e 120.000 ciclos mecânicos, e posteriormente foi utilizado o teste de microtração. Adicionalmente foram observados em microscopia eletrônica de varredura (MEV) e microscopia confocal de varredura a laser (MCVL). Os grupos foram analisados pelo teste da analise de variância (ANOVA), teste t pareado e teste Tukey, adotando o nível de significância de 5%. Não foram observadas diferenças significativas entre os grupos na permeabilidade inicial (p=0,48) e após o tratamento (p=0,70). O percentual de permeabilidade após o tratamento foram (A: 42,11; AL: 39,09; LAL: 35,78; FA: 40,38; FAL: 34,23; FLAL: 30,25). O teste t pareado mostrou que o tratamento LAL promoveu uma redução significativa da permeabilidade em relação à inicial, tendo o fosfato de cálcio sido (p=30,25) ou não aplicado (p=35,78). Os tratamentos tiveram diferenças significativas na resistência de união, foi observado que os grupos FAL(31,53MPa), FLAL(31,37MPa) e AL(29,72MPa) apresentaram as maiores médias, que diferiram estatisticamente dos grupos restaurados só com Adesivo. Os demais grupos não apresentaram diferenças significantes (A: 24,34MPa; FA: 26,40MPa; LAL: 29,68MPa). Podemos concluir que o laser Nd:YAG aplicado antes e depois do sistema adesivo (Com e sem Fosfato de Cálcio), influenciou na redução da permeabilidade dentinária e os diferentes tratamentos na dentina influenciam significativamente a resistência de união entre a dentina e a resina, os grupos FAL, FLAL e AL apresentaram os melhores resultados. A correlação entre os parâmetros não teve influencia(AU)


The objective of this study was to evaluate in vitro effect the association of calcium phosphate, Nd:YAG laser and adhesive system on dentin permeability and bond strength. Sixty dentin discs, approximately 6 mm in diameter and 1,5 mm high, were obtained from healthy human molars. The specimens were divided into two groups according to the prior application of calcium phosphate (TeethMate Desensitizer - Kuraray Noritake Dental Inc.). Each group was divided into three subgroups according to the treatment performed: A-Adhesive (Single Bond Universal - 3M-ESPE), AL- Adhesive + Laser (Nd: YAG 60 mJ) and LAL- Laser + Adhesive + Laser. The dentin permeability was measured in three moments: with smear layer present (initial), after opened tubules (maximum) and after treatment (final). The percentage of the initial and final permeability was calculated in relation to the maximum permeability. After adhesive photopolymerization, was applied the composite resin Filtek Z350 XT (3M-ESPE) with incremental technique. The specimens were cycled to 5000 thermal cycles and 120,000 mechanical cycles, and microtensile bond strength test was applied. Additionally they were observed in scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The groups were analyzed by ANOVA, paired t test and Tukey test (5%). No significant differences were observed between the groups on initial permeability (p=0.48) and after treatment (p=0.70). Permeability percentage after treatment was (A: 42.11, AL: 39.09, LAL: 35.78, FA: 40.38, FAL: 34.23, FLAL: 30.25). The paired t-test showed that LAL treatment promoted a significant reduction of the permeability in relation to the initial one, with calcium phosphate (p=30.25) or not applied (p=35.78). The treatments had significant differences in bond strength; FAL (31,53 MPa), FLAL (31,37 MPa) and AL (29,72 MPa) groups presented the highest averages, which differed statistically from the groups restored with only Adhesive. The other groups did not present statistically significant differences (A: 24.34 MPa, AF: 26.40 MPa, LAL: 29.68 MPa). It can be concluded that when the Nd:YAG laser was applied before and after the adhesive system (with and without Calcium Phosphate), it influenced the reduction of dentin permeability and the different treatments in dentin significantly influenced the bond strength between dentin and resin , the groups AL, LAL with application of Phosphate and AL without the use of Phosphate showed the best results. The correlation between the parameters had no influence(AU)


Asunto(s)
Humanos , Permeabilidad de la Dentina , Rayos Láser/efectos adversos , Rayos Láser/estadística & datos numéricos
15.
São José dos Campos; s.n; 2017. 78 p. il., tab., graf..
Tesis en Portugués | BBO - Odontología | ID: biblio-905914

RESUMEN

A mensuração da degradação de colágeno radicular é um importante parâmetro para avaliar a progressão de cáries na dentina ou a eficácia de métodos terapêuticos na prevenção de lesões não cariosas. O objetivo deste trabalho foi avaliar a degradação do colágeno da dentina radicular frente a métodos de prevenção de cárie, utilizando o teste da Hidroxiprolina e a microradiografia. Foram obtidos 40 blocos de dentina radicular com aproximadamente 1,5 mm de profundidade x 6 mm de diâmetro, a partir de incisivos bovinos, os quais foram submetidos ao processo de desmineralização artificial em tampão acetato (pH=5), a fim de induzir a formação de uma lesão cariosa. Em seguida as amostras foram submetidas aos tratamentos preventivos de cárie radicular: 1) Clorexidina 0,12% 1 min, 2) Flúor neutro 2% 1 min, 3) Nd: YAG Laser- 60 mJ 10 s e 4) Água Deionizada (controle) 1 min. Após os tratamentos as amostras foram expostas à degradação pela enzima colagenase (Tipo VII, Produto No. C0773, Sigma-Aldrich, St. Louis, MO, USA) por um período de 5 dias. Ao final do desafio da colagenase, a solução contendo a enzima foi coletada para ser submetida ao teste da hidroxiprolina, para a mensuração da quantidade de colágeno degradado por meio de colorimetria em espectrofotômetro. Em seguida as mesmas amostras foram submetidas à mais 2 dias de desmineralização. Em complemento ao ensaio da hidroxiprolina as amostras foram expostas à microradiografia transversal para visualização e medição da área degradada. Uma análise descritiva dos dados obtidos foi realizada de modo a determinar o teste estatístico a ser aplicado. A análise de variância (ANOVA) para a HYP revelou que não houve diferença estatisticamente significativa entre os tratamentos empregados (p>0,05). Os dados obtidos na microradiografia foram submetidos ao teste de Kruskal Wallis e teste de comparações múltiplas, Dunn. Os dados de reptetição, comparações entre a desmineralização inicial (5 dias) e a segunda desmineralização (2 dias), foi realizado individulamente em cada grupo por teste T de medidas repetidas ou Wilcoxon. Houve diferença significativa entre os grupos (p<0,0001). Dos tratamentos empregados, a clorexidina e o flúor foram eficazes na prevenção da progressão da cárie radicular(AU)


Quantification of collagen degradation is an important parameter to evaluate dentin caries progression of caries prevention aid. The aim of this study was to evaluate root collagen degradation against preventive methods by using the hydroxyproline assay and microradiography technique. Forty root dentin blocks were obtained with 1,5x6 mm (depth x diameter) from bovine incisors, which were submitted to artificial demineralization process by acetate buffer (PH=5), in order to induce a carious lesion. Then, the samples were submitted to preventive therapeutic treatment of root caries: 1) Chlorhexidine 0,12% 1 min, 2) Fluoride 2% 1 min, 3) Nd:YAG Laser - 60 mJ 10s, 4) Deionized Water (control) 1 min. After that, the samples were exposed to degradation by the collagenase enzyme (Type VII, Product No. C0773, Sigma- Aldrich, St. Louis, MO, USA) for 5 days. Following the collagenase challenge, the enzyme solution was collected for assaying hydroxyproline released from collgen matrix, where it is possilble to measure the amount of degraded collagen by colorimetry in a spectrophotometer. Soon after, the same samples were submitted to a further 2 days of demineralization process. In addition to the hydroxyproline assay the samples were exposed to the transverse microradiography for a visualization of the degraded area. Soon after the colorimetric test the same samples were submitted to further two days of demineralization. A descriptive analysis of the data will be performed to determine the statistical test to be applied. ANOVA test revealed that there was no difference between the treatments (p>0,05). The microradiography data were submitted to the Kruskal Wallis test and multiple comparison test, Dunn. The repetition data, comparisons between the initial (5 days) and the second (2 days) demineralization, were performed individually in each group by repeated measures T-test or Wilcoxon (p<0,0001). Among the proposed treatments, chlorhexidine and fluoride were effective in preventing root caries progression(AU)


Asunto(s)
Humanos , Caries Dental/prevención & control , Clorhexidina/administración & dosificación , Colágeno/efectos adversos , Dentina/anatomía & histología , Flúor/administración & dosificación , Rayos Láser/estadística & datos numéricos
16.
Chem Commun (Camb) ; 52(66): 10147-50, 2016 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-27456171

RESUMEN

Smooth and solid WS2 submicrospheres were prepared by a laser irradiation induced fragmentation and morphological reshaping process using bulk-slice WS2 particles as targets in solution. Such submicrospheres as additives in paraffin liquid show remarkably enhanced friction reduction and anti-wear properties in comparison with raw WS2 slices.


Asunto(s)
Productos Biológicos/síntesis química , Rayos Láser/estadística & datos numéricos , Microesferas , Compuestos de Tungsteno/síntesis química , Ensayo de Materiales/métodos , Propiedades de Superficie
17.
ImplantNewsPerio ; 1(4): 758-765, mai.-jun. 2016. ilus
Artículo en Portugués | LILACS, BBO - Odontología | ID: biblio-847039

RESUMEN

Existem condições clínicas em Periodontia na qual o freio labial está posicionado de forma penetrante nas papilas gengivais, ficando muito próximo à margem gengival, podendo predispor ao desenvolvimento de recessões gengivais. Também pode ocorrer dificuldade de higienização, infl amação persistente, restrição no movimento labial, interferência fonética e agravos estéticos, além de dificultar o fechamento de diastemas. Muitas vezes, é indicada a remoção cirúrgica de freios labiais utilizando lâminas de bisturi e, mais recentemente, o laser de alta intensidade. O laser, ao ser absorvido pelos tecidos, gera a vaporização e sublimação, resultando em corte e exérese, além de atuar como auxiliar na cicatrização, provavelmente através da bioestimulação. Seu meio ativo promove a vaporização completa e a coagulação nos tecidos, sem gerar propagação do aquecimento. Há maior controle da hemorragia transoperatória, resultando em um procedimento cirúrgico limpo, frequentemente dispensando suturas, facilitando a visibilidade, execução e remoção do freio labial. O objetivo deste trabalho foi demonstrar as vantagens do laser cirúrgico de alta intensidade (Nd:YAG; 808 nm; 1,2 W; 20 pps; 126 J) a partir de um relato de caso clínico de frenectomia realizada em uma paciente do sexo feminino, com 34 anos de idade, que apresenta freio labial persistente associado a diastema interincisal superior. O procedimento cirúrgico com laser de alta intensidade em tecidos moles apresentou algumas vantagens, como a redução do tempo cirúrgico, de morbidade e sintomatologia pós-operatórias.


There are clinical conditions in periodontics where the labia frenulum is deeply positioned into the gingival papillae getting very close to the gingival margins, predisposing the development of recessions, causing difficulties for cleaning, with persistent infl ammation, lip movement restrictions, phonetic interference, esthetic alteration, besides preventing diastema closure. Oftentimes, removal with a surgical blade or high-intensity lasers is recommended. The laser is absorbed by the tissues generating vaporization and sublimation which results in cutting and excision, and increased improved healing possibly due to its bio-stimulatory effect. Its active medium promotes complete tissue vaporization and coagulation, without heat propagation, control of the intraoperative bleeding and a clean surgery that often does not require sutures. This facilitates visibility, execution and removal of the labial frenulum. The aim of this paper was to demonstrate the surgical benefi ts of the high-intensity laser (Nd:YAG; 808 nm; 1.2 W; 20 pps; 126 J) in a case report of frenectomy for a 34 years-old female patient presenting persistent inter-incisal diastema associated with an atypical labial frenulum. The soft tissue laser therapy has the advantage of reduced clinical time and still not promoting edema, with minimal postoperative pain and side effects.


Asunto(s)
Humanos , Femenino , Adulto , Frenillo Labial/cirugía , Terapia por Láser , Rayos Láser/estadística & datos numéricos , Periodoncia
18.
ImplantNewsPerio ; 1(1): 58-66, jan.-fev. 2016. ilus
Artículo en Portugués | LILACS, BBO - Odontología | ID: biblio-846988

RESUMEN

Objetivo: fazer uma revisão da literatura sobre o laser de baixa intensidade (LLLT) e seus efeitos na osseointegração dos implantes de titânio. Material e métodos: uma busca eletrônica foi realizada nos bancos de dados PubMed/Medline e Cochrane Library, entre 1995 e 2015, limitando-se aos artigos em inglês e usando as seguintes palavras-chave: "LLLT", "dental implant" e "osseointegration", combinadas por operadores booleanos. Resultados: das 96 referências analisadas inicialmente, apenas 17 artigos foram incluídos (15 estudos em animais, dois estudos em humanos). Quinze artigos mostraram efeitos positivos da LLLT, enquanto dois foram neutros. Houve grande variabilidade no uso da LLLT, sobretudo no que se refere à dose utilizada, ao número de sessões, à energia de irradiação, e ao comprimento de onda. Conclusão: mais pesquisas sobre este tema são necessárias, utilizando doses padronizadas, assim como comprimento de onda e protocolos de aplicação pré-definidos.


Objective: to perform a systematic review on low-level laser therapy (LLLT) and its effects on the osseointegration of titanium implants. Material and methods: an electronic search was on the PubMed/Medline database and Cochrane Library between 1995 e 2015, restricted to the English literature and using the keywords: "LLLT", "dental implant", and "osseointegration" combined by Boolean operators. Results: from the 96 initially retrieved references, only 17 articles were included (15 animal studies, 2 human studies). Fifteen articles showed positive effects, while only two demonstrated neutral effects of LLLT. A great variability was found on LLLT regarding doses, number of sessions, energy, and wavelengths used. Conclusion: further research on this topic need to be made using standard doses, wavelengths, and pre-defi ned application protocols.


Asunto(s)
Humanos , Terapia por Láser , Rayos Láser/estadística & datos numéricos , Terapia por Luz de Baja Intensidad , Oseointegración/efectos de la radiación
19.
Food Chem ; 194: 366-72, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26471567

RESUMEN

The effect of pulsed light (from 1.75 to 26.25Jcm(-2)) on selected properties of wheat gluten powder and aqueous suspension (absorbance, particle size and microstructure, free sulfhydryl content, protein fractions, protein electrophoretic mobility and immunoreactivity) was investigated. Gluten photoreactivity was strongly affected by hydration. While minor photo-induced structure modifications were observed in gluten powder, pulsed light induced the development of browning and promoted partial depolymerisation of hydrated gluten proteins by disulphide exchange. These changes were associated with a significant decrease in immunoreactivity, suggesting that pulsed light could be exploited to efficiently modify structure and thus functionality of gluten.


Asunto(s)
Electroforesis en Gel de Poliacrilamida/métodos , Glútenes/química , Rayos Láser/estadística & datos numéricos , Triticum/química
20.
Sci Rep ; 5: 14742, 2015 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-26439499

RESUMEN

Cataract surgery is the most common surgical procedure and femtosecond laser assisted cataract surgery (FLACS) has gained increased popularity. FLACS requires the application of a suction device to stabilize the laser head and focus the laser beam accurately. This may cause a significant escalation in intra-ocular pressure (IOP), which poses potential risks for patients undergoing cataract surgery. In this study we aimed to assess the effect of the Ziemer LDV Z8 femtosecond cataract machine on IOP. We demonstrated through a porcine model that IOP was significantly higher with a flat interface but could be abrogated by reducing surgical compression and vacuum. Pressure was lower with a liquid interface, and further altering angulation of the laser arm could reduce the IOP to 36 mmHg. A pilot series in patients showed comparable pressure rises with the porcine model (30 mmHg). These strategies may improve the safety profile in patients vulnerable to high pressure when employing FLACS with the Ziemer LDV Z8.


Asunto(s)
Catarata/terapia , Presión Intraocular/fisiología , Rayos Láser/estadística & datos numéricos , Tonometría Ocular/instrumentación , Anciano , Animales , Humanos , Porcinos
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