SEM-EDS and biomechanical evaluation of implants with different surface treatments: An initial study

Aim: Alterations in implant surfaces can affect periimplant bone formation and shorten the healing time. The goal of the present study was a comparative scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS) and biomechanical evaluation of implants subjected to different surface treatments. Materials and Methods: Four implant surfaces were analyzed in the present study: machined commercial implants (TU); porous-surfaced commercial implants blasted with Al2O3 microspheres and acid-etched (TJA); laser beam-irradiated experimental implants (Laser) and laser beam-irradiated experimental implants with hydroxyapatite coating (HA). One sample for each surface underwent pre-surgery SEM/EDS analysis. Thirty-two implants (8 for each surface treatment) were then inserted into the tibia of 4 rabbits. After 8 weeks, the animals were euthanized and the implants retrieved by reverse torque and processed for post-surgery SEM/EDS analysis. Results: HA implants presented higher removal torque values when compared to Laser, TJA and TU groups. Post-surgery SEM micrographs clearly showed bone formation on all the examined surfaces; however, in the TU group bone covered only some areas of the implant surface, while in TJA, Laser and HA groups the entire implant surfaces were overlaid by newly formed bone. EDS analysis supported the results obtained by SEM and removal torque, showing that concentration of Ca and P increased from TU to TJA, Laser and HA implants. Conclusions: Implants with surfaces modified by laser beam with or without apatite coating showed more promising results.

Effect of surface treatments on the bond strength of a resin cement to commercially pure titanium

Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 μm Al2O3 particles; (2) 30 μm silica-modified Al2O3 particles (Cojet Sand); (3) 110 μm silica-modified Al2O3 particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100% adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC.

Treatments to optimize the use of artificial insemination and reproductive efficiency in beef cattle under tropical environments

Bos indicus cattle, the preferred genetic group in tropical climates, are characterized by having a lower reproductive efficiency than Bos taurus. The reasons for the poorer reproductive efficiency of the Bos indicus cows include longer lengths of gestation and postpartum anestrus, a short length of estrous behavior with a high incidence of estrus occurring during the dark hours, and puberty at older age and at a higher percentage of body weight relative to mature body weight. Moreover, geography, environment, economics, and social traditions are factors contributing for a lower use of reproductive biotechnologies in tropical environments. Hormonal protocols have been developed to resolve some of the reproductive challenges of the Bos indicus cattle and allow artificial insemination, which is the main strategy to hasten genetic improvement in commercial beef ranches. Most of these treatments use exogenous sources of progesterone associated with strategies to improve the final maturation of the dominant follicle, such as temporary weaning and exogenous gonadotropins. These treatments have caused large impacts on reproductive performance of beef cattle reared under tropical areas. Copyright © 2011 O. G. Sá Filho and J. L. M. Vasconcelos.

Effect of different pulse treatments on vase life of inflorescences of oncidium varicosum 'Samurai'

Oncidium varicosum is a species of orchid that is prevalent in South America. This species produces yellow flowers, which are commonly named golden shower, ballet dancer and Anita's flower. The study of the post-harvest physiology of flowers involves examination of factors related to quality loss of cut flowers, which is related not only to several physiological processes but also to interactions between the floral components and qualitative factors. In this context, our research involved the study of physiological aspects of the post-harvest physiology of cut inflorescences of Oncidium varicosum ('Samurai') after treatment with pulsing solutions containing silver salts, 8-HQC and sucrose. A reduction of relative water content of Oncidium flowers treated with pulsing STS (2 mM) was observed. The soluble carbohydrates and reducing sugars content decreased, and higher contents were measured in flowers treated with STS (2 mM). All parameters related to flower coloration were reduced in all treatments. Similar results were obtained for carotenoid content, except for the STS treatment (2 mM), which differed significantly from the other treatments on the 8th and 12th days of vase life. The inflorescences' longevity varied from 12 days (distilled water) to 15 days (STS 2 mM).

Effect of superstimulatory treatments on the expression of genes related to ovulatory capacity, oocyte competence and embryo development in cattle.

Multiple ovulation (superovulation) and embryo transfer has been used extensively in cattle. In the past decade, superstimulatory treatment protocols that synchronise follicle growth and ovulation, allowing for improved donor management and fixed-time AI (FTAI), have been developed for zebu (Bos indicus) and European (Bos taurus) breeds of cattle. There is evidence that additional stimulus with LH (through the administration of exogenous LH or equine chorionic gonadotrophin (eCG)) on the last day of the superstimulatory treatment protocol, called the 'P-36 protocol' for FTAI, can increase embryo yield compared with conventional protocols that are based on the detection of oestrus. However, inconsistent results with the use of hormones that stimulate LH receptors (LHR) have prompted further studies on the roles of LH and its receptors in ovulatory capacity (acquisition of LHR in granulosa cells), oocyte competence and embryo quality in superstimulated cattle. Recent experiments have shown that superstimulation with FSH increases mRNA expression of LHR and angiotensin AT(2) receptors in granulosa cells of follicles >8 mm in diameter. In addition, FSH decreases mRNA expression of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) in oocytes, but increases the expression of both in cumulus cells, without diminishing the capacity of cumulus-oocyte complexes to generate blastocysts. Although these results indicate that superstimulation with FSH is not detrimental to oocyte competence, supplementary studies are warranted to investigate the effects of superstimulation on embryo quality and viability. In addition, experiments comparing the cellular and/or molecular effects of adding eCG to the P-36 treatment protocol are being conducted to elucidate the effects of superstimulatory protocols on the yield of viable embryos.

Alternate treatments of jacobian singularities in polar coordinates within finite-difference schemes

Jacobian singularities of differential operators in curvilinear coordinates occur when the Jacobian determinant of the curvilinear-to-Cartesian mapping vanishes, thus leading to unbounded coefficients in partial differential equations. Within a finite-difference scheme, we treat the singularity at the pole of polar coordinates by setting up complementary equations. Such equations are obtained by either integral or smoothness conditions. They are assessed by application to analytically solvable steady-state heat-conduction problems.

Treatments for invasive carcinoma of the cervix: What are their impacts on the pelvic floor functions?

Aims: Describe the impact of surgery, radiotherapy and chemoradiation in the pelvic floor functions in cervical cancer patients. Materials and Methods: A prospective study with women submitted to radical hysterectomy (RH) (n = 20),exclusive radiotherapy (RT) (n= 20)or chemoradiation (CT/RT)(n = 20)for invasive cervical cancer. Urinary, intestinal and sexual function, as well as vaginal length and pelvic floor musclecontraction were evaluated. Comparisons between groups were performed by Kruskal-Wallis and Chi-square tests (p < 0.05). Results: The groups were similar in stress urinary incontinence incidence (p = 0.56), urinary urgency (p = 0.44),urge incontinence (p = 0.54),nocturia(p = 0.53), incomplete bowel emptying (p = 0.76),bowel urgency(p = 0.12)and soilage(p = 0.43). The CT/ RT group presented a higher urinary frequency(p < 0.001)and diarrhea(p = 0.025). Patients in the RH group were more sexually active(p = 0.01) and experienced less dyspareunia (p = 0.021). Vaginal length was shorter in RT group (5.5 ± 1.9 cm) and CT/ RT(.3 ± 1.5 cm) than in the RH group (7.4 ± 1.1 cm) (p < 0.001). Pelvic floor muscle contraction was similar (p = 0.302). Conclusions: RT and CT/RT treatment for cervical carcinoma are more associated to sexual and intestinal dysfunctions.

Cost-effectiveness comparison between pituitary down-regulation with a gonadotropin-releasing hormone agonist short regimen on alternate days and an antagonist protocol for assisted fertilization treatments

Objective: To compare cost-effectiveness between pituitary down-regulation with a GnRH agonist (GnRHa) short regimen on alternate days and GnRH antagonist (GnRHant) multidose protocol on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcome. Design: Prospective, randomized. Setting: A private center. Patient(s): Patients were randomized into GnRHa (n = 48) and GnRHant (n = 48) groups. Intervention(s): GnRHa stimulation protocol: administration of triptorelin on alternate days starting on the first day of the cycle, recombinant FSH (rFSH), and recombinant hCG (rhCG) microdose. GnRHant protocol: administration of a daily dose of rFSH, cetrorelix, and rhCG microdose. Main Outcome Measure(s): ICSI outcomes and treatment costs. Result(s): A significantly lower number of patients underwent embryo transfer in the GnRHa group. Clinical pregnancy rate was significantly lower and miscarriage rate was significantly higher in the GnRHa group. It was observed a significant lower cost per cycle in the GnRHa group compared with the GnRHant group ($5,327.80 ± 387.30 vs. $5,900.40 ± 472.50). However, mean cost per pregnancy in the GnRHa was higher than in the GnRHant group ($19,671.80 ± 1,430.00 vs. $11,328.70 ± 907.20). Conclusion(s): Although the short controlled ovarian stimulation protocol with GnRHa on alternate days, rFSH, and rhCG microdose may lower the cost of an individual IVF cycle, it requires more cycles to achieve pregnancy. Clinical Trial Registration Number: NCT01468441. © 2013 by American Society for Reproductive Medicine.

Efeito do barbatimão verdadeiro (Stryphnodendron adstringens Mart.) Coville, na dieta de frango de corte

Pós-graduação em Zootecnia - FCAV

Aditivos fitogênicos e ácidos orgânicos em dietas de frangos de corte

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prospecção de biocida em plantas amazônicas e exóticas, visando seu uso racional

O principal método de controle do carrapato bovino Boophilus microplus é o uso de carrapaticidas sintéticos. Entretanto, o rápido desenvolvimento de resistência ao princípio ativo, os riscos de resíduo nos produtos de origem animal e a contaminação ambiental tem incentivado a busca por fontes alternativas de controle desse parasita. Dentro desse contexto, o uso de fitoterápicos aponta como uma alternativa no controle do carrapato, podendo reduzir os impactos econômicos e ambientais ao uso de produtos químicos sintéticos. Assim, o objetivo deste trabalho foi avaliar “in vitro” o efeito dos óleos essenciais de capim-salsar (Cymbopogon interanius Jowitt) e priprioca (Cyperus articulatus L.), substâncias químicas isoladas do timbó (Derris nicou; Derris urucu): rotenona, rotenolona e deguelina e óleos de andiroba (Carapa guianensis Aublet.) e nim (Azadirachta indica A. Juss.), no controle do carrapato. As pesquisas foram desenvolvidas nas instalações da Unidade de Pesquisa Animal “Sen. Álvaro Adolpho”, da Empresa Brasileira de Pesquisa Agropecuária – Embrapa Amazônia Oriental, no município de Belém, estado do Pará, no período de março a julho de 2008. As fêmeas ingurgitadas de Boophilus microplus foram colhidas manualmente, de bovinos naturalmente infestados, em propriedade particular localizada à uma hora de Belém. Após a coleta, foram transportadas para o laboratório em vasilhames plásticos, identificados, limpos e aerados. No laboratório, foram lavadas em água corrente, secas em papel absorvente e pesadas em balança analítica (precisão de 0,0001g). A metodologia utilizada foi a imersão de teleóginas por tempo de cinco minutos. Após a imersão, os carrapatos foram secos em papel absorvente, fixados em placas de Petri e mantidos em temperatura ambiente para realização da postura. Durante todo período experimental a temperatura e umidade relativa do ar em laboratório foi aferida com auxílio de um termohigrometro. O delineamento experimental utilizado foi o inteiramente casualizado. Os percentuais de mortalidade de fêmeas ingurgitadas de B. microplus ,no dia 5 e 15, variaram de: 45% a 90%; 37% a 90% e 60 a 90%; 60% a 90%, para capim-salsar e priprioca, respectivamente. Os resultados referentes a postura não evidenciaram diferença estatística entre as concentrações 2% e 10%, em relação ao controle (água + etanol). Entretanto, houve diferença na concentração 50%, tanto para capim-salsar quanto priprioca. Para capim-salsar, nesta concentração, foi observada postura de ovos inférteis. Com relação aos percentuais de eficiência do produto, os valores obtidos foram de: 100%; 95,63%; 98,77%; 100% e 99,30%; 96,97%; 99,85% e 100%, para os efeitos do óleo essencial de capim-salsar e priprioca nas concentrações 2%, 5%, 10%, 50%, respectivamente. As taxas de mortalidade, no dia 5, variaram de 37% a 41%, 49% a 64% e 52% a 41% para rotenona, rotenolona e deguelina, da menor para maior concentração, respectivamente. Todas as substâncias testadas apresentaram taxa de mortalidade significativamente maior do que as obtidas pelo grupo controle (água + etanol). Os melhores resultados de percentual da postura foram de 49% e 26% para rotenona e deguelina a 200ppm, respectivamente e 34% para rotenolona a 100ppm. Os percentuais de eficiência nos testes com rotenona foram de 95,24% e 98,68%, para rotenolona da ordem de 97,29%; 98,08%; 100% e deguelina 95,45%; 98,23% e 100%, em 100ppm, 200ppm e 300ppm, respectivamente. Para andiroba e nim, o percentual de mortalidade foi observado no dia 15 e demonstrou um comportamento natural do ciclo biológico dos carrapatos, pois não houve diferença estatística significativa entre o controle (água + etanol) e os tratamentos nas diferentes concentrações. Para andiroba e nim a maior eficiência obtida foi de 98,01% e 100%, na concentração de 50%, respectivamente.

Comparison of shear bond strength of orthodontics brackets on composite resin restorations with different surface treatments

INTRODUÇÃO: frequentemente, os pacientes ortodônticos apresentam restaurações de resina composta; no entanto, existem poucos estudos que avaliam a melhor forma de colagem ortodôntica nessa situação. OBJETIVO: o objetivo do presente trabalho foi avaliar a força adesiva de braquetes ortodônticos em restaurações resinosas com tratamento de superfície. MÉTODOS: foram utilizados 51 incisivos inferiores bovinos divididos aleatoriamente em três grupos. No grupo controle (GC), os braquetes foram colados em esmalte dentário; nos grupos experimentais com tratamento (GCT) e sem tratamento (GST), os braquetes foram colados em restauração de resina previamente realizada, diferenciando-se pelo tratamento de superfície com broca diamantada. Os dentes foram incluídos em tubos de PVC com resina acrílica autopolimerizável. O ensaio de cisalhamento foi executado em máquina universal de ensaios Emic. Os grupos foram submetidos à ANOVA com pós-teste de Tukey para verificação da diferença estatística entre os grupos (α = 0,05). RESULTADOS: GC (6,62MPa) e GCT (6,82MPa) apresentaram resultados semelhantes, enquanto o GST (5,07MPa) obteve resultados estatisticamente menores (p < 0,05). CONCLUSÃO: conclui-se que a melhor técnica de colagem de braquetes ortodônticos em restaurações de resina composta é a de realização de desgaste sobre a superfície.

Potencial de óleos essenciais de plantas para o tratamento de enfermidade em peixes

Pós-graduação em Aquicultura - FCAV

Stabilization of dentin matrix after cross-linking treatments, in vitro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efficacy of Surface Treatments on the Bond Strength of Resin Cements to Two Brands of Zirconia Ceramic

Purpose: To compare the shear bond strength (SBS) of two cements to two Y-TZP ceramics subjected to different surface treatments.Materials and Methods: Zirconia specimens were made from Lava (n = 36) and IPS e.max ZirCAD (n = 36), and their surfaces were treated as follows: no treatment (control), silica coating with 30-mu m silica-modified alumina (Al2O3) particles (CoJet Sand), or coating with liners Lava Ceram for Lava and Intensive ZirLiner for IPS e.max ZirCAD. Composite resin cylinders were bonded to zirconia with Panavia F or RelyX Unicem resin cements. All specimens were thermocycled (6000 cycles at 5 degrees C/55 degrees C) and subjected to SBS testing. Data were analyzed by post-hoc test Tamhane T2 and Scheffe tests (alpha = 0.05). Failure mode was analyzed by stereomicroscope and SEM.Results: With both zirconia brands, CoJet Sand showed significantly higher SBS values than control groups only when used with RelyX Unicem (p = 0.0001). Surface treatment with liners gave higher SBS than control groups with both ceramic brands and cements (p < 0.001). With both zirconia brands, the highest SBS values were obtained with the CoJet and RelyX Unicem combination (> 13.47 MPa). Panavia F cement showed significantly better results when coupled with liner surface treatment rather than with CoJet (p = 0.0001, SBS > 12.23 MPa). In untreated controls, Panavia F showed higher bond strength than RelyX Unicem; the difference was significant (p = 0.016) in IPS e.max ZirCAD. The nontreated specimens and those treated with CoJet Sand exhibited a high percentage of adhesive and mixed A (primarily adhesive) failures, while the specimens treated with liners presented an increase in mixed A and mixed C (primarily cohesive) failures as well as some cohesive failure in the bulk of Lava Ceram for both cements.Conclusion: CoJet Sand and liner application effectively improved the SBS between zirconia and luting cements. This study suggests that different interactions between surface treatments and luting cements yield different SBS: in clinical practice, these interactions should be considered when combining luting cements with surface treatments in order to obtain the maximum bond strength to zirconia restorations.