Study of the carbon dioxide chemical fixation-activation by guanidines

Fixation of CO2 is one of the most important priorities of the scientific community dedicated to reduce global warming. In this work, we propose new methods for the fixation of CO2 using the guanidine bases tetramethylguanidine (TMG) and 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]-pyrimidine (TBD). In order to understand the reactions occurring during the CO2 fixation and release processes, we employed several experimental methods, including solution and solid-state NMR, FTIR, and coupled TGA-FTIR. Quantum mechanical NMR calculations were also carried out. Based on the results obtained, we concluded that CO2 fixation with both TMG and TBD guanidines is a kinetically reversible process, and the corresponding fixation products have proved to be useful as transcarboxylating compounds. Afterward, CO2 thermal releasing from this fixation product with TBD was found to be an interesting process for CO2 capture and isolation purposes. (C) 2008 Elsevier Ltd. All rights reserved.

Selectivity of the cyclic carbonate formation by fixation of carbon dioxide into epoxides catalyzed by Lewis bases

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Extraocular muscle fixation to porous polyethylene orbital implants using 2-octyl-cyanoacrylate

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Serological profile of buffalo (Bubalus bubalis) female calves vaccinated with standard Brucella abortus strain 19 vaccine using rose bengal, 2-mercaptoethanol and complement fixation tests

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Miniplate fixation for the repair of segmental mandibular defects filled with autogenous bone in cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Miniplate 1.5 fixation for the repair of mandibular osteotomies in cats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Which kind of miniplate to use in mandibular sagittal split osteotomy? An in vitro study

This study verified the resistance to displacement of six miniplate fixation methods after sagittal split osteotomy (SSO). SSO was performed in 30 polyurethane synthetic mandible replicas. The distal segments were advanced (4 mm) and specimens were grouped according to the fixation method: four-hole standard miniplate; four-hole locking miniplate; six-hole standard miniplate; six-hole locking miniplate; six-hole standard sagittal miniplate; six-hole locking sagittal miniplate. Biomechanical evaluation was performed by applying compression loads to three points on the second molar region, using an Instron universal testing machine until a 3 mm displacement of the segments occurred. Compression loads able to produce 3 mm displacement were recorded in kN and subjected to analysis of variance (P < 0.01) and Tukey's tests for comparison between groups (P < 0.05). The locking sagittal miniplate showed higher resistance to displacement than the regular four- and six-hole locking and standard miniplates. No significant differences were observed between the locking sagittal miniplate and the regular sagittal or the four-hole locking miniplates. Two of the three groups with the best results had locking plate fixation methods. Fixation of SSO with a single miniplate is better accomplished using six-hole locking sagittal miniplates, six-hole standard sagittal miniplates, or four-hole locking miniplates; these methods are more resistant to displacement.

Hyperbaric oxygen therapy treatment for the fixation of implant prosthesis in oncology patients irradiated

doi: 10.1111/j.1741-2358.2012.00636.x Hyperbaric oxygen therapy treatment for the fixation of implant prosthesis in oncology patients irradiated Objectives: This study aimed to present a clinical report of an irradiated oncologic patient who underwent hyperbaric oxygen therapy to be rehabilitated with implant-supported prosthesis. Materials and Methods: A 67-year-old man was admitted at Oral Oncology Center (FOA-UNESP) presenting a lesion on the mouth floor. After clinical evaluation, incisional biopsy and histopathological exam, a grade II squamous cell carcinoma was diagnosed. The patient was subjected to surgery to remove the lesion and partial glossectomy. Afterwards, the radiotherapy, in the left/right cervicofacial area of the supraclavicular fossa, was conducted. After 3 years of the surgery, the patient was submitted to hyperbaric oxygen therapy. Then, four implants were installed in patients mandible. Five months later, an upper conventional complete denture and lower full-arch implant-supported prosthesis were fabricated. Conclusion: The treatment resulted in several benefits such as improving his chewing efficiency, swallowing and speech, less denture trauma on the mucosa and improving his self-esteem.

Avaliação da alteração do plano oclusal em cirurgias ortognáticas combinadas com utilização de fixação interna rígida em pacientes com padrão facial de Classe II

OBJETIVO: avaliar a estabilidade de cirurgias bimaxilares com fixação interna rígida, na qual promoveu-se uma rotação anti-horária da mandíbula e conseqüente redução do ângulo do plano oclusal. METODOLOGIA: foram estudados 15 pacientes com padrão facial de Classe II e deficiência mandibular. Os movimentos cirúrgicos foram avaliados por meio de medidas lineares e angulares realizadas no programa CefX, obtidas de telerradiografias cefalométricas em norma lateral em três diferentes tempos: (T0) pré-operatório, (T1) pós-operatório imediato e (T2) pós-operatório de no mínimo 6 meses. RESULTADOS E CONCLUSÕES: os resultados demonstraram que a cirurgia bimaxilar promove mudanças faciais significativas e, principalmente, que a rotação anti-horária da mandíbula com redução do ângulo do plano oclusal mostrou-se estatisticamente estável, sendo uma opção confiável em cirurgias de pacientes com padrão facial de Classe II com deficiência mandibular.

Early Bone Healing and Biomechanical Fixation of Dual Acid-Etched and As-Machined Implants with Healing Chambers: An Experimental Study in Dogs

Purpose: To evaluate the biomechanical fixation, bone-to-implant contact (BIC), and bone morphology of screw-type root-form implants with healing chambers with as-machined or dual acid-etched (DAE) surfaces in a canine model. Materials and Methods: The animal model included the placement of machined (n = 24) and DAE (n = 24) implants along the proximal tibiae of six mongrel dogs, which remained in place for 2 or 4 weeks. Following euthanasia, half of the specimens were subjected to biomechanical testing (torque to interface failure) and the other half were processed for histomorphologic and histomorphometric (%BIC) assessments. Statistical analyses were performed by one-way analysis of variance at the 95% confidence level and the Tukey post hoc test for multiple comparisons. Results: At 4 weeks, the DAE surface presented significantly higher mean values for torque to interface failure overall. A significant increase in %BIC values occurred for both groups over time. For both groups, bone formation through the classic appositional healing pathway was observed in regions where intimate contact between the implant and the osteotomy walls occurred immediately after implantation. Where contact-free spaces existed after implantation (healing chambers), an intramembranous-like healing mode with newly formed woven bone prevailed. Conclusions: In the present short-term evaluation, no differences were observed in BIC between groups; however, an increase in biomechanical fixation was seen from 2 to 4 weeks with the DAE surface. INT J ORAL MAXILLOFAC IMPLANTS 2011;26:75-82

In vitro comparison of 1.5 mm vs. 2.0 mm screws for fixation in the sagittal split osteotomy

Purpose: Numerous "in vitro" investigations have been conducted to evaluate the role of screw size and pattern in determining optimal resistance to deformation, often these have been controversial. The aim of this study was to evaluate the effect of screw size and insertion technique on the stability of sagittal split osteotomies.Materials and methods: This study used twenty polyurethane replicas of human hemimandibles with a prefabricated sagittal split ramus osteotomy (SSRO). The hemimandibles were stabilized with 1.5 mm and 2.0 mm titanium screws inserted in an inverted L configuration. All specimens were tested to determine the strength and stability of the fixation.Results: In all cases there was failure of the synthetic bone before there was any evidence of screw failure. There were no significant differences in the load necessary to make the construct fail between the 1.5 or 2.0 mm screw sizes.Conclusion: There was no statistically significant difference between the strengths achieved with screws of 1.5 and 2.0 mm diameters for fixation of SSRO performed in synthetic mandibles. There was no fracture of the 1.5 mm or 2.0 mm diameter screws in any of the tests. 1.5 mm diameter screws in an inverted L pattern have as much stability and mechanical resistance as a 2.0 mm screw, may be safely used for this procedure. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.

Use of Rectangular Grid Miniplates for Fracture Fixation at the Mandibular Angle

Purpose: The aim of this study was to evaluate the clinical outcome of patients with mandibular angle fractures treated by intraoral access and a rectangular grid miniplate with 4 holes and stabilized with monocortical screws.Patients and Methods: This study included 45 patients with mandibular angle fractures from the Department of Oral and Maxillofacial Surgery São Paulo State University, Araraquara, Brazil, and from the Clinic of Oral and Maxillofacial Surgery at the University of Frankfurt, Germany. The 45 fractures of the mandibular angle were treated with a rectangular grid miniplate of a 2.0-mm system by an intraoral approach with monocortical screws. Clinical evaluations were postoperatively performed at 15 and 30 days and 3 and 6 months, and the complications encountered were recorded and treated.Results: The infection rate was 4.44% (2 patients), and in 1 patient it was necessary to replace hardware. This patient also had a fracture of the left mandibular body; 3 patients (6.66%) had minor occlusal changes that have been resolved with small occlusal adjustments. Before surgery, 15 patients (33.33%) presented with hypoesthesia of the inferior alveolar nerve; 4 (8.88%) had this change until the last clinical control, at 6 months.Conclusions: The rectangular grid miniplate used in this study was stable for the treatment of simple mandibular angle fractures through intraoral access, with low complication rates, easy handling, and easy adjustment, with a low cost. Concomitant mandibular fracture may increase the rate of complications. This plate should be indicated in fractures with sufficient interfragmentaty contact. (C) 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 69:1436-1441, 2011

Intermaxillary fixation as co-adjuvant treatment for morbid obesity

Background: the effective long-term treatments for morbid obesity is bariatric surgery. However, the associated surgical and anesthetic risks led the authors to evaluate intermaxillary fixation, a less aggressive procedure, as a preoperative treatment in selected patients with morid obesity.Methods: 22 patients (5 male, 17 female, ages 16-53 years, with BMI 44.9 +/- 5.4 kg/m(2)) underwent intermaxillary fixation. The procedure consisted of fitting brackets on the front face of the teeth and posterior application of elastic bands to impede mouth opening.Results: At the end of 6 weeks, weight loss was 7.4 +/- 2.6% there was general improvement in lipid profile, glycemia, and blood pressure. There was no recorded discomfort, pain, or any other difficulty during this treatment.Conclusion: Intermaxillary fixation can be used as a pre-surgical solution for weight reduction in preparation for bariatric surgery, improving co-morbid aspects such as blood pressure, glycemia, and lipid profile.

Short-Term Effects of the Use of Non-Rigid Tools for Postural Control by Adults with Intellectual Disabilities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biomechanical in vitro evaluation of three stable internal fixation techniques used in sagittal osteotomy of the mandibular ramus: a study in sheep mandibles

Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR) is the most common, allowing a great range of movements and stable internal fixation (SIF), therefore eliminating the need of maxillomandibular block in the postoperative period. Objectives: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. Material and methods: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group). In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group). In group III, fixation was performed with two-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group). All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. Results: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. Conclusion: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR.