Search results for "techniques"
showing 10 items of 4426 documents
Evaluation of consistency in spheroid invasion assays
2016
Multicellular tumor spheroids embedded in a matrix represent invaluable tools to analyze cell invasion. Spheroid sizes and invasiveness are the main observables easily measurable to evaluate effects of biological or pharmaceutical manipulations on invasion. They largely account for these 3-D platforms variability, leading to flaws in data interpretation. No method has been established yet that characterizes this variability and guarantees a reliable use of 3-D platforms. Spheroid initial/end sizes and invasiveness were systematically analyzed and compared in spheroids of U87MG cells generated by three different methods and embedded at different times in a collagen matrix. A normality test w…
On the performance of a linearized dual parallel Mach Zehnder electro-optic modulator
2014
The performance of a dual parallel differential Mach-Zehnder modulator broadband linearization architecture is analysed. This study provides experimental and analytical results showing an enhancement up to 20 dB in the 3rd-order intermodulation distortion factor at 5 GHz using RF and optical asymmetrical feeding factors.
Rapid hyperpolarization and purification of the metabolite fumarate in aqueous solution
2020
Significance Magnetic resonance imaging is hindered by inherently low sensitivity, which limits the method for the most part to observing water molecules in the body. Hyperpolarized molecules exhibit strongly enhanced MRI signals which opens the door for imaging low-concentration species in vivo. Biomolecules can be hyperpolarized and injected into a patient allowing for metabolism to be tracked in real time, greatly expanding the information available to the radiologist. Parahydrogen-induced polarization (PHIP) is a hyperpolarization method renowned for its low cost and accessibility, but is generally limited by low polarization levels, modest molecular concentrations, and contamination by…
Nonsurgical treatment of skeletal anterior open bite in adult patients: Posterior build-ups.
2016
ABSTRACT Objective: To (1) evaluate the efficacy of build-ups in the correction of anterior open bite in adults, (2) evaluate their efficacy in producing molar intrusion, (3) analyze skeletal and dental changes, and (4) assess the long-term stability. Materials and Methods: The sample consisted of 93 lateral cephalograms from 31 patients with skeletal and dental anterior open bite. The patients had received orthodontic treatment consisting of bonded resin blocks on the maxillary molars combined with Tip-Edge Plus bracket appliances. Cephalometric measurements were performed on radiographs taken before treatment (T1), after treatment (T2), and after a retention period (T3), which were analyz…
Molar distalization with pendulum appliances in the mixed dentition: effects on the position of unerupted canines and premolars.
2004
Introduction: The pendulum appliance allows for rapid molar distalization without the need for patient compliance. Its efficiency has been confirmed in a number of clinical studies. However, the potential interactions and positional changes between the deciduous molars used for dental anchorage and the erupted and unerupted permanent teeth have yet to be clarified when this appliance is used for molar distalization in the mixed dentition. Methods: Twenty-nine patients in the mixed dentition each received a modified pendulum appliance with a distal screw and a preactivated pendulum spring for bilateral distalization of the maxillary molars. The patients were divided into 4 groups based on de…
Movement evaluation of overerupted upper molars with absolute anchorage: an in-vitro study.
2010
Introduction: The overeruption of upper molars due to the premature loss of antagonist teeth can be treated with the help of miniscrews. The aim of this study was to evaluate the movement of a typodont molar according to the biomechanical approach used with miniscrews. Study design: The study was conducted with four plaster models filled with typodont wax. In each model we used one absolute anchorage on the palatal side and another on the buccal side in different positions, thus generating four different biomechanical systems. A force of 150 g was applied to each side of the resin tooth. Periapical radiographs were taken preintrusion and immediately after completion of the intrusion. Photog…
Hemostatic agents in endodontic surgery of maxillary molars : a randomized controlled pilot study of polytetrafluoroethylene (PTFE) strips as an adju…
2019
Background Hemostasis is of critical importance in endodontic surgery. Studies on bleeding control in maxillary molars are scarce. The present study compares the efficacy of two hemostatic techniques in controlling bleeding in endodontic surgery. Material and Methods A randomized two-arm pilot study involving 30 patients with peri-radicular lesions in maxillary molars (first and second molars) was carried out including the following hemostatic agents: polytetrafluoroethylene (PTFE) strips as an adjunct to epinephrine impregnated gauze (test group; n = 15) and aluminum chloride (Expasyl™) (control; n = 15). Bleeding control was independently assessed by the surgeon and by two blinded observe…
Immunohistochemical investigation on the pattern of vimentin expression in regenerated and intact monkey and human periodontal ligament.
2003
The expression of vimentin is well documented in the intact animal and human periodontal ligament (PDL), but there is limited information on the pattern of vimentin expression in the regenerated PDL. The aim of the present study was to investigate the pattern of vimentin expression in the regenerated and intact monkey and human PDL. A total of 12 chronic recession-type defects were created in three monkeys (Macaca fascicularis) and treated either with guided tissue regeneration (GTR), or with an enamel matrix protein derivative (EMD). After 5 months, the animals were sacrificed and specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded…
Effect of a plant-based hemostatic agent on microleakage of self-etching adhesives
2012
Objective: This in vitro study evaluated the effect of Ankaferd Blood Stopper (ABS) contamination on the micro-leakage of one-step and two-step self-etching adhesives.
Ultramorphology and dentine permeability changes induced by prophylactic procedures on exposed dentinal tubules in middle dentine
2010
Objectives: The purpose of this study was to evaluate the changes in dentinal permeability (i.e. hydraulic conductance) after prophylactic treatments performed using prophy-powders with air-polishing system or prophy-pastes on exposed middle dentine. The changes in dentine morphology were evaluated by SEM. Study design: Commercial prophylactic pastes and air-polishing powders were tested in this study. Dentine discs from human third molars were used to study the quantitative reduction of the dentine permeability under simulated pulpal pressure (20 cm H 2O). Further specimens were gold-coated and analysed using observed a SEM. Results: The results of this study showed different dentine perme…