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Purpose: To examine the effect of controlled progressive orthodontic loading on bone around implants subjected to overloading forces. Materials and Methods: Bilateral edentulous alveolar ridges were created in the posterior maxilla of five beagle dogs and left to heal for an 8-week period, after which 40 implants were placed. In the overloading group (OL), 16 implants were inserted and left to osseointegrate for 16 weeks; impressions were made, and metal crowns were mounted on with supraocclusal contacts with the antagonist teeth. Implants were exposed to dynamic overloading for 16 weeks. In the progressive loading + overloading group (PL+OL), 16 implants were left to osseointegrate for 8 weeks, and custom abutment cores were fabricated and coupled by pairs with Ni-Ti orthodontic springs. Ascending static forces of 100g, 200g, and 300g were each applied for a 3-week period, for a total 9-week progressive loading period. Thereafter, metal crowns with supraocclusal contacts were adapted, and a 16-week overloading protocol for implants was followed as for the overloading group. In the unloaded control group (UL), eight implants were inserted and left uncovered and unloaded for 32 weeks, that is, until the end of the experimental period, at which point all 40 implants were removed with the surrounding bone. Histologic, histomorphometric, and statistical analysis followed. Results: Higher bone-to-implant contact percentage was reported for the OL group (P =.006) and PL+OL group (P

During the past few decades, there have been two parallel streams of driving behavior research: models using trajectory data collected from the field (using video recordings, GPS, etc.) and models using data from driving simulators (in which the behavior of the drivers is recorded in controlled laboratory conditions). Although the former source of data is more realistic, it lacks information about the driver and is typically not suitable for testing effects of future vehicle technologies and traffic scenarios. In contrast, driving behavior models developed with driving simulator data may lack behavioral realism. However, no previous study has compared these two streams of mathematical models and investigated the transferability of the models developed with driving simulator data to real field conditions in a rigorous manner. The current study aimed to fill this research gap by investigating the transferability of two car-following models between a driving simulator and two comparable real-life traffic motorway scenarios, one from the United Kingdom and the other one from the United States. In this regard, stimulus–response–based car-following models were developed with three microscopic data sources: (a) experimental data collected from the University of Leeds driving simulator, (b) detailed trajectory data collected from UK Motorway 1, and (c) detailed trajectory data collected from Interstate 80 in California. The parameters of these car-following models were estimated by using the maximum likelihood estimation technique, and the transferability of the models was investigated by using statistical tests of parameter equivalence and transferability test statistics. Estimation results indicate transferability at the model level but not fully at the parameter level for both pairs of scenarios.

Oxygen reduction has been studied at three different designs of Au/Nafion®-based all-solid amperometric sensors. These consisted of a planar-type sensor (PTS) with all electrodes sputtered on the same face of the Nafion® membrane, a capillary planar type sensor (CPTS) with the introduction of a cover bearing a capillary, and a sandwich-type sensor (STS) with the working and counter electrode layers deposited on different sides of the polymer electrolyte membrane. The response of all sensors depended heavily on humidity and the degree of Nafion® hydration but, unlike the CPTS and STS configurations, no signs of a limiting current were recorded during voltammetric experiments at an open PTS device, indicating the absence of a significant diffusion barrier in that case. All three simple and inexpensive polymerbased sensors compared well with a commercial fuel cell-type sensor, regarding their response to gaseous oxygen concentration changes.

Although salt rejection from sea ice is a key process in deep-water formation in ice-covered seas, the concurrent rejection of CO2 and the subsequent effect on air–sea CO2 exchange have received little attention. We review the mechanisms by which sea ice directly and indirectly controls the air–sea CO2 exchange and use recent measurements of inorganic carbon compounds in bulk sea ice to estimate that oceanic CO2 uptake during the seasonal cycle of sea-ice growth and decay in ice-covered oceanic regions equals almost half of the net atmospheric CO2 uptake in ice-free polar seas. This sea-ice driven CO2 uptake has not been considered so far in estimates of global oceanic CO2 uptake. Net CO2 uptake in sea-ice–covered oceans can be driven by; (1) rejection during sea–ice formation and sinking of CO2-rich brine into intermediate and abyssal oceanic water masses, (2) blocking of air–sea CO2 exchange during winter, and (3) release of CO2-depleted melt water with excess total alkalinity during sea-ice decay and (4) biological CO2 drawdown during primary production in sea ice and surface oceanic waters.

Purpose: To report a severe ocular complication initiated ten days after intravitreal administration of bevacizumab (Avastin®), in a patient with exudative age-related macular degeneration (AMD). Patients and method: Case report. Results: Ten days after intravitreal injection of 1.25 mg Avastin®, the patient manifested acute loss of vision with excruciating pain. An extensive choroidal detachment was evident in close contact with the lens, which necessitated an emergency sclerotomy with reconstruction of the anterior chamber. Four months later, the eye proceeded to phthisis bulbi. Five months after the injection, the patient complained of mild pain, photophobia, and visual acuity deterioration from the fellow eye. The diagnosis of sympathetic ophthalmia was suggested and treated with intravitreal injections of triamcinolone acetonide every three months with good response, complicated by elevation of intraocular pressure which we managed with Ahmet valve implantation. Conclusion: Serious ocular complications after intravitreal of Avastin® can not be excluded, including massive choroidal hemorrhage and sympathetic ophthalmia of the fellow eye. © 2009 Brouzas et al, publisher and licensee Dove Medical Press Ltd.

Purpose: To evaluate retinal thickness and function in eyes with tilted disc syndrome with optical coherence tomography (OCT) and multifocal electroretinogram (mfERG). Methods: Twenty-one eyes of 12 patients (4 males and 8 females) with tilted disc were studied with OCT3 and mfERG and compared with 40 eyes of 20 age and sex-matched control subjects. The thickness of the fovea and the thickness of retinal nerve fibre layer (RNFL) along a 3.4-mm-diameter circle centred on the optic nerve head were evaluated using OCT3. The macular cone function was tested by mfERG. Results: The OCT-derived RNFL thickness was significantly decreased in the superior area of eyes with tilted disc with a mean value equal to 106.47 μm (SD 24.1). The mean response amplitude density of the fovea (11.75 nV/deg2) and parafovea (8.22 nV/deg2) was significantly lower in eyes with tilted disc than in normal eyes. Conclusion: OCT and mfERG can be objective tools for assessing anatomical and functional damage of the macula. Our results suggest that in tilted disc syndrome even without visual impairment the optic nerve and the macula show dysfunction not visible by other means. © Springer-Verlag 2009.

The aim of the study was the histomorphometric comparison of the osteogenic potential of beta-tricalcium phosphate (beta-TCP) alone or in a calcium sulfate matrix. Three round defects, 10 mm (diameter) x 5 mm (depth), were created on each iliac crest of 4 dogs. The defects were divided into 3 groups. Ten defects were filled with beta-TCP in a calcium sulfate (CS) matrix (Fortoss Vital; group A), 10 defects were filled with beta-TCP alone (Fortoss Resorb; group B), and 4 defects were left ungrafted to heal spontaneously (group C). All defects were left to heal for 4 months without the use of a barrier membrane. Histologic evaluation and morphometric analysis of undecalcified slides was performed using the areas of regenerated bone and graft remnants. All sites exhibited uneventful healing. In group A sites (beta-TCP/CS), complete bone formation was observed in all specimens, graft granules dominated the area, and a thin bridge of cortical bone was covering the defect. Group B (beta-TCP) defects were partially filled with new bone, the graft particles still dominated the area, while the outer cortex was not restored. In the ungrafted sites (group C), incomplete new bone formation was observed. The outer dense cortical layer was restored in a lower level, near the base of the defect. The statistical analysis revealed that the mean percentage of new bone regeneration in group A was higher than in group B (49.38% and 40.31%, respectively). A statistically significant difference existed between the 2 groups. The beta-TCP/CS group exhibited significantly higher new bone regeneration according to a marginal probability value (P = .004 < .05). The use of beta-TCP in a CS matrix produced significantly more vital new bone fill and preserved bone dimensions compared with the use of beta-TCP alone.

Purpose: To report a case of a tilted disc syndrome associated with choroidal neovascularization. Methods: A 55-year-old male patient presented with blurred vision and metamorphopsia of the left eye. He underwent complete ophthalmologic examination, fluorescein angiography, optical coherence tomography (OCT) and multifocal-electroretinogram (mf-ERG). Results: All features are consistent with a tilted disc syndrome complicated with a small neovascular membrane. OCT confirmed the presence of a serous retinal detachment. Mf-ERG confirmed a decrease of electrical activity of the photoreceptors in area 1 (fovea). The patient refused to be treated. Conclusion: Macular serous retinal detachment due to subretinal leakage is a rare complication of tilted disc syndrome. To the author's knowledge, this is the first time a tilted disc syndrome with choroidal neovascularization is documented by means of OCT and mf-ERG. These are the only objective tools in order to assess objectively the anatomical and functional damage accordingly. © Springer-Verlag 2007.