895 research outputs found
Maxillary Tuberosity Reconstruction with Transport Distraction Osteogenesis
Severe bone loss due to pathology in the maxillary tuberosity region is a challenging problem both surgically and prosthetically. Large bone grafts have a poor survival rate due to the delicate bony architecture in this area and presence of the maxillary sinus. Our case presentation describes a new technique for reconstructing severe bony defect in the maxillary tuberosity with horizontal distraction osteogenesis in a 45-year-old man. A 4 × 6 × 3 cm cyst was discovered in the left maxillary molar region and enucleated. Three months postoperatively, the area had a severe bone defect extending to the zygomatic buttress superiorly and hamular notch posteriorly. Three months later, a bone segment including the right upper second premolar was osteotomised and distracted horizontally. The bone segment was distracted 15 mm distally. After consolidation, implants were placed when the distractor was removed. A fixed denture was loaded over the implants after 3 months. Complete alveolar bone loss extending to the cranial base can be reconstructed with transport distraction osteogenesis. Distalisation of the alveolar bone segment adjacent to the bony defect is an easy method for reconstructing such severe defects
Efficiency of energy transfer in a light-harvesting system under quantum coherence
We investigate the role of quantum coherence in the efficiency of excitation
transfer in a ring-hub arrangement of interacting two-level systems, mimicking
a light-harvesting antenna connected to a reaction center as it is found in
natural photosynthetic systems. By using a quantum jump approach, we
demonstrate that in the presence of quantum coherent energy transfer and
energetic disorder, the efficiency of excitation transfer from the antenna to
the reaction center depends intimately on the quantum superposition properties
of the initial state. In particular, we find that efficiency is sensitive to
symmetric and asymmetric superposition of states in the basis of localized
excitations, indicating that initial state properties can be used as a
efficiency control parameter at low temperatures.Comment: Extended version of original paper. 7 pages, 2 figure
Effects of the topical hemostatic agent Ankaferd Blood Stopper on the incidence of alveolar osteitis after surgical removal of an impacted mandibular third molar
Background: Alveolar osteitis (AO) is a commonly seen post‑operative complication during the wound‑healing period after permanent tooth extraction or surgical removal of impacted third molar teeth.Objectives: The aim of this clinical study was to evaluate the effects of administration of the topical hemostatic agent Ankaferd Blood Stopper (ABS) into the socket on AO formation after impacted mandibular third molar extraction.Patients and Methods: Bilaterally, 100 half‑impacted mandibular third molars were extracted in 50 patients. Then, 1.0 mL ABS was administered to achieve hemostasis in one half of the sockets and as a control, the other half was irrigated with 1.0 mL physiological serum after surgery.Results: There was no statistically significant difference in terms of AO formation (P > 0.05) between the extraction sites. However, the postoperative pain in ABS administration sites was higher than in the other sites for the first 2 days after surgery (P < 0.05).Conclusions: The results showed that ABS administration did not increase the incidence of AO formation. Thus, ABS can be used safely for hemostasis after impacted mandibular third molar surgery.Key words: Alveolar osteitis, Ankaferd Blood Stopper, hemostasis, third mola
Embracing material surface imperfections in product design
Imperfection is not a usual aim within the context of industrialized product design. Under general norms, products are manufactured as
clones of a ‘perfect’ original and product surfaces are prized for their ‘perfect’ flawless state. The mass production of products against
these principles seems counterintuitive. Yet within the world of materials, and especially considering material surfaces, imperfection is
widespread. This research set out to identify and scrutinize circumstances when material imperfection in products is appreciated, from
mass manufacture to artisan practices. By synthesizing literature with analyses of material and product samples, five sources of surface
imperfections are characterized: inherent material properties, production effects, workmanship of risk, planned and foreseen events, and
everyday wear and tear. Following this, a research-focused concept design project is reported, leading to eleven product designs that
exemplify how to design for, and with, imperfect material surfaces. A significant challenge facing designers is one of persuasion: of
designing products where imperfect material surfaces are regarded as contributing to rather than detracting from product value. To this
end, the paper culminates in a visual guide to embracing material surface imperfections in design practice
Identification of illustrators
This paper is motivated by a book in which artists and illustrators from all over the world offer their personal interpretations of the declaration of human rights in pictures [1]. It was enthusiastic for a young reader to see an illustration of an artist that he already knows from his books . The characters were different, the topic was irrelevant, but still it was easy to identify the illustrators based on the style of the illustration. Inspired by the human's ability to identify illustrators, in this study we propose a method that can automatically learn to distinguish illustrations of different illustrators using computer vision techniques. © 2012 Springer-Verlag
On recognizing actions in still images via multiple features
We propose a multi-cue based approach for recognizing human actions in still images, where relevant object regions are discovered and utilized in a weakly supervised manner. Our approach does not require any explicitly trained object detector or part/attribute annotation. Instead, a multiple instance learning approach is used over sets of object hypotheses in order to represent objects relevant to the actions. We test our method on the extensive Stanford 40 Actions dataset [1] and achieve significant performance gain compared to the state-of-the-art. Our results show that using multiple object hypotheses within multiple instance learning is effective for human action recognition in still images and such an object representation is suitable for using in conjunction with other visual features. © 2012 Springer-Verlag
Distribution of entanglement in light-harvesting complexes and their quantum efficiency
Recent evidence of electronic coherence during energy transfer in
photosynthetic antenna complexes has reinvigorated the discussion of whether
coherence and/or entanglement has any practical functionality for these
molecular systems. Here we investigate quantitative relationships between the
quantum yield of a light-harvesting complex and the distribution of
entanglement among its components. Our study focusses on the entanglement yield
or average entanglement surviving a time scale comparable to the average
excitation trapping time. As a prototype system we consider the
Fenna-Matthews-Olson (FMO) protein of green sulphur bacteria and show that
there is an inverse relationship between the quantum efficiency and the average
entanglement between distant donor sites. Our results suggest that longlasting
electronic coherence among distant donors might help modulation of the
lightharvesting function.Comment: Version accepted for publication in NJ
Trapped Rydberg Ions: From Spin Chains to Fast Quantum Gates
We study the dynamics of Rydberg ions trapped in a linear Paul trap, and
discuss the properties of ionic Rydberg states in the presence of the static
and time-dependent electric fields constituting the trap. The interactions in a
system of many ions are investigated and coupled equations of the internal
electronic states and the external oscillator modes of a linear ion chain are
derived. We show that strong dipole-dipole interactions among the ions can be
achieved by microwave dressing fields. Using low-angular momentum states with
large quantum defect the internal dynamics can be mapped onto an effective spin
model of a pair of dressed Rydberg states that describes the dynamics of
Rydberg excitations in the ion crystal. We demonstrate that excitation transfer
through the ion chain can be achieved on a nanosecond timescale and discuss the
implementation of a fast two-qubit gate in the ion chain.Comment: 26 pages, 9 figure
Different patterns of pelvic ureteral endometriosis. What is the best treatment? Results of a retrospective analysis
Objective. Endometriosis is an estrogendependent disease. The incidence of urinary tract endometriosis (UE) increased during the last few years and, nowadays, it ranges from 0.3 to 12% of all women affected by the disease. The ureter is the second most common site affected. The ureteral endometriosis is classified in extrinsic and intrinsic. The aim of this study is to individuate the best treatments for each subset of ureteral endometriosis. Materials and Methods. 32 patients diagnosed with surgically treated UE were retrospectively reviewed. The patients were divided into 3 subsets (intrinsic UE, extrinsic UE with and without obstruction). The patients with intrinsic UE (n = 10) were treated with laser endoureterotomy. The patients with extrinsic UE (n = 22) were divided in two subsets with (n = 16) and without (n = 6) hydronephrosis. All the patients underwent ureteral stenting, and resection and reimplantation was performed in the first group, and when the mass was > 2.5 cm (n = 3) Boari flap was performed. Laparoscopic ureterolysis (shaving) was performed in the second group. Results. In the extrinsic subset of UE, we obtained an high therapeutic success (84%). Conversely, in the intrinsic subset there was a recurrence rate of the disease in 6/10 of the patients (60%). Conclusions. Ureterolysis seems to be a good treatment in extrinsic UE without obstruction. Resection and reimplantation allows excellent results in the extrinsic UE with obstruction. In the intrinsic subset, the endoureterotomy approach is inadequate
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