998 research outputs found

    Anatomical characteristics of the lingual foramen in ancient skulls: a cone beam computed tomography study in an Anatolian population

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    Background: The purpose of this study is to evaluate the anatomical features of lingual foramina and their bony canals in Anatolian ancient mandibles (9–10th century) by using cone beam computed tomography (CBCT). Materials and methods: Fifty-eight ancient dry mandibles were scanned with CBCT. Lingual foramina were grouped into midline, paramedian, posterior foramina and combination of these groups. Midline group was also classified according to internal surface of the mandible (gonial tubercles [GTs]). The incidence, vertical distance and diameter of lingual foramina were measured according to age groups and gender. Results: The incidence of the lingual foramen was 96.6%. Midline of the symphysis had the highest incidence (34.4%) of foramina (p < 0.05), followed by both midline and paramedian type (32.8%; p < 0.05). Classification in terms of GT represented class 3 as the most encountered group (28.6%). Number of foramina observed in the mandibles ranged from 0 to 6 with the incidence of 3.4% and 32.8%, respectively. The male and < 35 years groups presented larger measurement values in midline region (p < 0.05). Conclusions: Mandibular lingual foramina and bony canals are frequently present in ancient mandibles. When compared with modern subjects, similar findings are observed according to published literatures. CBCT is also proved to be an effective imaging modality in the detection of lingual foramina and canals in anthropological studies

    Assessment of paranasal sinus parameters according to ancient skulls’ gender and age by using cone-beam computed tomography

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    Background: The aim of this study was to determine whether paranasal sinus dimensions and volume can be useful to identify gender and age estimation for ancient skulls using cone-beam computed tomography (CBCT) images.  Materials and methods: CBCT scans of 32 ancient skulls of approximately 1000 years of age were included in this retrospective study. The gender and age estimation of the skulls were made by an independent anthropologist, which was considered as the gold standard. Paranasal sinuses’ dimensions (width and height) and volumes of each sinus were measured from the CBCT data set that was linked to the three-dimensional rendering software (Anatomage, Invivo 5.2). All measurements were performed by an independent observer. Intra-observer analysis was made. Mann-Whitney and Kruskal-Wallis tests were used to compare paranasal sinus parameters in terms of age estimation and gender (p < 0.05).  Results: The results demonstrated no statistically significant difference between measurements (p < 0.05). The measurements were found to be highly reprodu- cible. The mean volumes of frontal and sphenoid sinus were found to be higher in males. The distance from anterior-posterior wall of sphenoid sinus in axial sec- tions is larger in males (p > 0.05). The frontal sinus width and volume increased statistically with age above 60 years of age (p > 0.05).  Conclusions: The paranasal volume and dimensions’ measurements from CBCT data can be a promising technique to determine gender and age of ancient skulls because of its lower voxel sizes and higher resolution.

    An anatomical variant: evaluation of accessory canals of the canalis sinuosus using cone beam computed tomography

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    Background: The anatomical variation of the anterior superior alveolar nerve described as canalis sinuosus (CS) is a less known structure of anterior maxilla. Due to the fact that it contains anterior superior alveolar nerve as well as veins and arteries, exact localisation of this structure will allow surgeons to avoid complications. Hence, the aim of this study was to verify the presence, reveal the frequency and characteristics of accessory canals of CS.Materials and methods: This study was based on retrospective evaluation of cone beam computed tomography (CBCT) scans. A total of 1460 CBCT images were analysed and collected data were noted. The following parameters were recorded: age, sex, presence or absence of CS, location in relation to the adjacentteeth and impaction of canine teeth.Results: A total of 6668 accessory canals were found in 1460 CBCT images. Of these, 672 (46.0%) were from female patients, and 788 (54.0%) were from male patients. 1034 (70.8%) of 1460 images had at least one accessory canal of CS. Maxillary intercentral region is the area where accessory canals were seen mostfrequently (n = 653, 44.72%).Conclusions: Canalis sinuosus is a bony canal which is incidentally found and less known structure of anterior portion of maxilla. Knowing the accessory canals deriving from this structure will allow surgeons to avoid complications and non-integration after dental implant procedures. Conventional imaging modalities have limited value in detecting this neurovascular structures. Therefore CBCT may have an important role for accurate diagnosis to reveal anatomical variations

    Effect of Ankaferd Blood Stopper on Early Bone Tissue Healing in Extraction Sockets: An Experimental In vivo Study

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    Purpose: To investigate the effect of Ankaferd blood stopper (ABS) on early bone healing of extraction sockets in rats.Method: Twenty-eight male Wistar rats were divided into four groups. The maxillary right first molar tooth of the rats was extracted under general anesthesia. Two groups (C-1, n = 6 and C-2, n = 6) received saline solutions in the extraction sockets immediately and one day after the extraction, respectively, while two groups (A-1, n = 8 and A-2, n = 8) received ABS. The rats in A-1 and C-1 groups were sacrificed after 7 days of post-extraction while the rats in A-2 and C-2 groups were sacrificed after 28 days. Bone samples were taken from the maxillas, and tissues were prepared for histopathological analysis. Osteoid tissue (OT), mineralized bone tissue (MT), remaining area (RA), and inflammatory cell infiltration (ICI) were determined. The histomorphometric results were analyzed statistically using analysis of variance (ANOVA).Results Osteoid formation was highest in C-1 group (39.71 ± 9.68, p < 0.05). Differences in OT among other groups were not significant (p > 0.05). MT was higher in C-2 group (47.73 ± 12.15) than in other groups (p < 0.05). RA was highest in C-1 group (59.95 ± 12.75). ICI was significantly lower in control (C1 and C-2) groups than in ABS (A-1 and A-2) groups (p < 0.05).Conclusion: ABS administered topically to extraction sockets immediately after extraction has no effect on bone healing; in fact, ABS increases inflammation in vivo

    Three-dimensional volumetric analysis of the maxillary sinus: a cone-beam computed tomography study

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    Background: This study aimed to determine the volumetric size of the maxillary sinus and investigate the effect of gender and age on maxillary sinus volume (MSV) using cone-beam computed tomography (CBCT) images in a Turkish subpopulation. Materials and methods: This retrospective volumetric CBCT study was carried out on 133 individuals (84 females, 49 males) between 8 and 51 years old. MSV was measured using the MIMICS 21.0 software (Materialise HQ Technologielaan, Leuven, Belgium). All statistical analyses were performed using the SPSS 21.0 (SPSS, Chicago, IL, USA) software. Mean and standard deviation of both maxillary sinuses measurements were calculated and compared to gender and age. P values < 0.05 were considered to indicate statistical significance. Results: Mean volume of the right maxillary sinus was 13.173 cm3, while for the left was 13.194 cm3. There was no significant difference between right and left maxillary sinus volumes (p > 0.05). There was no significant correlation between MSV and age (p > 0.05). It was found that MSV did not change according to gender (p > 0.05). Conclusions: Right and left maxillary sinus volumes were not different from each other. Gender and age were not found to be related to maxillary sinus volume

    Numerical simulation of small perturbation on an accretion disk due to the collision of a star with the disk near the black hole

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    In this paper, perturbations of an accretion disk by a star orbiting around a black hole are studied. We report on a numerical experiment, which has been carried out by using a parallel-machine code originally developed by D\"{o}nmez (2004). An initially steady state accretion disk near a non-rotating (Schwarzschild) black hole interacts with a "star", modeled as an initially circular region of increased density. Part of the disk is affected by the interaction. In some cases, a gap develops and shock wave propagates through the disk. We follow the evolution for order of one dynamical period and we show how the non-axisymetric density perturbation further evolves and moves downwards where the material of the disk and the star become eventually accreted onto the central body. When the star perturbs the steady state accretion disk, the disk around the black hole is destroyed by the effect of perturbation. The perturbed accretion disk creates a shock wave during the evolution and it loses angular momentum when the gas hits on the shock waves. Colliding gas with the shock wave is the one of the basic mechanism of emitting the XX-rays in the accretion disk. The series of supernovae occurring in the inner disk could entirely destroy the disk in that region which leaves a more massive black hole behind, at the center of galaxies.Comment: 20pages, 8 figures, accepted for publication in Astrophysics and Space Scienc

    A review of rapid serial visual presentation-based brain-computer interfaces

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    International audienceRapid serial visual presentation (RSVP) combined with the detection of event related brain responses facilitates the selection of relevant information contained in a stream of images presented rapidly to a human. Event related potentials (ERPs) measured non-invasively with electroencephalography (EEG) can be associated with infrequent targets amongst a stream of images. Human-machine symbiosis may be augmented by enabling human interaction with a computer, without overt movement, and/or enable optimization of image/information sorting processes involving humans. Features of the human visual system impact on the success of the RSVP paradigm, but pre-attentive processing supports the identification of target information post presentation of the information by assessing the co-occurrence or time-locked EEG potentials. This paper presents a comprehensive review and evaluation of the limited but significant literature on research in RSVP-based brain-computer interfaces (BCIs). Applications that use RSVP-based BCIs are categorized based on display mode and protocol design, whilst a range of factors influencing ERP evocation and detection are analyzed. Guidelines for using the RSVP-based BCI paradigms are recommended, with a view to further standardizing methods and enhancing the inter-relatability of experimental design to support future research and the use of RSVP-based BCIs in practice

    Nuclear medicine procedures and the evaluation of male sexual organs: a short review

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    Sexuality consists of three aspects that are interrelated and inseparable, biological, physiological and social. The biological aspect considers the individual's capability to give and to receive pleasure. In consequence, it covers the functionality of the sexual organs and the physiology of human sexual response cycle. Diagnostic imaging modalities, such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) have been used to evaluate clinical disorders of the male reproductive system. PET and SPECT procedures basically involve the administration of a radiopharmaceutical that has a higher uptake in a specific tumor or tissue. The aim of this brief review is to present some radiopharmaceuticals that have been used in the clinical evaluation of the male sexual organs (testes, prostate, seminal vesicles, penis) related with male sexuality. This information could be useful in better understanding the male sexual response cycle, as well as the sexual disorders, when considering the male sexual organs and the pelvic floor. Moreover, the findings obtained with PET and SPECT imaging could help to evaluate the efficacy of clinical results of therapeutic procedures. In conclusion, the knowledge from these images could aid in better understanding the physiology of the different organs related with sexuality. Furthermore, they could be important tools to evaluate the physiological integrity of the involved organs, to improve clinical strategies and to accompany the patients under treatment

    Ba3Ga3N5 - A Novel Host Lattice for Eu2+ - Doped Luminescent Materials with Unexpected Nitridogallate Substructure

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    The alkaline earth nitridogallate Ba3Ga3N5 was synthesized from the elements in a sodium flux at 760°C utilizing weld shut tantalum ampules. The crystal structure was solved and refined on the basis of single-crystal X-ray diffraction data. Ba3Ga3N5 (space group C2/c (No. 15), a = 16.801(3), b = 8.3301(2), c = 11.623(2) Å, β = 109.92 (3)°, Z = 8) contains a hitherto unknown structural motif in nitridogallates, namely, infinite strands made up of GaN4 tetrahedra, each sharing two edges and at least one corner with neighboring GaN4 units. There are three Ba2+ sites with coordination numbers six or eight, respectively, and one Ba2+ position exhibiting a low coordination number 4 corresponding to a distorted tetrahedron. Eu2+ - doped samples show red luminescence when excited by UV irradiation at room temperature. Luminescence investigations revealed a maximum emission intensity at 638 nm (FWHM =2123 cm−1). Ba3Ga3N5 is the first nitridogallate for which parity allowed broadband emission due to Eu2+ - doping has been found. The electronic structure of both Ba3Ga3N5 as well as isoelectronic but not isostructural Sr3Ga3N5 was investigated by DFT methods. The calculations revealed a band gap of 1.53 eV for Sr3Ga3N5 and 1.46 eV for Ba3Ga3N5

    Production of Doubly Charged Higgs Bosons at Linear e-e- Colliders

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    Production of doubly charged Higgs bosons via the s-channel process e-e- -> H-- -> l-l- at future linear collider energies is studied by taking into account initial state radiation (ISR) and beamstrahlung (ISR + BS), final state radiation (FSR) and detector smearing effects. The discovery bounds of lepton flavour conserving and violating couplings are obtained for doubly charged Higgs bosons. It is found that future linear colliders with centre of mass energies and will be able to probe the doubly charged Higgs bosons with diagonal couplings down to 10^-4 and 10^-3, respectively.Comment: 22 pages, 12 figures, 4 table
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