218 research outputs found
RIBBONS: Rapid Inpainting Based on Browsing of Neighborhood Statistics
Image inpainting refers to filling missing places in images using neighboring
pixels. It also has many applications in different tasks of image processing.
Most of these applications enhance the image quality by significant unwanted
changes or even elimination of some existing pixels. These changes require
considerable computational complexities which in turn results in remarkable
processing time. In this paper we propose a fast inpainting algorithm called
RIBBONS based on selection of patches around each missing pixel. This would
accelerate the execution speed and the capability of online frame inpainting in
video. The applied cost-function is a combination of statistical and spatial
features in all neighboring pixels. We evaluate some candidate patches using
the proposed cost function and minimize it to achieve the final patch.
Experimental results show the higher speed of 'Ribbons' in comparison with
previous methods while being comparable in terms of PSNR and SSIM for the
images in MISC dataset
Microhardness of demineralized enamel following home bleaching and laser-assisted in office bleaching
Background: There is little data regarding the effect of tooth whitening on microhardness of white spot lesions.
This study was conducted to investigate the effect of home-bleaching and laser-assisted in-office bleaching on microhardness of demineralized enamel.
Material and Methods: Forty bovine incisors were selected and immersed in a demineralizing solution for 12 weeks
to induce white spot lesions. Enamel blocks were prepared and randomly assigned to two groups of 20 each. The
first group underwent home bleaching with 15% carbamide peroxide which was applied for 8 hours a day over a
period of 15 days. In the second group, in-office bleaching was performed by 40% hydrogen peroxide and powered by irradiation from an 810 nm gallium-aluminum-arsenide (GaAlAs) diode laser (CW, 2W). This process was
performed for 3 sessions every seven days, in 15 days. The specimens were stored in Fusayama Meyer artificial
saliva during the experiment. Surface microhardness was assessed before and after the bleaching therapies in both
groups.
Results: Microhardness decreased significantly following both home bleaching and laser-assisted in-office bleaching (
p
<0.05). There were no significant differences in hardness values among the two groups either before
(
p
=0.131) or after (
p
=0.182) the bleaching procedures.
Conclusions: Tooth whitening through home bleaching or laser-assisted in-office bleaching can result in a significant reduction in microhardness of white spot lesions. Therefore, it is suggested to take protective measures on
bleached demineralized enamel
Image Inpainting by Hyperbolic Selection of Pixels for Two Dimensional Bicubic Interpolations
Image inpainting is a restoration process which has numerous applications.
Restoring of scanned old images with scratches, or removing objects in images
are some of inpainting applications. Different approaches have been used for
implementation of inpainting algorithms. Interpolation approaches only consider
one direction for this purpose. In this paper we present a new perspective to
image inpainting. We consider multiple directions and apply both
one-dimensional and two-dimensional bicubic interpolations. Neighboring pixels
are selected in a hyperbolic formation to better preserve corner pixels. We
compare our work with recent inpainting approaches to show our superior
results
Comparison of the Efficacy of Educational Film and Clinical Demonstration for Instruction of Fiber-Reinforced Composite Post Restorations to Dental Students
Objective: Different educational tools are now commonly used in universities worldwide such as illustrations, audio and videotapes, etc. This study aimed to compare the efficacy of educational film and clinical demonstration for instruction of Fiber-Reinforced Composite (FRC) post restorations to dental students in Department of Restorative Dentistry.Methods: This interventional study was conducted on 70 fifth year dental students in Mashhad University. Students were divided into two groups. Group 1 students watched live demonstration of a treatment procedure (FRC post restoration) while group 2 watched the educational film of the same procedure. Both groups participated in a post-test. Also, students' perspectives were sought via a questionnaire. Data were analyzed using SPSS, Student’s t-test and Chi-square test.Results: The mean post-test score of group 2 students (educational film) was greater than that of group 1 students (clinical demonstration) and the difference in this respect between the two groups was statistically significant (p=0.008). Considering the score of 7 as an acceptable score, 44 students gained scores 7 or higher; out of which, 16 were in group 1 (clinical demonstration) and 28 were in group 2 (educational film). The difference in this regard between the two groups was statistically significant (p=0.003). Most students preferred watching the educational film to the crowded clinical demonstration sessions.Conclusion: Watching the educational film yielded greater test scores than the clinical demonstration
Phytochemical analysis of some plants from Lamiaceae family frequently used in folk medicine in Aligudarz region of Lorestan Province Lorestan ilinin Aligudarz bölgesinde halk ilaci olarak sikça kullanilan Lamiaceae familyasindan bazi bitkilerin fitokimyasal analizi
Many of the plants from the Lamiaceae family have been
traditionally used as medicine all over the world. Also, some
of the secondary metabolites isolated from this family have
shown interesting biological function. In this study we have
analyzed phytochemicals of some plants from Lamiaceae family
frequently used in folk medicine in Aligudarz region of Lorestan
province. In this regard, the plant species were collected and
systematically identified during 2014-2015. The traditional and
local uses of collected plants were questioned through informed
consent semi-structured interviews with local informants.
Phytochemical analysis was conducted to test the presence of
compounds such as alkaloids, flavonoids, saponins, tannins,
anthraquinone and glycosides. 25 plant species belonging to
13 genes were collected and identified. The most uses of the
plants were in treating cold, gastrointestinal disorders and
as flavoring agents. From 25 plant species, a number of 23
species had tannin, 22 species exhibited positive reactions to
flavonoids, 4 species showed positive reactions to alkaloids and
1 species exhibited positive reactions to saponins. This research
has provided insights on the use of secondary metabolites in
folk medicine for promotion of appropriate human health. The
studied plants in this article can be seen as a potential source for
discovering new drugs
Comparison of Tooth Discoloration Induced by Calcium-Enriched Mixture and Mineral Trioxide Aggregate
Introduction: The aim of this in vitro study was to evaluate the tooth discoloration induced by calcium-enriched mixture (CEM) cement and mineral trioxide aggregate (MTA). Methods and Materials: Forty five endodontically treated human maxillary central incisors were selected and divided into three groups (n=15) after removing the coronal 3 mm of the obturating materials. In the MTA group, white MTA plug was placed in pulp chamber and coronal zone of the root canal. In CEM cement group, CEM plug was placed in the tooth in the same manner. In both groups, a wet cotton pellet was placed in the access cavity and the teeth were temporarily sealed. After 24 h the teeth were restored with resin composite. In the negative control group the teeth were also restored with resin composite. The color change in the cervical third of teeth was measured with a colorimeter and was repeated 3 times for each specimen. The teeth were kept in artificial saliva for 6 months. After this period, the color change was measured again. Data were collected by Commission International de I'Eclairage's L*a*b color values, and corresponding ΔE values were calculated. The results were analyzed using the one-way ANOVA and post-hoc Tukey’s test with the significance level defined as 0.05. Results: There was no significant differences between CEM group and control group in mean discoloration. The mean tooth discoloration in MTA group was significantly greater than CEM and control groups (P<0.05). Conclusion: According to the result of the present study CEM cement did not induce tooth discoloration after six months. Therefore it can be used in vital pulp therapy of esthetically sensitive teeth.Keywords: Calcium-Enriched Mixture; Dental Cements; Mineral Trioxide Aggregate; Tooth Discoloration; Vital Pulp Therap
Multiple Crack Detection using Wavelet Transforms and Energy Signal Techniques
Wavelet transforms are efficient tools for structural health monitoring (SHM) and damage detection. However, these methods are encountered with some limitations in practice. Thus, signal energy analysis is used as an alternative technique for damage detection. In this paper, discrete wavelet transforms (DWT) and Teager energy operator (TEO) is applied to the curvature of the mode shapes of the beams, and the locations of the damages are identified. The results show that in comparison with the discrete wavelet transform, the signal energy operator has better performance. This superiority in detecting the damages, especially near the supports of the beam, is obvious and has enough sensitivities in low damage intensities. Additionally, the damage detection in the cases that the response data are noisy is investigated. For this purpose, by adding low-intensity noises to the curvature of the mode shapes, the abilities of the mentioned methods are evaluated. The results indicate that each method is not individually efficient in the detection of damages in noisy conditions, but the combination of them under noisy conditions is more reliabl
Cone-Beam Computed Tomography Evaluation of Maxillary First and Second Molars in Iranian Population: A Morphological Study
Introduction: The aim of this study was to identify the root and canal morphology of maxillary first and second molars in Iranian population by taking and analyzing cone-beam computed tomography (CBCT) scans. Methods and Materials: Extracted maxillary first (n=125) and second (n=125) molars were collected from native Iranians and scanned by using a CBCT scanner. The number of roots and configuration of root canal system were classified according to Vertucci’s classification. Results: Two (1.6%) maxillary first and two (1.6%) maxillary second molars had four roots. Prevalence of root fusion was 2.4% and 8.8% in maxillary first and second molars, respectively. The most common canal morphology in the mesiobuccal roots of three-rooted first and second molars was Type I (46.4% and 80.8%, respectively), followed by Type VI (17.6%) in first molars. The predominant morphology of distobuccal and palatal roots in first and second molars was Type I. Additional canal types were also identified. Conclusion: Profound knowledge of anatomic variations is necessary prior to cleaning and obturation of the root canal system. The most common discovered root morphology was three separate roots in both tooth types. The greatest variation in canal anatomy was discovered in the MB canals of both the first and second molars
Association study of rs7192 polymorphism of HLA-DRA gene with male infertility occurrence in Isfahan province of Iran
Background and aims: One third of male factors related to infertilities are basically unknown and it has been predicted to be most of the unknown infertilities based on genetic abnormalities. On the other hands, the effect of HLA-DRA genes on spermatogenesis has been shown recently. So, this study was aimed to assess the association of rs7192 polymorphic site of HLA-DRA gene on male infertility in Isfahan province of Iran.
Methods: 100 infertile men with azoospermia or severe oligozoospermia as case group and equal numbers of fertile men as control individuals were selected. Genomic DNA of peripheral blood was extracted after the written consent was taken. rs7192 polymorphic site has been analyzed by ARMS-PCR method in the case and control groups.
Results: According to the results, the frequency of G allele was higher in infertile men than the T allele; but, allele frequency differences was not significant between the case and control groups (OR=0.86, P=0.47). However, it has been shown that GG homozygous in comparison to TT homozygous show an increased risk of male infertility but it was not statistically significant (OR=1.47, P=0.4). In parallel, comparison of GG + GT genotypes to TT ones was not also statistically significant between infertile and fertile men (OR=1.43, P=0.4).
Conclusion: Association study of polymorphic rs7192 did not show any significant relationship among men infertile with azoospermia or severe oligozoospermia in Isfahan province of Iran
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