515 research outputs found

    Morphology of Root Canal Cross-sections of Resected Roots of First and Second Lower Molars

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    Precise preparation of the root canal ostium with a view to hermetical closing with retrograde root filling is an important prognostic factor determining the success of the procedure of tooth resection. Root canals interconnected with a narrow isthmus may cause problems both in endodontic treatment and in retrograde filling. The aim of this work is the research of the transverse cross-section of root canals of first and second lower molars on the resection model. The research encompasses 100 randomly selected molar teeth: 50 first and 50 second lower molars. The tooth root apexes were cut 3 mm below the apex and examined under an electron microscope, special attention being paid to the shape of root canal cross-sections. In the group of first molar teeth, in 20% the presence of an isthmus between canals in the proximal roots was observed; in the group of second molar teeth an isthmus between the canals of proximal roots occurred in 18% of the cases. It seems that the relatively high percentage (20%-18%) of the occurrence of an isthmus, 3 mm below the root apex, between two elongated transverse cross-section proximal root canals of first and second molars should encourage particular caution in the retrograde filling of the above-mentioned canals during the procedure of resection

    Analysis of microtomographic images in automatic defect localization and detection

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    The paper presents a fast method of fully automatic localization and classification of defects in aluminium castings based on computed microtomography images. In the light of current research and based on available publications, where such analysis is made on the basis of images obtained from standard radiography (x-ray), this is a new approach which uses microtomographic images (μ-CT). In addition, the above-mentioned solutions most often analyze a pre-separated portion of an image, which requires the initial operator interference. The authors’ own pre-processing methods, which allow to separate the element area and potential defect areas from μ-CT images, and methods of extraction of selected features describing these areas have been proposed in the solution discussed here. A neural network trained using the Levenberg–Marquardt method with error backpropagation has been used as a classifier. The optimal network structure 20–4–1 and a set of 20 features describing the analysed areas have been determined as a result of performed tests. The applied solutions have provided 89% correct detection for any defect size and 96.73% for large defects, which is comparable to the results obtained from methods using x-ray images. This has confirmed that it is possible to use μ-CT images in automatic defect localization in 3D. Thanks to this method, quantitative analysis of aluminium castings can be carried out without user interaction and fully automated

    Effects of curcumin on lipid membranes : an EPR spin-label study

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    DETERMINING THE DEGREE OF PLAYER ENGAGEMENT IN A COMPUTER GAME WITH ELEMENTS OF A SOCIAL CAMPAIGN USING COGNITIVE NEUROSCIENCE TECHNIQUES

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    Due to the popularity of video games in various applications, including both commercial and social marketing, there is a need to assess their content in terms of player satisfaction, already at the production stage. For this purpose, the indices used in EEG tests can be used. In this publication, a formula has been created based on the player's commitment to determining which elements in the game should be improved and for which graphic emblems connected with social campaigns were more memorable and whether this was related to commitment. The survey was conducted using a 2D platform game created in Unity based on observations of 28 recipients. To evaluate the elements occurring in the game at which we obtain a higher memory for graphic characters, a corresponding pattern was created based on player involvement. The optimal Index for moving and static objects and the Index for destruction were then selected based on the feedback. Referring to the issue of graphic emblems depicting social campaigns should be placed in a place where other activities such as fighting will not be distracted, everyone will be able to reach the level where the recently placed advertisement is. This study present the developed method to determine the degree of player's engagement in particular elements in the game using the EEG and to explore the relationship between the visibility of social advertising and engagement in a 2D platform game where the player has to collect three keys and defeat the ultimate opponent.&nbsp

    EPR studies on the properties of model photoreceptor membranes made of natural and synthetic lipids

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    AbstractThe membranes of retina photoreceptors have unique lipid composition. They contain a high concentration of polyunsaturated docosahexaenoic acid, with six double bonds, and are enriched in phosphatidylethanolamines. Based on their phospholipid composition and cholesterol content, membranes of photoreceptors can be divided into three types: plasma membrane, young disks membranes, and old disks membranes. High amount of docosahexaenoic acid, abundant illumination, and high respiratory demands make these membranes sensitive to oxidative stress and lipid peroxidation. Human retinas are not easily available for research, therefore most research is done on bovine retinas. However, to follow, in a controlled manner, the changes in membrane properties caused by different factors it seems advisable to apply carefully prepared models of photoreceptor membranes. Using synthetic lipids we prepared liposome models of three types of photoreceptor membranes, and by means of electron paramagnetic resonance spectroscopy and spin labeling technique we compared polarity and fluidity of those model membranes with the properties of membranes consisting of natural lipids extracted from photoreceptor outer segments of bovine retinas. Additionally, we studied the effect of oxidation on the membrane properties in the presence and in the absence of zeaxanthin, which is an antioxidant naturally present in the human retina. The results show that there are significant differences in polarity and fluidity between all investigated membranes, which reflect differences in their lipid composition. The properties of the membranes made of natural photoreceptor outer segment lipids are most similar to the ones of the models of old disks membranes. Oxidation did not change the membrane properties significantly; however, a slight ordering effect was observed in liposomes made of natural photoreceptor outer segment lipids and in the model of old disks membranes. Zeaxanthin affected polarity and fluidity mostly in the model of old disks membranes. The results show that by careful selection and appropriate proportions of lipid mixtures, it is possible to obtain synthetic membranes of the properties similar to the natural ones.</jats:p

    The impact of advertisements placement in the computer game on the effectiveness of social campaign messages

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    PURPOSE: The article focuses on two aspects, spatial location of advertisements and the engagement of the player during the gameplay and investigates, how they influence the effectiveness of advertising in the context of social campaign.DESIGN/METHODOLOGY/APPROACH: The analyses are conducted based on data collected in the survey and recorded by EEG and eye-tracker devices.FINDINGS: The results obtained for the memorization may indicate that message order (first or last) in a sequence of advertisements has major bearing on attention and recall. The computed outcomes of engagement indices show that, depending on the method of calculation, obtained results can differ. Moreover, research with the use of eye-tracking devices can allow for accurate predictions of advertising effectiveness, at least in terms of recall. Results allow to state that it would be recommended to place social advertisements in such spots where the player has less to do and is not distracted by any tasks required to achieve progress in the game.PRACTICAL IMPLICATIONS: The proposed solution of testing the effectiveness of computer games in presenting social campaigns messages can be used both by practitioners that develop such campaigns and by scientists aiming to conduct advertising research.ORIGINALITY/VALUE: Taking into account data from two different sources allows to capture both conscious and subconscious opinions about the social advertsising message in the game, which shows the comprehensive image of the advertisement’s effectiveness.The project was financed with the National Science Centre funds allocated according to the decision DEC-2016/21/B/HS4/03036.peer-reviewe

    Awareness of Genitourinary Cancers Risk Factors—A 2024 Population-Based Cross-Sectional Study in Poland

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    ObjectiveThis study aimed to assess the awareness of genitourinary cancers risk factors among adults in Poland and to identify factors associated with public awareness of risk factors for genitourinary cancers.MethodsThis cross-sectional survey was carried out between 1 and 4 March 2024 in a nationwide sample of 2,165 adults in Poland. Quota sampling was used. Data were collected using computer-assisted web interview (CAWI) method.ResultsRegardless of the type of cancer (kidney, bladder, or prostate cancer), a family history of cancer was the most recognized risk factor indicated by over half of respondents. Over one-third were aware that chemical exposure increases the risk for bladder cancer (39.4%) or prostate cancer (34.2%). Smoking was recognized as a risk factor for kidney cancer by 40.6% of respondents. Female gender, having higher education, being occupationally active and the presence of chronic diseases were the most important factors (p &lt; 0.05) associated with a higher level of awareness of genitourinary cancers risk factors.ConclusionThis study revealed gaps in public awareness of genitourinary cancers risk factors among adults in Poland, especially lifestyle-related and workplace-related risk factors

    Comparative actualistic study hints at origins of alleged Miocene coprolites of Poland

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    Excrement-shaped ferruginous masses have been recovered from the Miocene of Turów mine in south-western Poland. These siderite masses have been the subject of much controversy, having been interpreted either as being coprolites, cololithes or pseudofossils created by mechanical deformation of plastic sediment. Here we present the results of mineralogical, geochemical, petrographic and microtomographical analyses. Our data indicate that these masses consist of siderite and iron oxide rather than phosphate, and rarely contain recognizable food residues, which may suggest abiotic origins of these structures. On the other hand, evidence in support of a fecal origin include: (i) the presence of two distinct morphotypes differing in size and shape, (ii) the presence of rare hair-like structures or coalified inclusions and (iii) the presence of rare fine striations on the surface. Importantly, comparative actualistic study of recent vertebrate feces shows overall resemblance of the first morphotype (sausage-shaped with rare coalified debris) to excrements of testudinoid turtles (Testudinoidea), whose shell fragment was found in the investigated locality. The second morphotype (rounded to oval-shaped with hair-like structures), in turn, is similar to the feces of some snakes (Serpentes), the remains of which were noted in the Miocene of the neighborhood areas. Other potential producers (such as lizards and crocodiles) and even abiotic origins cannot be fully excluded but are less likely

    Comparative actualistic study hints at origins of alleged Miocene coprolites of Poland

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    Excrement-shaped ferruginous masses have been recovered from the Miocene of Turów mine in south-western Poland. These siderite masses have been the subject of much controversy, having been interpreted either as being coprolites, cololithes or pseudofossils created by mechanical deformation of plastic sediment. Here we present the results of mineralogical, geochemical, petrographic and microtomographical analyses. Our data indicate that these masses consist of siderite and iron oxide rather than phosphate, and rarely contain recognizable food residues, which may suggest abiotic origins of these structures. On the other hand, evidence in support of a fecal origin include: (i) the presence of two distinct morphotypes differing in size and shape, (ii) the presence of rare hair-like structures or coalified inclusions and (iii) the presence of rare fine striations on the surface. Importantly, comparative actualistic study of recent vertebrate feces shows overall resemblance of the first morphotype (sausage-shaped with rare coalified debris) to excrements of testudinoid turtles (Testudinoidea), whose shell fragment was found in the investigated locality. The second morphotype (rounded to oval-shaped with hair-like structures), in turn, is similar to the feces of some snakes (Serpentes), the remains of which were noted in the Miocene of the neighborhood areas. Other potential producers (such as lizards and crocodiles) and even abiotic origins cannot be fully excluded but are less likely
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