131 research outputs found
An In vitro Study of Bacterial Leakage of a Novel Implant Abutment Interface
Magister Scientiae Dentium - MSc(Dent)Background: The two-stage implant system has proven to be a successful technique in replacing missing teeth (Nascimento et al., 2008). Nevertheless, the presence of micro-gaps that could entrap microbes at the implant-abutment interface (IAI) is unavoidable. This microbial leakage has been considered as one of the causes of peri-implant infection and bone loss (Scarano et al., 2005). Several companies have attempted to manufacture an implant with a connection design that provides hermetic sealing against bacterial leakage. Studies indicated that implants with internal connection, in particular the conical (Morse taper) design, have better sealing capacity in the implant abutment interface than the external design (Koutouzis et al., 2011, Jaworski et al., 2012). An internal conical implant system with a novel connection design, known as the Grand Morse (GM) connection, is reported to offer secure connection against micro-leakage (Neodent® Implant Systems Inc., 2018).
Aims: The aim of this study was to test the sealing ability against bacterial leakage in the implant-abutment interface provided by an implant with a novel deep internal conical (GM) connection design
Comparative Untargeted Metabolic Profiling of Different Parts of Citrus sinensis Fruits via Liquid Chromatography–Mass Spectrometry Coupled with Multivariate Data Analyses to Unravel Authenticity
Differences between seven authentic samples of Citrus sinensis var. Valencia peel (albedo and flavedo) and juices from Spain and Uruguay, in addition to a concentrate obtained from Brazil, were investigated by untargeted metabolic profiling. Sixty-six metabolites were detected by nano-liquid chromatography coupled to a high-resolution electrospray-ionization quadrupole time-of-flight mass spectrometer (nLC-ESI-qTOF-MS) belonging to phenolic acids, coumarins, flavonoid glycosides, limonoids, terpenes, and fatty acids. Eleven metabolites were detected for the first time in Citrus sinensis and identified as citroside A, sinapic acid pentoside, apigenin-C-hexosyl-O-pentoside, chrysoeriol-C-hexoside, di-hexosyl-diosmetin, perilloside A, gingerol, ionone epoxide hydroxy-sphingenine, xanthomicrol, and coumaryl alcohol-O-hexoside. Some flavonoids were completely absent from the juice, while present most prominently in the Citrus peel, conveying more industrial and economic prospects to the latter. Multivariate data analyses clarified that the differences among orange parts overweighed the geographical source. PCA analysis of ESI-(−)-mode data revealed for hydroxylinoleic acid abundance in flavedo peel from Uruguay the most distant cluster from all others. The PCA analysis of ESI-(+)-mode data provided a clear segregation of the different Citrus sinensis parts primarily due to the large diversity of flavonoids and coumarins among the studied samples
Validation and Cross-Cultural Adaptation of Arabic Version of the Rhinosinusitis Disability Index (ar-RSDI)
Objective: Arabic is ranked fourth in the most spoken languages after Chinese, English, and Spanish. Our goal was to assess the validity of Arabic version of the Rhinosinusitis Disability index (ar-RSDI) which is rhinosinusitis-specific instrument to assess quality of life (QoL) of affected patients.Patients and Methods: Our study included 302 chronic rhinosinusitis (CRS) patients and 150 healthy controls. The RSDI English version was translated to Arabic and pretest trial was performed. We assessed the internal consistency using Cronbach´s alpha test. Correlation between item scores and total score of the ar-RSDI, and test-retest validity were evaluated using Spearman's ranks correlation coefficient. The ar-RSDI ability to discriminate between patients and controls, and sensitivity to changes after management of CRS were assessed by Mann-Whitney, and Wilcoxon signed ranks tests, respectively.Results: The ar-RDSI showed high internal consistency. Strong correlation between each item and subscale scores with the total ar-RDSI scores was detected. The test-retest validity of the ar-RSDI revealed a significant association between the total ar-RSDI and its subscale scores on the first and second readings. The ar-RSDI was able to distinguish between patients and controls where the differences between their mean values were all significant. There were significant differences in the ar-RSDI total and subscale scores for the patients' group before and after the intervention, which reflect the ar-RSDI ability to detect the sensitivity to changes.Conclusion: The ar-RSDI is a simple and reliable tool with good internal consistency, reproducibility, and validity for the QoL assessment in Arabic-speaking CRS patients in clinical practice
Plasmon-Exciton Resonant Energy Transfer: Across Scales Hybrid Systems
The presence of an excitonic element in close proximity of a plasmonic nanostructure, under certain conditions, may lead to a nonradiative resonant energy transfer known as Exciton Plasmon Resonant Energy Transfer (EPRET) process. The exciton-plasmon coupling and dynamics have been intensely studied in the last decade; still many relevant aspects need more in-depth studies. Understanding such phenomenon is not only important from fundamental viewpoint, but also essential to unlock many promising applications. In this review we investigate the plasmon-exciton resonant energy transfer in different hybrid systems at the nano- and mesoscales, in order to gain further understanding of such processes across scales and pave the way towards active plasmonic devices
Comparative Metabolite Fingerprinting of Four Different Cinnamon Species Analyzed via UPLC–MS and GC–MS and Chemometric Tools
The present study aimed to assess metabolites heterogeneity among four major Cinnamomum species, including true cinnamon (Cinnamomum verum) and less explored species (C. cassia, C. iners, and C. tamala). UPLC-MS led to the annotation of 74 secondary metabolites belonging to different classes, including phenolic acids, tannins, flavonoids, and lignans. A new proanthocyanidin was identified for the first time in C. tamala, along with several glycosylated flavonoid and dicarboxylic fatty acids reported for the first time in cinnamon. Multivariate data analyses revealed, for cinnamates, an abundance in C. verum versus procyandins, dihydro-coumaroylglycosides, and coumarin in C. cassia. A total of 51 primary metabolites were detected using GC-MS analysis encompassing different classes, viz. sugars, fatty acids, and sugar alcohols, with true cinnamon from Malaysia suggested as a good sugar source for diabetic patients. Glycerol in C. tamala, erythritol in C. iners, and glucose and fructose in C. verum from Malaysia were major metabolites contributing to the discrimination among species
Seroprevalences and local variation of human and livestock brucellosis in two villages in Gharbia Governorate, Egypt
This study aimed at assessing the epidemiology of brucellosis among both human and livestock populations in an endemic area in Egypt. A cross-sectional survey was conducted in two villages, where 616 inhabitants (aged 3-75 years) and 350 livestock of 97 households were enrolled. Sera were tested for Brucella spp. antibodies by tube agglutination test for both populations. Proportions of seropositive sera were 0.0 and 1.7% among the inhabitants, and 0.0 and 16% among livestock of villages I and II, respectively. Calculated seroprevalences considering the clustering of brucellosis within households were 0.03 for people and 5.2 for livestock in village II. The village variable (P = 0.07) and keeping sheep in the household (P = 0.01) were significant risk factors for human brucellosis, whereas only the village was significant for livestock (P < 0.001). Sheep showed the highest seropositive proportions of brucellosis among livestock. No association could be detected between human and livestock brucellosis. In conclusion, we found local variation of seroprevalences of brucellosis among human and livestock in the two surveyed villages. Further epidemiological studies have to be conducted in randomly selected governorates, not only to confirm the low seroprevelance of human brucellosis, but also to assess the risk factors of livestock infection for terms of prophylaxi
Knowledge-driven Biometric Authentication in Virtual Reality
With the increasing adoption of virtual reality (VR) in public spaces, protecting users from observation attacks is becoming essential to prevent attackers from accessing context-sensitive data or performing malicious payment transactions in VR. In this work, we propose RubikBiom, a knowledge-driven behavioural biometric authentication scheme for authentication in VR. We show that hand movement patterns performed during interactions with a knowledge-based authentication scheme (e.g., when entering a PIN) can be leveraged to establish an additional security layer. Based on a dataset gathered in a lab study with 23 participants, we show that knowledge-driven behavioural biometric authentication increases security in an unobtrusive way. We achieve an accuracy of up to 98.91% by applying a Fully Convolutional Network (FCN) on 32 authentications per subject. Our results pave the way for further investigations towards knowledge-driven behavioural biometric authentication in VR
Plasmon-Exciton Resonant Energy Transfer: Across Scales Hybrid Systems
The presence of an excitonic element in close proximity of a plasmonic nanostructure, under certain conditions, may lead to a nonradiative resonant energy transfer known as Exciton Plasmon Resonant Energy Transfer (EPRET) process. The exciton-plasmon coupling and dynamics have been intensely studied in the last decade; still many relevant aspects need more in-depth studies. Understanding such phenomenon is not only important from fundamental viewpoint, but also essential to unlock many promising applications. In this review we investigate the plasmon-exciton resonant energy transfer in different hybrid systems at the nano- and mesoscales, in order to gain further understanding of such processes across scales and pave the way towards active plasmonic devices. � 2016 Mohamed El Kabbash et al
- …