184 research outputs found

    Trend-analysis of dental hard-tissue conditions as function of tooth age

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    Objective This retrospective in-vitro study investigated tooth age effect on dental hard-tissue conditions. Methods Unidentified extracted premolars (n = 1500) were collected and their individual age was estimated (10–100 (±10) years old (yo)) using established dental forensic methods Dental caries, fluorosis and tooth wear (TW) were assessed using the International Caries Detection and Assessment System (ICDAS; 0–5 for crown and 0–2 for root), Thylstrup-Fejerskov (TFI; 0–9) and Basic Erosive Wear Examination (BEWE; 0–3) indices, respectively. Staining and color were assessed using the modified-Lobene (MLI) (0–3) and VITA shade (B1-C4) indices, respectively. Relationships between indices and age were tested using regression models. Results Starting at age ∼10yo, presence of caries increased from 35% to 90% at ∼50yo (coronal), and from 0% to 35% at ∼80yo (root). Caries severity increased from ICDAS 0.5 to 2 at ∼40yo and from ICDAS 0 to 0.5 at ∼60yo for coronal and root caries, respectively. Presence of TW increased from 25% (occlusal) and 15% (smooth-surfaces) to 100% at ∼80yo. TW severity increased from BEWE 0.5 to 2 at ∼50yo (occlusal) and ∼0.3 to 1.5 at ∼50yo (smooth-surfaces). Percentage and severity of fluorosis decreased from 70% to 10% at ∼80yo, and from TFI 1 to 0 at ∼90yo, respectively. Percentage of extrinsic staining increased from 0% to 85% at ∼80yo and its severity increased from MLI 0 to 2 at ∼70yo. Color changed from A3 to B3 at ∼50yo (crown), and from C2 to A4 at ∼85yo (root). Conclusions Aging is proportionally related to the severity of caries, TW, staining, and inversely to dental fluorosis. Teeth become darker with ag

    Odnosi između dentalne topografije, ukupne istrošenosti cakline, Bang i Ramm/Liversidge te Mollesonov procjena starosti za uzorak ljudskih pretkutnjaka

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    Objectives: Molar crown wear is often used in bioarchaeological research as a proxy for age at death. However, a small number of researchers have used premolars or compared the application of different methods of relative age estimation. Material and methods: Using a sample of 197 previously extracted maxillary first premolars from US dental patients, we considered three protocols for estimating age: the Bang and Ramm/Liversidge and Molleson (BRLM) age estimate method, occlusal topographic analysis, and the Smith system of macrowear scoring. A previous study utilizing the Bang and Ramm method yielded an age estimate range of 9.4 to 10.8 years for the sample. Results: Our analyses showed no associations between occlusal topography parameters (occlusal slope, relief, or faceting) and BRLM age estimates, but some concordance was found between Smith scoring and BRLM ages estimates and between Smith scoring and occlusal topography parameters. Conclusion: The results of the present study suggest that relationships between gross tooth wear, tooth shape, and dental age estimates are complex, and available methods should be considered together to gain a more comprehensive understanding of how teeth change their shape with wear through-out the lifecourse.Svrha: Trošenje zubne krune kutnjaka često se koristi u bioarheološkim istraživanjima za procjenu dobi u trenutku smrti. No u nekoliko takvih analiza upotrijebljeni su pretkutnjaci ili se uspoređivala primjena različitih metoda procjene relativne dobi. Materijal i metode: Koristeći se uzorkom od 197 izvađenih prvih maksilarnih pretkutnjaka stomatoloških pacijenata iz SAD-a, u radu razmatramo tri protokola za procjenu dobi – prema Bangu i Ramm/Liversidgeu te Mollesonu (BRLM), okluzalnu topografsku analizu i Smithovu metodu za sustav bodovanja makroistrošenosti. U prethodnoj studiji koja se koristila metodom Banga i Ramma dobiven je raspon procijenjene dobi od 9,4 do 10,8 godina za uzorak. Rezultati: Naše analize nisu pokazale povezanost između parametara okluzalne topografije (okluzalni nagib, reljef ili faseta) i procjene starosti BRLM-a, i određenu podudarnost između Smithova bodovanja i procjena starosti BRLM-a te između Smithova bodovanja i parametara okluzalne topografije. Zaključak: Dobiveni rezultati sugeriraju da su odnosi između gruboga trošenja zuba, njihova oblika i procjene starosti složeni, a dostupne metode treba razmotriti zajedno kako bi se steklo sveobuhvatnije razumijevanje o tome kako zubi tijekom života trošenjem mijenjaju oblik

    Watch your step!: a frustrated total internal reflection approach to forensic footwear imaging

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    Forensic image retrieval and processing are vital tools in the fight against crime e.g. during fingerprint capture. However, despite recent advances in machine vision technology and image processing techniques (and contrary to the claims of popular fiction) forensic image retrieval is still widely being performed using outdated practices involving inkpads and paper. Ongoing changes in government policy, increasing crime rates and the reduction of forensic service budgets increasingly require that evidence be gathered and processed more rapidly and efficiently. A consequence of this is that new, low-cost imaging technologies are required to simultaneously increase the quality and throughput of the processing of evidence. This is particularly true in the burgeoning field of forensic footwear analysis, where images of shoe prints are being used to link individuals to crime scenes. Here we describe one such approach based upon frustrated total internal reflection imaging that can be used to acquire images of regions where shoes contact rigid surfaces

    Foot Function Index for Arabic-speaking patients (FFI-Ar) : translation, cross-cultural adaptation and validation study

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    Background: Foot Function Index (FFI) is a valid and reliable outcome measure, which is widely used to measure the foot and ankle functional level and disorders. Until now, no validated Arabic version of the FFI is available. This study was conducted at a tertiary care hospital in Riyadh, Saudi Arabia. The purpose of this project was to translate and adapt the FFI into Arabic and to evaluate its psychometric properties of validity and reliability. Methods: The study consisted of two phases. The first phase was the translation and cultural adaptation of the FFI to Arabic. The next phase involved, testing the psychometric properties of the Arabic version of the FFI on a sample of 50 consecutive participants which included internal consistency, test–retest reliability, floor and ceiling effects and construct validity. Results: The mean age of the study participants was 38 ± 12.94 years. Both the genders were evenly enrolled with 50% of the participants as male and 50% as female. Majority of them complained of plantar fasciopathy (32%) followed by pes planus (22%) and ankle sprain (18%). The scores of FFI-Ar were normally distributed, confirmed by a significant Shapiro–Wilk test. The mean value of FFI-Ar total score was 47.73 ± 19.85. There were no floor or ceiling effects seen in any of the subscales and total score. The internal consistency was good with the Cronbach’s alpha value of 0.882, 0.936 and 0.850 for the pain, disability and activity limitation subscales, respectively. The reproducibility of the FFI-Ar was analysed by intra-class correlation coefficient which revealed good to excellent test–retest reliability. A significant correlation was found between FFI-Ar and SF-36 and numeric rating scale (NRS) confirming its construct validity. Conclusion: The FFI-Arabic version showed good validity and reliability in patients with foot and ankle problems. This tool can be used in usual practice and research for analysing foot and ankle disorders in Arabic-speaking people

    The recent progress on silver nanoparticles: Synthesis and electronic applications

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    Nanoscience enables researchers to develop new and cost-effective nanomaterials for energy, healthcare, and medical applications. Silver nanoparticles (Ag NPs) are currently increasingly synthesized for their superior physicochemical and electronic properties. Good knowledge of these characteristics allows the development of applications in all sensitive and essential fields in the service of humans and the environment. This review aims to summarize the Ag NPs synthesis methods, properties, applications, and future challenges. Generally, Ag NPs can be synthesized using physical, chemical, and biological routes. Due to the great and increasing demand for metal and metal oxide nanoparticles, researchers have invented a new, environmentally friendly, inexpensive synthetic method that replaces other methods with many defects. Studies of Ag NPs have increased after clear and substantial support from governments to develop nanotechnology. Ag NPs are the most widely due to their various potent properties. Thus, this comprehensive review discusses the different synthesis procedures and electronic applications of Ag NPs

    A semi-automated security advisory system to resist cyber-attack in social networks

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    Social networking sites often witness various types of social engineering (SE) attacks. Yet, limited research has addressed the most severe types of social engineering in social networks (SNs). The present study investigates the extent to which people respond differently to different types of attack in a social network context and how we can segment users based on their vulnerability. In turn, this leads to the prospect of a personalised security advisory system. 316 participants have completed an online-questionnaire that includes a scenario-based experiment. The study result reveals that people respond to cyber-attacks differently based on their demographics. Furthermore, people’s competence, social network experience, and their limited connections with strangers in social networks can decrease their likelihood of falling victim to some types of attacks more than others

    Structural and shielding properties of NiO/xCo3O4 nanocomposites synthesized by microwave irradiation method

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    In the present study, nanocomposites with different ratios of NiO and Co3O4 (x = 0.3, 0.5, and 0.7) have been prepared via microwave oven and characterized using XRD. FLUKA code has been used to estimate the values of the mass attenuation coefficient (μm) for all samples. From the measurement, we found that when the thickness of the samples increases, the gamma transmission values decrease. Besides, the μm values increase as the Co3O4 content increase from 0.3 to 0.7%. At selected photon energy, the HVL, TVL, and MFP values decrease with increasing Co3O4 concentrations. At low energies (0.1–0.5 MeV), the linear decreasing trend in MAC values indication that photoelectric effect (PEA) (∝1/E3.5) dominance over this region. Afterward, at medium energy regions (0.5–1.33 MeV), the decrements in MAC values are insignificant as the Compton scattering (CS) (∝1/E) phenomenon dominates. As a conclusion, CoNi3 has superior effectiveness as a shielding material. © 2020 The Author(s)The authors express their gratitude to the Deanship of Scientific Research at King Khalid University for funding this work through research groups program under grant number R.G.P. 2/33/41 and Universiti Putra Malaysia for the research and publication funding

    Role of transglutaminase 2 in PAC1 receptor mediated protection against hypoxia-induced cell death and neurite outgrowth in differentiating N2a neuroblastoma cells

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    The PAC1 receptor and tissue transglutaminase (TG2) play important roles in neurite outgrowth and modulation of neuronal cell survival. In this study, we investigated the regulation of TG2 activity by the PAC1 receptor in retinoic acid-induced differentiating N2a neuroblastoma cells. TG2 transamidase activity was determined using an amine incorporation and a peptide cross linking assay. In situ TG2 activity was assessed by visualising the incorporation of biotin-X-cadaverine using confocal microscopy. TG2 phosphorylation was monitored via immunoprecipitation and Western blotting. The role of TG2 in PAC1 receptor-induced cytoprotection and neurite outgrowth was investigated by monitoring hypoxia-induced cell death and appearance of axonal-like processes, respectively. The amine incorporation and protein crosslinking activity of TG2 increased in a time and concentration-dependent manner following stimulation with pituitary adenylate cyclase-activating polypeptide-27 (PACAP-27). PACAP-27 mediated increases in TG2 activity were abolished by the TG2 inhibitors Z-DON and R283 and by pharmacological inhibition of protein kinase A (KT 5720 and Rp-cAMPs), protein kinase C (Ro 31-8220), MEK1/2 (PD 98059), and removal of extracellular Ca2+. Fluorescence microscopy demonstrated PACAP-27 induced in situ TG2 activity. TG2 inhibition blocked PACAP-27 induced attenuation of hypoxia-induced cell death and outgrowth of axon-like processes. TG2 activation and cytoprotection were also observed in human SH-SY5Y cells. Together, these results demonstrate that TG2 activity was stimulated downstream of the PAC1 receptor via a multi protein kinase dependent pathway. Furthermore, PAC1 receptor-induced cytoprotection and neurite outgrowth are dependent upon TG2. These results highlight the importance of TG2 in the cellular functions of the PAC1 receptor

    Recent trends in the use of electrical neuromodulation in Parkinson's disease

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    Purpose of Review: This review aims to survey recent trends in electrical forms of neuromodulation, with a specific application to Parkinson’s disease (PD). Emerging trends are identified, highlighting synergies in state-of-the-art neuromodulation strategies, with directions for future improvements in stimulation efficacy suggested. Recent Findings: Deep brain stimulation remains the most common and effective form of electrical stimulation for the treatment of PD. Evidence suggests that transcranial direct current stimulation (tDCS) most likely impacts the motor symptoms of the disease, with the most prominent results relating to rehabilitation. However, utility is limited due to its weak effects and high variability, with medication state a key confound for efficacy level. Recent innovations in transcranial alternating current stimulation (tACS) offer new areas for investigation. Summary: Our understanding of the mechanistic foundations of electrical current stimulation is advancing and as it does so, trends emerge which steer future clinical trials towards greater efficacy
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