Nanosheet composed of gold nanoparticle/graphene/epoxy resin based on ultrasonic fabrication for flexible dopamine biosensor using surface-enhanced Raman spectroscopy

Construction of a fast, easy and sensitive neurotransmitters-based sensor could provide a promising way for the diagnosis of neurological diseases, leading to the discovery of more effective treatment methods. The current work is directed to develop for the first time a flexible Surface-Enhanced Raman Spectroscopy (SERS) based neurotransmitters sensor by using the ultrasonic-assisted fabrication of a new set of epoxy resin (EPR) nanocomposites based on graphene nanosheets (GNS) using the casting technique. The perspicuous epoxy resin was reinforced by the variable loading of GNS giving the general formula GNS/EPR1-5. The designed products have been fabricated in situ while the perspicuous epoxy resin was formed. The expected nanocomposites have been fabricated using 3%, 5%, 10%, 15% and 20% GNS loading was applied for such fabrication process. The chemical, physical and morphological properties of the prepared nanocomposites were investigated by using Fourier transforms infrared spectroscopy, X-ray diffraction, Thermogravimetric analysis, Differential Thermal gravimetry, and field emission scanning electron microscopy methods. The GNS/EPR1-5 nanocomposites were decorated with a layer of gold nanoparticles (Au NPs/GNS/EPR) to create surface-enhanced Raman scattering hot points. The wettability of the Au NPs/GNS/EPR was investigated in comparison with the different nanocomposites and the bare epoxy. Au NPs/GNS/EPR was used as a SERS-active surface for detecting different concentrations of dopamine with a limit of detection of 3.3 µM. Our sensor showed the capability to detect low concentrations of dopamine either in a buffer system or in human serum as a real sample.

Video Voiding Device for Diagnosing Lower Urinary Tract Dysfunction in Men

We introduce a novel diagnostic Visual Voiding Device (VVD), which has the ability to visually document urinary voiding events and calculate key voiding parameters such as instantaneous flow rate. The observation of the urinary voiding process along with the instantaneous flow rate can be used to diagnose symptoms of Lower Urinary Tract Dysfunction (LUTD) and improve evaluation of LUTD treatments by providing subsequent follow-up documentations of voiding events after treatments. The VVD enables a patient to have a urinary voiding event in privacy while a urologist monitors, processes, and documents the event from a distance. The VVD consists of two orthogonal cameras which are used to visualize urine leakage from the urethral meatus, urine stream trajectory, and its break-up into droplets. A third, lower back camera monitors a funnel topped cylinder where urine accumulates that contains a floater for accurate readings regardless of the urine color. Software then processes the change in level of accumulating urine in the cylinder and the visual flow properties to calculate urological parameters. Video playback allows for reexamination of the voiding process. The proposed device was tested by integrating a mass flowmeter into the setup and simultaneously measuring the instantaneous flow rate of a predetermined voided volume in order to verify the accuracy of VVD compared to the mass flowmeter. The VVD and mass flowmeter were found to have an accuracy of ±2 and ±3% relative to full scale, respectively. A VVD clinical trial was conducted on 16 healthy male volunteers ages 23-65.

Validation of the Arabic Version of the Early Childhood Oral Health Impact Scale (ECOHIS)

BACKGROUND

Assessment of the adverse effects of oral health problems on oral health-related quality of life (OHRQoL) is essential to ensure the well-being of children. The Early Childhood Oral Health Impact Scale (ECOHIS) is an instrument that was designed to assess caregivers' perceptions of OHRQoL in preschool children. Although it has been translated into many languages, it has yet to be validated in Arabic. Therefore, this study aimed to translate this questionnaire to Arabic (A-ECOHIS) and test its psychometric properties.

METHODS

Questionnaire responses from three samples of caregivers of preschool children ≤ 6 years of age were collected: (i) community-based (n = 422), from preschools selected as a stratified random sample; (ii) clinic-based, from those seeking pediatric dental care at a university clinic (n = 246); and (iii) a test-retest sample (n = 68), a clinic-based group of caregivers who completed questionnaires twice about siblings who were not receiving dental care. Children received a dental examination to assess their decayed, missed, filled teeth (dmft) scores. Convergent validity was evaluated by assessing the A-ECOHIS scores in relation to the response to a global question. Discriminant validity was evaluated by comparing the scores of children with varying levels of oral disease. Internal consistency was assessed by calculating Cronbach's alpha, and the test-retest reliability was assessed using intra-class correlation coefficients (ICCs).

RESULTS

The A-ECOHIS scores of the questionnaire sections and the global oral health rating were significantly correlated; Spearman correlation coefficients were, r = 0.55, P ≤ 0.01 (overall score), r = 0.54, P ≤ 0.01 (child section), and r = 0.51, P ≤ 0.01 (family section). The mean A-ECOHIS scores were also statistically significantly higher in children with higher dmft scores compared with lower dmft, and in the clinic-based sample compared with the community sample. The Cronbach's alpha value of the the child, family sections and overall questionnaire were, 0.80, 0.78, and 0.85, respectively. The intra-class correlation coefficient (ICC) of A-ECOHIS was 0.86.

CONCLUSION

The A-ECOHIS performed well on all psychometric tests to which it was applied. Thus, it is a valid and reliable instrument that can be used in Arabic-speaking caregivers of preschoolers aged 2 to 6 years.