ABSTRACT
Increasing demand for size-resolved identification and quantification of microplastic particles in drinking water and environmental samples requires the adequate validation of methods and techniques that can be used for this purpose. In turn, the feasibility of such validation depends on the existence of suitable certified reference materials (CRM). A new candidate reference material (RM), consisting of polyethylene terephthalate (PET) particles and a water matrix, has been developed. Here, we examine its suitability with respect to a homogeneous and stable microplastic particle number concentration across its individual units. A measurement series employing tailor-made software for automated counting and analysis of particles (TUM-ParticleTyper 2) coupled with Raman microspectroscopy showed evidence of the candidate RM homogeneity with a relative standard deviation of 12% of PET particle counts involving particle sizes >30 µm. Both the total particle count and the respective sums within distinct size classes were comparable in all selected candidate RM units. We demonstrate the feasibility of production of a reference material that is sufficiently homogeneous and stable with respect to the particle number concentration.
ABSTRACT
Background: To compare the treatment outcome of laser and its effectiveness in the management of gingival hyperpigmentation over scalpel surgical method. Methods: The patients were selected and were divided into two groups by the split-mouth design. Group A: Right half upper and lower central incisors to premolars were treated using the laser technique. GROUP B: Left half upper and lower central incisors to premolars were treated by Scalpel technique. This study was a comparative, split-mouth analytical study, and the results were observed for a period of 9 months. Results: Diode laser technique gave better results in this perio-esthetics procedure as compared to scalpel technique. However, recurrence of pigmentation has been reported even after this duration. Diode laser was superior over the scalpel technique in the aspect of operator convenience, reduced postoperative bleeding, and reducing the incidence of repigmentation in terms of intensity and extent of pigmentation. Patient comfort was more in scalpel technique. Conclusion: Laser can be used for better periodontal esthetic procedure over the standard scalpel technique, although repigmentation was reported in both groups. But delayed healing occurred on the laser side due to the thermal effect of the laser on the adjacent tissues. Provision of such advanced instruments to dental surgery can give better satisfaction to patient clientele in terms of good esthetic results.
ABSTRACT
Accurate quantification of small microplastics in environmental and food samples is a prerequisite for studying their potential hazard. Knowledge of numbers, size distributions and polymer type for particles and fibers is particularly relevant in this respect. Raman microspectroscopy can identify particles down to 1 [Formula: see text]m in diameter. Here, a fully automated procedure for quantifying microplastics across the entire defined size range is presented as the core of the new software TUM-ParticleTyper 2. This software implements the theoretical approaches of random window sampling and on-the-fly confidence interval estimation during ongoing measurements. It also includes improvements to image processing and fiber recognition (when compared to the previous software TUM-ParticleTyper for analysis of particles/fibers [Formula: see text] [Formula: see text]m), and a new approach to adaptive de-agglomeration. Repeated measurements of internally produced secondary reference microplastics were evaluated to assess the precision of the whole procedure.
ABSTRACT
Wastewater treatment plants (WWTPs) may represent point sources for microplastic discharge into the environment. Quantification of microplastic in effluents of WWTPs has been targeted by several studies although standardized methods are missing to enable a comparability of results. This study discusses theoretical and practical perspectives on best practices for microplastic sampling campaigns of WWTPs. One focus of the study was the potential for synergies between thermoanalytical and spectroscopic analysis to gain more representative sampling using the complementary information provided by the different analytical techniques. Samples were obtained before and after sand filtration from two WWTPs in Germany using cascade filtration with size classes of 5,000 - 100 µm, 100 - 50 µm, and 50 - 10 µm. For spectroscopic methods samples were treated by a Fenton process to remove natural organic matter, whereas TED-GC-MS required only sample extraction from the filter cascade. µFTIR spectroscopy was used for the 100 µm and 50 µm basket filters and µRaman spectroscopy was applied to analyze particles on the smallest basket filter (10 µm). TED-GC-MS was used for all size classes as it is size independent. All techniques showed a similar trend, where PE was consistently the most prominent polymer in WWTP effluents. Based on this insight, PE was chosen as surrogate polymer to investigate whether it can describe the total polymer removal efficiency of tertiary sand filters. The results revealed no significant difference (ANOVA) between retention efficiencies of tertiary sand filtration obtained using only PE and by analyzing all possible polymers with µFTIR and µRaman spectroscopy. Findings from this study provide valuable insights on advantages and limitations of cascade filtration, the benefit of complementary analyses, a suitable design for future experimental approaches, and recommendations for future investigations.
Subject(s)
Water Pollutants, Chemical , Water Purification , Environmental Monitoring , Microplastics , Plastics/analysis , Polymers , Spectrum Analysis , Wastewater/chemistry , Water Pollutants, Chemical/analysisABSTRACT
OBJECTIVE OF WORK: Wrong-site tooth extraction (WSTE) is the most common serious patient safety incident in dentistry. Safety checklists have significantly reduced wrong-site surgery, although their benefit is unproven in primary care dentistry. Our quality improvement project developed and implemented a checklist optimised for oral surgery procedures in primary care to reduce WSTE risk. MATERIAL AND METHODS: Local best practice for tooth extraction record-keeping (LBP), using national guidelines and standards was devised. We then retrospectively audited tooth extraction record-keeping against LBP. Deficiencies in current record-keeping practice were identified and used to design a checklist aimed at improving compliance. We provided a computerised safety checklist compliant with LBP to eleven clinicians at three general dental clinics within our region. The checklist included a pre-operative safety check, a pause to re-confirm the surgical site and a post-operative record-keeping proforma. The checklist was linked to our record-keeping software for use during tooth extraction. We audited checklist completion and compliance with LBP fortnightly for ten weeks. RESULTS: The introduction of a safety checklist resulted in increased compliance with LBP for tooth extraction record keeping. At week ten, 67% of records contained the computerised safety checklist. This resulted in a 50% increase in overall compliance with LBP for tooth extraction compared to baseline. CONCLUSIONS: A computerised safety checklist for tooth extraction in primary care has potential to improve patient safety by adopting measures to prevent WSTE and standardising communication between clinicians. Checklists in general practice should be encouraged.
ABSTRACT
The genetic landscape of Parkinson's disease (PD) is characterised by rare high penetrance pathogenic variants causing familial disease, genetic risk factor variants driving PD risk in a significant minority in PD cases and high frequency, low penetrance variants, which contribute a small increase of the risk of developing sporadic PD. This knowledge has the potential to have a major impact in the clinical care of people with PD. We summarise these genetic influences and discuss the implications for therapeutics and clinical trial design.
