Evaluation of Colloids and Activation Agents for Determination of Melamine Using UV-SERS

UV-SERS measurements offer a great potential for environmental or food (detection of food contaminats) analytics. Here, the UV-SERS enhancement potential of various kinds of metal colloids, such as Pd, Pt, Au, Ag, Au-Ag core-shell, and Ag-Au core-shell with different shapes and sizes, were studied using melamine as a test molecule. The influence of different activation (KF, KCl, KBr, K 2SO 4) agents onto the SERS activity of the nanomaterials was investigated, showing that the combination of a particular nanoparticle with a special activation agent is extremely crucial for the observed SERS enhancement. In particular, the size dependence of spherical nanoparticles of one particular metal on the activator has been exploited. By doing so, it could be shown that the SERS enhancement increases or decreases for increasing or decreasing size of a nanoparticle, respectively. Overall, the presented results demonstrate the necessity to adjust the nanoparticle size and the activation agent for different experiments in order to achieve the best possible UV-SERS results

Developing and evaluating the implementation of a complex intervention: using mixed methods to inform the design of a randomised controlled trial of an oral healthcare intervention after stroke

<p>Abstract</p> <p>Background</p> <p>Many interventions delivered within the stroke rehabilitation setting could be considered complex, though some are more complex than others. The degree of complexity might be based on the number of and interactions between levels, components and actions targeted within the intervention. The number of (and variation within) participant groups and the contexts in which it is delivered might also reflect the extent of complexity. Similarly, designing the evaluation of a complex intervention can be challenging. Considerations include the necessity for intervention standardisation, the multiplicity of outcome measures employed to capture the impact of a multifaceted intervention and the delivery of the intervention across different clinical settings operating within varying healthcare contexts. Our aim was to develop and evaluate the implementation of a complex, multidimensional oral health care (OHC) intervention for people in stroke rehabilitation settings which would inform the development of a randomised controlled trial.</p> <p>Methods</p> <p>After reviewing the evidence for the provision of OHC following stroke, multi-disciplinary experts informed the development of our intervention. Using both quantitative and qualitative methods we evaluated the implementation of the complex OHC intervention across patients, staff and service levels of care. We also adopted a pragmatic approach to patient recruitment, the completion of assessment tools and delivery of OHC, alongside an attention to the context in which it was delivered.</p> <p>Results</p> <p>We demonstrated the feasibility of implementing a complex OHC intervention across three levels of care. The complementary nature of the mixed methods approach to data gathering provided a complete picture of the implementation of the intervention and a detailed understanding of the variations within and interactions between the components of the intervention. Information on the feasibility of the outcome measures used to capture impact across a range of components was also collected, though some process orientated uncertainties including eligibility and recruitment rates remain to be further explored within a Phase II exploratory trial.</p> <p>Conclusions</p> <p>Complex interventions can be captured and described in a manner which facilitates evaluation in the form of exploratory and subsequently definitive clinical trials. If effective, the evidence captured relating to the intervention context will facilitate translation into clinical practice.</p

Isolation and characterisation of human gingival margin-derived STRO-1/MACS+ and MACS− cell populations

Recently, gingival margin-derived stem/progenitor cells isolated via STRO-1/magnetic activated cell sorting (MACS) showed remarkable periodontal regenerative potential in vivo. As a second-stage investigation, the present study's aim was to perform in vitro characterisation and comparison of the stem/progenitor cell characteristics of sorted STRO-1-positive (MACS+) and STRO-1-negative (MACS−) cell populations from the human free gingival margin. Cells were isolated from the free gingiva using a minimally invasive technique and were magnetically sorted using anti-STRO-1 antibodies. Subsequently, the MACS+ and MACS− cell fractions were characterized by flow cytometry for expression of CD14, CD34, CD45, CD73, CD90, CD105, CD146/MUC18 and STRO-1. Colony-forming unit (CFU) and multilineage differentiation potential were assayed for both cell fractions. Mineralisation marker expression was examined using real-time polymerase chain reaction (PCR). MACS+ and MACS− cell fractions showed plastic adherence. MACS+ cells, in contrast to MACS− cells, showed all of the predefined mesenchymal stem/progenitor cell characteristics and a significantly higher number of CFUs (P<0.01). More than 95% of MACS+ cells expressed CD105, CD90 and CD73; lacked the haematopoietic markers CD45, CD34 and CD14, and expressed STRO-1 and CD146/MUC18. MACS− cells showed a different surface marker expression profile, with almost no expression of CD14 or STRO-1, and more than 95% of these cells expressed CD73, CD90 and CD146/MUC18, as well as the haematopoietic markers CD34 and CD45 and CD105. MACS+ cells could be differentiated along osteoblastic, adipocytic and chondroblastic lineages. In contrast, MACS− cells demonstrated slight osteogenic potential. Unstimulated MACS+ cells showed significantly higher expression of collagen I (P<0.05) and collagen III (P<0.01), whereas MACS− cells demonstrated higher expression of osteonectin (P<0.05; Mann–Whitney). The present study is the first to compare gingival MACS+ and MACS− cell populations demonstrating that MACS+ cells, in contrast to MACS− cells, harbour stem/progenitor cell characteristics. This study also validates the effectiveness of the STRO-1/MACS+ technique for the isolation of gingival stem/progenitor cells. Human free gingival margin-derived STRO-1/MACS+ cells are a unique renewable source of multipotent stem/progenitor cells

Treatment of stage I-III periodontitis-The EFP S3 level clinical practice guideline

Background: The recently introduced 2017 World Workshop on the classification of periodontitis, incorporating stages and grades of disease, aims to link disease classification with approaches to prevention and treatment, as it describes not only disease severity and extent but also the degree of complexity and an individual's risk. There is, therefore, a need for evidence-based clinical guidelines providing recommendations to treat periodontitis. Aim: The objective of the current project was to develop a S3 Level Clinical Practice Guideline (CPG) for the treatment of Stage I–III periodontitis. Material and Methods: This S3 CPG was developed under the auspices of the European Federation of Periodontology (EFP), following the methodological guidance of the Association of Scientific Medical Societies in Germany and the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The rigorous and transparent process included synthesis of relevant research in 15 specifically commissioned systematic reviews, evaluation of the quality and strength of evidence, the formulation of specific recommendations and consensus, on those recommendations, by leading experts and a broad base of stakeholders. Results: The S3 CPG approaches the treatment of periodontitis (stages I, II and III) using a pre-established stepwise approach to therapy that, depending on the disease stage, should be incremental, each including different interventions. Consensus was achieved on recommendations covering different interventions, aimed at (a) behavioural changes, supragingival biofilm, gingival inflammation and risk factor control; (b) supra- and sub-gingival instrumentation, with and without adjunctive therapies; (c) different types of periodontal surgical interventions; and (d) the necessary supportive periodontal care to extend benefits over time. Conclusion: This S3 guideline informs clinical practice, health systems, policymakers and, indirectly, the public on the available and most effective modalities to treat periodontitis and to maintain a healthy dentition for a lifetime, according to the available evidence at the time of publication

Evaluation of proximal contact tightness of Class II resin composite restorations.

Contains fulltext : 88644.pdf (publisher's version ) (Open Access)OBJECTIVE: The objective of the current study was to compare in-vitro the proximal contact tightness (PCT) of Class II resin composite restorations (RCR) placed with different established and new placement techniques. METHODS: 105 ivorine lower left first molars with standardized MO cavities were randomly divided into seven groups (n = 15) as follows: SRing: sectional matrix and separation ring (Garrison Dental); CRing: circumferential matrix (1101-c, KerrHawe SA) with separation ring; CWedge: circumferential matrix with a wedge only; COptra: circumferential matrix and OptraContact (Vivadent); CCerana: circumferential matrix and a Cerana insert (Nordiska Dental); CElliot: circumferential matrix and Elliot separator (PFINGST & Co) and Walser: Walser matrix O-type (Dr Walser Dental GmbH). In all the groups, the matrix band was secured using a wooden wedge except for the Walser group, following manufacturer's recommendations. A Tofflemire retainer (Kerr Corporation) was used to apply the circumferential matrix band whenever it was used. All the prepared teeth were restored with resin composite (Premise, Kerr) mounted in a manikin head to simulate the clinical environment. PCT was measured using the Tooth Pressure Meter (University of Technology, Delft). The data were analyzed using one-way ANOVA and Tukey post-hoc tests (p < 0.05). RESULTS: Compared to the control group (SRing) (6.64 +/- 1.06N), all other systems resulted in significantly lower PCT values (p < 0.001). Within the circumferential matrix groups, CRing (4.01 +/- 0.53N) and CElliot (4.29 +/- 1.08N) showed significantly tighter contacts compared to the CWedge (0.37 +/- 0.22N), COptra (0.91 +/- 0.49N), CCerana (2.99 +/- 1.98N) and Walser (1.34 +/- 0.55N) (p < 0.05) group. Between CWedge and COptra, no significant difference was found (p = 0.57). CONCLUSION: The use of separation rings with sectional matrices provides superior contacts when placing Class II RCRs

Comparison of proximal contacts of class II resin composite restorations in vitro.

Item does not contain fulltextThis study investigated the tightness of the proximal contact when placing posterior resin composite restorations with circumferential and sectional matrix systems in an in vitro model using a special measuring device (Tooth Pressure Meter). A manikin model was used with an artificial first molar in which an MO-preparation was ground, simulating the clinical situation of an amalgam replacement. This preparation was duplicated, resulting in 160 identically prepared teeth. These teeth were divided into 8 groups (n=20). In 2 groups, circumferential matrix bands (flat or contoured) in a Tofflemire retainer were applied. In the remaining 6 groups, 3 different separation rings were combined with 2 types of sectional matrix bands. All the cavities were restored using Clearfil Photo Bond and Clearfil AP-X. The tightness of the proximal contact was measured using the Tooth Pressure Meter. Data were statistically analyzed using SPSS 12. ANOVA was used to find differences in proximal contact tightness between the groups. Tukey tests were used to find differences between the homogeneous subgroups. The use of sectional matrices combined with separation rings resulted in tighter proximal contacts compared to when circumferential systems were used (p<0.001). The use of these devices is therefore recommended when posterior resin composite restorations are placed

Turbulent deposition of aerosol nanoparticles on a wire screen

This paper presents experimental results of aerosol penetration through a wire screen for mobilityequivalent particle diameters between 2 and 10 nm, Reynolds numbers for the 2uid approaching the screen (Ret) between 300 and 6000, Peclet numbers (Pe) between 20 and 13 000, and wire diameters between 40 and 100 m. An empirical expression, D =(2:53 + 5:14 × 10−4 Ret)Pe(−0:65+2:58×10−5Ret), correlating the single 8ber e9ciency, D, with the Peclet and Reynolds numbers has been obtained. In the limit of very low Reynolds number (Stokes regime) the above expression reduces to D0 =2:53Pe−0:65, which is in good agreement with the widely accepted correlation for fan model 8lters, D0 =2:7Pe−2=3, of Cheng and Yeh.This work was partly supported by Comunidad AutPonoma de Madrid under grant 07M=0097=2000Peer reviewe