466 research outputs found
Khallaf and Sidebottom Guiding Stent for Temporomandibular Joint Arthrocentesis: A New Era for Joint Space Puncturing Techniques (Registered Technical Note)
Arthrocentesis is becoming the cornerstone of minimally-invasive surgical treatment for internal derangement of the temporomandibular joint (TMJID). Nitzan et al. first described arthrocentesis as the simplest form of surgery in the TMJID. Repeated arthrocentesis up to five times is 91% effective in treating patients with anterior disc displacement without reduction. It depends on lavage of the joint space through placement of two needles inside the superior joint space. The majority of surgeons use conventional puncturing technique (CPT), which is a blind technique for needle placement, in spite of its complications (extra-articular injection, multiple puncturing, facial nerve injury, intracranial penetration).Others use image guided puncturing techniques (CBCT,MSCT, MRI, or US) for superior joint space puncturing, which is proven to be a more accurate and precise technique with fewer complications. We fabricated a new customized guiding stent on a 3D soft and hard tissue model, printed out from MSCT, with adjusted depth and angulation for superior joint space puncturing. The puncturing using this new stent is easy and does not subject patients to imaging each time, as the confirmation of the needle positioning has already been done by the accurate measurements on MSCT. In addition, the procedure no longer requires general anesthesia or deep sedation. Clinically significant differences were noted between the use of IGPT and the present guiding stent, especially on the level of procedural time. These observations confirmed that the use of this stent was a predictable and highly efficient new approach for superior joint space puncturing
Further evidence on the extent and time course of repeat missing incidents involving children: A research note
This study examines the extent and time course of repeat missing incidents involving children. Using data from one UK police force (n = 2,251), we find (1) that the majority (65%) of missing incidents are repeats, (2) that a small group of repeatedly missing children (n = 43; 6%) account for a sizable proportion of all missing incidents (n=739, 33%) and (3) that the likelihood of a child going missing repeatedly is elevated in the weeks immediately following a previous missing incident. The implications of our findings for future research and for the prevention of missing incidents are discussed
Missing children: risks, repeats and responses
Investigating reports of missing children is a major source of demand for the police in the UK. Repeat disappearances are common, can indicate underlying vulnerabilities and have been linked with various forms of exploitation and abuse. Inspired by research on repeat victimisation, this paper examines the prevalence and temporal patterns of repeat missing episodes by children, as well as the characteristics of those involved. Using data on all missing children incidents recorded by one UK police service in 2015 (n = 3352), we find that: (a) 75% of missing incidents involving children were repeats, i.e. attributed to children who had already been reported missing in 2015; (b) a small proportion of repeatedly missing children (n = 59; 4%) accounted for almost a third of all missing children incidents (n = 952, 28%); (c) over half of all first repeat disappearances occurred within four weeks of an initial police recorded missing episode; and (d) children recorded as missing ten times or more over the one year study period were significantly more likely than those recorded missing once to be teenagers, in the care system or to have drug and/or alcohol dependencies. We conclude by discussing the implications of our findings for future research and the prevention of repeat disappearances by childre
A systematic review of tagging as a method to reduce theft in retail environments
Background: Retailers routinely use security tags to reduce theft. Presently, however, there has been no attempt to systematically review the literature on security tags. Guided by the acronym EMMIE, this paper set out to (1) examine the evidence that tags are effective at reducing theft, (2) identify the key mechanisms through which tags are expected to reduce theft and the conditions that moderate tag effectiveness, and (3) summarise information relevant to the implementation and economic costs of tagging. Methods: In this mixed-methods review, we performed systematic keyword searches of the published and unpublished literature, hand searched relevant journals, conducted forward and backward citation searches and consulted with four retailers. Studies were included if they reported an explicit goal of reducing the theft or shrinkage of items through the use of security tags in retail environments. Results: We identified 50 eligible studies, eight of which reported quantitative data on the effectiveness of tags in retail environments. Across these eight studies, five showed positive results associated with the introduction of tags, but heterogeneity in the type of tag and reported outcome measures precluded a meta-analysis. We identified three mechanisms through which tags might plausibly reduce theft-increase the risks, reduce the rewards, increase the effort-which were found to vary by tag type, and their activation dependent on five broad categories of moderator: retail store and staff, customers (including shoplifters), tag type, product type, and the involvement of the police and criminal justice system. Implementation challenges documented in the literature related mainly to staffing issues and tagging strategy. Finally, although estimates are available on the costs of tagging, our searches identified no highquality published economic evaluations of tagging. Conclusions: Through applying the EMMIE framework this review highlighted the complexity involved in security tagging in retail environments, whereby different kinds of tags are expected to reduce theft through different casual mechanisms which are dependent on a distinctive configuration of conditions. Based on the available evidence it is difficult to determine the effectiveness of tags as a theft reduction measure, albeit there is suggestive evidence that more visible tags are associated with greater reductions in theft than less visible tags
Isotopic substitution experiments in the hydrogenation of mandelonitrile over a carbon supported Pd catalyst: a nuclear magnetic resonance study
A mechanistic exploration of the liquid phase hydrogenation of the aromatic cyanohydrin mandelonitrile (C6H5CH(OH)CH2CN) over a carbon supported Pd catalyst to produce the primary amine, phenethylamine (C6H5CH2CH2NH2) is conducted. Prior examination showed the reaction to involve the production of the ketone intermediate 2-aminoacetophenone (C6H5C(O)CH2NH2), formed as a consequence of the presence of an acid catalysed tautomeric side reaction. The corresponding deuteration reaction, reported here and analysed by multinuclear NMR spectroscopy and mass spectrometry, is employed to further investigate accessible pathways. Examination of the resultant product distribution of the deuteration, and the location of deuterium incorporation establishes the role of a hydroxy-imine species as a key reaction intermediate. In addition, the acid catalysed tautomerism to the ketone is shown to be a reversible side reaction, but also a contributor to desired product formation. Moreover, an order for the three critical hydrogen consuming steps in phenethylamine formation is established. Hydrogenation of the nitrile functionality to afford the hydroxy-imine precedes hydrogenolysis of the hydroxyl group, with the final step being hydrogenation of the imine to form the target product, phenethylamine
Evaluation Of Platelet-Rich Plasma Effect On Treatment Of Temporomandibular Joint Anterior Disc Displacement
The use of Platelet-Rich-Plasma (PRP) may provide a new and improved treatment option for early and late Temporomandibular Joint (TMJ) disc displacement. However, there are no long-term studies on its use in TMJ arthritis in the literature. The present study evaluate 28 patients with different degrees of disc displacement over a period of time. These patients had experienced no pain reduction following conservative approaches (including splint therapy) and minimally invasive arthrocentesis treatment. All patients had evidence of disc displacement associated with pain and discomfort, and sometimes clicking. The patients were without systemic joint disease, septicarthritis, or autoimmune arthritis. Only patients who had not responded to conservative therapy were included in the present study. Pain intensity was recorded for each patient using a 0-10 VAS scale. Maximum Inter-incisal Opening (MIO) was also recorded. This assessment was performed at the pretreatment stage and then examinations 3,6,9,12 months respectively after administration of two intra-articular injections of autologous PRP.The results after 12 months revealed that intra-articular injection of autologous PRP appeared to be an effective treatment method for patients with disc displacement in this study. At the 12-months follow-up, all patients improved their mouth opening significantly. The majority of the PRP patients showed decreased pain. The average pain score before PRP administration was 7.5, while 3 months after PRP administration the pain score was 4.2. The pain score continued to decrease, reaching nearly 2 after 6 months and 0.5 by the end of 12 months. In conclusion, the use of PRP was found to be an effective and predictable treatment option for disc displacement
Matrix controlled channel diffusion of sodium in amorphous silica
To find the origin of the diffusion channels observed in sodium-silicate
glasses, we have performed classical molecular dynamics simulations of
NaO--4SiO during which the mass of the Si and O atoms has been
multiplied by a tuning coefficient. We observe that the channels disappear and
that the diffusive motion of the sodium atoms vanishes if this coefficient is
larger than a threshold value. Above this threshold the vibrational states of
the matrix are not compatible with those of the sodium ions. We interpret hence
the decrease of the diffusion by the absence of resonance conditions.Comment: 5 pages, 4 figure
How Strong is the Evidence-Base for Crime Reduction End Users?
To support the development and implementation of evidence-based crime reduction, we systematically identified and appraised 70 systematic reviews of single crime reduction measures published between 1975 and 2015. Using the EMMIE framework, we find that the quality of reporting on the Effectiveness of crime reduction measures is reasonably strong, particularly in systematic reviews published by the Cochrane and Campbell Collaborations. In contrast, evidence concerning the Mechanisms underpinning a crime reduction intervention, the conditions that Moderate effectiveness, Implementation challenges and the Economic costs and benefits of crime reduction was largely absent from the assessed systematic reviews. We conclude that there is a distinct lack of systematic review evidence in crime reduction that currently speaks to the knowledge needs of practitioners (i.e., how to make an intervention “work” for them)
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