465 research outputs found
Oral cancer: current role of radiotherapy and chemotherapy
The term oral cavity cancer (OSCC) constitutes cancers of the mucosal surfaces of the lips, floor of mouth, oral
tongue, buccal mucosa, lower and upper gingiva, hard palate and retromolar trigone. Treatment approaches for
OSCC include single management with surgery, radiotherapy [external beam radiotherapy (EBRT) and/or brachy
therapy], as well as adjuvant systemic therapy (chemotherapy and/or target agents); various combinations of these
modalities may also be used depending on the disease presentation and pathological findings. The selection of sole
or combined modality is based on various considerations that include disease control probability, the anticipated
functional and cosmetic outcomes, tumor resectability, patient general condition, and availability of resources and
expertise. For resectable OSCC, the mainstay of treatment is surgery, though same practitioners may advocate for
the use of radiotherapy alone in selected "early" disease presentations or combined with chemotherapy in more
locally advanced stage disease. In general, the latter is more commonly reserved for cases where surgery may be
problematic. Thus, primary radiotherapy ± chemotherapy is usually reserved for patients unable to tolerate or who
are otherwise unsuited for surgery. On the other hand, brachytherapy may be considered as a sole modality for
early small primary tumor. It also has a role as an adjuvant to surgery in the setting of inadequate pathologically
assessed resection margins, as does postoperative external beam radiotherapy ± chemotherapy, which is usually
reserved for those with unfavorable pathological features. Brachytherapy can also be especially useful in the reirradiation setting for persistent or recurrent disease or for a second primary arising within a previous radiation
field. Biological agents targeting the epithelial growth factor receptor (EGFR) have emerged as a potential modality in combination with radiotherapy or chemoradiotherpy and are currently under evaluation in clinical trials
Coherent adiabatic transport of atoms in radio-frequency traps
Coherent transport by adiabatic passage has recently been suggested as a high-fidelity technique to engineer the center-of-mass state of single atoms in inhomogeneous environments. While the basic theory behind this process is well understood, several conceptual challenges for its experimental observation have still to be addressed. One of these is the difficulty that currently available optical or magnetic micro-trap systems have in adjusting the tunneling rate time dependently while keeping resonance between the asymptotic trapping states at all times. Here we suggest that both requirements can be fulfilled to a very high degree in an experimentally realistic setup based on radio-frequency traps on atom chips. We show that operations with close to 100% fidelity can be achieved and that these systems also allow significant improvements for performing adiabatic passage with interacting atomic clouds
Spatial and energetic mode dynamics of cold atomic systems
In this thesis we relate the formal description of various cold atomic systems in the
energy eigenbasis, to the observable spatial mode dynamics. Herein the `spatial mode
dynamics' refers to the direction of photon emission following the spontaneous emission
of an excited fermion in the presence of a same species and spin ideal anisotropic Fermi
sea in its internal ground state. Due to the Pauli principle, the presence of the ground
state Fermi sea renders the phase space, anisotropic and only partially accessible, thereby
a ecting the direction of photon emission following spontaneous emission.
The spatial and energetic mode dynamics also refers to the quantum `tunneling' interaction
between localised spatial modes, synonymous with double well type potentials.
Here we relate the dynamics of the wavefunction in both the energetic and spatial representations.
Using this approach we approximate the relationship between the spatial
and energetic representations of a wavefunction spanning three spatial and energetic
modes. This is extended to a process known as Spatial Adiabatic Passage, which is a
technique to transport matter waves between localised spatial modes. This approach
allows us to interpret the transport of matter waves as a signature of a geometric phase
acquired by the one of the internal energy eigenstates of the system during the cyclical
evolution. We further show that this geometric phase may be used to create spatial
mode qubit and qutrit states
The analysis of biogenic amines by standard and novel methods
Biologically active amines in cheese and fish arising from metabolic activities of food-borne microorganisms have been implicated as the causative agents in many food poisoning outbreaks. An awareness of amine levels in foods today is therefore important in relation to food spoilage and safety.
In recent years there has been increased consumer awareness about food composition and safety and a corresponding increase in regulatory action. The food industry requires reliable and cost effective analytical methods for process and quality control to meet the needs of the consumer. Therefore, this study focussed on comparing conventional analytical methods involving HPLC and fluorimetry, for histamine analysis in food.
Irish cheeses and canned tuna samples were selected for analysis of histamine content by a standard fluorometric technique. The cheeses, Cheddar, Cooleney, Edam, Emmental and Brie were analysed over a three-week period and observations of any changes in histamine levels were made. All samples were stored at 4°C until analysis to replicate the retail outlet storage conditions. The histamine levels found in cheese in this study were low in comparison to levels in reported literature, ranging from 0.2 to 4.3 mg/lOOg and were non hazardous for consumption. Canned tuna was analysed by the same technique. Results from this study showed that the tuna contained high levels of histamine, 20 mg/lOOg that increased to hazardous levels upon putrefaction after a 96 hour period. A HPLC method of detection was established based on the derivitisation of histamine with dansyl chloride and UV detection with the aim of detecting histamine quantitatively in food samples and to facilitate correlation studies with the fluorometric method of detection. A novel method, based on an amine oxidase system coupled to an ammonia sensing calixarene, was investigated as an alternative and improved method of histamine detection
The effect of simulation-based training on initial performance of ultrasound-guided axillary brachial plexus blockade in a clinical setting – a pilot study
BACKGROUND: In preparing novice anesthesiologists to perform their first ultrasound-guided axillary brachial plexus blockade, we hypothesized that virtual reality simulation-based training offers an additional learning benefit over standard training. We carried out pilot testing of this hypothesis using a prospective, single blind, randomized controlled trial. METHODS: We planned to recruit 20 anesthesiologists who had no experience of performing ultrasound-guided regional anesthesia. Initial standardized training, reflecting current best available practice was provided to all participating trainees. Trainees were randomized into one of two groups; (i) to undertake additional simulation-based training or (ii) no further training. On completion of their assigned training, trainees attempted their first ultrasound-guided axillary brachial plexus blockade. Two experts, blinded to the trainees’ group allocation, assessed the performance of trainees using validated tools. RESULTS: This study was discontinued following a planned interim analysis, having recruited 10 trainees. This occurred because it became clear that the functionality of the available simulator was insufficient to meet our training requirements. There were no statistically significant difference in clinical performance, as assessed using the sum of a Global Rating Score and a checklist score, between simulation-based training [mean 32.9 (standard deviation 11.1)] and control trainees [31.5 (4.2)] (p = 0.885). CONCLUSIONS: We have described a methodology for assessing the effectiveness of a simulator, during its development, by means of a randomized controlled trial. We believe that the learning acquired will be useful if performing future trials on learning efficacy associated with simulation based training in procedural skills. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01965314. Registered October 17th 2013
Coherent transport by adiabatic passage on atom chips
Adiabatic techniques offer some of the most promising tools for achieving high-fidelity control of the center-of-mass degree of freedom of single atoms. Because the main requirement of these techniques is to follow an eigenstate of the system, constraints on timing and field strength stability are usually low, especially for trapped systems. In this paper we present a detailed example of a technique to adiabatically transport a single atom between different waveguides on an atom chip. To ensure that all conditions are fulfilled, we carry out fully three-dimensional simulations of the system, using experimentally realistic parameters. We also detail our method for simulating the system in very reasonable time scales on a consumer desktop machine by leveraging the power of graphics-processing-unit computing
Does Place Matter When Understanding Loneliness and Social Isolation?
Physical distancing and restriction of movements as measures to prevent the spread of Covid-19 required people to change their work, home and social lives. Loneliness and social isolation have emerged as key public health issues during the pandemic. Traditionally when considering loneliness the focus is often on individual factors rather than within the context of structural and environmental dimensions. This paper will utilise data from the Coping with Loneliness, Isolation and Covid-19 global online survey which had over 20, 000 global responses from people aged 18+ in 2020. Analysis will use the lens of ‘place’ and the 5-item UCLA scale and 6-item Lubben social network scale to understand the social and demographic characteristics and structural and environmental factors associated with those experiencing loneliness and/or social isolation in rural and urban areas both before and during the pandemic. The paper will conclude with key messages from a public health perspective
Self-management needs of Irish adolescents with Juvenile Idiopathic Arthritis (JIA): how can a Canadian web-based programme meet these needs?
Background Juvenile Idiopathic Arthritis (JIA) affects over 1000 children and adolescents in Ireland, potentially impacting health-related quality-of-life. Accessible self-management strategies, including Internet-based interventions, can support adolescents in Ireland where specialist rheumatology care is geographically-centralised within the capital city. This study interviewed adolescents with JIA, their parents, and healthcare professionals to (i) explore the self-management needs of Irish adolescents; and (ii) evaluate the acceptability of an adapted version of a Canadian JIA self-management programme (Teens Taking Charge: Managing Arthritis Online, or TTC) for Irish users. Methods Focus groups and interviews were conducted with Irish adolescents with JIA (N = 16), their parents (N = 13), and Irish paediatric healthcare professionals (HCPs; N = 22). Adolescents were aged 12–18 (Mage = 14.19 years), and predominantly female (62.5%). Participants identified the needs of adolescents with JIA and evaluated the usefulness of the TTC programme. Data were analysed using a thematic analysis approach. Results Five themes emerged: independent self-management; acquiring skills and knowledge to manage JIA; unique challenges of JIA in Ireland; views on web-based interventions; and understanding through social support. Adolescents acknowledged the need for independent self-management and gradually took additional responsibilities to achieve this goal. However, they felt they lacked information to manage their condition independently. Parents and adolescents emphasised the need for social support and felt a peer-support scheme could provide additional benefit to adolescents if integrated within the TTC programme. All participants endorsed the TTC programme to gain knowledge about JIA and offered suggestions to make the programme relevant to Irish users. Conclusions There is scope for providing easily-accessible, accurate information to Irish families with JIA. The acceptability of adapting an existing JIA self-management intervention for Irish users was confirmed
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