821 research outputs found
Breast compression techniques in screening mammography – A Maltese evaluation project
Introduction: In screening mammography, the radiographer should be responsible for providing mammograms of high diagnostic value, possibly without subjecting clients to a painful experience. This skill is demonstrated via the technique of breast compression and is explored in this study by analysing insights about methods and underlying principles in regards to this procedure. Methods: One-to-one semi-structured interviews were conducted with radiographers who perform screening mammography in Malta. For data analysis, a descriptive phenomenological approach following a simplified version of Hycner's (1985) method was adopted. Results: Five general themes were extracted from the data; meeting the client, preparing the client, the mammography procedure, pain from compression and client turnout. It was determined that the participants alter their breast compression technique according to the client rather than following a rigid step-by-step process and that explanation and requesting client feedback are essential to obtain cooperation. Additionally, mammography positioning and compression application are tailored in a way that encourage compliance, however not at the expense of degrading image quality. Ultimately, it is also believed that a proper breast compression technique positively influences client turnout. Conclusion: The results of this study demonstrate that radiographers should be flexible in their approach in order to carry out a successful breast compression technique. However, it has also been shown that such effectiveness in practice is gained from experience rather than initial training. If exposed to this study's findings, new mammographers would be able to form a robust core of knowledge before embarking on the challenging specialisation of mammography
Cows fed hydroponic fodder and conventional diet: effects on milk quality
The technology of green fodder production is especially important in arid and semiarid regions. Hydroponics improves on average the amount of crops in the same space, as traditional soil-based farming and can reduce water consumption compared to traditional farming methods. Limited research has been carried out on the use of hydroponic fodder and milk quality. A comparative study of traditional (Malta farm) and hydroponic fodder (Gozo farm) was conducted in Malta with 20 cows of the Holstein\u2013Friesian breed from two farms. Individual and bulk-tank milk samples were collected once a week for a period of 1 month in order to evaluate physical (pH, conductivity, density, freezing point) and chemical (fat, protein, ash, lactose, solid nonfat) parameters as well as mineral (Zn, Cu, Pb, Ba) content. Milk proximate and physical data were processed by analysis of variance (ANOVA) for repeated measures and an ANOVA procedure with farm and time as effects for minerals. The results indicated differences in fat content and pH, showing higher values (P < 0.05) in milk samples of cows fed with the hydroponic rather than the traditional fodder; a significant time effect (P < 0.001) was found in all qualitative analyses except for lactose and salts. Minerals were in the range as reported elsewhere; Cu and Pb content was significantly higher (P < 0.001) in the Gozo farm than the one in Malta, whereas Zn content showed higher values in Malta (P < 0.001) than Gozo. Although the proximate results were similar for both farms, except for the higher fat content for the Gozo farm, principal component analysis (PCA) revealed that milk quality for the Gozo farm was superior to that of the Malta farm. However, further studies are needed to determine the effects of different hydroponic fodder using a large herd size
The delayed type hypersensitivity response: a model for studying the defects in skin immunity in the old
Immunity declines during ageing, however the mechanisms involved are not known. In this study we show that the cutaneous delayed type hypersensitivity response (DTH) to recall antigens is significantly decreased in old individuals and that this was unrelated to CCR4, CLA or CD11a expression or physical capacity for migration of CD4+ T cells. Instead, there was defective activation of dermal blood vessels of these subjects that resulted from decreased TNF-α secretion by macrophages after antigen-challenge in vivo. However, isolated skin macrophages from these subjects could be induced to secrete TNF-α after stimulation with TLR 1/2 or TLR 4 ligands in vitro, indicating that the defect is reversible. The decreased conditioning of tissue microenvironments by macrophage-derived cytokines may therefore lead to defective immunosurveillance by memory T cells. This may be a predisposing factor for the development of malignancy and infection in the skin during ageing
ANTI-NMDA ENCEPHALITIS IN THE ACUTE SETTING
Background: Encephalitis associated with antibodies targeted against the N-methyl-D-aspartate (NMDA) receptor is
increasingly recognised as a major cause of an acute presentation of organic psychosis. Misdiagnosis and subsequent inappropriate
referral to psychiatric services is common and avoidable. This review focuses on addressing this issue in the acute setting.
Methods: The authors present a review of existing literature relating to the pathophysiology and presentation of anti-NMDA
receptor encephalitis, prior to proposing a management pathway avoiding delays to treatment incurred through misdiagnosis or
inappropriate referral.
Conclusions: Acute care physicians should have a low threshold for suspecting anti-NMDA receptor encephalitis in any patient
presenting with acute psychosis in the context of non-specific coryzal and constitutional symptoms in whom infective causes have
been excluded. The presence of pleocytosis and reduced protein in routine CSF analysis should further raise suspicion, and samples
should be sent for immunohistochemical testing. Availability and efficiency of this testing is currently suboptimal
ANTI-NMDA ENCEPHALITIS IN THE ACUTE SETTING
Background: Encephalitis associated with antibodies targeted against the N-methyl-D-aspartate (NMDA) receptor is
increasingly recognised as a major cause of an acute presentation of organic psychosis. Misdiagnosis and subsequent inappropriate
referral to psychiatric services is common and avoidable. This review focuses on addressing this issue in the acute setting.
Methods: The authors present a review of existing literature relating to the pathophysiology and presentation of anti-NMDA
receptor encephalitis, prior to proposing a management pathway avoiding delays to treatment incurred through misdiagnosis or
inappropriate referral.
Conclusions: Acute care physicians should have a low threshold for suspecting anti-NMDA receptor encephalitis in any patient
presenting with acute psychosis in the context of non-specific coryzal and constitutional symptoms in whom infective causes have
been excluded. The presence of pleocytosis and reduced protein in routine CSF analysis should further raise suspicion, and samples
should be sent for immunohistochemical testing. Availability and efficiency of this testing is currently suboptimal
NEUROPSYCHIATRIC MANIFESTATIONS OF COLLOID CYSTS: A REVIEW OF THE LITERATURE
Colloid cysts account for approximately 2% of primary brain tumours and the majority of cases are identified in the fourth and
fifth decade. They are small, gelatinous neoplasms lined by a single layer of mucin-secreting columnar epithelium that are thought to
arise from errors in folding of the primitive neuroepithelium. They develop in the rostral aspect of the third ventricle in the foramen
of Monro in 99% of cases and despite their benign histology carry a poor prognosis, with a mortality greater than 10% in
symptomatic cases.
The location of colloid cysts within the ventricular system results in obstruction of the foramen of Monro as the cyst grows,
disrupting the circulation of cerebrospinal fluid (CSF) and causing hydrocephalus. This is the mechanism behind the most common
presenting symptoms of postural headache, nausea and vomiting - a clinical picture synonymous with hydrocephalus and
intracranial pathology.
In addition to these classical neurological symptoms, there is a high prevalence of psychiatric symptoms in the patient population,
with symptoms ranging from anterograde amnesia to gustatory hallucination. These symptoms can occur with or without the
presence of hydrocephalus, and are thought to be secondary to compression of connecting pathways between the mesocortices and
subcortical limbic regions. These symptoms have been shown to be comparative in frequency to the classical symptoms, yet are
rarely the reason for referral to a neurological or neurosurgical service for investigation
Influenza vaccination survey in Maltese healthcare workers in the COVID-19 era
Introduction: Seasonal influenza globally infects 5%-15% annually, with a total of 3-5 million cases of severe illness and ≤500,000 deaths. Hospital-acquired influenza has a particularly high mortality, and healthcare workers are frequently the source of these infections. This study was carried out to ascertain last year’s influenza vaccination uptake in Malta’s government sector healthcare workers, and estimate the likely vaccine uptake rate in the coming winter season when COVID-19 is expected to be prevalent.
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Methods: A short, anonymous questionnaire was sent via the sector’s standard email services (open 30/06-17/072020).
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Results: There were a total of 735 (7.6%) responses from a total workforce of 9,681. The proportion of Maltese healthcare workers who did not take the vaccine last year but who are likely to take the vaccine this winter halved from 41% to 21%. Doctors had the highest baseline uptake (23% refused vaccination in 2019) and the highest likely uptake next winter (6% likely to refuse vaccination in 2020). Analysis by age showed a likely increase in vaccine uptake with increasing age across almost all age brackets.
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Discussion: Influenza vaccination is advantageous and incurs a trivial burden. Clinicians, legislators and ethicists are increasingly aware of this aspect of healthcare, and increasingly mandate compulsory seasonal influenza vaccination for healthcare workers, where vaccine refusal can be taken to equate to maleficent practice. Education with regard to the low risk of side effects may increase voluntary uptake. Institutions are also responsible for ensuring employee vaccination, and this is even more the case for next winter in the setting of the potential co-circulation of novel COVID-19 with influenza.peer-reviewe
H-ATLAS/GAMA and HeViCS – dusty early-type galaxies in different environments
The Herschel Space Observatory has had a tremendous impact on the study of extragalactic dust. Specifically, early-type galaxies (ETG) have been the focus of several studies. In this paper, we combine results from two Herschel studies – a Virgo cluster study Herschel Virgo Cluster Survey (HeViCS) and a broader, low-redshift Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS)/Galaxy and Mass Assembly (GAMA) study – and contrast the dust and associated properties for similar mass galaxies. This comparison is motivated by differences in results exhibited between multiple Herschel studies of ETG. A comparison between consistent modified blackbody derived dust mass is carried out, revealing strong differences between the two samples in both dust mass and dust-to-stellar mass ratio. In particular, the HeViCS sample lacks massive ETG with as high a specific dust content as found in H-ATLAS. This is most likely connected with the difference in environment for the two samples. We calculate nearest neighbour environment densities in a consistent way, showing that H-ATLAS ETG occupy sparser regions of the local Universe, whereas HeViCS ETG occupy dense regions. This is also true for ETG that are not Herschel-detected but are in the Virgo and GAMA parent samples. Spectral energy distributions are fit to the panchromatic data. From these, we find that in H-ATLAS the specific star formation rate anticorrelates with stellar mass and reaches values as high as in our Galaxy. On the other hand HeViCS ETG appear to have little star formation. Based on the trends found here, H-ATLAS ETG are thought to have more extended star formation histories and a younger stellar population than HeViCS ETG
A method to extract slip system dependent information for crystal plasticity models
A tool to implement a length scale dependency to classical crystal plasticity simulations is presented. Classical crystal plasticity models do not include a size effect; therefore, the size of the grain does not influence the simulated deformation. Classical crystal plasticity advancements have been through the inclusion of stress or strain gradient based constitutive models to improve the simulation of length scale dependent deformation. However, this tool presents an alternative to implementing a length scale, where the influence of slip pile-up in the form of dislocations at grain boundaries as a potential to explaining the Hall-Petch effect in materials. This is achieved by calculating the slip distance in adjacent grains for each slip system, by assuming the total slip length spans the grain in the slip direction. These calculations can occur in two ways. The first is the analysis occurs at the start of the simulation, therefore, only occurs once. If this approach is used, the computational cost of this tool is minute. However, if the simulations consider large deformations, during which it is expected that the grains are going to undergo large rotations, then it would be advantageous to the have the tool recalculate the information during the analysis. Consequently, the computational cost would depend on the resolution of the modelled geometry, the number of grains, and the number of slip systems. The tool also provides a capability to develop constitutive models based on complex grain boundary features which can be implemented in classical crystal plasticity models and gradient based crystal plasticity models. The described calculation process is implemented through a Fortran subroutine, which has been designed to be easily used in crystal plasticity simulations. The presented tool also includes Python code designed to link with microstructures built using DREAM.3D to extract the required input data to the Fortran subroutine. The proposed tool is not limited to classical crystal plasticity formulations, instead the data extracted and outputted from the Fortran subroutine can be used to serve alternative purposes in both stress and strain gradient crystal plasticity models. The proposed tool can be modified to extract additional data to that presented. The slip distance in the adjacent grain, the distance from the grain boundary of the current calculation point, and the interaction between slip systems between grains can be used in any crystal plasticity constitutive models
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