2,120 research outputs found
Optimal method of flow and volume monitoring in patients mechanically ventilated with heliumâoxygen (HeâO2) mixtures
Exploring the potential relationships between microvascular haemodynamics and density in bone: a feasibility study utilising near infrared spectroscopy
This is the author accepted manuscript. The final version is available from UKIO2019 via the link in this recordRoyal College of Radiologist
Edge-Based Compartmental Modeling for Infectious Disease Spread Part III: Disease and Population Structure
We consider the edge-based compartmental models for infectious disease spread
introduced in Part I. These models allow us to consider standard SIR diseases
spreading in random populations. In this paper we show how to handle deviations
of the disease or population from the simplistic assumptions of Part I. We
allow the population to have structure due to effects such as demographic
detail or multiple types of risk behavior the disease to have more complicated
natural history. We introduce these modifications in the static network
context, though it is straightforward to incorporate them into dynamic
networks. We also consider serosorting, which requires using the dynamic
network models. The basic methods we use to derive these generalizations are
widely applicable, and so it is straightforward to introduce many other
generalizations not considered here
Clinical review: Goal-directed therapy - what is the evidence in surgical patients? The effect on different risk groups
Patients with limited cardiac reserve are less likely to survive and develop more complications following major
surgery. By augmenting oxygen delivery index (DO2I) with a combination of intravenous fl uids and inotropes (goaldirected therapy (GDT)), postoperative mortality and morbidity of high-risk patients may be reduced. However,
although most studies suggest that GDT may improve outcome in high-risk surgical patients, it is still not widely
practiced. We set out to test the hypothesis that GDT results in greatest benefi t in terms of mortality and morbidity in patients with the highest risk of mortality and have undertaken a systematic review of the current literature to see if this is correct. We performed a systematic search of Medline, Embase and CENTRAL databases for randomized controlled trials (RCTs) and reviews of GDT in surgical patients. To minimize heterogeneity we excluded studies involving cardiac, trauma, and paediatric surgery. Extremely high risk, high risk and intermediate risks of mortality were defi ned as >20%, 5 to 20% and <5% mortality rates in the control arms of the trials, respectively. Metaanalyses were performed and Forest plots drawn using RevMan software. Data are presented as odd ratios (OR; 95%
confi dence intervals (CI), and P-values). A total of 32 RCTs including 2,808 patients were reviewed. All studies reported mortality. Five studies (including 300 patients) were excluded from assessment of complication rates as the number of patients with complications was not reported. The mortality benefi t of GDT was confi ned to the extremely high-risk group (OR = 0.20, 95% CI 0.09 to 0.41; P < 0.0001). Complication rates were reduced in all subgroups (OR = 0.45, 95% CI 0.34 to 0.60; P < 0.00001). The morbidity benefi t was greatest amongst patients in the extremely high-risk subgroup (OR = 0.27, 95% CI 0.15 to 0.51; P < 0.0001), followed by the intermediate risk subgroup (OR = 0.43, 95% CI 0.27 to 0.67; P = 0.0002), and the high-risk subgroup (OR 0.56, 95% CI 0.36 to 0.89; P = 0.01). Despite heterogeneity in trial quality and design, we found GDT to be beneficial in all high-risk patients undergoing major surgery. The mortality benefit
of GDT was confined to the subgroup of patients at extremely high risk of death. The reduction of complication rates was seen across all subgroups of GDT patients
A statistical network analysis of the HIV/AIDS epidemics in Cuba
The Cuban contact-tracing detection system set up in 1986 allowed the
reconstruction and analysis of the sexual network underlying the epidemic
(5,389 vertices and 4,073 edges, giant component of 2,386 nodes and 3,168
edges), shedding light onto the spread of HIV and the role of contact-tracing.
Clustering based on modularity optimization provides a better visualization and
understanding of the network, in combination with the study of covariates. The
graph has a globally low but heterogeneous density, with clusters of high
intraconnectivity but low interconnectivity. Though descriptive, our results
pave the way for incorporating structure when studying stochastic SIR epidemics
spreading on social networks
Internal jugular vein thrombosis in a warfarinised patient: a case report
<p>Abstract</p> <p>Introduction</p> <p>Internal jugular vein thrombosis (IJVT) is a rare but potentially fatal condition. It usually arises following trauma to the internal jugular vein but is also seen in association with coagulopathies and advanced malignancies as part of a para-neoplastic syndrome.</p> <p>Case presentation</p> <p>We report a case of a 44 year old woman with a strong past medical history and family history of thrombotic disease who presented with abdominal pain and ascites. A stage III ovarian carcinoma was diagnosed and she underwent debulking of the tumour. She sustained a peri-operative haemorrhage and required insertion of a central line into the right internal jugular vein. At one month follow-up she presented as an emergency with a left neck mass and painful swallowing. A duplex ultrasound of her neck identified a left IJVT to the level of the brachiocephalic vein which had occurred despite warfarinisation and an INR of greater than 2. She was commenced on intravenous heparin and the swelling resolved over the course of a week.</p> <p>Conclusion</p> <p>This case illustrates an unusual presentation of a rare condition. In this case, the precise aetiology is unclear as the IJVT may have been related to a coagulopathy or the presence of advanced malignancy and occurred despite adequate anticoagulation.</p
Perigraft air is not always pathological: a case report
© 2007 Ball et al; licensee BioMed Central Ltd
Bragg Grating Corrosion Sensor
Historically, corrosion has not been included in the calculation of the life expectancy of aircraft. It is well known how stress-corrosion cracking and corrosion fatigue can significantly reduce the life expectancy of structures. Therefore, it can be correctly assumed that some aircraft flying near their expected life might actually be flying well beyond their âsafe lifeâ. Furthermore, due to DoD present tight budget requirements, its is expected that some defense aircraft might not be retired at their original expected life but will be reconditioned to fly beyond that time. All of these considerations indicate that early detection, quantification and prevention of corrosion is of critical importance for military aircraft. This is particularly true for Navy aircraft which fly in the most corrosive environment of all services
Inferring R0 in emerging epidemics: the effect of common population structure is small
When controlling an emerging outbreak of an infectious disease, it is essential to know the key epidemiological parameters, such as the basic reproduction number R0 and the control effort required to prevent a large outbreak. These parameters are estimated from the observed incidence of new cases and information about the infectious contact structures of the population in which the disease spreads. However, the relevant infectious contact structures for new, emerging infections are often unknown or hard to obtain. Here, we show that, for many common true underlying heterogeneous contact structures, the simplification to neglect such structures and instead assume that all contacts are made homogeneously in the whole population results in conservative estimates for R0 and the required control effort. This means that robust control policies can be planned during the early stages of an outbreak, using such conservative estimates of the required control effort
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