A case of metastatic Wilms’ tumour with reversible distortion of mediastinal anatomy : a diagnostic challenge for the echocardiographer

Delineation and documentation of anatomy in the presence of significant mass pathology presents a diagnostic challenge. This often necessitates the implementation of more than one imaging modality in order to perform an adequate assessment. We present a three-year old boy with extensive distortion of mediastinal anatomy secondary to pleural metastases from a Wilms tumour. This limited the ability to accurately assess mediastinal anatomy and cardiac function at baseline. Reassessment following initiation of chemotherapy showed a significant reduction in size of metastases with complete resolution of the mediastinal distortion.peer-reviewe

Retroperitoneal fibrosis: a case of a patient (63y/o) treated with low-dose methotrexate (MTX) and 6-methylprednisolone (6-MP)

Retroperitoneal fibrosis (RPF), is a rare fibroinflammatory disease. The pathogenesis of RPF is still unclear and numerous theories have been reported such as environmental factors, immunologic process, genetic component, local inflammation and advanced atherosclerosis. RPF is characterized by the presence of a particular retroperitoneal fibrotic tissue which is white, woody and involving retroperitoneal structures such as the great vessels, ureters and psoas muscle. The main complication of RPF is the obstruction of local structures such as the ureters due to the fibrosis and the treatment of this aspect represents the main challenge for this pathology. RPF medical treatment consists of corticosteroids or/and immunosuppressive therapy. We report a case of a patient (63y/o) affected by idiopathic RPF treated with low-dose methotrexate (MTX) and 6-methylprednisolone (6-MP) for two years, describing and confirming the effectiveness and safety of a long-term low-dose MTX and 6-MP treatment

Searching for Dark Matter at the LHC with a Mono-Z

We investigate a mono-Z process as a potential dark matter search strategy at the LHC. In this channel a single Z boson recoils against missing transverse momentum, attributed to dark matter particles, $\chi$, which escape the detector. This search strategy is related, and complementary to, monojet and monophoton searches. For illustrative purposes we consider the process $q\bar{q} -> \chi\chi Z$ in a toy dark matter model, where the Z boson is emitted from either the initial state quarks, or from the internal propagator. Among the signatures of this process will be a pair of muons with high pT that reconstruct to the invariant mass of the Z, and large amounts of missing transverse energy. Being a purely electroweak signal, QCD and other Standard Model backgrounds are relatively easily removed with modest selection cuts. We compare the signal to Standard Model backgrounds and demonstrate that, even for conservative cuts, there exist regions of parameter space where the signal may be clearly visible above background in future LHC data, allowing either new discovery potential or the possibility of supplementing information about the dark sector beyond that available from other observable channels.Comment: 11 pages, 13 figure

Overdose prevention for injection drug users: Lessons learned from naloxone training and distribution programs in New York City

BACKGROUND: Fatal heroin overdose is a significant cause of mortality for injection drug users (IDUs). Many of these deaths are preventable because opiate overdoses can be quickly and safely reversed through the injection of Naloxone [brand name Narcan], a prescription drug used to revive persons who have overdosed on heroin or other opioids. Currently, in several cities in the United States, drug users are being trained in naloxone administration and given naloxone for immediate and successful reversals of opiate overdoses. There has been very little formal description of the challenges faced in the development and implementation of large-scale IDU naloxone administration training and distribution programs and the lessons learned during this process. METHODS: During a one year period, over 1,000 participants were trained in SKOOP (Skills and Knowledge on Opiate Prevention) and received a prescription for naloxone by a medical doctor on site at a syringe exchange program (SEP) in New York City. Participants in SKOOP were over the age of 18, current participants of SEPs, and current or former drug users. We present details about program design and lessons learned during the development and implementation of SKOOP. Lessons learned described in the manuscript are collectively articulated by the evaluators and implementers of the project. RESULTS: There were six primary challenges and lessons learned in developing, implementing, and evaluating SKOOP. These include a) political climate surrounding naloxone distribution; b) extant prescription drug laws; c) initial low levels of recruitment into the program; d) development of participant appropriate training methodology; e) challenges in the design of a suitable formal evaluation; and f) evolution of program response to naloxone. CONCLUSION: Other naloxone distribution programs may anticipate similar challenges to SKOOP and we identify mechanisms to address them. Strategies include being flexible in program planning and implementation, developing evaluation instruments for feasibility and simplicity, and responding to and incorporating feedback from participants

A CFD and experimental investigation into a non-intrusive method for measuring cooling air mass flow rate through a synchronous generator

This paper presents a detailed methodology for a non-intrusive measurement of cooling air mass flow rate that enables an overall machine evaluation. This approach enables the simultaneous measurement of air mass flow with shaft torque at differing operating points, while minimising the change in air flow introduced by the measurement system. The impact of geometric parameters in the designed system are investigated using a detailed 180° CFD model. Special attention was paid to minimising their influence on pressure drop, mass flow rate through the machine and measurement uncertainty. Based on the results of this investigation, the system was designed and manufactured and the experimentally measured data was used to validate the CFD predictions. For the as optimal identified configuration, the flow rate is predicted to decrease by 2.2 % relative to unrestricted operation. The achieved measurement uncertainty is ±2.6 % at synchronous speed

CFD optimisation of the thermal design for a vented electrical machine

Optimisation algorithms hold the potential to dramatically reduce computational time whilst ensuring the optimal solution is found. Within this paper, the feasibility of using this novel approach on complex 3-D Computational Fluid Dynamics models, which are required for thermal management of electrical machines, is proven. A model of a simplified generator is parameterised with the aim of minimising the peak stator temperature by varying the axial location of a single stator vent. By generating a single parameterised case, and automating the optimisation, the simulations are run independently after initial setup, hence reducing both computational and user time. Locating a vent in the optimal position reduced the peak stator temperature by 9.4 K. A sensitivity study linking peak temperature to vent position has been carried out developing a polynomial relationship between them for the aforementioned geometry. Mass flow and pressure distribution in the vent have been analysed in detail

Cardiovascular magnetic resonance (CMR) in restrictive cardiomyopathies

The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated

Item Ordering and Computerized Classification Tests With Cluster-Based Scoring: An Investigation of the Countdown Method

The countdown method is a well-known approach to reducing the average length of screening instruments that are presented by computer. In the countdown method, testing is terminated once the result of the screener (“positive” or “negative”) has been unambiguously determined from prior answers. Previous research has examined whether presenting dichotomously scored items in order from “least to most frequently endorsed” or “most to least frequently endorsed” is more efficient when the countdown method is used. The current study describes the Mean Score procedure, an extension of the above item ordering procedures to polytomously scored items, and evaluates its efficiency relative to the distribution of other possible item orderings in 2 real-data simulations. Both simulations involve item responses to the Posttraumatic Stress Disorder (PTSD) Checklist for DSM–5 (PCL-5). In the first simulation, items were scored polytomously, and a single cutoff point was used to determine the screening result. In the second simulation, items were converted to dichotomous scores, as well as categorized into 4 clusters; a positive result for the entire assessment was obtained if and only if a positive result was obtained for each cluster. The latter simulation also investigated the effect of reordering the clusters themselves on the efficiency of the countdown method. Results indicated that the Mean Score procedure does not necessarily produce the optimal ordering, but tends to assemble an efficient item ordering relative to the distribution of possible orderings. In the second simulation, reordering the clusters themselves affected efficiency. Future research directions are suggested