97 research outputs found
Is a Magnetic-Manual Targeting Device an Appealing Alternative for Distal Locking of Tibial Intramedullary Nails?
Background: In order to enable a radiation-free, accurate and simple positioning of distal locking screws, a combined magnetic and manual targeting system has been developed by Sanatmetal®. Where a low-frequency magnetic field is initially used to detect the position of the first drill hole and three more holes can be found with a mechanical template.
Objectives: Our cadaver study was performed to evaluate the accuracy and efficiency of this device.
Materials and Methods: In two runs, 30 probands (group 1: 10 students; group 2: 10 residents; group 3: 10 attendings), none of who being familiar with the device, tested the radiation-free system using 60 intact cadaver tibias. Each proband performed the surgical procedure twice in succession.
Results: Referring to the first attempts, 9.6, 7.2 and 7.1 minutes were the time periods required to insert the four distal screws and the relevant values for the second attempts were 8.6, 6.3 and 6.2 minutes; in both cases revealing a significant difference between group 1 and 2 and group 1 and 3. Furthermore, the mean values within each group indicated a significant decrease of the test duration. Out of the 240 drillings, only one failure (group 1) occurred, representing an accuracy of 99.58 %. Of the probands, 90 % rated the targeting device better than the free-hand technique and 77 % at least attested a high user-friendliness.
Conclusions: Due to our satisfactory test results, the brief training, the steep learning curve and the radiation-free technique the new device has to be considered an appealing alternative for distal locking
Bayesian averaging over Decision Tree models for trauma severity scoring
Health care practitioners analyse possible risks of misleading decisions and need to estimate and quantify uncertainty in predictions. We have examined the “gold” standard of screening a patient's conditions for predicting survival probability, based on logistic regression modelling, which is used in trauma care for clinical purposes and quality audit. This methodology is based on theoretical assumptions about data and uncertainties. Models induced within such an approach have exposed a number of problems, providing unexplained fluctuation of predicted survival and low accuracy of estimating uncertainty intervals within which predictions are made. Bayesian method, which in theory is capable of providing accurate predictions and uncertainty estimates, has been adopted in our study using Decision Tree models. Our approach has been tested on a large set of patients registered in the US National Trauma Data Bank and has outperformed the standard method in terms of prediction accuracy, thereby providing practitioners with accurate estimates of the predictive posterior densities of interest that are required for making risk-aware decisions
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
Bayesian averaging over decision tree models: an application for estimating uncertainty in trauma severity scoring
Introduction
For making reliable decisions, practitioners need to estimate uncertainties that exist in data and decision models. In this paper we analyse uncertainties of predicting survival probability for patients in trauma care. The existing prediction methodology employs logistic regression modelling of Trauma and Injury Severity Score(external) (TRISS), which is based on theoretical assumptions. These assumptions limit the capability of TRISS methodology to provide accurate and reliable predictions.
Methods
We adopt the methodology of Bayesian model averaging and show how this methodology can be applied to decision trees in order to provide practitioners with new insights into the uncertainty. The proposed method has been validated on a large set of 447,176 cases registered in the US National Trauma Data Bank in terms of discrimination ability evaluated with receiver operating characteristic (ROC) and precision–recall (PRC) curves.
Results
Areas under curves were improved for ROC from 0.951 to 0.956 (p = 3.89 × 10−18) and for PRC from 0.564 to 0.605 (p = 3.89 × 10−18). The new model has significantly better calibration in terms of the Hosmer–Lemeshow Hˆ" role="presentation">
statistic, showing an improvement from 223.14 (the standard method) to 11.59 (p = 2.31 × 10−18).
Conclusion
The proposed Bayesian method is capable of improving the accuracy and reliability of survival prediction. The new method has been made available for evaluation purposes as a web application
Decomposition and nutrient dynamics in a Spartina alterniflora marsh of the Bahia Blanca estuary, Argentina
Seroprevalence of Toxoplasma gondii in Gallus domesticus in Havana, Cuba
El estudio tuvo como objetivo determinar la seroprevalencia de T. gondii en Gallus domesticus en La Habana, Cuba. Se colectaron 300 muestras de sueros de pollitas White Leghorn L33 en fase de desarrollo en 2015, distribuidas a razón de 100 aves por cada lote incorporado a la unidad avícola desde procedencias diferentes. Las muestras fueron analizadas mediante un ELISA de inhibición y se utilizaron las pruebas Chi-cuadrado y Dócima de Duncan para comparar las proporciones de aves positivas entre los lotes estudiados. Se encontró una relativa baja seroprevalencia de T. gondii (9.6%), similar a otros hallazgos reportados a nivel internacional. Se evidenciaron diferencias significativas (p=0.0001) en la prevalencia de T. gondii entre los tres lotes de aves. Se concluye que la seroprevalencia de T. gondii en Gallus domesticus en La Habana es baja, aunque esta constituye un riesgo de infección para las poblaciones humanas y animales susceptibles.The aim of this study was to determine the seroprevalence of T. gondii in Gallus domesticus in Havana, Cuba. Three hundred serum samples were collected from White Leghorn pullets L33 in growing stage in 2015. Samples represented 100 birds per batch incorporated into the poultry unit from different origins. Samples were evaluated by an ELISA inhibition test and data was analyzed by the Chi-square and Duncan tests to compare proportions of positive birds among batches. A relatively low seroprevalence of T. gondii was found (9.6%), similar to other findings reported internationally. Significant differences (p=0.0001) in the prevalence of T. gondii among the three bird batches were found. It is concluded that the seroprevalence of T. gondii in Gallus domesticus in Havana is low, though this constitutes a risk of infection for susceptible human and animal populations
Intensive enteral nutrition is ineffective for individuals with severe alcoholic hepatitis treated with corticosteroids.
peer reviewedBACKGROUND & AIMS: Severe alcoholic hepatitis (AH) is a lifethreatening
disease for which adequate oral nutritional support
is recommended. We performed a randomized controlled trial to
determine whether the combination of corticosteroid and
intensive enteral nutrition therapy is more effective than corticosteroid
therapy alone in patients with severe AH. METHODS:
We enrolled 136 heavy consumers of alcohol (age, 18–75 y)
with recent onset of jaundice and biopsy-proven severe AH in
our study, performed at 18 hospitals in Belgium and 2 in
France, from February 2010 through February 2013. Subjects
were assigned randomly (1:1) to groups that received either
intensive enteral nutrition plus methylprednisolone or conventional
nutrition plus methylprednisolone (controls). In the
intensive enteral nutrition group, enteral nutrition was given
via feeding tube for 14 days. The primary end point was patient
survival for 6 months. RESULTS: In an intention-to-treat analysis,
we found no significant difference between groups in
6-month cumulative mortality: 44.4% of patients died in the
intensive enteral nutrition group (95% confidence interval [CI],
32.2%–55.9%) and 52.1% of controls died (95% CI, 39.4%–
63.4%) (P ¼ .406). The enteral feeding tube was withdrawn
prematurely from 48.5% of patients, and serious adverse
events considered to be related to enteral nutrition occurred in
5 patients. Regardless of group, a greater proportion of patients
with a daily calorie intake less than 21.5 kcal/kg/day died
(65.8%; 95% CI, 48.8–78.4) than patients with a higher intake
of calories (33.1%; 95% CI, 23.1%–43.4%) (P < .001).
CONCLUSIONS: In a randomized trial of patients with severe AH
treated with corticosteroids, we found that intensive enteral
nutrition was difficult to implement and did not increase survival.
However, low daily energy intake was associated with greater
mortality, so adequate nutritional intake should be a main goal for
treatment
Valutazione dei consumi di bevande energetiche e snack in ambiente scolastico ed extra-scolastico: utilizzo del questionario BSQ (beverage and snack questionnaire) nella programmazione di politiche di educazione alimentare.
Polineuropatia nell'industria calzaturiera: contributo sperimentale etiologico e clinico.
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