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The slamming phenomenon often occurs when the bottom of a ship hits the seawater with a relatively high velocity in irregular waves. In extreme sea conditions, the slam-induced dynamic loads can be quite large resulting in local structural damages and/or global deformation of the panels, in particular when ships face head sea waves with high forward speed. In this respect, high-speed vessels are affected by the slamming phenomenon as they are built with thin steel plates or aluminum. The paper presents finite element simulations performed with the explicit ls-dyna solver of an aluminum stiffened plate subjected to extreme slamming loadings so as to evaluate the large plastic deformation and failure of the stiffened plate and the effect of the heat affected zone (HAZ) due to the welding using the mechanical properties of an aluminum alloy grade 5083-H116. The outcomes of this study identify the parameters that have importance when estimating the extent of structural deformation due to slamming loads. [ABSTRACT FROM AUTHOR]

Abstract Closed-form expressions to estimate the energy absorption and damage extent for severe ship collision damages were initially developed in 1999 [1, 2], and further validated with experimental data in 2016 [3]. To gain further confidence for applications within design using the proposed analytical procedure, it is evident that more detailed and comprehensive comparisons and validations with experiments and numerical simulations are necessary. The purpose of the present paper is to use the analytical approach and finite element analyses to study in depth model-scale and full-scale collision tests so that to further quantify key calculation parameters and to verify the capability and accuracy of the proposed analytical method. In total 18 experimental tests and one full-scale collision accident are evaluated. The 18 experimental energy absorption-penetration and collision force-penetration curves, and the associated finite element simulations, are compared with results obtained from the analytical calculations. It can be concluded that the analytical method gives consistently good agreement with all experiments analysed here. Finally, an application of the analytical method is demonstrated by an example where speed restrictions are determined in a port to avoid LNG cargo leakage in an event of an LNG carrier being struck by another ship. Highlights • An analytical method for ship collision damage assessments is validated with 18 experiments and one full-scale collision accident data. • It is demonstrated that a consistent good agreement with the experiments is achieved when using a common criterion for the assessment. • Comparisons of energy-penetration and collision force-penetration curves between the experimental results, the analytical calculations and the finite element simulations are also provided. • An application example for managing collision risks at busy ports to avoid potential cargo leakage in an event of an LNG carrier struck by other ships is demonstrated. [ABSTRACT FROM AUTHOR]

The paper presents an experimental and numerical analysis of the residual stresses and strains induced during the cold bending of thick steel plates. Cold bending technique is widely used in the shipbuilding and offshore industry, and thus it is important to know about the changes in the material characteristics induced during the metal fabrication process. For this purpose, firstly, three-point cold bending experiments are conducted with a relatively small indenter on the specimens cut from a thick steel plate (54 mm), and afterwards, tension tests are carried out on tensile coupons cut from the already bent specimens. Thus, the mechanical properties (engineering stress-strain curve) of the tensile coupons cut from the loaded and unloaded locations are compared so that to determine the residual stresses and strains resulting from the bending process. A numerical simulation is performed with the explicit LS-DYNA finite element solver to replicate the experimentally determined residual stresses and strains. The simulation provides information of the distribution of the residual stresses and strains along the span and through the thickness of the specimens. It is found that the local deformation underneath the indenter harms severely the structural integrity, producing large residual stresses and strains during the bending process. This work illustrates the potential use of finite element analysis to evaluate the residual stresses and strains in metal fabrication processes. [ABSTRACT FROM AUTHOR]

The paper compares two methods based on finite element simulations to assess the external dynamics and the internal mechanics in ship collisions. One method treats independently the external dynamics and the internal mechanics (decoupled method), while the other one couples their interaction (coupled method). In the decoupled method, the external dynamics are evaluated by the analytical approach of Pedersen and Zhang (1998), and the internal mechanics are assessed by simulations performed with the LS-DYNA finite element solver. In the coupled method, both the external dynamics and the internal mechanics are evaluated directly by numerical simulations that follow the model of Pill and Tabri (2011). The two methods are compared to determine the differences in predicting the deformation and rupture of the collided ship structures and to assess the relationship between the structural deformation energy of the struck ship and the energy loss of the striking ship. The objective of the paper is to verify whether the decoupled method satisfies the predictions required for design appraisal assessments. The paper also illustrates the influence of the collision angle on the mechanics of ship collisions. [ABSTRACT FROM AUTHOR]

The paper is dedicated to enhance the industry practice in collision simulations of ship structures when only limited time and material data are available. The idea is to establish a simple, but effective procedure to determine the ‘critical failure strain’ as a function of coarse mesh sizes, so as to predict the critical energy to be absorbed during the impact. For this reason, more complicated effects, such as strain-state dependence, strain concentration on the lateral stiffening, welding, as well as accurate deformation mechanisms, are omitted. A new expression is introduced to estimate the failure strain of coarse meshed ship structures struck by an indenter with hemispherical shape where the ship side or bottom sustains local penetration during a bulbous bow collision or stranding. The expression is valid for mild and high strength steels, accounts for the size of the elements, and is derived from finite element simulations of coarse meshed plates punched until the onset of necking, which critical point is first determined by using fine meshed plates. This ‘simple’ criterion is validated against reported experiments of 3 stiffened plates and 6 double-hull structures quasi-statically punched by an indenter. For the 6 double-hull specimens evaluated here, the absorbed energy at the end of the impact event is predicted with sufficient accuracy when a coarse mesh of size 10 times the plate thickness is used (the difference is about 10%). [ABSTRACT FROM AUTHOR]

Closed-form analytical solutions for the energy released for deforming and crushing of structures and the impact impulse during ship collisions were developed and published in Marine Structures in 1998 [1]. The proposed mathematical models have been used by many engineers and researchers although the methods were only validated with time domain numerical simulation results at that time. Since then, model and full-scale measurements have been carried out and experimental results are available in the public domain. The purpose of the present paper is to use such experimental results to further analyze the validity and robustness of the closed-form analytical methods as well as to further improve some parameter's accuracy. In total, 60 experimental results have been analyzed and compared with the analytical results and this paper presents the outcome. It can be concluded that the analytical methods give a reasonable agreement with the experimental results. The paper also introduces a simple concept to account for the effective mass of liquids with free surface carried on board of a ship and it is shown how the analytical analysis procedure can be expanded to take into account the effect of ship roll on the energy released for crushing. [ABSTRACT FROM AUTHOR]

Experimental and numerical results of drop weight impact tests are presented, examining the plastic response and the crack initiation and propagation of small-scale damped rectangular aluminum plates laterally impacted by different indenter shapes. The experiments are conducted using a fully instrumented impact testing machine. The shape of the deformation of the specimens and the process of initiation and propagation of the material fracture are presented. The obtained force-displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The strain hardening of the material is defined using experimental data of quasi-static tensile tests and the critical failure strain is evaluated by measuring the thickness and the width at fracture of the tensile test pieces. The results show that the absorbed energy to petforate the specimens is highly sensitive to the shape of the striker. Thus, the crack propagation for each striker type is analyzed in terms of the force-displacement response. The failure modes are described by the matrix of the infinitesimal strain tensors and the shape of the deformation of the failing elements. [ABSTRACT FROM AUTHOR]

The paper presents a simplified analytical method to examine the energy absorbing mechanisms of small-scale stiffened plate specimens, quasi-statically punched at the mid-span by a rigid indenter with a knife or a flat edge shape. To validate this method, experiments and numerical simulations are conducted on specimens scaled from a tanker side panel limited by one span between the web frames and the stringers. Therefore, the paper provides practical information to estimate the extent of structural damage within ship side panels during collision accidents. The experimentally obtained force–displacement responses and shapes of the deformation show good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The numerical results manage to describe the process of initiation and propagation of the material fracture in the side panel specimens and provide detailed information of the energy dissipated by each structural component and its contribution to total energy during the entire deformation process. The analytical method derives expressions to estimate the relation between the plastic deformation and the energy dissipation of the stiffened plates. Both the plate and the stiffener elements dissipate the energy through rotation of the plastic hinges at the applied load and the support and the membrane tension over the plastically deformed region between the loading and the supports. The proposed simplified expressions give a good agreement with the experimental and numerical results. [ABSTRACT FROM AUTHOR]

The paper presents a simplified analytical method to examine the energy absorbing mechanisms of intact and damaged small-scale stiffened plate specimens, quasi-statically punched at the mid-span by a rigid wedge indenter. The specimens scaled from a tanker side panel are limited by one span between web frames and stringers. The influence of the initial damage on the impact response is based on the plastic behaviour of an intact specimen. The initial damage is provoked at one-quarter from the support by the same indenter that, afterwards, punches the specimen at the mid-span. In practice, initial imperfections of this type could be due to minor incidents during ship service operation, such as collision of ships with floating objects. To validate the proposed simplified method, experiments and numerical simulations are conducted. The experimentally obtained force-displacement responses and shapes of the deformation show good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The analytical method derives expressions to estimate the energy dissipated by the intact and the damaged specimens based on the plastic deformation mechanisms, assuming that both the plate and stiffener structural components absorb the incident energy through the rotation of the plastic hinges at the point of contact and at the supports and the membrane tension over the plastically deforming region between the loading and the supports. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents finite element simulations of a small-scale stiffened plate specimen quasi-statically punched at the mid-span by a rigid indenter, in order to examine its energy absorbing mechanisms and fracture. The specimen, scaled from a tanker side panel, is limited by one span between the web frames and the stringers. The paper provides practical information to estimate the extent of structural damage within ship side panels during collision accidents. Moreover, the results of this investigation should have relevance to evaluate grounding scenarios in which the bottom sustains local penetration. This is possible since the structural arrangement of the double hull and the double bottom of tanker vessels is very similar. The experimentally obtained force–displacement response and shape of the deformation show good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The numerical analysis includes aspects of particular relevance to the behaviour of ship structures subjected to accidental loads which could give rise to difficulties in interpreting finite element calculations. In particular, the paper comments on the material nonlinearities, the importance of specifying the precise boundary conditions and the joining details of the structure. The considerable practical importance of these aspects has been the focus of attention in previous publications of the authors which evaluate the experimental-numerical impact response of simple ship structural components, such as beams and plates. Therefore, this paper uses the definitions proposed in those references to evaluate its applicability in the scaled tanker side panel, as an example of a more complex ship structure. [Copyright &y& Elsevier]

Abstract: An analytical failure criterion is proposed to characterise ship plated structures manufactured with aluminium or steel materials subjected to low impact velocities. The criterion considers the critical deflection, force and absorbed energy of plates laterally impacted by a hemispherical indenter, and assumes that failure occurs at the presence of necking. The proposed expressions are compared with numerical results validated with drop weight experiments conducted on small-scaled rectangular aluminium and steel plates of the same bending stiffness. Thus, the impact tests and simulations could describe the behaviour of stiffness-equivalent shipbuilding materials subjected to rapidly varying loads. In addition, the criterion uses quasi-static theoretical formulae, including the plate thickness and the material power law coefficients to assess the deformation characteristics and the plate localisation. The experimental results show that the critical deflections are similar for both the aluminium and the steel plates, although differences are observed in the critical forces and energies. Even though the numerical simulations use most definitions reported in previous works, the emphasis is put on the material characterisation, where the fracture strain is obtained by measuring the tensile test pieces of the materials and using simplified equations to define the equivalent strain. The proposed criterion's theoretical expressions give a good agreement with the numerical results. The criterion shows that the absorbing capabilities of the plates are improved by increasing the strength coefficient of the material and the plate thickness, while other material coefficients could be omitted. It is also demonstrated that the critical defection increases and the force decreases with the strain hardening exponent. Moreover, the specific energy absorption of the material is used to evaluate the impact characteristics of the material. [Copyright &y& Elsevier]

Abstract: Experimental drop weight impact tests have been performed to examine the dynamic plastic response and failure of clamped pre-notched beams struck transversely by a mass with a spherical indenter. The laboratory results are compared with numerical simulations. The machined notches are 2.0 and 4.0mm in depth, and the beams are impacted at the mid-span and at one-quarter from the support. The experiments are conducted using a fully instrumented impact testing machine. The obtained force–displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The simulations aim at proposing techniques for defining the material characteristics and the boundary conditions of numerical models that analyse the large inelastic deformation and failure of ship structural components subjected to impact loading. The finite element model includes the experimental boundary condition so as to simulate small axial displacements of the specimen at the supports. The strain hardening of the material is defined using experimental data of the quasi-static tension tests and the strain rate sensitivity is evaluated using standard coefficients of the Cowper–Symonds constitutive model. The Cowper–Symonds model is also selected to estimate the dynamic critical failure strain by the use of the quasi-static failure strain predicted by numerical simulations of the tensile tests. Although the dynamic properties of the material should determine the response of the impacted specimens, the results show that the plastic response until failure is highly sensitive to the amount of restraint provided at the supports. [Copyright &y& Elsevier]

Experimental and numerical results of drop weight impact test are presented on the plas-tic behavior and fracture of rectangular plates stuck laterally by a mass with a hemi-spherical indent er. Six specimens were tested in order to study the influence of the impact velocity and the diameter of the indenter. The impact scenarios could represent abnormal actions on marine structures, such as ship collision and grounding or dropped objects on deck structures. The tests are conducted on a fully instrumented impact tester machine. The obtained force-displacement response is compared with numerical simulations, performed by the LS-DYNA finite element solver. The simulations aim at proposing techniques for defining the material and restraints on finite element models which analyze the crashworthiness of marine structures. The mesh size and the critical failure strain are predicted by numerical simulations of the tensile tests used to obtain the mechanical properties of the material. The experimental boundary conditions are modeled in order to represent the reacting forces developed during the impact. The results show that the critical impact energy until failure is strongly sensitive to the diameter of the striker. The shape of the failure modes is well predicted by the finite element models when a relatively fine mesh is used. Comments on the process of initiation and propagation of fracture are presented. [ABSTRACT FROM AUTHOR]

Abstract: Experimental drop weight impact tests have been performed to examine the dynamic response of small-scale stiffened plates struck laterally by a mass with a spherical indenter. The laboratory results are compared with numerical simulations. The plates stiffened with a flat bar or L profile are supported at two opposite edges and impacted at different velocities and locations along the span. The impact scenarios could represent incidents in marine structures, such as load actions due to dropped objects on decks. The experiments are conducted using a fully instrumented impact testing machine. The obtained force–displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The finite element model includes defining the experimental boundary conditions so as to simulate small axial displacements of the specimen at the supports. This representation can be used to analyze the structural crashworthiness of similar marine structures under collision scenarios. The strain hardening of the material is defined using experimental data of quasi-static tension tests and the strain rate sensitivity is evaluated using standard coefficients of the Cowper–Symonds constitutive model. The results show that the plastic response of the specimens is highly sensitive to the amount of restraint provided at the supports. Furthermore, it is found that in most of the specimens the contribution of the stiffeners to the impact response is insignificant, since the ends of the stiffener are free at the unsupported edges and the specimens experience small axial displacements at the supports. [Copyright &y& Elsevier]

Abstract: Experimental drop weight impact tests are performed to examine the dynamic response of web girders in a one-tenth scaled tanker double hull structure struck laterally by a knife edge indenter. The small stiffeners of the full-scale prototype are smeared in the small-scale specimen by increasing the thicknesses of the corresponding plates. The plastic response is evaluated at two impact velocities and the impact location is chosen between two web frames to assure damage to the outer shell plating and the stringers. The laboratory results are compared with numerical simulations performed by the LS-DYNA finite element solver. In the simulations, the strain hardening of the material is defined using experimental data of quasi-static tension tests and the strain rate sensitivity is evaluated using standard coefficients of the Cowper–Symonds constitutive model. The experimental permanent deflection and shape of the deformation show a good agreement with the collision simulations. It is found that the crushing resistance of the specimens is determined by the deformation mechanism of the stringers. Thus, the deformation process is described and compared with theoretical deformation modes for web girders subjected to large in-plane quasi-static loads. Additionally, the influence of the stiffeners on the shape of the deformation of the stringers is illustrated through simulations of stiffened structural elements. [Copyright &y& Elsevier]

Abstract: Experimental drop weight impact tests have been performed to examine the dynamic response of small-scale stiffened plates struck laterally by a mass with a spherical indenter. The laboratory results are compared with numerical simulations. The specimens are supported at two opposite edges and impacted at different locations along the span. In the unsupported edges, the ends of the stiffeners are either connected to transverse stiffeners or remain free. The impact scenarios could represent incidents in marine structures, such as load actions due to dropped objects on decks. The experiments are conducted using a fully instrumented impact testing machine. The obtained force–displacement responses show a good agreement with the simulations performed by the LS-DYNA finite element solver. The finite element model includes defining the experimental boundary condition so as to simulate small axial displacements of the specimen at the supports. This representation can be used to analyse the structural impact response of similar small-scale engineering structures. The strain hardening of the material is defined using experimental data of quasi-static tension tests and the strain rate sensitivity is evaluated using standard coefficients of the Cowper–Symonds constitutive model. The results show that the plastic response of the specimens is highly sensitive to the amount of restraint provided at the supports, particularly for the specimens with ends of the stiffeners free since they experience larger lateral deflections and, consequently, larger axial displacements at the supports. Furthermore, the contribution of the stiffeners to the impact response of the specimens is assessed through numerical simulations of unstiffened plates. [Copyright &y& Elsevier]

Abstract: In this paper, numerical results of a drop weight impact test examining the dynamic response of a clamped steel beams struck transversely at the centre by a mass with a rectangular indenter are presented. The numerical simulation showed that the results are very sensitive to the way in which the supports are modelled and thus this paper studies the modelling of the structural supports used to clamp the specimen beam in the experiment. The first approach simplifies the structural support as boundary condition on the nodes; the second model represents the entire support as the real approximation; the last approach uses simplified support plate model acting with the beam to simulate the experimental set up. The complete force–displacement curve is used to compare the plastic deformation of the impacted beams, thus the best approximation is selected for further calculations. The finite element model was performed using the LS-DYNA non-linear, dynamic finite element software. The numerical calculations can predict accurately the response of deflections, forces and absorbed energies, when proper boundary conditions are applied, in this case with shell elements representing the support plates. [Copyright &y& Elsevier]

This study was designed to evaluate the phenomenon of pressure recovery in pediatric patients with aortic stenosis and also to evaluate how observed differences between catheter and Doppler gradients can be predicted by Doppler echocardiography. Doppler measurements of aortic valve stenosis gradients are known to overestimate observed gradients in the catheterization laboratory. Pressure recovery has been shown to be a contributing factor to this discrepancy. However, the clinical relevance of correcting Doppler gradients using the pressure recovery equation has not been evaluated in the pediatric population. Simultaneously obtained catheter and Doppler gradients were studied in 14 patients (range, 0.03–18 years; mean, 4.1 years) with aortic valve stenosis. A total of 23 data points were measured because 9 patients underwent balloon valvuloplasty and had both a pre- and a post-balloon valvuloplasty data point in the study. The catheter gradients were then compared to peak, mean, and pressure recovery corrected Doppler gradients. Pressure recovery was calculated using a previously validated equation. As expected, measured echocardiographic continuous-wave peak Doppler gradients overestimated the observed catheter gradients (range, 16–93 mmHg; mean, 43 mmHg). The continuous-wave peak Doppler gradients, mean, and pressure recovery adjusted gradients were equally as good in correlating the observed catheter gradients to those obtained by Doppler echocardiography (r = 0.92). However, pressure recovery corrected Doppler gradients were in better agreement with catheter gradients than echocardiographic mean or peak Doppler gradients (95% limit of agreement: -9 to 19 mmHg for pressure recovery corrected gradients, -30 to 11 mmHg for mean Doppler gradients, and 2–83 mmHg for peak Doppler gradients). Measured continuous-wave peak Doppler gradients consistently overestimated catheter gradients. The noted differences may be predicted using the pressure recovery equation. Pressure recovery is a significant factor in children with aortic valve stenosis. [ABSTRACT FROM AUTHOR]

A conceptual design framework for collision and grounding analysis is proposed to evaluate the crashworthiness of double-hull structures. This work attempts to simplify the input parameters needed for the analysis, which can be considered as a step towards a design-oriented procedure against collision and grounding. Four typical collision and grounding scenarios are considered: (1) side structure struck by a bulbous bow, (2) side structure struck by a straight bow, (3) bottom raking, (4) bottom stranding. The analyses of these scenarios are based on statistical data of striking ship dimensions, velocities, collision angles and locations, as well as seabed shapes and sizes, grounding depth and location. The evaluation of the damage extent considers the 50- and 90-percentile values from the statistics of collision and grounding accidents. The external dynamics and internal mechanics are combined to analyse systematically the ship structural damage and energy absorption under accidental loadings. • A practical methodology for collision and grounding is proposed to evaluate the crashworthiness of double-hull structures. • The crashworthy assessment is performed for four typical collision and grounding scenarios. • The 50- and 90-percentile values from statistical collision and grounding accidents are considered. • The external dynamics and internal mechanics are combined to analyse the ship structural damage. [ABSTRACT FROM AUTHOR]

Background: The role of video-assisted thoracic surgery (VATS) in trauma has yet to be established. Up to the time of this writing, reviews of thoracoscopy in trauma have been primarily descriptive rather than analytic. This article analyzes the results of thoracoscopy (nonvideo and VATS) in trauma.Methods: Analysis was done by reviewing 28 nonoverlapping studies since the introduction of thoracoscopy in 1910, with a combined total of more than 500 patients.Results: Diagnostically, thoracoscopy has been used primarily to evaluate diaphragmatic injury, continued chest tube bleeding, and suspected cardiac injury. Thoracoscopy has a 98% (188/191 patients) accuracy rate in diagnosing diaphragmatic injuries. Therapeutically, thoracoscopy has been used primarily to control chest tube bleeding, evacuate retained hemothoraces, and evacuate empyemas. Thoracoscopy is 90% (89/99 patients) effective in evacuating retained hemothoraces, 86% (19/22 patients) effective in evacuating empyemas, and 82% (33/40 patients) effective in controlling chest tube bleeding. Thoracoscopy benefits include preventing 62% (323/514) of trauma patients from having a thoracotomy or laparotomy. Risks include a 2% (11/534 patients) procedure-related complication rate and a 0.8% (4/471 patients) missed injury rate. Technical failure rates are 10% (10/99 patients) and 4% (7/199 patients) in evacuation of retained hemothoraces and evaluation of diaphragmatic injuries, respectively.Conclusions: Analysis suggests that thoracoscopy (nonvideo and VATS) can be applied safely and effectively in the care of the injured patient. [ABSTRACT FROM AUTHOR]

The paper evaluates the response of an aluminium stiffened panel of a fast displacement craft under bow flare slamming loads by using three finite element methods: (1) a linear static analysis to calculate the structural elastic deformation and stress under the design load; (2) an independent analysis of the slamming load and the elastic structural response (a decoupled method); (3) a method that couples their interaction (a fully coupled method). These methods are compared to analyse the hydroelastic effect when predicting the structural loading and response. Similar results are obtained by the three methods and the linear static analysis based on design load evaluates with accuracy the local structural deformation and stress. The primary objective of the present work is to investigate the strength and safety of bow-flared structures when designing high-speed and fast displacement aluminium crafts subjected to slamming pressure loads. The influence of spray rail on the bow-flared slamming pressures and the effect of boundary conditions on the elastic structural responses are discussed. • The strength of bow-flared structures is assessed for high-speed aluminium crafts subjected to slamming pressure loads. • The response of an aluminium stiffened panel of a fast craft under bow flare slamming is assessed by 3 FEMs. • The slamming load is evaluated for a 2D rigid section, and the response are assessed by linear elastic analysis. • In the fully coupled method, the structural deformation and 3D hydrodynamic pressures are evaluated at each time step. [ABSTRACT FROM AUTHOR]

Background Gallstone disease ( GD) incidence and prevalence rates differ between populations. Diet and lifestyle may be involved in GD development. To our knowledge, no study to date has evaluated quantitative data on diet when studying the relationship between fat consumption levels and GD in an Argentinean population. The present study aimed to assess the association between dietary fat intake and GD. Methods A nested case-control study design was applied. Data were taken from subjects who participated in a previous cross-sectional study carried out in a random sample of asymptomatic people in Rosario, Argentina. Participants underwent a personal interview, and current weight and height, ancestor's ethnicity, and socio-economic status were recorded. Applying a food-frequency questionnaire and a food photography atlas, quantitative dietary data were estimated by combining the intake frequency, portion size and food composition. Logistic regression analysis was used to compute odds ratios and 95% confidence intervals adjusted by age, sex, ancestor's ethnicity, body mass index and daily total energy intake as potential confounders. Results In total, 114 patients were studied (49 cases and 65 controls), without any statistically significant differences for age, sex, socio-economic status, body mass index and ancestry. The mean energy intake was higher in cases than in controls, and significant differences were found for dietary fat consumption. Obese or overweight people have a higher GD risk than subjects with normal weight. Increased GD risks were associated with high intakes of energy, total fat, and saturated and monounsaturated fatty acids. Conclusions According to our results, total fat, saturated and monounsaturated fatty acids high intakes are associated with increased GD risk. [ABSTRACT FROM AUTHOR]