40 research outputs found
The Association Between Money and Opinion in Academic Emergency Medicine
Objectives: Financial conflicts of interest have come under increasing scrutiny in medicine, but their impact has not been quantified. Our objective was to use the results of a national survey of academic emergency medicine (EM) faculty to determine if an association between money and personal opinion exists.Methods: We conducted a web-based survey of EM faculty. Opinion questions were analyzed with regard to whether the respondent had either 1) received research grant money or 2) received money from industry as a speaker, consultant, or advisor. Responses were unweighted, and tests of differences in proportions were made using Chi-squared tests, with p<0.05 set for significance.Results: We received responses from 430 members; 98 (23%) received research grants from industry, while 145 (34%) reported fee-for-service money. Respondents with research money were more likely to be comfortable accepting gifts (40% vs. 29%) and acting as paid consultants (50% vs. 37%). They had a more favorable attitude with regard to societal interactions with industry and felt that industry-sponsored lectures could be fair and unbiased (52% vs. 29%). Faculty with fee-for-service money mirrored those with research money. They were also more likely to believe that industry-sponsored research produces fair and unbiased results (61% vs. 45%) and less likely to believe that honoraria biased speakers (49% vs. 69%).Conclusion: Accepting money for either service or research identified a distinct population defined by their opinions. Faculty engaged in industry-sponsored research benefitted socially (collaborations), academically (publications), and financially from the relationship. [West J Emerg Med. 2010; 11(2):126-132.
Combining Optimal Control Theory and Molecular Dynamics for Protein Folding
A new method to develop low-energy folding routes for proteins is presented. The novel aspect of the proposed approach is the synergistic use of optimal control theory with Molecular Dynamics (MD). In the first step of the method, optimal control theory is employed to compute the force field and the optimal folding trajectory for the atoms of a Coarse-Grained (CG) protein model. The solution of this CG optimization provides an harmonic approximation of the true potential energy surface around the native state. In the next step CG optimization guides the MD simulation by specifying the optimal target positions for the atoms. In turn, MD simulation provides an all-atom conformation whose positions match closely the reference target positions determined by CG optimization. This is accomplished by Targeted Molecular Dynamics (TMD) which uses a bias potential or harmonic restraint in addition to the usual MD potential. Folding is a dynamical process and as such residues make different contacts during the course of folding. Therefore CG optimization has to be reinitialized and repeated over time to accomodate these important changes. At each sampled folding time, the active contacts among the residues are recalculated based on the all-atom conformation obtained from MD. Using the new set of contacts, the CG potential is updated and the CG optimal trajectory for the atoms is recomputed. This is followed by MD. Implementation of this repetitive CG optimization - MD simulation cycle generates the folding trajectory. Simulations on a model protein Villin demonstrate the utility of the method. Since the method is founded on the general tools of optimal control theory and MD without any restrictions, it is widely applicable to other systems. It can be easily implemented with available MD software packages
Prediction of Optimal Folding Routes of Proteins That Satisfy the Principle of Lowest Entropy Loss: Dynamic Contact Maps and Optimal Control
An optimization model is introduced in which proteins try to evade high energy regions of the folding landscape, and prefer low entropy loss routes during folding. We make use of the framework of optimal control whose convenient solution provides practical and useful insight into the sequence of events during folding. We assume that the native state is available. As the protein folds, it makes different set of contacts at different folding steps. The dynamic contact map is constructed from these contacts. The topology of the dynamic contact map changes during the course of folding and this information is utilized in the dynamic optimization model. The solution is obtained using the optimal control theory. We show that the optimal solution can be cast into the form of a Gaussian Network that governs the optimal folding dynamics. Simulation results on three examples (CI2, Sso7d and Villin) show that folding starts by the formation of local clusters. Non-local clusters generally require the formation of several local clusters. Non-local clusters form cooperatively and not sequentially. We also observe that the optimal controller prefers “zipping” or small loop closure steps during folding. The folding routes predicted by the proposed method bear strong resemblance to the results in the literature
Soft tissue tumor imaging in adults: European Society of Musculoskeletal Radiology-Guidelines 2023—overview, and primary local imaging: how and where?
Objectives: Early, accurate diagnosis is crucial for the prognosis of patients with soft tissue sarcomas. To this end, standardization of imaging algorithms, technical requirements, and reporting is therefore a prerequisite. Since the first European Society of Musculoskeletal Radiology (ESSR) consensus in 2015, technical achievements, further insights into specific entities, and the revised WHO-classification (2020) and AJCC staging system (2017) made an update necessary. The guidelines are intended to support radiologists in their decision-making and contribute to interdisciplinary tumor board discussions. Materials and methods: A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements were scored online by level of agreement (0 to 10) during two iterative rounds. Either “group consensus,” “group agreement,” or “lack of agreement” was achieved. Results: Eight sections were defined that finally contained 145 statements with comments. Overall, group consensus was reached in 95.9%, and group agreement in 4.1%. This communication contains the first part consisting of the imaging algorithm for suspected soft tissue tumors, methods for local imaging, and the role of tumor centers. Conclusion: Ultrasound represents the initial triage imaging modality for accessible and small tumors. MRI is the modality of choice for the characterization and local staging of most soft tissue tumors. CT is indicated in special situations. In suspicious or likely malignant tumors, a specialist tumor center should be contacted for referral or teleradiologic second opinion. This should be done before performing a biopsy, without exception. Clinical relevance: The updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability both in individual patients and in future studies on individualized strategies. Key Points: • Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors. • MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy. • In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy
Soft tissue tumor imaging in adults: European Society of Musculoskeletal Radiology-Guidelines 2023-overview, and primary local imaging: how and where?
OBJECTIVES: Early, accurate diagnosis is crucial for the prognosis of patients with soft tissue sarcomas. To this end, standardization of imaging algorithms, technical requirements, and reporting is therefore a prerequisite. Since the first European Society of Musculoskeletal Radiology (ESSR) consensus in 2015, technical achievements, further insights into specific entities, and the revised WHO-classification (2020) and AJCC staging system (2017) made an update necessary. The guidelines are intended to support radiologists in their decision-making and contribute to interdisciplinary tumor board discussions. MATERIALS AND METHODS: A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements were scored online by level of agreement (0 to 10) during two iterative rounds. Either "group consensus," "group agreement," or "lack of agreement" was achieved. RESULTS: Eight sections were defined that finally contained 145 statements with comments. Overall, group consensus was reached in 95.9%, and group agreement in 4.1%. This communication contains the first part consisting of the imaging algorithm for suspected soft tissue tumors, methods for local imaging, and the role of tumor centers. CONCLUSION: Ultrasound represents the initial triage imaging modality for accessible and small tumors. MRI is the modality of choice for the characterization and local staging of most soft tissue tumors. CT is indicated in special situations. In suspicious or likely malignant tumors, a specialist tumor center should be contacted for referral or teleradiologic second opinion. This should be done before performing a biopsy, without exception. CLINICAL RELEVANCE: The updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability both in individual patients and in future studies on individualized strategies. KEY POINTS: • Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors. • MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy. • In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy
The value of magnetic resonance arthrography in the evaluation of repaired menisci
PubMed ID: 24719084Aim To evaluate the diagnostic value of direct magnetic resonance (MR) arthrography in detection of re-torn or unhealed menisci which were previously repaired. Materials and methods Twenty-six menisci of 24 symptomatic patients who had undergone a meniscus repair surgery were included in this retrospective study. These patients had been evaluated with gadolinium-enhanced direct MR arthrography. A subsequent second-look arthroscopy was performed thereafter. The findings of MR arthrography were compared with the arthroscopic findings. Results Sixteen recurrent meniscal lesions were detected with MR arthrography; the remaining ten repaired menisci were evaluated as healed. At second-look arthroscopy, six out of 26 repaired menisci were evaluated as completely healed. Eight of them had incomplete healing, and 12 of them were unhealed. MR arthrography had four falsenegative results, but there were none false-positive results. It was arthroscopically shown that three of these four falsenegative results were belonged to patients who had incomplete healing. MR arthrography had a sensitivity, specificity, and overall accuracy of 80, 100, and 84.6 %, respectively. When incomplete lesions were left out of analysis, its sensitivity and accuracy reached to 94.8 and 94.4 %. Conclusion The findings of this study showed that MR arthrography was a reliable diagnostic tool in evaluating previously repaired menisci. Yet diagnosis of incomplete meniscal lesions seemed to be challenging. © Springer-Verlag France 2014