367 research outputs found

    Закономерности изменения физико-механических свойств сплава Zr-1%Nb при комплексном ионно-плазменном модифицировании поверхности и наводороживании

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    В работе были изучены особенности изменения морфологии, структуры и физико-механических свойств циркониевого сплава Zr-1%Nb, подвергнутого комплексному ионно-плазменному модифицированию поверхности методами плазменно-иммерсионной ионной имплантации титана и осаждения покрытий нитрида титана. Показана высокая эффективность защиты сформированных структур от проникновения водорода в циркониевый сплав. Изучены механизмы сорбции и захвата водорода в титансодержащем модифицированном слое.In the present work, the features of the change in the morphology, structure, and physico-mechanical properties of zirconium alloy Zr-1%Nb subjected to complex ion-plasma surface modification by the methods of plasma-immersion titanium ion implantation and deposition of titanium nitride coatings were studied. The high protective properties of the formed structures against hydrogen permeation into the zirconium alloy is shown. Mechanisms of sorption and capture of hydrogen in a titanium-doped modified layer are studied

    Ideal Outcome After Pancreatoduodenectomy:A Transatlantic Evaluation of a Harmonized Composite Outcome Measure

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    OBJECTIVE: The aim of this study is to define and assess Ideal Outcome in the national or multicenter registries of North America, Germany, the Netherlands, and Sweden. BACKGROUND: Assessing outcomes after pancreatoduodenectomy among centers and countries requires a broad evaluation that cannot be captured by a single parameter. Previously, 2 composite outcome measures (textbook outcome and optimal pancreatic surgery) for pancreatoduodenectomy have been described from Europe and the United States. These composites were harmonized into ideal outcome (IO). METHODS: This analysis is a transatlantic retrospective study (2018-2020) of patients after pancreatoduodenectomy within the registries from North America, Germany, The Netherlands, and Sweden. After 3 consensus meetings, IO for pancreatoduodenectomy was defined as the absence of all 6 parameters: (1) in-hospital mortality, (2) severe complications-Clavien-Dindo ≥3, (3) postoperative pancreatic fistula-International Study Group of Pancreatic Surgery (ISGPS) grade B/C, (4) reoperation, (5) hospital stay &gt;75th percentile, and (6) readmission. Outcomes were evaluated using relative largest difference (RLD) and absolute largest difference (ALD), and multivariate regression models. RESULTS: Overall, 21,036 patients after pancreatoduodenectomy were included, of whom 11,194 (54%) reached IO. The rate of IO varied between 55% in North America, 53% in Germany, 52% in The Netherlands, and 54% in Sweden (RLD: 1.1, ALD: 3%, P &lt;0.001). Individual components varied with an ALD of 2% length of stay, 4% for in-hospital mortality, 12% severe complications, 10% postoperative pancreatic fistula, 11% reoperation, and 9% readmission. Age, sex, absence of chronic obstructive pulmonary disease, body mass index, performance status, American Society of Anesthesiologists (ASA) score, biliary drainage, absence of vascular resection, and histologic diagnosis were associated with IO. In the subgroup of patients with pancreatic adenocarcinoma, country, and neoadjuvant chemotherapy also was associated with improved IO. CONCLUSIONS: The newly developed composite outcome measure "Ideal Outcome" can be used for auditing and comparing outcomes after pancreatoduodenectomy. The observed differences can be used to guide collaborative initiatives to further improve the outcomes of pancreatic surgery.</p

    Transatlantic registries of pancreatic surgery in the United States of America, Germany, the Netherlands, and Sweden: Comparing design, variables, patients, treatment strategies, and outcomes

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    Background: Registries of pancreatic surgery have become increasingly popular as they facilitate both quality improvement and clinical research. We aimed to compare registries for design, variables collected, patient characteristics, treatment strategies, clinical outcomes, and pathology. Methods: Registered variables and outcomes of pancreatoduodenectomy (2014–2017) in 4 nationwide or multicenter pancreatic surgery registries from the United States of America (American College of Surgeons National Surgical Quality Improvement Program), Germany (Deutsche Gesellschaft für Allgemein- und Viszeralchirurgie - Studien-, Dokumentations- und Qualitätszentrum), the Netherlands (Dutch Pancreatic Cancer Audit), and Sweden (Swedish National Pancreatic and Periampullary Cancer Registry) were compared. A core registry set of 55 parameters was identified and evaluated using relative and absolute largest differences between extremes (smallest versus largest). Results: Overall, 22,983 pancreatoduodenectomies were included (15,224, 3,558, 2,795, and 1,406 in the United States of America, Germany, the Netherlands, and Sweden). Design of the registries varied because 20 out of 55 (36.4%) core parameters were not available in 1 or more registries. Preoperative chemotherapy in patients with pancreatic ductal adenocarcinoma was administered in 27.6%, 4.9%, 7.0%, and 3.4% (relative largest difference 8.1, absolute largest difference 24.2%, P < .001). Minimally invasive surgery was performed in 7.8%, 4.5%, 13.5%, and unknown (relative largest difference 3.0, absolute largest difference 9.0%, P < .001). Median length of stay was 8.0, 16.0, 12.0, and 11.0 days (relative largest difference 2.0, absolute largest difference 8.0, P < .001). Reoperation was performed in 5.7%, 17.1%, 8.7%, and 11.2% (relative largest difference 3.0, absolute largest difference 11.4%, P < .001). In-hospital mortality was 1.3%, 4.7%, 3.6%, and 2.7% (relative largest difference 3.6, absolute largest difference 3.4%, P < .001). Conclusion: Considerable differences exist in the design, variables, patients, treatment strategies, and outcomes in 4 Western registries of pancreatic surgery. The absolute largest differences of 24.3% for the use of preoperative chemotherapy, 9.0% for minimally invasive surgery, 11.4% for reoperation rate, and 3.4% for in-hospital mortality require further study and improvement. This analysis provides 55 core parameters for pancreatic surgery registries

    De-identification of primary care electronic medical records free-text data in Ontario, Canada

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    <p>Abstract</p> <p>Background</p> <p>Electronic medical records (EMRs) represent a potentially rich source of health information for research but the free-text in EMRs often contains identifying information. While de-identification tools have been developed for free-text, none have been developed or tested for the full range of primary care EMR data</p> <p>Methods</p> <p>We used <it>deid </it>open source de-identification software and modified it for an Ontario context for use on primary care EMR data. We developed the modified program on a training set of 1000 free-text records from one group practice and then tested it on two validation sets from a random sample of 700 free-text EMR records from 17 different physicians from 7 different practices in 5 different cities and 500 free-text records from a group practice that was in a different city than the group practice that was used for the training set. We measured the sensitivity/recall, precision, specificity, accuracy and F-measure of the modified tool against manually tagged free-text records to remove patient and physician names, locations, addresses, medical record, health card and telephone numbers.</p> <p>Results</p> <p>We found that the modified training program performed with a sensitivity of 88.3%, specificity of 91.4%, precision of 91.3%, accuracy of 89.9% and F-measure of 0.90. The validations sets had sensitivities of 86.7% and 80.2%, specificities of 91.4% and 87.7%, precisions of 91.1% and 87.4%, accuracies of 89.0% and 83.8% and F-measures of 0.89 and 0.84 for the first and second validation sets respectively.</p> <p>Conclusion</p> <p>The <it>deid </it>program can be modified to reasonably accurately de-identify free-text primary care EMR records while preserving clinical content.</p

    Transmural Ultrasound-based Visualization of Patterns of Action Potential Wave Propagation in Cardiac Tissue

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    The pattern of action potential propagation during various tachyarrhythmias is strongly suspected to be composed of multiple re-entrant waves, but has never been imaged in detail deep within myocardial tissue. An understanding of the nature and dynamics of these waves is important in the development of appropriate electrical or pharmacological treatments for these pathological conditions. We propose a new imaging modality that uses ultrasound to visualize the patterns of propagation of these waves through the mechanical deformations they induce. The new method would have the distinct advantage of being able to visualize these waves deep within cardiac tissue. In this article, we describe one step that would be necessary in this imaging process—the conversion of these deformations into the action potential induced active stresses that produced them. We demonstrate that, because the active stress induced by an action potential is, to a good approximation, only nonzero along the local fiber direction, the problem in our case is actually overdetermined, allowing us to obtain a complete solution. Use of two- rather than three-dimensional displacement data, noise in these displacements, and/or errors in the measurements of the fiber orientations all produce substantial but acceptable errors in the solution. We conclude that the reconstruction of action potential-induced active stress from the deformation it causes appears possible, and that, therefore, the path is open to the development of the new imaging modality

    An epistatic mini-circuitry between the transcription factors Snail and HNF4\uce\ub1 controls liver stem cell and hepatocyte features exhorting opposite regulation on stemness-inhibiting microRNAs

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    Preservation of the epithelial state involves the stable repression of epithelial-to-mesenchymal transition program, whereas maintenance of the stem compartment requires the inhibition of differentiation processes. A simple and direct molecular mini-circuitry between master elements of these biological processes might provide the best device to keep balanced such complex phenomena. In this work, we show that in hepatic stem cell Snail, a transcriptional repressor of the hepatocyte differentiation master gene HNF4\uce\ub1, directly represses the expression of the epithelial microRNAs (miRs)-200c and-34a, which in turn target several stem cell genes. Notably, in differentiated hepatocytes HNF4\uce\ub1, previously identified as a transcriptional repressor of Snail, induces the miRs-34a and-200a, b, c that, when silenced, causes epithelial dedifferentiation and reacquisition of stem traits. Altogether these data unveiled Snail, HNF4\uce\ub1 and miRs-200a, b, c and-34a as epistatic elements controlling hepatic stem cell maintenance/differentiation. \uc2\ua9 2012 Macmillan Publishers Limited. All rights reserved

    Outcomes After Minimally-invasive Versus Open Pancreatoduodenectomy: A Pan-European Propensity Score Matched Study

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    OBJECTIVE: To assess short-term outcomes after minimally invasive (laparoscopic, robot-assisted, and hybrid) pancreatoduodenectomy (MIPD) versus open pancreatoduodenectomy (OPD) among European centers. BACKGROUND: Current evidence on MIPD is based on national registries or single expert centers. International, matched studies comparing outcomes for MIPD and OPD are lacking. METHODS: Retrospective propensity score matched study comparing MIPD in 14 centers (7 countries) performing ≥10 MIPDs annually (2012-2017) versus OPD in 53 German/Dutch surgical registry centers performing ≥10 OPDs annually (2014-2017). Primary outcome was 30-day major morbidity (Clavien-Dindo ≥3). RESULTS: Of 4220 patients, 729/730 MIPDs (412 laparoscopic, 184 robot-assisted, and 130 hybrid) were matched to 729 OPDs. Median annual case-volume was 19 MIPDs (interquartile range, IQR 13-22), including the first MIPDs performed in 10/14 centers, and 31 OPDs (IQR 21-38). Major morbidity (28% vs 30%, P = 0.526), mortality (4.0% vs 3.3%, P = 0.576), percutaneous drainage (12% vs 12%, P = 0.809), reoperation (11% vs 13%, P = 0.329), and hospital stay (mean 17 vs 17 days, P > 0.99) were comparable between MIPD and OPD. Grade-B/C postoperative pancreatic fistula (POPF) (23% vs 13%, P < 0.001) occurred more frequently after MIPD. Single-row pancreatojejunostomy was associated with POPF in MIPD (odds ratio, OR 2.95, P < 0.001), but not in OPD. Laparoscopic, robot-assisted, and hybrid MIPD had comparable major morbidity (27% vs 27% vs 35%), POPF (24% vs 19% vs 25%), and mortality (2.9% vs 5.2% vs 5.4%), with a fewer conversions in robot-assisted- versus laparoscopic MIPD (5% vs 26%, P < 0.001). CONCLUSIONS: In the early experience of 14 European centers performing ≥10 MIPDs annually, no differences were found in major morbidity, mortality, and hospital stay between MIPD and OPD. The high rates of POPF and conversion, and the lack of superior outcomes (ie, hospital stay, morbidity) could indicate that more experience and higher annual MIPD volumes are needed

    Automatic de-identification of textual documents in the electronic health record: a review of recent research

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    <p>Abstract</p> <p>Background</p> <p>In the United States, the Health Insurance Portability and Accountability Act (HIPAA) protects the confidentiality of patient data and requires the informed consent of the patient and approval of the Internal Review Board to use data for research purposes, but these requirements can be waived if data is de-identified. For clinical data to be considered de-identified, the HIPAA "Safe Harbor" technique requires 18 data elements (called PHI: Protected Health Information) to be removed. The de-identification of narrative text documents is often realized manually, and requires significant resources. Well aware of these issues, several authors have investigated automated de-identification of narrative text documents from the electronic health record, and a review of recent research in this domain is presented here.</p> <p>Methods</p> <p>This review focuses on recently published research (after 1995), and includes relevant publications from bibliographic queries in PubMed, conference proceedings, the ACM Digital Library, and interesting publications referenced in already included papers.</p> <p>Results</p> <p>The literature search returned more than 200 publications. The majority focused only on structured data de-identification instead of narrative text, on image de-identification, or described manual de-identification, and were therefore excluded. Finally, 18 publications describing automated text de-identification were selected for detailed analysis of the architecture and methods used, the types of PHI detected and removed, the external resources used, and the types of clinical documents targeted. All text de-identification systems aimed to identify and remove person names, and many included other types of PHI. Most systems used only one or two specific clinical document types, and were mostly based on two different groups of methodologies: pattern matching and machine learning. Many systems combined both approaches for different types of PHI, but the majority relied only on pattern matching, rules, and dictionaries.</p> <p>Conclusions</p> <p>In general, methods based on dictionaries performed better with PHI that is rarely mentioned in clinical text, but are more difficult to generalize. Methods based on machine learning tend to perform better, especially with PHI that is not mentioned in the dictionaries used. Finally, the issues of anonymization, sufficient performance, and "over-scrubbing" are discussed in this publication.</p
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