3,227 research outputs found

    Posterior Arthroscopic Subtalar Arthrodesis: Clinical and Radiologic Review of 19 Cases

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    Arthroscopic subtalar arthrodesis has recently gained popularity in the treatment of primary subtalar or post-traumatic arthritis, coalition, or inflammatory diseases with subtalar arthritis. The present study reports the clinical and radiologic results of 19 patients (19 feet) who underwent posterior arthroscopic subtalar arthrodesis using 2 posterior portals. A total of 19 posterior arthroscopic subtalar arthrodeses (minimum follow-up of 24 months) performed without a bone graft and with 2 parallel screws were prospectively evaluated. The fusion rate was 94% (mean time to fusion 9.8 weeks). Modified American Orthopaedic Foot and Ankle Society ankle-hindfoot scale score (maximum 94 points) improved significantly from 43 to 80 points and the visual analog scale for pain score improved from 7.6 to 1.2. The 12-item short-form physical and mental scores at the last follow-up point were 52.5 and 56.4, respectively. One (5.3%) patient underwent open repeat fusion for nonunion, 2 (10.5%) patients required a second procedure for implant removal, and 1 (5.3%) experienced reversible neuropraxia. In conclusion, posterior arthroscopic subtalar arthrodesis is a safe technique with a good union rate and a small number of complications in patients with no or very little hindfoot deformity.info:eu-repo/semantics/publishedVersio

    Sacro-pelvic Anthropometry in the Portuguese Population and Its Implication for Screw Placement in Spinal Surgery: A Single Centre Retrospective Analysis

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    Objective The aim of this study was to assess the sacropelvic anthropometry in the Portuguese population, through the study of pelvic computed tomography (CT) scans. Methods Pelvic CT scans of 40 individuals were analyzed, and the length and angle measurements were performed according to predefined screw trajectories of S1 anterior (S1A), anterolateral (S1AL) and anteromedial (S1AM), S2 anterolateral (S2AL) and anteromedial (S2AM), S2 alar iliac (S2AI), iliac, and sacroiliac (SI) screws. Comparisons between genders were also performed. Results The S1A screw trajectory mean length was 30.80 mm. The S1AL mean length and lateral angle were 36.48 mm and 33.13°, respectively, and the S1AM s were 46.23 mm and 33.21°. The S2AL mean length was 28.66 mm and lateral angle was 26.52°, and the S2AM length and angle were 29.99 mm and 33.61°, respectively. The S2 alar-iliac screw trajectory mean length, lateral, and caudal angles were 125.84 mm, 36.78°, and 28.66°, respectively. The iliac screw trajectory mean length, lateral, and caudal angles were 136.73 mm, 23,86° and 24.01°, respectively. The sacroiliac screw trajectory length was 75.50 mm. The length of the screws was longer in men than in women, except for the S1A and SI screws, for which no difference was found between genders. Conclusion This study describes sacropelvic anatomical specifications. These defined morphometric details should be taken into consideration during surgical procedures

    A General Hybrid Modeling Framework for Systems Biology Applications: Combining Mechanistic Knowledge with Deep Neural Networks under the SBML Standard

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    This work was supported by the Associate Laboratory for Green Chemistry—LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). This work has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement number 870292 (BioICEP project). J.P. acknowledges a PhD grant (SFRD/BD14610472019), Fundação para a Ciência e Tecnologia (FCT) and R.S.C. the contract CEECIND/01399/2017In this paper, a computational framework is proposed that merges mechanistic modeling with deep neural networks obeying the Systems Biology Markup Language (SBML) standard. Over the last 20 years, the systems biology community has developed a large number of mechanistic models that are currently stored in public databases in SBML. With the proposed framework, existing SBML models may be redesigned into hybrid systems through the incorporation of deep neural networks into the model core, using a freely available python tool. The so-formed hybrid mechanistic/neural network models are trained with a deep learning algorithm based on the adaptive moment estimation method (ADAM), stochastic regularization and semidirect sensitivity equations. The trained hybrid models are encoded in SBML and uploaded in model databases, where they may be further analyzed as regular SBML models. This approach is illustrated with three well-known case studies: the Escherichia coli threonine synthesis model, the P58IPK signal transduction model, and the Yeast glycolytic oscillations model. The proposed framework is expected to greatly facilitate the widespread use of hybrid modeling techniques for systems biology applications.publishersversionpublishe

    A Very Rare Case of Coronary Artery Bypass Grafting in a Progeria Child

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    Hutchinson-Gilford progeria syndrome is a rare genetic disorder, characterized by progressive premature aging and early death in the first or second decade of life, usually secondary to cardiovascular events (myocardial infarction and stroke). We report a case of a 14-year-old boy with progeria syndrome and cardiac arrest due to myocardial infarction, who was submitted to an immediate coronary angiography which revealed left main stem and three-vessel coronary artery disease. A prompt double bypass coronary artery grafting surgery was performed, and, despite successful coronary reperfusion, the patient remained in coma and brain death was declared on fourth day after surgery.info:eu-repo/semantics/publishedVersio

    Espondilolise e espondilolistese ístmica de grau I no adolescente: Análise retrospectiva de 30 casos

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    Objectivo: a espondilolise e a espondilolistese ístmica grau I são causas de lombalgia nos adolescentes e associam-se a fractura de fadiga da pars interarticularis por movimentos repetidos de hiperextensão. Na literatura não existe consenso quanto aos benefícios do tratamento cirúrgico nestes doentes, muitas vezes atletas, e a controvérsia prolonga-se sobre qual a melhor técnica cirúrgica. Os autores descrevem a técnica cirúrgica que sistematicamente utilizam e analisam os resultados obtidos.Material e métodos: retrospectivamente, entre 2004 e 2013, foram avaliados 30 adolescentes, 12 com lise ístmica e 18 com espondilolistese ístmica grau I, operados pelo mesmo cirurgião. A reconstituição ístmica foi feita com autoenxerto de ilíaco e fixação pedicular posterior temporária. Avalia-se a taxa de consolidação, complicações, dor (VAS), função (ODI) e o grau de satisfaçãoResultados: a idade média foi 16.3 anos (13-18) e o seguimento 23.5 meses (14-48). Ocorreu consolidação em 100% dos casos. O VAS médio reduziu de 7.48 para 0.38 (p<0.0001) e, funcionalmente, o ODI médio melhorou de 38.55% para 1.59% (p<0.0001), de disfunção moderada para mínima. A todos os doentes foi retirado o material após 1 ano de reconstituição ístmica. No total, 63.3% dos doentes eram desportistas e todos retomaram o nível prévio. Não se verificou progressão da listese nem complicações significativas. Os doentes encontram-se satisfeitos e repetiriam o tratamento.Conclusão: as técnicas de artrodese obtêm bons resultados clínicos mas implicam perda de mobilidade segmentar e doença do nível adjacente. Comparativamente com técnicas dinâmicas, a técnica preconizada pelos autores permite não só a reconstituição ístmica eficaz como revela resultados superiores a médio prazo, o que supera a necessidade de segunda intervenção para extração do material. A reconstituição ístmica com autoenxerto e fixação pedicular posterior temporária na espondilolise ou espondilolistese ístmica grau I obteve excelentes resultados clínicos e elevada taxa de consolidação. Esta técnica é defendida pelos autores mesmo em atletas de alta competição

    Cell-free layer analysis in a polydimethysiloxane microchannel: A global approach

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    The cell-free layer (CFL) is a hemodynamic phenomenon that has an important contribution to the rheological properti es of blood flowing in microvessels. The present work aims to find the closest function describing RBCs flowing around the cell depleted layer in a polydimethysiloxane (PDMS) microchannel with a diverging and a converging bifurcation. The flow behaviour of the CFL was investigated by using a high-speed video microscopy system where special attention was devoted to its behaviour before the bifurcation and after the confluence of the microchannel. The numerical data was first obtained by using a manual tracking plugin and then analysed using the genetic algorithm approach. The results show that for the majority of the cases the function that more closely resembles the CFL boundary is the sum of trigonometric functions.The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/ 2010 and EXPL/EMS-SIS/2215/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER). R.O. Rodrigues, D. Pinho and V. Faustino acknowledge respectively, the PhD scholarships SFRH/BD/97658/2013, SFRH/BD/89077/2012 and SFRH/BD/99696/2014 granted by FCT.info:eu-repo/semantics/publishedVersio

    Establishing a link between endothelial cell metabolism and vascular behaviour in a type 1 diabetes mouse model

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    Background/Aims: Vascular complications contribute significantly to the extensive morbidity and mortality rates observed in people with diabetes. Despite well known that the diabetic kidney and heart exhibit imbalanced angiogenesis, the mechanisms implicated in this angiogenic paradox remain unknown. In this study, we examined the angiogenic and metabolic gene expression profile (GEP) of endothelial cells (ECs) isolated from a mouse model with type1 diabetes mellitus (T1DM). Methods: ECs were isolated from kidneys and hearts of healthy and streptozocin (STZ)-treated mice. RNA was then extracted for molecular studies. GEP of 84 angiogenic and 84 AMP-activated Protein Kinase (AMPK)-dependent genes were examined by microarrays. Real time PCR confirmed the changes observed in significantly altered genes. Microvessel density (MVD) was analysed by immunohistochemistry, fibrosis was assessed by the Sirius red histological staining and connective tissue growth factor (CTGF) was quantified by ELISA. Results: The relative percentage of ECs and MVD were increased in the kidneys of T1DM animals whereas the opposite trend was observed in the hearts of diabetic mice. Accordingly, the majority of AMPK-associated genes were upregulated in kidneys and downregulated in hearts of these animals. Angiogenic GEP revealed significant differences in Tgfß, Notch signaling and Timp2 in both diabetic organs. These findings were in agreement with the angiogenesis histological assays. Fibrosis was augmented in both organs in diabetic as compared to healthy animals. Conclusion: Altogether, our findings indicate, for the first time, that T1DM heart and kidney ECs present opposite metabolic cues, which are accompanied by distinct angiogenic patterns. These findings enable the development of innovative organ-specific therapeutic strategies targeting diabetic-associated vascular disorders.This work was supported by CAPES (Sciences without Borders - Full Doctorate Fellowship – Process 10010-13-0); FEDER funds by COMPETE: [POCI-01-0145-FEDER-007440, POCI-01-0145-FEDER-016385]; NORTE2020 [NORTE-01-0145FEDER-000012]; HealthyAging2020 [CENTRO-01-0145-FEDER-000012-N2323]; FCT - Fundação para a Ciência e a Tecnologia [UID/BIM/04293/2013, EXPL/BIM-MED/0492/2012, SFRH/BPD/88745/2012, SFRH/BD/111799/2015]; Claude Pepper Older Americans Independence Center; grant: P30 AG028718, NIGMS Award P20GM109096; European Structural and Investment Funds (ESIF). AUTHOR CONTRIBUTION: CS and RS participated in the design and conception of the study; CS performed the whole laboratory and statistical analyses and drafted the manuscript; VSP, PPO, DSN carried out the FACS assay design and data acquisition, as well as the interpretation of FACS data; SA advised and performed microarray and RT-PCR assays; IR headed the parafin embedded tissue and histologial staining; SG, EC were responsible for the animal studies and immunohistochemistry analyses; RC advised the methodological laboratorial analysis and animal studies; RS and EC critically revised the manuscript for important intellectual content. All authors were involved in drafting and revising the article. All authors read and approved the final version of the manuscript

    The impact of COVID-19 on memory: Recognition for masked and unmasked faces

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    Considering the current state of the worldwide pandemic, it is still common to encounter people wearing face protection masks. Although a safety measure against COVID-19, face masks might be compromising our capacity for face recognition. We conducted an online study where 140 participants observed masked and unmasked faces in a within-subjects design and then performed a recognition memory task. The best performance was found when there were no masks either at study and test phase, i.e., at the congruent unmasked condition. The worst performance was found for faces encoded with a mask but tested without it (i.e., masked-unmasked incongruent condition), which can be explained by the disruption in holistic face processing and the violation of the encoding specificity principle. Interestingly, considering the unmasked-masked incongruent condition, performance was probably affected by the violation of the encoding specificity principle but protected by holistic processing that occurred during encoding.info:eu-repo/semantics/publishedVersio
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