206 research outputs found

    PD disease state assessment in naturalistic environments using deep learning

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    Management of Parkinson's Disease (PD) could be improved significantly if reliable, objective information about fluctuations in disease severity can be obtained in ecologically valid surroundings such as the private home. Although automatic assessment in PD has been studied extensively, so far no approach has been devised that is useful for clinical practice. Analysis approaches common for the field lack the capability of exploiting data from realistic environments, which represents a major barrier towards practical assessment systems. The very unreliable and infrequent labelling of ambiguous, low resolution movement data collected in such environments represents a very challenging analysis setting, where advances would have significant societal impact in our ageing population. In this work we propose an assessment system that abides practical usability constraints and applies deep learning to differentiate disease state in data collected in naturalistic settings. Based on a large data-set collected from 34 people with PD we illustrate that deep learning outperforms other approaches in generalisation performance, despite the unreliable labelling characteristic for this problem setting, and how such systems could improve current clinical practice

    Periodic density functional theory calculations of bulk and the (010) surface of goethite

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    <p>Abstract</p> <p>Background</p> <p>Goethite is a common and reactive mineral in the environment. The transport of contaminants and anaerobic respiration of microbes are significantly affected by adsorption and reduction reactions involving goethite. An understanding of the mineral-water interface of goethite is critical for determining the molecular-scale mechanisms of adsorption and reduction reactions. In this study, periodic density functional theory (DFT) calculations were performed on the mineral goethite and its (010) surface, using the Vienna <it>Ab Initio </it>Simulation Package (VASP).</p> <p>Results</p> <p>Calculations of the bulk mineral structure accurately reproduced the observed crystal structure and vibrational frequencies, suggesting that this computational methodology was suitable for modeling the goethite-water interface. Energy-minimized structures of bare, hydrated (one H<sub>2</sub>O layer) and solvated (three H<sub>2</sub>O layers) (010) surfaces were calculated for 1 Ă— 1 and 3 Ă— 3 unit cell slabs. A good correlation between the calculated and observed vibrational frequencies was found for the 1 Ă— 1 solvated surface. However, differences between the 1 Ă— 1 and 3 Ă— 3 slab calculations indicated that larger models may be necessary to simulate the relaxation of water at the interface. Comparison of two hydrated surfaces with molecularly and dissociatively adsorbed H<sub>2</sub>O showed a significantly lower potential energy for the former.</p> <p>Conclusion</p> <p>Surface Fe-O and (Fe)O-H bond lengths are reported that may be useful in surface complexation models (SCM) of the goethite (010) surface. These bond lengths were found to change significantly as a function of solvation (i.e., addition of two extra H<sub>2</sub>O layers above the surface), indicating that this parameter should be carefully considered in future SCM studies of metal oxide-water interfaces.</p

    Induction chemotherapy followed by chemoradiotherapy versus chemoradiotherapy alone as neoadjuvant treatment for locally recurrent rectal cancer: study protocol of a multicentre, open-label, parallel-arms, randomized controlled study (PelvEx II)

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    Background A resection with clear margins (R0 resection) is the most important prognostic factor in patients with locally recurrent rectal cancer (LRRC). However, this is achieved in only 60 per cent of patients. The aim of this study is to investigate whether the addition of induction chemotherapy to neoadjuvant chemo(re)irradiation improves the R0 resection rate in LRRC. Methods This multicentre, international, open-label, phase III, parallel-arms study will enrol 364 patients with resectable LRRC after previous partial or total mesorectal resection without synchronous distant metastases or recent chemo- and/or radiotherapy treatment. Patients will be randomized to receive either induction chemotherapy (three 3-week cycles of CAPOX (capecitabine, oxaliplatin), four 2-week cycles of FOLFOX (5-fluorouracil, leucovorin, oxaliplatin) or FOLFORI (5-fluorouracil, leucovorin, irinotecan)) followed by neoadjuvant chemoradiotherapy and surgery (experimental arm) or neoadjuvant chemoradiotherapy and surgery alone (control arm). Tumours will be restaged using MRI and, in the experimental arm, a further cycle of CAPOX or two cycles of FOLFOX/FOLFIRI will be administered before chemoradiotherapy in case of stable or responsive disease. The radiotherapy dose will be 25 × 2.0 Gy or 28 × 1.8 Gy in radiotherapy-naive patients, and 15 × 2.0 Gy in previously irradiated patients. The concomitant chemotherapy agent will be capecitabine administered twice daily at a dose of 825 mg/m2 on radiotherapy days. The primary endpoint of the study is the R0 resection rate. Secondary endpoints are long-term oncological outcomes, radiological and pathological response, toxicity, postoperative complications, costs, and quality of life. Discussion This trial protocol describes the PelvEx II study. PelvEx II, designed as a multicentre, open-label, phase III, parallel-arms study, is the first randomized study to compare induction chemotherapy followed by neoadjuvant chemo(re)irradiation and surgery with neoadjuvant chemo(re)irradiation and surgery alone in patients with locally recurrent rectal cancer, with the aim of improving the number of R0 resections

    Evaluation of the respiratory function in myasthenia gravis: an important tool for clinical feature and diagnosis of the disease Avaliação da função respiratória na miastenia gravis: importância na caracterização clínica e no diagnóstico da doença

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    Myasthenic gravis may affect both inspiratory and expiratory muscles. Respiratory involvement occurred in almost all patients with myasthenia gravis in all clinical forms of the disease: 332 lung function tests done in 324 myasthenic patients without respiratory symptoms (age 34.6 ± 18.3 years) were examined. Lung volumes analysis showed that all the patients of both sexes with generalized or ocular myasthenia gravis showed "myasthenic pattern". Male patients with "ocular" form only presented the "myasthenic pattern" with lung impairment and had, from the lung function point of view, a more benign behaviour. Female patients with the "ocular" form exhibited a behaviour of respiratory variables similar to that of the generalized form. It was not observed modification of the variables that suggested obstruction of the higher airways. The "myasthenic pattern" was rarely observed in other neuromuscular diseases, except in patients with laryngeal stenosis.<br>O comprometimento respiratório é fator limitante na evolução clinica da miastenia gravis (MG) e as formas clínicas mais graves apresentavam acometimento bulbar e respiratório. Para avaliar a reserva respiratória foram examinados em 324 pacientes com MG (forma ocular 62, generalizada 246 e timomatosa 16) as seguintes variáveis da prova de função pulmonar (PFP): capacidade vital forçada (FVC); volume onde o fluxo expiratório é igual a 1 litro por segundo (VF=1); volume expiratório forçado no primeiro segundo (FEV1); fluxo expiratório forçado medido entre 0,2 e 1,2 litros (FEF); fluxo médio expiratório forçado, medido entre 25 e 75% da FVC (FMF); intervalo de tempo entre 25 e 75% da FVC (FMFT); tempo médio de trânsito na expiração forçada (MTT); capacidade pulmonar total (TLC); volume residual (RV); curva fluxo-volume para pesquisa do "padrão miastênico". A análise estatística realizada foi: "t pareado" entre paciente e seu padrão e "t não pareado" entre grupos. Conclusões: Todos os pacientes apresentaram o padrão miastênico e esta alteração da curva fluxo-volume sugeriu disfunção dos músculos da laringe. Nos pacientes com formas clinicamente localizadas as PFP também se mostraram alteradas revelando a generalização da sintomatologia mais frequentemente no sexo feminino. Não foi observada modificação das variáveis que indicam obstrução das vias aéreas decorrente do uso de anticolinesterásicos no tratamento da MG nem aumento de incidência de asma brônquica com o uso de drogas anticolinesterásicas
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