187 research outputs found
Dependency of lower limb joint reaction forces on femoral version
Background Musculoskeletal (MSK) models based on literature data are meant to represent a generic anatomy and are a popular tool employed by biomechanists to estimate the internal loads occurring in the lower limb joints, such as joint reaction forces (JRFs). However, since these models are normally just linearly scaled to an individual’s anthropometry, it is unclear how their estimations would be affected by the personalization of key features of the MSK anatomy, one of which is the femoral version angle. Research Question How are the lower limb JRF magnitudes computed through a generic MSK model affected by changes in the femoral version? Methods We developed a bone-deformation tool in MATLAB (shared at https://simtk.org/projects/bone_deformity) and used it to create a set of seven OpenSim models spanning from 2˚ femoral retroversion to 40˚ anteversion. We used these models to simulate the gait of an elderly individual with an instrumented prosthesis implanted at their knee joint (5th Grand Challenge dataset) and quantified both the changes in JRFs magnitude due to varying the skeletal anatomy and their accuracy against the correspondent in vivo measurements at the knee joint. Results Hip and knee JRF magnitudes were affected by the femoral version with variations from the unmodified generic model up to 17.9 ± 4.5% at the hip and 43.4 ± 27.1% at the knee joint. The ankle joint was unaffected by the femoral geometry. The MSK models providing the most accurate knee JRFs (root mean squared error: 0.370 ± 0.068 body weight, coefficient of determination: 0.757 ± 0.104, peak error range: 0.09−0.42 body weight) were those with femoral anteversion angle closer to that measured on the segmented bone of the individual. Significance Femoral version substantially affects hip and knee JRFs estimated with generic MSK models, suggesting that personalizing key MSK anatomical features might be necessary for accurate estimation of JRFs with these models
Sentinel lymph node biopsy in squamous cell carcinoma of the head and neck: 10 years of experience
Sentinel node (SN) biopsy of head and neck cancer is still considered investigational, and agreement on the width of the surgical sampling has not yet been reached. From May 1999 to Dec 2009, 209 consecutive patients entered a prospective study: 61.7% had primary tumour of the oral cavity and 23.9% of the oropharynx. SN was not found in 26 patients. Based on these data and definitive histopathological analysis, we proposed six hypothetic scenarios to understand the percentage of neck recurrences following different treatments Among patients with identified SN, 54 cases were pN+: 47 in SN and 7 in a different node. Considering the six hypothetic scenarios: "only SN removal", "SN level dissection", "neck dissection from the tumour site to SN level", "selective neck dissection of three levels (SND)", "dissection from level I to IV" and "comprehensive I-V dissection", neck recurrences could be expected in 6.5%, 3.8%, 2.18%, 2.73%, 1.09% and 1.09% of cases, respectively. SN biopsy can be considered a useful tool to personalize the surgical approach to a N0 carcinoma. The minimum treatment of the neck is probably dissection of the levels between the primary tumour and the level containing the SN(s). Outside the framework of a clinical study, the best treatment can still be considered SND
Towards Critical Occidentalism Studies: Re-inventing the 'West' and 'Japan' in Mangaesque Popular Cultures
This paper investigates the reproduction of the imagined geography of the ‘West’ in contemporary Japan by employing a relational, intersectional and positional approach in order to examine Occidentalism and its hegemonic identification and othering process. Particular attention will be paid to emerging Japanese subcultures enacting a parodic and sexualised re-invention of Westernness and Japaneseness within a globalising mangaesque media mix
Nível crítico de potássio em latossolo vermelho distroférrico para soja com tipo de crescimento indeterminado.
Produção de girassol em resposta à utilização de boro e a adubação nitrogenada de cobertura.
Resumo: Um experimento foi realizado na safrinha 2013 para avaliar a produtividade e altura de planta em função das doses de boro (B) e adubação nitrogenada na cultura do girassol. A semeadura foi realizada em 25 de fevereiro de 2013 com o híbrido de girassol BRS 323, em sucessão à soja em área de histórico de plantio direto. Foram utilizados seis doses de B no plantio (0, 1, 2, 4, 8 e 16 kg ha), na forma de ácido bórico (17% B), com e sem a aplicação de 50 kg ha de N, em cobertura, na forma de ureia (45% N), aplicado 20 dias após a emergência das plantas, com 4 repetições. Não se observou efeito de doses de B para as variáveis analisadas. No entanto, o rendimento de girassol e a altura das plantas foram fortemente influenciados pela aplicação de N em cobertura. Abstract: An experiment was carried out in 2013 growing season to evaluate yield and plant height in function of doses of boron (B) and nitrogen fertilization on the sunflower crop. Sowing was performed on February 25, 2013 using the sunflower hybid BS 323, in sucession to soybean, in a non-till area. We used 6 B doses at planting (0, 1, 2, 4, 8 and 16 kg ha th) using as boric acid (17% B) and, 50 kg ha N by urea (45% N) in topdressing, applied 20 days after seedling emergence, with 4 replications. We observed no effect of doses of B for the analyzed variables. However, the sunflower yield and plant height were strongly influenced by the presence of nitrogen
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