Managing the variability of biomechanical characteristics before the preliminary design stage of a medical device

The very high level of requirements for certification procedures often limit research and development departments to innovate using increments and iterations during the design process for medical devices (MD). Instead of this semi-empirical approach, a structured procedure, a breakthrough innovation should be used when designing an articular MD (prosthesis, implant). The search for concepts can be based on functional analysis and producing behavioural models of the joint in its natural state and/or equipped with the prosthesis. This paper shows how anatomical variables can be managed and integrated using a modular design approach.This study has been realized under the two joint action projects PESSOA 14630YA and PTDC/EME-PME/112977

Advances in the Construction and Design of Jet Grouting Methods in South America

This paper presents a brief historical development of the two most popular jet grouting methods used in South America, namely, the chemical churning pile method (CCP) and jumbo jet grouting. Advantages and limitations of each procedure are cited. A brief discussion follows covering the history of CCP jet grouting in South America. Field trials performed to improve the design methodology and construction of CCP and jumbo jet grouted columns are presented. Finally, three case histories are presented to illustrate the use of jumbo jet grouting where limited head room exists, jet grouting in close proximity to pile supported structures, formation of a diaphragm wall in gravelly soil with boulders. The paper closes with a short discussion of a recent tunnel project in which horizontal jet grouting is used as the temporary tunnel support

Diálogos entre José Saramago e Tomasi di Lampedusa

Embora distantes em termos geográficos e, de certa medida, temporais, José Saramago (1922-2010) e Tomasi di Lampedusa (1896-1957) se aproximam sobremaneira quando o assunto são suas obras ficcionais. Questões relacionadas à História, Política, Cultura e Identidade de seus países, respectivamente Portugal e Itália, são tratadas pelos escritores de forma crítica, em um diálogo constante com a realidade. No intuito de demonstrarmos um exemplo da profícua aproximação que pode haver na comparação entre obras dos dois autores, neste trabalho volveremos atenção para Il Gattopardo, publicado por Lampedusa em 1958, e Levantado do chão, trazido a lume por Saramago, em 1980. Nosso interesse está em demonstrar o modo como ambos os autores desenvolvem suas narrativas tendo em vista o cenário, o contexto sócio/histórico e os dramas identitários de indivíduos circunscritos a Portugal, caso de Levantado do Chão, e à ilha da Sicília, na Itália, caso de Il Gattopardo. Outrossim, verificaremos também as diferenças entre os dois textos no que se refere à representação dos elementos relacionados à realidade, mencionados acima

Microwave and Millimeter Wave Techniques

Contains reports on two research projects.Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Science Foundation (Grant AST77-26896

Carmustine, Etoposide, Cytarabine, and Melphalan (BEAM)–Campath Allogeneic Stem Cell Transplantation for Aggressive Non-Hodgkin Lymphoma: An Analysis of Outcomes from the British Society of Blood and Marrow Transplantation

AbstractThe role of allogeneic stem cell transplantation (SCT) in the management of aggressive non-Hodgkin lymphoma (NHL) remains to be defined, but the number of procedures performed continues to increase. We report here the outcomes of allogeneic SCT using carmustine, etoposide, cytarabine, and melphalan (BEAM)-Campath (Genzyme Corporation, Cambridge, MA) conditioning for aggressive NHL as reported to the British Society of Blood and Marrow Transplantation (BSBMT). This retrospective study identified 46 patients who reported to the BSBMT registry as having undergone BEAM-Campath conditioned allogeneic SCT for aggressive NHL between 1999 and 2010. Disease histology was diffuse large B cell lymphoma (DLBCL, n = 25), DLBCL/Burkitt lymphoma (n = 5), and T cell lymphoma (n = 16). At diagnosis, the median age was 42.5 (range, 17 to 59), 37 had advanced stage disease (Ann Arbor III/IV), 28 had 2 or more extra-nodal sites of disease, and 23 had elevated lactate dehydrogenase. International prognostic index was high or high/intermediate in 58%. The median number of prior therapies was 3 (range, 1 to 5) and 5 patients had previously undergone transplantation (4 autologous, 1 allogeneic). The median age at transplantation was 44.8 (range, 18 to 59), with 34 patients demonstrating chemo-sensitive disease and 22 undergoing transplantation in first response. Performance score was good in 40 patients and all engrafted with a median of 14 days (range, 11 to 27) to neutrophil recovery. At latest follow-up, 20 patients were alive with 17 in complete remission. Acute graft-versus-host disease (GVHD) developed in 7 patients and chronic GVHD developed in 13 (7 limited, 6 extensive). Five patients died from nonrelapse causes, with a cumulative incidence of nonrelapse mortality of 7% at 100 days and 11% at 3 and 5 years. Twenty-one patients died after lymphoma relapse, with a cumulative incidence of relapse/progression of 51% at 1 year and 53% at 5 years. Disease status at transplantation had no impact on relapse rate. Progression-free survival was 41% at 1 year and 36% at 5 years. Overall survival was 54% at 1 year and 42% at 5 years. Overall, BEAM-Campath–conditioned allogeneic SCT is well tolerated and able to deliver durable disease-free survival to a subset of patients with aggressive NHL. However, the high relapse rates indicate further investigation is needed to identify those patients most likely to benefit

Associations of outdoor fine particulate air pollution and cardiovascular disease in 157 436 individuals from 21 high-income, middle-income, and low-income countries (PURE): A prospective cohort study

Background: Most studies of long-term exposure to outdoor fine particulate matter (PM2·5) and cardiovascular disease are from high-income countries with relatively low PM2·5 concentrations. It is unclear whether risks are similar in low-income and middle-income countries (LMICs) and how outdoor PM2·5 contributes to the global burden of cardiovascular disease. In our analysis of the Prospective Urban and Rural Epidemiology (PURE) study, we aimed to investigate the association between long-term exposure to PM2·5 concentrations and cardiovascular disease in a large cohort of adults from 21 high-income, middle-income, and low-income countries.Methods: In this multinational, prospective cohort study, we studied 157 436 adults aged 35-70 years who were enrolled in the PURE study in countries with ambient PM2·5 estimates, for whom follow-up data were available. Cox proportional hazard frailty models were used to estimate the associations between long-term mean community outdoor PM2·5 concentrations and cardiovascular disease events (fatal and non-fatal), cardiovascular disease mortality, and other non-accidental mortality.Findings: Between Jan 1, 2003, and July 14, 2018, 157 436 adults from 747 communities in 21 high-income, middle-income, and low-income countries were enrolled and followed up, of whom 140 020 participants resided in LMICs. During a median follow-up period of 9·3 years (IQR 7·8-10·8; corresponding to 1·4 million person-years), we documented 9996 non-accidental deaths, of which 3219 were attributed to cardiovascular disease. 9152 (5·8%) of 157 436 participants had cardiovascular disease events (fatal and non-fatal incident cardiovascular disease), including 4083 myocardial infarctions and 4139 strokes. Mean 3-year PM2·5 at cohort baseline was 47·5 μg/m3 (range 6-140). In models adjusted for individual, household, and geographical factors, a 10 μg/m3 increase in PM2·5 was associated with increased risk for cardiovascular disease events (hazard ratio 1·05 [95% CI 1·03-1·07]), myocardial infarction (1·03 [1·00-1·05]), stroke (1·07 [1·04-1·10]), and cardiovascular disease mortality (1·03 [1·00-1·05]). Results were similar for LMICs and communities with high PM2·5 concentrations (\u3e35 μg/m3). The population attributable fraction for PM2·5 in the PURE cohort was 13·9% (95% CI 8·8-18·6) for cardiovascular disease events, 8·4% (0·0-15·4) for myocardial infarction, 19·6% (13·0-25·8) for stroke, and 8·3% (0·0-15·2) for cardiovascular disease mortality. We identified no consistent associations between PM2·5 and risk for non-cardiovascular disease deaths.Interpretation: Long-term outdoor PM2·5 concentrations were associated with increased risks of cardiovascular disease in adults aged 35-70 years. Air pollution is an important global risk factor for cardiovascular disease and a need exists to reduce air pollution concentrations, especially in LMICs, where air pollution levels are highest.Funding: Full funding sources are listed at the end of the paper (see Acknowledgments)

Ceftriaxone bone penetration in patients with septic non-union of the tibia

SummaryObjectivesA main determinant of clinical response to antibiotic treatment is drug concentration at the infected site. Data on ceftriaxone (CFX) bone penetration are lacking. We measured CFX concentrations in infected bone to verify their relationship with pharmacodynamic microbiological markers.MethodsEleven patients undergoing debridement for septic non-union of the tibia and receiving intravenous CFX were studied. Plasma and bone specimens were collected intraoperatively at a variable interval after CFX administration. Drug concentrations were measured by high-performance liquid chromatography with ultraviolet detection (HPLC-UV) method.ResultsBone samples were extracted at a mean of 3.3h (range 1.5–8.0h) since the start of CFX infusion. The mean±standard deviation intraoperative CFX plasma concentration was 128.4±30.8mg/l; the corresponding bone concentrations were 9.6±3.4mg/l (7.8%) in the cortical compartment and 30.8±8.6mg/l (24.3%) in the cancellous compartment. The mean 24-h area under the concentration–time curve (AUC24) values were 176.8±62.2 h*mg/l in cortical bone and 461.5±106.8 h*mg/l in cancellous bone. The time above the minimum inhibitory concentration (T>MIC) was 24h in all compartments. The estimated mean free AUC/MIC ratios and T>MIC were 140 and 24.4h, respectively, in cancellous bone and 42.4 and 21h, respectively, in cortical bone.ConclusionsCFX bone penetration was poor (<15%) in the cortical compartment and satisfactory in the more vascularized cancellous bone. The T>MIC and AUC/MIC ratios suggest that CFX achieves a satisfactory pharmacokinetic exposure in cancellous bone as far as pathogens with a MIC of <0.5 are concerned. However, considering free drug concentrations, pharmacokinetic/pharmacodynamic targets may not be fully achieved in cortical bone. As antibiotic exposure can be suboptimal in the infected cortical compartment, and drug penetration may be impaired into necrotic bone and sequesters, a radical surgical removal of purulent and necrotic tissues appears essential to shorten treatment duration and to prevent treatment failures

Exploring the Assessment of Summaries: Using Latent Semantic Analysis to Grade Summaries Written by Spanish Students

In this study we propose an integrated method to automatically assess summaries using LSA. The method is based on a regression equation calculated with a corpus of a hundred summaries (the training sample), and is validated on a different sample of summaries (the validation sample). The equation incorporates two parameters extracted from LSA: semantic similarity and vector length. A total of 396 students drawn from four stages of education participated in the study. The summaries of a short narrative text written by each participant were evaluated on a scale of 0-10 by four human graders and the scores compared to the evaluation of the summaries using LSA. The results supported that incorporating both parameters into the method resulted more successful than the traditional cosine measure, and that LSA showed a similar level of sensitivity to the quality of the summaries produced in different academic stages as that shown by the human graders. (C) 2013 The Authors. Published by Elsevier Ltd.This work was supported by Grant SEJ2006-09916 from the Spanish Ministry of Science and Technology and PSI 2009-31932 by the Spanish Ministry of Education.León, JA.; Olmos, R.; Escudero Domínguez, I.; Jorge-Botana, G.; Perry, DR. (2013). Exploring the Assessment of Summaries: Using Latent Semantic Analysis to Grade Summaries Written by Spanish Students. Elsevier. 83:151-155. https://doi.org/10.1016/j.sbspro.2013.06.0291511558