31 research outputs found

    Simulación computacional como herramienta para disminuir los costos asociados al diseño mecánico

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    La estimación del costo de una nueva pieza para un equipo mecánico, involucra varios factores, entre ellos su diseño, que es la etapa inicial. El objetivo de este trabajo es mostrar el efecto de la simulación computacional en los costos durante el proceso de diseño mecánico. El método empleado fue la simulación computacional a través del diseño asistido por computadoras (Computer Aided Design, CAD) y de la ingeniería asistida por computadoras (Computer Aided Engineering). Se obtiene como resultado que el desarrollo de un nuevo producto es más eficiente con el empleo de este último; el proceso iterativo de prueba-error se realizó virtualmente, lo que representa reducción de los costos de fabricación de los prototipos y otros gastos relacionados con las pruebas mecánicas. Los costos de materia prima disminuyeron al obtener geometrías optimizadas bajo las condiciones de trabajo predefinidas. Por otra parte, el tiempo requerido para obtener los planos de fabricación y las horas de trabajo del personal de diseño es inferior con el empleo de programas CAD. Así, ambos softwares deben usarse conjuntamente, pues se complementan. Se agilizó la selección de la variante de la pieza con menor costo de fabricación

    Plasma Treatment of Agave

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    Composites based on low-density polyethylene (LDPE) were prepared with Agave fiber powder (AFP) that was coated by plasma polymerization process using ethylene gas. Treated and pristine AFP were analyzed by infrared spectroscopy, scanning electron microscopy, and contact water angle for the assessment of surface properties. The polymer composites were prepared by melt mixing using 0, 5, 10, and 20 wt% of AFP and their mechanical and thermal properties were measured. Dispersion evaluation in water confirmed that the AFP treated changed from hydrophilic to hydrophobic behavior and it was also corroborated with water contact angle tests. The addition of treated and untreated AFP (200 mesh) at 20 wt% promotes an increase of Young’s modulus of the composites of up to 60% and 32%, respectively, in relation to the neat matrix. Also, an increase of crystallinity of LDPE was observed by the addition of treated and untreated AFP; however no significant effect on the crystallization temperature was observed in LDPE containing AFP

    Label-free plasmonic biosensor for rapid, quantitative, and highly sensitive COVID-19 serology: implementation and clinical validation

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    Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.H2020 Research and Innovation Programme of the European Commission Project, No. 101003544 Spanish Research Agency (AEI, grant no. SEV-2017-0706AEI, grant no. SEV-2017-0706) Spanish Ministry of Science and Innovation and the Spanish Research Agency and the European Social Fund (ESF)BES-2017-080527 GENCAT-DGRIS COVID EU H2020 Programme (644956) Plan Nacional de I+D+i 2013-2016 ISCIII- Ministerio de Ciencia e Innovación, Vall d’Hebron University Hospital Biobank PT17/0015/0047 European Virus Archive GLOBAL (EVA-GLOBAL) EU Horizon 2020 (grant agreement No. 871029) Fundació Glòria Soler for COVIDBANK collection Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0003)N

    Supporting information Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

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    15 pages. -- Content: 1. Supplementary text: 1.1.Chemical and biological reagents; 1.2.SPR biosensor device; 1.3.Plasmonic sensor chip preparation; 1.4.Clinical samples collection; 1.5.Stratification of convalescent COVID patients. Samples collection from Clinic Hospital (Barcelona); 1.6. Standard analytical techniques (ELISA, CLIA and LFA); 1.7.Data analysis; 1.8.Diagnostic sensitivity and specificity. -- 2. Figures. -- Tables S1-S3. -- References.Serological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL–1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment.Peer reviewe

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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