172 research outputs found
Algunas soluciones exactas para una ecuación de Klein Gordon
In solving practical problems in science and engineering arises as a direct consequence differential equations that explains the dynamics of the phenomena. Finding exact solutions to this equations provides importan information about the behavior of physical systems. The Lie symmetry method allows tofind invariant solutions under certain groups of transformations for differential equations.This method not very well known and used is of great importance in the scientific community. By this approach it was possible to find several exactinvariant solutions for the Klein Gordon Equation uxx − utt = k(u). A particularcase, The Kolmogorov equation uxx − utt = k1u + k2un was considered.These equations appear in the study of relativistic and quantum physics. The general solutions found, could be used for future explorations on the study for other specific K(u) functions.Al resolver problemas prácticos en ciencia e ingeniería surge como consecuencia directa las ecuaciones diferenciales que explican la dinámica de los fenómenos. Encontrar soluciones exactas a estas ecuaciones proporciona información importante sobre el comportamiento de los sistemas físicos. El método de simetría de Lie permite encontrar soluciones invariantes bajo ciertos grupos de transformaciones para ecuaciones diferenciales. Este método, poco conocido y utilizado, es de gran importancia en la comunidad científica. Mediante este enfoque, fue posible encontrar varias soluciones exactas invariables para la ecuación de Klein Gordon uxx - utt = k (u). Un caso particular, se consideró la ecuación de Kolmogorov uxx - utt = k1u + k2un. Estas ecuaciones aparecen en el estudio de la física relativista y cuántica. Las soluciones generales encontradas podrían utilizarse para futuras exploraciones en el estudio para otras funciones específicas de K (u)
International multicenter observational study on assessment of ventilatory management during general anaesthesia for robotic surgery and its effects on postoperative pulmonary complication (AVATaR) : study protocol and statistical analysis plan
Introduction: Robotic-assisted surgery (RAS) has emerged as an alternative minimally invasive surgical option. Despite its growing applicability, the frequent need for pneumoperitoneum and Trendelenburg position could significantly affect respiratory mechanics during RAS. AVATaR is an international multicenter observational study aiming to assess the incidence of postoperative pulmonary complications (PPC), to characterise current practices of mechanical ventilation (MV) and to evaluate a possible association between ventilatory parameters and PPC in patients undergoing RAS.
Methods and analysis: AVATaR is an observational study of surgical patients undergoing MV for general anaesthesia for RAS. The primary outcome is the incidence of PPC during the first five postoperative days. Secondary outcomes include practice of MV, effect of surgical positioning on MV, effect of MV on clinical outcome and intraoperative complications.
Ethics and dissemination: This study was approved by the Institutional Review Board of the Hospital Israelita Albert Einstein. The study results will be published in peer-reviewed journals and disseminated at international conferences.
Trial registration number: NCT02989415; Pre-results
When decisions on homologous structures cause ambiguous taxa relationships: the Neomorphinae (Aves, Cuculidae) example
Diseño de una empresa (Ocuparte S.A.S), orientada a la gestión de seguridad y salud en el trabajo, aplicado en empresas prestadoras de servicios en bienes raíces
CD-T 363.119 G165; 112 pEste proyecto busca, mediante la creación de la empresa “OCUPARTE S.A.S.”, brindar asesoría en el desarrollo, implementación y manejo de los sistemas de gestión de la Seguridad y Salud en el Trabajo para el ámbito de la propiedad horizontal, al mismo tiempo que se educa, concientiza y se crean estrategias de autocuidado, promoción y prevención de la salud en los trabajadores y empleadores a nivel empresarial en general.Universidad Libre Seccional Pereir
Low grade squamous intra-epithelial lesions and human papillomavirus infection in Colombian women
Low grade squamous intra-epithelial lesions could be considered as a manifestation of human papillomavirus exposition, however the discrepancy between rates of infection with human papillomavirus and development of low grade squamous intra-epithelial lesions is notable. Here we report a cross-sectional three-armed case–control study in the Colombian population, to compare the risk factors of women with low grade squamous intra-epithelial lesions with that of human papillomavirus DNA-negative and positive women with normal cytology
Persistence of HPV infection and risk of high-grade cervical intraepithelial neoplasia in a cohort of Colombian women
Little is known about the dynamics of human papillomavirus (HPV) infection and subsequent development of high-grade cervical intraepithelial neoplasia (CIN2/3), particularly in women >30 years of age. This information is needed to assess the impact of HPV vaccines and consider new screening strategies. A cohort of 1728 women 15–85 years old with normal cytology at baseline was followed every 6 months for an average of 9 years. Women with squamous intraepithelial lesions were referred for biopsy and treatment. The Kaplan–Meier method was used to estimate the median duration of infection and Cox regression analysis was undertaken to assess determinants of clearance and risk of CIN2/3 associated with HPV persistence. No difference in the likelihood of clearance was observed by HPV type or woman's age, with the exception of lower clearance for HPV16 infection in women under 30 years of age. Viral load was inversely associated with clearance. In conclusion, viral load is the main determinant of persistence, and persistence of HPV16 infections carry a higher risk of CIN2/3
Effects of Environmental Factors on Severity and Mortality of COVID-19
Background: Most respiratory viruses show pronounced seasonality, but for SARS-CoV-2, this still needs to be documented. Methods: We examined the disease progression of COVID-19 in 6,914 patients admitted to hospitals in Europe and China. In addition, we evaluated progress of disease symptoms in 37,187 individuals reporting symptoms into the COVID Symptom Study application. Findings: Meta-analysis of the mortality risk in seven European hospitals estimated odds ratios per 1-day increase in the admission date to be 0.981 (0.973–0.988, p < 0.001) and per increase in ambient temperature of 1°C to be 0.854 (0.773–0.944, p = 0.007). Statistically significant decreases of comparable magnitude in median hospital stay, probability of transfer to the intensive care unit, and need for mechanical ventilation were also observed in most, but not all hospitals. The analysis of individually reported symptoms of 37,187 individuals in the UK also showed the decrease in symptom duration and disease severity with time. Interpretation: Severity of COVID-19 in Europe decreased significantly between March and May and the seasonality of COVID-19 is the most likely explanation
American registry of ambulatory and acute decompensated heart failure (AMERICCAASS registry): rationale and design
Aims Heart failure (HF) is a highly prevalent and progressive condition associated with significant morbidity and mortalityrates. Acute decompensated HF precipitates millions of hospitalizations each year. Despite therapeutic advances, the overallprognosis of HF is poor. The varying clinical courses and outcomes of patients with this disease may be due toregion-specific gaps and since most HF studies are conducted in developed countries, the participation of Latin Americanand Caribbean countries is low. Considering this, the American Registry of Ambulatory and Acute Decompensated HeartFailure (AMERICCAASS) aims to characterize the population with ambulatory and acute decompensated HF in the American continent and to determine rehospitalization and survival outcomes during the 12 months of follow-up. Methods and results AMERICCAASS Registry is an observational, prospective, and hospital-based registry recruiting patientswith ambulatory or acute decompensated HF. The registry plans to include between two and four institutions per country from at least 20 countries in the Americas, and at least 60 patients recruited from each participant institution regardless of their ambulatory or acutely decompensated condition. Ambulatory patients with confirmed HF diagnosis or inpatients pre-senting with acute decompensated HF will be included. Follow-up will be performed at 12 months in ambulatory patientsor 1, 6, and 12 months after hospital discharge in acutely decompensated HF patients. This ongoing study began on 1 April2022, with recruitment scheduled to end on 30 November 2023, and follow-up on 31 January 2025. Ethics approval wasobtained from the Biomedical Research Ethics Committee of Fundación Valle del Lili. Data collected in the AMERICCAASS registry is being stored on the electronic platform REDCap (Research Electronic Data Capture), which allows different formsfor patient groups to enable unbiased analyses. For quantitative variables comparison, we will use the Student’s t-test ornon-parametric tests accordingly. Categorical variables will be presented as proportions, and groups will be compared with Fisher’s exact test. The significance level will be <0.05 for comparisons. Readmissions and post-discharge mortality will be calculated as proportions at 1, 6, and 12 months, with a survival analysis by conditional probability and the Kaplan–Meiermethod. Conclusions AMERICCAASS Registry is intended to be the most important registry of the continent for obtaining important information about demographics, aetiology, co-morbidities, and treatment received, either ambulatory or hospitalized. This registry may contribute to the optimization of national and regional evidence and public policies for the diagnosis and treatment of HF disease.Versión publicada - versión final del edito
Ventilation and outcomes following robotic-assisted abdominal surgery: an international, multicentre observational study
Background: International data on the epidemiology, ventilation practice, and outcomes in patients undergoing abdominal robotic-assisted surgery (RAS) are lacking. The aim of the study was to assess the incidence of postoperative pulmonary complications (PPCs), and to describe ventilator management after abdominal RAS. Methods: This was an international, multicentre, prospective study in 34 centres in nine countries. Patients ≥18 yr of age undergoing abdominal RAS were enrolled between April 2017 and March 2019. The Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score was used to stratify for higher risk of PPCs (≥26). The primary outcome was the incidence of PPCs. Secondary endpoints included the preoperative risk for PPCs and ventilator management. Results: Of 1167 subjects screened, 905 abdominal RAS patients were included. Overall, 590 (65.2%) patients were at increased risk for PPCs. Meanwhile, 172 (19%) patients sustained PPCs, which occurred more frequently in 132 (22.4%) patients at increased risk, compared with 40 (12.7%) patients at lower risk of PPCs (absolute risk difference: 12.2% [95% confidence intervals (CI), 6.8–17.6%]; P<0.001). Plateau and driving pressures were higher in patients at increased risk, compared with patients at low risk of PPCs, but no ventilatory variables were independently associated with increased occurrence of PPCs. Development of PPCs was associated with a longer hospital stay. Conclusions: One in five patients developed one or more PPCs (chiefly unplanned oxygen requirement), which was associated with a longer hospital stay. No ventilatory variables were independently associated with PPCs. Clinical trial registration: NCT02989415
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