Profile of antiretroviral agents use in Colombia

Introduction: Since the beginning of the epidemic, human immunodeficiency virus (HIV) has taken more than 36 million lives. Objective: To determine the antiretroviral drug prescription patterns in a population of individuals with HIV infection in Colombia. Materials and methods: Cross-sectional study analyzing the profiles of patients treated with antiretroviral drugs between April 1st and September 30th, 2015. The sociodemographic, pharmacological, and comorbidity variables were identified. Individuals with a positive diagnosis of HIV of all ages and both genders were included. Results: We found 641 patients with a mean age of 39.0±17 years who were predominantly male (60.2%). The most used medications were lamivudine-zidovudine (51.6%), lopinavir-ritonavir (36%) and efavirenz (24.5%). The combination of lamivudine-zidovudine plus lopinavir-ritonavir was the most prescribed regimen (29.5%), but a total of 80 different regimens was identified. Being an adult between the ages of 45-64 years (OR=2.25; 95%CI 1.367-3.713) was associated with a greater probability of receiving 4 or more antiretrovirals. A total of 267 (41.6%) patients used at least one comedication (range: 1-18 drugs), especially anti-ulcer (57.3%), lipid-lowering (28.8%) and anti-hypertensive (28.5%) drugs. Conclusions: Patients undergoing antiretroviral treatment are receiving medications with elevated intrinsic values at the recommended doses and present comorbidities associated with chronic agerelated conditions. However, these patients receive a great variety of regimens that are not included in the clinical practice guidelines

Medical geography in the study of hepatitis A, in the Coffee-triangle region, Colombia, 2007-2011

Objectives: There are few studies of geographical characterization of viral hepatitis. For this reason, we after estimating the incidence rates for Hepatitis A (HAV), we developed epidemiological GIS-based maps for this viral disease, within a well-defined geographic region (the coffee triangle) in Colombia. Study design: A retrospective cross-sectional analysis of surveillance data and GIS-based developing of epidemiological maps. Methods: Surveillance cases data (2007-2011) were used to estimate annual incidence rates using reference population data, on hepatitis, to develop the first maps of HAV in the 53 municipalities of the coffee-triangle region of Colombia (departments Caldas, Quindio, Risaralda). GIS used was Kosmo® 3.1. To summarize and compare the data among municipalities and departments (as units of analysis) we generate indicators such as accumulated incidence rates (AIR) and incidence rates ratios. Results: 1518 HAV cases were reported, 47% from Quindío, 30% Caldas and 22% Risaralda. Quindio presented with the highest AIR (131.54) among all the administrative units under study (Caldas, AIR: 46.39; Risaralda, AIR: 37.62). Interestingly, the highest rates in Quindio, during the period, could be related to the increased number of cases reported in two municipalities from 2008 (Quimbaya, AIR ratio: 4.0 and Montenegro: 3.61). The causes that underlie this augmentation will be subject to further research. Conclusions: Incidence rates for HAV is still high in the region. Showing epidemiological data, particularly in maps would allow planning actions oriented to interventions at the different forms of transmission that this disease has, which is highly important for decisions in public health policies

Techno-economic assessment of a rotary kiln shell radiation waste heat recovery system

© 2021 The Author(s) • Heat transfer from the rotary kiln surface was assessed through CFD simulations. • Influence of geometric parameters of the absorber was explored. • Incident heat flow to the absorber was used as input to a Recuperated ORC. • The waste heat recovery system is economically evaluated to determine its feasibility considering electricity prices. In this work, the feasibility of implementing a waste heat recovery system based on the capture of radiation emitted from the surface of a rotary kiln is evaluated by coupling CFD analysis and process modelling including mass, energy, and exergy balances. It is found a potential heat recovery of up to 4980 kW of heat with an annulus absorber panel which extends 30 m of the kiln length and reaches an average temperature of up to 240 °C. Such heat could be used to generate 864.25 kWe of electricity through a Recuperated ORC with a thermal efficiency ηth = 17.35% and an exergetic efficiency ηexg = 48.62% for a total saving of 16.6 MJe per tonne of clinker. An economic feasibility for this recovery alternative is highly dependent on the electricity price in the cement plant location. It is observed for markets with electricity prices exceeding 0.1 $/kWh, the return on investment could reach values of 5% corresponding to a NPV close to 0.06 MUSD.The Royal Academy of Engineerin

Potential savings in the cement industry using waste heat recovery technologies

Data availability: No data was used for the research described in the article.Appendix: Summary of relevant work on waste-heat recovery available online at https://www.sciencedirect.com/science/article/pii/S0360544223012045?via%3Dihub#appendix .Copyright © 2023 The Author(s).. This work describes technologies especially suitable for enhancing cement production process efficiency and overall plant performance by preheating raw material or generating electricity, thus reducing thermal losses, costs, and carbon dioxide emissions. Assessed systems for this purpose include power cycles such as the Organic Rankine Cycle, Tri-lateral Cycle, and Kalina cycle, and alternatives currently under development, such as thermoelectric generators and supercritical fluid cycles. Likewise, the zones of the cement production process with the most significant waste-heat recovery potential are pointed out, focusing on clinkerisation, which accounts for most of the thermal energy expenditure of a cement plant. In addition, the total carbon dioxide emissions related to cement manufacture and the participation of each production stage are presented. Finally, the potential for waste heat recovery in the cement industry of the first six Latin American producers is reviewed, which covers 82% of the total production in the region, based on the thermal and electrical requirements reported in the literature. The potential for emissions savings of carbon dioxide is estimated under the emission factor for the electricity system in each country.This research is funded by the The Royal Academy of Engineering through the Newton-Caldas Fund IAPP18-19\218 project that provides a framework where industry and academic institutions from Colombia and the UK collaborate in the heat recovery in large industrial systems

Exergo-economic comparison of waste heat recovery cycles for a cement industry case study

José J. Fierro ORCID ID: https://orcid.org/0000-0003-2306-611X; Carlos A. Marenco-Porto ORCID ID: https://orcid.org/0000-0002-2969-5040; César Nieto-Londoño ORCID ID: https://orcid.org/0000-0001-6516-9630; Ana Escudero-Atehortua ORCID ID: https://orcid.org/0000-0003-2962-4426; Hussam Jouhara ORCID ID: https://orcid.org/0000-0002-6910-6116; Luiz C. Wrobel ORCID ID: https://orcid.org/0000-0001-6702-0178.Copyright © 2022 The Authors. This work evaluates the performance regarding exergo-economic and emissions requirements of Waste Heat Recovery configurations (Organic Rankine cycle, Trilateral flash cycle, and Kalina cycle) under different operating conditions and working fluids. It was found that the best economic performance is presented by the Organic Rankine cycle that operates with Cyclo-Pentane and has two intermediate heat exchangers since it pushes the expansion temperature up while allowing a higher heat input to the cycle. As a result, it delivers 6.2 MW with a net present value, the net present value of 0.74 million dollars, saving up to 11480 tonnes of carbon dioxide per year. This performance far exceeds that obtained in the previous work, around 50% higher net-work with 80% higher net present value, and constitutes the best alternative in terms of performance to recover waste heat from the source evaluated. Regarding the Trilateral flash cycle, it can be stated that the net work and the exergetic performance are independent of the working fluid as long as there is not a very large volume change in the expander. The Kalina cycle presents slight exergy destruction, but the power delivered does not compensate for the high total capital cost due to the high pressures that must be handled, 55–120 bar, compared to the Organic Rankine cycle, 4–40 bar. An approach was made to more realistic cases where the methodology used facilitates selecting the best alternative when there is a budget restriction using the total capital cost and net work alternatively like a fixed requirement and net present value as the primary decision criterion.This research is funded by the The Royal Academy of Engineering through the Newton-Caldas Fund IAPP18-19\218 project that provides a framework where industry and academic institutions from Colombia and the UK collaborate in the heat recovery in large industrial systems

Subtyping of Clostridium difficile PCR ribotypes 591, 106 and 002, the dominant strain types circulating in Medellin, Colombia

We aimed to achieve a higher typing resolution within the three dominant Clostridium difficile ribotypes (591,106 and 002) circulating in Colombia. A total of 50 C. difficile isolates we had previously typed by PCR-ribotyping, representing the major three ribotypes circulating in Colombia, were analyzed. Twenty-seven isolates of ribotype 591, 12 of ribotype 106 and 11 of ribotype 002 were subtyped by multiple locus variable-number tandem-repeat analysis (MLVA). The presence of the PaLoc genes (tcdA/tcdB), toxin production in culture and antimicrobial susceptibility were also determined. From the total C. difficile ribotypes analyzed, 20 isolates (74%) of ribotype 591, nine (75%) of ribotype 106 and five (45.5%) of ribotype 002 were recovered from patients with Clostridium difficile infection (CDI). MLVA allowed us to recognize four and two different clonal complexes for ribotypes 591 and 002, respectively, having a summed tandem-repeat difference (STRD) 10. Six ribotype 591 and three ribotype 002 isolates belonging to a defined clonal complex were isolated on the same week in two different hospitals. All ribotypes harbored either tcdA+/tcdB+ or tcdA-/tcdB+ PaLoc genes. Moreover, 94% of the isolates were positive for toxin in culture. All isolates were susceptible to vancomycin and metronidazole, while 75% to 100% of the isolates were resistant to clindamycin, and less than 14.8% of ribotype 591 isolates were resistant to moxifloxacina. No significant differences were found among ribotypes with respect to demographic and clinical patients’ data; however, our results demonstrated a high molecular heterogeneity of C. difficile strains circulating in Colombia

Molecular, microbiological and clinical characterization of Clostridium difficile isolates from tertiary care hospitals in Colombia

In Colombia, the epidemiology and circulating genotypes of Clostridium difficile have not yet been described. Therefore, we molecularly characterized clinical isolates of C.difficile from patients with suspicion of C.difficile infection (CDI) in three tertiary care hospitals. C.difficile was isolated from stool samples by culture, the presence of A/B toxins were detected by enzyme immunoassay, cytotoxicity was tested by cell culture and the antimicrobial susceptibility determined. After DNA extraction, tcdA, tcdB and binary toxin (CDTa/CDTb) genes were detected by PCR, and PCR-ribotyping performed. From a total of 913 stool samples collected during 2013–2014, 775 were included in the study. The frequency of A/B toxins-positive samples was 9.7% (75/775). A total of 143 isolates of C.difficile were recovered from culture, 110 (76.9%) produced cytotoxic effect in cell culture, 100 (69.9%) were tcdA+/tcdB+, 11 (7.7%) tcdA-/tcdB+, 32 (22.4%) tcdA-/tcdB- and 25 (17.5%) CDTa+/CDTb+. From 37 ribotypes identified, ribotypes 591 (20%), 106 (9%) and 002 (7.9%) were the most prevalent; only one isolate corresponded to ribotype 027, four to ribotype 078 and four were new ribotypes (794,795, 804,805). All isolates were susceptible to vancomycin and metronidazole, while 85% and 7.7% were resistant to clindamycin and moxifloxacin, respectively. By multivariate analysis, significant risk factors associated to CDI were, staying in orthopedic service, exposure to third-generation cephalosporins and staying in an ICU before CDI symptoms; moreover, steroids showed to be a protector factor. These results revealed new C. difficile ribotypes and a high diversity profile circulating in Colombia different from those reported in America and European countries

LongITools:Dynamic longitudinal exposome trajectories in cardiovascular and metabolic noncommunicable diseases

The current epidemics of cardiovascular and metabolic noncommunicable diseases have emerged alongside dramatic modifications in lifestyle and living environments. These correspond to changes in our "modern" postwar societies globally characterized by rural-to-urban migration, modernization of agricultural practices, and transportation, climate change, and aging. Evidence suggests that these changes are related to each other, although the social and biological mechanisms as well as their interactions have yet to be uncovered. LongITools, as one of the 9 projects included in the European Human Exposome Network, will tackle this environmental health equation linking multidimensional environmental exposures to the occurrence of cardiovascular and metabolic noncommunicable diseases