Antimicrobial Aggregates for the In-Situ Control of Microbially Induced Concrete Corrosion

Concrete is the most common material used to transport storm water and sewage in the world. It is used for pipes, culverts, tunnels and variety of other subterranean appurtenances. Municipalities, water utilities, and many agencies recognize that concrete corrosion is emerging as one of the most serious problems plaguing this critical infrastructure. The dominant form of concrete deterioration in wastewater conveyance systems is microbially mediated (Microbial Induced Concrete Corrosion: MICC). This type of corrosion occurs as a result of ubiquitous microbiological sulfur cycling within sewers: Below the waterline, sulfate present in wastewater is reduced to sulfide (H2S) under anoxic conditions; this partitions into the headspace of pipes and other wastewater structures as H2S&nbsp;gas, which serves as a substrate for biofilms of acidogenic sulfur-oxidizing bacteria (SOBs) above the waterline. These biofilms produce sulfuric acid, which chemically dissolve the cement binder and compromise the concrete structure. While current mitigation technologies focus their attention on developing acid resistant materials, little research has been done on limiting acidophile development in these environments. In response to the current research gaps in this arena, the central aim of my work was to study the effects of substituting metal-impregnated sorbents for a fraction of the fine aggregates traditionally used in cements ─ for the express purpose of inhibiting the bacterial communities responsible for the corrosion in sewer systems. Laboratory investigations evaluated the inhibition potential of selected heavy metals against SOB communities, and resolved minimum inhibitory concentrations, individually and in combinations. Parallel studies characterized different sorbents along with their metal desorption profiles in response to biogenic acid. Field studies in the Denver Metropolitan wastewater collection system, then assessed anti-corrosion performance of cement mortar formulations with different loads of metal-impregnated sorbents.</p

Desarrollo de un prototipo de aplicación móvil para articular la oferta con la demanda de servicios domésticos, usando herramientas de geolocalización en la ciudad de Bogotá. : caso de estudio: barrio Marsella

Actualmente la tasa de desempleo supera los dos dígitos en el país de Colombia, siendo Bogotá una de las ciudades con mayor tasa de desempleo en el país. Así mismo existe unas necesidades insatisfechas, por parte de muchos ciudadanos, ya que no cuentan con personas de confianza para realizar los servicios domésticos dentro de sus casas, es por eso que surge la necesidad de crear una aplicación móvil que le de empleo a muchas personas y por otro lado, brinde la seguridad y confianza para realizar los diferentes servicios domésticos

Received strength signal intensity performance analysis in wireless sensor network using Arduino platform and XBee wireless modules

Today, through the monitoring of agronomic variables, the wireless sensor networks are playing an increasingly important role in precision agriculture. Among the emerging technologies used to develop prototypes related to wireless sensor network, we find the Arduino platform and XBee radio modules from the DIGI Company. In this article, based on field tests, we conducted a comparative analysis of received strength signal intensity levels, calculation of path loss with “log-normal shadowing” and free-space path loss models. In addition, we measure packet loss for different transmission, distances and environments with respect to an “Arduino Mega” board, and radio modules XBee PRO S1 and XBee Pro S2. The tests for the packet loss and received strength signal intensity level show the best performance for the XBee Pro S2 in the indoor, outdoor, and rural scenarios

Copper and cobalt improve the acid resistance of alkali-activated cements

Experimental evidence of a new acid degradation mechanism in alkali-activated cements (AACs) micro-doped with copper (Cu) and cobalt (Co) is presented in this work. Cu and Co incorporation into binary metakaolin and basic oxygen furnace (BOF) slag-based AACs reduced bulk permeable porosity and acid penetration and retarded the formation of calcium sulfate phases upon exposure to acid. Analysis of microstructural evolution and elemental mobility using X-ray diffraction and electron microprobe analysis (EMPA) showed that Cu and Co doping was associated with major differences in AAC leaching patterns when exposed to sulfuric acid. Converging lines of evidence suggest that acid resistance is improved by the preferential mobilization of Cu and Co, along with other multivalent cations (i.e., magnesium), at the acid degradation front(s), stabilizing the AAC binder and inhibiting further deterioration.</p

Rehabilitación oral en el adulto mayor de la vereda granizal del municipio de Bello Antioquia

Se analiza las principales causas de pérdida dental y el estado actual de las prótesis dentales que aquejan a los adultos mayores de la vereda Granizal con el fin de restablecer las funcionalidades bucales a partir de la rehabilitación ora

Rehabilitación oral en el adulto mayor de la vereda granizal del municipio de Bello Antioquia

Se analiza las principales causas de pérdida dental y el estado actual de las prótesis dentales que aquejan a los adultos mayores de la vereda Granizal con el fin de restablecer las funcionalidades bucales a partir de la rehabilitación ora

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

XVI International Congress of Control Electronics and Telecommunications: "Techno-scientific considerations for a post-pandemic world intensive in knowledge, innovation and sustainable local development"

Este título, sugestivo por los impactos durante la situación de la Covid 19 en el mundo, y que en Colombia lastimosamente han sido muy críticos, permiten asumir la obligada superación de tensiones sociales, políticas, y económicas; pero sobre todo científicas y tecnológicas. Inicialmente, esto supone la existencia de una capacidad de la sociedad colombiana por recuperar su estado inicial después de que haya cesado la perturbación a la que fue sometida por la catastrófica pandemia, y superar ese anterior estado de cosas ya que se encontraban -y aún se encuentran- muchos problemas locales mal resueltos, medianamente resueltos, y muchos sin resolver: es decir, habrá que rediseñar y fortalecer una probada resiliencia social existente - producto del prolongado conflicto social colombiano superado parcialmente por un proceso de paz exitoso - desde la tecnociencia local; como lo indicaba Markus Brunnermeier - economista alemán y catedrático de economía de la Universidad de Princeton- en su libro The Resilient Society…La cuestión no es preveerlo todo sino poder reaccionar…aprender a recuperarse rápido.This title, suggestive of the impacts during the Covid 19 situation in the world, and which have unfortunately been very critical in Colombia, allows us to assume the obligatory overcoming of social, political, and economic tensions; but above all scientific and technological. Initially, this supposes the existence of a capacity of Colombian society to recover its initial state after the disturbance to which it was subjected by the catastrophic pandemic has ceased, and to overcome that previous state of affairs since it was found -and still is find - many local problems poorly resolved, moderately resolved, and many unresolved: that is, an existing social resilience test will have to be redesigned and strengthened - product of the prolonged Colombian social conflict partially overcome by a successful peace process - from local technoscience; As Markus Brunnermeier - German economist and professor of economics at Princeton University - indicates in his book The Resilient Society...The question is not to foresee everything but to be able to react...learn to recover quickly.Bogot

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

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

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

The original version of this article unfortunately contained a mistake