Memory Effects in Nonequilibrium Transport for Deterministic Hamiltonian Systems

We consider nonequilibrium transport in a simple chain of identical mechanical cells in which particles move around. In each cell, there is a rotating disc, with which these particles interact, and this is the only interaction in the model. It was shown in \cite{eckmann-young} that when the cells are weakly coupled, to a good approximation, the jump rates of particles and the energy-exchange rates from cell to cell follow linear profiles. Here, we refine that study by analyzing higher-order effects which are induced by the presence of external gradients for situations in which memory effects, typical of Hamiltonian dynamics, cannot be neglected. For the steady state we propose a set of balance equations for the particle number and energy in terms of the reflection probabilities of the cell and solve it phenomenologically. Using this approximate theory we explain how these asymmetries affect various aspects of heat and particle transport in systems of the general type described above and obtain in the infinite volume limit the deviation from the theory in \cite{eckmann-young} to first-order. We verify our assumptions with extensive numerical simulations.Comment: Several change

Comparison of pulse rate variability and morphological features of photoplethysmograms in estimation of blood pressure

Photoplethysmography is an optical technique that produces a wealth of information about cardiovascular health. Therefore, the technology has become an integral part of personal health monitoring devices. Given the importance of blood pressure measurement and control in physical and mental health, in recent years, the estimation of blood pressure from photoplethysmography has been an active area of research with promising results. Most studies on the subject rely on the morphological features of the photoplethysmogram. These features are highly prone to noise, changes in sensor placement, and skin properties; including skin colour. To address these limitations, we investigated the feasibility of using pulse rate variability features which are known to be less prone to the aforementioned limitations. To this end, we collected high quality photoplethysmograms using a bespoke, research-grade device from 18 healthy subjects. Approximately 15 min of photoplethysmograms and continuous blood pressure waveforms were collected from each subject. We trained machine learning models based on different feature sets and compared their performances. The model with morphological features alone outperformed the model with pulse rate variability features, root mean squared error (RMSE) of 6.32 vs 7.23 mmHg. However, the best performance was obtained using the combined set of features (RMSE: 5.71 mmHg). Combined, the evidence shows that the estimation of BP from PRV, alone or in conjunction with morphological features, is feasible. In light of the limitations of morphological features in estimation of blood pressure, our findings lend support to further research on the use of pulse rate variability features

Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes.

OBJECTIVES: The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS). BACKGROUND: Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization. METHODS: The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. RESULTS: Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04). CONCLUSIONS: Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.info:eu-repo/semantics/publishedVersio

Carbonatación de un hormigón hibrido con alto contenido de escoria siderurgica de alto horno y su impacto en la corrosión del acero estructural

The aim of this research was to study the carbonation resistance of a blast furnace slag concrete (80% GBFS/20%OPC), with and without alkaline activation, and its influence on the corrosion of structural reinforcement. An OPC-based concrete produced under the same specifications was used as a reference material. To do this, the material was subjected to an accelerated carbonation process under controlled conditions (65% relative humidity, 1% CO2, 25°C). The half-cell potential (Ecorr), linear polarization resistance (LPR) tests showed that both concretes based on GBFS led to depassivation of the reinforcing steel at approximately 99 days, which is the time required for full carbonation of the evaluated concretes.El objetivo de esta investigación fue estudiar la resistencia a la carbonatación de un hormigón a base de escoria granulada de alto horno (80% GBFS/20%OPC), con y sin activación alcalina, y su influencia sobre la corrosión del acero estructural. Un hormigón basado en cemento portland producido con las mismas especificaciones fue usado como material de referencia. Para ello, el material fue sometido a un proceso de carbonatación acelerada bajo condiciones controladas (Humedad Relativa 65 %, 1% CO2, 25 °C). Los ensayos de potencial de media celda (Ecorr) y Resistencia a la polarización lineal (LPR) mostraron que los aceros estructurales aproximadamente a los 99 días alcanzan la despasivación en los hormigones basados en escoria, coincide este tiempo con el requerido para la completa carbonatación de los hormigones evaluados

Effect of an Albumin Infusion Treatment Protocol on Delayed Cerebral Ischemia and Relevant Outcomes in Patients with Subarachnoid Hemorrhage

Un protocolo de manejo institucional para pacientes con hemorragia subaracnoidea (HSA) basado en la evaluación cardíaca inicial, la permisividad de los balances negativos de líquidos y el uso de una infusión continua de albúmina como fluidoterapia principal durante los primeros 5 días de estancia en la unidad de cuidados intensivos (UCI). se implementó en nuestro hospital en 2014. Tenía como objetivo lograr y mantener la euvolemia y la estabilidad hemodinámica para prevenir eventos isquémicos y complicaciones en la UCI reduciendo los períodos de hipovolemia o inestabilidad hemodinámica. Este estudio tuvo como objetivo evaluar el efecto del protocolo de manejo implementado sobre la incidencia de isquemia cerebral retardada (ICD), la mortalidad y otros resultados relevantes en pacientes con HSA durante la estancia en la UCI.Q1Background An institutional management protocol for patients with subarachnoid hemorrhage (SAH) based on initial cardiac assessment, permissiveness of negative fluid balances, and use of a continuous albumin infusion as the main fluid therapy for the first 5 days of the intensive care unit (ICU) stay was implemented at our hospital in 2014. It aimed at achieving and maintaining euvolemia and hemodynamic stability to prevent ischemic events and complications in the ICU by reducing periods of hypovolemia or hemodynamic instability. This study aimed at assessing the effect of the implemented management protocol on the incidence of delayed cerebral ischemia (DCI), mortality, and other relevant outcomes in patients with SAH during ICU stay. Methods We conducted a quasi-experimental study with historical controls based on electronic medical records of adults with SAH admitted to the ICU at a tertiary care university hospital in Cali, Colombia. The patients treated between 2011 and 2014 were the control group, and those treated between 2014 and 2018 were the intervention group. We collected baseline clinical characteristics, cointerventions, occurrence of DCI, vital status after 6 months, neurological status after 6 months, hydroelectrolytic imbalances, and other SAH complication. Multivariable and sensitivity analyses that controlled for confounding and considered the presence of competing risks were used to adequately estimate the effects of the management protocol. The study was approved by our institutional ethics review board before study start. Results One hundred eighty-nine patients were included for analysis. The management protocol was associated with a reduced incidence of DCI (hazard ratio 0.52 [95% confidence interval 0.33–0.83] from multivariable subdistribution hazards model) and hyponatremia (relative risk 0.55 [95% confidence interval 0.37–0.80]). The management protocol was not associated with higher hospital or long-term mortality, nor with a higher occurrence of other unfavorable outcomes (pulmonary edema, rebleeding, hydrocephalus, hypernatremia, pneumonia). The intervention group also had lower daily and cumulative administered fluids compared with historic controls (p < 0.0001). Conclusions A management protocol based on hemodynamically oriented fluid therapy in combination with a continuous albumin infusion as the main fluid during the first 5 days of the ICU stay appears beneficial for patients with SAH because it was associated with reduced incidence of DCI and hyponatremia. Proposed mechanisms include improved hemodynamic stability that allows euvolemia and reduces the risk of ischemia, among others.Revista Internacional - IndexadaS

Epidemiological aspects of facial trauma in a third level hospital in Mexico

Background: Facial trauma is common in early adulthood and may require complex surgery and even high mortality. Methods: Retrospective, cross-sectional study at the Hospital General de México during the period from January 2018 to December 2021. Patients with a diagnosis of fracture of the facial region, who had a complete clinical record, of any age, were included. Patients who did not comply with the treatment in the hospital unit, with incomplete clinical records, were excluded. Through non-probability sampling, a sample of 156 patients was formed. The descriptive data analysis was carried out by calculating frequencies and percentages for the qualitative variables. For the quantitative variables, measures of central tendency and dispersion were calculated according to the distribution of the variables (mean and standard deviation). for variables with normal distribution and median with interquartile range for variables with non-normal distribution). Results: 156 patients were included, the male sex predominated (89.7%), the age group from 21 to 30 years (35.3%), the injury mechanism of aggression by a third party (54.5%). Facial fractures occurred in the following descending order: orbit (64.7%), zygoma (41.7% n=65), mandibular (23.1% n=36), nasal (22.4% n=35), maxilla (21.8% n=34), NOE (4.5% n=7), Le Fort (3.8% n=6), and palate (3.8% n=6). Within orbital fractures, the most frequently affected region was the orbital floor (42.3%). The patients with orbital fracture were mostly men (88.1% versus 11.9%). The highest frequency of these fractures was between the ages of 21 and 30 (38.6%). Surgical treatment of fractures in general was established in 44.9%, performing open reduction and internal fixation of fractures in 41.0%. Conclusions: The most frequent facial fractures are: orbit, zygoma, and mandibular; they mainly affect the male sex in the second decade of life, they are produced mainly by aggressions to third parties. The management of facial fractures is predominantly surgical, through open reduction and internal fixation

Aprovechamiento del residuo agroindustrial del mango común (Mangifera indica L.) en la obtención de azúcares fermentables

The common mango residue (Mangifera indica L.) is a plant material that contains a large amount of lignocellulosic tissue, which can be used to obtain fermentable metabolites and fermentation products. In this work, hydrolysis treatments were applied to the common mango residue in order to convert its polysaccharides to fermentable sugar units. Acid hydrolysis was applied at three different concentrations of dilute sulfuric acid. Also, enzymatic hydrolysis was applied with two types of commercial enzymes at different concentrations under standard working conditions. Similarly, thermal hydrolysis was applied at two different temperatures. For each applied treatment, tests were carried out on the concentration of total sugars, concentration of reducing sugars, percentage of cellulose and residual hemicellulose, data with which the best treatments were determined and combinations of the best hydrolysis treatments were carried out. The most significant treatment of the individual tests was that of acid hydrolysis at 0.50% v / v sulfuric acid at 80 ° C for one hour. In the combined treatments the most significant result was the treatment in which enzymatic hydrolysis (as pretreatment) plus thermal hydrolysis and acid hydrolysis were combined. For reasons of safety in the use of reagents, as well as elimination of adverse side effects for subsequent alcoholic fermentation, the procedure involving thermal hydrolysis as a pretreatment and enzymatic hydrolysis as the main treatment was selected, as the treatment of best application in production of fermentable metabolites from common mango residues with the purpose of producing alcohol later. Subsequent studies have allowed microbial hydrolysis to be addressed with Aspergillus niger and Trichoderma viride, as well as alcoholic fermentation after hydrolytic treatment using previous studies. Simultaneous hydrolysis and alcoholic fermentation, and more recently and in execution the simultaneity of the processes by adding a recombinant yeast that has the ability to ferment five-carbon sugars.El residuo del mango común (Mangifera indica L.) es un material vegetal que contiene gran cantidad de tejido lignocelulósico, el cual puede ser aprovechado para la obtención de metabolitos fermentables y productos de la fermentación. En este trabajo se aplicaron tratamientos de hidrólisis al residuo del mango común con el fin de hacer la conversión de sus polisacáridos a unidades de azúcares fermentables. Se aplicó hidrólisis ácida a tres concentraciones diferentes de ácido sulfúrico diluido. También, se aplicó hidrólisis enzimática con dos tipos de enzimas comerciales a diferentes concentraciones en las condiciones de trabajo estándar. De igual manera se aplicó hidrólisis térmica a dos temperaturas diferentes. A cada tratamiento aplicado se le efectuaron pruebas de concentración de azúcares totales, concentración de azúcares reductores, porcentaje de celulosa y hemicelulosa residual, datos con los cuales se determinaron los mejores tratamientos y se procedió a efectuar combinaciones de los mejores tratamientos de hidrólisis. El tratamiento más significativo de las pruebas individuales fue el de hidrólisis ácida a 0,50% v/v de ácido sulfúrico a 80◦C por una hora. En los tratamientos combinados el resultado más significativo fue el tratamiento en el que se combinaron la hidrólisis enzimática (como pretratamiento) más una hidrólisis térmica e hidrólisis ácida. Por razones de seguridad en el uso de reactivos, así como eliminación de efectos colaterales adversos para la fermentación alcohólica posterior, se seleccionó el procedimiento que involucra la hidrólisis térmica como pretratamiento y la hidrólisis enzimática como tratamiento principal, como el tratamiento de mejor aplicación en la producción de metabolitos fermentables a partir de residuos de mango común con finalidad producción de alcohol posteriormente. Estudios posteriores han permitido abordar la hidrólisis por vía microbiana con Aspergillus niger y Trichoderma viride, así como la fermentación alcohólica postratamiento hidrolítico usando los estudios previos. La hidrólisis y fermentación alcohólica simultáneas, y más recientemente y en ejecución la simultaneidad de los procesos adicionando una levadura recombinante que tiene capacidad de fermentar azúcares de cinco carbonos

Aprovechamiento del residuo agroindustrial del mango común (Mangifera indica L.) en la obtención de azúcares fermentables

The common mango waste (Mangifera indica L.) is a vegetable material containing a high level of lignocelluloses tissue which can be used to obtain fermentable metabolites and fermentation products. In this study hydrolysis treatments were applied to the common mango in order to make the conversion of its polysaccharides to fermentable sugar units. Acid hydrolysis was applied to three different concentrations of dilute sulphuric acid. An enzymatic hydrolysis with two types of commercial enzymes to different concentrations in standard work conditions, was also applied. In addition, a thermic hydrolysis was applied at two different temperatures. At each treatment, the following tests were applied: total sugar concentration, reduced sugar concentration, and percentage of cellulose and hemicellulose residuals. Based on the data obtained from the tests, the best treatments were identified and so the best combinations of the best hydrolysis treatments were carried out. The most significant treatment for individual tests was acid hydrolysis at 0, 50% v/v sulphuric acid at 80◦C for one hour. In the combined treatments the most relevant result was the treatment that combined the enzymatic hydrolysis (as pretreatment) plus a thermic hydrolysis and acid hydrolysis. For security reasons in the reagents use, as well as in the elimination of collateral adverse effects for further alcoholic fermentation, a procedure involving thermic hydrolysis as pretreatment and enzymatic hydrolysis, was chosen as the main treatment with the most appropriate application in the fermentable metabolites production from common mango waste in order to produce alcohol. Further studies have allowed approaching the hydrolysis via microbial with Aspergillus niger and Trichoderma viride, as well as the alcoholic fermentation post-treatment hydrolytic using previous studies. The simultaneous hydrolysis and alcoholic fermentation, and recently performing the simultaneity of the processes, adding a recombining yeast that has the capacity to ferment sugars from five carbons.El residuo del mango común (Mangifera indica L.) es un material vegetal que contiene gran cantidad de tejido lignocelulósico, el cual puede ser aprovechado para la obtención de metabolitos fermentables y productos de la fermentación. En este trabajo se aplicaron tratamientos de hidrólisis al residuo del mango común con el fin de hacer la conversión de sus polisacáridos a unidades de azúcares fermentables. Se aplicó hidrólisis ácida a tres concentraciones diferentes de ácido sulfúrico diluido. También, se aplicó hidrólisis enzimática con dos tipos de enzimas comerciales a diferentes concentraciones en las condiciones de trabajo estándar. De igual manera se aplicó hidrólisis térmica a dos temperaturas diferentes. A cada tratamiento aplicado se le efectuaron pruebas de concentración de azúcares totales, concentración de azúcares reductores, porcentaje de celulosa y hemicelulosa residual, datos con los cuales se determinaron los mejores tratamientos y se procedió a efectuar combinaciones de los mejores tratamientos de hidrólisis. El tratamiento más significativo de las pruebas individuales fue el de hidrólisis ácida a 0,50% v/v de ácido sulfúrico a 80◦C por una hora. En los tratamientos combinados el resultado más significativo fue el tratamiento en el que se combinaron la hidrólisis enzimática (como pretratamiento) más una hidrólisis térmica e hidrólisis ácida. Por razones de seguridad en el uso de reactivos, así como eliminación de efectos colaterales adversos para la fermentación alcohólica posterior, se seleccionó el procedimiento que involucra la hidrólisis térmica como pretratamiento y la hidrólisis enzimática como tratamiento principal, como el tratamiento de mejor aplicación en la producción de metabolitos fermentables a partir de residuos de mango común con finalidad producción de alcohol posteriormente. Estudios posteriores han permitido abordar la hidrólisis por vía microbiana con Aspergillus niger y Trichoderma viride, así como la fermentación alcohólica postratamiento hidrolítico usando los estudios previos. La hidrólisis y fermentación alcohólica simultáneas, y más recientemente y en ejecución la simultaneidad de los procesos adicionando una levadura recombinante que tiene capacidad de fermentar azúcares de cinco carbonos.PACS: 88.20.jm, 88.20.dr, 88.20.R