Musculoskeletal Conditions in Older Men and Women: An Emergency Room Study.

OBJECTIVE: To study the utilization of emergency room (ER) services for health complaints of the musculoskeletal (MSK) system in older men and women. METHODS: Data from all medical encounters at the ER of a teaching hospital for calendar years 2016-2020 were extracted from an electronic database. MSK encounters were defined as those with ICD 10-CM M and S codes in the primary diagnosis field of the database. Frequency distributions were calculated by year, sex, and age group for MSK and all encounters. The most frequent codes used by sex and age groups were assessed. RESULTS: The number of unique patients with medical encounters at the ER during the five-year period was 94,346. There was a total of 220,153 encounters (median:1 encounter per patient; interquartile range:1-3). A 33.2% reduction in the number of encounters occurred in 2020 compared to 2019. The total number of unique patients in the 60 yr. and older group was 24,412 (25.9% of all unique patients). The total number of encounters in the group 60 yr. and older was 56,294 (25.6% of all encounters). Women accounted for 31,488 (56%) encounters in this age group. A total of 12,744 encounters (22.6%) in older adults involved the MSK system and this proportion decreased with increasing age. The most common MSK conditions included low back pain, pain in joints, and femoral fractures. CONCLUSION: Older adults with MSK health conditions represent a substantial portion of ER patients. Many MSK health conditions could be evaluated and treated in other health care settings.

Musculoskeletal Conditions in the Emergency Room: A Teaching Opportunity for Medical Students and Residents.

OBJECTIVE: Assess the potential value of an emergency room (ER) for the teaching of musculoskeletal (MSK) medicine to medical students and residents in training. METHODS: Data from all encounters to the ER of a teaching hospital for calendar years 2016-2019 were extracted from an electronic database. Encounters with ICD-10-CM M codes (MSK system) and S codes (injury) were selected (MSK encounters). Frequency distributions were calculated by year, sex, and age group for all encounters and MSK encounters. Annual distributions of encounters involving the shoulder, hip, knee, and ankle joints were assessed. RESULTS: The number of unique patients seen during the four-year period was 84,094, and the number of encounters was 187,829 (Median: 1 encounter; interquartile range: 1-2). The mean number of encounters per year was 46,957 (range: 45,311- 48,382). There was no seasonal variation. Most patients were women (45,868; 54.6%) and young (20 29 yr.) adults (15,012; 17.8%), and these groups generated the largest numbers of encounters (women: 108,799; 57.9%; young adults: 35,969; 19.1%). A total of 41,353 encounters (22.0% of all encounters) involved the MSK system. The shoulder, hip, knee, and ankle were involved in 2,768 (1.5%), 1,592 (0.8%), 3,082 (1.6%), and 1,718 (0.9%) encounters, respectively. The most common conditions for each joint were shoulder pain, femoral fracture, knee contusion, and ankle sprain. CONCLUSION: Our findings suggest that ER physicians should have broad knowledge of MSK conditions and injuries. An ER is an excellent location for the teaching of MSK medicine to medical students and residents of other training programs.

A paradox of traffic and extra cars in a city as a collective behaviour.

Promoting walking or cycling and reducing cars' use is one of the city planners' main targets, contributing to a sustainable transport method. Yet, the number of vehicles worldwide is increasing as fast as the population, and motorized mobility has become the primary transport method in most cities. Here, we consider modal share as an emergent behaviour of personal decisions. All individuals minimize their commuting time and reach an equilibrium under which no person is willing to change their transportation mode. In terms of the minimum travel time, the best-case scenario is used to determine the extra commuting time and the excess cars, computed as a social inefficiency. Results show that commuting times could increase up to 25% with many more vehicles than optimum. Paradoxically, all individuals trying to minimize their time could collectively reach the maximum commuting times in the extreme case, with all individuals driving during rush hour.

Vaccination strategies against COVID-19 and the diffusion of anti-vaccination views.

Misinformation is usually adjusted to fit distinct narratives and propagates rapidly through social networks. False beliefs, once adopted, are rarely corrected. Amidst the COVID-19 crisis, pandemic-deniers and people who oppose wearing face masks or quarantine have already been a substantial aspect of the development of the pandemic. With the vaccine for COVID-19, different anti-vaccine narratives are being created and are probably being adopted by large population groups with critical consequences. Assuming full adherence to vaccine administration, we use a diffusion model to analyse epidemic spreading and the impact of different vaccination strategies, measured with the average years of life lost, in three network topologies (a proximity, a scale-free and a small-world network). Then, using a similar diffusion model, we consider the spread of anti-vaccine views in the network, which are adopted based on a persuasiveness parameter of anti-vaccine views. Results show that even if anti-vaccine narratives have a small persuasiveness, a large part of the population will be rapidly exposed to them. Assuming that all individuals are equally likely to adopt anti-vaccine views after being exposed, more central nodes in the network, which are more exposed to these views, are more likely to adopt them. Comparing years of life lost, anti-vaccine views could have a significant cost not only on those who share them, since the core social benefits of a limited vaccination strategy (reduction of susceptible hosts, network disruptions and slowing the spread of the disease) are substantially shortened.

A continuous binning for discrete, sparse and concentrated observations.

Discrete observations from data which are obtained from sparse, and yet concentrated events are often observed (e.g. road accidents or murders). Traditional methods to compute summary statistics often include placing the data in discrete bins but for this type of data this approach often results in large numbers of empty bins for which no function or summary statistic can be computed. Here, a method for dealing with sparse and concentrated observations is constructed, based on a sequence of non-overlapping bins of varying size, which gives a continuous interpolation of data for computing summary statistics of the values for the data, such as the mean. The method presented here overcomes the problem which sparsity and concentration present when computing functions to represent the data. Implementation of the method presented here is facilitated via open access to the code. •A new method for computing functions over sparse and concentrated data is constructed.•The method allows straightforward functions to be computed over partitions of the data, such as the mean, but also more complicated functions, such as coefficients, ratios, correlations, regressions and others.

Unravelling travellers' route choice behaviour at full-scale urban network by focusing on representative OD pairs in computer experiments.

In a city-scale network, trips are made in thousands of origin-destination (OD) pairs connected by multiple routes, resulting in a large number of alternatives with diverse characteristics that influence the route choice behaviour of the travellers. As a consequence, to accurately predict user choices at full network scale, a route choice model should be scalable to suit all possible configurations that may be encountered. In this article, a new methodology to obtain such a model is proposed. The main idea is to use clustering analysis to obtain a small set of representative OD pairs and routes that can be investigated in detail through computer route choice experiments to collect observations on travellers behaviour. The results are then scaled-up to all other OD pairs in the network. It was found that 9 OD pair configurations are sufficient to represent the network of Lyon, France, composed of 96,096 OD pairs and 559,423 routes. The observations, collected over these nine representative OD pair configurations, were used to estimate three mixed logit models. The predictive accuracy of the three models was tested against the predictive accuracy of the same models (with the same specification), but estimated over randomly selected OD pair configurations. The obtained results show that the models estimated with the representative OD pairs are superior in predictive accuracy, thus suggesting the scaling-up to the entire network of the choices of the participants over the representative OD pair configurations, and validating the methodology in this study.

A novel rare event approach to measure the randomness and concentration of road accidents.

BACKGROUND: Road accidents are one of the main causes of death around the world and yet, from a time-space perspective, they are a rare event. To help us prevent accidents, a metric to determine the level of concentration of road accidents in a city could aid us to determine whether most of the accidents are constrained in a small number of places (hence, the environment plays a leading role) or whether accidents are dispersed over a city as a whole (hence, the driver has the biggest influence). METHODS: Here, we apply a new metric, the Rare Event Concentration Coefficient (RECC), to measure the concentration of road accidents based on a mixture model applied to the counts of road accidents over a discretised space. A test application of a tessellation of the space and mixture model is shown using two types of road accident data: an urban environment recorded in London between 2005 and 2014 and a motorway environment recorded in Mexico between 2015 and 2016. FINDINGS: In terms of their concentration, about 5% of the road junctions are the site of 50% of the accidents while around 80% of the road junctions expect close to zero accidents. Accidents which occur in regions with a high accident rate can be considered to have a strong component related to the environment and therefore changes, such as a road intervention or a change in the speed limit, might be introduced and their impact measured by changes to the RECC metric. This new procedure helps us identify regions with a high accident rate and determine whether the observed number of road accidents at a road junction has decreased over time and hence track structural changes in the road accident settings.

Charge separation at disordered semiconductor heterojunctions from random walk numerical simulations.

Many recent advances in novel solar cell technologies are based on charge separation in disordered semiconductor heterojunctions. In this work we use the Random Walk Numerical Simulation (RWNS) method to model the dynamics of electrons and holes in two disordered semiconductors in contact. Miller-Abrahams hopping rates and a tunnelling distance-dependent electron-hole annihilation mechanism are used to model transport and recombination, respectively. To test the validity of the model, three numerical "experiments" have been devised: (1) in the absence of constant illumination, charge separation has been quantified by computing surface photovoltage (SPV) transients. (2) By applying a continuous generation of electron-hole pairs, the model can be used to simulate a solar cell under steady-state conditions. This has been exploited to calculate open-circuit voltages and recombination currents for an archetypical bulk heterojunction solar cell (BHJ). (3) The calculations have been extended to nanostructured solar cells with inorganic sensitizers to study, specifically, non-ideality in the recombination rate. The RWNS model in combination with exponential disorder and an activated tunnelling mechanism for transport and recombination is shown to reproduce correctly charge separation parameters in these three "experiments". This provides a theoretical basis to study relevant features of novel solar cell technologies.

A continuity equation for the simulation of the current-voltage curve and the time-dependent properties of dye-sensitized solar cells.

A numerical model that simulates the steady-state current-voltage curve and the time-dependent response of a dye-sensitized solar cell with a single continuity equation is derived. It is shown that the inclusion of the multiple-trapping model, the quasi-static approximation and non-linear recombination kinetics leads to a continuity equation for the total electron density in the photoanode with an electron density-dependent diffusion coefficient and a density-dependent pseudo-first order recombination constant. All parameters in the model can be related to quantities accessible experimentally. The required power exponents are taken from impedance spectroscopy measurements at different voltages. The model provides new insights into the physical interpretation of the power exponents. Modeling examples involving a high-efficiency TiO(2)-based dye solar cell and a ZnO-based dye solar cell are presented. It is demonstrated that the model reproduces the transient behavior of the cell under small perturbations. The spatial dependence of the recombination rate and the influence of film thickness and of voltage dependent injection efficiency on cell performance are studied. The implications of the model are discussed in terms of efficiencies potentially attainable in dye-sensitized solar cells and other kinds of solar cells with a diffusional mechanism of charge transport.

Análisis de concordancia entre la bioimpedancia vectorial y la espectroscópica / Analysis of concordance between the bioelectrical impedance vector analysis and the bioelectrical impedance spectroscopy in haemodialysis patients

Introducción: Los valores de los compartimentos corporales proporcionados por los dos sistemas de bioimpedancia más utilizados en España (bioimpedancia de monofrecuencia vectorial [BIVA] y bioimpedancia multifrecuencia espectroscópica [BIS]) son diferentes y no pueden intercambiarse. Objetivo: Analizar si la variabilidad intermétodo es debida a la diferente lectura de las variables bioeléctricas realizadas por los monitores o a las ecuaciones utilizadas por cada uno de ellos para el cálculo de los volúmenes y masas corporales. Otro objetivo fue comprobar si, a pesar de la variabilidad intermétodo, la clasificación de los estados de hidratación definidos por ambos monitores es concordante. Material y métodos: Estudio de corte transversal. En 54 enfermos tratados con hemodiálisis se hizo un análisis de bioimpedancia con los monitores BIVA y BIS inmediatamente antes de una sesión de diálisis. En 38 de ellos se repitió el estudio con el monitor BIVA al finalizar la misma sesión de diálisis. Resultados: Los datos de resistencia y ángulo de fase proporcionados por el monitor BIVA y por el monitor BIS a la frecuencia de 50 kHz son concordantes. En el caso de la resistencia, la variabilidad es de 1,3%, y el coeficiente de correlación intraclase, de 0,99. Para el ángulo de fase, la variabilidad es del 11,5%, y el coeficiente de (..) (AU)

Introduction: The values of body composition provided by the two most commonly used bioelectrical impedance systems in Spain, single-frequency bioelectrical impedance vector analysis (SF-BIVA) and multi-frequency bioelectrical impedance spectroscopy (MF-BIS) are different and not comparable. Objective: Analyse whether the inter-method variability is due to bioelectrical variables measured by the different monitors, or rather due to the equations used to calculate body volume and mass. Another objective was to determine whether, despite the inter-method variability, the classification of hydration status by the two methods is consistent. Material and Methods: Bioelectrical impedance was measured by SF-BIVA and MF-BIS immediately before a dialysis session in 54 patients on haemodialysis. In 38 patients, the study was repeated by SF-BIVA at the end of the same dialysis session. Results: Resistance and phase angle values provided by the two monitors at a frequency of 50kHz were consistent. For resistance, variability was 1.3% and the intra-class correlation coefficient was 0.99. For phase angle, variability and the intra-class correlation coefficient were 11.5% and 0.92, respectively. The volume values (..) (AU)

Analysis of concordance between the bioelectrical impedance vector analysis and the bioelectrical impedance spectroscopy in haemodialysis patients.

INTRODUCTION: The values of body composition provided by the two most commonly used bioelectrical impedance systems in Spain, single-frequency bioelectrical impedance vector analysis (SF-BIVA) and multi-frequency bioelectrical impedance spectroscopy (MF-BIS) are different and not comparable. OBJECTIVE: Analyse whether the inter-method variability is due to bioelectrical variables measured by the different monitors, or rather due to the equations used to calculate body volume and mass. Another objective was to determine whether, despite the inter-method variability, the classification of hydration status by the two methods is consistent. MATERIAL AND METHODS: Bioelectrical impedance was measured by SF-BIVA and MF-BIS immediately before a dialysis session in 54 patients on haemodialysis. In 38 patients, the study was repeated by SF-BIVA at the end of the same dialysis session. RESULTS: Resistance and phase angle values provided by the two monitors at a frequency of 50kHz were consistent. For resistance, variability was 1.3% and the intra-class correlation coefficient was 0.99. For phase angle, variability and the intra-class correlation coefficient were 11.5% and 0.92, respectively. The volume values for total body water, extracellular water, fat mass and body cell mass were biased, with a level of variability that would not be acceptable in clinical practice. The intra-class correlation coefficient also suggested a poor level of agreement. SF-BIVA systems define overhydration or dehydration as a vector below or above the tolerance ellipse of 75% on the longitudinal axis. MF-BIS uses two criteria for pre-dialysis hyper-hydration: overhydration (OH) greater than 2.5 litres, or greater than 15% of extracellular water. The degree of equivalence with the results of the SF-BIVA monitor was better with the second criterion (kappa: 0.81, excellent agreement) than with the first one (kappa: 0.71, acceptable agreement). The MF-BIS system defines post-dialysis normal hydration as a difference between OH and ultrafiltratation volume between ­1.1 and 1.1 litres and agreement with the SF-BIVA system for this parameter was acceptable (weighted kappa index: 0.64). CONCLUSIONS: The MF-BIS and SF-BIVA systems provide similar readings for bioelectrical parameters, and the wide variation in the quantification of volume and body mass must be attributed to the different equations used for calculation. Furthermore, the criteria used by both systems to define both pre- and post-dialysis hydration have an acceptable level of equivalence.

[Kidney transplantation. Experience at the University Hospital José González, UANL in Monterrey, Mexico]. / Trasplante renal. Experiencia en el Hospital Universitario José E. González, UANL, en Monterrey, México.

BACKGROUND: In patients with end-stage renal disease, successful renal allotransplantation improves the quality of life and increases survival as compared with long-term dialysis treatment. OBJECTIVE: To show our experience, effectiveness and results of renal transplantations at the University Hospital of UANL. MATERIAL AND METHODS: A retrospective study of renal transplantation performed at University Hospital of UANL was done. The transplant cases from 1967 to July 2001 and January 2003 to June 2011 were included. RESULTS: 280 kidney transplants were performed in 264 patients, 146 men and 118 women; 201 from deceased donor and 79 from living donor. The patient survival at 1, 3, and 5 years was 98.8, 85.9 and 85.9%, respectively. The graft survival at 1, 3, and 5 years, censored for death with functioning graft, was 98.8, 85.7 and 74.9%, respectively. CONCLUSIONS: Our results, in this population with unfavorable socioeconomic conditions, are comparable to those obtained in other institutions.

Inmunoglobulinas en líquidos cefalorraquídeo y suero de pacientes con meningitis tuberculosa / Inmunoglobulins in cerebrospinal fluid and serum of patients with tuberculous meningitis

Se realizaron determinaciones de las concentraciones séricas y en líquido cefalorraquídeo de IgG, IgA, e IgM por medio de nefelometría y se calcularon los valores absolutos y normalizados con base en los valores esperados en población normal, así como con el índice LCR/suero en: a) veinte pacientes con meningitis tuberculosa (M-TBC) comprobados por hallazgos bacteriológicos y/o autopsia; b) ocho pacientes con cuadro clínico de meningitis tuberculosa, en los cuales no se encontró el microorganismo; c) catorce pacientes cuyas evolución clínica se asemejó a la meningitis tuberosa pero luego se esclareció otra patologia y d) como controles 16 sujetos sin sintomatología ni signología meníngea y con citoquímico normal del LCR. Teniendo como base los valores establecidos en el grupo control, se apreció un gran aumento de las tres proteínas estudiadas en LCR en sus índices respectivos en los grupos de M-TBC. En el gupo con otros diagnósticos la IgA presentó valores muy elevados en LCR, mientras que para la IgG y la IgM los aumentos fueron moderados. Las concentraciones séricas de IgG e IgA fueron normales en todos los grupos de pacientes y la de IgM presentó un ligero aumento en M-TBC y en otras patologías. La edad en los controles correlacionó con los valores de IgG en el LCR y en menor grado con los de IgA e IgM. Igualmente los índices de IgG e IgM correlacionaroan con los de IgA en los pacientes con M-TBC y otros diagnósticos. La elevación de las Igs en LCR no parece ser de ayuda en el diagnóstico diferencial de la M-TBC, pero sí explica parcialmente la inmunopatolgénesis de la reación inflamatoria a nivel de SNC