Potential predictors for surgical delay in patients with intertrochanteric fractures and their impact on hospitalization length, in a Latin American trauma center.

INTRODUCTION: The incidence of intertrochanteric fractures is increasing, and health institutions must know the profile of their patients. This paper describes the relationship between clinical characteristics and attention process with surgical delay and prolonged hospitalization length in patients with intertrochanteric fractures admitted to a Latin-American trauma center. MATERIALS AND METHODS: Retrospective, comparative, cross-sectional study. The medical records of patients admitted for intertrochanteric fracture between August 1st 2019 and May 31st 2021 were reviewed to extract data regarding clinical characteristics, causes of surgery delay, and hospitalization length. Regression models were used to distinguish potential predictor variables on surgical delay and hospitalization length. RESULTS: 362 cases with intertrochanteric fractures were surgically treated during the study period. The mean time from admission to surgery was 4.2 ± 3.8 days. in 33,1% of the cases the surgery was performed within the first 48 h. A history of coronary heart disease (CHD) and chronic kidney disease were potential predictors of surgery delay (p<0.005). Only CHD was independently associated with surgery delay (OR 5.267 [95%CI 1.201-23.100); p = 0.028). Hospitalization was extended in cases where surgery was performed after 48 h (10,1 ± 6,2 days vs 5,9 ± 3,0 days; p<0.001). The regression model showed that for each day passed from fracture to admission and each day from admission to surgery, the hospitalization duration increased by 3,7 and 4,4 days, respectively. DISCUSSION: Patients with intertrochanteric fractures have comorbidities that potentially delay their surgical treatment and prolong hospitalization duration. The efficient use of hospital resources and the proper early evaluation of cardiac pathologies conducted during admission, could positively impact the achievement of surgical treatment within the first 48 h after the fracture, reducing hospitalization duration.

An integrated microfluidic-based biosensor using a magnetically controlled MNPs-enzyme microreactor to determine cholesterol in serum with fluorometric detection.

This work provides a microfluidic-based biosensor to determine total cholesterol in serum based on integrating the reaction/detection zone of a microfluidic chip of a magnetically retained enzyme microreactor (MREµR) coupled with the remote fluorometric detection through a bifurcated fiber-optic bundle (BFOB) connected with a conventional spectrofluorometer. The method is based on developing the enzymatic hydrolysis and oxidation of cholesterol at microscale size using both enzymes (cholesterol esterase (ChE) and cholesterol oxidase (ChOx)) immobilized on magnetic nanoparticles (MNPs). The biocatalyst reactions were followed by monitoring the fluorescence decreasing by the naphtofluorescein (NF) oxidation in the presence of the previous H2O2 formed. This microfluidic biosensor supposes the physical integration of a minimal MREµR as a bioactive enzyme area and the focused BFOB connected with the spectrofluorometer detector. The MREµR was formed by a 1 mm length of magnetic retained 2:1 ChE-MNP/ChOx-MNP mixture. The dynamic range of the calibration graph was 0.005-10 mmol L-1, expressed as total cholesterol concentration with a detection limit of 1.1 µmol L-1 (r2 = 0.9999, sy/x = 0.03, n = 10, r = 3). The precision expressed as the relative standard deviation (RSD%) was between 1.3 and 2.1%. The microfluidic-based biosensors showed a sampling frequency estimated at 30 h-1. The method was applied to determine cholesterol in serum samples with recovery values between 94.8 and 102%. The results of the cholesterol determination in serum were also tested by correlation with those obtained using the other two previous methods.

Semi-Selective Array for the Classification of Purines with Surface Plasmon Resonance Imaging and Deep Learning Data Analysis.

In process analytics or environmental monitoring, the real-time recording of the composition of complex samples over a long period of time presents a great challenge. Promising solutions are label-free techniques such as surface plasmon resonance (SPR) spectroscopy. They are, however, often limited due to poor reversibility of analyte binding. In this work, we introduce how SPR imaging in combination with a semi-selective functional surface and smart data analysis can identify small and chemically similar molecules. Our sensor uses individual functional spots made from different ratios of graphene oxide and reduced graphene oxide, which generate a unique signal pattern depending on the analyte due to different binding affinities. These patterns allow four purine bases to be distinguished after classification using a convolutional neural network (CNN) at concentrations as low as 50 µM. The validation and test set classification accuracies were constant across multiple measurements on multiple sensors using a standard CNN, which promises to serve as a future method for developing online sensors in complex mixtures.

Integrated microfluidic systems for fluorescence monitoring rapid kinetic reactions in bioanalysis.

A stopped-flow microfluidic fluorimetric biosensor to monitor alkaline phosphatase (ALP) activity and evaluate the potential inhibitors has been developed, integrating a magnetically retained enzyme microreactor (MREµR) in the reaction/detection zone of the microfluidic chip. The integration supposed the alignment of the MREµR at the sample compartment of a conventional spectrofluorometer using a 3D-printed device. The analytical signal is based on the fluorescence decrease in the signal obtained in the dephosphorylation reaction of the substrate 4-methylumbelliferone phosphate (4-MUP) by the retained ALP-MNPs in an alkaline medium caused by sulfonamides. The excitation and emission wavelengths to monitor the reaction were 363 and 444 nm, respectively. Three sulfonamides, acetazolamide, furosemide, and sulfasalazine, have been used as model analytes. The front-face operating mode of the spectrofluorometer was used to acquire the instrumental signals. The influence of the rotation angle of the microfluidic device on the efficiency of the signal collection has also been studied, obtaining the signals with greater intensity at 75° from the excitation beam. The dynamic range of the calibration graph was 16.81-1111.22 µg mL-1, expressed as sulfonamide concentration, with a limit of detection of 5.04 µg mL-1 (R2 = 0.9989, n = 10, r = 3) for acetazolamide. The method was applied to determine sulfonamide residues in tap water and milk samples, with 88.9-98.7% recovery values. The results have been compared with those obtained using a commercial device connected to the spectrofluorometer, getting faster reaction kinetics.

Study of the inhibition effects on glutathione peroxidase immobilized on MNPs using a stopped-flow microfluidic system.

A stopped-flow microfluidic system to monitor glutathione peroxidase (GPx) activity and evaluate potential inhibitors of the enzyme has been developed based on the integration of the microfluidic chip in the reaction/detection zone. This integration supposes the physical alignment at the optimal location of the microfluidic channel, both the magnetically retained enzyme microreactor (MREµR) and the remote luminescence detection using a focused bifurcated fiber optic bundle (BFOB) connected to a conventional spectrofluorometer detector. The method is based on the coupling of two competitive oxidative chemical reactions, in which glutathione (GSH) and homovanillic acid (HVA) competed for their interaction with hydrogen peroxide in the presence of the magnetically retained GPx-MNPs. The biocatalytic reaction was followed by monitoring the fluorescence of the biphenyl-HVA dimer formed. The dynamic range of the calibration graph was 0.45-10 µmol L-1, expressed as GSH concentration with a detection limit of 0.1 µmol L-1 (r2 = 0.9954, n = 10, r = 3). The precision expressed as the relative standard deviation (RSD%) was between 0.5 and 3.9%. The stopped-flow microfluidic system showed a sampling frequency of 25 h-1. The method was applied to the study of GPx inhibition provided by three inhibitory compounds, two metallic ions Hg(II) and Cu(II) and t-butyl hydroperoxide, and their presence in liquid samples, as water, milk, and edible oil. Recovery values between 88.7 and 99.4% were achieved in all instances.

Development of an aptamer-based SPR-biosensor for the determination of kanamycin residues in foods.

A biosensor in which an affinity reaction occurs in the sensitive microzone through the use of specific aptamers to determine kanamycin residues in agri-food samples has been developed. It is an irreversible and continuous flow aptameric biosensor (aptasensor) in which the signal variations are monitored by surface plasmon resonance (SPR) measurements based on the specific interaction of the aptamer with the antibiotic. The signal variation is proportional to the analyte concentration. Graphene is known for efficient binding of molecules with its π-electron system, so a monolayer of graphene prepared from chemical vapor deposition (CVD) has been compared to a multilayer of graphene made from reduced graphene oxide (rGO) for immobilization of the aptamer on the gold surface of the physicochemical transducer. The best results have been obtained with CVD graphene. The dynamic range was between 1 and 100 µmol L-1 of kanamycin concentration (r2 = 0.9981, n = 7, r = 4), with a limit of detection of 285 nmol L-1 and a sampling frequency of 6 h-1. The precision, expressed as relative standard deviation (RSD%), was established in the range of 1.49 and 3.89%, calculated for 1, 10, and 50 µmol L-1. The selectivity was studied applying the described method to determine other antibiotics, obtaining no significant difference in the analytical signal. The method was applied to determine kanamycin residues in milk samples with recovery values ranging between 90 and 96%.

Usefulness of Hybrid Magnetoliposomes for Aminoglycoside Antibiotic Residues Determination in Food Using an Integrated Microfluidic System with Fluorometric Detection.

A new microfluidic approach using hybrid magnetoliposomes (h-MLs) containing hydrophobic magnetic nanoparticles (Fe3O4@AuNPs-C12SH) and encapsulated N-acetylcysteine has been developed in this research to determine aminoglycoside antibiotic (AAG) residues in food using o-phthalaldehyde. Four AAGs, kanamycin, streptomycin, gentamicin, and neomycin, have been used as model analytes. The h-MLs have been used for reagent preconcentration and were retained using an external electromagnet device in the reaction/detection zone in a microfluidic system, inserted into the sample chamber of a conventional fluorimeter. The formation of a fluorescent isoindole derivate caused an increase in the luminescence signal, which was proportional to the analyte concentration. The dynamic range of the calibration graph was 0.1-1000 µmol L-1, expressed as AAG concentration, with an 8.7 nmol L-1 limit of detection for kanamycin and a sampling frequency of 8 h-1. The method was applied to determine AAG residues in milk and meat samples with recovery values between 87.2 and 107.4%.

Separation and characterization of liposomes using asymmetric flow field-flow fractionation with online multi-angle light scattering detection.

Liposomes, mainly formed by phospholipids and cholesterol that entrapped different compounds, were separated and characterized using asymmetric flow field-flow fractionation (AF4) coupled with a multi-angle light scattering detector (MALS). AF4 allows the separation of liposomes according to their hydrodynamic size, and the particle size can be estimated directly by their elution time. Besides, different synthesized liposome suspensions of liposomes with different species encapsulated in different places in liposomes were prepared with analytical purposes to be studied. These liposomes were: empty liposomes (e-Ls), magnetoliposomes (MLs) with Fe3O4@AuNPs-C12SH inside the lipid bilayer, and long-wavelength fluorophores encapsulated into the aqueous cavity of liposomes (Ls-LWF). The optimization process of the variables that affect the fractionation has been established. The separation effectiveness has been compared with the results achieved with a photon-correlation spectroscopy analyzer based on dynamic light scattering (DLS) and transmission electron microscopy (TEM), used in self-assembly structures characterization. In all cases, three different classes of liposomes have been obtained; two are commonly appaired in all studied samples, while only a third class is characteristic for each of the liposomes. This mean that the proposed methodology could be used for identifying liposomes according to the encapsulated material.

Luminescence continuous flow system for monitoring the efficiency of hybrid liposomes separation using multiphase density gradient centrifugation.

A method for monitoring the efficiency of the hybrid magnetoliposomes (h-MLs) separation using multiphase density gradient centrifugation (MDGC) coupled with a continuous flow system (CFS) is described. Several h-MLs suspensions containing hydrophobic magnetic gold nanoparticles (Fe3O4@AuNPs-C12SH) and different fluorophores encapsulated have been synthesized using the rapid solvent evaporation (RSE) method. The MDGC system was prepared using a non-linear multiphase density gradient formed with a bottom layer with 100% (v/v) sucrose solution and six layers containing a mixture of sucrose solution (with concentrations ranged between 10 and 55% v/v), and fixed concentrations of ficoll (30% v/v) and percoll (15% v/v) solutions. The density gradient profile was previously stabilized using a relative centrifugal force (RCF) of 4480×g for 30 min. The synthesized h-MLs were added to the density gradient profile and separated by centrifugation at 2520×g for 20 min. The efficiency of the separation procedure was tested, aspirating the separated extract into the CFS and lysing liposomes before their translation to the detector introducing surfactant solutions. The luminescence signals provided by the release of the encapsulated fluorophores and other materials provided the distribution status of the liposomes in each density gradient stage. The monitoring of the different samples revealed four different fractions (MLs, h-Ls, h-MLs, and non-encapsulated fluorophores) for each separated h-MLs. Additional information on the h-MLs has also been acquired by confocal microscopy.

Integration of a microfluidic system into a conventional luminescence detector using a 3D printed alignment device.

A useful 3D printed device for the inside microfluidic integration into a conventional optical detector has been developed. The coupling system supposes the complete integration of a microfluidic device inside the sample compartment of a conventional spectrofluorimeter. For this purpose, a commercial chip-holder, including a microfluidic chip, was anchored inside the detector using a "lab-built" 3D printing alignment prototype. The variables affecting the position of the 3D printed device, such as horizontal and vertical and rotary angles, were optimized. The usefulness of the microfluidic integration system has been tested using an organized suspension of separated hybrid magnetoliposomes containing nanomaterials that were previously separated using a multiphase density gradient centrifugation (MDGC) method. The whole integration system consists of three well-established parts: the impulsion unit, the displacement unit, and the microfluidic chip. The impulsion unit is formed by two syringe pumps, which propel under microflow-rate regime the solutions through to the microfluidic system. The first fluid incorporates an immiscible solution that provides the solution which fills positive oil/water (O/W) displacement unit. In this unit, the previously organized MDGC suspension, which includes different liposome populations, was layer-by-layer displaced to a y-mixer microfluidic chip. The separation content merges with the second solution propelled by the other syringe pump. This solution incorporates a surfactant that promotes the liposome lysis. The novelty supposes the easy incorporation of a 3D printer alignment device, which facilitates the incorporation of the microfluidic channel focused into the optical pathway of the luminescence detector. Graphical abstract.

Una visión transdisciplinaria del envejecimiento / Aging: a transdisciplinary approach

El envejecimiento está cambiando nuestra forma de vivir y convivir, con implicancias tan amplias que su abordaje por nicho de especialidad es insuficiente, haciendo fundamental generar una mirada integradora, y obligando a la academia a reconstruir sus bordes. La investigación transdisciplinaria se puede definir como los esfuerzos realizados por investigadores de diferentes disciplinas que trabajan conjuntamente para crear nuevas innovaciones conceptuales, teóricas, metodológicas y de traducción que integran y se mueven más allá de los enfoques específicos de la disciplina para abordar un problema común. La Universidad de Chile conformó la Red Transdisciplinaria sobre envejecimiento, la que agrupa a académicos de diferentes ámbitos del conocimiento, que comparten un interés común por explorar el envejecimiento, promoviendo un abordaje integrado. En enero de 2018, se realizó la quinta Escuela Internacional de Verano sobre Envejecimiento de la Universidad de Chile, donde un grupo de expertos nacionales e internacionales provenientes de distintas disciplinas que incluyeron el diseño, la salud, el urbanismo, la sociología, el derecho, la ingeniería y la arquitectura, plantearon sus posiciones, estudios y evidencias científicas en relación a una meta habitual de las personas mayores: envejecer en su entorno. Las ponencias y reflexiones integradoras se describen en esta revisión.

Aging is changing the way we live, with implications so wide that its approach by specialty is insufficient, making essential to generate an integrative view, forcing the academy to rebuild its edges. Transdisciplinary research is defined as the efforts made by researchers from different disciplines who work together to create new conceptual, theoretical, methodological and translation innovations that integrate and move beyond the specific approaches of the discipline to address a common problem. The University of Chile formed the Transdisciplinary Network on Aging, allowing the interaction of academics from different fields of knowledge, who share a common interest in exploring aging, promoting an integrated approach. In January 2018, the fifth International Summer School on Aging was held at the University of Chile, where a group of national and international experts from different disciplines including design, health, urban planning, sociology, law, engineering and architecture, raised their positions, studies and scientific evidence in relation to a common goal of the elderly: aging in place. The presentations and integrative analyzes are described in this review.

Factores sociales del estado de salud autorreportado de personas mayores, en Chile / Factors influencing self-reported health in Chilean older people

Background Self-reported health is subjective and depends on external factors such as socioeconomic status, presence of chronic diseases and working status, among others. Aim To determine which factors influence self-reported health among older people in Chile. Material and Methods A secondary analysis of the National Socioeconomic Characterization survey done in 2015. A dichotomous response model was used classifying health status as good or bad. A logit regression model was carried out. Results The model had a good calibration and correctly classified 72 and 68% of men and women, respectively. The main factors that influenced health status self-perception were: not having health problems; having undergone a mental health interview, to receive supplemental nutrition, education, to have a productive work; and to having a social network. Conclusions There are health, cultural, economic and environmental factors that influence self-perceived health status.

[Factors influencing self-reported health in Chilean older people]. / Factores sociales del estado de salud autorreportado de personas mayores, en Chile.

Background Self-reported health is subjective and depends on external factors such as socioeconomic status, presence of chronic diseases and working status, among others. Aim To determine which factors influence self-reported health among older people in Chile. Material and Methods A secondary analysis of the National Socioeconomic Characterization survey done in 2015. A dichotomous response model was used classifying health status as good or bad. A logit regression model was carried out. Results The model had a good calibration and correctly classified 72 and 68% of men and women, respectively. The main factors that influenced health status self-perception were: not having health problems; having undergone a mental health interview, to receive supplemental nutrition, education, to have a productive work; and to having a social network. Conclusions There are health, cultural, economic and environmental factors that influence self-perceived health status.

Global Reprogramming of Host Kinase Signaling in Response to Fungal Infection.

Cryptococcus neoformans (Cn) is a deadly fungal pathogen whose intracellular lifestyle is important for virulence. Host mechanisms controlling fungal phagocytosis and replication remain obscure. Here, we perform a global phosphoproteomic analysis of the host response to Cryptococcus infection. Our analysis reveals numerous and diverse host proteins that are differentially phosphorylated following fungal ingestion by macrophages, thereby indicating global reprogramming of host kinase signaling. Notably, phagocytosis of the pathogen activates the host autophagy initiation complex (AIC) and the upstream regulatory components LKB1 and AMPKα, which regulate autophagy induction through their kinase activities. Deletion of Prkaa1, the gene encoding AMPKα1, in monocytes results in resistance to fungal colonization of mice. Finally, the recruitment of AIC components to nascent Cryptococcus-containing vacuoles (CnCVs) regulates the intracellular trafficking and replication of the pathogen. These findings demonstrate that host AIC regulatory networks confer susceptibility to infection and establish a proteomic resource for elucidating host mechanisms that regulate fungal intracellular parasitism.

[Suicide in hospitalized patients and medical liability]. / Consideraciones acerca de la conducta suicida de pacientes hospitalizados y responsabilidad del médico tratante.

Suicide is a complex phenomenon that has accompanied human beings throughout history. Its strong association with mental disorders led to its medicalization and psychiatrists became the physicians in charge of diagnosing and treating patients at risk of suicide. This article discusses the potential limitations that psychiatrists may face when diagnosing suicide risk and providing optimal care. Evidence of the eventual inevitability of suicide and the tension that may arise between providing optimal treatments on the one hand and preserving the rights of patient's autonomy and dignity on the other is also presented. We propose that although diagnosing and adequately treating patients at risk of suicide would be the psychiatrist's responsibility, the act of suicide itself is personal and non-transferable. Considering the latter as part of the medical team's responsibilities would turn working with patients with mental disorders into a fearless act. Finally, suicide should be considered to be part of the natural history of the evolution of many mental disorders and, thus, should constitute a specific topic when training specialists.

A cluster-randomised clinical trial comparing two cardiovascular health education strategies in a child population: the Savinghearts project.

BACKGROUND: This paper describes a methodology for comparing the effects of an eduentertainment strategy involving a music concert, and a participatory class experience involving the description and making of a healthy breakfast, as educational vehicles for delivering obesity-preventing/cardiovascular health messages to children aged 7-8 years. METHODS/DESIGN: This study will involve a cluster-randomised trial with blinded assessment. The study subjects will be children aged 7-8 years of both sexes attending public primary schools in the Madrid Region. The participating schools (n=30) will be randomly assigned to one of two groups: 1) Group MC, in which the children will attend a music concert that delivers obesity-preventing/cardiovascular health messages, or 2) Group HB, in which the children will attend a participatory class providing the same information but involving the description and making of a healthy breakfast. The main outcome measured will be the increase in the number of correct answers scored on a knowledge questionnaire and in an attitudes test administered before and after the above interventions. The secondary outcome recorded will be the reduction in BMI percentile among children deemed overweight/obese prior to the interventions. The required sample size (number of children) was calculated for a comparison of proportions with an α of 0.05 and a ß of 0.20, assuming that the Group MC subjects would show values for the measured variables at least 10% higher than those recorded for the subjects of Group HB. Corrections were made for the design effect and assuming a loss to follow-up of 10%. The maximum sample size required will be 2107 children. Data will be analysed using summary measurements for each cluster, both for making estimates and for hypothesis testing. All analyses will be made on an intention-to-treat basis. DISCUSSION: The intervention providing the best results could be recommended as part of health education for young schoolchildren. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01418872.