Tangential velocity constraint for orbital maneuvers with Theory of Functional Connections.

Maneuvering a spacecraft in the cislunar space is a complex problem, since it is highly perturbed by the gravitational influence of both the Earth and the Moon, and possibly also the Sun. Trajectories minimizing the needed fuel are generally preferred in order to decrease the mass of the payload. A classical method to constrain maneuvers is mathematically modeling them using the Two Point Boundary Value Problem (TPBVP), defining spacecraft positions at the start and end of the trajectory. Solutions to this problem can then be obtained with optimization techniques like the nonlinear least squares conjugated with the Theory of Functional Connections (TFC) to embed the constraints, which recently became an effective method for deducing orbit transfers. In this paper, we propose a tangential velocity (TV) type of constraints to design orbital maneuvers. We show that the technique presented in this paper can be used to transfer a spacecraft (e.g. from the Earth to the Moon) and perform gravity assist maneuvers (e.g. a swing-by with the Moon). In comparison with the TPBVP, solving the TV constraints via TFC offers several advantages, leading to a significant reduction in computational time. Hence, it proves to be an efficient technique to design these maneuvers.

Citric Acid Conditioning as an Alternative to EDTA for Growth Factors Release and Stem Cell Response in Regenerative Endodontics: A Systematic Review of In Vitro Studies.

INTRODUCTION: Citric acid (CA) conditioning may be a promising alternative to ethylenediaminetetraacetic acid (EDTA) in regenerative endodontic procedures, as reported to improve growth factors' release from dentin. This review systematically investigated the effect of CA conditioning on the growth factors release from dentin and cell behavior compared to EDTA conditioning. METHODS: Searches were conducted (PubMed/MEDLINE, Scopus, Web of Science, Embase, SciELO, Cochrane Library, and grey literature) until May-2023. Only in vitro studies that evaluated the effects of CA on growth factors' release from dentin and cell behavior outcomes compared to EDTA were included. The studies were critically appraised using a modified Joanna Briggs Institute's checklist. Meta-analysis was unfeasible. RESULTS: Out of the 335 articles screened, nine were included. Among these, three studies used dentin discs/roots from permanent human teeth; the rest combined them with stem cells. 10% CA for 5 or 10 minute was the most used protocol. Meanwhile, EDTA concentrations ranged from 10% to 17%. In eight studies examining the release of growth factors, five reported a significant release of transforming growth factor-ß after dentin conditioning with 10% CA compared to 17% EDTA. Regarding cell behavior (6 studies), three studies assessed cell viability. The findings revealed that 10% CA conditioning showed cell viability similar to those of 17% EDTA. Additionally, in two out of three studies, it was observed that 10% CA conditioning did not affect cell morphology. The studies had a low risk of bias. CONCLUSIONS: The use of 10% CA to condition dentin for 5-10 minutes resulted in a notable transforming growth factor -ß1 release, but its cell responses were similar to those of EDTA.

Animal board invited review: Opportunities and challenges in using GWP* to report the impact of ruminant livestock on global temperature change.

Ruminant livestock is a large contributor of CH4 emissions globally. Assessing how this CH4 and other greenhouse gases (GHG) from livestock contribute to anthropogenic climate change is key to understanding their role in achieving any temperature targets. The climate impacts of livestock, as well as other sectors or products/services, are generally expressed as CO2-equivalents using 100-year Global Warming Potentials (GWP100). However, the GWP100 cannot be used to translate emission pathways of short-lived climate pollutants (SLCPs) emissions to their temperature outcomes. A key limitation of handling long- and short-lived gases in the same manner is revealed in the context of any potential temperature stabilisation goals: to achieve this outcome, emissions of long-lived gases must decline to net-zero, but this is not the case for SLCPs. A recent alternative metric, GWP* (so-called 'GWP-star'), has been proposed to overcome these concerns. GWP* allows for simple appraisals of warming over time for emission series of different GHGs that may not be obvious if using pulse-emission metrics (i.e. GWP100). In this article, we explore some of the strengths and limitations of GWP* for reporting the contribution of ruminant livestock systems to global temperature change. A number of case studies are used to illustrate the potential use of the GWP* metric to, for example, understand the current contribution of different ruminant livestock production systems to global warming, appraise how different production systems or mitigations compare (having a temporal element), and seeing how possible emission pathways driven by changes in production, emissions intensity and gas composition show different impacts over time. We suggest that for some contexts, particularly if trying to directly infer contributions to additional warming, GWP* or similar approaches can provide important insight that would not be gained from conventional GWP100 reporting.

Influence of Mechanical Cycling on Torque Values of Tapped-In and Screw-In Implant-Supported Crowns.

This study investigated the influence of mechanical cycling on screwed-in and tappedin implants restored with screw-retained metallic crowns. Three implant-abutmentcrown systems were evaluated: T1 (multi abutment) and T2 (standard abutment) received tapped-in abutments and S received a screwed-in abutment. The specimens were subjected to two million cycles of 0-150 N load, at 2 Hz, 30° inclination in a dry medium, and torque evaluation. Survival and removal torque were analyzed using chisquare, ANOVA, followed by Tukey's test. Differences between installation and removal torque were determined using a T-test for dependent samples. Analyses were performed in SPSS, considering α = 0.05. All specimens survived mechanical cycling in S, 40% in T1, 80% in T2 (p=0.008). Failures occurred due to loosening of the crown screw. A significant decrease in torque (p=0.000) was found. Group T1 had the lowest removal torque (1.6 ± 0.84 N.Cm²), followed by T2 (3 ± 1.49 N.Cm²) and S (6.3 ± 1.16 N. Cm²), and a statistical difference was found between Groups T1 and S. Both types of implantabutment connections were stable and can be considered for rehabilitative treatment, but failure and removal torque were influenced by the design of prosthetic abutment. Crowns were more susceptible to becoming loose in tapped-in systems.

Variantes del gen ABCB1 como factores de riesgo y factores moduladores de la edad de inicio en pacientes mexicanos con enfermedad desmielinizante / ABCB1 gene variants as risk factors and modulators of age of onset of demyelinating disease in Mexican patients

Introducción: Las variantes C1236T, G2677T/A y C3435T del gen ABCB1 alteran la función de la glicoproteína P y el transporte de sustancias endógenas y exógenas en la barrera hematoencefálica; además, actúan como factores de susceptibilidad para algunas enfermedades neurodegenerativas.El objetivo del estudio fue determinar la asociación de polimorfismos ABCB1 (C1236T, G2677T/A y C3435T), sus haplotipos y sus combinaciones de genotipos con la enfermedad desmielinizante.MétodoSe genotipificó a 199 pacientes con enfermedad desmielinizante y a 200 controles mestizos mexicanos mediante PCR-RFLP y secuenciación Sanger para comparar las frecuencias de alelos, genotipos, haplotipos y combinaciones de genotipos entre pacientes y controles. El análisis estadístico se realizó con regresión logística y χ2 de Pearson al 95% de confianza; se calculó la OR y se evaluó la asociación con enfermedad desmielinizante.ResultadosLos haplotipos TTT y CGC fueron los más frecuentes en pacientes y controles. El alelo G2677 (OR = 1,79; IC 95%: 1,12-2,86; p = 0,015) muestra asociación con enfermedad desmielinizante, así como los genotipos GG2677 (OR = 2,72; IC 95% = 1,11-6,68; p = 0,025) y CC3435 (OR = 1,82; IC 95%: 1,15-2,90; p = 0,010) y su combinación GG2677/CC3435 (OR = 2,02; IC 95%: 1,17-3,48; p = 0,010) y el haplotipo CAT (OR = 0,21; IC 95%: 0,05-0,66; p = 0,001).Los portadores TTTTTT presentaron la edad de inicio más temprana (23,0 ± 7,7 vs. 31,6 ± 10,7; p = 0,0001).ConclusionesLa combinación de genotipos GG2677/CC3435 está asociada al desarrollo de enfermedad desmielinizante en esta muestra, principalmente en el sexo masculino, en el cual puede darse acumulación tóxica de sustratos de glicoproteína P.En este estudio, la edad de inicio de la enfermedad desmielinizante podría ser modulada diferencialmente entre sexos por el alelo G2677 del gen ABCB1. (AU)

Introduction: The C1236T, G2677T/A, and C3435T variants of the ABCB1 gene alter the functioning of P-glycoprotein and the transport of endogenous and exogenous substances across the blood-brain barrier, and act as risk factors for some neurodegenerative diseases.This study aimed to determine the association between demyelinating disease and the C1236T, G2677T/A, and C3435T variants of ABCB1 and its haplotypes and combinations of genotypes.MethodsPolymerase chain reaction with restriction fragment length polymorphism analysis (PCR-RFLP) and Sanger sequencing were used to genotype 199 patients with demyelinating disease and 200 controls, all Mexicans of mixed race; frequencies of alleles, genotypes, haplotypes, and genotype combinations were compared between patients and controls. We conducted a logistic regression analysis and calculated chi-square values and 95% confidence intervals (CI); odds ratios (OR) were calculated to evaluate the association with demyelinating disease.ResultsThe TTT and CGC haplotypes were most frequent in both patients and controls. The G2677 allele was associated with demyelinating disease (OR: 1.79; 95% CI: 1.12-2.86; P = .015), as were the genotypes GG2677 (OR: 2.72; 95% CI: 1.11-6.68; P = .025) and CC3435 (OR: 1.82; 95% CI: 1.15-2.90; P = .010), the combination GG2677/CC3435 (OR: 2.02; 95% CI, 1.17-3.48; P = .010), and the CAT haplotype (OR: 0.21; 95% CI: 0.05-0.66; P = .001).TTTTTT carriers presented the earliest age of onset (23.0 ± 7.7 years, vs. 31.6 ± 10.7; P = .0001).ConclusionsThe GG2677/CC3435 genotype combination is associated with demyelinating disease in this sample, particularly among men, who may present toxic accumulation of P-glycoprotein substrates.In our study, the G2677 allele of ABCB1 may differentially modulate age of onset of demyelinating disease in men and women. (AU)

ABCB1 gene variants as risk factors and modulators of age of onset of demyelinating disease in Mexican patients.

INTRODUCTION: The C1236T, G2677T/A, and C3435T variants of the ABCB1 gene alter the functioning of P-glycoprotein and the transport of endogenous and exogenous substances across the blood-brain barrier, and act as risk factors for some neurodegenerative diseases. This study aimed to determine the association between demyelinating disease and the C1236T, G2677T/A, and C3435T variants of ABCB1 and its haplotypes and combinations of genotypes. METHODS: Polymerase chain reaction with restriction fragment length polymorphism analysis (PCR-RFLP) and Sanger sequencing were used to genotype 199 patients with demyelinating disease and 200 controls, all Mexicans of mixed race; frequencies of alleles, genotypes, haplotypes, and genotype combinations were compared between patients and controls. We conducted a logistic regression analysis and calculated chi-square values and 95% confidence intervals (CI); odds ratios (OR) were calculated to evaluate the association with demyelinating disease. RESULTS: The TTT and CGC haplotypes were most frequent in both patients and controls. The G2677 allele was associated with demyelinating disease (OR: 1.79; 95% CI, 1.12-2.86; P =  .015), as were the genotypes GG2677 (OR: 2.72; 95% CI, 1.11-6.68; P =  .025) and CC3435 (OR: 1.82; 95% CI, 1.15-2.90; P =  .010), the combination GG2677/CC3435 (OR: 2.02; 95% CI, 1.17-3.48; P =  .010), and the CAT haplotype (OR: 0.21; 95% CI, 0.05-0.66; P =  .001). TTTTTT carriers presented the earliest age of onset (23.0 ±â€¯7.7 years, vs 31.6 ±â€¯10.7; P =  .0001). CONCLUSIONS: The GG2677/CC3435 genotype combination is associated with demyelinating disease in this sample, particularly among men, who may present toxic accumulation of P-glycoprotein substrates. In our study, the G2677 allele of ABCB1 may differentially modulate age of onset of demyelinating disease in men and women.

Effectiveness of Twitter Threads to Improve Medical Student Electrocardiogram (ECG) Reading-Skills. The TwittUVa-ECG Non-Randomized Pre-Post Study.

Introduction: social media is increasingly used in medical education, but its real educational effectiveness is unclear. In this study we assess the effectiveness of Twitter threads (TTS) in improving electrocardiogram (ECG) basic reading skills (ECGBRS). Materials and Methods: Seven TTS describing ECGBRS were published from October 28, 2021, to November 24, 2021. Tests were used to assess medical students ECGBRS pre and post intervention. All third and sixth-year medical students were invited to participate. Sixty-three students were enrolled (33 third year and 30 sixth year). Nine (14.3%) participants dropped out. Results: Sixth year medical students had higher ECGBRS at baseline. The number of correct items increased after the Twitter intervention; median correct pre-test items were 20 out of 56, (interquartile range (IQR) 14-23), and median post-test were 29 out of 56, (IQR 21-36) (p < 0.001). The improvement in sixth year students was greater than for third year students; 10 more correct items (IQR 4-14) vs. 7 (IQR 1-14) items (p = 0.045). The more TTS followed, the greater the improvement in ECGBRS (p = 0.004). The QRS axis calculation was the ECG reading skill with the lowest scores. Most medical students were definitely (35%) or very probably (46%) interested in repeating another on-line learning experience and found the TTS extremely (39%) or very (46%) interesting. Conclusions: The use of specifically designed TTS was associated with improvement in medical students' interpretation of ECGs. The effectiveness of the threads was higher in the final years of medical school when basic skills had already been acquired. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-023-01885-x.

Selection of patients for percutaneous closure in nonlacunar cryptogenic stroke associated with patent foramen ovale. Data from the NORDICTUS cooperative registry.

INTRODUCTION: There is an extending use of percutaneous closure of patent foramen ovale (PFO) as therapy for PFO-associated cryptogenic strokes. The aim of our study was to investigate the clinical practice of percutaneous closure of PFO and to analyse the variables for decision-making on the selection of patients for this procedure. METHOD: A prospective observational multicentric survey was conducted using all the cases of cryptogenic stroke/transient ischaemic attack associated with PFO recorded in the NORDICTUS hospital registry during the period 2018-2021. Clinical data, radiological patterns, echocardiogram data and factors related to PFO-associated stroke (thromboembolic disease and paradoxical embolism criteria) were recorded. The indication for closure was analysed according to age (≤/> 60 years) and the characteristics of the PFO. RESULTS: In the group ≤ 60 years (n = 488), 143 patients (29.3%) underwent PFO closure. The most influential variables for this therapy were detection of a high-risk PFO (OR 4.11; IC 2.6-6.5, P < .001), criteria for paradoxical embolism (OR 2.61; IC 1.28-5.28; P = .008) and previous use of antithrombotics (OR 2.67; IC 1.38-5.18; P = .009). In the > 60 years group (n = 124), 24 patients had PFO closure (19%). The variables related to this option were history of pulmonary thromboembolism, predisposition to thromboembolic disease, paradoxical embolism criteria, and high-risk PFO. CONCLUSIONS: The detection of a high-risk PFO (large shunt, shunt with associated aneurysm) is the main criterion for a percutaneous closure-based therapy. Other conditions to consider in the eligibility of patients are the history of thromboembolic disease, paradoxical embolism criteria or the previous use of antithrombotics.

Análisis de la atención al infarto con elevación del segmento ST en España. Resultados del Registro de Código Infarto de la ACI-SEC / Analysis of the management of ST-segment elevation myocardial infarction in Spain. Results from the ACI-SEC Infarction Code Registry

Introducción y objetivos Las redes de Código Infarto deben garantizar una atención al infarto agudo de miocardio con elevación del segmento ST con buenos resultados clínicos y dentro de los parámetros de tiempo recomendados. No hay información contemporánea sobre el funcionamiento de estas redes en España. El objetivo es analizar las características clínicas de los pacientes atendidos, el tiempo hasta la reperfusión, las características de la intervención realizada y la mortalidad a 30 días. Métodos Registro prospectivo, observacional y multicéntrico de pacientes los consecutivos atendidos en 17 redes de Código Infarto en España (83 centros con Código Infarto) entre el 1 de abril y el 30 de junio de 2019. Resultados Se atendió a 5.401 pacientes (media de edad, 64±13 años; el 76,9% varones), de los que 4.366 (80,8%) sufrieron un infarto con elevación del ST. De estos, se trató al 87,5% con angioplastia primaria, al 4,4% con fibrinolisis y al 8,1% sin reperfusión. En los casos tratados con angioplastia primaria, el tiempo entre el inicio de los síntomas y la reperfusión fue 193 [135-315] min y el tiempo entre el primer contacto médico y la reperfusión, 107 [80-146] min. La mortalidad total a 30 días por infarto agudo de miocardio con elevación del ST fue del 7,9%, mientras que entre los pacientes tratados con angioplastia primaria fue del 6,8%. Conclusiones Se trató con angioplastia primaria a la inmensa mayoría de los pacientes con infarto agudo de miocardio con elevación del ST, y en más de la mitad de los casos el tiempo desde el primer contacto médico hasta la reperfusión fue <120 min. La mortalidad a 30 días fue relativamente baja (AU)

Introduction and objectives ST-segment elevation myocardial infarction (STEMI) networks should guarantee STEMI care with good clinical results and within the recommended time parameters. There is no contemporary information on the performance of these networks in Spain. The objective of this study was to analyze the clinical characteristics of patients, times to reperfusion, characteristics of the intervention performed, and 30-day mortality. Methods Prospective, observational, multicenter registry of consecutive patients treated in 17 STEMI networks in Spain (83 centers with the Infarction Code), between April 1 and June 30, 2019. Results A total of 5401 patients were attended (mean age, 64±13 years; 76.9% male), of which 4366 (80.8%) had confirmed STEMI. Of these, 87.5% were treated with primary angioplasty, 4.4% with fibrinolysis, and 8.1% did not receive reperfusion. In patients treated with primary angioplasty, the time between symptom onset and reperfusion was 193 [135-315] minutes and the time between first medical contact and reperfusion was 107 [80-146] minutes. Overall 30-day mortality due to STEMI was 7.9%, while mortality in patients treated with primary angioplasty was 6.8%. Conclusions Most patients with STEMI were treated with primary angioplasty. In more than half of the patients, the time from first medical contact to reperfusion was <120 minutes. Mortality at 30 days was relatively low (AU)

Prevalence of bovine mastitis-related pathogens, identified by mass spectrometry in flies (Insecta, Diptera) captured in the milking environment.

Diptera (Insecta) are able to transmit approximately 200 pathogenic microorganisms to humans and animals, causing more than 65 diseases, including bovine mastitis, which constitutes a major cause of economic losses in the dairy industry. In this scenario, 217 adult specimens of Diptera were collected from nine farms and identified to the family and/or species level. Of the 11 families recorded, Muscidae was the most prevalent (152 out of 217; 70%). All Diptera specimens were subjected to microbiological culture using conventional and selective media, and isolates were then identified at the species level by mass spectrometry. In total, 275 microorganisms were identified, with a predominance of pathogens related to environmental bovine mastitis (166/275 = 60·4%), that is, Enterococcus species (70/275 = 25·4%) and Escherichia coli (49/275 = 17·8%). Nontraditional agents related to bovine mastitis (called miscellaneous) were detected in 28% (77/275), as well as microorganisms with well-known zoonotic behaviour (e.g. Bacillus cereus). This is study contributes with knowledge of diversity of microorganisms carried by Diptera in the dairy environment, including pathogens associated with environmental and contagious bovine mastitis, and agents with human relevance. To our knowledge, a three-part chromogenic selective medium used to microbial culture of milk on farms was used for the first time to identification of pathogens in Diptera.

Gravitational perturbations correlated with the asteroid kinetic impact deflection technique.

This paper presents the use of the kinetic impact technique to deflect asteroids that may present some risk of collision with Earth. Within the work to be developed here, we intend to evaluate in more detail the possibility to deflect the orbit of the asteroid 101955 Bennu by applying variations in its velocity ([Formula: see text]v) at different positions along its orbital period and measuring effects of close encounters with planet Earth. We will see that, in a relatively long period of time, the asteroid has several close encounters with the planet, thus suffering a natural gravitational perturbation. With the application of the impulses, the relative distances change, causing variations in the energy of the asteroid and a large variation in the relative distance between the asteroid and Earth over a long period after the impulse. We present results related to the magnitude of the impulse applied, which is important because its defines the mass and velocity of the impactor to be considered. Then, we mapped the positions of the impulses along a period of the orbit of the asteroid. We finish by explaining what happens to the orbit of the asteroid during the periods of gravitational perturbation, since the close encounters amount to "Swing Bys" that intensify the variations of the relative distances between the bodies after the impulse is applied.

Registro de casos de indicación farmacéutica y derivaciones al médico utilizando la herramienta SEFAC e_XPERT / Registration of pharmaceutical indication cases and referrals to the doctor using the SEFAC e_XPERT tool

JUSTIFICACIÓN: según Foro, la Indicación Farmacéutica es un Servicio profesional farmacéutico asistencial (SPFA), en la que el farmacéutico, juega un papel fundamental en la mejora/alivio de problemas de salud autolimitados. Se deben emplear, para ello, protocolos consensuados con otros profesionales sanitarios para la derivación y emplear guías farmacológicas para el abordaje correcto de estas situaciones en Farmacia Comunitaria (FC). La plataforma SEFAC e_XPERT®. favorece la toma de decisiones en este SPFA.OBJETIVOS: cuantificar el número de Servicios de Indicación Farmacéutica (SIF) por problemas de salud consultado, así como el número de pacientes que han requerido derivación a otro profesional.METODOLOGÍA: estudio observacional, descriptivo y multicéntrico en FC realizado por alumnos de Prácticas Tuteladas (PT) de la Universidad de Alcalá, utilizando la plataforma SEFAC_eXPERT®.Se siguió el protocolo de Foro de Atención Farmacéutica en FC para realizar el servicio de indicación farmacéutica. Todos los datos registrados fueron anónimos. Para el análisis de los datos se utilizó Excel®.RESULTADOS: se han realizado 2249 casos de SIF, agrupados según síntomas: 21,1 % digestivos; 16,4 % respiratorios; 17,6 % dermatológicos; 17,8 % dolor y 27,1 % otros. Las actuaciones se han dividido si se ha indicado tratamiento farmacológico o no farmacológico, si sólo medidas higiénico-dietéticas (MHD) o ambas, siendo los síntomas más prevalentes: Ojo seco: 71 pacientes con tratamiento, 6 con MHD y 9 ambas: Insomnio: 65, 8, 8; Tos: 62, 7, 11; Dolor articular: 57, 36, 20; Síntomas catarrales: 53, 0, 1; Estreñimiento: 52, 4, 2.El número de derivaciones ha sido 430 (19 %), siendo los digestivos (132), “otros” (133) y respiratorios (121) los más numerosos. (AU)

Revisión de la medicación tras episodio de hipotensión / Review of medication after hypotension episode

PRESENTACIÓN: mujer de 86 años, polimedicada, tiene dos stents, padece diverticulitis e insuficiencia renal incipiente. Desde hace días está cansada, fatigada y mareada y como se siente peor acude a la farmacia comunitaria a medirse la presión arterial. Siguiendo el protocolo establecido en las guías se obtienen los siguientes valores:1º medida: PAS/PAD 12/6 (mmHg) FC 82 ppm2º medida: PAS/PAD 9.6/4 (mmHg) FC 86 ppm3º medida (tras 15 minutos) PAS/PAD 9/4 (mmHg) FC 85 ppm.EVALUACIÓN: con el fin de valorar si existe algún problema relacionado con los medicamentos (PRM) se revisan las prescripciones de su receta electrónica y se identifican los siguientes: Rifamixina: inseguridad no cuantitativa, pauta 1/8 h continuada durante años. En ficha técnica se indica no sobrepasar los 7 días de tratamiento. Furosemida: inseguridad cuantitativa, pauta en receta 3/24 (1-0.5-0). Desde hace un mes la pauta utilizada es, bajo indicación médica telefónica (1.5-1-0) Metamizol: inseguridad no cuantitativa, pauta 1/8 h. En ficha técnica se indica del riesgo de hipotensión severa, frecuentes (≥1/1000 y <1/100), dependiente de dosis y que se incrementa en hipovolemia o deshidratación.INTERVENCIÓN: se deriva al paciente a urgencias para valoración y se le cita para entregar carta de derivación al nefrólogo con el que tiene revisión en unos días.RESULTADO: el médico valora los PRM indicados y realiza los siguientes cambios: Rifamixina: 1/8 h los primeros 7 días de cada mesFurosemida: 1.5/24h (1-0.5-0) Metamizol: se sustituye por tramadol 37.5 mg/ paracetamol 325 mg 1/12 hCleboprida 500 mcg/ simeticona 200 mg: 1/8 h si dolor abdominal Además, el médico indica seguimiento de presión arterial en la farmacia comunitaria. Tras los cambios la paciente se encuentra mejor y sus valores de presión arterial se han normalizado con una media PAS/PAD 13/7 (mmHg) FC 72 ppm. (AU)

Biomecánica de la interfaz hueso-tornillo en instrumentación transpedicular de columna / Biomechanics of the bone-screw interface in transpedicular spinal instrumentation

Resumen: El aflojamiento de los implantes, la falla catastrófica de la interfaz hueso-tornillo, la migración de material y la pérdida de estabilidad de los componentes del ensamble de la fijación constituyen una seria complicación en la cirugía de columna de adultos. La contribución de la biomecánica se basa en la medición experimental y la simulación de las fijaciones transpediculares de columna. La trayectoria de inserción cortical mostró un incremento en la resistencia de la interfase tornillo-hueso respecto a la inserción pedicular tanto para fuerzas de tracción axiales al tornillo como en distribución de esfuerzos en la vértebra. Los tornillos de doble rosca tuvieron una resistencia similar a los pediculares estándar. Los tornillos de rosca parcial de cuatro filetes mostraron mejor resistencia a la fatiga en cuanto a mayor carga de rotura y número de ciclos para la falla. Los tornillos aumentados, ya sea con cemento o hidroxiapatita mejoraron también la resistencia a la fatiga en vértebras osteoporóticas. Las simulaciones de segmentos rígidos confirmaron la presencia de esfuerzos superiores en los discos intervertebrales que provocan el daño de los segmentos adyacentes. La parte posterior de las vértebras puede estar sometida a mayores esfuerzos, fundamentalmente en la superficie de la interfaz hueso-tornillo, por lo que son más susceptibles a la falla en esta región.

Abstract: Implant loosening, catastrophic failure of the bone-screw interface, material migration, and loss of stability of the fixation component assembly constitute a serious complication in adult spinal surgery. The contribution of biomechanics is based on experimental measurement and simulation of transpedicular spinal fixations. The cortical insertion trajectory showed an increase in the resistance of the screw-bone interface with respect to the pedicle insertion trajectory, both for axial traction forces to the screw and for stress distribution in the vertebra. The double-threaded screws and standard pedicle screws had similar strength. Partially threaded screws with four-thread showed better resistance to fatigue in terms of a higher failure load and number of cycles to fail. Cement or hydroxyapatite augmented screws with also showed a better fatigue resistance in osteoporotic vertebrae. Rigid segment simulations confirmed the presence of higher stresses on the intervertebral discs causing damage to adjacent segments. The posterior body of the vertebra may be subjected to high stresses, in the bone-screw interface, being this bone region more susceptible to failure.

[Biomechanics of the bone-screw interface in transpedicular spinal instrumentation]. / Biomecánica de la interfaz hueso-tornillo en instrumentación transpedicular de columna.

Implant loosening, catastrophic failure of the bone-screw interface, material migration, and loss of stability of the fixation component assembly constitute a serious complication in adult spinal surgery. The contribution of biomechanics is based on experimental measurement and simulation of transpedicular spinal fixations. The cortical insertion trajectory showed an increase in the resistance of the screw-bone interface with respect to the pedicle insertion trajectory, both for axial traction forces to the screw and for stress distribution in the vertebra. The double-threaded screws and standard pedicle screws had similar strength. Partially threaded screws with four-thread showed better resistance to fatigue in terms of a higher failure load and number of cycles to fail. Cement or hydroxyapatite augmented screws with also showed a better fatigue resistance in osteoporotic vertebrae. Rigid segment simulations confirmed the presence of higher stresses on the intervertebral discs causing damage to adjacent segments. The posterior body of the vertebra may be subjected to high stresses, in the bone-screw interface, being this bone region more susceptible to failure.

El aflojamiento de los implantes, la falla catastrófica de la interfaz hueso-tornillo, la migración de material y la pérdida de estabilidad de los componentes del ensamble de la fijación constituyen una seria complicación en la cirugía de columna de adultos. La contribución de la biomecánica se basa en la medición experimental y la simulación de las fijaciones transpediculares de columna. La trayectoria de inserción cortical mostró un incremento en la resistencia de la interfase tornillo-hueso respecto a la inserción pedicular tanto para fuerzas de tracción axiales al tornillo como en distribución de esfuerzos en la vértebra. Los tornillos de doble rosca tuvieron una resistencia similar a los pediculares estándar. Los tornillos de rosca parcial de cuatro filetes mostraron mejor resistencia a la fatiga en cuanto a mayor carga de rotura y número de ciclos para la falla. Los tornillos aumentados, ya sea con cemento o hidroxiapatita mejoraron también la resistencia a la fatiga en vértebras osteoporóticas. Las simulaciones de segmentos rígidos confirmaron la presencia de esfuerzos superiores en los discos intervertebrales que provocan el daño de los segmentos adyacentes. La parte posterior de las vértebras puede estar sometida a mayores esfuerzos, fundamentalmente en la superficie de la interfaz hueso-tornillo, por lo que son más susceptibles a la falla en esta región.

Low-dose radiation therapy for hand osteoarthritis: shaking hands again?

BACKGROUND: Hand osteoarthritis (HOA) is one of the most common causes of pain and functional disability in western countries and there is still no definitive cure. Low-dose radiation therapy (LDRT) has anti-inflammatory properties that have shown to be effective in the symptomatic relief of various degenerative musculoskeletal disorders. We designed a clinical protocol using LDRT for symptomatic HOA and present results and tolerance in the first 100 patients included. MATERIALS AND METHODS: Between April 2015 and March 2021, 100 patients with a median age of 60 were treated. Fifty-seven patients suffering from proximal/distal interphalangeal joint pain, 40 patients with thumb arthritis, 2 patients with radiocarpal joint affection and 1 patient with metacarpophalangeal joint pain were enrolled. LDRT comprised of 6 fractions of 0.5-1 Gy on every other day up to a total dose of 3-6 Gy. Clinical response was evaluated according to the visual analog scale (VAS) for pain level and the von Pannewitz score (VPS) for joint functionality. Any patients not achieving subjective adequate pain relief after 8 weeks of treatment were offered a second identical LDRT course. RESULTS: With a median follow-up of 10.5 months (range 7.55-12.45), 94% reported an improvement in the pain, with a significant reduction in the VAS level after 3, 6 and 12 months (p < 0.001). Sixty-three patients needed a second course of treatment at a median time interval of 12 weeks (range 9-14). The mean VAS score before treatment was 8 (range 3-10). After treatment, it was 5 (range 1-10). After 3, 6 and 12 months, the mean VAS scores were 4 (range 0-9), 3 (range 0-9) and 3.5 (range 0-9), respectively. Seventy patients reported functionality improvements after LDRT according to the von Pannewitz score. No acute or late complications were observed. CONCLUSION: LDRT appears to be safe and useful for HOA and is associated with good rates of pain relief and functionality improvements. However, further studies are necessary to confirm these promising results.

Preparation and Application of Nb2O5 Nanofibers in CO2 Photoconversion.

Increasing global warming due to NOx, CO2, and CH4, is significantly harming ecosystems and life worldwide. One promising methodology is converting pollutants into valuable chemicals via photocatalytic processes (by reusable photocatalysts). In this context, the present work aimed to produce a Nb2O5 photocatalyst nanofiber system by electrospinning to convert CO2. Based on the collected data, the calcination at 600 ∘C for 2 h resulted in the best condition to obtain nanofibers with homogeneous surfaces and an average diameter of 84 nm. As a result, the Nb2O5 nanofibers converted CO2 mostly into CO and CH4, reaching values around 8.5 µmol g-1 and 0.55 µmol g-1, respectively.

Cytotoxic effect of Vernonanthura polyanthes leaves aqueous extracts / Efeito citotóxico do extrato aquoso de folhas de Vernonanthura polyanthes

Abstract Vernonanthura polyanthes, popularly known as assa-peixe, is a medicinal plant that has been widely used by Brazilian Cerrado population for treatment of diseases without a detailed evaluation of their effectiveness, toxicity, and proper dosage. Thus, more studies investigating the safety of V. polyanthes aqueous extract before the use are needed. The purpose of this study was to evaluate the toxicity, cytotoxicity and genotoxicity of V. polyanthes leaves aqueous extract using the Artemia salina and Allium cepa assays. For the A. salina assay, three groups of 10 larvae were exposed to V. polyanthes leaves aqueous extract at the concentrations of 5, 10, 20, 40, and 80 mg/ml. For the A. cepa assay, 5 onion bulbs were exposed to V. polyanthes leaves aqueous extract at 10, 20, and 40 mg/ml, and then submitted to macroscopic and microscopic analysis. As result it was identified a toxicity and cytotoxicity of V. polyanthes dependent on the extract concentration. The A. salina assay suggests that the concentration of 24 mg/ml of the V. polyanthes extract is able to kill 50% of naupllis; while the A. cepa assay suggests that V. polyanthes leaves aqueous extract is toxic at concentrations higher than 20 mg/ml; however the cytotoxic effect in A. cepa root cells was observed at 40 mg/ml of the extract. It is important to say that the V. polyanthes leaves aqueous extract concentration commonly used in popular medicine is 20 mg/ml. Thus, the popular concentration used is very close to toxicity limit in A. salina model (24 mg/ml) and is the concentration which showed toxic effect in A. cepa root cells (20 mg/ml). No genotoxic activity of V. polyantes leaves aqueous extract was observed in the conditions used in this study. Because of the antiproliferative action and no genotoxic activity, V. polyanthes leaves aqueous extract may present compounds with potential use for human medicine. However more detailed studies need to be performed to confirm this potential.

Resumo Vernonanthura polyanthes, popularmente conhecida como assa-peixe, é uma planta medicinal amplamente utilizada pela população brasileira do Cerrado para o tratamento doenças, sem uma avaliação detalhada de sua eficácia, toxicidade e dosagem adequada. Dessa forma, são necessários estudos para investigar a segurança do uso do extrato aquoso de V. polyanthes. O objetivo deste estudo foi avaliar a toxicidade, citotoxicidade e genotoxicidade do extrato aquoso de folhas de V. polyanthes utilizando os ensaios de Artemia salina e Allium cepa. Para o ensaio de A. salina, três grupos de 10 larvas foram expostos ao extrato aquoso de folhas de V. polyanthes nas concentrações de 5, 10, 20, 40 e 80 mg/ml. Para o ensaio de A. cepa, 5 bulbos de cebola foram expostas ao extrato aquoso de folhas de V. polyanthes nas concentrações de 10, 20 e 40 mg/ml, e então submetidos a análise macroscópica e microscópica. O ensaio de A. salina sugere que a concentração de 24 mg/ml do extrato de V. polyanthes é capaz de matar 50% dos náuplios; enquanto o ensaio de A. cepa sugere que o extrato aquoso das folhas de V. polyanthes é tóxico em concentrações superiores a 20 mg/ml. O efeito citotóxico nas células da raiz de A. cepa foi observado apenas na concentração de 40 mg/ml. É importante dizer que a concentração de extrato aquoso de folhas de V. polyanthes comumente usada na medicina popular é de 20 mg/ml. Assim, a concentração popular utilizada está muito próxima do limite de toxicidade no modelo de A. salina (24 mg/ml) e é a mesma concentração que apresentou efeito tóxico nas células da raiz de A. cepa (20 mg/ml). Não foi observada atividade genotóxica do extrato aquoso de folhas de V. polyantes nas condições utilizadas neste trabalho. Por causa da ação antiproliferativa e ausência de atividade genotóxica, o extrato aquoso de folhas de V. polyanthes pode ser uma boa fonte natural de compostos antitumorais e pode apresentar potencial para uso na medicina. No entanto, estudos mais detalhados precisam ser realizados para confirmar esse potencial.

Perceived discrimination in patients with multiple sclerosis and depressive symptomatology.

BACKGROUND: Multiple Sclerosis is the central nervous system's most common demyelinating disease and the second leading cause of neurological disability in young adults. Its natural development involves physical and cognitive impairment. Patients commonly perceive discrimination against them, regardless of its occurrence, accepting it as an inherent part of the disease. OBJECTIVE: This study aimed to determine the association between perceived discrimination and the depressive symptoms and physical disability present in patients diagnosed with multiple sclerosis, treated at the Demyelinating Diseases Clinic of the National Institute of Neurology and Neurosurgery, Manuel Velasco Suárez. METHODS: A cross-sectional study was conducted in 98 patients diagnosed with multiple sclerosis. Demographic and clinical variables were obtained through clinical interviews. The severity of the disease was determined using the Extended Disability Status Scale (EDSS), depressive symptoms were assessed with the Beck Depression Inventory (BDI), and perceived discrimination was rated using the King Internalized Stigma Scale. RESULTS: The studied sample's mean age was 36.3 years, schooling 13.6 years, symptoms onset was at 26.2 years (with a delay in diagnosis of 3.2 years), and a disease evolution of 10.9 years. 71.4% were single; 52% had an unpaid work activity and 57.1% were women. The EDSS average was 3.5 points; 24.5% presented moderate to severe depressive symptoms and 53.1% referred perceived discrimination. CONCLUSIONS: Perceived discrimination in patients with multiple sclerosis was associated with earlier disease onset, depressive symptoms, and the lack of caregivers. Medical care and life quality improvement for this vulnerable group require greater education regarding the disease and the establishment of patient support programs.