Enhancing Fatigue Resistance in Asphalt Mixtures with a Novel Additive Derived from Recycled Polymeric Fibers from End-of-Life Tyres (ELTs).

Waste-tire textile fibers (WTTF) represent a challenge for the recycling industry since there are currently very few alternatives for their use. In this study, an evaluation of the effect of a new additive developed in two granular formats from WTTF on the fatigue behavior of asphalt mixtures was performed. For the first format of the WTTF-based additive, its effect was evaluated on hot-mix asphalt (HMA), while for the second format of the additive, the effects were evaluated on stone mastic asphalt (SMA). This second format represents an alternative that allows for the total replacement of the cellulose stabilizing additive used in the reference mix. The evaluation of fatigue damage in the mixes was performed using the four-point bending beam (4PB) test specified in European standard EN 12697-24. The test results show that the asphalt mixtures manufactured with WTTF-based additives exhibited a higher capacity to resist load cycles before failure compared to the reference mixtures. Likewise, once the asphalt mixtures were evaluated in a pavement structure by means of an empirical mechanistic analysis, the pavement structures composed of asphalt mixtures with WTTF-based additives showed significant improvements in their durability for the different load axes evaluated. For an average thickness of 15 cm of asphalt mix of a pavement-type structure, the use of the WTTF additive increases the durability of the structures by up to 129% and 112% compared to the HMA and SMA reference mixtures, respectively. These results show that both formats of the WTTF-based admixture improve the fatigue damage resistance of the HMA and SMA asphalt mixtures.

Pulsar glitches: observations and physical interpretation.

The interpretation of pulsar rotational glitches, the sudden increase in spin frequency of neutron stars, is a half-century-old challenge. The common view is that glitches are driven by the dynamics of the stellar interior, and connect in particular to the interactions between a large-scale neutron superfluid and the other stellar components. This thesis is corroborated by observational data of glitches and the post-glitch response seen in pulsars' rotation, which often involves very long timescales, from months to years. As such, glitch observables combined with consistent models incorporating the rich physics of neutron stars-from the lattice structure of their crust to the equation of state for matter beyond nuclear densities-can be very powerful at placing limits on, and reduce uncertainties of, the internal properties. This review summarises glitch observations, current data, and recent analyses, and connects them to the underlying mechanisms and microphysical parameters in the context of the most advanced theoretical glitch models to date.

Proper motion, spectra, and timing of PSR J1813-1749 using Chandra and NICER.

PSR J1813-1749 is one of the most energetic rotation-powered pulsars known, producing a pulsar wind nebula (PWN) and gamma-ray and TeV emission, but whose spin period is only measurable in X-ray. We present analysis of two Chandra datasets that are separated by more than ten years and recent NICER data. The long baseline of the Chandra data allows us to derive a pulsar proper motion µ R.A. = - ( 0 . ″ 067 ± 0 . ″ 010 ) yr-1 and µ decl. = - ( 0 . ″ 014 ± 0 . ″ 007 ) yr-1 and velocity v ⊥ ≈ 900-1600 km s-1 (assuming a distance d = 3 - 5 kpc), although we cannot exclude a contribution to the change in measured pulsar position due to a change in brightness structure of the PWN very near the pulsar. We model the PWN and pulsar spectra using an absorbed power law and obtain best-fit absorption N H = (13.1 ± 0.9) × 1022 cm-2, photon index Γ = 1.5 ± 0.1, and 0.3-10 keV luminosity L X ≈ 5.4 × 1034 erg s-1(d/ 5 kpc)2 for the PWN and Γ = 1.2 ± 0.1 and L X « 9.3 × 1033 erg s-1(d/ 5 kpc)2 for PSR J1813-1749. These values do not change between the 2006 and 2016 observations. We use NICER observations from 2019 to obtain a timing model of PSR J1813-1749, with spin frequency ν = 22.35 Hz and spin frequency time derivative v . = ( - 6.428 ± 0.003 ) × 10 - 11 Hz s-1. We also fit ν measurements from 2009-2012 and our 2019 value and find a long-term spin-down rate v . = ( - 6.3445 ± 0.0004 ) × 10 - 11 Hz s-1. We speculate that the difference in spin-down rates is due to glitch activity or emission mode switching.

Return of the Big Glitcher: NICER timing and glitches of PSR J0537-6910.

PSR J0537-6910, also known as the Big Glitcher, is the most prolific glitching pulsar known, and its spin-induced pulsations are only detectable in X-ray. We present results from analysis of 2.7 years of NICER timing observations, from 2017 August to 2020 April. We obtain a rotation phase-connected timing model for the entire timespan, which overlaps with the third observing run of LIGO/Virgo, thus enabling the most sensitive gravitational wave searches of this potentially strong gravitational wave-emitting pulsar. We find that the short-term braking index between glitches decreases towards a value of 7 or lower at longer times since the preceding glitch. By combining NICER and RXTE data, we measure a long-term braking index n = -1.25 ± 0.01. Our analysis reveals 8 new glitches, the first detected since 2011, near the end of RXTE, with a total NICER and RXTE glitch activity of 8.88 × 10-7 yr-1. The new glitches follow the seemingly unique time-to-next-glitch-glitch-size correlation established previously using RXTE data, with a slope of 5 d µHz-1. For one glitch around which NICER observes two days on either side, we search for but do not see clear evidence of spectral nor pulse profile changes that may be associated with the glitch.

Bactericidal Activity Study of ZrO2-Ag2O Nanoparticles.

In view of the continuous resistance to antibacterial agents by bacteria and the existing problems of silver nanoparticles as an antibacterial agent, this study reports on the synthesis of pure zirconium oxide, silver oxide, and ZrO2-Ag2O nanoparticles by sol-gel method. The nanoparticles were analyzed and tested for their antibacterial activity against gram-positive bacteria of Bacillus subtilis, Streptococcus mutans, Staphylococcus aureus, and gram-negative of Escherichia coli, Pseudomonas aeruginosa, and Klebsiella oxytoca. X-ray diffraction showed the monoclinic ZrO2, cubic Ag2O, and peaks corresponding to ZrO2 and Ag2O in their mixed samples. Scanning electron microscopy showed spherically shaped nanoparticles while dynamic light scattering analysis showed ZrO2 (76 nm), Ag2O (50 nm), and ZrO2-Ag2O samples between 14 and 42 nm. The Fourier Transformed Infrared spectroscopy spectra of ZrO2 gave bands at 480 cm-1 to 750 cm-1 (M-O stretching) with Ag2O at 580 cm-1, while ZrO2-Ag2O samples showed bands at 760 cm-1. The screening by agar diffusion assay revealed a pronounced increase in the antibacterial activity of ZrO2-Ag2O against all the tested bacteria when compared with the pure ZrO2 and Ag2O. The improved antibacterial activity of ZrO2-Ag2O largely results from the chemical stability conferred on it by the ZrO2 as observed from the zeta potential measurement.

Evaluación de higiene oral y características periodontales en pacientes con obesidad: estudio de casos y controles / Evaluation of oral hygiene and periodontal characteristics in patients with obesity: case-control study

Introducción: La obesidad sigue siendo considerada un serio problema de salud pública en el mundo. Aunque es bien sabido que esta condición puede aumentar el riesgo para desarrollar o agravar otras condiciones sistémicas; hoy en día, sigue siendo escasa la información que determine los niveles de asociación entre esta enfermedad sistémica con enfermedades orales como la periodontitis. Objetivo: El objetivo de este estudio fue medir la asociación de pacientes obesos con el desarrollo de periodontitis, así como hábitos de higiene oral. Material y métodos: Se realizó un estudio de casos y controles en 24 pacientes obesos y 24 pacientes sin obesidad. Las variables evaluadas fueron hábitos de higiene bucal, profundidad al sondeo, nivel de inserción clínica y nivel de inflamación gingival. Resultados: Los pacientes obesos tuvieron mayor riesgo para desarrollar bajas frecuencias de cepillado bucal diario (70.8%) y un incremento en la presencia de enfermedad periodontal (70.8%) comparado con los sujetos no obesos (25.0 y 58.3%, respectivamente), lo cual determinó asociaciones estadísticamente significativas (baja frecuencia de cepillado RM = 7.2, IC 95% = 2.0-26.1) y presencia de enfermedad periodontal (RM = 1.7, IC 95% = 0.5-5.7). Conclusiones: Es posible que la obesidad actúe como un factor que facilite la aparición de periodontitis por deficiencias en el cepillado dental diario (AU)

Introduction: Obesity is still considered a serious public health problem in the world. Although it is well known that this condition may increase the risk of developing or aggravating other systemic conditions; nowadays, the information that determines the levels of association between this systemic disease with oral diseases such as periodontitis still scarce. Objective: The objective of this study was to measure the association of obese patients with the development of periodontitis as well as oral hygiene habits. Material and methods: A case-control study was conducted in 24 obese patients and 24 patients without obesity. The variables evaluated were oral hygiene habits, depth of probing, clinical attachment level and gingival inflammation. Results: Obese patients had a higher risk of developing low frequencies of daily oral brushing (70.8%) and an increase in the presence of periodontal disease (70.8%) compared to non-obese subjects (25.0 and 58.3%, respectively) determining statistically significant associations (low frequency of brushing RM = 7.2, 95% CI = 2.0-26.1) and presence of periodontal disease (RM = 1.7, 95% CI = 0.5-5.7). Conclusions: It is possible that obesity acts as a factor that facilitates the presence of periodontitis due to deficiencies in daily toothbrushing (AU)

Evaluación de la adhesión de sistemas adhesivos de grabado total en esmalte dental bovino usando un agente desproteinizante: un estudio in vitro / Evaluation of adhesion of total etch adhesive systems on bovine dental enamel using a deproteinizing agent: an in vitro study

Introducción: Hoy en día, la mayoría de los pacientes requieren tratamiento de ortodoncia fija convencional, la cual utiliza procedimientos adhesivos afines con la superficie amelodentinaria. Aunque existen diferentes técnicas adhesivas que pueden ofrecer adecuados niveles de resistencia al desalojo, el uso del hipoclorito de sodio (NaClO) como agente desproteinizante no ha sido bien definido en materiales de cementación en aparatología ortodóncica convencional. Objetivo: El objetivo de este estudio fue determinar los niveles de resistencia al desalojo con pruebas de microtensión y análisis topográfico con microscopia electrónica de barrido. Material y métodos: 20 bloques de esmalte bovino fueron expuestos superficialmente a soluciones acondicionadoras (ácido ortofosfórico al 37%) con y sin agente desproteinizante (NaClO al 5.25%); finalmente, brackets individuales de ortodoncia fueron cementados con sistemas adhesivos y resinas compuestas de casas comerciales (Ormco y 3M). Las pruebas de resistencia al desalojo fueron realizadas con una máquina de fuerzas universales y el análisis topográfico con microscopia electrónica de barrido. Resultados: El uso del NaClO al 5.25% y la marca Ormco tuvieron estadísticamente los mejores niveles de adhesión que el grupo sin desproteinización y la casa comercial 3M, respectivamente. La topografía adamantina expuesta al agente desproteinizante mostró características de superficie relacionadas con el patrón de grabado tipo I. Conclusión: El uso de un agente desproteinizante (NaClO 5.25%) así como una marca comercial (Ormco) en particular podrían definir el aumento en los niveles de adhesión en superficies adamantinas con aparatología ortodóncica convencional (AU)

Introduction: Nowadays, patients require conventional fixed orthodontic treatment, which uses adhesive procedures related to the dentinal denture surface. Although there are different adhesive techniques that can offer adequate levels of bonding resistance, the use of NaClO as a deproteinizing agent has not been well defined in cementing materials in conventional orthodontic appliances. Objective: The objective of this study was to determine the levels of bond resistance using micro tension tests and topographic analysis with scanning electron microscopy. Material and methods: Twenty-blocks of bovine enamel were exposed superficially to conditioning solutions (37% orthophosphoric acid) with and without deproteinizing agent (5.25% NaClO); finally, individual orthodontic brackets were cemented with adhesive systems and resin composites of different trademarks (Ormco and 3M). Bonding resistance tests were performed with a universal force machine and topographic analysis was made with scanning electron microscopy. Results: The use of 5.25% NaClO and the Ormco brand had statistically better levels of adhesion than the group without deproteinization and the 3M brand, respectively. Adamantine topography exposed to the deproteinizing agent showed surface characteristics related to the type I etching pattern. Conclusion: The use of a deproteinizing agent (NaClO 5.25%) as well as a trademark (Ormco) in particular conditions could define the increase in adhesion levels on adamantine surfaces with conventional orthodontic appliances (AU)

Is "Leptin Resistance" Another Key Resistance to Manage Type 2 Diabetes?

Although novel pharmacological options for the treatment of type 2 diabetes mellitus (DM2) have been observed to modulate the functionality of several key organs in glucose homeostasis, successful regulation of insulin resistance (IR), body weight management, and pharmacological treatment of obesity remain notable problems in endocrinology. Leptin may be a pivotal player in this scenario, as an adipokine which centrally regulates appetite and energy balance. In obesity, excessive caloric intake promotes a low-grade inflammatory response, which leads to dysregulations in lipid storage and adipokine secretion. In turn, these entail alterations in leptin sensitivity, leptin transport across the blood-brain barrier and defects in post-receptor signaling. Furthermore, hypothalamic inflammation and endoplasmic reticulum stress may increase the expression of molecules which may disrupt leptin signaling. Abundant evidence has linked obesity and leptin resistance, which may precede or occur simultaneously to IR and DM2. Thus, leptin sensitivity may be a potential early therapeutic target that demands further preclinical and clinical research. Modulators of insulin sensitivity have been tested in animal models and small clinical trials with promising results, especially in combination with agents such as amylin and GLP-1 analogs, in particular, due to their central activity in the hypothalamus.

Neprilysin: A Potential Therapeutic Target of Arterial Hypertension?

Arterial hypertension is the most prevalent chronic disease in the adult population of developed countries and it constitutes a significant risk factor in the development of cardiovascular disease, contributing to the emergence of many comorbidities, among which heart failure excels, a clinical syndrome that nowadays represents a major health problem with uncountable hospitalizations and the indolent course of which progressively worsens until quality of life decreases and lastly death occurs prematurely. In the light of this growing menace, each day more efforts are invested in the field of cardiovascular pharmacology, searching for new therapeutic options that allow us to modulate the physiological systems that appear among these pathologies. Therefore, in the later years, the study of natriuretic peptides has become so relevant, which mediate beneficial effects at the cardiovascular level such as diuresis, natriuresis, and decreasing cardiac remodeling; their metabolism is mediated by neprilysin, a metalloproteinase, widely expressed in the human and capable of catalyzing many substrates. The modulation of these functions has been studied by decades, giving room to Sacubitril, the first neprilysin inhibitor, which in conjunction with an angiotensin receptor blocker has provided a high efficacy and tolerability among patients with heart failure, for whom it has already been approved and recommended. Nonetheless, in the matter of arterial hypertension, significant findings have arisen that demonstrate the potential role that it will play among the pharmacological alternatives in the upcoming years.

Morphology of the immature stages and notes on the natural history of the little-known plume moth Stenoptilodes juanfernandicus Gielis (Lepidoptera: Pterophoridae).

Stenoptilodes juanfernandicus Gielis, 1991 (Lepidoptera: Pterophoridae) was described from the Juan Fernandez Islands, Chile; it was subsequently recorded from the Galápagos Islands and mainland Ecuador. Its larva and pupa are described and illustrated for the first time with the aid of light and scanning electron microscopy. Descriptions are based on specimens collected as larvae displaying cryptic coloration feeding on inflorescences of Verbena hispida Ruiz Pav. (Verbenaceae) in the Andes of northern Chile. Several differences were found with the larva and pupa of congeneric representatives, suggesting that immature morphology should be further explored to assess its value in the taxonomy and systematics of Stenoptilodes Zimmerman, 1958. Verbena hispida is the first host plant recorded for S. juanfernandicus, a finding that will be helpful to further explore different Neotropical environments to better characterize the geographic range of this plume moth.

Data Mining and Endocrine Diseases: A New Way to Classify?

Data mining consists of using large database analysis to detect patterns, relationships and models in order to describe (or even predict) the appearance of a future event; to accomplish this, it uses classification methods, rules of association, regression patterns, link and cluster analyses. Recently this approach has been used to propose a new diabetes mellitus classification, using information analysis techniques through which the selection bias minimally influences categorization, this new focus that includes data mining previously implemented to predict, identify biomarkers, complications, therapies, health policies, genetic and environmental effects of this disease; it could be generalized in the field of endocrinology, in the classification of other endocrine diseases.

Dolor En Síndrome De Guillain Barré: Una Manifestación Subestimada / Pain In Guillain Barré Syndrome: An Underestimated Manifestation

RESUMEN El Síndrome de Guillain-Barré es una polineuropatía desmielinizante aguda que se presenta clínicamente con debilidad muscular y trastornos autonómicos de forma típica, mientras que los síntomas sensitivos suelen pasar desapercibidos. Se describe la historia clínica de un paciente masculino con cuadriparesia fláccida aguda y trastornos sensitivos tipo parestesias y alodinia que dificultaron el diagnóstico durante su abordaje inicial. Luego del abordaje diagnóstico completo se confirmó la presencia del Síndrome de Guillain-Barré. Pese a que los síntomas sensitivos dificultaron el diagnóstico durante el ingreso, es importante destacar que el dolor es una manifestación frecuente de este trastorno, siendo subestimado en numerosos pacientes.

ABSTRACT Guillain-Barré syndrome is an acute demyelinating polyneuropathy that presents clinically with muscular weakness and autonomic disorders in its typical form, while the sensory symptoms usually go unnoticed. We describe the clinical history of a male patient with acute flaccid quadriparesis and sensory disorders such as paresthesia and allodynia that hinder diagnosis within the initial approach. Complete diagnostic work up confirmed the presence of Guillain-Barré syndrome. Although the sensory symptoms confused the diagnosis during admission, it is important to highlight that pain is a frequent manifestation of this disorder, being underestimated in many patients.

Clinical Use of Marijuana: The Thin Line Between Good and Evil?

From centuries ago cannabis has been known as a botanic product with several properties, with medical use in the ancient world. Nowadays, it is recognized as the active component of marijuana, the drug with the highest rates of illicit use and abuse worldwide according to data provided by the World Health Organization. A huge debate has emerged in these past years with the growing interest to employ cannabis-based products with therapeutic purposes, a strategy that has increased in various European countries, Canada and more than half of the states that conform the United States, simultaneously with an important increase of flexibility in laws and regulations regarding the recreational use of this substance, especially in North America. Although valid arguments can exist for each side, the potential therapeutic use of substances that have ethical-legal implications such as the case of cannabis, require the prescribing doctor to be knowledgeable and to always be updated on the subject, a robust doctor-patient relationship and educational campaigns with truthful information that allow for full awareness of risks vs benefits.

Cigarette smoking and metabolic syndrome components: a cross-sectional study from Maracaibo City, Venezuela.

Background: A growing body of evidence suggests that cigarette smoking can cause the onset of metabolic syndrome prior to cardiovascular diseases. Therefore, the objective of this study was to evaluate the relationship between smoking habit and metabolic syndrome components in an adult population from Maracaibo city, Venezuela. Methods: The Maracaibo City Metabolic Syndrome Prevalence Study is a descriptive, cross-sectional study with random and multi-stage sampling. In this sub-study, 2212 adults from both genders were selected. On the basis of their medical background, they were classified as smokers, non-smokers and former smokers. Metabolic syndrome was defined according to Harmonizing 2009 criteria, using population-specific abdominal circumference cut-off points. The association between risk factors was evaluated using a logistic regression model. Results: In the studied population, 14.8% were smokers, 15.4% were former smokers. In the multivariate analysis, the presence of metabolic syndrome (smokers: OR, 1.54; 95% CI, 1.11-2.14; p=0.010) and its components were related to cigarette smoking, with the exception of hyperglycemia. High blood pressure was inversely associated with current smoking status (smokers: OR, 0.70 (0.51-0.95); p=0.025). Conclusion: Cigarette smoking represents a related factor with metabolic syndrome, being associated with low high-density lipoprotein-cholesterol, increased abdominal circumference and elevated triacylglyceride levels. Former smokers did not present a greater risk for developing this metabolic disease when compared to non-smokers. The effect of avoiding this habit should be evaluated in future studies in our population.

Pinning down the superfluid and measuring masses using pulsar glitches.

Pulsars are known for their superb timing precision, although glitches can interrupt the regular timing behavior when the stars are young. These glitches are thought to be caused by interactions between normal and superfluid matter in the crust of the star. However, glitching pulsars such as Vela have been shown to require a superfluid reservoir that greatly exceeds that available in the crust. We examine a model in which glitches tap the superfluid in the core. We test a variety of theoretical superfluid models against the most recent glitch data and find that only one model can successfully explain up to 45 years of observational data. We develop a new technique for combining radio and x-ray data to measure pulsar masses, thereby demonstrating how current and future telescopes can probe fundamental physics such as superfluidity near nuclear saturation.