An exploratory cross-sectional study on Mental health literacy of Spanish adolescents.

BACKGROUND: Mental health literacy (MHL) is especially important for young people, but comprehensive studies on MHL in adolescents are limited, with no nationwide studies in Spain. This research aims to study MHL among Spanish adolescents and its relationship with sociodemographic factors. METHODS: An exploratory study is carried out using stratified random sampling in Spanish adolescents (N = 1000), aged 12-16 years and balanced in terms of gender, age and territorial distribution. Data collection took place in October and November 2023 through online surveys using the CAWI methodology. Sociodemographic variables, contact with mental health and the Spanish version of the Mental Health Literacy Questionnaire (MHLq-E), a self-administered instrument of 32 Likert-type items (1-5) that assesses the dimensions of help-seeking skills, knowledge about causes and symptoms, and stigma, were evaluated. Descriptive and multivariate analyses of variance (MANOVA) were conducted. RESULTS: In general, adequate levels of literacy were observed, although some aspects related to help-seeking towards teachers, stigmatising attitudes towards people of low economic status and knowledge of severe mental health problems could be improved. The results show contact with previous mental health problems as a key variable for stigma and knowledge about symptomatology together with age. Likewise, gender and family educational level were found to be related to the ability to seek professional help. CONCLUSION: This study provides information on levels of MHL among Spanish adolescents and highlights significant socio-demographic variables. These findings pave the way for interventions aimed at improving adolescents' understanding, attitudes and skills to manage mental health problems, making possible to adapt content and focus on specific groups, thus increasing its effectiveness.

Flexible Force Sensor Based on a PVA/AgNWs Nanocomposite and Cellulose Acetate.

Nanocomposites are materials of special interest for the development of flexible electronic, optical, and mechanical devices in applications such as transparent conductive electrodes and flexible electronic sensors. These materials take advantage of the electrical, chemical, and mechanical properties of a polymeric matrix, especially in force sensors, as well as the properties of a conductive filler such as silver nanowires (AgNWs). In this work, the fabrication of a force sensor using AgNWs synthesized via the polyol chemical technique is presented. The nanowires were deposited via drop-casting in polyvinyl alcohol (PVA) to form the active (electrode) and resistive (nanocomposite) sensor films, with both films separated by a cellulose acetate substrate. The dimensions of the resulting sensor are 35 mm × 40 mm × 0.1 mm. The sensor shows an applied force ranging from 0 to 3.92 N, with a sensitivity of 0.039 N. The sensor stand-off resistance, exceeding 50 MΩ, indicates a good ability to detect changes in applied force without an external force. Additionally, studies revealed a response time of 10 ms, stabilization of 9 s, and a degree of hysteresis of 1.9%. The voltage response of the sensor under flexion at an angle of 85° was measured, demonstrating its functionality over a prolonged period. The fabricated sensor can be used in applications that require measuring pressure on irregular surfaces or systems with limited space, such as for estimating movement in robot joints.

Quantification of hCG Hormone Using Tapered Optical Fiber Decorated with Gold Nanoparticles.

In this study, a novel technique for the quantification of the human chorionic gonadotropin (hCG) hormone using localized surface plasmons and a tapered optical fiber decorated with gold nanoparticles (Au-NPs) is reported. The tapered optical fiber fabrication process involves stretching a single-mode optical fiber using the flame-brushing system. The waist of the tapered optical fiber reaches a diameter of 3 µm. Decoration of the taper is achieved through the photodeposition of 100 nm Au-NPs using the drop-casting technique and a radiation source emitting at 1550 nm. The presence of the hCG hormone in the sample solutions is verified by Fourier-transform infrared spectroscopy (FTIR), revealing the presence of bands related to functional groups, such as C=O (1630 cm-1), which are associated with proteins and lipids, components of the hCG hormone. Quantification tests for hormone concentrations were carried out by measuring the optical power response of the tapered optical fiber with Au-NPs under the influence of hCG hormone concentrations, ranging from 1 mIU/mL to 100,000 mIU/mL. In the waist of the tapered optical fiber, the evanescent field is amplified because of localized surface plasmons generated by the nanoparticles and the laser radiation through the optical fiber. Experimental results demonstrated a proportional relationship between measured radiation power and hCG concentration, with the optical power response decreasing from 4.45 mW down to 2.5 mW, as the hCG hormone concentration increased from 1 mIU/mL up to 100,000 mIU/mL. Furthermore, the spectral analysis demonstrated a spectral shift of 14.2 nm with the increment of the hCG hormone concentration. The measurement system exhibits promising potential as a sensor for applications in the biomedical and industrial fields.

Dual-Band CPW Graphene Antenna for Smart Cities and IoT Applications.

In this paper, a dual-band graphene coplanar waveguide antenna is designed for smart cities and internet of things applications. A graphene film is chosen as the conductive material for the radiation patches and ground plane with a thickness of 240 µm and an electric conductivity of 3.5 × 105 S/m. The dielectric is glass with a dielectric permittivity of 6 and a thickness of 2 mm. The implementation of the antenna on glass permits the integration of the antenna in smart cities and IoT applications. This antenna is based on two trapezoidal patches that generate the dual-band behavior. The overall dimensions of the antenna are 30 mm × 30 mm × 2 mm. The reflection coefficient, gain, and radiation patterns were measured and compared with the simulations. The antenna covers two frequency bands; the lower band covers the 2.45 GHz ISM band, and the upper band range covers from 4 to 7 GHz.

A fractional-order SIRD model with time-dependent memory indexes for encompassing the multi-fractional characteristics of the COVID-19.

COVID-19 is a novel coronavirus affecting all the world since December last year. Up to date, the spread of the outbreak continues to complicate our lives, and therefore, several research efforts from many scientific areas are proposed. Among them, mathematical models are an excellent way to understand and predict the epidemic outbreaks evolution to some extent. Due to the COVID-19 may be modeled as a non-Markovian process that follows power-law scaling features, we present a fractional-order SIRD (Susceptible-Infected-Recovered-Dead) model based on the Caputo derivative for incorporating the memory effects (long and short) in the outbreak progress. Additionally, we analyze the experimental time series of 23 countries using fractal formalism. Like previous works, we identify that the COVID-19 evolution shows various power-law exponents (no just a single one) and share some universality among geographical regions. Hence, we incorporate numerous memory indexes in the proposed model, i.e., distinct fractional-orders defined by a time-dependent function that permits us to set specific memory contributions during the evolution. This allows controlling the memory effects of more early states, e.g., before and after a quarantine decree, which could be less relevant than the contribution of more recent ones on the current state of the SIRD system. We also prove our model with Italy's real data from the Center for Systems Science and Engineering (CSSE) at Johns Hopkins University.

Stabilization and Synchronization of a Complex Hidden Attractor Chaotic System by Backstepping Technique.

In this paper, the stabilization and synchronization of a complex hidden chaotic attractor is shown. This article begins with the dynamic analysis of a complex Lorenz chaotic system considering the vector field properties of the analyzed system in the Cn domain. Then, considering first the original domain of attraction of the complex Lorenz chaotic system in the equilibrium point, by using the required set topology of this domain of attraction, one hidden chaotic attractor is found by finding the intersection of two sets in which two of the parameters, r and b, can be varied in order to find hidden chaotic attractors. Then, a backstepping controller is derived by selecting extra state variables and establishing the required Lyapunov functionals in a recursive methodology. For the control synchronization law, a similar procedure is implemented, but this time, taking into consideration the error variable which comprise the difference of the response system and drive system, to synchronize the response system with the original drive system which is the original complex Lorenz system.

Nonlinear Dynamics and Entropy of Complex Systems with Hidden and Self-Excited Attractors II.

According to the pioneering work of Leonov and Kuznetsov [...].

Synchronization of a Non-Equilibrium Four-Dimensional Chaotic System Using a Disturbance-Observer-Based Adaptive Terminal Sliding Mode Control Method.

In this paper, dynamical behavior and synchronization of a non-equilibrium four-dimensional chaotic system are studied. The system only includes one constant term and has hidden attractors. Some dynamical features of the governing system, such as invariance and symmetry, the existence of attractors and dissipativity, chaotic flow with a plane of equilibria, and offset boosting of the chaotic attractor, are stated and discussed and a new disturbance-observer-based adaptive terminal sliding mode control (ATSMC) method with input saturation is proposed for the control and synchronization of the chaotic system. To deal with unexpected noises, an extended Kalman filter (EKF) is implemented along with the designed controller. Through the concept of Lyapunov stability, the proposed control technique guarantees the finite time convergence of the uncertain system in the presence of disturbances and control input limits. Furthermore, to decrease the chattering phenomena, a genetic algorithm is used to optimize the controller parameters. Finally, numerical simulations are presented to demonstrate the performance of the designed control scheme in the presence of noise, disturbances, and control input saturation.

Modification of the Logistic Map Using Fuzzy Numbers with Application to Pseudorandom Number Generation and Image Encryption.

A modification of the classic logistic map is proposed, using fuzzy triangular numbers. The resulting map is analysed through its Lyapunov exponent (LE) and bifurcation diagrams. It shows higher complexity compared to the classic logistic map and showcases phenomena, like antimonotonicity and crisis. The map is then applied to the problem of pseudo random bit generation, using a simple rule to generate the bit sequence. The resulting random bit generator (RBG) successfully passes the National Institute of Standards and Technology (NIST) statistical tests, and it is then successfully applied to the problem of image encryption.

Nonlinear Dynamics and Entropy of Complex Systems with Hidden and Self-Excited Attractors.

In the last few years, entropy has been a fundamental and essential concept in information theory [...].

A New Fractional-Order Chaotic System with Different Families of Hidden and Self-Excited Attractors.

In this work, a new fractional-order chaotic system with a single parameter and four nonlinearities is introduced. One striking feature is that by varying the system parameter, the fractional-order system generates several complex dynamics: self-excited attractors, hidden attractors, and the coexistence of hidden attractors. In the family of self-excited chaotic attractors, the system has four spiral-saddle-type equilibrium points, or two nonhyperbolic equilibria. Besides, for a certain value of the parameter, a fractional-order no-equilibrium system is obtained. This no-equilibrium system presents a hidden chaotic attractor with a `hurricane'-like shape in the phase space. Multistability is also observed, since a hidden chaotic attractor coexists with a periodic one. The chaos generation in the new fractional-order system is demonstrated by the Lyapunov exponents method and equilibrium stability. Moreover, the complexity of the self-excited and hidden chaotic attractors is analyzed by computing their spectral entropy and Brownian-like motions. Finally, a pseudo-random number generator is designed using the hidden dynamics.

Tapered Optical Fiber Functionalized with Palladium Nanoparticles by Drop Casting and Laser Radiation for H₂ and Volatile Organic Compounds Sensing Purposes.

A comparative study on the sensing properties of a tapered optical fiber pristine and functionalized with the palladium nanoparticles to hydrogen and volatile organic compounds (VOCs), is presented. The sensor response and, response/recovery times were extracted from the measurements of the transient response of the device. The tapered optical fiber sensor was fabricated using a single-mode optical fiber by the flame-brushing technique. Functionalization of the optical fiber was performed using an aqueous solution of palladium chloride by drop-casting technique assisted for laser radiation. The detection principle of the sensor is based on the changes in the optical properties of palladium nanoparticles when exposed to reducing gases, which causes a variation in the absorption of evanescent waves. A continuous wave laser diode operating at 1550 nm is used for the sensor characterization. The sensor functionalized with palladium nanoparticles by this technique is viable for the sensing of hydrogen and VOCs, since it shows an enhancement in sensor response and response time compared to the sensor based on the pristine optical microfiber. The results show that the fabricated sensor is competitive with other fiber optic sensors functionalized with palladium nanoparticles to the hydrogen.

Countryside biogeography of Neotropical reptiles and amphibians.

The future of biodiversity and ecosystem services depends largely on the capacity of human-dominated ecosystems to support them, yet this capacity remains largely unknown. Using the framework of countryside biogeography, and working in the Las Cruces system of Coto Brus, Costa Rica, we assessed reptile and amphibian assemblages within four habitats that typify much of the Neotropics: sun coffee plantations (12 sites), pasture (12 sites), remnant forest elements (12 sites), and a larger, contiguous protected forest (3 sites in one forest). Through analysis of 1678 captures of 67 species, we draw four primary conclusions. First, we found that the majority of reptile (60%) and amphibian (70%) species in this study used an array of habitat types, including coffee plantations and actively grazed pastures. Second, we found that coffee plantations and pastures hosted rich, albeit different and less dense, reptile and amphibian biodiversity relative to the 326-ha Las Cruces Forest Reserve and neighboring forest elements. Third, we found that the small ribbons of "countryside forest elements" weaving through farmland collectively increased the effective size of a 326-ha local forest reserve 16-fold for reptiles and 14-fold for amphibians within our 236-km2 study area. Therefore, countryside forest elements, often too small for most remote sensing techniques to identify, are contributing -95% of the available habitat for forest-dependent reptiles and amphibians in our largely human-dominated study region. Fourth, we found large and pond-reproducing amphibians to prefer human-made habitats, whereas small, stream-reproducing, and directly developing species are more dependent on forest elements. Our investigation demonstrates that tropical farming landscapes can support substantial reptile and amphibian biodiversity. Our approach provides a framework for estimating the conservation value of the complex working landscapes that constitute roughly half of the global land surface, and which are experiencing intensification pressure worldwide.

Inhalable porous particles as dual micro-nano carriers demonstrating efficient lung drug delivery for treatment of tuberculosis.

Inhalation therapy treating severe infectious disease is among the more complex and emerging topics in controlled drug release. Micron-sized carriers are needed to deposit drugs into the lower airways, while nano-sized carriers are of preference for cell targeting. Here, we present a novel and versatile strategy using micron-sized spherical particles with an excellent aerodynamic profile that dissolve in the lung fluid to ultimately generate nanoparticles enabling to enhance both extra- and intra-cellular drug delivery (i.e., dual micro-nano inhalation strategy). The spherical particles are synthesised through the condensation of nano-sized amorphous silicon dioxide resulting in high surface area, disordered mesoporous silica particles (MSPs) with monodispersed size of 2.43 µm. Clofazimine (CLZ), a drug shown to be effective against multidrug-resistant tuberculosis, was encapsulated in the MSPs obtaining a dry powder formulation with high respirable fraction (F.P.F. <5 µm of 50%) without the need of additional excipients. DSC, XRPD, and Nitrogen adsorption-desorption indicate that the drug was fully amorphous when confined in the nano-sized pores (9-10 nm) of the MSPs (shelf-life of 20 months at 4 °C). Once deposited in the lung, the CLZ-MSPs exhibited a dual action. Firstly, the nanoconfinement within the MSPs enabled a drastic dissolution enhancement of CLZ in simulated lung fluid (i.e., 16-fold higher than the free drug), increasing mycobacterial killing than CLZ alone (p = 0.0262) and reaching concentrations above the minimum bactericidal concentration (MBC) against biofilms of M. tuberculosis (i.e., targeting extracellular bacteria). The released CLZ permeated but was highly retained in a Calu-3 respiratory epithelium model, suggesting a high local drug concentration within the lung tissue minimizing risk for systemic side effects. Secondly, the micron-sized drug carriers spontaneously dissolve in simulated lung fluid into nano-sized drug carriers (shown by Nano-FTIR), delivering high CLZ cargo inside macrophages and drastically decreasing the mycobacterial burden inside macrophages (i.e., targeting intracellular bacteria). Safety studies showed neither measurable toxicity on macrophages nor Calu-3 cells, nor impaired epithelial integrity. The dissolved MSPs also did not show haemolytic effect on human erythrocytes. In a nutshell, this study presents a low-cost, stable and non-invasive dried powder formulation based on a dual micro-nano carrier to efficiently deliver drug to the lungs overcoming technological and practical challenges for global healthcare.

A new buffering theory of social support and psychological stress.

A dynamical model linking stress, social support, and health has been recently proposed and numerically analyzed from a classical point of view of integer-order calculus. Although interesting observations have been obtained in this way, the present work conducts a fractional-order analysis of that model. Under a periodic forcing of an environmental stress variable, the perceived stress has been analyzed through bifurcation diagrams and two well-known metrics of entropy and complexity, such as spectral entropy and C0 complexity. The results obtained by numerical simulations have shown novel insights into how stress evolves with frequency and amplitude of the perturbation, as well as with initial conditions for the system variables. More precisely, it has been observed that stress can alternate between chaos, periodic oscillations, and stable behaviors as the fractional order varies. Moreover, the perturbation frequency has revealed a narrow interval for the chaotic oscillations, while its amplitude may present different values indicating a low sensitivity regarding chaos generation. Also, the perceived stress has been noted to be highly sensitive to initial conditions for the symptoms of stress-related ill-health and for the social support received from family and friends. This work opens new directions of research whereby fractional calculus might offer more insight into psychology, life sciences, mental disorders, and stress-free well-being.

Measurement Invariance and Latent Mean Differences Between American, Spanish and Chinese Adolescents Using the Social Anxiety Scale for Adolescents (SAS-A).

BACKGROUND: Social anxiety is one of the most prevalent disorders among adolescents (Stein et al., 2017). The main aim of this study was to analyze the equivalence of scores on the Social Anxiety Scale for Adolescents (SAS-A) using structural equation modeling and identify differences in latent means of social anxiety in China, Spain, and the USA. METHOD: Random sampling was used to recruit participants, which included 536 Chinese (46% girls), 1,178 Spanish (55.3% girls) and 866 North American (55.1% girls) adolescents. The participants' ages ranged between 14 and 17 years old. RESULTS: The SAS-A three-factor correlated model of social anxiety remained invariant between the Spanish and North American adolescents, but results could not be replicated in the Chinese adolescents [M2 = ΔS-Bχ² (Δdf, p) = 4732.56 (36, < .01)]. Analyses of latent differences between Spain and the USA showed that Spanish adolescents had higher scores than North Americans for Fear of Negative Evaluation (TS = -9.630; d = .44) and for Social Avoidance and General Anxiety towards people (TS = -2.717; d = .12). CONCLUSIONS: The results are interpreted according to the cultural traits of individualism-collectivism and self-construal, and practical implications are discussed.

Gerbode defect or left ventricular to right atrial shunt. Case report and literature review / Defecto tipo Gerbode o comunicación entre el ventrículo izquierdo y la aurícula derecha. Reporte de un caso y revisión de la literatura

Gerbode defect is a communication from the left ventricle to right atrium and it could be categorized in congenital or acquired. It is a rare condition that can represent as much as 0.08% of all septal defects. Those acquired defects can be associated to endocarditis and after valvular surgery. The objective is to report a case of Gerbode atria-ventricular septal defect in Instituto Nacional de Cardiología Ignacio Chavez. The present case is about a 36 years old male patient with a typical presentation of mitral regurgitation, the echocardiogram reports a perforation in the anterior mitral leaflet and a Gerbode ventricular septal defect, that represents the heterogeneity of the clinical presentation of this pathology, also we show the findings in imaging studies that contributed to diagnosis and its surgical resolution. Gerbode defect is an uncommon pathology, many times associated to other cardiovascular entity, difficulting diagnose. It requires image studies and a complete presurgical evaluation in order to achieve opportune diagnosis.

El defecto tipo Gerbode es una comunicación del ventrículo izquierdo a la aurícula derecha, que puede clasificarse como congénita o adquirida. Es una condición rara que puede representar hasta el 0.08% de los defectos septales congénitos. Los defectos adquiridos pueden asociarse a endocarditis y presentarse también posterior a cambios valvulares. El objetivo es reportar un caso de comunicación interventricular de Gerbode en el Instituto Nacional de Cardiología. Paciente varón, de 36 años, con presentación clínica típica de insuficiencia mitral, ecocardiografía con hallazgo de rotura de la valva anterior de la válvula mitral y comunicación interventricular tipo Gerbode. Se ponen de manifiesto la heterogeneidad clínica con la que se presenta esta patología y los hallazgos de imagen que contribuyen al diagnóstico y su resolución quirúrgica. La comunicación interventricular tipo Gerbode es una patología infrecuente, muchas veces asociada a otra afección cardiovascular, lo que la hace de difícil diagnóstico. Se requieren estudios de imagen y una evaluación preoperatoria completa para su detección oportuna.

Zaragoza technique of laparoscopic appendicectomy.

INTRODUCTION: Appendectomy is one of the most frequent emergency surgical procedures, currently with a preference for laparoscopic management worldwide. OBJECTIVE: To report a new laparoscopic appendectomy technique and its results. MATERIAL AND METHODS: Cohort study of patients with a diagnosis of appendicitis who are managed laparoscopically. In a total 1063 patients, 148 were operated on with the Zaragoza technique during the period from January 2002 to December 2018. The technique consists of making a window in the appendicular base between the meso and the appendicular wall, two prolene or silk sutures are placed, and the cecal appendix is cut between the two sutures, finally the mesoappendix is sectioned with a harmonic scalpel or bipolar clamp. RESULTS: From our results, we had 1.4% residual abscesses, 1.4% umbilical surgical wound infection and 0% mortality. DISCUSSION: Various laparoscopic management methods for appendectomy are reported in the literature, with a wide range in the results. We have obtained good results in patients subjected to our technique. CONCLUSIONS: The Zaragoza technique for laparoscopic appendectomy is an effective and safe option that prevents excessive manipulation of the inflamed appendix and is easily reproducible.

Diversity, natural history and conservation of amphibians and reptiles from the San Vito Region, southwestern Costa Rica.

We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41 of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades.

Historic distribution and challenges to bison recovery in the northern Chihuahuan desert.

Ecologists and conservationists have long assumed that large grazers, including bison (Bison bison), did not occur in post-Pleistocene southwestern North America. This perception has been influential in framing the debate over conservation and land use in the northern Chihuahuan Desert. The lack of an evolutionary history of large grazers is being used to challenge the validity of ranching as a conservation strategy and to limit the protection and reintroduction of bison as a significant component of desert grassland ecosystems. Archeological records and historical accounts from Mexican archives from AD 700 to the 19th century document that the historic range of the bison included northern Mexico and adjoining areas in the United States. The Janos-Hidalgo bison herd, one of the few free-ranging bison herds in North America, has moved between Chihuahua, Mexico, and New Mexico, United States, since at least the 1920s. The persistence of this cross-border bison herd in Chihuahuan Desert grasslands and shrublands demonstrates that the species can persist in desert landscapes. Additional lines of evidence include the existence of grazing-adapted grasslands and the results of experimental studies that document declines in vegetation density and diversity following the removal of large grazers. The Janos-Hidalgo herd was formed with animals from various sources at the turn of the 19th century. Yet the future of the herd is compromised by differing perceptions of the ecological and evolutionary role of bison in the Desert Grasslands of North America. In Mexico they are considered native and are protected by federal law, whereas in New Mexico, they are considered non-native livestock and therefore lack conservation status or federal protection. Evidence written in Spanish of the presence of bison south of the accepted range and evidence from the disciplines of archaeology and history illustrate how differences in language and academic disciplines, in addition to international boundaries, have acted as barriers in shaping comprehensive approaches to conservation. Bison recovery in the region depends on binational cooperation.