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Cellulose modified hydrogels can be produced directly from raw biopolymers in novel cellulose solvents such as NaOH/urea aqueous solution. The effect of cellulose characteristics on the synthesis of a cellulose-graft-(net-poly(acrylamide-co-acrylic acid)) and its performance as water absorbent/methylene blue dye removal material is analyzed. Three cellulose samples, one analytical grade and two obtained from teak wood sawdust with different pretreatments (one alkaline and the other, a novel one known as (gas phase) acid pretreatment) were compared. The starting raw celluloses were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and viscosity in cupri ethylenediamine hydroxide (CED) solution, whereas the chemically modified materials were characterized by SEM, FTIR, and TGA. The pretreatment used influences composition, crystallinity index and degree of polymerization (DP) of the cellulose obtained. The modified material produced with cellulose from alkaline pretreatment showed the highest swelling ratio in water absorption tests at room temperature (12,714 %); in contrast, the one with cellulose from acid pretreatment showed the lowest swelling ratio (7,470 %). However, this difference is not so significative in dye removal tests, where absorption capacity is 139 and 140 mg/g, respectively. The results indicate that cellulose composition, particularly structures with significant hemicellulose and lignin remaining content, has a major effect on the performance of modified materials for water absorption, and degree of polymerization has a major effect on adsorption capacity of methylene blue.
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Celulosa , Colorantes , Lignina , Agua , Madera , Lignina/química , Celulosa/química , Agua/química , Madera/química , Colorantes/química , Resinas Acrílicas/química , Azul de Metileno/química , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Purificación del Agua/métodos , Contaminantes Químicos del Agua/química , Acrilamidas/químicaRESUMEN
BACKGROUND: Suicidal behavior in adolescents is a growing public health problem. Knowing its risk factors is key for reducing it. OBJECTIVE: To identify the relationship between two suicidal behaviors (ideation and attempt) and eight mental health problems (MHPs) in Mexican adolescents. MATERIAL AND METHODS: Through an online survey of adolescent students from 20 states, the following information was screened: symptomatology of six MHPs (affective problems/depression, behavioral problems, somatic problems, inattention and hyperactivity problems, oppositional defiant problems and anxiety problems) and suicidal behavior (suicidal ideation and suicide attempts). MHP and suicidal behavior frequencies and percentages were analyzed, and associations were sought using binary logistic regression. RESULTS: Six-thousand seven hundred sixty-six adolescents completed the survey, out of whom 61.02% were females, with ages ranging between 11 and 19 years (16.38 ± 1.33); 10% reported suicidal behavior, and between 3 and 5%, MHPs. The predictors (χ2(8) = 387.13, p < 0.001) of suicidal behavior were affective problems/depression, behavioral problems, somatic problems, oppositional defiant problems and anxiety problems. CONCLUSION: Five mental health problems increased the risk of reporting suicidal behaviors.
ANTECEDENTES: Las conductas suicidas en adolescentes son un problema de salud pública que va en aumento. Conocer sus factores de riesgo es clave para reducirlas. OBJETIVO: Identificar la relación entre dos conductas suicidas (ideación e intento) y ocho problemas de salud mental (PSM) en adolescentes mexicanos. MATERIAL Y MÉTODOS: Mediante una encuesta en línea a adolescentes escolarizados de 20 estados, se tamizó la siguiente información: sintomatología de seis PSM (problemas afectivos/depresión, problemas conductuales, problemas somáticos, problemas de inatención e hiperactividad, problemas oposicionistas desafianes y problemas de ansiedad) y conducta suicida (ideación e intentos de suicidio). Se analizaron frecuencias y porcentajes y se indagó asociación mediante regresión logística binaria. RESULTADOS: Completaron la encuesta 6766 adolescentes entre 11 y 19 años (16.38 ± 1.33), 61.02 % del sexo femenino. El 10 % reportó conducta suicida y entre 3 y 5 %, PSM. Los factores predictivos (χ2(8) = 387.13, p < 0.001) de la conducta suicida fueron problemas afectivos/depresión, problemas conductuales, problemas somáticos, problemas oposicionistas desafiantes y problemas de ansiedad. CONCLUSIÓN: Cinco problemas de salud mental incrementaron el riesgo de reportar conductas suicidas.
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Trastornos Mentales , Ideación Suicida , Intento de Suicidio , Humanos , Adolescente , Femenino , México/epidemiología , Masculino , Intento de Suicidio/estadística & datos numéricos , Intento de Suicidio/psicología , Trastornos Mentales/epidemiología , Niño , Adulto Joven , Factores de Riesgo , Estudios TransversalesRESUMEN
Perovskite nanocrystals have excellent optical properties but suffer from environmental instability and production up-scaling which limit their commercial application. Here, we report the gram-scale ultrasound-mediated synthesis of silane passivated CsPbBr3 nanocrystals using (3-aminopropyl) triethoxysilane (APTS) as the primary surface ligand surface. The surface engineering endowed the CsPbBr3@SiOR NCs with extended environmental stability, a narrow emission bandwidth and a high photoluminescence quantum yield (PLQY > 75%). Thanks to these excellent optical properties, high-efficiency lateral and vertical photodetectors were fabricated. In particular, the layered vertical photodiode composed of ITO/Ga2O3/CsPbBr3/Au exhibited a broadband photoresponse from 350-700 nm with a responsivity peaking at 44.5.1 A W-1 and specific detectivity above 1013 Jones when illuminated at 470 nm wavelength and biased at +5 V. These results correspond to the best-in-class performance perovskite nanocrystal PD and confirm the extraordinary potential of CsPbBr3@SiOR for the development of efficient optoelectronic devices.
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Unraveling the fundamental biological processes underpinning cell functions and behavior remains a key challenge. Researchers working on cell biological processes might want to take a look at microscale cell flow as functionality genesis. This Commentary provides an outlook on how cell-microcirculation interplay promises to lead to exciting insights into the cell biology complexity.
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MicrocirculaciónRESUMEN
The abundance of microplastics (MPs) in the gastrointestinal tract (GT), gills (GI), and exoskeleton (EX) of Litopenaeus vannamei shrimp cultured in a commercial indoor super-intensive controlled (ISCO) system was investigated. Shrimp of 25 days (postlarvae; PL25), and one, three, five, and seven culture months were analyzed. The postlarvae PL25 MP abundance per individual and gram of PL (wet weight) was 0.2 ± 0.0 MPs and 3.5 ± 0.5 MPs/g. For L. vannamei juveniles at one, three, five, and seven culture months, the MP abundance per juvenile shrimp was 10.0 ± 0.3, 27.2 ± 1.6, 32.3 ± 3.1, and 40.3 ± 3.6 MPs/individual, respectively (expressed in MPs/g of tissue were 1.6 ± 0.1, 2.0 ± 0.2, 2.0 ± 0.3 and 1.5 ± 0.2, respectively). Fibers were the most common MP type in all shrimp age classes (42.1-68.7 %), and the predominant color was transparent (46.1-65.0 %). The MP size in all shrimp stages ranged between 15 and 4686 µm. In general, the predominant polymers identified were PE (37.4 %), NY (21.1 %), and PET (18.5 %). The MP variability through the culture cycle showed that as the age of shrimp increased, and the culture advanced the MP abundance and size also augmented. Conversely, there is a higher MP abundance in L. vannamei cultured in ISCO systems compared to shrimp cultured in traditional semi-intensive and intensive ponds and those from wild environments. The latter is probably due to the extensive use of plasticized materials (geomembrane and greenhouse installations) and their degradation, which cause a greater MP exposure to shrimp. The estimated oral MP intake by ISCO shrimp consumption was 647 MPs/capita/year, which can be 178 % more than from wild shrimp.
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Microplásticos , Penaeidae , Animales , Plásticos , Acuicultura , Alimentos MarinosRESUMEN
The response of plants to increasing atmospheric CO2 depends on the ecological context where the plants are found. Several experiments with elevated CO2 (eCO2) have been done worldwide, but the Amazonian forest understory has been neglected. As the central Amazon is limited by light and phosphorus, understanding how understory responds to eCO2 is important for foreseeing how the forest will function in the future. In the understory of a natural forest in the Central Amazon, we installed four open-top chambers as control replicates and another four under eCO2 (+250 ppm above ambient levels). Under eCO2, we observed increases in carbon assimilation rate (67%), maximum electron transport rate (19%), quantum yield (56%), and water use efficiency (78%). We also detected an increase in leaf area (51%) and stem diameter increment (65%). Central Amazon understory responded positively to eCO2 by increasing their ability to capture and use light and the extra primary productivity was allocated to supporting more leaf and conducting tissues. The increment in leaf area while maintaining transpiration rates suggests that the understory will increase its contribution to evapotranspiration. Therefore, this forest might be less resistant in the future to extreme drought, as no reduction in transpiration rates were detected.
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Dióxido de Carbono , Fotosíntesis , Fotosíntesis/fisiología , Bosques , Transporte de Electrón , Hojas de la PlantaRESUMEN
Resumen Antecedentes: Las conductas suicidas en adolescentes son un problema de salud pública que va en aumento. Conocer sus factores de riesgo es clave para reducirlas. Objetivo: Identificar la relación entre dos conductas suicidas (ideación e intento) y ocho problemas de salud mental (PSM) en adolescentes mexicanos. Material y métodos: Mediante una encuesta en línea a adolescentes escolarizados de 20 estados, se tamizó la siguiente información: sintomatología de seis PSM (problemas afectivos/depresión, problemas conductuales, problemas somáticos, problemas de inatención e hiperactividad, problemas oposicionistas desafianes y problemas de ansiedad) y conducta suicida (ideación e intentos de suicidio). Se analizaron frecuencias y porcentajes y se indagó asociación mediante regresión logística binaria. Resultados: Completaron la encuesta 6766 adolescentes entre 11 y 19 años (16.38 ± 1.33), 61.02 % del sexo femenino. El 10 % reportó conducta suicida y entre 3 y 5 %, PSM. Los factores predictivos (χ2(8) =387.13, p < 0.001) de la conducta suicida fueron problemas afectivos/depresión, problemas conductuales, problemas somáticos, problemas oposicionistas desafiantes y problemas de ansiedad. Conclusión: Cinco problemas de salud mental incrementaron el riesgo de reportar conductas suicidas.
Abstract Background: Suicidal behavior in adolescents is a growing public health problem. Knowing its risk factors is key for reducing it. Objective: To identify the relationship between two suicidal behaviors (ideation and attempt) and eight mental health problems (MHPs) in Mexican adolescents. Material and methods: Through an online survey of adolescent students from 20 states, the following information was screened: symptomatology of six MHPs (affective problems/depression, behavioral problems, somatic problems, inattention and hyperactivity problems, oppositional defiant problems and anxiety problems) and suicidal behavior (suicidal ideation and suicide attempts). MHP and suicidal behavior frequencies and percentages were analyzed, and associations were sought using binary logistic regression. Results: Six-thousand seven hundred sixty-six adolescents completed the survey, out of whom 61.02% were females, with ages ranging between 11 and 19 years (16.38 ± 1.33); 10% reported suicidal behavior, and between 3 and 5%, MHPs. The predictors (χ2(8) = 387.13, p < 0.001) of suicidal behavior were affective problems/depression, behavioral problems, somatic problems, oppositional defiant problems and anxiety problems. Conclusions: Five mental health problems increased the risk of reporting suicidal behaviors.
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BACKGROUND: Adverse Childhood Experiences (ACEs) have long-term consequences. The ACEs model has been extensively used in high-income countries. However, its effectiveness has yet to be demonstrated in low and middle-income countries and marginalized social groups. In indigenous populations, research has found inconsistent results in the prevalence and the relationship between ACEs and mental health outcomes. Therefore, the objectives of this study were 1) to determine the ACEs frequency among indigenous and non-indigenous Mexican adolescents; 2) to test the association between ACE scores and symptoms of Mental Health Problems (SMHP) in both groups; and 3) to review the ACEs model adequacy for the indigenous adolescents. PARTICIPANTS AND SETTINGS: Data from an online survey in 20 of the 32 states of Mexico were analyzed. We selected an 87 adolescent sample from indigenous families and 174 non-indigenous matched for age, sex, and state of residence, with a mean age of 16 years; 60 % were women. METHODS: ACE-IQ questionnaire and Youth Self Report instrument (eight SMHP) were used to collect data. ACEs' frequency was analyzed for each group, and Pearson correlations were used to identify the relationship between ACEs and SMHP. RESULTS: There was no statistical significance between Indigenous and non-Indigenous adolescents in the ACEs report. ACE scores were associated with eight SMHP. Correlations between ACE score and SMHP were higher in non-indigenous adolescents. CONCLUSIONS: ACEs were experienced similarly by both groups and were associated with mental health in all participants. Further research is needed to improve ACEs measurement in indigenous populations.
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Experiencias Adversas de la Infancia , Salud Mental , Humanos , Adolescente , Femenino , Masculino , México/epidemiología , Renta , Encuestas y CuestionariosRESUMEN
A novel multicomponent chemoenzymatic strategy for the preparation of enantioenriched ß-acyloxy thioethers has been developed. This robust methodology employs mild bases, air atmosphere, room temperature and avoids the use of foul-smelling thiols. Instead, potassium thioacetate is employed as a universal sulfur source. This chemoselective strategy tolerates aromatic and aliphatic components and diverse functional groups. The chirality is enzymatically defined by ADH-catalyzed bioreduction of α-haloketones delivering an enantioenriched halohydrin which is one of the three components, and the optical purity remains untouched in the final product. Semipreparative scale multicomponent reaction affords high yield of the products (up to 96%).
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BACKGROUND: Various factors, including mental health comorbidity, family dysfunction, interpersonal violence, and community and social violence, cause suicidal behavior. Adverse Childhood Experiences (ACEs) encompass these risk factors and are correlated with mental health problems and suicidal behavior in Mexican adolescents. METHODS: A survey was conducted among Mexican school-aged adolescents to measure ACEs, MHP symptoms, and suicidal behavior. A binary logistic regression was used to examine the relationship between these variables. The study was conducted with IRB approval, and all participants provided informed consent. Those at risk of suicide were referred for online psychological care. RESULTS: 7325 adolescents participated; 60 % were women, with an average age of 16 years (SD + 1), 87 % of the participants reported at least one ACE, 13 % symptoms of at least one MHP and 10 % suicidal behavior. MHP predictors of suicidal behavior were: conduct problems (OR = 5.67), symptoms of depression (OR = 3.27), obsessive-compulsive disorder (OR = 2.11), somatic problems (OR = 1.98), and attention deficit (OR = 1.69). EAI predictors were: live sexual violence (OR = 2.53), physical violence (OR = 2.21), negligence (OR = 2.05), bullying (OR = 2.10), and a family member with a mental health diagnosis (OR = 1.35). The cumulative effect of ACEs and MHP significantly increased the risk (OR = 78.08). CONCLUSIONS: 5 ACEs and 4 MHP were associated with suicidal behavior; their cumulative effect increased the risk to 78 times.
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Experiencias Adversas de la Infancia , Suicidio , Humanos , Femenino , Adolescente , Niño , Masculino , Ideación Suicida , Salud Mental , ViolenciaRESUMEN
BACKGROUND: Adverse Childhood Experiences (ACEs) may have short, middle, and long-term consequences on people's development and physical and mental health. There is a need for information on this subject in low- and middle-income countries and a need to reduce recall bias in ACEs research worldwide. OBJECTIVE: Hence our objectives were to translate, adapt and validate the Adverse Childhood Experiences extended version and to determine ACEs frequencies in a sample of Mexican adolescents. PARTICIPANTS AND SETTING: A convenience sample of 5835 schooled Mexican adolescents (age: M = 16.13, SD = 1.32; 61.01 % females) from 20 states in Mexico completed a survey. METHOD: A cross-sectional study was conducted with an extended version of the ACE-International Questionnaire (ACE-IQ), which assesses 23 ACEs organized into five categories: situations that cause household dysfunction, exposure to violence, violence from parents or guardians, interpersonal violence, and sociodemographic context. RESULTS: Evidence of construct validity and reliability of the questionnaire was obtained, and 16 ACEs were included in the final ACE-IQ version. 90 % of adolescents had one or more ACEs. Neglect was the most experienced ACE reported by 73.30 % of the participants, with no significant difference by age, sex, or geographic region. CONCLUSION: ACE-IQ questionnaire is a reliable and valid instrument to recommend its use for generating information on ACEs in studies on Mexican adolescents. The results on the frequency of ACEs revealed that 90 % of this schooled Mexican adolescent sample had experienced one or more ACEs, and about a third had experienced six or more.
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Violencia , Femenino , Humanos , Adolescente , Masculino , México/epidemiología , Estudios Transversales , Reproducibilidad de los Resultados , Encuestas y CuestionariosRESUMEN
BACKGROUND: Adverse Childhood Experiences (ACEs) have long-term consequences. The ACEs model has been extensively used in high-income countries. However, its effectiveness has yet to be demonstrated in low and middle-income countries and marginalized social groups. In indigenous populations, research has found inconsistent results in the prevalence and the relationship between ACEs and mental health outcomes. Therefore, the objectives of this study were 1) to determine the ACEs frequency among indigenous and non-indigenous Mexican adolescents; 2) to test the association between ACE scores and symptoms of Mental Health Problems (SMHP) in both groups; and 3) to review the ACEs model adequacy for the indigenous adolescents. PARTICIPANTS AND SETTINGS: Data from an online survey in 20 of the 32 states of Mexico were analyzed. We selected an 87 adolescent sample from indigenous families and 174 non-indigenous matched for age, sex, and state of residence, with a mean age of 16 years; 60 % were women. METHODS: ACE-IQ questionnaire and Youth Self Report instrument (eight SMHP) were used to collect data. ACEs' frequency was analyzed for each group, and Pearson correlations were used to identify the relationship between ACEs and SMHP. RESULTS: There was no statistical significance between Indigenous and non-Indigenous adolescents in the ACEs report. ACE scores were associated with eight SMHP. Correlations between ACE score and SMHP were higher in non-indigenous adolescents. CONCLUSIONS: ACEs were experienced similarly by both groups and were associated with mental health in all participants. Further research is needed to improve ACEs measurement in indigenous populations.
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Experiencias Adversas de la Infancia , Salud Mental , Humanos , Adolescente , Femenino , Masculino , México/epidemiología , Renta , Encuestas y CuestionariosRESUMEN
El quiste del conducto torácico en su porción cervical es una patología infrecuente con escasos casos reportados en la literatura mundial. Habitualmente, se presenta como un aumento de volumen blando e indoloro en la fosa supraclavicular izquierda, el cual puede generar sintomatología compresiva variable de las estructuras adyacentes. Presentamos el caso de una mujer de 76 años remitida a la consulta de otorrinolaringología por evidencia de una lesión quística en la fosa supraclavicular izquierda con estudio posterior concordante con quiste cervical del conducto torácico.
The cervical thoracic duct cyst is an infrequent entity, with only a few cases reported in the international literature. It usually presents as a painless swelling on the left supraclavicular fossa, that can generate symptoms due to compression of adjacent structures. We present the case of a 76-year-old women that was referred to otolaryngology due to a supraclavicular cyst, with subsequent diagnosis of cervical thoracic duct cyst.
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Humanos , Femenino , Anciano , Conducto Torácico/patología , Quiste Mediastínico/diagnóstico por imagen , Conducto Torácico/cirugía , Tomografía Computarizada por Rayos X/métodos , Quiste Mediastínico/cirugíaRESUMEN
BACKGROUND: Deep neural networks have been used to estimate age from ECGs, the electrocardiographic age (ECG-age), which predicts adverse outcomes. However, this prediction ability has been restricted to clinical settings or relatively short periods. We hypothesized that ECG-age is associated with death and cardiovascular outcomes in the long-standing community-based FHS (Framingham Heart Study). METHODS: We tested the association of ECG-age with chronological age in the FHS cohorts in ECGs from 1986 to 2021. We calculated the gap between chronological and ECG-age (Δage) and classified individuals as having normal, accelerated, or decelerated aging, if Δage was within, higher, or lower than the mean absolute error of the model, respectively. We assessed the associations of Δage, accelerated and decelerated aging with death or cardiovascular outcomes (atrial fibrillation, myocardial infarction, and heart failure) using Cox proportional hazards models adjusted for age, sex, and clinical factors. RESULTS: The study population included 9877 FHS participants (mean age, 55±13 years; 54.9% women) with 34 948 ECGs. ECG-age was correlated to chronological age (r=0.81; mean absolute error, 9±7 years). After 17±8 years of follow-up, every 10-year increase of Δage was associated with 18% increase in all-cause mortality (hazard ratio [HR], 1.18 [95% CI, 1.12-1.23]), 23% increase in atrial fibrillation risk (HR, 1.23 [95% CI, 1.17-1.29]), 14% increase in myocardial infarction risk (HR, 1.14 [95% CI, 1.05-1.23]), and 40% increase in heart failure risk (HR, 1.40 [95% CI, 1.30-1.52]), in multivariable models. In addition, accelerated aging was associated with a 28% increase in all-cause mortality (HR, 1.28 [95% CI, 1.14-1.45]), whereas decelerated aging was associated with a 16% decrease (HR, 0.84 [95% CI, 0.74-0.95]). CONCLUSIONS: ECG-age was highly correlated with chronological age in FHS. The difference between ECG-age and chronological age was associated with death, myocardial infarction, atrial fibrillation, and heart failure. Given the wide availability and low cost of ECG, ECG-age could be a scalable biomarker of cardiovascular risk.
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Fibrilación Atrial , Insuficiencia Cardíaca , Infarto del Miocardio , Humanos , Femenino , Adulto , Persona de Mediana Edad , Anciano , Masculino , Fibrilación Atrial/epidemiología , Insuficiencia Cardíaca/epidemiología , Estudios Longitudinales , Infarto del Miocardio/epidemiología , Electrocardiografía , Factores de RiesgoRESUMEN
Understanding diffusive processes in networks is a significant challenge in complexity science. Networks possess a diffusive potential that depends on their topological configuration, but diffusion also relies on the process and initial conditions. This article presents Diffusion Capacity, a concept that measures a node's potential to diffuse information based on a distance distribution that considers both geodesic and weighted shortest paths and dynamical features of the diffusion process. Diffusion Capacity thoroughly describes the role of individual nodes during a diffusion process and can identify structural modifications that may improve diffusion mechanisms. The article defines Diffusion Capacity for interconnected networks and introduces Relative Gain, which compares the performance of a node in a single structure versus an interconnected one. The method applies to a global climate network constructed from surface air temperature data, revealing a significant change in diffusion capacity around the year 2000, suggesting a loss of the planet's diffusion capacity that could contribute to the emergence of more frequent climatic events.
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Developments in synthetic biology usually bring the conception of individual artificial cells. A key feature of living systems is, however, the interaction between individuals, in which living units can interact autonomously and display a role differentiation such as the case of entities chasing each other. On the other hand, droplets have become a very useful and exciting medium for modern microengineering and biomedical technologies. In this Perspective, we show a brief discussion-outlook of different approaches to recreate predator-prey interactions in both swimmer and crawling droplet systems toward a new generation of synthetic life with impact in both fundamental insights and relevant applications.
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The production of biofuels, such as bioethanol from lignocellulosic biomass, is an important task within the sustainable energy concept. Understanding the metabolism of ethanologenic microorganisms for the consumption of sugar mixtures contained in lignocellulosic hydrolysates could allow the improvement of the fermentation process. In this study, the ethanologenic strain Escherichia coli MS04 was used to ferment hydrolysates from five different lignocellulosic agroindustrial wastes, which contained different glucose and xylose concentrations. The volumetric rates of glucose and xylose consumption and ethanol production depend on the initial concentration of glucose and xylose, concentrations of inhibitors, and the positive effect of acetate in the fermentation to ethanol. Ethanol yields above 80% and productivities up to 1.85 gEtOH/Lh were obtained. Furthermore, in all evaluations, a simultaneous co-consumption of glucose and xylose was observed. The effect of deleting the xyIR regulator was studied, concluding that it plays an important role in the metabolism of monosaccharides and in xylose consumption. Moreover, the importance of acetate was confirmed for the ethanologenic strain, showing the positive effect of acetate on the co-consumption rates of glucose and xylose in cultivation media and hydrolysates containing sugar mixtures.
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Represión Catabólica , Escherichia coli , Fermentación , Escherichia coli/metabolismo , Xilosa/metabolismo , Glucosa/metabolismo , Azúcares/metabolismo , Etanol/metabolismoRESUMEN
The thermal conductivity of nanostructures can be obtained using atomistic classical Molecular Dynamics (MD) simulations, particularly for semiconductors where there is no significant contribution from electrons to thermal conduction. In this work, we obtain and analyze the thermal conductivity of amorphous carbon (aC) nanowires (NW) with a 2 nm radius and aC nanotubes (NT) with 0.5, 1 and 1.3 nm internal radii and a 2 nm external radius. The behavior of thermal conductivity with internal radii, temperature and density (related to different levels of sp3 hybridization), is compared with experimental results from the literature. Reasonable agreement is found between our modeling results and the experiments for aC films. In addition, in our simulations, the bulk conductivity is lower than the NW conductivity, which in turn is lower than the NT conductivity. NTs thermal conductivity can be tailored as a function of the wall thickness, which surprisingly increases when the wall thickness decreases. While the vibrational density of states (VDOS) is similar for bulk, NW and NT, the elastic modulus is sensitive to the geometrical parameters, which can explain the enhanced thermal conductivity observed for the simulated nanostructures.
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Increases in human population lead to an increase in urban wastes, which could affect wildlife in several ways. Urban pollutants can affect erythrocytes of birds generating morphological membrane and nuclear anomalies. The Kelp Gull (Larus dominicanus) is an opportunistic species, which take advantage of urban environments, thus being highly exposed to environmental pollution. In northeastern Patagonia, the dynamic of the waste management was transformed in the last decade and consequently, gulls changed their movements in response to changes in waste management systems. The food available to the seagulls went from being a mixture of urban/fishing discards until 2015, when this landfill closures, to being domestic urban offerings. In order of evaluating genotoxicity and changes in pollutants exposition due to these changes, we analyzed the frequencies of erythrocytes nuclear abnormalities and micronuclei (ENAs and MN respectively) in 58 blood smears from adults extracted during the non-breeding season in two periods in landfills with different waste compositions: a mixed landfill (ML) in 2013 before closure (n = 24) versus an urban landfill (UL) (n = 34) in 2021. We found that the Kelp Gull showed high values of abnormalities with an average of 151.5 /10,000 RBC in comparison with other seabird species. The bud and notched types of ENAs were the most prevalent abnormalities in both sites. We did not find significate differences in the overall abnormality frequency between sites, however we found significant higher frequencies in displaced and tailed types of ENAs in ML. We also found poikilocytosis, as seen previously in other animals exposed experimentally to pollutants such as metals and crude oil. Cellular abnormalities found in the Kelp Gull suggest an exposition of individuals to pollutants in foraging areas. The hemispheric distribution and the synanthropic characteristics of the species denote its importance as a suitable global monitor of genotoxicity.
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Charadriiformes , Contaminantes Ambientales , Kelp , Petróleo , Animales , Aves , HumanosRESUMEN
The sensory-motor interaction is a hallmark of living systems. However, developing inanimate systems with "recognize and attack" abilities remains challenging. On the other hand, controlling the inter-droplet dynamics on surfaces is key in microengineering and biomedical applications. We show here that a pair of droplets can become intelligently interactive (chemospecific stimulus-response inter-droplet autonomous operation) when placed on a nanoporous thin film surface. We find an attacker-victim-like non-reciprocal interaction between spatially separated droplets leading to an only-in-one shape instability that triggers a drop projection to selectively couple, resembling cellular phenomenologies such as pseudopod emission and phagocytic-like functions. The nanopore-driven underlying communication and associated chemical activity are the main physical ingredients behind the observed behavior. Our results reveal that basic features found in many living cell types can emerge from a simple two-droplet framework. This work is a promising step towards the design of microfluidic smart robotics and for origin-of-life protocell models.