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CdSe nanoparticles were grown using a colloidal method, in which the pH was the main parameter that was varied (from 8 to 12) with the objective of knowing the morphological and structural effects after the synthesis process. The samples were characterized with X-ray diffraction and High-Resolution Transmission Electron Microscope to know their crystalline structure. We identified the formation of two crystalline phases in a single sample, as well as the different crystal direction of the material, the crystallites size was calculated from the X-ray diffraction pattern using the Debye- Scherrer equation. The distance between planes was also calculated using the Fast Fourier Transformation (FFT). The results and analysis of the experimental work are reported.
In this work, the anodization of grade 2 titanium was performed using a HCl-based electrolyte in order to obtain Titania nanostructures. Different glycerol concentrations were added to the HCl electrolyte to study the effect it has on the shape and density of the nanostructures, additionally, anodization time and voltage was also varied. The anodized samples were observed by SEM microscopy and studied by Raman spectroscopy and X-ray diffraction. Raman spectroscopy and XRD showed the formation of the anatase phase of the TiO2. By SEM it was possible to observe several changes in the shape of the structures, by adding glycerol ball-like structures were visible, anodization time did not change the shape of the nanostructures. However, the voltage variation showed a clear control on the shape of the structures, forming nanotubes at higher voltages. It was concluded that a better control of the shape and density of the nanostructures is achieved by adding glycerol, however, in order to overcome the resistance that the electrolyte brings, higher voltages are required.
We report a numerical analysis of the unforced break-up of free cylindrical threads of viscous Newtonian liquid whose interface is coated with insoluble surfactants, focusing on the formation of satellite droplets. The initial conditions are harmonic disturbances of the cylindrical shape with a small amplitude
, and whose wavelength is the most unstable one deduced from linear stability theory. We demonstrate that, in the limit
, the problem depends on two dimensionless parameters, namely the Laplace number,
, and the elasticity parameter,
are the liquid density, viscosity and initial surface tension, respectively,
is the Gibbs elasticity and
is the unperturbed thread radius. A parametric study is presented to quantify the influence of
on two key quantities: the satellite droplet volume and the mass of surfactant trapped at the satellite’s surface just prior to pinch-off,
, respectively. We identify a weak-elasticity regime,
, in which the satellite volume and the associated mass of surfactant obey the scaling law
reach a plateau of about
being in close agreement with previous experiments of low-viscosity threads with clean interfaces. For
, we reveal the existence of a discontinuous transition in
at a critical elasticity,
, such that
abruptly increase at
. The jumps experienced by both quantities reach a plateau when
, while they decrease monotonically as
increases up to
, where both become zero.
Glioblastoma (GBM) is one of the most aggressive types of cancer which currently does not have a cure. Its invasive nature and heterogeneity makes its complete surgical removal impossible. Hence, a targeted treatment is critically needed to effectively eradicate this cancer. In this work, the authors report the synthesis of hollow TiO2 nanospheres (HTiO2NS) and their functionalization with folic acid (FA) and zinc (II) tetranitrophthalocyanine (ZnPc) to achieve cell selectivity and light absorption in the visible range. In vitro cytotoxicity of the functionalized HTiO2NS against M059K cell line (Human GBM cancer cells) was tested. In vitro generation of reactive oxygen species by HTiO2NS–FA–ZnPc nanostructures under UV irradiation was detected by fluorescence probing. To identify HTiO2NS–FA–ZnPc cell localization, the nanoparticles were labeled with fluorescein isothiocyanate dye and visualized by fluorescence microscopy. Results illustrate that HTiO2NS–FA–ZnPc nanostructures have the potential to be used for targeted photodynamic therapy for the treatment of GBM cancer.
Parasites inflict many costs on their hosts. Understanding host–parasite relationship eco-evolutionary dynamics needs appreciation of how parasites affect individual fitness, survival and reproductive potential, and how they combine to influence population demography, dynamics and viability; also, how these processes drive microevolutionary processes that define natural and sexual selection. We synthesise work on the relationship between the red grouse and its main parasite, a gastrointestinal nematode. At individual level, we show how parasites impose a physiological cost, measured by immunosuppression and increased oxidative stress, and how their impact varies depending on contexts. We describe how parasite infection constrains expression of sexually selected traits and summarise how relationships between parasite, host and environment shape host population demography and dynamics. Genetic analyses in red grouse suggest nematode burden is moderately heritable, underpinned by a potentially large array of genes involved in the immune system, energy balance and broader homeostatic processes. There is no clear association between allele frequencies among populations and differences in nematode burdens. Possibly, beneficial alleles for parasite resistance cannot spread through the population due to the strong diversifying e?ects of gene ?ow and genetic drift.
In Respiratory Syncytial Virus infection, the early identification of infants at risk for severe disease in order to potentially decrease morbidity could be considered a major goal. Current guidelines recommend only clinical observation for this purpose in infants without known comorbidities. However, recent evidence shows that the presence of pulmonary hypertension in this population is a relevant risk factor for the development of a severe illness, even in healthy infants. The determination of plasmatic NT-proBNP levels could help to identify those cases that benefit of echocardiographic screening to detect pulmonary hypertension in this population during hospitalization.
Based on stratigraphic excavation data and associated radiocarbon dates we argue that the pre-Hispanic city of Cerro Jazmín, in the Mixteca Alta region of Oaxaca, underwent a period of political change between the Late Formative (300 b.c.–a.d. 50) and the Terminal Formative periods (a.d. 50–300). This shift is reflected in the city's layout and in the timing of construction and use of two different monumental sectors. During the city's Late Formative occupation, we found evidence of more exclusionary feasting activity taking place in a secluded monumental sector called the Sunken Courtyards near the hilltop. In the Terminal Formative, however, monumental construction expanded in the more accessible Tres Cerritos sector where larger and accessible public areas were the focus of activity. We argue that changes in the city's layout, along with the differing patterns of feasting, suggest that the city's leaders went from a more exclusionary form of government to a more collective political strategy during the Terminal Formative period. Despite of these efforts monumental construction largely stopped and the city's population declined by the start of the Classic period (a.d. 300).
Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.
Here we report the results of an experimental study where we measure the hydrodynamic force acting on a plate which is lifted from a water surface, suddenly starting to move upwards with an acceleration much larger than gravity. Our work focuses on the early stage of the plate motion, when the hydrodynamic suction forces due to the liquid inertia are the most relevant ones. Besides the force, we measure as well the acceleration at the centre of the plate and the time evolution of the wetted area. The results of this study show that, at very early stages, the hydrodynamic force can be estimated by a simple extension of the linear exit theory by Korobkin (J. Fluid Mech., vol. 737, 2013, pp. 368–386), which incorporates an added mass to the body dynamics. However, at longer times, the measured acceleration decays even though the applied external force continues to increase. Moreover, high-speed recordings of the disc displacement and the radius of the wetted area reveal that the latter does not change before the disc acceleration reaches its maximum value. We show in this paper that these phenomena are caused by the elastic deflection of the disc during the initial transient stage of water exit. We present a linearised model of water exit that accounts for the elastic behaviour of the lifted body. The results obtained with this new model agree fairly well with the experimental results.
This study examined (1) the association of dietary energy density from solid (EDS) and solid plus liquids (EDSL) with adiposity and cardiometabolic risk factors (CRF) in children with overweight and obesity, (2) the effect of under-reporting on the mentioned associations and (3) whether the association between ED and body composition and CRF is influenced by levels of physical activity. In a cross-sectional design, 208 overweight and obese children (8–12-year-old; 111 boys) completed two non-consecutive 24 h recalls. ED was calculated using two different approaches: EDS and EDSL. Under-reporters were determined with the Goldberg method. Body composition, anthropometry and fasting blood sample measurements were performed. Moderate to vigorous physical activity (MVPA) was registered with accelerometers (7-d-register). Linear regressions were performed to evaluate the association of ED with the previously mentioned variables. Neither EDS nor EDSL were associated with body composition or CRF. However, when under-reporters were excluded, EDS was positively associated with BMI (P=0·019), body fat percentage (P=0·005), abdominal fat (P=0·008) and fat mass index (P=0·018), while EDSL was positively associated with body fat percentage (P=0·008) and fat mass index (P=0·026). When stratifying the group according to physical activity recommendations, the aforementioned associations were only maintained for non-compliers. Cluster analysis showed that the low-ED and high-MVPA group presented the healthiest profile for all adiposity and CRF. These findings could partly explain inconsistencies in literature, as we found that different ED calculations entail distinct results. Physical activity levels and excluding under-reporters greatly influence the associations between ED and adiposity in children with overweight and obesity.
OBJECTIVES/SPECIFIC AIMS: Our overall objectives are to determine (i) whether natural disaster-related prenatal maternal stress (PNMS) alters infants’ effortful control (EC) at two years of age, and (ii) if the timing of exposure moderates its effects on toddlers EC. METHODS/STUDY POPULATION: We propose a longitudinal study with 50 mother-toddler dyads. Natural disaster-related PNMS would be measured at 12-15 and 18-24 months of age and will include: objective exposure and maternal distress. EC will be measured with a questionnaire and a Laboratory Temperament Assessment Battery at two years of age. RESULTS/ANTICIPATED RESULTS: We anticipate that children exposed to Hurricane-related PNMS would present low EC levels compared to those with low prenatal exposure. DISCUSSION/SIGNIFICANCE OF IMPACT: These results are expected to provide evidence for further promoting early intervention and ameliorating negative effects of PNMS on child outcomes.