Nanocomposites based on isotactic polypropylene (iPP) and different content of Al nanoparticles have been prepared in order to gain knowledge of their electromagnetic interference (EMI) shielding ...capability. This potential has been analyzed from attenuation upon reflection measurements at microwave frequency range. Moreover, shielding characteristics have been checked by Attenuated Total Reflectance (ATR) and correlated to the ones achieved by X-ray diffraction with synchrotron radiation. Very promising results have been obtained, with an excellent balance between shielding efficiency and sample weight. Hence, these materials are potentially good alternatives to replace metals for this application, avoiding electromagnetic environmental pollution. The effect of incorporation of Al nanoparticles on the iPP processing properties has been additionally evaluated by a rheological study at a very broad frequency range.
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•Nanocomposites of polypropylene and Al nanoparticles are an alternative for avoiding electromagnetic environmental pollution.•High contents in Al nanoparticles hinder polypropylene processability.•EMI capability is analyzed at microwave frequency range from attenuation upon reflection measurements.•These shielding results correlate well with those achieved by Attenuated Total Reflectance.
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•A novel methodology for designing carbon-based X-band microwave absorbers.•Modulating absorption properties via dielectric permittivity and sample thickness.•Effects of particle ...size, volume fraction and dielectric matrix materials.•Exploration of mono- and bi-slab geometries for microwave absorber design.•Waveguide as a test-laboratory and experimental free-space measurements validation.
This work introduces a methodology for the design of X-band microwave absorbers using carbon-graphite powder composites. The reflection loss (RL) is adjusted through variations in sample thickness, mono/bi-slab geometries, and effective dielectric constant. The impact of the particle size of the powders and the volume fraction (v.f.) of the composites on the effective dielectric permittivity has been systematically investigated. The Nicolson-Ross-Weir (NRW) conversion and the Birchak dielectric mixing model were employed. Optimal absorption conditions predicted by RL simulations were validated through experimental waveguide measurements for mono/bi-slab systems of paraffin-carbon composite samples. The mono-slabs with a particle size of 3.5 μm showed the best versatility for tailoring the RL in the X-band through v.f. variations while maintaining a fixed thickness of 2 mm. In addition, a bi-slab system (powder-paraffin/paraffin) for such powder size, at 18.0 % of v.f., showed an enhanced RL with a bandwidth of 2.6 GHz and a minimum of − 40 dB (at 11 GHz). Other dielectrics based on resin:paint mixtures were tested to replace the paraffin-matrix, revealing a strong powder-matrix interaction capable of modulating the effective dielectric permittivity. Finally, experimental antenna RL measurements conducted in free space were corroborated by theoretical simulations based on the waveguide characterizations.
Endometriosis is a chronic inflammatory disorder characterized by the abnormal growth of endometrial-like tissue outside the uterine cavity, affecting 10–15% of women of reproductive age. Pain is the ...most common symptom. Treatment options include surgery, which has limited effectiveness and high recurrence rates, and pharmacotherapy. Hormonal therapies, commonly used for symptom management, can have side effects and contraceptive outcomes, contributing to the infertility associated with endometriosis, with pain and lesions often reappearing after treatment cessation. Among its etiological factors, immunological and inflammatory dysregulation plays a significant role, representing an interesting target for developing new therapeutic strategies. This review critically analyzes recent studies to provide an updated synthesis of ongoing research into potential new pharmacotherapies focusing on lesion progression, pain relief, and improving quality of life. Immunotherapy, natural anti-inflammatory and antioxidant compounds and drug repurposing show promise in addressing the limitations of current treatments by targeting immunological factors, potentially offering non-invasive solutions for managing pain and infertility in endometriosis. Promising results have been obtained from in vitro and animal model studies, but clinical trials are still limited. More effort is needed to translate these findings into clinical practice to effectively reduce disease progression, alleviate pain symptoms and preserve the reproductive capacity, improving patients’ overall wellbeing.
For in vitro culture of plant and animal cells, one of the critical steps is to adjust the initial cell density. A typical example of this is isolated microspore culture, where specific cell ...densities have been determined for different species. Out of these ranges, microspore growth is not induced, or is severely reduced. A similar situation occurs in many other plant and animal cell culture systems. Traditionally, researchers have used counting chambers (hemacytometers) to calculate cell densities, but little is still known about their technical advantages. In addition, much less information is available about other, alternative methods. In this work, using isolated eggplant microspore cultures and fluorescent beads (fluorospheres) as experimental systems, we performed a comprehensive comparison of six methods to calculate cell densities: (1) a Neubauer improved hemacytometer, (2) an automated cell counter, (3) a manual-counting method, and three flow cytometry methods based on (4) autofluorescence, (5) propidium iodide staining, and (6) side scattered light (SSC).
Our results show that from a technical perspective, hemacytometers are the most reasonable option for cell counting, which may explain their widely spread use. Automated cell counters represent a good compromise between precision and affordability, although with limited accuracy. Finally, the methods based on flow cytometry were, by far, the best in terms of reproducibility and agreement between them, but they showed deficient accuracy and precision.
Together, our results show a thorough technical evaluation of each counting method, provide unambiguous arguments to decide which one is the most convenient for the particular case of each laboratory, and in general, shed light into the best way to determine cell densities for in vitro cell cultures. They may have an impact in such a practice not only in the context of microspore culture, but also in any other plant cell culture procedure, or in any process involving particle counting.
Ethanol affects not only the cytoskeletal organization and activity, but also intracellular trafficking in neurons in the primary culture. Polyphosphoinositide (PPIn) are essential regulators of many ...important cell functions, including those mentioned, cytoskeleton integrity and intracellular vesicle trafficking. Since information about the effect of chronic ethanol exposure on PPIn metabolism in neurons is scarce, this study analysed the effect of this treatment on three of these phospholipids.
Phosphatidylinositol (PtdIns) levels as well as the activity and/or levels of enzymes involved in their metabolism were analysed in neurons chronically exposed to ethanol. The levels of phospholipases C and D, and phosphatidylethanol formation were also assessed. The consequence of the possible alterations in the levels of PtdIns on the Golgi complex (GC) was also analysed.
We show that phosphatidylinositol (4,5)-bisphosphate and phosphatidylinositol (3,4,5)-trisphosphate levels, both involved in the control of intracellular trafficking and cytoskeleton organization, decrease in ethanol-exposed hippocampal neurons. In contrast, several kinases that participate in the metabolism of these phospholipids, and the level and/or activity of phospholipases C and D, increase in cells after ethanol exposure. Ethanol also promotes phosphatidylethanol formation in neurons, which can result in the suppression of phosphatidic acid synthesis and, therefore, in PPIn biosynthesis. This treatment also lowers the phosphatidylinositol 4-phosphate levels, the main PPIn in the GC, with alterations in their morphology and in the levels of some of the proteins involved in structure maintenance.
The deregulation of the metabolism of PtdIns may underlie the ethanol-induced alterations on different neuronal processes, including intracellular trafficking and cytoskeletal integrity.
Este estudio se basa en identificar la incorporación de elementos de juego en aplicaciones móviles del sector financiero español, específicamente se recoge una muestra de 38 aplicaciones ...pertenecientes a la banca móvil, que provienen de las tiendas AppStore del sistema operativo iOS y Google Play del sistema operativo Android excluyendo todas aquellas que no pertenecen a una entidad bancaria como es el caso de PayPal, FinTonic, Mapfre, Plus500, Trading 212 Forex & Stocks, Carrefour Pass Móvil, y se le aplica la taxonomía de elementos lúdicos proveniente de Raftopoulos, Walz y Greuter (2015) organizado en propósito, audiencia, estrategia tecnológica, experiencia lúdica y mecánicas de juego. Los resultados demuestran que los propósitos de tales aplicaciones es fomentar la fidelidad del cliente, presentando soluciones operativas y sincronizaciones de carteras. Por su parte, la audiencia se orienta a un perfil de edad ubicado entre 26 y 35 años, mientras que la estrategia tecnológica responde primordialmente a la adopción de sistemas de seguridad y privacidad. En complemento, la experiencia lúdica va paulatinamente adoptándose por la comunicación móvil de las entidades bancarias, especialmente en cuanto a socialización, configuración personalizada del panel central. Por último, las mecánicas más utilizadas son la recolección de recompensas y aplicación de mecánicas de progresión.
A combination of high-energy ball milling, vacuum filtering, and sedimentation processes has been demonstrated to be a useful approach to reduce, in a controlled way, the length of as-cast ...Fe73.5Si13.5Nb3Cu1B9 amorphous magnetic microwires (MWs) and annealed material at 550 °C in nitrogen conditions. Homogeneous compositional microstructures with fairly narrow size distributions between 1300 and 11.7 μm are achieved, exhibiting tunable response as a soft magnetic material and as a microwave absorber. From the magnetic perspective, the soft magnetic character is increased with smaller length of the MWs, whereas the remanence has the opposite behavior mainly due to the structural defects and the loss of the shape anisotropy. From the microwave absorption perspective, a novel potential applicability is tested in these refined microstructures. This innovation consists of coatings based on commercial paints with a filling percentage of 0.55% of MWs with different lengths deposited on metallic sheets. Large attenuation values around −40 dB are obtained in narrow spectral windows located in the GHz range, and their position can be varied by combining different optimized lengths of MW. As an example of this powerful mechanism for absorbing microwaves at specific frequencies, MW lengths of 2 mm and 50 μm are chosen, where precise tailoring of the minimum reflection loss (R L) is obtained in a range between 8.85 and 13.25 GHz. To confirm these experimental results, an effective medium standard model proposed for electrical permittivity is used. Experimental and theoretical results are consistent and these novel composites are also proposed as a feasible candidate for designing frequency-selective microwave absorbers on demand, with low filling percentages and high absorption intensity values.
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•The density of defects on CVD graphene affects its sensing performance.•Ultraviolet irradiation promotes full recovery and improved reproducibility.•Ultraviolet irradiation allows ...extremely low limits of nitrogen dioxide detection.•Tuning ultraviolet irradiation parameters change the sensing dynamics.•Ultraviolet irradiation effect was confirmed for nitrogen dioxide, ammonia and carbon monoxide.
Nitrogen dioxide (NO2) is a potential hazard to human health at low concentrations, below one part per million (ppm). NO2 can be monitored using gas sensors based on multi-layered graphene operating at ambient temperature. However, reliable detection of concentrations on the order of parts per million and lower is hindered by partial recovery and lack of reproducibility of the sensors after exposure. We show how to overcome these longstanding problems using ultraviolet (UV) light. When exposed to NO2, the sensor response is enhanced by 290 % − 550 % under a 275 nm wavelength light emitting diode irradiation. Furthermore, the sensor's initial state is completely restored after exposure to the target gas. UV irradiation at 68 W/m2 reduces the NO2 detection limit to 30 parts per billion (ppb) at room temperature. We investigated sensor performance optimization for UV irradiation with different power densities and target gases, such as carbon oxide and ammonia. Improved sensitivity, recovery, and reproducibility of UV-assisted graphene-based gas sensors make them suitable for widespread environmental applications.
Dendritic spines are specialised membrane protrusions of neuronal dendrites that receive the majority of excitatory synaptic inputs. Abnormal changes in their density, size and morphology have been ...associated with various neurological and psychiatric disorders, including those deriving from drug addiction. Dendritic spine formation, morphology and synaptic functions are governed by the actin cytoskeleton. Previous in vivo studies have shown that ethanol alters the number and morphology of spines, although the mechanisms underlying these alterations remain unknown. It has also been described how chronic ethanol exposure affects the levels, assembly and cellular organisation of the actin cytoskeleton in hippocampal neurons in primary culture. Therefore, we hypothesised that the ethanol-induced alterations in the number and shape of dendritic spines are due to alterations in the mechanisms regulating actin cytoskeleton integrity. The results presented herein show that chronic exposure to moderate levels of alcohol (30 mM) during the first 2 weeks of culture reduces dendritic spine density and alters the proportion of the different morphologies of these structures in hippocampal neurons, which affects the formation of mature spines. Apparently, these effects are associated with an increase in the G-actin/F-actin ratio due to a reduction of the F-actin fraction, leading to changes in the levels of the different factors regulating the organisation of this cytoskeletal component. The data presented herein indicate that these effects occur between weeks 1 and 2 of culture, an important period in dendritic spines development. These changes may be related to the dysfunction in the memory and learning processes present in children prenatally exposed to ethanol.
Co-based amorphous microwires presenting the giant magnetoimpedance effect are proposed as sensing elements for high sensitivity biosensors. In this work we report an experimental method for ...contactless detection of stress, temperature, and liquid concentration with application in medical sensors using the giant magnetoimpedance effect on microwires in the GHz range. The method is based on the scattering of electromagnetic microwaves by FeCoSiB amorphous metallic microwires. A modulation of the scattering parameter is achieved by applying a magnetic bias field that tunes the magnetic permeability of the ferromagnetic microwires. We demonstrate that the OFF/ON switching of the bias activates or cancels the amorphous ferromagnetic microwires (AFMW) antenna behavior. We show the advantages of measuring the performing time dependent frequency sweeps. In this case, the AC-bias modulation of the scattering coefficient versus frequency may be clearly appreciated. Furthermore, this modulation is enhanced by using arrays of microwires with an increasing number of individual microwires according to the antenna radiation theory. Transmission spectra show significant changes in the range of 3 dB for a relatively weak magnetic field of 15 Oe. A demonstration of the possibilities of the method for biomedical applications is shown by means of wireless temperature detector from 0 to 100 °C.
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