Search

ABSTRACTScientific advances and technological requirements to develop carbon fibre-reinforced polymers (CFRP) with excellent strength-to-weight ratios led to the high consumption of CFRP composites. The mechanical recycling of CFRP is a simpler, more economical, and environmentally responsible solution for effectively recovering this structural material that contains epoxy resin and carbon fibre. CFRP laminates were placed on a Computer Numerical Control (CNC) and milling cutting at 1100, 1800, and 2500 rpm. The recovered CFRP particles were mixed with acrylonitrile butadiene styrene (ABS) using the melt intercalation approach. Recovered CFRP particles increased the molecular mobility and reduced the thermal stability of ABS. The main differences between the ABS and the composites were a more pronounced necking region in the ABS than in the composites and a notable reduction in strain. The strain of the ABS was 27.58%, while in the composites, it was 4.29, 4.02, and 3.51%, depending on the cutting speed. Thus, ductility decreased up to 87% in the composites. This work’s successful CFRP mechanical recycling method provides epoxy powder, individual carbon fibres, and CFRP particles, opening a research field of great economic and environmental relevance in developing new materials.

Six 1,8-diazabicyclo(5.4.0)undec-7-ene-based ionic liquids (ILs) linked with ethyl or propyl hydroxyl cations, coupled with thiocyanate, dicyanamide and bistriflimide anions, were synthesized through a two-step reaction: quaternization and ion exchange. The characterization of the ILs was carried out using 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and Fourier-transform infrared spectroscopy (FTIR). The NMR results confirmed the structures of all the ILs, and these were supported by the FTIR results. In addition, the physicochemical properties, namely thermal stability, density and refractive index, were determined. The effects of the chain length in the cation and the identity of the anion on CO2 absorption were studied in a pressure drop equipment at different pressures. It was found that CO2 sorption increased with increasing pressure and the number of nitrile groups present. The highest CO2 sorption is reported to be 0.96 mol CO2 mol−1 IL at 20 bar.

La conservación de la vegetación en ambientes urbanos, especialmente de los pastizales, es una problemática poco abordada, pero de gran relevancia ecológica y social. En este artículo proponemos un debate abierto sobre la importancia de los pastizales urbanos y periurbanos, los desafíos para conservar su biodiversidad y las implicancias socioecológicas asociadas. Para ello, nos basamos en relevamientos de diversidad vegetal en cinco pastizales urbanos de la Región Metropolitana de Buenos Aires (RMBA), donde organizaciones socioambientales comprometidas participan en su conservación. Primero, exploramos las problemáticas de los pastizales, la definición de pastizal urbano y sus distintas acepciones en la literatura, así como la percepción y la valoración de la sociedad de estos espacios. Sintetizamos los beneficios que los pastizales urbanos aportan a la sociedad, incluyendo la conservación de la biodiversidad, la recreación y la educación ambiental. Luego, describimos las características específicas de cinco áreas de pastizales en la RMBA destinadas a conservación. En estas áreas, a pesar de la fragmentación de la matriz urbana y la presencia de especies exóticas invasoras, persiste una proporción significativa de especies nativas representativas del pastizal pampeano, valiosas para la conservación de la biodiversidad urbana. Esto evidencia la importancia ecológica de los pastizales urbanos y la necesidad de generar estrategias efectivas para conservar y restaurar sus fragmentos. Finalmente, analizamos las ventajas y oportunidades que estos fragmentos representan para la región. Proponemos soluciones a las problemáticas identificadas, como implementar prácticas de manejo adecuadas para reducir la invasión de especies exóticas y promover la restauración de los pastizales.

This research developed a bio-based polymer composite using polylactic acid (PLA) and agro-industrial residues from coffee by-products (without chemical modification and the use of coupling agents or stabilizers). Agro-industrial residues, such as spent coffee ground (SCG) and coffee silver skin (CSS) as filler, were added into the PLA matrix in different percentages by weight, from 0.5 to 10 wt%. The bio-composites were prepared using solvent-cast films and were characterized by various techniques, including FT-IR, TGA, DSC, XRD, SEM and mechanical tests. Bio-composites' formation was verified using FT-IR and SEM; the material showed good interfacial interaction, with percentages between 3 and 5 wt%. XRD and DSC determined the percentage crystallinity in the bio-composites. SEM found that the bio-composites form crystals, showing their limits after mechanical testing. The bio-composites exhibited enhanced thermal and mechanical properties compared to neat PLA.These bio-based composites show great potential for a wide range of applications in the food industry, including disposable and single-use materials, as well as food packaging. Moreover, their use can significantly contribute to the global demand for eco-friendly materials.

Summary: Single-cell microcultures (SCMs) form a monosynaptic circuit that allows stimulation and recording of postsynaptic responses using a single electrode. Here, we present a protocol to establish autaptic cultures from rat superior cervical ganglion neurons. We describe the steps for preparing SCMs, recording synaptic currents, and identifying and processing the recorded neurons for electron microscopy. We then detail procedures for visualizing synapses. This protocol is illustrated by correlating evoked and spontaneous neurotransmitter release with the ultrastructural features of synapses recorded.For complete details on the use and execution of this protocol, please refer to Velasco et al.1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

This mixed-method study made use of 87 curated students' artivism artworks. Data that were generated were analyzed both quantitatively and qualitatively. Artivism was used as one of the creative engagement activities in teaching art appreciation and contemporary issues. The outputs were graded. The perfect score was 20, the lowest score was 17. Descriptive statistical techniques were employed. The frequencies were used to determine the student’s critical ability. The correlation between students' social transformation engagement and art critical ability scores was determined using the Pearson Correlation Coefficient set at alpha .05. Results showed that students' critical ability was 'very high' as an entire group and when grouped according to sex. No significant differences were noted in the student's critical ability and artivism engagement. Analysis, interpretation, and judgment of student’s critical ability in artivism engagement are significantly related. The study contributes to the field of general education by expanding the existing knowledge base.

During the anaerobic digestion (AD) of food waste, the deliberate secession of substrate rapidly increases the microbial cell population, which can reach a maximum in 2–3 d. During short-term resting (STR), an increase in free NH3 due to an increase in pH is a key inhibitor of cell proliferation; therefore, cell growth would be further promoted if free NH3 was reduced. To explore adopting an STR technique to increase microbial cells in the AD of organic waste, we attempted to reduce free NH3 by controlling the pH in the reactors. Two semi-continuously treated reactors were fed with food waste at a loading rate of 3.0 g-VS/L/d for 40 days and then the feeding was stopped in both reactors until day 47. One of the reactors was maintained at pH 7.37 ± 0.03, whereas pH was not controlled in the other. During STR, the cell density in the pH-controlled condition reached a maximum of 7.48 × 1010 cells/mL, which was twice as high as that before STR, and 1.7-times higher than that in the non-pH-controlled condition. These results demonstrated that mitigating NH3 using pH can affect cell proliferation during STR. [ABSTRACT FROM AUTHOR]

Copyright of Ecologia Austral is the property of Asociacion Argentina de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Scientific advances and technological requirements to develop carbon fibre-reinforced polymers (CFRP) with excellent strength-to-weight ratios led to the high consumption of CFRP composites. The mechanical recycling of CFRP is a simpler, more economical, and environmentally responsible solution for effectively recovering this structural material that contains epoxy resin and carbon fibre. CFRP laminates were placed on a Computer Numerical Control (CNC) and milling cutting at 1100, 1800, and 2500 rpm. The recovered CFRP particles were mixed with acrylonitrile butadiene styrene (ABS) using the melt intercalation approach. Recovered CFRP particles increased the molecular mobility and reduced the thermal stability of ABS. The main differences between the ABS and the composites were a more pronounced necking region in the ABS than in the composites and a notable reduction in strain. The strain of the ABS was 27.58%, while in the composites, it was 4.29, 4.02, and 3.51%, depending on the cutting speed. Thus, ductility decreased up to 87% in the composites. This work's successful CFRP mechanical recycling method provides epoxy powder, individual carbon fibres, and CFRP particles, opening a research field of great economic and environmental relevance in developing new materials. [ABSTRACT FROM AUTHOR]

In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior.

Key Points 1. We improve the new beacon receiver to receive six RF channels successfully. 2. The first beacon observation data for FORMOSAT-7/COSMIC-2 at Taiwan. 3. The project method could be used to estimate the height of scintillation event.

We assessed the potential of dead seagrass Posidonia oceanica matte to act as a biogeochemical sink and provide a coherent archive of environmental change in a degraded area of the Mediterranean Sea (Augusta Bay, Italy). Change in sediment properties (dry bulk density, grain size), concentration of elements (Corg, Cinorg, N, Hg) and stable isotope ratios (δ13C, δ 15N) with sediment depth were measured in dead P. oceanica matte and unvegetated (bare) sediments in the polluted area, and an adjacent P. oceanica meadow. Principal Component Analysis (PCA) revealed a clear clustering by habitat, which explained 72% of variability in our samples and was driven mainly by the accumulation of N and Hg in finer sediments of the dead matte. Assessment of the temporal trends of Corg, N and Hg concentrations in the dead matte revealed changes in the accumulation of these elements over the last 120 years, with an increase following the onset of industrial activities 65 y BP (i.e., yr. 1950) that was sustained even after seagrass loss around 35 y BP. Despite a decrease in Hg concentrations in the early 1980s following the onset of pollution abatement, overall Hg levels were 2-fold higher in the local post-industrial period, with a Hg enrichment factor of 3.5 in the dead matte. Mean stocks of Corg, N and Hg in 25 cm thick sediment deposits (4.08 ± 2.10 kg Corg m-2, 0.14 ± 0.04 kg N m-2, 0.19 ± 0.04 g Hg m-2) and accumulation in the last 120 yr (35.3 ± 19.6 g Corg m-2 y-1, 1.2 ± 0.4 g N m-2 y-1, 0.0017 ± 0.0004 g Hg m-2 y-1) were higher in the dead matte than bare sediment or adjacent P. oceanica meadow. Our results indicate that dead P. oceanica matte maintained its potential as a biogeochemical sink and, like its living counterpart, dead matte can serve as an effective archive to allow for reconstructing environmental change in coastal areas of the Mediterranean where severe perturbations have led to P. oceanica loss. Appropriate management for contaminated areas should be prioritized to prevent release of pollutants and carbon from dead mattes.

The real-time chlorophyll-a pigment monitoring of C. reinhardtii is studied using our developed LED fluorescence light detection and ranging (LiDAR) system. It features a portable set-up that uses a pulsed LED module with an excitation wavelength of 385 nm. We were able to monitor the different growth phases of C. reinhardtii with specific cultivation parameters. The developed fluorescence LiDAR system showed the linear correlation of its chlorophyll-a signal with the optical density and EEM fluorescence measurements at 680 nm emission wavelength. Water quality and weather parameters were also measured, which explains the variation in the growth dynamics of C. reinhardtii during the sampling period. The results from the monitoring demonstrated a different technique that can be used in estimating algal biomass in the environment.

Arf-like protein 2 (ARL2) is a ubiquitously expressed small GTPase with multiple functions. In a cell culture, ARL2 participates with tubulin cofactor D (TBCD) in the neogenesis of tubulin αβ-heterodimers, the building blocks of microtubules. To evaluate this function in the retina, we conditionally deleted ARL2 in mouse retina at two distinct stages, either during the embryonic development (retArl2−/−) or after ciliogenesis specifically in rods (rodArl2−/−). retArl2−/− retina sections displayed distorted nuclear layers and a disrupted microtubule cytoskeleton (MTC) as early as postnatal day 6 (P6). Rod and cone outer segments (OS) did not form. By contrast, the rod ARL2 knockouts were stable at postnatal day 35 and revealed normal ERG responses. Cytoplasmic dynein is reduced in retArl2−/− inner segments (IS), suggesting that dynein may be unstable in the absence of a normal MTC. We investigated the microtubular stability in the absence of either ARL2 (retARL2−/−) or DYNC1H1 (retDync1h1−/−), the dynein heavy chain, and found that both the retArl2−/− and retDync1h1−/− retinas exhibited reduced microtubules and nuclear layer distortion. The results suggest that ARL2 and dynein depend on each other to generate a functional MTC during the early photoreceptor development.

Context: The prevalence of alopecia around the world is high and awareness continuously increased due to social stigma. There are limited commercially-available medications for the management of different forms of baldness, most of which are prohibitively expensive and presents with various adverse effects. Aims: To evaluate the flavonoid-rich ethyl acetate extract of Equisetum hyemale stem for its hair-regenerative properties in chemically-induced alopecia in Sprague Dawley rats. Methods: Various concentrations of the flavonoid-rich extract of E. hyemale were applied in depilated areas in dorsal rat skin after chemical induction of alopecia. Evidence of hair growth was observed for 28 days in a weekly basis. Histopathological analysis of rat skin was performed to demonstrate evidence of follicular hair growth. Results: The abundance of flavonoids in the ethyl acetate extract was established by total flavonoid contents and LC-MS analyses. The 2.5% E. hyemale extract exhibited hair-regenerative properties with high tensile strengths, combined masses and follicular growth, which was comparable to the positive control, 5% minoxidil (p>0.05). The highest rate of hair follicular development was observed in the telogen phase in rat skin after 28 days of treatment. Conclusions: The flavonoid-rich ethyl acetate extract of E. hyemale exhibits in situ hair-regenerative properties in chemically-induced alopecia in rats at 2.5% w/v concentration.

Cytoplasmic dynein (dynein 1), a major retrograde motor of eukaryotic cells, is a 1.4 MDa protein complex consisting of a pair of heavy chains (DYNC1H1) and a set of heterodimeric noncatalytic accessory components termed intermediate, light intermediate and light chains. DYNC1H1 (4644 amino acids) is the dynein backbone encoded by a gene consisting of 77 exons. We generated a floxed Dync1h1 allele that excises exons 24 and 25 and truncates DYNC1H1 during Six3Cre-induced homologous recombination. Truncation results in loss of the motor and microtubule-binding domain. Dync1h1F/F;Six3Cre photoreceptors degenerated rapidly within two postnatal weeks. In the postnatal day 6 (P6) Dync1h1F/F;Six3Cre central retina, outer and inner nuclear layers were severely disorganized and lacked a recognizable outer plexiform layer (OPL). Although the gene was effectively silenced by P6, DYNC1H1 remnants persisted and aggregated together with rhodopsin, PDE6 and centrin-2-positive centrosomes in the outer nuclear layer. As photoreceptor degeneration is delayed in the Dync1h1F/F;Six3Cre retina periphery, retinal lamination and outer segment elongation are in part preserved. DYNC1H1 strongly persisted in the inner plexiform layer (IPL) beyond P16 suggesting lack of clearance of the DYNC1H1 polypeptide. This persistence of DYNC1H1 allows horizontal, rod bipolar, amacrine and ganglion cells to survive past P12. The results show that cytoplasmic dynein is essential for retina lamination, nuclear positioning, vesicular trafficking of photoreceptor membrane proteins and inner/outer segment elaboration.

Abstract Cones are responsible for daylight, central, high acuity and color vision. Three proteins found in human cones, i.e. long-wavelength (L)-, middle-wavelength (M)-, and short-wavelength sensitive (S)-opsins, are responsible for red, green and blue color recognition, respectively. Human blue cone monochromacy (BCM) is characterized by functional loss of both L- and M-cone opsins due to mutations in the OPN1LW/OPN1MW gene cluster on the X chromosome. BCM patients, who rely on their vision from only S-cones and rods, suffer severely reduced visual acuity and impaired color vision. Recent studies show that there is sufficient cone structure remaining in the central fovea of BCM patients to consider AAV-mediated gene augmentation therapy. In contrast, mouse retina has only two opsins, S-opsin and M-opsin, but no L-opsin. We generated an M-opsin knockout mouse (Opn1mw −/−) expressing only S-opsin as a model for human BCM. We show that recombinant M-opsin delivered by AAV5 vectors rescues M-cone function in Opn1mw −/− mice. We also show that AAV delivered M-opsin localizes in the dorsal cone outer segments, and co-localizes with S-opsin in the ventral retina. Our study demonstrates that cones without M-opsin remain viable and respond to gene augmentation therapy, thereby providing proof-of-concept for cone function restoration in BCM patients.

In this study, semi-continuous anaerobic digestion of lignin-rich steam-exploded Ludwigia grandiflora (Lignin = 25.22% ± 4.6% total solids) was performed to understand better the effect of steam explosion on the substrate solubilisation and inhibitors formation during the process. Steam explosion pretreatment was performed at 180 °C for 30 min at a severity factor of 3.8 to enhance the biogas yield of the lignocellulosic biomass. The semi-continuous anaerobic digestion was performed in a continuously stirred tank reactor for 98 days at an initial hydraulic retention time of 30 days and an organic loading rate of 0.9 g-VS L−1 day−1. The performed steam explosion pretreatment caused biomass solubilisation, resulting in enhanced biogas production during the process. During the anaerobic digestion process, the average biogas yield was 265 mL g-VS−1, and the pH throughout the operation was in the optimum range of 6.5–8.2. Due to fluctuations in the biogas yield, the hydraulic retention time and organic loading rate were changed on day 42 (50 days and 0.5 g-VS L−1 day−1) and on day 49 (40 days and 0.7 g-VS L−1 day−1), and 1 M of NaOH was added to the liquid fraction of the steam-exploded L. grandiflora during the latter part of the operation to maintain the stability in the reactor. Therefore, the steam explosion pretreatment helped in the degradation of L. grandiflora by breaking the lignocellulose structure. In addition, changes in the operating conditions of the anaerobic digestion led to an increase in the biogas production towards the end of the process, leading to the stability in the CSTR.

In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior. [ABSTRACT FROM AUTHOR]