Self-assembled hydrogel nanoparticles for drug delivery applications

Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use of self-assembled polymeric nanogels for drug delivery applications, including small molecular weight drugs, proteins, peptides, oligosaccharides, vaccines and nucleic acids. The materials and techniques used in the development of self-assembling nanogels are also described

Mini-review and discussion of a potential standardization

Gonçalves, G., Andriolo, U., Gonçalves, L. M. S., Sobral, P., & Bessa, F. (2022). Beach litter survey by drones: Mini-review and discussion of a potential standardization. Environmental Pollution, 315(15 December), 1-8. [120370]. https://doi.org/10.1016/j.envpol.2022.120370The abundance of beach litter has been increasing globally during the last decades, and it is an issue of global concern. A new survey strategy, based on uncrewed aerial vehicles (UAV, aka drones), has been recently adopted to improve the monitoring of beach macro-litter items abundance and distribution. This work identified and analysed the 15 studies that used drone for beach litter surveys on an operational basis. The analysis of technical parameters for drone flight deployment revealed that flight altitude varied between 5 and 40 m. The analysis of final assessments showed that, through manual and/or automated items detection on images, most of studies provided litter bulk characteristics (type, material and size), along with litter distribution maps. The potential standardization of drone-based litter survey would allow a comparison among surveys, however it seems difficult to propose a standard set of flight parameters, given the wide variety of coastal environments, the different devices available, and the diverse objectives of drone-based litter surveys. On the other hand, in our view, a set of common outcomes can be proposed, based on the grid mapping process, which can be easily generated following the procedure indicated in the paper. This work sets the ground for the development of a standardized protocol for drone litter data collection, analysis and assessments. This would allow the provision of broad scale comparative studies to support coastal management at both national and international scales.publishersversionpublishe

Mineralization of olive mill wastewater over DSA

Bioenergy recovery from olive mill wastewater (OMW) has been effectively accomplished by anaerobic digestion [1]. Nevertheless, a post treatment is required to attain the discharge limit values. After the anaerobic treatment of OMW, the main issues are related to the remaining organic matter (COD), recalcitrant phenolic compounds (40-50%) and effluent dark-brown colour. The electrochemical treatment is proposed in this work as a final step to mineralise the OMW non-biodegradable fraction. The electrochemical oxidation of OMW anaerobically digested was investigated over DSAs. The performance of RuO2 and IrO2 based DSAs was studied by cyclic voltammetry and bulk electrolysis. The experiments were carried out with alkaline samples from the anaerobic reactor comprising 1 to 10 g COD/L, depending to the digester operational conditions. KNO3 was used as electrolyte, alternatively to the preferred NaCl [2], to avoid obtaining an effluent with higher toxicity than the initial one. It was found that RuO2 based anode was significantly more efficient than IrO2, mainly for the COD removal (Figure 1). With an electrolysis charge of Q=1517 C it was obtained COD removals of 9 and 52%, phenols removals of 72 and 98% and colour removal of 61 and 98%, for IrO2 and RuO2 type DSAs, respectively. The exclusion of the centrifugation/filtration step before the electrochemical treatment was considered, since the anaerobic treatment step reduces considerably the solids fraction. It is concluded that the electrochemical oxidation over DSAs is a suitable second step treatment for OMW disposal after the recovery of its energetic potential. The outcome energy from biogas production can balance or reduce the costs of the electrochemical treatment

Adsorption of fluorobenzene onto granular activated carbon: Isotherm and bioavailability studies

The adsorption of a recalcitran fluoroaromatic compound, fluorobenzene (FB), onto granular activated carbon (GAC) was evaluated. The respective isotherm was obtained and the Langmuir, Freundlich and Redlich–Peterson models were fitted to the experimental data, with the Redlich–Peterson model giving the best fitting. Freundlich model also provided a good fit but the Langmuir model could not adequately fit the experimental data, especially at high FB concentrations. Maximal adsorption capacity of FB onto GAC was foundto be 388 mg of FB per gram of GAC. The reversibility of the adsorption of FB onto GAC was investigated, both in the absence and presence of microorganisms. Abiotic desorption of FB occurred to a small extent (between 3% and 22%, for amounts of FB initially adsorbed to the GAC between 37 and 388 mg g 1), and bioregeneration of GAC was shown to occur when the matrix was exposed to a FB degrading culture, with 58–80% of the adsorbed FB being biodegraded. A residual amount of FB showed not to be bioavailable, suggesting that part of the adsorbed FB may be irreversibly bound. The fraction of the non-bioavailable FB increased at higher amounts of adsorbed FB, from 19% to 33%. The results indicate that the GAC employed in this study has a good capacity to adsorb FB and that bioregeneration of this matrix is a feasible process

Attack intensity of Corythucha ciliata (Hemiptera, Tingidae) on Platanus spp. in an urban area in Portugal: a comparison between pruned and unpruned trees.

Corythucha ciliata (Say, 1832), commonly known as sycamore lace bug (SLB), is an insect species native to North America. Since its accidental introduction in Europe (through Italy) in 1964, it has expanded across most European countries. The arrival of SLB in Portugal is uncertain but its distribution is wide. Sycamore (Platanus spp.), the only host of SLB, is one of the most widespread and important urban tree species in Portugal. It provides a wide range of environmental, social and economical benefits, which have been threatened by the invasion of this pest. SLB damages trees by feeding on the underside of the leaves causing discoloration and eventually premature senescence. While the long-term effect of SLB on the health of urban trees is yet to be fully assessed, there is compelling evidence that pruning further increases SLB damage. In this study we assessed the impact of pruning on the attack intensity of SLB. To test the hypothesis that pruning promotes the invasion of SLB, we compared the intensity of attack of pruned trees with unpruned trees. We collected sycamore leaves from pruned and unpruned trees and then assessed the intensity of attack by scaling damage by visual rating. Our findings show that pruned trees exhibit significantly higher attack intensities than unpruned trees (p < 0,001, χ2 goodness of fit). Based on these findings we recommend that sycamore pruning should be performed with caution (or even ceased), especially in urban areas where SLB is present

Enrichment of bacterial strains for the biodegradation of endocrine disrupting compounds from sediments of the Pearl River delta (PRD)

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Rheological and structural characterization of gels from whey protein hydrolysates/locust bean gum mixed systems

The gelling ability of whey proteins can be changed by limited hydrolysis and by the addition of other components such as polysaccharides. In this work the effect of the concentration of locust bean gum (LBG) on the heat-set gelation of aqueous whey protein hydrolysates (10% w/w) from pepsin and trypsin was assessed at pH 7.0. Whey protein concentrate (WPC) mild hydrolysis (up to 2.5% in the case of pepsin and 1.0% in the case of trypsin) ameliorates the gelling ability. The WPC synergism with LBG is affected by the protein hydrolysis. For a WPC concentration of 10% (w/w), no maximum value was found in the G′ dependence on LBG content in the case of the hydrolysates, unlike the intact WPC. However, for higher protein concentrations, the behaviour of gels from whey proteins or whey protein hydrolysates towards the presence of LBG becomes very similar. In this case, a small amount of LBG in the presence of salt leads to a big enhancement in the gel strength. Further increases in the LBG concentration led to a decrease in the gel strength

Did belowground N transfer in mixed plantations of Acacia mangium and Eucalyptus meet the Stress Gradient Hypothesis?

Belowground interactions in mixed forest plantations remain poorly understood as that of short-tenn nitrogen (N) transfer from N-fixing trees to non-N-fixing trees (Non-NFT) depending on nutrient availability. We investigated in this facilitation process met the Stress Gradient Hypothesis. which predicts that under stressful environmental conditions competition decreases and facilitation increases. A 15N pulse-labelling study was conducted in a five-year-old mixture of 50% Eucalyptus grandis x E. urophylla and 50% Acacia mangium with the hypothesis of higher transfer from acacia when no fertilization was applied. A complete randomized block design was set up with three replicates of fertilized and non-fertilized mixture. In each treatment of each block, a labeled solution of potassium nitrate (98 atom% 15N-N03) was injected into the stem of an Acacia tree with the same basal area as the average of the stand. The x (15N) was monitored over two months in each labeled acacia and four neighboring eucalypts. For both species, young leaves and tine roots were sampled at 7.14 and 30 days after injection. After 60 days. the x (15N) was determined in the wood, bark, branches, total foliage and fine roots of the 6 labeled acacias and 12 eucalypts trees The preliminary results showed that complete absorption of the labeled solution occurred between 28 and 60 days after labeling depending on Acacia trees and treatments. The dynamics in the proportion of Eucalyptus N derived from transfer will give insights into how this process may promote N nutrition of non-NFTs growing in unfertile tropical soils

Constructed wetlands as nature-based solutions for wastewater treatment in the hospitality industry: a review

The hospitality industry is increasing its awareness of how the integration of nature-based solutions can decrease its environmental impact while maintaining or increasing the service level of the sector. Constructed wetlands (CWs) constitute a promising sustainable solution for proper in situ domestic wastewater treatment. This literature review elucidates the status of CWs implementation in the hospitality industry to help foster the exchange of experiences in the field and deliver examples of approaches in different contexts to support future applications of this technology. Most of the studies reported in the literature were conducted in Europe, but studies emanating from Asia and South America are also available. The design of CWs, the horizontal and vertical subsurface flow CWs (HSFCW, VSFCW), and hybrid systems have been reported. The average removal efficiencies of the systems ranged from 83 to 95% for biochemical oxygen demand, 74 to 94% for chemical oxygen demand, 78 to 96% for total suspended solids, 75 to 85% for ammonium, 44 to 85% for ammonia, 50 to 73% for nitrate, 57 to 88% for total Kjeldahl nitrogen, 51 to 58% total nitrogen, and 66 to 99% for total phosphorus. The majority of the systems were implemented as decentralized treatment solutions using HSFCWs, with the second most common design being the hybrid CW systems in order to reduce area requirements, increase treatment efficiency, and prevent clogging. Overall, CWs are a promising sustainable solution which may support access to adequate sanitation worldwide as well as safe wastewater recycling and reuse, leading to more sustainable tourist destinations.info:eu-repo/semantics/publishedVersio