Microemulsion Based Nanostructures for Drug Delivery

Most of the active pharmaceutical compounds are often prone to display low bioavailability and biological degradation represents an important drawback. Due to the above, the development of a drug delivery system (DDS) that enables the introduction of a pharmaceutical compound through the body to achieve a therapeutic effect in a controlled manner is an expanding application. Henceforth, new strategies have been developed to control several parameters considered essential for enhancing delivery of drugs. Nanostructure synthesis by microemulsions (ME) consist of enclosing a substance within a wall material at the nanoscale level, allowing to control the size and surface area of the resulting particle. This nanotechnology has shown the importance on targeted drug delivery to improve their stability by protecting a bioactive compound from an adverse environment, enhanced bioavailability as well as controlled release. Thus, a lower dose administration could be achieved by minimizing systemic side effects and decreasing toxicity. This review will focus on describing the different biocompatible nanostructures synthesized by ME as controlled DDS for therapeutic purposes.

Estimation of greenhouse gas emissions of a tropical reservoir in Colombia

Tropical reservoirs are generally flooded in soils with a high content of organic matter. This, combined with high temperatures, favors the generation of carbon dioxide (CO2) and methane (CH4) by biological degradation, contributing to the impact on climate change. A tropical reservoir in Colombia was monitored for 7 years in the pre-fill, fill and post-fill stages, for the last of these during the day and night. Emissions from diffusive fluxes at the surface of the water were measured using a floating static chamber, while inverted funnel methodology was used to measure the fluxes by bubbling. The samples collected in the field were analyzed in the laboratory using a gas chromatograph with a mass detector. The results showed average emissions of 70,892.51 ± 41,079.16-ton CO2eq/year for pre-filling; 178,254.53 ± 105,838.01-ton CO2eq/year for filling; and 466,946.57-ton CO2eq/year for post-filling (for 5 years), concluding that the weather conditions and the filling percentage (Area surface and volume) had an impact on the generation of greenhouse gases at filling and post-filling stages, as did the organic matter present in the area of influence of the sampling point. Higher greenhouse gas emissions were found during the day compared to the results at night, indicating that temperature affects these processes, especially in tropical reservoirs. This study, currently unique in Colombia, will allow directing efforts towards mitigating the impacts of greenhouse gas emissions in tropical reservoirs.

Impregnation of Wood with Waste Engine Oil to Increase Water- and Bio-Resistance

Impregnation is a common method of protecting wood from external influences. This study proposes the use of spent engine oil as an impregnating composition for modifying birch wood to make it resistant to biological degradation and water. The indicators of water resistance and dimensional stability of wood such as wetting contact angle, thermogravimetric analysis, Fourier transform infrared spectroscopy (FTIR), and biodegradation tests have been determined. It has been found that treatment with spent engine oil significantly increases the dimensional stability (56.8% and 45.7% in tangential and radial directions) and water-resistant indicators of wood. Thermogravimetric analysis has showed that the curves for the impregnated specimens were different from the control group and had two sharp peaks at 302 and 357 °C. However, FTIR indicated that no clear chemical reactions occur between spent engine oil and wood. A study on wood resistance to biological degradation has showed a significant increase in resistance against brown rot (Poria placenta fungi) in the treated specimens, in contrast to the control group. Thus, impregnation of wood with spent engine oil makes it possible to increase wood resistance to water and biological degradation.

Analysis of Biological Degradation and Life Cycle Indicators of Mineral Diesel Fuel Mixtures, Containing 10% Biodiesel, Obtained by Simultaneous Oil Extraction and Transesterification

This article provides data on the environmental properties of biofuels obtained by the simultaneous extraction of oil from spoiled rapeseed and transesterification, with the addition of mineral diesel to the reaction mixture. The resulting reaction product contained 10% biodiesel: fatty acid methyl, ethyl, or butyl esters in mixtures with mineral diesel. The addition of biodiesel has been found to increase the rate of biodegradation of fuels. Such fuels are classified as partially biodegradable, according to the OECD classification. Life cycle analysis showed that the mixtures of biodiesel and mineral diesel have lower negative environmental impacts, compared to pure mineral diesel. The values of indicators such as abiotic depletion, acidification, global warming, ozone depletion, and human toxicity for these mixtures were 40–58% lower compared to the corresponding values for mineral diesel.

Microbial cysteine degradation is a source of hydrogen sulfide in oxic freshwater lakes

The sulfur-containing amino acid cysteine is abundant in the environment including in freshwater lakes. Biological degradation of cysteine can result in hydrogen sulfide (H2S), a toxic and ecologically relevant compound that is a central player in biogeochemical cycling in aquatic environments, including freshwater lakes. Here, we investigated the ecological significance of cysteine in oxic freshwater lake environments, using model systems of isolated cultures, controlled growth experiments, and multi-omics. We screened bacterial isolates enriched from natural lake water for their ability to produce H2S when provided cysteine. In total, we identified 29 isolates that produced H2S and belonged to the phylum Proteobacteria Bacteroidetes, and Actinobacteria. To understand the genomic and genetic basis for cysteine degradation and H2S production, we further characterized 3 freshwater isolates using whole-genome sequencing, and quantitatively tracked cysteine and H2S levels over their growth ranges: Stenotrophomonas maltophila, Stenotrophomonas bentonitica (Gammaproteobacteria) and Chryseobacterium piscium (Bacteroidetes). We observed a decrease in cysteine and increase in H2S, and identified genes involved in cysteine degradation in all 3 genomes. Finally, to assess the presence of these organisms and genes in the environment, we surveyed a five-year time series of metagenomic data from the same isolation source at Lake Mendota and identified their presence throughout the time series. Overall, our study shows that sulfur-containing amino acids can drive microbial H2S production in oxic environments. Future considerations of sulfur cycling and biogeochemistry in oxic environments should account for H2S production from degradation of organosulfur compounds.

Influence of spent drilling mud on sedimentation time of activated sludge flocs

Co-treatment of drilling muds with municipal wastewater in the reactors operating on the activated sludge principle constitutes a potentially safe method of their disposal. The method is based on the process of biological degradation of pollutants by assemblages of activated sludge organisms (prokaryotic and eukaryotic), which include different species described as functional and trophic groups. When the ecosystem in the bioreactor is in equilibrium, high wastewater treatment efficiency and process stability can be achieved. Analysis of qualitative and quantitative changes occurring in assemblages of activated sludge organisms may facilitate understanding the causes and mechanisms involved in the observed processes. In such a context, using a model of an SBR wastewater treatment plant, a study was performed to assess the feasibility of co-treating spent drilling mud with municipal wastewater using the activated sludge method. The floc constitutes the basic structural and physiological unit forming activated sludge. In this study, the sedimentation velocity of activated sludge flocs was analysed, and the obtained results were subjected to statistical analysis.

A review: the utilization potency of biopolymer as an eco-friendly scale inhibitors

Scale formation is one of the major issues in the petroleum industry. The development of these scale layers could result in production losses and equipment instability because of pipeline blockage, energy leakage, corrosion acceleration and severe accidents which will impact the safety of the production process. The utilization of chemical scale inhibitors (SIs) is considered an economical and successful route for the scale prevention. Two main components of the chemical SIs are phosphonate and polymer. Many of the phosphorous compounds are toxic and very expensive. Besides, portions of the phosphonate compounds are thermally less stable than polymeric scale inhibitors in a harsh environment of high temperature and high pressure (HTHP). This is considered as an issue as a good scale inhibitor should be able to be applied under wide range of temperature and pressure. Therefore, the continuous development in petroleum production imposes the need to develop a novel phosphorus-free scale inhibitor. Meanwhile, polymers have been broadly applied as a scale inhibitor in oil and gas fields because of their enhanced thermal stability and improved environmental compatibility. Polymeric scale inhibitors also show better dispersing efficiency. Today, the biopolymers have pulled in a tremendous consideration from the industry to replace the utilization of synthetic polymer due to their interesting qualities such as their lightness, strong mechanical properties, and appealing functionality. Biopolymers are insensitive toward brine salinity yet are vulnerable to biological degradation. Specifically, these polymers present enormous potential for environmental application because of their biodegradability, chemical adaptability and reactivity, biocompatibility, and nontoxicity. Recently, several new eco-friendly scale inhibitors have been reported in the literature. Hence, this paper provides a review of the utilization of biopolymer as scale inhibitor in the application of oil and gas industry under laboratory approach or field trial application. The types of scales, chemical scale inhibitors (SIs) and biopolymers are likewise reviewed here. The presented work in this paper is expected to enhance the fundamental understanding of scale formation, as well as contribute to the development process of biopolymer scale inhibitors.

Assessment of moisture and mould of hempcrete and straw panels

At present buildings contribute a third of total greenhouse gas emissions. There is a need for sustainable solutions and natural materials, which offer low-embodied energy and their low impact has a promising potential as construction alternatives. Hempcrete is a lightweight insulation material, which provides natural, airtight, and vapor-permeable insulation. Straw panels are also natural construction materials and they consist of extruded wheat straw and are surrounded with recycled paper on all sides. There are some risks, which can be associated with the use of such materials - infestation, biological degradation, presence of moisture, and structural degradation. The aim of the study is to determine the critical moisture level and mould resistance of hempcrete and straw panels. The results of this study are valuable to both scientists and structural engineers.