Search Results (9)

Glaucoma therapy aims at lowering intra-ocular pressure (IOP). Brinzolamide, a carbonic anhydrase inhibitor, is utilized as a second-line medication for treating ocular hypertension and primary open-angle glaucoma (POAG). The drug lowers the IOP making it a therapeutic agent against glaucoma, and due to its poor water solubility, is commercially available as Azopt^®, a 1% ophthalmic suspension. Adverse effects such as blurred vision, ocular irritation, discomfort, and bitter taste are associated with the use of the marketed brinzolamide formulation. This study aims to test the feasibility of formulating and in vitro testing of brinzolamide-PLGA nanoparticles for improved toxicity profile. The nanoparticles were prepared by the oil-in-water (O/W) emulsion-solvent evaporation method. Particle size and zeta potential were determined by dynamic light scattering (DLS). The morphology of the nanoparticles was determined by scanning electron microscopy (SEM). Encapsulation of the drug was verified by high-performance liquid chromatography (HPLC) and the compatibility of the polymer and drug was verified by Fourier transform infrared (FTIR) spectroscopy. The in vitro drug release profile was assessed employing the dialysis method. Intracellular localization of the nanoparticles was assessed by confocal microscopy utilizing Rhodamine 123-loaded nanoparticles. Cytotoxicity of the formulation was assessed on Statens Seruminstitut Rabbit Cornea (SIRC) and transfected Human Corneal Epithelial (SV40 HCEC) cell lines. The particle size of the nanoparticle formulations ranged from 202.3 ± 2.9 nm to 483.1 ± 27.9 nm for blank nanoparticles, and 129.6 ± 1.5 nm to 350.9 ± 8.5 nm for drug-loaded nanoparticles. The polydispersity of the formulations ranged from 0.071 ± 0.032 to 0.247 ± 0.043 for blank nanoparticles, and 0.089 ± 0.028 to 0.158 ± 0.004 for drug-loaded nanoparticles. Drug loading and encapsulation efficiencies ranged from 7.42–15.84% and 38.93–74.18%, respectively. The in vitro drug release profile for the optimized formulation was biphasic, with a ~54% burst release for the initial 3 h, followed by a cumulative 85% and 99% released at 24 and 65 h, respectively. Uptake study showed nanoparticles(NPs) localization in the cytoplasm and around the nuclei of the cells. Brinzolamide-PLGA nanoparticles were successfully developed, characterized, and tested in vitro. Preliminary data show intracellular localization of the nanoparticles in the cytoplasm of SIRC and SV40 HCEC cells. The formulations appeared to be relatively non-cytotoxic to the cells. The research data from the study provided preliminary data for successful development and promising in vitro absorption efficacy for brinzolamide-loaded PLGA nanoparticle formulation. Full article

An increasing body of evidence shows that seaweeds, including kelp, can be used as a tool to neutralize or remove excess nutrients and metals from the water column. Here we report on a preliminary field assessment showing potential nutrient and carbon removal differences in sugar kelp and ribbon kelp grown in common gardens. Seawater and tissue samples were collected systematically from two farms in Alaska. Results show differences between the %N and %C content between Alaria marginata and Saccharina latissima. Results also show that tissue nitrogen in ribbon kelp varies sharply due to nitrogen availability in the water column. In contrast, the percentage of tissue N in sugar kelp remains comparatively stable. Our outcomes provide insight into potential differences in nutrient removal and harvest timing for different kelp species. Full article

Floodplains are critically important ecosystems that provide a whole suite of ecosystem services, including nutrient and carbon sequestration, flood mitigation, water storage, and critical wildlife habitat. However, human modification of rivers and floodplains through channelization, artificial levee construction, reductions in the active floodplain area, and water management can significantly reduce the ecosystem function of river–floodplain systems. In this study, we evaluated the changes in the nutrient loading of the Kissimmee River floodplain during the restoration of the river–floodplain system. In addition to time-series loading analysis, we also evaluated soil nutrient concentrations across the lower portion of the Kissimmee River floodplain. During the 44-year nutrient loading time-series, the floodplain remained a nutrient exporter with changes in nutrient loading generally corresponding to both water quality (i.e., point source reductions) and hydrologic restoration activities in the watershed and Kissimmee River floodplain. During the study period, inputs of total phosphorus and total nitrogen loads from upstream either significantly increased or remained the same. In addition to external sources of nutrients, internal sources of nutrients from floodplain soils can also contribute to the total nutrient export from the system. These internal sources could be organic via the decomposition of organic matter or geologic from the original excavation of the canal and/or restoration backfilling. Soil nutrient concentrations vary between vegetative communities and landscape position and could be a significant source of phosphorus to the downstream system, which is plagued by eutrophic conditions. Therefore, as floodplain function in the Kissimmee River continues to be restored and managed, additional effort may be needed to address nutrient inputs and internal legacy nutrients. Full article

In the present study, oil-in-water (O/W) sunscreen emulsions were prepared containing different portions of lignin (LGN), multiwall carbon nanotubes (MWCNTs) and graphene oxide (GO) nanoadditives. The stability in terms of pH and viscosity of emulsions was thoroughly studied for up to 90 days, exhibiting high stability for all produced O/W emulsions. The antioxidant activity of emulsions was also analyzed, presenting excellent antioxidant properties for the emulsion that contains LGN due to its phenolic compounds. Moreover, the emulsions were evaluated for their ultraviolet (UV) radiation protection ability in terms of sun protection factor (SPF) and UV stability. SPF values varied between 6.48 and 21.24 while the emulsion containing 2% w/v MWCNTs showed the highest SPF index and all samples demonstrated great UV stability. This work hopefully aims to contributing to the research of more organic additives for cosmetic application with various purposes. Full article

Mechanisms of growth and dissociation, growth rates, and morphology of gas hydrates of methane, carbon dioxide, and two CH${}_4$:CO${}_2$ mixtures (80:20 and 30:70 nominal concentration) were studied using using high resolution images and very precise temperature control. Subcooling and a recently proposed mass transfer-based driving force were used to analyze the results. When crystal growth rates did not exceed 0.01 mm/s, all systems showed faceted, euhedral crystal habits at low driving forces. At higher driving forces and growth rates, morphologies were different for all systems. These results solve apparent contradictions in literature about the morphology of hydrates of methane, carbon dioxide, and their mixtures. Differences in the growth mechanism of methane-rich and carbon dioxide-rich hydrates were elucidated. It was also shown that hydrate growth of methane, carbon dioxide, and their mixtures proceed via partial dissociation of the growing crystal. Temperature gradients were used to dissociate hydrates at specific locations, which revealed a most interesting phenomenon: On dissociation, carbon dioxide-rich hydrates propagated onto the bare substrate while drawing water from the opposite side of the sample. Furthermore, it was shown that an abrupt change in morphology common to all systems could be correlated to a change in the slope of growth rate data. This change in morphology was explained by a shift in the crystal growth mechanism. Full article

Plastics are an indispensable material with numerous benefits and advantages compared to traditional materials, such as glass and paper. However, their widespread use has caused significant environmental pollution and most plastics are currently nonrenewable. Biobased polymers represent an important step for tackling these issues, however, the end-of-life disposal of such materials needs to be critically considered to allow for a transition to a circular economy for plastics. Poly(lactic acid) (PLA) is an important example of a biobased polymer, which is also biodegradable. However, industrial composting of PLA affords water and carbon dioxide only and in the natural environment, PLA has a slow biodegradation rate. Therefore, recycling processes are important for PLA, particularly chemical recycling, which affords monomers and useful platform chemicals, maintaining the usefulness and value of the material. This review covers the different methods of PLA chemical recycling, highlighting recent trends and advances in the area. Full article

Coffee grounds are an organic waste consisting of the ground, roasted and processed grain for the extraction of coffee, being of great volume the waste obtained, which, if not treated and preserved for a long time, emanates unpleasant aromas and becomes an optimal means for the proliferation of flies, and other pests. Activated carbon has the characteristic of being a material that has a large surface area; because of this, it is used in adsorption, which refers to the retention of atoms, ions, and molecules on its surface. In this paper, the production of activated carbon is presented by means of the physicochemical activation of coffee waste by calcining at 900 °C and subsequent activation with sulfuric acid, as well as the Box–Behnken design of three factors for chromium (III) adsorption optimization. It is determined that the optimal conditions for performing the adsorption are pH = 3 and a contact time of 140 min. According to the analysis of variance for the experimental design, it is determined that the initial chromium formation is not significant for the adsorption process. Under the optimal adsorb conditions of 96%, an application is given to the erasure of coffee for the production of activated carbon, which serves as the adsorbent agent applied to the removal of chromium (III) aqueous. The area of activated carbon obtained is 13657.89 ± 251.09 m²/g determined by the acetic acid adsorption isotherm method. Full article

Agriculture accounts for 10 to 12% of the World’s total greenhouse gas (GHG) emissions. Manure management alone is responsible for 13% of GHG emissions from the agricultural sector. During the last decade, Québec’s egg production systems have shifted from deep-pit housing systems to manure belt housing systems. The objective of this study was to measure and compare carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N₂O) emissions from three different cage layer housing systems: a deep liquid manure pit and a manure belt with natural or forced air drying. Deep liquid manure pit housing systems consist of “A” frame layer cages located over a closed pit containing the hens’ droppings to which water is added to facilitate removal by pumping. Manure belt techniques imply that manure drops on a belt beneath each row of battery cages where it is either dried naturally or by forced air until it is removed. The experiment was replicated with 360 hens reared into twelve independent bench-scale rooms during eight weeks (19–27 weeks of age). The natural and forced air manure belt systems reduced CO₂ (28.2 and 28.7 kg yr⁻¹ hen⁻¹, respectively), CH₄ (25.3 and 27.7 g yr⁻¹ hen⁻¹, respectively) and N₂O (2.60 and 2.48 g yr⁻¹ hen⁻¹, respectively) emissions by about 21, 16 and 9% in comparison with the deep-pit technique (36.0 kg CO₂ yr⁻¹ hen⁻¹, 31.6 g CH₄ yr⁻¹ hen⁻¹ and 2.78 g N₂O yr⁻¹ hen⁻¹). The shift to manure belt systems needs to be encouraged since this housing system significantly decreases the production of GHG. Full article

Life is an inordinately complex unsolved puzzle. Despite significant theoretical progress, experimental anomalies, paradoxes, and enigmas have revealed paradigmatic limitations. Thus, the advancement of scientific understanding requires new models that resolve fundamental problems. Here, I present a theoretical framework that economically fits evidence accumulated from examinations of life. This theory is based upon a straightforward and non-mathematical core model and proposes unique yet empirically consistent explanations for major phenomena including, but not limited to, quantum gravity, phase transitions of water, why living systems are predominantly CHNOPS (carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur), homochirality of sugars and amino acids, homeoviscous adaptation, triplet code, and DNA mutations. The theoretical framework unifies the macrocosmic and microcosmic realms, validates predicted laws of nature, and solves the puzzle of the origin and evolution of cellular life in the universe. Full article