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Emerging contaminants were used during the COVID-19 pandemic, including ivermectin. Studies that limit the optimal adsorption parameters of ivermectin are scarce in the literature. In this study, we analyzed the adsorption of ivermectin with a high surface area and porosity charcoal. Isotherms were better fitted to the Koble-Corrigan model. The maximum capacity was 203 μg g -1 at 328 K. Thermodynamics indicated a spontaneous and endothermic behavior. The equilibrium was quickly reached within the first few minutes regardless of the ivermectin concentration. The linear driving force (LDF) model fitted the kinetic data (q exp = 164.8 μg g -1 ; q pred = 148.1 μg g -1 ) at 100 μg L -1 of ivermectin. The model coefficient (K LDF ) and diffusivity (D s ) increased with increasing drug concentration. Two sloped curves were obtained in the column experiments, with a breakthrough time of 415 min and 970 min. The capacity of the column (q eq ) was 76 μg g -1 . The length of the mass transfer zone was 9.04 and 14.13 cm. Therefore, it can be concluded that the adsorption of ivermectin is highly sensitive to changes in pH, being favored in conditions close to neutrality. Commercial activated charcoal was highly efficient in removing the studied compound showing high affinity with very fast kinetics and a good performance in continuous operation mode., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study explores the potential of the corozo fruit ( Bactris guineensis ) palm tree in the Colombian Caribbean as a source for porous carbon material. Its specific surface area, pore volume, and average pore size were obtained using N 2 adsorption/desorption isotherms. The images of the precursor and adsorbent surface were obtained using scanning electron microscopy (SEM). Fourier transform infrared (FTIR) spectra were obtained to detect the main functional groups present and an X-ray diffraction analysis (XRD) was performed in order to analyze the structural organization of the materials. By carbonizing the fruit stone with zinc chloride, a porous carbon material was achieved with a substantial specific surface area (1125 m 2 g⁻ 1 ) and pore volume (3.241 × 10- 1 cm 3 g⁻ 1 ). The material was tested for its adsorption capabilities of the drug propranolol. The optimal adsorption occurred under basic conditions and at a dosage of 0.7 g L⁻ 1 . The Langmuir homogeneous surface model effectively described the equilibrium data and, as the temperature increased, the adsorption capacity improved, reaching a maximum of 134.7 mg g⁻ 1 at 328.15 K. The model constant was favorable to the temperature increase, increasing from 1.556 × 10 -1 to 2.299 × 10 -1 L mg -1 . Thermodynamically, the adsorption of propranolol was found to be spontaneous and benefited from higher temperatures, indicating an endothermic nature (12.39 kJ mol⁻ 1 ). The negative ΔG 0 values decreased from -26.28 to -29.99 kJ mol -1 , with the more negative value occurring at 328 K. The adsorbent material exhibited rapid kinetics, with equilibrium times ranging from 30 to 120 min, depending on the initial concentration. The kinetics data were well-represented by the general order and linear driving force models. The rate constant of the general order model diminished from 1.124 × 10 -3 to 9.458 × 10 -14 with an increasing concentration. In summary, the leftover stone from the Bactris guineensis plant can be utilized to develop activated carbon, particularly when activated using zinc chloride. This material shows promise for efficiently adsorbing propranolol and potentially other emerging pollutants.

The production of more efficient yeast-based fuel cells (YFCs) depends on a combination of effective proton exchange membranes, electron mediators and current collectors. The adhesion of organisms on electrode surface plays a key role in the electron transfer process optimizing the generated power density. In this work, it is reported the preparation of a new YFC prototype using membranes of polyvinyl alcohol/ phosphoric acid and anodes of carbon nanotubes/polyurethane. The high surface area for yeast adhesion and the strong interaction established between cells/carbon nanotubes favor the energy generation in fuel cell. To evaluate the influence of external mediators and the consumption of feed solution (glucose) on performance of YFC, the kinetics of current generation of resulting fuel cells was analyzed. Results reveal that increases in the impedance of electrodes on generated power can be minimized by periodical infusion of feed fuel, preserving 70% of maximum power, representing an important condition for prolonged activity of fuel cell., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study describes the in vitro anthelmintic activity of a hydroalcoholic extract from the fruit of Piper cubeba and its major isolated components against the eggs and larvae of gastrointestinal nematodes obtained from naturally-infected ovines. In vitro anthelmintic activity was evaluated using the egg hatch test (EHT), larval development test (LDT) and L3 migration inhibition test (LMT). The extract showed ovicidal and larvicidal activity, with an EC 50 of 200 μg/mL and 83.00 μg/mL in the EHT and LDT, respectively. The extract inhibited 100% of larval migration at the lowest tested concentration (95 μg/mL). The crude extract was purified using successive silica gel chromatographic columns, which revealed the lignans hinokinin, cubebin and dihydrocubebin as the major compounds that were present, which were then used in in vitro tests. Cubebin, dihydrocubebin and hinokinin showed higher activity than the crude extract, with an EC 50 for ovicidal activity of 150.00 μg/mL, 186.70 μg/mL and 68.38 μg/mL, respectively. In the LDT, cubebin presented an EC 50 of 14.89 μg/mL and dihydrocubebin of 30.75 μg/mL. Hinokinin inhibited 100% the larval development at all concentrations evaluated. In the LMT, dihydrocubebin inhibited 100% the larval migration in all concentrations evaluated while cubebin and hinokinin showed EC 50 values of 0.89 μg/mL and 0.34 μg/mL, respectively. P. cubeba extract is rich in several classes of active compounds, but here we demonstrate that the described anthelmintic activity may be related to the presence of these lignans, which are present in larger concentrations than other components of the extract. Our results demonstrate for first time the anthelmintic activity against gastrointestinal nematodes in sheep for this class of special metabolites that are present in P. cubeba fruit. However, future detailed studies are needed to evaluate the effectiveness of P. cubeba fruits extract and active lignans in in vivo tests., (Copyright © 2019 Elsevier B.V. All rights reserved.)

For over four decades, efforts have been underway for the evaluation of sickle cell retinopathy (SCR) in an attempt to identify peripheral high-risk vascular abnormalities based on Goldberg's classification (gold-standard) (1971). The macula is an area in the center of the retina that is responsible for high-resolution central vision and is also affected in SCR. With the development of new technologies for retinal imaging, the macula became a main focus of interest in the study of sickle cell disease (SCD). Optical coherence tomography angiography is a modern non-invasive method that allows qualitative and quantitative analysis of the retinal vascular network in the macular region. We identified 86 studies on SCD and optical coherence tomography angiography. Of those, 12 met the inclusion criteria for this systematic review. The prevalence of sickle cell maculopathy was 45.6% in the SCD population and it increased with age. We present the main vascular findings and discuss visual impairment and pathophysiology, genotypes, and peripheral high-risk vascular abnormalities. The role of the hematologist, general practitioner, and pediatrician in treatment is also reviewed., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Chikungunya virus (CHIKV) is an RNA virus transmitted by Aedes mosquitoes. The clinical manifestations include fever, arthralgia, rash, and other atypical clinical findings including ocular lesions. We report the case of a 57-year-old man with meningoencephalitis and anterior uveitis due to CHIKV. The patient had developed bilateral anterior uveitis with iris atrophy and a cotton wool spot on the left eye, and his serum, urine, saliva, and cerebrospinal fluid were positive for CHIKV by RT-PCR. The spectrum of the ophthalmologic manifestations and its pathophysiology in cases of CHIKV infections needs to be better understood. Additional studies examining the ocular lesions caused by CHIKV could improve the therapeutic goals of reducing the morbidity and sequels.