Brazilian Journal of Science

Intramolecular interaction analysis of forty amine derivatives with phosphodiesterase 4D using a theoretical model

Magdalena Álvarez-Ramírez — 2026-02-12

Several drugs, such as zatolmilast, orismilast, lotamilast, and GSK256066 (phosphodiesterase inhibitors) have been used to treat chronic heart failure. However, some of these drugs can produce different secondary effects such as arrhythmia, nausea, and vomiting. In the search for a new therapeutic alternative to treat chronic heart failure, this study aimed to characterize the interaction of some amino derivatives (1-40) with phosphodiesterase 4D using the 3iak protein as a theoretical tool in the DockingServer program. Besides, zatolmilast, orismilast, lotamilast, and GSK256066 were used as controls. The results showed differences in the interaction of amino derivatives with the 3iak protein surface compared with zatolmilast, orismilast, lotamilast, and GSK256066. Other data indicate that the inhibition constant for amino derivatives 7, 12, 15, 18, and 33 was lower compared with the controls. All these data suggest that compounds 7, 12, 15, 18, and 33 could act as phosphodiesterase 4D inhibitors. These data suggest that amino derivatives of phosphodiesterase 4D could be a good therapeutic alternative to treat heart failure.

Household carbon footprint integrating extension and teaching in an undergraduate course in environmental engineering

Gerson Araujo de Medeiros — 2026-02-12

The curricularization of university extension within the pedagogical projects of Engineering programs is a recent and still consolidating approach in Brazil. This study aimed to evaluate household carbon footprint management as an extension-based educational strategy in undergraduate Environmental Engineering. The extension project was conducted in 2024 and 2025 within the Environmental Management course of the Environmental Engineering program at São Paulo State University (Unesp), in Sorocaba, São Paulo, Brazil. Students assessed environmental management practices in household settings that could reduce carbon emissions. 15 residences located in 8 municipalities within approximately 100 km of São Paulo were evaluated. The project included: (a) raising residents’ awareness of climate change impacts; (b) inventorying logistics (Scope 1), energy consumption (Scope 2), and solid waste generation and management (Scope 3); (c) conducting dialogic activities with residents to discuss alternatives for reducing the carbon footprint; and (d) estimating the projected carbon footprint based on management options selected by the residents. The results indicated that logistics was the main source of household carbon dioxide emissions (69%), followed by household waste management (20%) and energy consumption (11%). Although all residents demonstrated awareness of climate change and willingness to reduce their carbon footprint, resistance to change was observed, particularly regarding logistics-related practices. Consequently, the projected reductions based on feasible actions reached 12% for logistics, 23% for waste management, and 19% for energy consumption. The integration of extension activities into the Environmental Engineering curriculum contextualized course content and provided students with practical experience in understanding the social, economic, and cultural factors that influence environmental management decision-making at the household level.

Sustainable water management for irrigated agriculture in Rwanda: systematic narrative review

Sonia Ikundabayo — 2026-02-28

Sustainable water management is fundamental to the performance of irrigated agriculture in Rwanda, where irrigation plays a critical role in food security, rural livelihoods, and national economic development. Over the past two decades, the Government of Rwanda has made substantial investments in irrigation infrastructure and policy initiatives, notably the Rwanda Irrigation Master Plan (RIMP) and the Strategic Plan for the Transformation of Agriculture (PSTA). Despite these efforts, irrigation coverage and water use efficiency remain below their estimated potential. Of the approximately 600,000 hectares considered suitable for irrigation, only about 10% is currently developed. This systematic narrative review synthesizes peer-reviewed and grey literature published between 2010 and 2025 to assess the status of irrigation systems, water management practices, institutional arrangements, environmental challenges, and emerging technological options in Rwanda. The review shows that around 148 irrigation schemes have been established across marshlands, hillsides, and valley bottoms; however, many schemes are constrained by underutilized infrastructure, sedimentation, high energy costs, limited farmer technical capacity, and weak operation and maintenance mechanisms. Surface irrigation remains the dominant practice, often associated with substantial water losses, while more efficient technologies such as drip and sprinkler systems demonstrate better performance but face low adoption due to financial and technical barriers. Integrated Water Resources Management (IWRM) is increasingly promoted as a guiding framework, emphasizing coordinated water allocation, social equity, and environmental sustainability. Nonetheless, persistent issues such as soil degradation, waterlogging, and inefficient resource use indicate gaps in governance, monitoring, and enforcement. Overall, the review highlights that achieving sustainable water management in Rwanda’s irrigated agriculture will require strengthening institutional capacity, expanding farmer training, scaling up efficient irrigation technologies, and reinforcing IWRM implementation at catchment and scheme levels. These measures are essential for improving productivity, enhancing resilience to climate variability, and safeguarding long-term environmental sustainability.

Adsorptive removal of Nickel(II) and Chromium(III) from aqueous solutions onto egg shell powder

Ajmal Shah — 2026-02-28

In the current research work, eggshell powder was utilized as an adsorbent for the adsorptive removal of Ni (II) and Cr (III) in a batch process. Eggshells were purchased from a local market in Peshawar, Pakistan. For the adsorption of the adsorbate Ni (II) and Cr (III) from the aqueous solution, the biosorbent, i.e., Egg Shell Powder, was utilized. Different parameters, such as pH, contact time, initial concentration, and adsorbent dose, were optimized. The value of qe and % removal was determined using the optimal conditions. The optimum pH for the adsorption of both Ni (II) and Cr (III) was found to be 4 and 9, respectively. The optimum contact times for Ni (II) and Cr (II) were 40 and 30 minutes. The optimum adsorbent dose for Ni (II) and Cr (III) was 0.2 & 0.1g. The (q_e) was determined for Ni (II) and Cr (III) at 25 °C with the increase in concentration of adsorbate. The optimum initial concentration for Ni (II) and Cr (III) was found to be 20 ppm and 40 ppm, respectively.

Microbiological quality assessment of drinking water sources in Tonosí, Panama, using an advanced portable analytical technique

Natasha Alejandra Gómez-Zanetti — 2026-02-28

The microbiological assessment of water is crucial for public health. It is particularly significant in developing countries. This study assess the microbiological quality of water sources for human consumption in the District of Tonosí, Republic of Panama, using a portable advanced technique to detect fecal coliforms. Tonosí is a rural area, characterized by its tropical climate. Its main economic activities are agriculture and livestock. Eleven points were identified and sampled during the dry season of 2023. The Potatest 2 microbiological water quality laboratory was used to analyze the water samples. The procedure involved filtering water samples using a Membrane Filtration Unit (MFU), followed by incubation. Physicochemical parameters such as temperature, pH, residual chlorine, color, turbidity, and suspended solids were also measured. Fecal coliforms were found in most sampling points, exceeding acceptable limits according to the DGNTI-COPANIT Technical Regulation 21-2019 for drinking water in Panama. Parameters such as water temperature and pH were within regulatory standards, while some color and turbidity values slightly exceeded the limits, indicating the need for monitoring. Low residual chlorine levels suggested inadequate disinfection. The study emphasizes the importance of regular monitoring and inter-institutional collaboration for effective water quality management.