In the present investigation, an ethanolic fraction (EF) of Lepechinia meyenii (salvia) was prepared and fractionated by gradient column chromatography, and the main secondary metabolites present in the EF were identified by HPLC-MS. Silver nanoparticles (AgNPs) were synthesized and conjugated with the EF of Lepechinia meyenii (salvia). The AgNPs synthesis was optimized using Plackett-Burman design and response surface methodology (RSM), considering the following independent variables: stirring speed, synthesis pH, synthesis time, synthesis temperature and EF volume. The AgNPs synthesized under the optimized conditions were characterized by UV visible spectroscopy (UV-VIS), Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering (DLS) and Scanning Transmission Electron Microscopy (STEM). The antibacterial activity of the AgNPs against Staphylococcus aureus (ATCC^® 25923) was evaluated. The following flavonoids were identified: rosmarinic acid, diosmin and hesperetin-7-O-rutinoside. The optimized conditions for the synthesis of nanoparticles were pH 9.45, temperature 49.8 °C, volume of ethanolic fraction 152.6 µL and a reaction time of 213.2 min. The obtained AgNPs exhibited an average size of 43.71 nm and a resonance plasmon of 410–420 nm. Using FT-IR spectroscopy, the disappearance of the peaks between 626.50 and 1379.54 cm⁻¹ was evident with the AgNPs, which would indicate the participation of these functional groups in the synthesis and protection of the nanoparticles. A hydrodynamic size of 47.6 nm was obtained by DLS, while a size of 40–60 nm was determined by STEM. The synthesized AgNPs conjugated with the EF showed a higher antibacterial activity than the EF alone. These results demonstrate that the AgNPs synthesized under optimized conditions conjugated with the EF of the Lepechinia meyenii (salvia) presented an increased antibacterial activity.

This article shows the results of an investigation that was carried out at the National University of Juliaca (UNAJ), for which surveys were designed and carried out among applicants, students from regular basic education (EBR), university students and graduates of engineering programs, to determine the importance of practical work in the laboratory, in the teaching-learning processes during their training, as a result, the value of the importance of laboratory work in the different stages of the Student training is essential, where both applicants, students and graduates exceed 85% in favorable opinion, while only 1% consider it irrelevant or of little importance. In addition, one of the conclusions is reached where, it is affirmed that the work in the laboratory allows the improvement in terms of the interests and attitudes of the student, allowing him to discover the knowledge for himself. It also influences the development of teaching and learning in laboratories at the university level. In this sense, 67% of graduates consider the skills not developed at work in the laboratory will affect their professional performance, which is why it is concluded that there is a discreet compliance with the programmed laboratory practices due to the equipment, infrastructure and inadequate system established for the development of the subjects.

El presente artículo muestra los resultados de una investigación que se realizó en la Universidad Nacional de Juliaca (UNAJ), para lo cual se diseñaron y efectuaron encuestas a postulantes, estudiantes provenientes de la educación básica regular (EBR), estudiantes universitarios y egresados de programas de ingeniería, para determinar la importancia del trabajo práctico en el laboratorio, en los procesos de enseñanza-aprendizaje durante su formación profesional, como resultado se tiene que el valor acerca de la importancia del trabajo en el laboratorio en las distintas etapas de la formación del alumno es fundamental, en donde, tanto postulantes, estudiantes y egresados superan el 85% en opinión favorable, en tanto solo un 1% lo considera irrelevante o de poca importancia. Además, se llega a una de las conclusiones en donde, se afirma que el trabajo en el laboratorio permite la mejora en cuanto a los intereses y actitudes del alumno, permitiendo que descubra por sí mismo los conocimientos. También influye en el desarrollo de la enseñanza y el aprendizaje en los laboratorios a nivel universitario. En tal sentido, un 67% de egresados considera las habilidades no desarrolladas en el trabajo en el laboratorio afectará su desempeño profesional por lo que se concluye que existe un discreto cumplimiento de las prácticas de laboratorio programadas debido al equipamiento, la infraestructura y el inadecuado sistema establecido para el desarrollo de las asignaturas. Palabras claves: Trabajo en el laboratorio, porcesos de enseámza-aprendizaje, formación en ingenieria, Juliaca.

Objective: The objective of this study was a review to compile research on phytoremediation methods—including phytoextraction, rhizofiltration, phytostabilisation, phytodegradation, and phytovolatilisation—using primary sources to address heavy metal contamination in water. Theoretical Framework: The study is a basic investigation that includes a contextualization regarding the water issue, as well as the treatment of wastewater. A description of the characteristics and quality indicators of water was carried out, along with the importance of the removal of contaminants such as heavy metals using different technologies like phytoextraction, rhizofiltration, phytostabilization, phytodegradation, and phytovolatilization. This led to a detailed description of artificial wetland techniques as a viable and sustainable alternative. Method: The methodology adopted for this research includes data collection and compilation of existing information; regarding the different techniques related to wastewater treatment with artificial wetlands, these systems utilize natural processes involving vegetation, soil, and microbial activity to remove contaminants from water. More than 100 articles have been legally downloaded, and systematised in the database to paraphrase sentences and cite appropriately. Results and Discussion: Phytoremediation is an environmentally friendly technical choice because of its low cost to remediate water and soil contamination through methods of phytoextraction, rhizofiltration, phytostabilisation, phytodegradation and phytovolatilisation for organic contaminants, pesticides, oil waste, heavy metals, antibiotics, etc. It is relevant to choose transgenic plant methods to insert DNA genes and conduct molecular mechanisms through experimental optimisation studies for lightened growth and hyperaccumulation of heavy metals, generating space for metal and biomass storage, and prior knowledge of the physiology and biochemical processes of the plants. Research Implications: The results can be applied or influence practices in environmental protection using Phytoremediation, which is based on a natural technique of plants and their microbiota associated with roots and tissues, endophytic bacteria as Aeromonas sp, Pseudomonas sp, Bacillus sp, Sinorhizobium meliloti, Chryseomonas sp, Curtobacterium sp, Sphingomonas sp, Erwinia sp, Flavimonas sp retain contaminants. On the other hand, aquatic macrophytes such as Lemna spp, Typha spp, Potamogeton spp, Azolla filiculoides, Ceratophyllum demersm, Eichhornia crassipes, and Phragmites australis constitute an effective and feasible complementary alternative for the treatment of contaminated waters. Originality/Value: This study contributes to the literature There are different phytoremediation methods such as phytoextraction, rhizofiltration, phytostabilisation, phytodegradation, and hytovolatilisation for organic contaminants, pesticides, petroleum waste, heavy metals, pharmaceutical antibiotics, etc. Each of the elements has specific applications depending on the conditions of the place and the type of contaminants in an ecosystem.

The aim of this study was to rigorously quantify and analyse the concentrations of atmospheric pollutants (PM₁₀, PM_2.5, SO₂, NO₂, CO, H₂S, and O₃) emitted by artisanal brick kilns in Juliaca City, Peru. The AERMOD dispersion model and a network of low-cost sensors (LCSs) were employed to characterise air quality at specific receptor sites. A georeferenced inventory of kiln operations was created to determine their parameters and operational intensity, providing a foundation for estimating emission factors and rates. Data were obtained from the United States Environmental Protection Agency (EPA) and supplemented with locally gathered meteorological records, which were processed for integration into the AERMOD model. The findings revealed that brick kilns are a principal source of atmospheric pollution in the region, with carbon monoxide (CO) emissions being especially pronounced. The LCSs facilitated the identification of pollutant concentrations at various locations and enabled the quantification of the specific contribution of brick production to ambient aerosol levels. Comparative assessments determined that these sources account for approximately 85% of CO emissions within the study area, underscoring a significant adverse impact on air quality and public health. Background pollutant levels, emission rates, spatial distributions, and concentration patterns were analysed within the assessment zones, resulting in solid model performance. These results provide a sound scientific basis for the formulation and implementation of targeted environmental mitigation policies in urban areas and the outskirts of Juliaca.

Publicado em 11 de outubro de 2022. A agronomia desde os tempos remotos atua como uma área de conhecimento que além de ampla, é necessária para o desenvolvimento econômico e social. Desse modo, a pesquisa e inovação nos segmentos que fazem parte do setor agrário são indispensáveis para promover um melhor desempenho no futuro. Nos últimos anos, a inclusão da tecnologia tem impulsionado a grade de estudo no campo das ciências agrárias. Tal avanço, evidentemente, permitiu que novas técnicas e melhorias chegassem até produtores, de forma a garantir um novo cenário, a fim de aliar produtividade e rendimento econômico. As ciências agrárias, em sua totalidade, agrupam um conjunto de conhecimentos que permitem uma melhor utilização dos recursos naturais. Assim, este livro intitulado “ORGANIZACIÓN, INVESTIGACIÓN, TECNOLOGÍA Y INNOVACIÓN EM CIENCIAS AGRÍCOLAS 4” tem como finalidade abranger uma série de estudos focados em apresentar métodos e tecnologias para impulsionar os processos agrícolas já existentes, desde técnicas no campo e laboratório. Os temas aqui abordados refletem estudos de artigos científicos e revisões bibliográficas, de maneira a reunir informações precisas e fundamentais para uma estratégia de aproveitamento dos recursos naturais. Nesse sentido, ao longo da obra são apresentados 10 trabalhos que objetivam imergir o (a) leitor (a) dentro de um panorama agronômico. Espera-se que este estudo permita ao presente leitor (a) a possibilidade de conhecer novos mecanismos de pesquisa para fins agropecuários, além de agregar mais conhecimento e um novo olhar sobre a importância da tecnologia no meio agrário. Raissa Rachel Salustriano da Silva-Matos Fernando Freitas Pinto Júnior Jonathas Araújo Lopes