Broad-spectrum antibiotics, such as tetracyclines, are used to treat and manage a range of infectious disorders. Since the kidneys are the primary organs responsible for excreting tetracyclines, clinicians should refrain from prescribing them to patients who have renal failure. Tetracyclines are one of the clinical waste products of today. One of the biggest problems in the field of pollution of the environment today is the persistence of different pharmaceutical residues, drug residues, pesticides, and metal ion species of the new-generation pollutants in surfaces and groundwater. In the present work, carboxymethyl cellulose (CMC)-CuO nanoparticles (CMC-CuO NPs) were synthesized using CuO NPs within different amounts of CMC (0.5, 1.0, 1.5 and 2.0 g) at 85 °C. The synthesized nanoparticles were characterized by XRD, FT IR, SEM, and TG-DTA analysis. According to XRD and SEM, the crystallize size and morphology influenced the dosage of CMC. FT-IR analysis confines the layer of CMC to the CuO nanoparticle surface. TG-DTA results indicated that the CMC content of CMC-CuO NPs was between the range of 69% and 75% by weight. The effects of some parameters such as initial concentration, pH, adsorbent dosage, and contact time on the adsorption of tetracycline from aqueous model solutions on CMC-CuO NPs were investigated with batch studies. It was found that the removal of tetracycline was obtained about 80% with optimized parameters of 10 mg/L concentration, 180 min contact time, 5 pH, and 0.3 g/25 mL dose. The synthesized CMC-CuO NPs nanocomposite may be a promising material for the removal of tetracycline in environmental pollution and toxicology.

The augmentation of firm performance via customer concentration is particularly indispensable for organizational evolution. Both trade credit financing and financing constraints play pivotal roles in the nexus between customer concentration and performance. This research constructs a moderated mediation model to rigorously investigate the impact of customer concentration on firm performance, positing trade credit financing as the mediating variable and financing constraints as the moderating variable. The relevant hypotheses are evaluated empirically using panel data compiled from listed manufacturing firms in China over the period 2013–2020, yielding 8 firm-year observations. The empirical outcomes denote that customer concentration exerts a positive influence on firm performance, albeit having a negative impact on trade credit financing. Trade credit financing serves as a partial mediator in the relationship between customer concentration and manufacturing firm performance. Financing constraints are found to positively moderate the mediating role of trade credit financing in the relationship between customer concentration and firm performance. This research broadens the understanding of the implications of customer relationships on trade credit financing and performance, thereby enriching the knowledge base for managing a firm’s financing channels more effectively.

Climate change has affected the coasts of the world due to numerous factors, including the change in the intensity and frequencies of the storms and the increase in the mean sea level, among others. Argentina has extensive coastal areas, and research and monitoring tasks are expensive and require a significant number of personnel to cover large geographical areas. Given this, citizen science has become a tool to increase scientific research's spatial and temporal extension. Therefore, the paper aims to analyze the methodology and development of the citizen science project in Villa Gesell and its lessons for applying them in future coastal environmental monitoring projects. The methodology was based on an experience of the project co-created between activists and researchers. This project included four phases for social and physical aspects: training for the citizens, theoretic and practical aspects of coastal dynamics, and how to measure its geomorphological and oceanographic variations; data collection: the activists who received the training performed the measurements to monitor the beach; data analysis by scientists; and dissemination of results; the report data were disseminated by citizens in their community. The analysis of case studies in citizen science projects generates a fundamental learning arena to apply in future projects. Among the positive aspects were the phases established for their development and the methodology used to collect beach monitoring data.

China's famous educator Mr. Tao Xingzhi once said that "education is the first, observation first", only scientific and effective observation can change the teachers' narrow understanding of kindergarten curriculum. From the observation record to the derived "Little Secrets in the Toilet" garden-based course, the original is just an ordinary life segment, become warm, have curriculum awareness. With an observational perspective, the teachers capture the interests and needs of the children in their lives, understand their experience levels, and provide valuable learning growth points. At the same time, in the activity, teachers reflect on their own educational content, organization mode and environment creation, and make dynamic adjustment and transformation, which promotes the development of children and improves teachers' leadership in the curriculum.

Knowledge of the presence of heavy metals in soils of agricultural areas is important to prevent their accumulation in cultivated plants. The objective of the present investigation was to evaluate the total concentrations and fractions of heavy metals Cd, Pb, Zn, Fe, Mn, Ni, Cu, Cr and Co in the tobacco-growing area of Pinar del Río, Cuba and their relationship with the physicochemical properties of soil. For the study, 59 samples of three types of soils were collected at 20 cm depth. The pseudo-total concentrations of metals in the soils are low and lower than the prevention values registered for Cuban soils. In general, the heavy metals studied present a high affinity for the most stable fractions of the soil, which means a low risk of transfer to the tobacco crop or accumulation in groundwater. The pseudo-total concentrations of heavy metals were low, below the alert values established for soils in the region. The heavy metals studied were mainly associated with the residual fraction, the second fraction with the highest association with metals was that linked to manganese and iron oxides. The principal component analysis showed that their main source is pedogenetic and that these elements are closely related to cation exchange capacity and calcium content.

Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote the solubilization of insoluble phosphate complexes, together benefiting plant nutrition. The use of these organisms in combination with minerals or rocks that provide nutrients is another alternative to maintain crop productivity. The objective of this work was to combine AMF and S with pyroclastic materials (ashes and pumicites) from the Puyehue volcano and phosphoric rocks (PR) from the Río Chico Group (Chubut) and to evaluate the performance of these mixtures as substrates for potted production of Lactuca sativa. To formulate the substrates, a mixture of Ter-rafertil® with ashes was used as a base. Penicillium thomii was the S and spores of the fungus Rhizophagus intraradices (AEGIS® Irriga) served as the source of AMF. Various combinations of microorganisms and the addition or not of RP were evaluated. The treatments were: (1) substrate; (2) substrate + AMF; (3) substrate + S; (4) substrate + AMF + S; (5) substrate: PR; (6) substrate: PR + AMF; (7) substrate: PR + S, and (8) substrate: PR + AMF + S. There were 3 replicates per treatment. The parameters evaluated were total and assimilable P content in the substrate, P in plant tissue and dry biomass. All of them were significantly higher in the plants grown in the substrate added with PR and inoculated with S and AMF. This work confirms that the S/AMF combination with volcanic ashes from Puyehue and PR from Grupo Río Chico formulated with a commercial substrate promote the growth of L. sativa. Thus, it is possible to increase the added value of geomaterials of national origin.