https://revistaschilenas.uchile.cl/handle/2250/42294 [0-9]{4} Mon, 11 May 2026 16:09:43 GMT 2026-05-11T16:09:43Z https://revistaschilenas.uchile.cl:443/bitstream/id/cad74465-818c-442e-bca4-00cdf3cfffde/ https://revistaschilenas.uchile.cl/handle/2250/42294 https://revistaschilenas.uchile.cl/handle/2250/253113 ONE-POT GREEN SYNTHESIS OF FLUORESCENT-QUANTUM CARBON DOTS FROM AVOCADO PEELS AND EVALUATION OF ITS ANTIMICROBIAL PROPETIES In this work, avocado peel was chosen as a low-value waste that could be used as a carbon source to synthesize carbon dots (APCQDs). To obtain it, the hydrothermal method was used in the absence of co-doping agents. The synthesis was carried out for 6 hours at 250 ºC. After purification by dialysis and lyophilization, CQDs that exhibited intense blue fluorescence (emission at 378 nm) were obtained. Field emission scanning electron microscopy (FESEM), evidence the spherical morphology of carbon dots within nanometer range. HPLC analysis and separation showed excellent separation even in columns with low porosity, indicating a separation mechanism where polarity predominates as the property that governs the separation. It is highlighted that avocado peel CQDs have potent antimicrobial activity against the pathogens Listeria monocytogenes ATCC 7644, Escherichia coli ATCC 11775, Staphylococcus aureus ATCC 9144, and Salmonella enterica ATCC 13076. The antioxidant effect was also evidenced in the DPPH and ORAC-FL. The synthesis method for APCQDs could be easily scaled up for gram scale synthesis of carbon quantum dots. https://revistaschilenas.uchile.cl/handle/2250/253113 https://revistaschilenas.uchile.cl/handle/2250/253112 IMPORTANCE OF DEW AS A REMOVER OF ATMOSPHERIC CATIONS AND ANIONS IN AN URBAN AREA OF SANTIAGO, CHILE ABSTRACT In an urban commune of Santiago, Chile, a monitoring campaign for dew and PM10 atmospheric particulate matter was implemented during 2022. The pH, conductivity, cation and anion concentrations of dew water, and the water-soluble fraction of PM10, were analyzed.   In the water-soluble fraction of PM10, the average cation concentrations were: 4.19 µgm3 for ammonia; 1.40 µgm-3  for  calcium; 0.46 µgm-3  for potassium; 0.36   µgm-3  for sodium; and 0.17 µgm-3  for  magnesium. In a decreasing order, concentrations were: NH4 ˃ Ca ˃ K ˃ Na ˃ Mg ˃ Zn ˃ Ba ˃ Cu ˃ Mn ˃ Al ˃ As ˃ V.   Among anions, the nitrate ion showed concentrations within the 4.49 to 20.09 µgm-3  range. The concentration of the carbonate ion ranged between 0 and 6.7 µgm-3 ; the sulphate ion ranged from 2.65 to 6.13 µgm-3  ; the chloride ion from 2.21 to 3.43 µgm-3 M; the phosphate ion varied between 2.08 and 2.33 µgm-3 ; the nitrite ion between 1.21 and 1.33 µgm-3 ; and the fluoride ion between 0.14 and 0.18. Simultaneously, 60 water dew events were collected during working days, with a total volume of 6465 mL, and 20 events on weekends. This volume was similar to the total level of rainfall in Santiago during 2022 (8217mL). In the dew water, the mean pH was 7.47, and the mean concentrations were: ammonia:13300 µgL-1, calcium: 12040 µgL-1 , potassium: 2600 µgL-1 , sodium 1530 µgL-1 , magnesium: 669 µgL-1 , zinc: 65 µgL-1, manganese: 50 µgL-1 , and copper:19 µgL-1. Among anions, mean concentration values were: chlorides: 8720 µgL-1 ; sulphates: 28938 µgL-1; nitrates: 32538 µgL-1: nitrites: 7556 µgL-1; and carbonates: 14540 µgL-1. Simple linear correlations between cations and anions present in dew water and PM10 showed values of 0.788 and 0.81, indicating a key removing role from the dew water in this city. In Santiago, dew water has a cleansing or removal effect as important as that of rain water https://revistaschilenas.uchile.cl/handle/2250/253112 https://revistaschilenas.uchile.cl/handle/2250/253118 STUDY OF THE ADSORPTION-DESORPTION PROCESS OF THE METALS: Cu, Mn, Pb and Zn IN VOLCANIC SOILS. ABSTRACT The study of the processes of adsorption – desorption of metallic trace elements or heavy metals in soils is crucial for the proposal of effective strategies for mitigation, reduction or elimination of these in natural systems. This work presents a study of the processes of adsorption and/desorption of Cu, Mn, Pb and Zn in two Chilean soils: Alhué (VI Region, Chile) and Nueva Braunau (X Region, Chile), both of volcanic origin and agricultural use. The soil samples studied were dried and sieved (< 2 mm or < 0.63 mm). The physicochemical characterization: pH, CE, MO, COT, N, P, CIC and texture was performed using described methods. The total fraction of each metal was obtained by microwave digestion with HNO3 and HCl. The contact time needed to reach equilibrium was determined by leaving the soil with the metal solution at different times (3, 6, 12, 24, 48 and 72 hours). The adsorption process was performed by a batch experiment, mixing different aliquots of metal solution with balancing solution (KNO3) 0.1 molL-1. Desorption was made from the 50/50 metal/balancing solution. The metals in the different soil samples and the total fraction in the soil were determined by AAS. The distribution of the total fraction of metals in decreasing order is in Alhué soil: Mn > Pb > Cu > Zn and in Nueva Braunau soil: Mn > Pb > Zn > Cu. It was determined that the contact time at which metals reach equilibrium is 48 hours for both soils, fitting appropriately with Elovich's model. The decreasing order of adsorption in the Alhué soil is: Cu > Zn > Pb > Mn and in the Nueva Braunau soil: Cu > Pb > Zn > Mn. The determination of the type of adsorption was made through the application of adsorption models of Langmuir and Freundlich. Cu adjusted according to the Langmuir model on both soils. Cu and Zn conformed to Freunlich's model. The desorption results are: Alhué soil: Pb > Mn > Zn > Cu and Nueva Braunau soil: Mn > Pb > Zn > Cu. The negative ΔG° (Gibbs free energy change) values obtained in the presents study indicate that the adsorption of metals onto soil samples is a spontaneous process and that the adsorption was an exothermic process excep for Mn in both soils. https://revistaschilenas.uchile.cl/handle/2250/253118 https://revistaschilenas.uchile.cl/handle/2250/253119 Synthesis of Curcumin-ferulic acid conjugate via Steglich esterification and anti-lung cancer activity of against Human non-small lung cancer cells (NSLCC) In the current work, the conjugate of curcumin and ferulic acid (compound 1) was developed and then examined utilizing a battery of biochemical assays to assess its pharmacological effectiveness against lung cancer.   The compound 1 was synthesized using steglich esterification in excellent yield and then evaluated for its ability to inhibit the growth of different types of human cancer cells, including cells of the gastric cancer (SGC-7901), breast cancer (MCF7), liver cancer (HepG-2), lung cancer (A549), and human cervical carcinoma (HeLa). It exhibited stronger inhibitory effects on A549 cells compared to the other cell types, indicating its potent anti-lung cancer activity. It induces substantial suppression of many kinases, including EGFR, PI3K, mTOR, and VEGFR2. It exhibited cell cycle suppression of G2/M phase, resulting in a significant rise in apoptosis rate in A549 cells. Compound 1 showed a notable suppression of telomerase activity and a rise in the depolarization of mitochondrial membrane potential in A549 cells. The present study showcased the creation of a curcumin-ferulic acid conjugate (referred to as Compound 1) as a very potent anticancer medication that selectively targets lung cancer cells. https://revistaschilenas.uchile.cl/handle/2250/253119