RESUMO
While atmospheric microplastics have attracted scientific attention as a significant source of microplastic contamination in the environment, studies in large population centers remain sparse. Here we present the first report on the occurrence and distribution of atmospheric microplastics in Mexico City (Latin America's second most densely populated city), collected using PM10 and PM2.5 active samplers at seven monitoring stations (urban, residential, and industrial) during the dry and wet seasons of 2020. The results showed that microplastics were detected in all of the samples examined, with mean microplastic concentrations (items m-3) of 0.205 ± 0.061 and 0.110 ± 0.055 in PM10 and PM2.5, respectively. The spatial distribution of microplastics showed seasonal variation, with greater abundances in locations closer to industrial and urban centers. There was also a significant difference in microplastic concentrations in PM10 and PM2.5 between the dry and wet seasons. The mean PM2.5/PM10 ratio was 0.576, implying that microplastics were partitioned more towards PM2.5 than PM10 in Mexico City. Fibers were the most prominent shape (>75 %), and blue was the most common color (>60 %). The size characteristics indicated microplastics of varying lengths, ranging from 39 to 5000 µm, with 66 % being <500 µm. Metal contaminants such as aluminum, iron, and titanium were detected using SEM-EDX on randomly selected microplastics. The microplastics were identified as cellophane, polyethylene, polyethylene terephthalate, polyamide, and cellulose (rayon) using ATR-FTIR spectral analysis. Our findings unravel the extent and characteristics of atmospheric microplastics in the Mexico City metropolitan area, which will aid future research to better understand their fate, transport, and potential health risks, demanding more investigations and close monitoring.
Assuntos
Plásticos , Poluentes Químicos da Água , Alumínio/análise , Celofane , Monitoramento Ambiental/métodos , Ferro/análise , México , Microplásticos , Nylons , Material Particulado/análise , Plásticos/análise , Polietilenotereftalatos , Polietilenos/análise , Titânio/análise , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Cellophane wrapping of the kidneys (Page kidney) induces perinephrits and hypertension, assumed to be due to renal ischemia resulting from parenchymal compression by the fibrous hull surrounding the kidneys. We investigated if interstitial nephritis, rather than plasma angiotensin activity, played a role in the development of hypertension in the Page kidney model. METHODS: We followed for 7 weeks rats with bilateral cellophane wrapping of the kidneys that received 20 mg/kg/day of the immunosuppressive antiproliferative drug mycophenolate mofetil (MMF) (two-kidney wrap/MMF) (N = 10) or vehicle (two-kidney wrap) (N = 10), and sham-operated rats (N = 10). RESULTS: The two-kidney wrap group had progressive increment in blood pressure, inflammatory damage occupying 25% to 50% of the renal tubulointerstitial region and increased number of angiotensin II-positive cells, angiotensin II content, and oxidative stress in the kidney. MMF treatment prevented the development of hypertension and renal inflammation without modifying the perinephritic hull or the increment it induced in the intrarenal pressure. The plasma levels of angiotensin II were similar in the two-kidney wrap group, the two-kidney wrap/MMF group and the sham-operated animals and unchanged from baseline, despite the blood pressure increase in the two-kidney wrap group. CONCLUSION: Our results indicate that renal wrap hypertension is unrelated to plasma angiotensin II levels and related to the inflammatory damage caused by the external compression of the kidney.
Assuntos
Hipertensão Renal/etiologia , Isquemia/complicações , Nefrite Intersticial/complicações , Angiotensina II/sangue , Animais , Pressão Sanguínea , Peso Corporal , Celofane , Modelos Animais de Doenças , Glutationa/metabolismo , Hipertensão Renal/patologia , Hipertensão Renal/prevenção & controle , Imunossupressores/farmacologia , Isquemia/tratamento farmacológico , Isquemia/patologia , Rim/metabolismo , Rim/patologia , Testes de Função Renal , Masculino , Malondialdeído/metabolismo , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/farmacologia , Nefrite Intersticial/tratamento farmacológico , Nefrite Intersticial/patologia , Pressão , Ratos , Ratos Sprague-DawleyRESUMO
The physiology of a colony of Pleurotus pulmonarius grown on potato dextrose agar overlaid with a Cellophane membrane (PDA-WC) was studied. On PDA-WC, the colony presented higher biomass density and productivity of fruit body formation (4.84+/-0.23 mg mycelial biomass/cm2 and 23.7+/-3.12 microg ml(-1) h(-1), respectively) than that which developed on potato dextrose agar without Cellophane (PDA-OC; 0.26+/-0.01 mg mycelial biomass/cm2 and 10.8+/-1.57 microg ml(-1) h(-1), respectively). In cultures developed on PDA-WC, intracellular laccases and beta-1,3-glucanases activities were lower [12+/-0.9 arbitrary units (AU)/g mycelial biomass and 1.33+/-0.1 international units (IU)/g mycelial biomass, respectively] than those observed on PDA-OC (20.65+/-1.0 AU/g mycelial biomass and 3.67+/-0.2 IU/g mycelial biomass, respectively). In cultures developed on PDA-WC, intracellular protein and glycogen concentrations were lower (1.9+/-0.9 and 117+/-3.5 mg/g mycelial biomass, respectively) than those observed on PDA-OC (14.3+/-1.1 and 347+/-2.9 mg/g mycelial biomass, respectively). The radial growth rate and the content of glucans in the cell wall were not significantly different between cultures developed on PDA-WC and PDA-OC. These results show that the use of the Cellophane as a tool to study in vitro fungal physiology might affect the interpretation of experimental results, since the physiology under otherwise similar conditions was different on medium with and without Cellophane.
Assuntos
Celofane , Pleurotus/crescimento & desenvolvimento , Pleurotus/fisiologia , Biomassa , Meios de Cultura , Proteínas Fúngicas/metabolismo , Glucanos/metabolismo , Glicogênio/metabolismo , Membranas Artificiais , Micologia/métodos , Pleurotus/enzimologiaRESUMO
BACKGROUND: Methods for the extraction of DNA from filamentous fungi are frequently laborious and time consuming because most of the available protocols include maceration in liquid nitrogen after the mycelium has been grown in a liquid culture. This paper describes a new method to replace those steps, which involves the growth of the mycelium on cellophane disks overlaid on solid medium and the use of glass beads for cell wall disruption. RESULTS: Extractions carried out by this method provided approximately 2 microg of total DNA per cellophane disk for the filamentous fungus Trichoderma reesei. To assess the DNA's quality, we made a PCR (Polymerase Chain Reaction) amplification of a gene introduced by a transformation in this fungus's genome (hph gene), with successful results. We also confirmed the quality of the DNA by the use of Southern blotting to analyze the presence of the same gene, which was easily detected, resulting in a sharply defined and strong band. CONCLUSIONS: The use of this method enabled us to obtain pure DNA from Trichoderma reesei, dispensing with the laborious and time-consuming steps involved in most protocols. The DNA obtained was found to be suitable for PCR and Southern blot analyses. Another advantage of this method is the fact that several samples can be processed simultaneously, growing the fungus on multiple well cell culture plates. In addition, the absence of maceration also reduces sample handling, minimizing the risks of contamination, a particularly important factor in work involving PCR.
Assuntos
Celofane , DNA Fúngico/isolamento & purificação , Micologia/métodos , Trichoderma/genética , Parede Celular/metabolismo , Criopreservação , Meios de Cultura/metabolismo , Vidro , Microesferas , Micologia/instrumentação , Nitrogênio/metabolismo , Trichoderma/crescimento & desenvolvimento , Trichoderma/metabolismoRESUMO
The use of walnut or peanut in the elaboration of cereal bars represents a possible risk of undesirable changes during their storage due to their high content of unsaturated fatty acids in the oil; oxidizing of the fatty acids is one of the main causes of deterioration. Development of new snack products implies the use of packages that should protect the food against the damage caused by light and reduce the oxygen concentration of in their interior. The objective of this investigation was to evaluate the physical, chemical and sensory changes in the storage of cereal bars with peanut or walnut and mezquite cotyledon subjected to two thermal treatments, packed in cellophane or milky polypropilene. Four types of bars were elaborated with 6% of mezquite cotyledon, treated by microwaves or toasted, and with 18% of peanut or walnut. The bars were stored for 90 days at room temperature; and each 30 days it was measured moisture content, peroxides index, water activity, sensory quality and acceptability. The peroxides values (4.9-13.8 meq/kg of oil) indicates that the shelf life of the bars in all the studied treatments was 90 days. The packaging materials used allows to maintain in good conditions, for 3 months, the cereals bars of moisture (7.4-11.2%), water activity (0.50-0.65) and sensory acceptability.
Assuntos
Grão Comestível/química , Fabaceae , Manipulação de Alimentos/métodos , Conservação de Alimentos/métodos , Plantas Medicinais , Arachis , Celofane , Micro-Ondas , Nozes , PolipropilenosRESUMO
Se detallan todos los pasos a llevar a cabo para realizar isoelectroenfoque en geles de poliacrilamida de 1 mm de espesor adheridos a un celofán como soporte. El gel se adhiere firmemente al celofán durante todos las operaciones (corrida, tinción y desteñido) y el soporte lo protege de las roturas, razón por la cual es fácilmente manejable. Se discute la optimización de las condiciones de trabajo para anfolito no comercial. Se muestra la buena resolución obtenida con dicho anfolito de sueros humanos normales y patológicos
Assuntos
Humanos , Proteínas/sangue , Ponto Isoelétrico/métodos , Celofane , Misturas AnfolíticasRESUMO
Se detallan todos los pasos a llevar a cabo para realizar isoelectroenfoque en geles de poliacrilamida de 1 mm de espesor adheridos a un celofán como soporte. El gel se adhiere firmemente al celofán durante todos las operaciones (corrida, tinción y desteñido) y el soporte lo protege de las roturas, razón por la cual es fácilmente manejable. Se discute la optimización de las condiciones de trabajo para anfolito no comercial. Se muestra la buena resolución obtenida con dicho anfolito de sueros humanos normales y patológicos (AU)