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1.
Chemosphere ; 357: 142061, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38642775

RESUMEN

Increasing amounts of amino-functionalized polystyrene nanoplastics (PS-NH2) are entering aquatic ecosystems, raising concerns. Hence, this study investigated 96-h acute toxicity of PS-NH2 and its combination with the pesticide atrazine (ATZ) in the absence/presence of humic acid (HA) on the microalgae Chlorella vulgaris (C. vulgaris). Results showed that both PS-NH2 and PS-NH2+ATZ reduced algal growth, photosynthetic pigments, protein content, and antioxidant capacity, while increasing enzymatic activities. Gene expression related to oxidative stress was altered in C. vulgaris exposed to these treatments. Morphological and intracellular changes were also observed. The combined toxicity of PS-NH2+ATZ demonstrated a synergistic effect, but the addition of environmentally relevant concentration of HA significantly alleviated its toxicity to C. vulgaris, indicating an antagonistic effect due to the emergence of an eco-corona, and entrapment and sedimentation of PS-NH2+ATZ particles by HA. This study firstly highlights the role of HA in mitigating the toxicity of PS-NH2 when combined with other harmful compounds, enhancing our understanding of HA's presence in the environment.


Asunto(s)
Atrazina , Chlorella vulgaris , Herbicidas , Sustancias Húmicas , Microplásticos , Poliestirenos , Contaminantes Químicos del Agua , Chlorella vulgaris/efectos de los fármacos , Atrazina/toxicidad , Herbicidas/toxicidad , Poliestirenos/toxicidad , Poliestirenos/química , Contaminantes Químicos del Agua/toxicidad , Microplásticos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Microalgas/efectos de los fármacos , Antioxidantes/metabolismo , Pruebas de Toxicidad Aguda , Fotosíntesis/efectos de los fármacos
2.
Chemosphere ; 358: 142111, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38663677

RESUMEN

In this study, microalgae Chlorella vulgaris (C. vulgaris) were simultaneously exposed to environmental concentrations of amino-functionalized polystyrene nanoplastics (PS-NH2; 0.05, 0.1, 0.2, 0.3 and 0.4 mg/L) and the world's second most used pesticide, the herbicide atrazine (ATZ; 10 µg/L), in the absence and presence of humic acid (HA; 1 mg/L) for 21 days. Due to the low concentrations of PS-NH2, the majority of them could not cause a significant difference in the end-points of biomass, chlorophylls a and b, total antioxidant, total protein, and superoxide dismutase and malondialdehyde compared to the control group (p > 0.05). On the other hand, by adding ATZ to the PS-NH2, all the mentioned end-point values showed a considerable difference from the control (p < 0.05). The exposure of PS-NH2+ATZ treatments to the HA could remarkably reduce their toxicity, additionally, HA was able to decrease the changes in the expression of genes related to oxidative stress (e.g., superoxide dismutase, glutathione reductase, and catalase) in the C. vulgaris in the most toxic treatment group (e.g., PS-NH2+ATZ). The synergistic toxicity of the PS-NH2+ATZ group could be due to their enhanced bioavailability for algal cells. Nevertheless, the toxicity alleviation in the PS-NH2+ATZ treatment group after the addition of HA could be due to the eco-corona formation, and changes in their zeta potential from positive to negative value, which would increase their electrostatic repulsion with the C. vulgaris cells, in such a way that HA also caused a decrease in the formation of C. vulgaris-NPs hetero-aggregates. This research underscores the complex interplay between PS-NH2, ATZ, and HA in aquatic environments and their collective impact on microalgal communities.


Asunto(s)
Atrazina , Chlorella vulgaris , Herbicidas , Sustancias Húmicas , Microplásticos , Estrés Oxidativo , Poliestirenos , Superóxido Dismutasa , Contaminantes Químicos del Agua , Chlorella vulgaris/efectos de los fármacos , Atrazina/toxicidad , Poliestirenos/toxicidad , Poliestirenos/química , Superóxido Dismutasa/metabolismo , Herbicidas/toxicidad , Herbicidas/química , Contaminantes Químicos del Agua/toxicidad , Microplásticos/toxicidad , Estrés Oxidativo/efectos de los fármacos , Microalgas/efectos de los fármacos , Clorofila/metabolismo , Malondialdehído/metabolismo , Antioxidantes/metabolismo , Biomasa , Clorofila A/metabolismo
3.
Front Chem ; 11: 1190102, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37113502

RESUMEN

Liquid electrolyte systems of aluminum-ion batteries (AIBs) have restrictive issues, such as high moisture sensitivity, strong corrosiveness, and battery leakage, so researchers have turned their attention to developing high safety, leak-free polymer electrolytes. However, the stability of the active factor of AIB systems is difficult to maintain with most of polymeric frameworks due to the special Al complex ion balance in chloroaluminate salts. Based on this, this work clarified the feasibility and specific mechanism of using polymers containing functional groups with lone pair electrons as frameworks of solid-state electrolytes for AIBs. As for the polymers reacting unfavorably with AlCl3, they cannot be used as the frameworks directly due to the decrease or even disappearance of chloroaluminate complex ions. In contrast, a class of polymers represented by polyacrylamide (PAM) can interact with AlCl3 and provide ligands, which not only have no effect on the activity of Al species but also provide chloroaluminate complex ions through complexation reactions. According to DFT calculations, amide groups tend to coordinates with AlCl2 + via O atoms to form [AlCl2(AM)2]+ cations, while disassociating chloroaluminate anions. Furthermore, the PAM-based solid-state and quasi-solid-state gel polymer electrolytes were also prepared to investigate their electrochemical properties. This work is expected to provide new theoretical and practical directions for the further development of polymer electrolytes for AIBs.

4.
Front Plant Sci ; 13: 913856, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36212318

RESUMEN

Sulfur-containing compounds are essential for plant development and environmental adaptation, and closely related to the flavor and nutrition of the agricultural products. Cysteine, the first organic sulfur-containing molecule generated in plants, is the precursor for most of these active substances. Serine acetyltransferase (SERAT) catalyzes the rate-limiting step of its formation. However, despite their importance, systematic analyses of these enzymes in individual species, especially in economically important crops, are still limited. Here, The SERAT members (SlSERATs, four in total) were identified and characterized in tomato. Phylogenetically, the four SlSERAT proteins were classified into three subgroups with distinct genomic structures and subcellular localizations. On the function, it was interesting to find that SlSERAT3;1, possessed a high ability to catalyze the formation of OAS, even though it contained a long C-terminus. However, it retained the essential C-terminal Ile, which seems to be a characteristic feature of SERAT3 subfamily members in Solanaceae. Besides, SlSERAT1;1 and SlSERAT2;2 also had high activity levels and their catalyzing abilities were significantly improved by the addition of an OAS-(thiol)-lyase protein. At the transcriptional level, the four SlSERAT genes had distinct expression patterns during tomato plant development. Under abiotic stress conditions, the chloroplast-localized SlSERATs were the main responders, and the SlSERATs adopted different strategies to cope with osmotic, ion toxicity and other stresses. Finally, analyses in the loss-of-function and overexpression lines of SlSERAT1;1 suggested that function redundancy existed in the tomato SERAT members, and the tomato SERAT member was ideal target for S-assimilation manipulating in molecular breeding.

5.
Angew Chem Int Ed Engl ; 59(49): 21909-21914, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32844513

RESUMEN

ZIF-8 membranes have emerged as the most promising candidate for propylene/propane (C3 H6 /C3 H8 ) separation through its precise molecular sieving characteristics. The poor reproducibility and durability, and high cost, thus far hinder the scalable synthesis and industrial application of ZIF-8 membranes. Herein, we report a semi-solid process featuring ultrafast and high-yield synthesis, and outstanding scalability for reproducible fabrication of ZIF-8 membranes. The membranes show excellent C3 H6 /C3 H8 separation performance in a wide temperature and pressure range, and remarkable stability over 6 months. The ZIF-8 membrane features dimethylacetamide entrapped ZIF-8 crystals retaining the same diffusion characteristics but offering enhanced adsorptive selectivity for C3 H6 /C3 H8 . The ZIF-8 membrane was prepared on a commercial flat-sheet ceramic substrate. A prototypical plate-and-frame membrane module with an effective membrane area of about 300 cm2 was used for efficient C3 H6 /C3 H8 separation.

6.
Cell Host Microbe ; 20(5): 642-653, 2016 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-27832591

RESUMEN

Nuclear mRNA export is highly regulated to ensure accurate cellular gene expression. Viral inhibition of cellular mRNA export can enhance viral access to the cellular translation machinery and prevent anti-viral protein production but is generally thought to be nonselective. We report that ORF10 of Kaposi's sarcoma-associated herpesvirus (KSHV), a nuclear DNA virus, inhibits mRNA export in a transcript-selective manner to control cellular gene expression. Nuclear export inhibition by ORF10 requires an interaction with an RNA export factor, Rae1. Genome-wide analysis reveals a subset of cellular mRNAs whose nuclear export is blocked by ORF10 with the 3' UTRs of ORF10-targeted transcripts conferring sensitivity to export inhibition. The ORF10-Rae1 interaction is important for the virus to express viral genes and produce infectious virions. These results suggest that a nuclear DNA virus can selectively interfere with RNA export to restrict host gene expression for optimal replication.


Asunto(s)
Transporte Activo de Núcleo Celular , Herpesvirus Humano 8/fisiología , Interacciones Huésped-Patógeno , Proteínas Asociadas a Matriz Nuclear/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , ARN Mensajero/metabolismo , Proteínas Virales/metabolismo , Replicación Viral , Animales , Línea Celular , Regulación de la Expresión Génica , Humanos , Modelos Biológicos , Unión Proteica
7.
J Virol ; 88(19): 11369-82, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25056896

RESUMEN

UNLABELLED: Kaposi's sarcoma-associated herpesvirus (KSHV) is associated with several human malignances. As saliva is likely the major vehicle for KSHV transmission, we studied in vitro KSHV infection of oral epithelial cells. Through infection of two types of oral epithelial cells, normal human oral keratinocytes (NHOKs) and papilloma-immortalized human oral keratinocyte (HOK16B) cells, we found that KSHV can undergo robust lytic replication in oral epithelial cells. By employing de novo lytic infection of HOK16B cells, we studied the functions of two previously uncharacterized genes, ORF18 and ORF30, during the KSHV lytic cycle. For this purpose, an ORF18-deficient virus and an ORF30-deficient virus were generated using a mutagenesis strategy based on bacterial artificial chromosome (BAC) technology. We found that neither ORF18 nor ORF30 is required for immediately early or early gene expression or viral DNA replication, but each is essential for late gene expression during both de novo lytic replication and reactivation. This critical role of ORF18 and ORF30 in late gene expression was also observed during KSHV reactivation. In addition, global analysis of viral transcripts by RNA sequencing indicated that ORF18 and ORF30 control the same set of viral genes. Therefore, we suggest that these two viral ORFs are involved in the same mechanism or pathway that coregulates the viral late genes as a group. IMPORTANCE: While KSHV can infect multiple cell types in vitro, only a few can support a full lytic replication cycle with progeny virions produced. Consequently, KSHV lytic replication is mostly studied through reactivation, which requires chemicals to induce the lytic cycle or overexpression of the viral transcriptional activator, RTA. In this study, we present a robust de novo lytic infection system based on oral epithelial cells. Using this system, we demonstrate the role of two viral ORFs, ORF18 and ORF30, in regulating viral gene expression during KSHV lytic replication. As the major route of KSHV transmission is thought to be via saliva, this new KSHV lytic replication system will have important utility in the field.


Asunto(s)
Regulación Viral de la Expresión Génica , Herpesvirus Humano 8/genética , Queratinocitos/virología , Sistemas de Lectura Abierta , Proteínas Virales/genética , Secuencia de Bases , Línea Celular , Cromosomas Artificiales Bacterianos , Herpesvirus Humano 8/metabolismo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Queratinocitos/patología , Datos de Secuencia Molecular , Mucosa Bucal/patología , Mucosa Bucal/virología , Eliminación de Secuencia , Transducción de Señal , Proteínas Virales/metabolismo , Activación Viral , Replicación Viral
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