RESUMO
Mammalian cells are surrounded by neighbouring cells and extracellular matrix (ECM), which provide cells with structural support and mechanical cues that influence diverse biological processes1. The Hippo pathway effectors YAP (also known as YAP1) and TAZ (also known as WWTR1) are regulated by mechanical cues and mediate cellular responses to ECM stiffness2,3. Here we identified the Ras-related GTPase RAP2 as a key intracellular signal transducer that relays ECM rigidity signals to control mechanosensitive cellular activities through YAP and TAZ. RAP2 is activated by low ECM stiffness, and deletion of RAP2 blocks the regulation of YAP and TAZ by stiffness signals and promotes aberrant cell growth. Mechanistically, matrix stiffness acts through phospholipase Cγ1 (PLCγ1) to influence levels of phosphatidylinositol 4,5-bisphosphate and phosphatidic acid, which activates RAP2 through PDZGEF1 and PDZGEF2 (also known as RAPGEF2 and RAPGEF6). At low stiffness, active RAP2 binds to and stimulates MAP4K4, MAP4K6, MAP4K7 and ARHGAP29, resulting in activation of LATS1 and LATS2 and inhibition of YAP and TAZ. RAP2, YAP and TAZ have pivotal roles in mechanoregulated transcription, as deletion of YAP and TAZ abolishes the ECM stiffness-responsive transcriptome. Our findings show that RAP2 is a molecular switch in mechanotransduction, thereby defining a mechanosignalling pathway from ECM stiffness to the nucleus.
Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteínas rap de Ligação ao GTP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Transformação Celular Neoplásica , Matriz Extracelular/química , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Feminino , Proteínas Ativadoras de GTPase/metabolismo , Quinases do Centro Germinativo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HEK293 , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos Nus , Camundongos SCID , Proteínas do Tecido Nervoso/metabolismo , Fosfolipase C gama/metabolismo , Fosfoproteínas/metabolismo , Transativadores , Fatores de Transcrição , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Transcriptoma , Proteínas de Sinalização YAP , Proteínas rap de Ligação ao GTP/genéticaRESUMO
AIM: It is unclear whether prognosis differs by age for early-stage hepatocellular carcinoma (HCC). We aimed to examine prognosis and recurrence after radiofrequency ablation (RFA) for early-stage HCC and to determine its prognostic factors for different age groups. METHODS: This retrospective study enrolled 1079 patients with initial early-stage HCC treated with RFA at two institutions. All patients in this study were divided into four groups: <70 years old (group1, n = 483), 70-74 years old (group2, n = 198), 75-79 years old (group3, n = 201), and ≥80 years old (group4, n = 197). Prognostic factors were evaluated by comparing survival and recurrence rates between each group. RESULTS: The median survival time and 5-year survival rates for each group were 113 months and 70.8% in group1, 99.2 months and 71.5% in group2, 91.3 months and 66.5% in group3, and 71 months and 52.6% in group 4, respectively. Group4 had a significantly shorter survival than the other groups (p < 0.05). There were no significant differences in recurrence-free survival among the groups. In group4, the most common cause of death was nonliver-related disease (69.4%). In all groups, modified albumin-bilirubin index grade was a factor contributing to prolonged prognosis, but only in group4 performance status (PS) was a significant factor (hazard ratio, 2.46; 95% confidence interval, 1.16-3.00; p = 0.009). CONCLUSION: For early-stage HCC in the elderly, preoperative evaluation of PS and management of other diseases could contribute to a prolonged prognosis.
RESUMO
Acetylation can be regulated by histone deacetylases (HDACs) and histone acetyltransferases (HATs), and the imbalance between HDACs and HATs can lead to cancers. Trichostatin A (TSA), as one of the typical HDAC inhibitors (HDACis), may regulate the acetylation level and thus prevent the proliferation of cancer cells, in which the metabolic change of glycolysis is involved. However, the dynamic process of glycolysis has not yet been explored, and the mechanism is still elusive. In this work, we constructed GFP-actin-HeLa cells to observe the dynamic change of glycolysis in situ and found that the GFP fluorescence enhanced significantly after TSA treatment, which was consistent with the change of pH in the cells (pHi) depending on the change of lactate originated from glycolysis. Furthermore, we confirmed that the glycolysis was inhibited after TSA treatment, and this process was associated with HIF-1α and c-Myc regulation. As such, this work not only demonstrates the usefulness of the GFP fluorescent probe for monitoring the metabolic process of glycolysis in situ, but also sheds new light on the mechanism of glycolysis suppression in the cancer cells treated with HDACi.
Assuntos
Glicólise , Histona Desacetilases , Humanos , Acetilação , Fluorescência , Células HeLa , Histona Desacetilases/metabolismoRESUMO
Awareness and interest in involving male caregivers in child mental health treatment has grown, especially for youth with disruptive behavior disorders like oppositional defiant disorder (ODD). The purpose of this study was to examine the relationship between male caregiver involvement and treatment engagement for child ODD. Children (n = 122) ages 7-11 and their caregivers participated in the 4 Rs 2 Ss Strengthening Families Program for child-onset ODD. Families were compared based on male caregiver presence. Families with a male caregiver were significantly more resourced with respect to income, educational status, and food security. Additionally, they were over three times less likely to drop out of the program than those without a male caregiver. The presence of a male caregiver was associated with increased resources and higher rates of engagement in services than single, female-headed families. Future research is needed to discern the underlying mechanisms of this association.
Assuntos
Cuidadores , Comportamento Problema , Adolescente , Masculino , Feminino , Humanos , Criança , Cuidadores/psicologia , Comportamento Problema/psicologia , Transtornos de Deficit da Atenção e do Comportamento Disruptivo/terapia , FamíliaRESUMO
The changes of active ingredients content, moisture status and texture characteristics during the moistening of Paeoniae Radix Alba were studied by low-field NMR and imaging(LF-NMR/MRI) and texture analyzer, so as to analyze the correlation between LF-NMR parameters, texture characteristics and active ingredient content of Paeoniae Radix Alba during the moistening at diffe-rent times. The results showed that MRI technology could directly, vividly and accurately characterize the degree of moistening and the process of water migration, and the degree of moistening was consistent with the judgment results of traditional experience. The characteristics of moisture migration and moisture phase state in the moistening process of Paeoniae Radix Alba were that the total water content increased and existed in the form of free water, with an increased moisture mobility. In the case of dampening, the total water content did not increase, but the more watery part of the medicinal material was distributed to the less watery part, with a reduced fluidity. Finally, the medicinal materials were moistened, which can be mutually verified with the MRI results. The free water content and the total water content of Paeoniae Radix Alba had extremely negative correlations with hardness, surface toughness, internal toughness, Paeoniflorin and albiflorin contents(P<0.01). It showed that the use of LF-NMR/MRI and texture analyzer could better characterize the moistening process. It provides data characterization for the scientific connotation of "less soaking and more moisturizing, and the drug is completely saturated with water", and the traditional experience of "observing the water head". The feasible and objective evaluation method was helpful to optimize the softening process parameters, scientifically standardize the operating specifications, define the scienti-fic connotation of traditional Chinese medicine softening, and promote the inheritance and innovation of traditional Chinese medicine processing.
Assuntos
Medicamentos de Ervas Chinesas , Paeonia , Imageamento por Ressonância Magnética , Medicina Tradicional Chinesa , ÁguaRESUMO
Dual emission (DE) in nanoclusters (NCs) is considerably significant in the research and application of ratiometric sensing, bioimaging, and novel optoelectronic devices. Exploring the DE mechanism in open-shell NCs with doublet or quartet emissions remains challenging because synthesizing open-shell NCs is difficult due to their inherent instability. Here, we synthesize two dual-emissive M1Ag13(PFBT)6(TPP)7 (M = Pt, Pd; PFBT = pentafluorobenzenethiol; TPP = triphenylphosphine) NCs with a 7-electron open-shell configuration to reveal the DE mechanism. Both NCs comprise a crown-like M1Ag11 kernel with Pt or Pd in the center surrounded by five PPh3 ligands and two Ag(SR)3(PPh3) motifs. The combined experimental and theoretical studies revealed the origin of DE in Pt1Ag13 and Pd1Ag13. Specifically, the high-energy visible emission and the low-energy near-infrared emission arise from two distinct quartet excited states: the core-shell charge transfer and core-based states, respectively. Moreover, PFBT ligands are found to play an important role in the existence of DE, as its low-lying π* levels result in energetically accessible core-shell transitions. This novel report on the dual-quartet phosphorescent emission in NCs with an open-shell electronic configuration advances insights into the origin of dual-emissive NCs and promotes their potential application in magnetoluminescence and novel optoelectronic devices.
RESUMO
BACKGROUND: Bemisia tabaci is a globally significant agricultural pest including in Australia, where it exhibits resistance to numerous insecticides. With a recent label change, buprofezin (group 16), is now used for whitefly management in Australia. This study investigated resistance to pyriproxyfen (group 7C), spirotetramat (group 23) and buprofezin using bioassays and available molecular markers. RESULTS: Bioassay and selection testing of B. tabaci populations detected resistance to pyriproxyfen with resistance ratios ranging from 4.1 to 56. Resistance to spirotetramat was detected using bioassay, selection testing and sequencing techniques. In populations collected from cotton, the A2083V mutation was detected in three populations of 85 tested, at frequencies ≤4.1%, whereas in limited surveillance of populations from an intensive horticultural region the frequency was ≥75.8%. The baseline susceptibility of B. tabaci to buprofezin was determined from populations tested from 2019 to 2020, in which LC50 values ranged from 0.61 to 10.75 mg L-1 . From the bioassay data, a discriminating dose of 200 mg L-1 was developed. Recent surveillance of 16 populations detected no evidence of resistance with 100% mortality recorded at doses ≤32 mg L-1 . A cross-resistance study found no conclusive evidence of resistance to buprofezin in populations with high resistance to pyriproxyfen or spirotetramat. CONCLUSIONS: In Australian cotton, B. tabaci pest management is challenged by ongoing resistance to pyriproxyfen, while resistance to spirotetramat is an emerging issue. The addition of buprofezin provides a new mode-of-action for whitefly pest management, which will strengthen the existing insecticide resistance management strategy. © 2023 Commonwealth of Australia. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Assuntos
Hemípteros , Inseticidas , Animais , Resistência a Inseticidas/genética , Hemípteros/genética , Austrália , Inseticidas/farmacologia , Gossypium/genéticaRESUMO
Due to the interest in the potential pharmacological application of dandelion, the chemical constituents and activities of Taraxacum mongolicum Hand.-Mazz were studied. Box-Behnken response surface methodology was employed to optimize the protocol for extraction of flavonoid from dandelion. The molecular structures of different flavonoid compounds were acquired and analyzed by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy. Several major flavonoid compounds were isolated and purified, namely, hesperetin-5'-O-ß-rhamnoglucoside, hesperetin-7-glucuronide, kaempferol-3-glucoside, baicalein, hyperseroside, which were extracted for the first time from dandelion. Hesperetin-5'-O-ß-rhamnoglucoside was identified as a new type of flavonoid that had never reported in the literature. This new flavonoid has outstanding antioxidant activity, as shown by its IC50 value (8.72 mg/L) for scavenging DPPH free radicals. The determination of the structure-related antioxidant activities could be interpreted based on DFT calculations. As such, we have not only illustrated the rich flavonoid contents in Taraxacum mongolicum Hand.-Mazz, but also revealed new types of flavonoid compounds in dandelion in terms of structure and antioxidant properties.
Assuntos
Flavonoides , Taraxacum , Flavonoides/química , Antioxidantes/análise , Taraxacum/química , Cromatografia Líquida , Espectrometria de MassasRESUMO
Here, we report the synthesis and atomic structure of a Ag15Cu12(SR)18(CH3COO)3·(C6H14) nanocluster (Ag15Cu12 for short, SR denotes cyclohexanethiol), confirmed by single-crystal X-ray diffraction (SC-XRD), electrospray ionization mass spectrometry (ESI-MS), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). X-ray crystallographic analysis revealed that Ag15Cu12 consisted of an irregular Ag12 core, stabilized by the Ag3Cu12(SR)18(CH3COO)3 shell. The shell consisted of two nearly planar Cu3(SR)6 moieties, three monomeric [-SR-Ag-SR-] units and three Cu2(CH3COO) staples. Furthermore, time-dependent density functional theory (TD-DFT) simulation was performed to interpret the optical absorption features of Ag15Cu12. Overall, this work will broaden and deepen the understanding of Ag-Cu alloy nanoclusters.
Assuntos
Ligas , Espectrometria de Massas por Ionização por Electrospray , Cristalografia por Raios X , Teoria da Densidade Funcional , Espectroscopia FotoeletrônicaRESUMO
The extensive abuse and inadvertent discharge of various antibiotics into the environment has become a serious problem for posing a big threat to human health. In order to deal with this problem, we utilized cold atmospheric plasma jet (CAPJ) to treat two different antibiotics, namely, norfloxacin and chloramphenicol, and investigated the efficiencies and corresponding mechanisms for removing the mixed antibiotics. In the application of the CAPJ technique, we made use of not only the direct plasma processing, but also the indirect plasma-activated water (PAW) treatment. The efficiency for mixed antibiotics treatment was considerably enhanced as compared to the efficiency for treatment of single antibiotics. The contributions from the CAPJ-induced reactive oxygen/nitrogen species (RONS) were examined, showing that ·OH and 1O2 played a major role in the degradation of norfloxacin and chloramphenicol in the direct plasma treatment, while 1O2 played a major role in the PAW treatment. The bio-toxicity evaluation was also provided to verify the ecological safety of the CAPJ treatment. As such, this work has not only showed the effectiveness of CAPJ treatment of mixed antibiotics, but also elucidated the mechanisms for the enhanced treatment efficiency, which may provide a new solution for treatment of antibiotics in the environment.
Assuntos
Norfloxacino , Gases em Plasma , Humanos , Norfloxacino/toxicidade , Cloranfenicol/toxicidade , Gases em Plasma/farmacologia , Água , Antibacterianos/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Espécies Reativas de Nitrogênio/metabolismoRESUMO
Background and aims: Acute myocardial infarction (AMI) is a prevalent medical condition associated with significant morbidity and mortality rates. The principal underlying factor leading to myocardial infarction is atherosclerosis, with dyslipidemia being a key risk factor. Nonetheless, relying solely on a single lipid level is insufficient for accurately predicting the onset and progression of AMI. The present investigation aims to assess established clinical indicators in China, to identify practical, precise, and effective tools for predicting AMI. Methods: The study enrolled 267 patients diagnosed with acute myocardial infarction as the experimental group, while the control group consisted of 73 hospitalized patients with normal coronary angiography. The investigators collected general clinical data and relevant laboratory test results and computed the Atherogenic Index of Plasma (AIP) for each participant. Using acute myocardial infarction status as the dependent variable and controlling for confounding factors such as smoking history, fasting plasma glucose (FPG), low-density lipoprotein cholesterol (LDL-C), blood pressure at admission, and diabetes history, the researchers conducted multivariate logistic regression analysis with AIP as an independent variable. Receiver operating characteristic (ROC) curves were employed to determine the predictive value of AIP and AIP combined with LDL-C for acute myocardial infarction. Result: The results of the multivariate logistic regression analysis indicated that the AIP was an independent predictor of acute myocardial infarction. The optimal cut-off value for AIP to predict AMI was -0.06142, with a sensitivity of 81.3%, a specificity of 65.8%, and an area under the curve (AUC) of 0.801 (95% confidence interval [CI]: 0.743-0.859, P < 0.001). When AIP was combined with LDL-C, the best cut-off value for predicting acute myocardial infarction was 0.756107, with a sensitivity of 79%, a specificity of 74%, and an AUC of 0.819 (95% CI: 0.759-0.879, P < 0.001). Conclusions: The AIP is considered an autonomous determinant of risk for AMI. Utilizing the AIP index alone, as well as in conjunction with LDL-C, can serve as effective predictors of AMI.
RESUMO
We explored the impacts of nitrogen (N) inputs and the rhizosphere effect on the properties of rhizosphere and bulk soils in a salinized grassland in Northern Shanxi under N addition rates of 0, 1, 2, 4, 8, 16, 24 and 32 g N·m-2·a-1. The results showed that N addition significantly decreased soil pH, but significantly increased Ca2+, NO3--N and inorganic nitrogen contents in rhizosphere and bulk soil. With the increases of N addition rates, the contents of Ca2+, NO3--N, inorganic nitrogen in rhizosphere and bulk soils and total nitrogen in rhizosphere soil increased gradually, whereas the contents of Na+, K+, Mg2+, NH4+-N and amino acid in rhizosphere soil, and total nitrogen in bulk soil first increased and then decreased. Results of the principal component analysis showed that the responses of soil properties to low (≤8 g·m-2·a-1) and high nitrogen addition rates (>8 g·m-2·a-1) were significantly different. Compared with bulk soil, soil pH, the contents of organic acids and amino acids in rhizosphere soil were significantly lower by 0.71 units, 44.3% and 9.8%, respectively, while the contents of K+, Ca2+, Mg2+, NH4+-N, inorganic nitrogen, total carbon and total nitrogen in rhizosphere soil were significantly higher by 51.0%, 47.6%, 20.8%, 215.5%, 139.3%, 31.7% and 65.3%, respectively. These results indicated that rhizosphere effect on soil properties was stronger than that of nitrogen addition.
Assuntos
Rizosfera , Solo , Solo/química , Nitrogênio/análise , Pradaria , Microbiologia do SoloRESUMO
Studying the seed trait-stem trait-individual spatial pattern system is helpful for understanding the developmental direction of plant dynamics and populations under grazing disturbance as well as the antagonistic relationship between animals and plants, but few systematic analyses of this spatial pattern system have been carried out. Kobresia humilis is the dominant species in alpine grasslands. We studied K. humilis seed traits and their relationship with K. humilis reproductive individuals, the relationship between reproductive and vegetative stems, and the weights and spatial patterns of reproductive and nonreproductive individuals under four grazing treatments: no grazing (control), light grazing, moderate grazing and heavy grazing. We explored the relationship among seed size and seed number with reproductive stems and vegetative stems along the grazing gradient and assessed the spatial pattern changes between reproductive and nonreproductive individuals. The results showed the following: (1) Seed size increased with increasing grazing intensity, and the coefficient of variation for seed size and seed number in the heavy grazing treatment was greater than 0.6. (2) The structural equation model showed that grazing treatment had a positive effect on seed number, seed size and reproductive stem number and a negative effect on reproductive stem weight. (3) Grazing treatment did not affect the resource allocation to reproductive stems and vegetative stems per unit length of reproductive K. humilis individuals. (4) Compared with the number of reproductive individuals in the no grazing treatment, the number in the heavy grazing treatment decreased significantly, and the negative correlation between reproductive individuals and nonreproductive individuals changed from a full-scale negative correlation to a small-scale negative correlation and a large-scale positive correlation. Our study showed that grazing could activate and change the resource allocation pattern of dominant species in a grassland and have significant positive effects on reproductive stem number, reproductive stem weight, seed number and seed size. Along a grazing intensity gradient, with the increase in distance between reproductive and nonreproductive individuals, the transformation of intraspecific relationships from a negative correlation to a positive correlation is an ecological strategy conducive to population survival.
RESUMO
To investigate the effects of specific immunotherapy on the NKT cells in peripheral blood and the ability of NKT cells to proliferate in response to alpha-galactosylceramide (alpha-GalCer) in house-dust-mite- (HDM-) sensitized asthma children, peripheral blood mononuclear cells were isolated from 42 asthmatic children, of whom 24 were on specific immunotherapy (SIT) for more than a year and 20 were healthy. Compared with control group, the ratio of peripheral blood NKT and CD4(+)NKT cells was significantly decreased (P < 0.01) and was elevated in SIT asthma group (P < 0.05), respectively, but it was still less than the normal control group (P < 0.01). The level of IL-4 in serum secreted by NKT cells in asthma group was significantly higher than that of control group (P < 0.01), particularly apparent after 72 hours. The level of IL-4 in SIT group decreased significantly (P < 0.01). The level of IL-10 in serum secreted by NKT cells in asthma group was decreased significantly than that of the control group (P < 0.01) especially in 48 hours, while that of SIT group was increased significantly (P < 0.01). These results suggest that the pathogenesis of asthma may be related to the ratio and dysfunction of NKT and CD4(+)NKT cells.
Assuntos
Asma/imunologia , Asma/terapia , Galactosilceramidas/administração & dosagem , Leucócitos Mononucleares/imunologia , Células T Matadoras Naturais/imunologia , Pyroglyphidae/imunologia , Adolescente , Animais , Asma/sangue , Linfócitos T CD4-Positivos/imunologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Galactosilceramidas/imunologia , Humanos , Imunoterapia/métodos , Interleucina-10/sangue , Interleucina-10/imunologia , Interleucina-4/sangue , Interleucina-4/imunologia , MasculinoRESUMO
Metastasis is responsible for a large majority of death from malignant solid tumors. Bone is one of the most frequently affected organs in cancer metastasis, especially in breast and prostate cancer. Development of bone metastasis requires cancer cells to successfully complete a number of challenging steps, including local invasion and intravasation, survival in circulation, extravasation and initial seeding, and finally, formation of metastatic colonies after a period of dormancy or indolent growth. During this process, cancer cells often undergo a series of cellular and molecular changes to gain cellular plasticity that helps them adapt to various environments they encounter along the journey of metastasis. Understanding the mechanisms behind cellular plasticity and adaptation during the formation of bone metastasis is crucial for the development of novel therapies.
Assuntos
Neoplasias Ósseas , Neoplasias da Próstata , Neoplasias Ósseas/secundário , Plasticidade Celular , Humanos , Masculino , Metástase NeoplásicaRESUMO
Recent studies have revealed significant impact of anthropogenic aerosols to both climate and human health. Even though significant efforts have been made across the globe, studies related to aerosols over Southeast Africa remain scanty, hence causing high uncertainty in predicting and understanding the impacts of these aerosols. The present study therefore analyzed long-term spatial and temporal distribution of aerosol optical depth at 550 nanometer wavelength (AOD550) over the entire Southeast Africa. Relatively low AOD550 has been detected over the region in comparison to highly polluted regions across the globe. The highest annual average (>0.2) was observed over Lake Malawi, Zambezi valley, and the coastal areas of Central Mozambique while low annual values were recorded over northeast of Mozambique, and the eastern areas of Zimbabwe. In terms of seasonality, AOD550 was observed to be high (>0.3) during the dry months of September-October-November (SON) while being low (<0.1) during March-April-May (MAM) and June-July-August (JJA) in most areas. The seasonality of AOD550 was observed to be highly influenced by changes in seasonal biomass burning and seasonal atmospheric circulation. Statistical analyses revealed an insignificant change of AOD550 between 2002 and 2020 in most areas of the study domain. Regional open burning of biomass like bush fires and burning of crop residues during the dry months are the main sources of aerosol concentration. Therefore, the present study advocates the regulation and institutionalization of proactive and strategic mechanisms that curtail open burning activities within the region.
Assuntos
Poluentes Atmosféricos , Aerossóis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Humanos , Estações do Ano , ZimbábueRESUMO
Tetracycline is a common antibiotic and is often carelessly released into the natural environment, thus constantly posing potential threats to the environment. Currently, due to lack of effective methods to remove it from the environmental water system, researchers are still exploring new ways to deal with tetracycline. In this work, we employed atmospheric-pressure non-thermal plasma (NTP) to treat tetracycline in water and investigated the involved degradation mechanism. The enhanced degradation efficiency was acquired and investigated, and the degradation mechanism by the plasma-generated active species were explored. The tetracycline degradation pathways via especially the interactions with plasma-generated hydroxyl radical and ozone were examined by virtue of UV spectroscopy, three-dimensional fluorescence spectroscopy, high performance liquid chromatography-mass spectrometry (HPLC-MS), together with the assistance of theoretical simulations. Moreover, the toxicological evaluation of NTP treatment of tetracycline was also provided, which confirmed that the biological toxicity of tetracycline degradation products was negligible. Therefore, this work provides not only the effective way of treating antibiotics by engineered plasma technology, but also the insights into the mechanisms of degradation of antibiotics by NTP.
Assuntos
Gases em Plasma , Poluentes Químicos da Água , Antibacterianos/toxicidade , Pressão Atmosférica , Tetraciclina/toxicidade , Poluentes Químicos da Água/análiseRESUMO
Cold atmospheric plasma (CAP) possesses the ability of high-efficiency disinfection. It is reported that mixtures of reactive oxygen species (ROS) including ·OH, 1O2, O2- and H2O2 generated from CAP have better antimicrobial ability than mimicked solution of mixture of single ROS type, but the reason is not clear. In this study, CAP was applied to treat yeasts in water in order to investigate the fungal inactivation efficiency and mechanism. The results showed that plasma treatment for 5 min could result in >2-log reduction of yeast cells, and application of varied ROS scavengers could significantly increase the yeast survival rate, indicating that ·OH and 1O2 played the pivotal role in yeast inactivation. Moreover, the synergistic effect of 1O2 with other plasma-generated ROS was revealed. 1O2 could diffuse into cells and induce the depolarization of mitochondrial membrane potential (MMP), and different levels of MMP depolarization determined different cell death modes. Mild damage of mitochondria during short-term plasma treatment could lead to apoptosis. For long-term plasma treatment, the cell membrane could be severely damaged by the plasma-generated ·OH, so a large amount of 1O2 could induce more depolarization of MMP, leading to increase of intracellular O2- and Fe2+ which subsequently caused cell inactivation. 1O2 could also induce protein aggregation and increase of RIP1/RIP3 necrosome, leading to necroptosis. With participation of 1O2, endogenous ·OH could also be generated via Fenton and Haber-Weiss reactions during plasma treatment, which potentiated necroptosis. Adding l-His could mitigate membrane damage, inhibit the drop of MMP and the formation of necrosome, and thus prevent the happening of necroptosis. These findings may deepen the understanding of plasma sterilization mechanisms and provide guidance for microbial killing in the environment.
Assuntos
Gases em Plasma , Oxigênio Singlete , Desinfecção/métodos , Peróxido de Hidrogênio , Oxigênio , Espécies Reativas de Oxigênio/metabolismo , Saccharomyces cerevisiae , ÁguaRESUMO
Methyl parathion (MP) as an organophosphorus pesticide has been used in the control of agricultural pests and diseases. Due to its high toxicity and persistence in the environment, MP may pose threat to human health when it is released into environmental water. For MP treatment, people have found that oxidative degradation of MP may generate some intermediates which are more toxic than MP itself, such as methyl paraoxon. Herein, we proposed a new method of applying dielectric barrier discharge (DBD) non-thermal plasma technology to treat MP in aqueous solution, and investigated the influences of different gases, pH value, discharge voltage/power, and main active species on the MP removal efficiency. In particular, the safety of DBD treatment was concerned with analysis of the biological toxicity of the byproducts from the DBD oxidation, and the DBD-induced degradation together with the involved mechanism was explored therein. The results showed that the production of toxic intermediates could be effectively suppressed or avoided under certain treatment conditions. As such, this work demonstrates that the proper application of DBD plasma technology with necessary caution can detoxify methyl parathion effectively, and also provides a practical guide for low-temperature plasma application in treatment of various organophosphorus pesticides in agricultural wastewater.
Assuntos
Metil Paration , Praguicidas , Gases em Plasma , Poluentes Químicos da Água , Gases , Humanos , Metil Paration/toxicidade , Compostos Organofosforados , Praguicidas/toxicidade , Águas Residuárias , Água , Poluentes Químicos da Água/análiseRESUMO
BACKGROUND: Species within the Bemisia tabaci cryptic species complex can cause significant crop damage. We used high-throughput amplicon sequencing to identify the species composition and resistance allele genotypes in field populations from cotton fields in Australia. For selected populations, the resistance phenotype was determined in bioassays and compared with sequencing data. RESULTS: A metabarcoding approach was used to analyse the species composition in 144 field populations collected between 2013 and 2021. Two mixed AUS I and MEAM1 populations were detected, whereas the remaining 142 populations consisted of MEAM1 only. High-throughput sequencing of organophosphate and pyrethroid resistance gene amplicons showed that the organophosphate resistance allele F331W was fixed (> 99%) in all MEAM1 populations, whereas the pyrethroid resistance allele L925I in the voltage-gated sodium channel gene was detected at varying frequencies [1.0%-7.0% (43 populations); 27.7% and 42.1% (two populations); 95%-97.5% (three populations)]. Neither organophosphate nor pyrethroid resistance alleles were detected in the AUS I populations. Pyrethroid bioassays of 85 MEAM1 field-derived populations detected no resistance in 51 populations, whereas 32 populations showed low frequency resistance, and 2 populations were highly resistant. CONCLUSIONS: We demonstrate that high-throughput sequencing and bioassays are complementary approaches. The detection of target site mutations and the phenotypic provides a comprehensive analysis of the low-level resistance to pyrethroids that is present in Australian cotton farms. By contrast, a limited survey of whitefly populations from horticulture found evidence of high-level resistance against pyrethroids. Furthermore, we found that the F331W allele (linked to organophosphate resistance) is ubiquitous in Australian MEAM1. © 2022 Commonwealth of Australia. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.