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Livestock wastewater (LWW) has a complex characteristic of high organic matter content, metals, nutrients, and pharmaceutical compounds. Advanced oxidation processes (AOP) are a potential option for treating this wastewater. This study evaluated real LWW and the performance of UV/H2O2 and UV/peroxymonosulfate (UV/PMS) for its treatment. The experiments were conducted in a UV photoreactor (16 mW/m2, λ = 254 nm). The oxidant agents (Ox) tested were H2O2 and PMS, each at low, medium, and high TOC/Ox molar ratios. A pretreatment based on chemical precipitation was implemented. Annually, the LWW showed total organic carbon (TOC) values of 859 ± 13.37 mg/L, 168.85 ± 1.62 mg/L of total Kjeldahl nitrogen (TKN), and toxicity of 96% v/v. In the dry season, albendazole (ABZ) (95.3 ± 35.16 mg/L), Cu (4.3 ± 0.23 mg/L), Fe (3.8 ± 0.38 mg/L), and suspended solids (SS) (1015 ± 586.9 mg/L) were identified, so pretreatment was implemented. The UV/PMS process with the lowest molar ratio [TOC/Ox 1:0.75] removed significantly lower TOC concentrations (p < 0.05), but toxicity decreased entirely. The study of mineralization and toxicity provided insight into the changes in LWW during treatment with AOP. Furthermore, it contributed to establishing the technical basis for implementing efficient treatment processes.
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Plasmids are extrachromosomal genetic elements commonly found in bacteria. They are known to fuel bacterial evolution through horizontal gene transfer, and recent analyses indicate that they can also promote intragenomic adaptations. However, the role of plasmids as catalysts of bacterial evolution beyond horizontal gene transfer is poorly explored. In this study, we investigated the impact of a widespread conjugative plasmid, pOXA-48, on the evolution of several multidrug-resistant clinical enterobacteria. Combining experimental and within-patient evolution analyses, we unveiled that plasmid pOXA-48 promotes bacterial evolution through the transposition of plasmid-encoded insertion sequence 1 (IS1) elements. Specifically, IS1-mediated gene inactivation expedites the adaptation rate of clinical strains in vitro and fosters within-patient adaptation in the gut microbiota. We deciphered the mechanism underlying the plasmid-mediated surge in IS1 transposition, revealing a negative feedback loop regulated by the genomic copy number of IS1. Given the overrepresentation of IS elements in bacterial plasmids, our findings suggest that plasmid-mediated IS1 transposition represents a crucial mechanism for swift bacterial adaptation.
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BACKGROUND: The management of febrile neutropenia (FN) in pediatric cancer patients has traditionally been conducted in a hospital setting. However, recent evidence has indicated that outpatient management of FN can be equally effective compared to inpatient care. Based on this evidence, we conducted a cost-minimization analysis (CMA) specifically focused on pediatric cancer patients in Mexico. METHODS: A piggy-back study was conducted during the execution of a non-inferiority clinical trial that compared outpatient treatment to inpatient treatment for FN in children with cancer. A CMA was performed from a societal perspective using patient-level data. In the previous study, we observed that step-down oral outpatient management of low-risk FN was as safe and effective as inpatient intravenous management. Direct and indirect costs were collected prospectively. The costs were adjusted for inflation and converted to US dollars, with values standardized to July 2022 costs. Statistical analysis using bootstrap methods was employed to obtain robust estimations for decision-making within the Mexican public health care system. RESULTS: A total of 117 FN episodes were analyzed, with 60 in the outpatient group and 57 in the inpatient group; however, complete cost data were available for only 115 FN episodes. The analysis revealed an average savings of $1,087 per FN episode managed on an outpatient basis, representing a significant 92% reduction in total cost per FN episode compared to inpatient treatment. Length of hospital stay and inpatient consultations emerged as the primary cost drivers within the inpatient care group. CONCLUSION: This CMA demonstrates that the step-down outpatient management approach is cost-saving when compared to inpatient management of FN in pediatric cancer patients. The mean difference observed between the treatment groups provides support for decision-making within the public health care system, as outpatient management of FN allows for substantial cost savings without compromising patient health.
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Atención Ambulatoria , Neoplasias , Humanos , Neoplasias/terapia , Neoplasias/complicaciones , Niño , Atención Ambulatoria/economía , México , Femenino , Masculino , Preescolar , Adolescente , Fiebre/terapia , Fiebre/economía , Neutropenia Febril/terapia , Neutropenia Febril/economía , Análisis Costo-BeneficioRESUMEN
New particle formation (NPF) substantially affects the global radiation balance and climate. Iodic acid (IA) is a key marine NPF driver that recently has also been detected inland. However, its impact on continental particle nucleation remains unclear. Here, we provide molecular-level evidence that IA greatly facilitates clustering of two typical land-based nucleating precursors: dimethylamine (DMA) and sulfuric acid (SA), thereby enhancing particle nucleation. Incorporating this mechanism into an atmospheric chemical transport model, we show that IA-induced enhancement could realize an increase of over 20% in the SA-DMA nucleation rate in iodine-rich regions of China. With declining anthropogenic pollution driven by carbon neutrality and clean air policies in China, IA could enhance nucleation rates by 1.5 to 50 times by 2060. Our results demonstrate the overlooked key role of IA in continental NPF nucleation and highlight the necessity for considering synergistic SA-IA-DMA nucleation in atmospheric modeling for correct representation of the climatic impacts of aerosols.
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Mosquitoes, as insect vectors, play a crucial role in transmitting viruses and parasites, leading to millions of human deaths in tropical and subtropical regions worldwide. This study aimed to evaluate the effects of ethanolic extracts of three species within the genus Myrothecium (M. roridum, M. dimerum, and M. nivale) on Aedes aegypti mosquito larvae to assess the inhibitory effect on growth and development, as well as to determine mortality. We quantify the average lethal concentrations and provide a qualitative characterization of the chemical groups responsible for their potential. Phytochemical screening revealed the presence of alkaloids, flavonoids, and terpenoids in the ethanolic extracts of the three fungal species. Tannins were found only in the extracts of M. dimerum and M. roridum. We observed a clear dependence of the effects of the crude extracts on mosquito larvae on the concentrations used and the duration of exposure. The toxic effect was observed after 48 h at a concentration of 800 ppm for both M. dimerum and M. nivale, while M. roridum showed effectiveness after 72 h. All three species within the genus Myrothecium exhibited 100% biological activity after 72 h of exposure at 600 ppm. At lower concentrations, there was moderate growth and development inhibitory activity in the insect life cycle. The study highlights the effectiveness of crude Myrothecium extracts in combating mosquito larvae, with effects becoming apparent between 48 and 72 h of exposure. This initial approach underscores the potential of the fungus's secondary metabolites for further in-depth analysis of their individual effects or synergies between them.
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Shipping emissions were measured in Dunkirk, France. Elevated aerosol extinction coefficients (AEC), nitrogen dioxide (NO2) and sulphur dioxide (SO2) were observed up to 500 m from surface. Formaldehyde (HCHO) did not show an increase every time, which suggests that oxidation of emitted volatile organic compounds (VOCs) took longer than the transport to the observation path and dilution of direct emissions had occurred. Background NO2, HCHO, and SO2 levels were higher when the wind came over land or the surrounding industrial area, indicating that land-based sources contribute significantly; however, clear spikes in NO2 and SO2 were observed whenever ship plumes were sampled. Observations show that the ship emission contribution to pollution is significant, but land-based sources still dominate. The SO2/NO2 ratio was low throughout the campaign, although varying according to the ship type, confirming that the new fuel content regulations are being followed by most ships in this region.
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Contaminantes Atmosféricos , Monitoreo del Ambiente , Navíos , Dióxido de Azufre , Dióxido de Azufre/análisis , Contaminantes Atmosféricos/análisis , Mar del Norte , Dióxido de Nitrógeno/análisis , Compuestos Orgánicos Volátiles/análisis , Francia , Formaldehído/análisis , Aerosoles/análisis , Emisiones de Vehículos/análisisRESUMEN
Bromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea-salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br-) by O2 and H2O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br-, O2 and H3O+ could spontaneously generate Br and HO2 radicals through a proton-electron transfer process at the air-water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br- and the production of Br2. The estimated gaseous Br2 production rate was up to 1.55×1010 molecules cm-2 â s-1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br- activation could promote the multiphase oxidation of SO2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br- activation. Our findings highlight the crucial role of the proton-electron transfer process in Br2 production; here, H3O+ facilitates the activation of Br- by O2, serves as a significant source of atmospheric reactive bromine and exerts a profound impact on the atmospheric oxidation capacity.
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Salmonella enterica serovar Typhimurium is an invasive, facultative intracellular gastrointestinal pathogen that destroys the brush border of polarized epithelial cells (PEC). The brush border is critical for the functions of PEC because it resorbs nutrients from the intestinal lumen and builds a physical barrier to infecting pathogens. The manipuation of PEC during infection by Salmonella was investigated by live-cell imaging and ultrastructural analysed of the brush border. We demonstrate that the destruction of the brush border by Salmonella significantly reduces the resorption surface of PEC along with the abrogation of endocytosis at the apical side of PEC. Both these changes in the physiology of PEC were associated with the translocation of type III secretion system effector protein SopE. Additionally, the F-actin polymerization rate at the apical side of PEC was highly altered by SopE, indicating that reduced endocytosis observed in infected PEC is related to the manipulation of F-actin polymerization mediated by SopE and, to a lesser extent, by effectors SopE2 or SipA. We further observed that in the absence of SopE, Salmonella effaced microvilli and induced reticular F-actin by bacterial accumulation during prolonged infection periods. In contrast to strains translocating SopE, strains lacking SopE did not alter resorption by PEC. Finally, we observed that after engulfment of Salmonella, ezrin was lost from the apical side of PEC and found later in early endosomes containing Salmonella. Our observations suggest that the destruction of the brush border by Salmonella may contribute to the pathogenesis of diarrhea.
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Plasmids are extrachromosomal genetic elements commonly found in bacteria. Plasmids are known to fuel bacterial evolution through horizontal gene transfer (HGT), but recent analyses indicate that they can also promote intragenomic adaptations. However, the role of plasmids as catalysts of bacterial evolution beyond HGT remains poorly explored. In this study, we investigate the impact of a widespread conjugative plasmid, pOXA-48, on the evolution of various multidrug-resistant clinical enterobacteria. Combining experimental and within-patient evolution analyses, we unveil that plasmid pOXA-48 promotes bacterial evolution through the transposition of plasmid-encoded insertion sequence 1 (IS1) elements. Specifically, IS1-mediated gene inactivations expedite the adaptation rate of clinical strains in vitro and foster within-patient adaptation in the gut microbiota. We decipher the mechanism underlying the plasmid-mediated surge in IS1 transposition, revealing a negative feedback loop regulated by the genomic copy number of IS1. Given the overrepresentation of IS elements in bacterial plasmids, our findings propose that plasmid-mediated IS transposition represents a crucial mechanism for swift bacterial adaptation.
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BACKGROUND: The present study aimed to evaluate nutritional intake among a group of male patients in the dental clinic with and without periodontal disease to search for associations between nutritional profile and periodontal health. METHODS: To this purpose, nutritional intake of macronutrients, fiber, vitamins, and minerals were compared evaluating both clinical parameters and periodontal status. Non periodontitis patients were compared with stage III and IV periodontitis and its extension according to the 2017 classification. RESULTS: After multivariate analysis, statistically significant associations were found between the dietary intake of energy, total fat, cholesterol, calcium, saturated fat, monounsaturated fat and folic acid and iodine and periodontitis status. This study reports an inverse association between cholesterol and iodine and periodontitis and a direct association with saturated fat, monounsaturated fat, and folic acid. CONCLUSIONS: Maintaining an adequate intake of fat, iodine, calcium, and cholesterol and avoiding an excessive intake of energy, saturated fat, monounsaturated fat, and folic acid could be important to controlling periodontitis.
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Periodontitis , Humanos , Masculino , Periodontitis/complicaciones , Persona de Mediana Edad , Adulto , Ingestión de Energía , Estado Nutricional , Ácido Fólico/administración & dosificación , Dieta/efectos adversos , Grasas de la Dieta/administración & dosificación , Grasas de la Dieta/efectos adversos , Fibras de la Dieta/administración & dosificaciónRESUMEN
Tropospheric reactive bromine is important for atmospheric chemistry, regional air pollution, and global climate. Previous studies have reported measurements of atmospheric reactive bromine species in different environments, and proposed their main sources, e.g. sea-salt aerosol (SSA), oceanic biogenic activity, polar snow/ice, and volcanoes. Typhoons and other strong cyclonic activities (e.g. hurricanes) induce abrupt changes in different earth system processes, causing widespread destructive effects. However, the role of typhoons in regulating reactive bromine abundance and sources remains unexplored. Here, we report field observations of bromine oxide (BrO), a critical indicator of reactive bromine, on the Huaniao Island (HNI) in the East China Sea in July 2018. We observed high levels of BrO below 500 m with a daytime average of 9.7 ± 4.2 pptv and a peak value of â¼26 pptv under the influence of a typhoon. Our field measurements, supported by model simulations, suggest that the typhoon-induced drastic increase in wind speed amplifies the emission of SSA, significantly enhancing the activation of reactive bromine from SSA debromination. We also detected enhanced BrO mixing ratios under high NOx conditions (ppbv level) suggesting a potential pollution-induced mechanism of bromine release from SSA. Such elevated levels of atmospheric bromine noticeably increase ozone destruction by as much as â¼40% across the East China Sea. Considering the high frequency of cyclonic activity in the northern hemisphere, reactive bromine chemistry is expected to play a more important role than previously thought in affecting coastal air quality and atmospheric oxidation capacity. We suggest that models need to consider the hitherto overlooked typhoon- and pollution-mediated increase in reactive bromine levels when assessing the synergic effects of cyclonic activities on the earth system.
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BACKGROUND: Cardiovascular diseases (CVD) have significant health and economic burdens. In South America, the loss of productivity related to these diseases has not yet been well explored. OBJECTIVE: Estimate the potentially productive years of life lost (PPYLL) and loss of productivity related to premature mortality associated with CVD in South America, in 2019. METHODS: Mortality data available from the 2019 Global Burden of Disease Study were used to estimate the burden of disease attributable to CVD. For monetary calculations of productivity loss, a proxy of the human capital approach was used. Data were stratified by sex, in working age groups. RESULTS: The total number of deaths due to CVD in South America in 2019 was 754,324, and the total number of PPYLL was 2,040,973. The total permanent loss of productivity was approximately US$ 3.7 billion and US$ 7.8 billion in purchasing power parity, equivalent to 0.11% of the gross domestic product. The cost per death was US$ 22,904, and the ratio between men and women for the cost per death was 1.45. The variation in scenarios indicates that the estimates are robust, even with important differences between countries. CONCLUSIONS: CVD impose a significant economic burden on countries in South America. The characterization of this burden can support governments in the allocation of resources for the planning and execution of health policies and interventions in promotion, prevention, and recovery.
FUNDAMENTO: As doenças cardiovasculares (DCV) têm ônus sanitário e econômico significativos. Na América do Sul (AS), a perda de produtividade relacionada a estas enfermidades ainda não foi bem explorada. OBJETIVO: Estimar os anos de vida produtiva perdidos (AVPP) e a perda de produtividade relacionados a mortalidade prematura associada as DCV na AS, em 2019. MÉTODOS: Empregou-se dados de mortalidade disponíveis no Global Burden of Disease Study 2019 na estimativa da carga de doença atribuível a DCV. Para os cálculos monetários da perda da produtividade usou-se uma proxy da abordagem de capital humano. Estratificou-se por sexo, nas faixas etárias de trabalho. RESULTADOS: O número total de mortes por DCV na AS no ano de 2019 foi de 754.324 e os AVPP foram 2.040.973. A perda permanente de produtividade total foi de aproximadamente US$ 3,7 bilhões e US$ 7,8 bilhões em paridade do poder de compra, equivalente a 0,11% do produto interno bruto. O custo por morte foi de US$ 22.904, e a razão desse custo por óbito, entre homens e mulheres foi 1,45. A variação dos cenários aponta robustez nas estimativas, mesmo com diferenças importantes entre os países. CONCLUSÕES: As DCV impõem um ônus econômico significativo a este bloco de países. A caracterização deste fardo pode amparar os governos na alocação de recursos destinados ao planejamento e execução de políticas e intervenções sanitárias, sejam de promoção, prevenção ou recuperação.
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Enfermedades Cardiovasculares , Costo de Enfermedad , Masculino , Humanos , Femenino , Costos de la Atención en Salud , América del Sur/epidemiología , EficienciaRESUMEN
Mercury (Hg) is a contaminant of global concern, and an accurate understanding of its atmospheric fate is needed to assess its risks to humans and ecosystem health. Atmospheric oxidation of Hg is key to the deposition of this toxic metal to the Earth's surface. Short-lived halogens (SLHs) can provide halogen radicals to directly oxidize Hg and perturb the budget of other Hg oxidants (e.g., OH and O3). In addition to known ocean emissions of halogens, recent observational evidence has revealed abundant anthropogenic emissions of SLHs over continental areas. However, the impacts of anthropogenic SLHs emissions on the atmospheric fate of Hg and human exposure to Hg contamination remain unknown. Here, we show that the inclusion of anthropogenic SLHs substantially increased local Hg oxidation and, consequently, deposition in/near Hg continental source regions by up to 20%, thereby decreasing Hg export from source regions to clean environments. Our modeling results indicated that the inclusion of anthropogenic SLHs can lead to higher Hg exposure in/near Hg source regions than estimated in previous assessments, e.g., with increases of 8.7% and 7.5% in China and India, respectively, consequently leading to higher Hg-related human health risks. These results highlight the urgent need for policymakers to reduce local Hg and SLHs emissions. We conclude that the substantial impacts of anthropogenic SLHs emissions should be included in model assessments of the Hg budget and associated health risks at local and global scales.
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Mercurio , Humanos , Mercurio/toxicidad , Mercurio/análisis , Monitoreo del Ambiente/métodos , Ecosistema , China , IndiaRESUMEN
Deep convection in the Asian summer monsoon is a significant transport process for lifting pollutants from the planetary boundary layer to the tropopause level. This process enables efficient injection into the stratosphere of reactive species such as chlorinated very-short-lived substances (Cl-VSLSs) that deplete ozone. Past studies of convective transport associated with the Asian summer monsoon have focused mostly on the south Asian summer monsoon. Airborne observations reported in this work identify the East Asian summer monsoon convection as an effective transport pathway that carried record-breaking levels of ozone-depleting Cl-VSLSs (mean organic chlorine from these VSLSs ~500 ppt) to the base of the stratosphere. These unique observations show total organic chlorine from VSLSs in the lower stratosphere over the Asian monsoon tropopause to be more than twice that previously reported over the tropical tropopause. Considering the recently observed increase in Cl-VSLS emissions and the ongoing strengthening of the East Asian summer monsoon under global warming, our results highlight that a reevaluation of the contribution of Cl-VSLS injection via the Asian monsoon to the total stratospheric chlorine budget is warranted.
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INTRODUCTION/OBJECTIVES: Mutations in the ARMC5 (armadillo repeat containing 5, OMIM 615549) gene, a putative tumor suppressor gene, have recently been identified as a common cause of sporadic and familial bilateral macronodular adrenal hyperplasia (BMAH). Familial BMAH is thought to be caused by two mutations, one germline and the other somatic, as suggested by the 2-hit theory. The objective is to describe a new mutation and develop its clinical characteristics and implications. METHODS, RESULTS AND CONCLUSIONS: We present an affected family with 11 members carrying a novel mutation of the ARMC5 gene (NM_001288767.1): c.2162T>C p. (Leu721Pro). Two of the carriers developed clinical Cushing's syndrome (CS), two mild autonomous cortisol secretion (MACS) and one presented with autonomous cortisol secretion (ACS). Four patients developed other tumors, three of whom died from this cause. It is not known whether these tumors could be related to the described mutation.
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Hiperplasia Suprarrenal Congénita , Síndrome de Cushing , Neoplasias , Humanos , Hiperplasia Suprarrenal Congénita/complicaciones , Hiperplasia Suprarrenal Congénita/genética , Síndrome de Cushing/genética , Mutación de Línea Germinal , Hidrocortisona , Hiperplasia , Proteínas Supresoras de Tumor/genéticaRESUMEN
Resumo Fundamento: As doenças cardiovasculares (DCV) têm ônus sanitário e econômico significativos. Na América do Sul (AS), a perda de produtividade relacionada a estas enfermidades ainda não foi bem explorada. Objetivo: Estimar os anos de vida produtiva perdidos (AVPP) e a perda de produtividade relacionados a mortalidade prematura associada as DCV na AS, em 2019. Métodos: Empregou-se dados de mortalidade disponíveis no Global Burden of Disease Study 2019 na estimativa da carga de doença atribuível a DCV. Para os cálculos monetários da perda da produtividade usou-se uma proxy da abordagem de capital humano. Estratificou-se por sexo, nas faixas etárias de trabalho. Resultados: O número total de mortes por DCV na AS no ano de 2019 foi de 754.324 e os AVPP foram 2.040.973. A perda permanente de produtividade total foi de aproximadamente US$ 3,7 bilhões e US$ 7,8 bilhões em paridade do poder de compra, equivalente a 0,11% do produto interno bruto. O custo por morte foi de US$ 22.904, e a razão desse custo por óbito, entre homens e mulheres foi 1,45. A variação dos cenários aponta robustez nas estimativas, mesmo com diferenças importantes entre os países. Conclusões: As DCV impõem um ônus econômico significativo a este bloco de países. A caracterização deste fardo pode amparar os governos na alocação de recursos destinados ao planejamento e execução de políticas e intervenções sanitárias, sejam de promoção, prevenção ou recuperação.
Abstract Background: Cardiovascular diseases (CVD) have significant health and economic burdens. In South America, the loss of productivity related to these diseases has not yet been well explored. Objective: Estimate the potentially productive years of life lost (PPYLL) and loss of productivity related to premature mortality associated with CVD in South America, in 2019. Methods: Mortality data available from the 2019 Global Burden of Disease Study were used to estimate the burden of disease attributable to CVD. For monetary calculations of productivity loss, a proxy of the human capital approach was used. Data were stratified by sex, in working age groups. Results: The total number of deaths due to CVD in South America in 2019 was 754,324, and the total number of PPYLL was 2,040,973. The total permanent loss of productivity was approximately US$ 3.7 billion and US$ 7.8 billion in purchasing power parity, equivalent to 0.11% of the gross domestic product. The cost per death was US$ 22,904, and the ratio between men and women for the cost per death was 1.45. The variation in scenarios indicates that the estimates are robust, even with important differences between countries. Conclusions: CVD impose a significant economic burden on countries in South America. The characterization of this burden can support governments in the allocation of resources for the planning and execution of health policies and interventions in promotion, prevention, and recovery.
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In this study, the phytochemical profile of fifty olive leaves (OL) extracts from Spain, Italy, Greece, Portugal, and Morocco was characterized and their anti-cholinergic, anti-inflammatory, and antioxidant activities were evaluated. Luteolin-7-O-glucoside, isoharmnentin, and apigenin were involved in the acetylcholinesterase (AChE) inhibitory activity, while oleuropein and hydroxytyrosol showed noteworthy potential. Secoiridoids contributed to the cyclooxygenase-2 inhibitory activity and antioxidant capacity. Compounds such as oleuropein, ligstroside and luteolin-7-O-glucoside, may exert an important role in the ferric reducing antioxidant capacity. It should be also highlighted the role of hydroxytyrosol, hydroxycoumarins, and verbascoside concerning the antioxidant activity. This research provides valuable insights and confirms that specific compounds within OL extracts contribute to distinct anti-cholinergic, anti-inflammatory, and anti-oxidative effects.
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Antioxidantes , Glucósidos Iridoides , Olea , Alcohol Feniletílico/análogos & derivados , Antioxidantes/química , Acetilcolinesterasa , Olea/química , Ciclooxigenasa 2 , Extractos Vegetales/química , Iridoides/análisis , Fitoquímicos/análisis , Hojas de la Planta/química , Antiinflamatorios/farmacología , Antiinflamatorios/análisis , Antagonistas Colinérgicos/análisisRESUMEN
Intracellular bacteria have evolved mechanisms to invade host cells, establish an intracellular niche that allows survival and replication, produce progeny, and exit the host cell after completion of the replication cycle to infect new target cells. Bacteria exit their host cell by (i) initiation of apoptosis, (ii) lytic cell death, and (iii) exocytosis. While bacterial egress is essential for bacterial spreading and, thus, pathogenesis, we currently lack information about egress mechanisms for the obligate intracellular pathogen C. burnetii, the causative agent of the zoonosis Q fever. Here, we demonstrate that C. burnetii inhibits host cell apoptosis early during infection, but induces and/or increases apoptosis at later stages of infection. Only at later stages of infection did we observe C. burnetii egress, which depends on previously established large bacteria-filled vacuoles and a functional intrinsic apoptotic cascade. The released bacteria are not enclosed by a host cell membrane and can infect and replicate in new target cells. In summary, our data argue that C. burnetii egress in a non-synchronous way at late stages of infection. Apoptosis-induction is important for C. burnetii egress, but other pathways most likely contribute.
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Coxiella burnetii , Fiebre Q , Humanos , Coxiella burnetii/metabolismo , Fiebre Q/metabolismo , Fiebre Q/microbiología , Fiebre Q/patología , Apoptosis/fisiología , Transducción de Señal , Vacuolas/metabolismo , Interacciones Huésped-PatógenoRESUMEN
Our understanding of ocean-cloud interactions and their effect on climate lacks insight into a key pathway: do biogenic marine emissions form new particles in the open ocean atmosphere? Using measurements collected in ship-borne air-sea interface tanks deployed in the Southwestern Pacific Ocean, we identified new particle formation (NPF) during nighttime that was related to plankton community composition. We show that nitrate ions are the only species for which abundance could support NPF rates in our semicontrolled experiments. Nitrate ions also prevailed in the natural pristine marine atmosphere and were elevated under higher sub-10 nm particle concentrations. We hypothesize that these nucleation events were fueled by complex, short-term biogeochemical cycling involving the microbial loop. These findings suggest a new perspective with a previously unidentified role of nitrate of marine biogeochemical origin in aerosol nucleation.