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1.
Nat Immunol ; 24(12): 2150-2163, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37872316

RESUMEN

Severe dengue (SD) is a major cause of morbidity and mortality. To define dengue virus (DENV) target cells and immunological hallmarks of SD progression in children's blood, we integrated two single-cell approaches capturing cellular and viral elements: virus-inclusive single-cell RNA sequencing (viscRNA-Seq 2) and targeted proteomics with secretome analysis and functional assays. Beyond myeloid cells, in natural infection, B cells harbor replicating DENV capable of infecting permissive cells. Alterations in cell type abundance, gene and protein expression and secretion as well as cell-cell communications point towards increased immune cell migration and inflammation in SD progressors. Concurrently, antigen-presenting cells from SD progressors demonstrate intact uptake yet impaired interferon response and antigen processing and presentation signatures, which are partly modulated by DENV. Increased activation, regulation and exhaustion of effector responses and expansion of HLA-DR-expressing adaptive-like NK cells also characterize SD progressors. These findings reveal DENV target cells in human blood and provide insight into SD pathogenesis beyond antibody-mediated enhancement.


Asunto(s)
Virus del Dengue , Dengue , Dengue Grave , Niño , Humanos , Linfocitos B , Células Asesinas Naturales
2.
Cell ; 177(6): 1405-1418.e17, 2019 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-31130379

RESUMEN

How do genes modify cellular growth to create morphological diversity? We study this problem in two related plants with differently shaped leaves: Arabidopsis thaliana (simple leaf shape) and Cardamine hirsuta (complex shape with leaflets). We use live imaging, modeling, and genetics to deconstruct these organ-level differences into their cell-level constituents: growth amount, direction, and differentiation. We show that leaf shape depends on the interplay of two growth modes: a conserved organ-wide growth mode that reflects differentiation; and a local, directional mode that involves the patterning of growth foci along the leaf edge. Shape diversity results from the distinct effects of two homeobox genes on these growth modes: SHOOTMERISTEMLESS broadens organ-wide growth relative to edge-patterning, enabling leaflet emergence, while REDUCED COMPLEXITY inhibits growth locally around emerging leaflets, accentuating shape differences created by patterning. We demonstrate the predictivity of our findings by reconstructing key features of C. hirsuta leaf morphology in A. thaliana. VIDEO ABSTRACT.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Cardamine/crecimiento & desarrollo , Hojas de la Planta/crecimiento & desarrollo , Arabidopsis/genética , Cardamine/genética , Linaje de la Célula/genética , Biología Computacional/métodos , Regulación de la Expresión Génica de las Plantas/genética , Hojas de la Planta/genética , Proteínas de Plantas/metabolismo
3.
Immunity ; 54(10): 2180-2182, 2021 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-34644551

RESUMEN

RNA interference (RNAi) provides antiviral defense in many organisms, including plants, insects, and nematodes. In this issue of Immunity, Fang et al. (2021) utilize designer peptides targeting viral suppressors of RNAi to provide evidence for the relevance of RNAi to antiviral immunity in mammals, also revealing the potential of this approach toward antiviral therapy.


Asunto(s)
Antivirales , Animales , Antivirales/uso terapéutico , Interferencia de ARN
4.
Proc Natl Acad Sci U S A ; 121(26): e2321877121, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38905239

RESUMEN

How tissue-level information encoded by fields of regulatory gene activity is translated into the patterns of cell polarity and growth that generate the diverse shapes of different species remains poorly understood. Here, we investigate this problem in the case of leaf shape differences between Arabidopsis thaliana, which has simple leaves, and its relative Cardamine hirsuta that has complex leaves divided into leaflets. We show that patterned expression of the transcription factor CUP-SHAPED COTYLEDON1 in C. hirsuta (ChCUC1) is a key determinant of leaf shape differences between the two species. Through inducible genetic perturbations, time-lapse imaging of growth, and computational modeling, we find that ChCUC1 provides instructive input into auxin-based leaf margin patterning. This input arises via transcriptional regulation of multiple auxin homeostasis components, including direct activation of WAG kinases that are known to regulate the polarity of PIN-FORMED auxin transporters. Thus, we have uncovered a mechanism that bridges biological scales by linking spatially distributed and species-specific transcription factor expression to cell-level polarity and growth, to shape diverse leaf forms.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Polaridad Celular , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos , Hojas de la Planta , Ácidos Indolacéticos/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Polaridad Celular/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Cardamine/genética , Cardamine/metabolismo , Cardamine/crecimiento & desarrollo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética
5.
EMBO J ; 41(11): e111210, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35471636

RESUMEN

Recent work reported the existence of a mammalian cell-autonomous antiviral defence based on RNA interference (RNAi), which relies on the accumulation of virus-derived small interfering RNAs (vsiRNAs) to guide the degradation of complementary viral RNAs. In a new study, Zhang et al (2022) find that, in infected mice, vsiRNAs can enter the bloodstream via their incorporation into extracellular vesicles (EVs) and confer sequence-specific antiviral activity to recipient cells, thus indicating that mammalian antiviral RNAi participates in both cell-autonomous and non-cell-autonomous host defence.


Asunto(s)
Antivirales , Virus , Animales , Mamíferos/genética , Ratones , Interferencia de ARN , ARN Bicatenario , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , ARN Viral/genética
6.
J Immunol ; 212(5): 894-903, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38231122

RESUMEN

The immune response is central to the pathogenesis of cutaneous leishmaniasis (CL). However, most of our current understanding of the immune response in human CL derives from the analysis of systemic responses, which only partially reflect what occurs in the skin. In this study, we characterized the transcriptional dynamics of skin lesions during the course of treatment of CL patients and identified gene signatures and pathways associated with healing and nonhealing responses. We performed a comparative transcriptome profiling of serial skin lesion biopsies obtained before, in the middle, and at the end of treatment of CL patients (eight who were cured and eight with treatment failure). Lesion transcriptomes from patients who healed revealed recovery of the stratum corneum, suppression of the T cell-mediated inflammatory response, and damping of neutrophil activation, as early as 10 d after initiation of treatment. These transcriptional programs of healing were consolidated before lesion re-epithelization. In stark contrast, downregulation of genes involved in keratinization was observed throughout treatment in patients who did not heal, indicating that in addition to uncontrolled inflammation, treatment failure of CL is mediated by impaired mechanisms of wound healing. This work provides insights into the factors that contribute to the effective resolution of skin lesions caused by Leishmania (Viannia) species, sheds light on the consolidation of transcriptional programs of healing and nonhealing responses before the clinically apparent resolution of skin lesions, and identifies inflammatory and wound healing targets for host-directed therapies for CL.


Asunto(s)
Leishmania braziliensis , Leishmania , Leishmaniasis Cutánea , Humanos , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/genética , Piel/patología , Cicatrización de Heridas/genética , Leishmania braziliensis/fisiología
7.
Nat Mater ; 23(4): 460-469, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38561520

RESUMEN

Non-layered transition metal carbides (TMCs) and layered transition metal dichalcogenides (TMDs) are two well-studied material families that have individually received considerable attention over the past century. In recent years, with the shift towards two-dimensional materials and heterostructures, a field has emerged that is focused on the structure and properties of TMC/TMD heterostructures, which through chemical conversion exhibit diverse types of heterostructure configuration that host coupled 2D-3D interfaces, giving rise to exotic properties. In this Review, we highlight experimental and computational efforts to understand the routes to fabricate TMC/TMD heterostructures. Furthermore, we showcase how controlling these heterostructures can lead to emergent electronic transport, optical properties and improved catalytic properties.

8.
PLoS Pathog ; 19(10): e1011722, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37812640

RESUMEN

Sequential dengue virus (DENV) infections often generate neutralizing antibodies against all four DENV serotypes and sometimes, Zika virus. Characterizing cross-flavivirus broadly neutralizing antibody (bnAb) responses can inform countermeasures that avoid enhancement of infection associated with non-neutralizing antibodies. Here, we used single cell transcriptomics to mine the bnAb repertoire following repeated DENV infections. We identified several new bnAbs with comparable or superior breadth and potency to known bnAbs, and with distinct recognition determinants. Unlike all known flavivirus bnAbs, which are IgG1, one newly identified cross-flavivirus bnAb (F25.S02) was derived from IgA1. Both IgG1 and IgA1 versions of F25.S02 and known bnAbs displayed neutralizing activity, but only IgG1 enhanced infection in monocytes expressing IgG and IgA Fc receptors. Moreover, IgG-mediated enhancement of infection was inhibited by IgA1 versions of bnAbs. We demonstrate a role for IgA in flavivirus infection and immunity with implications for vaccine and therapeutic strategies.


Asunto(s)
Flavivirus , Infección por el Virus Zika , Virus Zika , Humanos , Anticuerpos ampliamente neutralizantes , Transcriptoma , Anticuerpos Neutralizantes , Inmunoglobulina G , Inmunoglobulina A , Anticuerpos Antivirales
9.
J Neurosci Res ; 102(5): e25339, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38741550

RESUMEN

Diets rich in saturated fats are more detrimental to health than those containing mono- or unsaturated fats. Fatty acids are an important source of energy, but they also relay information regarding nutritional status to hypothalamic metabolic circuits and when in excess can be detrimental to these circuits. Astrocytes are the main site of central fatty acid ß-oxidation, and hypothalamic astrocytes participate in energy homeostasis, in part by modulating hormonal and nutritional signals reaching metabolic neurons, as well as in the inflammatory response to high-fat diets. Thus, we hypothesized that how hypothalamic astrocytes process-specific fatty acids participates in determining the differential metabolic response and that this is sex dependent as males and females respond differently to high-fat diets. Male and female primary hypothalamic astrocyte cultures were treated with oleic acid (OA) or palmitic acid (PA) for 24 h, and an untargeted metabolomics study was performed. A clear predictive model for PA exposure was obtained, while the metabolome after OA exposure was not different from controls. The observed modifications in metabolites, as well as the expression levels of key metabolic enzymes, indicate a reduction in the activity of the Krebs and glutamate/glutamine cycles in response to PA. In addition, there were specific differences between the response of astrocytes from male and female mice, as well as between hypothalamic and cerebral cortical astrocytes. Thus, the response of hypothalamic astrocytes to specific fatty acids could result in differential impacts on surrounding metabolic neurons and resulting in varied systemic metabolic outcomes.


Asunto(s)
Astrocitos , Hipotálamo , Ácido Oléico , Ácido Palmítico , Animales , Astrocitos/efectos de los fármacos , Astrocitos/metabolismo , Ácido Oléico/farmacología , Femenino , Ácido Palmítico/farmacología , Hipotálamo/metabolismo , Hipotálamo/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Caracteres Sexuales , Células Cultivadas
10.
Nat Mater ; 22(9): 1152-1159, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37500960

RESUMEN

Photomechanical crystals composed of three-dimensionally ordered and densely packed photochromes hold promise for high-performance photochemical actuators. However, bulk crystals with high structural ordering are severely limited in their flexibility, resulting in poor processibility and a tendency to fragment upon light exposure, while previous nano- or microcrystalline composites have lacked global alignment. Here we demonstrate a photon-fuelled macroscopic actuator consisting of diarylethene microcrystals in a polyethylene terephthalate host matrix. These microcrystals survive large deformations and show a high degree of three-dimensional ordering dictated by the anisotropic polyethylene terephthalate, which critically also has a similar stiffness. Overall, these ordered and compliant composites exhibit rapid response times, sustain a performance of over at least hundreds of cycles and generate work densities exceeding those of single crystals. Our composites represent the state-of-the-art for photochemical actuators and enable properties unattainable by single crystals, such as controllable, reversible and abrupt jumping (photosalient behaviour).

11.
Opt Lett ; 49(3): 678-681, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38300088

RESUMEN

Characterizing laser frequency noise is essential for applications including optical sensing and coherent optical communications. Accurate measurement of ultra-narrow linewidth lasers over a wide frequency range using existing methods is still challenging. Here we present a method for characterizing the frequency noise of lasers using a high-finesse plano-concave optical microresonator (PCMR) acting as a frequency discriminator. To enable noise measurements at a wide range of laser frequencies, an array of PCMRs was produced with slight variations of thickness resulting in a series of discriminators operating at a series of periodical frequencies. This method enables measuring the frequency noise over a wide linewidth range (15 Hz to <100 MHz) over the 1440-1630 nm wavelength range. To assess the performance of the method, four different lasers were characterized, and the results were compared to the estimations of a commercial frequency noise analyzer.

12.
BMC Cancer ; 24(1): 9, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166767

RESUMEN

BACKGROUND: The use of taxanes following the first trimester of pregnancy is endorsed by current clinical guidelines. However, evidence regarding their safety in terms of obstetric and neonatal outcomes is limited. METHODS: A comprehensive literature search was performed using the MEDLINE, CENTRAL and Web of Sciences databases from their inception up to 12/16/2022. Eligibility criteria included gestational taxane use, presentation of original findings, and individual case data presented. A descriptive statistical analysis was undertaken. RESULTS: A total of 159 patients treated with taxane-containing regimens during pregnancy were identified, resulting in 162 fetuses exposed in utero. The majority of patients had breast cancer (n = 88; 55.3%) or cervical cancer (n = 45; 28.3%). The most commonly employed taxane was paclitaxel (n = 131; 82.4%). A total of 111 (69.8%) patients were also treated with other cytotoxic drugs during pregnancy, including platinum salts (n = 70; 63.0%) and doxorubicin/cyclophosphamide (n = 20; 18.0%). While most patients received taxanes during the second trimester of pregnancy (n = 79; 70.0%), two were exposed to taxanes in the first trimester. Obstetric outcomes were reported in 105 (66.0%) cases, with the most frequent adverse events being preterm contractions or premature rupture of membranes (n = 12; 11.4%), pre-eclampsia/HELLP syndrome (n = 6; 5.7%), and oligohydramnios/anhydramnios (n = 6; 5.7%). All cases with pregnancy outcome available resulted in live births (n = 132). Overall, 72 (54.5%) neonates were delivered preterm, 40 (30.3%) were classified as small for gestational age (SGA), and 2 (1.5%) had an Apgar score of < 7 at 5 min. Perinatal complications included acute respiratory distress syndrome (n = 14; 10.6%), hyperbilirubinemia (n = 5; 3.8%), and hypoglycemia (n = 2; 1.5%). In addition, 7 (5.3%) cases of congenital malformations were reported. At a median follow-up of 16 months, offspring health status was available for 86 (65.2%), of which 13 (15.1%) had a documented complication, including delayed speech development, recurrent otitis media, and acute myeloid leukemia. CONCLUSIONS: Taxanes appear to be safe following the first trimester of pregnancy, with obstetric and fetal outcomes being similar to those observed in the general obstetric population. Future studies should aim to determine the most effective taxane regimen and dosage for use during gestation, with a specific focus on treatment safety.


Asunto(s)
Oligohidramnios , Taxoides , Recién Nacido , Femenino , Embarazo , Humanos , Taxoides/efectos adversos , Paclitaxel/uso terapéutico , Resultado del Embarazo , Hidrocarburos Aromáticos con Puentes/efectos adversos
13.
J Evol Biol ; 37(1): 123-129, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38285663

RESUMEN

Vertical gradients in microclimate, resource availability, and interspecific interactions are thought to underly stratification patterns in tropical insect communities. However, only a few studies have explored the adaptive significance of vertical space use during the early stages of reproductive isolation. We analysed flight-height variation across speciation events in Heliconius butterflies, representing parallel colonizations of high-altitude forest. We measured flight-height in wild H. erato venus and H. chestertonii, parapatric lowland and mountain specialists, respectively, and found that H. chestertonii consistently flies at a lower height. By comparing our data to previously published results for the ecologically equivalent H. e. cyrbia (lowland) and H. himera (high altitude), we found that the species flying closest to the ground are those that recently colonized high-altitude forests. We show that these repeated trends largely result from shared patterns of ecological selection producing parallel trait-shifts in H. himera and H. chestertonii. Although our results imply a signature of local adaptation, we did not find an association between resource distribution and flight-height in H. e. venus and H. chestertonii. We discuss how this pattern may be explained by variations in forest structure and microclimate. Overall, our findings underscore the importance of behavioural adjustments during early divergence mediated by altitude-shifts.


Asunto(s)
Mariposas Diurnas , Animales , Altitud , Fenotipo
14.
BMC Infect Dis ; 24(1): 298, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38454329

RESUMEN

PURPOSE: The significant proportion of asymptomatic patients and the scarcity of genotypic analysis of lymphogranuloma venereum (LGV), mainly among men who have sex with men (MSM), triggers a high incidence of underdiagnosed patients, highlighting the importance of determining the most appropriate strategy for LGV diagnosis, at both clinical and economical levels. MATERIALS AND METHODS: We conducted L1-L3 serovar detection by molecular biology in stored Chlamydia trachomatis-positive samples from MSM patients with HIV, another STI or belonging to a Pre-exposure prophylaxis program, to make a cost effectiveness study of four diagnostic strategies with a clinical, molecular, or mixed approach. RESULTS: A total of 85 exudates were analyzed: 35urethral (31 symptomatic/4 positive) and 50 rectal (22 symptomatic/25 positive), 70/85 belonging to MSM with associated risk factors. The average cost per patient was €77.09 and €159.55 for clinical (Strategy I) and molecular (Strategy IV) strategies respectively. For molecular diagnosis by genotyping of all rectal exudate samples previously positive for CT (Strategy II), the cost was €123.84. For molecular diagnosis by genotyping of rectal and/or urethral exudate samples from all symptomatic patients (proctitis or urethritis) with a previous positive result for CT (Strategy III), the cost was €129.39. The effectiveness ratios were 0.80, 0.95, 0.91, and 1.00 for each strategy respectively. The smallest ICER was €311.67 for Strategy II compared to Strategy I. CONCLUSIONS: With 30% asymptomatic patients, the most cost-effective strategy was based on genotyping all rectal exudates. With less restrictive selection criteria, thus increasing the number of patients with negative results, the most sensitive strategies tend to be the most cost-effective, but with a high incremental cost-effectiveness ratio.


Asunto(s)
Linfogranuloma Venéreo , Minorías Sexuales y de Género , Masculino , Humanos , Linfogranuloma Venéreo/diagnóstico , Linfogranuloma Venéreo/epidemiología , Chlamydia trachomatis/genética , Homosexualidad Masculina , Análisis de Costo-Efectividad , Genotipo
15.
Acta Anaesthesiol Scand ; 68(2): 214-225, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37903745

RESUMEN

BACKGROUND: Delirium is an acute disorder of attention and cognition with an incidence of up to 70% in the adult intensive care setting. Due to the association with significantly increased morbidity and mortality, it is important to identify who is at the greatest risk of an acute episode of delirium while being cared for in the intensive care. The objective of this study was to determine the ability of the cumulative deficit frailty index and clinical frailty scale to predict an acute episode of delirium among adults admitted to the intensive care. METHODS: This study is a secondary analysis of the Deli intervention study, a hybrid stepped-wedge cluster randomized controlled trial to assess the effectiveness of a nurse-led intervention to reduce the incidence and duration of delirium among adults admitted to the four adult intensive care units in the south-west of Sydney, Australia. Important predictors of delirium were identified using a bootstrap approach and the absolute risks, based on the cumulative deficit frailty index and the clinical frailty scale are presented. RESULTS: During the 10-mth data collection period (May 2019 and February 2020) 2566 patients were included in the study. Both the cumulative deficit frailty index and the clinical frailty scale on admission, plus age, sex, and APACHE III (AP III) score were able to discriminate between patients who did and did not experience an acute episode of delirium while in the intensive care, with AUC of 0.701 and 0.703 (moderate discriminatory ability), respectively. The addition of a frailty index to a prediction model based on age, sex, and APACHE III score, resulted in net reclassified of risk. Nomograms to individualize the absolute risk of delirium using these predictors are also presented. CONCLUSION: We have been able to show that both the cumulative deficits frailty index and clinical frailty scale predict an acute episode of delirium among adults admitted to intensive care.


Asunto(s)
Delirio , Fragilidad , Adulto , Humanos , Cuidados Críticos , Delirio/diagnóstico , Delirio/epidemiología , Fragilidad/diagnóstico , Hospitalización , Unidades de Cuidados Intensivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Masculino , Femenino
16.
Molecules ; 29(5)2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38474596

RESUMEN

Euphorbia is a large genus of the Euphorbiaceae family. Around 250 species of the Euphorbia genus have been studied chemically and pharmacologically; different compounds have been isolated from these species, especially diterpenes and triterpenes. Several reports show that several species have anti-inflammatory activity, which can be attributed to the presence of diterpenes, such as abietanes, ingenanes, and lathyranes. In addition, it was found that some diterpenes isolated from different Euphorbia species have anti-cancer activity. In this review, we included compounds isolated from species of the Euphorbia genus with anti-inflammatory or cytotoxic effects published from 2018 to September 2023. The databases used for this review were Science Direct, Scopus, PubMed, Springer, and Google Scholar, using the keywords Euphorbia with anti-inflammatory or cytotoxic activity. In this review, 68 studies were collected and analyzed regarding the anti-inflammatory and anti-cancer activities of 264 compounds obtained from 36 species of the Euphorbia genus. The compounds included in this review are terpenes (95%), of which 68% are diterpenes, especially of the types ingenanes, abietanes, and triterpenes (approximately 15%).


Asunto(s)
Antineoplásicos , Diterpenos , Euphorbia , Triterpenos , Euphorbia/química , Abietanos , Estructura Molecular , Diterpenos/química , Triterpenos/química , Antiinflamatorios
17.
Molecules ; 29(9)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38731445

RESUMEN

Reducing high concentrations of pollutants such as heavy metals, pesticides, drugs, and dyes from water is an emerging necessity. We evaluated the use of Luffa cylindrica (Lc) as a natural non-conventional adsorbent to remove azo dye mixture (ADM) from water. The capacity of Lc at three different doses (2.5, 5.0, and 10.0 g/L) was evaluated using three concentrations of azo dyes (0.125, 0.250, and 0.500 g/L). The removal percent (R%), maximum adsorption capacity (Qm), isotherm and kinetics adsorption models, and pH influence were evaluated, and Fourier-transform infrared spectroscopy and scanning electron microscopy were performed. The maximum R% was 70.8% for 10.0 g L-1Lc and 0.125 g L-1 ADM. The Qm of Lc was 161.29 mg g-1. Adsorption by Lc obeys a Langmuir isotherm and occurs through the pseudo-second-order kinetic model. Statistical analysis showed that the adsorbent dose, the azo dye concentration, and contact time significantly influenced R% and the adsorption capacity. These findings indicate that Lc could be used as a natural non-conventional adsorbent to reduce ADM in water, and it has a potential application in the pretreatment of wastewaters.


Asunto(s)
Compuestos Azo , Colorantes , Luffa , Contaminantes Químicos del Agua , Purificación del Agua , Luffa/química , Compuestos Azo/química , Compuestos Azo/aislamiento & purificación , Adsorción , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Cinética , Colorantes/química , Concentración de Iones de Hidrógeno , Espectroscopía Infrarroja por Transformada de Fourier , Agua/química
18.
Entropy (Basel) ; 26(1)2024 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-38248204

RESUMEN

Entropy estimation is a fundamental problem in information theory that has applications in various fields, including physics, biology, and computer science. Estimating the entropy of discrete sequences can be challenging due to limited data and the lack of unbiased estimators. Most existing entropy estimators are designed for sequences of independent events and their performances vary depending on the system being studied and the available data size. In this work, we compare different entropy estimators and their performance when applied to Markovian sequences. Specifically, we analyze both binary Markovian sequences and Markovian systems in the undersampled regime. We calculate the bias, standard deviation, and mean squared error for some of the most widely employed estimators. We discuss the limitations of entropy estimation as a function of the transition probabilities of the Markov processes and the sample size. Overall, this paper provides a comprehensive comparison of entropy estimators and their performance in estimating entropy for systems with memory, which can be useful for researchers and practitioners in various fields.

19.
Medicina (Kaunas) ; 60(2)2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38399519

RESUMEN

Non-valvular atrial fibrillation (NVAF) is the most common cardiac arrhythmia in the general population, and its prevalence increases among patients with chronic kidney disease (CKD) undergoing hemodialysis. This population presents high risk of both hemorrhagic and thrombotic events, with little evidence regarding the use of oral anticoagulation treatment (OAT) and multiple complications arising from it; however, stroke prevention with percutaneous left atrial appendage closure (LAAC) is an alternative to be considered. We retrospectively describe the safety and efficacy of percutaneous LAAC in eight patients with NVAF and CKD on hemodialysis during a 12-month follow-up. The mean age was 78.8 years (range 64-86; SD ± 6.7), and seven patients were male. The mean CHA2DS2-VASC and HAS-BLED scores were high, 4.8 (SD ± 1.5) and 3.8 (SD ± 1.3), respectively. Seventy-five percent of the patients were referred for this intervention due to a history of major bleeding, with gastrointestinal bleeding being the most common type, while the remaining twenty-five percent of the patients were referred because of a high risk of bleeding. The percutaneous LAAC procedure was successfully completed in 100% of the patients, with complete exclusion of the appendage without complications or leaks exceeding 5 mm. There was one death not related to the procedure four days after the intervention. Among the other seven patients, no deaths, cardioembolic events or major bleeding were reported during the follow-up period. In our sample, percutaneous LAAC appears to be a safe and effective alternative to anticoagulation in patients with NVAF and CKD on hemodialysis.


Asunto(s)
Apéndice Atrial , Fibrilación Atrial , Fallo Renal Crónico , Insuficiencia Renal Crónica , Accidente Cerebrovascular , Humanos , Masculino , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Femenino , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Accidente Cerebrovascular/epidemiología , Fibrilación Atrial/complicaciones , Fibrilación Atrial/cirugía , Cierre del Apéndice Auricular Izquierdo , Estudios Retrospectivos , Resultado del Tratamiento , Hemorragia/complicaciones , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Insuficiencia Renal Crónica/complicaciones , Anticoagulantes/uso terapéutico , Diálisis Renal/efectos adversos , Apéndice Atrial/cirugía
20.
Small ; 19(6): e2205800, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36587989

RESUMEN

The ability to control the density and spatial distribution of substitutional dopants in semiconductors is crucial for achieving desired physicochemical properties. Substitutional doping with adjustable doping levels has been previously demonstrated in 2D transition metal dichalcogenides (TMDs); however, the spatial control of dopant distribution remains an open field. In this work, edge termination is demonstrated as an important characteristic of 2D TMD monocrystals that affects the distribution of substitutional dopants. Particularly, in chemical vapor deposition (CVD)-grown monolayer WS2 , it is found that a higher density of transition metal dopants is always incorporated in sulfur-terminated domains when compared to tungsten-terminated domains. Two representative examples demonstrate this spatial distribution control, including hexagonal iron- and vanadium-doped WS2 monolayers. Density functional theory (DFT) calculations are further performed, indicating that the edge-dependent dopant distribution is due to a strong binding of tungsten atoms at tungsten-zigzag edges, resulting in the formation of open sites at sulfur-zigzag edges that enable preferential dopant incorporation. Based on these results, it is envisioned that edge termination in crystalline TMD monolayers can be utilized as a novel and effective knob for engineering the spatial distribution of substitutional dopants, leading to in-plane hetero-/multi-junctions that display fascinating electronic, optoelectronic, and magnetic properties.

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