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Transmembrane peptides play important roles in many biological processes by interacting with lipid membranes. This study investigates how the transmembrane domain of the influenza A virus M2 protein, M2TM, affects the structure and mechanics of model lipid bilayers. Atomic force microscopy (AFM) imaging revealed small decreases in bilayer thickness with increasing peptide concentrations. AFM-based force spectroscopy experiments complemented by theoretical model analysis demonstrated significant decreases in bilayer's Young's modulus (E) and lateral area compressibility modulus (KA). This suggests that M2TM disrupts the cohesive interactions between neighboring lipid molecules, leading to a decrease in both the bilayer's resistance to indentation (E) and its ability to resist lateral compression/expansion (KA). The large decreases in bilayer elastic parameters (i.e., E and KA) contrast with small changes in bilayer thickness, implying that bilayer mechanics are not solely dictated by bilayer thickness in the presence of transmembrane peptides. The observed significant reduction in bilayer mechanical properties suggests a softening effect on the bilayer, potentially facilitating membrane curvature generation, a crucial step for M2-mediated viral budding. In parallel, our Raman spectroscopy revealed small but statistically significant changes in hydrocarbon chain vibrational dynamics, indicative of minor disordering in lipid chain conformation. Our findings provide useful insights into the complex interplay between transmembrane peptides and lipid bilayers, highlighting the significance of peptide-lipid interactions in modulating membrane structure, mechanics, and molecular dynamics.
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Layered Ta2M3Te5 (M = Pd, Ni) has emerged as a platform to study 2D topological insulators, which have exotic properties such as spin-momentum locking and the presence of Dirac fermions for use in conventional and quantum-based electronics. In particular, Ta2Ni3Te5 has been shown to have superconductivity under pressure and is predicted to have second-order topology. Despite being an interesting material with fascinating physics, the detailed crystalline and phononic properties of this material are still unknown. In this study, we use transmission electron microscopy (TEM) and polarized Raman spectroscopy (PRS) to reveal the anisotropic properties of exfoliated few-layer Ta2Ni3Te5. An electron diffraction and TEM study reveals structural anisotropy in the material, with a preferential crystal orientation along the [010] direction. Through Raman spectroscopy, we discovered 15 vibrational modes, 3 of which are ultralow-frequency modes, which show anisotropic response with sample orientation varying with the polarization of the incident beam. Using angle-resolved PRS, we assigned the vibrational symmetries of 11 modes to Ag and two modes to B3g. We also found that linear dichroism plays a role in understanding the Raman signature of this material, which requires the use of complex elements in the Raman tensors. The anisotropy of the Raman scattering also depends on the excitation energies. Our observations reveal the anisotropic nature of Ta2Ni3Te5, establish a quick and nondestructive Raman fingerprint for determining sample orientation, and represent a significant advance in the fundamental understanding of the two-dimensional topological insulator (2DTI) Ta2Ni3Te5 material.
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The capacity to manipulate magnetization in 2D dilute magnetic semiconductors (2D-DMSs) using light, specifically in magnetically doped transition metal dichalcogenide (TMD) monolayers (M-doped TX2 , where M = V, Fe, and Cr; T = W, Mo; X = S, Se, and Te), may lead to innovative applications in spintronics, spin-caloritronics, valleytronics, and quantum computation. This Perspective paper explores the mediation of magnetization by light under ambient conditions in 2D-TMD DMSs and heterostructures. By combining magneto-LC resonance (MLCR) experiments with density functional theory (DFT) calculations, we show that the magnetization can be enhanced using light in V-doped TMD monolayers (e.g., V-WS2 , V-WSe2 ). This phenomenon is attributed to excess holes in the conduction and valence bands, and carriers trapped in magnetic doping states, mediating the magnetization of the semiconducting layer. In 2D-TMD heterostructures (VSe2 /WS2 , VSe2 /MoS2 ), the significance of proximity, charge-transfer, and confinement effects in amplifying light-mediated magnetism is demonstrated. We attributed this to photon absorption at the TMD layer that generates electron-hole pairs mediating the magnetization of the heterostructure. These findings will encourage further research in the field of 2D magnetism and establish a novel design of 2D-TMDs and heterostructures with optically tunable magnetic functionalities, paving the way for next-generation magneto-optic nanodevices.
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BACKGROUND: Health and Wellness Coaching (HWC) may be beneficial in chronic condition care. We sought to appraise its effectiveness on quality of life (QoL), self-efficacy (SE), depression, and anxiety. METHODS: We searched MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane CENTRAL for randomized trials published January 2005 - March 2023 that compared HWC to standard clinical care or another intervention without coaching. We examined QoL, SE, depression, or anxiety outcomes. Meta-analysis utilizing the random-effects model was used to estimate the pooled standardized mean difference (SMD). RESULTS: Thirty included studies demonstrated that HWC improved QoL within 3 months (SMD 0.62 95 % CI 0.22-1.02, p = 0.002), SE within 1.5 months (SMD 0.38, 95 % CI 0.03-0.73, p = 0.03), and depression at 3, 6, and 12 months (SMD 0.67, 95 % CI 0.13-1.20, p = 0.01), (SMD 0.72, 95 % CI 0.19-1.24, p = 0.006), and (SMD 0.41, 95 % CI 0.09-0.73, p = 0.01) Certainty in the evidence for most outcomes was either very low or low primarily due to the high risk of bias, heterogeneity, and imprecision. CONCLUSION: HWC improves QoL, SE, and depression across chronic illness populations. Future research needs to standardize intervention reporting and outcome collection. PRACTICE IMPLICATIONS: Future HWC studies should standardize intervention components, reporting, and outcome measures, apply relevant chronic illness theories, and aim to follow participants for greater than one year.
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Tutoria , Qualidade de Vida , Humanos , Depressão/terapia , Doença Crônica , Medidas de Resultados Relatados pelo PacienteRESUMO
Background: The acquisition of language in infants is largely the result of the process of brain maturation, as well as environmental stimulation. Currently, society is in an era of technology and use of electronic devices from an early age. Objective: The aim of this study was to demonstrate if the amount of time of use of electronic devices in children under 5 years of age affects language development. Methods: An observational, comparative, survey-type study was carried out in 269 infants of both sexes, with an age range of 6 to <60 months. The language development section of the Child Development Scale (EDI) was used. A logistic regression was performed to determine the strength of association between the factors to be studied. Results: 269 participants were included, of which 224 (83.2%) presented their level of neurological maturation, 44 infants (16.4%) presented laged development and one (0.4%) was classified as having developmental delay. It was found that the number of daily hours that an electronic device is used behaved as a risk factor by increasing the risk of delayed language development by 1.37 times for each hour of exposure (OR: 1.37, CI95%: 1.15-1.62). Conclusions: It was shown that a greater number of hours of use of electronic devices is a risk factor for delayed language development in children under 5 years of age. Therefore, it is vital to limit its use in this population.
Introducción: la adquisición del lenguaje en los infantes es, en gran medida, resultado del proceso de maduración cerebral, así como de la estimulación ambiental. En la actualidad, la sociedad se encuentra en una era de tecnología y uso de dispositivos electrónicos desde temprana edad. Objetivo: evaluar el efecto del tiempo de uso de dispositivos electrónicos en los menores de 5 años en el área del lenguaje. Métodos: se realizó un estudio observacional, comparativo, tipo encuesta, en infantes con rango de edad de 6 a < 60 meses de ambos sexos. Se utilizó la sección para medir desarrollo del lenguaje de la Escala de Desarrollo Infantil (EDI). Adicionalmente, se llevó a cabo una regresión logística con el objetivo de determinar la fuerza de asociación entre los factores a estudiar. Resultados: se incluyeron 269 participantes, de los cuales 224 de ellos (83.2%) correspondían a su nivel de maduración neurológica, 44 infantes (16.4%) presentaron rezago en su desarrollo y uno (0.4%) se clasificó con retraso en el desarrollo. Encontramos que el número de horas diarias utilizando algún dispositivo electrónico se comportó como factor de riesgo, aumentando 1.37 veces el riesgo de retraso en el desarrollo del lenguaje por cada hora de exposición (OR: 1.37, IC95%: 1.15-1.62). Conclusiones: un mayor número de horas de uso de los dispositivos electrónicos es factor de riesgo para presentar retraso en el desarrollo del lenguaje en menores de 5 años.
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Desenvolvimento da Linguagem , Idioma , Masculino , Lactente , Feminino , Criança , Humanos , Pré-Escolar , Fatores de RiscoRESUMO
OBJECTIVE: To assess the prevalence of bullying in medical residents and its associated factors. METHODS: In this systematic review and meta-analysis, articles from MEDLINE, EMBASE, Scopus, PsycInfo, Cochrane databases, and Web of Science were searched. Published and unpublished cross-sectional studies were included. Cochrane's Q test and I2 statistics were used to assess the existence of heterogeneity. Subgroup analysis and sensitivity analysis were performed on evidence of heterogeneity. Egger's test and funnel plots were performed to investigate publication bias. RESULTS: A total of 13 cross-sectional studies with a total of 44 566 study participants from different medical residencies were analyzed. The overall prevalence of bullying was 51% (95% CI 36-66). Furthermore, female residents and residents that belong to a minority group had higher odds of experiencing bullying compared to their peers. CONCLUSION: A high prevalence of bullying in medical residents exists around the world. There is a need for education, dissemination, and more effective interventions among the residents and authorities about bullying to build and promote adequate behaviors and diminish bullying prevalence.
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Internato e Residência , Humanos , Feminino , Prevalência , Estudos Transversais , Projetos de PesquisaRESUMO
BACKGROUND: The morbidity and mortality of intracranial aneurysm rupture motivate the risk evaluation of the patient´s characteristics and aneurysm's morphology. Brain vessel variants lead to hemodynamic changes that could increase risk. This study aims to evaluate the fetal posterior cerebral artery (fPCA) as a risk factor for the formation, rupture, and recurrence of the posterior communicating artery (PComA) aneurysm. METHODS: A search strategy was performed in MEDLINE, Scopus, Web of Science, and EMBASE databases for studies that evaluated the risk of appearance, rupture, and recurrence of PComA aneurysms with the presence of fPCA. Newcastle-Ottawa Scale and AXIS were used for quality assessment. The primary and secondary outcomes were evaluated and interpreted with an odds ratio (OR) and their 95% confidence intervals (CI). RESULTS: A total of 577 articles were reviewed. Thirteen studies were included for the qualitative analysis, and ten studies for the meta-analysis. All cohort studies were classified as poor quality, and all cross-sectional studies with moderate risk. The unadjusted OR resulted in 1.57 (n = 6, 95% CI 1.13-2.19, p = <0.001, I2 =0%) between the presence of fPCA and PComA aneurysm rupture. CONCLUSION: There is a significant association of aneurysm formation and rupture of PComA aneurysms in the presence of fPCA. This may be triggered by the hemodynamic alterations caused by the variation, leading to changes in the vessel wall.
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Aneurisma Roto , Aneurisma Intracraniano , Humanos , Aneurisma Intracraniano/complicações , Aneurisma Intracraniano/diagnóstico por imagem , Artéria Cerebral Posterior/diagnóstico por imagem , Estudos Transversais , Estudos Retrospectivos , Aneurisma Roto/etiologiaRESUMO
Circulating microRNAs (c-miRNAs) during pregnancy could provide information regarding the functional status of the mother and fetus. However, it remains unclear which pregnancy-related processes are actually reflected by changes c-miRNAs. Here, we used large-scale c-miRNA profiling of maternal plasma during and post-pregnancy, and compared it with that of non-pregnant women. Fetal growth measurements and fetal sex data were used to identify associated changes in these transcripts. Surprisingly, c-miRNA subpopulations with prominent expression in maternal/fetal compartments (placenta, amniotic fluid, umbilical cord plasma and breast milk) were found to be under-expressed in circulation throughout pregnancy relative to non-pregnant plasma profiles. Furthermore, we found a bias in global c-miRNA expression in association with fetal sex right from the first trimester, in addition to a specific c-miRNA signature of fetal growth. Our results demonstrate the existence of specific temporal changes in c-miRNA populations associated with specific pregnancy-related compartments and processes, including fetal sex, and growth.
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MicroRNA Circulante , MicroRNAs , Gravidez , Feminino , Humanos , Placenta/metabolismo , MicroRNAs/metabolismo , Líquido Amniótico/metabolismoRESUMO
The magnetic proximity effect (MPE) has recently been explored to manipulate interfacial properties of two-dimensional (2D) transition metal dichalcogenide (TMD)/ferromagnet heterostructures for use in spintronics and valleytronics. However, a full understanding of the MPE and its temperature and magnetic field evolution in these systems is lacking. In this study, the MPE has been probed in Pt/WS2/BPIO (biphase iron oxide, Fe3O4 and α-Fe2O3) heterostructures through a comprehensive investigation of their magnetic and transport properties using magnetometry, four-probe resistivity, and anomalous Hall effect (AHE) measurements. Density functional theory (DFT) calculations are performed to complement the experimental findings. We found that the presence of monolayer WS2 flakes reduces the magnetization of BPIO and hence the total magnetization of Pt/WS2/BPIO at T > ~120 K-the Verwey transition temperature of Fe3O4 (TV). However, an enhanced magnetization is achieved at T < TV. In the latter case, a comparative analysis of the transport properties of Pt/WS2/BPIO and Pt/BPIO from AHE measurements reveals ferromagnetic coupling at the WS2/BPIO interface. Our study forms the foundation for understanding MPE-mediated interfacial properties and paves a new pathway for designing 2D TMD/magnet heterostructures for applications in spintronics, opto-spincaloritronics, and valleytronics.
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To determine the effect of Trendelenburg position on the diameter or cross-section area of the internal jugular vein (IJV) a systematic review and metanalysis was performed. Studies that evaluated the cross-sectional area (CSA) and anteroposterior (AP) diameter of the right internal jugular vein (RIJV) with ultrasonography in supine and any degree of head-down tilt (Trendelenburg position) were analyzed. A total of 22 articles (613 study subjects) were included. A >5° Trendelenburg position statistically increases RIJV CSA and AP diameter. Further inclination from 10° does not statistically benefit IJV size. This position should be recommended for CVC placement, when patient conditions allow it, and US-guided cannulation is not available.
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Cateterismo Venoso Central , Decúbito Inclinado com Rebaixamento da Cabeça , Veias Jugulares , Humanos , Veias Jugulares/diagnóstico por imagem , Posicionamento do Paciente , UltrassonografiaRESUMO
We report a systematic investigation of the magnetic properties including the exchange bias (EB) effect in an iron oxide nanocube system with tunable phase and average size (10, 15, 24, 34, and 43 nm). X-ray diffraction and Raman spectroscopy reveal the presence of Fe3O4, FeO, andα-Fe2O3phases in the nanocubes, in which the volume fraction of each phase varies depending upon particle size. While the Fe3O4phase is dominant in all and tends to grow with increasing particle size, the FeO phase appears to coexist with the Fe3O4phase in 10, 15, and 24 nm nanocubes but disappears in 34 and 43 nm nanocubes. The nanocubes exposed to air resulted in anα-Fe2O3oxidized surface layer whose thickness scaled with particle size resulting in a shell made ofα-Fe2O3phase and a core containing Fe3O4or a mixture of both Fe3O4and FeO phases. Magnetometry indicates that the nanocubes undergo Morin (of theα-Fe2O3phase) and Verwey (of the Fe3O4phase) transitions at â¼250 K and â¼120 K, respectively. For smaller nanocubes (10, 15, and 24 nm), the EB effect is observed below 200 K, of which the 15 nm nanocubes showed the most prominent EB with optimal antiferromagnetic (AFM) FeO phase. No EB is reported for larger nanocubes (34 and 43 nm). The observed EB effect is ascribed to the strong interfacial coupling between the ferrimagnetic (FiM) Fe3O4phase and AFM FeO phase, while its absence is related to the disappearance of the FeO phase. The Fe3O4/α-Fe2O3(FiM/AFM) interfaces are found to have negligible influence on the EB. Our findings shed light on the complexity of the EB effect in mixed-phase iron oxide nanosystems and pave the way to design exchange-coupled nanomaterials with desirable magnetic properties for biomedical and spintronic applications.
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Senescent cells accumulate within tissues during aging and secrete an array of pro-inflammatory molecules known as senescent-associated secretory phenotype (SASP), which contribute to the appearance and progression of various chronic degenerative diseases. Novel pharmacological approaches aimed at modulating or eliminating senescent cells´ harmful effects have recently emerged: Senolytics are molecules that selectively eliminate senescent cells, while senomorphics modulate or decrease the inflammatory response to specific SASP. So far, the physicochemical, structural, and pharmacological properties that define these two kinds of pharmacological approaches remain unclear. Therefore, the identification and correct choice of molecules, based on their physicochemical, structural, and pharmacological properties, likely to exhibit the desired senotherapeutic activity is crucial for developing effective, selective, and safe senotherapies. Here we compared the physicochemical, structural, and pharmacological properties of 84 senolytics and 79 senomorphics using a chemoinformatic and systems pharmacology approach. We found great physicochemical, structural, and pharmacological similarities between them, also reflected in their cellular responses measured through transcriptome perturbations. The identified similarities between senolytics and senomorphics might explain the dual activity of some of those molecules. These findings will help design and discover new, more effective, and highly selective senotherapeutic agents.
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Senescência Celular , Senoterapia , Senescência Celular/fisiologia , Quimioinformática , Doença Crônica , Humanos , Farmacologia em RedeRESUMO
Background: Specific IgE against Staphylococcus can be found in approximately 40% of patients with allergies, also in patients without allergies because they may be sensitized. These antibodies are functional, and they can induce histamine release contributing to chronic pruritus which can worsen disease severity. The objective of this study was to compare levels of specific IgE against S. aureus toxins in those populations. Methods: A cross-sectional, comparative non-blinded survey was made at the Regional Center for Allergy and Clinical Immunology. Ninety-nine adults between 18 and 70 years of age with allergic rhinitis (AR) and without allergic rhinitis (wAR) were recruited. A clinical history and demographic data, and allergic sensitization patterns to 35 aeroallergens were obtained, and participants were classified according to their severity using the Allergic Rhinitis and Its Impact on Asthma (ARIA) classification. Specific IgE levels were determined using ImmunoCAP™ 100 platform. Results: The median age (IQR) of the participants was 23 (20-33.7); 56.2% were women. The most frequent comorbidities were asthma and obesity. Of the patients with AR, 46.7% were classified as mild intermittent and 25% as moderate persistent. IgE levels against staph toxins A, B, and TSST were significantly higher in the AR group vs the wAR group [median IQR 0.01 (0.01-0.03) vs. 0.01 (0-0.02), p = 0.01; 0.02 (0.01-0.03) vs. 0.01 (0-0.02), p= 0.02; 0.04 (0.02-0.09) vs. 0.01 (0-0.04), p=0.002, respectably]. A significant difference was found in serum IgE levels against Staph B toxin between severity subgroups. Conclusion: People with AR have higher IgE levels against staph toxins A, B and TSST than wAR subjects. However, it is not possible declare that the IgE titers were related to disease severity.
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Magnetic field- and polarization-dependent measurements on bright and dark excitons in monolayer WSe2 combined with time-dependent density functional theory calculations reveal intriguing phenomena. Magnetic fields up to 25 T parallel to the WSe2 plane lead to a partial brightening of the energetically lower lying exciton, leading to an increase of the dephasing time. Using a broadband femtosecond pulse excitation, the bright and partially allowed excitonic state can be excited simultaneously, resulting in coherent quantum beating between these states. The magnetic fields perpendicular to the WSe2 plane energetically shift the bright and dark excitons relative to each other, resulting in the hybridization of the states at the K and K' valleys. Our experimental results are well captured by time-dependent density functional theory calculations. These observations show that magnetic fields can be used to control the coherent dephasing and coupling of the optical excitations in atomically thin semiconductors.
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Two-dimensional (2D) semiconducting materials have promising applications in flexible optoelectronics, nanophotonics, and sensing based on the broad tunability of their optical and electronic properties. 2D nanobubbles form exciton funnels due to localized strain that can be used as local emitters for information processing. Their nanoscale optical characterization requires the use of near-field scanning probe microscopy (SPM). However, previous near-field studies of 2D materials were performed on SiO2/Si and metallic substrates using the plasmonic gap mode to increase the signal-to-noise ratio. Another challenge is the deterministic control of bubble size and location. We addressed these challenges by investigating the photoluminescence (PL) signals of freestanding monolayer lateral WSe2-MoSe2 heterostructures under the influence of strain exerted by a plasmonic SPM tip. For first time, we performed tip-enhanced PL imaging of freestanding 2D materials and studied the competition between the PL enhancement mechanisms by nanoindentation as a function of the tip-sample distance. We observed the tunability of PL as a function of bubble size, which opens new possibilities to design optoelectronic nanodevices.
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2D heterostructures made of transition metal dichalcogenides (TMD) have emerged as potential building blocks for new-generation 2D electronics due to their interesting physical properties at the interfaces. The bandgap, work function, and optical constants are composition dependent, and the spectrum of applications can be expanded by producing alloy-based heterostructures. Herein, the successful synthesis of monolayer and bilayer lateral heterostructures, based on ternary alloys of MoS2(1- x ) Se2 x -WS2(1- x ) Se2 x , is reported by modifying the ratio of the source precursors; the bandgaps of both materials in the heterostructure are continuously tuned in the entire range of chalcogen compositions. Raman and photoluminescence (PL) spatial maps show good intradomain composition homogeneity. Kelvin probe measurements in different heterostructures reveal composition-dependent band alignments, which can further be affected by unintentional electronic doping during the growth. The fabrication of sequential multijunction lateral heterostructures with three layers of thickness, composed of quaternary and ternary alloys, is also reported. These results greatly expand the available tools kit for optoelectronic applications in the 2D realm.
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Mexico has experienced one of the highest COVID-19 mortality rates in the world. A delayed implementation of social distancing interventions in late March 2020 and a phased reopening of the country in June 2020 has facilitated sustained disease transmission in the region. In this study we systematically generate and compare 30-day ahead forecasts using previously validated growth models based on mortality trends from the Institute for Health Metrics and Evaluation for Mexico and Mexico City in near real-time. Moreover, we estimate reproduction numbers for SARS-CoV-2 based on the methods that rely on genomic data as well as case incidence data. Subsequently, functional data analysis techniques are utilized to analyze the shapes of COVID-19 growth rate curves at the state level to characterize the spatiotemporal transmission patterns of SARS-CoV-2. The early estimates of the reproduction number for Mexico were estimated between Rt ~1.1-1.3 from the genomic and case incidence data. Moreover, the mean estimate of Rt has fluctuated around ~1.0 from late July till end of September 2020. The spatial analysis characterizes the state-level dynamics of COVID-19 into four groups with distinct epidemic trajectories based on epidemic growth rates. Our results show that the sequential mortality forecasts from the GLM and Richards model predict a downward trend in the number of deaths for all thirteen forecast periods for Mexico and Mexico City. However, the sub-epidemic and IHME models perform better predicting a more realistic stable trajectory of COVID-19 mortality trends for the last three forecast periods (09/21-10/21, 09/28-10/27, 09/28-10/27) for Mexico and Mexico City. Our findings indicate that phenomenological models are useful tools for short-term epidemic forecasting albeit forecasts need to be interpreted with caution given the dynamic implementation and lifting of social distancing measures.
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COVID-19/epidemiologia , COVID-19/transmissão , Previsões , Pandemias/estatística & dados numéricos , Humanos , México/epidemiologia , Modelos Estatísticos , Fatores SocioeconômicosRESUMO
The purpose was to assess prevalence of suicidality, depression, post-traumatic stress disorder (PTSD), and anxiety among female sex workers (FSW). A systematic review and meta-analysis was performed. Search strategy was performed in MEDLINE, Scopus, Web of Science, EMBASE, Ovid and Cochrane Central Database from inception until March 2020. Considered for inclusion were cross-sectional studies performed on FSW that assessed prevalence of any of the following: suicide attempt or suicidal ideation, depression, PTSD, or anxiety. Five reviewers, independently and in duplicate, selected all eligible articles in an abstract and full-text screening phase and, moreover, extracted information from each study. A binomial-normal generalized linear mixed model was employed to estimate prevalence of the conditions. From 8035 studies yielded in the search strategy, 55 were included for analysis. The overall prevalence of suicidal ideation and attempt was 27% (95% C.I. 18-39%) and 20% (95% C.I. 13-28%), respectively. Furthermore, overall prevalence of depression and PTSD was 44% (95% C.I. 35-54%) and 29% (95% C.I. 18-44%), respectively. Eleven studies were classified as high quality. Findings indicate that there is an overall high prevalence of suicidality, depression, and PTSD among FSW. Development of accessible large-scale interventions that assess mental health among this population remains critical.
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Profissionais do Sexo , Transtornos de Estresse Pós-Traumáticos , Suicídio , Ansiedade/epidemiologia , Depressão/epidemiologia , Feminino , Humanos , Prevalência , Transtornos de Estresse Pós-Traumáticos/epidemiologiaRESUMO
Transcriptomes are known to organize themselves into gene co-expression clusters or modules where groups of genes display distinct patterns of coordinated or synchronous expression across independent biological samples. The functional significance of these co-expression clusters is suggested by the fact that highly coexpressed groups of genes tend to be enriched in genes involved in common functions and biological processes. While gene co-expression is widely assumed to reflect close regulatory proximity, the validity of this assumption remains unclear. Here we use a simple synthetic gene regulatory network (GRN) model and contrast the resulting co-expression structure produced by these networks with their known regulatory architecture and with the co-expression structure measured in available human expression data. Using randomization tests, we found that the levels of co-expression observed in simulated expression data were, just as with empirical data, significantly higher than expected by chance. When examining the source of correlated expression, we found that individual regulators, both in simulated and experimental data, fail, on average, to display correlated expression with their immediate targets. However, highly correlated gene pairs tend to share at least one common regulator, while most gene pairs sharing common regulators do not necessarily display correlated expression. Our results demonstrate that widespread co-expression naturally emerges in regulatory networks, and that it is a reliable and direct indicator of active co-regulation in a given cellular context.
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Biologia Computacional/métodos , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Sequências Reguladoras de Ácido Nucleico , Fatores de Transcrição/metabolismo , Adolescente , Adulto , Algoritmos , Encéfalo/fisiologia , Criança , Pré-Escolar , Perfilação da Expressão Gênica/métodos , Humanos , Lactente , Recém-Nascido , Adulto JovemRESUMO
Exponential growth in the field of covalent-organic frameworks (COFs) is emanating from the direct correlation between designing principles and desired properties. The comparison of catalytic activity between single-pore and dual-pore COFs is of importance to establish structure-function relationship. Herein, the synthesis of imine-linked dual-pore [(BPyDC)]x % -ETTA COFs (x = 0%, 25%, 50%, 75%, 100%) with controllable bipyridine content is fulfilled by three-component condensation of 4,4',4â³,4'â³-(ethene-1,1,2,2-tetrayl)tetraaniline (ETTA), 4,4'-biphenyldialdehyde, and 2,2'-bipyridyl-5,5'-dialdehyde in different stoichiometric ratio. The strong coordination of bipyridine moieties of [(BPyDC)]x % -ETTA COFs with palladium imparts efficient catalytic active sites for selective functionalization of sp2 CH bond to CX (X = Br, Cl) or CO bonds in good yield. To broaden the scope of regioselective CH functionalization, a wide range of electronically and sterically substituted substrates under optimized catalytic condition are investigated. A comparison of the catalytic activity of palladium decorated dual-pore frameworks with single-pore imine-linked Pd(II)â@âPy-2,2'-BPyDC frameworkâ is undertaken. The finding of this work provides a sporadic example of chelation-assisted CH functionalization and disclosed an in-depth comparison of the relationship between superior catalytic activity and core properties of rationally designed imine linked frameworks.