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Sleep facilitates abstraction, but the exact mechanisms underpinning this are unknown. Here, we aimed to determine whether triggering reactivation in sleep could facilitate this process. We paired abstraction problems with sounds, then replayed these during either slow-wave sleep (SWS) or rapid eye movement (REM) sleep to trigger memory reactivation in 27 human participants (19 female). This revealed performance improvements on abstraction problems that were cued in REM, but not problems cued in SWS. Interestingly, the cue-related improvement was not significant until a follow-up retest 1 week after the manipulation, suggesting that REM may initiate a sequence of plasticity events that requires more time to be implemented. Furthermore, memory-linked trigger sounds evoked distinct neural responses in REM, but not SWS. Overall, our findings suggest that targeted memory reactivation in REM can facilitate visual rule abstraction, although this effect takes time to unfold.SIGNIFICANCE STATEMENT The ability to abstract rules from a corpus of experiences is a building block of human reasoning. Sleep is known to facilitate rule abstraction, but it remains unclear whether we can manipulate this process actively and which stage of sleep is most important. Targeted memory reactivation (TMR) is a technique that uses re-exposure to learning-related sensory cues during sleep to enhance memory consolidation. Here, we show that TMR, when applied during REM sleep, can facilitate the complex recombining of information needed for rule abstraction. Furthermore, we show that this qualitative REM-related benefit emerges over the course of a week after learning, suggesting that memory integration may require a slower form of plasticity.
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Sinais (Psicologia) , Consolidação da Memória , Humanos , Feminino , Sono REM/fisiologia , Aprendizagem/fisiologia , Sono/fisiologia , Consolidação da Memória/fisiologiaRESUMO
2-Acetyl-3,4-dihydropyrans, assembled from acetylene gas and ketones in a one-pot procedure, are ethynylated with acetylenes (KOBut/DMSO, 15 °C, 2 h) to give acetylenic alcohols, which readily cyclize (TFA, rt, 5 min) to 7-ethynyl-6,8-dioxabicyclo[3.2.1]octanes in up to 92% yield. The ring closure of the above acetylenic alcohols can be performed without their isolation from the reaction mixture. Thus, the synthesis of 7-ethynyl-6,8-dioxabicyclo[3.2.1]octanes can be realized in just two synthetic operations from simple and available starting materials under mild transition-metal-free conditions.
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Tetrahydropyrrolo[1,2-d]oxadiazoles have been synthesized in good-to-excellent yields via the cycloaddition of nitrile oxides (in situ generated from aldoximes) to readily accessible functionalized Δ1-pyrrolines. The reaction proceeds smoothly at room temperature in a two-phase system in the presence of sodium hypochloride as an oxidant to diastereoselectively afford pharmaceutically prospective 1,2,4-oxadiazolines fused with a five-membered ring. The reaction tolerates a broad range of substrates, including those with oxidant-sensitive functional groups and competitive reaction sites.
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An efficient one-pot synthesis of 1,2,5-trisubstituted-1,2-dihydro-3H-pyrrole-3-thiones (up to 91% yield), representatives of essentially new heterocyclic systems, by the successive treatment of available propargylamines with acyl chlorides (PdCl2/CuI/Ph3P/Et3N, toluene, 40-45 °C, 3 h) and sodium sulfide (Na2S·9H2O, EtOH, 20-25 °C, 7 h) has been developed. The synthesis comprises the addition of sulfide anions to the formed aminoacetylenic ketones followed by dehydrative cyclization of the prototropically rearranged adducts.
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We have discovered that three molecules of arylacetylene are rapidly (15 min) assembled with one molecule of nitrile at room temperature in the KOBut/DMSO system to afford 2-aryl-3-arylethynyl-4-aryl-5-benzyl-1H-pyrroles in up to 76% yield. We assume that this unprecedented self-organization process involves the cascade addition of acetylenic carbanions, first to the CîN, then to the CîC and CîC bonds of the intermediates, followed by pyrrole ring closure via the intramolecular nucleophilic addition of the NH functional group to the CîC bond of the final intermediates.
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A convenient synthesis of pyrrolo[2,1-a]isoquinolinium salts from 1-pyrrolines and alkynes through rhodium-catalyzed C-H functionalization/N-annulation tandem reaction is described. The protocol features a good substrate tolerance, mild reaction conditions, and high yields of target products. Exploration of the alkyne scope unexpectedly revealed a novel labile functional group-promoted rhodium-catalyzed C-H functionalization/C-annulation/elimination cascade reaction of 1-pyrrolines with electron-deficient alkynes.
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Semistabilized diazatrienyl anions are generated by the reaction of 2-pyridylarylimines with arylacetylenes in superbase systems MOtBu (M = Li, Na, K)/DMSO at ambient temperature for 15 min. The initial intermediate N-centered propargyl-1,3-diaza-1,3,5-trienyl anions undergo intermolecular cyclization to benzyl imidazopyridine anions (formally [3 + 2] cycloaddition), further intercepting a second molecule of the starting pyridylimines or a proton of medium to afford (Z)-stilbene/imidazopyridine ensembles and benzyl imidazopyridines. The charge distribution in all intermediate anions and their synthetic evolution are consistent with quantum-chemical analysis (B2PLYPD/6-311+G**//B3LYP/6-31+G*).
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Pure (E)-alkenoyl dihydropyrans are stereoselectively assembled from 2-acetyl-3,4-dihydropyrans (products of one-pot self-organization of acetylene gas and ketones) and aromatic aldehydes (52-86% yields). Furthermore, (E)-alkenoyl dihydropyrans undergo ring opening (acid hydrolysis) to afford 5-hydroxy-1,6-diketones (44-67% yields) and acetyl-2-(E)-styryl-2,3-dihydroxycyclopentanes (19-32% yields), both as single diastereomers.
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Acetileno , Cetonas , Ciclopentanos , Estrutura Molecular , EstereoisomerismoRESUMO
6-Methylene-5-oxaspiro[2.4]heptanones have been synthesized via base-catalyzed dimerization of available alkynyl cyclopropyl ketones. The reaction proceeds effectively in the presence of the t-BuOK/t-BuOH/THF catalytic system at room temperature to afford the desired spirocycles in a regio- and stereoselective manner. A wider synthetic utility of alkynyl cyclopropyl ketones as novel building blocks was demonstrated by the synthesis of diverse spirocyclopropanes.
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Cetonas , Catálise , EstereoisomerismoRESUMO
BACKGROUND: Evidence from low-income settings around early education interventions that can improve young children's development is sparse, particularly with regard to the most marginalized children. This study used a two-arm parallel cluster randomized control design to evaluate the impact of an adapted staff training programme on the developmental outcomes of children attending community-based early learning centres in Thyolo district, rural Malawi. METHODS: At baseline we randomly selected 48 centres, from each of which 20 children were randomly selected, although data from one centre was incomplete resulting in 932 children from 47 centres. Centres were randomly allocated to either the intervention or control arm. Twelve months later, follow-up data were collected from 44 centres. At baseline and endline, community-based childcare centre (CBCC) managers provided information about the centre, and parents/guardians provided information on the children, including the primary outcomes of age-standardized development scores in the language and social domains, measured using the Malawi Developmental Assessment Tool. Children in the bottom 2.5 percentile of either domain were considered to have a delay; a third outcome variable, Any Delay, was developed to indicate children with a delay in either or both domains. Centre-level mean scores were calculated, and linear regression models were constructed to assess differences between baseline and endline and between allocation groups. RESULTS: Analysis of the difference between baseline and endline measures in the allocation groups shows a non-significant reduction in delay associated with the study intervention across all domains. Adjustment for baseline characteristics within the CBCCs showed little impact on the magnitude of the observed effect, and the difference remained non-significant. CONCLUSIONS: Despite no observed differences between allocation groups, the data did indicate a positive change in the intervention groups in both domains, particularly language. Community-based early learning in Malawi holds tremendous potential for promoting inclusive development and learning.
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Creches , Desenvolvimento Infantil , Criança , Pré-Escolar , Intervenção Educacional Precoce/métodos , Humanos , Malaui , Pais/educaçãoRESUMO
Background and Purpose: IV tPA (intravenous thrombolysis with alteplase) and mechanical thrombectomy (MT) utilization increased in acute ischemic stroke hospitalizations in the United States over the last decade. It is uncertain whether this increase occurred equally across all age, sex, and racial groups. Methods: Adult acute ischemic stroke hospitalizations (weighted n=4 442 657) contained in the 2008 to 2017 National Inpatient Sample were identified using International Classification of Diseases codes. Proportions of hospitalizations with IV tPA and MT were computed according to age, sex, and race. Joinpoint and multivariable-adjusted logistic regression models were used to evaluate trends over time. Results: Across this period, 32.4% of all hospitalizations were in patients ≥80 years, and 64.7% of these were women. IV tPA and MT use differed by age with highest proportion of utilization of both treatments in patients aged 18 to 39 years (IV tPA, 12.3%) and lowest percentage in patients aged ≥90 years (IV tPA, 7.9%). Utilization of both procedures increased over time in all age groups, but the pace of increase was faster in patients ≥90 years compared with patients aged 18 to 39 years (MT: odds ratio, 1.25 [95% CI, 1.201.35] per unit increase in year, P interaction <0.001). Frequency of utilization of IV tPA and MT was lower in Black patients compared with White patients in most age groups. Usage of both procedures increased over time in all races and after 2015, IV tPA utilization was >10% in all demographic subgroups except in Black patients 60 to 79 years and Black patients ≥80 years. Analysis of race-by-time interaction revealed the Black-vs-White treatment gaps for IV tPA (odds ratio, 1.02 [95% CI, 1.011.03]) and MT (odds ratio, 1.08 [95% CI,1.051.12]) declined over time (both P interaction <0.01). Sex-related differences in IV tPA use were noted, but this gap also declined over time. Conclusions: Age- and sex-related treatment gaps in IV tPA and MT reduced over the last decade. Racial disparity in IV tPA and MT utilization persists with particularly lower frequency of usage of both acute stroke treatments in Black patients compared with White patients, but race-associated treatment gaps also declined over time.
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Fibrinolíticos/uso terapêutico , Disparidades em Assistência à Saúde/tendências , Racismo/tendências , Acidente Vascular Cerebral/terapia , Trombectomia/tendências , Ativador de Plasminogênio Tecidual/uso terapêutico , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores Sexuais , Acidente Vascular Cerebral/epidemiologia , Fatores de Tempo , Estados Unidos/epidemiologia , Adulto JovemRESUMO
The mechanism of aldol condensation of ketones in KOH/DMSO superbasic media has been investigated using the B2PLYP(D2)/6-311+G**//B3LYP/6-31+G* quantum-chemical approach. It is found that the interaction of three ketone molecules resulting in the formation of the cyclohex-2-enone structure [isophorone or 3,5-dicyclohexyl-5-methylspiro(5.5)undec-2-en-1-one] is thermodynamically more favorable than the interaction of two, three, or four molecules of ketone, resulting in the formation of linear products of the condensation. The formation of the condensation products with the isophorone skeleton can significantly hinder the cascade reactions of ketones with acetylenes [to afford 6,8-dioxabicyclo(3.2.1)octanes or acylcyclopentenols] promoted by superbases. In particular, the kinetically more preferable reactions of autovinylation of 2-methyl-3-butyn-2-ol and autocondensation of acetone are the reasons why interaction of acetone with acetylene does not lead to the products of the cascade assemblies. The predominant formation of the products of these side reactions is confirmed experimentally.
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A novel one-pot two-step approach for the synthesis of 2,4,6-triarylpyridines via t-BuOK/DMSO-promoted C-vinylation of a variety of methyl ketones with electron-deficient acetylenes (alkynones) followed by a cyclization of the in situ generated unsaturated 1,5-dicarbonyl species with ammonium acetate has been developed. This approach possesses competitive advantages such as high regioselectivity, available starting materials and the absence of transition-metal catalysts, oxidants and undesirable byproducts. A wide synthetic utility of the developed approach was demonstrated by the synthesis of trisubstituted, tetrasubstituted and fused pyridines.
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BACKGROUND: Visual impairment in children is a significant public health problem affecting millions of children globally. Many eye problems experienced by children can be easily diagnosed and treated. We conducted a qualitative study with teachers and optometrists involved in a school-based vision screening programme in Quetta district of Pakistan to explore their experiences of training, vision screening and referrals and to identify factors impacting on the effectiveness of the programme. METHODS: Between April 2018 and June 2018, we conducted semi-structured in-depth interviews with 14 teachers from eight purposefully selected schools with high rates of inaccurate (false positive) referrals. Interviews were also conducted with three optometrists from a not-for profit private eye care hospital that had trained the teachers. Interviews were audio recorded and professionally transcribed. NVIVO software version 12 was used to code and thematically analyze the data. RESULTS: Findings suggest that the importance of school-based vision screening was well understood and appreciated by the teachers and optometrists. Most participants felt that there was a strong level of support for the vision screening programme within the participating schools. However, there were a number of operational issues undermining the quality of screening. Eight teachers felt that the duration of the training was insufficient; the training was rushed; six teachers said that the procedures were not sufficiently explained, and the teachers had no time to practice. The screening protocol was not always followed by the teachers. Additionally, many teachers reported being overburdened with other work, which affected both their levels of participation in the training and the time they spent on the screening. CONCLUSIONS: School-based vision screening by teachers is a cost-effective strategy to detect and treat children's vision impairment early on. In the programme reviewed here however, a significant number of teachers over referred children to ophthalmic services, overwhelming their capacity and undermining the efficiency of the approach. To maximise the effectiveness and efficiency of school-based screening, future initiatives should give sufficient attention to the duration of the teacher training, experience of trainers, support supervision, refresher trainings, regular use of the screening guidelines, and the workload and motivation of those trained.
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Capacitação de Professores , Seleção Visual , Criança , Humanos , Paquistão , Pesquisa Qualitativa , Instituições AcadêmicasRESUMO
Expedient protocols for the synthesis of three types of highly functionalized azaheterocyclic scaffolds (dihydropyridazines, tetrahydropyridazines, and partially saturated tricyclic systems) from readily available hydroxypyrrolines and hydrazides are described. The directions of the transformation of a common initial intermediate, namely a Brønsted acid-activated hydroxypyrroline, depend on the reaction conditions and the structure of the hydrazides.
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Unique bridgehead nitrones, 8-oxa-6-azabicyclo[3.2.1]oct-6-ene 6-oxides, have been assembled diastereoselectively via acetyldihydropyrans, products of one-pot self-organization of two molecules of ketones and two molecules of acetylene, which after oximation undergo acid-catalyzed ring closure. The proposed mechanism includes the enol double-bond protonation, followed by intramolecular cyclization involving the interaction of the carbocation formed with a nitrogen atom. A broad range of substrates tolerate this facile transformation, in which the bridgehead nitrones were isolated in high yields.
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Highly arylated α-alkenyl-ß-diketones are synthesized via a two-step sequence consisting of (i) potassium tert-butoxide/DMSO-catalyzed (E)-stereoselective C-H functionalization of ketones with acetylenes followed by (ii) magnesium bromide etherate/DIPEA-soft enolization of the formed ß,γ-unsaturated ketones and regioselective acylation with acyl chlorides. The method is compatible with a broad range of substrates and shown to be applicable as an intermediate stage in the construction of polyarylated heterocycles.
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Aldimines react with aryl- and hetarylacetylenes in the presence of KOBut/dimethyl sulfoxide (DMSO) or NaOBut/DMSO systems under exceptionally mild conditions (14 °C, 1 h) to afford C-H-vinylated products, 1-azadienes of E configuration relative to the C-C bond, in up to 72% yield. Vinylation involves the unprecedentedly fast multiposition proton transfer in the intermediate adducts of acetylene to the CâN bond. This new Csp2-Csp2 bond-forming reaction opens a straightforward pot-, atom-, step-, and energy-economic access to synthetically valuable 1-azadienes.
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Sulfur-containing pyrroles (1-3), tris(2-pyridyl)phosphine(selenide) sulfide (4-5) and 4-benzyl-6-(thiophen-2-yl)pyrimidin-2-amine (6) were synthesized and characterized by elemental analysis, IR and NMR spectra. In this study, the synthesized compounds of nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) were evaluated against the human erythrocyte carbonic anhydrase I, and II isoenzymes, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase enzymes. The synthesized heterocyclic compounds showed IC50 values in range of 33.32-60.79 nM against hCA I, and 37.05-66.64 nM against hCA II closely associated with various physiological and pathological processes. On the other hand, IC50 values were found in range of 13.13-22.21 nM against AChE, 0.54-31.22 nM against BChE, and 13.51-26.55 nM against α-glycosidase as a hydrolytic enzyme. As a result, nitrogen, phosphorus, selenium and sulfur-containing heterocyclic compounds (1-6) demonstrated potent inhibition profiles against indicated metabolic enzymes. Therefore, we believe that these results may contribute to the development of new drugs particularly in the treatment of some global disorders including glaucoma, Alzheimer's disease and diabetes.
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Acetilcolinesterase/química , Butirilcolinesterase/química , Inibidores de Glicosídeo Hidrolases/química , Compostos Heterocíclicos/síntese química , Nitrogênio/química , Fósforo/química , Selênio/química , Compostos Heterocíclicos/química , Humanos , Relação Estrutura-AtividadeRESUMO
BACKGROUND: In sub-Saharan Africa (SSA), the delivery of eye care services continues to be undermined by health systems performance bottlenecks. There is a growing focus by partners in the sector on the analysis of the different components of eye care within the wider health system context to diagnose and manage interactions in ways that achieve more effective improvements. However, there has been no attempt to date to systematically synthesize these studies. In this study, we conducted a meta-synthesis of eye health system assessments to gain a more comprehensive understanding of the current systems and how they can be strengthened across different SSA contexts. METHODS: We conducted a comprehensive search for eye health system assessment reports using global and regional websites of the WHO and other organizations supporting eye care in sub-Saharan Africa. A range of online databases with no language restrictions (PubMed, EMBASE, MEDLINE, PsycINFO and CINAHL) were searched for peer-reviewed publications referring to eye health system assessment (EHSA) or eye care service assessment tool (ECSAT). Assessments were included if they used the ECSAT or EHSA tool; were conducted in sub-Saharan Africa; and had been completed with full reports available in the public domain by January 15, 2019. A combination of framework and thematic syntheses was used. RESULTS: Our search strategies yielded a total of 12 assessments conducted in nine countries using the ECSAT/EHSA tool in Sub-Saharan Africa. Eight assessments met our inclusion criteria: four were from West Africa, two from East Africa and two from Southern Africa. Across the eight countries, findings show considerable progress and improvements in the areas of governance, organisation, financing, provision, and coverage of eye care. However, several systemwide weaknesses were found to continue to impede quality eye health service planning and delivery across the countries included in this review. CONCLUSIONS: These findings highlight the need for national governments and iNGOs to invest in conducting and wider use of these assessments. Such analyses are particularly useful in building links between different system elements and in finding innovative, more flexible solutions and partnerships - needed to address avoidable vision loss in resource poor settings.