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For cells to initiate and sustain a differentiated state, it is necessary that a 'memory' of this state is transmitted through mitosis to the daughter cells1-3. Mammalian switch/sucrose non-fermentable (SWI/SNF) complexes (also known as Brg1/Brg-associated factors, or BAF) control cell identity by modulating chromatin architecture to regulate gene expression4-7, but whether they participate in cell fate memory is unclear. Here we provide evidence that subunits of SWI/SNF act as mitotic bookmarks to safeguard cell identity during cell division. The SWI/SNF core subunits SMARCE1 and SMARCB1 are displaced from enhancers but are bound to promoters during mitosis, and we show that this binding is required for appropriate reactivation of bound genes after mitotic exit. Ablation of SMARCE1 during a single mitosis in mouse embryonic stem cells is sufficient to disrupt gene expression, impair the occupancy of several established bookmarks at a subset of their targets and cause aberrant neural differentiation. Thus, SWI/SNF subunit SMARCE1 has a mitotic bookmarking role and is essential for heritable epigenetic fidelity during transcriptional reprogramming.
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Diferenciação Celular , Proteínas Cromossômicas não Histona , Epigênese Genética , Mitose , Animais , Camundongos , Diferenciação Celular/genética , Cromatina/genética , Montagem e Desmontagem da Cromatina/genética , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Mitose/genética , Proteínas Cromossômicas não Histona/deficiência , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Subunidades Proteicas/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Elementos Facilitadores Genéticos/genética , Regiões Promotoras Genéticas/genética , Divisão Celular/genética , Epigênese Genética/genéticaRESUMO
The human genome functions as a three-dimensional chromatin polymer, driven by a complex collection of chromosome interactions1-3. Although the molecular rules governing these interactions are being quickly elucidated, relatively few proteins regulating this process have been identified. Here, to address this gap, we developed high-throughput DNA or RNA labelling with optimized Oligopaints (HiDRO)-an automated imaging pipeline that enables the quantitative measurement of chromatin interactions in single cells across thousands of samples. By screening the human druggable genome, we identified more than 300 factors that influence genome folding during interphase. Among these, 43 genes were validated as either increasing or decreasing interactions between topologically associating domains. Our findings show that genetic or chemical inhibition of the ubiquitous kinase GSK3A leads to increased long-range chromatin looping interactions in a genome-wide and cohesin-dependent manner. These results demonstrate the importance of GSK3A signalling in nuclear architecture and the use of HiDRO for identifying mechanisms of spatial genome organization.
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Cromatina , Posicionamento Cromossômico , Cromossomos Humanos , Genoma Humano , Quinases da Glicogênio Sintase , Ensaios de Triagem em Larga Escala , Análise de Célula Única , Humanos , Cromatina/efeitos dos fármacos , Cromatina/genética , Cromatina/metabolismo , Posicionamento Cromossômico/efeitos dos fármacos , Cromossomos Humanos/efeitos dos fármacos , Cromossomos Humanos/genética , Cromossomos Humanos/metabolismo , DNA/análise , DNA/metabolismo , Genoma Humano/efeitos dos fármacos , Genoma Humano/genética , Quinases da Glicogênio Sintase/antagonistas & inibidores , Quinases da Glicogênio Sintase/deficiência , Quinases da Glicogênio Sintase/genética , Ensaios de Triagem em Larga Escala/métodos , Interfase , Reprodutibilidade dos Testes , RNA/análise , RNA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Análise de Célula Única/métodos , CoesinasRESUMO
Historically, the majority of patients with complement-mediated atypical hemolytic uremic syndrome (CaHUS) progress to end-stage kidney disease (ESKD). Single-arm trials of eculizumab with a short follow-up suggested efficacy. We prove, for the first time to our knowledge, in a genotype matched CaHUS cohort that the 5-year cumulative estimate of ESKD-free survival improved from 39.5% in a control cohort to 85.5% in the eculizumab-treated cohort (hazard ratio, 4.95; 95% confidence interval [CI], 2.75-8.90; P = .000; number needed to treat, 2.17 [95% CI, 1.81-2.73]). The outcome of eculizumab treatment is associated with the underlying genotype. Lower serum creatinine, lower platelet count, lower blood pressure, and younger age at presentation as well as shorter time between presentation and the first dose of eculizumab were associated with estimated glomerular filtration rate >60 ml/min at 6 months in multivariate analysis. The rate of meningococcal infection in the treated cohort was 550 times greater than the background rate in the general population. The relapse rate upon eculizumab withdrawal was 1 per 9.5 person years for patients with a pathogenic mutation and 1 per 10.8 person years for those with a variant of uncertain significance. No relapses were recorded in 67.3 person years off eculizumab in those with no rare genetic variants. Eculizumab was restarted in 6 individuals with functioning kidneys in whom it had been stopped, with no individual progressing to ESKD. We demonstrated that biallelic pathogenic mutations in RNA-processing genes, including EXOSC3, encoding an essential part of the RNA exosome, cause eculizumab nonresponsive aHUS. Recessive HSD11B2 mutations causing apparent mineralocorticoid excess may also present with thrombotic microangiopathy.
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Síndrome Hemolítico-Urêmica Atípica , Falência Renal Crônica , Microangiopatias Trombóticas , Humanos , Pré-Escolar , Síndrome Hemolítico-Urêmica Atípica/tratamento farmacológico , Síndrome Hemolítico-Urêmica Atípica/genética , Contagem de Plaquetas , Proteínas do Sistema Complemento , Estudos de Coortes , Falência Renal Crônica/genéticaRESUMO
Although the orchestrating role of Interleukin-36 cytokines in regulating inflammation at barrier tissue sites, is well established, whether they play a significant role in the settings of metabolic health and disease, has yet to be fully established. Several recent studies have demonstrated that IL-36 cytokine expression is elevated among adult patients with obesity, and can play roles in regulating both insulin sensitivity and driving inflammation. In this report, we have extended these analyses to paediatric patients and identified an association between elevated serum levels of expression of the specific Interleukin-36 subfamily member, IL-36ß, among children with obesity displaying insulin sensitivity, compared to children with obesity who are insulin resistant. While these data further indicate a possible protective role for IL-36 in metabolic health, they also differ with previous findings from an adult patient cohort, where elevated levels of the related cytokine, IL-36γ, were found to occur in association with improved metabolic health. While highlighting important differences between paediatric and adult patient cohorts in the context of metabolic disease associated with obesity, these data underscore the need for a deeper mechanistic analysis of the role of IL-36 cytokines in disease.
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Resistência à Insulina , Interleucina-1 , Obesidade Infantil , Humanos , Resistência à Insulina/fisiologia , Criança , Masculino , Feminino , Interleucina-1/sangue , Obesidade Infantil/sangue , Obesidade Infantil/complicações , Adolescente , Inflamação/sangueRESUMO
A convenient method for preparing 3-aryl isoquinolines via a base-promoted tandem reaction is presented. Simply combining commercially available 2-methyl-arylaldehydes, benzonitriles, NaN(SiMe3)2, and Cs2CO3 enabled the synthesis of a variety of isoquinolines (23 examples, ≤90% yield). Among the syntheses of isoquinolines, the transition metal-free method described here is straightforward, practical, and operationally simple.
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BACKGROUND: Biological sex influences the risk of depression and cognitive impairment, but its role in relation to postoperative delirium is unclear. This analysis investigates sex differences in delirium risk after coronary artery bypass graft (CABG) surgery and sex-related differences in relation to affective and cognitive symptoms. METHODS: This is a secondary analysis of the Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study, a single-site, observational study of a CABG surgery cohort (n = 149). Preoperative characteristics are stratified by sex, and baseline variables that differ by sex are evaluated to understand whether sex modifies their relationships with delirium. We also evaluate sex differences in one-month depression and cognition. RESULTS: Female sex is associated with several delirium risk factors, including higher risk of preoperative depression and middle cerebral artery (MCA) stenosis. MCA stenosis was statistically associated with delirium only among women (OR 15.6, 95% CI 1.5, 164.4); mild cognitive impairment (MCI) was associated with delirium only in men (OR 4.6, 95% CI 1.2, 17.9). Other sex-based differences failed to reach statistical significance. Depression remained commoner among women 1 month post-CABG. CONCLUSIONS: Women in this CABG cohort were more likely to have depression at baseline and 1 month postoperatively, as well as MCA stenosis and postoperative delirium. Sex might modify the relationship between post-CABG delirium and its risk factors including MCA stenosis and MCI. Cerebrovascular disease deserves study as a potential explanation linking female sex and a range of poor outcomes among women with coronary heart disease.
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BACKGROUND: Recent work has demonstrated that children with unintentional cannabis ingestions often undergo extensive ancillary testing such as head imaging or lumbar puncture. To better understand the yield of these tests, our objective was to describe the frequency of additional significant diagnoses in children with cannabis ingestion. METHODS: We performed a retrospective cross-sectional study of the Pediatric Health Information System (PHIS) database, including ED encounters from January 2016 to April 2023 with a diagnosis indicating cannabis exposure in children <6 years of age. We assessed the frequency of co-diagnoses that would be found on head imaging, lumbar puncture, or toxicology testing. RESULTS: We included 4132 ED encounters for cannabis ingestion from 47 hospitals. Of these, 1243 (30%) received head imaging and 130 (3.1%) underwent lumbar puncture. There were 23 children (0.6%) with diagnosis of skull fracture or intracranial hemorrhage, 4 (<0.1%) with intracranial neoplasm, and 0 (0%) with a diagnosis for meningitis or intracranial abscess. Presence of discharge diagnosis for other drugs was also uncommon. The most frequent drug ingestion co-diagnoses were cocaine in 43 (1.0%) and opioids in 22 (0.5%) encounters. CONCLUSION: In children with cannabis intoxication, high rates of head imaging and lumbar puncture are likely driven by the signs of altered mental status at presentation. These data suggest that if cannabis ingestion is considered early and identified quickly with testing, neuroimaging, particularly that with ionizing radiation, may be low yield.
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Cannabis , Transtornos Mentais , Criança , Humanos , Pré-Escolar , Estudos Transversais , Estudos Retrospectivos , Neuroimagem , Serviço Hospitalar de EmergênciaRESUMO
During the Coronavirus disease pandemic, many U.S. veterans with posttraumatic stress disorder (PTSD) experienced increased symptomology and worsened mental health and well-being due in part to social isolation and loneliness. The Mission Alliance project explored these ramifications and prioritized critical issues expressed by U.S. veterans and stakeholders (N = 182) during virtual regional meetings (N = 32). Field notes created specifically for this project were recorded and thematically analyzed. Emerging themes included: (1) social isolation: missed opportunities, collapsed social circles, work-life balance, fostering relationships, and evolving health care delivery; (2) loneliness: deteriorated mental health, suffered with PTSD together but alone, looked out for each other, ambivalence toward technology, and strained and broken systems; (3) mental health: sense of chaos, increased demand and decreased access, aggravation, implementation of tools, innovative solutions, fear and loss, and availability of resources; (4) wellbeing: sense of purpose, holistic perspective on well-being, recognition of balance, persisting stigma, redefined pressures, freedom to direct treatment, and reconnection and disconnection. A PTSD-related patient centered outcomes research (PCOR)/comparative effectiveness research (CER) agenda was developed from these themes. Establishment of a veteran and stakeholder network is suggested to support, facilitate, and promote the PTSD-related PCOR/CER agenda. Furthermore, enhancement of opportunities for veterans with PTSD and stakeholders to partner in PCOR/CER is required to develop and conduct projects that lead to PTSD-related comprehensive care of veterans affected by traumatic events with the potential to translate findings to other populations.
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COVID-19 , Transtornos de Estresse Pós-Traumáticos , Veteranos , Humanos , Saúde Mental , Veteranos/psicologia , Solidão , COVID-19/epidemiologia , Transtornos de Estresse Pós-Traumáticos/terapia , Transtornos de Estresse Pós-Traumáticos/psicologia , Isolamento SocialRESUMO
Soil erosion is a significant environmental issue worldwide. It affects water quality, biodiversity, and land productivity. New Zealand government agencies and regional councils work to mitigate soil erosion through policies, management programmes, and funding for soil conservation projects. Information about cost-effectiveness is crucial for planning, targeting, and implementing erosion mitigation to achieve improvements in sediment-related water quality. While there is a good understanding of the costs of erosion mitigation measures, there is a dearth of literature on their cost-effectiveness in reducing sediment loads and improving water quality at the catchment level. In this study, we estimate the cost-effectiveness of erosion mitigation measures in meeting visual water clarity targets. The analysis utilizes the spatially explicit SedNetNZ erosion process and sediment budget modelling in the Manawatu-Whanganui Region and region-specific mitigation costs. The erosion mitigation measures considered in the analysis include afforestation, bush retirement, riparian retirement, space-planted trees, and gully tree planting. We modelled two scenarios with on-farm erosion mitigation implemented across the region from 2021 to 2100, resulting in a 48% and 60% reduction of total sediment load. We estimate the marginal costs to achieve the visual national bottom line for water clarity, as assessed by the length of waterways that meet the clarity targets. We also estimate the marginal costs of improving average water clarity, which can be linked with non-market valuation studies when conducting a cost-benefit analysis. We find that gully tree planting and space-planted trees are the most cost-effective mitigation measures and that riparian retirement is the least cost-effective. Moreover, cost-effectiveness is highly dependent on current land use and the biophysical features of the landscape. Our estimates can be used in cost-benefit analysis to plan and prioritize soil erosion mitigation at the catchment and regional levels.
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Conservação dos Recursos Naturais , Análise Custo-Benefício , Erosão do Solo , Nova Zelândia , Erosão do Solo/prevenção & controle , Qualidade da Água , SoloRESUMO
A mild photoredox catalyzed construction of sulfides, disulfides, selenides, sulfoxides and sulfones from unstrained ketone precursors is introduced. Combination of this deacylative process with SN 2 or coupling reactions provides novel and convenient modular strategies toward unsymmetrical or symmetric disulfides. Reactivity studies favor a bromine radical that initiates a HAT (Hydrogen Atom Transfer) from the aminal intermediate resulting in expulsion of a C-centered radical that is intercepted to make C-S and C-Se bonds. Gram scale reactions, broad substrate scope and tolerance towards various functional groups render this method appealing for future applications in the synthesis of organosulfur and selenium complexes.
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Hydrogen atom transfer (HAT) processes are among the most useful approaches for the selective construction of C(sp3)-C(sp3) bonds. 1,5-HAT with heteroatom-centered radicals (Oâ¢, Nâ¢) have been well established and are favored relative to other 1,n-HAT processes. In comparison, net 1,2-HAT processes have been observed infrequently. Herein, the first amidyl radicalls are reported that preferentially undergo a net 1,2-HAT over 1,5-HAT. Beginning with single electron transfer from 2-azaallyl anions to N-alkyl N-aryloxy amides, the latter generate amidyl radicals. The amidyl radical undergoes a net-1,2-HAT to generate a C-centered radical that participates in an intermolecular radical-radical coupling with the 2-azaallyl radical to generate 1,2-diamine derivatives. Mechanistic and EPR experiments point to radical intermediates. Density functional theory calculations provide support for a base-assisted, stepwise-1,2-HAT process. It is proposed that the generation of amidyl radicals under basic conditions can be greatly expanded to access α-amino C-centered radicals that will serve as valuable synthetic intermediates.
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BACKGROUND: Although men of African ancestry (AA) have the highest mortality rate from prostate cancer (PCa), relatively little is known about the germline variants that are associated with PCa risk in AA men. The goal of this study is to systematically evaluate rare, recurrent nonsynonymous variants across the exome for their association with PCa in AA men. METHODS: Whole exome sequencing (WES) of germline DNA in two AA PCa patient cohorts of Johns Hopkins Hospital (N = 960) and Wayne State University (N = 747) was performed. All nonsynonymous variants present in both case cohorts, with a carrier rate between 0.5% and 1%, were identified. Their carrier rates were compared with rates from 8128 African/African American (AFR) control subjects from The Genome Aggregation Database (gnomAD) using Fisher's exact test. Significant variants, defined as false discovery rate (FDR) adjusted p-value ≤ 0.05, were further evaluated in AA PCa cases (N = 132) and controls (N = 1184) from the UK Biobank (UKB). RESULTS: Two variants reached a pre-specified statistical significance level. The first was p.R14Q in GPRC5C (found in 0.47% of PCa cases and 0.01% of population controls); odds ratio (OR) for PCa was 37.46 (95% confidence interval CI 4.68-299.72), pexact = 7.01E-06, FDR-adjusted p-value = 0.05. The second was p.R511Q in IGF1R (found in 0.53% of PCa cases and 0.01% of population controls); OR for PCa was 21.54 (95%CI 4.65-99.76), pexact = 5.51E-06, FDR-adjusted p-value = 0.05. The mean percentage of African ancestry was similar between variant carriers and noncarriers of each variant, p > 0.05. In the UKB AA men, GPRC5C R14Q was 0.76% and 0.08% in cases and controls, respectively, OR for PCa was 9.00 (95%CI 0.56-145.23), pexact = 0.19. However, IGF1R R511Q was not found in cases or controls. CONCLUSIONS: This WES study identified two rare, recurrent nonsynonymous PCa risk-associated variants in AA. Confirmation in additional large populations of AA PCa cases and controls is required.
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Mutação em Linhagem Germinativa , Neoplasias da Próstata , Humanos , Masculino , Negro ou Afro-Americano , Células Germinativas , Heterozigoto , Neoplasias da Próstata/etnologia , Neoplasias da Próstata/genética , População NegraRESUMO
2-Arylindoles are privileged structures widely present in biologically active molecules. New sustainable synthetic routes toward their synthesis are, therefore, in high demand. Herein, a mixed base-promoted benzylic C-H deprotonation of commercially available ortho-anisoles, addition of the resulting anion to benzonitriles, and SNAr to displace the methoxy group provide indoles. A diverse array of 2-arylindoles is prepared with good yields (>30 examples, yields up to 99%) without added transition metal catalysts.
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SIGIRR has been described as a negative regulator of several IL-1R/TLR family members and has been implicated in several inflammatory disease conditions. However, it is unknown whether it can suppress IL-36 family cytokines, which are members of the broader IL-1 superfamily that have emerged as critical orchestrators of psoriatic inflammation in both humans and mice. In this study, we demonstrate that SIGIRR is downregulated in psoriatic lesions in humans and mice, and this correlates with increased expression of IL-36 family cytokines. Using Sigirr -/- mice, we identify, for the first time (to our knowledge), SIGIRR as a negative regulator of IL-36 responses in the skin. Mechanistically, we identify dendritic cells and keratinocytes as the primary cell subsets in which IL-36 proinflammatory responses are regulated by SIGIRR. Both cell types displayed elevated IL-36 responsiveness in absence of SIGIRR activity, characterized by enhanced expression of neutrophil chemoattractants, leading to increased neutrophil infiltration to the inflamed skin. Blockade of IL-36R signaling ameliorated exacerbated psoriasiform inflammation in Sigirr -/- mice and inhibited neutrophil infiltration. These data identify SIGIRR activity as an important regulatory node in suppressing IL-36-dependent psoriatic inflammation in humans and mice.
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Inflamação/metabolismo , Interleucina-1/metabolismo , Infiltração de Neutrófilos/fisiologia , Receptores de Interleucina-1/metabolismo , Pele/metabolismo , Animais , Citocinas/metabolismo , Regulação para Baixo/fisiologia , Queratinócitos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Psoríase/metabolismo , Transdução de Sinais/fisiologiaRESUMO
OBJECTIVE: Depression in patients undergoing coronary artery graft bypass (CABG) surgery is associated with morbidity and mortality, making its early identification and clinical management crucial. Vasculopathy and older age, hallmarks of patients requiring CABG, are also features of vascular depression. In this study, we assess for features of vascular depression in patients undergoing CABG surgery. METHODS: This is a cross-sectional analysis of a single-site prospective observational cohort study of patients undergoing CABG surgery. Subjects were assessed preoperatively using the Depression Interview and Structured Hamilton (DISH), depression scales, transcranial Doppler, neuropsychological testing, and clinical dementia rating (CDR). RESULTS: Of 161 subjects (mean age 66.2 ± 9.3, female 25%) who completed DISH, 18 had major or minor depression, 17 of whom had a past history of major or minor depression (mean age of onset 35.8 years-old). Pre-CABG depression was associated with greater functional impairment on CDR Sum of Boxes (OR = 3.7, 95% CI: 1.4, 9.7) and worse performance on letter fluency test (OR = 0.90, 95% CI: 0.81, 0.99) and trail-making tests (A: OR = 1.06, 95% CI: 1.01, 1.12; B: OR 1.02, 95% CI: 1.01, 1.04). Pre-CABG depression was not associated with middle cerebral artery (MCA) stenosis. CONCLUSIONS: Pre-CABG depression is associated with cognitive and functional impairment similar to vascular depression, but we did not find evidence of an association with older age of onset and MCA stenosis. Further studies on white matter disease in this population are needed to examine the vascular depression hypothesis for pre-CABG depression.
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Depressão Vascular , Humanos , Feminino , Idoso , Constrição Patológica , Estudos Transversais , Estudos Prospectivos , Ponte de Artéria Coronária/efeitos adversos , CogniçãoRESUMO
Isoprene has the highest emission into Earth's atmosphere of any nonmethane hydrocarbon. Atmospheric processing of alkenes, including isoprene, via ozonolysis leads to the formation of zwitterionic reactive intermediates, known as Criegee intermediates (CIs). Direct studies have revealed that reactions involving simple CIs can significantly impact the tropospheric oxidizing capacity, enhance particulate formation, and degrade local air quality. Methyl vinyl ketone oxide (MVK-oxide) is a four-carbon, asymmetric, resonance-stabilized CI, produced with 21 to 23% yield from isoprene ozonolysis, yet its reactivity has not been directly studied. We present direct kinetic measurements of MVK-oxide reactions with key atmospheric species using absorption spectroscopy. Direct UV-Vis absorption spectra from two independent flow cell experiments overlap with the molecular beam UV-Vis-depletion spectra reported recently [M. F. Vansco, B. Marchetti, M. I. Lester, J. Chem. Phys. 149, 44309 (2018)] but suggest different conformer distributions under jet-cooled and thermal conditions. Comparison of the experimental lifetime herein with theory indicates only the syn-conformers are observed; anti-conformers are calculated to be removed much more rapidly via unimolecular decay. We observe experimentally and predict theoretically fast reaction of syn-MVK-oxide with SO2 and formic acid, similar to smaller alkyl-substituted CIs, and by contrast, slow removal in the presence of water. We determine products through complementary multiplexed photoionization mass spectrometry, observing SO3 and identifying organic hydroperoxide formation from reaction with SO2 and formic acid, respectively. The tropospheric implications of these reactions are evaluated using a global chemistry and transport model.
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BACKGROUND: Suicide is the second leading cause of death among adolescents in the United States (Centers for Disease Control and Prevention [CDC], 2017, Death rates due to suicide and homicide among persons age 10-24: United States, 2000-2017) constituting a significant public health crisis. The demand for psychiatric emergency services and inpatient beds is increasing, while the number of beds available decreases or remains static (National Association of State Mental Health Program Directors, 2017, Trend in psychiatric inpatient capacity, United States and Each State, 1970-2014. www.nasmhpd.org/sites/default/files/TACPaper.2.Psychiatric-Inpatient-Capacity_508C.pdf) leading to delays in treatment and exacerbation of symptoms for some adolescents awaiting care. This pilot project describes the development, feasibility, and acceptability of a creative, values-based safety planning intervention for adolescents hospitalized on an acute inpatient psychiatric unit and the impact of this intervention on length of stay and readmissions to acute psychiatric care. METHODS: Thirty patients experiencing a suicidal crisis participated in the Rapid Stabilization Pathway (RSP) during their inpatient psychiatric admission. RESULTS: Results indicate that, compared to patients who underwent inpatient treatment as usual (TAU), RSP patients were discharged after a significantly shorter length of stay (4 vs. 6.1 weekdays respectively, p < .001). Further, there was no significant difference in readmission to the inpatient unit or to the psychiatric emergency room among RSP and TAU patients at 30, 60, and 90 days postdischarge. CONCLUSIONS: These findings have significant implications for acute inpatient programming. The RSP intervention treated patients in a shorter amount of time without any increase in re-admissions. Further, the shortened length of stay allowed for more patients to be treated on the inpatient unit and a significant cost savings. Future directions for programming and outcome research are discussed.
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Adolescente Hospitalizado , Transtornos Mentais , Adolescente , Humanos , Criança , Adulto Jovem , Adulto , Readmissão do Paciente , Transtornos Mentais/terapia , Tempo de Internação , Pacientes Internados/psicologia , Projetos Piloto , Assistência ao Convalescente , Alta do PacienteRESUMO
Aziridines are highly valued synthetic targets in organic and medicinal chemistry. The organocatalytic synthesis of such structures with broad substrate scope and good diastereoselectivity, however, is rare. Herein, we report a broadly applicable and diastereoselective synthetic method for the synthesis of trans-aziridines from imines and benzylic or alkyl halides utilizing sulfenate anions (PhSO- ) as the catalyst. Substrates bearing heterocyclic aromatic groups, alkyl, and electron-rich and electron-poor aryl groups were shown to be compatible with this method (33â examples), giving good yields and high diastereoselectivities (trans : cis >20 : 1). Further functionalization of aziridines containing cyclopropyl or cyclobutyl groups was achieved through ring-opening reactions, with a cyclobutyl-substituted norephedrine derivative obtained through a four-step synthesis. We offer a mechanistic proposal involving reversible addition of the deprotonated benzyl sulfoxide to the imine to explain the high trans-diastereoselectivity.
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Aziridinas , Aziridinas/química , Ânions/química , Iminas/química , Catálise , EstereoisomerismoRESUMO
A novel, selective and high-yielding palladium-catalyzed carbonylative arylation of a variety of weakly acidic (pKa 25-35 in DMSO) benzylic and heterobenzylic C(sp3 )-H bonds with aryl bromides has been achieved. This system is applicable to a range of pro-nucleophiles for access to sterically and electronically diverse α-aryl or α,α-diaryl ketones, which are ubiquitous substructures in biologically active compounds. The Josiphos SL-J001-1-based palladium catalyst was identified as the most efficient and selective, enabling carbonylative arylation with aryl bromides under 1â atm CO to provide the ketone products without the formation of direct coupling byproducts. Additionally, (Josiphos)Pd(CO)2 was identified as the catalyst resting state. A kinetic study suggests that the oxidative addition of aryl bromides is the turnover-limiting step. Key catalytic intermediates were also isolated.
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Recent years have witnessed marked progress in the efficient synthesis of various enantioenriched 1,2,3,4-tetrahydroquinoxalines. However, enantio- and diastereoselective access to trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines remains much less explored. Herein we report that a frustrated Lewis pair-based catalyst generated via in situ hydroboration of 2-vinylnaphthalene with HB(C6 F5 )2 allows for the one-pot tandem cyclization/hydrosilylation of 1,2-diaminobenzenes and 1,2-diketones with commercially available PhSiH3 to exclusively afford trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with excellent diastereoselectivities (>20 : 1â dr). Furthermore, this reaction can be rendered asymmetric by using an enantioenriched borane-based catalyst derived from HB(C6 F5 )2 and a binaphthyl-based chiral diene to give rise to enantioenriched trans-2,3-disubstituted 1,2,3,4-tetrahydroquinoxalines in high yields with almost complete diastereo- and enantiocontrol (>20 : 1â dr, up to >99 %â ee). A wide substrate scope, good tolerance of diverse functionality and up to 20-gram scale production are demonstrated. The enantio- and diastereocontrol are achieved by the judicious choice of borane catalyst and hydrosilane. The catalytic pathway and the origin of the excellent stereoselectivity are elucidated by mechanistic experiments and DFT calculations.