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Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized and what roles they play during this process have remained elusive. Comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain (FB) neurons, we identify that a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon differentiation. Such a subcellular relocation of circRNAs is modulated by the poly(A)-binding protein PABPC1. In the H9 nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and trapped by the nuclear basket protein TPR to prevent their export. Modulating (A)-rich motifs in circRNAs alters their subcellular localization, and introducing (A)-rich circRNAs in H9 cytosols results in mRNA translation suppression. Moreover, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs, including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.
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Transporte Ativo do Núcleo Celular , Adenosina , Núcleo Celular , Neurogênese , Neurônios , Proteína I de Ligação a Poli(A) , RNA Circular , RNA , RNA Circular/metabolismo , RNA Circular/genética , Neurônios/metabolismo , Adenosina/metabolismo , Núcleo Celular/metabolismo , Humanos , Proteína I de Ligação a Poli(A)/metabolismo , Proteína I de Ligação a Poli(A)/genética , Animais , RNA/metabolismo , RNA/genética , Linhagem Celular , Diferenciação Celular , Citoplasma/metabolismo , Prosencéfalo/metabolismoRESUMO
The nucleolus is the most prominent membraneless condensate in the nucleus. It comprises hundreds of proteins with distinct roles in the rapid transcription of ribosomal RNA (rRNA) and efficient processing within units comprising a fibrillar centre and a dense fibrillar component and ribosome assembly in a granular component1. The precise localization of most nucleolar proteins and whether their specific localization contributes to the radial flux of pre-rRNA processing have remained unknown owing to insufficient resolution in imaging studies2-5. Therefore, how these nucleolar proteins are functionally coordinated with stepwise pre-rRNA processing requires further investigation. Here we screened 200 candidate nucleolar proteins using high-resolution live-cell microscopy and identified 12 proteins that are enriched towards the periphery of the dense fibrillar component (PDFC). Among these proteins, unhealthy ribosome biogenesis 1 (URB1) is a static, nucleolar protein that ensures 3' end pre-rRNA anchoring and folding for U8 small nucleolar RNA recognition and the subsequent removal of the 3' external transcribed spacer (ETS) at the dense fibrillar component-PDFC boundary. URB1 depletion leads to a disrupted PDFC, uncontrolled pre-rRNA movement, altered pre-rRNA conformation and retention of the 3' ETS. These aberrant 3' ETS-attached pre-rRNA intermediates activate exosome-dependent nucleolar surveillance, resulting in decreased 28S rRNA production, head malformations in zebrafish and delayed embryonic development in mice. This study provides insight into functional sub-nucleolar organization and identifies a physiologically essential step in rRNA maturation that requires the static protein URB1 in the phase-separated nucleolus.
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Nucléolo Celular , Exossomos , Precursores de RNA , Processamento Pós-Transcricional do RNA , RNA Ribossômico , Peixe-Zebra , Animais , Camundongos , Nucléolo Celular/metabolismo , Desenvolvimento Embrionário , Exossomos/metabolismo , Cabeça/anormalidades , Microscopia , Proteínas Nucleares/metabolismo , Precursores de RNA/metabolismo , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , RNA Ribossômico 28S/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
Recent studies show that antiviral systems are remarkably conserved from bacteria to mammals, demonstrating that unique insights into these systems can be gained by studying microbial organisms. Unlike in bacteria, however, where phage infection can be lethal, no cytotoxic viral consequence is known in the budding yeast Saccharomyces cerevisiae even though it is chronically infected with a double-stranded RNA mycovirus called L-A. This remains the case despite the previous identification of conserved antiviral systems that limit L-A replication. Here, we show that these systems collaborate to prevent rampant L-A replication, which causes lethality in cells grown at high temperature. Exploiting this discovery, we use an overexpression screen to identify antiviral functions for the yeast homologs of polyA-binding protein (PABPC1) and the La-domain containing protein Larp1, which are both involved in viral innate immunity in humans. Using a complementary loss of function approach, we identify new antiviral functions for the conserved RNA exonucleases REX2 and MYG1; the SAGA and PAF1 chromatin regulatory complexes; and HSF1, the master transcriptional regulator of the proteostatic stress response. Through investigation of these antiviral systems, we show that L-A pathogenesis is associated with an activated proteostatic stress response and the accumulation of cytotoxic protein aggregates. These findings identify proteotoxic stress as an underlying cause of L-A pathogenesis and further advance yeast as a powerful model system for the discovery and characterization of conserved antiviral systems.
Assuntos
Micovírus , Proteínas de Saccharomyces cerevisiae , Humanos , Animais , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Antivirais , Micovírus/genética , Micovírus/metabolismo , RNA de Cadeia Dupla , Imunidade Inata , Mamíferos/genética , Fatores de Transcrição/genética , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent gastrointestinal malignancies with high mortality worldwide. Emerging evidence indicates that long noncoding RNAs (lncRNAs) are involved in human cancers, including ESCC. However, the detailed mechanisms of lncRNAs in the regulation of ESCC progression remain incompletely understood. LUESCC was upregulated in ESCC tissues compared with adjacent normal tissues, which was associated with gender, deep invasion, lymph node metastasis, and poor prognosis of ESCC patients. LUESCC was mainly localized in the cytoplasm of ESCC cells. Knockdown of LUESCC inhibited cell proliferation, colony formation, migration, and invasion in vitro and suppressed tumor growth in vivo. Mechanistic investigation indicated that LUESCC functions as a ceRNA by sponging miR-6785-5p to enhance NRSN2 expression, which is critical for the malignant behaviors of ESCC. Furthermore, ASO targeting LUESCC substantially suppressed ESCC both in vitro and in vivo. Collectively, these data demonstrate that LUESCC may exerts its oncogenic role by sponging miR-6785-5p to promote NRSN2 expression in ESCC, providing a potential diagnostic marker and therapeutic target for ESCC patients.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , MicroRNAs , RNA Longo não Codificante , Humanos , Linhagem Celular Tumoral , Progressão da Doença , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago/genética , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , MicroRNAs/metabolismo , Invasividade Neoplásica/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismoRESUMO
Achieving structural and stereogenic diversity from the same starting materials remains a fundamental challenge in organic synthesis, requiring precise control over the selectivity. Here, we report divergent catalytic methods that selectively yield either cycloaddition or addition/elimination products from bicyclo[1.1.0]butanes and α,ß-unsaturated ketones. By employing chiral Lewis acid or Brønsted acid catalysts, we achieved excellent regio-, diastereo-, and enantioselectivity across all three distinct transformations, affording a diverse array of synthetically valuable chiral bicyclo[2.1.1]hexanes and cyclobutenes. The divergent outcomes are controlled by the differential activation of the substrates by the specific chiral catalyst with the reaction conditions dictating the pathway selectivity. This strategy demonstrates the power of divergent catalysis in creating molecular complexity and diversity, offering a valuable tool for the synthesis of enantioenriched chiral building blocks.
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Circular RNAs (circRNAs) produced from back-spliced exons are widely expressed, but individual circRNA functions remain poorly understood owing to the lack of adequate methods for distinguishing circRNAs from cognate messenger RNAs with overlapping exons. Here, we report that CRISPR-RfxCas13d can effectively discriminate circRNAs from mRNAs by using guide RNAs targeting sequences spanning back-splicing junction (BSJ) sites featured in RNA circles. Using a lentiviral library that targets sequences across BSJ sites of highly expressed human circRNAs, we show that a group of circRNAs are important for cell growth mostly in a cell-type-specific manner and that a common oncogenic circRNA, circFAM120A, promotes cell proliferation by preventing the mRNA for family with sequence similarity 120A (FAM120A) from binding the translation inhibitor IGF2BP2. Further application of RfxCas13d-BSJ-gRNA screening has uncovered circMan1a2, which has regulatory potential in mouse embryo preimplantation development. Together, these results establish CRISPR-RfxCas13d as a useful tool for the discovery and functional study of circRNAs at both individual and large-scale levels.
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Sistemas CRISPR-Cas , Neoplasias do Colo/patologia , Regulação Neoplásica da Expressão Gênica , RNA Circular/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Processamento Alternativo , Animais , Apoptose , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Restenosis after angioplasty is caused usually by neointima formation characterized by aberrant vascular smooth muscle cell (VSMC) dedifferentiation. Myeloid-derived growth factor (MYDGF), secreted from bone marrow-derived monocytes and macrophages, has been found to have cardioprotective effects. In this study we investigated the effect of MYDGF to postinjury neointimal formation and the underlying mechanisms. Rat carotid arteries balloon-injured model was established. We found that plasma MYDGF content and the level of MYDGF in injured arteries were significantly decreased after balloon injury. Local application of exogenous MYDGF (50 µg/mL) around the injured vessel during balloon injury markedly ameliorated the development of neointimal formation evidenced by relieving the narrow endovascular diameter, improving hemodynamics, and reducing collagen deposition. In addition, local application of MYDGF inhibited VSMC dedifferentiation, which was proved by reversing the elevated levels of osteopontin (OPN) protein and decreased levels of α-smooth muscle actin (α-SMA) in the left carotid arteries. We showed that PDGF-BB (30 ng/mL) stimulated VSMC proliferation, migration and dedifferentiation in vitro; pretreatment with MYDGF (50-200 ng/mL) concentration-dependently eliminated PDGF-BB-induced cell proliferation, migration and dedifferentiation. Molecular docking revealed that MYDGF had the potential to bind with sphingosine-1-phosphate receptor 2 (S1PR2), which was confirmed by SPR assay and Co-IP analysis. Pretreatment with CCG-1423 (Rho signaling inhibitor), JTE-013 (S1PR2 antagonist) or Ripasudil (ROCK inhibitor) circumvented the inhibitory effects of MYDGF on VSMC phenotypic switching through inhibiting S1PR2 or its downstream RhoA-actin monomers (G-actin) /actin filaments (F-actin)-MRTF-A signaling. In summary, this study proves that MYDGF relieves neointimal formation of carotid arteries in response to balloon injury in rats, and suppresses VSMC dedifferentiation induced by PDGF-BB via S1PR2-RhoA-G/F-actin-MRTF-A signaling pathway. In addition, our results provide evidence for cross talk between bone marrow and vasculature.
Assuntos
Actinas , Neointima , Ratos , Animais , Becaplermina/farmacologia , Neointima/tratamento farmacológico , Neointima/metabolismo , Actinas/metabolismo , Ratos Sprague-Dawley , Receptores de Esfingosina-1-Fosfato/metabolismo , Fator Estimulador de Colônias de Granulócitos/metabolismo , Fator Estimulador de Colônias de Granulócitos/farmacologia , Músculo Liso Vascular , Simulação de Acoplamento Molecular , Proliferação de Células , Transdução de Sinais , Movimento Celular , Miócitos de Músculo Liso/metabolismo , Células CultivadasRESUMO
OBJECTIVE: To evaluate the complications associated with microwave ablation (MWA) in treating persistent/recurrent hyperparathyroidism (HPT) post-surgical or ablative treatments. MATERIALS AND METHODS: From January 2015 to December 2022, 87 persistent/recurrent HPT patients (primary HPT [PHPT]: secondary HPT [SHPT] = 13:74) who underwent MWA after surgical or ablative treatment were studied. Grouping was based on ablation order (initial vs. re-MWA), prior treatment (parathyroidectomy [PTX] vs. MWA), and etiology (PHPT vs. SHPT). The study focused on documenting and comparing treatment complications and analyzing major complication risk factors. RESULT: Among the 87 patients, the overall complication rate was 17.6% (15/87), with major complications at 13.8% (12/87) and minor complications at 3.4% (3/87). Major complications included recurrent laryngeal nerve (RLN) palsy (12.6%) and Horner syndrome (1.1%), while minor complications were limited to hematoma (3.4%). Severe hypocalcemia noted in 21.6% of SHPT patients. No significant differences in major complication rates were observed between initial and re-MWA groups (10.7% vs. 13.8%, p = 0.455), PTX and MWA groups (12.5% vs. 15.4%, p = 0.770), or PHPT and SHPT groups (15.4% vs. 13.5%, p > 0.999). Risk factors for RLN palsy included ablation of superior and large parathyroid glands (>1.7 cm). All patients recovered spontaneously except for one with permanent RLN palsy in the PTX group (2.1%). CONCLUSION: Complication rates for MWA post-surgical or ablative treatments were comparable to initial MWA rates. Most complications were transient, indicating MWA as a viable and safe treatment option for persistent/recurrent HPT patients.
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Técnicas de Ablação , Hiperparatireoidismo Secundário , Ablação por Radiofrequência , Humanos , Micro-Ondas/efeitos adversos , Técnicas de Ablação/efeitos adversos , Ablação por Radiofrequência/efeitos adversos , Hiperparatireoidismo Secundário/cirurgia , Paralisia/etiologia , Estudos RetrospectivosRESUMO
OBJECTIVE: Thermal ablation (TA) is a safe and effective treatment for benign thyroid nodules (BTNs). However, there has been no consensus on the optimal maximum diameter (MD) of BTNs for TA. This study aimed to identify the optimal MD of BTNs for TA based on complete disappearance rate after TA. MATERIALS AND METHODS: This retrospective study included 639 BTNs treated with TA from June 2014 to January 2022. The complete disappearance rate of BTNs after TA was summarized, related influencing factors were explored, and the optimal MD of BTNs for TA was identified. RESULTS: At the final follow-up (median: 40 months, range: 24-95 months), the overall volume reduction rate was 95.4 ± 9.0%, and 50.5% of the BTNs (323/639) completely disappeared. The MD was significantly negatively correlated with complete disappearance (odds ratio 0.89, 95% confidence interval 0.87-0.92; p < 0.001). Calcification, comet-tail artifacts, multilocular cysts, and composition of BTNs, as well as diabetes were negatively correlated with complete disappearance. Restricted cubic spline indicated that an MD of 25.0 mm was the optimal threshold of BTNs for TA, which was confirmed by subgroup logistic regression analysis. Compared with BTNs with MD ≤ 25.0 mm, those with MD > 25.0 mm had a greater complication rate (6.5% vs. 2.4%, p = 0.012). CONCLUSIONS: The MD of BTNs was negatively correlated with complete disappearance after TA; an MD > 25.0 mm indicated a reduced likelihood of complete disappearance compared with an MD ≤ 25.0 mm. An MD of 25.0 mm is an appropriate threshold of BTNs for TA on the basis of complete disappearance rate.
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Nódulo da Glândula Tireoide , Humanos , Nódulo da Glândula Tireoide/cirurgia , Feminino , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto , Técnicas de Ablação/métodos , Idoso , Adulto Jovem , AdolescenteRESUMO
OBJECTIVE: To assess the feasibility, efficacy, and safety of microwave ablation in treating follicular thyroid neoplasms and suspicious follicular thyroid neoplasms. METHODS: In this retrospective study, the data of patients treated with microwave ablation for follicular neoplasms from December 2016 to January 2024 were summarized. The changes in nodule size, volume, technical success rate, disease progression, complete tumor resolution, thyroid function, and complications post-ablation were evaluated. RESULTS: Seventy-four patients (15 men, 59 women; mean age 46.3 ± 15.2 years) with follicular neoplasms were included. Over a median follow-up of 13 months, complete ablation was achieved, giving a 100% technical success rate. At the first month post-ablation, the maximum diameter of nodules showed no significant change (p = 0.287). From the third month, both maximum diameter and volume significantly decreased (p < 0.005 for all). Volume reduction rates remained stable at one and three months (p = 0.389 and 0.06, respectively) but increased significantly thereafter (p < 0.005 for all). By 24 months, the median maximum diameter had reduced from 2.3 cm to 0 cm, achieving a median volume reduction rate of 100%. Nodules disappeared completely in 20.3% (15/74). Local recurrence was noted in 2.7% of cases (2/74), with no metastasis or neoplasm-related deaths reported. Thyroid function remained unchanged post-treatment (p > 0.05). The complication and side effect rates were 8.1% and 4.1%, respectively. CONCLUSIONS: Initial findings suggest microwave ablation is an effective and safe treatment for follicular neoplasms, with low incidences of disease progression and complications, while maintaining thyroid function.
Assuntos
Micro-Ondas , Neoplasias da Glândula Tireoide , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Neoplasias da Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Micro-Ondas/uso terapêutico , Estudos Retrospectivos , Adenocarcinoma Folicular/cirurgia , Adenocarcinoma Folicular/patologia , Resultado do Tratamento , Técnicas de Ablação/métodos , Técnicas de Ablação/efeitos adversos , IdosoRESUMO
OBJECTIVES: This study aimed to investigate drivers' disengagement from nondriving related tasks (NDRT) during scheduled takeovers and to evaluate its impact on takeover performance. BACKGROUND: During scheduled takeovers, drivers typically have sufficient time to prepare. However, inadequate disengagement from NDRTs can introduce safety risks. METHOD: Participants experienced scheduled takeovers using a driving simulator, undergoing two conditions, with and without an NDRT. We assessed their takeover performance and monitored their NDRT disengagement from visual, cognitive, and physical perspectives. RESULTS: The study examined three NDRT disengagement timings (DTs): DT1 (disengaged before the takeover request), DT2 (disengaged after the request but before taking over), and DT3 (not disengaged). The impact of NDRT on takeover performance varied depending on DTs. Specifically, DT1 demonstrated no adverse effects; DT2 impaired takeover time, while DT3 impaired both takeover time and quality. Additionally, participants who displayed DT1 exhibited longer eye-off-NDRT duration and a higher eye-off-NDRT count during the prewarning stage compared to those with DT2 and DT3. CONCLUSION: Drivers can benefit from earlier disengagement from NDRTs, demonstrating resilience to the adverse effects of NDRTs on takeover performance. The disengagement of cognition is often delayed compared to that of eyes and hands, potentially leading to DT3. Moreover, visual disengagement from NDRTs during the prewarning stage could distinguish DT1 from the other two. APPLICATION: Our study emphasizes considering NDRT disengagement in designing systems for scheduled takeovers. Measures should be taken to promote early disengagement, facilitate cognitive disengagement, and employ visual disengagement during the prewarning period as predictive indicators of DTs.
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Condução de Veículo , Humanos , Adulto , Masculino , Feminino , Atenção/fisiologia , Adulto Jovem , Análise e Desempenho de Tarefas , Simulação por Computador , Fatores de Tempo , Direção Distraída , Desempenho Psicomotor/fisiologiaRESUMO
Mitochondria are essential organelles that generate energy via oxidative phosphorylation. Plant mitochondrial genome encodes some of the respiratory complex subunits, and these transcripts require accurate processing, including C-to-U RNA editing and intron splicing. Pentatricopeptide repeats (PPR) proteins are involved in various organellar RNA processing events. PPR596, a P-type PPR protein, was previously identified to function in the C-to-U editing of mitochondrial rps3 transcripts in Arabidopsis. Here, we demonstrate that PPR596 functions in the cis-splicing of nad2 intron 3 in mitochondria. Loss of the PPR596 function affects the editing at rps3eU1344SS, impairs nad2 intron 3 splicing and reduces the mitochondrial complex I's assembly and activity, while inducing alternative oxidase (AOX) gene expression. This defect in nad2 intron splicing provides a plausible explanation for the slow growth of the ppr595 mutants. Although a few P-type PPR proteins are involved in RNA C-to-U editing, our results suggest that the primary function of PPR596 is intron splicing.
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Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo , Regulação da Expressão Gênica de Plantas , Íntrons/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Plantas/genética , Splicing de RNARESUMO
Maize is an important crop used for food, feed, and fuel. Abiotic stress is an important factor affecting maize yield. The EPF/EPFL gene family encodes class-specific secretory proteins that play an important role in the response to abiotic stress in plants. In order to explore and utilize the EPF/EPFL family in maize, the family members were systematically identified, and their chromosomal localization, physicochemical properties, cis-acting element prediction in promoters, phylogenetic tree construction, and expression pattern analysis were carried out using bioinformatics techniques. A total of 18 ZmEPF/EPFL proteins were identified in maize, which are mostly alkaline and a small portion acidic. Subcellular localization results showed that ZmEPF6, ZmEPF12, and ZmEPFL2 are localized in the nucleus and cytoplasm. Analysis of cis-acting elements revealed that members of the ZmEPF/EPFL family contain regulatory elements such as light response, anoxic, low temperature, and hormone response regulatory elements. RT-qPCR results showed that these family members are indeed responding to cold stress and hormone treatments. These results of this study provide a theoretical basis for improving the abiotic stress resistance of maize in future research.
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Regulação da Expressão Gênica de Plantas , Família Multigênica , Filogenia , Proteínas de Plantas , Estresse Fisiológico , Zea mays , Zea mays/genética , Zea mays/metabolismo , Zea mays/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Regiões Promotoras GenéticasRESUMO
This study investigates the perspectives of Canadian student and licenced pilots on general aviation pilot training and licencing practices. Employing a mixed-methods approach, this research critiques the reliance on flight hours as the sole competence metric and examines the alignment of existing practices with modern aviation's complexities. Findings reveal a divergence in opinions between novice and experienced pilots on flight hours' importance, with a consensus towards a competency-based evaluation model. The study identifies critical shortcomings in existing training practices, such as the challenge of integrating technology, fostering advanced skills, and efficiently utilising instructional resources. It suggests recommendations for regulatory enhancements, aiming to ensure training practices evolve in line with the changing requirements of aviation safety and technology. The conclusion calls for urgent reform, underlining the imperative for training adaptations that can prepare pilots to proficiently manage the complexities of contemporary airspace, thus safeguarding their proficiency and safety.
A survey conducted among Canadian student and licenced pilots to examine perspectives on general aviation pilot training and licencing practices uncovered critical shortcomings. The findings advocate for a strong preference for competency-based evaluations, urging reforms and regulatory improvements to ensure alignment with the evolving landscape of aviation safety and technological advancements.
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Stroke is the leading cause of death and long-term disability worldwide. But treatments are not available to promote functional recovery, and efficient therapies need to be investigated. Stem cell-based therapies hold great promise as potential technologies to restore function in brain disorders. Loss of GABAergic interneurons after stroke may result in sensorimotor defects. Here, by transplanting human brain organoids resembling the MGE domain (human MGE organoids, hMGEOs) derived from human induced pluripotent stem cells (hiPSCs) into the infarcted cortex of stroke mice, we found that grafted hMGEOs survived well and primarily differentiated into GABAergic interneurons and significantly restored the sensorimotor deficits of stroke mice for a long time. Our study offers the feasibility of stem cell replacement therapeutics strategy for stroke.
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Células-Tronco Pluripotentes Induzidas , Acidente Vascular Cerebral , Humanos , Camundongos , Animais , Células-Tronco Pluripotentes Induzidas/fisiologia , Acidente Vascular Cerebral/terapia , Encéfalo , Interneurônios , Diferenciação CelularRESUMO
Splicing of plant mitochondrial introns is facilitated by numerous nucleus-encoded protein factors. Although some splicing factors have been identified in plants, the mechanism underlying mitochondrial intron splicing remains largely unclear. In this study, we identified a small P-type pentatricopeptide repeat (PPR) protein containing merely four PPR repeats, small PPR protein 2 (SPR2), which is required for the splicing of more than half of the introns in maize (Zea mays) mitochondria. Null mutations of Spr2 severely impair the splicing of 15 out of the 22 mitochondrial Group II introns, resulting in substantially decreased mature transcripts, which abolished the assembly and activity of mitochondrial complex I. Consequently, embryogenesis and endosperm development were arrested in the spr2 mutants. Yeast two-hybrid, luciferase complementation imaging, bimolecular fluorescence complementation, and semi-in vivo pull-down analyses indicated that SPR2 interacts with small MutS-related domain protein PPR-SMR1, both of which are required for the splicing of 13 introns. In addition, SPR2 and/or PPR-SMR1 interact with other splicing factors, including PPR proteins EMPTY PERICARP16, PPR14, and chloroplast RNA splicing and ribosome maturation (CRM) protein Zm-mCSF1, which participate in the splicing of specific intron(s) of the 13 introns. These results prompt us to propose that SPR2/PPR-SMR1 serves as the core component of a splicing complex and possibly exerts the splicing function through a dynamic interaction with specific substrate recognizing PPR proteins in mitochondria.
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Regulação da Expressão Gênica de Plantas , Zea mays , Zea mays/metabolismo , Íntrons/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Sementes/genética , Splicing de RNA/genética , Mitocôndrias/metabolismo , Fatores de Processamento de RNA/genéticaRESUMO
BACKGROUND: IBD is becoming a global health challenge, with substantial variations in incidence and death rates between Eastern and Western countries. OBJECTIVE: This study aimed to investigate the burden and trends of IBD in 5 Asian countries, the United States, and the United Kingdom. DESIGN: This was a cross-sectional study. SETTING: Data were obtained from Global Burden of Disease 2019 Study. PATIENTS: Patients with IBD were included. MAIN OUTCOME MEASURES: Incidence, death, and age-standardized rates of IBD were measured. RESULTS: The age-standardized incidence and rates of death from IBD gradually decreased worldwide from 1990 to 2019. The age-standardized incidence rate in the United States decreased from 1990 to 2000 and then increased gradually from 2000 to 2019; the age-standardized incidence rates in the United Kingdom, Mongolia, and China increased gradually from 1990 to 2019, whereas in the Democratic People's Republic of Korea, it decreased from 1990 to 1995 and increased gradually from 1995 to 2019. The age-standardized death rate in the Republic of Korea exhibited a rising trend until 1995, fell significantly up to 2015, and then stabilized from 2015 to 2019. The age-standardized death rate in the United States showed a rising trend until 2007, and then decreased gradually from 2007 to 2019, whereas the rate in the United Kingdom showed a rising trend until 2010 and decreased from 2010 to 2019. The age-standardized death rates in China, Mongolia, the Democratic People's Republic of Korea, and Japan decreased gradually from 1990 to 2019. The age-standardized incidence and death rates in the United States and United Kingdom in recent decades were higher than those in the 5 Asian countries. The peak age-standardized incidence rates in the 7 countries were among people of 20 to 60 years of age. The age-standardized death rates in all 7 countries exhibited rising trends with increasing age, with older individuals, particularly those aged ≥70 years, accounting for the most deaths. LIMITATIONS: Limitations of this study include data from different countries with different quality and accuracy. CONCLUSIONS: There have been large variations in the burdens and trends of IBD between 5 Asian countries, the United States, and the United Kingdom during the past 3 decades. These findings may help policymakers to make better public decisions and allocate appropriate resources. See Video Abstract at http://links.lww.com/DCR/B996 . CARGA Y TENDENCIAS DE LA ENFERMEDAD INFLAMATORIA INTESTINAL EN CINCO PASES ASITICOS DESDE HASTA UNA COMPARACIN CON LOS ESTADOS UNIDOS Y EL REINO UNIDO: ANTECEDENTES:La enfermedad inflamatoria intestinal se está convirtiendo en un desafío en la salud mundial, con variaciones sustanciales en las tasas de incidencia y mortalidad entre los países orientales y occidentales.OBJETIVO:Investigar la carga y las tendencias de la enfermedad inflamatoria intestinal en cinco países asiáticos, EE. UU. y el Reino Unido.DISEÑO:Estudio transversal.ESCENARIO:Estudio de carga global de morbilidad 2019.PACIENTES:Enfermedad inflamatoria intestinal.PRINCIPALES MEDIDAS DE RESULTADO:Incidencia, muerte y tasas estandarizadas por edad de enfermedad inflamatoria intestinal.RESULTADOS:Las tasas de incidencia y muerte estandarizadas por edad de la enfermedad inflamatoria intestinal disminuyeron gradualmente en todo el mundo desde 1990 hasta 2019. La tasa de incidencia estandarizada por edad en los EE. UU. disminuyó de 1990 a 2000 y luego aumentó gradualmente de 2000 a 2019, las tasas en el Reino Unido, Mongolia y China aumentaron gradualmente de 1990 a 2019, mientras que la tasa en la República Popular Democrática de Corea disminuyó de 1990 a 1995 y aumentó gradualmente de 1990 a 2019. La tasa de mortalidad estandarizada por edad en la República de Corea exhibió un tendencia ascendente hasta 1995, cayó significativamente hasta 2015 y luego se estabilizó de 2015 a 2019. La tasa de mortalidad estandarizada por edad en los EE. UU. mostró una tendencia ascendente hasta 2007 y luego disminuyó gradualmente de 2007 a 2019, mientras que la tasa en el Reino Unido mostró una tendencia ascendente hasta 2010 y disminuyó de 2010 a 2019. Las tasas de mortalidad estandarizadas por edad en China, Mongolia, la República Popular Democrática de Corea y Japón disminuyeron gradualmente de 1990 a 2019. La tasa de incidencia estandarizada por edad y mortalidad en los EE. UU. y el Reino Unido en la última década fueron más altas que las de los cinco países asiáticos. Las tasas máximas de incidencia estandarizadas por edad en los siete países se dieron entre personas de 20 a 60 años. Las tasas de mortalidad estandarizadas por edad en los siete países exhibieron tendencias crecientes con el aumento de la edad, y las personas mayores, en particular las de ≥70 años, representaron la mayoría de las muertes.LIMITACIONES:Datos de diferentes países con diferente calidad y precisión.CONCLUSIONES:Ha habido grandes variaciones en las cargas y tendencias de la enfermedad inflamatoria intestinal entre cinco países asiáticos, EE. UU. y el Reino Unido durante las últimas tres décadas. Estos hallazgos pueden ayudar a los formuladores de políticas a tomar mejores decisiones públicas y asignar los recursos apropiados. Consulte Video Resumen en http://links.lww.com/DCR/B996 . (Traducción- Dr. Francisco M. Abarca-Rendon ).
Assuntos
Doenças Inflamatórias Intestinais , Humanos , Estados Unidos/epidemiologia , Idoso , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Estudos Transversais , Reino Unido/epidemiologia , Ásia/epidemiologia , Doenças Inflamatórias Intestinais/epidemiologiaRESUMO
OBJECTIVE: To study the safety of improved hydrodissection based on the periparathyroidal fascial space during microwave ablation (MWA) for secondary hyperparathyroidism (SHPT). MATERIALS AND METHODS: Data from 337 patients (162 males and 175 females; mean age, 50.8 ± 12.8 [range, 16-84] years) who underwent MWA for SHPT were retrospectively reviewed. Among them, 177 patients underwent traditional hydrodissection (traditional group) and 160 patients underwent improved hydrodissection based on periparathyroidal fascial spaces (improved group). Safety enhancement was analyzed by comparing the complications between the two groups. The characteristics of the hydrodissected fascial spaces, complications, and the follow-up results were recorded. The baseline data, clinical parameters, laboratory indices and characteristics of SHPT lesions were analyzed to assess the risk factors associated with hoarseness. RESULTS: Hydrodissection was successfully performed in all the enrolled patients according to the protocol. Six periparathyroid fascial spaces were hydrodissected, depending on the location of the SHPT lesions. The incidence of hoarseness due to recurrent laryngeal nerve injury, the most common complication of thermal ablation for SHPT lesions, was lower in the improved group than in the traditional group (6.9% vs. 13.0%, p = 0.044). The median hoarseness recovery time in the improved group was shorter than that in the traditional group (2 vs. 6 months, p < 0.001). There was no difference in technical efficiency between the two groups (improved group vs. traditional group: 75.0% vs. 70.6%; p > 0.05). CONCLUSIONS: Compared with traditional hydrodissection, improved hydrodissection based on periparathyroidal fascial spaces could enhance safety during MWA for SHPT.
Assuntos
Técnicas de Ablação , Hiperparatireoidismo Secundário , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Ablação/métodos , Rouquidão/complicações , Hiperparatireoidismo Secundário/cirurgia , Micro-Ondas/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento , Adolescente , Adulto Jovem , Idoso , Idoso de 80 Anos ou maisRESUMO
To address the problem of mechanical defect identification in a high-voltage circuit breaker (HVCB), this paper studies the circuit breaker vibration signal and proposes a method of feature extraction based on phase-space reconstruction of the vibration substages. To locate mechanical defects in circuit breakers, vibration signals are divided into different substages according to the time sequence of the parts of the circuit breakers. The largest Lyapunov exponent (LLE) of the vibration signals' substages is calculated, and then the substages are reconstructed in high-dimensional phase space. The geometric features of the phase trajectory mean center distance (MCD) and vector diameter offset (VDO) are calculated, and the LLE, MCD, and VDO are selected as the three fault identification features of the vibration substages. The eigenvalue anomaly rate of each substage of the vibration signal under defect state are calculated and analyzed to locate the vibration substage of the mechanical defect. Finally, a fault diagnosis model is constructed by a support vector machine (SVM), and the common mechanical defects of circuit breakers simulated in the laboratory are effectively identified.
RESUMO
This research explores the enantioselective hydrosulfonylation of various α,ß-unsaturated carbonyl compounds via the use of visible light and redox-active chiral Ni-catalysis, facilitating the synthesis of enantioenriched α-chiral sulfones with remarkable enantioselectivity (exceeding 99 % ee). A significant challenge entails enhancing the reactivity between chiral metal-coordinated carbonyl compounds and moderate electrophilic sulfonyl radicals, aiming to minimize the background reactions. The success of our approach stems from two distinctive attributes: 1) the Cl-atom abstraction employed for sulfonyl radical generation from sulfonyl chlorides, and 2) the single-electron reduction to produce a key enolate radical Ni-complex. The latter process appears to enhance the feasibility of the sulfonyl radical's addition to the electron-rich enolate radical. An in-depth investigation into the reaction mechanism, supported by both experimental observations and theoretical analysis, offers insight into the intricate reaction process. Moreover, the versatility of our methodology is highlighted through its successful application in the late-stage functionalization of complex bioactive molecules, demonstrating its practicality as a strategy for producing α-chiral sulfones.