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Brugada syndrome (BrS) is a hereditary arrhythmia syndrome characterized by right bundle branch block on an electrocardiogram and persistent ST-segment elevation in the right precordial leads. In this study, we describe the establishment of an induced pluripotent stem cell (iPSC) line derived from a BrS patient carrying the novel heterogeneous missense mutation (c.3118G>C; p.G1040R) in the sodium channel protein type 5 subunit alpha (SCN5A) gene. Skin fibroblasts underwent reprogramming using a non-integrated Sendai viral method. Generated iPSC line exhibited embryonic stem cell-like morphology, maintained a normal karyotype, expressed pluripotency markers, and demonstrated the capacity to differentiate into three germ layers.
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Mutations in the nuclear envelope (NE) protein lamin A/C (encoded by LMNA), cause a severe form of dilated cardiomyopathy (DCM) with early-onset life-threatening arrhythmias. However, molecular mechanisms underlying increased arrhythmogenesis in LMNA-related DCM (LMNA-DCM) remain largely unknown. Here we show that a frameshift mutation in LMNA causes abnormal Ca2+ handling, arrhythmias and disformed NE in LMNA-DCM patient-specific iPSC-derived cardiomyocytes (iPSC-CMs). Mechanistically, lamin A interacts with sirtuin 1 (SIRT1) where mutant lamin A/C accelerates degradation of SIRT1, leading to mitochondrial dysfunction and oxidative stress. Elevated reactive oxygen species (ROS) then activates the Ca2+/calmodulin-dependent protein kinase II (CaMKII)-ryanodine receptor 2 (RYR2) pathway and aggravates the accumulation of SUN1 in mutant iPSC-CMs, contributing to arrhythmias and NE deformation, respectively. Taken together, the lamin A/C deficiency-mediated ROS disorder is revealed as central to LMNA-DCM development. Manipulation of impaired SIRT1 activity and excessive oxidative stress is a potential future therapeutic strategy for LMNA-DCM.
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Cardiomiopatia Dilatada , Células-Tronco Pluripotentes Induzidas , Lamina Tipo A , Miócitos Cardíacos , Estresse Oxidativo , Espécies Reativas de Oxigênio , Sirtuína 1 , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/patologia , Lamina Tipo A/metabolismo , Lamina Tipo A/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Humanos , Sirtuína 1/metabolismo , Sirtuína 1/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Fenótipo , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/genética , Arritmias Cardíacas/patologia , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Mutação da Fase de Leitura , Cálcio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Membrana Nuclear/metabolismo , Mitocôndrias/metabolismo , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/genéticaRESUMO
Post-operative radiotherapy for post-menopausal women with early breast cancer and N1 disease is controversial. Although locoregional control is improved, overall survival (OS) benefit is unclear. The clinical benefit of post-operative irradiation in this group of patients over 10 years was reviewed. We aimed to evaluate the OS, disease-free survival (DFS), and factors affecting OS and DFS. A retrospective review of 191 post-menopausal women with early breast cancer and N1 disease from 2004 to 2011 was performed. Demographics, post-operative histology, adjuvant treatment, OS, and DFS were evaluated. Post-operative radiation was given to 95 of 191 women (49.7%). Younger age at diagnosis (p < 0.001), a greater number of involved nodes (p = 0.004), lymphovascular invasion (LVI), and a higher tumor grade (p = 0.001) were more likely in women who received post-operative radiation. Nodal radiation did not improve 10-year DFS (p = 0.084) or OS (p = 0.203). Post-operative nodal radiation was associated with significant improvement in 10-year OS in women who received only hormonal therapy (p = 0.047) and no other systemic therapy. Women with unfavorable risk factors were more likely to receive post-operative radiation, likely due to a perceived higher risk of recurrence. Nodal radiation did not significantly improve 10-year DFS or OS in early breast cancer patients with N1 disease, and the benefit was not clearly demonstrated. However, in those who were on hormonal therapy, radiotherapy was beneficial in improving overall survival.
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Tadalafil (TD) has poor water solubility but is well absorbed without affecting food intake when administered orally. Owing to patient adherence and therapeutic characteristics, a TD-loaded orodispersible film (TDF) is preferable. However, the mechanistic role of dietary status on the clinical pharmacokinetic analysis of TDF in human volunteers should be investigated because the gastrointestinal environment varies periodically according to meal intervals, although commercial 20 mg TD-loaded tablets (TD-TAB, Cialis® tablet) may be taken with or without food. TDF was prepared by dispersing TD in an aqueous solution and polyethylene glycol 400 to ensure good dispersibility of the TD particles. In the fasting state, each T/R of Cmax and AUC between TD-TAB and TDF showed bioequivalence with 0.936-1.105 and 1.012-1.153, respectively, and dissolution rates in 1000 mL water containing 0.5% SLS were equivalent. In contrast, TDF was not bioequivalent to TD-TAB under the fed conditions by the Cmax T/R of 0.610-0.798. The increased dissolution rate of TDF via the micronization of drug particles and the reduced viscosity of the second meal content did not significantly affect the bioequivalence. Interestingly, an increase in second meal intake time from 4 h to 6 h resulted in the bioequivalence by the Cmax T/R of 0.851-0.998 of TD-TAB and TDF. The predictive diffusion direction model for physical digestion of TD-TAB and TDF in the stomach after the first and second meal intake was successfully simulated using computational fluid dynamics modeling, accounting for the delayed drug diffusion of TDF caused by prolonged digestion of stomach contents under postprandial conditions.
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BACKGROUND: Acute graft-versus-host disease (aGVHD), which is mainly mediated by allogeneic T cells, is a decisive factor in the success of allogeneic hematopoietic stem cell transplantation (allo-HCT). Prophylaxis for aGVHD in clinical patients is unsatisfactory, and there is still a huge unmet need for novel approaches. Icariin (ICA) shows potent anti-inflammatory activity and suppresses T cell-mediated immune responses. Thus, ICA is a potential drug for the prevention of aGVHD. However, there is no data assessing the impact of ICA on aGVHD after allo-HCT. PURPOSE: This study aimed to investigate the protective effect of ICA against aGVHD and its mechanisms. Moreover, the impact of ICA on the graft-versus-leukemia (GVL) effect and engraftment of donor hematopoietic and immune cells were assessed. METHODS: Different murine models of allo-HCT were developed to study the influence of the ICA on GVHD and GVL effect. Flow cytometry was used to analyze the growth of leukemia cells, alterations in different immune cells, and apoptosis. Cell proliferation was determined using a CCK-8 assay. RNA sequencing and quantitative proteomic analysis were performed to elucidate the underlying mechanisms, which were further verified by polymerase chain reaction or functional experiments. RESULTS: Different concentrations of ICA exhibited opposite effects: low-concentration ICA promoted, while high concentrations suppressed the proliferation and function of T cells. A high dose of ICA administration during days +3 to +5 post-allo-HCT can alleviate murine aGVHD but does not affect the course of chronic GVHD (cGVHD), the GVL effect against both acute myeloid and lymphoblastic leukemia, or the recovery of donor hematological and immune cells. ICA extensively represses the expansion, function, and infiltration of donor alloreactive T cells, while preserving regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSC). Quantitative proteomic analysis showed that downregulation of integrin-linked kinase (ILK) and lymphocyte cytosolic protein 2 (LCP2) expression was possibly associated with ICA-mediated aGVHD protective effects. Furthermore, an inhibitor of ILK, which can alleviate murine aGVHD administered early after allo-HCT. CONCLUSION: These findings suggest that the bioactivities of ICA are associated with its concentration and that ICA can effectively mitigate aGVHD without losing GVL activity or engraftment of donor hematopoietic and immune cells. Thus, ICA may be a promising drug for preventing aGVHD in clinical settings.
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HLA-C*02 246 has one nucleotide change from HLA-C*02:02:02:01 at nucleotide 523 changing Arginine to Cysteine at residue 151.
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Alelos , Sequência de Bases , Éxons , Antígenos HLA-C , Teste de Histocompatibilidade , Humanos , Antígenos HLA-C/genética , Análise de Sequência de DNA/métodos , Alinhamento de Sequência , Substituição de Aminoácidos , CódonRESUMO
Electroencephalogram (EEG) plays a pivotal role in the detection and analysis of epileptic seizures, which affects over 70 million people in the world. Nonetheless, the visual interpretation of EEG signals for epilepsy detection is laborious and time-consuming. To tackle this open challenge, we introduce a straightforward yet efficient hybrid deep learning approach, named ResBiLSTM, for detecting epileptic seizures using EEG signals. Firstly, a one-dimensional residual neural network (ResNet) is tailored to adeptly extract the local spatial features of EEG signals. Subsequently, the acquired features are input into a bidirectional long short-term memory (BiLSTM) layer to model temporal dependencies. These output features are further processed through two fully connected layers to achieve the final epileptic seizure detection. The performance of ResBiLSTM is assessed on the epileptic seizure datasets provided by the University of Bonn and Temple University Hospital (TUH). The ResBiLSTM model achieves epileptic seizure detection accuracy rates of 98.88-100% in binary and ternary classifications on the Bonn dataset. Experimental outcomes for seizure recognition across seven epilepsy seizure types on the TUH seizure corpus (TUSZ) dataset indicate that the ResBiLSTM model attains a classification accuracy of 95.03% and a weighted F1 score of 95.03% with 10-fold cross-validation. These findings illustrate that ResBiLSTM outperforms several recent deep learning state-of-the-art approaches.
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To study the biocompatibility of nanohydroxyapatite (nmHA)-SiO2 fiber material and its efficacy in guided bone regeneration. â The cytotoxicity of the nmHA-SiO2 fiber material to MC3T3-E1 cells was determined by CCK-8 assay. The adhesion of cells on the surface of the material was observed. â¡ Bone defects were prepared in the skull of three groups of New Zealand white rabbits. The following treatments were administered: implantation of nmHA-SiO2, implantation of Bio-Oss, and no treatment. The defects were then covered with nmHA-SiO2 membrane or Hai'ao oral repair membrane. Animal samples were analyzed by gross observation, micro-computed tomography, hematoxylin-eosin staining and Masson staining. The data were statistically analyzed by multivariate analysis of variance to evaluate the repair of bone defects. â The nmHA-SiO2 fiber material has suitable biocompatibility. â¡ The nmHA-SiO2 fiber material performed more effectively as a barrier membrane than other bone substitute materials in GBR model rabbits.
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Materiais Biocompatíveis , Regeneração Óssea , Durapatita , Dióxido de Silício , Animais , Coelhos , Dióxido de Silício/química , Durapatita/química , Durapatita/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Microtomografia por Raio-X , Teste de Materiais , Camundongos , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Crânio/cirurgia , Crânio/diagnóstico por imagem , Propriedades de Superfície , MineraisRESUMO
HNF4A and HNF1A encode transcription factors that are important for the development and function of the pancreas and liver. Mutations in both genes have been directly linked to Maturity Onset Diabetes of the Young (MODY) and type 2 diabetes (T2D) risk. To better define the pleiotropic gene regulatory roles of HNF4A and HNF1A, we generated a comprehensive genome-wide map of their binding targets in pancreatic and hepatic cells using ChIP-Seq. HNF4A was found to bind and regulate known (ACY3, HAAO, HNF1A, MAP3K11) and previously unidentified (ABCD3, CDKN2AIP, USH1C, VIL1) loci in a tissue-dependent manner. Functional follow-up highlighted a potential role for HAAO and USH1C as regulators of beta cell function. Unlike the loss-of-function HNF4A/MODY1 variant I271fs, the T2D-associated HNF4A variant (rs1800961) was found to activate AKAP1, GAD2 and HOPX gene expression, potentially due to changes in DNA-binding affinity. We also found HNF1A to bind to and regulate GPR39 expression in beta cells. Overall, our studies provide a rich resource for uncovering downstream molecular targets of HNF4A and HNF1A that may contribute to beta cell or hepatic cell (dys)function, and set up a framework for gene discovery and functional validation.
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Diabetes Mellitus Tipo 2 , Regulação da Expressão Gênica , Fator 1-alfa Nuclear de Hepatócito , Fator 4 Nuclear de Hepatócito , Hepatócitos , Células Secretoras de Insulina , Fator 4 Nuclear de Hepatócito/metabolismo , Fator 4 Nuclear de Hepatócito/genética , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Fator 1-alfa Nuclear de Hepatócito/genética , Células Secretoras de Insulina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Hepatócitos/metabolismo , Humanos , Animais , Camundongos , Proteínas de Ancoragem à Quinase A/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Especificidade de Órgãos/genéticaRESUMO
BACKGROUND: Clinical core medical knowledge (CCMK) learning is essential for medical trainees. Adaptive assessment systems can facilitate self-learning, but extracting experts' CCMK is challenging, especially using modern data-driven artificial intelligence (AI) approaches (e.g., deep learning). OBJECTIVES: This study aims to develop a multi-expert knowledge-aggregated adaptive assessment scheme (MEKAS) using knowledge-based AI approaches to facilitate the learning of CCMK in otolaryngology (CCMK-OTO) and validate its effectiveness through a one-month training program for CCMK-OTO education at a tertiary referral hospital. METHODS: The MEKAS utilized the repertory grid technique and case-based reasoning to aggregate experts' knowledge to construct a representative CCMK base, thereby enabling adaptive assessment for CCMK-OTO training. The effects of longitudinal training were compared between the experimental group (EG) and the control group (CG). Both groups received a normal training program (routine meeting, outpatient/operation room teaching, and classroom teaching), while EG received MEKAS for self-learning. The EG comprised 22 UPGY trainees (6 postgraduate [PGY] and 16 undergraduate [UGY] trainees) and 8 otolaryngology residents (ENT-R); the CG comprised 24 UPGY trainees (8 PGY and 16 UGY trainees). The training effectiveness was compared through pre- and post-test CCMK-OTO scores, and user experiences were evaluated using a technology acceptance model-based questionnaire. RESULTS: Both UPGY (z = -3.976, P < 0.001) and ENT-R (z = -2.038, P = 0.042) groups in EG exhibited significant improvements in their CCMK-OTO scores, while UPGY in CG did not (z = -1.204, P = 0.228). The UPGY group in EG also demonstrated a substantial improvement compared to the UPGY group in CG (z = -4.943, P < 0.001). The EG participants were highly satisfied with the MEKAS system concerning self-learning assistance, adaptive testing, perceived satisfaction, intention to use, perceived usefulness, perceived ease of use, and perceived enjoyment, rating it between an overall average of 3.8 and 4.1 out of 5.0 on all scales. CONCLUSIONS: The MEKAS system facilitates CCMK-OTO learning and provides an efficient knowledge aggregation scheme that can be applied to other medical subjects to efficiently build adaptive assessment systems for CCMK learning. Larger-scale validation across diverse institutions and settings is warranted further to assess MEKAS's scalability, generalizability, and long-term impact.
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Otolaringologia , Humanos , Otolaringologia/educação , Inteligência Artificial , Masculino , Feminino , Competência ClínicaRESUMO
A photonic-assisted microwave frequency measurement (MFM) method based on optical heterodyne detection is proposed and experimentally demonstrated. In the proposed MFM system, a linearly chirped optical waveform (LCOW) from a three-electrode distributed Bragg reflector laser diode (DBR-LD) and a multi-wavelength signal from a Mach-Zehnder modulator (MZM), where the signal under test (SUT) is modulated on an optical carrier from a distributed feedback laser diode (DFB-LD), are heterodyne detected by the photodetector (PD). A bandpass filter then filters the detected signal, and the envelope is detected by an oscilloscope. Then, frequency-to-time mapping is realized, and the signal frequency is measured. Thanks to the fast tuning rate and large tuning range of the DBR-LD, the proposed MFM system has a high measurement speed and a broad instantaneous measurement bandwidth. In the experimental demonstration, a measurement error below 39.1â MHz is achieved at an instantaneous bandwidth of 20â GHz and a measurement speed of 1.12â GHz/µs. The MFM of a frequency-hopping signal is also experimentally demonstrated. The successful demonstration of the MFM system with a simple structure provides a new optical solution for realizing broadband and fast microwave frequency measurements.
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We described a copper(I)-catalyzed atom economic and selective hydroamination-cyclization of alkynyl-tethered quinazolinones to prepare a variety of indole-fused pyrazino[1,2-a]quinazolinones in good to excellent yields ranging from 39% to 99% under mild reaction conditions. Control experiments revealed that coordination-directed method of quinazolinone moiety with copper(I) was important for the selective hydroamination-cyclization of alkynes at the N1-atom instead of N3-atom of quinazolinone. The reaction could be easily performed at gram scales and some prepared indole-fused pyrazino[1,2-a]quinazolinones with donating groups on the indole moiety showed a distinct fluorescence emission wavelength with blue shift under the acid conditions.
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This study addresses the limited tools available for assessing food safety risks from cytotoxic Bacillus cereus group strains in contaminated food. We quantified the growth, in skim milk broth, of 17 cytotoxic B. cereus strains across 6 phylogenetic groups with various virulence gene profiles. The strains did not grow in HTST milk at 4 or 6°C. At 10°C, 15 strains exhibited growth; at 8°C, one strain grew; and all strains grew at temperatures ≥ 14°C. Using growth data from 16 strains, we developed linear secondary growth models and an exposure assessment model. This model, simulating a 5-stage HTST milk supply chain and up to 35 d of consumer storage with an initial contamination of 100 cfu/mL, estimated that 2.81 ± 0.66% and 4.13 ± 2.53% of milk containers would surpass 105 cfu/mL of B. cereus by d 21 and 35, respectively. A sensitivity analysis identified the initial physiological state of cells (Q0) as the most influential variable affecting predictions for specific isolates. What-if scenarios indicated that increases in mean and variability of consumer storage temperatures significantly affected the predicted B. cereus concentrations in milk. This model serves as an initial tool for risk-based food safety decision making regarding low-level B. cereus contamination.
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Plants are increasingly vulnerable to environmental stresses because of global warming and climate change. Stress-induced reactive oxygen species (ROS) accumulation results in plant cell damage and even cell death. Anthocyanins are important antioxidants that scavenge ROS to maintain ROS homeostasis. However, the mechanism underlying ROS-induced anthocyanin accumulation is unclear. In this study, we determined that the HD-Zip I family member transcription factor PuHB40 mediates ROS-dependent anthocyanin biosynthesis under high-light stress in pear (Pyrus ussuriensis). Specifically, PuHB40 induces the PuMYB123-like-PubHLH3 transcription factor complex for anthocyanin biosynthesis. PuHB40-mediated transcriptional activation depends on its phosphorylation level, which is regulated by protein phosphatase PP2A. Elevated ROS content maintains high PuHB40 phosphorylation levels, while also enhancing PuHB40-induced PuMYB123-like transcription by decreasing PuPP2AA2 expression, ultimately leading to increased anthocyanin biosynthesis. Our study reveals a pathway regulating ROS-induced anthocyanin biosynthesis in pear, further clarifying the mechanism underlying abiotic stress-induced anthocyanin biosynthesis, which may have implications for improving plant stress tolerance.
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OBJECTIVES: To explore the prevention and management of venous thromboembolism (VTE) following major orthopaedic surgery (MOS) by fostering doctor-to-patient cultivation of musculoskeletal ability, guided by King's theory of goal attainment. METHODS: A cohort of patients (n = 116) undergoing MOS was selected for the study, and were divided into two groups: the regular group and the observation group, with patients in the regular group experiencing routine nursing care and management and those in the observation group undergoing musculoskeletal ability cultivation based on King's theory of goal attainment. Baseline data, limb vascular ultrasonography, coagulation function, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, VTE prevention efficacy, Exercise of Self-care Ability Scale (ESCA) score, and nursing satisfaction were analysed comparatively. RESULTS: There was no significant within-group difference in baseline data (P > 0.05). Following the interventions, the observation group demonstrated statistically significant reductions in the Musculoskeletal-Integrated Imaging Score, various dimensions of WOMAC scores, and D-dimer (D-D) levels (P < 0.05) both in comparison to their levels before interventions and to those observed in the regular group (P < 0.05). Additionally, the observation group exhibited increases in prothrombin time levels and various dimensions of ESCA scores (P < 0.05) post-intervention, surpassing the pre-intervention levels and those obtained in the regular group (P < 0.05). Furthermore, the observation group exhibited a significantly lower incidence of VTE (P < 0.05) and higher nursing satisfaction (P < 0.05) compared to the regular group. CONCLUSIONS: Nursing intervention measures, utilizing doctor-to-patient cultivation of musculoskeletal ability based on King's theory of goal attainment, have demonstrated a significant clinical benefit for VTE prevention and control in post-MOS patients. This approach not only effectively prevented VTE in post MOS patients but also enhanced their satisfaction towards nursing care.
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Fibroblast growth factor 5 (FGF5) plays key roles in promoting the transition from the anagen to catagen during the hair follicle cycle. The sheep serves as an excellent model for studying hair growth and is frequently utilized in various research processes related to human skin diseases. We used the CRISPR/Cas9 system to generate four FGF5-edited Dorper sheep and only low levels of FGF5 were detected in the edited sheep. The density of fine wool in GE sheep was markedly increased, and the proportion of fine wool with a diameter of 14.4-20.0 µm was significantly higher. The proliferation signal in the skin of gene-edited (GE) sheep was stronger than in wild-type (WT) sheep. FGF5 editing decreased cortisol concentration in the skin, further activated the activity of antioxidant enzymes such as Glutathione peroxidase (GSH-Px), and regulated the expression of Wnt signaling pathways containing Wnt agonists (Rspondins, Rspos) and antagonists (Notum) in hair regeneration. We suggest that FGF5 not only mediates the activation of antioxidant pathways by cortisol, which constitutes a highly coordinated microenvironment in hair follicle cells, but also influences key signals of the Wnt pathway to regulate secondary hair follicle (SHF) development. Overall, our findings here demonstrate that FGF5 plays a significant role in regulating SHF growth in sheep and potentially serves as a molecular marker of fine wool growth in sheep breeding.
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Fator 5 de Crescimento de Fibroblastos , Glutationa Peroxidase , Folículo Piloso , Via de Sinalização Wnt , Lã , Animais , Fator 5 de Crescimento de Fibroblastos/metabolismo , Fator 5 de Crescimento de Fibroblastos/genética , Ovinos , Lã/metabolismo , Folículo Piloso/metabolismo , Folículo Piloso/crescimento & desenvolvimento , Glutationa Peroxidase/metabolismo , Glutationa Peroxidase/genética , Edição de Genes , Hidrocortisona/metabolismo , Proliferação de Células , Sistemas CRISPR-Cas/genéticaRESUMO
Green ammonia synthesis through electrocatalytic nitrate reduction reaction (eNO3RR) can serve as an effective alternative to the traditional energy-intensive Haber-Bosch process. However, achieving high Faradaic efficiency (FE) at industrially relevant current density in neutral medium poses significant challenges in eNO3RR. Herein, with the guidance of theoretical calculation, a metallic CoNi-terminated catalyst is successfully designed and constructed on copper foam, which achieves an ammonia FE of up to 100% under industrial-level current density and very low overpotential (-0.15 V versus reversible hydrogen electrode) in a neutral medium. Multiple characterization results have confirmed that the maintained metal atom-terminated surface through interaction with copper atoms plays a crucial role in reducing overpotential and achieving high current density. By constructing a homemade gas stripping and absorption device, the complete conversion process for high-purity ammonium nitrate products is demonstrated, displaying the potential for practical application. This work suggests a sustainable and promising process toward directly converting nitrate-containing pollutant solutions into practical nitrogen fertilizers.
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Receptores ErbB , Neoplasias Pulmonares , Proteínas de Ligação a Retinoblastoma , Feminino , Humanos , Masculino , Receptores ErbB/genética , Genótipo , Neoplasias Pulmonares/genética , Mutação , Proteínas de Ligação a Retinoblastoma/genética , Carcinoma de Pequenas Células do Pulmão/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Atomically precise metal nanoclusters (NCs) are emerging as idealized model catalysts for imprecise metal nanoparticles to unveil their structure-activity relationship. However, the directional synthesis of robust metal NCs with accessible catalytic active sites remains a great challenge. In this work, we achieved bulky carboranealkynyl-protected copper NCs, the monomer Cu13·3PF6 and nido-carboranealkynyl bridged dimer Cu26·4PF6, with fair stability as well as accessible open metal sites step by step through external ligand shell modification and metal-core evolution. Both Cu13·3PF6 and Cu26·4PF6 demonstrate remarkable catalytic activity and selectivity in electrocatalytic nitrate (NO3-) reduction to NH3 reaction, with the dimer Cu26·4PF6 displaying superior performance. The mechanism of this catalytic reaction was elucidated through theoretical computations in conjunction with in situ FTIR spectra. This study not only provides strategies for accessing desired copper NC catalysts but also establishes a platform to uncover the structure-activity relationship of copper NCs.