Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 962
Filtrar
1.
Proc Natl Acad Sci U S A ; 121(16): e2322924121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38607933

RESUMO

Many Mendelian disorders, such as Huntington's disease (HD) and spinocerebellar ataxias, arise from expansions of CAG trinucleotide repeats. Despite the clear genetic causes, additional genetic factors may influence the rate of those monogenic disorders. Notably, genome-wide association studies discovered somewhat expected modifiers, particularly mismatch repair genes involved in the CAG repeat instability, impacting age at onset of HD. Strikingly, FAN1, previously unrelated to repeat instability, produced the strongest HD modification signals. Diverse FAN1 haplotypes independently modify HD, with rare genetic variants diminishing DNA binding or nuclease activity of the FAN1 protein, hastening HD onset. However, the mechanism behind the frequent and the most significant onset-delaying FAN1 haplotype lacking missense variations has remained elusive. Here, we illustrated that a microRNA acting on 3'-UTR (untranslated region) SNP rs3512, rather than transcriptional regulation, is responsible for the significant FAN1 expression quantitative trait loci signal and allelic imbalance in FAN1 messenger ribonucleic acid (mRNA), accounting for the most significant and frequent onset-delaying modifier haplotype in HD. Specifically, miR-124-3p selectively targets the reference allele at rs3512, diminishing the stability of FAN1 mRNA harboring that allele and consequently reducing its levels. Subsequent validation analyses, including the use of antagomir and 3'-UTR reporter vectors with swapped alleles, confirmed the specificity of miR-124-3p at rs3512. Together, these findings indicate that the alternative allele at rs3512 renders the FAN1 mRNA less susceptible to miR-124-3p-mediated posttranscriptional regulation, resulting in increased FAN1 levels and a subsequent delay in HD onset by mitigating CAG repeat instability.


Assuntos
Doença de Huntington , MicroRNAs , Humanos , Regiões 3' não Traduzidas/genética , Endodesoxirribonucleases , Exodesoxirribonucleases/genética , Estudo de Associação Genômica Ampla , Doença de Huntington/genética , MicroRNAs/genética , Enzimas Multifuncionais
2.
Am J Hum Genet ; 109(5): 885-899, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35325614

RESUMO

Genome-wide association studies (GWASs) of Huntington disease (HD) have identified six DNA maintenance gene loci (among others) as modifiers and implicated a two step-mechanism of pathogenesis: somatic instability of the causative HTT CAG repeat with subsequent triggering of neuronal damage. The largest studies have been limited to HD individuals with a rater-estimated age at motor onset. To capitalize on the wealth of phenotypic data in several large HD natural history studies, we have performed algorithmic prediction by using common motor and cognitive measures to predict age at other disease landmarks as additional phenotypes for GWASs. Combined with imputation with the Trans-Omics for Precision Medicine reference panel, predictions using integrated measures provided objective landmark phenotypes with greater power to detect most modifier loci. Importantly, substantial differences in the relative modifier signal across loci, highlighted by comparing common modifiers at MSH3 and FAN1, revealed that individual modifier effects can act preferentially in the motor or cognitive domains. Individual components of the DNA maintenance modifier mechanisms may therefore act differentially on the neuronal circuits underlying the corresponding clinical measures. In addition, we identified additional modifier effects at the PMS1 and PMS2 loci and implicated a potential second locus on chromosome 7. These findings indicate that broadened discovery and characterization of HD genetic modifiers based on additional quantitative or qualitative phenotypes offers not only the promise of in-human validated therapeutic targets but also a route to dissecting the mechanisms and cell types involved in both the somatic instability and toxicity components of HD pathogenesis.


Assuntos
Doença de Huntington , Cognição , DNA , Estudo de Associação Genômica Ampla , Humanos , Proteína Huntingtina/genética , Doença de Huntington/genética , Doença de Huntington/patologia , Expansão das Repetições de Trinucleotídeos
3.
Chem Soc Rev ; 53(5): 2693-2737, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38318782

RESUMO

In recent decades, significant progress has been achieved in rational developments of electrocatalysts through constructing novel atomistic structures and modulating catalytic surface topography, realizing substantial enhancement in electrocatalytic activities. Numerous advanced catalysts were developed for electrochemical energy conversion, exhibiting low overpotential, high intrinsic activity, and selectivity. Yet, maintaining the high catalytic performance under working conditions with high polarization and vigorous microkinetics that induce intensive degradation of surface nanostructures presents a significant challenge for commercial applications. Recently, advanced operando and computational techniques have provided comprehensive mechanistic insights into the degradation of surficial functional structures. Additionally, various innovative strategies have been devised and proven effective in sustaining electrocatalytic activity under harsh operating conditions. This review aims to discuss the most recent understanding of the degradation microkinetics of catalysts across an entire range of anodic to cathodic polarizations, encompassing processes such as oxygen evolution and reduction, hydrogen reduction, and carbon dioxide reduction. Subsequently, innovative strategies adopted to stabilize the materials' structure and activity are highlighted with an in-depth discussion of the underlying rationale. Finally, we present conclusions and perspectives regarding future research and development. By identifying the research gaps, this review aims to inspire further exploration of surface degradation mechanisms and rational design of durable electrocatalysts, ultimately contributing to the large-scale utilization of electroconversion technologies.

4.
Nano Lett ; 24(14): 4224-4232, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38557115

RESUMO

In this study, we identify the local structures of ex-solved nanoparticles using machine-learned potentials (MLPs). We develop a method for training machine-learned potentials by sampling local structures of heterointerface configurations as a training set with its efficacy tested on the Ni/MgO system, illustrating that the error in interface energy is only 0.004 eV/Å2. Using the developed scheme, we train an MLP for the Ni/La0.5Ca0.5TiO3 ex-solution system and identify the local structures for both exo- and endo-type particles. The established model aligns well with the experimental observations, accurately predicting a nucleation size of 0.45 nm. Lastly, the density functional theory calculations on the established atomistic model verify that the kinetic barrier for the dry reforming of methane are substantially reduced by 0.49 eV on the ex-solved catalysts compared to that on the impregnated catalysts. Our findings offer insights into the local structures, growth mechanisms, and underlying origin of the catalytic properties of ex-solved nanoparticles.

5.
J Am Chem Soc ; 146(11): 7752-7762, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38447176

RESUMO

Electrochemical nitrogen reduction reaction (eNRR) offers a sustainable route for ammonia synthesis; however, current electrocatalysts are limited in achieving optimal performance within narrow potential windows. Herein, inspired by the heliotropism of sunflowers, we present a biomimetic design of Ru-VOH electrocatalyst, featuring a dynamic Ru-O-V pyramid electron bridge for eNRR within a wide potential range. In situ spectroscopy and theoretical investigations unravel the fact that the electrons are donated from Ru to V at lower overpotentials and retrieved at higher overpotentials, maintaining a delicate balance between N2 activation and proton hydrogenation. Moreover, N2 adsorption and activation were found to be enhanced by the Ru-O-V moiety. The catalyst showcases an outstanding Faradaic efficiency of 51.48% at -0.2 V (vs RHE) with an NH3 yield rate exceeding 115 µg h-1 mg-1 across the range of -0.2 to -0.4 V (vs RHE), along with impressive durability of over 100 cycles. This dynamic M-O-V pyramid electron bridge is also applicable to other metals (M = Pt, Rh, and Pd).

6.
Small ; : e2401546, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38705853

RESUMO

The design of high-energy facets in electrocatalysts has attracted significant attention due to their potential to enhance electrocatalytic activity. In this review, the significance of high-energy facets in various electrochemical reactions are highlighted, including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), nitrogen reduction reaction (NRR), and carbon dioxide reduction reaction (CRR). Their importance in various electrochemical reactions and present strategies for constructing high-energy facets are discussed, including alloying, heterostructure formation, selective etching, capping agents, and coupling with substrates. These strategies enable control over crystallographic orientation and surface morphology, fine-tuning electrocatalytic properties. This study also addresses future directions and challenges, emphasizing the need to better understand fundamental mechanisms. Overall, high-energy facets offer exciting opportunities for advancing electrocatalysis.

7.
Small ; 20(21): e2309351, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38102093

RESUMO

It is a great demand to develop high-performance electrodes for metal-air batteries to boost cathodic oxygen reduction/evolution dynamics and avoid anodic dendrites. The optimization of catalysis at electrode can be conducted by increasing effective surface exposure, active site density, and unsaturated coordination, via using metal clusters or atomic catalysts, along with conductive or defective supports. Herein, the polarized and synergistic cooperation between dual single atom sites (Fe-N4/Co-N4) are developed through electrolytical exfoliation of defect-enriched π-conjugated macrocyclic polyphthalocyanines to expose more active sites on hollow carbonized shells (HCS). Such FeCo-N4/HCS exhibits outstanding performance in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), to achieve high-performance in an aqueous zinc battery (AZB) with a high discharge capacity (763.6 mAhg-1) after 750 cycles at 10 mA cm-2, showing stable discharge voltage and excellent durability. It also possesses high performance in a lithium-O2 battery owing to abundant defects, synergistic Fe-N4/Co-N4 active sites, reduced energy barriers, and boosted charge and mass transfer and reaction kinetics. This study provides novel perspectives to expand dual single-metal catalysts on macrocycles in the exploration of efficient, durable, and eco-friendly energy devices.

8.
Small ; 20(24): e2309841, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38217292

RESUMO

The demand for the exploration of highly active and durable electro/photocatalysts for renewable energy conversion has experienced a significant surge in recent years. Metal-organic frameworks (MOFs), by virtue of their high porosity, large surface area, and modifiable metal centers and ligands, have gained tremendous attention and demonstrated promising prospects in electro/photocatalytic energy conversion. However, the small pore sizes and limited active sites of 3D bulk MOFs hinder their wide applications. Developing 2D MOFs with tailored thickness and large aspect ratio has emerged as an effective approach to meet these challenges, offering a high density of exposed active sites, better mechanical stability, better assembly flexibility, and shorter charge and photoexcited state transfer distances compared to 3D bulk MOFs. In this review, synthesis methods for the most up-to-date 2D MOFs are first overviewed, highlighting their respective advantages and disadvantages. Subsequently, a systematic analysis is conducted on the identification and electronic structure modulation of catalytic active sites in 2D MOFs and their applications in renewable energy conversion, including electrocatalysis and photocatalysis (electro/photocatalysis). Lastly, the current challenges and future development of 2D MOFs toward highly efficient and practical electro/photocatalysis are proposed.

9.
BMC Cancer ; 24(1): 397, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553680

RESUMO

BACKGROUND: High-risk stage III colon cancer has a considerably poorer prognosis than stage II and low-risk stage III colon cancers. Nevertheless, most guidelines recommend similar adjuvant treatment approaches for all these stages despite the dearth of research focusing on high-risk stage III colon cancer and the potential for improved prognosis with intensive adjuvant treatment. Given the the proven efficacy of triplet chemotherapy in metastatic colorectal cancer treatment, the goal of this study is to evaluate the oncologic efficacy and safety of mFOLFIRINOX in comparison to those of the current standard of care, mFOLFOX 6, as an adjuvant treatment for patients diagnosed with high-risk stage III colon cancer after radical resection. METHODS: This multicenter, randomized (1:1), open-label, phase II trial will assess and compare the effectiveness and toxicity of mFOLFIRINOX and mFOLFOX 6 in patients with high-risk stage III colon cancer after radical resection. The goal of the trial is to enroll 312 eligible patients, from 11 institutes, aged between 20 and 70 years, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, or between 70 and 75 with an ECOG performance status of 0. Patients will be randomized into two arms - Arm A, the experimental arm, and Arm B, the reference arm - and will receive 12 cycles of mFOLFIRINOX and mFOLFOX 6 every 2 weeks, respectively. The primary endpoint of this study is the 3-year disease-free survival, and secondary endpoints include the 3-year overall survival and treatment toxicity. DISCUSSION: The Frost trial would help determine the oncologic efficacy and safety of adjuvant triplet chemotherapy for high-risk stage III colon cancers and ultimately improve prognoses. TRIAL REGISTRATION: ClinicalTrials.gov NCT05179889, registered on 17 December 2021.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias do Colo , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimioterapia Adjuvante , Ensaios Clínicos Fase II como Assunto , Neoplasias do Colo/patologia , Intervalo Livre de Doença , Estudos Multicêntricos como Assunto , Intervalo Livre de Progressão , Ensaios Clínicos Controlados Aleatórios como Assunto , Fluoruracila/uso terapêutico
10.
Gynecol Oncol ; 183: 68-73, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38520881

RESUMO

OBJECTIVE: To investigate pathologic complete response (pCR) and recurrence outcomes using various progestin treatment strategies in patients with atypical hyperplasia/endometrial intraepithelial neoplasia (AH/EIN). METHODS: Medical records of patients diagnosed with AH/EIN and undergoing follow-up endometrial biopsy after progestin treatment between 2011 and 2020 were retrospectively reviewed. Clinical factors and treatment outcomes were analyzed according to initial progestin treatment (oral progestin [OP], levonorgestrel-releasing intrauterine device [LNG-IUD], and combination), OP dose, and maintenance treatment using Pearson's χ2, Fisher's exact test, and Kaplan-Meier analysis. RESULTS: Of 124 patients included, 74, 37, and 13 were in the OP, LNG-IUD, and combination groups, respectively. The pCR rate was 79.8% and recurrence rate was 21.2%. The pCR rates within 3 and 6 months were significantly higher in the OP group than in the LNG-IUD group, but were not significantly different within 12 and 24 months. Recurrence rate was significantly higher in the OP group than in the LNG-IUD group. The pCR rate and recurrence rate had no significant differences between the combination group and the other groups. Excluding the LNG-IUD group, 53 and 34 patients received low- and high-dose OP, respectively. The pCR and recurrence rates were comparable between the low- and high-dose OP groups. Maintenance therapy was significantly associated with lower recurrence rate. CONCLUSIONS: Although OP alone achieved more short-term pCR than the other groups, more recurrences occurred after pCR than LNG-IUD alone. High-dose OP as well as combination of OP and LNG-IUD did not increase pCR or reduce recurrence. Maintenance therapy may reduce the recurrence rate after pCR.


Assuntos
Hiperplasia Endometrial , Neoplasias do Endométrio , Levanogestrel , Progestinas , Humanos , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Hiperplasia Endometrial/tratamento farmacológico , Hiperplasia Endometrial/patologia , Adulto , Progestinas/administração & dosagem , Levanogestrel/administração & dosagem , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/patologia , Resultado do Tratamento , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Dispositivos Intrauterinos Medicados , Idoso , Carcinoma in Situ/tratamento farmacológico , Carcinoma in Situ/patologia
11.
J Cutan Pathol ; 51(5): 353-359, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38199812

RESUMO

BACKGROUND: Venous malformations (VMs) are distinguished from lymphatic malformations (LMs) when specific diagnostic skin lesions are present. In the deep type, this is difficult by clinico-radiologic evaluation alone. We aimed to investigate the usefulness of lymphatic vessel endothelial cell (LEC) markers for the differential diagnosis of the deep VMs and LMs. METHODS: A retrospective study was conducted based on the medical records of patients with VMs and LMs who underwent biopsy with both D2-40 and PROX-1 immunohistochemistry. We compared the initial clinico-radiological diagnosis with the final pathological diagnosis and identified which ones showed a difference. RESULTS: From 261 patients who had VMs and LMs, 111 remained after the exclusion of those who showed definite surface diagnostic features. After pathological diagnosis with the expressions of D2-40 and PROX-1, 38 of 111 (34.2%) patients' final diagnoses were changed. Among these 38 cases, diagnosis was not changed by D2-40 positivity alone, but changed by PROX-1 positivity alone (52.6%) or by both (47.4%). The diagnostic changes were more frequent in the deep category (43.7%) than in the superficial category. CONCLUSIONS: Identifying the expression of D2-40, and especially PROX-1, in the differential diagnosis of VMs and LMs may provide important treatment guidelines and understanding their natural course.


Assuntos
Vasos Linfáticos , Dermatopatias , Malformações Vasculares , Humanos , Imuno-Histoquímica , Estudos Retrospectivos , Malformações Vasculares/diagnóstico , Malformações Vasculares/metabolismo , Pele , Dermatopatias/metabolismo
12.
BMC Musculoskelet Disord ; 25(1): 379, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38745277

RESUMO

BACKGROUND: Biomarkers that predict the treatment response in patients with knee osteoarthritis are scarce. This study aimed to investigate the potential role of synovial fluid cell counts and their ratios as biomarkers of primary knee osteoarthritis. METHODS: This retrospective study investigated 96 consecutive knee osteoarthritis patients with knee effusion who underwent joint fluid aspiration analysis and received concomitant intra-articular corticosteroid injections and blood tests. The monocyte-to-lymphocyte ratio (MLR) and neutrophil-to-lymphocyte ratio (NLR) were calculated. After 6 months of treatment, patients were divided into two groups: the responder group showing symptom resolution, defined by a visual analog scale (VAS) score of ≤ 3, without additional treatment, and the non-responder group showing residual symptoms, defined by a VAS score of > 3 and requiring further intervention, such as additional medication, repeated injections, or surgical treatment. Unpaired t-tests and univariate and multivariate logistic regression analyses were conducted between the two groups to predict treatment response after conservative treatment. The predictive value was calculated using the area under the receiver operating characteristic curve, and the optimal cutoff value was determined. RESULTS: Synovial fluid MLR was significantly higher in the non-responder group compared to the responder group (1.86 ± 1.64 vs. 1.11 ± 1.37, respectively; p = 0.02). After accounting for confounding variables, odds ratio of non-responder due to increased MLR were 1.63 (95% confidence interval: 1.11-2.39). The optimal MLR cutoff value for predicting patient response to conservative treatment was 0.941. CONCLUSIONS: MLR may be a potential biomarker for predicting the response to conservative treatment in patients with primary knee osteoarthritis.


Assuntos
Tratamento Conservador , Linfócitos , Monócitos , Osteoartrite do Joelho , Líquido Sinovial , Humanos , Osteoartrite do Joelho/terapia , Osteoartrite do Joelho/diagnóstico , Estudos Retrospectivos , Masculino , Feminino , Líquido Sinovial/citologia , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Tratamento Conservador/métodos , Injeções Intra-Articulares , Biomarcadores/análise , Biomarcadores/sangue , Valor Preditivo dos Testes , Contagem de Leucócitos
13.
J Arthroplasty ; 39(3): 645-650, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37757984

RESUMO

BACKGROUND: This study aimed to investigate the clinical outcomes of fixed-bearing medial unicompartmental knee arthroplasty (UKA) for tibia vara knees and the associated changes in joint space malalignment (JSM) and joint line obliquity (JLO). METHODS: We retrospectively analyzed a consecutive group of 100 patients who underwent fixed-bearing medial UKA with a preoperative medial proximal tibia angle (MPTA) ≥86° (n = 50) and MPTA <86° (n = 50) and who had a minimum 5-year follow-up. Radiological parameters, including the hip-knee-ankle angle, MPTA, and the postoperative JSM and JLO, were measured. Functional evaluation was performed using the range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index score. RESULTS: The MPTA <86° group showed significantly higher postoperative JLO (91.8 versus 90.4°, respectively; P = .002) and JSM (6.1 versus 4.2°, respectively; P = .026) compared to the MPTA ≥86° group. Functional outcomes, including range of motion, visual analog scale, Knee Society Knee Score, Knee Society Function Score, and Western Ontario and McMaster Universities Osteoarthritis Index scores, were not significantly different between the 2 groups. CONCLUSIONS: Fixed-bearing medial UKA is a safe and effective surgical option for patients who have tibia vara knees, as an increase in JLO and JSM postoperatively does not have a clinically relevant impact, even after a minimum 5-year follow-up.


Assuntos
Artroplastia do Joelho , Doenças do Desenvolvimento Ósseo , Osteoartrite do Joelho , Osteocondrose/congênito , Humanos , Artroplastia do Joelho/métodos , Osteoartrite do Joelho/cirurgia , Seguimentos , Estudos Retrospectivos , Articulação do Joelho/cirurgia , Tíbia/cirurgia
14.
Hum Mol Genet ; 30(R2): R254-R263, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34169318

RESUMO

Huntington's disease (HD) is a devastating neurogenetic disorder whose familial nature and progressive course were first described in the 19th century but for which no disease-modifying treatment is yet available. Through the active participation of HD families, this disorder has acted as a flagship for the application of human molecular genetic strategies to identify disease genes, understand pathogenesis and identify rational targets for development of therapies.


Assuntos
Suscetibilidade a Doenças , Doença de Huntington/etiologia , Alelos , Animais , Biomarcadores , Gerenciamento Clínico , Estudos de Associação Genética , Ligação Genética , Predisposição Genética para Doença , Humanos , Doença de Huntington/diagnóstico , Doença de Huntington/terapia , Modelos Biológicos
15.
Hum Mol Genet ; 30(3-4): 135-148, 2021 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-33432339

RESUMO

Huntington's disease pathogenesis involves a genetic gain-of-function toxicity mechanism triggered by the expanded HTT CAG repeat. Current therapeutic efforts aim to suppress expression of total or mutant huntingtin, though the relationship of huntingtin's normal activities to the gain-of-function mechanism and what the effects of huntingtin-lowering might be are unclear. Here, we have re-investigated a rare family segregating two presumed HTT loss-of-function (LoF) variants associated with the developmental disorder, Lopes-Maciel-Rodan syndrome (LOMARS), using whole-genome sequencing of DNA from cell lines, in conjunction with analysis of mRNA and protein expression. Our findings correct the muddled annotation of these HTT variants, reaffirm they are the genetic cause of the LOMARS phenotype and demonstrate that each variant is a huntingtin hypomorphic mutation. The NM_002111.8: c.4469+1G>A splice donor variant results in aberrant (exon 34) splicing and severely reduced mRNA, whereas, surprisingly, the NM_002111.8: c.8157T>A NP_002102.4: Phe2719Leu missense variant results in abnormally rapid turnover of the Leu2719 huntingtin protein. Thus, although rare and subject to an as yet unknown LoF intolerance at the population level, bona fide HTT LoF variants can be transmitted by normal individuals leading to severe consequences in compound heterozygotes due to huntingtin deficiency.


Assuntos
Regulação da Expressão Gênica , Proteína Huntingtina/genética , Mutação , Transtornos do Neurodesenvolvimento/genética , Sequência de Aminoácidos , Linhagem Celular , Criança , Pré-Escolar , Feminino , Humanos , Proteína Huntingtina/química , Proteína Huntingtina/metabolismo , Mutação com Perda de Função , Masculino , Mutação de Sentido Incorreto , Transtornos do Neurodesenvolvimento/metabolismo , Linhagem , Fenótipo , Splicing de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA
16.
Am J Hum Genet ; 107(1): 96-110, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32589923

RESUMO

A recent genome-wide association study of Huntington disease (HD) implicated genes involved in DNA maintenance processes as modifiers of onset, including multiple genome-wide significant signals in a chr15 region containing the DNA repair gene Fanconi-Associated Nuclease 1 (FAN1). Here, we have carried out detailed genetic, molecular, and cellular investigation of the modifiers at this locus. We find that missense changes within or near the DNA-binding domain (p.Arg507His and p.Arg377Trp) reduce FAN1's DNA-binding activity and its capacity to rescue mitomycin C-induced cytotoxicity, accounting for two infrequent onset-hastening modifier signals. We also idenified a third onset-hastening modifier signal whose mechanism of action remains uncertain but does not involve an amino acid change in FAN1. We present additional evidence that a frequent onset-delaying modifier signal does not alter FAN1 coding sequence but is associated with increased FAN1 mRNA expression in the cerebral cortex. Consistent with these findings and other cellular overexpression and/or suppression studies, knockout of FAN1 increased CAG repeat expansion in HD-induced pluripotent stem cells. Together, these studies support the process of somatic CAG repeat expansion as a therapeutic target in HD, and they clearly indicate that multiple genetic variations act by different means through FAN1 to influence HD onset in a manner that is largely additive, except in the rare circumstance that two onset-hastening alleles are present. Thus, an individual's particular combination of FAN1 haplotypes may influence their suitability for HD clinical trials, particularly if the therapeutic agent aims to reduce CAG repeat instability.


Assuntos
Endodesoxirribonucleases/genética , Exodesoxirribonucleases/genética , Doença de Huntington/genética , Enzimas Multifuncionais/genética , Linhagem Celular , Estudo de Associação Genômica Ampla/métodos , Células HEK293 , Haplótipos/genética , Humanos , Polimorfismo de Nucleotídeo Único/genética
17.
Small ; 19(12): e2205940, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36585361

RESUMO

Janus architectures have garnered great research efforts in recent years, leading to outstanding advances in electrocatalysis. Benefiting from the synergistic combination of their anisotropy which endows the manifestation of various co-existing electrochemical properties, and their compartmentalized structure that enables each functional domain to retain its inherent activity, with little to no interference from other domains, Janus architectures show great potential as exceptionally versatile electrocatalysts to complement a plethora of electrocatalytic processes. Thus, coupled with the growing interest in Janus architectures for electrocatalysis, it is imperative to investigate and reconsider their design strategies and future directions.

18.
Small ; 19(10): e2206844, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36642855

RESUMO

Designing robust electrocatalysts for water-splitting is essential for sustainable hydrogen generation, yet difficult to accomplish. In this study, a fast and facile two-step technique to synthesize Ru/RuO2 aerogels for catalyzing overall water-splitting under alkaline conditions is reported. Benefiting from the synergistic combination of high porosity, heterointerface, and tensile strain effects, the Ru/RuO2 aerogel exhibits low overpotential for oxygen evolution reaction (189 mV) and hydrogen evolution reaction (34 mV) at 10 mA cm-2 , surpassing RuO2 (338 mV) and Pt/C (53 mV), respectively. Notably, when the Ru/RuO2 aerogels are applied at the anode and cathode, the resultant water-splitting cell reflected a low potential of 1.47 V at 10 mA cm-2 , exceeding the commercial Pt/C||RuO2 standard (1.63 V). X-ray adsorption spectroscopy and theoretical studies demonstrate that the heterointerface of Ru/RuO2 optimizes charge redistribution, which reduces the energy barriers for hydrogen and oxygen intermediates, thereby enhancing oxygen and hydrogen evolution reaction kinetics.

19.
Small ; 19(41): e2302738, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37291982

RESUMO

Metal-organic frameworks (MOFs) and their derivatives have attracted much attention in the field of photo/electrocatalysis owing to their ultrahigh porosity, tunable properties, and superior coordination ability. Regulating the valence electronic structure and coordination environment of MOFs is an effective way to enhance their intrinsic catalytic performance. Rare earth (RE) elements with 4f orbital occupancy provide an opportunity to evoke electron rearrangement, accelerate charged carrier transport, and synergize the surface adsorption of catalysts. Therefore, the integration of RE with MOFs makes it possible to optimize their electronic structure and coordination environment, resulting in enhanced catalytic performance. In this review, progress in current research on the use of RE-modified MOFs and their derivatives for photo/electrocatalysis is summarized and discussed. First, the theoretical advantages of RE in MOF modification are introduced, with a focus on the roles of 4f orbital occupancy and RE ion organic coordination ligands. Then, the application of RE-modified MOFs and their derivatives in photo/electrocatalysis is systematically discussed. Finally, research challenges, future opportunities, and prospects for RE-MOFs are also discussed.

20.
Small ; 19(35): e2301186, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37116095

RESUMO

Broad spectral response and high photoelectric conversion efficiency are key milestones for realizing multifunctional, low-power optoelectronic devices such as artificial synapse and reconfigurable memory devices. Nevertheless, the wide bandgap and narrow spectral response of metal-oxide semiconductors are problematic for efficient metal-oxide optoelectronic devices such as photonic synapse and optical memory devices. Here, a simple titania (TiO2 )/indium-gallium-zinc-oxide (IGZO) heterojunction structure is proposed for efficient multifunctional optoelectronic devices, enabling widen spectral response range and high photoresponsivity. By overlaying a TiO2 film on IGZO, the light absorption range extends to red light, along with enhanced photoresponsivity in the full visible light region. By implementing the TiO2 /IGZO heterojunction structure, various synaptic behaviors are successfully emulated such as short-term memory/long-term memory and paired pulse facilitation. Also, the TiO2 /IGZO synaptic transistor exhibits a recognition rate up to 90.3% in recognizing handwritten digit images. Moreover, by regulating the photocarrier dynamics and retention behavior using gate-bias modulation, a reconfigurable multilevel (≥8 states) memory is demonstrated using visible light.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA