Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 972
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 597(7877): 503-510, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34552257

RESUMO

Large, distributed collections of miniaturized, wireless electronic devices1,2 may form the basis of future systems for environmental monitoring3, population surveillance4, disease management5 and other applications that demand coverage over expansive spatial scales. Aerial schemes to distribute the components for such networks are required, and-inspired by wind-dispersed seeds6-we examined passive structures designed for controlled, unpowered flight across natural environments or city settings. Techniques in mechanically guided assembly of three-dimensional (3D) mesostructures7-9 provide access to miniature, 3D fliers optimized for such purposes, in processes that align with the most sophisticated production techniques for electronic, optoelectronic, microfluidic and microelectromechanical technologies. Here we demonstrate a range of 3D macro-, meso- and microscale fliers produced in this manner, including those that incorporate active electronic and colorimetric payloads. Analytical, computational and experimental studies of the aerodynamics of high-performance structures of this type establish a set of fundamental considerations in bio-inspired design, with a focus on 3D fliers that exhibit controlled rotational kinematics and low terminal velocities. An approach that represents these complex 3D structures as discrete numbers of blades captures the essential physics in simple, analytical scaling forms, validated by computational and experimental results. Battery-free, wireless devices and colorimetric sensors for environmental measurements provide simple examples of a wide spectrum of applications of these unusual concepts.


Assuntos
Biomimética , Equipamentos e Provisões Elétricas , Miniaturização/instrumentação , Sementes , Vento , Tecnologia sem Fio/instrumentação , Colorimetria , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Fenômenos Mecânicos , Microfluídica , Vigilância da População/métodos , Rotação
2.
Hum Mol Genet ; 32(23): 3276-3298, 2023 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-37688574

RESUMO

Cyclin-dependent kinase-like 5 (CDKL5) is a serine-threonine kinase enriched in the forebrain to regulate neuronal development and function. Patients with CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition caused by mutations of CDKL5 gene, present early-onset epilepsy as the most prominent feature. However, spontaneous seizures have not been reported in mouse models of CDD, raising vital questions on the human-mouse differences and the roles of CDKL5 in early postnatal brains. Here, we firstly measured electroencephalographic (EEG) activities via a wireless telemetry system coupled with video-recording in neonatal mice. We found that mice lacking CDKL5 exhibited spontaneous epileptic EEG discharges, accompanied with increased burst activities and ictal behaviors, specifically at postnatal day 12 (P12). Intriguingly, those epileptic spikes disappeared after P14. We next performed an unbiased transcriptome profiling in the dorsal hippocampus and motor cortex of Cdkl5 null mice at different developmental timepoints, uncovering a set of age-dependent and brain region-specific alterations of gene expression in parallel with the transient display of epileptic activities. Finally, we validated multiple differentially expressed genes, such as glycine receptor alpha 2 and cholecystokinin, at the transcript or protein levels, supporting the relevance of these genes to CDKL5-regulated excitability. Our findings reveal early-onset neuronal hyperexcitability in mouse model of CDD, providing new insights into CDD etiology and potential molecular targets to ameliorate intractable neonatal epilepsy.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia , Espasmos Infantis , Humanos , Animais , Camundongos , Transcriptoma/genética , Espasmos Infantis/genética , Espasmos Infantis/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Epilepsia/genética , Prosencéfalo/metabolismo , Camundongos Knockout
3.
Proc Natl Acad Sci U S A ; 119(32): e2121425119, 2022 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-35914147

RESUMO

Distribution of Earth's biomes is structured by the match between climate and plant traits, which in turn shape associated communities and ecosystem processes and services. However, that climate-trait match can be disrupted by historical events, with lasting ecosystem impacts. As Earth's environment changes faster than at any time in human history, critical questions are whether and how organismal traits and ecosystems can adjust to altered conditions. We quantified the relative importance of current environmental forcing versus evolutionary history in shaping the growth form (stature and biomass) and associated community of eelgrass (Zostera marina), a widespread foundation plant of marine ecosystems along Northern Hemisphere coastlines, which experienced major shifts in distribution and genetic composition during the Pleistocene. We found that eelgrass stature and biomass retain a legacy of the Pleistocene colonization of the Atlantic from the ancestral Pacific range and of more recent within-basin bottlenecks and genetic differentiation. This evolutionary legacy in turn influences the biomass of associated algae and invertebrates that fuel coastal food webs, with effects comparable to or stronger than effects of current environmental forcing. Such historical lags in phenotypic acclimatization may constrain ecosystem adjustments to rapid anthropogenic climate change, thus altering predictions about the future functioning of ecosystems.


Assuntos
Ecossistema , Zosteraceae , Aclimatação , Animais , Evolução Biológica , Biomassa , Cadeia Alimentar , Invertebrados , Zosteraceae/genética
4.
Hum Mol Genet ; 31(13): 2207-2222, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35134179

RESUMO

Manganese (Mn) is an essential mineral, but excess exposure can cause dopaminergic neurotoxicity. Restless legs syndrome (RLS) is a common neurological disorder, but the etiology and pathology remain largely unknown. The purpose of this study was to identify the role of Mn in the regulation of an RLS genetic risk factor BTBD9, characterize the function of BTBD9 in Mn-induced oxidative stress and dopaminergic neuronal dysfunction. We found that human subjects with high blood Mn levels were associated with decreased BTBD9 mRNA levels, when compared with subjects with low blood Mn levels. In A549 cells, Mn exposure decreased BTBD9 protein levels. In Caenorhabditis elegans, loss of hpo-9 (BTBD9 homolog) resulted in more susceptibility to Mn-induced oxidative stress and mitochondrial dysfunction, as well as decreased dopamine levels and alternations of dopaminergic neuronal morphology and behavior. Overexpression of hpo-9 in mutant animals restored these defects and the protection was eliminated by mutation of the forkhead box O (FOXO). In addition, expression of hpo-9 upregulated FOXO protein levels and decreased protein kinase B levels. These results suggest that elevated Mn exposure might be an environmental risk factor for RLS. Furthermore, BTBD9 functions to alleviate Mn-induced oxidative stress and neurotoxicity via regulation of insulin/insulin-like growth factor signaling pathway.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Síndromes Neurotóxicas , Síndrome das Pernas Inquietas , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Dopamina/metabolismo , Humanos , Insulina/genética , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Manganês/toxicidade , Síndromes Neurotóxicas/genética , Estresse Oxidativo/genética , Síndrome das Pernas Inquietas/genética , Síndrome das Pernas Inquietas/metabolismo , Transdução de Sinais
5.
Am J Hum Genet ; 108(3): 458-468, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33609447

RESUMO

Determination of the clinical relevance of rare germline variants of uncertain significance (VUSs) in the BRCA2 cancer predisposition gene remains a challenge as a result of limited availability of data for use in classification models. However, laboratory-based functional data derived from validated functional assays of known sensitivity and specificity may influence the interpretation of VUSs. We evaluated 252 missense VUSs from the BRCA2 DNA-binding domain by using a homology-directed DNA repair (HDR) assay and identified 90 as non-functional and 162 as functional. The functional assay results were integrated with other available data sources into an ACMG/AMP rules-based classification framework used by a hereditary cancer testing laboratory. Of the 186 missense variants observed by the testing laboratory, 154 were classified as VUSs without functional data. However, after applying protein functional data, 86% (132/154) of the VUSs were reclassified as either likely pathogenic/pathogenic (39/132) or likely benign/benign (93/132), which impacted testing results for 1,900 individuals. These results indicate that validated functional assay data can have a substantial impact on VUS classification and associated clinical management for many individuals with inherited alterations in BRCA2.


Assuntos
Proteína BRCA2/genética , Neoplasias da Mama/genética , Predisposição Genética para Doença , Reparo de DNA por Recombinação/genética , Neoplasias da Mama/patologia , Feminino , Variação Genética/genética , Humanos , Mutação de Sentido Incorreto/genética , Relação Estrutura-Atividade
6.
N Engl J Med ; 384(5): 440-451, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33471974

RESUMO

BACKGROUND: Population-based estimates of the risk of breast cancer associated with germline pathogenic variants in cancer-predisposition genes are critically needed for risk assessment and management in women with inherited pathogenic variants. METHODS: In a population-based case-control study, we performed sequencing using a custom multigene amplicon-based panel to identify germline pathogenic variants in 28 cancer-predisposition genes among 32,247 women with breast cancer (case patients) and 32,544 unaffected women (controls) from population-based studies in the Cancer Risk Estimates Related to Susceptibility (CARRIERS) consortium. Associations between pathogenic variants in each gene and the risk of breast cancer were assessed. RESULTS: Pathogenic variants in 12 established breast cancer-predisposition genes were detected in 5.03% of case patients and in 1.63% of controls. Pathogenic variants in BRCA1 and BRCA2 were associated with a high risk of breast cancer, with odds ratios of 7.62 (95% confidence interval [CI], 5.33 to 11.27) and 5.23 (95% CI, 4.09 to 6.77), respectively. Pathogenic variants in PALB2 were associated with a moderate risk (odds ratio, 3.83; 95% CI, 2.68 to 5.63). Pathogenic variants in BARD1, RAD51C, and RAD51D were associated with increased risks of estrogen receptor-negative breast cancer and triple-negative breast cancer, whereas pathogenic variants in ATM, CDH1, and CHEK2 were associated with an increased risk of estrogen receptor-positive breast cancer. Pathogenic variants in 16 candidate breast cancer-predisposition genes, including the c.657_661del5 founder pathogenic variant in NBN, were not associated with an increased risk of breast cancer. CONCLUSIONS: This study provides estimates of the prevalence and risk of breast cancer associated with pathogenic variants in known breast cancer-predisposition genes in the U.S. population. These estimates can inform cancer testing and screening and improve clinical management strategies for women in the general population with inherited pathogenic variants in these genes. (Funded by the National Institutes of Health and the Breast Cancer Research Foundation.).


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Variação Genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Mutação , Razão de Chances , Risco , Análise de Sequência de DNA , Adulto Jovem
7.
Bioinformatics ; 39(9)2023 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-37665736

RESUMO

MOTIVATION: Allowance for increasingly large samples is a key to identify the association of genetic variants with Alzheimer's disease (AD) in genome-wide association studies (GWAS). Accordingly, we aimed to develop a method that incorporates patients with mild cognitive impairment and unknown cognitive status in GWAS using a machine learning-based AD prediction model. RESULTS: Simulation analyses showed that weighting imputed phenotypes method increased the statistical power compared to ordinary logistic regression using only AD cases and controls. Applied to real-world data, the penalized logistic method had the highest AUC (0.96) for AD prediction and weighting imputed phenotypes method performed well in terms of power. We identified an association (P<5.0×10-8) of AD with several variants in the APOE region and rs143625563 in LMX1A. Our method, which allows the inclusion of individuals with mild cognitive impairment, improves the statistical power of GWAS for AD. We discovered a novel association with LMX1A. AVAILABILITY AND IMPLEMENTATION: Simulation codes can be accessed at https://github.com/Junkkkk/wGEE_GWAS.


Assuntos
Doença de Alzheimer , Estudo de Associação Genômica Ampla , Humanos , Estudo de Associação Genômica Ampla/métodos , Incerteza , Estudos de Associação Genética , Fenótipo , Aprendizado de Máquina , Doença de Alzheimer/genética
8.
Chemistry ; 30(10): e202302552, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-37997029

RESUMO

This work demonstrated the first synthetic application of direct C-H olefinations in the step-saving preparation of various hole-transporting materials (HTM) for efficient perovskite solar cells (PSC). Cross-dehydrogenative couplings of naphthodithiophene (NDT) with vinyl arenes under palladium-catalysis facilely generated various new oligo(hetero)aryls with internal alkenes. Reaction conditions were optimized, which gave the product isolated yields of up to 71 % with high (E)-stereoselectivity. These readily accessible NDT core-based small molecules involving olefin as π-spacers displayed immediate power conversion efficiencies of up to 17.2 % without a device oxidation process that is required for the commercially available spiro-OMeTAD and most other existing HTMs while fabricated in corresponding PSC devices.

9.
Mol Psychiatry ; 28(7): 3121-3132, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37198259

RESUMO

Genome-wide association studies (GWAS) of Alzheimer's disease are predominantly carried out in European ancestry individuals despite the known variation in genetic architecture and disease prevalence across global populations. We leveraged published GWAS summary statistics from European, East Asian, and African American populations, and an additional GWAS from a Caribbean Hispanic population using previously reported genotype data to perform the largest multi-ancestry GWAS meta-analysis of Alzheimer's disease and related dementias to date. This method allowed us to identify two independent novel disease-associated loci on chromosome 3. We also leveraged diverse haplotype structures to fine-map nine loci with a posterior probability >0.8 and globally assessed the heterogeneity of known risk factors across populations. Additionally, we compared the generalizability of multi-ancestry- and single-ancestry-derived polygenic risk scores in a three-way admixed Colombian population. Our findings highlight the importance of multi-ancestry representation in uncovering and understanding putative factors that contribute to risk of Alzheimer's disease and related dementias.


Assuntos
Doença de Alzheimer , Predisposição Genética para Doença , Humanos , Doença de Alzheimer/etnologia , Doença de Alzheimer/genética , Negro ou Afro-Americano/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Polimorfismo de Nucleotídeo Único/genética , População do Leste Asiático/genética , População Europeia/genética , População do Caribe/genética , Hispânico ou Latino/genética , População da América do Sul/genética
10.
Mol Cell Biochem ; 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39110278

RESUMO

The CCND1 mRNA possesses at least two distinct lengths of the 3'-untranslated region (3'UTR), with the long isoform containing multiple AU-rich elements (AREs). The tandem zinc finger (TZF) domains of human ZFP36 family members have the capacity to bind to AREs and promote mRNA degradation. Our previous study demonstrated that mutations in the TZF domain of ZFP36L1 or ZFP36L2 increased the CCND1 expression. In this study, we investigated whether ZFP36L1 and ZFP36L2 could downregulate the expression of the long 3'UTR isoform of CCND1 mRNA in human colorectal cancer (CRC) cells. Firstly, the Gene Expression Profiling Interactive Analysis 2 database indicated downregulation of ZFP36 and ZFP36L1, while E2F1 and CCND1 were upregulated in human CRC tissues compared to normal colorectal tissues. Overexpression of ZFP36L1 and/or ZFP36L2 in T-REx-293, DLD-1, and HCT116 cells led to a decrease in the total CCND1, long isoform ratio of CCND1 mRNA, and E2F1 expression. Conversely, knockdown of ZFP36L1 and ZFP36L2 in HCT116 cells resulted in an increase in total CCND1, long isoform ratio of CCND1 mRNA, and E2F1 expression. Knockdown of E2F1 decreased CCND1 expression, indicating a potential role for E2F1 in regulating CCND1 expression at the transcriptional level. These findings suggest that ZFP36L1 and ZFP36L2 play a negative role in CCND1 expression. The underlying mechanisms might involve the reduction of E2F1 transactivation at the transcriptional level and the promotion of AREs-mediated decay of the long 3'UTR isoform of CCND1 through posttranscriptional processes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA