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1.
Environ Res ; 241: 117655, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37980995

RESUMO

The synergetic effect between dual oxides in binary metal oxides (BMO) makes them promising electrode materials for the detection of toxic chemicals, and biological compounds. In addition, the interaction between the cations and anions of diverse metals in BMO tends to create more oxygen vacancies which are beneficial for energy storage devices. However, specifically targeted synthesis of BMO is still arduous. In this work, we prepared a nickel oxide/tin oxide composite (NiO/SnO2) through a simple solvothermal technique. The crystallinity, specific surface area, and morphology were fully characterized. The synthesized BMO is used as a bifunctional electrocatalyst for the electrochemical detection of dopamine (DPA) and for the hydrogen evolution reaction (HER). As expected, the active metals in the NiO/SnO2 composite afforded a higher redox current at a reduced redox potential with a nanomolar level detection limit (4 nm) and excellent selectivity. Moreover, a better recovery rate is achieved in the real-time detection of DPA in human urine and DPA injection solution. Compared to other metal oxides, NiO/SnO2 composite afforded lower overpotential (157 mV @10 mA cm-2), Tafel slope (155 mV dec-1), and long-term durability, with a minimum retention rate. These studies conclude that NiO/SnO2 composite can act as a suitable electrode modifier for electrochemical sensing and the HER.


Assuntos
Dopamina , Óxidos , Humanos , Catálise , Eletrodos , Hidrogênio
2.
PLoS Genet ; 12(5): e1006048, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27176626

RESUMO

The evolutionarily conserved family of AP-2 transcription factors (TF) regulates proliferation, differentiation, and apoptosis. Mutations in human AP-2 TF have been linked with bronchio-occular-facial syndrome and Char Syndrome, congenital birth defects characterized by craniofacial deformities and patent ductus arteriosus, respectively. How mutations in AP-2 TF cause the disease phenotypes is not well understood. Here, we characterize the aptf-2(qm27) allele in Caenorhabditis elegans, which carries a point mutation in the conserved DNA binding region of AP-2 TF. We show that compromised APTF-2 activity leads to defects in dorsal intercalation, aberrant ventral enclosure and elongation defects, ultimately culminating in the formation of morphologically deformed larvae or complete arrest during epidermal morphogenesis. Using cell lineaging, we demonstrate that APTF-2 regulates the timing of cell division, primarily in ABarp, D and C cell lineages to control the number of neuroblasts, muscle and epidermal cells. Live imaging revealed nuclear enrichment of APTF-2 in lineages affected by the qm27 mutation preceding the relevant morphogenetic events. Finally, we found that another AP-2 TF, APTF-4, is also essential for epidermal morphogenesis, in a similar yet independent manner. Thus, our study provides novel insight on the cellular-level functions of an AP-2 transcription factor in development.


Assuntos
Anormalidades Múltiplas/genética , Caenorhabditis elegans/genética , Diferenciação Celular/genética , Permeabilidade do Canal Arterial/genética , Desenvolvimento Embrionário/genética , Face/anormalidades , Dedos/anormalidades , Fator de Transcrição AP-2/genética , Anormalidades Múltiplas/patologia , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Linhagem da Célula/genética , Permeabilidade do Canal Arterial/patologia , Epiderme/crescimento & desenvolvimento , Face/patologia , Dedos/patologia , Humanos , Morfogênese/genética , Mutação , Células-Tronco Neurais/metabolismo
3.
PLoS Genet ; 11(3): e1005082, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25807459

RESUMO

Glycosylphosphatidylinositol (GPI) is a post-translational modification resulting in the attachment of modified proteins to the outer leaflet of the plasma membrane. Tissue culture experiments have shown GPI-anchored proteins (GPI-APs) to be targeted to the apical membrane of epithelial cells. However, the in vivo importance of this targeting has not been investigated since null mutations in GPI biosynthesis enzymes in mice result in very early embryonic lethality. Missense mutations in the human GPI biosynthesis enzyme pigv are associated with a multiple congenital malformation syndrome with a high frequency of Hirschsprung disease and renal anomalies. However, it is currently unknown how these phenotypes are linked to PIGV function. Here, we identify a temperature-sensitive hypomorphic allele of PIGV in Caenorhabditis elegans, pigv-1(qm34), enabling us to study the role of GPI-APs in development. At the restrictive temperature we found a 75% reduction in GPI-APs at the surface of embryonic cells. Consequently, ~80% of pigv-1(qm34) embryos arrested development during the elongation phase of morphogenesis, exhibiting internal cysts and/or surface ruptures. Closer examination of the defects revealed them all to be the result of breaches in epithelial tissues: cysts formed in the intestine and excretory canal, and ruptures occurred through epidermal cells, suggesting weakening of the epithelial membrane or membrane-cortex connection. Knockdown of piga-1, another GPI biosynthesis enzymes resulted in similar phenotypes. Importantly, fortifying the link between the apical membrane and actin cortex by overexpression of the ezrin/radixin/moesin ortholog ERM-1, significantly rescued cyst formation and ruptures in the pigv-1(qm34) mutant. In conclusion, we discovered GPI-APs play a critical role in maintaining the integrity of the epithelial tissues, allowing them to withstand the pressure and stresses of morphogenesis. Our findings may help to explain some of the phenotypes observed in human syndromes associated with pigv mutations.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Proteínas do Citoesqueleto/genética , Desenvolvimento Embrionário/genética , Glicosilfosfatidilinositóis/biossíntese , Doença de Hirschsprung/genética , Manosiltransferases/genética , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/biossíntese , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas do Citoesqueleto/biossíntese , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Glicosilfosfatidilinositóis/genética , Doença de Hirschsprung/metabolismo , Humanos , Manosiltransferases/biossíntese , Manosiltransferases/metabolismo , Camundongos , Mutação , Processamento de Proteína Pós-Traducional/genética , Temperatura
4.
Development ; 138(14): 2915-24, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21653614

RESUMO

The migration of neuroblasts along the anteroposterior body axis of C. elegans is controlled by multiple Wnts that act partially redundantly to guide cells to their precisely defined final destinations. How positional information is specified by this system is, however, still largely unknown. Here, we used a novel fluorescent in situ hybridization methods to generate a quantitative spatiotemporal expression map of the C. elegans Wnt genes. We found that the five Wnt genes are expressed in a series of partially overlapping domains along the anteroposterior axis, with a predominant expression in the posterior half of the body. Furthermore, we show that a secreted Frizzled-related protein is expressed at the anterior end of the body axis, where it inhibits Wnt signaling to control neuroblast migration. Our findings reveal that a system of regionalized Wnt gene expression and anterior Wnt inhibition guides the highly stereotypic migration of neuroblasts in C. elegans. Opposing expression of Wnts and Wnt inhibitors has been observed in basal metazoans and in the vertebrate neurectoderm. Our results in C. elegans support the notion that a system of posterior Wnt signaling and anterior Wnt inhibition is an evolutionarily conserved principle of primary body axis specification.


Assuntos
Padronização Corporal/fisiologia , Caenorhabditis elegans/embriologia , Movimento Celular/fisiologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Glicoproteínas/metabolismo , Neurônios/fisiologia , Transdução de Sinais/fisiologia , Proteínas Wnt/metabolismo , Animais , Clonagem Molecular , Hibridização in Situ Fluorescente , Peptídeos e Proteínas de Sinalização Intracelular , Neurônios/citologia , Plasmídeos/genética
5.
Clin Ophthalmol ; 18: 1217-1224, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38737597

RESUMO

Aim: To determine the prevalence of dry eye (DE) and some related factors in patients with type 2 diabetic nephropathy (T2DN). Methods: We performed a cross-sectional study on 338 people, who were divided into 2 groups: 169 T2DN patients and 169 patients diagnosed with type 2 diabetic mellitus (T2DM) without renal complications as a control group. The Ocular Surface Disease Index (OSDI) and test fluorescein tear-film break-up time (TBUT) were done in all 338 subjects. Patients with OSDI scores < 13 and TBUT values equal to or under 10 seconds were diagnosed with dry eye. Results: The prevalence of DE in T2DN patients was significantly higher than T2DM group (55.6% versus 37.3%). The T2DN groups with dry eye had a median duration of DM, the proportion of hypertension, peripheral nerve complications, anemia, proportion of using insulin, and concentration of plasma glucose, HbA1C, urea, creatinine, CRP-hs significantly higher than those of T2DN without dry eye. Advanced age, high HbA1C level, and decreased eGFR were independent factors associated with dry eye in T2DN patients. Conclusion: Dry eye was a common condition associated with advanced age, high HbA1C levels, and decreased GFR in T2DN patients.

6.
Chem Commun (Camb) ; 58(89): 12431-12434, 2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36259756

RESUMO

The fabrication of hollow mesoporous nanosilica with well-defined structural features for optimizing the integration of functional components is a challenge. Herein, we report a facile preparation of hollow fibrous nanosilica (HFNS) with high specific surface area (666 m2 g-1), fiber-like mesoporous architectures in the inner and outer shells, and large pore channels (16.22 nm) via selective self-etching of dendritic fibrous nanosilica in an aqueous medium. The specific surface area and pore diameter increased significantly after the formation of a cavity in the center, resulting in HFNS. The HFNS can serve as a robust support for the controllable growth of gold nanoparticles with maximum catalytic performance for 4-nitrophenol reduction.


Assuntos
Nanopartículas Metálicas , Dióxido de Silício , Dióxido de Silício/química , Ouro/química , Catálise
7.
Comput Biol Med ; 135: 104418, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34052016

RESUMO

Accurate automated medical image recognition, including classification and segmentation, is one of the most challenging tasks in medical image analysis. Recently, deep learning methods have achieved remarkable success in medical image classification and segmentation, clearly becoming the state-of-the-art methods. However, most of these methods are unable to provide uncertainty quantification (UQ) for their output, often being overconfident, which can lead to disastrous consequences. Bayesian Deep Learning (BDL) methods can be used to quantify uncertainty of traditional deep learning methods, and thus address this issue. We apply three uncertainty quantification methods to deal with uncertainty during skin cancer image classification. They are as follows: Monte Carlo (MC) dropout, Ensemble MC (EMC) dropout and Deep Ensemble (DE). To further resolve the remaining uncertainty after applying the MC, EMC and DE methods, we describe a novel hybrid dynamic BDL model, taking into account uncertainty, based on the Three-Way Decision (TWD) theory. The proposed dynamic model enables us to use different UQ methods and different deep neural networks in distinct classification phases. So, the elements of each phase can be adjusted according to the dataset under consideration. In this study, two best UQ methods (i.e., DE and EMC) are applied in two classification phases (the first and second phases) to analyze two well-known skin cancer datasets, preventing one from making overconfident decisions when it comes to diagnosing the disease. The accuracy and the F1-score of our final solution are, respectively, 88.95% and 89.00% for the first dataset, and 90.96% and 91.00% for the second dataset. Our results suggest that the proposed TWDBDL model can be used effectively at different stages of medical image analysis.


Assuntos
Aprendizado Profundo , Neoplasias Cutâneas , Teorema de Bayes , Humanos , Redes Neurais de Computação , Neoplasias Cutâneas/diagnóstico por imagem , Incerteza
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