Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 310
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Small ; 20(8): e2304999, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37821412

RESUMEN

Rapid and precise acute myocardial infarction (AMI) diagnosis is essential for preventing patient death. In addition, the complementary roles of creatine kinase muscle brain (CK-MB) and cardiac troponin I (cTnI) cardiac biomarkers in the early and late stages of AMI demand their simultaneous detection, which is difficult to implement using conventional fluorescence and electrochemical technologies. Here, a nanotechnology-based one-stop immuno-surface-enhanced Raman scattering (SERS) detection platform is reported for multiple cardiac indicators for the rapid screening and progressive tracing of AMI events. Optimal SERS is achieved using optical property-based, excitation wavelength-optimized, and high-yield anisotropic plasmonic gold nanocubes. Optimal immunoassay reaction efficiencies are achieved by increasing immobilized antibodies. Multiple simultaneous detection strategies are implemented by incorporating two different Raman reports with narrow wavenumbers corresponding to two indicators and by establishing a computational SERS mapping process to accurately detect their concentrations, irrespective of multiple enzymes in the human serum. The SERS platform precisely estimated AMI onset and progressive timing in human serum and made rapid AMI identification feasible using a portable Raman spectrometer. This integrated platform is hypothesized to significantly contribute to emergency medicine and forensic science by providing timely treatment and observation.


Asunto(s)
Infarto del Miocardio , Humanos , Forma MB de la Creatina-Quinasa , Infarto del Miocardio/diagnóstico , Troponina I , Biomarcadores , Inmunoensayo
2.
Anal Bioanal Chem ; 416(6): 1363-1374, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38285226

RESUMEN

Several countries have exempted synthetic nicotine from existing regulatory frameworks, resulting in the widespread substitution of synthetic nicotine (SN) in almost all e-cigarette products available. However, it remains uncertain whether the purported synthetic nicotine is indeed genuine SN. There is a need to develop biological indicators and an analytical method that more clearly distinguishes between the two sources. Impurities in neat tobacco-derived nicotine (TDN) were characterized and identified through non-targeted and targeted analysis. Gas chromatography-tandem mass spectrometry (GC-MS/MS) conditions were optimized for detecting biological indicators in e-cigarette products. Nine tobacco-related alkaloids were identified and selected as biological indicators for TDN. A liquid-liquid extraction and GC-MS/MS quantitative method were developed to detect nine biological indicators in e-cigarette products with the limit of quantification ranging from 0.2 to 4.2 µg L-1 using 0.5 mL of e-liquid. This method was applied to 50 e-cigarette brands purchased in the Korean market. The developed method was able to easily and accurately identify the origin of nicotine even using a small amount of e-liquid sample. It is expected that effective e-cigarette regulation will be possible if the nicotine biological indicator and high-sensitivity analysis method developed in this study are used.


Asunto(s)
Sistemas Electrónicos de Liberación de Nicotina , Nicotina , Nicotina/análisis , Biomarcadores Ambientales , Espectrometría de Masas en Tándem/métodos , Cromatografía de Gases y Espectrometría de Masas
3.
Bull Environ Contam Toxicol ; 112(5): 74, 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38733375

RESUMEN

Polycyclic aromatic hydrocarbons (PAHs), dust, and wax were measured in pine needles, and PAHs were also measured in surface soil. Pearson correlation analysis was performed between the analytical values. The main compounds responsible for the increase in total PAHs were non-carcinogenic phenanthrene and fluoranthene. Therefore, the % content of carcinogenic PAHs decreased with a slope = -0.037 (r = 0.47, p < 0.01), as the total PAH concentration in pine needles increased. Correlations between individual PAHs in pine needles and surface soil were very high when only low-number ring PAHs (2R- and 3R-PAHs) were statistically analyzed and significant when only high-number ring PAHs were statistically analyzed. Low-number ring PAH mainly moves in the gas phase and diffuses into the wax layer, so it was found to be statistically significant with the wax content of pine needles. High-number ring PAHs showed a high correlation with the amount of dust in pine needles because they mainly attached to dust particles and accumulated on the surface of pine needles. The ratios of fluoranthene/pyrene and methylphenanthrene/phenanthrene for predicting the origin of atmospheric PAHs have also been proven valid for pine needles.


Asunto(s)
Monitoreo del Ambiente , Pinus , Hidrocarburos Policíclicos Aromáticos , Hidrocarburos Policíclicos Aromáticos/análisis , Pinus/química , República de Corea , Hojas de la Planta/química , Fenantrenos/análisis , Contaminantes del Suelo/análisis , Contaminantes Atmosféricos/análisis
4.
Gut ; 72(2): 242-255, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35705367

RESUMEN

OBJECTIVE: Cell-cell (CC) and cell-matrix (CM) adhesions are essential for epithelial cell survival, yet dissociation-induced apoptosis is frequently circumvented in malignant cells. DESIGN: We explored CC and CM dependence in 58 gastric cancer (GC) organoids by withdrawing either ROCK inhibitor, matrix or both to evaluate their tumorigenic potential in terms of apoptosis resistance, correlation with oncogenic driver mutations and clinical behaviour. We performed mechanistic studies to determine the role of diffuse-type GC drivers: ARHGAP fusions, RHOA and CDH1, in modulating CC (CCi) or CM (CMi) adhesion independence. RESULTS: 97% of the tumour organoids were CMi, 66% were CCi and 52% were resistant to double withdrawal (CCi/CMi), while normal organoids were neither CMi nor CCi. Clinically, the CCi/CMi phenotype was associated with an infiltrative tumour edge and advanced tumour stage. Moreover, the CCi/CMi transcriptome signature was associated with poor patient survival when applied to three public GC datasets. CCi/CMi and CCi phenotypes were enriched in diffuse-type GC organoids, especially in those with oncogenic driver perturbation of RHO signalling via RHOA mutation or ARHGAP fusions. Inducible knockout of ARHGAP fusions in CCi/CMi tumour organoids led to resensitisation to CC/CM dissociation-induced apoptosis, upregulation of focal adhesion and tight junction genes, partial reversion to a more normal cystic phenotype and inhibited xenograft formation. Normal gastric organoids engineered with CDH1 or RHOA mutations became CMi or CCi, respectively. CONCLUSIONS: The CCi/CMi phenotype has a critical role in malignant transformation and tumour progression, offering new mechanistic information on RHO-ROCK pathway inhibition that contributes to GC pathogenicity.


Asunto(s)
Adhesión Celular , Uniones Célula-Matriz , Neoplasias Gástricas , Humanos , Uniones Célula-Matriz/metabolismo , Uniones Célula-Matriz/patología , Progresión de la Enfermedad , Organoides/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patología
5.
BMC Pulm Med ; 23(1): 441, 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37964259

RESUMEN

BACKGROUND: Little is known about the differences in medium to long-term recovery on spirometry, 6-minute walking distance (6MWD) and health-related quality of life (HRQoL) between COVID-19 and SARS. METHODS: We performed a 12-month prospective study on COVID-19 survivors. The changes in dynamic lung volumes at spirometry (%predicted FEV1, %predicted FVC), 6MWD and HRQoL at 1-3, 6 to 12 months were compared against a historical cohort of SARS survivors using the same study protocol. The residual radiological changes in HRCT in COVID-19 survivors were correlated with their functional capacity. RESULTS: 108 COVID-19 survivors of various disease severity (asymptomatic 2.9%, mild 33.3%, moderate 47.2%, severe 8.3%, critical 8.3%) were recruited. When compared with 97 SARS survivors, 108 COVID-19 survivors were older (48.1 ± 16.4 vs. 36.1 ± 9.5 years, p < 0.001) and required less additional support during hospitalization; with lower dynamic lung volumes, shorter 6MWD and better physical component score. Both groups of survivors had comparable changes in these parameters at subsequent follow-ups. Both COVID-19 and SARS survivors had similar mental component score (MCS) at 6 and 12 months. COVID-19 survivors initially experienced less (between-group difference, -3.1, 95% confidence interval [CI] -5.5 to -0.7, p = 0.012) and then more improvement (between-group difference 2.9, 95%, CI 0.8 to 5.1, p = 0.007) than SARS survivors in the MCS at 1-3 to 6 months and 6 to 12 months respectively. Forty (44.0%) out of 91 COVID-19 survivors had residual abnormalities on HRCT at 12 months, with a negative correlation between the severity scores of parenchymal changes and 6MWD (r=-0.239, p < 0.05). CONCLUSIONS: COVID-19 survivors demonstrated a similar recovery speed in dynamic lung volumes and exercise capacity, but different paces of psychological recovery as SARS survivors in the convalescent phase. The severity of parenchymal changes in HRCT is negatively correlated with the 6MWD of COVID-19 survivors. TRIAL REGISTRATION: This prospective study was registered at ClinicalTrials.gov on 2 November 2020 (Identifier: NCT04611243).


Asunto(s)
COVID-19 , Calidad de Vida , Humanos , Estudios Prospectivos , Pruebas de Función Respiratoria , Espirometría
6.
J Korean Med Sci ; 38(45): e391, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37987110

RESUMEN

BACKGROUND: Phthalates and bisphenol A (BPA) are endocrine-disrupting chemicals and may cause immunological disorders in children. Therefore, according to the region, we investigated urinary phthalates and BPA levels and the relationship between urinary phthalate, aeroallergen sensitization, and eosinophil count during the coronavirus disease 2019 pandemic. METHODS: In total, 203 schoolchildren (134 residential and 69 industrial) aged 7-10 years were enrolled between July 2021 and July 2022. The BPA, metabolites of four high-molecular-weight phthalates (Σ4HMWP) and three low-molecular-weight phthalates (Σ3LMWP), were measured in the urine samples. Total eosinophil count and transepidermal water loss (TEWL) were also measured along with the skin prick test. RESULTS: The two groups had no differences in terms of BPA. The industrial group had significantly more plastic container usage, and there was a difference in the Σ3LMWP (P < 0.001) between the two groups but no difference in the Σ4HMWP (P = 0.234). The quartiles of urinary Σ4HMWP and Σ3LMWP (P < were not associated with the total eosinophil count, vitamin D level, or TEWL. After adjusting for cofactors, the quartiles of urinary Σ4HMWP and Σ3LMWP were significantly associated with total eosinophil count (P < 0.001) but not with aeroallergen sensitization or vitamin D. CONCLUSION: Exposure to phthalates was significantly associated with eosinophil count but not with aeroallergen sensitization or vitamin D. Therefore, reducing the use of plastic containers may effectively prevent exposure to phthalates and reduce Th2 cell-mediated inflammation in children.


Asunto(s)
Contaminantes Ambientales , Ácidos Ftálicos , Niño , Humanos , Eosinófilos/metabolismo , Ácidos Ftálicos/orina , Vitamina D , Compuestos de Bencidrilo/orina , Exposición a Riesgos Ambientales/efectos adversos
7.
Biomed Chromatogr ; 36(6): e5360, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35261063

RESUMEN

A method to determine 8 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs) and 16 polycyclic aromatic hydrocarbons (PAHs) was described using dispersive liquid-liquid microextraction (DLLME) of a small amount of plasma or serum sample and gas chromatography-tandem mass spectrometry (GC-MS/MS). The appropriate selection of the extraction solvent and dispersing solvent contributes to a high extraction yield and a clean extract. To verify the developed method, the interference, linearity of the calibration curve, detection limit, precision and accuracy were evaluated. The calibration curves were linear by 2-3 orders of magnitude with correlation coefficients above 0.997 in all cases. The LODs of PCBs, OCPs and PAHs were measured in the ranges of 0.0006-0.0029, 0.001-0.029 and 0.0002-0.012 ng/mL. The intraday precision achieved by this method was 2.19-10.3% (PCBs), 1.65-14.3% (OCPs) and 0.91-12.8% (PAHs), and the intraday accuracy 1.56-7.37% (PCBs), 2.34-19.6% (OCPs) and 1.49-15.7% (PAHs). The advantage of this method is that the analysis of PCBs, OCPs, and PAHs can be performed in a single chromatographic run, and the low detection limit enables monitoring of target substances in low exposure general public samples, and the analysis procedure is relatively simple and fast.


Asunto(s)
Hidrocarburos Clorados , Microextracción en Fase Líquida , Plaguicidas , Bifenilos Policlorados , Hidrocarburos Policíclicos Aromáticos , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Solventes/análisis , Espectrometría de Masas en Tándem
8.
Environ Monit Assess ; 194(4): 268, 2022 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-35266055

RESUMEN

The simultaneous determination of 8 polychlorinated biphenyls (PCBs), 23 organic chlorine pesticides (OCPs), and 35 polycyclic aromatic hydrocarbons (PAHs) in black-tailed gull eggs was described using ultrasound-assisted extraction and gas chromatography-tandem mass spectrometry (GC-MS/MS). The ranges of the lower limits of detection for PCBs, OCPs, and PAHs were 0.006-0.029, 0.01-0.10, and 0.01-0.20 µg kg-1, respectively. The intraday precision was in the range of 0.650-12.9% and the intraday accuracy was in the range of 86.6-113%. When the proposed method was used to analyze the target compounds in gull eggs collected from six sites in the Republic of Korea, the analytical results demonstrated concentration ranges of 113.32-394.07 µg kg-1 for total PCBs, 422.92-1082.09 µg kg-1 for total OCPs, and 134.50-231.27 µg kg-1 for total PAHs in the samples. The PCA results for PAHs and OCPs were well differentiated by sampling site, whereas those for PCBs differed little by sampling site. There were more pyrogenic PAHs in the West Sea and the South Sea with many industrial areas than in the East Sea with few industrial areas. Differences in the OCP patterns of samples from the West Sea close to China were considered to be related to the use of DDT in China until recently. PCBs were accumulated in the samples regardless of region, so there was no significant difference in the PCB patterns between the samples obtained from the three Seas.


Asunto(s)
Charadriiformes , Hidrocarburos Clorados , Plaguicidas , Bifenilos Policlorados , Hidrocarburos Policíclicos Aromáticos , Animales , Cloro/análisis , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Bifenilos Policlorados/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Espectrometría de Masas en Tándem
9.
Anal Chem ; 93(8): 3778-3785, 2021 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-33576598

RESUMEN

Metabolomics shows tremendous potential for the early diagnosis and screening of cancer. For clinical application as an effective diagnostic tool, however, improved analytical methods for complex biological fluids are required. Here, we developed a reliable rapid urine analysis system based on surface-enhanced Raman spectroscopy (SERS) using 3D-stacked silver nanowires (AgNWs) on a glass fiber filter (GFF) sensor and applied it to the diagnosis of pancreatic cancer and prostate cancer. Urine samples were pretreated with centrifugation to remove large debris and with calcium ion addition to improve the binding of metabolites to AgNWs. The label-free urine-SERS detection using the AgNW-GFF SERS sensor showed different spectral patterns and distinguishable specific peaks in three groups: normal control (n = 30), pancreatic cancer (n = 22), and prostate cancer (n = 22). Multivariate analyses of SERS spectra using unsupervised principal component analysis and supervised orthogonal partial least-squares discriminant analysis showed excellent discrimination between the pancreatic cancer group and the prostate cancer group as well as between the normal control group and the combined cancer groups. The results demonstrate the great potential of the urine-SERS analysis system using the AgNW-GFF SERS sensor for the noninvasive diagnosis and screening of cancers.


Asunto(s)
Neoplasias Pancreáticas , Neoplasias de la Próstata , Vidrio , Humanos , Masculino , Neoplasias Pancreáticas/diagnóstico , Neoplasias de la Próstata/diagnóstico , Plata , Espectrometría Raman
10.
Analyst ; 146(1): 305-314, 2021 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-33146158

RESUMEN

A cyclodextrin-decorated gold nanosatellite (AuNSL) substrate was developed as a surface-enhanced Raman scattering sensor for the selective sensing of bipyridylium pesticides such as paraquat (PQ), diquat (DQ), and difenzoquat (DIF). The AuNSL structure was fabricated via vacuum deposition of gold nanoparticles (AuNPs) on a gold nanopillar substrate, and a large density of hot-spots was formed for Raman signal enhancement. Thiolated ß-cyclodextrin (SH-CD) was surface-modified on the AuNSL as a chemical receptor. The detection limit of PQ, DQ, and DIF on the SH-CD-coated AuNSL (CD-AuNSL) was 0.05 ppm for each, and showed linear correlation in a concentration range of 10 ppm-0.05 ppm. Then, selective bipyridylium pesticide detection was performed by comparing the Raman intensity of each pesticide with and without the washing step. After the washing step, 90% of the PQ, DQ, and DIF Raman signals were maintained on the CD-AuNSL substrate with a uniform selectivity in a mapping area of 200 µm × 200 µm. Furthermore, selective pesticide detection was performed using a ground-apple solution without pretreatment. Raman signals were clearly observed after the washing step and they showed a limit of detection down to a concentration of 0.05 ppm for each pesticide. Principal component analysis (PCA) of the binary and ternary mixtures of PQ, DQ, and DIF showed that each component could be easily identified via the typical Raman fingerprint analysis. The developed CD-AuNSL is expected to be applied for various chemical sensors, especially for pyridine-containing toxic substances in the environment and metabolite biomarkers in biofluids.


Asunto(s)
Ciclodextrinas , Nanopartículas del Metal , Plaguicidas , Oro , Plaguicidas/análisis , Espectrometría Raman
11.
Mar Drugs ; 19(4)2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33921174

RESUMEN

Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra tenera) and Haliotis discus hannai (abalone viscera), were screened for their inhibitory activity against SARS-CoV-2 virus entry. Most of them showed significant antiviral activities at an IC50 of 12~289 µg/mL against SARS-CoV-2 pseudovirus in HEK293/ACE2, except for P. tenera (IC50 > 1000 µg/mL). The crude polysaccharide of S. horneri showed the strongest antiviral activity, with an IC50 of 12 µg/mL, to prevent COVID-19 entry, and abalone viscera and H. fusiforme could also inhibit SARS-CoV-2 infection with an IC50 of 33 µg/mL and 47 µg/mL, respectively. The common properties of these crude polysaccharides, which have strong antiviral activity, are high molecular weight (>800 kDa), high total carbohydrate (62.7~99.1%), high fucose content (37.3~66.2%), and highly branched polysaccharides. These results indicated that the crude polysaccharides from seaweeds and abalone viscera can effectively inhibit SARS-CoV-2 entry.


Asunto(s)
COVID-19/virología , Gastrópodos/química , Polisacáridos/farmacología , SARS-CoV-2/fisiología , Algas Marinas/química , Internalización del Virus/efectos de los fármacos , Animales , Antivirales/química , Antivirales/farmacología , Células HEK293 , Humanos , Concentración 50 Inhibidora , Polisacáridos/química , Vísceras
12.
Gut ; 69(12): 2165-2179, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32217638

RESUMEN

OBJECTIVE: Sporadic early-onset colorectal cancer (EOCRC) has bad prognosis, yet is poorly represented by cell line models. We examine the key mutational and transcriptomic alterations in an organoid biobank enriched in EOCRCs. DESIGN: We established paired cancer (n=32) and normal organoids (n=18) from 20 patients enriched in microsatellite-stable EOCRC. Exome and transcriptome analysis was performed. RESULTS: We observed a striking diversity of molecular phenotypes, including PTPRK-RSPO3 fusions. Transcriptionally, RSPO fusion organoids resembled normal colon organoids and were distinct from APC mutant organoids, with high BMP2 and low PTK7 expression. Single cell transcriptome analysis confirmed the similarity between RSPO fusion organoids and normal organoids, with a propensity for maturation on Wnt withdrawal, whereas the APC mutant organoids were locked in progenitor stages. CRISPR/Cas9 engineered mutation of APC in normal human colon organoids led to upregulation of PTK7 protein and suppression of BMP2, but less so with an engineered RNF43 mutation. The frequent co-occurrence of RSPO fusions with SMAD4 or BMPR1A mutation was confirmed in TCGA database searches. RNF43 mutation was found in organoid from a leukaemia survivor with a novel mutational signature; and organoids with POLE proofreading mutation displayed ultramutation. The cancer organoid genomes were stable over long culture periods, while normal human colon organoids tended to be subject to clonal dominance over time. CONCLUSIONS: These organoid models enriched in EOCRCs with linked genomic data fill a gap in existing CRC models and reveal distinct genetic profiles and novel pathway cooperativity.


Asunto(s)
Neoplasias Colorrectales/genética , Perfil Genético , Organoides/patología , Proteína de la Poliposis Adenomatosa del Colon/genética , Proteína Morfogenética Ósea 2/genética , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/genética , Sistemas CRISPR-Cas , Moléculas de Adhesión Celular/genética , Perfilación de la Expresión Génica , Fusión Génica , Humanos , Modelos Genéticos , Mutación , Proteínas Tirosina Quinasas Receptoras/genética , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética , Proteína Smad4/genética , Trombospondinas/genética , Bancos de Tejidos , Ubiquitina-Proteína Ligasas/genética , Regulación hacia Arriba , Secuenciación del Exoma
13.
Diabetes Obes Metab ; 22(10): 1869-1873, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32406573

RESUMEN

We aimed to evaluate the efficacy and safety profile of lobeglitazone compared with sitagliptin as an add-on to metformin in patients with type 2 diabetes as well as other components of metabolic syndrome. Patients inadequately controlled by metformin were randomly assigned to lobeglitazone (0.5 mg, n = 121) or sitagliptin (100 mg, n = 126) for 24 weeks. The mean changes in HbA1c of the lobeglitazone and sitagliptin groups were -0.79% and -0.86%, respectively; the between-group difference was 0.08% (95% confidence interval, -0.14% to 0.30%), showing non-inferiority. The proportion of patients having two or more factors of other metabolic syndrome components decreased to a greater extent in the lobeglitazone group than in the sitagliptin group (-11.9% vs. -4.8%; P < .0174). Favourable changes in the lipid metabolism were also observed with lobeglitazone, which had a similar safety profile to sitagliptin. Lobeglitazone was comparable with sitagliptin as an add-on to metformin in terms of efficacy and safety.


Asunto(s)
Diabetes Mellitus Tipo 2 , Síndrome Metabólico , Metformina , Glucemia , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Método Doble Ciego , Quimioterapia Combinada , Hemoglobina Glucada/análisis , Humanos , Hipoglucemiantes/efectos adversos , Metformina/efectos adversos , Pirimidinas , Fosfato de Sitagliptina/efectos adversos , Tiazolidinedionas , Resultado del Tratamiento
14.
Brain ; 142(12): 3753-3770, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31605140

RESUMEN

Amyotrophic lateral sclerosis (ALS) presents with focal muscle weakness due to motor neuron degeneration that becomes generalized, leading to death from respiratory failure within 3-5 years from symptom onset. Despite the heterogeneity of aetiology, TDP-43 proteinopathy is a common pathological feature that is observed in >95% of ALS and tau-negative frontotemporal dementia (FTD) cases. TDP-43 is a DNA/RNA-binding protein that in ALS and FTD translocates from being predominantly nuclear to form detergent-resistant, hyperphosphorylated aggregates in the cytoplasm of affected neurons and glia. Mutations in TARDBP account for 1-4% of all ALS cases and almost all arise in the low complexity C-terminal domain that does not affect RNA binding and processing. Here we report an ALS/FTD kindred with a novel K181E TDP-43 mutation that is located in close proximity to the RRM1 domain. To offer predictive gene testing to at-risk family members, we undertook a series of functional studies to characterize the properties of the mutation. Spectroscopy studies of the K181E protein revealed no evidence of significant misfolding. Although it is unable to bind to or splice RNA, it forms abundant aggregates in transfected cells. We extended our study to include other ALS-linked mutations adjacent to the RRM domains that also disrupt RNA binding and greatly enhance TDP-43 aggregation, forming detergent-resistant and hyperphosphorylated inclusions. Lastly, we demonstrate that K181E binds to, and sequesters, wild-type TDP-43 within nuclear and cytoplasmic inclusions. Thus, we demonstrate that TDP-43 mutations that disrupt RNA binding greatly enhance aggregation and are likely to be pathogenic as they promote wild-type TDP-43 to mislocalize and aggregate acting in a dominant-negative manner. This study highlights the importance of RNA binding to maintain TDP-43 solubility and the role of TDP-43 aggregation in disease pathogenesis.


Asunto(s)
Proteínas de Unión al ADN/genética , Mutación , Agregación Patológica de Proteínas/genética , Proteínas de Unión al ARN/genética , Médula Espinal/metabolismo , Proteinopatías TDP-43/genética , Adulto , Proteínas de Unión al ADN/metabolismo , Humanos , Masculino , Neuroglía/metabolismo , Neuronas/metabolismo , Fosforilación , Agregación Patológica de Proteínas/metabolismo , Agregación Patológica de Proteínas/patología , Proteínas de Unión al ARN/metabolismo , Médula Espinal/patología , Proteinopatías TDP-43/metabolismo , Proteinopatías TDP-43/patología
15.
Analyst ; 144(24): 7162-7167, 2019 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-31710050

RESUMEN

The detection of toxic gas molecules using the surface-enhanced Raman spectroscopy (SERS) technique is very challenging due to the low affinity of gas molecules. Here, we report extremely sensitive SERS-based NO2 gas sensors based on 3D nanoporous Au nanostructures with a high affinity for NO2 gas molecules and high density of hotspots.

16.
J Nanosci Nanotechnol ; 19(3): 1474-1479, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30469208

RESUMEN

In this study, a thermoelectric module substrate was fabricated by subjecting an aluminum plate to a surface treatment process. To achieve this, the aluminum-based substrate was carried out to electrolytic etching, anodization, and Ni plating. The anodization of aluminum created an oxide film, which served as an insulation layer, while the Ni plating formed a conductive circuit layer. The substrate fabricated in this study exhibited excellent insulation performance, demonstrating its potential for future use in thermoelectric module substrates. Its adhesion properties were verified using a cross-cut adhesion test; microstructures of the surface and cross-section revealed the successful formation of the oxide film and Ni circuit layers on the aluminum base. From the results of these, it is clearly confirmed that the anodized aluminum substrate developed in this study provides suitable insulating performances and bonding nature with Ni electrode.

17.
J Nanosci Nanotechnol ; 19(3): 1749-1754, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30469259

RESUMEN

In this study, a method for electroless Ni-P plating with excellent adhesion via chemical wet etching to fabricate Bi-Te thermoelectric modules is proposed. The electroless Ni-P plating formed through the proposed method showed excellent adherence without peeling, even under heat treatment of 200 °C for 24 h. Wet etching and electroless Ni-P plating was performed on a Bi-Te thermoelectric module, which showed the excellent bond strength of approximately 10 MPa. The surface roughness of the Bi-Te thermoelectric element was increased significantly by the wet etching process, which secured the adherence of the Ni-P plating by anchoring to this induced surface roughness.

18.
J Nanosci Nanotechnol ; 19(3): 1738-1742, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30469257

RESUMEN

A method for directly bonding thermoelectric elements onto copper electrodes without applying a solder paste was developed in this study. A tin coating of thickness approximately 50 µm was deposited via electroplating onto the surface of a Bi2Te3-based thermoelectric element, which had a nickel diffusion barrier layer. The resulting structure was subsequently subjected to direct thermocompression bonding at 250 °C on a hotplate for 3 min at a pressure of 1.1 kPa. Scanning electron microscopy imaging confirmed that a strong and uniform bond was formed at the copper electrode-thermoelectric element interface, and the melted or solidified tin layer remained defect-free. The thermoelectric module fabricated using tin plating had an average bonding strength similar to that fabricated using soldering.

19.
Pak J Pharm Sci ; 32(5): 2025-2031, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31813867

RESUMEN

Metformin is one of the most common medicines for the treatment of type 2 diabetes, however, recent studies suggest that concomitant antihyperglycemic agents should be administered for better efficacy. Yukmijihwang-tang (YMJHT) is a nephroprotective polyherb prescribed for renal disorders or diabetic mellitus in traditional Korean medicine. Therefore, the pharmacokinetics between metformin and YMJHT were examined for their coadministration. Rats were orally coadministered with metformin and YMJHT as a combination group or metformin and distilled water as the corresponding control. Then, the metformin concentration in plasma and its pharmacokinetic parameters including maximum concentration (Cmax) and area under the plasma concentration time curve (AUC) were analyzed. There were no interactions between metformin and YMJHT in the single coadministration at intervals within 5 min. However, pretreatments with YMJHT for 6 days increased the metformin concentration and its Cmax and AUC (p<0.05). The repeated coadministration for 8 days increased the Cmax of metformin (p<0.05). Conversely, when the combination was coadministered at 2h -intervals, there were no interactions between metformin and YMJHT after a single dosing or repeated dosing of coadministration for 7 days. These results of the present study will help structure proper dosing regimens for the concomitant therapy of metformin and YMJHT.


Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Interacciones de Hierba-Droga/fisiología , Metformina/farmacocinética , Plantas Medicinales/efectos adversos , Animales , Área Bajo la Curva , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Quimioterapia Combinada/efectos adversos , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/farmacología , Masculino , Metformina/farmacología , Ratas , Ratas Sprague-Dawley
20.
J Nanosci Nanotechnol ; 18(9): 6404-6409, 2018 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-29677804

RESUMEN

In this study, electrolytic etching, anodic oxidation, and copper electroplating were applied to aluminum to produce a plate on which a copper circuit for a thermoelectric module was formed. An oxide film insulating layer was formed on the aluminum through anodic oxidation, and platinum was coated by sputtering to produce conductivity. Finally, copper electroplating was performed directly on the substrate. In this structure, the copper plating layer on the insulating layer served as a conductive layer in the circuit. The adhesion of the copper plating layer was improved by electrolytic etching. As a result, the thermoelectric module fabricated in this study showed excellent adhesion and good insulation characteristics. It is expected that our findings can contribute to the manufacture of plates applicable to thermoelectric modules with high dissipation performance.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA