Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Emerg Infect Dis ; 30(3): 616-619, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38407167

RESUMEN

In Jeju Island, South Korea, a patient who consumed raw pig products had subdural empyema, which led to meningitis, sepsis, and status epilepticus. We identified Streptococcus suis from blood and the subdural empyema. This case illustrates the importance of considering dietary habits in similar clinical assessments to prevent misdiagnosis.


Asunto(s)
Empiema Subdural , Sepsis , Infecciones Estreptocócicas , Streptococcus suis , Humanos , Animales , Porcinos , Empiema Subdural/diagnóstico , Streptococcus suis/genética , República de Corea , Conducta Alimentaria , Infecciones Estreptocócicas/diagnóstico , Infecciones Estreptocócicas/tratamiento farmacológico
2.
J Korean Med Sci ; 38(20): e156, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37218355

RESUMEN

BACKGROUND: Severe fever with thrombocytopenia syndrome virus (SFTSV) is transmitted through tick bites. Ticks are potential vectors for the bacterium Coxiella burnetii that causes Query fever. Here, we analyzed SFTSV and C. burnetii co-infection rates in ticks in rural areas of Jeju Island, South Korea. METHODS: Free ticks were collected from the natural environment of the island between 2016 and 2019, and SFTSV RNA was extracted. Additionally, ribosomal RNA gene sequencing was used to identify Coxiella species. RESULTS: Haemaphysalis longicornis was the most common tick species followed by H. flava. Tick number gradually increased from April, peaked in August, and was lowest in March. Of all the collected ticks, 82.6% (2,851/3,458) were nymphs, 17.9% (639/3,458) adults, and 0.1% (4/3,458) larvae. SFTSV-infected ticks comprised 12.6% of all ticks; their numbers were the lowest in November-December, increased from January, and were mostly identified in the adult stage during June-August. C. burnetii infections were detected in 4.4% of the SFTSV-infected H. longicornis ticks. C. burnetii co-infection was mainly observed in the nymph stage of H. longicornis, with the highest infection rate in January, followed by December and November. CONCLUSION: Our findings suggest that Jeju Island has a high SFTSV and potential C. burnetii infection in ticks. This study provides important insights regarding SFTS and Q fever risk to humans in South Korea.


Asunto(s)
Coinfección , Coxiella burnetii , Ixodidae , Phlebovirus , Síndrome de Trombocitopenia Febril Grave , Garrapatas , Humanos , Animales , Coxiella burnetii/genética , Phlebovirus/genética , República de Corea/epidemiología
3.
Small ; 18(40): e2202912, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36058645

RESUMEN

Development of efficient surface passivation methods for semiconductor devices is crucial to counter the degradation in their electrical performance owing to scattering or trapping of carriers in the channels induced by molecular adsorption from the ambient environment. However, conventional dielectric deposition involves the formation of additional interfacial defects associated with broken covalent bonds, resulting in accidental electrostatic doping or enhanced hysteretic behavior. In this study, centimeter-scaled van der Waals passivation of transition metal dichalcogenides (TMDCs) is demonstrated by stacking hydrocarbon (HC) dielectrics onto MoSe2 field-effect transistors (FETs), thereby enhancing the electric performance and stability of the device, accompanied with the suppression of chemical disorder at the HC/TMDCs interface. The stacking of HC onto MoSe2 FETs enhances the carrier mobility of MoSe2 FET by over 50% at the n-branch, and a significant decrease in hysteresis, owing to the screening of molecular adsorption. The electron mobility and hysteresis of the HC/MoSe2 FETs are verified to be nearly intact compared to those of the fabricated HC/MoSe2 FETs after exposure to ambient environment for 3 months. Consequently, the proposed design can act as a model for developing advanced nanoelectronics applications based on layered materials for mass production.

4.
Arch Microbiol ; 204(9): 591, 2022 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-36053331

RESUMEN

Recent research has claimed virulence factors or antimicrobial resistance in commensal or non-pathogenic Neisseria spp. This study aimed to isolate and analyze commensal microorganisms related to the genus Neisseria from the oral cavity of a patient with head and neck cancer. We successfully isolated strain MA1-1 and identified its functional gene contents. Although strain MA1-1 was related to Neisseria flava based on 16S rRNA gene sequence similarity, genomic relatedness analysis revealed that strain MA1-1 was closely related to Neisseria mucosa, reported as a commensal Neisseria species. The strain MA1-1 genome harbored genes for microaerobic respiration and the complete core metabolic pathway with few transporters for nutrients. A number of genes have been associated with virulence factors and resistance to various antibiotics. In addition, the comparative genomic analysis showed that most genes identified in the strain MA1-1 were shared with other Neisseria spp. including two well-known pathogens, Neisseria gonorrhoeae and Neisseria meningitidis. This indicates that the gene content of intra-members of the genus Neisseria has been evolutionarily conserved and is stable, with no gene recombination with other microbes in the host. Finally, this study provides more fundamental interpretations for the complete gene sequence of commensal Neisseria spp. and will contribute to advancing public health knowledge.


Asunto(s)
Neoplasias de Cabeza y Cuello , Neisseria meningitidis , Farmacorresistencia Microbiana , Genómica , Neoplasias de Cabeza y Cuello/genética , Humanos , Neisseria/genética , Neisseria meningitidis/genética , ARN Ribosómico 16S/genética , Factores de Virulencia/genética
5.
Curr Microbiol ; 78(8): 3321-3327, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34170378

RESUMEN

A Gram-stain-negative, rod-shaped, and strictly aerobic bacterium designated strain G2-bT was isolated from the marine sediment around Jeju Island, South Korea. Strain G2-bT was found to be catalase- and oxidase-positive, white-pigmented, motile with polar flagellum, and to grow optimally at 25 °C, pH 7.0 in the presence of 4% (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain G2-bT belongs to the genus Salinimonas and was closely related Salinimonas sediminis N102T (96.7% sequence similarity), Salinimonas iocasae KX18D6T (95.4%), Salinimonas lutimaris DPSR-4T (94.7%), and Salinimonas chungwhensis BH030046T (94.6%). Strain G2-bT possessed ubiquinone 8 as the sole respiratory quinone, summed feature 3 and summed feature 8 as the major fatty acids, and phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. The genome size and G + C content of the strain G2-bT were determined to be 3,765,169 bp, and 49.7%, respectively, as a complete circular genome. Based on the genomic analyses (e.g., average nucleotide identity and digital DNA-DNA hybridization), the strain G2-BT likely represents a new species in the genus Salinimonas, for which we propose to name this novel bacterium Salinimonas marina sp. nov., and the type strain is designated G2-BT (= KCTC 72817T = VTCC 910110T).


Asunto(s)
Sedimentos Geológicos , Fosfolípidos , Alteromonadaceae , Técnicas de Tipificación Bacteriana , ADN Bacteriano/genética , Ácidos Grasos/análisis , Filogenia , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN
6.
Sensors (Basel) ; 20(19)2020 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-33036332

RESUMEN

Tin sulfide (SnS) is known for its effective gas-detecting ability at low temperatures. However, the development of a portable and flexible SnS sensor is hindered by its high resistance, low response, and long recovery time. Like other chalcogenides, the electronic and gas-sensing properties of SnS strongly depend on its surface defects. Therefore, understanding the effects of its surface defects on its electronic and gas-sensing properties is a key factor in developing low-temperature SnS gas sensors. Herein, using thin SnS films annealed at different temperatures, we demonstrate that SnS exhibits n-type semiconducting behavior upon the appearance of S vacancies. Furthermore, the presence of S vacancies imparts the n-type SnS sensor with better sensing performance under UV illumination at room temperature (25 °C) than that of a p-type SnS sensor. These results are thoroughly investigated using various experimental analysis techniques and theoretical calculations using density functional theory. In addition, n-type SnS deposited on a polyimide substrate can be used to fabricate high-stability flexible sensors, which can be further developed for real applications.

7.
Biochem Biophys Res Commun ; 513(1): 172-178, 2019 05 21.
Artículo en Inglés | MEDLINE | ID: mdl-30952432

RESUMEN

The NFAT family of transcription factors plays an important role in immune system development and function. NFATc1 and NFATc2 are highly expressed in peripheral T cells, and several isoforms are produced via the use of different promoters and polyadenylation sites. The specific isoforms with relatively long C-termini, NFATc1/C and NFATc2/A, have been shown to be modified by SUMO within their specific C-terminal regions, which regulates NFAT protein localization and transactivation activity. Here, we demonstrate that an isoform NFATc1/A, which has a short C-terminus and does not contain the sumoylation sites found in the long isoforms, is also modified by SUMO. NFATc1/A sumoylation increased with low level expression of SUMO E3 ligases, specifically PIAS1, PIAS3, and PIASy, in co-transfected cells. PIAS3 interacted with NFATc1/A and an active site mutant failed to promote NFATc1/A sumoylation, indicating a role for PIAS3 as a SUMO E3 ligase. A lysine residue at 351 within the central regulatory domain was identified as the major SUMO attachment site in both co-transfection and in vitro assays. Sumoylation of NFATc1/A did not affect nuclear translocation upon ionomycin and phorbol 12-myristate 13-acetate treatment. However, although sumoylation of NFATc1/A slightly increased protein stability, it inhibited transactivation activity for reporter genes driven by promoters containing NFAT sites. Our results indicate that the transactivation activity of NFATc1/A is negatively regulated by PIAS protein-mediated sumoylation, and that SUMO is a general regulator of NFAT family members with either long or short C-termini.


Asunto(s)
Factores de Transcripción NFATC/metabolismo , Proteínas Inhibidoras de STAT Activados/metabolismo , Sumoilación , Activación Transcripcional , Secuencia de Aminoácidos , Línea Celular , Humanos , Factores de Transcripción NFATC/química , Estabilidad Proteica
8.
Mol Cell Proteomics ; 16(4 suppl 1): S92-S107, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28179408

RESUMEN

Herpes simplex virus (HSV-1) lytic infection results in global changes to the host cell proteome and the proteins associated with host chromatin. We present a system level characterization of proteome dynamics during infection by performing a multi-dimensional analysis during HSV-1 lytic infection of human foreskin fibroblast (HFF) cells. Our study includes identification and quantification of the host and viral proteomes, phosphoproteomes, chromatin bound proteomes and post-translational modifications (PTMs) on cellular histones during infection. We analyzed proteomes across six time points of virus infection (0, 3, 6, 9, 12 and 15 h post-infection) and clustered trends in abundance using fuzzy c-means. Globally, we accurately quantified more than 4000 proteins, 200 differently modified histone peptides and 9000 phosphorylation sites on cellular proteins. In addition, we identified 67 viral proteins and quantified 571 phosphorylation events (465 with high confidence site localization) on viral proteins, which is currently the most comprehensive map of HSV-1 phosphoproteome. We investigated chromatin bound proteins by proteomic analysis of the high-salt chromatin fraction and identified 510 proteins that were significantly different in abundance during infection. We found 53 histone marks significantly regulated during virus infection, including a steady increase of histone H3 acetylation (H3K9ac and H3K14ac). Our data provide a resource of unprecedented depth for human and viral proteome dynamics during infection. Collectively, our results indicate that the proteome composition of the chromatin of HFF cells is highly affected during HSV-1 infection, and that phosphorylation events are abundant on viral proteins. We propose that our epi-proteomics approach will prove to be important in the characterization of other model infectious systems that involve changes to chromatin composition.


Asunto(s)
Cromatina/virología , Prepucio/virología , Herpes Simple/metabolismo , Herpesvirus Humano 1/metabolismo , Proteómica/métodos , Proteínas Virales/metabolismo , Células Cultivadas , Cromatina/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Fibroblastos/citología , Fibroblastos/metabolismo , Fibroblastos/virología , Prepucio/citología , Prepucio/metabolismo , Lógica Difusa , Regulación Viral de la Expresión Génica , Células HeLa , Histonas/metabolismo , Humanos , Masculino , Fosforilación , Procesamiento Proteico-Postraduccional
9.
Mol Cell Proteomics ; 16(12): 2079-2097, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28972080

RESUMEN

Viral DNA genomes replicating in cells encounter a myriad of host factors that facilitate or hinder viral replication. Viral proteins expressed early during infection modulate host factors interacting with viral genomes, recruiting proteins to promote viral replication, and limiting access to antiviral repressors. Although some host factors manipulated by viruses have been identified, we have limited knowledge of pathways exploited during infection and how these differ between viruses. To identify cellular processes manipulated during viral replication, we defined proteomes associated with viral genomes during infection with adenovirus, herpes simplex virus and vaccinia virus. We compared enrichment of host factors between virus proteomes and confirmed association with viral genomes and replication compartments. Using adenovirus as an illustrative example, we uncovered host factors deactivated by early viral proteins, and identified a subgroup of nucleolar proteins that aid virus replication. Our data sets provide valuable resources of virus-host interactions that affect proteins on viral genomes.


Asunto(s)
Dependovirus/fisiología , Proteoma/metabolismo , Simplexvirus/fisiología , Virus Vaccinia/fisiología , Proteínas Virales/metabolismo , Virosis/metabolismo , Células A549 , Línea Celular Tumoral , Replicación del ADN , Genoma Viral , Células HeLa , Interacciones Huésped-Patógeno , Humanos , Mapas de Interacción de Proteínas , Proteómica/métodos , Replicación Viral
10.
PLoS Pathog ; 12(8): e1005850, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27564865

RESUMEN

Interferon-stimulated gene 15 (ISG15) encodes an ubiquitin-like protein that covalently conjugates protein. Protein modification by ISG15 (ISGylation) is known to inhibit the replication of many viruses. However, studies on the viral targets and viral strategies to regulate ISGylation-mediated antiviral responses are limited. In this study, we show that human cytomegalovirus (HCMV) replication is inhibited by ISGylation, but the virus has evolved multiple countermeasures. HCMV-induced ISG15 expression was mitigated by IE1, a viral inhibitor of interferon signaling, however, ISGylation was still strongly upregulated during virus infection. RNA interference of UBE1L (E1), UbcH8 (E2), Herc5 (E3), and UBP43 (ISG15 protease) revealed that ISGylation inhibits HCMV growth by downregulating viral gene expression and virion release in a manner that is more prominent at low multiplicity of infection. A viral regulator pUL26 was found to interact with ISG15, UBE1L, and Herc5, and be ISGylated. ISGylation of pUL26 regulated its stability and inhibited its activities to suppress NF-κB signaling and complement the growth of UL26-null mutant virus. Moreover, pUL26 reciprocally suppressed virus-induced ISGylation independent of its own ISGylation. Consistently, ISGylation was more pronounced in infections with the UL26-deleted mutant virus, whose growth was more sensitive to IFNß treatment than that of the wild-type virus. Therefore, pUL26 is a viral ISG15 target that also counteracts ISGylation. Our results demonstrate that ISGylation inhibits HCMV growth at multiple steps and that HCMV has evolved countermeasures to suppress ISG15 transcription and protein ISGylation, highlighting the importance of the interplay between virus and ISGylation in productive viral infection.


Asunto(s)
Citocinas/metabolismo , Infecciones por Citomegalovirus/inmunología , Regulación Viral de la Expresión Génica/fisiología , Interacciones Huésped-Parásitos/fisiología , Ubiquitinas/metabolismo , Proteínas Virales/metabolismo , Línea Celular , Citocinas/inmunología , Citomegalovirus/inmunología , Citomegalovirus/metabolismo , Infecciones por Citomegalovirus/metabolismo , Técnica del Anticuerpo Fluorescente , Humanos , Immunoblotting , Inmunoprecipitación , Reacción en Cadena de la Polimerasa , Transfección , Técnicas del Sistema de Dos Híbridos , Ubiquitinas/inmunología , Proteínas Virales/inmunología
11.
Breast Cancer Res Treat ; 165(2): 311-320, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28601930

RESUMEN

PURPOSE: We investigated the oncologic outcomes by intrinsic subtype and age in young breast cancer patients and whether survival differences were related to treatment changes over time. METHODS: A retrospective analysis was performed on 9633 invasive breast cancer patients treated at Asan Medical Center from January 1989 to December 2008. We also enrolled a matched cohort adjusting for tumor size, lymph node metastasis, subtypes, and tumor grade. Patients aged <35 years were included in the younger group (n = 602) and those aged ≥35 years were included in the older group (n = 3009). RESULTS: The younger patients showed a significantly higher T stage, a more frequent axillary node presentation, higher histologic grade, and higher incidence of triple-negative subtype tumors than older patients and also received more chemotherapy and were less likely to undergo hormone therapy. The younger patients with hormone receptor (HR)-positive tumors showed significantly poorer disease-free survival (DFS), loco-regional recurrence-free survival, distant metastasis-free survival, and breast cancer-specific survival outcomes than older patients. Younger patients with HR-positive and human epidermal growth factor receptor 2 (HER2)-negative tumor subtypes had a significantly improved DFS over time (p = 0.032). Within the HR-positive/Her2-negative subtype, more women received gonadotropin-releasing hormone agonist and tamoxifen treatment from 2003 to 2008 compared with 1989 to 2002 (p = 0.001 and p = 0.075, respectively). CONCLUSIONS: HR-positive young breast cancer patients have a poorer survival compared with older patients, even with more frequent chemotherapy, but more recent use of tamoxifen and ovarian suppression might improve this outcome in these patients.


Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/mortalidad , Adulto , Factores de Edad , Antineoplásicos Hormonales/administración & dosificación , Antineoplásicos Hormonales/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/patología , Terapia Combinada , Bases de Datos Factuales , Femenino , Hormona Liberadora de Gonadotropina/metabolismo , Humanos , Estimación de Kaplan-Meier , Persona de Mediana Edad , Clasificación del Tumor , Metástasis de la Neoplasia , Estadificación de Neoplasias , Oportunidad Relativa , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , República de Corea , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
12.
Macromol Rapid Commun ; 36(11): 1103-7, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25847485

RESUMEN

Sulfur-rich materials have recently attracted keen interest for their potentials in optical, electrochemical, and pesticidal applications as well as their utility in dynamic covalent bond chemistry. Many sulfur-rich polymers, however, are insoluble and processing methods are therefore very limited. The synthesis and characterization of water-dispersible polymer nanoparticles (NPs) with the sulfur content exceeding 75% by weight, obtained from the interfacial polymerization between 1,2,3-trichloropropane and sodium polysulfide in water is reported here. The interfacial polymerization yields well-defined sulfur-rich NPs in the presence of surfactants, which are capable of serving a dual role as a phase transfer catalyst on top of emulsifiers. Such dual role allows for the control of the product NP size by varying its concentration. The surfactants can be easily removed by centrifugation and redispersion in water is also reported here. The resulting sulfur-rich NPs are characterized through elemental analysis, dynamic light scattering, ζ-potential measurements, and scanning electron microscopy.


Asunto(s)
Polímeros/química , Propano/análogos & derivados , Sulfuros/química , Azufre/química , Agua/química , Dispersión Dinámica de Luz , Nanopartículas/química , Nanopartículas/ultraestructura , Polimerizacion , Propano/química
13.
J Virol ; 87(23): 12949-56, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24067963

RESUMEN

Macrophages play important roles in host immune defense against virus infection. During infection by herpes simplex virus 1 (HSV-1), macrophages acquire enhanced antiviral potential. Restriction of HSV-1 replication and progeny production is important to prevent viral spread, but the cellular mechanisms that inhibit the DNA virus in macrophages are unknown. SAMHD1 was recently identified as a retrovirus restriction factor highly expressed in macrophages. The SAMHD1 protein is expressed in both undifferentiated monocytes and differentiated macrophages, but retroviral restriction is limited to differentiated cells by modulation of SAMHD1 phosphorylation. It is proposed to block reverse transcription of retroviral RNA into DNA by depleting cellular deoxynucleotide triphosphates (dNTPs). Viruses with DNA genomes do not employ reverse transcription during infection, but replication of their viral genomes is also dependent on intracellular dNTP concentrations. Here, we demonstrate that SAMHD1 restricts replication of the HSV-1 DNA genome in differentiated macrophage cell lines. Depleting SAMHD1 in THP-1 cells enhanced HSV-1 replication, while ectopic overexpression of SAMHD1 in U937 cells repressed HSV-1 replication. SAMHD1 did not impact viral gene expression from incoming HSV-1 viral genomes. HSV-1 restriction involved the dNTP triphosphohydrolase activity of SAMHD1 and was partially overcome by addition of exogenous deoxynucleosides. Unlike retroviruses, restriction of HSV-1 was not affected by SAMHD1 phosphorylation status. Our results suggest that SAMHD1 functions broadly to inhibit replication of DNA viruses in nondividing macrophages.


Asunto(s)
Replicación del ADN , Herpes Simple/metabolismo , Herpes Simple/virología , Herpesvirus Humano 1/genética , Macrófagos/virología , Proteínas de Unión al GTP Monoméricas/metabolismo , Línea Celular , Regulación hacia Abajo , Herpes Simple/genética , Herpesvirus Humano 1/fisiología , Interacciones Huésped-Patógeno , Humanos , Macrófagos/metabolismo , Proteínas de Unión al GTP Monoméricas/genética , Proteína 1 que Contiene Dominios SAM y HD , Replicación Viral
14.
Heliyon ; 10(7): e28726, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38586394

RESUMEN

Background: Human cytomegalovirus (HCMV) is a common herpesvirus that can cause a range of symptoms, from mild conditions such as fevers to severe illnesses like pneumonia. Early and accurate diagnosis of HCMV infection is crucial, particularly for vulnerable populations with limited medical care. However, current diagnostic methods are often expensive, time-consuming, and require skilled technicians. Materials and methods: We developed an HCMV-RPA-CRISPR diagnosis platform for the rapid and cost-effective detection of HCMV infection. This method utilizes recombinase polymerase amplification (RPA) to amplify the HCMV target gene isothermally without the need for thermal cycling equipment. The platform integrates the CRISPR/Cas12a system, significantly enhancing specificity and sensitivity. A total of 13 clinical blood samples were tested to evaluate the platform's effectiveness and accuracy. Additionally, a lateral flow assay (LFA) and fluorescence detection were incorporated for straightforward and rapid visual interpretation of the results. Results: The assay effectively detected concentrations as low as a single copy of the positive control plasmid per microliter in under 1 h, without requiring specialized equipment or training. In clinical sample evaluations, both the fluorescence readout and LFA exhibited 100% sensitivity and specificity, identifying four HCMV-positive and nine HCMV-negative samples. Conclusion: The HCMV-RPA-CRISPR diagnosis platform is comparably effective to qPCR for HCMV diagnosis. Its applicability in common clinical laboratories, clinics, and point-of-care settings, particularly in resource-limited environments, makes it a valuable tool for widespread HCMV screening and diagnosis.

15.
ACS Appl Mater Interfaces ; 16(22): 28613-28624, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38785040

RESUMEN

Constructing pertinent nanoarchitecture with abundant exposed active sites is a valid strategy for boosting photocatalytic hydrogen generation. However, the controllable approach of an ideal architecture comprising vertically standing transition metal chalcogenides (TMDs) nanosheets on a 3D graphene network remains challenging despite the potential for efficient photocatalytic hydrogen production. In this study, we fabricated edge-rich 3D structuring photocatalysts involving vertically grown TMDs nanosheets on a 3D porous graphene framework (referred to as 3D Gr). 2D TMDs (MoS2 and WS2)/3D Gr heterostructures were produced by location-specific photon-pen writing and metal-organic chemical vapor deposition for maximum edge site exposure enabling efficient photocatalytic reactivity. Vertically aligned 2D Mo(W)S2/3D Gr heterostructures exhibited distinctly boosted hydrogen production because of the 3D Gr caused by synergetic impacts associated with the large specific surface area and improved density of exposed active sites in vertically standing Mo(W)S2. The heterostructure involving graphene and TMDs corroborates an optimum charge transport pathway to rapidly separate the photogenerated electron-hole pairs, allowing more electrons to contribute to the photocatalytic hydrogen generation reaction. Consequently, the size-tailored heterostructure showed a superior hydrogen generation rate of 6.51 mmol g-1 h-1 for MoS2/3D graphene and 7.26 mmol g-1 h-1 for WS2/3D graphene, respectively, which were 3.59 and 3.76 times greater than that of MoS2 and WS2 samples. This study offers a promising path for the potential of 3D structuring of vertical TMDs/graphene heterostructure with edge-rich nanosheets for photocatalytic applications.

16.
J Microbiol Biotechnol ; 34(4): 804-811, 2024 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-38379304

RESUMEN

Foamy viruses (FVs) are generally recognized as non-pathogenic, often causing asymptomatic or mild symptoms in infections. Leveraging these unique characteristics, FV vectors hold significant promise for applications in gene therapy. This study introduces a novel platform technology using a pseudo-virus with single-round infectivity. In contrast to previous vector approaches, we developed a technique employing only two vectors, pcHFV lacking Env and pCMV-Env, to introduce the desired genes into target cells. Our investigation demonstrated the efficacy of the prototype foamy virus (PFV) dual-vector system in producing viruses and delivering transgenes into host cells. To optimize viral production, we incorporated the codon-optimized Env (optEnv) gene in pCMV-Env and the Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element (WPRE) at the 3' end of the transgene in the transfer vector. Consequently, the use of optEnv led to a significant enhancement in transgene expression in host cells. Additionally, the WPRE exhibited an enhancing effect. Furthermore, the introduced EGFP transgene was present in host cells for a month. In an effort to expand transgene capacity, we further streamlined the viral vector, anticipating the delivery of approximately 4.3 kbp of genes through our PFV dual-vector system. This study underscores the potential of PFVs as an alternative to lentiviruses or other retroviruses in the realm of gene therapy.


Asunto(s)
Técnicas de Transferencia de Gen , Vectores Genéticos , Spumavirus , Transgenes , Spumavirus/genética , Vectores Genéticos/genética , Humanos , Terapia Genética/métodos , Animales , Células HEK293 , Proteínas Fluorescentes Verdes/genética , Línea Celular
17.
Toxicol In Vitro ; 99: 105870, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38848825

RESUMEN

Particulate matter 2.5 (PM2.5) causes skin aging, inflammation, and impaired skin homeostasis. Hyperoside, a flavanol glycoside, has been proposed to reduce the risk of diseases caused by oxidative stress. This study evaluated the cytoprotective potential of hyperoside against PM2.5-induced skin cell damage. Cultured human HaCaT keratinocytes were pretreated with hyperoside and treated with PM2.5. Initially, the cytoprotective and antioxidant ability of hyperoside against PM2.5 was evaluated. Western blotting was further employed to investigate endoplasmic reticulum (ER) stress and cellular senescence and for evaluation of cell cycle regulation-related proteins. Hyperoside inhibited PM2.5-mediated ER stress as well as mitochondrial damage. Colony formation assessment confirmed that PM2.5-impaired cell proliferation was restored by hyperoside. Moreover, hyperoside reduced the activation of PM2.5-induced ER stress-related proteins, such as protein kinase R-like ER kinase, cleaved activating transcription factor 6, and inositol-requiring enzyme 1. Hyperoside promoted cell cycle progression in the G0/G1 phase by upregulating the PM2.5-impaired cell cycle regulatory proteins. Hyperoside significantly reduced the expression of PM2.5-induced senescence-associated ß-galactosidase and matrix metalloproteinases (MMPs), such as MMP-1 and MMP-9. Overall, hyperoside ameliorated PM2.5-impaired cell proliferation, ER stress, and cellular senescence, offering potential therapeutic implications for mitigating the adverse effects of environmental pollutants on skin health.

18.
Free Radic Biol Med ; 208: 384-393, 2023 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-37659699

RESUMEN

Ferroptosis is a novel form of cell death triggered by iron-dependent lipid peroxidation. Recent findings suggest that inhibiting system χc-induces ferroptosis by reducing intracellular cystine levels, and that ferroptosis in renal tubular epithelial cells (RTECs) contributes to acute kidney injury (AKI) and diabetic nephropathy. Moreover, 2-deoxy-d-ribose (dRib) has been shown to inhibit cystine uptake through xCT, the functional unit of system χc-, in ß-cells. This study aimed to investigate if dRib induces ferroptosis in RTECs and identify the underlying mechanisms. dRib treatment reduced cystine uptake and glutathione (GSH) content, and increased intracellular levels of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), lipid reactive oxygen species (ROS), and cell death in both NRK-52E cells and primary cultured RTECs. However, treatment with inhibitors of ferroptosis, such as deferoxamine (DFO), ferrostatin-1 (Fer-1), and liproxstatin-1 (Lip-1), counteracted the effects of dRib on GSH, MDA, 4-HNE, and lipid ROS levels, as well as cell death. Additionally, 2-mercaptoethanol (2-ME) treatment or xCT gene overexpression protected against dRib-induced changes. Moreover, transmission electron microscopy revealed dRib-induced mitochondrial shrinkage, decrease in cristae number, and outer membrane rupture. Furthermore, dRib treatment upregulated the expression of genes associated with ferroptosis, and downregulated xCT protein expression. The decrease in xCT protein caused by dRib was consistently observed even when treated with the protein synthesis inhibitor cycloheximide. However, treatment with the proteasome inhibitor MG132 reversed the dRib-induced decrease in xCT protein expression. Additionally, dRib increased xCT protein ubiquitination. Overall, dRib induces ferroptosis in RTECs by degrading xCT protein through ubiquitin-proteasome system (UPS), resulting in reduced intracellular cystine uptake. Therefore, targeting the regulation of system χc-through UPS could be a potential therapeutic approach for AKI and diabetic nephropathy.


Asunto(s)
Lesión Renal Aguda , Nefropatías Diabéticas , Ferroptosis , Humanos , Especies Reactivas de Oxígeno/metabolismo , Estrés Oxidativo , Ribosa/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Apoptosis , Cistina/metabolismo , Proteolisis , Glutatión/metabolismo , Células Epiteliales/metabolismo , Ubiquitinas/metabolismo , Lípidos
19.
ACS Appl Mater Interfaces ; 15(5): 7274-7281, 2023 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-36719071

RESUMEN

We successfully demonstrated the improvement and stabilization of the electrical properties of a graphene field effect transistor by fabricating a sandwiched amorphous boron nitride (a-BN)/graphene (Gr)/a-BN using a directly grown a-BN film. The a-BN film was grown via low-pressure chemical vapor deposition (LPCVD) at a low growth temperature of 250 °C and applied as a protection layer in the sandwiched structure. Both structural and chemical states of the as-grown a-BN were verified by various spectroscopic and microscopic analyses. We analyzed the Raman spectra of Gr/SiO2 and a-BN/Gr/a-BN structures to determine the stability of the device under exposure to ambient air. Following exposure, the intensity of the 2D/G-peak ratio of Gr/SiO2 decreased and the position of the G and 2D peaks red-shifted due to the degradation of graphene. In contrast, the peak position of encapsulated graphene is almost unchanged. We also confirmed that the mobility of a-BN/Gr/a-BN structure is 17,941 cm2/Vs. This synthetic strategy could provide a facile way to synthesize uniform a-BN film for encapsulating various van der Waals materials, which is beneficial for future applications in nanoelectronics.

20.
Psychiatry Res ; 320: 115035, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36584504

RESUMEN

To promote recovery in psychosis, targeting modifiable factors related to recovery is critical. Using more strict definition of full recovery, we examined predictors for recovery in patients with early stage schizophrenia spectrum disorders (SSD) followed up to 6.5 years. The target subjects were 375 patients with early stage SSD who had been over at least 1-year after registration and evaluated. The criteria for full recovery were having the score of the Positive and Negative Syndrome Scale (PANSS) 8-item ≤ 2 and adequate functional recovery for at least 1-year. We performed univariate Cox and stepwise Cox regression in both total and acute patients. In stepwise Cox regression, several independent predictors for recovery, i.e., negative symptoms of the PANSS, duration of untreated psychosis (DUP) and non-professional job were identified in patients with early stage SSD. In acute patients, other factors such as professional job and subjective well-being under neuroleptics were more important. The present study identified independent predictors for recovery modifiable by various psychosocial intervention and early intervention services. Moreover, it highlights the need of providing different treatment strategies depending on clinical status.


Asunto(s)
Antipsicóticos , Trastornos Psicóticos , Esquizofrenia , Humanos , Esquizofrenia/diagnóstico , Trastornos Psicóticos/psicología , Antipsicóticos/uso terapéutico , Recuperación de la Función , Psicología del Esquizofrénico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA