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1.
Int J Biol Macromol ; 277(Pt 4): 134464, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39098701

RESUMO

In this study, lignin nanoparticles (LN) and octadecylamine-modified LN (LN-ODA) were utilized as coating materials to enhance the hydrophobic, antioxidant, and ultraviolet radiation-shielding (UV-shielding) properties of a TEMPO-oxidized nanocellulose film (TOCNF). The water contact angle (WCA) of the TOCNF was approximately 53° and remained stable for 1 min, while the modified LN-ODA-coated TOCNF reached over 130° and maintained approximately 85° for an hour. Pure TOCNF exhibited low antioxidant properties (4.7 %), which were significantly enhanced in TOCNF-LN (81.6 %) and modified LN-ODA (10.3 % to 27.5 %). Modified LN-ODA-coated TOCNF exhibited antioxidant properties two to six times higher than those of pure TOCNF. Modified LN-ODA exhibited thermal degradation max (Tmax) at 421 °C, while pure LN showed the main degradation temperature at approximately Tmax 330 °C. The thermal stability of TOCNF-LN-ODA-coated materials remained consistent with that of pure TOCNF, while the crystallinity index of the sample showed a slight decrease due to the amorphous nature of the lignin structure. The tensile strength of TOCNF was approximately 114.1 MPa and decreased to 80.1, 51.3, and 30.3 MPa for LN-ODA coating at 5, 10, and 15 g/m2, respectively.


Assuntos
Antioxidantes , Óxidos N-Cíclicos , Interações Hidrofóbicas e Hidrofílicas , Lignina , Nanofibras , Nanopartículas , Raios Ultravioleta , Lignina/química , Antioxidantes/química , Óxidos N-Cíclicos/química , Nanopartículas/química , Nanofibras/química , Oxirredução , Celulose Oxidada/química , Celulose/química
2.
Front Cell Dev Biol ; 12: 1369634, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756696

RESUMO

Introduction: Prohibitin (PHB) is an essential scaffold protein that modulates signaling pathways controlling cell survival, metabolism, inflammation, and bone formation. However, its specific role in periodontium development remains less understood. This study aims to elucidate the expression pattern and function of PHB in periodontium development and its involvement in alveolar bone formation. Methods: Immunolocalization of PHB in the periodontium of postnatal (PN) mice were examined. Phb morpholino was micro-injected into the right-side mandible at PN5, corresponding to the position where the alveolar bone process forms in relation to the lower first molar. The micro-injection with a scramble control (PF-127) and the left-side mandibles were used as control groups. Five days post-micro-injection, immunohistochemical analysis and micro-CT evaluation were conducted to assess bone mass and morphological changes. Additionally, expression patterns of signaling molecules were examined following Phb downregulation using 24-h in vitro cultivation of developing dental mesenchyme at E14.5. Results: The immunostaining of PHB showed its localization in the periodontium at PN5, PN8, and PN10. The in vitro cultivation of dental mesenchyme resulted in alterations in Bmps, Runx2, and Wnt signalings after Phb knock-down. At 5 days post-micro-injection, Phb knocking down showed weak immunolocalizations of runt-related transcription factor (RUNX2) and osteocalcin (OCN). However, knocking down Phb led to histological alterations characterized by decreased bone mass and stronger localizations of Ki67 and PERIOSTIN in the periodontium compared 1 to control groups. The micro-CT evaluation showed decreased bone volume and increased PDL space in the Phb knock-down specimens, suggesting its regulatory role in bone formation. Discussion: The region-specific localization of PHB in the margin where alveolar bone forms suggests its involvement in alveolar bone formation and the differentiation of the periodontal ligament. Overall, our findings suggest that Phb plays a modulatory role in alveolar bone formation by harmoniously regulating bone-forming-related signaling molecules during periodontium development.

3.
J Hazard Mater ; 436: 129165, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35739705

RESUMO

Nanozyme-based dye degradation methods are promising for the remediation of water pollution. Though Pd nanoparticles (PdNPs) are known to act as nanozymes, their dye degradation capability has not been investigated. Low nanozyme activities, easy aggregation, difficulties in recovery and reuse are the major challenges in achieving this. For the first time, cellulose nanofibrils-supported PdNPs (PdNPs/PCNF) as a novel nanozyme with good peroxidase and oxidase-mimicking activities and easy recyclability is explored for dye degradation. An efficient and rapid method of PdNPs/PCNF preparation was demonstrated by adjusting the pH and microwave irradiation. Enzyme kinetic studies revealed good kinetic parameters and specific activities of 415 and 277 U/g for peroxidase and oxidase, respectively. PdNPs/PCNF offered 99.64% degradation of methylene blue within 12 min (0.468 min-1) with 0.4 M H2O2 at pH 5.0. Mechanistic studies revealed the involvement of hydroxyl and superoxide radicals. Owing to the network-like structure of PCNF, films and foams were prepared, their dye degradation potentials were compared, and recyclability was tested. Successful degradation of mixed dye solutions and spiked real water samples was achieved and a continuous flow method was demonstrated using a foam-packed column.


Assuntos
Nanopartículas , Peroxidase , Celulose , Corantes/química , Peróxido de Hidrogênio , Cinética , Nanopartículas/química , Oxirredutases/metabolismo , Peroxidase/metabolismo
4.
Crit Care Med ; 38(1): 175-80, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20050336

RESUMO

OBJECTIVE: To investigate whether adding rifampicin to vancomycin could cure more patients with nosocomial methicillin-resistant Staphylococcus aureus pneumonia compared with vancomycin-only. DESIGN: Prospective randomized open-label study. SETTING: Medical intensive care unit in Seoul, Korea. PATIENTS: Ninety-three of 183 patients with Gram-positive nosocomial pneumonia. INTERVENTIONS: The enrolled patients with subsequently documented methicillin-resistant Staphylococcus aureus pneumonia (modified intention-to-treat population) were treated with vancomycin (1 g intravenous every 12 hrs) plus rifampicin (300 mg twice daily by mouth) (n = 41) or with vancomycin-only (n = 42). The intended treatment (at least 5 days) was completed in 30 patients in the vancomycin plus rifampicin group and 34 patients in the vancomycin-only group (per protocol population). MEASUREMENTS AND MAIN RESULTS: The primary outcome was the clinical cure rate on day 14 of treatment. The secondary outcomes were intensive care unit mortality on days 28 and 60, and microbiological eradication on day 14. The clinical cure rate in the modified intention-to-treat population was 53.7% (22 of 41) in the vancomycin plus rifampicin group, and 31.0% (13 of 42) in the vancomycin-only group (p = .047), and the respective rates in the per protocol population were 63.3% (19 of 30) and 38.2% (13 of 34) (p = .079). The respective mortality rates were nine (22.0%) of 41 and 16 (38.1%) of 42 on day 28 (p = .151), and 11 (26.8%) of 41 and 21 (50.0%) of 42 on day 60 (p = .042). The microbiological eradication rate did not differ between groups (p = .472). CONCLUSIONS: Vancomycin plus rifampicin seems to be more effective than vancomycin alone in the treatment of nosocomial methicillin-resistant Staphylococcus aureus pneumonia.


Assuntos
Infecção Hospitalar/tratamento farmacológico , Mortalidade Hospitalar , Staphylococcus aureus Resistente à Meticilina , Pneumonia Estafilocócica/tratamento farmacológico , Rifampina/administração & dosagem , Vancomicina/administração & dosagem , Centros Médicos Acadêmicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Cuidados Críticos/métodos , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Unidades de Terapia Intensiva , Coreia (Geográfico) , Masculino , Pessoa de Meia-Idade , Pneumonia Estafilocócica/diagnóstico , Pneumonia Estafilocócica/mortalidade , Probabilidade , Estudos Prospectivos , Medição de Risco , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Análise de Sobrevida , Resultado do Tratamento
5.
Carbohydr Polym ; 240: 116356, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32475600

RESUMO

A novel microwave-assisted green method that synchronously synthesizes silver nanoparticles (AgNPs) and AgNPs decorated holocellulose nanofibrils (AgNPs/HCNF) within a minute and without using a reducing agent is reported. As obtained nanomaterials were well characterized using various analytical techniques. AgNPs applied as a colorimetric probe for the selective recognition of Hg(II) (linear range 10-200 µg L-1, detection limit 1.16 µg L-1). The probe was able to quantify Hg(II) in spiked tap, bore, and lake water samples and paper strips were developed to facilitate the onsite detection. Furthermore, freeze-drying of the AgNPs/HCNF nanocomposite produced aerogel that served as an excellent catalyst for the reduction of Congo red and methylene blue. The aerogel was easily recovered and reused without a decrease in activity or deterioration of its structure for five cycles. These results indicate the great potential of the AgNPs/HCNF aerogel for waste water treatment and catalytic applications.


Assuntos
Celulose/química , Vermelho Congo/química , Mercúrio/análise , Nanopartículas Metálicas/química , Azul de Metileno/química , Nanofibras/química , Micro-Ondas , Oxirredução , Prata/química
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