Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Macromol Rapid Commun ; 44(1): e2200292, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35578983

RESUMEN

This study reports the exploration of a solvent-free supramolecular templated synthesis strategy toward highly core-cross-linked star-shaped polymers (CSPs). To achieve this, a kind of cross-linkable giant surfactant, based on a functionalized polyhedral oligomeric silsesquioxanes (POSS) head tethered with a diblock copolymer tail containing reactive benzocyclobutene groups, is designed and prepared. By varying the volume fraction of linear block copolymer tail, these giant surfactants can self-assemble into a body-centered cubic (BCC) structure in bulk, in which the supramolecular spheres are composed of a core of POSS cages, a middle shell of crosslinkable poly(4-vinylbenzocyclobutene) (PBCB) blocks, and a corona of inert polystyrene (PS) blocks. The solvent-free thermally induced cross-linking reaction of the benzocyclobutene groups can be finished in 5 min upon heating, resulting in well-defined polymeric spheres with over 90 linear chains surrounding the cross-linked cores. The outer PS blocks serve as the protection corona to ensure that cross-linking of giant surfactants occurs in each supramolecular spherical domain. Given the modular design and diversity of the POSS-based giant surfactants, it is believed that the strategy may enable access to a wide range of CSPs.


Asunto(s)
Polímeros , Tensoactivos , Polímeros/química , Solventes
2.
J Nurs Manag ; 30(7): 3350-3359, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36056581

RESUMEN

AIM: This study aimed to investigate the effect of career identity on career success among Chinese male nurses and to examine the mediating role of work engagement in this relationship. BACKGROUND: Recently, with the development of the nursing career, male nurses take up a higher share and play a more important role in the nursing team. With its own particularity and advantages, this group's stability closely relates to the future of the nursing team. Therefore, promoting the career success of the male nurses is essential to the nursing team development. METHODS: The data were collected in China. A sample of 557 male nurses completed measures of career identity, work engagement and career success scale. Structural equation model was adopted to verify the research hypotheses. RESULTS: Career identity was significantly and positively related to male nurses' work engagement and career success (p < .01). And work engagement partially mediated the association between career identity and career success. CONCLUSION: Career identity is critical to predicting and enhancing male nurses' career success. Work engagement plays an intervening mechanism explaining how career identity promotes career success among male nurses. IMPLICATIONS FOR NURSING MANAGEMENT: Nursing management should minimize the impact of the traditional concept, implement the gender equality and provide moderate care for male nurses to facilitate balanced development of gender by upgrading the management system. The administrators should carry out skill training based on male nurses' features and the need of the department. Given full play to their respective advantages, male nurses will make great progress in professional development and achieve greater career identity and work engagement. Meanwhile, the further exploration of better incentive mechanism also makes sense in improving career identity and work engagement by the reform of performance appraisal mechanism and salary adjustment according to their ability.


Asunto(s)
Enfermeros , Compromiso Laboral , Masculino , Humanos , Estudios Transversales , China , Encuestas y Cuestionarios
3.
Front Endocrinol (Lausanne) ; 14: 1310003, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38152124

RESUMEN

Background: Bilirubin has been widely reported to be a protective factor against diabetic kidney disease (DKD) in Asian populations. However, few large-sample analyses have been conducted in American populations. This study aimed to investigate the association between serum total bilirubin (STB) level and DKD in a US diabetic cohort. Methods: This cross-sectional study enrolled participants from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Univariate and multivariate logistic regression analyses were performed to assess the association between STB level and DKD. Three models were conducted to control the potential confounding factors. Subgroup analysis was carried out for further validation. Results: Among the 5,355 participants, the median age [interquartile range (IQR)] was 62 [52-71] years; 2,836 (52.96%) were male, and 1,576 (29.43%) were diagnosed with DKD. In the entire cohort, no significant association between STB level and DKD was observed in any logistic regression models (p > 0.05). Subgroup analysis revealed that, in U.S. diabetic males, STB levels > 11.98 µmol/L were associated with a nearly 30% lower risk of DKD than STB levels ≤ 8.55 µmol/L. Additionally, a moderate STB level (8.56-11.98 µmol/L) was found associated with a nearly 25% lower risk of DKD in U.S. diabetic patients over 65 years old. Conclusion: The association of STB level with DKD may depict differences across diverse populations, among which the impact of race, sex, and age requires thorough consideration and relevant inferences should be interpreted cautiously.


Asunto(s)
Diabetes Mellitus , Nefropatías Diabéticas , Humanos , Masculino , Estados Unidos/epidemiología , Anciano , Femenino , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/etiología , Encuestas Nutricionales , Estudios Transversales , Bilirrubina , Modelos Logísticos
4.
Int J Med Mushrooms ; 22(4): 367-377, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32558501

RESUMEN

Medicinal mushrooms fruiting bodies have been used as food or medicine for years but cultured mycelium is faster to grow and costs less. This research studied the antioxidant activities of three species (five strains) of medicinal mushroom mycelia (Cordyceps militaris, Ganoderma tsugae I and II, Trametes versicolor I and II). Two-stage extractions were performed: first the sample was extracted with 70% ethanol, and then the residue was extracted with 95°C hot water. Both ethanolic and hot water extracts showed effective concentration (EC50) values of 0.29-4.22 mg/mL, indicating that these extracts were remarkably effective in antioxidant activities. The ethanolic extracts displayed more effective reducing power, scavenging, and chelating ability (EC50 0.33-2.37 mg/mL) than hot water extracts (EC50 0.58-4.22 mg/g). Besides, ethanolic extracts contained higher total phenol content (75.49-144.99 GAE mg/g) than the hot water extracts (22.77-58.68 GAE mg/g). Furthermore, the ethanolic extracts contained flavonoids but not the hot water extract. Overall, these mycelia were highly effective in the antioxidant activities and might be potent antioxidants.


Asunto(s)
Antioxidantes/farmacología , Hongos/química , Antioxidantes/química , Técnicas de Cultivo Celular por Lotes , Etanol/química , Flavonoides/análisis , Flavonoides/farmacología , Hongos/clasificación , Hongos/crecimiento & desarrollo , Micelio/química , Micelio/clasificación , Micelio/crecimiento & desarrollo , Fenol/análisis , Fenol/farmacología , Agua/química
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 61(1-2): 281-6, 2005 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-15556451

RESUMEN

Simple, rapid and sensitive spectrofluorimetric methods are described, for the first time, for the determination of ciprofloxacin (CIP), norfloxacin (NOR), pefloxacin (PEF) and fleroxacin (FLE). The methods are based on the charge-transfer (CT) reaction of these drugs as n-electron donors with 7,7,8,8-tetracyanoquinodimethane (TCNQ) as pi-electron acceptor. TCNQ was found to react with these drugs to produce intensely transfer reaction complexes and the fluorescence intensity of the complexes was enhanced in 21-35 fold higher than that of the studied fluoroquinolones itself. The formation of such complexes was also confirmed by both infrared and ultraviolet-visible measurements. The different experimental parameters that affect the fluorescence intensity were carefully studied. At the optimum reaction conditions, the drug-TCNQ complexes showed excitation maxima ranging from 277 to 284 nm and emission maxima ranging from 451 to 458 nm. Rectilinear calibration graphs were obtained in the concentration range of 0.03-0.9, 0.04-1.2, 0.04-1.3 and 0.08-2.4 microg ml(-1) for CIP, NOR, PEF and FLE, respectively. The developed methods were applied successfully for the determination of the studied drugs in their pharmaceutical dosage forms with a good precision and accuracy compared to official and reported methods as revealed by t- and F-tests.


Asunto(s)
Fluoroquinolonas/química , Nitrilos/química , Estructura Molecular , Solventes/química , Espectrometría de Fluorescencia , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA