Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 236
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Br Poult Sci ; 65(3): 297-306, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38456722

RESUMEN

1. The ferritin heavy chain (FHC) has a vital impact on follicular development in geese, due to its ability to regulate apoptosis of granulosa cells (GCs) and follicular atresia. However, its specific regulatory mechanisms remain unclear. The present study characterised how FHC regulates oxidative stress, cell proliferation and apoptosis in goose GCs by interfering with and overexpressing the FHC gene.2. After 72 h of interference with FHC expression, the activity of GCs decreased remarkably (p < 0.05), reactive oxygen species (ROS) levels and the expression levels of antioxidant enzyme genes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) increased significantly (p < 0.05). The overexpression of FHC for 72 h was found to significantly reduce the expression of CAT and SOD genes (p < 0.05).3. Interfering with FHC expression revealed that the expression levels of the cell proliferation gene Aurora kinase A (AURORA-A) were significantly decreased (p < 0.05), while the expression levels of the apoptosis genes B-cell lymphoma-2 (BCL-2) and cysteine aspartate-specific protease 8 (CASPASE 8) increased (p < 0.05). Further research has shown that, when interfering with FHC expression for 72 h, apoptosis rate increased by 1.19-fold (p < 0.05), but the current data showed a lower apoptosis rate after FHC overexpression by 59.41%, 63.39%, and 52.31% at three different treatment times (p < 0.05).4. In conclusion, FHC improved the antioxidant capacity of GCs, promotes GCs proliferation, and inhibits GCs apoptosis of ovarian follicles in Sichuan white geese.


Asunto(s)
Apoferritinas , Apoptosis , Proliferación Celular , Gansos , Células de la Granulosa , Estrés Oxidativo , Animales , Femenino , Gansos/fisiología , Células de la Granulosa/fisiología , Apoferritinas/genética , Apoferritinas/metabolismo , Proteínas Aviares/genética , Proteínas Aviares/metabolismo , Especies Reactivas de Oxígeno/metabolismo
2.
J Chem Phys ; 158(5): 054501, 2023 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-36754828

RESUMEN

Multiple-step nucleation pathways have been observed during mineral formation in both inorganic and biomineral systems. These pathways can involve precursor aqueous species, amorphous intermediates, or metastable phases. Despite the widespread occurrence of these processes, elucidating the precise nucleation steps and the transformation mechanisms between each step remains a challenging task. Using a suite of potentiometric, microscopic, and spectroscopic tools, we studied the nucleation pathway of SrSO4 as a function of the physico-chemical solution parameters. Our observations reveal that below a threshold supersaturation, nucleation is driven by bound species, akin to the prenucleation cluster model, which directly leads to the formation of the stable phase celestine, SrSO4. At higher supersaturations, this situation is altered, with nucleation dominated by the consumption of free ions. Importantly, this change in nucleation mechanism is coupled to the formation of a hemihydrate metastable phase, SrSO4 · 1/2H2O, which eventually transforms into celestine, adhering to Ostwald's rule of stages. This transformation is a solution-mediated process, also occurring in the presence of a fluid film and is controlled by the physico-chemical parameters of the surrounding environment. It proceeds through the dissolution of the metastable phase and the de novo crystallization of the final phase. Overall, our results reveal that ion association taking place during the prenucleation stage dictates whether the nucleation pathway goes through an intermediate phase or not. This also underlines that although Ostwald's rule of stages is a common process, it is not a prerequisite for mineral formation-even in systems where it can occur.

3.
Zhonghua Nei Ke Za Zhi ; 62(12): 1458-1464, 2023 Dec 01.
Artículo en Zh | MEDLINE | ID: mdl-38044073

RESUMEN

Objectives: Microvascular obstruction (MVO) is a specific cardiac magnetic resonance (CMR) imaging feature in patients with acute myocardial infarction. The purpose of this study was to elucidate the predictive value of MVO in left ventricular adverse remodeling after primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI). Methods: A total of 167 patients with STEMI undergoing primary PCI in the Chinese PLA General Hospital from 2016 to 2020 were enrolled in this prospective cohort study, the average age of study patients was 57±10 years old, with 151 males (90.4%) and 16 females (9.6%). The patients were divided into the MVO group (n=81) and non-MVO group (n=86) according to the presence or absence of MVO on CMR imaging, respectively. The primary endpoint of the study was the occurrence of left ventricular adverse remodeling, which was defined as an increase in left ventricular end diastolic volume (LVEDV) by >20% at 6 months after primary PCI compared with the baseline. Patients who completed follow-up were diagnosed as left ventricular adverse remodeling or no left ventricular adverse remodeling according to CMR. The baseline data, perioperative data, and related data of end points were compared between the MVO group and non-MVO group. Finally, the predictive value of MVO in left ventricular adverse remodeling was calculated by receiver operating characteristic curve analysis. Results: In the baseline data, preoperative thrombolysis in myocardial infarction (TIMI) flow (χ2=13.74, P=0.003) and postoperative TIMI flow (χ2=14.87, P=0.001) were both obviously decreased in the MVO group. After 6 months of follow-up, the incidence of left ventricular adverse remodeling in the MVO group was significantly higher than that in the non-MVO group [37.0%(27/73) vs. 18.9%(14/74), χ2=5.96, P=0.015]. The left ventricular end systolic volume at 6 months post infarction in the MVO group was significantly larger than that in the non-MVO group [(94±32) vs. (68±20) ml, t=-5.98, P<0.001], as well as the LVEDV [(169±38) vs. (143±29) ml, t=-4.74, P<0.001]. Receiver operating characteristic curve showed that the area under the curve of MVO size for predicting left ventricular adverse remodeling was 0.637. Conclusion: The risk of left ventricular adverse remodeling is significantly increased in patients with MVO after primary PCI for acute STEMI.


Asunto(s)
Intervención Coronaria Percutánea , Infarto del Miocardio con Elevación del ST , Masculino , Femenino , Humanos , Persona de Mediana Edad , Anciano , Infarto del Miocardio con Elevación del ST/cirugía , Infarto del Miocardio con Elevación del ST/diagnóstico , Estudios Prospectivos , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/métodos , Circulación Coronaria , Remodelación Ventricular , Resultado del Tratamiento , Valor Predictivo de las Pruebas , Microcirculación , Función Ventricular Izquierda
4.
Med J Malaysia ; 78(3): 263-269, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37271834

RESUMEN

INTRODUCTION: Acne vulgaris (AV) is a common inflammatory skin disease affecting adolescents and young adults. It affects one's self-esteem and social relationship. In addition, poor adherence to treatment can cause poor treatment response and disease recurrence. This study aims to determine the effectiveness of medical education and counselling on treatment adherence and disease severity. METHODS: This is a non-randomised interventional study with age- and treatment- matched control conducted in a tertiary dermatology clinic from July 2021 to June 2022. Patients in the intervention group received a 10 min video presentation on acne, followed by treatment counselling. The adherence rate was determined objectively (pill counting and tube weighing) and subjectively (ECOB questionnaire). The disease severity was assessed using the Comprehensive Acne Severity Scale (CASS) and Global Acne Grading System (GAGS). RESULTS: A total of 100 patients completed the 12-week study. With intervention, patients have better adherence to topical medication (5% benzoyl peroxide gel: 71% vs 57.9%, p= 0.031; 0.05% tretinoin cream: 58.7% vs 45.4%, p= 0.044) at week 12. However, the intervention program did not improve adherence to oral medication. Overall, with intervention, a significantly higher percentage of improvement in disease severity was noted (47.3% vs. 39.1%, p=0.044). Nonadherence to treatment was attributed mostly to forgetfulness in 54% of the patients, followed by a busy lifestyle (41%) and little knowledge of acne (26%). CONCLUSION: Patients have significantly better adherence to topical medication with education and counselling. Better adherence to treatment leads to more remarkable disease improvement.


Asunto(s)
Acné Vulgar , Educación Médica , Adolescente , Adulto Joven , Humanos , Acné Vulgar/tratamiento farmacológico , Peróxido de Benzoílo/uso terapéutico , Índice de Severidad de la Enfermedad , Cumplimiento y Adherencia al Tratamiento , Consejo , Resultado del Tratamiento
5.
Artículo en Zh | MEDLINE | ID: mdl-36052594

RESUMEN

Objective: To establish a GDH-3 air sample tube for simultaneous determination of twelve kinds of chlorobenzene compounds (CBs) in workplace air by gas chromatography. And to established a matching determination method. Methods: In October 2020, the vapor and aerosol CBs in workplace air were collected by GDH-3 air sampling tube, and desorption and elution with 3.00 ml toluene for 15 min, then the solution separated by DB-23 capillary column, and finally detected with microcell electron capture detector. Results: The quantitative determination ranges of twelve isomers of CBs were 0.71×10(-3)-2000.00 mg/L, with the correlative coefficients were 0.99967-0.99998. The minimum detectable concentrations were 0.04-112.63 µg/m(3), and the minimum quantification concentrations were 0.14-375.42 µg/m(3) (15.00 L sample, 3.00 ml sample solution) . The average elution efficiencies were 96.00%-104.00%. The within-run relative standard deviations (RSDs) were 2.54%-6.12%, and the between-run RSDs were 3.85%-7.87%. Sealed samples could be stable at room temperature for at least 15 days. Conclusion: GDH-3 air sample tube can be used for simultaneous determination of twelve kinds of CBs in workplace air by gas chromatography. The established supporting measurement method meets the measurement requirements of the occupational health standard detection method, and the it's suitable for the simultaneous determination of 12 kinds of CBS in the air.


Asunto(s)
Contaminantes Ocupacionales del Aire , Contaminantes Ocupacionales del Aire/análisis , Clorobencenos/análisis , Cromatografía de Gases/métodos , Investigación , Lugar de Trabajo
6.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 38(11): 859-863, 2020 Nov 20.
Artículo en Zh | MEDLINE | ID: mdl-33287485

RESUMEN

Objective: To develop a new solid sorbent tube for simultaneously capturing ethylene oxide (EO) , propylene oxide (PO) and epichlorohydrin (ECH) in air, and establish a complete set of method. Methods: In June 2018, EO, PO and ECH in air were captured by the new solid sorbent tube filled with carbon aerogel adsorbent, desorbed with solution of 5% (V/V) methanol-methylene chloride, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EO, PO and ECH were 0.24-960.00, 0.60-2384.00 and 0.12-472.40 mg/L respectively, and the related coefficients were between 0.99995-0.99997. The relative standard deviations (RSD) within the group were 1.66%-4.09%, 1.36%-4.43%, and 1.99%-5.65%, respectively, and the RSD between the group were 2.69%-4.95%, 2.77%-5.30%, and 3.27%-6.67%, respectively. The average desorption efficiencies were 88.25%-94.50%, 98.17%-98.60%, and 97.79%-101.04%, respectively. The samples could be stored at 4 ℃ refrigerator for at least 27 days. Conclusion: The newly developed solid sorbent tube filled with carbon aerogel adsorbent and its complete set of gas chromatography method could be used for sampling and quantitative detection of EO, PO and ECH in workplace air.


Asunto(s)
Contaminantes Ocupacionales del Aire , Aire , Contaminantes Ocupacionales del Aire/análisis , Cromatografía de Gases , Cloruro de Metileno , Lugar de Trabajo
20.
Artículo en Zh | MEDLINE | ID: mdl-31177722

RESUMEN

Objective: To develop a solvent desorption-gas chromatography method for simultaneous determination of methyl methacrylate (MMA) , ethyl methacrylate (EMA) , n-propyl methacrylate (PMA) and butyl methacrylate (BMA) in workplace air. Methods: MMA, EMA, PMA and BMA in workplace air were captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of MMA, EMA, PMA and BMA were 0-8 305.00 mg/L, 0-9 080.50 mg/L, 0-8 899.00 mg/L and 0-8 371.00 mg/L respectively, and the related coefficients were between 0.999 96-0.999 98. The relative standard deviations (RSD) within the group were 0.56%-1.71%, 0.45%-1.65%, 0.51%-1.49% and 0.45%-1.50% respectively, and the RSD between the group were 1.14%-2.79%, 0.79%-2.13%, 0.93%-2.30% and 1.09%-2.84% respectively. The average desorption efficiencies were 95.76%-99.58%, 97.82%-102.28%, 98.55%-102.28%and 98.70%-102.40% respectively. The minimum quantification concentrations were 0.12 mg/m(3), 0.10 mg/m(3), 0.07 mg/m(3) and 0.07 mg/m(3) respectively (3.00 L sample) . The samples could be stored at room temperature for at least 7 days. Conclusion: This method could be used for monitoring of MMA, EMA, PMA and BMA in workplace air.


Asunto(s)
Contaminantes Ocupacionales del Aire , Lugar de Trabajo , Acrilatos/análisis , Contaminantes Ocupacionales del Aire/análisis , Disulfuro de Carbono , Cromatografía de Gases
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA