Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Int J Biol Macromol ; 259(Pt 2): 129320, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38218276

RESUMEN

Polysaccharides possess excellent moisturizing effects due to their abundance of hydrophilic groups and film-forming properties. Additionally, they can produce a refreshing aroma during the pyrolysis process. However, there is scarce research on their application in the tobacco field. Herein, we investigated the effects of low molecular weight fenugreek polysaccharide (FP) obtained through ethanol fractionation and DEAE-52 cellulose column chromatography on moisture retention and aroma enhancement in tobacco. The moisture retention test revealed that the addition of FP increased the moisture retention index (MRI) of tobacco by 11.72 %-16.69 %, indicating that the hydrophilic nature of polysaccharides facilitated the migration of free water in tobacco to bound water, resulting in reduced water activity. Moreover, the contact angle between polysaccharide and tobacco was <90°, enabling better infiltration into tobacco and slowing down tobacco shrinkage caused by water loss. Among all the components, EFP-20 and EFP-40 demonstrated superior performance. Furthermore, FP exhibited excellent thermal stability below 200 °C and can decomposed to produce aromatic substances at high temperatures. It also demonstrated the ability to adsorb ethyl heptanoate and thermally decompose to produce a substantial amount of heptanoic acid. Consequently, the incorporation of FP in tobacco demonstrated favorable effects on both moisturization and aroma enhancement.


Asunto(s)
Productos de Tabaco , Trigonella , Odorantes/análisis , Peso Molecular , Polisacáridos/farmacología , Polisacáridos/química , Agua/química
2.
Chem Biodivers ; 21(2): e202301684, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38224313

RESUMEN

To develop new chemicals that are stable at high temperatures with biological activity, a pyrrole intermediate was firstly synthesized using glucosamine hydrochloride as raw materials through cyclization and oxidation. Further, two novel pyrrole ester derivatives were prepared via Steglich esterification from pyrrole intermediate with vanillin and ethyl maltol, respectively. Nuclear magnetic resonance (1 H-NMR, 13 C NMR), infrared spectroscopy (IR) and high resolution mass spectrometry (HRMS) were used to confirm the target compounds. Thermal behavior of the compounds was investigated by thermogravimetry (TG), differential scanning calorimeter (DSC) and the pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) methods. The plausible pyrolytic mechanism was proposed. Additionally, their biological activities against the pathogens Fusarium graminearum, Fusarium oxysporum, Fusarium moniliforme, Phytophthora nicotianae, and Rhizoctonia solani were assessed. These target compounds showed outstanding antifungal activities and the highest inhibitor rates of 62.50 % and 68.75 % against R. solani with EC50 values of 0.0296 and 0.0200 mg mL-1 , respectively. SDHI protein sequence was molecularly docked to identify the binding mechanisms in the active pocket and examine the interactions between both the molecules and the SDHI protein.


Asunto(s)
Antifúngicos , Fusarium , Antifúngicos/química , Ésteres/farmacología , Pirroles/farmacología , Espectrometría de Masas , Espectroscopía de Resonancia Magnética , Relación Estructura-Actividad
3.
Ecotoxicol Environ Saf ; 263: 115361, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37597289

RESUMEN

Cadmium (Cd) removal from soil to reduce Cd accumulation in plants is essential for agroecology, food safety, and human health. Cd enters plants from soil and affects plant growth and development. Hydrogels can easily combine with Cd, thereby altering its bioavailability in soil. However, few studies have evaluated the effects of hydrogel on the complex phytotoxicity caused by Cd uptake in plants and the microbial community structure. Herein, a new poly (acrylic acid)-grafted starch and potassium humate composite (S/K/AA) hydrogel was added to soil to evaluate its impact on tobacco growth and the soil microenvironment. The results indicate that the addition of S/K/AA hydrogel can significantly improve the biomass, chlorophyll (Chl) content, and photosynthetic capacity of tobacco plants during Cd stress conditions, and decrease Cd concentration, probably by affecting Cd absorption through the expression of Cd absorption transporters (e.g., NRAMP5, NRAMP3, and IRT1). Moreover, the application of S/K/AA hydrogel not only reduced the accumulation of reactive oxygen species (ROS), but also reduced the antioxidant activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), suggesting that S/K/AA hydrogel alleviates Cd toxicity via a non-antioxidant pathway. Notably, we further analyzed the effectiveness of the hydrogel on microbial communities in Cd-contaminated soil and found that it increased the Cd-tolerant microbial community (Arthrobacter, Massilia, Streptomyces), enhancing the remediation ability of Cd-contaminated soil and helping tobacco plants to alleviate Cd toxicity. Overall, our study provides primary insights into how S/K/AA hydrogel affects Cd bioavailability and alleviates Cd toxicity in plants.


Asunto(s)
Arthrobacter , Cadmio , Humanos , Cadmio/toxicidad , Disponibilidad Biológica , Nicotiana , Hidrogeles
4.
RSC Adv ; 13(11): 7673-7681, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36908540

RESUMEN

Ammonia borane (AB) is a potential hydrogen storage material with high-efficiency hydrolytic dehydrogenation under a suitable catalyst. Noble metal catalysts have drawn a lot of attention. In this study, a carbon-coated zeolite was obtained by calcination at high temperatures using glucose as a carbon source. Pt nanoparticles were fixed on a core-shell composite support by a simple chemical reduction method. A series of catalysts were prepared with different synthesis parameters. The results show that PSC-2 has excellent catalytic performance for hydrolytic dehydrogenation of AB in alkaline solution at room temperature, and the turnover frequency (TOF) is 593 min-1. The excellent catalytic performance is attributed to the carbon layer on the zeolite surface which inhibits the aggregation or deformation of metals in the catalytic reaction. The metal-support interaction activates the water and accelerates the rate-limiting step of hydrolysis. The activation energy (E a = 44 kJ mol-1) was calculated based on the reaction temperature. In addition, the kinetics of AB hydrolysis was studied, and the effects of catalyst concentration, AB concentration and NaOH concentration on AB hydrolysis rate were further investigated. The high-efficiency catalyst prepared in this work provides a new strategy for the development of chemical hydrogen production in the field of catalysis.

5.
Artículo en Inglés | MEDLINE | ID: mdl-35682391

RESUMEN

Previous research suggests that volunteering can mitigate the negative mental health impacts of unemployment but has yielded mixed results. This study extends the previous literature by examining whether volunteering can buffer the negative impacts of both unemployment and economic inactivity on mental health. Using nationally representative panel data from the United Kingdom Longitudinal Household Study (2010-2020) and fixed effects models, this study yields three important findings: First, volunteering cannot mitigate the adverse effects of unemployment, regardless of gender. Second, frequent volunteering (at least once per month) can benefit the mental health of economically inactive groups (e.g., family care and long-term sickness). Third, the study reveals the gendered patterns of the impacts of volunteering. Specifically, frequent volunteering can buffer the negative impacts of family care or long-term sickness for men, and the negative impacts of unpaid work for women. Overall, these findings contribute towards a more nuanced understanding of the buffering role of volunteering and its gendered patterns. Policymakers should offer more volunteering opportunities and training to these economically inactive groups to reduce their risk of mental issues.


Asunto(s)
Salud Mental , Desempleo , Femenino , Humanos , Estudios Longitudinales , Masculino , Desempleo/psicología , Reino Unido , Voluntarios/psicología
6.
Sci Rep ; 11(1): 21991, 2021 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-34754009

RESUMEN

In order to explore the effects of biochar on root system and growth characteristics of flue-tobacco, three years of field experiments were conducted to study the influence of different biochar application levels [600 (T1), 1200 (T2), 1800(T3), 2400 (T4), 3000 (T5) kg/ha] and no fertilizer (CK) on the root physiological indexes and growth index of tobacco. Compared with local conventional fertilization, the application rate of N fertilizer in each treatment (except for control) was reduced by 40% to analyze the effects of different amount of biochar on the physiological indexes of tobacco roots and leaf photosynthesis during flourishing. The results showed that tobacco plants' root development status in the flourishing period was consistent with the photosynthetic physiological indexes, chlorophyll content, and leaf-area coefficient. Compared with the control, the application of biochar could increase the root vigor by 177.8%. Biochar improved the roots, increasing the total root area by 91.35% and the number of root tips by 100.9%. Meanwhile, biochar increased the net photosynthetic rate of tobacco leaves by 77.3% and the total tobacco biomass by 72.5%. Studies have shown that biochar can promote the development of tobacco roots, and then enhance the photosynthesis of leaves, so that tobacco plants can grow healthily, which is conducive to the tobacco production and the cultivation of soil.


Asunto(s)
Carbón Orgánico , Nicotiana/crecimiento & desarrollo , Raíces de Plantas/crecimiento & desarrollo , Clorofila/metabolismo , Fertilizantes , Nitrógeno , Fotosíntesis , Hojas de la Planta/metabolismo , Hojas de la Planta/fisiología , Nicotiana/metabolismo , Nicotiana/fisiología
7.
Am J Health Behav ; 43(6): 1171-1185, 2019 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-31662175

RESUMEN

Objectives: This paper reports on the first study in China that used nationally representative data to compare mental health and depressive feeling between empty-nest and non-empty-nest elderly people (over 60 years old), and examine whether the health disparities (if any) can be explained by differences in family, emotional, housework, and economic support. Methods: We used the 2010 China General Social Survey and multivariate regression models to examine mental health and depressive feeling of 556 non-empty-nest and 210 empty-nest elderly people in China. Results: After controlling for various socio-demographic characteristics, although the empty-nest elderly were significantly more likely to report depressive feeling and poor mental health than non-empty-nest elderly, the difference was only statistically significant for depressive feeling. Importantly, the disparity in both depressive feeling and mental health can be mediated by differences in family economic support and household economic pressure. Conclusions: Our results highlight the risks of depressive feeling arising from the empty-nest living arrangement of elderly people and suggest that a poorer economic situation may result from decreased mental health. Drawing upon these results, future public policies aimed at improving mental health of empty-nest elderly may need to be more targeted to improve their economic conditions such as ameliorating pension and social welfare system shortcomings.


Asunto(s)
Depresión/etiología , Depresión/psicología , Soledad , Salud Mental , Características de la Residencia , Anciano , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Medición de Riesgo , Encuestas y Cuestionarios
8.
Int J Mol Sci ; 20(15)2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31374993

RESUMEN

Cadmium (Cd) is an environmental pollutant that potentially threatens human health worldwide. Developing approaches for efficiently treating environmental Cd is a priority. Selenium (Se) plays important role in the protection of plants against various abiotic stresses, including heavy metals. Previous research has shown that Se can alleviate Cd toxicity, but the molecular mechanism is still not clear. In this study, we explore the function of auxin and phosphate (P) in tobacco (Nicotiana tabacum), with particular focus on their interaction with Se and Cd. Under Cd stress conditions, low Se (10 µM) significantly increased the biomass and antioxidant capacity of tobacco plants and reduced uptake of Cd. We also measured the auxin concentration and expression of auxin-relative genes in tobacco and found that plants treated with low Se (10 µM) had higher auxin concentrations at different Cd supply levels (0 µM, 20 µM, 50 µM) compared with no Se treatment, probably due to increased expression of auxin synthesis genes and auxin efflux carriers. Overexpression of a high affinity phosphate transporter NtPT2 enhanced the tolerance of tobacco to Cd stress, possibly by increasing the total P and Se content and decreasing Cd accumulation compared to that in the wild type (WT). Our results show that there is an interactive mechanism among P, Se, Cd, and auxin that affects plant growth and may provide a new approach for relieving Cd toxicity in plants.


Asunto(s)
Cadmio/toxicidad , Contaminantes Ambientales/toxicidad , Ácidos Indolacéticos/metabolismo , Nicotiana/metabolismo , Selenio/metabolismo , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Nicotiana/efectos de los fármacos , Nicotiana/genética , Nicotiana/crecimiento & desarrollo
9.
Am J Health Behav ; 43(4): 866-876, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31239027

RESUMEN

Objectives: Large-scale influxes of international immigrants into England have stimulated heated debate about whether the increasing ethnic diversity has undermined local residents' life satisfaction and wellbeing. In this paper, we provide the first nationally representative evidence on the relationship between international immigration and local residents' life satisfaction in England. Methods: We used multilevel linear regression models to analyze nationally representative data (2011-2012) from 23,143 respondents and neighborhood level data from the 2011 Census. Results: The results show that the local share of international immigrants who arrived in 2010-2011, in particular the non-white immigrants, has a significantly adverse impact on local people's life satisfaction. Further analysis shows that the adverse impact of migration is particularly pronounced for local residents who do not have a job or from intermediate social class. Conclusions: This study enables a better understanding of the link between international immigration and life satisfaction, highlighting the need of public policies to be more targeted to areas that experienced great influxes of international immigrants by facilitating positive interactions and communication between international immigrants and the local residents.


Asunto(s)
Diversidad Cultural , Emigrantes e Inmigrantes/estadística & datos numéricos , Emigración e Inmigración/estadística & datos numéricos , Empleo/estadística & datos numéricos , Satisfacción Personal , Clase Social , Adulto , Censos , Inglaterra , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multinivel
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...